11,352 research outputs found
Cold-Formed Steel Sections with Web Openings Subjected to Web Crippling under Two-Flange Loading Conditions â Part I : Tests and Finite Element Analysis
The results of 82 web crippling tests are presented, with 20 tests conducted on channel sections without web openings and 62 tests conducted on channel sections with web openings. The tests consider both end-two-flange and interior-two-flange loading conditions. In the case of the tests with web openings, the hole was located directly under the concentrated load. The concentrated load was applied through bearing plates; the effect of different bearing lengths is investigated. In addition, the cases of both flanges fastened and unfastened to the support were considered. A non-linear elasto-plastic finite element model is described, and the results compared against the laboratory test results; a good agreement was obtained in terms of both strength and failure modes
Structural diversity of neuronal calcium sensor proteins and insights for activation of retinal guanylyl cyclase by GCAP1.
Neuronal calcium sensor (NCS) proteins, a sub-branch of the calmodulin superfamily, are expressed in the brain and retina where they transduce calcium signals and are genetically linked to degenerative diseases. The amino acid sequences of NCS proteins are highly conserved but their physiological functions are quite different. Retinal recoverin controls Ca(2) (+)-dependent inactivation of light-excited rhodopsin during phototransduction, guanylyl cyclase activating proteins 1 and 2 (GCAP1 and GCAP2) promote Ca(2) (+)-dependent activation of retinal guanylyl cyclases, and neuronal frequenin (NCS-1) modulates synaptic activity and neuronal secretion. Here we review the molecular structures of myristoylated forms of NCS-1, recoverin, and GCAP1 that all look very different, suggesting that the attached myristoyl group helps to refold these highly homologous proteins into different three-dimensional folds. Ca(2) (+)-binding to both recoverin and NCS-1 cause large protein conformational changes that ejects the covalently attached myristoyl group into the solvent exterior and promotes membrane targeting (Ca(2) (+)-myristoyl switch). The GCAP proteins undergo much smaller Ca(2) (+)-induced conformational changes and do not possess a Ca(2) (+)-myristoyl switch. Recent structures of GCAP1 in both its activator and Ca(2) (+)-bound inhibitory states will be discussed to understand structural determinants that control their Ca(2) (+)-dependent activation of retinal guanylyl cyclases
The Work Environment Index: Technical Background Paper
The vast majority of Americans work for a living. The track record of different states varies widely when it comes to providing decent opportunities for working people. The Work Environment Index (WEI) captures these differences and provides a basis for evaluating how well each state does in creating an economy that supports its working population. The purpose of this article is to detail the construction of the WEI and to explain the design of the Index. This paper serves as a technical companion to the report Decent Work In America: The 2005 Work Environment Index. Many factors contribute to a good environment for working people: quality jobs, adequate opportunities for employment, basic social protections, and being treated fairly. The WEI is a composite measure of these different dimensions and provides a basis for comparing the quality of the work environment in all 50 states and the District of Columbia. The WEI has multiple objectives: 1) to capture and quantify the various dimensions of the work environment on a state-by-state basis. 2) to provide a direct, relatively transparent, and easy-to-understand measurement that is firmly rooted in publicly available data sources. 3) to provide a basis for making comparisons between the states that are fair and objective. 4) to create a tool for analyzing other socio-economic issues at the state level: e.g. poverty rate differentials, job quality and quantity trade-offs, and patterns of economic growth.labor, work environment, business climate, decent work, poverty, job growth, economic growth, business start-ups
Decent Work in America: The 2005 Work Environment Index
What are the factors that make for a decent work environment and how do the conditions of work vary in different parts of the United States? To address these and similarly important questions in a clear and accessible way, we have developed a new approach for measuring the work environment on a state-bystate basis throughout the United States (including the District of Columbia) â the Work Environment Index (WEI). This is the first installment of the WEI, and we intend to update it every year. The WEI is a unique social indicator that brings together in one measure a range of factors that, in combination, define the quality of our working lives in the U.S. today. The WEI examines three basic dimensions of the U.S. work environment: job opportunities, job quality and workplace fairness. We rank the 50 states and the District of Columbia according to these three categories. Based on our measures of job opportunities, job quality, and workplace fairness, we find that, overall, Delaware offers the best relative work environment in the United States. Other states with