7 research outputs found
Cirsium species show disparity in patterns of genetic variation at their range-edge, despite similar patterns of reproduction and isolation
Genetic variation was assessed across the UK geographical range of Cirsium acaule and Cirsium heterophyllum. A decline in genetic diversity and increase in population divergence approaching the range edge of these species was predicted based on parallel declines in population density and seed production reported seperately. Patterns were compared with UK populations of the widespread Cirsium arvense.Populations were sampled along a latitudinal transect in the UK and genetic variation
assessed using microsatellite markers. Cirsium acaule
shows strong isolation by distance, a significant decline in diversity and an increase in divergence among range-edge populations. Geographical structure is also evident in
C. arvense, whereas no such patterns are seen in C.heterophyllum. There is a major disparity between patterns of genetic variation in C. acaule and
C. heterophyllum despite very similar patterns in seed production and population isolation in these species. This suggests it may be misleading to make assumptions
about the geographical structure of genetic variation within species based solely on the present-day reproduction and distribution of populations
The impacts of foot and mouth disease on a peripheral tourism area: the role and effect of crisis management.
This study reports on the consequences of endemic cattle and sheep disease (2001) on two separate areas on the tourist industry; (a) the Grampian Region of Scotland (indirectly affected) and (b) Cumbria in England (directly affected), and secondly on the effects of various crisis management strategies to alleviate the ensuing problems in both areas. Data were collected by a survey of a sample of 200 tourism orientated SME operators in Grampian and 170 businesses in Cumbria. The results show two forms of impact caused by the disease, direct and those less obvious or tangible. Direct impact was the dramatic loss of trade, most dramatically experienced by the lack of tourists visiting the areas. Indirect effects included loss of supply, change to the product offered and cuts in future investment. In the combination of these impacts, it was clear that the effects would have longevity far beyond the period of the actual crisis. Although the actual presence of the disease was geographically limited in Grampian, the consequences rippled out to affect areas that had no direct connection. In Cumbria, the effects were only slightly more severe but the response more direct and initially effective. Significantly the data also demonstrated a perception of minimal effort by the government to limit the consequences to the farming industry especially in Grampian. We conclude that the tourist industry in peripheral regions is fragile and highly vulnerable to any external shocks. However, we also note the ability of small rural firms to respond to such catastrophes and to avert the worst impacts of crisis
Post-match changes in neuromuscular function and the relationship to match demands in amateur rugby league matches
Objectives: The current study investigated the change in neuromuscular contractile properties following competitive rugby league matches and the relationship with physical match demands. Design: Eleven trained, male rugby league players participated in 2–3 amateur, competitive matches (n = 30). Methods: Prior to, immediately (within 15-min) and 2 h post-match, players performed repeated counter-movement jumps (CMJ) followed by isometric tests on the right knee extensors for maximal voluntary contraction (MVC), voluntary activation (VA) and evoked twitch contractile properties of peak twitch force (Pt), rate of torque development (RTD), contraction duration (CD) and relaxation rate (RR). During each match, players wore 1 Hz Global Positioning Satellite devices to record distance and speeds of matches. Further, matches were filmed and underwent notational analysis for number of total body collisions. Results: Total, high-intensity, very-high intensity distances covered and mean speed were 5585 ± 1078 m, 661 ± 265, 216 ± 121 m and 75 ± 14 m min−1, respectively. MVC was significantly reduced immediately and 2 h post-match by 8 ± 11 and 12 ± 13% from pre-match (p 0.05). Correlation analyses indicated that total playing time (r = −0.50) and mean speed (r = −0.40) were moderately associated to the change in post-match MVC, while mean speed (r = 0.35) was moderately associated to VA. Conclusions: The present study highlights the physical demands of competitive amateur rugby league result in interruption of peripheral contractile function, and post-match voluntary torque suppression may be associated with match playing time and mean speeds
