101 research outputs found
The Journey Home: Flight Related Factors on Refugee Decisions to Return
Normative practice for forced displacement is to voluntarily repatriate refugees once conditions
are stable in the country of origin, which typically translates to the end of violence. However,
Syrian refugees have been returning over the past few years even though there is yet to be a
definitive end to the Syrian civil war. Therefore, this paper asks how refugees form decisions on
when and whether they should return despite ongoing violence and instability in their country
of origin? For now, we focus upon one part of the picture: how prior exposure to violence in the
country of origin affects their subsequent decision to return home from their host country. To
explore this relationship, we designed an original survey, implemented among Syrian refugees
hosted in Lebanon (N=2,000), to causally identify the effects of prior conflict exposure on
refugeesâ decisions to return. We find that Syrian refugees are more willing to leave Lebanon
and return home when they have prior experience of violence in Syria. We explain this initially
counterintuitive finding as reflecting that they better understand their tolerance to violence,
because they are âexpertsâ and are more capable of assessing risk. In contrast, refugees who
were not directly exposed to violence before fleeing their homes are more unsure of the threats
associated to returning and are unwilling, therefore, to accept the risk of doing so
The Journey Home: Flight Related Factors on Refugee Decisions to Return
The international refugee regime promotes voluntary repatriation as the preferred solution to
refugee crises. It is commonly held that it is safe for refugees to return once conditions are
stable in the country of origin, which typically translates to when the violence between combatants ceases. However, the empirical record suggests that refugee returns are far from uniform
in relationship to the presence or absence or level of violence in a conflict setting. In other
words, we know remarkably little about the conditions under which refugee returns actually
occur. In response to this shortfall in knowledge, we ask: how do refugees form decisions on
when and whether they should return despite ongoing violence and instability in their country
of origin? We focus upon one crucial part of the picture, in particular: how does prior exposure
to violence in the country of origin affect refugeesâ subsequent decisions to return? To explore
this relationship, we designed an original survey, implemented among 2,000 Syrian refugees
hosted in Lebanon to causally identify the effects of prior conflict exposure on refugeesâ decisions to return. We find that Syrian refugees are more willing to leave Lebanon and return
home when they have prior experience of violence in Syria. We explain this counter-intuitive
finding as a reflection of these particular refugees as âexpertsâ who are better able to understand
and assess their risk tolerance of violence. In contrast, refugees more removed from violence
before fleeing their homes harbor more uncertainty of the threats associated with returning and
are unwilling to accept the risk of doing so
Quantitative model for inferring dynamic regulation of the tumour suppressor gene p53
Background: The availability of various "omics" datasets creates a prospect of performing the study of genome-wide genetic regulatory networks. However, one of the major challenges of using mathematical models to infer genetic regulation from microarray datasets is the lack of information for protein concentrations and activities. Most of the previous researches were based on an assumption that the mRNA levels of a gene are consistent with its protein activities, though it is not always the case. Therefore, a more sophisticated modelling framework together with the corresponding inference methods is needed to accurately estimate genetic regulation from "omics" datasets.
Results: This work developed a novel approach, which is based on a nonlinear mathematical model, to infer genetic regulation from microarray gene expression data. By using the p53 network as a test system, we used the nonlinear model to estimate the activities of transcription factor (TF) p53 from the expression levels of its target genes, and to identify the activation/inhibition status of p53 to its target genes. The predicted top 317 putative p53 target genes were supported by DNA sequence analysis. A comparison between our prediction and the other published predictions of p53 targets suggests that most of putative p53 targets may share a common depleted or enriched sequence signal on their upstream non-coding region.
Conclusions: The proposed quantitative model can not only be used to infer the regulatory relationship between TF and its down-stream genes, but also be applied to estimate the protein activities of TF from the expression levels of its target genes
Speed has an effect on multiple-object tracking independently of the number of close encounters between targets and distractors
Multiple-object tracking (MOT) studies have shown that tracking ability declines as object speed increases. However, this might be attributed solely to the increased number of times that target and distractor objects usually pass close to each other (âclose encountersâ) when speed is increased, resulting in more targetâdistractor confusions. The present study investigates whether speed itself affects MOT ability by using displays in which the number of close encounters is held constant across speeds. Observers viewed several pairs of disks, and each pair rotated about the pairâs midpoint and, also, about the center of the display at varying speeds. Results showed that even with the number of close encounters held constant across speeds, increased speed impairs tracking performance, and the effect of speed is greater when the number of targets to be tracked is large. Moreover, neither the effect of number of distractors nor the effect of targetâdistractor distance was dependent on speed, when speed was isolated from the typical concomitant increase in close encounters. These results imply that increased speed does not impair tracking solely by increasing close encounters. Rather, they support the view that speed affects MOT capacity by requiring more attentional resources to track at higher speeds
Lateral wedge insoles for reducing biomechanical risk factors for medial knee osteoarthritis progression : a systematic review and meta-analysis
Objective
Lateral wedge insoles are intended to reduce biomechanical risk factors of medial knee osteoarthritis (OA) progression, such as increased knee joint load; however, there has been no definitive consensus on this topic. The aim of this systematic review and meta-analysis was to establish the within-subject effects of lateral wedge insoles on knee joint load in people with medial knee OA during walking.
