RESUMO
Nests are essential constructions that determine fitness, yet their structure can vary substantially across bird species. While there is evidence supporting a link between nest architecture and the habitat a species occupies, we still ignore what ecological and evolutionary processes are linked to different nest types. Using information on 3175 species of songbirds, we show that-after controlling for latitude and body size-species that build domed nests (i.e. nests with a roof) have smaller ranges, are less likely to colonise urban environments and have potentially higher extinction rates compared to species with open and cavity nests. Domed nests could be a costly specialisation, and we show that these nests take more time to be built, which could restrict breeding opportunities. These diverse strands of evidence suggest that the transition from domed to open nests in passerines could represent an important evolutionary innovation behind the success of the largest bird radiation.
Assuntos
Aves Canoras , Animais , Evolução Biológica , Tamanho Corporal , Ecossistema , Comportamento de NidaçãoRESUMO
BACKGROUND: A high academic workload may have adverse consequences among university students. AIM: To design and validate an instrument to measure both real and perceived academic workload for health care students. MATERIAL AND METHODS: The questionnaire was designed based on a bibliographic revision and the conduction of two focus groups conformed by undergraduate students from a Faculty of Medicine. Afterwards, it was submitted to qualitative pre-tests. The final instrument consists of a self-applied questionnaire with both a characterization section (10 questions) and one concerning academic workload by subject and semester (five and two questions, respectively). A national and international panel of 14 experts evaluated the survey content's validity. The analysis was performed according to the Content Validity Ratio and the Content Validity Index. RESULTS: The complete instrument was validated with an 84% consensus between the judges. Each section of the instrument was approved separately with a 77% and a 94% agreement, respectively. After being individually analyzed by the judges, each question was validated. The wording of questions was improved taking the experts comments into consideration. CONCLUSIONS: The proposed instrument constitutes a contribution for the measurement of real and perceived academic workload for students.
Assuntos
Estudantes , Carga de Trabalho , Atenção à Saúde , Instalações de Saúde , Humanos , Inquéritos e QuestionáriosRESUMO
Background: A high academic workload may have adverse consequences among university students. Aim: To design and validate an instrument to measure both real and perceived academic workload for health care students. Material and Methods: The questionnaire was designed based on a bibliographic revision and the conduction of two focus groups conformed by undergraduate students from a Faculty of Medicine. Afterwards, it was submitted to qualitative pre-tests. The final instrument consists of a self-applied questionnaire with both a characterization section (10 questions) and one concerning academic workload by subject and semester (five and two questions, respectively). A national and international panel of 14 experts evaluated the survey content's validity. The analysis was performed according to the Content Validity Ratio and the Content Validity Index. Results: The complete instrument was validated with an 84% consensus between the judges. Each section of the instrument was approved separately with a 77% and a 94% agreement, respectively. After being individually analyzed by the judges, each question was validated. The wording of questions was improved taking the experts comments into consideration. Conclusions: The proposed instrument constitutes a contribution for the measurement of real and perceived academic workload for students.
Assuntos
Humanos , Estudantes , Carga de Trabalho , Inquéritos e Questionários , Atenção à Saúde , Instalações de SaúdeRESUMO
Many organisms use different antipredator strategies throughout their life, but little is known about the reasons or implications of such changes. For years, it has been suggested that selection by predators should favour uniformity in local warning signals. If this is the case, we would expect high resemblance in colour across life stages in aposematic animals where young and adults share similar morphology and habitat. In this study, we used shield bugs (Hemiptera: Pentatomoidea) to test whether colour and colour diversity evolve similarly at different life stages. Since many of these bugs are considered to be aposematic, we also combined multi-species analyses with predation experiments on the cotton harlequin bug to test whether there is evidence of selection for uniformity in colour across life stages. Overall, we show that the diversity of colours used by both life stages is comparable, but adults are more cryptic than nymphs. We also demonstrate that nymphs and adults of the same species do not tend to look alike. Experiments on our model system suggest that predators can generalise among life stages that look different, and exhibit strong neophobia. Altogether, our results show no evidence of selection favouring colour similarity between adults and nymphs in this speciose clade.
