Design and testing of a high power spacecraft thermal management system

The design and test results are presented of an ammonia hybrid capillary pumped loop thermal control system which could be used for heat acquisition and transport on future large space platforms and attached payloads, such as those associated with the NASA Space Station. The High Power Spacecraft Thermal Management System (HPSTM) can operate as either a passive, capillary pumped two phase thermal control system, or, when additional pressure head is required, as a mechanically pumped loop. Testing has shown that in the capillary mode, the HPSTM evaporators can acquire a total heat load of between 600 W and 24 kW, transported over 10 meters, at a maximum heat flux density of 4.3 W/sq cm. With the mechanical pump circulating the ammonia, a heat acquisition potential of 52 kW was demonstrated for 15 minutes without an evaporator failure. These results represent a significant improvement over the maximum transport capability previously displayed in other capillary systems. The HPSTM system still retains the proven capillary capabilities of heat load sharing and flow control between evaporator plates, rapid power cycling, and nonuniform heating in both the capillary and hybrid operating modes

Microbial Degradation of the Leachable and Lignocellulosic Components of Leaves and Wood from \u3cem\u3eRhizophora mangle\u3c/em\u3e in a Tropical Mangrove Swamp

Preparations of uniformly [14C] labeled mangrove leaves and specifically radiolabeled [14C-lignin] lignocelluloses and [14C -polysaccharide]lignocelluloses from mangrove leaves and wood were used in experiments to determine the microbial rates of mineralization of the leachable and lignocellulosic components of mangrove detritus in aerobic and anaerobic sediments of a tropical mangrove swamp. The bulk of the leachable fraction from mangrove leaves was mineralized relatively rapidly and was assimilated into microbial biomass with high efficiency (30 %). In contrast, rates of mineralization of the lignocellulosic component of mangrove leaves and wood were 10fold lower than mineralization rates of the leachable fraction. The polysaccharide component of the lignocelluloses was mineralized at rates 2 times higher than rates of mineralization of the lignin component, indicating that mangrove detritus becomes relatively enriched in lignin-derived carbon with time. Anaerobic rates of mineralization of the leachable and lignocellulosic components of mangrove leaves and wood were 10 to 30 times lower than respective aerobic mineralization rates, suggesting a very long residence time for mangrove detritus in anaerobic sediments. Comparison of the rates of degradation of mangrove detritus in sediments from a mangrove swamp and a salt marsh demonstrated that the lignocellulolytic potential in sediments of the two marine ecosystems are similar, but that lignocellulose from mangroves is less biodegradable than lignocellulose from the salt-marsh plants, Spartina alterniflora and Juncus roemerianus

HAMEV and SQRED: Fortran 77 Subroutines for Computing the Eigenvalues of Hamiltonian Matrices Using Van Loanss Square Reduced Method

This paper describes LAPACK-based Fortran 77 subroutines for the reduction of a Hamiltonian matrix to square-reduced form and the approximation of all its eigenvalues using the implicit version of Van Loan's method. The transformation of the Hamilto- nian matrix to a square-reduced Hamiltonian uses only orthogonal symplectic similarity transformations. The eigenvalues can then be determined by applying the Hessenberg QR iteration to a matrix of half the order of the Hamiltonian matrix and taking the square roots of the computed values. Using scaling strategies similar to those suggested for algebraic Riccati equations can in some cases improve the accuracy of the computed eigenvalues. We demonstrate the performance of the subroutines for several examples and show how they can be used to solve some control-theoretic problems

Integrating protein structures and precomputed genealogies in the Magnum database: Examples with cellular retinoid binding proteins

