The cave-like sense organ in the antennae of Triatominae bugs

In the second segment of the antennae of haematophagous reduviids an unusual cave-like organ is found the function os which was investigated in Triatoma infestans. the morphology of the organ makes it difficult to ascribe it to a mechno- or chemoreceptive function, but shows some characteristics shared with thermoreceptors of other animals. The electrical activity of sense cells was recorded in the presence of stimuli that evoke behavioural responses in this species, i.e. warm, CO2, lactic and butyric acids at different concentrations. The three compounds tested failed to evoke a response at all concentrations assayed. Only thermal stimulation evinced a clear modification in the electrical activity of the sense cells.Both the morphological and electrophysiological findings support a thermoreceptive finding, habitat selection and circadian synchronization.

Inflammatory response of endothelial cells to hepatitis C virus recombinant envelope glycoprotein 2 protein exposure

The hepatitis C virus (HCV) encodes approximately 10 different structural and non-structural proteins, including the envelope glycoprotein 2 (E2). HCV proteins, especially the envelope proteins, bind to cell receptors and can damage tissues. Endothelial inflammation is the most important determinant of fibrosis progression and, consequently, cirrhosis. The aim of this study was to evaluate and compare the inflammatory response of endothelial cells to two recombinant forms of the HCV E2 protein produced in different expression systems (Escherichia coli and Pichia pastoris). We observed the induction of cell death and the production of nitric oxide, hydrogen peroxide, interleukin-8 and vascular endothelial growth factor A in human umbilical vein endothelial cells (HUVECs) stimulated by the two recombinant E2 proteins. The E2-induced apoptosis of HUVECs was confirmed using the molecular marker PARP. The apoptosis rescue observed when the antioxidant N-acetylcysteine was used suggests that reactive oxygen species are involved in E2-induced apoptosis. We propose that these proteins are involved in the chronic inflammation caused by HCV.

Evaluating leaf litter beetle data sampled by Winkler extraction from Atlantic forest sites in southern Brazil

Evaluating leaf litter beetle data sampled by Winkler extraction from Atlantic forest sites in southern Brazil. To evaluate the reliability of data obtained by Winkler extraction in Atlantic forest sites in southern Brazil, we studied litter beetle assemblages in secondary forests (5 to 55 years after abandonment) and old-growth forests at two seasonally different points in time. For all regeneration stages, species density and abundance were lower in April compared to August; but, assemblage composition of the corresponding forest stages was similar in both months. We suggest that sampling of small litter inhabiting beetles at different points in time using the Winkler technique reveals identical ecological patterns, which are more likely to be influenced by sample incompleteness than by differences in their assemblage composition. A strong relationship between litter quantity and beetle occurrences indicates the importance of this variable for the temporal species density pattern. Additionally, the sampled beetle material was compared with beetle data obtained with pitfall traps in one old-growth forest. Over 60% of the focal species captured with pitfall traps were also sampled by Winkler extraction in different forest stages. Few beetles with a body size too large to be sampled by Winkler extraction were only sampled with pitfall traps. This indicates that the local litter beetle fauna is dominated by small species. Hence, being aware of the exclusion of large beetles and beetle species occurring during the wet season, the Winkler method reveals a reliable picture of the local leaf litter beetle community.

Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae)

Dichroplus maculipennis and Borellia bruneri are two of the 18 grasshopper species of actual or potential economic relevance as pests in Argentina. The objective of this study was to estimate the sex ratios for adults and older nymphs of D. maculipennis and B. bruneri in the field, and analyze possible temporal variations. The study was conducted during seven seasons (2005-06 to 2011-12) in representative plant communities of the southern Pampas region. A total of 4536 individuals of D. maculipennis, and 6038 individuals of B. bruneri were collected. The sex ratio registered in older nymphs for D. maculipennis and B. bruneri did not deviate from a 1:1 ratio (p > 0.05), suggesting that these species have such a primary sex ratio. However, a significant bias in sex composition in adults of both species was observed (p < 0.05). The sex ratio in adults of D. maculipennis was different in five of the 18 sampling dates carried out. In three sampling dates it was biased toward males, while in the other two it was biased toward females. Taking into account the sex ratio by sampling season, significant differences were recorded in two seasons. In 2007-08 the sex ratio was biased toward males (1 F:2.26 M), while in 2008-09 it was biased toward females (1.35 F:1 M). The sex ratio in adults of B. bruneri was always biased toward males (p < 0.05). We conclude that results obtained in this study indicate that various factors like differential survival, dispersion, predation, among others, could have modified the primary sex ratio in these species.