Methods
Six databases were searched from inception until February 13th 2015. Included studies reported on the acute biomechanical effects of lateral wedge insoles in people with medial knee osteoarthritis during walking. Primary outcomes of interest relating to the biomechanical risk of disease progression were the 1st and 2nd peak external knee adduction moment (EKAM) and knee adduction angular impulse (KAAI). Eligible studies were pooled using random-effects meta-analysis.
Results
Eighteen studies were included with a total of 534 participants. Lateral wedge insoles resulted in a small but statistically significant reduction in the 1st peak EKAM (SMD: -0.19; 95% CI -0.23 â -0.15) and 2nd peak EKAM (SMD: -0.25; 95% CI -0.32 â -0.19) with a low level of heterogeneity (I2 = 5% and 30%, respectively). There was a favourable but small reduction in the KAAI with lateral wedge insoles (SMD: -0.14; 95% CI -0.21 â -0.07, I2 =31%). Risk of methodological bias scores (Quality Index) ranged from 8 to 13 out of 16.
Conclusions
Lateral wedge insoles cause small reductions in the EKAM and KAAI in people with medial knee OA during walking. At present, they appear ineffective at attenuating structural changes in people with medial knee OA as a whole and may be better suited to targeted use in biomechanical phenotypes associated with larger reductions in knee load
Strongly magnetized pulsars: explosive events and evolution
Well before the radio discovery of pulsars offered the first observational
confirmation for their existence (Hewish et al., 1968), it had been suggested
that neutron stars might be endowed with very strong magnetic fields of
-G (Hoyle et al., 1964; Pacini, 1967). It is because of their
magnetic fields that these otherwise small ed inert, cooling dead stars emit
radio pulses and shine in various part of the electromagnetic spectrum. But the
presence of a strong magnetic field has more subtle and sometimes dramatic
consequences: In the last decades of observations indeed, evidence mounted that
it is likely the magnetic field that makes of an isolated neutron star what it
is among the different observational manifestations in which they come. The
contribution of the magnetic field to the energy budget of the neutron star can
be comparable or even exceed the available kinetic energy. The most magnetised
neutron stars in particular, the magnetars, exhibit an amazing assortment of
explosive events, underlining the importance of their magnetic field in their
lives. In this chapter we review the recent observational and theoretical
achievements, which not only confirmed the importance of the magnetic field in
the evolution of neutron stars, but also provide a promising unification scheme
for the different observational manifestations in which they appear. We focus
on the role of their magnetic field as an energy source behind their persistent
emission, but also its critical role in explosive events.Comment: Review commissioned for publication in the White Book of
"NewCompStar" European COST Action MP1304, 43 pages, 8 figure
The evolution of degenerative marrow (Modic) changes in the cervical spine in neck pain patients
PURPOSE: To evaluate the natural course of end plate marrow (Modic) changes (MC) in the cervical spine on MRI scans of patients with neck pain. A few longitudinal studies have assessed the development of MC over time in the lumbar spine but only two recent studies evaluated MC in the cervical spine in asymptomatic volunteers and those with whiplash. Thus, this study now reports on the natural course of MC in the cervical spine in symptomatic patients.
METHODS: From the cervical MRI scans of 426 neck pain patients (mean age 61.2Â years), 64 patients had follow-up MRI studies. The prevalence and types of MC were retrospectively assessed on the follow-up scans and compared to the original MRI findings.
RESULTS: With an average of 2.5Â years between the two MRI scans, the prevalence of MC type 1 (MC1) noted at baseline (7.4Â % or 19 motion segments) slightly increased (8.2Â % or 21 segments) but the prevalence of MC2 (14.5Â % or 37 segments) increased considerably (22.3Â % or 57 segments). In addition, 14 new MC1 segments and 8 new MC2 segments were noted. Twelve segments with MC1 at baseline converted to MC2 at follow-up. No conversion from MC2 to MC1 or reverting to a normal image was observed.
CONCLUSIONS: MC in the cervical spine are a dynamic phenomenon similar to the lumbar spine
Sentinel Node Identification Rate and Nodal Involvement in the EORTC 10981-22023 AMAROS Trial
Background
The randomized EORTC 10981-22023 AMAROS trial investigates whether breast cancer patients with a tumor-positive sentinel node biopsy (SNB) are best treated with an axillary lymph node dissection (ALND) or axillary radiotherapy (ART). The aim of the current substudy was to evaluate the identification rate and the nodal involvement.
Methods
The first 2,000 patients participating in the AMAROS trial were evaluated. Associations between the identification rate and technical, patient-, and tumor-related factors were evaluated. The outcome of the SNB procedure and potential further nodal involvement was assessed.
Results
In 65 patients, the sentinel node could not be identified. As a result, the sentinel node identification rate was 97% (1,888 of 1,953). Variables affecting the success rate were age, pathological tumor size, histology, year of accrual, and method of detection. The SNB results of 65% of the patients (n = 1,220) were negative and the patients underwent no further axillary treatment. The SNB results were positive in 34% of the patients (n = 647), including macrometastases (n = 409, 63%), micrometastases (n = 161, 25%), and isolated tumor cells (n = 77, 12%). Further nodal involvement in patients with macrometastases, micrometastases, and isolated tumor cells undergoing an ALND was 41, 18, and 18%, respectively.
Conclusions
With a 97% detection rate in this prospective international multicenter study, the SNB procedure is highly effective, especially when the combined method is used. Further nodal involvement in patients with micrometastases and isolated tumor cells in the sentinel node was similarâboth were 18%
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