This study tries to highlight the role of magnetic and seismic data in the prevention of building cracking, which constitutes a geotechnical risk in Agadez City. This city is built on the faulted and fractured sandsto...This study tries to highlight the role of magnetic and seismic data in the prevention of building cracking, which constitutes a geotechnical risk in Agadez City. This city is built on the faulted and fractured sandstone formations of the “Agadez Sandstones Formations”, which were deposited in unconformity on the basement of the Aïr Mountain. This study focuses on the prevention of geotechnical damages related to building cracking in the Agadez region through geophysical methods, which are well known for investigating tectonic structures and their directions on the surface and subsurface. A methodological approach integrated the seismic and magnetic data interpretation combined with field measurement on the cracked building and its underlying substratum, represented by Agadez sandstones and basement. The extraction of seismic lineaments from the West African seismic map showed the seismic directions oriented NW-SE (N135˚ to N160˚), passing through the studied area. The structural interpretation of the magnetic map shows that the Agadez region is also affected by the subsurface lineaments mainly oriented in NW-SE (N135˚) directions, which are similar to the identified seismic lineaments in the same zone. A structural study carried out on the Agadez sandstones and the underlying basement showed that faults and fractures oriented N120˚ to N165˚ affect both the basement of the Aïr Mountains and the sandstone formations on which the city of Agadez is built. These observations showed that building cracking in the Agadez region has a higher propagation tendency according to the directions ranging from NW-SE (N135˚) to NNW-SSE (N165˚). Therefore, the building’s cracking has a stronger propagation component according to these mean directions that are not recommended for building. To prevent and reduce the risks related to building cracking in Agadez region, it is highly recommended to build in the minor directions of cracking propagation, which correspond to NE and SW directions.展开更多
In Niger, farms have been facing negative effects of climate change for several decades. The objective of this work is to assess the vulnerability of farms in Tillabery department by proposing an adaptation approach. ...In Niger, farms have been facing negative effects of climate change for several decades. The objective of this work is to assess the vulnerability of farms in Tillabery department by proposing an adaptation approach. A five-step method and descriptive analysis were used on a sample of 250 farmers. The degree of damage caused by pests and crop diseases is significant, with respective proportions of 52.50% and 40.40%. It appears that the main climate risk factors for vulnerability are droughts, floods, soil degradation, and pest invasions. Additionally, the average level of exposure to agricultural operations is very high, with an index of 0.6. The sensitivity index remained constant in the range of 0.3 to 0.6 and is significant (reaching an index of 0.8). However, 61.2% of farms have a medium level of vulnerability and 33.3% have a high vulnerability to the effects of climate change. Nonetheless, a concerning trend regarding the vulnerability of farms has been observed. To assist policymakers and development actors in improving the vulnerability level of these production units, four phases of action are proposed: a diagnostic phase, evaluation, estimation of adaptation needs, implementation, and proper monitoring of actions.展开更多
Millet [Pennisetum glaucum (L.) R. Br. (Poaceae)] is one of the most widely consumed crops in Niger. Its production, despite the efforts of farmers, is confronted with weed problems, in particular Sesbania pachycarpa ...Millet [Pennisetum glaucum (L.) R. Br. (Poaceae)] is one of the most widely consumed crops in Niger. Its production, despite the efforts of farmers, is confronted with weed problems, in particular Sesbania pachycarpa DC. (Fabaceae). The aim of the present study in this area is to assess the impact of Sesbania pachycarpa on millet growth and yield. To achieve this objective, a completely randomized Fisher block design of twenty-four elementary plots was set up with four replications. The data collected were millet plant heights and plot yields. The data collected were subjected to analysis of variance and Duncan’s test at the 5% threshold for comparisons of mean heights and yields with the control kept clean from sowing to millet harvesting. The results showed the sensitivity of millet plants to Sesbania pachycarpa. The results revealed that the threshold density for damage could be estimated at 6 Sesbania pachycarpa plants/m2 and the critical interference period at the fourth week after sowing. This study showed that the presence of Sesbania pachycarpa influences millet yield. Indeed, the best yields were obtained in plots without Sesbania pachycarpa. Millet yield decreased with increasing Sesbania pachycarpa density. The average percentage yield reduction was 36.79%, with a minimum of 21.25% and a maximum of 80%. The findings of this study complete the efforts of developing weed control techniques in pearl millet fields densely populated with Sesbania pachycarpa.展开更多
Cowpea, Vigna unguiculata L. Walp, is an important food grain legume in Niger facing production losses due to insect pests. This study aims to determine the efficiency of non-chemical methods for managing these pests....Cowpea, Vigna unguiculata L. Walp, is an important food grain legume in Niger facing production losses due to insect pests. This study aims to determine the efficiency of non-chemical methods for managing these pests. A trial was conducted during the 2020 and 2022 cropping seasons at the INRAN station in the Maradi region. A Fischer experimental design with 6 repetitions was used to compare 4 treatments: synthetic chemical pesticide;the entomopathogenic fungus Beauveria bassiana;aqueous extracts of neem seeds, and control. Observations were carried out every three days. The cowpea pod-sucking bug, pod borer, and thrips were the main insect pests recorded. In terms of effectiveness, the synthetic pesticide was the best treatment. It reduced insect pest densities by 71.35% to 90.40% in 2020 and by 35.11% to 42.13% in 2022. Grain yields varied between treatments. Neem seed extract followed the synthetic pesticide and significantly reduced insect infestations in both years. The synthetic pesticide and neem seed extract resulted in yields 3 to 5 times higher than the control treatment in 2020. By contrast, B. bassiana 115 and neem seed extract produced similar yields in 2022. Therefore, the results of this study showed that B. bassiana 115 and neem seed extract have insecticidal potential and could be used as an ecological alternative for managing cowpea insect pests in the Sahel.展开更多
Rationale: The contamination of soil with crude oil poses significant environmental and ecological threats. Bioremediation, particularly through the use of organisms like Pleurotus ostreatus (mushroom) and Eisenia fet...Rationale: The contamination of soil with crude oil poses significant environmental and ecological threats. Bioremediation, particularly through the use of organisms like Pleurotus ostreatus (mushroom) and Eisenia fetida (earthworm), has emerged as a promising approach to mitigate crude oil pollution. Understanding the effectiveness of these organisms in reducing hydrocarbon levels in contaminated soil is crucial for devising sustainable remediation strategies. Objectives: This study aimed to evaluate the efficacy of Pleurotus ostreatus and Eisenia fetida in remediating crude oil-polluted soil. Specifically, it sought to assess the hydrocarbon profiles in soil treated with these organisms across varying concentrations of crude oil pollution. Method: Crude oil concentration levels ranging from 0% to 10% were applied to soil samples alongside control treatments, including soil only, soil with earthworms, and soil with mushrooms. Each treatment was replicated five times using a randomized complete block design. Standard methods were employed to determine the hydrocarbon contents of the soil. Results: The results indicated a significant increase (P Pleurotus ostreatus and Eisenia fetida exhibited noteworthy reductions in these hydrocarbon levels. At the three-month mark, mushrooms demonstrated a remarkable ability to reduce hydrocarbon content by 70% - 90% compared to the pollution treatment. In contrast, earthworms exhibited minimal potential for hydrocarbon reduction, particularly at both three and six-month intervals. For instance, TOC reduction reached a maximum of 96% with mushroom treatment and 85% with earthworm treatment at 5% crude oil pollution over six months. Conclusion: The findings highlight the effectiveness of Pleurotus ostreatus in significantly reducing hydrocarbon levels in crude oil-polluted soil compared to Eisenia fetida. Mushroom-treated soils consistently exhibited substantial reductions in TOC, TPH, TOG, PAH, and THC over the study period, suggesting their potential as a viable bioremediation agent. In contrast, while earthworms showed some capability in reducing hydrocarbon content, their effectiveness was comparatively limited. Recommendation: Based on the results, it is recommended to utilize Pleurotus ostreatus for the bioremediation of crude oil-polluted soils. Further research could explore optimizing remediation protocols involving mushroom-based treatments for enhanced efficiency. Statement of Significance: This study contributes valuable insights into the application of bioremediation techniques for mitigating crude oil contamination in soil. The demonstrated efficacy of Pleurotus ostreatus underscores its potential as a sustainable and eco-friendly solution for remediating hydrocarbon-polluted environments, offering a promising avenue for environmental restoration and conservation efforts.展开更多
