817 research outputs found
Sustainable rangeland grazing in Norse Faroe
The introduction of domestic livestock - particularly sheep - and rangeland grazing by Norse settlers to Faroe during the 9th century has generally been described as a major pressure on a sensitive landscape, leading to rapid and widespread vegetation change and contributing to land degradation. This view has, however, been developed without consideration of Norse grazing management practices which may have served to minimise grazing impacts on landscapes as well as sustaining and enhancing vegetation and livestock productivity. These alternative scenarios are considered using a historical grazing management simulation model with Faroese climate and vegetation inputs and given archaeological, historical and palaeo-environmental parameters. Three contrasting rangeland areas are investigated and, based on the maximum number of ewe / lamb pairs the rangeland could sustain, modeling suggests that utilisable biomass declined with the onset of grazing activity, but not to a level that would cause major changes in vegetation cover or contribute to soil erosion even under climatically determined poor growth conditions. When rangeland areas partitioned into what are termed hagi and partir are modeled, grazing levels are still within rangeland carrying capacities, but productivities are variable. Some rangeland areas increase biomass and livestock productivity's and biomass utilisation rates while other rangeland areas that were too finely partitioned were likely to suffer substantial decline in livestock productivities. Partitioning of rangeland is a likely contributor to long-term differentiation of landscapes and the relative success of settlements across Faroe beyond the Norse period
Kate Loves Topshop: Celebrity Endorsements and the Lovemarks Concept in a Fashion Retail Context
Fashion designers and retailers often employ celebrities as endorsers due to celebrities’ power to influence consumer attitudes, drive sales and command loyalty. This power may be predicated on the transfer of a celebrity’s perceived personality to the promoted brand, thus enhancing consumer attitudes toward it. Celebrity endorsement is regarded as one component of contemporary brand management, the practice of which has two consequences: first, consumers increasingly expect ‘good’ brand performance from ALL brands; second, brands correspondingly find it difficult to continually distinguish themselves. One response has been the Lovemarks concept (Roberts 2005). A Lovemark is distinguished from conventional brands by inspiring deep, long-lasting relationships based on emotional responses invoked by the characteristics and personality it represents. While the Lovemark model is considered useful to practitioners (Bain 2004; Cooper & Pawle 2006), its academic study is limited, especially in its application to established marketing concepts. Here, a qualitative case-study explores the Lovemark concept in context of celebrity endorsement by examining the congruency between emotions felt for UK fashion retailer Topshop, and its associated celebrity, Kate Moss. Findings suggest that emotional responses to a celebrity have resonance on attitudes toward a brand; these and implications for practice and theory will be presented
Using Nuclear Magnetic Resonance Spectroscopy to Develop Physiological Profiles for Bighorn Sheep (Poster)
This study employs new techniques using nuclear magnetic resonance (NMR) to assess the relative health, physiological condition, and reproductive function of wild bighorn sheep (Ovis canadensis) in Montana and Wyoming. Ongoing bighorn studies in Montana and the Greater Yellowstone Ecosystem are focused on herd attributes and the population dynamics which are affected by disease, climate, habitat and physiology. Indices of herd health and physiological status are typically obtained through expensive and time consuming lab assays and field measurements. Recently, NMR spectroscopy has been used to revolutionize the assessment of human metabolic health, and we expect that there is similar potential for studies of wildlife populations. Using NMR spectroscopy to assess metabolites associated with disease, nutrition and stress may eliminate the need for many traditional assays and techniques used today. NMR can be used to evaluate a large suite of metabolites associated with a variety of physiological functions from as little as 500 uL of serum or plasma. Blood samples from 242 sheep from 13 different herds were collected during the winters of 2013-14 and 2014-15 to develop a comprehensive metabolite panel for bighorn sheep. We have used a recently developed statistical program known as MetaboAnalystâ„¢ to begin to analyze and evaluate differences in NMR metabolic profiles among herds and across the fall-winter season when nutritional and physiological stress is expected to be acute. We will be presenting the results of this preliminary study and discussing the potential for application in wildlife management
Nuclear Magnetic Resonance Spectroscopy Metabolic Profiles to Distinguish Geographically Isolated Populations of Mountain Goats
