16,572 research outputs found
The influence of joints and composite floor slabs on effective tying of steel structures in preventing progressive collapse
The event of the terrorist attack at 11th September 2001 in the USA has attracted increasing
attention of researchers and engineers on progressive collapse of structures. It has gradually become a
general practice for engineers to consider progressive collapse resistance in their design. In this paper,
progressive collapse of steel frames with composite floor slabs is simulated by the finite element method.
The numerical results are compared with test results. The influence of the joints and the concrete slabs on
the effective tying of steel beams is investigated through parametric studies. From the analysis, methods of
preventing progressive collapse that can be considered in design and when retrofitting existing structures
are proposed. The results show that retrofitting a structure with pre-stressed steel cables and an increase of
crack resistance in the concrete near joints can effectively improve effective tying of a structure, which
results in an enhanced structural capacity in preventing progressive collapse
Finite-size scaling considerations on the ground state microcanonical temperature in entropic sampling simulations
In this work we discuss the behavior of the microcanonical temperature
obtained by means of numerical entropic
sampling studies. It is observed that in almost all cases the slope of the
logarithm of the density of states is not infinite in the ground state,
since as expected it should be directly related to the inverse temperature
. Here we show that these finite slopes are in fact due to
finite-size effects and we propose an analytic expression for the
behavior of when . To
test this idea we use three distinct two-dimensional square lattice models
presenting second-order phase transitions. We calculated by exact means the
parameters and for the two-states Ising model and for the and
states Potts model and compared with the results obtained by entropic sampling
simulations. We found an excellent agreement between exact and numerical
values. We argue that this new set of parameters and represents an
interesting novel issue of investigation in entropic sampling studies for
different models
Combining Multiple Measures of Students' Opportunities to Develop Analytic, Text-Based Writing Skills
Guided by evidence that teachers contribute to student achievement outcomes, researchers have been reexamining how to study instruction and the classroom opportunities teachers create for students. We describe our experience measuring students' opportunities to develop analytic, text-based writing skills. Utilizing multiple methods of data collection-writing assignment tasks, daily logs, and an annual survey-we generated a composite that was used in prediction models to examine multivariate outcomes, including scores on a state accountability test and a project-developed response-to-text assessment. Our findings demonstrate that students' opportunities to develop analytic, text-based writing skills predicted classroom performance on the project-developed response-to-text assessment. We discuss the importance of considering the measure(s) of learning when examining teaching-learning associations as well as implications for combining multiple measures for purposes of better construct representation. © 2012 Copyright Taylor and Francis Group, LLC
Meat tenderness and water holding capacity are associated with a 959 A G mutation in the MyoG gene of Chinese indigenous cattle
Myogenin (MyoG) gene has mapped at 25 to 73 cm interval on BTA 16 where several quantitative trait loci for carcass weight and marbling are located. In this study, we determined the associations between gene-specific single nucleotide polymorphisms (SNP) in MyoG gene, to investigate whether this polymorphism affected meat quality characteristics and to evaluate the allelic and genotypic frequencies of six native Chinese cattle breeds. The breeds were Jiaxian red (JXR), Luxi (LX), Nan-yang (NY), Qinchuan (QC), Xia-Nan (XN) and Xue long (XL). Our results suggested a transition of A → G at position 959 in exon 1 of the MyoG gene in cattle that caused the substitution (959Serine/959Cysteine). The A959G SNP was significantly associated with water holding capacity and meat tenderness (P < 0.05), while no effect of genotype on back fat thickness, rib area, loin eye height, eye muscle width and marbling was disclosed (P > 0.05). The x2-test revealed that the genotype distributions among the five cattle breeds (JXR, LX, NY, QC and XL) agreed with Hardy-Weinberg equilibrium (P > 0.05), although, one breed (XN) was not in Hardy-Weinberg equilibrium (P < 0.01). We concluded that, A959G SNP can be used as an efficacious genetic marker for meat quality traits in native Chinese cattle breeds but a much large number of animals are required for Marker assisted selection.Key words: Cattle, genotypic frequencies, myogenin (MyoG) gene, meat quality, single nucleotide polymorphism
Plasma-nitrided Ga2O3(Gd2O3) as interfacial passivation layer for InGaAs metal-oxide-semiconductor capacitor with HfTiON gate dielectric
published_or_final_versio
No evidence for substrate accumulation in Parkinson brains with GBA mutations
To establish whether Parkinson's disease (PD) brains previously described to have decreased glucocerebrosidase activity exhibit accumulation of the lysosomal enzyme's substrate, glucosylceramide, or other changes in lipid composition
Effect of acute physiological free fatty acid elevation in the context of hyperinsulinemia on fiber type-specific IMCL accumulation.
It is well described that increasing free fatty acids (FFAs) to high physiological levels reduces insulin sensitivity. In sedentary humans, intramyocellular lipid (IMCL) is inversely related to insulin sensitivity. Since muscle fiber composition affects muscle metabolism, whether FFAs induce IMCL accumulation in a fiber type-specific manner remains unknown. We hypothesized that in the setting of acute FFA elevation by lipid infusion within the context of a hyperinsulinemic-euglycemic clamp, IMCL will preferentially accumulate in type 1 fibers. Normal-weight participants (n = 57, mean ± SE: age 24 ± 0.6 yr, BMI 22.2 ± 0.3 kg/m(2)) who were either endurance trained or sedentary by self-report were recruited from the University of Minnesota (n = 31, n = 15 trained) and University of Pittsburgh (n = 26, n = 14 trained). All participants underwent a hyperinsulinemic-euglycemic clamp in the context of a 6-h infusion of either lipid or glycerol control. A vastus lateralis muscle biopsy was obtained at baseline and end-infusion (6 h). The muscle biopsies were processed and analyzed at the University of Pittsburgh for fiber type-specific IMCL accumulation by Oil-Red-O staining. Regardless of training status, acute elevation of FFAs to high physiological levels (~400-600 meq/l) increased IMCL preferentially in type 1 fibers (+35 ± 11% compared with baseline, +29 ± 11% compared with glycerol control: P < 0.05). The increase in IMCL correlated with a decline in insulin sensitivity as measured by the hyperinsulinemic-euglycemic clamp (r = -0.32, P < 0.01) independent of training status. Regardless of training status, increase of FFAs to a physiological range within the context of hyperinsulinemia shows preferential IMCL accumulation in type 1 fibers.NEW & NOTEWORTHY This novel human study examined the effects of FFA elevation in the setting of hyperinsulinemia on accumulation of fat in specific types of muscle fibers. Within the context of the hyperinsulinemic-euglycemic clamp, we found that an increase of FFAs to a physiological range sufficient to reduce insulin sensitivity is associated with preferential IMCL accumulation in type 1 fibers
The Optimal Analysis of Default Probability for a Credit Risk Model
A credit risk mathematical model is investigated. Under regular conditions, a different recovery scheme is proposed, which is an extension of the recovery of treasury value scheme (RTV) with time-continuous liquidation. Assuming that a function depends on the optimal time for the liquidation and the recovery rate, we obtain the functional expression of the risky bond price. When the firm value follows a jump-diffusion process with a Log-exponentially distributed jump, we develop a method to obtain the optimal default probability with time-continuous liquidation
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