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PubMed2001

Substance use problems reported by college students: combined marijuana and alcohol use versus alcohol-only use.

This study examines the relationships among selected demographic characteristics, alcohol use only, alcohol plus marijuana use and substance-use related problems. Data are from 409 randomly selected undergraduate college students attending a large urban university. Poly-substance users were more likely than alcohol only users to be younger and experience all substance-use related problems studied. The relationship between poly-substance use and increased substance use-associated problems was also identified when controlling for other common predictors of substance use problems.

Adolescent↗

PubMed2006

Genetic variation in the CCL18-CCL3-CCL4 chemokine gene cluster influences HIV Type 1 transmission and AIDS disease progression.

CCL3 (MIP-1 alpha), CCL4 (MIP-1 beta), and CCL18 (DC-CK1/PARC/AMAC-1) are potent chemoattractants produced by macrophages, natural killer cells, fibroblasts, mast cells, CD4(+) T cells, and CD8(+) T cells. CCL3 and CCL4 are natural ligands for the primary human immunodeficiency virus type 1 (HIV-1) coreceptor CCR5 and are also known to activate and enhance the cytotoxicity of natural killer cells. Genomic DNAs from >3,000 participants enrolled in five United States-based natural-history cohorts with acquired immunodeficiency syndrome (AIDS) were genotyped for 21 single-nucleotide polymorphisms (SNPs) in a 47-kb interval on chromosome 17q12 containing the genes CCL3, CCL4, and CCL18. All 21 SNPs were polymorphic in African Americans (AAs), whereas 7 of the 21 had minor-allele frequencies <0.01 in European Americans (EAs). Substantial linkage disequilibrium was observed in a 37-kb interval containing 17 SNPs where many pairwise D' values exceeded 0.70 in both racial groups, but particularly in EAs. Four and three haplotype blocks were observed in AAs and EAs, respectively. Blocks were strongly correlated with each other, and common haplotype diversity within blocks was limited. Two significant associations are reported that replicate an earlier study. First, among AA members of the AIDS Link to the Intravenous Experience cohort of injection drug users, frequencies of three correlated SNPs covering 2,231 bp in CCL3 were significantly elevated among highly exposed, persistently HIV-1-uninfected individuals compared with HIV-1-infected seroconvertors (P = .02-.03). Second, seven highly correlated SNPs spanning 36 kb and containing all three genes were significantly associated with more-rapid disease progression among EAs enrolled in the Multicenter AIDS Cohort Study cohort (P = .01-.02). These results reiterate the importance of chemokine gene variation in HIV-1/AIDS pathogenesis and emphasize that localized linkage disequilibrium makes the identification of causal mutations difficult.

Chemokine CCL3↗

PubMed1999

Intercomparison of calibration procedures for 192Ir HDR sources in Brazil.

The lack of well established dosimetry protocols for HDR sources is a point of great concern regarding the uniformity of procedures within a particular country and worldwide. The main objective of this paper is to report the results from ten institutions of an intercomparison of calibration procedures for 192Ir HDR sources currently in use in Brazil. The treatment irradiator of one institution was calibrated by a reference system and used by all participants with their own measuring electrometers and ionization chambers under the same experimental conditions. Two methods were used: the calibration jig and the well-type ionization chamber. Each participant was allowed to use their own method and formalism. The results of this exercise were very positive since this was the first time in Brazil that a group of users gathered to share their experience and openly discuss the physical concepts behind the calibration procedures. The results were all within +/-3.0%, except one case where -4.6% was observed and later identified as a problem with the Nk value for x-rays. Though the magnitude of the deviations found was generally acceptable considering the diversity of formalisms currently in use, a proposal is now being prepared to be adopted as a national protocol. The identification of the institutions was left out for the sake of confidentiality.

Brachytherapy↗

PubMed2001

Presence for design: conveying atmosphere through video collages.

