Radiosensitive period of pecking response during embryological development of domestic chicks.

Gave gamma irradiation to 174 cross-bred chick embryos on Days 2-12 of incubation in 2-day steps. A 5-fold increase in between-Ss variance and a 3-fold increase in within-Ss variance resulted when Ss were tested with induced pecking responses, but only in groups treated on Days 6 and 8. There were no difference in variances between groups treated on any other day nor in the controls. It is claimed that comparison of means is an inappropriate and misleading test for treatment effects. Results are discussed in terms of both raised thresholds and loss of negative feedback in the response system. (24 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

K-ras point mutations are rare events in premalignant forms of Barrett's oesophagus

OBJECTIVE: In Barrett's adenocarcinomas, in contrast to squamous oesophageal carcinomas, K-ras point mutations are thought to be a frequent event. The frequency of K-ras point mutations in premalignant forms of Barrett's oesophagus (metaplasia, dysplasia) leading to adenocarcinoma with increased risk is currently not known. To establish the frequency of K-ras mutations in premalignant forms of Barrett's oesophagus, we investigated oesophageal biopsy specimens with Barrett's metaplastic and dysplastic epithelium for point mutations in the K-ras gene/codons 12, 13. DESIGN: A total of 412 biopsies from patients with Barrett's oesophagus were histologically classified into biopsies with metaplasia (n = 252), dysplasia (n = 105) and adenocarcinoma (n = 11), as well as biopsies distant from disease (normal, n = 37 and hyperplastic squamous epithelium, n = 7). METHODS: DNA from biopsy specimens was amplified by polymerase chain reaction (PCR) with a modified primer for generating a restriction site in the case of wild type in codon 12. Wild-type or point mutations in the K-ras gene/codons 12, 13 were detected by restriction fragment length analysis of the PCR products. RESULTS: Point mutations in K-ras/codon 12 were found in 9 biopsies (n = 1 in metaplasia, n = 4 in dysplasias, n = 4 in adenocarcinomas). All the other biopsies showed the wild type of K-ras/codon 12. No K-ras/codon 13 mutation (GGCgly-->GACasp) was observed. CONCLUSION: Mutations in K-ras/codon 12 were rarely found in premalignant forms of Barrett's oesophagus. Whereas the screening for K-ras point mutations in metaplastic sites of Barrett's epithelium seems not to be of practical value, the screening for mutations in dysplastic lesions might be helpful to estimate the individual risk for progression of Barrett's epithelium to adenocarcinoma. A further evaluation in larger numbers of patients is needed.     

Identification and immunolocalization of ecto-ATPDase in chicken stomach

The distribution of the extracellular adenosine tri- and di-phosphatase (ecto-ATPDase) in adult chicken tissues was investigated using a monoclonal antibody (MC18) generated previously from chicken oviduct. Ecto-ATPDase was determined to be most abundant in stomach by Western blot analysis of crude tissue homogenates. The ecto-ATPDase activity from solubilized stomach microsomes and a purified oviduct control was depleted 64% and 72%, respectively, by immunoprecipitation with MC18. Both oviduct and stomach ecto-ATPDases had an M(r) of approximately 80 kDa based on SDS-PAGE analysis. In addition, the enzymology of the ecto-ATPDase from both tissues was very similar. It is concluded that the same ecto-ATPDase is present in stomach and oviduct. Furthermore, immunolocalization of the stomach ecto-ATPDase with MC18 showed the enzyme to be localized in the apical membranes of the oxyntico-peptic cells, suggesting a role for the ecto-ATPDase in secretion.     

Effect of pH and energy spilling on bacterial protein synthesis by carbohydrate-limited cultures of mixed rumen bacteria

Rumen contents were obtained from a cow fed 2.5 kg concentrates and 2.5 kg timothy hay twice daily, and the mixed rumen bacterial inoculum (pH 6.3) was separated from large feed particles and protozoa by centrifugation. Bacteria were incubated in artificial media at pH 6.7 and 6.0. When starch, sucrose, cellobiose, xylan, pectin, or a mix of carbohydrates were provided to pH 6.7 incubations at 1 mM/h for 10 h, fermentation was carbohydrate-limited, less than 20% of the carbohydrate was converted to lactate, molar ratio of methane to hexose fermented was as great as 49%, and pH remained constant. When initial pH was lowered to 6.0, methane production was nearly eliminated, volatile fatty acid production was reduced, and there was a small decrease (less than .5) in final pH. At pH 6.0, lactate production was increased in all incubations except xylan and pectin, and pH had a greater effect on acid production than the type of carbohydrate provided. Bacterial protein synthesis was reduced 34 to 69% when initial pH was 6.0, but these reductions were greater than decreases in carbohydrate utilization, increases in lactate, and associated decreases in adenosine 5'-triphosphate production. Because less adenosine 5'-triphosphate was used for protein synthesis, it appeared that low pH diverted energy to nongrowth functions.     

Advanced methods for safe visualization on automotive displays

Camera Monitor Systems (CMSs), for example, for backup cameras or mirror replacements, become increasingly important and already cover safety aspects such as guaranteed latency and no frame freeze. Today's approaches deal only with supervision of the digital interface, LCD backlight, and power supply. This paper introduces methods for advanced safety monitoring of panel electronics and optical display output that aim to enable future CMS based automotive use cases. Our methods are based on correlation of physical measurements with predicted values derived from a corresponding display model. This model was made via calibration measurements and many test patterns. Correlation of the monitoring results with predicted values corresponds to the probability that the RGB data are shown as intended. This implies that an overlying system, an Automotive Safety Integrity Level (ASIL) Prepared Video Safety System (APVSS), ensures that only safety verified RGB data are provided to the panel electronics. In case of failures, our methods enable a safe system state, for example, by deactivating the panel. An additional challenge is to allow graceful degradations, a safe but slightly degraded image may provide a better customer experience compared with no information. We successfully verified our approach by a fully functional prototype and extensive evaluation towards “light‐to‐light” (camera to display output) supervision.     

The new build to print design of the ITER Torus Cryopump

The common design of the cryopumps for pumping the divertor and the cryostat has been completed at ITER following more than 10 years of development including prototyping and a number of design studies. This final design, which will be validated by building a Pre-Production Cryopump, achieves a number of simplifications and is expected to solve issues identified in previous concepts.The paper will present the build to print manufacturing design of the cryopump according to European Standards. The fabrication and qualification methods will be discussed and a summary of the main manufacturing methods will be given. The design of the valve assembly and its integration in the cryopump with the valve shaft double bellows will be described in detail.