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Possible Trends (possible + trend)
Selected AbstractsThe equilibrium assumption in estimating the parameters of metapopulation modelsJOURNAL OF ANIMAL ECOLOGY, Issue 1 2000Atte Moilanen 1.,The construction of a predictive metapopulation model includes three steps: the choice of factors affecting metapopulation dynamics, the choice of model structure, and finally parameter estimation and model testing. 2.,Unless the assumption is made that the metapopulation is at stochastic quasi-equilibrium and unless the method of parameter estimation of model parameters uses that assumption, estimates from a limited amount of data will usually predict a trend in metapopulation size. 3.,This implicit estimation of a trend occurs because extinction-colonization stochasticity, possibly amplified by regional stochasticity, leads to unequal numbers of observed extinction and colonization events during a short study period. 4.,Metapopulation models, such as those based on the logistic regression model, that rely on observed population turnover events in parameter estimation are sensitive to the implicit estimation of a trend. 5.,A new parameter estimation method, based on Monte Carlo inference for statistically implicit models, allows an explicit decision about whether metapopulation quasi-stability is assumed or not. 6.,Our confidence in metapopulation model parameter estimates that have been produced from only a few years of data is decreased by the need to know before parameter estimation whether the metapopulation is in quasi-stable state or not. 7.,The choice of whether metapopulation stability is assumed or not in parameter estimation should be done consciously. Typical data sets cover only a few years and rarely allow a statistical test of a possible trend. While making the decision about stability one should consider any information about the landscape history and species and metapopulation characteristics. [source] Association between periodontal disease, bacterial vaginosis, and sexual risk behavioursJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 10 2010Emily Craig Zabor Zabor EC, Klebanoff M, Yu K, Zhang J, Nansel T, Andrews W, Schwebke J, Jeffcoat M. Association between periodontal disease, bacterial vaginosis, and sexual risk behaviours. J Clin Periodontol 2010; 37: 888,893. doi: 10.1111/j.1600-051X.2010.01593.x. Abstract Background: Both periodontal disease and bacterial vaginosis may cause adverse pregnancy outcomes. This study evaluated the association between periodontal disease and bacterial vaginosis. Materials and Methods: Data from 3569 women enrolled in the Longitudinal Study of Vaginal Flora were used. Periodontal disease, defined as greater than three sites with ,4 mm attachment loss, was assessed by specially calibrated hygienists at baseline. Positive bacterial vaginosis status was based on a Nugent Gram stain score ,7. Pairs of independent variables were compared with Pearson's ,2 and risk ratios were calculated through log-binomial regression. Results: Twenty-eight per cent of women with bacterial vaginosis had periodontal disease compared with 22% without , corresponding to 1.29 (95% CI: 1.13, 1.47) times greater risk of periodontal disease among women with bacterial vaginosis. In adjusted analysis the risk ratio dropped to 1.23 (95% CI: 1.08, 1.40). Receptive oral sex with an uncircumcised partner was associated with 1.28 times (95% CI: 0.97, 1.69) the risk for periodontal disease compared with receptive oral sex with a circumcised partner, though the association is not statistically significant. Conclusions: In this population, there is a small but significant association between periodontal disease and bacterial vaginosis and a possible trend between receptive oral sex with an uncircumcised partner and periodontal disease. [source] Where are z= 4 Lyman Break Galaxies?MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2006Results from conditional luminosity function models of luminosity-dependent clustering ABSTRACT Using the conditional luminosity function (CLF) , the luminosity distribution of galaxies in a dark matter halo , as a way to model galaxy statistics, we study how z= 4 Lyman Break Galaxies (LBGs) are distributed in dark matter haloes. For this purpose, we measure luminosity-dependent clustering of LBGs in the Subaru/XMM,Newton Deep Field by separating a sample of 16 920 galaxies to three magnitude bins in i, band between 24.5 and 27.5. Our model fits to data show a possible trend for more-luminous galaxies to appear as satellites in more-massive haloes; the minimum halo mass in which satellites appear is 3.9+4.1,3.5× 1012, 6.2+3.8,4.9× 1012 and 9.6+7.0,4.6× 1012 M, (1, errors) for galaxies with 26.5 < i, < 27.5, 25.5 < i, < 26.5 and 24.5 < i, < 25.5 mag, respectively. The satellite fraction of galaxies at z= 4 in these magnitude bins is 0.13,0.3, 0.09,0.22 and 0.03,0.14, respectively, where the 1, ranges account for differences coming from two different estimates of the z= 4 LF from the literature. To jointly explain the LF and the large-scale linear bias factor of z= 4 LBGs as a function of rest UV luminosity requires central galaxies to be brighter in UV at z= 4 than present-day galaxies in same dark matter mass haloes. Moreover, UV luminosity of central galaxies in haloes with total mass greater than roughly 1012 M, must decrease from z= 4 to today by an amount more than the luminosity change for galaxies in haloes below this mass. This mass-dependent luminosity evolution is preferred at more than 3, confidence level compared to a pure-luminosity evolution scenario where all galaxies decrease in luminosity by the same amount from z= 4 to today. The scenario preferred by the data is consistent with the ,downsizing' picture of galaxy evolution. [source] The promotion of green electricity in Europe: present and futureENVIRONMENTAL POLICY AND GOVERNANCE, Issue 4 2004Pablo del Río Public support schemes for electricity from renewable energy sources (RES-E) are undergoing a period of change. Two interrelated processes can be discerned at both the EU and member state (MS) levels. On the one hand, the RES-E Directive sets targets for consumption of renewable electricity for the year 2010 and opens the possibility that the European Commission sets a community support framework for RES-E promotion in the future. On the other hand, different types of support scheme have been and are used by countries in order to promote the deployment of renewable