Residual Stress Analysis of Composite Cannon Barrel

The objective of this paper is to describe the process and results of a residual stress analysis done on a composite cannon barrel. A cross section of a full cannon barrel was cut off to be used in the analysis. The barrel cross section was composed of an inner steel layer that was wrapped in an outer composite layer. The residual stress analysis was done using x-ray diffraction (XRD). The XRD machine uses different types of x-ray tubes based on what material it is analyzing. For this reason, the first portion of the experiment dealt with finding the exact material of the inner steel layer of the barrel. It was concluded that the majority of the barrel was composed of iron. This meant that a chromium x-ray tube had to be used in the XRD machine. Once the material composition was found, the next step was to determine how much the barrel needed to be polished down before accurate readings could be obtained. The reason this is necessary is because the cutting of the barrel would introduce stress into the system through the friction from the blade. By chemically eating away the metal, a depth in the material could be obtained where the residual stress level was not affected by the cutting. The results showed that at a depth of 200 microns or greater, accurate results were obtained. It was also observed that the inner portion of the barrel was in compression while the outer was in tension. Once the barrel was analyzed, the outer composite layer was cut off. It was predicted that the material in the inner steel layer would relax if the outer layer was removed. When placed in the XRD machine, the hypothesis was confirmed. The inner ring of the steel layer went from -396 MPa to -300 MPa, but the residual stress in the outer layer did not change

GECKO: a complete large-scale gene expression analysis platform

BACKGROUND: Gecko (Gene Expression: Computation and Knowledge Organization) is a complete, high-capacity centralized gene expression analysis system, developed in response to the needs of a distributed user community. RESULTS: Based on a client-server architecture, with a centralized repository of typically many tens of thousands of Affymetrix scans, Gecko includes automatic processing pipelines for uploading data from remote sites, a data base, a computational engine implementing ~ 50 different analysis tools, and a client application. Among available analysis tools are clustering methods, principal component analysis, supervised classification including feature selection and cross-validation, multi-factorial ANOVA, statistical contrast calculations, and various post-processing tools for extracting data at given error rates or significance levels. On account of its open architecture, Gecko also allows for the integration of new algorithms. The Gecko framework is very general: non-Affymetrix and non-gene expression data can be analyzed as well. A unique feature of the Gecko architecture is the concept of the Analysis Tree (actually, a directed acyclic graph), in which all successive results in ongoing analyses are saved. This approach has proven invaluable in allowing a large (~ 100 users) and distributed community to share results, and to repeatedly return over a span of years to older and potentially very complex analyses of gene expression data. CONCLUSIONS: The Gecko system is being made publicly available as free software . In totality or in parts, the Gecko framework should prove useful to users and system developers with a broad range of analysis needs

Methylphenidate Attenuates Rats' Preference for a Novel Spatial Stimulus Introduced into a Familiar Enviroment: Assessment Using a Force Plate Actometer

Methylphenidate is a psychostimulant widely used in the treatment of attention deficit hyperactivity disorder (ADHD). Here we report a novel paradigm that affords inferences about habituation and attention to a novel stimulus in a familiar environment in a single test session without prior training of the animals. The paradigm was used to assess the effects of methylphenidate (2.5 and 5.0 mg/kg, sc) in young adult, male, Long-Evans rats. Methylphenidate increased locomotor activity during the initial exposure to the test apparatus in a non-dose-related manner. However, upon introduction of a novel spatial stimulus (an alcove) in the familiar environment, methylphenidate-treatment resulted in dose-related increases in distance traveled and inhibition of long dwell times in the alcove, the latter behavior being characteristic of vehicle-treated rats’ response to the alcove condition. These results demonstrate the utility of this paradigm in the elucidation of the behavioral effects of a drug commonly used in the treatment of ADHD. Findings also suggest that species-typical response preferences in rats (e.g., refuge-seeking) may emerge in experimental settings that add spatial novelty to otherwise featureless test enclosures commonly used to assess locomotor activity

Creation of an Enhanced Recovery after Surgery (ERAS) Guideline for neonatal intestinal surgery patients: A knowledge synthesis and consensus generation approach and protocol study

