2,752 research outputs found
Renormalisation of heavy-light light ray operators
We calculate the renormalisation of different light ray operators with one
light degree of freedom and a static heavy quark. Both - and
-kernels are considered. A comparison with the light-light case suggests
that the mixing with three-particle operators is solely governed by the light
degrees of freedom. Additionally we show that conformal symmetry is already
broken at the level of the one loop counterterms due to the additional
UV-renormalisation of a cusp in the two contributing Wilson-lines. This general
feature can be used to fix the -renormalisation kernels up to a
constant. Some examples for applications of our results are given.Comment: 23 pages, 5 figures; v2: changed some wording, added a few references
and one appendix concerning some subtleties related to gauge fixing and ghost
terms; v3: clarified calculation in section 3.2., added an explicit
calculation in section 5.2, corrected a few typos and one figure, added a few
comments, results unchanged, except for typesetting matches version to appear
in JHE
Operator product expansion in QCD in off-forward kinematics: Separation of kinematic and dynamical contributions
We develop a general approach to the calculation of target mass and finite
t=(p'-p)^2 corrections in hard processes which can be studied in the framework
of the operator product expansion and involve momentum transfer from the
initial to the final hadron state. Such corrections, which are usually referred
to as kinematic, can be defined as contributions of operators of all twists
that can be reduced to total derivatives of the leading twist operators. As the
principal result, we provide a set of projection operators that pick up the
"kinematic" part of an arbitrary flavor-nonsinglet twist-four operator in QCD.
A complete expression is derived for the time-ordered product of two
electromagnetic currents that includes all kinematic corrections to twist-four
accuracy. The results are immediately applicable to the studies of
deeply-virtual Compton scattering, transition gamma^*-> M gamma form factors
and related processes. As a byproduct of this study, we find a series of
"genuine" twist-four flavor-nonsinglet quark-antiquark-gluon operators which
have the same anomalous dimensions as the leading twist quark-antiquark
operators.Comment: 68 pages, 2 figures. Misprints in Eq.(5.64) and several equations in
Sec.6 are corrected. For readers' convenience all corrections are marked in
re
Parentsâ experiences of health visiting for children with Down syndrome
© MA Healthcare Limited.Children with Down syndrome have an increased likelihoodof experiencing serious health conditions. Health visitors canhave an important role in monitoring and promoting healthand development for young children with Down syndrome.This study aimed to explore parentsâ experiences of healthvisiting services for children with Down syndrome. Twentyfour parents of children with Down syndrome aged 0â5 yearscompleted a brief questionnaire about the number and natureof visits from health visitors in the previous 12 months andtheir support needs. Some parents commented that otherprofessionals met the needs of their child, whereas others saidthat they would like more advice and support from healthvisitors. A further exploration of broader health serviceprovision, including health visiting, for young children withDown syndrome is needed.Peer reviewedFinal Accepted Versio
A computationally inspired in-vivo approach identifies a link between amygdalar transcriptional heterogeneity, socialization and anxiety
Pharmaceutical breakthroughs for anxiety have been lackluster in the last half-century. Converging behavior and limbic
molecular heterogeneity has the potential to revolutionize biomarker-driven interventions. However, current in vivo models
too often deploy artificial systems including directed evolution, mutations and fear induction, which poorly mirror clinical
manifestations. Here, we explore transcriptional heterogeneity of the amygdala in isogenic mice using an unbiased multidimensional
computational approach that segregates intra-cohort reactions to moderate situational adversity and intersects
it with high content molecular profiling. We show that while the computational approach stratifies known features of
clinical anxiety including nitric oxide, opioid and corticotropin signaling, previously unrecognized druggable biomarkers
emerge, such as calpain11 and scand1. Through ingenuity pathway analyses, we further describe a role for neurosteroid
estradiol signaling, heat shock proteins, ubiquitin ligases and lipid metabolism. In addition, we report a remarkable
behavioral pattern that maps to molecular features of anxiety in mice through counterphobic social attitudes, which
manifest as increased, yet spatially distant socialization. These findings provide an unbiased approach for interrogating
anxiolytics, and hint toward biomarkers underpinning behavioral and social patterns that merit further exploration
COâ reduction driven by a pH gradient
