38 research outputs found
A survey of castration methods and associated livestock management practices performed by bovine veterinarians in the United States
<p>Abstract</p> <p>Background</p> <p>Castration of male calves destined for beef production is a common management practice performed in the United States amounting to approximately 15 million procedures per year. Societal concern about the moral and ethical treatment of animals is increasing. Therefore, production agriculture is faced with the challenge of formulating animal welfare policies relating to routine management practices such as castration. To enable the livestock industry to effectively respond to these challenges there is a need for more data on management practices that are commonly used in cattle production systems. The objective of this survey was to describe castration methods, adverse events and husbandry procedures performed by U.S. veterinarians at the time of castration. Invitations to participate in the survey were sent to email addresses of 1,669 members of the American Association of Bovine Practitioners and 303 members of the Academy of Veterinary Consultants.</p> <p>Results</p> <p>After partially completed surveys and missing data were omitted, 189 responses were included in the analysis. Surgical castration with a scalpel followed by testicular removal by twisting (calves <90 kg) or an emasculator (calves >90 kg) was the most common method of castration used. The potential risk of injury to the operator, size of the calf, handling facilities and experience with the technique were the most important considerations used to determine the method of castration used. Swelling, stiffness and increased lying time were the most prevalent adverse events observed following castration. One in five practitioners report using an analgesic or local anesthetic at the time of castration. Approximately 90% of respondents indicated that they vaccinate and dehorn calves at the time of castration. Over half the respondents use disinfectants, prophylactic antimicrobials and tetanus toxoid to reduce complications following castration.</p> <p>Conclusions</p> <p>The results of this survey describe current methods of castration and associated management practices employed by bovine veterinarians in the U.S. Such data are needed to guide future animal well-being research, the outcomes of which can be used to develop industry-relevant welfare guidelines.</p
High-Grade B-cell Lymphoma, Not Otherwise Specified: A Multi-Institutional Retrospective Study
In this multi-institutional retrospective study, we examined the characteristics and outcomes of 160 patients with high-grade B-cell lymphoma, not otherwise specified (HGBL-NOS)-a rare category defined by high-grade morphologic features and lack of MYC rearrangements with BCL2 and/or BCL6 rearrangements ( double hit ). Our results show that HGBL-NOS tumors are heterogeneous: 83% of patients had a germinal center B-cell immunophenotype, 37% a dual-expressor immunophenotype (MYC and BCL2 expression), 28% MYC rearrangement, 13% BCL2 rearrangement, and 11% BCL6 rearrangement. Most patients presented with stage IV disease, a high serum lactate dehydrogenase, and other high-risk clinical factors. Most frequent first-line regimens included dose-adjusted cyclophosphamide, doxorubicin, vincristine, and etoposide, with rituximab and prednisone (DA-EPOCH-R; 43%); rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP; 33%); or other intensive chemotherapy programs. We found no significant differences in the rates of complete response (CR), progression-free survival (PFS), or overall survival (OS) between these chemotherapy regimens. CR was attained by 69% of patients. PFS at 2 years was 55.2% and OS was 68.1%. In a multivariable model, the main prognostic factors for PFS and OS were poor performance status, lactate dehydrogenase \u3e3 Ă upper limit of normal, and a dual-expressor immunophenotype. Age \u3e60 years or presence of MYC rearrangement were not prognostic, but patients with TP53 alterations had a dismal PFS. Presence of MYC rearrangement was not predictive of better PFS in patients treated with DA-EPOCH-R vs R-CHOP. Improvements in the diagnostic criteria and therapeutic approaches beyond dose-intense chemotherapy are needed to overcome the unfavorable prognosis of patients with HGBL-NOS
Control of flatness for chemical mechanical planarization
To measure and control the topography of wafer surfaces at nanometer scale is essential for semiconductor manufacturing. Flatness control of chemical mechanical planarization requires compact metrology to be integrated in-line in CMP tools. Furthermore, the metrology has to be able to determine flatness on patterned wafers with high resolution. Wave front sensing based on methods according to Makyoh and Shack Hartmann enabled instantaneous, non-destructive flatness inspection of patterned wafer surfaces as, e.g., surfaces from shallow trench isolation or interconnect processes. Besides the unique capability of measuring patterned wafers, the methods are applicable to control bare silicon wafer processing as well. The achieved resolution for measuring flatness was found to be better than 100nm at 1 to 2mm lateral resolution
Highly sensitive wavefront sensor for characterization of micro- to nanometer-scale surface flatness deviations
Wave front sensing is an optical method allowing non-contacting topography measurements of flat surfaces. Applications of the method are, for instance, the characterization of optical components, semiconductor surfaces, or subcomponents used in semiconductor manufacturing equipment. The method developed here is covering the characterization of flatness on mirror-like surfaces within three orders of magnitude from micro- to nanometer scale. This is due to the high range of detectable surface slopes from very low to relatively high values. Therefore, the method is applicable to both, micro- and nanometer scale height deviations on surfaces. The wave front sensing is capable of studying the topography in a real-time operating mode. The technique enables vertical resolution of approximately 10 nm at a lateral resolution of 0.6 mm on bare silicon wafer surfaces. Moreover, highly reflective surfaces with height deviations of 10-15 ”m could be easily resolved at a lateral resolution of 2.4 mm. In this study, we focused on the application in semiconductor surfaces and manufacturing equipment: measurements were performed on bare wafers as well as on the mirror-like surface of a wafer holder used for wafer polishing (a 'polishing head'). An obstacle for measurements is a low reflectivity of surfaces. Both, metallic surfaces and silicon wafers, however, show high surface reflectivity
