Skin care products are often designed to provide tangible, physical benefits to skin health. Alleviation of dry skin and minimization of the signs of aging and post-injury scarring are important benefits targeted by m...Skin care products are often designed to provide tangible, physical benefits to skin health. Alleviation of dry skin and minimization of the signs of aging and post-injury scarring are important benefits targeted by many products on the market. Equally important to these benefits are favorable, desirable sensory attributes, without which products are unlikely to be used and repurchased. Other products are designed primarily to deliver sensory—or sensual—benefits (e.g., many cosmetic creams). This review considers the tactile sensory experience delivered by skin care products by examining: 1) their instrumentally-measured rheology and tribology;2) their influence on the skin’s mechanics (e.g., compliance);3) their implications for changing sensory function (e.g., tactile sensitivity);and 4) the possibility that skin care products alter their own perception. Products that contain chemosensates (e.g., capsaicin, menthol) or pharmaceutical actives are not considered here. Although numerous perceptual-physical links have been reported, formulation rules by which products can be designed for optimal skinfeels are currently unavailable from the existing literature. This is because of inconsistencies among studies in the perceptual attributes investigated, the physical characterizations chosen to describe the products, and analysis methods employed. To provide a robust method for designing products with beneficial and desirable skinfeels, we propose the use of 1) a consistent lexicon that fully describes the perceptual experience of any product investigated, 2) a means of recording the mechanical events at the fingertip skin that occur when a skin care product is manually applied to the body. This approach contrasts with previous instrumental (in vitro) methods that may not generalize well to product-treated human skin (in vivo). Ongoing studies that record mechanical events at the skin surface show promise in identifying realistic models of the perception of skin care products.展开更多
Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long-term adaptability to an increasingly human-dominated landscape.The aim of this...Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long-term adaptability to an increasingly human-dominated landscape.The aim of this study was to determine and compare the influence of ground-based food availability,remotely sensed plant productivity,and indigenous forest use on the ranging patterns of the endangered samango monkey(Cercopithecus albogularis schwarzi).We collected monthly ranging data on two habituated samango monkey groups,from February 2012 to December 2016,from our field site in the Soutpansberg Mountains,South Africa.We used linear mixed models to explore how food availability,plant productivity,and indigenous forest use influenced monthly ranging patterns,while controlling for group size,number of sample days and day length.We found that as more areas of high plant productivity(derived from remotely sensed EVI)were incorporated into the ranging area,both total and core monthly ranging areas decreased.In addition,both total ranging area and mean monthly daily path length decreased as more indigenous forest was incorporated into the ranging area.However,we found no effect of either ground-based food availability or remotely sensed plant productivity on ranging patterns.Our findings demonstrate the behavioral flexibility in samango monkey ranging,as samangos can utilize matrix habitat during periods of low productivity but are ultimately dependent on access to indigenous forest patches.In addition,we highlight the potential of using remotely sensed areas of high plant productivity to predict ranging patterns in a small ranging,forest-dwelling guenon,over ground-based estimates of food availability.展开更多
Preference for uninfected mates is presumed beneficial as it minimizes one＇s risk of contracting an infection and infecting one＇s offspring. In avian systems, visual ornaments are often used to indi- cate parasite b...Preference for uninfected mates is presumed beneficial as it minimizes one＇s risk of contracting an infection and infecting one＇s offspring. In avian systems, visual ornaments are often used to indi- cate parasite burdens and facilitate mate choice. However, in mammals, olfactory cues have been proposed to act as a mechanism allowing potential mates to be discriminated by infection status. The effect of infection upon mammalian mate choice is mainly studied in captive rodents where ex- perimental trials support preference for the odors of uninfected mates and some data suggest scent marking is reduced in individuals with high infection burdens. Nevertheless, whether such effects occur in nonmodel and wild systems remains poorly understood. Here, we investigate the interplay between parasite load （estimated using fecal egg counts） and scent marking behavior in a wild population of banded mongooses Mungos mungo. Focusing on a costly protozoan parasite of the genus Isospora and the nematode worm Toxocara, we first show that banded mongooses that engage in frequent, intensive scent marking have lower Isospora loads, suggesting marking behavior may be an indicator trait regarding infection status. We then use odor presentations to demonstrate that banded mongooses mark less in response to odors of opposite sexed individuals with high Isospora and Toxocara loads. As both of these parasites are known to have detrimental effects upon the health of preweaned young in other species, they would appear key targets to avoid during mate choice. Results provide support for scent as an important ornament and mechanism for advertising parasitic infection within wild mammals.展开更多
