315 research outputs found
Studies in the biology of the fleece of the Scottish mountain Blackface breed of sheep
1. A short history of the Scottish Mountain Black - face breed is given with particular reference
to the development of the fleece.2. Data are presented of the analyses of the fleeces
of 150 Scottish Blackface rams of different
ages and of 40 ewe-hoggs aged one year.3. The analyses were obtained from the examination
of four staples from the fleece, one from the
point of each shoulder and one from the point
of each haunch.4. The three classes of fibres to be found in the
Blackface fleece are described -- wool, long
hair -like fibres, and kemp. Mention is made
of the varying character of the fleeces in
different parts of Scotland.5. A description is given of the technique of
analysis for arriving at the count and weight
proportions of the fleece, on which the
discussion and conclusions are based.6. Data are presented of the differential growth
rate of the fibre types and the shedding
periods of the classes of fibres are discussed.7. The conclusions which are deduced from the
statistical treatment of the results of the
fleece analyses are discussed, and a short
speculative survey is made of the position
which Blackface wool holds or may hold in the
market.8. Graphs, histograms, and photographs explain
points of importance wherever possible and
summaries of statistical results are given.9. Tables of analyses of the fleeces are appended
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Proceedings of the Rank Forum on Vitamin D
The Rank Forum on Vitamin D was held on 2nd and 3rd July 2009 at the University of Surrey, Guildford, UK. The workshop consisted of a series of scene-setting presentations to address the current issues and challenges concerning vitamin D and health, and included an open discussion focusing on the identification of the concentrations of serum 25-hydroxyvitamin D (25(OH)D) (a marker of vitamin D status) that may be regarded as optimal, and the implications this process may have in the setting of future dietary reference values for vitamin D in the UK. The Forum was in agreement with the fact that it is desirable for all of the population to have a serum 25(OH)D concentration above 25 nmol/l, but it discussed some uncertainty about the strength of evidence for the need to aim for substantially higher concentrations (25(OH)D concentrations . 75 nmol/l). Any discussion of ‘optimal’ concentration of serum 25(OH)D needs to define ‘optimal’ with care since it is important to consider the normal distribution of requirements and the vitamin D needs for a wide range of outcomes. Current UK reference values concentrate on the requirements of particular subgroups of the population; this differs from the approaches used in other European countries where a wider range of age groups tend to be covered. With the re-emergence of rickets and the public health burden of low vitamin D status being already apparent, there is a need for urgent action from policy makers and risk managers. The Forum highlighted
concerns regarding the failure of implementation of existing strategies in the UK for achieving current vitamin D recommendations
Parenting in youth sport: A position paper on parenting expertise
This article was published in the journal, Psychology of Sport and Exercise [© Elsevier] and the definitive version is available at: http://dx.doi.org/10.1016/j.psychsport.2014.03.001Objectives: In line with the aims of this special issue, the purpose of this paper is to forward a position on the concept of sport parenting expertise through the presentation of six key postulates. Design: Literature review and position statement. Method: By adopting methods associated with an academic position paper, a statement is presented that we believe encapsulates sport parenting expertise. Six key postulates of parenting expertise, formulated from critically reviewing and interpreting relevant literature, are then presented. Results: We propose that sport parenting expertise is dependent on the degree to which parents demonstrate a range of competencies; namely that parents, (a) select appropriate sporting opportunities and provide necessary types of support, (b) understand and apply appropriate parenting styles, (c) manage the emotional demands of competitions, (d) foster healthy relationships with significant others, (e) manage organizational and developmental demands associated with sport participation, and, (f) adapt their involvement to different stages of their child's athletic career. Conclusion: Expertise in sport parenting requires parents to develop knowledge and utilize a range of intrapersonal, interpersonal, and organizational skills in order to support their child, manage themselves, and operate effectively in the wider youth sport environment. Recommendations for applied researchers to further investigate these postulates and substantiate the components of sport parenting expertise are offered
Clinical delineation and natural history of the PIK3CA-related overgrowth spectrum.