Basic physiological studies on mountain goats (Oreamnos americanus) are conspicuously lacking in the literature, and the physiology of this species is perhaps the least known of the high mountain ungulates. The objective of this study was to evaluate metabolic profiles of female mountain goats from five geographically distinct populations using Nuclear Magnetic Resonance (NMR) spectroscopy. Serum samples were collected from nannies located in Alaska in September (AK) from Glacier in August (GMT), from the Grand Tetons in November-December (GT), from NE Yellowstone in December (NEY) and from Absaroka in March (AB). Serum was extracted with acetone, dried and re-suspended in a standard NMR buffer. NMR spectra were analyzed with Chenomixâ„¢ software. Metabolites were identified and concentrations determined using the Chenomixâ„¢ database and the Human Metabolome Database. We identified 55 metabolites in the serum of mountain goats using this emerging technology. Of these 42 metabolites differed among the herds (P < 0.05). Of these 42 metabolites; creatinine, lactate and pyruvate distinguished (P < 0.05) each herd from another. Furthermore, using Principal Component Analyses of these metabolites allowed us to clearly differentiate metabolic profiles in carbohydrate, protein and lipid metabolism in nannies from these five populations. This study has the potential to enhance our understanding of how changes in nutrition, reproduction, susceptibility to disease, and survival rates drive population dynamics
An Initial Assessment of the Potential of Genomic Analysis to Help Inform Bighorn Sheep Management
Genetic research may be a useful approach for understanding factors that could impact productivity and restoration of bighorn sheep (Ovis canadensis) herds. For example, genetic consequences of inbreeding in small populations can impact recruitment and local adaptations can influence translocation success. This modest pilot study quantified genetic attributes of bighorn sheep populations with a range of different herd histories in Montana and Wyoming to investigate genetic similarity and differences, genetic heterogeneity and genetic distance. Employing an Ovine array containing about 700,000 single nucleotide polymorphisms (SNPs) with approximately 24,000 markers that are informative for Rocky Mountain bighorn sheep, we used whole genome genotyping to analyze genetic material. This technique represents a significant advancement in genetic analysis of bighorn sheep, as most previous studies have used microsatellites and less than 200 genetic markers. We analyzed approximately fifteen individuals from each of four different populations that we predicted would differ in genetic characteristics, due to population dissimilarities that potentially impacted their genetics, including origin (native/reintroduced), population size, bottleneck history, degree of connectivity, and augmentation history. We selected four populations that provided a spectrum of these herd attributes, including the Tendoys, Stillwater and Glacier National Park in Montana and the northeastern Greater Yellowstone Area in Wyoming. We present the results of this effort and examine expected and observed heterogeneity and genetic distance estimates to evaluate the potential for links between genetics and herd demography. We discuss the utility of genetic analyses in improving knowledge of bighorn sheep populations and potential implications for bighorn sheep management
Protection mechanisms in the resurrection plant Xerophyta viscosa (Baker): both sucrose and raffinose family oligosaccharides (RFOs) accumulate in leaves in response to water deficit
Changes in water-soluble carbohydrates were examined in the leaves of the resurrection plant Xerophyta viscosa under conditions of water deficit. Sucrose and raffinose family oligosaccharides (RFOs), particularly raffinose, increased under these conditions, with the highest concentrations evident at 5% relative water content [RWC; 23.5 mg g−1 dry weight (DW) and 17.7 mg g−1 DW, respectively]. Importantly, these effects were reversible, with concentrations returning to levels comparable with that of the full turgor state 7 d after water deficit conditions were alleviated, providing evidence that both sucrose and RFOs may play a protective role in desiccated leaf tissue of X. viscosa. Further, because the sucrose-to-raffinose mass ratio of 1.3:1 observed in the dehydrated state was very low, compared with published data for other resurrection plants (always >5), it is suggested that, in X. viscosa leaves, RFOs serve the dual purpose of stress protection and carbon storage. XvGolS, a gene encoding a galactinol synthase enzyme responsible for the first catalytic step in RFO biosynthesis, was cloned and functionally expressed. In leaf tissue exposed to water deficit, XvGolS transcript levels were shown to increase at 19% RWC. GolS activity in planta could not be correlated with RFO accumulation, but a negative correlation was observed between RFO accumulation and myo-inositol depletion, during water deficit stress. This correlation was reversed after rehydration, suggesting that during water deficit myo-inositol is channelled into RFO synthesis, but during the rehydration process it is channelled to metabolic pathways related to the repair of desiccation-induced damag