All life on Earth is built of organic molecules, so the primordial sources of reduced carbon remain a major open question in studies of the origin of life. A variant of the alkaline-hydrothermal-vent theory for life's emergence suggests that organics could have been produced by the reduction of CO2 via H2 oxidation, facilitated by geologically sustained pH gradients. The process would be an abiotic analog-and proposed evolutionary predecessor-of the Wood-Ljungdahl acetyl-CoA pathway of modern archaea and bacteria. The first energetic bottleneck of the pathway involves the endergonic reduction of CO2 with H2 to formate (HCOO-), which has proven elusive in mild abiotic settings. Here we show the reduction of CO2 with H2 at room temperature under moderate pressures (1.5 bar), driven by microfluidic pH gradients across inorganic Fe(Ni)S precipitates. Isotopic labeling with 13C confirmed formate production. Separately, deuterium (2H) labeling indicated that electron transfer to CO2 does not occur via direct hydrogenation with H2 but instead, freshly deposited Fe(Ni)S precipitates appear to facilitate electron transfer in an electrochemical-cell mechanism with two distinct half-reactions. Decreasing the pH gradient significantly, removing H2, or eliminating the precipitate yielded no detectable product. Our work demonstrates the feasibility of spatially separated yet electrically coupled geochemical reactions as drivers of otherwise endergonic processes. Beyond corroborating the ability of early-Earth alkaline hydrothermal systems to couple carbon reduction to hydrogen oxidation through biologically relevant mechanisms, these results may also be of significance for industrial and environmental applications, where other redox reactions could be facilitated using similarly mild approaches
Reaction of a polar gravelâspit system to atmospheric warming and glacier retreat as reflected by morphology and internal sediment geometries (South Shetland Islands, Antarctica)
Sedimentary architecture and morphogenetic evolution of a polar bay-mouth gravel-spit system are revealed based on topographic mapping, sedimentological data, radiocarbon dating and ground-penetrating radar investigations. Data document variable rates of spit progradation in reaction to atmospheric warming synchronous to the termination of the last glacial re-advance (LGR, 0.45â0.25 ka BP), the southern hemisphere equivalent of the Little Ice Age cooling period. Results show an interruption of spit progradation that coincides with the proposed onset of accelerated isostatic rebound in reaction to glacier retreat. Spit growth resumed in the late 19th century after the rate of isostatic rebound decreased, and continues until today. The direction of modern spit progradation, however, is rotated northwards compared with the growth axis of the early post-LGR spit. This is interpreted to reflect the shift and strengthening in the regional wind field during the last century. A new concept for the interplay of polar gravel-spit progradation and glacio-isostatic adjustment is presented, allowing for the prediction of future coastal evolution in comparable polar settings
Womenâs experiences of receiving care for pelvic organ prolapse: a qualitative study
Background Pelvic organ prolapse is a common urogenital condition affecting 41â50% of women over the age of 40. To achieve early diagnosis and appropriate treatment, it is important that care is sensitive to and meets womenâs needs, throughout their patient journey. This study explored womenâs experiences of seeking diagnosis and treatment for prolapse and their needs and priorities for improving person-centred care. Methods Twenty-two women receiving prolapse care through urogynaecology services across three purposefully selected NHS UK sites took part in three focus groups and four telephone interviews. A topic guide facilitated discussions about womenâs experiences of prolapse, diagnosis, treatment, follow-up, interactions with healthcare professionals, overall service delivery, and ideals for future services to meet their needs. Data were analysed thematically. Results Three themes emerged relating to womenâs experiences of a) Evaluating what is normal b) Hobsonâs choice of treatment decisions, and c) The trial and error of treatment and technique. Women often delayed seeking help for their symptoms due to lack of awareness, embarrassment and stigma. When presented to GPs, their symptoms were often dismissed and unaddressed until they became more severe. Women reported receiving little or no choice in treatment decisions. Choices were often influenced by health professionalsâ preferences which were subtly reflected through the framing of the offer. Womenâs embodied knowledge of their condition and treatment was largely unheeded, resulting in decisions that were inconsistent with womenâs preferences and needs. Physiotherapy based interventions were reported as helping women regain control over their symptoms and life. A need for greater awareness of prolapse and physiotherapy interventions among women, GPs and consultants was identified alongside greater focus on prevention, early diagnosis and regular follow-up. Greater choice and involvement in treatment decision making was desired. Conclusions As prolapse treatment options expand to include more conservative choices, greater awareness and education is needed among women and professionals about these as a first line treatment and preventive measure, alongside a multi-professional team approach to treatment decision making. Women presenting with prolapse symptoms need to be listened to by the health care team, offered better information about treatment choices, and supported to make a decision that is right for them
Hydrodynamic modelling of protein conformation in solution: ELLIPS and HYDRO
The last three decades has seen some important
advances in our ability to represent the conformation of
proteins in solution on the basis of hydrodynamic measurements.
