3,390 research outputs found
Design and Development of Microswitches for Micro-Electro-Mechanical Relay Matrices
Many different micro-electro-mechanical switches were designed in the Multi-User MEMS processes (MUMPs) and deep x-ray lithography and electroforming (LIGA) processes. The switches were composed of actuators that operated based upon either electrostatic forces or thermal forces. A thermally activated beam flexure actuator that operated based upon differential heating was used extensively. This actuator, which was fabricated in the MUMPs process, was able to deflect up to 12 microns with a total input power of less than 25 mW. The thermal resistance, which was needed to model this actuator, was determined from a material constant, 1.9 ± 0.08 m1.5-°C-W-1 for the POLYl layer in MUMPs and 7.4 ± 0.88 m1.5-°C-W-1 for the POLY2 layer in MUMPs, which was extracted from 1020 actuator test cases. A switch using a hinge mechanism that allowed metal-to-metal contacts to be formed was also developed in the MUMPs process. The contact resistance of these devices was determined to be 9.91 ± 6.22 kΩ. An electrostatically deformable microbridge structure (2 µm thick, 40 µm wide, 332 µm long, and with a capacitive gap of 2 µm) was also employed as a switch. A voltage of 53.3 volts applied between the microbridge and two drive electrodes was able to force the center of the microbridge to touch a sense electrode. The observed contact resistance for this connection was 300 ± 89.7 Ω
Ciliated Protozoan Colonization of Substrates From Weeks Bay, Alabama
Ciliated protozoan colonization of artificial substrates was examined during a 12-mo period from Jan. to Dec. 2001 in Weeks Bay, Alabama. Artificial substrates (glass slides) were suspended in the water at three locations in the Bay for a period of I wk/mo, and the population density of the stalked peritrich Vorticella was determined. Environmental data collected during the colonization period were compared with the population results. There was a positive correlation between colonization and water temperature at two sites and between phosphate and colonization at one site. Additionally, a negative correlation was determined between colonization and dissolved oxygen at two sites, between colonization and nitrate at one site, and between colonization and pH at one site. The protozoan assemblage varied from month to month, although the overall dominance of Vorticella was maintained. Although the size of the population of Vorticella is likely influenced by a number of different variables, we believe that temperature and bacterial abundance are the likely controlling factors
Settlement of the Acorn Barnacle Balanus From Mobile Bay and Weeks Bay, Alabama
Barnacle cyprids and metamorphosed settlers were collected using glass slides as artificial substrates at six sites in the Mobile Bay area. Three sites were located in Weeks Bay, Alabama, where the highest settlement concentration occurred near the entrance to Mobile Bay. Two sites in the north end of Weeks Bay near the Fish River had very reduced settlement. The remaining three locations were on the north shore of Dauphin Island, Alabama. Settlement at Dauphin Island was most abundant at the deeper of two sites at the Dauphin Island Sea Lab boat dock, possibly because the substrates were exposed to less wave action. The other two sites at Dauphin Island were shallow and relatively unsettled when compared with the deep site. Adult barnacles recovered from the Weeks Bay and Dauphin Island locations include Balanus eburneus, B. venustus, B. improvisus, and B. subalbidus. Our data indicate two primary settlement periods for these species, late winter to spring and late summer to fall, with the highest settlement occurring in Feb. and March
A SPATIAL MODEL OF REGIONAL VARIATIONS IN EMPLOYMENT GROWTH IN APPALACHIA
In this study, a spatial equilibrium model of employment growth is developed and empirically estimated by Generalized Spatial Two-Stage Least Squares (GS2SLS) estimator using cross-sectional data from Appalachian counties for 1990-2000. Besides the existence of spatial spillover effects, the results suggest that agglomerative effects that arise from the demand and the supply side contribute to employment growth in the study area during the study period. The policy implications of the findings are: (1) Regional cooperation of counties and communities is advisable and may in fact be necessary to design effective policies to encourage employment growth; and (2) Policy makers at the county level may need to design policies that can attract people with high endowments of human capital and higher income into their respective counties.APPALACHIA, EMPLOYMENT GROWTH, SPATIAL MODEL
