8,596 research outputs found
The Porphyromonas gingivalis hemagglutinins HagB and HagC are major mediators of adhesion and biofilm formation
Porphyromonas gingivalis is a bacterium associated with chronic periodontitis that possesses a family of genes encoding hemagglutinins required for heme acquisition. In this study we generated ÎhagB and ÎhagC mutants in strain W83 and demonstrate that both hagB and hagC are required for adherence to oral epithelial cells. Unexpectedly, a double ÎhagB/ÎhagC mutant had less severe adherence defects than either of the single mutants, but was found to exhibit increased expression of the gingipain-encoding genes rgpA and kgp, suggesting that a ÎhagB/ÎhagC mutant is only viable in populations of cells that exhibit increased expression of genes involved in heme acquisition. Disruption of hagB in the fimbriated strain ATCC33277 demonstrated that HagB is also required for stable attachment of fimbriated bacteria to oral epithelial cells. Mutants of hagC were also found to form defective single and multi-species biofilms that had reduced biomass relative to biofilms formed by the wild-type strain. This study highlights the hitherto unappreciated importance of these genes in oral colonization and biofilm formation
Local Labor Market Conditions and the Jobless Poor: How Much Does Local Job Growth Help in Rural Areas?
The employment outcomes of a group of jobless poor Oregonians are tracked in order to analyze the relative importance of local labor market conditions on their employment outcomes. Local job growth increases the probability that a jobless poor adult will get a job and shortens the length of time until she finds a job. After accounting for both the effects of personal demographic characteristics and local job growth, there is little evidence that the probability of employment or the duration of joblessness differs in rural compared with urban areas.employment, local labor markets, rural labor markets, rural poverty, unemployment, welfare reform, Labor and Human Capital,
EMPLOYMENT OUTCOMES FOR LOW-INCOME ADULTS IN RURAL AND URBAN LABOR MARKETS
This study analyzes the impact of local labor market conditions on the probability of employment and duration of employment for low-income adults in Oregon. We find that economic conditions (lower employment growth and higher unemployment rates) help to explain the less successful employment outcomes for low-income adults in non-metro areas.rural labor markets, employment, low-income workers, Labor and Human Capital,
Accounting for the Decline in AFDC Caseloads: Welfare Reform or Economic Growth?
Nationwide, AFDC caseloads have decreased by about 18 percent since March 1994, while some states, such as Wisconsin, Indiana, and Oregon, have seen declines of 40 percent or more. Two factors are frequently suggested as possible causes: state-level experiments with welfare reform and strong economic growth. In this paper, we use state-level monthly panel data from 1987 to 1996 to assess the importance of each of these factors by estimating a model of AFDC caseloads as a dynamic function of time-dependent state welfare reform variables (welfare waivers) and economic variables such as per capita employment. Our results from the dynamic model suggest that the decline in per capita AFDC caseloads is attributable largely to the economic growth of states and not to waivers from federal welfare policies. In the 26 states experiencing at least a 20 percent decline in per capita AFDC caseloads between 1993 and 1996, we attribute 78 percent of the decline to business-cycle factors and 6 percent to welfare waivers.
<i>In vitro</i> bioassays for the study of endocrine-disrupting food additives and contaminants
Investigations into the Sarcomeric Protein and Ca2+-Regulation Abnormalities Underlying Hypertrophic Cardiomyopathy in Cats (Felix catus).
