Propagation of charged particle waves in a uniform magnetic field

This paper considers the probability density and current distributions generated by a point-like, isotropic source of monoenergetic charges embedded into a uniform magnetic field environment. Electron sources of this kind have been realized in recent photodetachment microscopy experiments. Unlike the total photocurrent cross section, which is largely understood, the spatial profiles of charge and current emitted by the source display an unexpected hierarchy of complex patterns, even though the distributions, apart from scaling, depend only on a single physical parameter. We examine the electron dynamics both by solving the quantum problem, i. e., finding the energy Green function, and from a semiclassical perspective based on the simple cyclotron orbits followed by the electron. Simulations suggest that the semiclassical method, which involves here interference between an infinite set of paths, faithfully reproduces the features observed in the quantum solution, even in extreme circumstances, and lends itself to an interpretation of some (though not all) of the rich structure exhibited in this simple problem.Comment: 39 pages, 16 figure

Evaluation of adapted parent training for challenging behaviour in pre-school children with moderate to severe intellectual developmental disabilities: A randomised controlled trial

Copyright: \ua9 2024 Royston et al. This 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. OBJECTIVES: There is limited evidence on the effectiveness of parenting interventions to improve disruptive behaviour in children with intellectual developmental disabilities. This clinical trial evaluated whether an adapted group parenting intervention for preschool children with intellectual developmental disabilities who display challenging behaviour is superior to treatment as usual in England. STUDY DESIGN: 261 children aged 30-59 months with moderate to severe intellectual developmental disabilities and challenging behaviour were randomised to either the intervention (Stepping Stones Triple P) and treatment as usual or treatment as usual alone. The primary outcome was the parent-rated Child Behaviour Checklist at 52 weeks after randomisation. A health economic evaluation was also completed. RESULTS: We found no significant difference between arms on the primary outcome (mean difference -4.23; 95% CI: -9.99 to 1.53; p = 0.147). However, a subgroup analysis suggests the intervention was effective for participants randomised before the COVID-19 pandemic (mean difference -7.12; 95% CI: -13.44 to -0.81; p = 0.046). Furthermore, a complier average causal effects analysis (mean difference -11.53; 95% CI: -26.97 to 3.91; p = 0.143) suggests the intervention requires participants to receive a sufficient intervention dose. The intervention generated statistically significant cost savings (-\ua31,057.88; 95% CI -\ua33,218.6 to -\ua346.67) but the mean point estimate in Quality Adjusted Life Years was similar in both groups. CONCLUSION: This study did not find an effect of the intervention on reducing challenging behaviour, but this may have been influenced by problems with engagement. The intervention could be considered by services as an early intervention if families are supported to attend, especially given its low cost

Paradigm of tunable clustering using binarization of consensus partition matrices (Bi-CoPaM) for gene discovery

Copyright @ 2013 Abu-Jamous et al. This 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.Clustering analysis has a growing role in the study of co-expressed genes for gene discovery. Conventional binary and fuzzy clustering do not embrace the biological reality that some genes may be irrelevant for a problem and not be assigned to a cluster, while other genes may participate in several biological functions and should simultaneously belong to multiple clusters. Also, these algorithms cannot generate tight clusters that focus on their cores or wide clusters that overlap and contain all possibly relevant genes. In this paper, a new clustering paradigm is proposed. In this paradigm, all three eventualities of a gene being exclusively assigned to a single cluster, being assigned to multiple clusters, and being not assigned to any cluster are possible. These possibilities are realised through the primary novelty of the introduction of tunable binarization techniques. Results from multiple clustering experiments are aggregated to generate one fuzzy consensus partition matrix (CoPaM), which is then binarized to obtain the final binary partitions. This is referred to as Binarization of Consensus Partition Matrices (Bi-CoPaM). The method has been tested with a set of synthetic datasets and a set of five real yeast cell-cycle datasets. The results demonstrate its validity in generating relevant tight, wide, and complementary clusters that can meet requirements of different gene discovery studies.National Institute for Health Researc

Great Expectations: The role of the wig stylist (sheitel macher) in orthodox Jewish salons

Wigs are curious liminal objects that hover somewhere between the categories of prosthesis and clothing and offer a variety of possibilities from transformation to hair substitution, covering and disguise. In this article I focus on the particular demands and expectations placed upon the sheitel (Yiddish term for wig) worn by increasing numbers of married Jewish women who identify as frum (Torah-observant). Based on research in Jewish wig salons in Britain and the United States and on Jewish online forums, internet discussions and blogs with a wider geographic reach, this article sets out to show the complex web of material, social, emotional, aesthetic and moral concerns that cluster around the sheitel and to highlight the role of the sheitel macher (wig stylist) in managing these anxieties and expectations. If all wigs are fraught with expectations in terms of their capacity to enable successful social performances, sheitels, it is argued, carry a particularly high burden of expectations owing to their contested and multivalent role as material embodiments of religious commitment, social status and fashion competence and owing to the ambivalent feelings many Jewish women have towards their wigs

