Observation and understanding of anisotropic strain relaxation in selectively grown SiGe fin structures

The performance of heterogeneous 3D transistor structures critically depends on the composition and strain state of the buffer, channel and source/drain regions. In this paper we used an in-line high resolution x-ray diffraction (HRXRD) tool to study in detail the composition and strain in selectively grown SiGe/Ge fin structures with widths down to 20 nm. For this purpose we arranged fins of identical dimensions into larger arrays which were then analyzed using an x-ray beam several tens of micrometers in size. Asymmetric reciprocal space maps measured both parallel and perpendicular to the fins allowed us to extract the lattice parameters in all three spatial directions. Our results demonstrate an anisotropic in-plane strain state of the selectively grown SiGe buffer in case of narrower fins with significantly reduced relaxation in the direction along the fin. This observation was verified using nano-beam electron diffraction, and is explained based on the reduced probability for dislocation half-loops to evolve in trenches narrower than a few times the critical radius. Moreover, we introduce and discuss in detail a methodology for the determination of the composition in case of an anisotropic in-plane strain state which differs from the procedure commonly used for blanket layers. Our findings verify the importance of in-line HRXRD measurements for process development and monitoring as well as the fundamental study of relaxation and defect formation in confined volumes.

GeSn/Ge heterostructure short-wave infrared photodetectors on silicon

A surface-illuminated photoconductive detector based on Ge0.91Sn0.09 quantum wells with Ge barriers grown on a silicon substrate is demonstrated. Photodetection up to 2.2µm is achieved with a responsivity of 0.1 A/W for 5V bias. The spectral absorption characteristics are analyzed as a function of the GeSn/Ge heterostructure parameters. This work demonstrates that GeSn/Ge heterostructures can be used to developed SOI waveguide integrated photodetectors for short-wave infrared applications.

Single-electron capacitance spectroscopy of individual dopants in silicon

Motivated by recent transport experiments and proposed atomic-scale semiconductor devices, we present measurements that extend the reach of scanned-probe methods to discern the properties of individual dopants tens of nanometers below the surface of a silicon sample. Using a capacitance-based approach, we have both spatially resolved individual subsurface boron acceptors and detected spectroscopically single holes entering and leaving these minute systems of atoms. A resonance identified as the B+ state is shown to shift in energy from acceptor to acceptor. We examine this behavior with respect to nearest-neighbor distances. By directly measuring the quantum levels and testing the effect of dopant-dopant interactions, this method represents a valuable tool for the development of future atomic-scale semiconductor devices.

Relationship between aqueous humor protein level and outflow facility in patients with uveitis

PURPOSE

To determine whether there is a relationship between the aqueous humor protein level and outflow facility in patients with uveitis.

METHODS

Aqueous humor protein levels were determined by laser flare photometry, and outflow facility was determined by Schiotz tonography.

RESULTS

Thirty patients with uveitis and 10 control subjects were studied. Outflow facility was lower in patients with uveitis (0.21 +/- 0.12 microl/min x mm Hg) than in control subjects (0.33 +/- 0.05 microl/min x mm Hg, P < 0.001). Patients with uveitis and laser flare photometry results (flare) more than 20 photon units/msec (n = 21) had a lower outflow facility (0.17 +/- 0.07 microl/min x mm Hg) than patients with uveitis and flare less than 20 photon units/msec (n = 9, 0.32 +/- 0.14 microl/min x mm Hg, P = 0.004). Furthermore, no difference was identified between outflow facility in patients with active uveitis (those who had anterior chamber cells) and flare less than 20 photon units/msec and outflow in control subjects. In patients with uveitis, there was a linear correlation between flare and outflow facility (r = -0.50, P = 0.005). There was no relationship between flare measurements and either intraocular pressure or aqueous humor cell levels when scored with a clinical, semiquantitative system.

