3,776 research outputs found

    A Classical Model Correspondence for G-symmetric Random Tensor Networks

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    We consider the scaling of entanglement entropy in random Projected Entangled Pairs States (PEPS) with an internal symmetry given by a finite group G. We systematically demonstrate a correspondence between this entanglement entropy and the difference of free energies of a classical Ising model with an addition non-local term. This non-local term counts the number of domain walls in a particular configuration of the classical spin model. We argue that for that overwhelming majority of such states, this gives rise to an area law scaling with well-defined topological entanglement entropy. The topological entanglement entropy is shown to be log|G| for a simply connected region A and which manifests as a difference in the number of domain walls of ground state energies for the two spin models

    Mental Toughness in Strength and Conditioning Training: Is it really necessary? Perspectives of elite NCAA Strength and Conditioning coaches

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    In recent years, there has been an increased awareness and consideration of the association of mental toughness (MT) in high performance in sports. However, MT remains both one of the most accepted and misunderstood terms in applied sport psychology, especially when it comes to strength and conditioning training and female student-athletes. PURPOSE: To investigate the beliefs of Strength and Conditioning Coaches (SSC) of women’s collegiate basketball in regards to MT. In more detail, based on the literature, field tendencies, and practice, 8 areas of interest were covered: 1) Conceptualization, 2) Value, 3) Development, 4) Gender Differences, 5) Measurement, 6) Differences in the responsibilities to develop MT when compared to basketball coaches, 7) Implementation, and 8) Level of interest in learning more. METHODS: Ten National Collegiate Athletic Association (NCAA) Division 1 SCCs for women’s basketball from the same Power 5 conference were recruited via email. The study followed an observational and cross-sectional model while a fixed and convergent mixed-method design was used. Data were collected on a quantitative instrument (i.e., questionnaire) and on a qualitative instrument (i.e., interview). Eight SCCs completed the Stronger Than Average Mentality (S.T.A.M.) questionnaire on Qualtrics. S.T.A.M. is a 34-item instrument, which was piloted first. In addition, its items’ reliability was estimated using Guttman’s λ2. Six participated in a semi-structured interview of 10 open-ended questions. Both instruments’ items were developed based on the same 8 areas of interest stated above. Capturing the descriptive information about the sample was the goal of analysis of the quantitative data (i.e., descriptive statistics), while data reduction was the goal of analysis of the qualitative data (i.e., thematic analysis). Then, integration of the results from the two strands was performed looking for corroborating or complementary information, which resulted in a 90% inter-rater agreement. In cases of conflict, analytic induction was run. RESULTS: There was convergence of the findings in all 8 areas of interest. In more detail, all SCC’s find MT to be important and would like to know more about it. The majority of SCC’s claimed that they know what MT is, that MT can be developed, that the head coach has more responsibility towards developing MT, and that they know how to measure it. However, there was high variability when ranking MT’s key attributes, while there was no consensus on whether MT can be developed in student-athletes or on whether there are gender differences in MT. None SCC reported use of an instrument for measurement. CONCLUSION: MT is of value in strength and conditioning in this conference. The findings confirm conclusions of previous research, which indicated that –although MT is reported to be widely used– at the same time, it is a very unclear term. More education of the coaches is necessary, especially in regards to the key components of MT, MT training, and MT measurement. Future research should perhaps use a more grounded theory approach and recruit SCC’s from other sports and different environments (e.g., conference, level, country). The development in this age and the transferability outside sports are two issues that should be addressed in future research efforts

    Microspectrophotometric Analysis of Yellow Polyester Fiber Dye Loadings with Chemometric Techniques

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    Microspectrophotometry is a quick, accurate, and reproducible method to compare colored fibers for forensic purposes. Applying chemometric techniques to spectroscopic data can provide valuable information, especially when looking at a complex dataset. In this study, background subtracted and normalized visible spectra from ten yellow polyester exemplars dyed with different concentrations of the same dye ranging from 0.1% to 3.5% (w/w), were analyzed by agglomerative hierarchical clustering (AHC), principal component analysis (PCA), and discriminant analysis (DA). Systematic changes in the wavelength of maximum absorption, peak shape and signal-to-background ratio were noted as dye loading increased. In general, classifying the samples into ten groups (one for each exemplar) had poor accuracy (i.e., 51%). However, classification was much more accurate (i.e., 96%) using three classes of fibers that were identified by AHC as having low (0.10–0.20 wt%), medium (0.40–0.75 wt%), and high (1.5–3.5 wt%) dye loadings. An external validation with additional fibers and data generated by independent analysts confirmed these findings. Lastly, it was also possible to discriminating pairs of exemplars with small differences in dye loadings as a simulation of questioned (Q) versus known (K) comparisons

    A Classical Model Correspondence for G-symmetric Random Tensor Networks

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    We consider the scaling of entanglement entropy in random Projected Entangled Pairs States (PEPS) with an internal symmetry given by a finite group G. We systematically demonstrate a correspondence between this entanglement entropy and the difference of free energies of a classical Ising model with an addition non-local term. This non-local term counts the number of domain walls in a particular configuration of the classical spin model. We argue that for that overwhelming majority of such states, this gives rise to an area law scaling with well-defined topological entanglement entropy. The topological entanglement entropy is shown to be log|G| for a simply connected region A and which manifests as a difference in the number of domain walls of ground state energies for the two spin models