Product designers use imagery for inspiration in their creative design process. To support creativity, designers apply many tools and techniques, which often rely on their ability to be inspired by found and previously made visual material and to experience the atmosphere of the user environment. Computer tools and developments in VR offer perspectives to support this kind of imagery and presence in the design process. But currently these possibilities come at too high a technological overhead and price to be usable in the design practice. This article proposes an expressive and technically lightweight approach using the possibilities of VR and computer tools, by creating a sketchy environment using video collages. Instead of relying on highly realistic or even "hyperreal" graphics, these video collages use lessons learned from theater and cinema to get a sense of atmosphere across. Product designers can use these video collages to reexperience their observations in the environment in which a product is to be used, and to communicate this atmosphere to their colleagues and clients. For user-centered design, video collages can also provide an environmental context for concept testing with prospective user groups.

Communication↗

PubMed2005

Perception of sign language and its application to visual communications for deaf people.

Video communication systems for deaf people are limited in terms of quality and performance. Analysis of visual attention mechanisms for sign language may enable optimization of video coding systems for deaf users. Eye-movement tracking experiments were conducted with profoundly deaf volunteers while watching sign language video clips. Deaf people are found to fixate mostly on the facial region of the signer to pick up small detailed movements associated with facial expression and mouth shapes. Lower resolution, peripheral vision is used to process information from larger, rapid movements of the signer in the video clips. A coding scheme that gives priority to the face of the signer may be applied to improve perception of video quality for sign language communication.

Adult↗

PubMed2000

The evolution of external quality evaluation: observations from the Joint Commission on Accreditation of Healthcare Organizations.

The Joint Commission on Accreditation of Healthcare Organizations, the oldest health care accrediting body in the world, currently accredits almost 20000 organizations in the USA. Although continuing to be professionally-sponsored, accreditation's rapid growth in recent years has been driven by the external users of accreditation--government, purchasers, and public--rather than by the original users, the professionals themselves. This experience in the USA suggests that over time successful external quality evaluation mechanisms throughout the world will involve representatives of the public, purchasers, and government in establishing standards and setting policies. Without this involvement, these stakeholders are unlikely to find the mechanisms credible in addressing their needs, and will seek alternatives--adding cost and duplication to the external quality evaluation system. Successful mechanisms are also likely to provide more detailed information about an organization's performance to the public, purchasers, and the government, while creating evaluation processes that provide for innovation and support improvement in efficiency, as well as quality, through incorporation of aspects of the Baldrige and European Foundation for Quality Management approaches to organizational excellence. Finally, successful evaluation mechanisms are likely to create a special focus on the safety of care, incorporating aspects of the International Organization for Standardization's ISO 9000 approach to quality management. While the specific nature, priority, and timing of these changes will differ from country to country, they are likely to influence the evolution of external quality evaluation throughout the world. External evaluation of health care organizations' quality holds great promise, but its long-term success depends on responding to all those who will want to depend on it.

Diffusion of Innovation↗

PubMed1984

Apple II PASCAL programs for molecular biologists.

A collection of PASCAL programs designed for the Apple II microcomputer is presented. These DNA sequence handling and analysis programs are interactive and may be used even by people with no computer experience. The package allows the user to enter a sequence from the keyboard, to modify it, to generate the reverse complement, to create new sequences from parts of other ones, to display or print sequences in various formats. Some analysis tasks are also performed: Translation, searches for restriction sites, for homology with subsequences, either perfect or with an adjustable match percentage. In addition, two programs are also included: The first one allows DNA data sequences generated with a BASIC program under the CP/M operating system to be used with these PASCAL programs. The second one is designed for the automatic assembly of DNA fragments sequences, obtained with the GILBERT-MAXAM or M13 techniques, into a complete sequence.

Amino Acid Sequence↗

PubMed2003

PROTINFO: Secondary and tertiary protein structure prediction.

Information about the secondary and tertiary structure of a protein sequence can greatly assist biologists in the generation and testing of hypotheses, as well as design of experiments. The PROTINFO server enables users to submit a protein sequence and request a prediction of the three-dimensional (tertiary) structure based on comparative modeling, fold generation and de novo methods developed by the authors. In addition, users can submit NMR chemical shift data and request protein secondary structure assignment that is based on using neural networks to combine the chemical shifts with secondary structure predictions. The server is available at http://protinfo.compbio.washington.edu.

