Institute of Molecular Physiology, University of Sheffield, Western
Bank, Sheffield, United Kingdom
North, R. Alan
Molecular Physiology of P2X Receptors. Physiol. Rev. 82: 1013-1067, 2002. P2X ...receptors are membrane ion
channels that open in response to the binding of extracellular ATP.
Seven genes in vertebrates encode P2X receptor subunits, which
are 40-50% identical in amino acid sequence. Each subunit has two
transmembrane domains, separated by an extracellular domain (~280
amino acids). Channels form as multimers of several subunits. Homomeric
P2X 1 , P2X 2 , P2X 3 , P2X 4 , P2X 5 , and P2X 7 channels and heteromeric
P2X 2/3 and P2X 1/5 channels have been most fully
characterized following heterologous expression. Some agonists (e.g.,
-methylene ATP) and antagonists e.g., 2',3'- O -(2,4,6-trinitrophenyl)-ATP are strongly selective
for receptors containing P2X 1 and P2X 3
subunits. All P2X receptors are permeable to small monovalent cations;
some have significant calcium or anion permeability. In many cells,
activation of homomeric P2X 7 receptors induces a
permeability increase to larger organic cations including some
fluorescent dyes and also signals to the cytoskeleton; these changes
probably involve additional interacting proteins. P2X receptors are
abundantly distributed, and functional responses are seen in neurons,
glia, epithelia, endothelia, bone, muscle, and hemopoietic tissues. The
molecular composition of native receptors is becoming understood, and
some cells express more than one type of P2X receptor. On smooth
muscles, P2X receptors respond to ATP released from sympathetic motor
nerves (e.g., in ejaculation). On sensory nerves, they are involved in
the initiation of afferent signals in several viscera (e.g., bladder,
intestine) and play a key role in sensing tissue-damaging and
inflammatory stimuli. Paracrine roles for ATP signaling through P2X
receptors are likely in neurohypophysis, ducted glands, airway
epithelia, kidney, bone, and hemopoietic tissues. In the last case,
P2X 7 receptor activation stimulates cytokine release by
engaging intracellular signaling pathways.
In forest ecosystems, many functional processes are governed by local canopy gap dynamics, caused by either natural or anthropogenic factors. Quantifying the size and spatial distribution of canopy ...gaps enables an improved understanding and predictive modelling of multiple environmental phenomena. For instance knowledge of canopy gap dynamics can help us elucidate time‐integrated effects of tree mortality, regrowth and succession rates, carbon flux patterns, species heterogeneity and three‐dimensional spacing within structurally complex forest ecosystems.
Airborne Laser Scanning (ALS) has emerged as a technology that is well‐suited for mapping forest canopy gaps in a wide variety of forest ecosystems and across spatial scales. New technological and algorithmic advances, including ALS remote‐sensing, coupled with optimized frameworks for data processing and detection of forest canopy gaps, are allowing an enhanced understanding of forest structure and functional processes.
This paper introduces ForestGapR, a cutting‐edge open source r package for forest gap analysis from canopy height models derived from ALS and other remote sensing sources. The ForestGapR package offers tools to (a) automate forest canopy gap detection, (b) compute a series of gap statistics, including gap‐size frequency distributions and spatial distribution, (c) map gap dynamics (when multitemporal ALS data are available) and (d) convert forest canopy gaps detected into raster or vector layers as per user requirements.
As case studies, we run ForestGapR on ALS data collected over four different tropical forest regions worldwide. We hope this new package will enable further research towards understanding the distribution, dynamics and role of canopy gaps not only in tropical forests, but in other forest types elsewhere.
Objective To determine maternal and fetal outcomes in women with mechanical heart valves managed with therapeutic dose enoxaparin during pregnancy.
Design Retrospective audit.
Setting ...Hospital‐based high‐risk antenatal clinics.
Population Pregnant women with mechanical heart valves attending high‐risk antenatal clinics, treated with enoxaparin (1 mg/kg twice daily) during pregnancy.
Methods Women with mechanical heart valves treated with enoxaparin at any stage during pregnancy (1997–2008) identified using a database of women with mechanical heart valves attending the high‐risk clinics and a prospective database of women prescribed enoxaparin for any indication during pregnancy.
Main outcome measures Maternal outcomes included thromboembolic and haemorrhagic complications. Pregnancy and fetal outcomes included miscarriage, stillbirth, baby death and live birth, small‐for‐gestational‐age infants, warfarin embryopathy and warfarin‐related fetal loss.