electricity. A move from tendering/bidding systems and feed-in tariffs to tradable green certificates can be observed in some MSs. This move may take place in the future in some other MSs while others will certainly continue to rely on their current scheme. This paper provides an overview and assessment of the instruments currently used to promote renewable electricity in Europe and considers some possible trends in the choice of support schemes in the future. Copyright © 2004 John Wiley &,Sons, Ltd and ERP,Environment. [source] SCL-90-R profiles in a sample of severely violent psychiatric inpatientsAGGRESSIVE BEHAVIOR, Issue 6 2002Stål Bjørkly Abstract A sample of 39 patients who had committed serious violent acts toward others were assessed with the revised Symptom Checklist (SCL-90-R). The SCL-90-R is a self-report symptom inventory for the measurement of psychopathology in psychiatric and medical patients. In addition to the patients' self-report, an observer-rated SCL-90-R was obtained. This was accomplished by letting one pair of nurses complete SCL-90-R ratings for each patient. The first aim of the study was to compare the SCL-90-R self-report scores of the patient sample with the psychiatric inpatient norms [Derogatis LR (1992): Clinical Psychometric Research Inc]. Another purpose of this study was to explore possible trends of discordance between the observer ratings and the self-reports of the study group. Always considering the limitations of the small sample, it was nevertheless also of interest to look for possible sex differences and differences between violent subgroups and between diagnostic groups in the self-reported scores as well as in the observer ratings. The most striking findings of the present study were that the self-reported scores were lower than the inpatient norms for SCL-90-R and that the patients' self-reported levels of distress were significantly lower than those found in the observer ratings. Underreporting of psychopathology as a marker of violence risk is discussed in light of these findings. In this study, women reported higher distress levels than men in the Interpersonal Sensitivity symptom dimension. There were no significant differences concerning SCL-90-R ratings between patients who had committed homicide, attempted homicide, or physically assaulted another person in a serious but not life-threatening way. Aggr. Behav. 28:446,457, 2002. © 2002 Wiley-Liss, Inc. [source] Trends in self-reported sleep duration and insomnia-related symptoms in Finland from 1972 to 2005: a comparative review and re-analysis of Finnish population samplesJOURNAL OF SLEEP RESEARCH, Issue 1 2008ERKKI KRONHOLM Summary A hypothesis concerning habitual sleep reduction and its adverse consequences among general population in modern societies has received wide publicity in the mass media, although scientific evidence supporting the hypothesis is scarce. Similarly, there is an extensively distributed belief, at least in Finland, that the prevalence of insomnia-related symptoms is increasing, but evidence for this is even sparser. These issues are important because of the known increased risk of mortality and health risks associated with sleep duration deviating from 7 to 8 h. To reveal possible trends in self-reported sleep duration and insomnia-related symptoms, we reanalyzed all available data from surveys carried out in Finland from 1972 to 2005. The main results were that a minor decrease of self-reported sleep duration has taken place in Finland, especially among working aged men. However, the size of the reduction (about 4%) was relatively small, approximately 5.5 min per each 10 years during the 33 years' time interval under study. The proportion of 7 h sleepers has increased and, correspondingly, the proportion of 8 h sleepers has decreased, but the extreme ends of the sleep duration distribution remained unchanged. Tentative evidence suggesting an increase in insomnia-related symptoms among working aged population during the last 10 years was found. In conclusion, the Finnish data during the past 33 years indicate a general decrease in self-reported sleep duration of about 18 min and an increase of sleep complaints, especially among the employed middle-aged population. [source] Conservation status and causes of decline of the threatened New Zealand Long-tailed Bat Chalinolobus tuberculatus (Chiroptera: Vespertilionidae)MAMMAL REVIEW, Issue 2 2000Colin F. J. O'Donnell ABSTRACT Historical anecdotes and preliminary monitoring since 1990 indicate that New Zealand Long-tailed Bats (Chalinolobus tuberculatus, Vespertilionidae) are now rare or absent at many sites where formerly they were common. Chalinolobus tuberculatus appeared to be common throughout New Zealand in the 1800s but by 1900,30 it was becoming scarce in many districts. Formal surveys in the South Island since 1990 either failed to find C. tuberculatus, or recorded bats in low numbers. Of eight sites where transect counts were undertaken, bats were recorded frequently at two sites (45,66% of counts; Eglinton and Dart Valleys), rarely at four sites (2.4,10.7% of counts), and were not recorded at the remaining two sites despite considerable survey effort. Of 10 sites where stationary counts using automatic detector units were used, no C. tuberculatus were recorded in three areas (153 nights combined), they were found rarely at six sites (2.1,21.0% of nights; 461 nights combined) and were recorded commonly only in the Eglinton Valley (85% of 120 nights). Assertions that C. tuberculatus are ,common' and that the conservation status is ,secure' are questionable and this review supports suggestions that the species should be classed as ,Vulnerable'. Possible causes of decline have been suggested including clearance and logging of lowland forests, predation by introduced mammals and owls, competition for roost sites by introduced mammals, birds and wasps, and human interference and disturbance at roosting sites. However, authors' claims have all been speculative and unsubstantiated. There has been no research undertaken to quantify these claims, and this is required urgently. The results of these preliminary surveys provide a new baseline against which future population trends might be compared. Increased effort using standardized monitoring techniques, applied at a national level, is required to confirm the possible trends and to help identify the best sites where conservation managers may attempt to restore the population level. [source] | |||||||||||||