Advances in theoretical modeling capabilities have
been matched by commensurate advances in the precision of
hydrodynamic measurements. We consider the advances in
whole-body (simple ellipsoid-based) modelingâstill useful
for providing an overall idea of molecular shape, particularly
for those systems where only a limited amount of data is
availableâand outline the ELLIPS suite of algorithms
which facilitates the use of this approach. We then focus
on bead modeling strategies, particularly the surface or
shellâbead approaches and the HYDRO suite of algorithms.
We demonstrate how these are providing great insights into
complex issues such as the conformation of immunoglobulins
and other multi-domain complexes
Sugar Ka Saathi â A Case Study Designing Digital Self-management Tools for People Living with Diabetes in Pakistan
This paper presents the results of an iterative participatory process to design a smart self-management tool for less-literate people living with diabetes in Pakistan. Initially, interviews and focus groups with sixty-nine people living with diabetes identified issues that they face when self-managing including un-controllable factors, lack of diabetes awareness, low-tech mobile phones, and poor internet availability. We developed personas grounded in the scoping results and adjusted our PD approach to focus on more tangible design artefacts before running narrative scoping PD sessions. Working from older, illiterate persona, we designed a phone-line delivered Interactive Voice Response (IVR) system.
We developed a functional IVR Prototype âSugar ka Saathiâ (Diabetes Companion) with input from a group of 4 Pakistan-based healthcare professionals, to act as a design probe in the PD process. We tested the IVR probe with fifty-seven of the original scoping participants which validated the knowledge transferred by the IVR and its acceptability. Invisible design videos were shown to elaborate the IVR and community concept to thirteen participants through two filmed videos using our existing persona characters from the scoping studies, these videos helped to engage older people with diabetes in PD sessions
Using the gut microbiota as a novel tool for examining colobine primate GI health
Primates of the Colobinae subfamily are highly folivorous. They possess a sacculated foregut and are believed to rely on a specialized gut microbiota to extract sufficient energy from their hard-to-digest diet. Although many colobines are endangered and would benefit from captive breeding programs, maintaining healthy captive populations of colobines can be difficult since they commonly suffer from morbidity and mortality due to gastrointestinal (GI) distress of unknown cause. While there is speculation that this GI distress may be associated with a dysbiosis of the gut microbiota, no study has directly examined the role of the gut microbiota in colobine GI health. In this study, we used high-throughput sequencing to examine the gut microbiota of three genera of colobines housed at the San Diego Zoo: doucs (Pygathrix) (N=7), colobus monkeys (Colobus) (N=4), and langurs (Trachypithecus) (N=5). Our data indicated that GI-healthy doucs, langurs, and colobus monkeys possess a distinct gut microbiota. In addition, GI-unhealthy doucs exhibited a different gut microbiota compared to GI-healthy individuals, including reduced relative abundances of anti-inflammatory Akkermansia. Finally, by comparing samples from wild and captive Asian colobines, we found that captive colobines generally exhibited higher relative abundances of potential pathogens such as Desulfovibrio and Methanobrevibacter compared to wild colobines, implying an increased risk of gut microbial dysbiosis. Together, these results suggest an association between the gut microbiota and GI illness of unknown cause in doucs. Further studies are necessary to corroborate these findings and determine cause-and-effect relationships. Additionally, we found minimal variation in the diversity and composition of the gut microbiota along the colobine GI tract, suggesting that fecal samples may be sufficient for describing the colobine gut microbiota. If these findings can be validated in wild individuals, it will facilitate the rapid expansion of colobine gut microbiome research
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