Early and Late Pathogenic Events of Newborn Mice Encephalitis Experimentally Induced by Itacaiunas and Curionópolis Bracorhabdoviruses Infection

In previous reports we proposed a new genus for Rhabdoviridae and described neurotropic preference and gross neuropathology in newborn albino Swiss mice after Curionopolis and Itacaiunas infections. In the present report a time-course study of experimental encephalitis induced by Itacaiunas and Curionopolis virus was conducted both in vivo and in vitro to investigate cellular targets and the sequence of neuroinvasion. We also investigate, after intranasal inoculation, clinical signs, histopathology and apoptosis in correlation with viral immunolabeling at different time points. Curionopolis and Itacaiunas viral antigens were first detected in the parenchyma of olfactory pathways at 2 and 3 days post-inoculation (dpi) and the first clinical signs were observed at 4 and 8 dpi, respectively. After Curionopolis infection, the mortality rate was 100% between 5 and 6 dpi, and 35% between 8 and 15 dpi after Itacaiunas infection. We identified CNS mice cell types both in vivo and in vitro and the temporal sequence of neuroanatomical olfactory areas infected by Itacaiunas and Curionopolis virus. Distinct virulences were reflected in the neuropathological changes including TUNEL immunolabeling and cytopathic effects, more intense and precocious after intracerebral or in vitro inoculations of Curionopolis than after Itacaiunas virus. In vitro studies revealed neuronal but not astrocyte or microglial cytopathic effects at 2 dpi, with monolayer destruction occurring at 5 and 7 dpi with Curionopolis and Itacaiunas virus, respectively. Ultrastructural changes included virus budding associated with interstitial and perivascular edema, endothelial hypertrophy, a reduced and/or collapsed small vessel luminal area, thickening of the capillary basement membrane, and presence of phagocytosed apoptotic bodies. Glial cells with viral budding similar to oligodendrocytes were infected with Itacaiunas virus but not with Curionopolis virus. Thus, Curionopolis and Itacaiunas viruses share many pathological and clinical features present in other rhabdoviruses but distinct virulence and glial targets in newborn albino Swiss mice brain

Carcass persistence and detectability : reducing the uncertainty surrounding wildlife-vehicle collision surveys

Carcass persistence time and detectability are two main sources of uncertainty on roadkill surveys. In this study, we evaluate the influence of these uncertainties on roadkill surveys and estimates. To estimate carcass persistence time, three observers (including the driver) surveyed 114km by car on a monthly basis for two years, searching for wildlife-vehicle collisions (WVC). Each survey consisted of five consecutive days. To estimate carcass detectability, we randomly selected stretches of 500m to be also surveyed on foot by two other observers (total 292 walked stretches, 146 km walked). We expected that body size of the carcass, road type, presence of scavengers and weather conditions to be the main drivers influencing the carcass persistence times, but their relative importance was unknown. We also expected detectability to be highly dependent on body size. Overall, we recorded low median persistence times (one day) and low detectability (<10%) for all vertebrates. The results indicate that body size and landscape cover (as a surrogate of scavengers' presence) are the major drivers of carcass persistence. Detectability was lower for animals with body mass less than 100g when compared to carcass with higher body mass. We estimated that our recorded mortality rates underestimated actual values of mortality by 2±10 fold. Although persistence times were similar to previous studies, the detectability rates here described are very different from previous studies. The results suggest that detectability is the main source of bias across WVC studies. Therefore, more than persistence times, studies should carefully account for differing detectability when comparing WVC studies

Produtividade de híbridos de tomate submetidos ao cultivo superadensado Yield of tomato hybrids subjected to a super density cropping

