936 resultados para Individual behaviour
Change in individual growth rate and its link to gill-net fishing in two sympatric whitefish species
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Size-selective fishing is expected to affect traits such as individual growth rate, but the relationship between the fishery-linked selection differentials and the corresponding phenotypic changes is not well understood. We analysed a 25-year monitoring survey of sympatric populations of the two Alpine whitefish Coregonus albellus and C. fatioi. We determined the fishing-induced selection differentials on growth rates, the actual change of growth rates over time, and potential indicators of reproductive strategies that may change over time. We found marked declines in adult growth rate and significant selection differentials that may partly explain the observed declines. However, when comparing the two sympatric species, the selection differentials on adult growth were stronger in C. albellus while the decline in adult growth rate seemed more pronounced in C. fatioi. Moreover, the selection differential on juvenile growth was significant in C. albellus but not in C. fatioi, while a significant reduction in juvenile growth over the last 25 years was only found in C. fatioi. Our results suggest that size-selective fishing affects the genetics for individual growth in these whitefish, and that the link between selection differentials and phenotypic changes is influenced by species-specific factors.
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The toxic and behavioural effects of niclosamide (Bayluscide WP 70®) on Biomphalaria straminea from a highly endemic area of schistosomiasis in northeastern Brazil were investigated through laboratory bioassays. The LD50 and LD90 were 0.114 mg/l and 0.212 mg/l, respectively. Water-leaving behaviour occurred among 14% to 30% of the snails in the presence of sublethal doses of niclosamide and among 16% of the controls. It was concluded that both the relatively low susceptibility to niclosamide and water-leaving behaviour of local B. straminea may be responsible for the recolonization of transmission foci after mollusciciding. It was suggested that recently improved measures of snail control, such as controlled-release formulations of niclosamide and plant molluscicides should be considered in areas where snail control is recommended
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Intensification of farming over the past 50 years has homogenised the landscape structure and contributed to the decline of bird populations in Europe. To better target the conservation of the Barn Owl Tyto alba, we assessed the influence of the landscape structure on breeding performance in western Switzerland. The analyses considered a 23-year data set of breeding parameters collected in an area dominated by intensive agriculture. Using a Geographic Information System approach, landscape characteristics were described around 194 nest sites. Our analyses showed that nest-box occupancy, laying date, clutch and brood size, egg volume and probability of producing a second annual clutch were not significantly associated with any of the eight principal landscape variables (agricultural land, woodland, urban area, hedgerows, cereals, sugar beet, maize and meadow). Nevertheless, the probability that a breeding pair occupied a nest-box decreased the more roads there were surrounding the nest-box. The absence of strong associations between habitat features and breeding parameters suggests that prey availability may be relatively similar between the different breeding sites. In our study area Barn Owls can always find suitable foraging habitats around most nest-boxes.
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The following hypotheses were tested for groups of simultaneous hermaphrodites Biomphalaria tenagophila: (a) snails that have low reproductive success during the process of self-fertilization do not increase their reproductive success after the end of grouping; (b) the copulation behaviour and the presence of one snail whose eggs have a low viability rate influence the partner's reproductive success by cross-fertilization. Groups were constituted by a homozygous pigmented snail and two albinos: one with a viability rate higher than 70% ("good reproducers") and the other less than 10% ("bad reproducers"). All pigmented snails had viability rates higher than 70%. The "good" and "bad" reproducer albino snails had similar copulation behaviour. However, after the end of grouping, the "bad reproducers" continued to have viability rates less than 10% over 30 days. In 100% of the cases that pigmented snails copulated (performing either a male role or simultaneously male and female roles) exclusively with "good" reproducer albinos, they presented high reproductive success (producing, on average of 8.4 pigmented embryos/egg-mass). However, in 100% of the cases that pigmented snails copulated with both partners, the "good" reproducer albino snails produced none or very few embryos (the highest average was 2.2 pigmented embryos/egg-mass). Therefore, the production of viable embryos by cross-fertilization was more influenced by self-fertilization performance than by copulation behaviour. The presence of a snail whose eggs have a low viability rate could decrease their partners reproductive success
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An increasing number of studies have sprung up in recent years seeking to identify individual inventors from patent data. Different heuristics have been suggested to use their names and other information disclosed in patent documents in order to find out “who is who” in patents. This paper contributes to this literature by setting forth a methodology to identify them using patents applied to the European Patent Office (EPO hereafter). As in the large part of this literature, we basically follow a three-steps procedure: (1) the parsing stage, aimed at reducing the noise in the inventor’s name and other fields of the patent; (2) the matching stage, where name matching algorithms are used to group possible similar names; (3) the filtering stage, where additional information and different scoring schemes are used to filter out these potential same inventors. The paper includes some figures resulting of applying the algorithms to the set of European inventors applying to the EPO for a large period of time.
