2,027 research outputs found
An integer programming Model for the Hospitals/Residents Problem with Couples
The Hospitals/Residents problem with Couples (hrc) is a generalisation of the classical Hospitals/Residents problem (hr) that is important in practical applications because it models the case where couples submit joint preference lists over pairs of (typically geographically close) hospitals. In this paper we give a new NP-completeness result for the problem of deciding whether a stable matching exists, in highly restricted instances of hrc. Further, we present an Integer Programming (IP) model for hrc and extend it the case where preference lists can include ties. Further, we describe an empirical study of an IP model for HRC and its extension to the case where preference lists can include ties. This model was applied to randomly generated instances and also real-world instances arising from previous matching runs of the Scottish Foundation Allocation Scheme, used to allocate junior doctors to hospitals in Scotland
Integer programming methods for special college admissions problems
We develop Integer Programming (IP) solutions for some special college
admission problems arising from the Hungarian higher education admission
scheme. We focus on four special features, namely the solution concept of
stable score-limits, the presence of lower and common quotas, and paired
applications. We note that each of the latter three special feature makes the
college admissions problem NP-hard to solve. Currently, a heuristic based on
the Gale-Shapley algorithm is being used in the application. The IP methods
that we propose are not only interesting theoretically, but may also serve as
an alternative solution concept for this practical application, and also for
other ones
How many neurons are sufficient for perception of cortical activity?
Many theories of brain function assume that information is encoded and behaviour is controlled through sparse, distributed patterns of activity. It is therefore crucial to place a lower bound on the amount of neural activity that can drive behaviour and to understand how neuronal networks operate within these constraints. We use an all-optical approach to test this lower limit by driving behaviour with targeted two-photon optogenetic activation of small ensembles of L2/3 pyramidal neurons in mouse barrel cortex while using two-photon calcium imaging to record the impact on the local network. By precisely titrating the number of neurons in activated ensembles we demonstrate that the lower bound for detection of cortical activity is ~14 pyramidal neurons. We show that there is a very steep sigmoidal relationship between the number of activated neurons and behavioural output, saturating at only ~37 neurons, and that this relationship can shift with learning. By simultaneously measuring activity in the local network, we show that the activation of stimulated ensembles is balanced by the suppression of neighbouring neurons. This surprising behavioural sensitivity in the face of potent network suppression supports the sparse coding hypothesis and suggests that perception of cortical activity balances a trade-off between minimizing the impact of noise while efficiently detecting relevant signals
Systemic Sclerosis–Associated Interstitial Lung Disease: How to Incorporate Two Food and Drug Administration–Approved Therapies in Clinical Practice
Systemic sclerosis (SSc; scleroderma) has the highest individual mortality of all rheumatic diseases and interstitial lung disease (ILD) is among the leading causes of SSc-related death. Two drugs are now approved by the Food & Drug Administration (FDA) and indicated for slowing the rate of decline in pulmonary function in patients with SSc-ILD: nintedanib (a tyrosine kinase inhibitor) and tocilizumab (the first biologic agent targeting the interleukin-6 pathway in SSc). In addition, two generic drugs with cytotoxic and immunoregulatory activity, mycophenolate mofetil and cyclophosphamide, have shown comparable efficacy in a Phase II trial but are not FDA-approved for SSc-ILD. In light of the heterogeneity of the disease, the optimal therapeutic strategy in the management of patients with SSc-ILD is still to be determined. The objectives of this review are two-fold: (1) review the body of research focused on the diagnosis and treatment of SSc-ILD; and (2) propose a practical approach for diagnosis, stratification, management, and therapeutic decision-making in this clinical context. This review presents a practical classification of SSc patients in terms of disease severity (subclinical vs. clinical ILD) and associated risk of progression (low vs. high risk). The pharmacological and non-pharmacological options as first and second-line therapy, as well as potential combination approaches, are discussed in light of the recent approval of tocilizumab for SSc-ILD
The unique ethical challenges of conducting research in the rehabilitation medicine population
BACKGROUND: The broad topic of research ethics is one which has been relatively well-investigated and discussed. Unique ethical issues have been identified for such populations as pediatrics, where the issues of consent and assent have received much attention, and obstetrics, with concerns such as the potential for research to cause harm to the fetus. However, little has been written about ethical concerns which are relatively unique to the population of patients seen by the practitioner of rehabilitation medicine. DISCUSSION: This paper reviews unique ethical concerns in conducting research in this population, including decision-making capacity, communication, the potential for subject overuse, the timing of recruitment, hope for a cure and therapeutic misconception and the nature of the health care provider-research subject relationship. SUMMARY: Researchers in the area of rehabilitation medicine should be aware of some of the unique ethical challenges posed by this patient population and should take steps to address any potential concerns in order to optimize subject safety and ensure that studies meet current ethical guidelines and standards
Anthropometric indices of Gambian children after one or three annual rounds of mass drug administration with azithromycin for trachoma control.
