Intra-specific pelage color variation in a South American small rodent species / Variação intraespecífica da cor da pelagem de uma espécie de pequeno roedor sul-americano

Intra-specific color variation is often underestimated by researchers, and among mammals, intra-specific differences in coloration are poorly documented for most species. The main goal of this study was to apply an objective color measurement methodology to the study of a specific problem: the detection, if any, of patterns of changes in the fur color of specimens of Akodon budini in relation to biological (i.e., sex) and environmental (i.e., season) variables. We hypothesize that coat color will be more homogeneous in males than in females and that coat color will be darker in winter than in summer, the latter being orange. We measured the pelage color on five points over the dorsal surface of 26 A. budini museum specimens using a spectroradiometer and a diffuse illumination cabin. We used Principal Component Analysis to describe the association between the color variables, sex and season, and each of the observations. We then used general linear models of Analysis of Variance to examine relationships between color data, season, and sex. The results clearly confirm the hypothesis related to seasonal coat color change but do not directly confirm the hypothesis related to changes in coat color in relation to sex, and we show the complexity of the studied pattern. In conclusion, undoubtedly, the studied variables should accordingly be considered when studying the coloration of specimens for characterization, identification and discrimination of different taxonomic units based on color.

Variação de cor intra-específica é muitas vezes subestimada pelos pesquisadores, e entre espécies de mamíferos, as diferenças intra-específicas na coloração são pouco conhecidas para a maioria das espécies. O principal objetivo deste estudo foi aplicar uma metodologia objetiva de medição de cor para o estudo de um problema específico: a detecção de padrões de mudanças na cor da pele de espécimes de Akodon budini em relação a variáveis biológicas (i.e., sexo) e ambientais (i.e., temporada), se houver. Nossa hipótese é que a cor da pelagem do sexo masculino será mais homogênea do que a de fêmeas e que a cor da pelagem do inverno vai ser mais escura do que a de verão, sendo esta última mais laranja. Medimos a cor da pelagem em cinco pontos sobre a superfície dorsal de 26 espécimes de museu de A. budini usando um espectroradiômetro e uma cabine de iluminação difusa. Usamos Análise de Componentes Principais para descrever a associação entre as variáveis de cor, sexo e temporada, e cada uma das observações. Em seguida, usamos modelos lineares gerais da Análise de Variância para verificar as relações entre os dados de cor, temporada, e sexo. Os resultados confirmam claramente a hipótese relacionada à mudança sazonal de cor da pelagem, mas não confirmam diretamente a hipótese relacionada com alterações na cor da pelagem em relação ao sexo, e vamos mostrar a complexidade do modelo estudado. Em conclusão, sem dúvida, as variáveis estudadas devem consequentemente ser tidas em conta quando se estuda a coloração de amostras para caracterização, identificação e discriminação de diferentes unidades taxonômicas com base na cor.

Intra-specific pelage color variation in a South American small rodent species / Variação intraespecífica da cor da pelagem de uma espécie de pequeno roedor sul-americano

Abstract Intra-specific color variation is often underestimated by researchers, and among mammals, intra-specific differences in coloration are poorly documented for most species. The main goal of this study was to apply an objective color measurement methodology to the study of a specific problem: the detection, if any, of patterns of changes in the fur color of specimens of Akodon budini in relation to biological (i.e., sex) and environmental (i.e., season) variables. We hypothesize that coat color will be more homogeneous in males than in females and that coat color will be darker in winter than in summer, the latter being orange. We measured the pelage color on five points over the dorsal surface of 26 A. budini museum specimens using a spectroradiometer and a diffuse illumination cabin. We used Principal Component Analysis to describe the association between the color variables, sex and season, and each of the observations. We then used general linear models of Analysis of Variance to examine relationships between color data, season, and sex. The results clearly confirm the hypothesis related to seasonal coat color change but do not directly confirm the hypothesis related to changes in coat color in relation to sex, and we show the complexity of the studied pattern. In conclusion, undoubtedly, the studied variables should accordingly be considered when studying the coloration of specimens for characterization, identification and discrimination of different taxonomic units based on color.

Resumo Variação de cor intra-específica é muitas vezes subestimada pelos pesquisadores, e entre espécies de mamíferos, as diferenças intra-específicas na coloração são pouco conhecidas para a maioria das espécies. O principal objetivo deste estudo foi aplicar uma metodologia objetiva de medição de cor para o estudo de um problema específico: a detecção de padrões de mudanças na cor da pele de espécimes de Akodon budini em relação a variáveis biológicas (i.e., sexo) e ambientais (i.e., temporada), se houver. Nossa hipótese é que a cor da pelagem do sexo masculino será mais homogênea do que a de fêmeas e que a cor da pelagem do inverno vai ser mais escura do que a de verão, sendo esta última mais laranja. Medimos a cor da pelagem em cinco pontos sobre a superfície dorsal de 26 espécimes de museu de A. budini usando um espectroradiômetro e uma cabine de iluminação difusa. Usamos Análise de Componentes Principais para descrever a associação entre as variáveis de cor, sexo e temporada, e cada uma das observações. Em seguida, usamos modelos lineares gerais da Análise de Variância para verificar as relações entre os dados de cor, temporada, e sexo. Os resultados confirmam claramente a hipótese relacionada à mudança sazonal de cor da pelagem, mas não confirmam diretamente a hipótese relacionada com alterações na cor da pelagem em relação ao sexo, e vamos mostrar a complexidade do modelo estudado. Em conclusão, sem dúvida, as variáveis estudadas devem consequentemente ser tidas em conta quando se estuda a coloração de amostras para caracterização, identificação e discriminação de diferentes unidades taxonômicas com base na cor.

