96 research outputs found

    Generalized iterated wreath products of cyclic groups and rooted trees correspondence

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    Consider the generalized iterated wreath product Zr1Zr2Zrk\mathbb{Z}_{r_1}\wr \mathbb{Z}_{r_2}\wr \ldots \wr \mathbb{Z}_{r_k} where riNr_i \in \mathbb{N}. We prove that the irreducible representations for this class of groups are indexed by a certain type of rooted trees. This provides a Bratteli diagram for the generalized iterated wreath product, a simple recursion formula for the number of irreducible representations, and a strategy to calculate the dimension of each irreducible representation. We calculate explicitly fast Fourier transforms (FFT) for this class of groups, giving literature's fastest FFT upper bound estimate.Comment: 15 pages, to appear in Advances in the Mathematical Science

    Gender Differences in Clinical Presentation and Outcomes of Epidemic Kaposi Sarcoma in Uganda

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    The incidence of Kaposi sarcoma (KS) has increased dramatically among women in sub-Saharan Africa since the onset of the HIV pandemic, but data on KS disease in women are limited. To identify gender-related differences in KS presentation and outcomes, we evaluated the clinical manifestations and response in men and women with AIDS-associated KS in Uganda.HIV-infected adults with KS attending the Infectious Diseases Institute (IDI) and Uganda Cancer Institute (UCI) in Kampala, Uganda between 2004 and 2006 were included in a retrospective cohort. Evaluation of KS presentation was based on the clinical features described at the initial KS visit. Response was evaluated as the time to "improvement", as defined by any decrease in lesion size, lesion number, or edema. The cohort consisted of 197 adults with HIV and KS: 55% (108/197) were women. At presentation, the median CD4 T-cell count was significantly lower in women (58 cells/mm(3); IQR 11-156 cells/mm(3)) than men (124 cells/mm(3); IQR 22-254 cells/mm(3)) (p = 0.02). Women were more likely than men to present with lesions of the face (OR 2.8, 95% CI, 1.4, 5.7; p = 0.005) and hard palate (OR 2.0, 95% CI, 1.1, 3.7; p = 0.02), and were less likely than men to have lower extremity lesions (OR 0.54, 95% CI, 0.3, 0.99; p = 0.05). Women were less likely than men to demonstrate clinical improvement (HR = 0.52, CI 0.31, 0.88; p = 0.01) in multivariate analysis.The clinical presentation and response of KS differs between men and women in Uganda. These data suggest that gender affects the pathophysiology of KS, which may have implications for the prevention, diagnosis, and treatment of KS in both men and women. Prospective studies are needed to identify predictors of response and evaluate efficacy of treatment in women with KS, particularly in Africa where the disease burden is greatest

    Cancer patients' needs during hospitalisation: a quantitative and qualitative study

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    BACKGROUND: The evaluation of cancer patients needs, especially during that delicate period when they are hospitalized, allows the identification of those areas of care that require to be improved. Aims of the study were to evaluate the needs in cancer inpatients and to improve the understanding of the meanings of the needs expressed. METHODS: The study was conducted during a "sample day", with all the cancer patients involved having been hospitalized at the Istituto Nazionale Tumori of Milan (INT) for at least 48 hours beforehand. The study was carried out using quantitative and qualitative methodologies. The quantitative part of the study consisted in making use of the Needs Evaluation Questionnaire (NEQ), a standardized questionnaire administered by the INT Psychology Unit members, supported by a group of volunteers from the Milan section of the Italian League Against Cancer. The aim of the qualitative part of the study, by semi-structured interviews conducted with a small sample of 8 hospitalized patients, was to improve our understanding of the meanings, implications of the needs directly described from the point of view of the patients. Such an approach determines the reasons and conditions of the dissatisfaction in the patient, and provides additional information for the planning of improvement interventions. RESULTS: Of the 224 eligible patients, 182 (81%) completed the questionnaire. Four of the top five needs expressed by 40% or more of the responders concerned information needs (diagnosis, future conditions, dialogue with doctors, economic-insurance solutions related to the disease). Only one of the 5 was concerned with improved "hotel" services (bathrooms, meals, cleanliness). Qualitative analysis showed that the most expressed need (to receive more information on their future conditions) has the meaning to know how their future life will be affected more than to know his/her actual prognosis. CONCLUSIONS: Some of the needs which emerged from this investigation could be immediately satisfied (the need for psychological support, the need for economic aid, the need for spiritual support), while others will have to be faced in the longer term; for example, the presence of a high percentage of needs in patient-physician relationships and/or information-communication issues, could be resolved by setting up structured introductory training courses for all clinicians in the institution. On the other hand, the needs related to the living infrastructure (bathrooms, meals, etc...) could encourage the Institution to improve its services

