364 research outputs found
Induced disjoint paths in circular-arc graphs in linear time
The Induced Disjoint Paths problem is to test whether an graph G on n vertices with k distinct pairs of vertices (si,ti) contains paths P1,…,Pk such that Pi connects si and ti for i=1,…,k, and Pi and Pj have neither common vertices nor adjacent vertices (except perhaps their ends) for 1≤
Expanding the methodological toolbox of HRM researchers:The added value of latent bathtub models and optimal matching analysis
Researchers frequently rely on general linear models (GLMs) to investigate the impact of human resource management (HRM) decisions. However, the structure of organizations and recent technological advancements in the measurement of HRM processes cause contemporary HR data to be hierarchical and/or longitudinal. At the same time, the growing interest in effects at different levels of analysis and over prolonged periods of time further drives the need for HRM researchers to differentiate from traditional methodology. While multilevel techniques have become more common, this article proposes two additional methods that may complement the current methodological toolbox of HRM researchers. Latent bathtub models can accurately describe the multilevel mechanisms occurring in organizations, even if the outcome resides at the higher level of analysis. Optimal matching analysis can be useful to unveil longitudinal patterns in HR data, particularly in contexts where HRM processes are measured on a continuous basis. Illustrating the methods’ applicability to research on employee engagement, this paper demonstrates that the HRM community—both research and practice—can benefit from a more diversified methodological toolbox, drawing on techniques from within and outside the direct field to improve the decision-making process
Anomalous Negative Magnetoresistance Caused by Non-Markovian Effects
A theory of recently discovered anomalous low-field magnetoresistance is
developed for the system of two-dimensional electrons scattered by hard disks
of radius randomly distributed with concentration For small magnetic
fields the magentoresistance is found to be parabolic and inversely
proportional to the gas parameter, With increasing field the magnetoresistance becomes linear
in a good agreement with the
experiment and numerical simulations.Comment: 4 pages RevTeX, 5 figure
Hospital admissions, transfers and costs of guillain-Barré syndrome
Background Guillain-Barré syndrome (GBS) has a highly variable clinical course, leading to frequent transfers within and between hospitals and high associated costs. We defined the current admissions, transfers and costs in relation to disease severity of GBS. Methods Dutch neurologists were requested to report patients diagnosed with GBS between November 2009 and November 2010. Information regarding clinical course and transfers was obtained via neurologists and general practitioners. Results 87 GBS patients were included with maximal GBS disability score of 1 or 2 (28%), 3 or 4 (53%), 5 (18%) and 6 (1%). Four mildly affected GBS patients were not hospital admitted. Of the 83 hospitalized patients 68 (82%) were initially admitted at a neurology department, 4 (5%) at an ICU, 4 (5%) at pediatrics, 4 (5%) at pediatrics neurology and 3 (4%) at internal medicine. Median hospital stay was 17 days (IQR 11-26 days, absolute range 1-133 days). Transfers between departments or hospitals occurred in 33 (40%) patients and 25 (30%) were transferred 2 times or more. From a cost-effectiveness perspective 21 (25%) of the admissions was suboptimal. Median costs for hospital admission of GBS patients were 15,060 Euro (IQR 11,226-23,683). Maximal GBS disability score was significantly correlated with total length of stay, number of transfers, ICU admission and costs. Conclusions Hospital admissions for GBS patients are highly heterogeneous, with frequent transfers and higher costs for those with mo
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A simple method for integrating a complex model into an ensemble data assimilation system using MPI
This paper details a strategy for modifying the source code of a complex model so that the model may be used in a data assimilation context, {and gives the standards for implementing a data assimilation code to use such a model}. The strategy relies on keeping the model separate from any data assimilation code, and coupling the two through the use of Message Passing Interface (MPI) {functionality}. This strategy limits the changes necessary to the model and as such is rapid to program, at the expense of ultimate performance. The implementation technique is applied in different models with state dimension up to . The overheads added by using this implementation strategy in a coupled ocean-atmosphere climate model are shown to be an order of magnitude smaller than the addition of correlated stochastic random errors necessary for some nonlinear data assimilation techniques
