A geometric model of a V-slit Sun sensor correcting for spacecraft wobble

A V-Slit sun sensor is body-mounted on a spin-stabilized spacecraft. During injection from a parking or transfer orbit to some final orbit, the spacecraft may not be dynamically balanced. This may result in wobble about the spacecraft spin axis as the spin axis may not be aligned with the spacecraft's axis of symmetry. While the widely used models in Spacecraft Attitude Determination and Control, edited by Wertz, correct for separation, elevation, and azimuthal mounting biases, spacecraft wobble is not taken into consideration. A geometric approach is used to develop a method for measurement of the sun angle which corrects for the magnitude and phase of spacecraft wobble. The algorithm was implemented using a set of standard mathematical routines for spherical geometry on a unit sphere

Limitations of Water Resources Infrastructure for Reducing Community Vulnerabilities to Extremes and Uncertainty of Flood and Drought

Debate and deliberation surrounding climate change has shifted from mitigation toward adaptation, with much of the adaptation focus centered on adaptive practices, and infrastructure development. However, there is little research assessing expected impacts, potential benefits, and design challenges that exist for reducing vulnerability to expected climate impacts. The uncertainty of design requirements and associated government policies, and social structures that reflect observed and projected changes in the intensity, duration, and frequency of water-related climate events leaves communities vulnerable to the negative impacts of potential flood and drought. The results of international research into how agricultural infrastructure features in current and planned adaptive capacity of rural communities in Argentina, Canada, and Colombia indicate that extreme hydroclimatic events, as well as climate variability and unpredictability are important for understanding and responding to community vulnerability. The research outcomes clearly identify the need to deliberately plan, coordinate, and implement infrastructures that support community resiliency.Fil: McMartin, Dena W.. University of Regina; CanadáFil: Hernani Merino, Bruno H.. University of Regina; CanadáFil: Bonsal, Barrie. Environment Canada; CanadáFil: Hurlbert, Margot. University of Regina; CanadáFil: Villalba, Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Cientifícas y Tecnológicas; ArgentinaFil: Ocampo, Olga L.. Universidad Autónoma de Manizales; ColombiaFil: Upegui, Jorge Julián Vélez. Universidad Nacional de Colombia; ColombiaFil: Poveda, Germán. Universidad Nacional de Colombia; ColombiaFil: Sauchyn, David J.. University of Regina; Canad

Advances in prevention and therapy of neonatal dairy calf diarrhoea : a systematical review with emphasis on colostrum management and fluid therapy

Neonatal calf diarrhoea remains the most common cause of morbidity and mortality in preweaned dairy calves worldwide. This complex disease can be triggered by both infectious and non-infectious causes. The four most important enteropathogens leading to neonatal dairy calf diarrhoea are Escherichia coli, rota-and coronavirus, and Cryptosporidium parvum. Besides treating diarrhoeic neonatal dairy calves, the veterinarian is the most obvious person to advise the dairy farmer on prevention and treatment of this disease. This review deals with prevention and treatment of neonatal dairy calf diarrhoea focusing on the importance of a good colostrum management and a correct fluid therapy

Training a Scoring Function for the Alignment of Small Molecules

A comprehensive data set of aligned ligands with highly similar binding pockets from the Protein Data Bank has been built. Based on this data set, a scoring function for recognizing good alignment poses for small molecules has been developed. This function is based on atoms and hydrogen-bond projected features. The concept is simply that atoms and features of a similar type (hydrogen-bond acceptors/donors and hydrophobic) tend to occupy the same space in a binding pocket and atoms of incompatible types often tend to avoid the same space. Comparison with some recently published results of small molecule alignments shows that the current scoring function can lead to performance better than those of several existing methods

Congenital anomalies in newborns to women employed in jobs with frequent exposure to organic solvents - a register-based prospective study