Cowpea, Vigna unguiculata (L.) Walp. is an economically important seed legume that helps combat food and nutrition insecurity in the Sahel, particularly Niger. However, its yield remains low due to insect pest attacks...Cowpea, Vigna unguiculata (L.) Walp. is an economically important seed legume that helps combat food and nutrition insecurity in the Sahel, particularly Niger. However, its yield remains low due to insect pest attacks. This study was conducted at a station and in seven villages in the Maradi and Tahoua regions. It aimed to test the effectiveness of neem seed biopesticides [Azadirachta indica A. Juss] and sanitized human urine for integrated insect pest management. The cowpea variety UAM09 1055-6 was used for the experiments. The experimental trial was a Fisher block design consisting of five treatments: neem oil, neem seed extract (NSE), hygienized human urine (HHU), chemical pesticide, and a control, replicated five times at the station and twice in farmers’ environments. The study shows that Megalurothrips sjostedti Trybom, Clavigralla tomentosicollis Stål and Maruca vitrata Fabricius are the main insect pests. Plots treated with synthetic pesticides were the least infested by C. tomentosicollis. They were followed by neem seed extract and HHU treatments, which recorded an infestation level of 2.44 and 20.5 times lower than controls at the station and in farming environments. The density of thrips was 1.06 to 32.6 times lower in treated plots compared to controls. The proportion of pods damaged by M. vitrata was 1.95, 2.55, and 2.77 times lower in plots treated with HHU, NSE, and synthetic pesticide, respectively, compared to controls. Grain yields were 1.80 and 2.62 times higher in UHH and NSE treatments compared to control plots, both at the station and in farmers’ environments. A yield increase of 44.58% and 61.92% was noted for these treatments at the station and in farmers’ environments, respectively. These results may promote the dissemination of NSE and HHU biopesticide technologies in rural areas as an alternative method for integrated pest management of cowpeas.展开更多
Introduction: Lower respiratory infections in general, and acute bronchiolitis in particular, represent a major cause of morbidity in children in Niger. The aim of this study was to investigate the epidemiological, di...Introduction: Lower respiratory infections in general, and acute bronchiolitis in particular, represent a major cause of morbidity in children in Niger. The aim of this study was to investigate the epidemiological, diagnostic and therapeutic features of acute bronchiolitis in infants in the Pediatrics A department of the National Hospital in Zinder. Patients and Methods: This was a descriptive, cross-sectional study with prospective data collection conducted from April 1 to May 31, 2024. All infants aged 0 to 24 months hospitalized with acute bronchiolitis in the pediatric ward A of Zinder National Hospital were included in the study. Epidemiological, diagnostic and therapeutic aspects were the characteristics studied. Data analysis was performed using Epi info 7 software. Results: During the study period, acute bronchiolitis accounted for 51% of hospitalizations, and infants aged 3 - 11 months were the most affected (52.90%). The sex ratio was 1.6. The average age of patients was 10.40 ± 6.91 months, with extremes of 1 and 24 months. 98.50% of patients came from urban areas, and the socioeconomic level of families was average in 47.49% of cases. Mixed breastfeeding was practiced in 59.63% of cases. Average hospital admission time was 4.22 days. The main clinical signs were cough (43.18%), rhinorrhea (70.85%), ronchi (35.33%), crepitating rales (26.54%), sibilant rales (24.11%), signs of struggle (14.02%) and polypnea (70.85%). Paraclinical findings included chest distension, hyperleukocytosis and anemia, with 47.48%, 55.14% and 78.31% respectively. Therapeutically, nebulization was used in 93.08% of cases, respiratory physiotherapy (41.34%), corticosteroid therapy (34.08%), antibiotic therapy (21.50%), oxygen therapy (20.11%) and antipyretics (4.68%) were prescribed. Progression was favorable in 93.08% of patients, with a case-fatality rate of 1.12%. Conclusion: With its high frequency, acute bronchiolitis is a public health problem. Boys were the most affected by the condition, and the predominant age group was 3 to 11 months. Management was essentially based on nebulization and physiotherapy.展开更多
Pearl millet, Pennisetum glaucum (Leeke) R. Br, is the main cereal crop in Niger. This crop is seriously attacked by the millet Head miner (MHM), Heliocheilus albipunctella (de Joannis) (Lepidoptera, Noctuidae) causin...Pearl millet, Pennisetum glaucum (Leeke) R. Br, is the main cereal crop in Niger. This crop is seriously attacked by the millet Head miner (MHM), Heliocheilus albipunctella (de Joannis) (Lepidoptera, Noctuidae) causing significant yield losses. This study to optimize biological control of this pest was carried out in Niger in the laboratory and in a farming environment. In the laboratory, the larval paralysis and emergence of the parasitoid Habrobracon hebetor Say (Hymenoptera: Braconidae) were compared between release jute bags, plastic boxes and cardboard boxes. In a farming environment, direct releases were carried out with plastic boxes and releases with jute bags in 12 villages of the Maradi region during the cropping seasons of 2021 and 2022. The results indicated that 25 larvae of Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) in the boxes were all paralyzed by 2 females of H. hebetor within 7 hours 30 minutes. The emergence of adults began on the 7th day after the beginning of the experiment for a period of two weeks and three weeks respectively in the boxes and jute bags. The production varied from 107.08 to 110.17 parasitoids and was comparable between the Jute bags, plastic boxes and cardboard boxes. In Farmers’ fields, the parasitoid release with the two methods caused the parasitism rates that varied from 64.32 to 66.52% depending on the year but in 2022 the rate of parasitism was higher in the fields with direct releases using plastic boxes (72.66%) compared to those released with jute bags (56.35%). Plastic boxes and cardboard boxes can be used for the production of the H. hebetor parasitoids. These results can be recommended to the cottage industries in the Sahel in order to improve the production and release methods of H. hebetor and make them more adapted to farmers’ fields.展开更多
The fate of wetlands in arid regions has become a matter of concern in the context of global warming. The Inner Niger Delta (IND) has received increasing attention from researchers and others to explore whether this l...The fate of wetlands in arid regions has become a matter of concern in the context of global warming. The Inner Niger Delta (IND) has received increasing attention from researchers and others to explore whether this largest wetland in Africa will shrivel due to climate change and increasing water use. An essential study goal is to understand what has been done so far in the Research of Inner-Niger-Delta Wetland in order to address its future challenges. The present study provides a comprehensive analysis of climate related research on the IND wetland through bibliometric means to diagnosis the evolution, lag and hotspot of relevant features in the literature. Key aspects of analysis included 1) trends of IND wetland related research 2) nature of collaboration networks, 3) co-occurrence of keywords and 4) emerging themes related to IND wetland over the last three decades, between the years 1991-2022. The results indicate that the IND wetland gained momentum in 2000, peaking in 2013 and then in 2018. IND wetland research has, on average, reach 2.5 publication in 2000 and exceed 5 papers by 2017. The leading countries that have produced high numbers of published documents are in order, France, Nigeria, USA, Germany and Mali. Therefore, more efficient scientific collaboration among regional African institutions is recommended to face local perspectives. The identified emerging topics are Niger delta, climate change, floods and rivers. The variables considered in analyses are river discharge, evapotranspiration, water level and rain. Variables relevant to global temperature warming are missing, which implies that researches on Inner Niger Delta wetland are less focusing on climate change and variability analyses.展开更多
