4,989 research outputs found
Cluster randomised trials in the medical literature: two bibliometric surveys
Background: Several reviews of published cluster randomised trials have reported that about half did not take clustering into account in the analysis, which was thus incorrect and potentially misleading. In this paper I ask whether cluster randomised trials are increasing in both number and quality of reporting. Methods: Computer search for papers on cluster randomised trials since 1980, hand search of trial reports published in selected volumes of the British Medical Journal over 20 years. Results: There has been a large increase in the numbers of methodological papers and of trial reports using the term 'cluster random' in recent years, with about equal numbers of each type of paper. The British Medical Journal contained more such reports than any other journal. In this journal there was a corresponding increase over time in the number of trials where subjects were randomised in clusters. In 2003 all reports showed awareness of the need to allow for clustering in the analysis. In 1993 and before clustering was ignored in most such trials. Conclusion: Cluster trials are becoming more frequent and reporting is of higher quality. Perhaps statistician pressure works
Monocyte:T cell interaction regulates human T cell activation through a CD28/CD46 crosstalk
International audienc
Aerodynamic imaging by mosquitoes inspires a surface detector for autonomous flying vehicles
Some flying animals use active sensing to perceive and avoid obstacles. Nocturnal mosquitoes exhibit a behavioral response to divert away from surfaces when vision is unavailable, indicating a short-range, mechanosensory collision-avoidance mechanism. We suggest that this behavior is mediated by perceiving modulations of their self-induced airflow patterns as they enter a ground or wall effect. We used computational fluid dynamics simulations of low-altitude and near-wall flights based on in vivo high-speed kinematic measurements to quantify changes in the self-generated pressure and velocity cues at the sensitive mechanosensory antennae. We validated the principle that encoding aerodynamic information can enable collision avoidance by developing a quadcopter with a sensory system inspired by the mosquito. Such low-power sensing systems have major potential for future use in safer rotorcraft control systems
Indirect interaction between two native thistles mediated by an invasive exotic floral herbivore
Spatial and temporal variation in insect floral herbivory is common and often important. Yet, the determinants of such variation remain incompletely understood. Using 12 years of flowering data and 4 years of biweekly insect counts, we evaluated four hypotheses to explain variation in damage by the Eurasian flower head weevil, Rhinocyllus conicus, to the native North American wavyleaf thistle, Cirsium undulatum. The four factors hypothesized to influence weevil impact were variations in climate, weevil abundance, phenological synchrony, and number of flower heads available, either on wavyleaf thistle or on the other co-occurring, acquired native host plant (Platte thistle, Cirsium canescens), or on both. Climate did not contribute significantly to an explanation of variation in R. conicus damage to wavyleaf thistle. However, climate did influence weevil synchrony with wavyleaf flower head initiation, and phenological synchrony was important in determining R. conicus oviposition levels on wavyleaf thistle. The earlier R. conicus was active, the less it oviposited on wavyleaf thistle, even when weevils were abundant. Neither weevil abundance nor availability of wavyleaf flower heads predicted R. conicus egg load. Instead, the strongest predictor of R. conicus egg load on wavyleaf thistle was the availability of flower heads on Platte thistle, the more common, earlier flowering native thistle in the sand prairie. Egg load on wavyleaf thistle decreased as the number of Platte thistle flower heads at a site increased. Thus, wavyleaf thistle experienced associational defense in the presence of flowering by its now declining native congener, Platte thistle. These results demonstrate that prediction of damage to a native plant by an exotic insect may require knowledge of both likely phenological synchrony and total resource availability to the herbivore, including resources provided by other nontarget native species
Parenting Style and Suicidal Behavior: A Focused Review
Objectives. Parenting is the general child-rearing practice that has both long- and short-term impacts on the physical, emotional,
mental, and social development of the children. We aims at seeing the relationship between parenting style and suicidal behaviors.
