2,762 research outputs found
Drifting Oscillations in Axion Monodromy
We study the pattern of oscillations in the primordial power spectrum in
axion monodromy inflation, accounting for drifts in the oscillation period that
can be important for comparing to cosmological data. In these models the
potential energy has a monomial form over a super-Planckian field range, with
superimposed modulations whose size is model-dependent. The amplitude and
frequency of the modulations are set by the expectation values of moduli
fields. We show that during the course of inflation, the diminishing energy
density can induce slow adjustments of the moduli, changing the modulations. We
provide templates capturing the effects of drifting moduli, as well as drifts
arising in effective field theory models based on softly broken discrete shift
symmetries, and we estimate the precision required to detect a drifting period.
A non-drifting template suffices over a wide range of parameters, but for the
highest frequencies of interest, or for sufficiently strong drift, it is
necessary to include parameters characterizing the change in frequency over the
e-folds visible in the CMB. We use these templates to perform a preliminary
search for drifting oscillations in a part of the parameter space in the Planck
nominal mission data.Comment: 48 pages, 5 figure
A Verified Certificate Checker for Finite-Precision Error Bounds in Coq and HOL4
Being able to soundly estimate roundoff errors of finite-precision
computations is important for many applications in embedded systems and
scientific computing. Due to the discrepancy between continuous reals and
discrete finite-precision values, automated static analysis tools are highly
valuable to estimate roundoff errors. The results, however, are only as correct
as the implementations of the static analysis tools. This paper presents a
formally verified and modular tool which fully automatically checks the
correctness of finite-precision roundoff error bounds encoded in a certificate.
We present implementations of certificate generation and checking for both Coq
and HOL4 and evaluate it on a number of examples from the literature. The
experiments use both in-logic evaluation of Coq and HOL4, and execution of
extracted code outside of the logics: we benchmark Coq extracted unverified
OCaml code and a CakeML-generated verified binary
Origins of Relative Age Effects in Youth Football - A Nationwide Analysis
Introduction: Relative age effects (RAEs) refer to the overrepresentation of players born earlier in the selection year compared to late-born players within the same age category. To date, the origins and mechanisms of RAEs are still unclear. To evaluate the development of RAEs in terms of age group and selection level, we analyzed data of all registered child and adolescent football players in Switzerland.
Methods: Age category, selection level, and birthdate from all licensed 101,991 Swiss child and youth football players assigned to a specific team [9,149 girls (9.0%) and 92,842 boys (91.0%); age range: 4.6–19.6 years] were analyzed. Additionally, out of 1,128 clubs, 54 clubs provided their documented waiting lists (1,224 players). Birthdate distributions were split by age category, sex, and birth quarter (Q1 = January to March, Q4 = October to December). RAEs were calculated using odds ratios (Q1 vs. Q4) with 95% confidence intervals (95% CI).
Results: We found small RAEs among U8 players (OR 1.44 [95% CI 1.31, 1.59]) and U10 (OR 1.24 [95% CI 1.16, 1.32]). The RAE was negligible in all other age categories, independent of gender. In children's football, 5,584 (71.3%) teams performed selections. In teams without selection, there were no obvious RAEs. However, teams with selections for the same age category showed small RAEs with an overrepresentation of Q1 athletes in the first team (OR = 1.29 [95% CI 1.24, 1.35]) and inverse RAEs with an underrepresentation of Q1 athletes in the last team (OR = 0.85 [95% CI 0.82, 0.89]). Only small RAEs were observed on the waiting lists for the U8 (OR = 1.48 [1.13, 1.95]).
Discussion and Conclusion: RAEs have a small, but consistent effect on participation in Swiss children's football at the grassroots level. Contrary to expectations, no inverse RAEs were found on the waiting lists. Nonetheless, first time coach selections seem to be the origin of RAEs. To protect young athletes from discrimination, RAE biases should be analyzed and eliminated at all stages of sport participation, selection, and dropout situations. Modifications to the organizational structure of sport and athlete development systems are recommended to prevent RAE-related discrimination in youth sports
Foraging Strategies of Invasive Macaca fascicularis may Promote Plant Invasion in Mauritius
peer reviewedThe effectiveness of seed dispersal by frugivorous primates may vary between seasons and plant species, depending on foraging strategies. We investigated how foraging strategies of an invasive frugivorous primate (the long-tailed macaque, Macaca fascicularis) affect seed dispersal effectiveness (SDE) between native and invasive plants in Mauritius’ native remnant forests. By collecting behavioural data on a group of partially habituated macaques via scan sampling from December 2019 until December 2020 (mean 19.2 ± SD 7.3 hours per month), we investigated seasonal patterns in diet, home range, and fruit availability to identify foraging strategies and determine fruit preference. We simultaneously assessed SDE for invasive vs native plants by quantifying native and invasive fruits consumed or dropped intact by macaques during feeding bouts (n = 114). Macaques fed increasingly on ripe invasive fruits and less on other food items as fruit availability increased, due to preference for invasive fruits and disproportionate availability of invasive vs native fruits. When fruit became scarcer, macaques had larger home ranges, increasingly fed on scarce unripe native and invasive fruits, and expanded their diet by eating orchard crops, indicating use of energy-maximizing strategies. Macaques consumed more native than invasive fruits when unripe and commonly destroyed seeds of native fruits, indicating higher SDE for invasive vs native plants. Higher discard rates of unripe compared to ripe fruits further reinforced these differences in SDE. Our results highlight potential facilitation of plant invasion by an invasive primate, due to foraging strategies shaped by the availability of invasive fruits
Event Specific Body Characteristics of Elite Alpine Skiers in Relation to International Rankings.
