Escherichia coli and Lactobacillus plantarum responses to osmotic stress

Artificial insemination using cryopreserved semen is a common management tool of the contemporary livestock producer. However, cryopreservation is detrimental to sperm function and fertility, killing some 50% of the spermatozoa during the process. Prediction of cryopreservation damage from prefreeze samples remains elusive. Computer-automated sperm head morphometry was used in this study to determine the effects of cryopreservation on bovine sperm head morphometry. Semen was collected from 18 bulls and was divided. One portion was extended to 200 x 10(6) sperm/ml and a microscope slide was prepared, while the remaining portion was cryopreserved in a Triscitrate-yolk extender. After thawing, the cryopreserved samples were prepared on microscope slides. All slides were air dried and were stained with hematoxylin and rose bengal. The morphometric dimensions for length, width, width/length, area, and perimeter for a minimum of 200 sperm heads were analyzed from each slide by computer-aided sperm head morphometry analysis, and the mean measurements were recorded. Bull sperm heads were significantly (P < 0.01) smaller in cryopreserved spermatozoa than in the companion extended samples for length (8.56+/-0.07 vs. 8.63+/-0.08 microm), width (4.39+/-0.05 vs. 4.48+/-0.05 microm), area (28.42+/-0.07 vs. 29.14+/-0.08 microm), and perimeter (23.33+/-0.21 vs. 23.70+/-0.23 microm) for all bulls. Width/length was also different (0.513 vs. 0.519). In addition, differences (P < 0.05) were found within 14 of 18 bulls for at least four of the morphometric parameters. The percent change in measures after cryopreservation were correlated (P < or = 0.05) to the variability of the extended sample. Variations in sperm head measurements were lower (P < or = 0.05) in extended samples of the four bulls in which no changes occurred than in extended samples of the remaining 14 bulls. These data suggest that the variability in sperm head measurements of individual bulls, or ejaculates, may be an indicator of sperm cryosurvivability.     

Coarsening of SiO2 particles in copper and MnS inclusions in steel

A model to simulate the diffusion-controlled coarsening and dissolution kinetics of particles within a metallic matrix is formulated. With an arbitrary size distribution of particles, the model can be used to calculate the change in the size distribution of particles during coarsening or dissolution. Other system parameters, such as average radius of particles, volume fraction, average distance between particles, surface area, and matrix composition are also calculated. An important result is that kinetics do not generally obey the often-applied Lifshiftz-Slyozov-Wagner theory for diffusion controlled coarsening based upon concentration profiles around isolated spheres. In such a formulation, the direct effect of the surrounding particles is neglected. In our model, which is a modification of the coarsening kinetics described by Weins and Cahn, the effect of surrounding particles is incorporated because the system is taken to be a system of point potentials, each with a potential according to its radius of curvature. Calculations are on silica particles in a copper matrix and on manganese sulfide inclusions in iron, with emphasis on the latter, in order to predict their behavior during homogenization or soaking treatments. The effect of the composition of manganese, from 0.1 to 1.2 wt pct, on the coarsening of sulfides in a “high” sulfur (0.017 wt pct) steel and a “low” sulfur (0.003 wt pct) steel was investigated. As expected, the model predicts that manganese strongly reduces the rate of coarsening, particularly for times of ten hours or less in the temperature range of 1100 to 1400 °C. Calculated results also indicate that the rate of dissolution is very low at temperatures greater than the solvus for manganese sulfide inclusions in austenite.     

Billing third party payers for pharmaceutical care services

OBJECTIVE: To describe the steps pharmacists must complete when seeking compensation from third party payers for pharmaceutical care services. DATA SOURCES: Government publications; professional publications, including manuals and newsletters; authors' personal experience. DATA SYNTHESIS: Pharmacists in increasing numbers are meeting with success in getting reimbursed by third party payers for patient care activities. However, many pharmacists remain reluctant to seek compensation because they do not understand the steps involved. Preparatory steps include obtaining a provider/supplier number, procuring appropriate claim forms, developing data collection and documentation systems, establishing professional fees, creating a marketing plan, and developing an accounting system. To bill for specific patient care services, pharmacists need to collect the patient's insurance information, obtain a statement of medical necessity from the patient's physician, complete the appropriate claim form accurately, and submit the claim with supporting documentation to the insurer. Although many claims from pharmacists are rejected initially, pharmacists who work with third party payers to understand the reasons for denial of payment often receive compensation when claims are resubmitted. CONCLUSION: Pharmacists who follow these guidelines for billing third party payers for pharmaceutical care services should notice an increase in the number of paid claims.     

Fast and rigorous use of thermal time constant to characterize back end of the line test structure in advanced technology

Thermal time constant analysis (TTC) opens a wide range of applications: structure identification, 3D localization for very deep micron technologies. In this paper, we describe a new analysis methodology for TTC signatures induced by modulated thermal laser stimulation (TLS). Previous approaches did not allow a fast and rigorous method to acquire and treat transient TLS signals. To overcome these limitations we have done a theoretical study, based on the Fourier transform of an analytical model describing temporal dependency of the TLS signal, which is powerful for signature interpretation. This analysis flow is applied to 65 nm reliability test structure.     

Effect of Slag Impregnation on Thermal Degradations in Refractories

Degradation in bauxite refractory linings used in steel plants is localized in the slag-impregnated zone of refractories. It is proposed to estimate the contribution of the pressure of the impregnated liquid on the degradation of refractories. The study of the gradient of chemical composition allows for the evaluation of the liquid content, the oxide content in the liquid phase, and the "slag" viscosity. The thermomechanical analysis of a porous refractory impregnated by slag enables us to propose analytical expressions for a rapid estimate of the maximum "slag pressure" and its location as well as the level of thermoelastic stresses.     

Determination of temperature change inside IC packages during laser ablation of molding compound

In addition to chemical jet etch method, decapsulation performances of electronic packages for failure analysis are virtually enhanced using lasers. Nevertheless circuits inside package could be subjected to a local thermal elevation during the package ablation process. In this paper, we introduce an innovative technique to measure the thermal behavior of an encapsulated system in situ and in real time during laser decapsulation. Measurements of the heat elevation during ablation process in the three regions of interest for failure analysis are discussed: over IC, bonding and lead-frame.     

Accumulation and depuration of polychlorinated biphenyls from field-collected sediment in three freshwater organisms

As laboratory-based bioaccumulation methods are standardized and expanded to include other test species, kinetic studies assessing the major classes of contaminants with these species are needed to adequately select the standard duration for bioaccumulation tests. In the present study we measured the uptake (28-d exposure) of polychlorinated biphenyls (PCBs; total and selected congeners) from field-contaminated sediment in the oligochaete Lumbriculus variegatus, mayfly nymph Hexagenia spp., and fathead minnow Pimephales promelas. Depuration (25 d) of PCBs was measured in organisms that had been transferred to clean sediment after the 28-d exposure. Uptake and elimination of PCBs was rapid in L. variegatus and Hexagenia spp. Tissue residues reached steady-state concentrations within 28 d; elimination rates and biota-sediment accumulation factors (BSAFs) of the PCB congeners were not correlated with K(OW). Uptake and elimination rates of PCBs were slower in P. promelas, and it is not clear whether steady-state was reached in fish tissues. Elimination rates of the PCB congeners significantly decreased with increasing K(OW) in fish. The appropriateness of a 28-d exposure for measuring steady-state concentrations in tissue of the invertebrates was confirmed, but further study is required for fish.