Sexual dimorphism in the mandible of the armadillo Chaetophractus villosus (Desmarest, 1804) (Dasypodidae) from northern Patagonia, Argentina.

The aim of this study was to study the sexual dimorphism in adult Chaetophractus villosus (Desmarest, 1804), from northern Patagonia, Argentina. Eight mandibular traits were measured in 37 males and 34 females. Univariate and multivariate morphometric analysis were applied to the data set. Results showed that C. villosus was sexually dimorphic, with higher absolute values corresponding to females. The total length of the mandible was the most important variable to discriminate sexes, followed by the height at the level of the last tooth and body length. The percentages of sex discrimination were high, as they were when a new sample (17 males, 13 females) was tested. Females have larger mandibles than males independently of their larger cranial size. They also showed a higher degree of correlation between variables, suggesting a more stable shape for the mandible than in males.

Sexual dimorphism in the mandible of the armadillo Chaetophractus villosus (Desmarest, 1804) (Dasypodidae) from northern Patagonia, Argentina / Dimorfismo sexual da mandíbula do tatu Chaetophractus villosus (Desmarest, 1804) (Dasypodidae) do norte da Patagônia Argentina

The aim of this study was to study the sexual dimorphism in adult Chaetophractus villosus (Desmarest, 1804), from northern Patagonia, Argentina. Eight mandibular traits were measured in 37 males and 34 females. Univariate and multivariate morphometric analysis were applied to the data set. Results showed that C. villosus was sexually dimorphic, with higher absolute values corresponding to females. The total length of the mandible was the most important variable to discriminate sexes, followed by the height at the level of the last tooth and body length. The percentages of sex discrimination were high, as they were when a new sample (17 males, 13 females) was tested. Females have larger mandibles than males independently of their larger cranial size. They also showed a higher degree of correlation between variables, suggesting a more stable shape for the mandible than in males.

O presente estudo examinou o dimorfismo sexual dos adultos de Chaetophractus villosus (Desmarest, 1804) do norte da Patagônia Argentina. Oito parâmetros mandibulares foram medidos em 37 machos e 34 fêmeas. Análises morfométricas univariada e multivariada foram aplicadas à série de dados. Os resultados mostraram que C. villosus apresenta dimorfismo sexual, com todos os valores absolutos mais elevados nas fêmeas. O comprimento total da mandíbula foi a variável mais importante para discriminar os sexos, seguidos pela altura no nível dos últimos dentes e pelo comprimento do corpo da mandíbula. As porcentagens de discriminação dos sexos foram elevadas, quando uma amostra nova (17 machos, 13 fêmeas) foi testada. As fêmeas têm as mandíbulas maiores que os machos, independentemente de seu tamanho cranial maior. Mostraram também um grau mais elevado de correlação entre variáveis, sugerindo uma forma mais estável para a mandíbula que nos machos.

A CAD system for nodule detection in low-dose lung CTs based on region growing and a new active contour model.

A computer-aided detection (CAD) system for the selection of lung nodules in computer tomography (CT) images is presented. The system is based on region growing (RG) algorithms and a new active contour model (ACM), implementing a local convex hull, able to draw the correct contour of the lung parenchyma and to include the pleural nodules. The CAD consists of three steps: (1) the lung parenchymal volume is segmented by means of a RG algorithm; the pleural nodules are included through the new ACM technique; (2) a RG algorithm is iteratively applied to the previously segmented volume in order to detect the candidate nodules; (3) a double-threshold cut and a neural network are applied to reduce the false positives (FPs). After having set the parameters on a clinical CT, the system works on whole scans, without the need for any manual selection. The CT database was recorded at the Pisa center of the ITALUNG-CT trial, the first Italian randomized controlled trial for the screening of the lung cancer. The detection rate of the system is 88.5% with 6.6 FPs/CT on 15 CT scans (about 4700 sectional images) with 26 nodules: 15 internal and 11 pleural. A reduction to 2.47 FPs/CT is achieved at 80% efficiency.

Laparoscopic splenectomy for hematologic diseases: a preliminary analysis performed on the Italian Registry of Laparoscopic Surgery of the Spleen (IRLSS).

