296 research outputs found
Riparian ecotones and spatial variation of fish assemblages in Portuguese lowland streams
The first results of a long-term study on the role of riparian ecotones on the population and community
dynamics of Iberian stream fish are presented and discussed . Riparian and macrophyte cover, bank
slope and depth were among the most important variables affecting fish distribution . In general small
fish favoured shallow areas with high macrophyte cover, whereas large fish dominated in deep areas with
a high riparian cover . Slight spatial changes in terrestrial prey use were found suggesting a minor role
for this resource during autumn . Finally, no significant spatial differences were found for linear growth,
although some differences were obtained for the condition facto
Ant colony optimization with immigrants schemes for the dynamic railway junction rescheduling problem with multiple delays
Train rescheduling after a perturbation is a challenging task and is an important concern of the railway industry as delayed trains can lead to large fines, disgruntled customers and loss of revenue. Sometimes not just one delay but several unrelated delays can occur in a short space of time which makes the problem even more challenging. In addition, the problem is a dynamic one that changes over time for, as trains are waiting to be rescheduled at the junction, more timetabled trains will be arriving, which will change the nature of the problem. The aim of this research is to investigate the application of several different ant colony optimization (ACO) algorithms to the problem of a dynamic train delay scenario with multiple delays. The algorithms not only resequence the trains at the junction but also resequence the trains at the stations, which is considered to be a first step towards expanding the problem to consider a larger area of the railway network. The results show that, in this dynamic rescheduling problem, ACO algorithms with a memory cope with dynamic changes better than an ACO algorithm that uses only pheromone evaporation to remove redundant pheromone trails. In addition, it has been shown that if the ant solutions in memory become irreparably infeasible it is possible to replace them with elite immigrants, based on the best-so-far ant, and still obtain a good performance
Atividade física, qualidade de vida e depressão durante a gravidez
This study examines physical activity patterns among women, from pre-pregnancy to the second trimester of pregnancy, and the relationship between physical activity status based on physical activity guidelines and health-related quality of life (HRQoL) and depression over pregnancy. 56 healthy pregnant women self reported physical activity, HRQoL and depression at 10-15 and 19-24 weeks of pregnancy and physical activity before pregnancy. Whereas vigorous leisure physical activity decreased after conception, moderate leisure physical activity and work related physical activity remained stable over time. The prevalence of recommended physical activity was 39.3% and 12.5% in the 1st and 2nd trimesters of pregnancy respectively, and 14.3% pre-pregnancy. From the 1st to the 2nd pregnancy trimester, most
physical HRQoL dimensions scores decreased and only mental component increased, independently
of physical activity status. No changes in mean depression scores were observed. These data suggest
that physical activity patterns change with pregnancy and that physical and mental components
are differentially affected by pregnancy course, independently of physical activity status.Este estudo examina os padrões de atividade física antes
da concepção até o segundo trimestre de gravidez
e a relação entre o nível de atividade física, com base
nas recomendações de atividade física, a qualidade de
vida relacionada à saúde (QVRS) e depressão ao longo
da gravidez. Cinquenta e seis grávidas saudáveis reportaram
nível de atividade física, QVRS e depressão
às 10-15 e 19-24 semanas de gravidez, além de atividade
física antes da concepção. Enquanto a atividade
física vigorosa no lazer diminuiu depois da concepção,
as atividades físicas moderadas no lazer e no trabalho
mantiveram-se estáveis. A prevalência de atividade fí-
sica recomendada foi de 39,3%, 12,5% e 14,3% antes,
no primeiro e no segundo trimestres de gravidez, respectivamente.
Independentemente do estatuto de atividade
física, a maior parte dos escores nas dimensões
físicas da QVRS diminui do primeiro para o segundo
trimestre de gestação, e apenas o componente mental
aumenta. Não se verificaram alterações nos escores
médios de depressão. Estes dados sugerem que, com a
gravidez, há alteração nos padrões de atividade física;
além disso, os componentes físico e mental são diferentemente
afetados pelo curso da gestação, independentemente
do nível de atividade física
Positive functioning inventory: initial validation of a 12-item self-report measure of well-being
Background: This paper describes the validation of the Positive Functioning Inventory (PFI-12). This is a 12-item self-report tool developed to assess a spectrum of functioning ranging from states of mental distress to states of well-being.
Method: Two samples (Sample 1: N = 242, mean age = 20 years. Sample 2: N = 301, mean age = 20 years) completed self-report measures of personality and social, physical and psychological functioning.
Results: Evidence is provided for internal-consistency reliability, test-retest reliability, incremental validity, and convergent and discriminant validity in relation to a number of other measures of personality, social, physical and psychological functioning.