Determination of hydraulic properties of a tropical soil of Hawaii using column experiments and inverse modeling

A method for determining soil hydraulic properties of a weathered tropical soil (Oxisol) using a medium-sized column with undisturbed soil is presented. The method was used to determine fitting parameters of the water retention curve and hydraulic conductivity functions of a soil column in support of a pesticide leaching study. The soil column was extracted from a continuously-used research plot in Central Oahu (Hawaii, USA) and its internal structure was examined by computed tomography. The experiment was based on tension infiltration into the soil column with free outflow at the lower end. Water flow through the soil core was mathematically modeled using a computer code that numerically solves the one-dimensional Richards equation. Measured soil hydraulic parameters were used for direct simulation, and the retention and soil hydraulic parameters were estimated by inverse modeling. The inverse modeling produced very good agreement between model outputs and measured flux and pressure head data for the relatively homogeneous column. The moisture content at a given pressure from the retention curve measured directly in small soil samples was lower than that obtained through parameter optimization based on experiments using a medium-sized undisturbed soil column.

Anatomical variations of the celiac trunk and hepatic arterial system: an analysis using multidetector computed tomography angiography

Abstract Objective: To analyze the prevalence of anatomical variations of celiac arterial trunk (CAT) branches and hepatic arterial system (HAS), as well as the CAT diameter, length and distance to the superior mesenteric artery. Materials and Methods: Retrospective, cross-sectional and predominantly descriptive study based on the analysis of multidetector computed tomography images of 60 patients. Results: The celiac trunk anatomy was normal in 90% of cases. Hepatosplenic trunk was found in 8.3% of patients, and hepatogastric trunk in 1.7%. Variation of the HAS was observed in 21.7% of cases, including anomalous location of the right hepatic artery in 8.3% of cases, and of the left hepatic artery, in 5%. Also, cases of joint relocation of right and left hepatic arteries, and trifurcation of the proper hepatic artery were observed, respectively, in 3 (5%) and 2 (3.3%) patients. Mean length and caliber of the CAT were 2.3 cm and 0.8 cm, respectively. Mean distance between CAT and superior mesenteric artery was 1.2 cm (standard deviation = 4.08). A significant correlation was observed between CAT diameter and length, and CAT diameter and distance to superior mesenteric artery. Conclusion: The pattern of CAT variations and diameter corroborate the majority of the literature data. However, this does not happen in relation to the HAS.

Multidetector computed tomography angiography of the celiac trunk and hepatic arterial system: normal anatomy and main variants

Abstract Although digital angiography remains as the gold standard for imaging the celiac arterial trunk and hepatic arteries, multidetector computed tomography in association with digital images processing by software resources represents a useful tool particularly attractive for its non invasiveness. Knowledge of normal anatomy as well as of its variations is helpful in images interpretation and to address surgical planning on a case-by-case basis. The present essay illustrates several types of anatomical variations of celiac trunk, hepatic artery and its main branches, by means of digitally reconstructed computed tomography images, correlating their prevalence in the population with surgical implications.

A segunda lei da termodinâmica

Considering intrinsic characteristics of the system exclusively, both statistical and information theory interpretations of the second law are used to provide more comprehensive meanings for the concepts of entropy, temperature, and Helmholtz and Gibbs energies. The coherence of Clausius inequality to these concepts is emphasized. The aim of this work is to re-discuss the second law of thermodynamics in accordance to homogeneous processes thermodynamics, a temporal science which is the very special oversimplification of continuum mechanics for spatially constant intensive properties.

