742 research outputs found
Traveling waves for nonlinear Schr\"odinger equations with nonzero conditions at infinity, II
We prove the existence of nontrivial finite energy traveling waves for a
large class of nonlinear Schr\"odinger equations with nonzero conditions at
infinity (includindg the Gross-Pitaevskii and the so-called "cubic-quintic"
equations) in space dimension . We show that minimization of the
energy at fixed momentum can be used whenever the associated nonlinear
potential is nonnegative and it gives a set of orbitally stable traveling
waves, while minimization of the action at constant kinetic energy can be used
in all cases. We also explore the relationship between the families of
traveling waves obtained by different methods and we prove a sharp nonexistence
result for traveling waves with small energy.Comment: Final version, accepted for publication in the {\it Archive for
Rational Mechanics and Analysis.} The final publication is available at
Springer via http://dx.doi.org/10.1007/s00205-017-1131-
Glucose enhancement of memory is modulated by trait anxiety in healthy adolescent males
Glucose administration is associated with memory enhancement in healthy young individuals under conditions of divided attention at encoding. While the specific neurocognitive mechanisms underlying this âglucose memory facilitation effectâ are currently uncertain, it is thought that individual differences in glucoregulatory efficiency may alter an individualâs sensitivity to the glucose memory facilitation effect. In the present study, we sought to investigate whether basal hypothalamicâpituitaryâadrenal axis function (itself a modulator of glucoregulatory efficiency), baseline self-reported stress and trait anxiety influence the glucose memory facilitation effect. Adolescent males (age rangeâ=â14â17 years) were administered glucose and placebo prior to completing a verbal episodic memory task on two separate testing days in a counter-balanced, within-subjects design. Glucose ingestion improved verbal episodic memory performance when memory recall was tested (i) within an hour of glucose ingestion and encoding, and (ii) one week subsequent to glucose ingestion and encoding. Basal hypothalamicâpituitaryâadrenal axis function did not appear to influence the glucose memory facilitation effect; however, glucose ingestion only improved memory in participants reporting relatively higher trait anxiety. These findings suggest that the glucose memory facilitation effect may be mediated by biological mechanisms associated with trait anxiety
Drug Development for Rare Paediatric Epilepsies: Current State and Future Directions
Rare diseases provide a challenge in the evaluation of new therapies. However, orphan drug development is of increasing interest because of the legislation enabling facilitated support by regulatory agencies through scientific advice, and the protection of the molecules with orphan designation. In the landscape of the rare epilepsies, very few syndromes, namely Dravet syndrome, Lennox-Gastaut syndrome and West syndrome, have been subject to orphan drug development. Despite orphan designations for rare epilepsies having dramatically increased in the past 10Â years, the number of approved drugs remains limited and restricted to a handful of epilepsy syndromes. In this paper, we describe the current state of orphan drug development for rare epilepsies. We identified a large number of compounds currently under investigation, but mostly in the same rare epilepsy syndromes as in the past. A rationale for further development in rare epilepsies could be based on the match between the drug mechanisms of action and the knowledge of the causative gene mutation or by evidence from animal models. In case of the absence of strong pathophysiological hypotheses, exploratory/basket clinical studies could be helpful to identify a subpopulation that may benefit from the new drug. We provide some suggestions for future improvements in orphan drug development such as promoting paediatric drug investigations, better evaluation of the incidence and the prevalence, together with the natural history data, and the development of new primary outcomes
Relevance of a photo-Fenton like technology based on peroxymonosulphate for 17b-estradiol removal from wastewater
The objective of this work was to evaluate the effectiveness of sulphate radical based homogeneous
advanced oxidation technologies (SR-AOTs) involving peroxymonosulphate (PMS) as an oxidant and ferrous
iron (Fe(II)) as a catalyst, for the removal of 17b-estradiol (E2) from wastewater effluents collected
downstream of a biological WWTP in Perpignan (France). This molecule is used as a surrogate for endocrine
disrupting compounds (EDCs) due to its high biological activity at very low concentration levels (ng/
L). For this purpose, two different laboratory-scale devices have been employed, one for indoor experiments
working with controlled and artificial UV light centered on k = 365 nm emission, and the other
at a larger scale for outdoor experiments using direct solar irradiation. Comparison of kinetic studies with
those obtained with commonly used hydroxyl radical based advanced oxidation technologies (HR-AOTs),
i.e., UVâVis/H2O2/Fe(II) and UV/TiO2 revealed the higher efficiency of the former over the latter ones. Estrogenicity
measurement through bioassays confirmed the complete removal of 17b-estradiol after only a
few minutes treatment. Determination of E2 transformation pathways upon sulphate radical reactivity