CONCLUSIONS

Outflow facility is significantly reduced in patients with uveitis who have high aqueous humor protein levels. Outflow facility appears to be normal in patients with active uveitis whose flare levels are low, and therefore the association between flare and outflow facility does not appear to be an indirect reflection of elevated anterior chamber cells. It is possible that elevated aqueous humor protein levels contribute to the development of uveitic glaucoma in some individuals by decreasing aqueous humor outflow facility, although a causal relationship cannot be established on the basis of this study.

Confirmatory factor analyses of the full and short versions of the Marlowe-Crowne Social Desirability Scale

Over the years, researchers have developed various short versions of the Marlowe-Crowne Social Desirability Scale (D. P. Crowne & D. Marlowe, 1960). The authors used confirmatory factor analyses (J. L. Arbuckle, 1997) as well as item and scale analyses to evaluate the adequacy of the full version and various short versions. Overall, the results from 232 Canadian undergraduates showed (a) that all the short versions in the present study are a significant improvement in fit over the 33-item full scale and (b) that W. M. Reynolds's (1982) Forms A and B are the best fitting short versions. No gender differences were found for the full scale or any of the short versions. The results show that the full scale could be improved psychometrically and that the psychometrically sound short versions should be available because they require less administration time than the full scale.

Trifluoromethyl ketones and methyl fluorophosphonates as inhibitors of group IV and VI phospholipases A(2): structure-function studies with vesicle, micelle, and membrane assays

A series of fatty alkyl trifluoromethyl ketones and methyl fluorophosphonates have been prepared and tested as inhibitors and inactivators of human groups IV and VI phospholipases A(2) (cPLA(2) and iPLA(2)). Compounds were analyzed with phospholipid vesicle-, detergent-phospholipid mixed-micelle-, and natural membrane-based assays, and, with few exceptions, the relative inhibitor potencies measured with the three assays were similar. Ph(CH(2))(4)COCF(3) and Ph(CH(2))(4)PO(OMe)F emerged as a potent inhibitor and inactivator, respectively, of iPLA(2), and both are poorly effective against cPLA(2). Of all 13 fatty alkyl trifluoromethyl ketones tested, the trifluoromethyl ketone analog of arachidonic acid is the most potent cPLA(2) inhibitor, and structurally similar compounds including the trifluoromethyl ketone analog of docosahexenoic acid are much poorer cPLA(2) inhibitors. Inactivation of cPLA(2) by fatty alkyl fluoromethylphosphonates is greatly promoted by binding of enzyme to the interface. The use of both vesicles and mixed micelles to assay phospholipase A(2) inhibitors and inactivators present at low mol fraction in the interface provides reliable rank order potencies of a series of compounds that correlate with their behavior in a natural membrane assay.

Regiospecificity and catalytic triad of lysophospholipase I

A 25-kDa murine lysophospholipase (LysoPLA I) has been cloned and expressed, and Ser-119 has been shown to be essential for the enzyme activity (Wang, A., Deems, R. A., and Dennis, E. A. (1997) J. Biol. Chem. 272, 12723-12729). In the present study, we show that LysoPLA I represents a new member of the serine hydrolase family with Ser-119, Asp-174, and His-208 composing the catalytic triad. The Asp-174 and His-208 are conserved among several esterases and are demonstrated herein to be essential for LysoPLA I activity as the mutation of either residue to Ala abolished LysoPLA I activity, whereas the global conformation of the mutants remained unchanged. Furthermore, the predicted secondary structure of LysoPLA I resembles that of the alpha/beta-hydrolase fold, with Ser-119, Asp-174, and His-208 occupying the conserved topological location of the catalytic triad in the alpha/beta-hydrolases. Structural modeling of LysoPLA I also indicates that the above three residues orient in such a manner that they would comprise a charge-relay network necessary for catalysis. In addition, the regiospecificity of LysoPLA I was studied using 31P NMR, and the result shows that LysoPLA I has similar LysoPLA1 and LysoPLA2 activity. This finding suggests that LysoPLA I may play an important role in removing lysophospholipids produced by both phospholipase A1 and A2 in vivo.

