144 research outputs found
Winter selection of habitats within intertidal foraging areas by mink (Mustela vison)
Patterns of habitat selection by American mink Mustela vison within foraging areas located on the shore, were studied in a coastal environment of Scotland from November to March in 1983/84, 1984/85 and 1994/95. The abundance of prey in the intertidal zone was modelled in relation to abiotic environmental characteristics. Four factors were found to be important predictors of prey abundance: the position within the tidal zone, the abundance and size of rockpools, the nature of the substratum and the presence of fresh water streams. The model was used to predict prey abundance in different areas of the shore. We then investigated whether mink were choosing areas with higher prey abundance at different tidal levels and within, as opposed to between, core areas (areas with a relatively high density of fixes, encompassing usually one or more dens). Only when foraging at low or mid-tide and within core areas were mink found to behave selectively. They showed no significant preference for areas rich in prey when foraging at high tide and between core areas. Mink were also found to avoid areas with fresh water streams and to prefer foraging in the mid-tide zone. The findings are discussed in relation to prey abundance and competition with the otter Lutra lutra
Extracts of different polarity of Daphne laureola L. as valuable source of antioxidant and neuroprotective compounds
In this study, Daphne laureola L., an European-Mediterranean species, was investigated for its antioxidant properties using different in vitro bioassays, namely 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), Ferric Reducing Activity Power (FRAP), and β-carotene bleaching assays. The acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity using the Ellman’s method was also examined. The aerial parts of D. laureola were subjected to exhaustive and subsequent macerations with solvents at different polarity, such as methanol, dichloromethane, and n-hexane. Dichloromethane extract was the most promising in DPPH and FRAP tests with IC50 values of 32.2 μg/mL and 71.5
μM Fe(II)/g, respectively. Methanol extract showed the most promising inhibition of lipid peroxidation evaluated by β-carotene bleaching test with an IC50 value of 6.6 μg/mL after 30 min of incubation. This extract was the most active against AChE (IC50 value of 56.9 μg/mL). An interesting result was obtained against BChE by the n-hexane extract, with an IC50 value of 49.7 μg/mL. In conclusion, the results suggest that D. laureola may provide a substantial source of phytochemicals, which act as natural antioxidants and acetylcholinesterase inhibitors, and may be beneficial in the treatment of Alzheimer disease
In vitro and in vivo studies of Cucurbita pepo L. flowers: chemical profile and bioactivity
Edible flowers consumption has increased in recent years due to their rich content of healthy phytochemicals. The aim of this study was to analyse the chemical profile of Cucurbita pepo L. flowers, and to explore their antioxidant and hypoglycaemic prop- erties. Moreover, in order to assess in vivo effects, biochemical analysis, Reactive Oxygen Metabolites (d-ROMs) and Biological Antioxidant Potential (BAP) tests were performed on mice serum. High Performance Liquid Chromatography-Diode Array Detection (HPLC-DAD) analyses revealed the presence of (þ)-catechin, ()-epicatechin, rutin, and syringic acid as main constituents. 2,20- Azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and Ferric Reducing Antioxidant Power (FRAP) tests showed interest- ing results. The extract exhibited the strongest inhibitory effect on a-glucosidase (IC50 of 144.77lg/mL). In vivo results confirmed the hypoglycaemic effects, also affecting lipid metabolism but did not revealed benefits on ROS production. These results may add some information supporting the use of C. pepo flowers as func- tional foods and/or nutraceuticals
Comprehensive vascular imaging using optical coherence tomography-based angiography and photoacoustic tomography
Studies have proven the relationship between cutaneous vasculature abnormalities and dermatological disorders, but to image vasculature noninvasively in vivo, advanced optical imaging techniques are required. In this study, we imaged a palm of a healthy volunteer and three subjects with cutaneous abnormalities with photoacoustic tomography (PAT) and optical coherence tomography with angiography extension (OCTA). Capillaries in the papillary dermis that are too small to be discerned with PAT are visualized with OCTA. From our results, we speculate that the PA signal from the palm is mostly from hemoglobin in capillaries rather than melanin, knowing that melanin concentration in volar skin is significantly smaller than that in other areas of the skin. We present for the first time OCTA images of capillaries along with the PAT images of the deeper vessels, demonstrating the complementary effective imaging depth range and the visualization capabilities of PAT and OCTA for imaging human skin in vivo. The proposed imaging system in this study could significantly improve treatment monitoring of dermatological diseases associated with cutaneous vasculature abnormalities
Recommended from our members
The compensatory potential of increased immigration following intensive American mink population control is diluted by male-biased dispersal
Attempts to mitigate the impact of invasive species on native ecosystems increasingly target large land masses where control, rather than eradication, is the management objective. Depressing numbers of invasive species to a level where their impact on native biodiversity is tolerable requires overcoming the impact of compensatory immigration from non-controlled portions of the landscape. Because of the expected scale-dependency of dispersal, the overall size of invasive species management areas relative to the dispersal ability of the controlled species will determine the size of any effectively conserved core area unaffected by immigration from surrounding areas. However, when dispersal is male-biased, as in many mammalian invasive carnivores, males may be overrepresented amongst immigrants, reducing the potential growth rate of invasive species populations in re-invaded areas. Using data collected from a project that gradually imposed spatially comprehensive control on invasive American mink (Neovison vison) over a 10,000 km2 area of NE Scotland, we show that mink captures were reduced to almost zero in 3 years, whilst there was a threefold increase in the proportion of male immigrants. Dispersal was often long distance and linking adjacent river catchments, asymptoting at 38 and 31 km for males and females respectively. Breeding and dispersal were spatially heterogeneous, with 40 % of river sections accounting for most captures of juvenile (85 %), adult female (65 %) and immigrant (57 %) mink. Concentrating control effort on such areas, so as to turn them into “attractive dispersal sinks” could make a disproportionate contribution to the management of recurrent re-invasion of mainland invasive species management areas
Mink Farms Predict Aleutian Disease Exposure in Wild American Mink
BACKGROUND: Infectious diseases can often be of conservation importance for wildlife. Spillover, when infectious disease is transmitted from a reservoir population to sympatric wildlife, is a particular threat. American mink (Neovison vison) populations across Canada appear to be declining, but factors thus far explored have not fully explained this population trend. Recent research has shown, however, that domestic mink are escaping from mink farms and hybridizing with wild mink. Domestic mink may also be spreading Aleutian disease (AD), a highly pathogenic parvovirus prevalent in mink farms, to wild mink populations. AD could reduce fitness in wild mink by reducing both the productivity of adult females and survivorship of juveniles and adults. METHODS: To assess the seroprevalence and geographic distribution of AD infection in free-ranging mink in relation to the presence of mink farms, we conducted both a large-scale serological survey, across the province of Ontario, and a smaller-scale survey, at the interface between a mink farm and wild mink. CONCLUSIONS/SIGNIFICANCE: Antibodies to AD were detected in 29% of mink (60 of 208 mink sampled); however, seroprevalence was significantly higher in areas closer to mink farms than in areas farther from farms, at both large and small spatial scales. Our results indicate that mink farms act as sources of AD transmission to the wild. As such, it is likely that wild mink across North America may be experiencing increased exposure to AD, via disease transmission from mink farms, which may be affecting wild mink demographics across their range. In light of declining mink populations, high AD seroprevalence within some mink farms, and the large number of mink farms situated across North America, improved biosecurity measures on farms are warranted to prevent continued disease transmission at the interface between mink farms and wild mink populations
- …