BACKGROUND: When accurate models for the divergent evolution of protein sequences are integrated with complementary biological information, such as folded protein structures, analyses of the combined data often lead to new hypotheses about molecular physiology. This represents an excellent example of how bioinformatics can be used to guide experimental research. However, progress in this direction has been slowed by the lack of a publicly available resource suitable for general use. RESULTS: The precomputed Magnum database offers a solution to this problem for ca. 1,800 full-length protein families with at least one crystal structure. The Magnum deliverables include 1) multiple sequence alignments, 2) mapping of alignment sites to crystal structure sites, 3) phylogenetic trees, 4) inferred ancestral sequences at internal tree nodes, and 5) amino acid replacements along tree branches. Comprehensive evaluations revealed that the automated procedures used to construct Magnum produced accurate models of how proteins divergently evolve, or genealogies, and correctly integrated these with the structural data. To demonstrate Magnum's capabilities, we asked for amino acid replacements requiring three nucleotide substitutions, located at internal protein structure sites, and occurring on short phylogenetic tree branches. In the cellular retinoid binding protein family a site that potentially modulates ligand binding affinity was discovered. Recruitment of cellular retinol binding protein to function as a lens crystallin in the diurnal gecko afforded another opportunity to showcase the predictive value of a browsable database containing branch replacement patterns integrated with protein structures. CONCLUSION: We integrated two areas of protein science, evolution and structure, on a large scale and created a precomputed database, known as Magnum, which is the first freely available resource of its kind. Magnum provides evolutionary and structural bioinformatics resources that are useful for identifying experimentally testable hypotheses about the molecular basis of protein behaviors and functions, as illustrated with the examples from the cellular retinoid binding proteins

Phylogenomic approaches to common problems encountered in the analysis of low copy repeats: The sulfotransferase 1A gene family example

BACKGROUND: Blocks of duplicated genomic DNA sequence longer than 1000 base pairs are known as low copy repeats (LCRs). Identified by their sequence similarity, LCRs are abundant in the human genome, and are interesting because they may represent recent adaptive events, or potential future adaptive opportunities within the human lineage. Sequence analysis tools are needed, however, to decide whether these interpretations are likely, whether a particular set of LCRs represents nearly neutral drift creating junk DNA, or whether the appearance of LCRs reflects assembly error. Here we investigate an LCR family containing the sulfotransferase (SULT) 1A genes involved in drug metabolism, cancer, hormone regulation, and neurotransmitter biology as a first step for defining the problems that those tools must manage. RESULTS: Sequence analysis here identified a fourth sulfotransferase gene, which may be transcriptionally active, located on human chromosome 16. Four regions of genomic sequence containing the four human SULT1A paralogs defined a new LCR family. The stem hominoid SULT1A progenitor locus was identified by comparative genomics involving complete human and rodent genomes, and a draft chimpanzee genome. SULT1A expansion in hominoid genomes was followed by positive selection acting on specific protein sites. This episode of adaptive evolution appears to be responsible for the dopamine sulfonation function of some SULT enzymes. Each of the conclusions that this bioinformatic analysis generated using data that has uncertain reliability (such as that from the chimpanzee genome sequencing project) has been confirmed experimentally or by a "finished" chromosome 16 assembly, both of which were published after the submission of this manuscript. CONCLUSION: SULT1A genes expanded from one to four copies in hominoids during intra-chromosomal LCR duplications, including (apparently) one after the divergence of chimpanzees and humans. Thus, LCRs may provide a means for amplifying genes (and other genetic elements) that are adaptively useful. Being located on and among LCRs, however, could make the human SULT1A genes susceptible to further duplications or deletions resulting in 'genomic diseases' for some individuals. Pharmacogenomic studies of SULT1Asingle nucleotide polymorphisms, therefore, should also consider examining SULT1A copy number variability when searching for genotype-phenotype associations. The latest duplication is, however, only a substantiated hypothesis; an alternative explanation, disfavored by the majority of evidence, is that the duplication is an artifact of incorrect genome assembly

Understanding Parental Educational Involvement: The Roles of Parental General and Child-Specific School Readiness Beliefs