Rationale: The quality of groundwater in the Mgbede Oil Fields of South-South Nigeria has raised significant concerns due to the risk of contamination from industrial activities, especially gas flaring. Evaluating the...Rationale: The quality of groundwater in the Mgbede Oil Fields of South-South Nigeria has raised significant concerns due to the risk of contamination from industrial activities, especially gas flaring. Evaluating the effects of these operations on groundwater quality is essential for safeguarding the health and well-being of local communities, as well as protecting the environment. Objective: This study aimed to evaluate the quality of groundwater in the Mgbede Oil Fields, specifically examining whether the water meets international drinking water standards and identifying any contaminants present due to gas flaring. Method: Purposeful selection of water sampling points was employed to ensure the objectives of the study were met. Groundwater samples were collected from various locations within the Mgbede Oil Fields and analyzed for key quality parameters, including pH, manganese, and turbidity, among others. Results: The analysis revealed that while most groundwater samples were within acceptable international drinking water limits, there were notable exceptions. pH levels ranged from 5.17 to 6.16, manganese concentrations from 0.001 to 0.136 mg/L, and turbidity levels from 0.00 to 825 mg/L. All sampled locations exhibited traces of manganese and high acidity, indicating particulate pollution likely resulting from gas flaring activities. Conclusions: The study concluded that the groundwater quality in the Mgbede Oil Fields is negatively impacted by continuous gas flaring. Contaminants such as manganese and increased acidity levels exceed acceptable international standards, posing potential risks to environmental health. Recommendations: To mitigate these risks, it is recommended that immediate measures should be taken to reduce gas flaring and its associated particulate emissions. Regular monitoring of groundwater quality should be implemented to track improvements and ensure compliance with international standards. Additionally, introducing filtration systems or alternative water sources could help protect the health of local communities. Significance Statement: This study underscores the significant impact of industrial activities, specifically gas flaring, on groundwater quality in the Mgbede Oil Fields. The findings highlight the urgent need for regulatory measures and continuous monitoring to safeguard environmental health and ensure the availability of safe drinking water.展开更多
BACKGROUND The gluten-free diet(GFD)has limitations,and there is intense research in the development of adjuvant therapies.AIM To examine the effects of orally administered Aspergillus niger prolyl endopeptidase prote...BACKGROUND The gluten-free diet(GFD)has limitations,and there is intense research in the development of adjuvant therapies.AIM To examine the effects of orally administered Aspergillus niger prolyl endopeptidase protease(AN-PEP)on inadvertent gluten exposure and symptom prevention in adult celiac disease(CeD)patients following their usual GFD.METHODS This was an exploratory,double-blind,randomized,placebo-controlled trial that enrolled CeD patients on a long-term GFD.After a 4-wk run-in period,patients were randomized to 4 wk of two AN-PEP capsules(GliadinX;AVI Research,LLC,United States)at each of three meals per day or placebo.Outcome endpoints were:(1)Average weekly stool gluten immunogenic peptides(GIP)between the run-in and end of treatments and between AN-PEP and placebo;(2)celiac symptom index(CSI);(3)CeD-specific serology;and(4)quality of life.Stool samples were collected for GIP testing by ELISA every Tuesday and Friday during run-ins and treatments.RESULTS Forty patients were randomized for the intention-to-treat analysis,and three were excluded from the per-protocol assessment.Overall,628/640(98.1%)stool samples were collected.GIP was undetectable(<0.08μg/g)in 65.6%of samples,and no differences between treatment arms were detected.Only 0.5%of samples had GIP concentrations sufficiently high(>0.32μg/g)to potentially cause mucosal damage.Median GIP concentration in the AN-PEP arm was 44.7%lower than in the run-in period.One-third of patients exhibiting GIP>0.08μg/g during run-in had lower or undetectable GIP after AN-PEP treatment.Compared with the run-in period,the proportion of symptomatic patients(CSI>38)in the AN-PEP arm was significantly lower(P<0.03).AN-PEP did not result in changes in specific serologies.CONCLUSION This exploratory study conducted in a real-life setting revealed high adherence to the GFD.The AN-PEP treatment did not significantly reduce the overall GIP stool concentration.However,given the observation of a significantly lower prevalence of patients with severe symptoms in the AN-PEP arm,further clinical research is warranted.展开更多
Pectinex XXL,a commercially prepared pectinase,was investigated for its potential application in the fruit juice industry.Polygalacturonic acid was used as the substrate for determining the enzymatic properties of Pec...Pectinex XXL,a commercially prepared pectinase,was investigated for its potential application in the fruit juice industry.Polygalacturonic acid was used as the substrate for determining the enzymatic properties of Pectinex XXL using the DNS method.According to the results,the optimal pH for Pectinex XXL activity was 4.5,and the enzyme was stable in the pH range of 3.0~4.5.The optimal pH and pH stability range are consistent with those of some tropical and subtropical fruits.The optimal temperature for Pectinex XXL activity was 60℃,and the enzyme remained stable after one hour in a water bath set at 40℃.Additionally,the enzymatic activity was not inhibited in the presence of 1 mmol/L of Na^(+),Mg^(2+),Ba^(2+),Co^(2+),Zn^(2+),and Fe^(2+),whereas it was slightly inhibited in the presence of 2 mmol/L of K^(+)and Fe^(2+)and partially inhibited in the presence of 1 and 2 mmol/L of Ca^(2+)and Mn^(2+),demonstrating its good stability in acids and excellent thermal catalytic performance.Based on the above experimental results,depectinization experiments were performed on plantain and cherry tomato juices using different amounts of Pectinex XXL.After one hour reaction with 16 U/mL of the enzyme,the yields of the plantain and cherry tomato juices were substantially increased by 119.03%and 15.97%,respectively,while their light transmittance was remarkably enhanced by 37.65%and 12.35%,respectively.Furthermore,the enzyme reduced the viscosity of the plantain and cherry tomato juices by 88.29%and 29.50%,respectively.The juice production experiments confirmed that this enzyme can significantly improve the yield and light transmittance of plantain juice,while effectively reducing its viscosity.These findings indicate the potential of Pectinex XXL in the industrial production of plantain juice.展开更多
This study characterized the AA-01 depleted hydrocarbon reservoir in the KOKA field, Niger Delta, using a multidimensional approach. This investigation involved data validation analysis, evaluation of site suitability...This study characterized the AA-01 depleted hydrocarbon reservoir in the KOKA field, Niger Delta, using a multidimensional approach. This investigation involved data validation analysis, evaluation of site suitability for CO_(2) storage, and compositional simulation of hydrocarbon components. The primary objective was to determine the initial components and behavior of the hydrocarbon system required to optimize the injection of CO_(2) and accompanying impurities, establishing a robust basis for subsequent sequestration efforts in the six wells in the depleted KOKA AA-01 reservoir. The process, simulated using industry software such as ECLIPSE, PVTi, SCAL, and Petrel, included a compositional fluid analysis to confirm the pressure volume temperature(PVT) hydrocarbon phases and components. This involved performing a material balance on the quality of the measured data and matching the initial reservoir pressure with the supplied data source. The compositional PVT analysis adopted the Peng–Robinson equation of state to model fluid flow in porous media and estimate the necessary number of phases and components to describe the system accurately. Results from this investigation indicate that the KOKA AA-01 reservoir is suitable for CO_(2)sequestration. This conclusion is based on the reservoir's good quality, evidenced by an average porosity of 0.21 and permeability of 1 111.0 mD, a measured lithological depth of 9 300 ft, and characteristic reservoir – seal properties correlated from well logs. The study confirmed that volumetric behavior predictions are directly linked to compositional behavior predictions, which are essential during reservoir initialization and data quality checks. Additionally, it highlighted that a safe design for CO_(2) storage relies on accurately representing multiphase behaviour across wide-ranging pressure–temperature–composition conditions.展开更多
