485 research outputs found
Development of a curved pipe capability for the NASTRAN finite element program
A curved pipe element capability for the NASTRAN structural analysis program is developed using the NASTRAN dummy element feature. A description is given of the theory involved in the subroutines which describe stiffness, mass, thermal and enforced deformation loads, and force and stress recovery for the curved pipe element. Incorporation of these subroutines into NASTRAN is discussed. Test problems are proposed. Instructions on use of the new element capability are provided
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Semigroups
The purpose of this paper is to present some fundamental properties of algebraic semigroups. The development of the theory of semigroups has appeared for the most part in the past few years of this century. A semigroup is the result of a weakening of the axioms for a group. Thus all groups are semigroups. That the study of semigroups is very closely related to the abstract study of general transformations is, perhaps, one of the reasons for the rapid development of semigroup theory
A Consistent Dark Matter Interpretation For CoGeNT and DAMA/LIBRA
In this paper, we study the recent excess of low energy events observed by
the CoGeNT collaboration and the annual modulation reported by the DAMA/LIBRA
collaboration, and discuss whether these signals could both be the result of
the same elastically scattering dark matter particle. We find that, without
channeling but when taking into account uncertainties in the relevant quenching
factors, a dark matter candidate with a mass of approximately ~7.0 GeV and a
cross section with nucleons of sigma_{DM-N} ~2x10^-4 pb (2x10^-40 cm^2) could
account for both of these observations. We also comment on the events recently
observed in the oxygen band of the CRESST experiment and point out that these
could potentially be explained by such a particle. Lastly, we compare the
region of parameter space favored by DAMA/LIBRA and CoGeNT to the constraints
from XENON 10, XENON 100, and CDMS (Si) and find that these experiments cannot
at this time rule out a dark matter interpretation of these signals.Comment: 8 pages, 6 figure
Application of Wavelet Transform on Signal Analysis
This research was supported by a Grant in Aid of Research by Sigma Xi, The Scientific Research Society
The engineering classroom is still relevant
Citation: Fitzsimmons, E. J., Tucker-Kulesza, S. E., Li, X., Jeter, W., & Fallin, J. R. (2016). The engineering classroom is still relevant.Attrition in engineering is a complex issue with dynamically linked variables related to teaching methods in the classroom, student learning behaviors, and student perceptions of difficult material. Extensive research has been conducted in order to understand common, yet ineffective teaching practices in engineering that result in the loss of numerous future engineers. The objective of this study was to determine student actions necessary to achieve a desired grade in any engineering course, regardless of course delivery method and instructor effectiveness in the classroom. An anonymous survey was disseminated and logistic regression models were developed in order to determine relationships between self-regulated learning behaviors and final grades in seven freshman to senior engineering classes taught by civil engineering faculty. A total of five prediction models were developed for each letter grade, with the failing grade "F" serving as the baseline condition, or null model. The models found three significant variables that affect a student's final grade: regular class attendance, note-taking during class, and if he or she could keep up with the instructor during lecture. These interactive learning behaviors were all identified as critical for success, defining success as receiving an "A" in an engineering course. The combination of students taking notes and attending class showed the highest probability of a student receiving an "A." Results of this study have been summarized into a graphic that the authors show and discuss during the first class with students. This powerful graphic shows students what they can do in classes of all levels of civil engineering to succeed in their ever-changing learning environment. © American Society for Engineering Education, 2016
Stellar Orbit Constraints on Neutralino Annihilation at the Galactic Center
Dark matter annihilation has been proposed to explain the TeV gamma rays
observed from the Galactic Center. We study constraints on this hypothesis
coming from the mass profile around the Galactic Center measured by observing
stellar dynamics. We show that for current particle models, the constraints on
the dark matter density profile from measurements of mass by infrared
observations are comparable to the constraints from the measurements of the TeV
source extension.Comment: replaced with accepted version, improved presentation, some figures
corrected, results unchange
A GAL4 Driver Resource for Developmental and Behavioral Studies on the Larval CNS of Drosophila
SummaryWe report the larval CNS expression patterns for 6,650 GAL4 lines based on cis-regulatory regions (CRMs) from the Drosophila genome. Adult CNS expression patterns were previously reported for this collection, thereby providing a unique resource for determining the origins of adult cells. An illustrative example reveals the origin of the astrocyte-like glia of the ventral CNS. Besides larval neurons and glia, the larval CNS contains scattered lineages of immature, adult-specific neurons. Comparison of lineage expression within this large collection of CRMs provides insight into the codes used for designating neuronal types. The CRMs encode both dense and sparse patterns of lineage expression. There is little correlation between brain and thoracic lineages in patterns of sparse expression, but expression in the two regions is highly correlated in the dense mode. The optic lobes, by comparison, appear to use a different set of genetic instructions in their development
The cancer gene WWOX behaves as an inhibitor of SMAD3 transcriptional activity via direct binding
Background: The WW domain containing protein WWOX has been postulated to behave as a tumor suppressor in breast and other cancers. Expression of this protein is lost in over 70% of ER negative tumors. This prompted us to investigate the phenotypic and gene expression effects of loss of WWOX expression in breast cells.
