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Differing Effects (differing + effects)
Selected AbstractsThe Social Capital of Blacks and Whites: Differing Effects of the Mass Media in the United StatesHUMAN COMMUNICATION RESEARCH, Issue 2 2006Christopher E. Beaudoin This study relied on telephone survey interviews of adults in two U.S. metropolitan areas to examine whether the relationship between mass media use and social capital varies according to ethnicity. A multigroup approach taken with structural equation modeling validates a four-factor model of social capital for Blacks and Whites and then, with the implementation of a comprehensive model that also includes mass media inputs, tests for structural variance between the ethnic groups. A well-fitting comprehensive model is achieved, with significant differences between Blacks and Whites in terms of the mass media use structures. In support of the two hypotheses, the relationship between news use and social capital is less positive for Blacks than for Whites and the relationship between entertainment TV viewing and social capital is more negative for Blacks than for Whites. These findings are discussed in terms of literature involving mass media effects on social capital, news coverage of ethnic groups, and ethnic differences in self-conceptualization and media responses. [source] Differing effects of substrate and non-substrate transport inhibitors on glutamate uptake reversalJOURNAL OF NEUROCHEMISTRY, Issue 6 2001Christopher M. Anderson Na+ -dependent excitatory amino acid transporters (EAATs) normally function to remove extracellular glutamate from brain extracellular space, but EAATs can also increase extracellular glutamate by reversal of uptake. Effects of inhibitors on EAATs can be complex, depending on cell type, whether conditions favor glutamate uptake or uptake reversal and whether the inhibitor itself is a substrate for the transporters. The present study assessed EAAT inhibitors for their ability to inhibit glutamate uptake, act as transporter substrates and block uptake reversal in astrocyte and neuron cultures. lthreo -,-hydroxyaspartate (l -TBHA), dlthreo -,-benzyloxyaspartate (dl -TBOA), ltrans -pyrrolidine-2,4-dicarboxylic acid (ltrans -2,4-PDC) (+/,)- cis -4-methy- trans -pyrrolidine-2,4-dicarboxylic acid (cis -4-methy- trans -2,4-PDC) and lantiendo -3,4-methanopyrrolidine-2,4-dicarboxylic acid (lantiendo -3,4-MPDC) inhibited l -[14C]glutamate uptake in astrocytes with equilibrium binding constants ranging from 17 µm (dl -TBOA and l -TBHA) , 43 µm (cis -4-methy- trans -2,4-PDC). Transportability of inhibitors was assessed in astrocytes and neurons. While l -TBHA, ltrans -2,4-PDC, cis -4-methy- trans -2,4-PDC and lantiendo -3,4-MPDC displayed significant transporter substrate activities in neurons and astrocytes, dl -TBOA was a substrate only in astrocytes. This effect of dl -TBOA was concentration-dependent, leading to complex effects on glutamate uptake reversal. At concentrations low enough to produce minimal dl -TBOA uptake velocity (, 10 µm), dl -TBOA blocked uptake reversal in ATP-depleted astrocytes; this blockade was negated at concentrations that drove substantial dl -TBOA uptake (> 10 µm). These findings indicate that the net effects of EAAT inhibitors can vary with cell type and exposure conditions. [source] Keratinocyte growth factor and scatter factor expression by regionally defined oral fibroblastsEUROPEAN JOURNAL OF ORAL SCIENCES, Issue 1 2003Scott Thomas William McKeown Keratinocyte growth factor (KGF) and hepatocyte growth factor/scatter factor (SF) are two signalling molecules thought to play important roles in regulating epithelial,mesenchymal interactions. Expression of both factors by fibroblasts in subepithelial connective tissue may play a role in maintaining epithelial integrity in health and in the apical migration of junctional epithelium in periodontitis. The aims of this study were (a) to compare expression levels of KGF and SF by periodontal ligament (PDL) and gingival fibroblasts; and (ii) to determine the effects of interleukin (IL)-1,, transforming growth factor (TGF)-,1, platelet-derived growth factor (PDGF)-BB and epidermal growth factor (EGF) on KGF/SF expression by these cell populations. Three paired PDL and gingival fibroblast strains were developed. The KGF and SF protein levels were analysed by enzyme-linked immunosorbent assay. Relative levels of KGF and SF mRNA in cytokine-treated cultures were determined using semiquantitative reverse transcriptase polymerase chain reaction. No differences in the levels of KGF and SF produced by PDL and gingival (SOG) populations were found. In both cell types IL-1, stimulated KGF and SF expression, while TGF-,1 significantly inhibited expression at both the mRNA and protein levels. Epidermal growth factor and PDGF-BB induced differing effects on expression, stimulating SF protein production but inhibiting KGF output in both fibroblast populations. Differences in response to EGF and PDGF were also seen between paired PDL and gingival fibroblasts. [source] The Family Experience of "Sudden Health": The Case of Intractable EpilepsyFAMILY PROCESS, Issue 4 2003DAVID B. SEABURN Ph.D. This article reports the experience of "sudden health" among six families who participated in an exploratory qualitative study of families with a member who elects to have corrective surgery for intractable epilepsy. Families were interviewed pre- and post surgery (6,8months) and the interviews were analyzed using a constant comparative methodology. Findings indicated that (1) families were organized in two primary ways (nesting and crisis) to deal with epilepsy and the aftermath of surgery and (2) "sudden health" had differing effects on these families depending on their organizational style, emotional communication process, and developmental dynamics. [source] Catholic Schooling, Protestant Schooling, and Religious Commitment in Young AdulthoodJOURNAL FOR THE SCIENTIFIC STUDY OF RELIGION, Issue 2 2009Jeremy E. Uecker If and how Catholic and Protestant schools influence the religious lives of their students once they have graduated is unclear. Methodological limitations and inconsistencies in previous studies have resulted in confusing and often contradictory findings. Using data from two waves of the National Longitudinal Study of Adolescent Health (N,= 11,212), I compare the religious lives of young adults who attended Catholic, Protestant, and secular schools as adolescents. The results suggest that Protestant schoolers are