We comment here on the article by Stefanolo et al entitled“Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet”,published in the World Journal of Gastroen...We comment here on the article by Stefanolo et al entitled“Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet”,published in the World Journal of Gastroenterology.Celiac disease is a well-recognized systemic autoimmune disorder.In genetically susceptible people,the most evident damage is located in the small intestine,and is caused and worsened by the ingestion of gluten.For that reason,celiac patients adopt a gluten-free diet(GFD),but it has some limitations,and it does not prevent re-exposure to gluten.Research aims to develop adjuvant therapies,and one of the most studied alternatives is supplementation with Aspergillus niger prolyl endopeptidase protease(AN-PEP),which is able to degrade gluten in the stomach,reducing its concentration in the small intestine.The study found a high adherence to the GFD,but did not address AN-PEP as a gluten immunogenic peptide reducer,as it was only tested in patients following a GFD and not in gluten-exposing conditions.This study opens up new research perspectives in this area and shows that further study is needed to clarify the points that are still in doubt.展开更多
Wellbore instability and sand production are all common challenges in the Niger Delta oil province,resulting in high drilling and production cost as well as damage to oil facilities.The vulnerability of lithologic for...Wellbore instability and sand production are all common challenges in the Niger Delta oil province,resulting in high drilling and production cost as well as damage to oil facilities.The vulnerability of lithologic formations to wellbore instability and resultant sand production is investigated in the four delineated reservoirs of the“Areo”field,western part of Niger Delta Basin.The foundation for establishing the geomechanical properties in this study was a 1-dimensional mechanical earth model,using gamma ray(GR),density(RHOB),compressional slowness(DTC),and shear slowness(DTS)logs.Within the Areo oil field,two wells(well 001 and well 002)were correlated.The evaluated formations are still primarily composed of compacted shale and unconsolidated sandstone,with reservoir sand units exhibiting lower elastic and rock strength properties than shale units.High compressibility and porosity make sand more brittle,while low compressibility and porosity make shale stiffer due to high moduli.The maximum force that can be applied to a shale unit without causing it to fail is 17.23 MPa,which is the maximum average rock strength of the shale.It means that shale requires more vertical stress or pressure than sand does in order to deform it(15.06 MPa).The three sand prediction approaches used in the analysis of sand production predictions have cut-off values that are higher than the average values of the formations.The Schlumberger sand production index method(S/I)indicates that the reservoir has potential for sand influx in the two wells,with the average of the four reservoirs studied in wells 001 and 002 being 1.551012 psi and 1.141012 psi respectively.However,when a formation's sand production index is less than 1.241012 psi,as it is in this study,the formation is likely to produce sand.These findings support the notion that the defined sandstone units are highly unconsolidated and have a high potential for producing sands;therefore,sand control techniques must be factored into process optimization and cost reduction plans.展开更多
The utilization of sequence stratigraphic concepts in identifying sands and their spatial continuity in distinct gross depositional settings is key,especially in frontier settings where data paucity is a common challe...The utilization of sequence stratigraphic concepts in identifying sands and their spatial continuity in distinct gross depositional settings is key,especially in frontier settings where data paucity is a common challenge.In the Baka field,onshore Niger Delta,detailed reservoir correlation guided by sequence stratigraphic framework analysis showed the distribution of sand and shale units constituting reservoirseal pairs(RSP)correlatable across the field.Within the 3rd-order packages,it is observed that the lowstand systems tract(LST)and highstand systems tract(HST)contain more RSPs and thicker 4th-and 5th-order sands than the transgressive systems tract(TST).In terms of bathymetry,it is noted that irrespective of systems tracts,the RSP Index(RI)decreases from the proximal shallow/inner shelf settings to the more distal outer shelf areas.Amongst all three systems tracts,intervals interpreted as lowstand prograding complexes contain the best developed sands and highest RSP.Sand development within the LSTs has been controlled by a pronounced growth fault regime accompanied by high subsidence and sedimentation rates.This is linked to the basinward migration of the sands during prolonged sea-level fall,creating significant accommodation space for sand deposition.On the other hand,the TSTs known to mark periods of progressive sea-level rise and landward migration of sandy facies,show thinner sands enclosed in much thicker,laterally extensive,and better-preserved deeper marine shales.Interpreted seismic sections indicate intense growth faulting and channelization that influenced the syn-and postdepositional development of the sand packages across the field.The initial timing of deformation of subregional faults in this area coincides with periods of abrupt falls in sea level.This approach could be useful for predicting sand-prone areas in frontier fields as well as possible reservoir-seal parameters required for some aspects of petroleum system analysis and quick-look volume estimation.展开更多
The main consequences of climate change in the Sahel have been the metamorphosis of surface conditions. These metamorphoses have resulted in surface degradation, of which silting up of watersheds is the main phenomeno...The main consequences of climate change in the Sahel have been the metamorphosis of surface conditions. These metamorphoses have resulted in surface degradation, of which silting up of watersheds is the main phenomenon. The objective of this study is to assess the environmental trends of the Kourfa pond watershed. The study is based on diachronic mapping with Landsat satellite images and Google Earth images, over the period 1986 to 2021. The study reveals that vegetation (whose rate of regression doubled between 1986 and 2021) has decreased to the benefit of crop areas (whose rate of increase multiplied by 3.61 between 1986 and 2021). Bare soil and encrusted areas have also decreased, with regression rates almost double than those of 1986. In addition, the Kourfa waterholes have experienced two types of changes over 35 years: one progressive between 2011 and 2016 and the other regressive between 2001 and 2021 compared to 1986. The ravine network has been multiplied by a factor of 2.4, with density more than doubled and the connectivity of the hydrographic networks has risen from 2 to 4, with significant bank recession. This dynamic of the Kourfa pond is linked to the high drainage, the increasing complexity of the gully network and the erosion due to the retreat of the watershed banks, all of which contribute to the silting-up of the Kourfa watershed.展开更多
