巴西塞拉都(Cerrado)地区氧化土土壤紧实性评估研究

The Cerrado region of Brazil, one of the fastest-growing agricultural areas in the world, is undergoing very rapid mechanization; this development is good for the country’s economy but may also snowball into substantial loss of agricultural land and other environmental degradation if the soil susceptibility and vulnerability to compaction is not well understood. In this study we explored different techniques for estimating soil intrinsic abilities to withstand applied pressure using the prevalent Oxisols of the Cerrado region under native vegetation. Undisturbed samples were collected from three sites within the region and subjected to 1) compressibility test: 2) manual penetration resistance test; 3) automated penetration resistance test; and 4) packing density analysis. The four methods produced analogous results. Our results showed the significant influence of soil structure on the inherent strength and compaction susceptibility of the soils. We also established the association of soil structure with the mineralogy of the soil. It is noteworthy that the packing density which was developed from very simple and easily obtained parameters could give a picture of the tendency of the soil to compact. Thus, this approach would be useful in developing compaction susceptibility maps for the region. It could be concluded that most of the Oxisols in the Cerrado region would support mechanized agricultural production very successfully. However, there is need for careful management of the mechanization process to avert degradation. The management techniques should include conservationist practices such as no till in order to maintain as much as possible the favorable structure and drainage of these very old soils.     

黍族植物的叶片扩张和蒸腾作用对土壤水分亏缺的响应特征

Plant processes, such as leaf expansion, stomatal conductance and transpiration, are affected by soil water, particularly in water-stressed environments. Quantifying the effects of soil water on plant processes, especially leaf expansion and transpiration, could be useful for crop modeling. In order to quantify the leaf expansion and transpiration in response to soil water deficit in three millet species, common (Panicum miliaceum L.), pearl (Pennisetum glaucum L.) and foxtail (Setaria italica L.) millets, a pot experiment was performed at the Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran. The soil water status was characterized by the fraction of transpirable soil water (FTSW). Leaf area and transpiration were measured daily. Relative leaf area expansion (RL) and relative transpiration (RT) data were plotted against FTSW. Finally the FTSW thresholds for RL and RT were calculated using linear-plateau and logistic models. The results showed that the thresholds for RL and RT were 0.68 and 0.62, respectively, based on all measured data of the three millet species using the linear-plateau model, indicating that RL and RT were constant when FTSW decreased from 1 to the threshold point. Thereafter, until FTSW = 0, RL and RT declined linearly with a slope of 1.48 and 1.43, respectively. Although millet is cultivated as a resistant crop in arid, semiarid and marginal lands, it showed an early response to soil water deficit at high FTSW thresholds. As leaf expansion and transpiration can be considered morphological and physiological variables, respectively, the results in this study indicate that millet has strong morphological flexibility when faced with soil water deficit.     

Multiple Squamous Cell Carcinomas Arising from Multiple Cutaneous Follicular Cysts in a Dog

Résumé— Des épithéliomas spinocellulaires se sont développés à partir de kystes folliculaires multiples chez un chien croisé berger Catalan de 6 ans. Le chien est mort après un suivi de 29 mois. Des métastases ont été trouvées dans les poumons et au niveau des métacarpiens 1 et 2 de la patte antérieure gauche. [Multiple squamous cell carcinomas arising from multiple cutaneous follicular cysts in a dog (Épithéliomas spinocel-lalaires multiples se développant à partir de kystes folliculaires multiples chez un chien).
Resumen— Un perro Pastor Catalan desarrolló carcinomas de células planas a partir de multiples quistes foliculares. El perro murió a los 29 meses del seguimiento. Se detectaron carcinomas de células escamosas metástaticos en los pulmones y en los metacarpos I y II de la extremidad izquierda. [Multiple squamous cell carcinomas arising from multiple cutaneous follicular cysts in a dog. (Múltiples carcinomas de células planas surgidos a partir de multiples quised foliculares cutáneo en un perro).
Abstract— Squamous cell carcinomas developed in multiple follicular cysts in a 6-year-old Catalan shepherd cross dog. The dog died after a 29-month follow-up period. Metastatic squamous cell carcinoma was detected in the lungs and metacarpal bones 1 and 2 of the left front paw.     

