170 research outputs found

    Principal investigator in a box: Version 1.2 documentation

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    Principal Investigator (PI) in a box is a computer system designed to help optimize the scientific results of experiments that are performed in space. The system will assist the astronaut experimenters in the collection and analysis of experimental data, recognition and pursuit of 'interesting' results, optimal use of the time allocated to the experiment, and troubleshooting of the experiment apparatus. This document discusses the problems that motivate development of 'PI-in-a-box', and presents a high- level system overview and a detailed description of each of the modules that comprise the current version of the system

    Development of RTM and powder prepreg resins for subsonic aircraft primary structures

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    Dow developed a thermoset resin which could be used to produce composites via the RTM process. The composites formed are useful at 200 F service temperatures after moisture saturation, and are tough systems that are suitable for subsonic aircraft primary structure. At NASA's request, Dow also developed a modified version of the RTM resin system which was suitable for use in producing powder prepreg. In the course of developing the RTM and powder versions of these resins, over 50 different new materials were produced and evaluated

    PI in the sky: The astronaut science advisor on SLS-2

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    The Astronaut Science Advisor (ASA, also known as Principal-Investigator-in-a-Box) is an advanced engineering effort to apply expert systems technology to experiment monitoring and control. Its goal is to increase the scientific value of information returned from experiments on manned space missions. The first in-space test of the system will be in conjunction with Professor Larry Young's (MIT) vestibulo-ocular 'Rotating Dome' experiment on the Spacelab Life Sciences 2 mission (STS-58) in the Fall of 1993. In a cost-saving effort, off-the-shelf equipment was employed wherever possible. Several modifications were necessary in order to make the system flight-worthy. The software consists of three interlocking modules. A real-time data acquisition system digitizes and stores all experiment data and then characterizes the signals in symbolic form; a rule-based expert system uses the symbolic signal characteristics to make decisions concerning the experiment; and a highly graphic user interface requiring a minimum of user intervention presents information to the astronaut operator. Much has been learned about the design of software and user interfaces for interactive computing in space. In addition, we gained a great deal of knowledge about building relatively inexpensive hardware and software for use in space. New technologies are being assessed to make the system a much more powerful ally in future scientific research in space and on the ground

    LiQD Cornea: Pro-regeneration collagen mimetics as patches and alternatives to corneal transplantation

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    Transplantation with donor corneas is the mainstay for treating corneal blindness, but a severe worldwide shortage necessitates the development of other treatment options. Corneal perforation from infection or inflammation is sealed with cyanoacrylate glue. However, the resulting cytotoxicity requires transplantation. LiQD Cornea is an alternative to conventional corneal transplantation and sealants. It is a cell-free, liquid hydrogel matrix for corneal regeneration, comprising short collagen-like peptides conjugated with polyethylene glycol and mixed with fibrinogen to promote adhesion within tissue defects. Gelation occurs spontaneously at body temperature within 5 min. Light exposure is not required-particularly advantageous because patients with corneal inflammation are typically photophobic. The self-assembling, fully defined, synthetic collagen analog is much less costly than human recombinant collagen and reduces the risk of immune rejection associated with xenogeneic materials. In situ gelation potentially allows for clinical application in outpatient clinics instead of operating theaters, maximizing practicality, and minimizing health care costs

    Management of cull dairy cows—Consensus of an expert consultation in Canada

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    Many cull dairy cows enter the marketing system and travel to widely dispersed and specialized slaughter plants, and they may experience multiple handling events (e.g., loading, unloading, mixing), change of ownership among dealers, and feed and water deprivation during transport and at livestock markets. The objectives of this study were to describe the diverse management of cull dairy cows in Canada and establish consensus on ways to achieve improvements. A 2-day expert consultation meeting was convened, involving farmers, veterinarians, regulators, and experts in animal transport, livestock auction, and slaughter. The 15 participants, recruited from across Canada, discussed regional management practices for cull cattle, related risk factors, animal welfare problems, and recommendations. An audio recording of the meeting was used to extract descriptive data on cull cattle management and identify points of agreement. Eight consensus points were reached: (1) to assemble information on travel times and delays from farm to slaughter; (2) to increase awareness among producers and herd veterinarians of potential travel distances and delays; (3) to promote pro-active culling; (4) to improve the ability of personnel to assess animal condition before loading; (5) to identify local options for slaughter of cull dairy cows; (6) to investigate different management options such as emergency slaughter and mobile slaughter; (7) to ensure that all farms and auctions have, or can access, personnel trained and equipped for euthanasia; and (8) to promote cooperation among enforcement agencies and wider adoption of beneficial regulatory options

    Extracellular DNA release, quorum sensing, and PrrF1/F2 small RNAs are key players in Pseudomonas aeruginosa tobramycin-enhanced biofilm formation

