The magnitude and directions of strains and stresses in edge loaded concrete slabs

The concrete industry in the United States represents one of the fastest growing segments of the national economy. Many reasons for this may be given, among which are, the durability of concrete structures, the local availability of a large portion of the materials used in concrete, and its wide range of adaptability to the designs of engineers and architects. One of the most recent changes in concrete usage is the change from reinforced concrete to prestressed concrete. The term prestressed as used herein refers to any type of reinforced concrete in which the reinforcing material has a stress prior to the application of loads on the structure. Prestressed concrete is not new. It has been used successfully in Europe for several years and recently in the United States, particularly in buildings and bridges, to some extent. Many of the prestressed concrete projects in the United States are of a more or less experimental nature, trying different methods of stressing in order to perfect better anchorage and improve construction procedures. Recently the use of prestressed concrete has been proposed as a surface for highways. Concrete as a surface for highways has many advantages over other forms of paving, the main one being its relatively long usable life. This feature by itself makes concrete a widely used paving material. The disadvantages of concrete are many among which are, high initial cost, longer period of construction, and many construction joints which cause rough riding characteristics. Another disadvantage is a maintenance problem occurring when older concrete pavements fail due to transverse cracks. These cracks often occur during the first year or two of the pavement\u27s life, but do not cause serious problems until they become quite large and cause rough areas in the surface of the pavement. Transverse cracks are of two types. First, construction joints to allow for length changes caused by the expansion or contraction due to temperature changes in the pavement, and second, failures caused by deflection of the slab and subgrade due to heavy loads applied to the pavement. Cracks occurring in pavements poured on certain types of subgrade soil often develop a condition called pumping. This action consists of the deflection of the slab under moving loads which results in the ejection of water carrying soil particles in suspension. Conventional steel reinforcement has been used with varying degrees of success to correct the above mentioned disadvantages of concrete pavements. Cracks still occurred and construction joints were left at varying intervals. These cracks cause trouble on a somewhat reduced scale but the cost of a reinforced pavement is much higher in both material costs and labor costs. Prestressing concrete pavements may be a means of eliminating most of the cracks and many of the construction joints which are the major source of difficulty. This research project has as a goal a prestressed highway pavement which will have as many as possible of concrete\u27s inherent good advantages, and the fewest possible disadvantages --Introduction, pages 1-2

Gender differences in diet-induced steatotic disease in Cyp2b-null mice

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease; however, progression to nonalcoholic steatohepatitis (NASH) is associated with most adverse outcomes. CYP2B metabolizes multiple xeno- and endobiotics, and male Cyp2b-null mice are diet-induced obese (DIO) with increased NAFLD. However, the DIO study was not performed long enough to assess progression to NASH. Therefore, to assess the role of Cyp2b in fatty liver disease progression from NAFLD to NASH, we treated wildtype (WT) and Cyp2b-null mice with a normal diet (ND) or choline-deficient, L-amino acid-defined high fat diet (CDAHFD) for 8 weeks and determined metabolic and molecular changes. CDAHFD-fed WT female mice gained more weight and had greater liver and white adipose tissue mass than their Cyp2b-null counterparts; males experienced diet-induced weight loss regardless of genotype. Serum biomarkers of liver injury increased in both CDAHFD-fed female and male mice; however CDAHFD-fed Cyp2b-null females exhibited significantly lower serum ALT, AST, and ASP concentrations compared to WT mice, indicating Cyp2b-null females were protected from liver injury. In both genders, hierarchical clustering of RNA-seq data demonstrates several gene ontologies responded differently in CDAHFD-fed Cyp2b-null mice compared to WT mice (lipid metabolism \u3e fibrosis \u3e inflammation). Oil Red O staining and direct triglycerides measurements confirmed that CDAHFD-fed Cyp2b-null females were protected from NAFLD. CDAHFD-fed Cyp2b-null mice showed equivocal changes in fibrosis with transcriptomic and serum markers suggesting less inflammation due to glucocorticoid-mediated repression of immune responses. In contrast to females, CDAHFD-fed Cyp2b-null males had higher triglyceride levels. Results indicate that female Cyp2b-null mice are protected from NAFLD while male Cyp2b-null mice are more susceptible to NAFLD, with few significant changes in NASH development. This study confirms that increased NAFLD development does not necessarily lead to progressive NASH. Furthermore, it indicates a role for Cyp2b in fatty liver disease that differs based on gender

Onset of human preterm and term birth is related to unique inflammatory transcriptome profiles at the maternal fetal interface.