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In simultaneous hermaphrodites, gender conflicts that arise from two potential mates sharing the same gender preference may be solved through conditional reciprocity (or gamete trading). Conditional reciprocity had initially been considered widespread, but recent studies suggest that its real occurrence may have been overestimated, possibly because most mating observations have been performed on isolated pairs of individuals. Some resulting patterns (e. g., non-random alternation of sexual roles) were indeed compatible with conditional reciprocity but could also have stemmed from the two partners independently executing their own mating strategy and being experimentally enforced to do so with the same partner. Non-random alternation of gender roles was recently documented in the simultaneously hermaphroditic freshwater snail Physa acuta. To distinguish between conditional and unconditional gender alternations, we observed copulations of individually marked snails reared at three contrasted densities. We showed that density affected the overall frequency of copulations during the first 2 days of the experiment with high-density boxes showing more copulations than low density boxes, but it did not affect gender alternation patterns. A change in gender role was observed more often than expected by chance over two successive copulations by the same individual, confirming previous studies. However, gender switches did not preferentially occur with the same partner. We conclude that gender alternation is not due to conditional reciprocity in P. acuta. It may rather stem from each individual having a preference for gender alternation. We finally discuss the mechanisms and the potential extent of this unconditional reciprocity.
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The position of Muslims in Western societies is the subject of intense study and debate. However, remarkably little attention has been paid to the practice of European Muslims and how Muslim religiosity relates to conventional measures of social and economic integration. In this paper we draw on theories of secularization, assimilation, revitalization and integration to explore the correlates of attendance at religious meetings for Muslims of different backgrounds in the Netherlands and the UK. We conclude that patterns of religiosity and secularisation cannot be generalised across national contexts.
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The response to intra- and interspecific assembling signals was tested in three species of Chagas' disease vectors. As previously described for Triatoma infestans, larvae of both species, T. sordida and T. guasayana, aggregated on papers impregnated with their own excrement. Moreover, bugs belonging to each of the three species also aggregated on papers contaminated with faeces from the other two, with the only exception of the larvae of T. guasayana, which did not assemble on faeces of T. sordida. In all cases, the response to interspecific excrement was as strong as that to the intraspecific one. The non-specificity of the signal is discussed in the context of the ecological association of the three species and their role as vectors of Chagas' disease
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BACKGROUND: In patients with malignant pleural mesothelioma undergoing a multimodality therapy, treatment toxicity may outweigh the benefit of progression-free survival. The subjective experience across different treatment phases is an important clinical outcome. This study compares a standard with an individual quality of life (QoL) measure used in a multi-center phase II trial. PATIENTS AND METHODS: Sixty-one patients with stage I-III technically operable pleural mesothelioma were treated with preoperative chemotherapy, followed by pleuropneumonectomy and subsequent radiotherapy. QoL was assessed at baseline, at day 1 of cycle 3, and 1, 3 and 6 months post-surgery by using the Rotterdam Symptom Checklist (RSCL) and the Schedule for the Evaluation of Quality of Life-Direct Weighting (SEIQoL-DW), a measure that is based on five individually nominated and weighted QoL-domains. RESULTS: Completion rates were 98% (RSCL) and 92% (SEIQoL) at baseline and 98%/89% at cycle 3, respectively. Of the operated patients (N=45) RSCL and SEIQoL were available from 86%/72%, 93%/74%, and 94%/76% at months 1, 3, and 6 post-surgery. Average assessment time for the SEIQoL was 24min compared to 8min needed for the RSCL. Median changes from baseline indicate that both RSCL QoL overall score and SEIQoL index remained stable during chemotherapy with a clinically significant deterioration (change>or=8 points) 1 month after surgery (median change of -66 and -14 for RSCL and SEIQoL, respectively). RSCL QoL overall scores improved thereafter, but remained beneath baseline level until 6 months after surgery. SEIQoL scores improved to baseline-level at month 3 after surgery, but worsened again at month 6. RSCL QoL overall score and SEIQoL index were moderately correlated at baseline (r=.30; p<or=.05) and at 6-month follow-up (r=.42; p<or=.05) but not at the other time points. CONCLUSION: The SEIQoL assessment seems to be feasible within a phase II clinical trial, but may require more effort from staff. More distinctive QoL changes in accordance with clinical changes were measured with the RSCL. Our findings suggest that the two measures are not interchangeable: the RSCL is to favor when mainly information related to the course of disease- and treatment is of interest.
