3,958 research outputs found
Proof of ultra-violet finiteness for a planar non-supersymmetric Yang-Mills theory
This paper focuses on a three-parameter deformation of N=4 Yang-Mills that
breaks all the supersymmetry in the theory. We show that the resulting
non-supersymmetric gauge theory is scale invariant, in the planar
approximation, by proving that its Green functions are ultra-violet finite to
all orders in light-cone perturbation theory.Comment: 13 pages, 1 figure; v2: minor correction
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Batch effects account for the main findings of an in utero human intestinal bacterial colonization study
Abstract: A recent study by Rackaityte et al. reported evidence for a low level of bacterial colonization, specifically of Micrococcus luteus, in the intestine of second trimester human fetuses. We have re-analyzed their sequence data and identified a batch effect which violates the underlying assumptions of the bioinformatic method used for contamination removal. This batch effect resulted in Micrococcus not being identified as a contaminant in the original work and being falsely assigned to the fetal samples. We further provide evidence that the micrographs presented by Rackaityte et al. are unlikely to show Micrococci or other bacteria as the size of the particles shown exceeds that of related bacterial cells. Finally, phylogenetic analysis showed that the microbes cultured from the fetal samples differed significantly from those detected by sequencing. Overall, our findings show that the presence of Micrococcus in the fetal gut is not supported by the primary sequence data. Our findings underline important aspects of the nature of contamination for both sequencing and culture approaches in microbiome studies and the appropriate use of automated contamination identification tools
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Batch effects account for the main findings of an in utero human intestinal bacterial colonization study
Abstract: A recent study by Rackaityte et al. reported evidence for a low level of bacterial colonization, specifically of Micrococcus luteus, in the intestine of second trimester human fetuses. We have re-analyzed their sequence data and identified a batch effect which violates the underlying assumptions of the bioinformatic method used for contamination removal. This batch effect resulted in Micrococcus not being identified as a contaminant in the original work and being falsely assigned to the fetal samples. We further provide evidence that the micrographs presented by Rackaityte et al. are unlikely to show Micrococci or other bacteria as the size of the particles shown exceeds that of related bacterial cells. Finally, phylogenetic analysis showed that the microbes cultured from the fetal samples differed significantly from those detected by sequencing. Overall, our findings show that the presence of Micrococcus in the fetal gut is not supported by the primary sequence data. Our findings underline important aspects of the nature of contamination for both sequencing and culture approaches in microbiome studies and the appropriate use of automated contamination identification tools
Extinction of cue-evoked drug-seeking relies on degrading hierarchical instrumental expectancies
There has long been need for a behavioural intervention that attenuates cue-evoked drug-seeking, but the optimal method remains obscure. To address this, we report three approaches to extinguish cue-evoked drug-seeking measured in a Pavlovian to instrumental transfer design, in non-treatment seeking adult smokers and alcohol drinkers. The results showed that the ability of a drug stimulus to transfer control over a separately trained drug-seeking response was not affected by the stimulus undergoing Pavlovian extinction training in experiment 1, but was abolished by the stimulus undergoing discriminative extinction training in experiment 2, and was abolished by explicit verbal instructions stating that the stimulus did not signal a more effective response-drug contingency in experiment 3. These data suggest that cue-evoked drug-seeking is mediated by a propositional hierarchical instrumental expectancy that the drug-seeking response is more likely to be rewarded in that stimulus. Methods which degraded this hierarchical expectancy were effective in the laboratory, and so may have therapeutic potential
Clinical validation of automated audiometry with continuous noise-monitoring in a clinically heterogeneous population outside a sound-treated environment
OBJECTIVE : Examine the accuracy of automated audiometry in a clinically heterogeneous
population of adults using the KUDUwave automated audiometer.
DESIGN : Prospective accuracy study. Manual audiometry was performed in a sound-treated
room and automated audiometry was not conducted in a sound-treated environment.
STUDY SAMPLE : 42 consecutively recruited participants from a tertiary otolaryngology
department in Western Australia.
RESULTS : Absolute mean differences ranged between 5.12 – 9.68 dB (air-conduction) and 8.26
– 15.00 dB (bone-conduction). 86.5% of manual and automated 4FAs were within 10 dB (i.e.
±5 dB); 94.8% were within 15 dB. However, there were significant (p<0.05) differences
between automated and manual audiometry at 0.25, 0.5, 1 and 2 kHz (air-conduction) and 0.5
and 1 kHz (bone-conduction). The effect of age (≥55 years) on accuracy (p = 0.014) was not
significant on linear regression (p>0.05; R2 = 0.11). The presence of a hearing loss (better ear
≥26 dB) did not significantly affect accuracy (p = 0.604; air-conduction), (p = 0.218; boneconduction).