On reminder effects, drop-outs and dominance: evidence from an online experiment on charitable giving

We present the results of an experiment that (a) shows the usefulness of screening out drop-outs and (b) tests whether different methods of payment and reminder intervals affect charitable giving. Following a lab session, participants could make online donations to charity for a total duration of three months. Our procedure justifying the exclusion of drop-outs consists in requiring participants to collect payments in person flexibly and as known in advance and as highlighted to them later. Our interpretation is that participants who failed to collect their positive payments under these circumstances are likely not to satisfy dominance. If we restrict the sample to subjects who did not drop out, but not otherwise, reminders significantly increase the overall amount of charitable giving. We also find that weekly reminders are no more effective than monthly reminders in increasing charitable giving, and that, in our three months duration experiment, standing orders do not increase giving relative to one-off donations

The structure of the PapD-PapGII pilin complex reveals an open and flexible P5 pocket

P pili are hairlike polymeric structures that mediate binding of uropathogenic Escherichia coli to the surface of the kidney via the PapG adhesin at their tips. PapG is composed of two domains: a lectin domain at the tip of the pilus followed by a pilin domain that comprises the initial polymerizing subunit of the 1,000-plus-subunit heteropolymeric pilus fiber. Prior to assembly, periplasmic pilin domains bind to a chaperone, PapD. PapD mediates donor strand complementation, in which a beta strand of PapD temporarily completes the pilin domain's fold, preventing premature, nonproductive interactions with other pilin subunits and facilitating subunit folding. Chaperone-subunit complexes are delivered to the outer membrane usher where donor strand exchange (DSE) replaces PapD's donated beta strand with an amino-terminal extension on the next incoming pilin subunit. This occurs via a zip-in-zip-out mechanism that initiates at a relatively accessible hydrophobic space termed the P5 pocket on the terminally incorporated pilus subunit. Here, we solve the structure of PapD in complex with the pilin domain of isoform II of PapG (PapGIIp). Our data revealed that PapGIIp adopts an immunoglobulin fold with a missing seventh strand, complemented in parallel by the G1 PapD strand, typical of pilin subunits. Comparisons with other chaperone-pilin complexes indicated that the interactive surfaces are highly conserved. Interestingly, the PapGIIp P5 pocket was in an open conformation, which, as molecular dynamics simulations revealed, switches between an open and a closed conformation due to the flexibility of the surrounding loops. Our study reveals the structural details of the DSE mechanism

Evaluation of adapted parent training for challenging behaviour in pre-school children with moderate to severe intellectual developmental disabilities: a randomised controlled trial

Objectives: There is limited evidence on the effectiveness of parenting interventions to improve disruptive behaviour in children with intellectual developmental disabilities. This clinical trial evaluated whether an adapted group parenting intervention for preschool children with intellectual developmental disabilities who display challenging behaviour is superior to treatment as usual in England. Study design: 261 children aged 30–59 months with moderate to severe intellectual developmental disabilities and challenging behaviour were randomised to either the intervention (Stepping Stones Triple P) and treatment as usual or treatment as usual alone. The primary outcome was the parent-rated Child Behaviour Checklist at 52 weeks after randomisation. A health economic evaluation was also completed. Results: We found no significant difference between arms on the primary outcome (mean difference -4.23; 95% CI: -9.99 to 1.53; p = 0.147). However, a subgroup analysis suggests the intervention was effective for participants randomised before the COVID-19 pandemic (mean difference -7.12; 95% CI: -13.44 to -0.81; p = 0.046). Furthermore, a complier average causal effects analysis (mean difference -11.53; 95% CI: -26.97 to 3.91; p = 0.143) suggests the intervention requires participants to receive a sufficient intervention dose. The intervention generated statistically significant cost savings (-£1,057.88; 95% CI -£3,218.6 to -£46.67) but the mean point estimate in Quality Adjusted Life Years was similar in both groups. Conclusion: This study did not find an effect of the intervention on reducing challenging behaviour, but this may have been influenced by problems with engagement. The intervention could be considered by services as an early intervention if families are supported to attend, especially given its low cost

Machine Learning in Automated Text Categorization

The automated categorization (or classification) of texts into predefined categories has witnessed a booming interest in the last ten years, due to the increased availability of documents in digital form and the ensuing need to organize them. In the research community the dominant approach to this problem is based on machine learning techniques: a general inductive process automatically builds a classifier by learning, from a set of preclassified documents, the characteristics of the categories. The advantages of this approach over the knowledge engineering approach (consisting in the manual definition of a classifier by domain experts) are a very good effectiveness, considerable savings in terms of expert manpower, and straightforward portability to different domains. This survey discusses the main approaches to text categorization that fall within the machine learning paradigm. We will discuss in detail issues pertaining to three different problems, namely document representation, classifier construction, and classifier evaluation.Comment: Accepted for publication on ACM Computing Survey