Optical inspection of flat reflective surfaces by a wave front sensor
The wave front sensor used in this paper is based on Makyoh method: the studied sample is illuminated by a collimated light beam and the reflected beam is collected by a camera. Previously it was demonstrated that this method enables the determination of surface flatness in the nanometer range. For this purpose the deformation of an initially planar wave front is detected and evaluated using patterns projected on the surface. This paper demonstrates that the sensor can also be used without patterns for characterization of surfaces flatness in the sub-micrometer and micrometer ranges. The intensity distribution image obtained can be interpreted in terms of topography as follows: convex areas of the studied surface defocus the beam (dark regions on the image) while the concave areas focus it (bright regions). The main result of this work is the development of a new approach for the fast assessment of the surface quality. This approach estimates the areas and the intensiti es of bright regions on the image and gives the value of the maximum concavity on the studied surface. For evaluation of data a simulation of the reflected from the given profile was made. The setup parameters, e.g. distances between the optical components, were optimized with the parameters obtained from the 2D simulation of the wave front sensor. This paper demonstrates the feasibility of wave front sensing for the topography analysis of reflective surfaces such as bare wafers' surfaces, metallic thin films, etc. used in semiconductor industry
Highly sensitive wavefront sensor for visual inspection of bare and patterned silicon wafers
Wave front sensing allows determination of topography and flatness of reflecting surfaces. As there is no contact to the surface, the method enables a contamination free and non-destructive surface analysis which meets the requirements of semiconductor and optical industries. This paper demonstrates that the sensor is suitable for defect estimation on the studied surface without topography reconstruction, where defect is considered as a dimple or a mound on the wafer surface. Based on the development, it is possible to reduce the evaluation time for the measurements by the reduction of both processing time for topography calculation and the number of acquired images. The method judges whether the surface of the studied sample is defect-free. That is a key for fast and reliable inspection. The Makyoh image shows the light distribution of the beam reflected from the surface. The images of bare wafers show unevenly alternate bright and dark areas. These areas appear due to the focusing and defocusing of the wave front and are caused by the local surface defects. The intensity changes are qualitatively interpreted with the help of the geometrical optics, and the maximum curvature of the defects on the studied surface is roughly estimated. Furthermore, the measurements of the sample rotated underneath the fixed sensor prove that the intensity changes are the result of the surface shape and not due to the aberration in the optical system. According to the results the method is useful for characterization of both micro- and nanometer scale surface flatness deviations
Steam pasteurization of beef carcasses
This research evaluated the effectiveness of
a newly patented steam-pasteurization process
for reducing bacterial populations on the surfaces
of freshly slaughtered beef carcasses. The
process was developed jointly by Frigoscandia
Food Processing Systems (Bellevue, WA) and
Excel Corp. (Wichita, KS), a division of Cargill
(Minneapolis, MN). In laboratory studies,
portions of prerigor beef carcasses inoculated
with very high levels of three pathogens, Salmonella,
Escherichia coli O157:H7, and Listeria,
were treated in a prototype steam-pasteurization
chamber, which effectively eliminated at least
99.9% of all three pathogens and was most
effective when used in combination with other
standard commercial decontamination methods.
The effectiveness of a full-scale, automated,
steam-pasteurization system was evaluated in a
commercial beef slaughter facility. The commercial
system was very effective, reducing the
naturally occurring overall bacterial population
by over 90% and reducing the population of E.
coli (nonpathogenic) and related organisms to
undetectable levels. Steam pasteurization is
very effective at reducing bacterial contamination
on unchilled beef carcasses and
should be viewed as one step in an overall
process of reducing the risk of pathogenic
bacteria in beef and beef products
Wave front sensor for highly accurate characterization of flatness on wafer surfaces
Semiconductor manufacturing processes start on bare silicon substrates having excellent surface flatness. In the subsequent process chain of manufacturing of integrated circuits, it is crucial to maintain this initial surface flatness. New lithography technologies, as for example immersion lithography and Extreme Ultra Violet (EUV), require high flatness of the exposure surfaces as e.g. the depth of focus is impacted. Integrated device manufacturers use different technologies involving materials such as metals, semiconductors, and isolators to build three-dimensional structures on the wafer. The miscellaneousness of materials on the surface of wafers with highly integrated circuits limits the use of metrology developed for flatness analysis of bare silicon wafers. Nevertheless, it is essential for semiconductor manufacturing to measure and control the topography of wafer surfaces at nanometer scale. Wave front sensing was developed to characterize topography on bare and patterned wafer surfaces. Post processing of the acquired data applied 2 D Gaussian high pass filters to obtain the flatness data. The standard deviation of the flatness data after filtering was almost independent with respect to the lateral resolution. On bare wafer surfaces, the standard deviation was found to be below 1 nm, on patterned surfaces to be below 10 nm. Both, changes in reflectivity and filtering were found to impact and limit the accuracy of the determination of flatness. The accuracy of flatness measurement was found to be better than 20 nm. The results were validated by using a wavefront sensor according to the method of Makyoh. The technique has a high potential to provide high speed, contactless, and local inspection of flatness on bare and patterned wafer surfaces