Use of Innovative Concrete Mixes for Improved Constructability and Sustainability of Bridge Decks 2010-2011

Bridge deck crack surveys were performed on twelve bridges on US-59 to determine the effects of mixture proportions, deck type, and girder types on the crack density of reinforced concrete bridge decks. Of the twelve, eight have prestressed concrete girders and four have steel girders. Four of the decks with prestressed girders have partial-depth precast deck panels, two are monolithic, and two have overlays. Of the four decks with steel girders, two have overlays and two are monolithic. The surveys were performed, crack maps were analyzed, and cracking trends were observed. The results for the US-59 bridge decks were compared with crack densities obtained in a study of low-cracking high-performance concrete (LC-HPC) bridge decks in Kansas. The monolithic concrete bridge decks supported by prestressed concrete girders within this study exhibit less cracking than decks supported by steel girders in the first three years. At an age of approximately three years, the US-59 monolithic decks on prestressed girders with deck panels are not displaying significant cracking at the joints of the panels. The US-59 decks supported by prestressed girders without overlays exhibit significantly less cracking than the decks on prestressed girders with overlays. No benefits of using fibers in either the overlay or in the deck have been observed in this study

Use of Innovative Concrete Mixes for Improved Constructability and Sustainability of Bridge Decks, 2010-2013

Bridge deck crack surveys were performed on twelve bridges on US-59 south of Lawrence, KS to determine the effects of mixture proportions, concrete properties, deck type, and girder type on the crack density of reinforced concrete bridge decks. Of the twelve decks surveyed, eight are supported by prestressed concrete girders and four are supported by steel girders. Four of the decks supported by prestressed girders are cast on partial-depth precast deck panels, two are monolithic with synthetic fibers, and two have overlays. Of the four decks supported by steel girders, two have silica fume overlays (SFO) and two are monolithic. One of two decks with a silica fume overlay contains synthetic fibers in the overlay. Following the surveys, crack maps were plotted and analyzed and cracking trends were observed. The results for the US-59 bridge decks are compared with crack densities obtained in a study of low-cracking high-performance concrete (LC-HPC) bridge decks. The monolithic concrete bridge decks supported by prestressed concrete girders within this study exhibit less cracking than decks supported by steel girders. At an age of approximately three and a half years, the US-59 monolithic decks supported by prestressed girders with deck panels are not displaying significant cracking; most of the cracks are short transverse cracks aligned with the joints between the deck panels. The US-59 decks supported by prestressed girders with overlays exhibit significantly more cracking than the decks on prestressed girders without overlays. Bridge decks supported by steel girders without overlays have slightly higher crack densities than the decks with overlays. No benefits of using fibers in either the overlay or deck have been observed in this study, the sample size, however, is small. An increase in crack density was observed with an increase in average concrete slump for decks supported by both prestressed and steel girders. Decks with deck panels supported by prestressed girders exhibited an increased crack density with an increase in paste content

High-Density SNP Screening of the Major Histocompatibility Complex in Systemic Lupus Erythematosus Demonstrates Strong Evidence for Independent Susceptibility Regions

A substantial genetic contribution to systemic lupus erythematosus (SLE) risk is conferred by major histocompatibility complex (MHC) gene(s) on chromosome 6p21. Previous studies in SLE have lacked statistical power and genetic resolution to fully define MHC influences. We characterized 1,610 Caucasian SLE cases and 1,470 parents for 1,974 MHC SNPs, the highly polymorphic HLA-DRB1 locus, and a panel of ancestry informative markers. Single-marker analyses revealed strong signals for SNPs within several MHC regions, as well as with HLA-DRB1 (global p = 9.99×10−16). The most strongly associated DRB1 alleles were: *0301 (odds ratio, OR = 2.21, p = 2.53×10−12), *1401 (OR = 0.50, p = 0.0002), and *1501 (OR = 1.39, p = 0.0032). The MHC region SNP demonstrating the strongest evidence of association with SLE was rs3117103, with OR = 2.44 and p = 2.80×10−13. Conditional haplotype and stepwise logistic regression analyses identified strong evidence for association between SLE and the extended class I, class I, class III, class II, and the extended class II MHC regions. Sequential removal of SLE–associated DRB1 haplotypes revealed independent effects due to variation within OR2H2 (extended class I, rs362521, p = 0.006), CREBL1 (class III, rs8283, p = 0.01), and DQB2 (class II, rs7769979, p = 0.003, and rs10947345, p = 0.0004). Further, conditional haplotype analyses demonstrated that variation within MICB (class I, rs3828903, p = 0.006) also contributes to SLE risk independent of HLA-DRB1*0301. Our results for the first time delineate with high resolution several MHC regions with independent contributions to SLE risk. We provide a list of candidate variants based on biologic and functional considerations that may be causally related to SLE risk and warrant further investigation