Methods. A search was conducted in Medline, Embase, and PsychINFO to identify the articles assessing the relationship between
different types of parenting styles and suicidal behavior. We included 32 articles in the review published from inception to search
date. Results. Among the 32 studies, 27 studies used a cross-sectional study design, 17 were published between 2011 and 2020, and
most of the studies included respondents with ages between 9 and 21 years. A wide variety of the used instruments to assess
suicidal behavior, and parenting style was noted. Eight studies revealed that authoritarian parenting style is one of the
predictors of suicidal behavior, while one study reported the authoritarian parenting style as a resilient factor. Both dominating
and flexible parenting styles were associated with higher suicidal behavior, and two studies reported that the permissive style is
a contributing factor to suicidal ideation among participants. Conclusion. This review identified the supportive notion that
authoritarian parenting style has an association with suicidal behavior in adolescence, and later life. However, a prudential
judgment is warranted due to the heterogeneity of study methods, population, contexts, and measurement tools
Mycobacterium tuberculosis Responds to Chloride and pH as Synergistic Cues to the Immune Status of its Host Cell
PubMed ID: 23592993This 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 microaerophilic microbiota of de-novo paediatric inflammatory bowel disease: the BISCUIT study
<p>Introduction: Children presenting for the first time with inflammatory bowel disease (IBD) offer a unique opportunity to study aetiological agents before the confounders of treatment. Microaerophilic bacteria can exploit the ecological niche of the intestinal epithelium; Helicobacter and Campylobacter are previously implicated in IBD pathogenesis. We set out to study these and other microaerophilic bacteria in de-novo paediatric IBD.</p>
<p>Patients and Methods: 100 children undergoing colonoscopy were recruited including 44 treatment naïve de-novo IBD patients and 42 with normal colons. Colonic biopsies were subjected to microaerophilic culture with Gram-negative isolates then identified by sequencing. Biopsies were also PCR screened for the specific microaerophilic bacterial groups: Helicobacteraceae, Campylobacteraceae and Sutterella wadsworthensis.</p>
<p>Results: 129 Gram-negative microaerophilic bacterial isolates were identified from 10 genera. The most frequently cultured was S. wadsworthensis (32 distinct isolates). Unusual Campylobacter were isolated from 8 subjects (including 3 C. concisus, 1 C. curvus, 1 C. lari, 1 C. rectus, 3 C. showae). No Helicobacter were cultured. When comparing IBD vs. normal colon control by PCR the prevalence figures were not significantly different (Helicobacter 11% vs. 12%, p = 1.00; Campylobacter 75% vs. 76%, p = 1.00; S. wadsworthensis 82% vs. 71%, p = 0.312).</p>
<p>Conclusions: This study offers a comprehensive overview of the microaerophilic microbiota of the paediatric colon including at IBD onset. Campylobacter appear to be surprisingly common, are not more strongly associated with IBD and can be isolated from around 8% of paediatric colonic biopsies. S. wadsworthensis appears to be a common commensal. Helicobacter species are relatively rare in the paediatric colon.</p>
Conveying Audience Emotions through Humanoid Robot Gestures to an Orchestra during a Live Musical Exhibition
In the last twenty years, robotics have been applied in many
heterogeneous contexts. Among them, the use of humanoid robots during
musical concerts have been proposed and investigated by many authors.
In this paper, we propose a contribution in the area of robotics application
in music, consisting of a system for conveying audience emotions
during a live musical exhibition, by means of a humanoid robot. In particular,
we provide all spectators with a mobile app, by means of which
they can select a specific color while listening to a piece of music (act).
Each color is mapped to an emotion, and the audience preferences are
then processed in order to select the next act to be played. This decision,
based on the overall emotion felt by the audience, is then communicated
by the robot through body gestures to the orchestra. Our first results
show that spectators enjoy such kind of interactive musical performance,
and are encouraging for further investigations
Light Sneutrino Dark Matter at the LHC
In supersymmetric (SUSY) models with Dirac neutrino masses, a weak-scale
trilinear A-term that is not proportional to the small neutrino Yukawa
couplings can induce a sizable mixing between left and right-handed sneutrinos.
The lighter sneutrino mass eigenstate can hence become the lightest SUSY
particle (LSP) and a viable dark matter candidate. In particular, it can be an
excellent candidate for light dark matter with mass below ~10 GeV. Such a light
mixed sneutrino LSP has a dramatic effect on SUSY signatures at the LHC, as
charginos decay dominantly into the light sneutrino plus a charged lepton, and
neutralinos decay invisibly to a neutrino plus a sneutrino. We perform a
detailed study of the LHC potential to resolve the light sneutrino dark matter
scenario by means of three representative benchmark points with different
gluino and squark mass hierarchies. We study in particular the determination of
the LSP (sneutrino) mass from cascade decays involving charginos, using the mT2
variable. Moreover, we address measurements of additional invisible sparticles,
in our case the lightest neutralino, and the question of discrimination against
the MSSM.Comment: 25 pages, 16 figure
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