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INTRODUCTION: The phase III EORTC 22033-26033/NCIC CE5 intergroup trial compares 50.4 Gy radiotherapy with up-front temozolomide in previously untreated low-grade glioma. We describe the digital EORTC individual case review (ICR) performed to evaluate protocol radiotherapy (RT) compliance. METHODS: Fifty-eight institutions were asked to submit 1-2 randomly selected cases. Digital ICR datasets were uploaded to the EORTC server and accessed by three central reviewers. Twenty-seven parameters were analysed including volume delineation, treatment planning, organ at risk (OAR) dosimetry and verification. Consensus reviews were collated and summary statistics calculated. RESULTS: Fifty-seven of seventy-two requested datasets from forty-eight institutions were technically usable. 31/57 received a major deviation for at least one section. Relocation accuracy was according to protocol in 45. Just over 30% had acceptable target volumes. OAR contours were missing in an average of 25% of cases. Up to one-third of those present were incorrectly drawn while dosimetry was largely protocol compliant. Beam energy was acceptable in 97% and 48 patients had per protocol beam arrangements. CONCLUSIONS: Digital RT plan submission and review within the EORTC 22033-26033 ICR provide a solid foundation for future quality assurance procedures. Strict evaluation resulted in overall grades of minor and major deviation for 37% and 32%, respectively.
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The spider crab Maja squinado is an endangered Mediterranean species; therefore, culturing it successfully is essential for developing restocking programs. The survival, growth and development of post-larval stages (juvenile crabs, C1-C8) were studied using larvae obtained from adult individuals collected in the Catalan Sea. The juvenile crab stages were cultured individually from a megalopal stage using a semi-open recirculation system to obtain the precise growth data of each juvenile crab stage until C8. Development up to C8 at 20ºC lasted 154±10 days. Survival from C1 to C8 was 5.8 %. Moult increment values in cephothoracic length were similar in all the crab stages (21-35 %). Intermoult duration (9±1 in C1-C2 to 51±8 days in C7-C8) increased sharply from juvenile stage 5. Males and females can be distinguished from C4 based on sexual dimorphism in the pleopods and the presence of gonopores. The allometric growth of the pleon is sex-dependent from C4, with females showing positive allometry and males isometric growth. The juvenile growth rate was lower compared with that of the previously studied Atlantic species Maja brachydactyla.
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BACKGROUND: Community-acquired pneumonia (CAP) is a serious cause of morbidity among children in developed countries. The real impact of 7-valent pneumococcal conjugate vaccine (PCV7) on pneumococcal pneumonia is difficult to assess accurately. METHODS: Children aged ≤16 years with clinical and radiological pneumonia were enrolled in a multicenter prospective study. Children aged ≤16 years admitted for a minor elective surgery was recruited as controls. Nasopharyngeal samples for PCR serotyping of S. pneumoniae were obtained in both groups. Informations on age, gender, PCV7 vaccination status, day care/school attendance, siblings, tobacco exposure were collected. RESULTS: In children with CAP (n=236), 54% of the nasopharyngeal swabs were PCR-positive for S. pneumoniae compared to 32% in controls (n=105) (p=0.003). Serotype 19A was the most common pneumococcal serotype carried in children with CAP (13%) and in controls (15%). Most common serotypes were non-vaccine types (39.4% for CAP and 47.1% for controls) and serotypes included only in PCV13 (32.3% for CAP and 23.5% for controls). There was no significant difference in vaccine serotype distribution between the two groups. In fully vaccinated children with CAP, the proportion of serotypes carried only in PCV13 was higher (51.4%) than in partially vaccinated or non vaccinated children (27.6% and 28.6% respectively, p=0.037). CONCLUSIONS: Two to 4 years following introduction of PCV7, predominant S. pneumoniae serotypes carried in children with CAP were non PCV7 serotypes, and the 6 new serotypes included in PCV13 accounted for 51.4% of carried serotypes in fully vaccinated children.