BackgroundPreterm birth is a main determinant of neonatal mortality and morbidity and a major contributor to the overall mortality and burden of disease. However, research of the preterm birth is hindered by the imprecise definition of the clinical phenotype and complexity of the molecular phenotype due to multiple pregnancy tissue types and molecular processes that may contribute to the preterm birth. Here we comprehensively evaluate the mRNA transcriptome that characterizes preterm and term labor in tissues comprising the pregnancy using precisely phenotyped samples. The four complementary phenotypes together provide comprehensive insight into preterm and term parturition.MethodsSamples of maternal blood, chorion, amnion, placenta, decidua, fetal blood, and myometrium from the uterine fundus and lower segment (n = 183) were obtained during cesarean delivery from women with four complementary phenotypes: delivering preterm with (PL) and without labor (PNL), term with (TL) and without labor (TNL). Enrolled were 35 pregnant women with four precisely and prospectively defined phenotypes: PL (n = 8), PNL (n = 10), TL (n = 7) and TNL (n = 10). Gene expression data were analyzed using shrunken centroid analysis to identify a minimal set of genes that uniquely characterizes each of the four phenotypes. Expression profiles of 73 genes and non-coding RNA sequences uniquely identified each of the four phenotypes. The shrunken centroid analysis and 10 times 10-fold cross-validation was also used to minimize false positive finings and overfitting. Identified were the pathways and molecular processes associated with and the cis-regulatory elements in gene's 5' promoter or 3'-UTR regions of the set of genes which expression uniquely characterized the four phenotypes.ResultsThe largest differences in gene expression among the four groups occurred at maternal fetal interface in decidua, chorion and amnion. The gene expression profiles showed suppression of chemokines expression in TNL, withdrawal of this suppression in TL, activation of multiple pathways of inflammation in PL, and an immune rejection profile in PNL. The genes constituting expression signatures showed over-representation of three putative regulatory elements in their 5'and 3' UTR regions.ConclusionsThe results suggest that pregnancy is maintained by downregulation of chemokines at the maternal-fetal interface. Withdrawal of this downregulation results in the term birth and its overriding by the activation of multiple pathways of the immune system in the preterm birth. Complications of the pregnancy associated with impairment of placental function, which necessitated premature delivery of the fetus in the absence of labor, show gene expression patterns associated with immune rejection

Association between rapidly progressive glomerulonephritis and the properdin factor BfF and different HLA-D region products

AbstractAssociation between rapidly progressive glomerulonephritis and the properdin factor BfF and different HLA-D region products. Frequencies of the HLA antigens ABC, DR and MT, as well as of the properdin factor alleles were determined in 24 unrelated patients presenting with immune complex mediated idiopathic rapidly progressive glomerulonephritis (RPGN) type II. As in Goodpasture syndrome (RPGN type I with pulmonary hemorrhage), a significant association with the B-cell alloantigen HLA-DR 2 was demonstrated (relative risk for HLA-DR 2 positive individuals was 3.54; P < 0.01). In addition a marked increase of the HLA specificity MT 3 was shown, which is supposed to belong to an antigen system of a second HLA-D region locus. The highest relative risk of 14.67 (P < 0.00001), however, was calculated for all patients carrying the BfF phenotype. Increased numbers of patients positive for HLA-DR 2 and -MT 3, as well as BfF suggested immune response genes or disease-related mutations on different haplotypes responsible for a MHC (major histocompatibility complex) associated predisposition of RPGN type II.Association entre la glomérulonéphrite rapidement progressive et le BfF du facteur de la properdine et les produits des différentes régions HLA-D. Les fréquences des antigènes HLA, ABC, DR et MT, ainsi que les allèles du facteur de la properdine ont été déterminées chez 24 malades non consanguins ayant une glomérulonéphrite rapidement progressive idiopathique médiée par des immunescomplexes (RPGN) de type IL Comme dans le syndrome de Goodpasture (RPGN de type I avec hémorragie pulmonaire), une association significative avec l'alloantigène cellulaire B HLA-DR 2 a été démontrée (le risque relatif pour des individus positifs à HLA-DR 2 était 3,54; P < 0,01). En plus, une augmentation marquée de la spécificité HLA-MT 3 a été montrée, laquelle est supposée appartenir à un système antigénique d'un second locus HLA-D. Le risque relatif le plus élevé, 14,67 (P < 0,00001), cependant, était calculé pour tous les malades porteurs du phénotype BfF. Les nombres augmentés de malades positifs pour HLA-DR 2 et-MT3, comme pour BfF suggéraient une réponse immune de gènes ou de mutations induites par la maladie sur différents haplotypes responsables d'une MHC (complexe principal d'histocompatibilité) associés à la prédisposition à une RPGN de type II

