6,719 research outputs found

    Asymmetric effects of monetary policy in the United States

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    This paper tests for the presence of asymmetric effects of monetary policy on output. The asymmetries that the authors examine are related to the size and sign of monetary policy shocks and are based on economic theory. Using M1 as the basis for measuring monetary policy shocks, they find evidence in line with previous evidence of larger real effects resulting from positive shocks than from negative shocks—although the authors cannot reject symmetry either. However, using the federal funds rate instead, a measure that is more closely related to the actual conduct of monetary policy, they find that only small negative shocks affect real aggregate activity. The results are interpreted in terms of menu-cost models.Monetary policy ; Macroeconomics

    Indices of Conflict Triggers in Femi Ajewole’s Theatrical Performances in Oyo State, Southwest, Nigeria

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    Conflicts may be triggered by various factors. When not managed can lead to conflict escalation. This paper interrogates the theatrical performances of Christ Chosen Vessels (CCV), a Christian Drama Ministry. Scholars have established theatrical performances remain a tool for change. However, there is limited literature on the role of theatrical performances in peace and conflict studies. This paper analyses the conflict triggers in the theatrical performances of CCV. This study is guided by social identity theory by Henri Tajfel. It adopted qualitative research and case study design. Primary sources of data include KII (2); IDI (2); police reports; and video CDs (3) of selected performances of CCV. Secondary sources include books, journals and theses. Descriptive methods were used to analyze data. Findings showed religious codes, language, characterization, and costume served as conflict triggers. It was concluded that theatrical performances can trigger conflicts. This paper recommends theatrical artists must consider the sensitivity of others in the process of creativity in respect of diversity for peaceful coexistence

    Tailoring laser pulses with spectral and fluence constraints using optimal control theory

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    Within the framework of optimal control theory we develop a simple iterative scheme to determine optimal laser pulses with spectral and fluence constraints. The algorithm is applied to a one-dimensional asymmetric double well where the control target is to transfer a particle from the ground state, located in the left well, to the first excited state, located in the right well. Extremely high occupations of the first excited state are obtained for a variety of spectral and/or energetic constraints. Even for the extreme case where no resonance frequency is allowed in the pulse the algorithm achieves an occupation of almost 100%

    Absolute properties of the binary system BB Pegasi

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    We present a ground based photometry of the low-temperature contact binary BB Peg. We collected all times of mid-eclipses available in literature and combined them with those obtained in this study. Analyses of the data indicate a period increase of 3.0(1) x 10^{-8} days/yr. This period increase of BB Peg can be interpreted in terms of the mass transfer 2.4 x 10^{-8} Ms yr^{-1} from the less massive to the more massive component. The physical parameters have been determined as Mc = 1.42 Ms, Mh = 0.53 Ms, Rc = 1.29 Rs, Rh = 0.83 Rs, Lc = 1.86 Ls, and Lh = 0.94 Ls through simultaneous solution of light and of the radial velocity curves. The orbital parameters of the third body, that orbits the contact system in an eccentric orbit, were obtained from the period variation analysis. The system is compared to the similar binaries in the Hertzsprung-Russell and Mass-Radius diagram.Comment: 17 pages, 3 figures, accepted for Astronomical Journa

    Testing the Wagner’s Hypothesis on Public Expenditure and Output Growth Causality in Nigeria

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    This study tests the validity of Wagner’s hypothesis on public expenditure and output growth in Nigeria from 1970 – 2016 using annual time series data. Phillips Perron unit root test (PP), Johansen cointegration test, Vector Error Correction Model (VECM) and pair wise Granger causality econometric analytical methods were employed. The stationary property of the research variables was confirmed and other tests in the study revealed a unidirectional causation from government expenditure to economic growth in the country. The finding of the study therefore invalidates the applicability of Wagner’s hypothesis in Nigeria within the study period. The study recommends the need for appropriate policies on effective utilization of public fund knowing that it has positive effect on the level of economic growth in the country. Keywords: Wagner’s hypothesis, Output Growth, Public Expenditure, Cointegration, VECM, Causality. DOI: 10.7176/RHSS/9-24-09 Publication date: December 31st 201

    Inhibition of DNA damage response at telomeres improves the detrimental phenotypes of Hutchinson–Gilford Progeria Syndrome