Brain-derived neurotrophic factor is down regulated after bovine alpha-herpesvirus 5 infection in both wild-type and TLR3/7/9 deficient mice

Neurotrophic factors have been implicated in the control of neuronal survival and plasticity in different brain diseases. Meningoencephalitis caused by bovine alpha-herpesvirus 5 (BoHV-5) infection is a frequent neurological disease of young cattle, being the involvement of apoptosis in the development of neuropathological changes frequently discussed in the literature. It’s well known that Toll-like receptors (TLRs) can activate neuroinflammatory response and consequently lead to neuronal loss. However, there are no studies evaluating the expression of neurotrophic factors and their association with brain pathology and TLRs during the infection by BoHV-5. The current study aimed to analyze brain levels of neurotrophic factors along with neuropathological changes during acute infection by BoHV-5 in wild-type (WT) and TLR3/7/9 (TLR3/7/9^−/−) deficiency mice. The infection was induced by intracranial inoculation of 1 × 10⁴ TCID₅₀ of BoHV-5. Infected animals presented similar degrees of clinical signs and neuropathological changes. Both infected groups had meningoencephalitis and neuronal damage in CA regions from hippocampus. BoHV-5 infection promoted the proliferation of Iba-1 positive cells throughout the neuropil, mainly located in the frontal cortex. Moreover, significant lower levels of brain-derived neurotrophic factor (BDNF) were detected in both BoHV-5 infected WT and TLR3/7/9 deficient mice, compared with non-infected animals. Our study showed that BDNF down regulation was associated with brain inflammation, reactive microgliosis and neuronal loss after bovine alpha-herpesvirus 5 infection in mice. Moreover, we demonstrated that combined TLR3/7/9 deficiency does not alter those parameters.     

Differences in adipose tissue inflammation and oxidative status in C57BL/6 and ApoE−/− mice fed high fat diet

Apolipoprotein E deficient (Apo E?/?) mice are more resistant to the development of obesity compared to C57BL/6 wild type mice. They also hold a high basal oxidative status due to the loss of antioxidant action of apolipoprotein E. Since obesity is also an inducer of inflammation, we studied the effect of high‐fat diet on obesity and oxidative stress in C57BL/6 and Apo E?/? mice for 9 weeks. The results confirmed that Apo E?/? mice fed high‐fat diet are more resistant to the increase of both body weight and adiposity compared to C57BL/6 mice. Despite this, Apo E?/? mice presented a higher basal oxidative stress that was enhanced by high‐fat diet. Macrophage infiltration, macrophage forming crown‐like structures and proinflammatory adipokines (interleukin 6 and tumor necrosis factor alpha) were all higher in adipose tissue from Apo E?/? compared to C57BL/6 mice, regardless of diet type. In conclusion, although Apo E?/? mice are more resistant to becoming obese, they develop more severe adipose tissue inflammation companied by its consequences.     

Topographic laparoscopy for buffaloes in the quadruped position

This study aimed to describe the anatomical topography of the abdominal cavity of buffaloes in the quadruped position to establish the best endosurgical access and vantage points and identify possible limitations. Laparoscopies were performed on 10 healthy female buffaloes obtained from the Universidade Federal Rural da Amazônia to explore possible access points to the abdomen. Techniques for assessing and possibly observing certain organs and structures through the left and right flanks of 10 animals have been described. In five animals, access was created through the right side of the last intercostal space to allow more cranial access to the abdominal cavity. Despite the presence of the rumen, access through the left flank allowed the visualization of the structures of the gastrointestinal tract and the genitourinary system. With access through the right flank, however, imaging was hampered by the presence of the greater omentum and its deep and superficial walls, which prevented the progression of the endoscope. Access through the last right intercostal space allowed the visualization of the cranial structures of the abdominal cavity, such as the caudate process, right lobe of the liver, right kidney, and pancreas. Laparoscopic access through the left flank and the last intercostal space in healthy buffaloes in the quadruped position is feasible, and it is promising for the exploration, diagnosis, and treatment of various disorders in buffaloes.     

Comparison of the cardio‐respiratory effects of methadone and morphine in conscious dogs††

The effects of methadone and morphine were compared in conscious dogs. Six animals received morphine sulfate (1 mg/kg) or methadone hydrochloride (0.5 mg/kg [MET0.5] or 1.0 mg/kg [MET1.0]) intravenously (i.v.) in a randomized complete block design. Cardiopulmonary variables were recorded before (baseline), and for 120 min after drug administration. One outlier was not included in the statistical analysis for hemodynamic data. Morphine decreased heart rate (HR) compared to baseline from 30 to 120 min (?15% to ?26%), while cardiac index (CI) was reduced only at 120 min (?19%). Greater and more prolonged reductions in HR (?32% to ?46%) and in CI (?24% to ?52%) were observed after MET1.0, while intermediate reductions were recorded after MET0.5 (?19 to ?28% for HR and ?17% to ?27% for CI). The systemic vascular resistance index (SVRI) was increased after methadone; MET1.0 produced higher SVRI values than MET0.5 (maximum increases: 57% and 165% for MET0.5 and MET1.0, respectively). Compared to morphine, oxygen partial pressure (PaO₂) was lower (?12% to ?13%) at 5 min of methadone (0.5 and 1.0 mg/kg), while carbon dioxide partial pressure (PaCO₂) did not change significantly. It was concluded that methadone induces cardiovascular changes that are dose‐related and is a more potent cardiovascular depressant agent than morphine in conscious dogs.