bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unemployment and under‐employment in adults with vision impairment: The RVIB Employment Survey
Authors: McCarty Cathy A , Burgess Mary , Keeffe Jill E 
Published: July 2002

Purpose: The purpose of this study was to describe the labour force status in Victorian adults with vision impairment and any factors associated with unemployment and under‐employment. Methods: Participants were recruited in 1997. A telephone interview was conducted by trained interviewers. Results: A total of 250 people participated. They ranged in age from 19 to 59 years (mean 40.7 years) and 119 (48%) were male. Thirty‐nine (16%) people regarded themselves to be totally blind. Nearly everyone (n = 241, 96%) had been employed at some time during their lifetime; however, only 149 (60%) were currently employed. The current rate of participation in the labour force was 73.3% (95% CL, 67.8%, 78.8%) and the current unemployment rate was 18.2% (95% CL, 12.6%, 23.9%). The current rate of under‐employment was 16.0% (95% CL, 10.7%, 21.4%). A total of 126 (50%) people had used services that help with employment at some stage; this was not significantly associated with current employment status (P > 0.10). The factors significantly associated with unemployment in multivariate analyses were a self‐report of eyesight limiting time available for work or other activities (OR = 3.02; 95% CL, 1.56, 5.85) and currently looking for work (OR = 5.92; 95% CL, 2.94, 11.9); never having worked was of borderline significance (OR = 5.26; 95% CL, 0.85, 32.7) as a result of the small numbers of people surveyed. The only factor significantly associated with under‐employment was self‐employment (OR = 5.46; 95% CL, 1.95, 15.3). Discussion: Results from this study reveal that visual function is not a predictor of labour force status. The relatively low use of specialty employment services and the rather high rate of discouraged job seekers suggest that the employment outcomes of people who use these services should be investigated further, and that attention should be directed at improving retention of employment in people with vision impairment.
Evaluating the outcomes of low vision rehabilitation
Authors: Harper Robert , Doorduyn Kate , Reeves Barney , Slater Linda 
Published: July 2002

SummaryThe requirement for those providing healthcare to measure outcomes raises the fundamental question of how these should be measured. Both the scale of the low vision population and the different models of care proposed make it a pressing need to determine outcomes using valid and reliable measures. In this study we describe the development and piloting of a questionnaire designed to meet this requirement. The questionnaire was piloted on 56 subjects with age‐related macular degeneration (ARMD). Test‐retest reliability of the questionnaire was estimated using a further sample of 28 subjects with ARMD. Pilot testing confirmed the feasibility of administering the questionnaire to an elderly population with ARMD. A total of 87% of the sample reported using an LVA (65% on a daily basis), predominantly for a reading task. The number of tasks an LVA was used for, its frequency of use, length of continuous use and ease of use are significantly associated with the rating of an LVA as important/less important (P<0.0001), but the acuity achieved with the device is not significantly associated with rated importance (P=0.11), reinforcing doubt about the validity of visual function outcomes. The limitations of this pilot study and earlier case series in describing the outcomes of low vision care are discussed and a randomised controlled trial using a broad range of outcomes is proposed in order to fully describe the effectiveness of low vision rehabilitation and inform the debate about models of care.
Guar Gum Reduces Postprandial Hypotension in Older People
Authors: Jones Karen L. , MacIntosh Caroline , Su Yu‐Chung , Wells Fiona , Chapman Ian M. , Tonkin Anne , Horowitz Michael 
Published: July 2002