Hypertrophic cardiomyopathy (HCM) is the most common single gene inherited cardiomyopathy. In cats (Felix catus) HCM is even more prevalent and affects 16% of the outbred population and up to 26% in pedigree breeds such as Maine Coon and Ragdoll. Homozygous MYBPC3 mutations have been identified in these breeds but the mutations in other cats are unknown. At the clinical and physiological level feline HCM is closely analogous to human HCM but little is known about the primary causative mechanism. Most identified HCM causing mutations are in the genes coding for proteins of the sarcomere. We therefore investigated contractile and regulatory proteins in left ventricular tissue from 25 cats, 18 diagnosed with HCM, including a Ragdoll cat with a homozygous MYBPC3 R820W, and 7 non-HCM cats in comparison with human HCM (from septal myectomy) and donor heart tissue. Myofibrillar protein expression was normal except that we observed 20â44% MyBP-C haploinsufficiency in 5 of the HCM cats. Troponin extracted from 8 HCM and 5 non-HCM cat hearts was incorporated into thin filaments and studied by in vitro motility assay. All HCM cat hearts had a higher (2.06 ± 0.13 fold) Ca2+-sensitivity than non-HCM cats and, in all the HCM cats, Ca2+-sensitivity was not modulated by troponin I phosphorylation. We were able to restore modulation of Ca2+-sensitivity by replacing troponin T with wild-type protein or by adding 100 ÎŒM Epigallocatechin 3-gallate (EGCG). These fundamental regulatory characteristics closely mimic those seen in human HCM indicating a common molecular mechanism that is independent of the causative mutation. Thus, the HCM cat is a potentially useful large animal model
A study of 60 Gigahertz intersatellite link applications
Applications of intersatellite links operating at 60 GHz are reviewed. Likely scenarios, ranging from transmission of moderate and high data rates over long distances to low data rates over short distances are examined. A limited parametric tradeoff is performed with system variables such as radiofrequency power, receiver noise temperature, link distance, data rate, and antenna size. Present status is discussed and projections are given for both electron tube and solid state transmitter technologies. Monolithic transmit and receive module technology, already under development at 20 to 30 GHz, is reviewed and its extension to 60 GHz, and possible applicability is discussed
Who are Non-Resident Fathers?: A British Socio-Demographic Profile
Despite international growth of, and policy interest in, divorce and separation since the 1970s, there is still surprisingly little known about non-residential fatherhood. This paper presents a 'father-centric' analysis and provides one of the first profiles of non-residential fatherhood in early millennium UK. Using data from Understanding Society Wave 1, a nationally representative survey of over 30,000 households in the UK, we found 1,070 men self-identifying as having a non-resident child under 16 years old (https://www.understandingsociety.ac.uk). We estimate a prevalence of 5 per cent of British men having a non-resident dependent child. Through latent class analysis, four distinct groups of non-resident fathers are identified: 'Engaged' fathers, 'Less Engaged' fathers, 'Disengaged' fathers and 'Distance' fathers. Our analysis finds that non-resident fathers form a heterogeneous group in terms of their socio-demographic profile and family behaviour. It is recommended that legislation and policy concerning fathers in post-separation families are sensitive to variation as well as commonality in socio-economic conditions and family lives and situations
Adaptive Comparative Judgment for Polytechnic Transformation: Assessment across the Curriculum
The authors are investigating potential applications of adaptive comparative judgment (ACJ) across numerous environments and learning scenarios within the Purdue Polytechnic Institute as part of Purdue’s efforts to transform the undergraduate learning experience. Six courses or program areas were selectedfor the study, involving a wide variation in subjects, subject matter, and assessment artifacts. The authors anticipate that positive results from these pilot studies will encourage broader and deeper applications of ACJ in the Purdue Polytechnic, across Purdue University, and in other academic institutions. Results from these scenarios will be disseminated in future conferences and scholarly journals
Britain's slow movement to a Gender Egalitarian Equilibrium: Parents and Employment in the UK 2001 - 2013
This paper examines the working lives of British couple families across the first decade of the
millennium using EU Labour Force Survey data (2001-2013) taking a multiple equilibria approach
(Esping-Andersen and Billari, 2015). We identify a growth in dual full-time earners, increased
working hours of mothers in part-time employment and a growing proportion of households with
ânon-standardâ working patterns, suggesting both a convergence and greater diversity in economic
provisioning within parent couple households. We find that household employment patterns remain
strongly associated with maternal education and family size but are becoming less sensitive to the
age of youngest child. The dual full-time earner model is growing in significance for British parents
of young children but a new gender egalitarian equilibrium has not yet been reached
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