Dynamic changes in 5-hydroxymethylation signatures underpin early and late events in drug exposed liver
Aberrant DNA methylation is a common feature of neoplastic lesions, and early detection of such changes may provide powerful mechanistic insights and biomarkers for carcinogenesis. Here, we investigate dynamic changes in the mouse liver DNA methylome associated with short (1 day) and prolonged (7, 28 and 91 days) exposure to the rodent liver non-genotoxic carcinogen, phenobarbital (PB). We find that the distribution of 5mC/5hmC is highly consistent between untreated individuals of a similar age; yet, changes during liver maturation in a transcriptionally dependent manner. Following drug treatment, we identify and validate a series of differentially methylated or hydroxymethylated regions: exposure results in staged transcriptional responses with distinct kinetic profiles that strongly correlate with promoter proximal region 5hmC levels. Furthermore, reciprocal changes for both 5mC and 5hmC in response to PB suggest that active demethylation may be taking place at each set of these loci via a 5hmC intermediate. Finally, we identify potential early biomarkers for non-genotoxic carcinogenesis, including several genes aberrantly expressed in liver cancer. Our work suggests that 5hmC profiling can be used as an indicator of cell states during organ maturation and drug-induced responses and provides novel epigenetic signatures for non-genotoxic carcinogen exposur
Immediate Memory and Electrophysiologic Effects of Prefrontal Cortex Transcranial Direct Current Stimulation on Neurotypical Individuals and Individuals with Chronic Traumatic Brain Injury: A Pilot Study.
PURPOSE/AIM: Memory impairment post-TBI is common, frequently persistent, and functionally debilitating. The purposes of this pilot study were to assess and to compare immediate behavioral auditory working memory and electrophysiologic effects of three different, randomized, conditions of left dorsolateral prefrontal cortex (LDLPFC) transcranial direct current stimulation (tDCS) applied to four neurotypical adults and four adults with chronic traumatic brain injury (TBI). MATERIALS/METHODS: Pre- and post- anodal, cathodal, and sham tDCS auditory memory performance, auditory event-related potentials (P300 amplitude and latency) and power of alpha and theta EEG bands were measured across individuals in each group. RESULTS: Post-anodal tDCS only, the neurotypical and TBI groups both demonstrated significantly improved immediate auditory memory function. Also post-anodal tDCS, the TBI group demonstrated significantly increased P300 amplitude versus post-sham tDCS. The neurotypical group demonstrated no pre- post tDCS electrophysiologic changes across conditions. CONCLUSIONS: These findings are consistent with findings of other studies of immediate tDCS effects on other types of memory in neurotypical individuals and in individuals with Parkinson's disease, Alzheimer's disease, and stroke and suggest that individuals with memory impairments second to chronic TBI may benefit from LDLPFC anodal tDCS. Pairing tDCS with traditional behavioral memory interventions may facilitate TBI rehabilitation outcomes and warrants continued investigation
Comparative analysis of affinity-based 5-hydroxymethylation enrichment techniques
The epigenetic modification of 5-hydroxymethylcytosine (5hmC) is receiving great attention due to its potential role in DNA methylation reprogramming and as a cell state identifier. Given this interest, it is important to identify reliable and cost-effective methods for the enrichment of 5hmC marked DNA for downstream analysis. We tested three commonly used affinity-based enrichment techniques; (i) antibody, (ii) chemical capture and (iii) protein affinity enrichment and assessed their ability to accurately and reproducibly report 5hmC profiles in mouse tissues containing high (brain) and lower (liver) levels of 5hmC. The protein-affinity technique is a poor reporter of 5hmC profiles, delivering 5hmC patterns that are incompatible with other methods. Both antibody and chemical capture-based techniques generate highly similar genome-wide patterns for 5hmC, which are independently validated by standard quantitative PCR (qPCR) and glucosyl-sensitive restriction enzyme digestion (gRES-qPCR). Both antibody and chemical capture generated profiles reproducibly link to unique chromatin modification profiles associated with 5hmC. However, there appears to be a slight bias of the antibody to bind to regions of DNA rich in simple repeats. Ultimately, the increased specificity observed with chemical capture-based approaches makes this an attractive method for the analysis of locus-specific or genome-wide patterns of 5hm
A targeted capture approach to generating reference sequence databases for chloroplast gene regions
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