A Spatial Panel Simultaneous-Equations Model of Business Growth, Migration Behavior, Local Public Services and Household Income in Appalachia
In this paper we develop a spatial panel simultaneous-equations model of business growth, migration behavior, local public services and median household income in a partial lag-adjustment growth-equilibrium framework and utilizing a one-way error component model for the disturbances. This model is an extension of the jobs follow people or people follow jobs literature and it improved previous models in the growth-equilibrium tradition by: (1) explicitly modeling local government and regional income in the growth process; (2) explicitly modeling gross in-migration and gross out-migration separately in order to spell out the differential effects, which used to be glossed over under net population change in previous studies; (3) explicitly incorporating both spatially lagged dependent variables and spatially lagged error terms to account for spatial spillover effects in the data set; and (4) extending and generalizing the modeling and estimation of simultaneous systems of spatially interrelated cross sectional equations into a panel data setting. To estimate the model, we develop a five-step new estimation strategy by generalizing the Generalized Spatial Three-Stage Least Squares (GS3SLS) approach outlined in Kelejian and Prucha (2004) into a panel data setting. The empirical implementation of the model uses county-level data from the 418 Appalachian counties for 1980-2000. Generally, the results from these model estimations are consistent with the theoretical expectations and empirical findings in the equilibrium growth literature and provide support to the basic hypotheses of this study. First, the estimates show the existence of feedback simultaneities among the endogenous variables of the model. Second, the results also show the existence of conditional convergence with respect to the respective endogenous variable of each equation of the model and the speed of adjustment parameters are generally comparable to those in literature. Third, the results from the parameter estimation of the model indicate the existence of spatial autoregressive lag effects and spatial cross-regressive lag effects with respect to the endogenous variables of the model. One of the key conclusions is that sector specific policies should be integrated and harmonized in order to give the desirable outcome. Besides, regionally focusing resources for development policy may yield greater returns than treating all locations the same.Community/Rural/Urban Development,
Air temperature and inflammatory and coagulation responses in men with coronary or pulmonary disease during the winter season
Background and Objective Air temperature changes are associated with increased cardiovascular and respiratory risk, but the roles of inflammatory and coagulation markers are not well understood. We investigated the associations between temperature and several blood markers in patients with coronary heart disease (CHD) and pulmonary disease (PD). Methods Two studies were conducted in Erfurt, Germany, over two successive winters. 578 and 381 repeated blood measurements were collected from 57 CHD and 38 PD patients, respectively. Data on patient characteristics and disease history were gathered at baseline. Meteorological data were collected from existing networks. Associations were analysed using additive mixed models with random patient effects. Effect modification by diabetes status was investigated only in CHD patients, as only two PD patients had diabetes. Results Mean daily air temperature varied between -13 degrees C and 16 degrees C in both study periods. A 10 degrees C decrease in the 5-day temperature average before blood withdrawal led to an increase in platelet counts (% change from the mean: 3.0%, 95% CI 0.6% to 5.5%) and fibrinogen (5.5%, 1.3% to 9.7%), no change in C-reactive protein in PD patients, and a decrease in C-reactive protein in CHD patients. A 2-day delayed increase in factor VII associated with temperature decrease was seen in CHD patients (4.9%; 0.7% to 9.2%), while PD patients showed no effect. `Effects in CHD patients without diabetes' into `Effects on factor VII in CHD patients without diabetes'. Conclusions This study suggests that temperature decrease is associated with change in several blood parameters. The complex interplay of blood markers at low temperature may contribute to the observed association between cold and cardiovascular mortality and morbidity