Intra-specific pelage color variation in a South American small rodent species.

Intra-specific color variation is often underestimated by researchers, and among mammals, intra-specific differences in coloration are poorly documented for most species. The main goal of this study was to apply an objective color measurement methodology to the study of a specific problem: the detection, if any, of patterns of changes in the fur color of specimens of Akodon budini in relation to biological (i.e., sex) and environmental (i.e., season) variables. We hypothesize that coat color will be more homogeneous in males than in females and that coat color will be darker in winter than in summer, the latter being orange. We measured the pelage color on five points over the dorsal surface of 26 A. budini museum specimens using a spectroradiometer and a diffuse illumination cabin. We used Principal Component Analysis to describe the association between the color variables, sex and season, and each of the observations. We then used general linear models of Analysis of Variance to examine relationships between color data, season, and sex. The results clearly confirm the hypothesis related to seasonal coat color change but do not directly confirm the hypothesis related to changes in coat color in relation to sex, and we show the complexity of the studied pattern. In conclusion, undoubtedly, the studied variables should accordingly be considered when studying the coloration of specimens for characterization, identification and discrimination of different taxonomic units based on color.

Safety of SSRIs during pregnancy: a controlled study.

OBJECTIVE: The objective of our study was to analyze the efficacy and the safety of SSRIs during pregnancy. METHODS: A group of 30 pregnant women affected by Major Depressive Disorder by SCID I interview (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Text Revision criteria) and treated with selective serotonin reuptake inhibitor (SSRI) were included in the study. They were matched to a comparison group of 26 pregnant women. RESULTS: There were no statistically significant differences in any of the pregnancy outcomes of interest between the treated women and comparison group. There was no statistically significant association in newborns of women treated with an SSRI and the control group in the first and fifth minute Apgar score, and no newborns were admitted to neonatal Intensive Care Units. CONCLUSIONS: No definitive association between use of SSRIs during pregnancy and an increased risk of birth defects or other adverse outcomes could be found.

Current indications for laparoscopy in day-case surgery.

Day-surgery setting allows to combine patients' satisfaction to cost-saving policies that seems to be more and more important for a modern hospital management. Minimally invasive surgery seems to be the ideal surgical approach for day-case procedures since, reducing trauma to a minimal level, allows patients to return quick to a normal life with minimal nursing assistance. Extensive review of the most recent article has been performed in this article in order to define the current evidences that support the use of laparoscopic surgery in a day-case setting. Laparoscopic cholecystectomy, anti-reflux procedure and hernia repair seems to be justified according to the results of the published data. Patients' selection and hospital organization seem to be mandatory in order to obtain successful results.

Laparoscopic cholecystectomy as day-surgery procedure: current indications and patients' selection.

AIM OF THE STUDY: To review the current indications, to establish predictive factors of success and the safety of LC as a day-surgery procedure. METHODS: Randomized clinical trials were searched on PubMed between January 2000 and June 2008 using "laparoscopic cholecystectomy", "day-surgery" as keywords. RESULTS: A total of 20 trials was identified and analyzed. The indications for LC in day-surgery unit were symptomatic and chronic cholelitiasis without evidence of common bile duct stones; acute cholecystitis and pancreatitis cases were excluded. The trials considered as inclusion criteria: ASA score, BMI, social aspect and the preoperative workout included: abdominal US, liver function tests and routine preoperative tests, while the results considered the reasons for hospital stays and for readmission and measured patient satisfaction; some trials included analyze of costs of LC as day-surgery procedure the role of the surgeon's experience. DISCUSSION: The present study confirms that day-surgery LC is safe and feasibility in selected patients; serious complications are rare and most frequently prolonged hospital stay and the readmission are connected with minor and more easily controlled complications or social reasons. Outpatient surgery requires careful planning and preparation in order to reach acceptable patients' satisfaction: preoperative workout is extremely imports allowing to reduce errors selection. Considering surgical training, it has been demonstrated that in the centres in which the trainees are involved in day-surgery LC there not significant difference in terms of number of complications, patient outcomes, prolonged stay and readmission. The adequate control of pain, nausea or vomiting is essential component in day-case LC service and it is possible at home after LC. CONCLUSION: Day-case laparoscopic cholecystectomy is feasible with an acceptable discharge rate and level of patient satisfaction. The success depends on appropriate patient selection and on well-trained staff and skilful operative technique together with safe anaesthesia.

The time course of the lower threshold of motion during rapid events of adaptation.

To examine how the time course of rapid events of adaptation affect motion vision, the lower threshold of motion (LTM) was measured for suprathreshold sinusoidal gratings in presence of transient and steady glare. In the case of the transient condition, glare and stimulus were presented separated in time by a variable extent (SOA: 50-450 ms). A two alternative forced choice paradigm using the method of constant stimuli was adopted to measure the LTM. It was found that LTM follows the characteristic Crawford's time course of adaptation. Results are similar for two stimulus duration (300 and 500 ms). It was proposed that the increment of contrast threshold for displacing gratings (C(tq)) due to the loss of sensitivity produced by the sudden onset of the glare source can explain the results.