789 research outputs found
MIUS integration and subsystems test program
The MIUS Integration and Subsystems Test (MIST) facility at the Lyndon B. Johnson Space Center was completed and ready in May 1974 for conducting specific tests in direct support of the Modular Integrated Utility System (MIUS). A series of subsystems and integrated tests was conducted since that time, culminating in a series of 24-hour dynamic tests to further demonstrate the capabilities of the MIUS Program concepts to meet typical utility load profiles for a residential area. Results of the MIST Program are presented which achieved demonstrated plant thermal efficiencies ranging from 57 to 65 percent
Machine learning reveals sequence-function relationships in family 7 glycoside hydrolases
Family 7 glycoside hydrolases (GH7) are among the principal enzymes for cellulose degradation in nature and industrially. These enzymes are often bimodular, including a catalytic domain and carbohydrate-binding module (CBM) attached via a flexible linker, and exhibit an active site that binds cello-oligomers of up to ten glucosyl moieties. GH7 cellulases consist of two major subtypes: cellobiohydrolases (CBH) and endoglucanases (EG). Despite the critical importance of GH7 enzymes, there remain gaps in our understanding of how GH7 sequence and structure relate to function. Here, we employed machine learning to gain data-driven insights into relation-ships between sequence, structure, and function across the GH7 family. Machine-learning models, trained only on the number of residues in the active-site loops as features, were able to discriminate GH7 CBHs and EGs with up to 99% ac-curacy, demonstrating that the lengths of loops A4, B2, B3, and B4 strongly correlate with functional subtype across the GH7 family. Classification rules were derived such that specific residues at 42 different sequence positions each predicted the functional subtype with accuracies surpassing 87%. A random forest model trained on residues at 19 positions in the catalytic domain predicted the presence of a CBM with 89.5% accuracy. Our machine learning results recapitulate, as top-performing features, a substantial number of the sequence positions determined by previous experimental studies to play vital roles in GH7 activity. We surmise that the yet-to-be-explored sequence positions among the top-performing features also contribute to GH7 functional variation and may be exploited to understand and manipulate function
Defining the Interactions of Cellobiohydrolase with Substrate through Structure Function Studies: Cooperative Research and Development Final Report, CRADA Number CRD-10-409
NREL researchers will use their expertise and skilled resources in numerical computational modeling to generate structure-function relationships for improved cellulase variant enzymes to support the development of cellulases with improved performance in biomass conversion
Portfolio Vol. III N 4
Moll, Willlie. I Was in Kitchener Camp. Prose. 5-6.
Barrington, John. The Pledging of Homer McGunk. Prose. 7-9.
Stewart, John. In Time of Death. Prose. 10.
Lindsey, Arthur Ward. Retrospect. Prose. 11-13.
Phillips, Allison. Blue Moon. Poetry. 14.
Yoxall, Lindsey E. Pro Patria. Prose. 15-16.
Beckham, Adela. Wind--Dreams. Poetry. 18.
Fields, Brooks. The Doctor Takes a Trip. Prose. 19-20.
Deane, Dorothy. Review of New Books. Prose. 21.
Smith, Duke. Review of New Recordings. Prose. 21.
Timrud, David. Refugee. Prose. 22-23
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Technoeconomic and life-cycle analysis of single-step catalytic conversion of wet ethanol into fungible fuel blendstocks
Technoeconomic and life-cycle analyses are presented for catalytic conversion of ethanol to fungible hydrocarbon fuel blendstocks, informed by advances in catalyst and process development. Whereas prior work toward this end focused on 3-step processes featuring dehydration, oligomerization, and hydrogenation, the consolidated alcohol dehydration and oligomerization (CADO) approach described here results in 1-step conversion of wet ethanol vapor (40 wt% in water) to hydrocarbons and water over a metal-modified zeolite catalyst. A development project increased liquid hydrocarbon yields from 36% of theoretical to >80%, reduced catalyst cost by an order of magnitude, scaled up the process by 300-fold, and reduced projected costs of ethanol conversion 12-fold. Current CADO products conform most closely to gasoline blendstocks, but can be blended with jet fuel at low levels today, and could potentially be blended at higher levels in the future. Operating plus annualized capital costs for conversion of wet ethanol to fungible blendstocks are estimated at 1.44/GJ in the future, similar to the unit energy cost of producing anhydrous ethanol from wet ethanol (100 per barrel but not at 60 per barrel. Life-cycle greenhouse gas emission reductions for CADO-derived hydrocarbon blendstocks closely follow those for the ethanol feedstock
Largest GWAS of PTSD (N=20 070) yields genetic overlap with schizophrenia and sex differences in heritability
The Psychiatric Genomics Consortium-Posttraumatic Stress Disorder group (PGC-
PTSD) combined genome-wide case–control molecular genetic data across 11
multiethnic studies to quantify PTSD heritability, to examine potential shared
genetic risk with schizophrenia, bipolar disorder, and major depressive
disorder and to identify risk loci for PTSD. Examining 20 730 individuals, we
