Search results for "Positive"
showing 10 items of 1875 documents
New results on the Roper resonance and the P_{11} partial wave
2008
Properties of the Roper resonance, the first scalar excitation of the nucleon, are determined. Pole positions and residues of the $P_{11}$ partial wave are studied in a combined analysis of pion- and photo-induced reactions. We find the Roper pole at $\{(1371\pm7)-i(92\pm10)\}$ MeV and an elasticity of $0.61\pm 0.03$. The largest decay coupling is found for the $N\sigma$ ($\sigma=(\pi\pi)$-$S$-wave). The analysis is based on new data on $\gamma p\to p\pi^0\pi^0$ for photons in the energy range from the two-pion threshold to 820 MeV from TAPS at Mainz and from 0.4 to 1.3 GeV from Crystal Barrel at Bonn and includes further data from other experiments. The partial wave analysis excludes the p…
Development of spontaneous airway changes consistent with human asthma in mice lacking T-bet.
2002
Human asthma is associated with airway infiltration by T helper 2 (TH2) lymphocytes. We observed reduced expression of the TH1 transcription factor, T-bet, in T cells from airways of patients with asthma compared with that in T cells from airways of nonasthmatic patients, suggesting that loss of T-bet might be associated with asthma. Mice with a targeted deletion of the T-bet gene and severe combined immunodeficient mice receiving CD4+cells from T-bet knockout mice spontaneously demonstrated multiple physiological and inflammatory features characteristic of asthma. Thus, T-bet deficiency, in the absence of allergen exposure, induces a murine phenotype reminiscent of both acute and chronic h…
Infectious Tolerance
2002
Regulatory CD4(+)CD25(+) T cells (Treg) are mandatory for maintaining immunologic self-tolerance. We demonstrate that the cell-cell contact-mediated suppression of conventional CD4(+) T cells by human CD25(+) Treg cells is fixation resistant, independent from membrane-bound TGF-beta but requires activation and protein synthesis of CD25(+) Treg cells. Coactivation of CD25(+) Treg cells with Treg cell-depleted CD4(+) T cells results in anergized CD4(+) T cells that in turn inhibit the activation of conventional, freshly isolated CD4(+) T helper (Th) cells. This infectious suppressive activity, transferred from CD25(+) Treg cells via cell contact, is cell contact-independent and partially medi…
Average Tax Rate Cyclicality in OECD Countries: A Test of Three Fiscal Policy Theories
2011
This paper investigates the cyclical properties of the average effective tax rate in 26 OECD countries over 1965-2003 in order to test the validity of three theories of fiscal policy: (i) the standard Keynesian theory which recommends that tax policy should be counter-cyclical, (ii) the Tax Smoothing hypothesis, which implies that changes in GDP should be uncorrelated with tax rates, and (iii) the positive theory of Battaglini and Coate (2008) which predicts that the average tax rate should be negatively correlated with GDP. Our main finding is that the correlations of tax rates with cyclical GDP are generally quite small and statistically indistinguishable from zero. This finding is quite …
Discussing the Concepts of Cluster and Industrial District
2016
The significance and popularity of the cluster and industrial district concepts claim for a deeper reflection. The analysis of one of the European Commission’s (EC) policy documents shows inconsistencies that do not impede the formulation of normative statements. That way we answer the question of why and how cluster ideas have substituted industrial district principles and the consequences derived from that phenomenon.
Music Education, Creativity and Technology: An Exploratory Study on Teaching Strategies and Creative Activities With Ex Novo Software
2022
Resumen Objetivo. Analizar las estrategias y las actividades creativas que el profesorado de música realiza en sus aulas mediante un software construido por las personas investigadoras que facilita la creación sonora colaborativa en contextos docentes. Método. El trabajo se ha realizado mediante un enfoque exploratorio-descriptivo a través de una experiencia didáctica desarrollada durante 12 semanas en aula y después se encuestó a 27 docentes de educación primaria y secundaria. La encuesta recogió información sobre actividades de aula realizadas, procesos creativos llevados a cabo, estrategias docentes adoptadas, recursos de aula y uso del software en las actividades. Resultados. Los result…
Attitudes and perceptions of faculty members in the process adopting innovation: The OpenCourseWare initiative at the University of Valencia, Spain
2014
The OpenCourseWare project, an open learning resource repository, was established at the University of Valencia between 2008 and2009. It initially consisted of only 10 subjects, none of which was in the field of Health Sciences. The objective of this research was toinvestigate the attitudes and perceptions of faculty members in the field of Health Sciences with regard to the project to identify strategies to increase its use and expand its coverage. We applied Rogers’ innovation-diffusion theory along with a qualitative approach using theoretical sampling, semi-structured interviews and open coding. The results indicate the existence of two categories of faculty members. In the first group,…
What Do Secondary Students Really Learn during Investigations with Living Animals? Parameters for Effective Learning with Social Insects
2016
ABSTRACTExemplary for social insects, Temnothorax ants allow for various hands-on investigations in biology classes. The aim of this study was to provide a quantitative and qualitative analysis of secondary school students’ learning achievement after teaching units with ants lasting between one and six weeks. The questionnaires included transfer and factual knowledge tasks divided into eight fields of knowledge. Students (N = 459) from 22 classes participated in the study and received different treatments: The experimental group (n = 366) started their investigations by initial observation using stereo microscopes, while the control group (n = 93) conducted ant research without this i…
Job insecurity among temporary workers: Looking through the gender lens
2014
Based on the gender model and the life context model, the financial and domestic responsibilities and expectations associated with getting a new assignment are tested as potential gender specific moderators of the link between job insecurity and commitment, performance, and depressive moods. In a cross-sectional international questionnaire study of 1981 temporary workers’ three-way interactions between job insecurity, gender, and the moderators were tested. Expectations play a moderating role for women only, intensifying the negative relationship between job insecurity and commitment. Financial responsibility strengthened the negative relationship of job insecurity with commitment, as well…
Effects of network pressure on water meter under-registration: an experimental analysis
2018
Abstract. In water supply systems, a considerable amount of apparent loss is caused by meter under-registration. Water meters are subject to intrinsic systemic error depending on the actual flow rates passing through them. Furthermore, the moving parts of the meter are subject to wear and tear that progressively reduce meter accuracy. The increase in systemic error is especially evident at low flow rates because of growing friction in the rotating mechanism, which requires a higher flow to start the meter (starting flow). The aim of this paper is to experimentally investigate metering error in an attempt to find a direct link between meter age, network pressure and apparent losses caused by…