Os tomaticultores da região de Caçador-SC necessitam de resultados experimentais do cultivo superadensado, com os híbridos cultivados nas condições edafoclimáticas da região, para que possam decidir sobre a adoção deste sistema. Desta forma, o objetivo deste trabalho foi avaliar o cultivo superadensado de tomate com híbridos utilizados em Caçador. Dois experimentos foram realizados na Epagri em Caçador, durante as safras 2007/2008 e 2008/2009. Os tratamentos, na safra 2007/2008, consistiram na combinação de dois híbridos (Miramar e T92), dois métodos de tutoramento (vertical e em "V") e dois métodos de condução de plantas (uma haste por planta no espaçamento de 0,15 m entre plantas e duas hastes por planta no espaçamento de 0,3 m entre plantas). Na safra 2008/2009, os tratamentos consistiram na combinação de dois híbridos (Paron e Plutão) e dois métodos de condução de plantas superadensado (uma haste por planta no espaçamento entre plantas de 0,15 m e duas hastes por planta no espaçamento entre plantas de 0,3 m). Foi incluído ainda o método de condução e densidade de plantas tradicional (duas hastes por planta no espaçamento entre plantas de 0,6 m). O delineamento experimental foi de blocos completos ao acaso, com quatro repetições, no esquema de parcelas sub-subdivididas, na safra 2007/2008, e de parcelas subdivididas, na safra 2008/2009. Os tratamentos possuíam 44.444 hastes/ha, com exceção dos tratamentos com condução tradicional de plantas (22.222 hastes/ha). Foram analisados a produtividade total, comercial e descarte, massa média de frutos comerciais, frutos comerciais (%) e descarte (%) em relação ao número total de frutos e severidade de doenças foliares. Os híbridos testados não interferem nas respostas agronômicas ao adensamento de plantas. O sistema superadensado de tomate proporcionou aumento, em média, de 73,2% na produtividade comercial de frutos, em relação à densidade tradicional de plantas. A produtividade comercial de frutos no tomateiro superadensado tutorado em "V" foi 19,2% maior que o tomateiro superadensado tutorado verticalmente. A condução de uma haste por planta aumentou 10,4% a produtividade comercial de frutos em relação à condução de duas hastes por planta no tomateiro superadensado. O tomateiro superadensado proporcionou aumento da severidade foliar de pinta-preta, em relação à densidade tradicional de plantas.<br>Farmers of Caçador, Santa Catarina State, Brazil, need experimental results of tomato super density cropping system, since the ecological conditions of this region permit them decide to adopt this system or not. The aim of this work was to evaluate the tomato super density cropping system with hybrids used in Caçador. Two experiments were carried out at Epagri, Experimental Station of Caçador, during the 2007/2008 and 2008/2009 harvest period. The treatments in 2007/2008 were the combination of two hybrids (Miramar and T92), two methods of staking (in vertical and "V") and two methods of training plants (one stem per plant in the spacing of 0.15 m between plants and two stems per plant in the spacing of 0.3 m between plants). In 2008/2009, the treatments were the combination of two hybrids (Paron and Plutão) and two super density methods of training plants (one stem per plant in the spacing of 0.15 m between plants and two stems per plant in the spacing of 0.3 m between plants) plus the traditional density and method of training plants (two stems per plant in the spacing of 0.6 m between plants). The experimental design was of randomized complete blocks with four replications in a split-split-plot, in 2007/2008, and a split-plot in the 2008/2009 season. All treatments had 44,444 stems/ha, except for the treatments with traditional methods of training plants (22,222 stems/ha). The variables analyzed were total, marketable and unmarketable yield, average mass of fruits, marketable and unmarketable percentage of fruits in relation to the total number of fruits, and severity of leaf diseases. The tomato hybrids do not interfere in agronomic responses to the super density of plants. The super density of plants increased, on average, 73.2% the marketable yield, in relation to the traditional density of plants. The marketable yield of the super density of plants in the "V" staking was 19.2% higher than the super density of plants in the vertically staking. The plant training with one stem per plant increased 10.4% the marketable yield in relation to the plant training with two stems per plant in the super density of plants. The super density of plants increased the leaf severity of early blight, in relation to the traditional density of plants

Influence of enriched environment on viral encephalitis outcomes: behavioral and neuropathological changes in albino Swiss mice

An enriched environment has previously been described as enhancing natural killer cell activity of recognizing and killing virally infected cells. However, the effects of environmental enrichment on behavioral changes in relation to virus clearance and the neuropathology of encephalitis have not been studied in detail. We tested the hypothesis that environmental enrichment leads to less CNS neuroinvasion and/or more rapid viral clearance in association with T cells without neuronal damage. Stereology-based estimates of activated microglia perineuronal nets and neurons in CA3 were correlated with behavioral changes in the Piry rhabdovirus model of encephalitis in the albino Swiss mouse. Two-month-old female mice maintained in impoverished (IE) or enriched environments (EE) for 3 months were behaviorally tested. After the tests, an equal volume of Piry virus (IEPy, EEPy)-infected or normal brain homogenates were nasally instilled. Eight days post-instillation (dpi), when behavioral changes became apparent, brains were fixed and processed to detect viral antigens, activated microglia, perineuronal nets, and T lymphocytes by immuno- or histochemical reactions. At 20 or 40 dpi, the remaining animals were behaviorally tested and processed for the same markers. In IEPy mice, burrowing activity decreased and recovered earlier (8–10 dpi) than open field (20–40 dpi) but remained unaltered in the EEPy group. EEPy mice presented higher T-cell infiltration, less CNS cell infection by the virus and/or faster virus clearance, less microgliosis, and less damage to the extracellular matrix than IEPy. In both EEPy and IEPy animals, CA3 neuronal number remained unaltered. The results suggest that an enriched environment promotes a more effective immune response to clear CNS virus and not at the cost of CNS damag