Origem e distribuição do nervo isquiático no veado-catingueiro (Mazama gouazoubira)

Este estudo teve como objetivo descrever a origem e a distribuição do nervo isquiático no veado-catingueiro (Mazama gouazoubira). Dois animais da espécie, obtidos post mortem por atropelamento em rodovia, foram utilizados para o estudo, obedecendo aos critérios da Lei Vigente (Lei 1.153/95). Através da dissecação, a pele foi completamente removida e os animais foram fixados em solução aquosa de formaldeído a 10%. Através de um acesso dorso-lateral, os músculos glúteo superficial, bíceps femoral e glúteo médio foram seccionados no seu local de inserção e rebatidos. Desta forma foi possível visualizar a origem e a distribuição do nervo isquiático, em ambos os antímeros dos animais. As imagens foram registradas com câmera fotográfica digital (Câmera Sony a200, 10.2mpx) e os resultados foram descritos com base na Nomina Anatômica Veterinária. Os dados da origem do nervo isquiático nos dois espécimes estudados mostraram que esta ocorre a partir dos ramos ventrais de L6 e S1, podendo ter contribuição de S2. Após a sua emergência pelo forame isquiático maior, em ambos os antímeros, o nervo isquiático fornece ramos para suprir os músculos glúteo médio, glúteo profundo, glúteo superficial, gluteobíceps, bíceps da coxa, semimembranoso, semitendinoso e gastrocnêmio. Próximo ao meio da coxa o nervo isquiático divide-se em nervo tibial e nervo fibular comum os quais inervam os músculos da região distal do membro pélvico. Além disso, o nervo cutâneo caudal da sura pode se originar dos nervos fibular comum ou do nervo tibial. Em conclusão, nos espécimes de Mazama gouazoubira estudados, o nervo isquiático teve sua origem a partir dos ramos ventrais espinais de L6 e S1, podendo ou não ter a contribuição de S2. Na sua distribuição originam-se o nervo glúteo caudal, o nervo cutâneo femoral caudal e ramos musculares, que, conjuntamente inervam os músculos glúteo médio, glúteo profundo, glúteo superficial, gluteobíceps, bíceps da coxa, semitendinoso, semimembranoso, adutor e gastrocnêmio. Distalmente o nervo isquiático bifurca-se Em nervo tibial e fibular comum, os quais inervam a porção distal do membro pélvico.

Distribuição dos brônquios lobares dos pulmões do veado-catingueiro Mazama gouazoubira

Este estudo teve como objetivo descrever a lobação do pulmão do veado-catingueiro Mazama gouazoubira. Dois animais da espécie, obtidos post mortem por atropelamento em rodovia, foram utilizados para o estudo, obedecendo aos critérios da Lei Vigente (Lei 1.153/95). Através da dissecação, a pele foi completamente removida e os animais foram fixados em solução de formaldeído a 10%. Através de um acesso ventral, o bloco de vísceras foi removido e posteriormente os pulmões foram dissecados do bloco por uma secção na região torácica da traqueia e de outras estruturas do hilo pulmonar. Os pulmões e a árvore brônquica foram dissecados, fotografados, as imagens foram registradas com câmera fotográfica digital (Câmera Sony a200, 10.2mpx). Os pulmões apresentaram-se unidos pelas estruturas que penetravam a região do hilo pulmonar, o pulmão direito do veado-catingueiro mostrou ser composto pelos lobos cranial (segmento cranial e segmento caudal), médio, caudal e acessório. O pulmão esquerdo apresentou apenas lobo cranial (segmentado em parte cranial e parte caudal) e lobo caudal. A árvore brônquica se inicia emergindo para o pulmão direito um brônquio traqueal acima da bifurcação da traqueia que sequencialmente serão denominados de brônquios principais direito e esquerdo, os quais no nível do hilo pulmonar penetram nos pulmões direito e esquerdo respectivamente. Os pulmões e árvore brônquica de M. gouazoubira apresentaram a mesma descrição anatômica de outros ruminantes, como bubalinos, ovinos e bovinos.