1,095 research outputs found
Long range correlations generated by phase separation. Exact results from field theory
We consider near-critical planar systems with boundary conditions inducing phase separation. While order parameter correlations decay exponentially in pure phases, we show by direct field theoretical derivation how phase separation generates long range correlations in the direction parallel to the interface, and determine their exact analytic form. The latter leads to specific contributions to the structure factor of the interface
Domain wall brane in squared curvature gravity
We suggest a thick braneworld model in the squared curvature gravity theory.
Despite the appearance of higher order derivatives, the localization of gravity
and various bulk matter fields is shown to be possible. The existence of the
normalizable gravitational zero mode indicates that our four-dimensional
gravity is reproduced. In order to localize the chiral fermions on the brane,
two types of coupling between the fermions and the brane forming scalar is
introduced. The first coupling leads us to a Schr\"odinger equation with a
volcano potential, and the other a P\"oschl-Teller potential. In both cases,
the zero mode exists only for the left-hand fermions. Several massive KK states
of the fermions can be trapped on the brane, either as resonant states or as
bound states.Comment: 18 pages, 5 figures and 1 table, references added, improved version
to be published in JHE
Adaptive Evolution of the Myo6 Gene in Old World Fruit Bats (Family: Pteropodidae)
PMCID: PMC3631194This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
The Cyprinodon variegatus genome reveals gene expression changes underlying differences in skull morphology among closely related species
Genes in durophage intersection set at 15 dpf. This is a comma separated table of the genes in the 15 dpf durophage intersection set. Given are edgeR results for each pairwise comparison. Columns indicating whether a gene is included in the intersection set at a threshold of 1.5 or 2 fold are provided. (CSV 13ĂÂ kb
Directed -in vitro- evolution of Precambrian and extant Rubiscos
Rubisco is an ancient, catalytically conserved yet slow enzyme, which plays a central role in the
biosphereâs carbon cycle. The design of Rubiscos to increase agricultural productivity has hitherto
relied on the use of in vivo selection systems, precluding the exploration of biochemical traits that are
not wired to cell survival. We present a directed -in vitro- evolution platform that extracts the enzyme
from its biological context to provide a new avenue for Rubisco engineering. Precambrian and extant
form II Rubiscos were subjected to an ensemble of directed evolution strategies aimed at improving
thermostability. The most recent ancestor of proteobacteria -dating back 2.4 billion years- was uniquely
tolerant to mutagenic loading. Adaptive evolution, focused evolution and genetic drift revealed a
panel of thermostable mutants, some deviating from the characteristic trade-offs in CO2-fixing speed
and specificity. Our findings provide a novel approach for identifying Rubisco variants with improved
catalytic evolution potential.This work was supported by the REPSOL Research contracts Rubolution (RC020401120018), Rubolution 2.0 (RC
020401140042), the CSIC project PIE-201780E043 and the Australian Research Council grant CE140100015
Engaging terminally ill patients in end of life talk: How experienced palliative medicine doctors navigate the dilemma of promoting discussions about dying
Objective:
To examine how palliative medicine doctors engage patients in end-of-life (hereon, EoL) talk. To examine whether the practice of âeliciting and responding to cuesâ, which has been widely advocated in the EoL care literature, promotes EoL talk.
Design:
Conversation analysis of video- and audio-recorded consultations.
Participants:
Unselected terminally ill patients and their companions in consultation with experienced palliative medicine doctors.
Setting:
Outpatient clinic, day therapy clinic, and inpatient unit of a single English hospice.
Results:
Doctors most commonly promoted EoL talk through open elaboration solicitations; these created opportunities for patients to introduce Ă then later further articulate Ă EoL considerations in such a way that doctors did not overtly ask about EoL matters. Importantly, the wording of elaboration solicitations avoided assuming that patients had EoL concerns. If a patient responded to open elaboration solicitations without introducing EoL considerations, doctors sometimes pursued EoL talk by switching to a less participatory and more presumptive type of solicitation, which suggested the patient might have EoL concerns. These more overt solicitations were used only later in consultations, which indicates that doctors give precedence to patients volunteering EoL considerations, and offer them opportunities to take the lead in initiating EoL talk.
There is evidence that doctors treat elaboration of patientsâ talk as a resource for engaging them in EoL conversations. However, there are limitations associated with labelling that talk as âcuesâ as is common in EoL communication contexts. We examine these limitations and propose âpossible EoL considerationsâ as a descriptively more accurate term.