Structure of the Collett-Lester Fear of Death and Dying Scale

The study examined the factor and cluster structures and internal consistency reliabilities of the Collett-Lester Fear of Death Scale. Data were reanalyzed from an earlier study of 88 subjects who completed the scale under neutral conditions. The four subscales showed only weak recovery in the four-factor solution and gender loaded on the factor reflecting the Fear of Death of Others subscale. The two-factor solution showed that items reflecting the death and dying of "self" tended to load on the first factor whereas items concerning "others" loaded on the second factor. A Ward's cluster analysis yielded five meaningful clusters of items. Not surprisingly, the four subscales showed only moderate internal consistency reliabilities whereas the overall scale was acceptable. Comments are presented for improving the scale as well as for using the scale in applied settings.

Policies and procedures in the workplace: how health care organizations compare

Many organizations are implementing programs and services to manage the human and economic costs of stress. A mail survey was conducted of 500 randomly selected Canadian organizations having at least 500 employees. The survey tapped four major areas: organizational policies and procedures for managing stress; programs and services offered; perceived benefits and constraints for the organization; and projected future directions in this area. Analyses of returns from 210 organizations-43 health and 167 non-health-revealed various findings. For example, over half of health care organizations have policies and procedures as opposed to less than half of non-health care organizations. Also, health care organizations place greater emphasis on smoking cessation, weight control programs and on stress management training. Although some Canadian organizations are addressing stress, much more could and should be done, especially by organizations that do not yet recognize the impact of stress on employees and their work performance.

Management training: how Canadian health care organizations compare

Management training has been receiving increasing attention over the past decade. The present study reports on a survey of 1,000 randomly selected Canadian organizations having at least 500 employees. Analysis of returns from 56 health care organizations and 169 other Canadian organizations yielded many notable findings. Only 36 percent of health care and 37 percent of other organizations report formal policies and procedures for management training. Fortunately, many health care organizations are evolving toward a more articulated and comprehensive approach to management training; however, the constraint of limited funds for training is frequently cited. Overall, both health care and other Canadian organizations recognize the importance of management training for achieving organizational goals and they are striving to improve such training.

Resection of advanced stage neuroblastoma with the cavitron ultrasonic surgical aspirator

Current protocols for the treatment of neuroblastoma emphasize total or near total resection of tumor to improve survival. This is preferentially performed as a primary procedure, or is attempted at a second-look operation. Unfortunately, this tumor often grows to large size with invasion of the spinal canal, or encasement of major vascular or other retroperitoneal structures. A primary attempt at complete removal may result in difficult-to-control hemorrhage or injury to, or loss of, vital organs. A second-look procedure carries other intrinsic risks. It often must be performed during a period of chemotherapeutically induced hematologic and immunologic suppression. The presence of adhesions and dense scar tissue increases the complexity of the dissection. The Cavitron Ultrasonic Surgical Aspirator (CUSA) combines continuous fragmentation, irrigation, and aspiration in one instrument. Tissues high in water content are selectively fragmented and aspirated, while tissues high in collagen and elastin (such as blood vessels and pseudocapsular walls) are selectively spared. Five patients, two with large pelvic dumbell tumors, two with large intrathoracic tumors, and one with a seemingly unresectable large right adrenal tumor (crossing the midline with extensive aortocaval nodal involvement) had total or near-total resection accomplished using the CUSA. In these patients, initial resection of the relatively soft inner part of the tumor left a collapsed pseudocapsule, which was then removed under greatly improved exposure in a relatively small field. The constant aspiration virtually eliminated tumor spillage. Since most vessels were skeletonized without penetration, total blood loss was minimized. There were no intraoperative or postoperative complications.