high WEI rankings include New Hampshire, Minnesota, Vermont and Iowa. The states with the lowest WEI rankings are Louisiana, Texas, Arkansas, Utah, South Carolina and Mississippi. Our state-by-state WEI ranking enables us to consider a crucial and widely-discussed issue: Do the states that provide a relatively decent work environment end up paying a penalty in terms of their overall economic climate? For example, do states that rank high according to the WEI score poorly in terms of their overall growth rate, the pace at which new businesses are being formed in the state, or their rate of new job creation? In fact, we find that overall economic conditions in states with a high WEI rank are at least as favorable, if not somewhat more favorable, than those with low WEI rankings. Along with this, we also find that poverty rates in states with high WEI rankings are consistently lower than states with low WEI rankings.labor, work environment, business climate, decent work, poverty, job growth, economic growth, business start-up
SAT-158 Offspring Exposed to Maternal High Fat Diet Exhibits Systemic Inflammation and Pancreatic Islet Dysfunction
Offspring born to overweight mothers are more likely to develop dysregulated immune response1, obesity1 and pancreatic islet dysfunction2. These offspring have increased inflammation at birth3 and at least until childhood4. We hypothesize that heightened inflammation in offspring of overweight mothers increases offspring risks of pancreatic islet dysfunction. We induced maternal overweight by providing 45% high fat diet (HFD) to female mice 2 - 4 weeks before pregnancy until weaning. When compared to controls, P21 weanlings of HFD mothers had impaired glucose tolerance in dose and gender dependent manner [GTT AUC: male 2-week HFD* 30 ± 6% higher; male 4-week HFD* 37± 3% higher: 9-11/group; female 2-week HFD 13 ± 5% higher; female 4-week HFD* 22 ± 3% higher: 3-9/group, *p<0.05 compared to controls]. Glucose intolerance persisted in 8-week-old male from 2-week HFD mothers (p<0.05, n=6-9/group), with decreased pancreatic islets glucose induced calcium response measured using Fura-2AM calcium imaging (F1/F0 Con:2.00 ± 0.06, HFD2W: 1.69±0.12*, HFD4w: 0.71±0.09*, n =3/group). Cytokines production in the serum, macrophage response and metabolic phenotypes of offspring were assessed on postnatal day 21 (P21) and at 8 weeks old. Compared to control pups, weanling of HFD mothers had elevated serum/plasma IL-1b level along with increased polarization of M1 macrophages and decreased M2 macrophages, as well as an increase of IL-1b secretion in LPS-stimulated macrophages. At 8 weeks of age, HFD male offspring had increased activation markers of splenic dendritic cells indicating a development of systemic inflammatory response early in life. Taken together, our findings suggest that mice offspring from HFD mothers have pancreatic dysfunction, and an inflammatory response. This work is funded by the Riley Childrenâs Foundation. 1. Kelishadi, R., Roufarshbaf, M., Soheili, S., Payghambarzadeh, F. & Masjedi, M. Association of Childhood Obesity and the Immune System: A Systematic Review of Reviews. Child. Obes. Print 13, 332-346 (2017). 2. Graus-Nunes, F. et al. Pregestational maternal obesity impairs endocrine pancreas in male F1 and F2 progeny. Nutrition 31, 380-387 (2015). 3. Dosch, N. C. et al. Maternal Obesity Affects Inflammatory and Iron Indices in Umbilical Cord Blood. J. Pediatr. 172, 20-28 (2016). 4. Leibowitz, K. L. et al. Maternal obesity associated with inflammation in their children. World J. Pediatr. WJP 8, 76-79 (2012)
Virtual assembly rapid prototyping of near net shapes
Virtual reality (VR) provides another dimension to many engineering applications. Its immersive and interactive nature allows an intuitive approach to study both cognitive activities and performance evaluation. Market competitiveness means having products meet form, fit and function quickly. Rapid Prototyping and Manufacturing (RP&M) technologies are increasingly being applied to produce functional prototypes and the direct manufacturing of small components. Despite its flexibility, these systems have common drawbacks such as slow build rates, a limited number of build axes (typically one) and the need for post processing. This paper presents a Virtual Assembly Rapid Prototyping (VARP) project which involves evaluating cognitive activities in assembly tasks based on the adoption of immersive virtual reality along with a novel non-layered rapid prototyping for near net shape (NNS) manufacturing of components. It is envisaged that this integrated project will facilitate a better understanding of design for manufacture and assembly by utilising equivalent scale digital and physical prototyping in one rapid prototyping system. The state of the art of the VARP project is also presented in this paper
Effect of Socio-Demographics, Health-Related Problems, and Family Structure on Chronic Absenteeism Among Children
Purpose/Background: From 5 to 7.5 million school children are chronically absent, defined as missing â„15 days of school within a year. Students miss schools due to various reasons such as health, socioeconomic status, and environmental factors. We examined childâs health and behavior, family structure, and socio-demographics to understand chronic absenteeism.
