1,823 research outputs found
MONTE CARLO EVIDENCE ON COINTEGRATION AND CAUSATION
The small sample performance of Granger causality tests under different model dimensions, degree of cointegration, direction of causality, and system stability are presented. Two tests based on maximum likelihood estimation of error-correction models (LR and WALD) are compared to a Wald test based on multivariate least squares estimation of a modified VAR (MWALD). In large samples all test statistics perform well in terms of size and power. For smaller samples, the LR and WALD tests perform better than the MWALD test. Overall, the LR test outperforms the other two in terms of size and power in small samples.Causality tests, Cointegration, Likelihood ratio, Wald statistic, Monte Carlo Experiments, Research Methods/ Statistical Methods,
What is the impact of pensions on saving?
The enormous growth in both Social Security and private pension plans has stimulated much interest in the impact of these retirement programs on individual saving behavior and the level of national saving. The first issue is the extent to which employees covered by pension plans reduce their own direct saving in response to expected retirement benefits; the response of individuals to guaranteed retirement income will determine, to a large extent, their well-being in retirement. For a nation concerned about saving and capital formation, the second issue is the impact of collectivized retirement saving plans on the national saving rate. This impact will depend not only on individual responses to promised pension benefits, but also on the extent to which firms undertake direct saving, and, if they do not, the extent to which shareholders recognize and compensate for unfunded pension liabilities. The effect of pensions on national saving also requires determining the degree to which increased saving induced by favorable tax provisions exceeds the loss of government revenues. ; This paper will lay out the questions that need to be answered in order to determine the impact of private pension plans on saving, highlight those aspects of pensions that may complicate the analysis, summarize the results of empirical research in this area, and finally make recommendations for improvements in the data.Saving and investment ; Pensions
Stochastic level-set method for shape optimisation
We present a new method for stochastic shape optimisation of engineering
structures. The method generalises an existing deterministic scheme, in which
the structure is represented and evolved by a level-set method coupled with
mathematical programming. The stochastic element of the algorithm is built on
the methods of statistical mechanics and is designed so that the system
explores a Boltzmann-Gibbs distribution of structures. In non-convex
optimisation problems, the deterministic algorithm can get trapped in local
optima: the stochastic generalisation enables sampling of multiple local
optima, which aids the search for the globally-optimal structure. The method is
demonstrated for several simple geometrical problems, and a proof-of-principle
calculation is shown for a simple engineering structure.Comment: 17 pages, 10 fig
An Evaluation of Math Assessment Policy Process in a Southwestern School District
An Evaluation of Math Assessment Policy Process in a Southwestern School District
by
Alicia Taber O\u27Brien
EdS, Walden University, 2011
MA, Western Governors University, 2004
BS, New Mexico State University, 1994
Doctoral Study Submitted in Partial Fulfillment
of the Requirements for the Degree of
Doctor of Education
Teacher Leadership
Walden University
September 2015
This project study addressed the lack of evaluation of a math assessment policy in a rural elementary school district in the southwestern United States. This district implemented a math assessment policy in the spring of 2005, yet no evaluation had been conducted to determine whether the policy and its continued implementation were meeting the intended outcomes. Two conceptual frameworks that drove the study were Sabatier\u27s theories of policy process and Bardach\u27s eightfold path to policy analysis. Using interviews of the district\u27s 3 K-12 math teachers and 5 administrators who had proximity to the math assessment policy, this case study explored how the math assessment policy was implemented, as well as whether the policy had met the goals it was originally created to address. Data were deconstructed by coding and then reconstructed in order to create a thick description of the findings. A review of local media documents was also used to illustrate the community\u27s response and reaction to the local district\u27s assessment policies. The 5 themes that developed from analysis of the interview data focused on uncertainty in the ranks, sharing power, collaborating among the mathematics disciplines, policy evolution, and policy outcomes. The results presented in the evaluation report showed that administrators believed the policy was achieving its goals but teachers did not. The evaluation included an executive summary with recommendations to facilitate better communication about the policy throughout the district. Positive social change implications resulting from the evaluation of the math assessment policy include changing the decision-making process at the local district from a top-down model to include more input from practitioners in order to create policies that maximize student success and teacher support