Introduction: The association of diabetes and pregnancy is associated with a significantly higher risk of perinatal morbidity and mortality. The aim of this study was to investigate the perinatal morbidity and mortali...Introduction: The association of diabetes and pregnancy is associated with a significantly higher risk of perinatal morbidity and mortality. The aim of this study was to investigate the perinatal morbidity and mortality associated with maternal diabetes at the Issaka Gazoby Maternity Hospital in Niamey. Methodology: This was a prospective case-control study conducted from April to September 2021 at the Issaka Gazoby Maternity Hospital in Niamey. “Cases” were neonates born to diabetic mothers, and “controls” were neonates born to non-diabetic mothers. The main dependent variable was the occurrence of perinatal complications. Analysis was performed using Epi info software 7.2.1. Pearson’s Chi2 test or Fisher’s exact test were used (p Results: Of the 2,225 admissions during the study period, 31 newborns were born to diabetic mothers (1.4%). Diabetic mothers were 2.8 times more likely to have a history of abortion (67.7% vs. 28.6%;OR = 2.82;p = 0.001). Similarly, a history of macrosomia was found in 29.0% of diabetic mothers versus 9.5% of controls (OR = 2.15;p = 0.01). Macrosomia was also more common in newborns of diabetic mothers (38.7% vs. 9.5%;OR = 2.63;p Conclusion: The risks of ante- and perinatal complications such as abortion, fetal macrosomia and stillbirth, as well as neonatal pathological events (macrosomia and malformations) were greater in newborns of diabetic mothers.展开更多
Spatio-temporal variability and dynamics in Sahelian agro-pastoral zones make each local situation a special case. These specificities must be considered to guide the dissemination of agricultural options with a view ...Spatio-temporal variability and dynamics in Sahelian agro-pastoral zones make each local situation a special case. These specificities must be considered to guide the dissemination of agricultural options with a view to sustainable development. The territorial scale of municipalities is not sufficient for this necessary contextualization;the scale of the “village terroir” seems to be a better option. This is the hypothesis we put forward in the framework of the Global Collaboration for Resilient Food Systems program (CRFS), i.e. local context is spatially defined by village terroir. The study is based on data collected through participatory mapping and surveys in “village terroirs” in three regions of Niger (Maradi, Dosso and Tillabéri). Then the links between farm managers and their cultivated land, as well as the spatio-temporal dynamics of local context are analyzed. This study provides evidence of the existence and functional usefulness of the village terroir for farmers, their land management and their activities. It demonstrates the usefulness of contextualizing agricultural options at this scale. Their analysis elucidates the links between “terroirs village” and the specific functioning of the agrosocio-ecosystems acting on each of them, thus laying the systemic and geographical foundations for a model of the spatio- temporal dynamics of “village terroirs”. This initial work has opened up new perspectives in modeling and sustainable development.展开更多
文摘This study tries to highlight the role of magnetic and seismic data in the prevention of building cracking, which constitutes a geotechnical risk in Agadez City. This city is built on the faulted and fractured sandstone formations of the “Agadez Sandstones Formations”, which were deposited in unconformity on the basement of the Aïr Mountain. This study focuses on the prevention of geotechnical damages related to building cracking in the Agadez region through geophysical methods, which are well known for investigating tectonic structures and their directions on the surface and subsurface. A methodological approach integrated the seismic and magnetic data interpretation combined with field measurement on the cracked building and its underlying substratum, represented by Agadez sandstones and basement. The extraction of seismic lineaments from the West African seismic map showed the seismic directions oriented NW-SE (N135˚ to N160˚), passing through the studied area. The structural interpretation of the magnetic map shows that the Agadez region is also affected by the subsurface lineaments mainly oriented in NW-SE (N135˚) directions, which are similar to the identified seismic lineaments in the same zone. A structural study carried out on the Agadez sandstones and the underlying basement showed that faults and fractures oriented N120˚ to N165˚ affect both the basement of the Aïr Mountains and the sandstone formations on which the city of Agadez is built. These observations showed that building cracking in the Agadez region has a higher propagation tendency according to the directions ranging from NW-SE (N135˚) to NNW-SSE (N165˚). Therefore, the building’s cracking has a stronger propagation component according to these mean directions that are not recommended for building. To prevent and reduce the risks related to building cracking in Agadez region, it is highly recommended to build in the minor directions of cracking propagation, which correspond to NE and SW directions.
文摘In Niger, farms have been facing negative effects of climate change for several decades. The objective of this work is to assess the vulnerability of farms in Tillabery department by proposing an adaptation approach. A five-step method and descriptive analysis were used on a sample of 250 farmers. The degree of damage caused by pests and crop diseases is significant, with respective proportions of 52.50% and 40.40%. It appears that the main climate risk factors for vulnerability are droughts, floods, soil degradation, and pest invasions. Additionally, the average level of exposure to agricultural operations is very high, with an index of 0.6. The sensitivity index remained constant in the range of 0.3 to 0.6 and is significant (reaching an index of 0.8). However, 61.2% of farms have a medium level of vulnerability and 33.3% have a high vulnerability to the effects of climate change. Nonetheless, a concerning trend regarding the vulnerability of farms has been observed. To assist policymakers and development actors in improving the vulnerability level of these production units, four phases of action are proposed: a diagnostic phase, evaluation, estimation of adaptation needs, implementation, and proper monitoring of actions.
文摘Millet [Pennisetum glaucum (L.) R. Br. (Poaceae)] is one of the most widely consumed crops in Niger. Its production, despite the efforts of farmers, is confronted with weed problems, in particular Sesbania pachycarpa DC. (Fabaceae). The aim of the present study in this area is to assess the impact of Sesbania pachycarpa on millet growth and yield. To achieve this objective, a completely randomized Fisher block design of twenty-four elementary plots was set up with four replications. The data collected were millet plant heights and plot yields. The data collected were subjected to analysis of variance and Duncan’s test at the 5% threshold for comparisons of mean heights and yields with the control kept clean from sowing to millet harvesting. The results showed the sensitivity of millet plants to Sesbania pachycarpa. The results revealed that the threshold density for damage could be estimated at 6 Sesbania pachycarpa plants/m2 and the critical interference period at the fourth week after sowing. This study showed that the presence of Sesbania pachycarpa influences millet yield. Indeed, the best yields were obtained in plots without Sesbania pachycarpa. Millet yield decreased with increasing Sesbania pachycarpa density. The average percentage yield reduction was 36.79%, with a minimum of 21.25% and a maximum of 80%. The findings of this study complete the efforts of developing weed control techniques in pearl millet fields densely populated with Sesbania pachycarpa.
文摘Cowpea, Vigna unguiculata L. Walp, is an important food grain legume in Niger facing production losses due to insect pests. This study aims to determine the efficiency of non-chemical methods for managing these pests. A trial was conducted during the 2020 and 2022 cropping seasons at the INRAN station in the Maradi region. A Fischer experimental design with 6 repetitions was used to compare 4 treatments: synthetic chemical pesticide;the entomopathogenic fungus Beauveria bassiana;aqueous extracts of neem seeds, and control. Observations were carried out every three days. The cowpea pod-sucking bug, pod borer, and thrips were the main insect pests recorded. In terms of effectiveness, the synthetic pesticide was the best treatment. It reduced insect pest densities by 71.35% to 90.40% in 2020 and by 35.11% to 42.13% in 2022. Grain yields varied between treatments. Neem seed extract followed the synthetic pesticide and significantly reduced insect infestations in both years. The synthetic pesticide and neem seed extract resulted in yields 3 to 5 times higher than the control treatment in 2020. By contrast, B. bassiana 115 and neem seed extract produced similar yields in 2022. Therefore, the results of this study showed that B. bassiana 115 and neem seed extract have insecticidal potential and could be used as an ecological alternative for managing cowpea insect pests in the Sahel.