Methods: Gene expression microarrays and standard in vitro assays were performed on stably silenced WWOX (shRNA) normal breast cells. Bioinformatic analyses were used to identify gene networks and transcriptional regulators affected by WWOX silencing. Co-immunoprecipitations and GST-pulldowns were used to demonstrate a direct interaction between WWOX and SMAD3. Reporter assays, ChIP, confocal microscopy and in silico analyses were employed to determine the effect of WWOX silencing on TGFβ-signaling.
Results: WWOX silencing affected cell proliferation, motility, attachment and deregulated expression of genes involved in cell cycle, motility and DNA damage. Interestingly, we detected an enrichment of targets activated by the SMAD3 transcription factor, including significant upregulation of ANGPTL4, FST, PTHLH and SERPINE1 transcripts. Importantly, we demonstrate that the WWOX protein physically interacts with SMAD3 via WW domain 1. Furthermore, WWOX expression dramatically decreases SMAD3 occupancy at the ANGPTL4 and SERPINE1 promoters and significantly quenches activation of a TGFβ responsive reporter. Additionally, WWOX expression leads to redistribution of SMAD3 from the nuclear to the cytoplasmic compartment. Since the TGFβ target ANGPTL4 plays a key role in lung metastasis development, we performed a meta-analysis of ANGPTL4 expression relative to WWOX in microarray datasets from breast carcinomas. We observed a significant inverse correlation between WWOX and ANGPTL4. Furthermore, the WWOX lo/ANGPTL4hi cluster of breast tumors is enriched in triple-negative and basal-like sub-types. Tumors with this gene expression signature could represent candidates for anti-TGFβ targeted therapies.
Conclusions: We show for the first time that WWOX modulates SMAD3 signaling in breast cells via direct WW-domain mediated binding and potential cytoplasmic sequestration of SMAD3 protein. Since loss of WWOX expression increases with breast cancer progression and it behaves as an inhibitor of SMAD3 transcriptional activity these observations may help explain, at least in part, the paradoxical pro-tumorigenic effects of TGFβ signaling in advanced breast cancer.Facultad de Ciencias MédicasCentro de Investigaciones Inmunológicas Básicas y Aplicada
The cancer gene WWOX behaves as an inhibitor of SMAD3 transcriptional activity via direct binding
Background: The WW domain containing protein WWOX has been postulated to behave as a tumor suppressor in breast and other cancers. Expression of this protein is lost in over 70% of ER negative tumors. This prompted us to investigate the phenotypic and gene expression effects of loss of WWOX expression in breast cells. Methods: Gene expression microarrays and standard in vitro assays were performed on stably silenced WWOX (shRNA) normal breast cells. Bioinformatic analyses were used to identify gene networks and transcriptional regulators affected by WWOX silencing. Co-immunoprecipitations and GST-pulldowns were used to demonstrate a direct interaction between WWOX and SMAD3. Reporter assays, ChIP, confocal microscopy and in silico analyses were employed to determine the effect of WWOX silencing on TGFβ-signaling. Results: WWOX silencing affected cell proliferation, motility, attachment and deregulated expression of genes involved in cell cycle, motility and DNA damage. Interestingly, we detected an enrichment of targets activated by the SMAD3 transcription factor, including significant upregulation of ANGPTL4, FST, PTHLH and SERPINE1 transcripts. Importantly, we demonstrate that the WWOX protein physically interacts with SMAD3 via WW domain 1. Furthermore, WWOX expression dramatically decreases SMAD3 occupancy at the ANGPTL4 and SERPINE1 promoters and significantly quenches activation of a TGFβ responsive reporter. Additionally, WWOX expression leads to redistribution of SMAD3 from the nuclear to the cytoplasmic compartment. Since the TGFβ target ANGPTL4 plays a key role in lung metastasis development, we performed a meta-analysis of ANGPTL4 expression relative to WWOX in microarray datasets from breast carcinomas. We observed a significant inverse correlation between WWOX and ANGPTL4. Furthermore, the WWOXlo/ANGPTL4hi cluster of breast tumors is enriched in triple-negative and basal-like sub-types. Tumors with this gene expression signature could represent candidates for anti-TGFβ targeted therapies. Conclusions: We show for the first time that WWOX modulates SMAD3 signaling in breast cells via direct WW-domain mediated binding and potential cytoplasmic sequestration of SMAD3 protein. Since loss of WWOX expression increases with breast cancer progression and it behaves as an inhibitor of SMAD3 transcriptional activity these observations may help explain, at least in part, the paradoxical pro-tumorigenic effects of TGFβ signaling in advanced breast cancer.Fil: Ferguson, Brent W.. University of Texas; Estados UnidosFil: Gao, Xinsheng. University of Texas; Estados UnidosFil: Zelazowski, Maciej J.. University of Texas; Estados UnidosFil: Lee, Jaeho. University of Texas; Estados UnidosFil: Jeter, Collene R.. University of Texas; Estados UnidosFil: Abba, Martín Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Inmunológicas Básicas y Aplicadas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Aldaz, Claudio Marcelo. University of Texas; Estados Unido
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