Materials & Methods: The population included children ages 6 to 17 years from the Medical Expenditure Panel Survey (MEPS) years 2008-2013. Multivariable logistic regressions were used to identify the risk factors of chronic absenteeism, adjusting for the complex sampling design.
Results: Among socio-demographic variables, age â„14 years, race/ethnicity, lower-income family, public health insurance, US-born, and speaking English at home were associated with chronic absenteeism. Asians, Mexican Hispanics, and blacks have lower chronic absenteeism than whites. Among health-related variables, children using an inhaler for asthma, having behavioral problems, and less healthy than other children were more likely to be chronically absent. Among family variables, a smaller family size was a risk factor for chronic absenteeism.
Discussion/Conclusion: Asthma and behavioral problems were highly associated with chronic absenteeism. The identification of children at risk for chronic absenteeism will help the educational professionals identify the barriers to academic achievements and develop integrated educational interventions and policies to support disadvantaged children
Virtual bloXing - assembly rapid prototyping for near net shapes
Virtual reality (VR) provides another dimension to many engineering applications. Its immersive and interactive nature allows an intuitive approach to study both cognitive activities and performance evaluation. Market competitiveness means having products meet form, fit and function quickly. Rapid Prototyping and Manufacturing (RP&M) technologies are increasingly being applied to produce functional prototypes and the direct manufacturing of small components. Despite its flexibility, these systems have common drawbacks such as slow build rates, a limited number of build axes (typically one) and the need for post processing. This paper presents a Virtual Assembly Rapid Prototyping (VARP) project which involves evaluating cognitive activities in assembly tasks based on the adoption of immersive virtual reality along with a novel nonlayered rapid prototyping for near net shape (NNS) manufacturing of components. It is envisaged that this integrated project will facilitate a better understanding of design for manufacture and assembly by utilising equivalent scale digital and physical prototyping in one rapid prototyping system. The state of the art of the VARP project is also presented in this paper
The development of glycosaminoglycan-based materials to promote chondrogenic differentiation of mesenchymal stem cells
Tissue engineering strategies represent exciting potential therapies to repair cartilage injuries; however, difficulty regenerating the complex extracellular matrix (ECM) organization of native cartilage remains a significant challenge. Cartilaginous ECM molecules, specifically chondroitin sulfate (CS) glycosaminoglycan, may possess the ability to promote and direct MSC differentiation down a chondrogenic lineage. CS may interact with the stem cell microenvironment through its highly negative charge, generation of osmotic pressure, and sequestration of growth factors; however, the role of CS in directing differentiation down a chondrogenic lineage remains unclear. The overall goal of this dissertation was to develop versatile biomaterial platforms to control CS presentation to mesenchymal stem cells (MSCs) in order to improve understanding of the interactions with CS that promote chondrogenic differentiation.
To investigate chondrogenic response to a diverse set of CS materials, progenitor cells were cultured in the presence of CS proteoglycans and CS chains in a variety of 2D and 3D material systems. Surfaces were coated with aggrecan proteoglycan to alter cell morphology, CS-based nano- and microspheres were developed as small particle carriers for growth factor delivery, and desulfated chondroitin hydrogels were synthesized to examine electrostatic interactions with growth factors and the role of sulfation in the chondrogenic differentiation of MSCs. Together these studies provided valuable insight into the unique ability of CS-based materials to control cellular microenvironments via morphological and material cues to promote chondrogenic differentiation in the development of tissue engineering strategies for cartilage regeneration and repair.PhDCommittee Chair: Temenoff, Johnna; Committee Member: Bellamkonda, Ravi; Committee Member: Gall, Kenneth; Committee Member: GarcĂa, AndrĂ©s; Committee Member: Levenston, Marc; Committee Member: McDevitt, Tod
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