947 research outputs found
Assessing risk of breast cancer in an ethnically South-East Asia population (results of a multiple ethnic groups study)
10.1186/1471-2407-12-529BMC Cancer12-BCMA
The circadian clock rephases during lateral root organ initiation in Arabidopsis thaliana
The endogenous circadian clock enables organisms to adapt their growth and development to environmental changes. Here we describe how the circadian clock is employed to coordinate responses to the key signal auxin during lateral root (LR) emergence. In the model plant, Arabidopsis thaliana, LRs originate from a group of stem cells deep within the root, necessitating that new organs emerge through overlying root tissues. We report that the circadian clock is rephased during LR development. Metabolite and transcript profiling revealed that the circadian clock controls the levels of auxin and auxin-related genes including the auxin response repressor IAA14 and auxin oxidase AtDAO2. Plants lacking or overexpressing core clock components exhibit LR emergence defects. We conclude that the circadian clock acts to gate auxin signalling during LR development to facilitate organ emergence
The Microscopic Origin of Residual Stress for Flat Self-Actuating Piezoelectric Cantilevers
In this study, flat piezoelectric microcantilevers were fabricated under low-stress Pb(Zr0.52Ti0.48)O3 (PZT) film conditions. They were analyzed using the Raman spectrum and wafer curvature methods. Based on the residual stress analysis, we found that a thickness of 1 Îźm was critical, since stress relaxation starts to occur at greater thicknesses, due to surface roughening. The (111) preferred orientation started to decrease when the film thickness was greater than 1 Îźm. The d33 value was closely related to the stress relaxation associated with the preferred orientation changes. We examined the harmonic response at different PZT cantilever lengths and obtained a 9.4-Îźm tip displacement at 3 Vp-p at 1 kHz. These analyses can provide a platform for the reliable operation of piezoelectric microdevices, potentially nanodevice when one needs to have simultaneous control of the residual stress and the piezoelectric properties
Differences in hip bone mineral density may explain the hip fracture pattern in osteoarthritic hips
Introduction In patients with osteoarthritis of the hip (OAH), trochanteric fractures are much more common than femoral neck fractures. One reason may be altered bone composition in the proximal femurs. OAH often leads to a fixed external rotation of the hip, leading to difficulties in positioning during DXA measurements. We compared BMD in OAH-affected legs and healthy legs
Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy
Background
A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets.
Methods
Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendallâs tau for dichotomous variables, or JonckheereâTerpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis.
Results
A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both pâ<â0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROCâ=â0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all pâ<â0.001).
Conclusion
We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty
Duration of fever and serious bacterial infections in children: a systematic review
Background: Parents of febrile children frequently contact primary care. Longer duration of fever has been related to increased risk for serious bacterial infections (SBI). However, the evidence for this association remains controversial. We assessed the predictive value of duration of fever for SBI. Methods: Studies from MEDLINE, Embase and Cochrane databases (from January 1991 to December 2009) were retrieved. We included studies describing children aged 2 months to 6 years in countries with high Haemophilus influenzae type b vaccination coverage. Duration of fever had to be studied as a predictor for serious bacterial infections. Results: Seven studies assessed the association between duration of fever and serious bacterial infections; three of these found a relationship. Conclusion: The predictive value of duration of fever for identifying serious bacterial infections in children remains inconclusive. None of these seven studies was performed in primary care. Studies evaluating the duration of fever and its predictive value in children in primary care are required
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Bengali translation and characterisation of four cognitive and trait measures for autism spectrum conditions in India
Background
Autism is characterised by atypical social-communicative behaviour and restricted range of interests and repetitive behaviours. These features exist in a continuum in the general population. Behavioural measures validated across cultures and languages are required to quantify the dimensional traits of autism in these social and non-social domains. Bengali is the seventh most spoken language in the world. However, there is a serious dearth of data on standard measures of autism-related social and visual cognition in Bengali.
Methods
Bengali translations of two measures related to social-communicative functioning (the Childrenâs Reading the Mind in the Eyes Test (RMET) and a facial emotion recognition test with stimuli taken from the Karolinska Directed Emotional Faces database), one measure of visual perceptual disembedding (the Embedded Figures Test), and a questionnaire measure (the Childrenâs Empathy Quotient) were tested in 25 children with autism spectrum conditions (ASC) and 26 control children (mean ageâ=â10.7 years) in Kolkata, India. Group differences were analysed by t test and multiple regression (after accounting for potential effects of gender, IQ, and age).
Results
Behavioural and trait measures were associated with group differences in the expected directions: ASC children scored lower on the Childrenâs Empathy Quotient and the RMET, as well as on facial emotion recognition, but were faster and more accurate on the Embedded Figures Test. Distributional properties of these measures within groups are similar to those reported in Western countries.
Conclusions
These results provide an empirical demonstration of cross-cultural generalisability and applicability of these standard behavioural and trait measures related to autism, in a major world language
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
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