OBJECTIVE: To determine whether slowing of gastric emptying and glucose absorption with guar gum would reduce the fall in blood pressure after an oral glucose load in older subjects.DESIGN: A randomized, experimental, cross‐over study.SETTING: Department of Nuclear Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia.PARTICIPANTS: Ten healthy subjects, age 67 to 78.MEASUREMENTS: Simultaneous measurements of gastric emptying, blood pressure, blood glucose, serum insulin, and oral glucose absorption (3‐O‐methyl‐D‐glucose [3‐OMG]) on two occasions after ingestion of 300 mL water containing 50 g glucose and 30 mL lemon juice, 3 g 3‐OMG labeled with 99mTc‐sulphur colloid; with or without 9 g guar gum. Blood pressure and gastric emptying were monitored for 180 minutes.RESULTS: The magnitude of the falls in systolic (P = .02), diastolic (P < .05), and mean arterial (P = .05) blood pressure were less, and gastric emptying slower (P < .05), after guar. Blood glucose, insulin, and 3‐OMG concentrations were reduced (P < .001 for all) by guar. 3‐OMG concentrations were inversely related to the intragastric retention of glucose (r = −0.72, P = .02) and blood pressure was inversely related to 3‐OMG (r = −0.64, P < .05) after the drink without guar. The blood glucose concentration was related to 3‐OMG (r > 0.64, P < .05).CONCLUSION: Guar gum reduces the magnitude of the fall in blood pressure after oral glucose. Slowing of gastric emptying and glucose absorption may represent a novel approach to the treatment of postprandial hypotension.
Are Aggressive Treatment Strategies Less Cost‐Effective for Older Patients? The Case of Ventilator Support and Aggressive Care for Patients with Acute Respiratory Failure
Authors: Hamel Mary Beth , Phillips Russell S. , Davis Roger B. , Teno Joan , Desbiens Norman , Lynn Joanne , Tsevat Joel 
Published: July 2002

OBJECTIVES:A common assumption is that life‐sustaining treatments are much less cost‐effective for older patients than for younger patients. We estimated the incremental cost‐effectiveness of providing mechanical ventilation and intensive care for patients of various ages who had acute respiratory failure.DESIGN:Retrospective analysis of data on acute respiratory failure from Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments (SUPPORT).SETTING:Acute hospital.PARTICIPANTS:1,005 with acute respiratory failure; 963 received ventilator support and 42 had ventilator support withheld.MEASUREMENTS:We studied 1,005 patients enrolled in a five‐center study of seriously ill patients (SUPPORT) with acute respiratory failure (pneumonia or acute respiratory distress syndrome and an Acute Physiology Score ≥10) requiring ventilator support. For cost‐effectiveness analyses, we estimated life expectancy based on long‐term follow‐up of SUPPORT patients and estimated utilities (quality‐of‐life weights) using time‐tradeoff questions. We used hospital fiscal data and Medicare data to estimate healthcare costs. We divided patients into three age groups (<65, 65–74, and ≥75 years); for each age group, we performed separate analyses for patients with a ≤50% probability of surviving at least 2 months (high‐risk group) and those with a> 50% probability of surviving at least 2 months (low‐risk group).RESULTS:Of the 963 patients who received ventilator support, 44% were female; 48% survived 6 months; and the median (25th, 75th percentile) age was 63 (46, 75) years. For the 42 patients for whom ventilator support was withheld, the median survival was 3 days. For low‐risk patients (>50% estimated 2‐month survival), the incremental cost (1998 dollars) per quality‐adjusted life‐year (QALY) saved by providing ventilator support and aggressive care increased across the three age groups ($32,000 for patients age <65, $44,000 for those age 65–74, and $46,000 for those age ≥75). For high‐risk patients, the incremental cost‐effectiveness was much less favorable and was least favorable for younger patients ($130,000 for patients age <65, $100,000 for those age 65–74, and $96,000 for those age ≥75). When we varied our assumptions from 50% to 200% of our baseline estimates in sensitivity analyses, results were most sensitive to the costs of the index hospitalization.CONCLUSIONS:For patients with relatively good short‐term prognoses, we found that ventilator support and aggressive care were economically worthwhile, even for patients 75 years and older. For patients with poor short‐term prognoses, ventilator support and aggressive care were much less cost‐effective for adults of all ages.
Evaluation of Different Methods for Assessing Intracellular Fluid in Healthy Older People: A Cross‐Validation Study
Authors: Dittmar Manuela , Reber Helmut 
Published: July 2002