far more religious as young adults than those who attended a secular school, a difference that is at least partially explained by the schools' religious environment. But young adults who attended Catholic schools report levels of religiosity that are similar to those educated in a secular school, and are actually lower for some outcomes. Studies of religious schoolers that ignore the religious tradition of the school overlook these differing effects and forfeit statistical explanatory power. [source] Increased Right Ventricular Repolarization Gradients Promote Arrhythmogenesis in a Murine Model of Brugada SyndromeJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 10 2010CLAIRE A. MARTIN M.R.C.P. Repolarization Gradients in Brugada Syndrome.,,Introduction: Brugada syndrome (BrS) is associated with loss of Na+ channel function and increased risks of a ventricular tachycardia exacerbated by flecainide but reduced by quinidine. Previous studies in nongenetic models have implicated both altered conduction times and repolarization gradients in this arrhythmogenicity. We compared activation latencies and spatial differences in action potential recovery between different ventricular regions in a murine Scn5a+/, BrS model, and investigated the effect of flecainide and quinidine upon these. Methods and Results: Langendorff-perfused wild-type and Scn5a+/, hearts were subjected to regular pacing and a combination of programmed electrical stimulation techniques. Monophasic action potentials were recorded from the right (RV) and left ventricular (LV) epicardium and endocardium before and following flecainide (10 ,M) or quinidine (5 ,M) treatment, and activation latencies measured. Transmural repolarization gradients were then calculated from the difference between neighboring endocardial and epicardial action potential durations (APDs). Scn5a+/, hearts showed decreased RV epicardial APDs, accentuating RV, but not LV, transmural gradients. This correlated with increased arrhythmic tendencies compared with wild-type. Flecainide increased RV transmural gradients, while quinidine decreased them, in line with their respective pro- and antiarrhythmic effects. In contrast, Scna5+/, hearts showed slowed conduction times in both RV and LV, exacerbated not only by flecainide but also by quinidine, in contrast to their differing effects on arrhythmogenesis. Conclusion: We use a murine genetic model of BrS to systematically analyze LV and RV action potential kinetics for the first time. This establishes a key role for accentuated transmural gradients, specifically in the RV, in its arrhythmogenicity. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1153-1159) [source] Do Higher Real Minimum Wages Lead to More High School Dropouts?AMERICAN JOURNAL OF ECONOMICS AND SOCIOLOGY, Issue 2 2009Evidence from Maryland Across Races We explore whether higher levels of the real minimum wage have differing effects on high school dropout rates across students of various races and ethnicities (whites, African Americans, Hispanics, and Asians). Using a panel of data across Maryland counties and annual observations in 1993,2004, we found higher real minimum wages to be associated with higher dropout rates for Hispanic students, but not for other races and ethnicities. We used a variety of model specifications and explanatory variables, including real income, the unemployment rate, teen pregnancy rates, and educational attainment among adults. Several of our findings are broadly consistent with commonly reported sociological observations regarding how behavioral choices may be affected by different levels across races and ethnicities of cultural integration of recent immigrants, family cohesiveness, the value placed on education, small business ownership, and hourly (vs. salaried) employment. [source] Bioeconomic analysis of protected area use in fisheries management,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 4 2007Jared Greenville Protected areas in fishery management have been suggested to hedge management failures and variation in harvests. In this paper, a stochastic bioeconomic model of a two-species fishery in the Manning Bioregion is used to test the performance of protected areas as a management tool in a fishery. The establishment of a protected area is analysed under the assumption of heterogenous environments that are linked via density-dependent or sink-source stock dispersal relationships. The sensitivity of the results to different degrees of management is also explored. The model is applied to the Ocean Prawn Trawl, and Ocean Trap and Line fisheries within Manning Bioregion in New South Wales, Australia. The focus of the study is placed on the biological and institutional characteristics that yield benefits to the fishery. It was found that protected area use in the Manning Bioregion is likely to have differing effects on the two fisheries examined, benefiting Ocean Trap and Line fishers but adversely affecting Ocean Prawn Trawl fishers. Overall, it is unlikely that protected area use will lead to an increase resource rent in the fishery. [source] Low molecular weight inhibitors of matrix metalloproteinases can enhance the expression of matrix metalloproteinase-2 (gelatinase A) without inhibiting its activationCANCER, Issue 6 2003Erika H. M. Kerkvliet Ph.D. Abstract BACKGROUND In the current study, the authors investigated the effects of synthetic low molecular weight inhibitors of matrix metalloproteinases (MMPs) on the expression and activation of MMP-2 in a three-dimensional tissue system. METHODS Rabbit periosteal explants were cultured with or without various concentrations of the MMP inhibitors CT1166, CT1399, or CT1746, and conditioned media and tissue extracts were analyzed for the expression and activity of MMP-2. RESULTS The data showed that blocking the activity of all MMPs with relatively high inhibitor concentrations completely prevented the conversion of pro-MMP-2 into its active form and that the level of protein was decreased. Selective inhibition of the activity of gelatinases (MMP-2 and MMP-9) by using low inhibitor concentrations, however, induced a higher level of active MMP-2 and increased its expression significantly. CONCLUSIONS The current observations indicate that selective inhibitors of MMPs affect the expression and activity of MMP-2, thus providing clues regarding the differing effects such inhibitors appear to have when applied in vivo. Cancer 2003;97:1582,88. © 2003 American Cancer Society. DOI 10.1002/cncr.11193 [source] | |||||||||||||