Comment on “Football-specific fitness testing: adding value or confirming the evidence?”

The recent point–counter-point exchange arising from the article by Mendez-Villanueva and Buchheit (2013) (Football-specific fitness testing: Adding value or confirming the evidence? Journal of Sports Sciences, 31, 1503–1508) has generated an interesting debate on the real-world utility of fitness testing in professional association football (soccer). In the present authors’ opinion, this exchange could also have been placed more in the context of the physical testing and subsequent benchmark profiling of the youth player within elite academy talent identification and development processes. This point is further strengthened by the current media debate at the time of writing on the development of elite youth football players in England and the Elite Player Performance Plan or EPPP (The Premier League. (2011). Elite Player Performance Plan. London: Author) published by the English Premier League as part of a vision for the future development of youth football in the League and throughout the English professional game. The EPPP recommends the implementation of a national database to enable comparison of Academy player performances against national physical testing “benchmark” profiles. In continuing the above debate, this letter questions the real-world utility and potential pitfalls of nationwide athletic benchmark profiling programmes for elite youth football

The wider context of performance analysis and it application in the football coaching process

The evolving role of PA and the associated proliferation of positions and internships within high performance sport has driven consideration for a change, or at least a broadening, of emphasis for use of PA analysis. In order to explore the evolution of PA from both an academic and practitioner perspective this paper considers the wider conceptual use of PA analysis. In establishing this, the paper has 4 key aims: (1) To establish working definitions of PA and where it sits within the contemporary sports science and coaching process continuum; (2) To consider how PA is currently used in relation to data generation; (3) To explore how PA could be used to ensure transfer of information, and; (4) To give consideration to the practical constrains potentially faced by coach and analyst when implementing PA strategies in the future

AMPK hierarchy: A matter of space and time

AMP-activated protein kinase (AMPK) is a key sensor of energy balance in eukaryotic cells, responding to low energy status by switching off anabolic pathways and upregulating catabolic processes. Zong and colleagues now show that different intensities of stimulation trigger activation of specific subcellular pools of AMPK, resulting in phosphorylation of different downstream targets

Circular 89

A yield trial in which 43 named varieties and numbered selections of potatoes were compared was conducted during the 1991 growing season at the University of Alaska Fairbanks, Agricultural and Forestry Experiment Station’s Palmer Research Center, Matanuska Research Farm, located six miles west of Palmer, Alaska. Varieties with a history of commercial production in the Matanuska Valley (Alaska 114, Bake-King, Green Mountain, and Superior) are included and serve as a comparative base for newly developed varieties, numbered selections or older varieties that have not been tested at this location. Varieties that compare favorably with the above listed standards may warrant consideration by commercial growers. Nonirrigated trials have been conducted annually since 1982, whereas irrigated trials were initiated in 1985 (AFES Circulars 49, 54, 58, 65, 71, 77, and 84). These circulars are available at the AFES Offices in Fairbanks and Palmer. Included in this report are the results of abbreviated versions of the AFES potato yield trial conducted by cooperating individuals and agencies at other locations in Alaska including Delta Junction, Fairbanks, Homer, Kenai- Soldotna, and Kodiak.[Part 1: Potato Variety Performance] -- Introduction -- Matanuska Farm Yield Trials -- Trials at Other Locations in Alaska -- [Part 2: Commercial Potato Crop Data Summary] -- Introduction -- Potato Varieties and Yields -- Acreage per grower -- Irrigation -- Seed and Planting -- Fertilizer -- Other Cultural Practices -- Chemical Contro

Evolutionary history and hybridization in Passerina buntings

Understanding the genetic basis of speciation is of fundamental importance to evolutionary biology and hybrid zones offer unique natural laboratories in which to investigate the ecological and evolutionary processes important in creating and maintaining biological diversity. By comparing introgression patterns of different loci, researchers can begin to identify genetic regions that contribute to reproductive isolation between hybridizing taxa. In taxa, like birds, with heterogametic females, Haldane’s rule predicts that mtDNA and z-linked loci will introgress less than autosomal loci. I tested this prediction using the hybrid zone between Passerina cyanea (Indigo Bunting) and Passerina amoena (Lazuli Bunting), two species that hybridize where their breeding ranges overlap in the Great Plains of North America. Although a recent mtDNA-based phylogenetic hypothesis of the genus Passerina suggested these two species are not sister taxa, I found, using DNA sequence data from ten nuclear loci, that they are more closely related to each other than either is to P. caerulea (the mtDNA sister to P. ameona). Both cline-based and coalescent-based analyses of mtDNA (two genes), z-linked (two loci), and autosomal (four) loci indicated a reduction in introgression of both mtDNA and z-linked loci, relative to autosomal loci. These patterns, consistent with the predictions of Haldane’s rule, suggested the sex-chromosomes may play a large role in reproductive isolation between P. cyanea and P. amoena. Using DNA sequence data from an additional eight z-linked loci, I explored patterns of differential introgression of ten z-linked loci. Introgression of one z-linked locus, VLDLR9, was significantly less than introgression of the other nine loci, pointing to a candidate region for reproductive isolation between P. cyanea and P. amoena. Interestingly, VLDLR9 is an intron of the very-low density lipoprotein receptor, which plays an active role in egg laying. Additionally, in a particular strain of chickens, a point mutation in the VLDLR gene produces females that do not lay eggs. While my data are insufficient to adequately address the role VLDLR may play in maintaining reproductive isolation between P. cyanea and P. amoena, the hypothesis that female buntings may have trouble laying eggs warrants further investigation