Additive manufacturing method of prototyping novel mm-wave and THz sources
To rapidly prototype novel mm-wave and THz sources there is a requirement to create intricate structures to produce and radiate electromagnetic fields. The motivation for this work is to create improved electron-beam-driven, vacuum electronic mm-wave and sub-THz sources by exploiting dispersion engineering. Although such structures can be manufactured by other techniques, additive manufacturing has proven to be quick, reliable and cost-effective. This research is allowing the prototyping of novel mm-wave and sub-THz coherent sources
Efficacy of a self-help manual in increasing resilience in carers of adults with depression in Thailand
Caring for a person with a mental illness can have adverse effects on caregivers; however, little is known about how best to help such caregivers. The aim of the present study was to examine the efficacy of a cognitive behaviour therapy-guided self-help manual in increasing resilience in caregivers of individuals with depression, in comparison to caregivers who receive routine support only. A randomized, controlled trial was conducted, following CONSORT guidelines, with 54 caregivers allocated to parallel intervention (self-help manual) (n = 27) or control (standard support) (n = 27) groups. Resilience was assessed at baseline, post-test (week 8), and follow up (week 12). Intention-to-treat analyses were undertaken. Repeated-measures ANOVA indicated a significant difference in resilience scores between the three time points, showing a large effect. Pairwise comparisons between intervention and control groups indicated resilience to be significantly different between baseline and post-test, and between baseline and follow up, but not between post-test and follow up. Overall, the intervention group showed a slightly greater increase in resilience over time than the control group; however, the time–group interaction was not significant. Guided self-help is helpful in improving caregivers’ resilience and could be used as an adjunct to the limited support provided to carers by mental health nurses and other clinicians
1862-08-05 Dr. Phipps requests discharge of Augustus M. Lawlin
https://digitalmaine.com/cw_me_2nd_regiment_corr/1402/thumbnail.jp
Neuroendocrine morbidity after pediatric optic gliomas: a longitudinal analysis of 166 children over 30 years
Context: 50% of pediatric low-grade gliomas affect the optic pathway, hypothalamus and suprasellar
areas (OP/HSGs) resulting in significant long-term neuroendocrinopathy.
Objective: To dissect tumor- from treatment-related risk factors for OP/HSG-associated
neuroendocrinopathy.
Design: Retrospective case notes analysis of 166 children with newly-diagnosed OP/HSGs at our
quaternary center between 1980 –2010 by multivariate Cox, linear and logistic regression.
Results: Patients were of median (range) age 4.9 (0.2–15.4) years at diagnosis and followed up for
8.3 (0.04 –26.8) years. Despite high 20-year overall survival (81.0%), progression-free and endocrine
event-free (EEFS) survival were 47.2% and 20.8% respectively. EEFS declined up to 15 years postdiagnosis,
with hypothalamic involvement (p0.001) being implicated more than radiotherapy
(p0.008) in earlier endocrinopathy; the reverse being true of its density (radiotherapy p0.001;
hypothalamic involvement p0.006). GH deficiency (GHD) was commonest (40.3%), followed by
central precocious puberty (CPP, 26.0%), gonadotropin (GnD, 20.4%), TSH (13.3%), and ACTH
(13.3%) deficiencies. GHD increased with later treatment eras (p0.01), but replacement did not
increase progression. CPP was associated with future GnD (p0.05). Posterior pituitary dysfunction
(PPD, 7.2%) occurred in 57.9% after only biopsies or shunt procedures, and was associated with 6/13
deaths. 50.2% became obese. Tumor extent, surgery and increased endocrinopathy, rather than
radiotherapy, predicted visuo-cognitive morbidity.
Conclusions: This first longitudinal OP/HSG-specific study demonstrates that hypothalamo-pituitary
dysfunction evolves hierarchically over decades. Tumor location predicts its speed of onset and
radiotherapy its density. GnD can evolve from previous CPP, whilst life-threatening PPD can occur
after any surgery. Our data suggest that recent radiation-avoiding chemotherapeutic strategies
have increased GHD without improving survival
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