文摘Rationale: The contamination of soil with crude oil poses significant environmental and ecological threats. Bioremediation, particularly through the use of organisms like Pleurotus ostreatus (mushroom) and Eisenia fetida (earthworm), has emerged as a promising approach to mitigate crude oil pollution. Understanding the effectiveness of these organisms in reducing hydrocarbon levels in contaminated soil is crucial for devising sustainable remediation strategies. Objectives: This study aimed to evaluate the efficacy of Pleurotus ostreatus and Eisenia fetida in remediating crude oil-polluted soil. Specifically, it sought to assess the hydrocarbon profiles in soil treated with these organisms across varying concentrations of crude oil pollution. Method: Crude oil concentration levels ranging from 0% to 10% were applied to soil samples alongside control treatments, including soil only, soil with earthworms, and soil with mushrooms. Each treatment was replicated five times using a randomized complete block design. Standard methods were employed to determine the hydrocarbon contents of the soil. Results: The results indicated a significant increase (P Pleurotus ostreatus and Eisenia fetida exhibited noteworthy reductions in these hydrocarbon levels. At the three-month mark, mushrooms demonstrated a remarkable ability to reduce hydrocarbon content by 70% - 90% compared to the pollution treatment. In contrast, earthworms exhibited minimal potential for hydrocarbon reduction, particularly at both three and six-month intervals. For instance, TOC reduction reached a maximum of 96% with mushroom treatment and 85% with earthworm treatment at 5% crude oil pollution over six months. Conclusion: The findings highlight the effectiveness of Pleurotus ostreatus in significantly reducing hydrocarbon levels in crude oil-polluted soil compared to Eisenia fetida. Mushroom-treated soils consistently exhibited substantial reductions in TOC, TPH, TOG, PAH, and THC over the study period, suggesting their potential as a viable bioremediation agent. In contrast, while earthworms showed some capability in reducing hydrocarbon content, their effectiveness was comparatively limited. Recommendation: Based on the results, it is recommended to utilize Pleurotus ostreatus for the bioremediation of crude oil-polluted soils. Further research could explore optimizing remediation protocols involving mushroom-based treatments for enhanced efficiency. Statement of Significance: This study contributes valuable insights into the application of bioremediation techniques for mitigating crude oil contamination in soil. The demonstrated efficacy of Pleurotus ostreatus underscores its potential as a sustainable and eco-friendly solution for remediating hydrocarbon-polluted environments, offering a promising avenue for environmental restoration and conservation efforts.
文摘Cowpea, Vigna unguiculata (L.) Walp. is an economically important seed legume that helps combat food and nutrition insecurity in the Sahel, particularly Niger. However, its yield remains low due to insect pest attacks. This study was conducted at a station and in seven villages in the Maradi and Tahoua regions. It aimed to test the effectiveness of neem seed biopesticides [Azadirachta indica A. Juss] and sanitized human urine for integrated insect pest management. The cowpea variety UAM09 1055-6 was used for the experiments. The experimental trial was a Fisher block design consisting of five treatments: neem oil, neem seed extract (NSE), hygienized human urine (HHU), chemical pesticide, and a control, replicated five times at the station and twice in farmers’ environments. The study shows that Megalurothrips sjostedti Trybom, Clavigralla tomentosicollis Stål and Maruca vitrata Fabricius are the main insect pests. Plots treated with synthetic pesticides were the least infested by C. tomentosicollis. They were followed by neem seed extract and HHU treatments, which recorded an infestation level of 2.44 and 20.5 times lower than controls at the station and in farming environments. The density of thrips was 1.06 to 32.6 times lower in treated plots compared to controls. The proportion of pods damaged by M. vitrata was 1.95, 2.55, and 2.77 times lower in plots treated with HHU, NSE, and synthetic pesticide, respectively, compared to controls. Grain yields were 1.80 and 2.62 times higher in UHH and NSE treatments compared to control plots, both at the station and in farmers’ environments. A yield increase of 44.58% and 61.92% was noted for these treatments at the station and in farmers’ environments, respectively. These results may promote the dissemination of NSE and HHU biopesticide technologies in rural areas as an alternative method for integrated pest management of cowpeas.
文摘Introduction: Lower respiratory infections in general, and acute bronchiolitis in particular, represent a major cause of morbidity in children in Niger. The aim of this study was to investigate the epidemiological, diagnostic and therapeutic features of acute bronchiolitis in infants in the Pediatrics A department of the National Hospital in Zinder. Patients and Methods: This was a descriptive, cross-sectional study with prospective data collection conducted from April 1 to May 31, 2024. All infants aged 0 to 24 months hospitalized with acute bronchiolitis in the pediatric ward A of Zinder National Hospital were included in the study. Epidemiological, diagnostic and therapeutic aspects were the characteristics studied. Data analysis was performed using Epi info 7 software. Results: During the study period, acute bronchiolitis accounted for 51% of hospitalizations, and infants aged 3 - 11 months were the most affected (52.90%). The sex ratio was 1.6. The average age of patients was 10.40 ± 6.91 months, with extremes of 1 and 24 months. 98.50% of patients came from urban areas, and the socioeconomic level of families was average in 47.49% of cases. Mixed breastfeeding was practiced in 59.63% of cases. Average hospital admission time was 4.22 days. The main clinical signs were cough (43.18%), rhinorrhea (70.85%), ronchi (35.33%), crepitating rales (26.54%), sibilant rales (24.11%), signs of struggle (14.02%) and polypnea (70.85%). Paraclinical findings included chest distension, hyperleukocytosis and anemia, with 47.48%, 55.14% and 78.31% respectively. Therapeutically, nebulization was used in 93.08% of cases, respiratory physiotherapy (41.34%), corticosteroid therapy (34.08%), antibiotic therapy (21.50%), oxygen therapy (20.11%) and antipyretics (4.68%) were prescribed. Progression was favorable in 93.08% of patients, with a case-fatality rate of 1.12%. Conclusion: With its high frequency, acute bronchiolitis is a public health problem. Boys were the most affected by the condition, and the predominant age group was 3 to 11 months. Management was essentially based on nebulization and physiotherapy.
文摘Pearl millet, Pennisetum glaucum (Leeke) R. Br, is the main cereal crop in Niger. This crop is seriously attacked by the millet Head miner (MHM), Heliocheilus albipunctella (de Joannis) (Lepidoptera, Noctuidae) causing significant yield losses. This study to optimize biological control of this pest was carried out in Niger in the laboratory and in a farming environment. In the laboratory, the larval paralysis and emergence of the parasitoid Habrobracon hebetor Say (Hymenoptera: Braconidae) were compared between release jute bags, plastic boxes and cardboard boxes. In a farming environment, direct releases were carried out with plastic boxes and releases with jute bags in 12 villages of the Maradi region during the cropping seasons of 2021 and 2022. The results indicated that 25 larvae of Corcyra cephalonica Stainton (Lepidoptera: Pyralidae) in the boxes were all paralyzed by 2 females of H. hebetor within 7 hours 30 minutes. The emergence of adults began on the 7th day after the beginning of the experiment for a period of two weeks and three weeks respectively in the boxes and jute bags. The production varied from 107.08 to 110.17 parasitoids and was comparable between the Jute bags, plastic boxes and cardboard boxes. In Farmers’ fields, the parasitoid release with the two methods caused the parasitism rates that varied from 64.32 to 66.52% depending on the year but in 2022 the rate of parasitism was higher in the fields with direct releases using plastic boxes (72.66%) compared to those released with jute bags (56.35%). Plastic boxes and cardboard boxes can be used for the production of the H. hebetor parasitoids. These results can be recommended to the cottage industries in the Sahel in order to improve the production and release methods of H. hebetor and make them more adapted to farmers’ fields.
文摘The fate of wetlands in arid regions has become a matter of concern in the context of global warming. The Inner Niger Delta (IND) has received increasing attention from researchers and others to explore whether this largest wetland in Africa will shrivel due to climate change and increasing water use. An essential study goal is to understand what has been done so far in the Research of Inner-Niger-Delta Wetland in order to address its future challenges. The present study provides a comprehensive analysis of climate related research on the IND wetland through bibliometric means to diagnosis the evolution, lag and hotspot of relevant features in the literature. Key aspects of analysis included 1) trends of IND wetland related research 2) nature of collaboration networks, 3) co-occurrence of keywords and 4) emerging themes related to IND wetland over the last three decades, between the years 1991-2022. The results indicate that the IND wetland gained momentum in 2000, peaking in 2013 and then in 2018. IND wetland research has, on average, reach 2.5 publication in 2000 and exceed 5 papers by 2017. The leading countries that have produced high numbers of published documents are in order, France, Nigeria, USA, Germany and Mali. Therefore, more efficient scientific collaboration among regional African institutions is recommended to face local perspectives. The identified emerging topics are Niger delta, climate change, floods and rivers. The variables considered in analyses are river discharge, evapotranspiration, water level and rain. Variables relevant to global temperature warming are missing, which implies that researches on Inner Niger Delta wetland are less focusing on climate change and variability analyses.