Anatomy of Escherichia coli σ(70) promoters

Information theory was used to build a promoter model that accounts for the −10, the −35 and the uncertainty of the gap between them on a common scale. Helical face assignment indicated that base −7, rather than −11, of the −10 may be flipping to initiate transcription. We found that the sequence conservation of σ(70) binding sites is 6.5 ± 0.1 bits. Some promoters lack a −35 region, but have a 6.7 ± 0.2 bit extended −10, almost the same information as the bipartite promoter. These results and similarities between the contacts in the extended −10 binding and the −35 suggest that the flexible bipartite σ factor evolved from a simpler polymerase. Binding predicted by the bipartite model is enriched around 35 bases upstream of the translational start. This distance is the smallest 5′ mRNA leader necessary for ribosome binding, suggesting that selective pressure minimizes transcript length. The promoter model was combined with models of the transcription factors Fur and Lrp to locate new promoters, to quantify promoter strengths, and to predict activation and repression. Finally, the DNA-bending proteins Fis, H-NS and IHF frequently have sites within one DNA persistence length from the −35, so bending allows distal activators to reach the polymerase

Spousal Influences on Parents' Non-Market Time Choices

This paper considers the effect of spouse's characteristics on three aggregated non-paid time uses, active leisure time; child caregiving time; and home production time, using the American Time Use Survey (ATUS). The time diary of each married individual with children under the age of 13 (mothers and fathers) is analyzed, both in terms of the level of non-paid time and the wife's share of the total level of the daily activity for the couple. Three spousal variables: the relative wage of the wife compared to her husband, spouses' weekly hours of employment; and, in the level equations only, the spouses' time in the same activity are considered. Each of these spousal variables needs to be estimated in order to address issues of both endogeneity and missing data. Three alternative strategies to address these problems are explored: predictions within the sample, predictions from outside the sample and propensity matching which marries mothers with time diaries to fathers with time diaries who have propensity scores similar to the women's husband. The results show very little effect of one spouse on the level of other spouse's unpaid time use. This absence of spousal effects is similar to the reduction of spousal effects in employment time described in Blau and Kahn (2005). In terms of the share of wife's time in the activity, we find higher relative wages of the mother compared to her husband leads to a greater share of child care done by the mother on both weekdays and weekends. No consistent effect of relative wages is found on the mother's share of leisure or home production

On Spanish Dvandva and its restrictions

As noted by Bauer, real dvandva compounds –that is, coordinative compounds that properly express the aggregation of two different entities, not the intersection of properties in one entity– are extremely rare in English or Spanish. This article explores the empirical domain of dvandva compounding in Spanish, and notes that they are productive when not used as heads within their phrases. We propose that the explanation for this is that Spanish can only productively build dvandva compounds using flat structures without internal hierarchy. This causes the compound to look externally for a head noun that defines the interpretation of the relation established between the two members of the dvandva. The proposal also explains why proper names is preferred in dvandva compounding, given that they do not denote properties

Fine-mapping of common genetic variants associated with colorectal tumor risk identified potential functional variants

Genome-wide association studies (GWAS) have identified many common single nucleotide polymorphisms (SNPs) associated with colorectal cancer risk. These SNPs may tag correlated variants with biological importance. Fine-mapping around GWAS loci can facilitate detection of functional candidates and additional independent risk variants. We analyzed 11,900 cases and 14,311 controls in the Genetics and Epidemiology of Colorectal Cancer Consortium and the Colon Cancer Family Registry. To fine-map genomic regions containing all known common risk variants, we imputed high-density genetic data from the 1000 Genomes Project. We tested single-variant associations with colorectal tumor risk for all variants spanning genomic regions 250-kb upstream or downstream of 31 GWAS-identified SNPs (index SNPs). We queried the University of California, Santa Cruz Genome Browser to examine evidence for biological function. Index SNPs did not show the strongest association signals with colorectal tumor risk in their respective genomic regions. Bioinformatics analysis of SNPs showing smaller P-values in each region revealed 21 functional candidates in 12 loci (5q31.1, 8q24, 11q13.4, 11q23, 12p13.32, 12q24.21, 14q22.2, 15q13, 18q21, 19q13.1, 20p12.3, and 20q13.33). We did not observe evidence of additional independent association signals in GWAS-identified regions. Our results support the utility of integrating data from comprehensive fine-mapping with expanding publicly available genomic databases to help clarify GWAS associations and identify functional candidates that warrant more onerous laboratory follow-up. Such efforts may aid the eventual discovery of disease-causing variant(s).National Institutes of Health; National Cancer Institute; U.S. Department of Health and Human Services

Review of the projected impacts of climate change on coastal fishes in southern Africa

The coastal zone represents one of the most economically and ecologically important ecosystems on the planet, none more so than in southern Africa. This manuscript examines the potential impacts of climate change on the coastal fishes in southern Africa and provides some of the first information for the Southern Hemisphere, outside of Australasia. It begins by describing the coastal zone in terms of its physical characteristics, climate, fish biodiversity and fisheries. The region is divided into seven biogeographical zones based on previous descriptions and interpretations by the authors. A global review of the impacts of climate change on coastal zones is then applied to make qualitative predictions on the likely impacts of climate change on migratory, resident, estuarine-dependent and catadromous fishes in each of these biogeographical zones. In many respects the southern African region represents a microcosm of climate change variability and of coastal habitats. Based on the broad range of climate change impacts and life history styles of coastal fishes, the predicted impacts on fishes will be diverse. If anything, this review reveals our lack of fundamental knowledge in this field, in particular in southern Africa. Several research priorities, including the need for process-based fundamental research programs are highlighted