Bayesian modeling of recombination events in bacterial populations

Background: We consider the discovery of recombinant segments jointly with their origins within multilocus DNA sequences from bacteria representing heterogeneous populations of fairly closely related species. The currently available methods for recombination detection capable of probabilistic characterization of uncertainty have a limited applicability in practice as the number of strains in a data set increases. Results: We introduce a Bayesian spatial structural model representing the continuum of origins over sites within the observed sequences, including a probabilistic characterization of uncertainty related to the origin of any particular site. To enable a statistically accurate and practically feasible approach to the analysis of large-scale data sets representing a single genus, we have developed a novel software tool (BRAT, Bayesian Recombination Tracker) implementing the model and the corresponding learning algorithm, which is capable of identifying the posterior optimal structure and to estimate the marginal posterior probabilities of putative origins over the sites. Conclusion: A multitude of challenging simulation scenarios and an analysis of real data from seven housekeeping genes of 120 strains of genus Burkholderia are used to illustrate the possibilities offered by our approach. The software is freely available for download at URL http://web.abo.fi/fak/ mnf//mate/jc/software/brat.html

Bostonia. Volume 4

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

The impact of Hurricane Sandy on the shoreface and inner shelf of Fire Island, New York : large bedform migration but limited erosion

© The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution.. The definitive version was published in Continental Shelf Research 98 (2015): 13-25, doi:10.1016/j.csr.2015.03.001.We investigate the impact of superstorm Sandy on the lower shoreface and inner shelf offshore the barrier island system of Fire Island, NY using before-and-after surveys involving swath bathymetry, backscatter and CHIRP acoustic reflection data. As sea level rises over the long term, the shoreface and inner shelf are eroded as barrier islands migrate landward; large storms like Sandy are thought to be a primary driver of this largely evolutionary process. The “before” data were collected in 2011 by the U.S. Geological Survey as part of a long-term investigation of the Fire Island barrier system. The “after” data were collected in January, 2013, ~two months after the storm. Surprisingly, no widespread erosional event was observed. Rather, the primary impact of Sandy on the shoreface and inner shelf was to force migration of major bedforms (sand ridges and sorted bedforms) 10’s of meters WSW alongshore, decreasing in migration distance with increasing water depth. Although greater in rate, this migratory behavior is no different than observations made over the 15-year span prior to the 2011 survey. Stratigraphic observations of buried, offshore-thinning fluvial channels indicate that long-term erosion of older sediments is focused in water depths ranging from the base of the shoreface (~13-16 m) to ~21 m on the inner shelf, which is coincident with the range of depth over which sand ridges and sorted bedforms migrated in response to Sandy. We hypothesize that bedform migration regulates erosion over these water depths and controls the formation of a widely observed transgressive ravinement; focusing erosion of older material occurs at the base of the stoss (upcurrent) flank of the bedforms. Secondary storm impacts include the formation of ephemeral hummocky bedforms and the deposition of a mud event layer.This work was funded primarily by a rapid response grant from the Jackson School of Geosciences, The University of Texas/Austi