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    Biofilms are structured microbial communities that are the leading cause of numerous chronic infections which are difficult to eradicate. Within the lungs of individuals with cystic fibrosis (CF), Pseudomonas aeruginosa causes persistent biofilm infection that is commonly treated with aminoglycoside antibiotics such as tobramycin. However, sublethal concentrations of this aminoglycoside were previously shown to increase biofilm formation by P. aeruginosa, but the underlying adaptive mechanisms still remain elusive. Herein, we combined confocal laser scanning microscope analyses, proteomics profiling, gene expression assays and phenotypic studies to unravel P. aeruginosa potential adaptive mechanisms in response to tobramycin exposure during biofilm growth. Under this condition, we show that the modified biofilm architecture is related at least in part to increased extracellular DNA (eDNA) release, most likely as a result of biofilm cell death. Furthermore, the activity of quorum sensing (QS) systems was increased, leading to higher production of QS signaling molecules. We also demonstrate upon tobramycin exposure an increase in expression of the PrrF small regulatory RNAs, as well as expression of iron uptake systems. Remarkably, biofilm biovolumes and eDNA relative abundances in pqs and prrF mutant strains decrease in the presence of tobramycin. Overall, our findings offer experimental evidences for a potential adaptive mechanism linking PrrF sRNAs, QS signaling, biofilm cell death, eDNA release, and tobramycin-enhanced biofilm formation in P. aeruginosa. These specific adaptive mechanisms should be considered to improve treatment strategies against P. aeruginosa biofilm establishment in CF patients’ lungs

    Vulnerability to high risk sexual behaviour (HRSB) following exposure to war trauma as seen in post-conflict communities in eastern uganda: a qualitative study

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    <p>Abstract</p> <p>Background</p> <p>Much of the literature on the relationship between conflict-related trauma and high risk sexual behaviour (HRSB) often focuses on refugees and not mass in-country displaced people due to armed conflicts. There is paucity of research about contexts underlying HRSB and HIV/AIDS in conflict and post-conflict communities in Uganda. Understanding factors that underpin vulnerability to HRSB in post-conflict communities is vital in designing HIV/AIDS prevention interventions. We explored the socio-cultural factors, social interactions, socio-cultural practices, social norms and social network structures that underlie war trauma and vulnerability to HRSB in a post-conflict population.</p> <p>Methods</p> <p>We did a cross-sectional qualitative study of 3 sub-counties in <it>Katakwi </it>district and 1 in <it>Amuria </it>in Uganda between March and May 2009. We collected data using 8 FGDs, 32 key informant interviews and 16 in-depth interviews. We tape-recorded and transcribed the data. We followed thematic analysis principles to manage, analyse and interpret the data. We constantly identified and compared themes and sub-themes in the dataset as we read the transcripts. We used illuminating verbatim quotations to illustrate major findings.</p> <p>Results</p> <p>The commonly identified HRSB behaviours include; transactional sex, sexual predation, multiple partners, early marriages and forced marriages. Breakdown of the social structure due to conflict had resulted in economic destruction and a perceived soaring of vulnerable people whose propensity to HRSB is high. Dishonour of sexual sanctity through transactional sex and practices like incest mirrored the consequence of exposure to conflict. HRSB was associated with concentration of people in camps where idleness and unemployment were the norm. Reports of girls and women who had been victims of rape and defilement by men with guns were common. Many people were known to have started to display persistent worries, hopelessness, and suicidal ideas and to abuse alcohol.</p> <p>Conclusions</p> <p>The study demonstrated that conflicts disrupt the socio-cultural set up of communities and destroy sources of people's livelihood. Post-conflict socio-economic reconstruction needs to encompass programmes that restructure people's morals and values through counselling. HIV/AIDS prevention programming in post-conflict communities should deal with socio-cultural disruptions that emerged during conflicts. Some of the disruptions if not dealt with, could become normalized yet they are predisposing factors to HRSB. Socio-economic vulnerability as a consequence of conflict seemed to be associated with HRSB through alterations in sexual morality. To pursue safer sexual health choices, people in post-conflict communities need life skills.</p

    Genome-wide association study of placental weight identifies distinct and shared genetic influences between placental and fetal growth

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    A well-functioning placenta is essential for fetal and maternal health throughout pregnancy. Using placental weight as a proxy for placental growth, we report genome-wide association analyses in the fetal (n = 65,405), maternal (n = 61,228) and paternal (n = 52,392) genomes, yielding 40 independent association signals. Twenty-six signals are classified as fetal, four maternal and three fetal and maternal. A maternal parent-of-origin effect is seen near KCNQ1. Genetic correlation and colocalization analyses reveal overlap with birth weight genetics, but 12 loci are classified as predominantly or only affecting placental weight, with connections to placental development and morphology, and transport of antibodies and amino acids. Mendelian randomization analyses indicate that fetal genetically mediated higher placental weight is causally associated with preeclampsia risk and shorter gestational duration. Moreover, these analyses support the role of fetal insulin in regulating placental weight, providing a key link between fetal and placental growth
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