OBJECTIVES: To cross‐validate existing anthropometric and bioimpedance equations to establish their validity and accuracy for estimating intracellular water (ICW) in healthy older Germans and to develop a new equation with improved accuracy and precision for predicting ICW from multifrequency bioimpedance analysis (MFBIA).DESIGN: Cross‐validation study.SETTING: University of Mainz.PARTICIPANTS: One hundred fifty‐five healthy volunteers aged 60 to 80 years (77 men, 78 women; mean ages ± standard deviation 67.7 ± 4.8 and 68.6 ± 5.5 years, respectively).MEASUREMENTS: ICW was measured by whole‐body counting of 40potassium (40K) (40K method) as the reference method and compared by cross‐validation techniques against five existing bioimpedance and three anthropometric prediction equations. A new equation for estimating ICW from MFBIA was developed using the 40K method as criterion method.RESULTS: Compared with the 40K method, the existing bioimpedance and anthropometric equations showed large prediction errors in ICW estimates for older men (−32.3% to +37.7%) and women (−34.2% to +26.6%), depending significantly and positively on ICW volume and inversely on weight. A new equation for estimating ICW from MFBIA was developed (R2 = 0.933, standard error of the estimate (SEE) = 0.92 L) involving phase angle at 5 kHz, impedance, height, and gender, with data from 100 subjects chosen at random. Cross‐validation on an independent group (n = 55, R2 = 0.958, SEE = 0.68 L) showed no significant bias (0.013 ± 1.52 L).CONCLUSIONS: Published bioimpedance and anthropometric prediction equations are not applicable to older Germans because they might be population‐specific. The bioimpedance equation of the manufacturer of the bioimpedance analyzer used in this study provides accurate estimates of ICW for normal weight, but not overweight, older men. The newly developed equation improves accuracy and precision of ICW estimates by MFBIA.
Mode-coupling theory of the dynamics of polymer liquids: Qualitative predictions for flexible chain and ring melts
Authors: Schweizer Kenneth S. 
Published: July 2002

The qualitative predictions of the mode–mode-coupling (MMC) theory developed in the preceding paper are determined for various transport properties and time correlation functions. The degree of polymerization N dependence of the self-diffusion constant D of long flexible chain and rigid rod melts are found to be in agreement with the reptation/tube model scaling predictions. Ideal ring polymer liquids also follow a D∝N−2 law, but for collapsed non-Gaussian rings a stronger power law dependence is obtained. The viscoelastic properties of chain melts are derived from a linear generalized Langevin equation (GLE), which at long times consists of the usual Rouse terms plus a chain length and internal normal mode-dependent frictional contribution.
The latter novel term gives rise to of order N slow internal modes, and hence a plateau modulus, and a shear viscosity and recoverable compliance which scale as N3 and N0, respectively. All the predictions are derived from the MMC dynamic memory function by neglecting end effects, and without a priori invoking the existence of static entanglements, a confining tube, nor curvilinear diffusion. The molecular weight dependent renormalizations arise from time-dependent intermolecular force fluctuations on the radius of gyration and longer length scales. An alternative mathematical approximation for the viscosity memory function leads to an asymptotic scaling law of N3.5 for chain melts. This nonreptation prediction follows from the physical assumption that the fluctuating repulsive forces exerted by the surrounding matrix on the internal modes of a probe polymer can fully relax only after a time proportional to the probe translational diffusion time. The qualitative form of the mode-coupling GLE in the terminal relaxation regime can be approximately interpreted in terms of curvilinear reptation à la the Doi–Edwards formulation. However, this physical interpretation is not uniquely established, and the alternative possibility of isotropic, but highly cooperative, motion is not precluded. The viscoelastic properties of flexible ring melts are found to be qualitatively similar to their chain polymer counterparts.
A general microscopic approach for including the effects of matrix polymer mobility is formulated in terms of the collective dynamic structure factor of the melt. The qualitative implications for self-diffusion and crossover phenomena are studied, and a self-consistent theory for the shear viscosity is derived.
Coverage-dependent dipole coupling for carbon monoxide adsorbed at ordered platinum(111)-aqueous interfaces: Structural and electrochemical implications
Authors: Chang Si-Chung , Weaver Michael J. 
Published: July 2002