CONCLUSIONS : This study provides clinical validation of automated audiometry using the
KUDUwave in a clinically heterogeneous population, without the use of a sound-treated
environment. Whilst threshold variations were statistically significant, future research is
needed to ascertain the clinical significance of such variation.http://www.tandfonline.com/loi/iija202017-05-31hb2016Speech-Language Pathology and Audiolog
Hardy's inequality for functions vanishing on a part of the boundary
We develop a geometric framework for Hardy's inequality on a bounded domain
when the functions do vanish only on a closed portion of the boundary.Comment: 26 pages, 2 figures, includes several improvements in Sections 6-8
allowing to relax the assumptions in the main results. Final version
published at http://link.springer.com/article/10.1007%2Fs11118-015-9463-
Quantum physics meets biology
Quantum physics and biology have long been regarded as unrelated disciplines,
describing nature at the inanimate microlevel on the one hand and living
species on the other hand. Over the last decades the life sciences have
succeeded in providing ever more and refined explanations of macroscopic
phenomena that were based on an improved understanding of molecular structures
and mechanisms. Simultaneously, quantum physics, originally rooted in a world
view of quantum coherences, entanglement and other non-classical effects, has
been heading towards systems of increasing complexity. The present perspective
article shall serve as a pedestrian guide to the growing interconnections
between the two fields. We recapitulate the generic and sometimes unintuitive
characteristics of quantum physics and point to a number of applications in the
life sciences. We discuss our criteria for a future quantum biology, its
current status, recent experimental progress and also the restrictions that
nature imposes on bold extrapolations of quantum theory to macroscopic
phenomena.Comment: 26 pages, 4 figures, Perspective article for the HFSP Journa
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Implementation of U.K. Earth system models for CMIP6
We describe the scientific and technical implementation of two models for a core set of
experiments contributing to the sixth phase of the Coupled Model Intercomparison Project (CMIP6).
The models used are the physical atmosphere-land-ocean-sea ice model HadGEM3-GC3.1 and the
Earth system model UKESM1 which adds a carbon-nitrogen cycle and atmospheric chemistry to
HadGEM3-GC3.1. The model results are constrained by the external boundary conditions (forcing data)
and initial conditions.We outline the scientific rationale and assumptions made in specifying these.
Notable details of the implementation include an ozone redistribution scheme for prescribed ozone
simulations (HadGEM3-GC3.1) to avoid inconsistencies with the model's thermal tropopause, and land use
change in dynamic vegetation simulations (UKESM1) whose influence will be subject to potential biases in
the simulation of background natural vegetation.We discuss the implications of these decisions for
interpretation of the simulation results. These simulations are expensive in terms of human and CPU
resources and will underpin many further experiments; we describe some of the technical steps taken to
ensure their scientific robustness and reproducibility
Higher Order Evaluation of the Critical Temperature for Interacting Homogeneous Dilute Bose Gases
We use the nonperturbative linear \delta expansion method to evaluate
analytically the coefficients c_1 and c_2^{\prime \prime} which appear in the
expansion for the transition temperature for a dilute, homogeneous, three
dimensional Bose gas given by T_c= T_0 \{1 + c_1 a n^{1/3} + [ c_2^{\prime}
\ln(a n^{1/3}) +c_2^{\prime \prime} ] a^2 n^{2/3} + {\cal O} (a^3 n)\}, where
T_0 is the result for an ideal gas, a is the s-wave scattering length and n is
the number density. In a previous work the same method has been used to
evaluate c_1 to order-\delta^2 with the result c_1= 3.06. Here, we push the
calculation to the next two orders obtaining c_1=2.45 at order-\delta^3 and
c_1=1.48 at order-\delta^4. Analysing the topology of the graphs involved we
discuss how our results relate to other nonperturbative analytical methods such
as the self-consistent resummation and the 1/N approximations. At the same
orders we obtain c_2^{\prime\prime}=101.4, c_2^{\prime \prime}=98.2 and
c_2^{\prime \prime}=82.9. Our analytical results seem to support the recent
Monte Carlo estimates c_1=1.32 \pm 0.02 and c_2^{\prime \prime}= 75.7 \pm 0.4.Comment: 29 pages, 3 eps figures. Minor changes, one reference added. Version
in press Physical Review A (2002
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