12,775 research outputs found
Summertime, and the livin is easy: Winter and summer pseudoseasonal life expectancy in the United States
In temperate climates, mortality is seasonal with a winter-dominant pattern,
due in part to pneumonia and influenza. Cardiac causes, which are the leading
cause of death in the United States, are also winter-seasonal although it is
not clear why. Interactions between circulating respiratory viruses (f.e.,
influenza) and cardiac conditions have been suggested as a cause of
winter-dominant mortality patterns. We propose and implement a way to estimate
an upper bound on mortality attributable to winter-dominant viruses like
influenza. We calculate 'pseudo-seasonal' life expectancy, dividing the year
into two six-month spans, one encompassing winter the other summer. During the
summer when the circulation of respiratory viruses is drastically reduced, life
expectancy is about one year longer. We also quantify the seasonal mortality
difference in terms of seasonal "equivalent ages" (defined herein) and
proportional hazards. We suggest that even if viruses cause excess winter
cardiac mortality, the population-level mortality reduction of a perfect
influenza vaccine would be much more modest than is often recognized
Malmquist Indices of Pre and Post-Deregulation Productivity, Efficiency and Technological Change in the Singaporean Banking Sector
By the end of the 1990s, the Singaporean government had recognised the need to open up its banking sector so as to remain competitive in the global economy. The Monetary Authority of Singapore thus began deregulation of the banking sector in 1999 to strengthening the competitiveness of local banks relative to their foreign competition through mergers. This paper employs a nonparametric Malmquist productivity index to provide measure of productivity, technological change and efficiency gains over the period 1995-2005. The findings reveal some total factor productivity growth associated with deregulation and scale efficiency improvement largely from mergers amongst the local banks.Efficiency, productivity; deregulation; Malmquist indices; banking
Model-based controller design for a plastic film extrusion process
This paper reports the development and implementation of a model-based cross-directional controller for plastic film extrusion and other web-forming processes. The controller design has a similar structure to that of internal model control (IMC) with the addition of an observer whose gain is designed to minimise process and model mis-match. The observer gain is obtained by solving a multi-objective optimisation through the application of a genetic algorithm and simulation results are presented in this paper demonstrating improvements that can be achieved by the proposed controller over two existing CD controllers
A graphical programming interface for a children's constructionist learning environment
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.Includes bibliographical references (p. 41).by Andrew C. Cheng.M.Eng
A control and monitoring oriented model of a film manufacturing process
This paper describes the development of a control and monitoring oriented model of a plastic film manufacturing process. The model is mainly derived from first-principles and has been implemented in the Matlab/Simulink dynamic simulation environment. The development of the model forms the first phase of a project that aims to develop a nonlinear sub-space based monitoring, fault detection and trouble shooting system for the film manufacturing process
Examining the quality of adolescent–parent relationships among Chilean families
The purpose of this study was to examine if adolescents reports of warm and harsh parenting practices by their mothers and fathers varied as a function of demographic, youth and their mothers or mother figures' individual and family characteristics. Data are from 707 community-dwelling adolescents (mean age=14, SD=1.4) and their mothers or mother figures in Santiago, Chile. Having a warmer relationship with both parents was inversely associated with the adolescents' age and positively associated with adolescents' family involvement and parental monitoring. Both mothers' and fathers' harsh parenting were positively associated with adolescent externalizing behaviors and being male and inversely associated with youth autonomy and family involvement. These findings suggest that net of adolescent developmental emancipation and adolescent behavioral problems, positive relationships with parents, especially fathers, may be nurtured through parental monitoring and creation of an interactive family environment, and can help to foster positive developmental outcomes.http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC3839673&blobtype=pdfAccepted manuscrip
Hard X-ray Emission and the Ionizing Source in LINERs
We report X-ray fluxes in the 2--10 keV band from LINERs (low-ionization
nuclear emission-line regions) and low-luminosity Seyfert galaxies obtained
with the ASCA satellite. Observed X-ray luminosities are in the range between
4e39 and 5e41 ergs/s, which are significantly smaller than that of the
``classical'' low-luminosity Seyfert 1 galaxy NGC 4051. We found that X-ray
luminosities in 2--10 keV of LINERs with broad Halpha emission in their optical
spectra (LINER 1s) are proportional to their Halpha luminosities. This
correlation strongly supports the hypothesis that the dominant ionizing source
in LINER 1s is photoionization by hard photons from low-luminosity AGNs. On the
other hand, the X-ray luminosities of most LINERs without broad Halpha emission
(LINER 2s) in our sample are lower than LINER 1s at a given Halpha luminosity.