Making a smooth transition to the K–12 (kindergarten through Grade 12) classroom context sets the stage for academic success throughout the life course. Parents’ early education-related behaviors are linked with children’s adjustment, yet less is known about how parental school readiness beliefs motivate parenting practices at this educational transition. We investigated the associations between parental school readiness beliefs (general and child-specific) following the transition to kindergarten and parents’ involvement the following year. Using data from the Early Childhood Longitudinal Study—Kindergarten 2011 cohort (N = 9,790), general school readiness beliefs and child-specific academic and behavioral competency beliefs were associated with school-based involvement in first grade. Kindergarten parents who held higher child-specific academic competency beliefs also reported less homework involvement and had greater teacher-reported classroom-based involvement in first grade. Family poverty status differences did not emerge. Findings can inform efforts to increase parental involvement by elucidating the ways in which parents’ beliefs about their children motivate involvement strategies

Primary cutaneous anaplastic large cell lymphoma shows a distinct miRNA expression profile and reveals differences from tumor-stage mycosis fungoides

Copyright @ 2012 John Wiley & SonsThe miRNA expression profiles of skin biopsies from 14 primary cutaneous anaplastic large cell lymphoma (C-ALCL) patients were analysed with miRNA microarrays using the same control group of 12 benign inflammatory dermatoses (BID) as previously used to study the miRNA expression profile of tumor-stage mycosis fungoides (MF). We identified 13 differentially expressed miRNAs between C-ALCL and BID. The up-regulation of miR-155, miR-27b, miR-30c and miR-29b in C-ALCL was validated by miRNA-Q-PCR on independent study groups. Additionally, the miRNA expression profiles of C-ALCL were compared with those of tumor-stage MF. Although miRNA microarray analysis did not identify statistically significant differentially expressed miRNAs, miRNA-Q-PCR demonstrated statistically significantly differential expression of miR-155, miR-27b, miR-93, miR-29b and miR-92a between tumor-stage MF and C-ALCL. This study, the first describing the miRNA expression profile of C-ALCL, reveals differences with tumor-stage MF, suggesting a different contribution to the pathogenesis of these lymphomas.This work was funded by grants from Netherlands Organization for Scientific Research (NWO) (MHV) and the Fondation Rene´ Touraine (MvK), and grants from the Leukaemia and Lymphoma Research (EB) and the Julian Starmer-Smith Memorial Fund (CHL)

A clinical evaluation of the Alpha D progressive addition lens

A randomly selected clinic population (n=18) of emmetropes and contact lens wearing presbyopes was fit with the Alpha D progressive additions lens. Subjects were asked to wear the lens for three weeks then respond to a questionnaire assessing adaptation, visual acuity, visual comfort, and acceptability of the Alpha D lens. Subjects reported early adaptation, minor symptomatology, and an overall feeling of visual comfort with the lens. Distortion was reported as a problem as well as difficulty when utilized for desk work. Subject preference between the Alpha D lens and previous lens forms (bifocals, hair eyes, and progressive addition lenses) was mixed, finding 50% preferring the Alpha D lens over their original form

Characteristics and Predictors for Students Classified with Emotional and Behavioral Disorder Who Have Also Experienced Maltreatment

Though experiencing maltreatment (abuse or neglect) appears to be common in students with the special education label of emotional and behavioral disorders (EBD), little research has been devoted to this topic by EBD educators. This paper uses archived file drawer data from 1992 that focuses on 149 students newly classified with EBD for whom a wide range of enrollment variables was collected, and who were subsequently followed up on an average of 8 years later to assess their educational outcomes. At enrollment, experiences of maltreatment were determined to have occurred in 57.7% of these participants. The group who experienced maltreatment was predicted at enrollment only by the family stress of having at least one natural parent with a history of psychiatric illness, although the concordance was not strong (52.3%). When the children who experienced maltreatment were next divided into two longitudinal groups according to educational outcomes (52.3% successful), the enrollment variables of the presence of anxiety and/or depressive disorder and younger age predicted the successful outcome group with good concordance (76.0%). Professional and programmatic implications for educators of students identified with EBD who have also experienced maltreatment are discussed, along with practical recommendations for serving this population