470 research outputs found
Estimation and Inference in Short Panel Vector Autoregressions with Unit Roots and Cointegration
This paper considers estimation and inference in panel vector autoregressions (PVARs) with fixed effects when the time dimension of the panel is finite, and the cross-sectional dimension is large. A Maximum Likelihood (ML) estimator based on a transformed likelihood function is proposed and shown to be consistent and asymptotically normally distributed irrespective of the unit root and cointegrating properties of the underlying PVAR model. The transformed likelihood framework is also used to derive unit root and cointegration tests in panels with short time dimension; these tests have the attractive feature that they are based on standard chi-squared and normal distributed statistics. Examining Generalised Method of Moments (GMM) estimation as an alternative to our proposed ML estimator, it is shown that conventional GMM estimators based on standard orthogonality conditions break down if the underlying time series contain unit roots.Panel vector autoregressions, Fixed effects, Unit roots, Cointegration
Dynamics of contact line motion during the wetting of rough surfaces and correlation with topographical surface parameters
Dynamics of contact line motion and wettability is essential in many industrial applications such as liquid coating, lubrication, printing, painting, condensation, etc. However, the wettability of surfaces depends not only on liquid–solid chemical properties but also can be strongly affected by surface roughness. As a practical application of controlled wettability, we can mention the self-cleaning surfaces, protective clothing, microfluidics devices, electro wetting, etc. In this article, we experimentally investigate the spreading of droplets deposited onto rough surfaces. Anisotropic surfaces were prepared by abrasive polishing on the following materials: aluminium alloy AA7064, titanium alloy Ti-6Al-4V, steel AISI 8630, copper alloy UNS C17000, machinable glass ceramic, and poly-methylmethacrylate. Topographical 2D parameters were calculated according to the following standards, defining Geometrical Product Specifications (GPS): ISO 4287, ISO 12085, ISO 13565, ISO 12780, and ISO 12181. The influence of topographical parameters on wettability and spreading phenomenon has been evaluated by statistical covariance analysis. The following parameters have strong influence on fluid spreading on rough surfaces: Rmr is the relative material ratio of the roughness profile, Trc is the microgeometric material ratio, Pmr is the relative material ratio of the raw profile, Kr is the mean slope of the roughness motifs, RONt is the peak to valley roundness deviation, and Psk is the Skewness of the raw profile. The physical meaning of selected parameters is discussed, and Kr (the mean slope of the roughness motifs) is selected as the most important and physically meaningful parameter. It has been found that for all tested materials, fluid spreading shows increasing tendency when mean slope of the roughness motifs (Kr) increases. SCANNING 33: 1–8, 2011. © 2011 Wiley Periodicals, Inc
Photon-noise limited sensitivity in titanium nitride kinetic inductance detectors
We demonstrate photon-noise limited performance at sub-millimeter wavelengths
in feedhorn-coupled, microwave kinetic inductance detectors (MKIDs) made of a
TiN/Ti/TiN trilayer superconducting film, tuned to have a transition
temperature of 1.4~K. Micro-machining of the silicon-on-insulator wafer
backside creates a quarter-wavelength backshort optimized for efficient
coupling at 250~\micron. Using frequency read out and when viewing a variable
temperature blackbody source, we measure device noise consistent with photon
noise when the incident optical power is ~0.5~pW, corresponding to noise
equivalent powers ~3 W/. This
sensitivity makes these devices suitable for broadband photometric applications
at these wavelengths
Transformations of tryptamine and tryptophan by basidiomycetes
The product formed from tryptamine by Trichloloma nudum was identified as indoleacetic acid (IAA) and from tryptophan by Cantharellus cibrarius as indolelactic acid (ILA). The products were extracted from the spent media with organic solvents. Purification and identification of the crystalline transformation products were accomplished by means of paper chromatography, spectrophotometry and thin layer chromatography.
The conversion of tryptamine and tryptophan was also studied in cultures of Lencopaxillus paradoxus, Pluteus granularis and Pleuatus ostreatus. Only Pluteus granularis was found to transform tryptamine into IAA. Lencopaxillus paradoxus transformed tryptamine into oxindoleacetic acid (OIAA).
Paper chromatography proved to be useful for the qualitative identification of indoleacetic acid, indolelactic acid, oxindole-acetic acid and anthranilic acid. Spectrophotometry was employed for the quantitative estimation of the substances formed --Abstract, page ii
Global Ethics and Nanotechnology: A Comparison of the Nanoethics Environments of the EU and China
The following article offers a brief overview of current nanotechnology policy, regulation and ethics in Europe and The People’s Republic of China with the intent of noting (dis)similarities in approach, before focusing on the involvement of the public in science and technology policy (i.e. participatory Technology Assessment). The conclusions of this article are, that (a) in terms of nanosafety as expressed through policy and regulation, China PR and the EU have similar approaches towards, and concerns about, nanotoxicity—the official debate on benefits and risks is not markedly different in the two regions; (b) that there is a similar economic drive behind both regions’ approach to nanodevelopment, the difference being the degree of public concern admitted; and (c) participation in decision-making is fundamentally different in the two regions. Thus in China PR, the focus is on the responsibility of the scientist; in the EU, it is about government accountability to the public. The formulation of a Code of Conduct for scientists in both regions (China PR’s predicted for 2012) reveals both similarity and difference in approach to nanotechnology development. This may change, since individual responsibility alone cannot guide S&T development, and as public participation is increasingly seen globally as integral to governmental decision-making
ALP-enigma protein ALP-1 functions in actin filament organization to promote muscle structural integrity in Caenorhabditis elegans
Journal ArticleMutations that affect the Z-disk-associated ALP-Enigma proteins have been linked to human muscular and cardiac diseases. Despite their clear physiological significance for human health, the mechanism of action of ALP-Enigma proteins is largely unknown. In Caenorhabditis elegans, the ALP-Enigma protein family is encoded by a single gene, alp-1; thus C. elegans provides an excellent model to study ALP-Enigma function. Here we present a molecular and genetic analysis of ALP-Enigma function in C. elegans
USING E-BALANCED SCORECARD IN MANAGING THE PERFORMANCE AND EXCELLENCE OF ACADEMICIANS
The corporate performance and measurement discipline is dynamically changing. Organizations will increasingly identify sets of performance issues and build tracking mechanisms to monitor how the enterprise is doing. As a practice, performance measurement and management requires objectivity and careful planning in order to see its successful, continuous implementation. University Malaya is currently looking at the balanced scorecard (BSC) as the performance measurement and management tool in assessing the whole spectrum of what defines an excellent organization. This study specifically researches the use of an electronic BSC system (e-BSC) in measuring the performance and excellence of academicians in University Malaya from the perspectives of Financial, Customer, Internal Business Process (IBP) and Learning and Growth (L&G). To substantiate this research work, a survey and several interviews were conducted. Graphs are presented to depict the user requirements of the development of the e-BSC System. Furthermore, based on the obtained information too, the performance measurement framework is proposed. The advantage of adopting an automated balanced scorecard to manage the performance of academicians is that it sanctions excellence and provides a platform for better organization-wide alignment of strategies. The demand for a better performance measurement system has thus far been proven through the findings obtained
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