BACKGROUND: Mass drug administration (MDA) with azithromycin, carried out for the control of blinding trachoma, has been linked to reduced mortality in children. While the mechanism behind this reduction is unclear, it may be due, in part, to improved nutritional status via a potential reduction in the community burden of infectious disease. To determine whether MDA with azithromycin improves anthropometric indices at the community level, we measured the heights and weights of children aged 1 to 4 years in communities where one (single MDA arm) or three annual rounds (annual MDA arm) of azithromycin had been distributed. METHODS: Data collection took place three years after treatment in the single MDA arm and one year after the final round of treatment in the annual MDA arm. Mean height-for-age, weight-for-age and weight-for-height z scores were compared between treatment arms. RESULTS: No significant differences in mean height-for-age, weight-for-age or weight-for-height z scores were found between the annual MDA and single MDA arms, nor was there a significant reduction in prevalence of stunting, wasting or underweight between arms. CONCLUSIONS: Our data do not provide evidence that community MDA with azithromycin improved anthropometric outcomes of children in The Gambia. This may suggest reductions in mortality associated with azithromycin MDA are due to a mechanism other than improved nutritional status
Spatially Explicit Data: Stewardship and Ethical Challenges in Science
Scholarly communication is at an unprecedented turning point created in part by the increasing saliency of data stewardship and data sharing. Formal data management plans represent a new emphasis in research, enabling access to data at higher volumes and more quickly, and the potential for replication and augmentation of existing research. Data sharing has recently transformed the practice, scope, content, and applicability of research in several disciplines, in particular in relation to spatially specific data. This lends exciting potentiality, but the most effective ways in which to implement such changes, particularly for disciplines involving human subjects and other sensitive information, demand consideration. Data management plans, stewardship, and sharing, impart distinctive technical, sociological, and ethical challenges that remain to be adequately identified and remedied. Here, we consider these and propose potential solutions for their amelioration
Prevalence of childhood and early adolescence mental disorders among children attending primary health care centers in Mosul, Iraq: a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Children and adolescents are more vulnerable to the affects of war and violence than adults. At the time of initiation of this study, nothing was known about the prevalence of childhood and early adolescence mental disorders. The aim of the present study is to measure the point prevalence of mental disorders among children of 1–15 years age in the city of Mosul, Iraq.</p> <p>Methods</p> <p>A cross-sectional study design was adopted. Four primary health care centers were chosen consecutively as a study setting. The subjects of the present study were mothers who came to the primary health care center for vaccination of their children. The chosen mothers were included by systematic sampling randomization. All children (aged 1–15) that each mother had were considered in the interview and examination.</p> <p>Results</p> <p>Out of 3079 children assessed, 1152 have childhood mental disorders, giving a point prevalence of 37.4%, with a male to female ratio of to 1.22:1. The top 10 disorders among the examined children are post-traumatic stress disorder (10.5%), enuresis (6%), separation anxiety disorder (4.3%), specific phobia (3.3%) stuttering and refusal to attend school (3.2% each), learning and conduct disorders (2.5% each), stereotypic movement (2.3%) and feeding disorder in infancy or early childhood (2.0%). Overall, the highest prevalence of mental disorders was among children 10–15 years old (49.2%) while the lowest was among 1–5 year olds (29.1%). Boys are more affected than girls (40.2% and 33.2%, respectively).</p> <p>Conclusion</p> <p>Childhood mental disorders are a common condition highly prevalent amongst the children and early adolescents in Mosul. Data from the present study mirrors the size of the problem in local community. Several points deserve attention, the most important of which include giving care at the community level, educating the public on mental health, involving communities and families, monitoring community mental health indicators, and providing treatment at primary health care level.</p
Diffusion Tensor Imaging and Tractography in Brown-Sequard Syndrome
This report illustrates the utility of DTI and DTT in delineating regions of cord injury in two patients with traumatic Brown-Sequard syndrome. Our results indicate that DTI provides clinically relevant information that supplements conventional MR imaging for patients with acute SCI
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Ribose 2′-O-methylation provides a molecular signature for the distinction of self and non-self mRNA dependent on the RNA sensor Mda5
The 5'-cap-structures of higher eukaryote mRNAs are ribose 2'-O-methylated. Likewise, a number of viruses replicating in the cytoplasm of eukayotes have evolved 2'-O-methyltransferases to modify autonomously their mRNAs. However, a defined biological role of mRNA 2'-O-methylation remains elusive. Here we show that viral mRNA 2'-O-methylation is critically involved in subversion of type-I-interferon (IFN-I) induction. We demonstrate that human and murine coronavirus 2'-O-methyltransferase mutants induce increased IFN-I expression, and are highly IFN-I sensitive. Importantly, IFN-I induction by 2'-O-methyltransferase-deficient viruses is dependent on the cytoplasmic RNA sensor melanoma differentiation-associated gene 5 (MDA5). This link between MDA5-mediated sensing of viral RNA and mRNA 2'-O-methylation suggests that RNA modifications, such as 2'-O-methylation, provide a molecular signature for the discrimination of self and non-self mRNA
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