    THE CHANDRA VARIABLE GUIDE STAR CATALOG

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    Variable stars have been identified among the optical-wavelength light curves of guide stars used for pointing control of the Chandra X-ray Observatory. We present a catalog of these variable stars along with their light curves and ancillary data. Variability was detected to a lower limit of 0.02 mag amplitude in the 4000-10000 Ã… range using the photometrically stable Aspect Camera on board the Chandra spacecraft. The Chandra Variable Guide Star Catalog (VGUIDE) contains 827 stars, of which 586 are classified as definitely variable and 241 are identified as possibly variable. Of the 586 definite variable stars, we believe 319 are new variable star identifications. Types of variables in the catalog include eclipsing binaries, pulsating stars, and rotating stars. The variability was detected during the course of normal verification of each Chandra pointing and results from analysis of over 75,000 guide star light curves from the Chandra mission. The VGUIDE catalog represents data from only about 9 years of the Chandra mission. Future releases of VGUIDE will include newly identified variable guide stars as the mission proceeds. An important advantage of the use of space data to identify and analyze variable stars is the relatively long observations that are available. The Chandra orbit allows for observations up to 2 days in length. Also, guide stars were often used multiple times for Chandra observations, so many of the stars in the VGUIDE catalog have multiple light curves available from various times in the mission. The catalog is presented as both online data associated with this paper and as a public Web interface. Light curves with data at the instrumental time resolution of about 2 s, overplotted with the data binned at 1 ks, can be viewed on the public Web interface and downloaded for further analysis. VGUIDE is a unique project using data collected during the mission that would otherwise be ignored. The stars available for use as Chandra guide stars are generally 6-11 mag and are commonly spectral types A and later. Due to the selection of guide stars entirely for positional convenience, this catalog avoids the possible bias of searching for variability in objects where it is to be expected. Statistics of variability compared to spectral type indicate the expected dominance of A-F stars as pulsators. Eclipsing binaries are consistently 20%-30% of the detected variables across all spectral types.United States. National Aeronautics and Space Administration (Smithsonian Astrophysical Observatory. Contract NAS8-03060)United States. National Aeronautics and Space Administration (Smithsonian Astrophysical Observatory. Contract SV3-73016

    Temperature Assessment on a Reclaimed Surface Mine During Northern Bobwhite Breeding Season: Considerations for Habitat Management

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    Ground-level air temperatures were assessed within 4 distinct habitat areas on a managed reclaimed surface mine at Peabody Wildlife Management Area, Kentucky, 26 June–17 July 2015, during the northern bobwhite (Colinus virginianus) brood season. Habitat consisted of disked and nondisked areas of native grass and an invasive species, sericea lespedeza (Lespedeza cuneata). Disked areas offered more open space for bobwhite mobility and experienced higher average temperatures than nondisked sites. Although statistically significant, differences in air temperature between disked and nondisked areas were likely too small to have practical implications for bobwhite habitat management in Kentucky under current climatic conditions. This will likely change in the future as the regional climate warms and periods of excessive heat are more likely to occur. Consequently, managers may want to consider microclimate when making management decisions

    Long-Term Genomic and Epigenomic Dysregulation as a Consequence of Prenatal Alcohol Exposure: A Model for Fetal Alcohol Spectrum Disorders

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    There is abundant evidence that prenatal alcohol exposure leads to a range of behavioral and cognitive impairments, categorized under the term fetal alcohol spectrum disorders (FASDs). These disorders are pervasive in Western cultures and represent the most common preventable source of neurodevelopmental disabilities. The genetic and epigenetic etiology of these phenotypes, including those factors that may maintain these phenotypes throughout the lifetime of an affected individual, has become a recent topic of investigation. This review integrates recent data that has progressed our understanding FASD as a continuum of molecular events, beginning with cellular stress response and ending with a long-term footprint of epigenetic dysregulation across the genome. It reports on data from multiple ethanol-treatment paradigms in mouse models that identify changes in gene expression that occur with respect to neurodevelopmental timing of exposure and ethanol dose. These studies have identified patterns of genomic alteration that are dependent on the biological processes occurring at the time of ethanol exposure. This review also adds to evidence that epigenetic processes such as DNA methylation, histone modifications, and non-coding RNA regulation may underlie long-term changes to gene expression patterns. These may be initiated by ethanol-induced alterations to DNA and histone methylation, particularly in imprinted regions of the genome, affecting transcription which is further fine-tuned by altered microRNA expression. These processes are likely complex, genome-wide, and interrelated. The proposed model suggests a potential for intervention, given that epigenetic changes are malleable and may be altered by postnatal environment. This review accentuates the value of mouse models in deciphering the molecular etiology of FASD, including those processes that may provide a target for the ammelioration of this common yet entirely preventable disorder

    Serological Patterns of Brucellosis, Leptospirosis and Q Fever in Bos indicus Cattle in Cameroon

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    Brucellosis, leptospirosis and Q fever are important infections of livestock causing a range of clinical conditions including abortions and reduced fertility. In addition, they are all important zoonotic infections infecting those who work with livestock and those who consume livestock related products such as milk, producing non-specific symptoms including fever, that are often misdiagnosed and that can lead to severe chronic disease. This study used banked sera from the Adamawa Region of Cameroon to investigate the seroprevalences and distributions of seropositive animals and herds. A classical statistical and a multi-level prevalence modelling approach were compared. The unbiased estimates were 20% of herds were seropositive for Brucella spp. compared to 95% for Leptospira spp. and 68% for Q fever. The within-herd seroprevalences were 16%, 35% and 39% respectively. There was statistical evidence of clustering of seropositive brucellosis and Q fever herds. The modelling approach has the major advantage that estimates of seroprevalence can be adjusted for the sensitivity and specificity of the diagnostic test used and the multi-level structure of the sampling. The study found a low seroprevalence of brucellosis in the Adamawa Region compared to a high proportion of leptospirosis and Q fever seropositive herds. This represents a high risk to the human population as well as potentially having a major impact on animal health and productivity in the region
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