AMP-activated protein kinase: the current landscape for drug development

Since the discovery of AMP-activated protein kinase (AMPK) as a central regulator of energy homeostasis, many exciting insights into its structure, regulation and physiological roles have been revealed. While exercise, caloric restriction, metformin and many natural products increase AMPK activity and exert a multitude of health benefits, developing direct activators of AMPK to elicit beneficial effects has been challenging. However, in recent years, direct AMPK activators have been identified and tested in preclinical models, and a small number have entered clinical trials. Despite these advances, which disease(s) represent the best indications for therapeutic AMPK activation and the long-term safety of such approaches remain to be established

Occupational Experience Qualifications of Vocational Business Education Teachers in Utah

On December 18, 1963, President Johnson signed into law the Vocational Act of 1963. With its passage, cooperative secondary school office education and distributive education received needed encouragement and financial assistance. Educators in business are, as never before, challenged to prepare effective teacher-coordinators for the cooperative part-time program in business. The instructor of a vocational course should have a thorough and up-to-date knowledge of his subject area. One of the ways in which the vocational business education teacher can obtain this knowledge is through actual job-related experience. The Peabody Report, compiled by the George Peabody College for Teachers, under the direction of W. D. McClurkin, states: No work experience is required for the teacher in a non-cooperative program but 2,000 hours are required for a teacher in the cooperative office education program. Many teachers do not meet this requirement. The Utah State Plan for Vocational Education sets forth the occupational experience requirement for vocational business education teachers as follows: distributive education: Teachers who instruct marketing programs shall have an accumulative total of at least one year of occupational experience in the field of distribution. office occupations: Teachers who instruct office occupations programs shall have had an accumulative total of at least one year of occupational experience in office occupations fields. The shortage of teachers qualified to teach in the cooperative office education program is a problem of concern to the Office Occupation\u27s Department of the Vocational Education Division. 5 Before the value of the occupational experience requirement can be assessed, steps must be taken to determine if the requirement is being adhered to. An appraisal of what conditions and practices currently exist must be made

Interpreting physical performance in professional soccer match-play: Should we be more pragmatic in our approach?

Academic and practitioner interest in the physical performance of male professional soccer players in the competition setting determined via time-motion analyses has grown substantially over the last four decades leading to a substantial body of published research and aiding development of a more systematic evidence-based framework for physical conditioning. Findings have forcibly shaped contemporary opinions in the sport with researchers and practitioners frequently emphasising the important role that physical performance plays in match outcomes. Time-motion analyses have also influenced practice as player conditioning programmes can be tailored according to the different physical demands identified across individual playing positions. Yet despite a more systematic approach to physical conditioning, data indicate that even at the very highest standards of competition, the contemporary player is still susceptible to transient and end-game fatigue. Over the course of this article, the author suggests that a more pragmatic approach to interpreting the current body of time-motion analysis data and its application in the practical setting is nevertheless required. Examples of this are addressed using findings in the literature to examine: a) the association between competitive physical performance and ‘success’ in professional soccer, b) current approaches to interpreting differences in time-motion analysis data across playing positions and, c) whether data can realistically be used to demonstrate the occurrence of fatigue in match-play. Gaps in the current literature and directions for future research are also identified

Gene Sampling Strategies for Multi-Locus Population Estimates of Genetic Diversity (θ)

BACKGROUND: Theoretical work suggests that data from multiple nuclear loci provide better estimates of population genetic parameters than do single loci, but just how many loci are needed and how much sequence is required from each has been little explored. METHODOLOGY/PRINCIPLE FINDINGS: To investigate how much data is required to estimate the population genetic parameter θ (4N(e)μ) accurately under ideal circumstances, we simulated datasets of DNA sequences under three values of θ per site (0.1, 0.01, 0.001), varying in both the total number of base pairs sequenced per individual and the number of equal-length loci. From these datasets we estimated θ using the maximum likelihood coalescent framework implemented in the computer program Migrate. Our results corroborated the theoretical expectation that increasing the number of loci impacted the accuracy of the estimate more than increasing the sequence length at single loci. However, when the value of θ was low (0.001), the per-locus sequence length was also important for estimating θ accurately, something that has not been emphasized in previous work. CONCLUSIONS/SIGNIFICANCE: Accurate estimation of θ required data from at least 25 independently evolving loci. Beyond this, there was little added benefit in terms of decreasing the squared coefficient of variation of the coalescent estimates relative to the extra effort required to sample more loci