The observed X-ray luminosities in these objects are insufficient to power
their Halpha luminosities, suggesting that their primary ionizing source is
other than an AGN, or that an AGN, if present, is obscured even at energies
above 2 keV.Comment: 11 pages, 3 figures, To appear in the Astrophyscal Jouna
Evidence for AGN-driven Outflows in Young Radio Quasars
We present near-infrared spectra of young radio quasars [P(1.4GHz) ~ 26-27
W/Hz] selected from the Wide-Field Infrared Survey Explorer. The detected
objects have typical redshifts of z ~ 1.6-2.5 and bolometric luminosities ~
10^47 erg/s. Based on the intensity ratios of narrow emission lines, we find
that these objects are mainly powered by active galactic nuclei (AGNs),
although star formation contribution cannot be completely ruled out. The host
galaxies experience moderate levels of extinction, A(V) ~ 0-1.3 mag. The
observed [O III] luminosities and rest-frame J-band magnitudes constrain the
black hole masses to lie in the range ~ 10^8.9-10^9.7 solar mass. From the
empirical correlation between black hole mass and host galaxy mass, we infer
stellar masses of ~ 10^11.3-10^12.2 solar mass. The [O III] line is
exceptionally broad, with full width at half maximum ~1300 to 2100 km/s,
significantly larger than that of ordinary distant quasars. We argue that these
large line widths can be explained by jet-induced outflows, as predicted by
theoretical models of AGN feedback.Comment: To appear in The Astrophysical Journal Letter
Ecological factors and adolescent marijuana use: results of a prospective study in Santiago, Chile
PURPOSE: Despite the growing evidence that ecological factors contribute to substance use, the relationship of ecological factors and illicit drugs such as marijuana use is not well understood, particularly among adolescents in Latin America. Guided by social disorganization and social stress theories, we prospectively examined the association of disaggregated neighborhood characteristics with marijuana use among adolescents in Santiago, Chile, and tested if these relationships varied by sex.
METHODS: Data for this study are from 725 community-dwelling adolescents participating in the Santiago Longitudinal Study, a study of substance using behaviors among urban adolescents in Santiago, Chile. Adolescents completed a two-hour interviewer administered questionnaire with questions about drug use and factors related to drug using behaviors.
RESULTS: As the neighborhood levels of drug availability at baseline increased, but not crime or noxious environment, adolescents had higher odds of occasions of marijuana use at follow up, approximately 2 years later (odds ratio [OR] = 1.39; 95% CI = 1.16–1.66), even after controlling for the study’s covariates. No interactions by sex were significant.
DISCUSSION: The findings suggest that “poverty”, “crime”, and “drug problems” may not be synonyms and thus can be understood discretely. As Latin American countries re-examine their drug policies, especially those concerning decriminalizing marijuana use, the findings suggest that attempts to reduce adolescent marijuana use in disadvantaged neighborhoods may do best if efforts are concentrated on specific features of the “substance abuse environment”.We are extremely grateful to the families in Chile for their participation in this study. This study received support from the U.S. National Institute on Drug Abuse (R01 DA021181; T32 DA007267) and the Vivian A. and James L. Curtis School of Social Work Research and Training Center. (R01 DA021181 - U.S. National Institute on Drug Abuse; T32 DA007267 - U.S. National Institute on Drug Abuse; Vivian A. and James L. Curtis School of Social Work Research and Training Center
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