BACKGROUND: The Italian Registry of Laparoscopic Surgery of the Spleen (IRLSS) was developed to provide at the national level an informative tool useful for performing multicenter studies in the field of spleen laparoscopic surgery. In this first study analyzing the IRLSS data, a cohort of patients with hematologic diseases was retrospectively investigated for potential predictive parameters that could affect the outcome of laparoscopic splenectomy. METHODS: A total of 309 patients who underwent laparoscopic splenectomy for hematologic diseases in 17 Italian centers (between February 1, 1993, and September 30, 2004) were entered in the IRLSS. Their records were analyzed retrospectively by the Student's t-test, chi-square, and logistic regression. RESULTS: The mean operative time was 141 min (range, 30-420 min). Conversion was necessary in 21 cases (7%), and approximately 1 accessory spleen in 25 patients (9%) was found. The mean spleen weight was 1191 g (range, 85-4,500 g). Perioperative death occurred in two cases (0.6%). No complications were experienced by 253 patients (81.9%), who had a mean hospital stay of 5.4 days (range, 2-30 days). Overall morbidity occurred in 56 patients (18.1%), mainly associated with transient fever (n = 22), pleural effusion (n = 13), and actual or suspected hemorrhage (n = 12), requiring a reintervention for 7 patients. Multivariate analysis found that body mass index (p = 0.024) and clinical indication (p = 0.004) were independent predictors for surgical conversion. The clinical indication was almost significant as an independent predictor for the occurrence of postoperative complication (p = 0.05). CONCLUSIONS: This first study analyzing the IRLSS data shows that laparoscopic splenectomy may represent the gold standard treatment for hematologic diseases with normal-size spleen. The low morbidity and mortality rate suggests that laparoscopic splenectomy can be successfully proposed also for splenomegaly in hematologic malignancies.

Sleepiness in a population of Italian shiftwork policemen.

The aim of this study was to evaluate the effects of shiftwork on sleepiness, sleep disorders and sleep related accidents in a population of policemen. Data concerning age and physical characteristics, working conditions, sleep problems and accidents were collected by a questionnaire. Sleepiness was evaluated by the Epworth Sleepiness Scale (ESS) while the presence of sleep disorders was evaluated by a score (SD-score) drawn from indicators of insomnia, breathing disorders, periodic limb movements-restless leg syndrome and hypersomnia. The effects of age, gender, body mass index, working condition and seniority on ESS, SD-score and accidents were analysed by linear and logistic regression. Participants were 1280 policemen: 611 shiftworkers and 669 non-shiftworkers. The ESS scores were not higher in shiftworkers than in non-shiftworkers, but the SD-score was found to be significantly influenced by shiftwork condition and seniority. The occurrence of sleep-related accidents was found to have been significantly increased for shiftworkers and related to the presence of indicators of sleep disorders. The sleepiness could be underestimated or even overcome by the influence of stressing conditions. However our data should alert occupational health physicians for the diagnosis and prevention of possible lurking intrinsic sleep disorders likely to influence health problems and risk of accidents in shiftworkers.

Effect of macroscopic deformation on lung microstructure.

Using an anisotropic theory of diffuse light scattering in lungs, we measured the fractional changes in geometric mean linear intercepts in orthogonal directions when freshly excised rabbit lungs were subjected to isovolume uniaxial strains. Results from the optical technique were compared with morphometric estimates of fractional changes in mean linear intercepts from the same strained and unstrained (control) lobes, with the conclusion that diffuse light scattering is adequate to estimate changes in mean free paths in different directions. We compared optical estimates of fractional changes in mean linear intercepts with the macroscopic strain field measured by displacements of pleural markers; this relationship did not significantly differ from the line of identity. We conclude that the microscopic strain field is closely matched to the macroscopic strain field during uniaxial distortion. This suggests that surface reorientation may not play a large role in the origin of the low shear modulus of the lung, but this cannot be definitively stated without comparison of these experimental results to specific model predictions of the changes in mean linear intercepts in shear deformation.