Surface infrared spectra in the terminal C–O stretching region are reported for various 12CO/13CO mixtures adsorbed on an ordered Pt(111) electrode in 0.1 M HClO4 as a function of CO coverage θ (0.05≲θ≲0.6) and electrode potential E. Contributions to the coverage-induced shift in the C–O stretching frequency νtCO arising from dynamic dipole–dipole coupling ΔνD, and from static dipole and ‘‘chemical’’ effects ΔνC, are obtained from the mixed isotope spectra. Similar to the corresponding ultrahigh vacuum (UHV) system, the former provides the largest contribution, ΔνD being 30–35 cm−1 for saturated CO layers (θ≊0.6). Substantial differences in the νtCO -θ (and ΔνD -θ) dependencies were observed for CO adlayers formed by dosing from suitably low solution concentrations (∼2×10−5 M), and from saturated irreversibly adsorbed layers by means of partial electrooxidative stripping.
Using the latter ‘‘stripping’’ procedure, only small (≲5 cm−1) decreases in νtCO and ΔνD were observed as θ is decreased over the range 0.1≲θ&lt;0.6, whereas the former ‘‘dosing’’ procedure yielded substantially larger νtCO -θ and ΔνD -θ dependencies, especially in the presence of coadsorbed hydrogen (at −0.25 V vs SCE) rather than coadsorbed water (at 0.1 V). These behavioral differences are interpreted in terms of coverage-dependent CO island formation. For electrooxidative stripping conditions, extensive island formation survives to low CO coverages, providing direct evidence that CO electrooxidation occurs via nucleation and growth at the island edges. For dosing conditions, smaller and more coverage-dependent CO patches are apparently obtained in the presence of coadsorbed hydrogen. These undergo slightly more facile electrooxidation than the CO islands formed at intermediate coverages by prior stripping. The coverage-dependent frequencies and intensities of the bridging CO form (νbCO ≊1800–1850 cm−1) vs the terminal CO form (νtCO ≊2020–2075 cm−1) are also examined in comparison with corresponding data for related UHV systems. In contrast to Pt(111)/CO in UHV, the bridging site is occupied even at low dosed coverages (θ≳0.05): this is also suggestive of the presence of CO islands having high local coverages. Similarities are noted with vibrational spectra obtained for Pt(111)/CO with coadsorbed water and hydrogen in UHV.
Electronic spectral shifts of aromatic molecule–rare-gas heteroclusters
Authors: Shalev Eli , Ben-Horin Narda , Even Uzi , Jortner Joshua 
Published: July 2002

In this paper, a semiempirical theory for the spectral shifts of the electronic origin of the S0→S1 transition of (aromatic molecule)⋅(rare-gas)n heteroclusters is advanced and applied. Neglecting the modifications of intermolecular overlap and exchange interactions upon electronic excitation, the dispersive contributions to the spectral shift are evaluated to second order, accounting for finite-size structural features of the large molecule by the utilization of the multicenter monopole representation of the intermolecular interactions. The spectral shifts for nonpolar aromatic hydrocarbons in or on rare-gas heteroclusters are represented in terms of differences between electrostatic interactions involving an electrostatic field (due to the molecular transition monopoles charge distribution) and an induced dipole (originating from the rare-gas polarizability). The transition monopoles incorporated all the one- and two-electron ππ* excitations of the aromatic molecule, which were represented by Hückel or self-consistent molecular orbitals (MO). The dispersive spectral shifts were semiempirically scaled to correct the systematic overestimate of the transition monopoles within these simple MO schemes. The red spectral shift was recast in terms of a sum of two-atom (carbon atom–rare-gas) and three-atom (carbon atom–rare-gas–carbon atom) contributions, which are subsequently summed over the contributions of all the rare-gas atoms, with each term involving products of an electronic factor and a geometric factor.
The electronic factors exhibit a linear dependence of the spectral shift on the rare-gas polarizability, while the geometric factors incorporate the structural effects of the contributions of the individual rare-gas atoms to the spectral shift, predicting the nonadditivity of the spectral shift per added rare-gas atom and the exhibition of distinct spectral shifts for different structural isomers. The semiempirical theory in conjunction with structural information emerging from (pairwise) potential optimization for small and medium-sized (n=1–8) heteroclusters and from molecular dynamics simulation for medium-sized and large heteroclusters (n=5–34) was applied. The theory accounts for the spectral shifts of small and medium-sized rare-gas heteroclusters of pentacene and tetracene as well as for small, medium-sized, and large heteroclusters of 9,10 dichloroanthracene, but not for the general pattern of the spectral shifts for anthracene⋅An (A=Ar, Kr; n=1–8) and for perylene⋅Arn (n=2). The confrontation between theory and experiment for the spectral shifts of pentacene⋅Arn (n=1–8), tetracene⋅Arn (n=1–8), tetracene⋅Krn (n=1–8), 9,10 dichloroanthracene⋅Arn (n=1–34) and 9,10 dichloroanthracene⋅Krn (n=1–20), allows for the elucidation of the size dependence of spectral shifts, for the identification of structural isomers in small and medium-sized heteroclusters, and for the exploration of spectral inhomogeneous broadening in large heteroclusters.
Structure and equation of state of a long chain amphiphile monolayer adsorbed on ice Ih: A molecular dynamics study
Authors: Bell Kyle-Pierre , Rice Stuart A. 
Published: July 2002