Rational optimization of a short human P-selectin-binding peptide leads to nanomolar affinity antagonists
2400506
Efficient design and analysis of randomized controlled trials in rare neurological diseases: An example in Guillain-Barre syndrome
Background
Randomized controlled trials (RCTs) pose specific challenges in rare and heterogeneous neurological diseases due to the small numbers of patients and heterogeneity in disease course. Two analytical approaches have been proposed to optimally handle these issues in RCTs: covariate adjustment and ord
The proportion of postmenopausal breast cancer cases in the Netherlands attributable to lifestyle-related risk factors
We aimed to estimate the proportion of Dutch postmenopausal breast cancer cases in 2010 that is attributable to lifestyle-related risk factors. We calculated population attributable fractions (PAFs) of potentially modifiable risk factors for postmenopausal breast cancer in Dutch women aged >50 in 2010. First, age-specific PAFs were calculated for each risk factor, based on their relative risks for postmenopausal breast cancer (from meta-analyses) and age-specific prevalence in the population (from national surveys) around the year 2000, assuming a latency period of 10 years. To obtain the overall PAF, age-specific PAFs were summed in a weighted manner, using the age-specific breast cancer incidence rates (2010) as weights. 95 % confidence intervals for PAF estimates were derived by Monte Carlo simulations. Of Dutch women >40 years, in 2000, 51 % were overweight/obese, 55 % physically inactive (<5 days/week 30 min activity), 75 % regularly consumed alcohol, 42 % ever smoked cigarettes and 79 % had a low-fibre intake (<3.4 g/1000 kJ/day). These factors combined had a PAF of 25.7 % (95 % CI 24.2–27.2), corresponding to 2,665 Dutch postmenopausal breast cancer cases in 2010. PAFs were 8.8 % (95 % CI 6.3–11.3) for overweight/obesity, 6.6 % (95 % CI 5.2–8.0) for alcohol consumption, 5.5 % (95 % CI 4.0–7.0) for physical inactivity, 4.6 % (95 % CI 3.3–6.0) for smoking and 3.2 % (95 % CI 1.6–4.8) for low-fibre intake. Our findings imply that modifiable risk factors are jointly responsible for approximately one out of four Dutch postmenopausal breast cancer cases. This suggests that incidence rates can be lowered substantially by living a more healthy lifestyle
A reversion of an IL2RG mutation in combined immunodeficiency providing competitive advantage to the majority of CD8+ T cells
Mutations in the common gamma chain (γc, CD132, encoded by the IL2RG gene) can lead to B+T-NK-X-linked severe combined immunodeficiency, as a consequence of unresponsiveness to γc-cytokines such as interleukins-2, -7 and -15. Hypomorphic mutations in CD132 may cause combined immunodeficiencies with a variety of clinical presentations. We analyzed peripheral blood mononuclear cells of a 6-year-old boy with normal lymphocyte counts, who suffered from recurrent pneumonia and disseminated mollusca contagiosa. Since proliferative responses of T cells and NK cells to γc -cytokines were severely impaired, we performed IL2RG gene analysis, showing a heterozygous mutation in the presence of a single X-chromosome. Interestingly, an IL2RG reversion to normal predominated in both naïve and antigen-primed CD8+ T cells and increased over time. Only the revertant CD8+T cells showed normal expression of CD132 and the various CD8+T cell populations had a different T-cell receptor repertoire. Finally, a fraction of γδ+T cells and differentiated CD4+CD27-effector-memory T cells carried the reversion, whereas NK or B cells were repeatedly negative. In conclusion, in a patient with a novel IL2RG mutation, gene-reverted CD8+T cells accumulated over time. Our data indicate that selective outgrowth of particular T-cell subsets may occur following reversion at the level of committed T progenitor cells
Water Management Solution of Reservoir Storage Function Under Condition of Measurement Uncertainties in Hydrological Input Data
AbstractThe paper describes a possible procedure of the rate uncertainty implementation to the continuous water stage measurement and uncertainties of state - discharge rating curve point positions, which the stage -discharge rating curves were fitted into the uncertainties of the real discharge series members. Then the members of discharge series under uncertainty impact were tested on the calculated values of the reservoir storage volume. The next step was the implementation of the uncertainties of the real discharge series members on the generation of the artificial discharge series of mean monthly discharge using the AR and ARMA generators and the determination of their impact on the calculated values of the reservoir storage volume
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