Objective:
This explorative study examined potential performance indicators through a correlational analysis between morphological measures and international ranking within each alpine ski event for each gender separately.
Methods:
A cross-sectional sample of 58 elite alpine skiers were allocated into a technical or speed event group based on their international ski rankings. Several two-way (2 * 2) (M)ANOVA’s were used to examine the effect of gender and event group on age, BMI, sum of 6 skinfolds and somatotype. Forward stepwise discriminant analysis selected the most discriminating somatotype component between gender and/or event. Bivariate Pearson correlations between registered variables and international rankings per alpine ski event were examined for each gender separately.
Results:
Female speed specialists possessed more relative fat mass (P = 0.022) than female technical specialists. Irrespective of gender, technical specialists were lighter (P < 0.001) and had less relative fat mass than speed specialists (P = 0.008). Pearson values indicated moderate associations between speed rankings and body weight. High female speed rankings were associated with higher relative fat mass. High male speed rankings were associated with lower ectomorphy.
Conclusion:
Additional body weight appears to be beneficial in SPEED events. Fat mass correlated positively with higher rankings of female SPEED specialists. This observation should be monitored in female alpine skiers so that performance thresholds of relative body fat can be determined
Persistent Borrelia Infection in Patients with Ongoing Symptoms of Lyme Disease
Introduction: Lyme disease is a tickborne illness that generates controversy among medical providers and researchers. One of the key topics of debate is the existence of persistent infection with the Lyme spirochete, Borrelia burgdorferi, in patients who have been treated with recommended doses of antibiotics yet remain symptomatic. Persistent spirochetal infection despite antibiotic therapy has recently been demonstrated in non-human primates. We present evidence of persistent Borrelia infection despite antibiotic therapy in patients with ongoing Lyme disease symptoms. Methods: In this pilot study, culture of body fluids and tissues was performed in a randomly selected group of 12 patients with persistent Lyme disease symptoms who had been treated or who were being treated with antibiotics. Cultures were also performed on a group of ten control subjects without Lyme disease. The cultures were subjected to corroborative microscopic, histopathological and molecular testing for Borrelia organisms in four independent laboratories in a blinded manner. Results: Motile spirochetes identified histopathologically as Borrelia were detected in culture specimens, and these spirochetes were genetically identified as Borrelia burgdorferi by three distinct polymerase chain reaction (PCR)-based approaches. Spirochetes identified as Borrelia burgdorferi were cultured from the blood of seven subjects, from the genital secretions of ten subjects, and from a skin lesion of one subject. Cultures from control subjects without Lyme disease were negative for Borrelia using these methods. Conclusions: Using multiple corroborative detection methods, we showed that patients with persistent Lyme disease symptoms may have ongoing spirochetal infection despite antibiotic treatment, similar to findings in non-human primates. The optimal treatment for persistent Borrelia infection remains to be determined
Evaluation of In-vitro Antibiotic Susceptibility of Different Morphological Forms of Borrelia burgdorferi
Background: Lyme disease is a tick-borne illness caused by the spirochete Borrelia burgdorferi. Although antibiotic therapy is usually effective early in the disease, relapse may occur when administration of antibiotics is discontinued. Studies have suggested that resistance and recurrence of Lyme disease might be due to formation of different morphological forms of B. burgdorferi, namely round bodies (cysts) and biofilm-like colonies. Better understanding of the effect of antibiotics on all morphological forms of B. burgdorferi is therefore crucial to provide effective therapy for Lyme disease. Methods: Three morphological forms of B. burgdorferi (spirochetes, round bodies, and biofilmlike colonies) were generated using novel culture methods. Minimum inhibitory concentration and minimum bactericidal concentration of five antimicrobial agents (doxycycline, amoxicillin, tigecycline, metronidazole, and tinidazole) against spirochetal forms of B. burgdorferi were evaluated using the standard published microdilution technique. The susceptibility of spirochetal and round body forms to the antibiotics was then tested using fluorescent microscopy (BacLight™ viability staining) and dark field microscopy (direct cell counting), and these results were compared with the microdilution technique. Qualitative and quantitative effects of the antibiotics against biofilm-like colonies were assessed using fluorescent microscopy and dark field microscopy, respectively. Results: Doxycycline reduced spirochetal structures ∼90% but increased the number of round body forms about twofold. Amoxicillin reduced spirochetal forms by ∼85%–90% and round body forms by ∼68%, while treatment with metronidazole led to reduction of spirochetal structures by ∼90% and round body forms by ∼80%. Tigecycline and tinidazole treatment reduced both spirochetal and round body forms by ∼80%–90%. When quantitative effects on biofilmlike colonies were evaluated, the five antibiotics reduced formation of these colonies by only 30%–55%. In terms of qualitative effects, only tinidazole reduced viable organisms by ∼90%. Following treatment with the other antibiotics, viable organisms were detected in 70%–85% of the biofilm-like colonies. Conclusion: Antibiotics have varying effects on the different morphological forms of B. burgdorferi. Persistence of viable organisms in round body forms and biofilm-like colonies may explain treatment failure and persistent symptoms following antibiotic therapy of Lyme disease
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