    FluTE, a Publicly Available Stochastic Influenza Epidemic Simulation Model

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    Mathematical and computer models of epidemics have contributed to our understanding of the spread of infectious disease and the measures needed to contain or mitigate them. To help prepare for future influenza seasonal epidemics or pandemics, we developed a new stochastic model of the spread of influenza across a large population. Individuals in this model have realistic social contact networks, and transmission and infections are based on the current state of knowledge of the natural history of influenza. The model has been calibrated so that outcomes are consistent with the 1957/1958 Asian A(H2N2) and 2009 pandemic A(H1N1) influenza viruses. We present examples of how this model can be used to study the dynamics of influenza epidemics in the United States and simulate how to mitigate or delay them using pharmaceutical interventions and social distancing measures. Computer simulation models play an essential role in informing public policy and evaluating pandemic preparedness plans. We have made the source code of this model publicly available to encourage its use and further development

    Performance measures of the specialty referral process: a systematic review of the literature

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    <p>Abstract</p> <p>Background</p> <p>Performance of specialty referrals is coming under scrutiny, but a lack of identifiable measures impedes measurement efforts. The objective of this study was to systematically review the literature to identify published measures that assess specialty referrals.</p> <p>Methods</p> <p>We performed a systematic review of the literature for measures of specialty referral. Searches were made of MEDLINE and HealthSTAR databases, references of eligible papers, and citations provided by content experts. Measures were eligible if they were published from January 1973 to June 2009, reported on validity and/or reliability of the measure, and were applicable to Organization for Economic Cooperation and Development healthcare systems. We classified measures according to a conceptual framework, which underwent content validation with an expert panel.</p> <p>Results</p> <p>We identified 2,964 potentially eligible papers. After abstract and full-text review, we selected 214 papers containing 244 measures. Most measures were applied in adults (57%), assessed structural elements of the referral process (60%), and collected data via survey (62%). Measures were classified into non-mutually exclusive domains: need for specialty care (N = 14), referral initiation (N = 73), entry into specialty care (N = 53), coordination (N = 60), referral type (N = 3), clinical tasks (N = 19), resource use (N = 13), quality (N = 57), and outcomes (N = 9).</p> <p>Conclusions</p> <p>Published measures are available to assess the specialty referral process, although some domains are limited. Because many of these measures have been not been extensively validated in general populations, assess limited aspects of the referral process, and require new data collection, their applicability and preference in assessment of the specialty referral process is needed.</p

    A genetic locus and gene expression patterns associated with the priming effect on lettuce seed germination at elevated temperatures