We report the results of molecular dynamics simulations of the structure of the rotator phase of a monolayer of a long chain alkyl carboxylic acid, H(CH2)15COOH, supported on the 0001 face of ice Ih, as a function of area per molecule. The potential field generated by this surface has an ordered component arising from the lattice of oxygens and an irregular component arising from the disordered distribution of hydrogens. Consequently, the many possible head group pinning sites of the ice Ih 0001 surface are irregularly distributed and not commensurate with the oxygen lattice. Our results, which are derived from simulations that use a pseudoatom model of the amphiphile molecule and a rigid lattice model of the ice surface, show that the constraint imposed by the potential field of the rigid ice Ih 0001 surface generates properties of the ice supported monolayer that are different from those of the corresponding liquid water supported monolayer. As expected, we find that the head groups are pinned and that as the area per molecule is increased the monolayer develops a collective tilt; the collective tilt increases as the area per molecule increases. More striking, we find that the projection of the unit cell of the monolayer in the plane of the surface remains, on average, hexagonal for all collective tilt angles and all surface coverages. In contrast, the introduction of a collective tilt of the molecules in the L2 (rotator) phase of a liquid water supported monolayer is always accompanied by a distortion of the projection of the unit cell in the plane of the surface, typically from hexagonal at zero tilt to centered rectangular for all nonzero tilt.
Despite this difference in packing structure, and the pinning of the head groups, the surface pressure as a function of area per molecule, and the collective tilt as a function of area per molecule of a monolayer supported on ice Ih closely resemble those for the L2 phase of a monolayer supported at the air/water interface. The only structural data available for monolayers of long chain molecules on ice Ih refer to a low-temperature (∼100 K) and high surface density (∼18 Å2 per molecule), under which conditions the amphiphile molecules pack in a herringbone structure with a rectangular unit cell in the interface plane. The difference between the properties of this low-temperature monolayer on ice Ih, which is not in a rotator phase, and the properties of the rotator phase we have simulated is briefly discussed.
Polymorphism of dopamine D2 and D4 receptor genes and Slavic‐surnamed alcoholic patients
Authors: OVCHINNIKOV IGOR V. , DRUZINA EKATERINA , OVTCHINNIKOVA OLGA , ZAGOROVSKAYA TATIANA , NEBARAKOVA TAMARA , ANOKHINA IRINA P. 
Published: July 2002

AbstractThe association between alcoholism and the Taq1 “A” and “B” polymorphic alleles at the DRD2 gene and 48‐bp tandem repeat in exon 3 of dopamine D4 receptor (DRD4) gene in 42 unrelated Slavic‐surnamed patients and 76 normal controls was examined. The frequency of the A1 allele was higher in alcoholic patients and in alcoholic patients with a family history of alcoholism than in controls (χ2= 3.45, p < 0.001 and χ2= 3.97, p < 0.001, respectively). Moreover, the frequency of the A1 allele was higher in alcoholics with a family history of alcoholism than in alcoholics without a family history (χ2= 3.33, p < 0.001).The results of association analysis for both the Taq1 “B” and DRD4 alleles were negative for alcoholics in general, subgroups of alcoholics and normal controls. However, the 7‐repeat allele (DRD4*7R) of DRD4 gene occurred at significantly higher frequency in alcoholics with a family history of alcoholism compared with those without a family history (χ2= 3.42, p < 0.01).The results indicate that the A1 allele of the DRD2 gene is associated with susceptibility to alcoholism in general.The A1 allele, as well as the DRD4*7R allele, is significantly prevalent among alcoholics with a family history, in comparison with alcoholics without a family history, reflecting different roles of genetic factors in development of alcoholism.
Expression of ZntA, a Zinc‐Transporting P1‐Type ATPase, is Specifically Regulated by Zinc and Cadmium
Authors: Noll Meenakshi , Lutsenko Svetlana 
Published: July 2002

AbstractAll cells have developed various mechanisms to regulate precisely the availability of important micronutrients such as zinc and copper; in many cells, this regulation is mediated by P‐type ATPases. Most of the P1‐ATPases have been described very recently, and little is known about their molecular mechanism and regulation. Here, we demonstrate that the expression of ZntA, a Zn,Cd‐transporting P‐type ATPase of