through intermediates identification by mass spectrometry revealed that the oxidation of phenol moiety
into quinone might be the main step responsible for the decrease in estrogenicity. UVâVis/PMS/Fe(II) system
appears to be the most suitable method for the treatment of aqueous solutions containing E2
Convergence of Ginzburg-Landau functionals in 3-d superconductivity
In this paper we consider the asymptotic behavior of the Ginzburg- Landau
model for superconductivity in 3-d, in various energy regimes. We rigorously
derive, through an analysis via {\Gamma}-convergence, a reduced model for the
vortex density, and we deduce a curvature equation for the vortex lines. In a
companion paper, we describe further applications to superconductivity and
superfluidity, such as general expressions for the first critical magnetic
field H_{c1}, and the critical angular velocity of rotating Bose-Einstein
condensates.Comment: 45 page
Travelling waves for the Gross-Pitaevskii equation II
The purpose of this paper is to provide a rigorous mathematical proof of the
existence of travelling wave solutions to the Gross-Pitaevskii equation in
dimensions two and three. Our arguments, based on minimization under
constraints, yield a full branch of solutions, and extend earlier results,
where only a part of the branch was built. In dimension three, we also show
that there are no travelling wave solutions of small energy.Comment: Final version accepted for publication in Communications in
Mathematical Physics with a few minor corrections and added remark
Temporal changes in ewe vaginal microbiota throughout gestation
Introduction: Numerous factors are known to influence reproductive efficiency in ewes, but few studies have investigated the potential role of vaginal microbiota in sheep reproductive success. The objective of this study was to thoroughly characterize the ewe vaginal microbiota throughout the course of pregnancy.
Methods: Vaginal samples were collected from 31 pregnant Hampshire and Hampshire X Suffolk crossbred ewes on a weekly basis from pre-breeding to pregnancy testing and then biweekly until just after lambing. To characterize the vaginal microbial communities, DNA was extracted and 16S rRNA gene Illumina MiSeq amplicon sequencing was performed.
Results and Discussion: Alpha diversity metrics indicated an increase in species richness, evenness, and overall diversity throughout gestation. Distinct shifts in the bacterial communities were observed during gestation and were segregated into three periods: early gestation, a transitional period and mid/late gestation. During early gestation, Actinobacillus, Histophilus, and unclassified Leptotrichiaceae were found in greater relative abundance. During the transitional period, a population shift occurred characterized by increasing relative abundance of Streptococcus and Staphylococcus. During mid/late gestation, Staphylococcus, Streptococcus, and Ureaplasma had the greatest relative abundance. These shifts in the microbial population throughout the eweâs gestation are likely related to hormonal changes triggered by the growing conceptus, specifically increasing blood concentration of progesterone. The transitional period shift in vaginal microbial communities potentially aligns with the placental take-over of progesterone production from the corpus luteum at approximately day 50 after conception (gestational week 7). Understanding the
observed variability of the vaginal microbiota throughout pregnancy will allow for future comparison of ewes that did not become pregnant or had abnormal pregnancies, which could lead to the discovery of potential bacterial biomarkers for pregnancy outcome; this understanding could also lead to development of probiotics to improve sheep reproductive success.This article is published as Cassas MS, Jonas LC, Anderson CJ, Schmitz-Esser S and Youngs CR (2024) Temporal changes in ewe vaginal microbiota throughout gestation. Front. Microbiol. 15:1359678. doi: 10.3389/fmicb.2024.1359678.© 2024 Cassas, Jonas, Anderson, Schmitz-Esser and Youngs. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms
Cross-scale Multi-instance Learning for Pathological Image Diagnosis
Analyzing high resolution whole slide images (WSIs) with regard to
information across multiple scales poses a significant challenge in digital
pathology. Multi-instance learning (MIL) is a common solution for working with
high resolution images by classifying bags of objects (i.e. sets of smaller
image patches). However, such processing is typically performed at a single
scale (e.g., 20x magnification) of WSIs, disregarding the vital inter-scale
information that is key to diagnoses by human pathologists. In this study, we
propose a novel cross-scale MIL algorithm to explicitly aggregate inter-scale
relationships into a single MIL network for pathological image diagnosis. The
contribution of this paper is three-fold: (1) A novel cross-scale MIL (CS-MIL)
algorithm that integrates the multi-scale information and the inter-scale
relationships is proposed; (2) A toy dataset with scale-specific morphological
features is created and released to examine and visualize differential
cross-scale attention; (3) Superior performance on both in-house and public
datasets is demonstrated by our simple cross-scale MIL strategy. The official
implementation is publicly available at https://github.com/hrlblab/CS-MIL
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