文摘Rationale: The quality of groundwater in the Mgbede Oil Fields of South-South Nigeria has raised significant concerns due to the risk of contamination from industrial activities, especially gas flaring. Evaluating the effects of these operations on groundwater quality is essential for safeguarding the health and well-being of local communities, as well as protecting the environment. Objective: This study aimed to evaluate the quality of groundwater in the Mgbede Oil Fields, specifically examining whether the water meets international drinking water standards and identifying any contaminants present due to gas flaring. Method: Purposeful selection of water sampling points was employed to ensure the objectives of the study were met. Groundwater samples were collected from various locations within the Mgbede Oil Fields and analyzed for key quality parameters, including pH, manganese, and turbidity, among others. Results: The analysis revealed that while most groundwater samples were within acceptable international drinking water limits, there were notable exceptions. pH levels ranged from 5.17 to 6.16, manganese concentrations from 0.001 to 0.136 mg/L, and turbidity levels from 0.00 to 825 mg/L. All sampled locations exhibited traces of manganese and high acidity, indicating particulate pollution likely resulting from gas flaring activities. Conclusions: The study concluded that the groundwater quality in the Mgbede Oil Fields is negatively impacted by continuous gas flaring. Contaminants such as manganese and increased acidity levels exceed acceptable international standards, posing potential risks to environmental health. Recommendations: To mitigate these risks, it is recommended that immediate measures should be taken to reduce gas flaring and its associated particulate emissions. Regular monitoring of groundwater quality should be implemented to track improvements and ensure compliance with international standards. Additionally, introducing filtration systems or alternative water sources could help protect the health of local communities. Significance Statement: This study underscores the significant impact of industrial activities, specifically gas flaring, on groundwater quality in the Mgbede Oil Fields. The findings highlight the urgent need for regulatory measures and continuous monitoring to safeguard environmental health and ensure the availability of safe drinking water.
基金Supported by the Asociación de Celíacos y Sensibles al Gluten de Madrid,No.ACM2020)and Research Committee Argentine Society of Gastroenterology,No.2020.
文摘BACKGROUND The gluten-free diet(GFD)has limitations,and there is intense research in the development of adjuvant therapies.AIM To examine the effects of orally administered Aspergillus niger prolyl endopeptidase protease(AN-PEP)on inadvertent gluten exposure and symptom prevention in adult celiac disease(CeD)patients following their usual GFD.METHODS This was an exploratory,double-blind,randomized,placebo-controlled trial that enrolled CeD patients on a long-term GFD.After a 4-wk run-in period,patients were randomized to 4 wk of two AN-PEP capsules(GliadinX;AVI Research,LLC,United States)at each of three meals per day or placebo.Outcome endpoints were:(1)Average weekly stool gluten immunogenic peptides(GIP)between the run-in and end of treatments and between AN-PEP and placebo;(2)celiac symptom index(CSI);(3)CeD-specific serology;and(4)quality of life.Stool samples were collected for GIP testing by ELISA every Tuesday and Friday during run-ins and treatments.RESULTS Forty patients were randomized for the intention-to-treat analysis,and three were excluded from the per-protocol assessment.Overall,628/640(98.1%)stool samples were collected.GIP was undetectable(<0.08μg/g)in 65.6%of samples,and no differences between treatment arms were detected.Only 0.5%of samples had GIP concentrations sufficiently high(>0.32μg/g)to potentially cause mucosal damage.Median GIP concentration in the AN-PEP arm was 44.7%lower than in the run-in period.One-third of patients exhibiting GIP>0.08μg/g during run-in had lower or undetectable GIP after AN-PEP treatment.Compared with the run-in period,the proportion of symptomatic patients(CSI>38)in the AN-PEP arm was significantly lower(P<0.03).AN-PEP did not result in changes in specific serologies.CONCLUSION This exploratory study conducted in a real-life setting revealed high adherence to the GFD.The AN-PEP treatment did not significantly reduce the overall GIP stool concentration.However,given the observation of a significantly lower prevalence of patients with severe symptoms in the AN-PEP arm,further clinical research is warranted.
文摘Pectinex XXL,a commercially prepared pectinase,was investigated for its potential application in the fruit juice industry.Polygalacturonic acid was used as the substrate for determining the enzymatic properties of Pectinex XXL using the DNS method.According to the results,the optimal pH for Pectinex XXL activity was 4.5,and the enzyme was stable in the pH range of 3.0~4.5.The optimal pH and pH stability range are consistent with those of some tropical and subtropical fruits.The optimal temperature for Pectinex XXL activity was 60℃,and the enzyme remained stable after one hour in a water bath set at 40℃.Additionally,the enzymatic activity was not inhibited in the presence of 1 mmol/L of Na^(+),Mg^(2+),Ba^(2+),Co^(2+),Zn^(2+),and Fe^(2+),whereas it was slightly inhibited in the presence of 2 mmol/L of K^(+)and Fe^(2+)and partially inhibited in the presence of 1 and 2 mmol/L of Ca^(2+)and Mn^(2+),demonstrating its good stability in acids and excellent thermal catalytic performance.Based on the above experimental results,depectinization experiments were performed on plantain and cherry tomato juices using different amounts of Pectinex XXL.After one hour reaction with 16 U/mL of the enzyme,the yields of the plantain and cherry tomato juices were substantially increased by 119.03%and 15.97%,respectively,while their light transmittance was remarkably enhanced by 37.65%and 12.35%,respectively.Furthermore,the enzyme reduced the viscosity of the plantain and cherry tomato juices by 88.29%and 29.50%,respectively.The juice production experiments confirmed that this enzyme can significantly improve the yield and light transmittance of plantain juice,while effectively reducing its viscosity.These findings indicate the potential of Pectinex XXL in the industrial production of plantain juice.
文摘This study characterized the AA-01 depleted hydrocarbon reservoir in the KOKA field, Niger Delta, using a multidimensional approach. This investigation involved data validation analysis, evaluation of site suitability for CO_(2) storage, and compositional simulation of hydrocarbon components. The primary objective was to determine the initial components and behavior of the hydrocarbon system required to optimize the injection of CO_(2) and accompanying impurities, establishing a robust basis for subsequent sequestration efforts in the six wells in the depleted KOKA AA-01 reservoir. The process, simulated using industry software such as ECLIPSE, PVTi, SCAL, and Petrel, included a compositional fluid analysis to confirm the pressure volume temperature(PVT) hydrocarbon phases and components. This involved performing a material balance on the quality of the measured data and matching the initial reservoir pressure with the supplied data source. The compositional PVT analysis adopted the Peng–Robinson equation of state to model fluid flow in porous media and estimate the necessary number of phases and components to describe the system accurately. Results from this investigation indicate that the KOKA AA-01 reservoir is suitable for CO_(2)sequestration. This conclusion is based on the reservoir's good quality, evidenced by an average porosity of 0.21 and permeability of 1 111.0 mD, a measured lithological depth of 9 300 ft, and characteristic reservoir – seal properties correlated from well logs. The study confirmed that volumetric behavior predictions are directly linked to compositional behavior predictions, which are essential during reservoir initialization and data quality checks. Additionally, it highlighted that a safe design for CO_(2) storage relies on accurately representing multiphase behaviour across wide-ranging pressure–temperature–composition conditions.
