Issues and recommendations for the recruitment and retention of older ethnic minority adults into clinical research.

A burgeoning literature indicates that treatment of mental disorders offsets mortality, morbidity, and poor quality of life in senior citizens. Unfortunately, ethnic minority senior citizens, who are in most need of mental health services, have not been well represented in psychosocial research. This lack of attention is due, in large part, to difficulties that may arise in recruitment and retention of older ethnic minority adults in research studies. The purpose of this article is to discuss successful methods for recruiting older ethnic minority adults into psychosocial research and to offer specific suggestions for keeping this population involved in longitudinal studies. Also included is a discussion of past research and present data from treatment studies that used the methods discussed in this article. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychometric evaluation of the Beck Anxiety Inventory with older medical patients.

Disadvantaged older medical outpatients (N?=? 197; ages 55–92) completed the Beck Anxiety Inventory (BAI). The instrument demonstrated high internal consistency and no significant differences by sex or race, suggesting that it is appropriate to use with diverse populations. Total BAI score correlated negatively with age. Confirmatory factor analysis revealed a good fit to a 4-factor model consisting of cognitive, autonomic, neuromotor, and panic symptoms. Although scores on the BAI and 2 widely used depression scales were significantly correlated, factor analysis distinguished BAI and depression scale items, suggesting that the instruments measure distinct constructs. These findings suggest that the BAI could serve as a valuable screening test for anxiety symptoms among primary care patients who are older and have low income. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Low Voltage Ride Through of Wind Farms With Cage Generators: STATCOM Versus SVC

This paper analyzes the extent to which the low voltage ride through (LVRT) capability of wind farms using squirrel cage generators can be enhanced by the use of a STATCOM, compared to the thyristor controlled static var compensator (SVC). The transient stability margin is proposed as the indicator of LVRT capability. A simplified analytical approach based on torque-slip characteristics is first proposed to quantify the effect of the STATCOM and the SVC on the transient stability margin. Results from experiments with a STATCOM and a 7.5 kW induction machine emulating a wind turbine are used to validate the suggested analytical approach. Further verifications based on detailed time-domain simulations are also provided. Calculations, simulations and measurements confirm how the increased STATCOM rating can provide an increased transient stability margin and thus enhanced LVRT capability. Compared to the SVC, the STATCOM gives a larger contribution to the transient margin as indicated by both calculations and simulations. The inaccuracies introduced by neglecting the flux transients in the suggested approach are discussed and found reasonable for an estimation method when considering the simplicity compared to detailed time-domain simulation studies. A method for estimating the required rating of different compensation devices to ensure stability after a fault is suggested based on the same approach.     

Density Functional Study of the β″ Phase in Al-Mg-Si Alloys

The β″ phase is the major hardening precipitate in Al-Mg-Si alloys. It was studied by atomistic calculations based on density functional theory (DFT), using an atomistic model where the precipitate was embedded in an Al matrix. This allowed quantifying and visualizing the coherency strain in the matrix and within the precipitates. The elastic strain was found to decrease exponentially in the matrix as a function of distance from the precipitate interface. The formation enthalpy of several different chemical compositions of β″ was calculated, and the most stable composition was found to be Mg₅Al₂Si₄. A study of the calculated valence charge density and electron localization function showed that the covalency network between Si-atoms in the precipitate structure is broken when the precipitate contains Al.     

Water resources development projects in Nigeria

Conceived essentially on a basis of agro‐technical and economic criteria, and without adequate knowledge of all other relevant socio‐economic and cultural factors, water resources development projects in Northern Nigeria have proved hazardous. There is a great risk of upsetting traditional farming systems rather than improving them. The imposition of various schemes, expropriation of land, massive displacement of the rural population, introduction of capital‐intensive technology, dictation of cropping patterns, and prohibitive and regressive farm charges are some of the hazards and uncertainties the farmers have had to cope with. This paper examines the various coping mechanisms adopted by the farmers. Their responses are discussed in relation to agitation, rebellion tactics, and risk‐aversion strategies.     