Efficacy of bucindolol in systemic hypertension

The hemodynamic effects of oral bucindolol, a non-selective beta-adrenergic blocking agent with intrinsic sympathomimetic activity and direct vasodilating properties, were studied at rest and during handgrip exercise with a flotation-directed pulmonary artery catheter in 12 patients with mild to moderate essential hypertension. After the initial dose of 150 mg of bucindolol, blood pressure (BP) was significantly reduced and cardiac output was increased (from 5.9 +/- 0.8 to 6.8 +/- 1.6 liters/min) in the supine position and during exercise (p less than 0.05). Systemic vascular resistance was reduced (from 1,555 +/- 339 to 1,311 +/- 467 dynes s cm-5, p less than 0.01) at rest and without significant changes during exercise. There were increases in heart rate (13 +/- 13%, p less than 0.01) and right atrial (69 +/- 77%, p less than 0.05), pulmonary arterial (38 +/- 24 %, p less than 0.001) and pulmonary artery wedge pressures (62 +/- 46%, p less than 0.001) during exercise. Bucindolol did not change these variables at rest or during exercise. Bucindolol increased plasma norepinephrine levels both at rest (from 330 +/- 151 to 588 +/- 320 ng/liter, p less than 0.01) and during exercise (from 468 +/- 220 to 685 +/- 390 ng/liter, p less than 0.05). After 4 weeks of bucindolol with doses of 50 to 200 mg 3 times daily, BP was reduced in both supine and standing positions (mean arterial BP of 11 +/- 7% [p less than 0.001] and 11 +/- 6% [p less than 0.001], respectively), without changes in cardiac output, systemic vascular resistance or plasma norepinephrine level.(ABSTRACT TRUNCATED AT 250 WORDS)

Post-shooting stress reactions among police officers

Post-shooting stress reactions were studied in a large police force to develop a psychological services policy and procedures in support of members of the force. Two empirical studies were conducted using a mail survey of a total of 66 members involved in shootings plus clinical interviews of a sample of these members. The results showed that members experienced most stress reactions within three days of the shooting. The average time for feeling that they were back to normal working, social, and family life was 20 weeks. There was strong support for various proposed psychological services and actions to support members involved in shootings. Recommendations were made concerning the conduct of psychological debriefings, counselling and brief therapy, the use of peer counsellors, services for affected police families, and stress training in the force.

Suicide among police in a federal force

Suicide among police has gained the attention of numerous police forces over the past two decades. The great variation in reported police suicide rates and caveats concerning such statistics are addressed. The paper reports the results of a study of suicide among members (n = 35) of the Royal Canadian Mounted Police (RMCP) between 1960 and 1983. The average annual rate (14.1 per 100,000) of suicide in this force was approximately half that of the comparable general population, and the most common means of suicide was by service revolver (77% of cases). Recommendations are made for suicide prevention and postvention actions in police forces. Finally, the need for reliable, long-term police suicide data bases is stressed.

Sympathoadrenal responses to stress: the linking of type A behavior pattern to ischemic heart disease

This report is an analysis of the findings of blood pressure, pulse rate, adrenergic and noradrenergic responses to laboratory and clinical stresses in subjects according to Type A and Type B behavior patterns. Thirty-three experiments of Type A - B cardiovascular and sympathoadrenal responses to a variety of laboratory stressors were identified. Twenty-nine of these were analyzed and the data of 20 were pooled to give mean values for the percentage increments of systolic and diastolic blood pressures, pulse rates, and plasma levels of NE and E for Type A vs B patients respectively; (15 +/- 2 vs 10 +/- 1, P less than .05; 13 +/- 1 vs 8 +/- 1, P less than .02; 19 +/- 2 vs 13 +/- 2, P less than .05, 60 +/- 11 vs 19 +/- 8, P less than .02; and 106 +/- 45 vs 23 +/- 12, P less than .1). Seventy-five percent of the analyzed experiments provided evidence for heightened cardiovascular and sympathoadrenal responsivity in Type A subjects. NE and E appear to be hormonal intermediates which play a lethal role in ischemic heart disease. Neutralization of neural tone may be an important goal in the therapy of hypertensives with Type A behavior pattern.