Results Thirty‐one women underwent 47 pregnancies. In 34 pregnancies (72.3%), anticoagulation was with predominantly enoxaparin and 13 (27.7%) pregnancies women received mainly warfarin, with enoxaparin given in the first trimester and/or peri‐delivery. Seven (14.9%) thrombotic complications occurred, of which five (10.6%) were associated with enoxaparin treatment. Non‐compliance or sub‐therapeutic anti‐Xa levels contributed in each case. Antenatal and postpartum haemorrhagic complications occurred in eight (17%) and 15 (32%) pregnancies respectively. Of 35 pregnancies continuing after 20 weeks’ gestation, 96% (22/23) of women taking predominantly enoxaparin had a surviving infant compared with 75% (9/12) in women taking primarily warfarin. Four perinatal deaths occurred, three attributable to warfarin.
Conclusions Compliance with therapeutic dose enoxaparin and aspirin during pregnancy in women with mechanical heart valves is associated with a low risk of valve thrombosis and good fetal outcomes, but close monitoring is essential.
Please cite this paper as: McCowan L, Roberts C, Dekker G, Taylor R, Chan E, Kenny L, Baker P, Moss‐Morris R, Chappell L, North R on behalf of the SCOPE consortium. Risk factors for ...small‐for‐gestational‐age infants by customised birthweight centiles: data from an international prospective cohort study. BJOG 2010;117:1599–1607.
Objective To identify clinical and ultrasound variables associated with the birth of small‐for‐gestational‐age (SGA) infants by customised centiles, subclassified according to whether their mothers were normotensive or developed hypertensive complications.
Design Prospective, multicentre cohort study.
Setting Participating centres of the Screening for Pregnancy Endpoints (SCOPE) study in Auckland, New Zealand, Adelaide, Australia, Manchester and London, UK, and Cork, Ireland.
Population The 3513 nulliparous participants of the SCOPE study.
Methods Women were interviewed at 15 ± 1 weeks, and had ultrasound growth measurements and umbilical and uterine Doppler studies at 20 ± 1 weeks. Variables associated with SGA infants were identifed using logistic regression.
Main outcome measures Small for gestational age (i.e. a birthweight of less than the tenth customised centile), normotensive‐SGA and hypertensive‐SGA. Comparison groups for statistical analyses were non‐SGA, normotensive non‐SGA and hypertensive non‐SGA.
Results Among 376 (10.7%) SGA infants, 281 (74.7%) were normotensive‐SGA and 95 (25.3%) were hypertensive‐SGA. Independent risk factors for normotensive‐SGA were low maternal birthweight, low fruit intake pre‐pregnancy, cigarette smoking, increasing maternal age, daily vigorous exercise, being a tertiary student, head and abdominal circumference of less than the tenth centile and increasing uterine artery Doppler indices at the 20‐week scan. Protective factors were: high green leafy vegetable intake pre‐pregnancy, and rhesus‐negative blood group. Risk factors for hypertensive‐SGA were conception by in vitro fertilisation, previous early pregnancy loss and femur length of less than tenth centile at the 20‐week scan.
Conclusions Risk factors for infants who are SGA by customised centiles have been identified in a cohort of healthy nulliparous women. A number of these factors are modifiable; however, further studies are needed to replicate these findings.
This book presents an in-depth discussion of the biological and ecological geography of the oceans. It synthesizes locally restricted studies of the ocean to generate a global geography of the vast ...marine world.Based on patterns of algal ecology, the book divides the ocean into four primary compartments, which are then subdivided into secondary compartments.*Includes color insert of the latest in satellite imagery showing the world's oceans, their similarities and differences*Revised and updated to reflect the latest in oceanographic research*Ideal for anyone interested in understanding ocean ecology -- accessible and informative
Working together Poteete, Amy R; Janssen, Marco A; Ostrom, Elinor
2010., 20100412, 2010, 2010-04-12, 20100101
eBook
Advances in the social sciences have emerged through a variety of research methods: field-based research, laboratory and field experiments, and agent-based models. However, which research method or ...approach is best suited to a particular inquiry is frequently debated and discussed.Working Togetherexamines how different methods have promoted various theoretical developments related to collective action and the commons, and demonstrates the importance of cross-fertilization involving multimethod research across traditional boundaries. The authors look at why cross-fertilization is difficult to achieve, and they show ways to overcome these challenges through collaboration.