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    Hutchinson–Gilford progeria syndrome (HGPS) is a genetic disorder characterized by premature aging features. Cells from HGPS patients express progerin, a truncated form of Lamin A, which perturbs cellular homeostasis leading to nuclear shape alterations, genome instability, heterochromatin loss, telomere dysfunction and premature entry into cellular senescence. Recently, we reported that telomere dysfunction induces the transcription of telomeric non-coding RNAs (tncRNAs) which control the DNA damage response (DDR) at dysfunctional telomeres. Here we show that progerin-induced telomere dysfunction induces the transcription of tncRNAs. Their functional inhibition by sequence-specific telomeric antisense oligonucleotides (tASOs) prevents full DDR activation and premature cellular senescence in various HGPS cell systems, including HGPS patient fibroblasts. We also show in vivo that tASO treatment significantly enhances skin homeostasis and lifespan in a transgenic HGPS mouse model. In summary, our results demonstrate an important role for telomeric DDR activation in HGPS progeroid detrimental phenotypes in vitro and in vivo

    Design and validation of a three-instrument toolkit for the assessment of competence in electrocardiogram rhythm recognition

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    Background: Rapid and accurate interpretation of cardiac arrhythmias by nurses has been linked with safe practice and positive patient outcomes. Although training in electrocardiogram (ECG) rhythm recognition is part of most undergraduate nursing programmes, research continues to suggest that nurses and nursing students lack competence in recognising cardiac rhythms. In order to promote patient safety, nursing educators must develop valid and reliable assessment tools that allow the rigorous assessment of this competence before nursing students are allowed to practise without supervision. Aim: To develop and psychometrically evaluate a toolkit to holistically assess competence in ECG rhythm recognition. Methods: Following a convenience sampling technique, 293 nursing students from a nursing faculty in a Spanish university were recruited for the study. The following three instruments were developed and psychometrically tested: a knowledge assessment tool (ECG-KAT), a skills assessment tool (ECG-SAT) and a self-efficacy assessment tool (ECG-SES). Reliability and validity (content, criterion and construct) of these tools were meticulously examined. Results: A high Cronbach’s alpha coefficient demonstrated the excellent reliability of the instruments (ECG-KAT=0.89; ECG-SAT=0.93; ECG-SES=0.98). An excellent context validity index (S-CVI/Ave>0.94) and very good criterion validity were evidenced for all the tools. Regarding construct validity, principal component analysis revealed that all items comprising the instruments contributed to measure knowledge, skills or self-efficacy in ECG rhythm recognition. Moreover, known-groups analysis showed the tools’ ability to detect expected differences in competence between groups with different training experiences. Conclusion: The three-instrument toolkit developed showed excellent psychometric properties for measuring competence in ECG rhythm recognition

    Wideband magnetic losses and their interpretation in HGO steel sheets

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    The magnetic properties of high-permeability grain-oriented (HGO) Fe-Si sheets have been investigated in the frequency range 1 Hz-10 kHz, with attention devoted to the role of thickness on the behavior of the magnetic losses and the phenomenology of skin effect. The study is focused on the wideband response of 0.174 mm and 0.289 mm thick sheets, comparatively tested at peak polarization values ranging between 0.25 T and 1.7 T. The experiments associate fluxmetric measurements with direct Kerr observations of the dynamics of the domain walls. A picture of the magnetization process comes to light, where the dynamics of the flux reversal takes hold under increasing frequencies through the motion of increasingly bowed 180 degrees walls, eventually merging at the sheet surface for a fraction of the semi-period. This effect can be consistently predicted, starting from the Kerrbased knowledge of the equilibrium wall spacing, by the numerical modeling of the motion of an extended array of 180 degrees domain walls, subjected to the balanced action of the applied and eddy current fields, and the elastic reaction of the bowed walls. This model can be incorporated into the general concept of loss separation, by calculating the classical loss component through the solution of the Maxwell's diffusion equation under a magnetic constitutive law identified with the normal DC curve. The numerical domain wall model and the loss decomposition consistently predict that the excess loss component, playing a major role in these grain-oriented materials at power frequencies, tends to disappear in the upper induction-frequency corner

    Can electro-magnetic field, anisotropic source and varying Λ\Lambda be sufficient to produce wormhole spacetime ?

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    It is well known that solutions of general relativity which allow for traversable wormholes require the existence of exotic matter (matter that violates weak or null energy conditions [WEC or NEC]). In this article, we provide a class of exact solution for Einstein-Maxwell field equations describing wormholes assuming the erstwhile cosmological term Λ\Lambda to be space variable, viz., Λ=Λ(r)\Lambda = \Lambda (r). The source considered here not only a matter entirely but a sum of matters i.e. anisotropic matter distribution, electromagnetic field and cosmological constant whose effective parts obey all energy conditions out side the wormhole throat. Here violation of energy conditions can be compensated by varying cosmological constant. The important feature of this article is that one can get wormhole structure, at least theoretically, comprising with physically acceptable matters.Comment: Some changes have been mad
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