report a molecular genetics-based heritability estimate (h2SNP) for European-
American females of 29% that is similar to h2SNP for schizophrenia and is
substantially higher than h2SNP in European-American males (estimate not
distinguishable from zero). We found strong evidence of overlapping genetic
risk between PTSD and schizophrenia along with more modest evidence of overlap
with bipolar and major depressive disorder. No single-nucleotide polymorphisms
(SNPs) exceeded genome-wide significance in the transethnic (overall) meta-
analysis and we do not replicate previously reported associations. Still, SNP-
level summary statistics made available here afford the best-available
molecular genetic index of PTSD—for both European- and African-American
individuals—and can be used in polygenic risk prediction and genetic
correlation studies of diverse phenotypes. Publication of summary statistics
for ∼10 000 African Americans contributes to the broader goal of increased
ancestral diversity in genomic data resources. In sum, the results demonstrate
genetic influences on the development of PTSD, identify shared genetic risk
between PTSD and other psychiatric disorders and highlight the importance of
multiethnic/racial samples. As has been the case with schizophrenia and other
complex genetic disorders, larger sample sizes are needed to identify specific
risk loci
The Gestational Diabetes Management System (GooDMomS): development, feasibility and lessons learned from a patient-informed, web-based pregnancy and postpartum lifestyle intervention
Abstract Background Gestational diabetes mellitus (GDM) contributes to the epidemic of diabetes and obesity in mothers and their offspring. The primary objective of this pilot study was to: 1) refine the GDM Management System (GooDMomS), a web-based pregnancy and postpartum behavioral intervention and 2) assess the feasibility of the intervention. Methods In phase 1, ten semi-structured interviews were conducted with women experiencing current or recent GDM mellitus GDM to garner pilot data on the web based intervention interface, content, and to solicit recommendations from women about refinements to enhance the GooDMomS intervention site. Interviews were audiotaped, transcribed and independently reviewed to identify major themes with Atlas.ti v7.0. In phase 2, a single-arm feasibility study was conducted and 23 participants were enrolled in the GooDMomS program. Participants received web lessons, self-tracking of weight and glucose, automated feedback and access to a message board for peer support. The primary outcome was feasibility, including recruitment and retention and acceptability. Secondary outcomes included the proportion of women whose gestational weight gain (GWG) was within the Institute of Medicine (IOM) guidelines and who were able to return to their pre-pregnancy weight after delivery. Results Comments from semi-structured interviews focused on: 1) usability of the on-line self-monitoring diary and tracking system, 2) access to a safe, reliable social network for peer support and 3) ability of prenatal clinicians to access the on-line diary for clinical management. Overall, 21 (91 %) completed the pregnancy phase. 15/21 (71 %) of participants were within the Institute of Medicine (IOM) guidelines for GWG. Sixteen (70 %) completed the postpartum phase. 7/16 (43 %) and 9/16 (56 %) of participants returned to their pre-pregnancy weight at 6 and 30 weeks postpartum, respectively. Conclusions This study documents the feasibility of the GooDMomS program. The results can have implications for web technology in perinatal care and inform the current care paradigm for women with GDM. Findings are supportive of further research with recruitment of a larger sample of participants and comparison of the outcomes with the intervention and standard care. Trial registration The study was registered at ClinicalTrials.gov on May 15, 2012 under protocol no. NCT01600534
The P body protein LSm1 contributes to stimulation of hepatitis C virus translation, but not replication, by microRNA-122
The P body protein LSm1 stimulates translation and replication of hepatitis C virus (HCV). As the liver-specific microRNA-122 (miR-122) is required for HCV replication and is associated with P bodies, we investigated whether regulation of HCV by LSm1 involves miR-122. Here, we demonstrate that LSm1 contributes to activation of HCV internal ribosome entry site (IRES)-driven translation by miR-122. This role for LSm1 is specialized for miR-122 translation activation, as LSm1 depletion does not affect the repressive function of miR-122 at 3′ untranslated region (UTR) sites, or miR-122–mediated cleavage at a perfectly complementary site. We find that LSm1 does not influence recruitment of the microRNA (miRNA)-induced silencing complex to the HCV 5′UTR, implying that it regulates miR-122 function subsequent to target binding. In contrast to the interplay between miR-122 and LSm1 in translation, we find that LSm1 is not required for miR-122 to stimulate HCV replication, suggesting that miR-122 regulation of HCV translation and replication have different requirements. For the first time, we have identified a protein factor that specifically contributes to activation of HCV IRES-driven translation by miR-122, but not to other activities of the miRNA. Our results enhance understanding of the mechanisms by which miR-122 and LSm1 regulate HCV
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