Personality correlates of the Fear of Death and Dying Scale

A total of 88 female and male undergraduates completed the Fear of Death and Dying Scale, the Eysenck Personality Questionnaire, and the State-Trait Anxiety Inventory A-Trait scale. The four subscales on the Fear of Death and Dying Scale correlated significantly with the Neuroticism and Anxiety scales, but were independent of the Lie scale. No sex differences were found on the four subscales. These findings lend support to the validity of the Fear of Death and Dying Scale and its independence of social desirability.

Effects of kainic and other amino acids on synaptic excitation in rat hippocampal slices: 1. Extracellular analysis

The actions of kainic acid on excitatory synaptic responses in rat hippocampal slices have been investigated and compared with the effects of other excitatory amino acids. Kainate administered iontophoretically or via the superfusate produced a large and long lasting potentiation of the population spike evoked in the CA1 region by Schaffer collateral-commissural stimulation. This potentiation was associated with a reduction in the field EPSP recorded in the dendritic region (stratum radiatum) but with no change in the presynaptic fibre volley or with any long lasting alteration in the antidromic population spike. The results suggest that one effect of kainate may be to produce dendritic depolarisation in CA1 pyramidal neurones. Kainate in equivalent amounts elicited similar potentiations of the population spike recorded in the dentate gyrus in response to either lateral or medial perforant path stimulation. Smaller amounts of kainate than those required to affect either CA1 or dentate pathways were able to potentiate the mossy fibre-evoked population spike in the CA3 region. Folic acid, which shares kainate's ability to produce seizures and distant brain damage when injected into the brain, elicited similar potentiations of synaptic excitation. Higher doses of folate than of kainate were required which is consistent with its weaker epileptogenic actions in vivo. In contrast, N-methyl-aspartate, ibotenate, L-glutamate and L-aspartate were unable to mimic kainate's potentiating action. In higher doses the substances depressed the population spike for long periods. These data suggest that potentiation of synaptic events may underlie the ability of kainate (and folate) to elicit seizures and distant brain damage.

Nursing students: personality dimensions and attitudes toward women

100 female nursing students completed the Eysenck Personality Questionnaire and the Attitudes Toward Women Scale. A pattern of high Lie and low Psychoticism scores was found. Nursing students were more conservative than female undergraduates and more liberal than male undergraduates as indicated by the Attitudes Toward Women Scale. Scores on the four scales in the Eysenck Personality Questionnaire were independent of scores on the Attitudes Toward Women Scale.

Group Embedded-Figures Test: psychometric data

The study examined the performance of 266 undergraduates on the Group Embedded-figures Test. Item analyses, distribution characteristics, internal consistency, sex differences, and differences across independent samples were examined.

An evaluation of the Briggs-Nebes modified version of Annett's handedness inventory

The Briggs-Nebes (1975) modified version of Annett's (1967) handedness inventory was administered to 59 female and 51 male undergraduates and 101 nursing students. J-shaped distributions of scores in the dextral direction and significant sex differences such that males were more sinistral than females were found. The inventory was found to be multi-dimensional with up to three factors, power, skill, and rhythm in order of importance. The utility of the modified inventory was supported and recommendations were made concerning the use of subscale or factor scores in addition to overall scores.

The orthogonal rotation of factors in clinical research: a critical note

Examined the current trends in rotation procedures used in factor analyses in clinical research. It was found that orthogonal rotations, usually varimax procedure, were overwhelmingly the rotational choice. It was suggested that in many analyses, investigators in this area of research may be imposing orthogonality on data that might better be interpreted as oblique factors. Guidelines were presented for consideration in the selection and reporting of rotational procedures in clinical research.

A psychometric investigation of the Eysenck Personality Questionnaire

The Eysenck Personality Questionnaire was administered to 139 females and 123 males. Scale statistics were obtained and hierachial factor analyses were performed. The P scale was found to have low internal consistency reliabilities and to covary with the L scale in the female subsample. Factor analyses showed recovery of E scale items in a secondary factor, Social Extraversion, without an impulsivity primary factor. No P and N dimensions recovered; rather components of each scale interrelated in two meaningful dimensions at the tertiary level.