文摘Skin care products are often designed to provide tangible, physical benefits to skin health. Alleviation of dry skin and minimization of the signs of aging and post-injury scarring are important benefits targeted by many products on the market. Equally important to these benefits are favorable, desirable sensory attributes, without which products are unlikely to be used and repurchased. Other products are designed primarily to deliver sensory—or sensual—benefits (e.g., many cosmetic creams). This review considers the tactile sensory experience delivered by skin care products by examining: 1) their instrumentally-measured rheology and tribology;2) their influence on the skin’s mechanics (e.g., compliance);3) their implications for changing sensory function (e.g., tactile sensitivity);and 4) the possibility that skin care products alter their own perception. Products that contain chemosensates (e.g., capsaicin, menthol) or pharmaceutical actives are not considered here. Although numerous perceptual-physical links have been reported, formulation rules by which products can be designed for optimal skinfeels are currently unavailable from the existing literature. This is because of inconsistencies among studies in the perceptual attributes investigated, the physical characterizations chosen to describe the products, and analysis methods employed. To provide a robust method for designing products with beneficial and desirable skinfeels, we propose the use of 1) a consistent lexicon that fully describes the perceptual experience of any product investigated, 2) a means of recording the mechanical events at the fingertip skin that occur when a skin care product is manually applied to the body. This approach contrasts with previous instrumental (in vitro) methods that may not generalize well to product-treated human skin (in vivo). Ongoing studies that record mechanical events at the skin surface show promise in identifying realistic models of the perception of skin care products.
文摘Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long-term adaptability to an increasingly human-dominated landscape.The aim of this study was to determine and compare the influence of ground-based food availability,remotely sensed plant productivity,and indigenous forest use on the ranging patterns of the endangered samango monkey(Cercopithecus albogularis schwarzi).We collected monthly ranging data on two habituated samango monkey groups,from February 2012 to December 2016,from our field site in the Soutpansberg Mountains,South Africa.We used linear mixed models to explore how food availability,plant productivity,and indigenous forest use influenced monthly ranging patterns,while controlling for group size,number of sample days and day length.We found that as more areas of high plant productivity(derived from remotely sensed EVI)were incorporated into the ranging area,both total and core monthly ranging areas decreased.In addition,both total ranging area and mean monthly daily path length decreased as more indigenous forest was incorporated into the ranging area.However,we found no effect of either ground-based food availability or remotely sensed plant productivity on ranging patterns.Our findings demonstrate the behavioral flexibility in samango monkey ranging,as samangos can utilize matrix habitat during periods of low productivity but are ultimately dependent on access to indigenous forest patches.In addition,we highlight the potential of using remotely sensed areas of high plant productivity to predict ranging patterns in a small ranging,forest-dwelling guenon,over ground-based estimates of food availability.
文摘Preference for uninfected mates is presumed beneficial as it minimizes one＇s risk of contracting an infection and infecting one＇s offspring. In avian systems, visual ornaments are often used to indi- cate parasite burdens and facilitate mate choice. However, in mammals, olfactory cues have been proposed to act as a mechanism allowing potential mates to be discriminated by infection status. The effect of infection upon mammalian mate choice is mainly studied in captive rodents where ex- perimental trials support preference for the odors of uninfected mates and some data suggest scent marking is reduced in individuals with high infection burdens. Nevertheless, whether such effects occur in nonmodel and wild systems remains poorly understood. Here, we investigate the interplay between parasite load （estimated using fecal egg counts） and scent marking behavior in a wild population of banded mongooses Mungos mungo. Focusing on a costly protozoan parasite of the genus Isospora and the nematode worm Toxocara, we first show that banded mongooses that engage in frequent, intensive scent marking have lower Isospora loads, suggesting marking behavior may be an indicator trait regarding infection status. We then use odor presentations to demonstrate that banded mongooses mark less in response to odors of opposite sexed individuals with high Isospora and Toxocara loads. As both of these parasites are known to have detrimental effects upon the health of preweaned young in other species, they would appear key targets to avoid during mate choice. Results provide support for scent as an important ornament and mechanism for advertising parasitic infection within wild mammals.