VLSI parallel shift sort algorithm and design

A hardware algorithm called the parallel shift sort (PSS) is presented. The PSS is a hardware adaption of sorting by insertion. The function of the PSS is verified using an invariant method. Since the PSS uses an array of identical cells of low complexity, it is well suited for VLSI implementation. Some of the more important details of an NMOS implementation on a 5.4×5.4 mm chip are shown. The chip which contains approximately 8000 transistors is designed with lambda rules using a 4 μm line width process. A microcomputer expansion card with an array of sorting chips is described logically. The card's sorting time is of order O(N), where N is the product of the number of chips in the array and the number of cells in each chip (16 for the described chip implementation). The card is also capable of sorting arbitrarily wide keys in time proportional to N × K where K is the number of words in the sorting key width.     

Energy-efficient cooperative routing in BER constrained multishop networks

Due to the limited energy supplies of nodes, in many applications like wireless sensor networks energy-efficiency is crucial for extending the lifetime of these networks. We study the routing problem for multihop wireless ad hoc networks based on cooperative transmission. The source node wants to transmit messages to a single destination. Other nodes in the network may operate as relay nodes. In this paper, we propose a cooperative multihop routing for the purpose of power savings, constrained on a required bit error rate (BER) at the destination. We derive analytical results for line and grid network topologies. It is shown that energy savings of 100% are achievable in line and grid networks with a large number of nodes for BER = 10⁻⁴ constraint at the destination.     

Vapour phase deposition and thermal decarbonylation of Re2(CO)10 on gamma-alumina: infrared studies

Dirheniumdecacarbonyl vacuum sublimed onto mesoporous -alumina forms Lewis type adducts where an axial CO group is coordinated to an A1³⁺ ion at the metal oxide surface, as revealed by IR spectroscopy. Vacuum heating of the surface adduct at 773 K brings about decarbonylation, with intermediate formation of a surface-bound mononuclear tricarbonyl which was completely decarbonylated on prolonged heating at the same temperature. The resulting material strongly chemisorbs CO to yield mainly a surface-bound pentacarbonyl species. This suggests that the supported metal remains primarily in a zero-valent and well dispersed state.     

The possible reduction of alumina to aluminum using hydrogen

Theoretical considerations based on published thermodynamic data show that condensed aluminum should not be formed by direct reaction between hydrogen and alumina. Nevertheless, laboratory experiments by the authors and observations reported by others in the literature have led to the hypothesis that hydrogen dissolved in molten aluminum can possibly reduce alumina to aluminum at high temperature (700–1,700°C). For more information, contact H. Kvande, Hydro Aluminium, N-0246 Oslo, Norway; telephone 47 22 73 9155; fax 47 22 73 7778; e-mail Halvor.Kvande@hydro.com.     

Structure and drug release of superabsorbent sponge prepared by polyelectrolyte complexation and freezing‐induced phase separation

Superabsorbent sponge with uniform porous structure was prepared by polyelectrolyte complex (PEC) of polyacrylic acid (PAA) with inorganic polymers, high polymer state polyaluminum chloride (HPSPAC), in combination with freezing‐induced phase separation (FIPS). The above superabsorbent sponge was prepared under mild conditions, without strong heat, oxidation, or corrosion, which is an ideal superabsorbent material for drug embedding. Structure analysis and swelling kinetics of the superabsorbent sponge as well as kinetics of the release of the model drug, 4‐acetaminophen (AMP), from the sponge were investigated. In addition, effects of the crosslinker HPSPAC, the pH of the solution, and the concentration of NaCl solution on the structure and the swelling property of the sponge and sustained‐release kinetics were explored. Further, the relationship between the structure of the superabsorbent sponge and its swelling property as well as sustained drug‐release characteristics was investigated. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012