4,502 research outputs found
Spatial prioritisation of revegetation sites for dryland salinity management: an analytical framework using GIS
[Abstract]: To address the lack of analytical and modelling techniques in prioritising revegetation sites for dryland salinity management, a case study of the Hodgson Creek catchment in Queensland, Australia, was conducted. An analytical framework was developed, incorporating the use of spatial datasets (Landsat 7 image, DEM, soil map, and salinity map) which were processed using image processing techniques and a geographic information system (GIS). Revegetation sites were mapped and their priority determined based on recharge area, land use/cover and sub-catchment salinity. The analytical framework presented here enhances the systematic use of land information, widens the scope for scenario testing, and improves the testing of alternative revegetation options. The spatial patterns of revegetation sites could provide an additional set of information relevant in the design of revegetation strategies
Endometrial injury in women undergoing assisted reproductive techniques
ACKNOWLEDGEMENTS We would like to express our appreciation to Dra Abha Maheshwari for her important authorial contribution to the previous version of this review. We also acknowledge the important help provided by the Cochrane Menstrual Disorders and Subfertility Group team, specially by Marian Showell, Trials Search Co-ordinator; by Helen Nagels, Managing Editor; and by Prof. Cindy Farquhar, Co-ordinating Editor. Finally, we would like to express our gratitude to the following investigators, who provided essential information for the preparation of this review: TK Aleyamma, Erin F Wolff, Lukasz Polanski, Nava Dekel, Neeta Singh, Suleyman Guven and Tracy YeungPeer reviewedPublisher PD
Problem behavior and heart rate reactivity in adopted adolescents: Longitudinal and concurrent relations.
The present longitudinal study examined resting heart rate and heart rate variability and reactivity to a stressful gambling task in adopted adolescents with aggressive, delinquent, or internalizing behavior problems and adopted adolescents without behavior problems (total N=151). Early-onset delinquent adolescents showed heart rate hyporeactivity to the stress-eliciting gambling task compared to late-onset delinquent adolescents and adolescents without behavior problems. Heart rate, heart rate variability, and reactivity to stress were not related to environmental factors such as early-childhood parental sensitivity, parental socioeconomic status, or adoptee's health status at arrival. We conclude that the distinction between delinquency and aggression and between childhood-onset and adolescence-onset delinquency is important for the study of stress reactivity in adolescents. Copyright © 2008, Society for Research on Adolescence
Comparative Effects of Haemodialysis and Haemofiltration on Plasma Atrial Natriuretic Peptide
The effects of 4 h haemodialysis (15 patients) or 4 h haemofiltration (five patients) on plasma concentrations of atrial natriuretic peptide (ANP) were compared by means of a sensitive radioreceptor binding assay, and related to accompanying changes in body weight, blood pressure and plasma renin activity. Before dialysis, plasma ANP concentrations were considerably elevated: haemodialysis group 10-484 pmol/l (mean 156 pmol/l); haemofiltration group 72-320 pmol/l (mean 170 pmol/l). Although plasma concentrations of ANP fell markedly with treatment in both groups: post-haemodialysis 2-187 pmol/l (mean 67 pmol/l); post-haemofiltration 47-135 pmol/l (mean 79 pmol/l), after treatment it remained above the normal range in 14 of the 20 patients. Pretreatment plasma ANP was related to systolic blood pressure (r=0.459; P<0.05) but bore no relationship to mean or diastolic blood pressure, or plasma renin activity. The fall in plasma ANP concentration during treatment correlated with the postural blood pressure drop after dialysis (r=0.505; P<0.05), but was unrelated to changes in weight or plasma renin activity with haemodialysis or haemofiltration. Plasma ANP concentrations rose rapidly again in the 60 min after dialysis treatment, without change in body weight. These results show that high levels of biologically active ANP circulate in end-stage renal disease. The fact that these are not reduced to normal by haemodialysis or haemofiltration, despite restoration to normovolaemic or hypovolaemic state, suggests that the increased levels of ANP in end-stage renal failure are due to both hypervolaemia and other factors, which may include occult cardiac dysfunction and loss of renal clearanc
