Numerical modeling of water balance for temporary landfill cover in North Germany

At the end of waste disposal in 2005, a temporary mineral system was constructed to cover the waste body of the municipal landfill in Rastorf (N Germany). The aim of this study was to evaluate the effectiveness of this temporary cover system in limiting the infiltration of surface water into the waste body. The numerical modeling for the hydrological year 2012 was performed in FEFLOW 6.0. The required input data for modeling were achieved by laboratory measurements of the saturated hydraulic conductivity and the water retention characteristics of the mineral layers. The assumed initial and boundary conditions were based on in‐situ measurements of matrix potential and volumetric water content at three different measuring points by tensiometers, FDR sensors and observed meteorological conditions. The model was applied according to Darcy's and Richards' equations for variably saturated flow. Our results allowed assessing the components of water balance for a temporary cover system, especially water seepage into the waste body. The correlation between the measured and modeled volumetric soil water content in the layered temporary cover system was observed (R² = 0.56 to 0.90). Deviations between the measured and modeled values are superficially related to the soil´s heterogeneity. In conclusion, the measured and modeled water balance parameters indicate that the temporary coverage system remains effective in limiting the infiltration rate. However, our studies revealed that the calculated and measured water seepage exceeded the values allowable by the German regulations. Additional studies have to assess variations in the soil water characteristics caused by weather‐related wetting and drying cycles and influence of waste settlement changing the profile of slope.     

Cerebellar degeneration in dairy calves: clinical, pathologic, and serologic features of an epizootic caused by bovine viral diarrhea virus

Three of nine dairy calves born in the spring/summer wee severely ataxic at birth. Necropsy of the 3 affected calves revealed severe cerebellar degeneration (hypoplasia). Clinical signs were inapparent in the adult cows. Serum neutralization titers of the cows and calves indicated high bovine viral diarrhea titers.     

Bone grafting

Bone grafts in clinical practice are primarily used to help achieve bony union in cases of indolent healing of fractures or pseudoarthrosis; to supplement the healing of certain fresh fractures; to promote fusion (arthrodesis) of joints damaged by injury, disease, or deformity, and to fill defects in bone created by tumors, chronic infection, or injury. This article considers the types and functions of bone grafts.     

Risk factors for lower respiratory tract disease in a cohort of feedlot cattle

Using data collected from company lot records, potential risk factors related to feedlot management, the cattle, and climate were determined. The risk factors were analyzed by use of weighted multiple regression techniques to determine their effects on the incidence of lower respiratory tract disease in a cohort of 95 lots containing 17,696 cattle. The gender of the cattle, the number of days that groups of cattle filled a lot, pregnancy checking of heifers, and the average temperature change in the first 14 days in which the cattle were on feed significantly influenced the incidence of lower respiratory disease. The incidence of lower respiratory tract disease was most influenced by risk factors in the first 30 days on feed.     

Hemodynamic effects of xylazine in the calf

The hemodynamic effects of sedative level doses of xylazine in five chronically instrumented calves were studied. These effects included immediate and prolonged reductions in heart rate, cardiac output, arterial blood pressure, and left ventricular dp/dt max. Stroke volume showed an initial decrease in value with a return in 15 minutes to base-line values. Total peripheral resistance, end-diastolic left ventricular pressure, end-diastolic left ventricular volume, and left ventricular residual fraction were increased after drug administration. The results indicate that a depressed myocardium results from xylazine administration. With one exception (the absence of a hypertensive response), these effects largely parallel, both quantitatively and qualitatively, those seen with this drug in other species. Sedation by xylazine is produced in cattle at doses which are small compared to those which is required for sedation in other species. These same small doses in cattle also cause hemodynamic changes.