Somatic mutations in the phosphatidylinositol/AKT/mTOR pathway cause segmental overgrowth disorders. Diagnostic descriptors associated with PIK3CA mutations include fibroadipose overgrowth (FAO), Hemihyperplasia multiple Lipomatosis (HHML), Congenital Lipomatous Overgrowth, Vascular malformations, Epidermal nevi, Scoliosis/skeletal and spinal (CLOVES) syndrome, macrodactyly, and the megalencephaly syndrome, Megalencephaly-Capillary malformation (MCAP) syndrome. We set out to refine the understanding of the clinical spectrum and natural history of these phenotypes, and now describe 35 patients with segmental overgrowth and somatic PIK3CA mutations. The phenotypic data show that these previously described disease entities have considerable overlap, and represent a spectrum. While this spectrum overlaps with Proteus syndrome (sporadic, mosaic, and progressive) it can be distinguished by the absence of cerebriform connective tissue nevi and a distinct natural history. Vascular malformations were found in 15/35 (43%) and epidermal nevi in 4/35 (11%) patients, lower than in Proteus syndrome. Unlike Proteus syndrome, 31/35 (89%) patients with PIK3CA mutations had congenital overgrowth, and in 35/35 patients this was asymmetric and disproportionate. Overgrowth was mild with little postnatal progression in most, while in others it was severe and progressive requiring multiple surgeries. Novel findings include: adipose dysregulation present in all patients, unilateral overgrowth that is predominantly left-sided, overgrowth that affects the lower extremities more than the upper extremities and progresses in a distal to proximal pattern, and in the most severely affected patients is associated with marked paucity of adipose tissue in unaffected areas. While the current data are consistent with some genotype-phenotype correlation, this cannot yet be confirmed
The relationship between vitamin D status and muscle strength in young healthy adults from sunny climate countries currently living in the northeast of Scotland
Summary: The current study examined the relationship between vitamin D status and muscle strength in young healthy adults: residents (>6 months) and newcomers (0–3 months), originally from sunny climate countries but currently living in the northeast of Scotland. Our longitudinal data found a positive, albeit small, relationship between vitamin D status and knee extensor isometric strength. Introduction: Vitamin D has been suggested to play a role in muscle health and function, but studies so far have been primarily in older populations for falls prevention and subsequent risk of fractures. Methods: Vitamin D status was assessed in a healthy young adults from sunny climate countries (n = 71, aged 19–42 years) with 56% seen within 3 months of arriving in Aberdeen [newcomers; median (range) time living in the UK = 2 months (9–105 days)] and the remainder resident for >6 months [residents; 23 months (6–121 months)]. Participants attended visits every 3 months for 15 months. At each visit, fasted blood samples were collected for analysis of serum 25-hydroxyvitamin D [25(OH)D], parathyroid hormone (PTH), carboxy-terminal collagen crosslinks (CTX) and N-terminal propeptide of type I collagen (P1NP). Maximal voluntary contractions (MVC) were performed for grip strength (both arms) and for maximal isometric strength of the knee extensors (right knee). Results: There were small seasonal variations in 25(OH)D concentrations within the newcomers and residents, but no seasonal variation in bone turnover markers. There was a positive, albeit small, association between 25(OH)D and knee extensor maximal isometric strength. Mixed modelling predicted that for each 1 nmol/L increase in 25(OH)D, peak torque would increase by 1 Nm (p = 0.04). Conclusions: This study suggests that vitamin D may be important for muscle health in young adults migrating from sunnier climates to high latitudes, yet the potential effect is small
Wild zebra finches choose neighbours for synchronized breeding
Organisms should aim to time their reproduction to match the optimal ecological conditions and thus maximize their fitness. However, social cues have been identified as determinants of reproductive decisions and might also be involved in coordinating the timing of reproduction. Breeding synchronously with other individuals can bring several advantages, including a reduced individual predation risk and an increased opportunity for social foraging. The behavioural mechanisms underlying reproductive synchrony are versatile and not well understood, particularly in species inhabiting unpredictable environments. In contrast to highly seasonal environments, more variable and unpredictable environments can support periods of extended breeding with lower levels of synchronous breeding overall, but opportunities for individuals to breed synchronously at a finer temporal and spatial scale. Zebra finches, Taeniopygia guttata, are a highly social species, naturally inhabiting the ecologically unpredictable arid zone of Australia. In the wild, reproduction at a broad population level is not highly synchronized and, at any time during a period of breeding activity, reproductive attempts can be found at different stages. However, previous work has suggested that at a finer spatial scale neighbours tend to breed at approximately the same time. Using nestboxes, we tested whether wild zebra finches preferentially seek to settle and initiate a breeding attempt adjacent to conspecifics at an early stage of breeding (nest building), as opposed to others at later stages of breeding and with which the opportunity to breed synchronously was reduced or absent. Pairs were more likely to initiate egg laying in nestboxes close to conspecifics at an early stage of breeding, suggesting that they do try to maximize the level of synchronicity with neighbours. Our results indicate the importance of social effects on both the phenology and spatial distribution of breeding
Recombination and Population Structure in Salmonella enterica
Salmonella enterica is a bacterial pathogen that causes enteric fever and gastroenteritis in humans and animals. Although its population structure was long described as clonal, based on high linkage disequilibrium between loci typed by enzyme electrophoresis, recent examination of gene sequences has revealed that recombination plays an important evolutionary role. We sequenced around 10% of the core genome of 114 isolates of enterica using a resequencing microarray. Application of two different analysis methods (Structure and ClonalFrame) to our genomic data allowed us to define five clear lineages within S. enterica subspecies enterica, one of which is five times older than the other four and two thirds of the age of the whole subspecies. We show that some of these lineages display more evidence of recombination than others. We also demonstrate that some level of sexual isolation exists between the lineages, so that recombination has occurred predominantly between members of the same lineage. This pattern of recombination is compatible with expectations from the previously described ecological structuring of the enterica population as well as mechanistic barriers to recombination observed in laboratory experiments. In spite of their relatively low level of genetic differentiation, these lineages might therefore represent incipient species
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