Introduction: Enhanced Recovery After Surgery (ERAS) guidelines integrate evidence-based practices into multimodal care pathways designed to optimise patient recovery following surgery. The objective of this project is to create an ERAS protocol for neonatal abdominal surgery. The protocol will identify and attempt to bridge the gaps between current practices and best evidence. Our study is the first paediatric ERAS protocol endorsed by the International ERAS Society. Methods: A research team consisting of international clinical and family stakeholders as well as methodological experts have iteratively defined the scope of the protocol in addition to individual topic areas. A modified Delphi method was used to reach consensus. The second phase will include a series of knowledge syntheses involving a rapid review coupled with expert opinion. Potential protocol elements supported by synthesised evidence will be identified. The Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) system will be used to determine strength of recommendations and the quality of evidence. The third phase will involve creation of the protocol using a modified RAND/UCLA Appropriateness Method. Group consensus will be used to rate each element in relation to the quality of evidence supporting the recommendation and the appropriateness for guideline inclusion. This protocol will form the basis of a future implementation study. Ethics and dissemination: This study has been registered with the ERAS Society. Human ethics approval (REB 18-0579) is in place to engage patient families within protocol development. This research is to be published in peer-reviewed journals and will form the care standard for neonatal intestinal surgery

DEVELOPMENTAL EFFECTS OF DIETARY N-3 FATTY ACIDS ON ACTIVITY AND RESPONSE TO NOVELTY

Insufficient availability of n-3 polyunsaturated fatty acids (PUFA) during pre- and neonatal development decreases accretion of docosahexaenoic acid (DHA, 22:6n-3) in the developing brain. Low tissue levels of DHA are associated with neurodevelopmental disorders including attention deficit hyperactivity disorder (ADHD). In this study, 1st-and 2nd-litter male Long-Evans rats were raised from conception on a Control diet containing α-linolenic acid (4.20 g/kg diet), the dietarily essential fatty acid precursor of DHA, or a diet Deficient in α-linolenic acid (0.38 g/kg diet). The Deficient diet resulted in a decrease in brain phospholipid DHA of 48% in 1st-litter pups and 65% in 2nd-litter pups. Activity, habituation, and response to spatial change in a familiar environment were assessed in a single-session behavioral paradigm at postnatal days 28 and 70, inclusive. Activity and habituation varied by age with younger rats exhibiting higher activity, less habituation, and less stimulation of activity induced by spatial novelty. During the first and second exposures to the test chamber, 2nd-litter Deficient pups exhibited higher levels of activity than Control rats or 1st-litter Deficient pups and less habituation during the first exposure, but were not more active after introduction of a novel spatial stimulus. The higher level of activity in a familiar environment, but not after introduction of a novel stimulus is consistent with clinical observations in ADHD. The observation of this effect only in 2nd-litter rats fed the Deficient diet suggests that brain DHA content, rather than dietary n-3 PUFA content, likely underlies these effects

Consensus Guidelines for Perioperative Care in Neonatal Intestinal Surgery: Enhanced Recovery After Surgery (ERAS\u3csup\u3e®\u3c/sup\u3e) Society Recommendations

Background: Enhanced Recovery After Surgery (ERAS®) Society guidelines integrate evidence-based practices into multimodal care pathways that have improved outcomes in multiple adult surgical specialties. There are currently no pediatric ERAS® Society guidelines. We created an ERAS® guideline designed to enhance quality of care in neonatal intestinal resection surgery. Methods: A multidisciplinary guideline generation group defined the scope, population, and guideline topics. Systematic reviews were supplemented by targeted searching and expert identification to identify 3514 publications that were screened to develop and support recommendations. Final recommendations were determined through consensus and were assessed for evidence quality and recommendation strength. Parental input was attained throughout the process. Results: Final recommendations ranged from communication strategies to antibiotic use. Topics with poor-quality and conflicting evidence were eliminated. Several recommendations were combined. The quality of supporting evidence was variable. Seventeen final recommendations are included in the proposed guideline. Discussion: We have developed a comprehensive, evidence-based ERAS guideline for neonates undergoing intestinal resection surgery. This guideline, and its creation process, provides a foundation for future ERAS guideline development and can ultimately lead to improved perioperative care across a variety of pediatric surgical specialties

Microbiological oceanography in the region west of the Antarctic Peninsula: Microbial dynamics, nitrogen cycle and carbon flux

Microorganisms are ubiquitous in Southern Ocean habitats and playa vital role in production and ttans-fcnnation of organic matter. Compared to other coastal and oceanic habitats, however, microbial processes in antarctic marine habitats are poorly understood. One major reason is the spatially and temporally variable nature of the habitat and the general inaccessibility of selected habitats (e.g., multi-year pack ice in austral winter). Despite these limitations, the region west of the Antarctic Peninsula is beginning to provide an op-portunity for yeaHound field investigations. Progress to date has focused on the role of microorganisms in the biogeochemical cycling of carbon and associated elements, the regulation of bacterial populations and the relationships between primary production and particulate matter export from the euphotic zone. 1be emergent patterns of carbon and energy flow and of microbial population inter-actions comprise a prospectus and a challenge for future studies in this region. 1