<p>Abstract</p> <p>Background</p> <p>The foetal effects of occupational exposure to organic solvents in pregnancy are still unclear. Our aim was to study the risk of non-chromosomal congenital anomalies at birth in a well-defined population of singletons born to women employed as painters and spoolers in early pregnancy, compared to women in non-hazardous occupations.</p> <p>Method</p> <p>The study population for this prospective cohort study was singleton newborns delivered to working mothers in the industrial community of Mončegorsk in the period 1973-2005. Occupational information and characteristics of the women and their newborns was obtained from the local population-based birth register.</p> <p>Results</p> <p>The 597 women employed as painters, painter-plasterers or spoolers had 712 singleton births, whereof 31 (4.4%) were perinatally diagnosed with 37 malformations. Among the 10 561 newborns in the group classified as non-exposed, 397 (3.9%) had one or more malformations. The overall prevalence in the exposed group was 520/10 000 births [95% confidence limits (CL): 476, 564], and 436/10 000 births (95% CL: 396, 476) in the unexposed. Adjusted for young maternal age, smoking during pregnancy, maternal congenital malformation and year of birth, the odds ratio (OR) was 1.24 (95% CL: 0.85, 1.82); for multiple anomalies it was 1.54 (95% CL: 0.66, 3.59).</p> <p>The largest organ-system specific difference in prevalence between the two groups was observed for malformations of the circulatory system: 112/10 000 (95% CL: 35, 190) in the exposed group, and 42/10 000 (95% CL: 29, 54) in the unexposed, with an adjusted OR of 2.03 (95% CL: 0.85, 4.84). The adjusted ORs for malformations of the genital organs and musculoskeletal system were 2.24 (95% CI: 0.95, 5.31) and 1.12 (95% CI: (0.62, 2.02), respectively.</p> <p>Conclusion</p> <p>There appeared to be a higher risk of malformations of the circulatory system and genital organs at birth among newborns to women in occupations with organic solvent exposure during early pregnancy (predominantly employed as painters). However, the findings were not statistically conclusive. Considering that these two categories of malformations are not readily diagnosed perinatally, the difference in prevalence between the exposed and unexposed may have been underestimated.</p

Small Molecules Targeted to a Non-Catalytic “RVxF” Binding Site of Protein Phosphatase-1 Inhibit HIV-1

HIV-1 Tat protein recruits host cell factors including CDK9/cyclin T1 to HIV-1 TAR RNA and thereby induces HIV-1 transcription. An interaction with host Ser/Thr protein phosphatase-1 (PP1) is critical for this function of Tat. PP1 binds to a Tat sequence, Q35VCF38, which resembles the PP1-binding “RVxF” motif present on PP1-binding regulatory subunits. We showed that expression of PP1 binding peptide, a central domain of Nuclear Inhibitor of PP1, disrupted the interaction of HIV-1 Tat with PP1 and inhibited HIV-1 transcription and replication. Here, we report small molecule compounds that target the “RVxF”-binding cavity of PP1 to disrupt the interaction of PP1 with Tat and inhibit HIV-1 replication. Using the crystal structure of PP1, we virtually screened 300,000 compounds and identified 262 small molecules that were predicted to bind the “RVxF”-accommodating cavity of PP1. These compounds were then assayed for inhibition of HIV-1 transcription in CEM T cells. One of the compounds, 1H4, inhibited HIV-1 transcription and replication at non-cytotoxic concentrations. 1H4 prevented PP1-mediated dephosphorylation of a substrate peptide containing an RVxF sequence in vitro. 1H4 also disrupted the association of PP1 with Tat in cultured cells without having an effect on the interaction of PP1 with the cellular regulators, NIPP1 and PNUTS, or on the cellular proteome. Finally, 1H4 prevented the translocation of PP1 to the nucleus. Taken together, our study shows that HIV- inhibition can be achieved through using small molecules to target a non-catalytic site of PP1. This proof-of-principle study can serve as a starting point for the development of novel antiviral drugs that target the interface of HIV-1 viral proteins with their host partners

Landscape Impacts of Hydraulic Fracturing Development and Operations on Surface Water and Watersheds

Landscapes and watersheds are complex cultural biogeoclimatic systems that are not easily bounded, measured or understood by a single body of expertise. This makes it very challenging to locate and synthesize the best available science to identify what decision‐makers need to know about landscape and watershed impacts of hydraulic fracturing. ‘Landscape’ is not a physical object as much as it is a spatial context for multiple natural processes and human activities. As such, what decision‐makers need to know depends upon the specific locations and situational conditions in which hydraulic fracturing is operating. Fracking exists in landscape and watershed contexts that are highly variable at different scales and across different regions. There is a relatively high degree of certainty, within predictable engineered limits, about specific well‐based fracking operations. In contrast, there is a lot of uncertainty about how complex social ecological landscape and watershed systems function. Potential landscape and watershed impacts exist in the context of a complex and integrated system of spatial and functional inter‐connections and inter‐relationships and needs to be understood in this system context (Figure A‐1). We approached landscape and watershed impacts of hydraulic fracturing from a multi‐disciplinary social and natural science framework in order to try and capture this complexity. We emerged with common agreement around the difficulties presented by ‘silos’ of expertise when trying to deal with complex systems. The primary learning from our multidisciplinary approach is the need for greater institutional opportunities to integrate and coordinate a spectrum of approaches to address knowledge gaps in multiple system interactions across scales and involving system threshold effects that may be social in nature as well as biogeochemical