The authors provide numerous examples of collaborative, multimethod research related to collective action and the commons. They examine the pros and cons of case studies, meta-analyses, large-N field research, experiments and modeling, and empirically grounded agent-based models, and they consider how these methods contribute to research on collective action for the management of natural resources. Using their findings, the authors outline a revised theory of collective action that includes three elements: individual decision making, microsituational conditions, and features of the broader social-ecological context.
Acknowledging the academic incentives that influence and constrain how research is conducted,Working Togetherreworks the theory of collective action and offers practical solutions for researchers and students across a spectrum of disciplines.
Words made flesh Edwards, Rebecca
2012, 20120326, 2014, 2012-03-26, Letnik:
4
eBook, Book
During the early nineteenth century, schools for the deaf appeared in the United States for the first time. These schools were committed to the use of the sign language to educate deaf students. ...Manual education made the growth of the deaf community possible, for it gathered deaf people together in sizable numbers for the first time in American history. It also fueled the emergence of Deaf culture, as the schools became agents of cultural transformations. Just as the Deaf community began to be recognized as a minority culture, in the 1850s, a powerful movement arose to undo it, namely oral education. Advocates of oral education, deeply influenced by the writings of public school pioneer Horace Mann, argued that deaf students should stop signing and should start speaking in the hope that the Deaf community would be abandoned, and its language and culture would vanish. In this revisionist history, Words Made Flesh explores the educational battles of the nineteenth century from both hearing and deaf points of view. It places the growth of the Deaf community at the heart of the story of deaf education and explains how the unexpected emergence of Deafness provoked the pedagogical battles that dominated the field of deaf education in the nineteenth century, and still reverberate today.
Obsessive-compulsive disorder (OCD) is a common, debilitating neuropsychiatric illness with complex genetic etiology. The International OCD Foundation Genetics Collaborative (IOCDF-GC) is a ...multi-national collaboration established to discover the genetic variation predisposing to OCD. A set of individuals affected with DSM-IV OCD, a subset of their parents, and unselected controls, were genotyped with several different Illumina SNP microarrays. After extensive data cleaning, 1465 cases, 5557 ancestry-matched controls and 400 complete trios remained, with a common set of 469,410 autosomal and 9657 X-chromosome single nucleotide polymorphisms (SNPs). Ancestry-stratified case-control association analyses were conducted for three genetically-defined subpopulations and combined in two meta-analyses, with and without the trio-based analysis. In the case-control analysis, the lowest two P-values were located within DLGAP1 (P=2.49 × 10(-6) and P=3.44 × 10(-6)), a member of the neuronal postsynaptic density complex. In the trio analysis, rs6131295, near BTBD3, exceeded the genome-wide significance threshold with a P-value=3.84 × 10(-8). However, when trios were meta-analyzed with the case-control samples, the P-value for this variant was 3.62 × 10(-5), losing genome-wide significance. Although no SNPs were identified to be associated with OCD at a genome-wide significant level in the combined trio-case-control sample, a significant enrichment of methylation QTLs (P<0.001) and frontal lobe expression quantitative trait loci (eQTLs) (P=0.001) was observed within the top-ranked SNPs (P<0.01) from the trio-case-control analysis, suggesting these top signals may have a broad role in gene expression in the brain, and possibly in the etiology of OCD.
Abstract
A significant increase in treatment pace and scale is needed to restore dry western US forest resilience owing to increasingly frequent and severe wildfire and drought. We propose a ...pyrosilviculture approach to directly increase large-scale fire use and modify current thinning treatments to optimize future fire incorporation. Recommendations include leveraging wildfire’s “treatment” in areas burned at low and moderate severity with subsequent pyrosilviculture management, identifying managed wildfire zones, and facilitating and financing prescribed fire with “anchor,” “ecosystem asset,” and “revenue” focused thinning treatments. Pyrosilviculture would also expand prescribed-burn and managed-wildfire objectives to include reducing stand density, increasing forest heterogeneity, and selecting for tree species and phenotypes better adapted to changing climate and disturbance regimes. The potential benefits and limitations of this approach are discussed. Fire is inevitable in dry western US forests and pyrosilviculture focuses on proactively shifting more of that fire into managed large-scale burns needed to restore ecosystem resilience.
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