Decomposing socio-economic inequality in colorectal cancer screening uptake in England
Colorectal cancer (CRC) is the second largest cause of cancer death in the UK. Since 2010, CRC screening based on Faecal Occult Blood testing has been offered by the NHS in England biennially to all persons age 60-69 years. Several studies have demonstrated a gradient in uptake using area-level markers of socio-economic status (SES), but few have examined the individual-level contributors to the gradient. We aimed to quantify the extent of SES inequality in CRC screening uptake in England using individual-level data, and to identify individual factors associated with this inequality. We used data from 1833 participants (aged 61-69) in Wave 5 (collected in years 2010/11) of the English Longitudinal Study of Ageing (ELSA) eligible for having been sent at least one CRC screening invitation. Uptake was defined by self-report of ever having been screened as part of the National Screening Programme. We assessed socio-economic inequality using the corrected concentration index of uptake against SES rank, which was derived by regressing a range of SES markers against net non-pension household wealth. Other demographic and health-related variables were included in the analysis. Factors associated with inequality were measured using concentration index decomposition. There was a significant pro-rich gradient in screening uptake (concentration index: 0.16, 95% CI:0.11-0.22), mostly explained within our model by differences in non-pension wealth (38.7%), partner screening status (15.9%), sickness/disability (13.5%), and health literacy (8.5%). Interventions aimed at reducing inequalities in CRC screening uptake should focus on improving acceptability of screening in populations with low levels of education and literacy barriers
Anger provocation increases limbic and decreases medial prefrontal cortex connectivity with the left amygdala in reactive aggressive violent offenders
New Insights into Uniformly Accelerated Detector in a Quantum Field
We obtained an exact solution for a uniformly accelerated Unruh-DeWitt
detector interacting with a massless scalar field in (3+1) dimensions which
enables us to study the entire evolution of the total system, from the initial
transient to late-time steady state. We find that the Unruh effect as derived
from time-dependent perturbation theory is valid only in the transient stage
and is totally invalid for cases with proper acceleration smaller than the
damping constant. We also found that, unlike in (1+1)D results, the (3+1)D
uniformly accelerated Unruh-DeWitt detector in a steady state does emit a
positive radiated power of quantum nature at late-times, but it is not
connected to the thermal radiance experienced by the detector in the Unruh
effect proper.Comment: 6 pages, invited talk given by SYL at the conference of International
Association for Relativistic Dynamics (IARD), June 2006, Storrs, Connecticut,
US
Clumps into Voids
We consider a spherically symmetric distribution of dust and show that it is
possible, under general physically reasonable conditions, for an overdensity to
evolve to an underdensity (and vice versa). We find the conditions under which
this occurs and illustrate it on a class of regular Lemaitre-Tolman-Bondi
solutions. The existence of this phenomenon, if verified, would have the result
that the topology of density contours, assumed fixed in standard structure
formation theories, would have to change and that luminous matter would not
trace the dark matter distribution so well.Comment: LaTeX, 17 pages, 4 figures. Submitted to GRG 20/4/200
ISUOG updated consensus statement on the impact of cfDNA aneuploidy testing on screening policies and prenatal ultrasound practice
Quantum field and uniformly accelerated oscillator
We present an exact treatment of the influences on a quantum scalar field in
its Minkowski vacuum state induced by coupling of the field to a uniformly
accelerated harmonic oscillator. We show that there are no radiation from the
oscillator in the point of view of a uniformly accelerating observer. On the
other hand, there are radiations in the point of view of an inertial observer.
It is shown that Einstein-Podolsky-Rosen (EPR) like correlations of Rindler
particles in Minkowski vacuum states are modified by a phase factor in front of
the momentum-symmetric Rindler operators. The exact quantization of a
time-dependent oscillator coupled to a massless scalar field was given.Comment: 28 pages, LaTe
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