Generation of Alternate Indole Diterpene Architectures in Two Species of <i>Aspergilli</i>
The significant structural
diversity and potent bioactivity of
the fungal indole diterpenes (IDTs) has attracted considerable interest
in their biosynthesis. Although substantial skeletal diversity is
generated by the action of noncanonical terpene cyclases, comparatively
little is known about these enzymes, particularly those involved in
the generation of the subgroup containing emindole SA and DA, which
show alternate terpenoid skeletons. Here, we describe the IDT biosynthetic
machinery generating these unusual IDT architectures from Aspergillus striatus and Aspergillus
desertorum. The function of four putative cyclases
was interrogated via heterologous expression. Two specific cyclases
were identified that catalyze the formation of epimers emindole SA
and DA from A. striatus and A. desertorum, respectively. These cyclases are both
clustered along with all the elements required for basic IDT biosynthesis
yet catalyze an unusual Markovnikov-like cyclization cascade with
alternate stereochemical control. Their identification reveals that
these alternate architectures are not generated by mechanistically
sloppy or promiscuous enzymes, but by cyclases capable of delivering
precise regio- and stereospecificities
Loss of the pregnancy-induced rise in cortisol concentrations in the ewe impairs the fetal insulin-like growth factor axis
A map of human genome variation from population-scale sequencing
The 1000 Genomes Project aims to provide a deep characterization of human genome sequence variation as a foundation for investigating the relationship between genotype and phenotype. Here we present results of the pilot phase of the project, designed to develop and compare different strategies for genome-wide sequencing with high-throughput platforms. We undertook three projects: low-coverage whole-genome sequencing of 179 individuals from four populations; high-coverage sequencing of two mother-father-child trios; and exon-targeted sequencing of 697 individuals from seven populations. We describe the location, allele frequency and local haplotype structure of approximately 15 million single nucleotide polymorphisms, 1 million short insertions and deletions, and 20,000 structural variants, most of which were previously undescribed. We show that, because we have catalogued the vast majority of common variation, over 95% of the currently accessible variants found in any individual are present in this data set. On average, each person is found to carry approximately 250 to 300 loss-of-function variants in annotated genes and 50 to 100 variants previously implicated in inherited disorders. We demonstrate how these results can be used to inform association and functional studies. From the two trios, we directly estimate the rate of de novo germline base substitution mutations to be approximately 10−8 per base pair per generation. We explore the data with regard to signatures of natural selection, and identify a marked reduction of genetic variation in the neighbourhood of genes, due to selection at linked sites. These methods and public data will support the next phase of human genetic researc
Effect of once-yearly zoledronic acid on the spine and hip as measured by quantitative computed tomography: results of the HORIZON Pivotal Fracture Trial.
Changes in bone mineral density and bone strength following treatment with zoledronic acid (ZOL) were measured by quantitative computed analysis (QCT) or dual-energy X-ray absorptiometry (DXA). ZOL treatment increased spine and hip BMD vs placebo, assessed by QCT and DXA. Changes in trabecular bone resulted in increased bone strength.
INTRODUCTION: To investigate bone mineral density (BMD) changes in trabecular and cortical bone, estimated by quantitative computed analysis (QCT) or dual-energy X-ray absorptiometry (DXA), and whether zoledronic acid 5 mg (ZOL) affects bone strength.
METHODS: In 233 women from a randomized, controlled trial of once-yearly ZOL, lumbar spine, total hip, femoral neck, and trochanter were assessed by DXA and QCT (baseline, Month 36). Mean percentage changes from baseline and between-treatment differences (ZOL vs placebo, t-test) were evaluated.
RESULTS: Mean between-treatment differences for lumbar spine BMD were significant by DXA (7.0%, p < 0.01) and QCT (5.7%, p < 0.0001). Between-treatment differences were significant for trabecular spine (p = 0.0017) [non-parametric test], trabecular trochanter (10.7%, p < 0.0001), total hip (10.8%, p < 0.0001), and compressive strength indices at femoral neck (8.6%, p = 0.0001), and trochanter (14.1%, p < 0.0001).
CONCLUSIONS: Once-yearly ZOL increased hip and spine BMD vs placebo, assessed by QCT vs DXA. Changes in trabecular bone resulted in increased indices of compressive strength