SELECTING THE "BEST" PREDICTION MODEL: AN APPLICATION TO AGRICULTURAL COOPERATIVES
A credit scoring function incorporating statistical selection criteria was proposed to evaluate the credit worthiness of agricultural cooperative loans in the Fifth Farm Credit District. In-sample (1981-1986) and out-of-sample (1988) prediction performance of the selected models were evaluated using rank transformation discriminant analysis, logit, and probit. Results indicate superior out-of-sample performance for the management oriented approach relative to classification of unacceptable loans, and poor performance of the rank transformation in out-of-sample prediction.Agribusiness,
Smoking and Drug Policy for the Appalachian School of Law
The goals identified to guide this study were: 1. To identify the guidelines for grant funding from the Appalachian Regional commission and the standards for the accreditation from the American Bar Association; 2. to review State and Federal Regulations governing the use of tobacco and drugs in the workplace; 3. To identify smoking and drug policies available at the accredited law schools in Virginia; 4. To prepare a smoking and drug policy for the Appalachian School of La
On the G-protein-coupled receptor heteromers and their allosteric receptor-receptor interactions in the central nervous system: focus on their role in pain modulation
The modulatory role of allosteric receptor-receptor interactions in the pain pathways of the Central Nervous System and the peripheral nociceptors has become of increasing interest. As integrators of nociceptive and antinociceptive wiring and volume transmission signals, with a major role for the opioid receptor heteromers, they likely have an important role in the pain circuits and may be involved in acupuncture. The delta opioid receptor (DOR) exerts an antagonistic allosteric influence on the mu opioid receptor (MOR) function in a MOR-DOR heteromer. This heteromer contributes to morphine-induced tolerance and dependence, since it becomes abundant and develops a reduced G-protein-coupling with reduced signaling mainly operating via beta-arrestin 2 upon chronic morphine treatment. A DOR antagonist causes a return of the Gi/o binding and coupling to the heteromer and the biological actions of morphine. The gender- and ovarian steroid-dependent recruitment of spinal cord MOR/kappa opioid receptor (KOR) heterodimers enhances antinociceptive functions and if impaired could contribute to chronic pain states in women. MOR1D heterodimerizes with gastrin-releasing peptide receptor (GRPR) in the spinal cord, mediating morphine induced itch. Other mechanism for the antinociceptive actions of acupuncture along meridians may be that it enhances the cross-desensitization of the TRPA1 (chemical nociceptor)-TRPV1 (capsaicin receptor) heteromeric channel complexes within the nociceptor terminals located along these meridians. Selective ionotropic cannabinoids may also produce cross-desensitization of the TRPA1-TRPV1 heteromeric nociceptor channels by being negative allosteric modulators of these channels leading to antinociception and antihyperalgesia
Signs of community and change: Mapping Spanish linguistic landscapes in Alabama
Cipria and O’Rourke present findings from their study of the “linguistic landscape” in Tuscaloosa, Alabama, focusing on signage incorporating Spanish words for billboards, tiendas and shops, services, churches, and restaurants
Pouring Salt on a Wound: Pseudomonas aeruginosa Virulence Factors Alter Na+ and Cl− Flux in the Lung
Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen with multiple niches in the human body, including the lung. P. aeruginosa infections are particularly damaging or fatal for patients with ventilator-associated pneumonia, chronic obstructive pulmonary disease, and cystic fibrosis (CF). To establish an infection, P. aeruginosa relies on a suite of virulence factors, including lipopolysaccharide, phospholipases, exoproteases, phenazines, outer membrane vesicles, type III secreted effectors, flagella, and pili. These factors not only damage the epithelial cell lining but also induce changes in cell physiology and function such as cell shape, membrane permeability, and protein synthesis. While such virulence factors are important in initial infection, many become dysregulated or nonfunctional during the course of chronic infection. Recent work on the virulence factors alkaline protease (AprA) and CF transmembrane conductance regulator inhibitory factor (Cif) show that P. aeruginosa also perturbs epithelial ion transport and osmosis, which may be important for the long-term survival of this microbe in the lung. Here we discuss the literature regarding host physiology-altering virulence factors with a focus on Cif and AprA and their potential roles in chronic infection and immune evasion
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