文摘We comment here on the article by Stefanolo et al entitled“Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet”,published in the World Journal of Gastroenterology.Celiac disease is a well-recognized systemic autoimmune disorder.In genetically susceptible people,the most evident damage is located in the small intestine,and is caused and worsened by the ingestion of gluten.For that reason,celiac patients adopt a gluten-free diet(GFD),but it has some limitations,and it does not prevent re-exposure to gluten.Research aims to develop adjuvant therapies,and one of the most studied alternatives is supplementation with Aspergillus niger prolyl endopeptidase protease(AN-PEP),which is able to degrade gluten in the stomach,reducing its concentration in the small intestine.The study found a high adherence to the GFD,but did not address AN-PEP as a gluten immunogenic peptide reducer,as it was only tested in patients following a GFD and not in gluten-exposing conditions.This study opens up new research perspectives in this area and shows that further study is needed to clarify the points that are still in doubt.
文摘Wellbore instability and sand production are all common challenges in the Niger Delta oil province,resulting in high drilling and production cost as well as damage to oil facilities.The vulnerability of lithologic formations to wellbore instability and resultant sand production is investigated in the four delineated reservoirs of the“Areo”field,western part of Niger Delta Basin.The foundation for establishing the geomechanical properties in this study was a 1-dimensional mechanical earth model,using gamma ray(GR),density(RHOB),compressional slowness(DTC),and shear slowness(DTS)logs.Within the Areo oil field,two wells(well 001 and well 002)were correlated.The evaluated formations are still primarily composed of compacted shale and unconsolidated sandstone,with reservoir sand units exhibiting lower elastic and rock strength properties than shale units.High compressibility and porosity make sand more brittle,while low compressibility and porosity make shale stiffer due to high moduli.The maximum force that can be applied to a shale unit without causing it to fail is 17.23 MPa,which is the maximum average rock strength of the shale.It means that shale requires more vertical stress or pressure than sand does in order to deform it(15.06 MPa).The three sand prediction approaches used in the analysis of sand production predictions have cut-off values that are higher than the average values of the formations.The Schlumberger sand production index method(S/I)indicates that the reservoir has potential for sand influx in the two wells,with the average of the four reservoirs studied in wells 001 and 002 being 1.551012 psi and 1.141012 psi respectively.However,when a formation's sand production index is less than 1.241012 psi,as it is in this study,the formation is likely to produce sand.These findings support the notion that the defined sandstone units are highly unconsolidated and have a high potential for producing sands;therefore,sand control techniques must be factored into process optimization and cost reduction plans.
基金sponsored by the Shell Petroleum Development Company of Nigeria Limited(SPDC).
文摘The utilization of sequence stratigraphic concepts in identifying sands and their spatial continuity in distinct gross depositional settings is key,especially in frontier settings where data paucity is a common challenge.In the Baka field,onshore Niger Delta,detailed reservoir correlation guided by sequence stratigraphic framework analysis showed the distribution of sand and shale units constituting reservoirseal pairs(RSP)correlatable across the field.Within the 3rd-order packages,it is observed that the lowstand systems tract(LST)and highstand systems tract(HST)contain more RSPs and thicker 4th-and 5th-order sands than the transgressive systems tract(TST).In terms of bathymetry,it is noted that irrespective of systems tracts,the RSP Index(RI)decreases from the proximal shallow/inner shelf settings to the more distal outer shelf areas.Amongst all three systems tracts,intervals interpreted as lowstand prograding complexes contain the best developed sands and highest RSP.Sand development within the LSTs has been controlled by a pronounced growth fault regime accompanied by high subsidence and sedimentation rates.This is linked to the basinward migration of the sands during prolonged sea-level fall,creating significant accommodation space for sand deposition.On the other hand,the TSTs known to mark periods of progressive sea-level rise and landward migration of sandy facies,show thinner sands enclosed in much thicker,laterally extensive,and better-preserved deeper marine shales.Interpreted seismic sections indicate intense growth faulting and channelization that influenced the syn-and postdepositional development of the sand packages across the field.The initial timing of deformation of subregional faults in this area coincides with periods of abrupt falls in sea level.This approach could be useful for predicting sand-prone areas in frontier fields as well as possible reservoir-seal parameters required for some aspects of petroleum system analysis and quick-look volume estimation.
文摘The main consequences of climate change in the Sahel have been the metamorphosis of surface conditions. These metamorphoses have resulted in surface degradation, of which silting up of watersheds is the main phenomenon. The objective of this study is to assess the environmental trends of the Kourfa pond watershed. The study is based on diachronic mapping with Landsat satellite images and Google Earth images, over the period 1986 to 2021. The study reveals that vegetation (whose rate of regression doubled between 1986 and 2021) has decreased to the benefit of crop areas (whose rate of increase multiplied by 3.61 between 1986 and 2021). Bare soil and encrusted areas have also decreased, with regression rates almost double than those of 1986. In addition, the Kourfa waterholes have experienced two types of changes over 35 years: one progressive between 2011 and 2016 and the other regressive between 2001 and 2021 compared to 1986. The ravine network has been multiplied by a factor of 2.4, with density more than doubled and the connectivity of the hydrographic networks has risen from 2 to 4, with significant bank recession. This dynamic of the Kourfa pond is linked to the high drainage, the increasing complexity of the gully network and the erosion due to the retreat of the watershed banks, all of which contribute to the silting-up of the Kourfa watershed.
文摘Introduction: The association of diabetes and pregnancy is associated with a significantly higher risk of perinatal morbidity and mortality. The aim of this study was to investigate the perinatal morbidity and mortality associated with maternal diabetes at the Issaka Gazoby Maternity Hospital in Niamey. Methodology: This was a prospective case-control study conducted from April to September 2021 at the Issaka Gazoby Maternity Hospital in Niamey. “Cases” were neonates born to diabetic mothers, and “controls” were neonates born to non-diabetic mothers. The main dependent variable was the occurrence of perinatal complications. Analysis was performed using Epi info software 7.2.1. Pearson’s Chi2 test or Fisher’s exact test were used (p Results: Of the 2,225 admissions during the study period, 31 newborns were born to diabetic mothers (1.4%). Diabetic mothers were 2.8 times more likely to have a history of abortion (67.7% vs. 28.6%;OR = 2.82;p = 0.001). Similarly, a history of macrosomia was found in 29.0% of diabetic mothers versus 9.5% of controls (OR = 2.15;p = 0.01). Macrosomia was also more common in newborns of diabetic mothers (38.7% vs. 9.5%;OR = 2.63;p Conclusion: The risks of ante- and perinatal complications such as abortion, fetal macrosomia and stillbirth, as well as neonatal pathological events (macrosomia and malformations) were greater in newborns of diabetic mothers.
文摘Spatio-temporal variability and dynamics in Sahelian agro-pastoral zones make each local situation a special case. These specificities must be considered to guide the dissemination of agricultural options with a view to sustainable development. The territorial scale of municipalities is not sufficient for this necessary contextualization;the scale of the “village terroir” seems to be a better option. This is the hypothesis we put forward in the framework of the Global Collaboration for Resilient Food Systems program (CRFS), i.e. local context is spatially defined by village terroir. The study is based on data collected through participatory mapping and surveys in “village terroirs” in three regions of Niger (Maradi, Dosso and Tillabéri). Then the links between farm managers and their cultivated land, as well as the spatio-temporal dynamics of local context are analyzed. This study provides evidence of the existence and functional usefulness of the village terroir for farmers, their land management and their activities. It demonstrates the usefulness of contextualizing agricultural options at this scale. Their analysis elucidates the links between “terroirs village” and the specific functioning of the agrosocio-ecosystems acting on each of them, thus laying the systemic and geographical foundations for a model of the spatio- temporal dynamics of “village terroirs”. This initial work has opened up new perspectives in modeling and sustainable development.