Conclusion: The tool promises to be useful to practitioners and researchers who wish to assess positive psychological functioning
Human and murine clonal CD8+ T cell expansions arise during tuberculosis because of TCR selection
The immune system can recognize virtually any antigen, yet T cell responses against several pathogens, including Mycobacterium tuberculosis, are restricted to a limited number of immunodominant epitopes. The host factors that affect immunodominance are incompletely understood. Whether immunodominant epitopes elicit protective CD8+ T cell responses or instead act as decoys to subvert immunity and allow pathogens to establish chronic infection is unknown. Here we show that anatomically distinct human granulomas contain clonally expanded CD8+ T cells with overlapping T cell receptor (TCR) repertoires. Similarly, the murine CD8+ T cell response against M. tuberculosis is dominated by TB10.44-11-specific T cells with extreme TCRß bias. Using a retro genic model of TB10.44-11-specific CD8+ Tcells, we show that TCR dominance can arise because of competition between clonotypes driven by differences in affinity. Finally, we demonstrate that TB10.4-specific CD8+ T cells mediate protection against tuberculosis, which requires interferon-? production and TAP1-dependent antigen presentation in vivo. Our study of how immunodominance, biased TCR repertoires, and protection are inter-related, provides a new way to measure the quality of T cell immunity, which if applied to vaccine evaluation, could enhance our understanding of how to elicit protective T cell immunity.This work was supported by the Portuguese Foundation for Science and Technology individual fellowship (CNA) www.fct.pt, a National Institutes of Health Grant R01 AI106725 (SMB) www.nih.gov, and a Center for AIDS Research Grant P30 AI 060354 (SMB) www.nih.gov. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Police performance measurement: an annotated bibliography
This study provides information to assist those involved in performance measurement in police organisations. The strategies used to identify the literature are described. Thematic sections cover; general overviews; methodological issues; performance management in other industries; national, international and cross-national studies; frameworks (e.g. Compstat; the Balanced Scorecard); criticisms (particularly unintended consequences); crime-specific measures; practitioner guides; performance evaluation of individual staff; police department plans and evaluations; annotated bibliographies in related areas, and; other literature. Our discussion offers two conclusions: the measures best aligned with performance are typically more expensive, while most operational data should only provide contextual information; the philosophy of open governance should be pursued to promote transparency, accountability and communication to improve police performance
Population ecology of the sea lamprey (Petromyzon marinus) as an invasive species in the Laurentian Great Lakes and an imperiled species in Europe
The sea lamprey Petromyzon marinus (Linnaeus) is both an invasive non-native species in the Laurentian Great Lakes of North America and an imperiled species in much of its native range in North America and Europe. To compare and contrast how understanding of population ecology is useful for control programs in the Great Lakes and restoration programs in Europe, we review current understanding of the population ecology of the sea lamprey in its native and introduced range. Some attributes of sea lamprey population ecology are particularly useful for both control programs in the Great Lakes and restoration programs in the native range. First, traps within fish ladders are beneficial for removing sea lampreys in Great Lakes streams and passing sea lampreys in the native range. Second, attractants and repellants are suitable for luring sea lampreys into traps for control in the Great Lakes and guiding sea lamprey passage for conservation in the native range. Third, assessment methods used for targeting sea lamprey control in the Great Lakes are useful for targeting habitat protection in the native range. Last, assessment methods used to quantify numbers of all life stages of sea lampreys would be appropriate for measuring success of control in the Great Lakes and success of conservation in the native range
Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.
Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability
Radiotherapy in the treatment of Graves ophthalmopathy—to do it or not?
To the objective of this study is to evaluate the role and toxicity of radiotherapy in the treatment of Graves ophthalmopathy. In the years 2000–2003, 121 patients with malignant exophthalmos were treated with radiotherapy of the retrobulbar area to the total dose of 20 Gy in ten fractions with a 6 MeV photon beam. The treatment was performed by the team of the Clinic of Oncology of the Jagiellonian University Medical College in Cracow. The radiotherapy was preceded by intravenous steroid therapy: methylprednisolone acetate administered at the dose of 2 g/week for four consecutive weeks. The highest efficacy, expressed as improvement of all ocular symptoms, was observed for the combined treatment. Female and non-diabetic patients responded positively to the combined treatment. Radiotherapy combined with steroid therapy in the treatment of Graves ophthalmopathy seems to be an effective treatment for strictly defined indications. In the treatment of Graves–Basedow disease, radiotherapy is a well-tolerated treatment modality. Diabetes is a factor that worsens prognosis in Graves ophthalmopathy and female sex is a favourable factor for this condition
The clinical meaningfulness of ADAS-Cog changes in Alzheimer's disease patients treated with donepezil in an open-label trial
Background: In 6-month anti-dementia drug trials, a 4-point change in the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) is held to be clinically important. We examined how this change compared with measures of clinical meaningfulness.
Methods: This is a secondary analysis of a 12 month open-label study of 100 patients (71 women) diagnosed with mild to moderate AD treated with 5–10 mg of donepezil daily. We studied the observed case, 6-month change from baseline on the ADAS-Cog, the Clinician's Interview Based Impression of Change-Plus Caregiver Input (CIBIC-Plus), patient-Goal Attainment Scaling (PGAS) and clinician-GAS (CGAS).
Results: At 6 months, donepezil-treated patients (n = 95) were more likely to show no change (+/ - 3 points) on the ADAS-Cog (56%) than to improve (20%) or decline (24%) by 4-points. ADAS- Cog change scores were little correlated with other measures: from -0.09 for PGAS to 0.27 for the CIBIC-Plus. While patients who improved on the ADAS-Cog were less likely to decline on the clinical measures (26%), 43% of patients who declined on the ADAS-Cog improved on at least two of the clinical measures.
Conclusion: The ADAS-Cog did not capture all clinically important effects. In general, ADAS-Cog improvement indicates clinical improvement, whereas many people with ADAS-Cog decline do not show clinical decline. The open-label design of this study does not allow us to know whether this is a treatment effect, which requires further investigation
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