The State-Trait Anxiety Inventory A-Trait Scale: dimensions and their generalization

The State-Trait Anxiety Inventory A-Trait scale was administered to 152 female and 158 male students. Principal-components factor analyses yielded four orthogonal factors for each sex. The findings indicated that factor pattern comparisons should be made prior to pooling data across sex for psychometric investigations. Also, limited support was found for the generalization of dimensions across sex and samples both within and between cultures.

Note on the relationship between trait anxiety and the Eysenck Personality Questionnaire

Administered the State-Trait Anxiety Inventory A-Trait scale and the Eysenck Personality Questionnaire to 97 females and 105 males under neutral conditions. The interrelationships gave limited support to Eysenck's hypothesis that anxiety is a dimension oblique to extraversion and neuroticism such that high anxiety is associated with high introversion and neuroticism. Trait anxiety was independent of the psychoticism and lie dimensions.

Measurement of neo-Pavlovian properties of higher nervous activity by motor reaction-time tasks

A preliminary study involving 80 paid subjects, 40 of each sex, investigated the usefulness of motor response-time tasks as measures of three neo-Pavlovian properties of higher nervous activity, excitatory strength, dynamism, and mobility. Six independent factors were extracted from a set of variables measuring those properties. These factors demonstrated the independence of the three properties, of the excitatory and inhibitory processes in dynamism and mobility, and of strength and sensitivity at least when such tasks are used as measures of properties in the auditory modality. These findings are promising, however, further investigation is required to validate these tasks against the classical tests of properties of higher nervous activity.

Personality dimensions and reversible perspective in Embedded Figures Test

The study examined the relationship between performance on reversible-perspective items in individual and group embedded-figures tests and remaining items, personality and performance variables in two samples of normal females. Performance on the reversible-perspective items was better than on the remaining items in the individual test and as good as other items in the group test. Those who experienced difficulty in solving the reversible-perspective items had more "psychiatric" complaints and greater sociability than subjects who experienced little difficulty.

Cautionary note on the use of short state-anxiety measures

The report noted that the use of high item-remainder coefficients as the sole criterion in the selection of items for short state-anxiety scales from full scales can lead to inaccurate interpretation of results. It was demonstrated that the use of a four-item state-anxiety scale from the State-Trait Anxiety Inventory A-State scale based on high item-remainder coefficients changed relationships in a previously reported study which used full-scale scores. It was proposed that such changes in relationships were the result of selecting four items which happen to load on only one of three dimensions of the A-State scale. The criterion of high item-remainder coefficents alone may be inadequate in the formation of short state-anxiety scales.

Components underlying the relation between field dependence and extraversion

Components of Eysenck's Extraversion scale were examined to account for previous findings indicating that field independence, as measured by individual and group forms of the embedded-figures test, is associated with Introversion. In two of the three samples of female unversity students, field independence, as measured by the Group Embedded Figures Test, was associated with low impulsivity and slow decision time, as measured by items on Eysenck's Extraversion scale.

Anxiety and perceptual articulation

The study investigated Witkin's suggestion that low manifest anxiety is associated with relatively high perceptual articulation, whereas high anxiety is associated with relatively low perceptual articulation. Previous research typically has not provided adequate control for subjects' IQ; therefore, results may have been confounded by differences in subjects' ability. The study attempted to clarify the relationship between state and trait anxiety and perceptual articulation when IQ was controlled for 60 female subjects, who fell within a predetermined IQ range and were blocked into low, moderate and high A-Trait groups. Half of each group was assigned to either low or high ego-involving conditions. All subjects completed the Embedded-figures Test, Gestalt Completion and Concealed Words Test. Contrary to Witkin, the study yielded no significant relationship between anxiety and perceptual articulation.