Conclusions:
Through communicating Ă via open elaboration solicitations Ă in ways that create opportunities for patients to volunteer EoL considerations, doctors navigate a core dilemma in promoting EoL talk: giving patients opportunities to choose whether to engage in conversations about EoL whilst being sensitive to their communication needs, preferences and state of readiness for such dialogue
f(R) theories
Over the past decade, f(R) theories have been extensively studied as one of
the simplest modifications to General Relativity. In this article we review
various applications of f(R) theories to cosmology and gravity - such as
inflation, dark energy, local gravity constraints, cosmological perturbations,
and spherically symmetric solutions in weak and strong gravitational
backgrounds. We present a number of ways to distinguish those theories from
General Relativity observationally and experimentally. We also discuss the
extension to other modified gravity theories such as Brans-Dicke theory and
Gauss-Bonnet gravity, and address models that can satisfy both cosmological and
local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in
Relativity, Published version, Comments are welcom
Identifying and tracking key climate adaptation actors in the UK
To understand how climate adaptation planning and decision-making will progress, a better understanding is needed as to which organisations are expected to take on key responsibilities. Methodological challenges have impeded efforts to identify and track adaptation actors beyond the coarse scale of nation states. Yet, for effective adaptation to succeed, who do national governments need to engage, support and encourage? Using the UK as a case study, we conducted a systematic review of official government documents on climate adaptation, between 2006 and 2015, to understand which organisations are identified as key to future adaptation efforts and tracked the extent to which these organisations changed over time. Our unique longitudinal dataset found a very large number of organisations (nâ=â568). These organisations varied in size (small-medium enterprises to large multinationals), type (public, private and not-for-profit), sector (e.g. water, energy, transport and health), scale (local, national and international), and roles and responsibilities (policymaking, decision-making, knowledge production, retail). Importantly, our findings reveal a mismatch between official government policies that repeatedly call on private organisations to drive adaptation, on the one hand, and a clear dominance of the public sector on the other hand. Yet, the capacity of organisations to fulfil the roles and responsibilities assigned to them, particularly in the public sector, is diminishing. Unless addressed, climate adaptation actions could be assigned to those either unable, or unwilling, to implement them
Haemoglobin level at birth is associated with short term outcomes and mortality in preterm infants
Background Blood volume and haemoglobin (Hb) levels are increased by delayed umbilical cord clamping, which has been reported to improve clinical outcomes of preterm infants. The objective was to determine whether Hb level at birth was associated with short term outcomes in preterm infants born at â€32 weeks gestation. Methods Data were collected retrospectively from electronic records: Standardised Electronic Neonatal Database, Electronic Patient Record, Pathology (WinPath), and Blood Bank Electronic Database. The study was conducted in a tertiary perinatal centre with around 5,500 deliveries and a neonatal unit admission of 750 infants per year. All inborn preterm infants of 23 to 32 weeks gestational age (GA) admitted to the neonatal unit from January 2006 to September 2012 were included. The primary outcomes were intra-ventricular haemorrhage, necrotising entero-colitis, broncho-pulmonary dysplasia, retinopathy of prematurity, and death before discharge. The secondary outcomes were receiving blood transfusion and length of intensive care and neonatal unit days. The association between Hb level (g/dL) at birth and outcomes was analysed by multiple logistic regression adjusting for GA and birth weight (BWt). Results Overall, 920 infants were eligible; 28 were excluded because of missing data and 2 for lethal congenital malformation. The mean (SD) GA was 28.3 (2.7) weeks, BWt was 1,140 (414) g, and Hb level at birth was 15.8 (2.6) g/dL. Hb level at birth was significantly associated with all primary outcomes studied (P <0.001) in univariate analyses. Once GA and BWt were adjusted for, only death before discharge remained statistically significant; the OR of death for infants with Hb level at birth <12 g/dL compared with those with Hb level at birth of â„18 g/dL was 4.1 (95% CI, 1.4â11.6). Hb level at birth was also significantly associated with blood transfusion received (P <0.01) but not with duration of intensive care or neonatal unit days. Conclusions Low Hb level at birth was significantly associated with mortality and receiving blood transfusion in preterm infants born at â€32 weeks gestation. Further studies are needed to determine the association between Hb level at birth and long-term neurodevelopmental outcomes
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