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    Seeds of most cultivated varieties of lettuce (Lactuca sativa L.) fail to germinate at warm temperatures (i.e., above 25–30°C). Seed priming (controlled hydration followed by drying) alleviates this thermoinhibition by increasing the maximum germination temperature. We conducted a quantitative trait locus (QTL) analysis of seed germination responses to priming using a recombinant inbred line (RIL) population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. Priming significantly increased the maximum germination temperature of the RIL population, and a single major QTL was responsible for 47% of the phenotypic variation due to priming. This QTL collocated with Htg6.1, a major QTL from UC96US23 associated with high temperature germination capacity. Seeds of three near-isogenic lines (NILs) carrying an Htg6.1 introgression from UC96US23 in a Salinas genetic background exhibited synergistic increases in maximum germination temperature in response to priming. LsNCED4, a gene encoding a key enzyme (9-cis-epoxycarotinoid dioxygenase) in the abscisic acid biosynthetic pathway, maps precisely with Htg6.1. Expression of LsNCED4 after imbibition for 24 h at high temperature was greater in non-primed seeds of Salinas, of a second cultivar (Titan) and of NILs containing Htg6.1 compared to primed seeds of the same genotypes. In contrast, expression of genes encoding regulated enzymes in the gibberellin and ethylene biosynthetic pathways (LsGA3ox1 and LsACS1, respectively) was enhanced by priming and suppressed by imbibition at elevated temperatures. Developmental and temperature regulation of hormonal biosynthetic pathways is associated with seed priming effects on germination temperature sensitivity

    Trends in parameterization, economics and host behaviour in influenza pandemic modelling: a review and reporting protocol.

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    BACKGROUND: The volume of influenza pandemic modelling studies has increased dramatically in the last decade. Many models incorporate now sophisticated parameterization and validation techniques, economic analyses and the behaviour of individuals. METHODS: We reviewed trends in these aspects in models for influenza pandemic preparedness that aimed to generate policy insights for epidemic management and were published from 2000 to September 2011, i.e. before and after the 2009 pandemic. RESULTS: We find that many influenza pandemics models rely on parameters from previous modelling studies, models are rarely validated using observed data and are seldom applied to low-income countries. Mechanisms for international data sharing would be necessary to facilitate a wider adoption of model validation. The variety of modelling decisions makes it difficult to compare and evaluate models systematically. CONCLUSIONS: We propose a model Characteristics, Construction, Parameterization and Validation aspects protocol (CCPV protocol) to contribute to the systematisation of the reporting of models with an emphasis on the incorporation of economic aspects and host behaviour. Model reporting, as already exists in many other fields of modelling, would increase confidence in model results, and transparency in their assessment and comparison

    Applications of CRISPR–Cas systems in neuroscience

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    Genome-editing tools, and in particular those based on CRISPR-Cas (clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein) systems, are accelerating the pace of biological research and enabling targeted genetic interrogation in almost any organism and cell type. These tools have opened the door to the development of new model systems for studying the complexity of the nervous system, including animal models and stem cell-derived in vitro models. Precise and efficient gene editing using CRISPR-Cas systems has the potential to advance both basic and translational neuroscience research.National Institute of Mental Health (U.S.) (Grant 5DP1-MH100706)National Institute of Mental Health (U.S.) (Grant 1R01-MH110049)National Institute of Diabetes and Digestive and Kidney Diseases (U.S.) (Grant 5R01DK097768-03

    Community Violence and Youth: Affect, Behavior, Substance Use, and Academics

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    Community violence is recognized as a major public health problem (WHO, World Report on Violence and Health,2002) that Americans increasingly understand has adverse implications beyond inner-cities. However, the majority of research on chronic community violence exposure focuses on ethnic minority, impoverished, and/or crime-ridden communities while treatment and prevention focuses on the perpetrators of the violence, not on the youth who are its direct or indirect victims. School-based treatment and preventive interventions are needed for children at elevated risk for exposure to community violence. In preparation, a longitudinal, community epidemiological study, The Multiple Opportunities to Reach Excellence (MORE) Project, is being fielded to address some of the methodological weaknesses presented in previous studies. This study was designed to better understand the impact of children’s chronic exposure to community violence on their emotional, behavioral, substance use, and academic functioning with an overarching goal to identify malleable risk and protective factors which can be targeted in preventive and intervention programs. This paper describes the MORE Project, its conceptual underpinnings, goals, and methodology, as well as implications for treatment and preventive interventions and future research
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