Internet↗

PubMed1995

Epidemiology of tobacco use and dependence.

Knowledge of the epidemiology of tobacco use and dependence can be used to guide research initiatives, intervention programs, and policy decisions. Both the reduction in the prevalence of smoking among US adults and black adolescents and the decline in per capita consumption are encouraging. These changes have probably been influenced by factors operating at the individual (e.g., school-based prevention programs and cessation programs) and environmental (e.g., mass media educational strategies, the presence of smoke-free laws and policies, and the price of tobacco products) levels (for a discussion of these factors, see, e.g., refs. 2, 48, 52, 183, and 184). The lack of progress among adolescents, especially whites and males, and the high risk for experimenters of developing tobacco dependence present cause for great concern (48, 183-186). In addition to those discussed above, several areas of research can be recommended. 1. Better understanding of the clustering of tobacco use with the use of other drugs, other risk behaviors, and other psychiatric disorders could better illuminate the causal processes involved, as well as the special features of the interventions needed to prevent and treat tobacco dependence. 2. To better understand population needs, trend analyses of prevalence, initiation, and cessation should, whenever possible, incorporate standardized measures of these other risk factors. Future research should compare the effect of socioeconomic status variables on measures of smoking behavior among racial/ethnic groups in the United States. 3. For reasons that may be genetic, environmental, or both, some persons do not progress beyond initial experimentation with tobacco use (2, 48, 183, 187-192), but about one-third to one-half of those who experiment with cigarettes become regular users (48, 193, 194). Factors, both individual and environmental, that can influence the susceptibility of individuals to tobacco dependence need further attention. 4. To estimate their sensitivity and specificity, comparisons of the National Household Survey on Drug Abuse indicators of dependence with DSM-based criteria are needed. Public health action continues to be warranted to reduce the substantial morbidity and mortality caused by tobacco use (195). A paradigm for such action has been recommended and involves preventing the onset of use, treating tobacco dependence, protecting non-smokers from exposure to secondhand smoke, promoting nonsmoking messages while limiting the effect of tobacco advertising and promotion on young people, increasing the real (inflation-adjusted) price of tobacco products, and regulating tobacco products (186).

Adolescent↗

PubMed2006

How is the collaborative-practice competency operationalized by mental health workers?

The recovery-focused competencies currently endorsed in policy emphasize collaborative relationships between mental health workers, service users, families and communities. Based on a qualitative research methodology, multi-disciplined practitioners shared their perceptions as to how mental health workers could operationalize collaborative relationships. Two community mental health centres were the setting for three focus groups, where 16 voluntary participants contributed to focused discussions. Participants discussed the pragmatics of how they work collaboratively; identifying knowledge and attitudes that underpin their practice, and elaborating on environmental influences that impact on a collaborative approach. Findings from the study recommend the practitioner role as one of advocacy and facilitation. The collaborative approach, which is inextricably related to the quality of the practitioner-service user relationship, aids sense-making for service users of their mental health experience. This requires of practitioners the qualities of openness, expression of hope, genuineness and people-first attitude that supports the building of knowledge rather than communicating it.

Clinical Competence↗

PubMed2006

Unprotected sex among HIV-positive injection drug-using women and their serodiscordant male partners: role of personal and partnership influences.

We investigated the characteristics of human immunodeficiency virus (HIV)-positive injection drug-using women who reported unprotected vaginal and/or anal sex with HIV-negative or unknown serostatus (serodiscordant) male partners. Of 426 female study participants, 370 were sexually active. Of these women, 39% (144/370) and 40% (148/370) reported vaginal and/or anal sex with serodiscordant main and casual partners, respectively. Sixty percent of women inconsistently used condoms with their serodiscordant main partners, whereas 53% did so with casual partners. In multivariate analysis, during sex with main partners, inconsistent condom users were less likely to feel confident about achieving safe sex (self-efficacy), personal responsibility for limiting HIV transmission, and that their partner supported safe sex. Inconsistent condom use was also more likely among women who held negative beliefs about condoms and in couplings without mutual disclosure of HIV status. Regarding sex with casual partners, inconsistent condom users were more likely to experience psychologic distress, engage in sex trading, but they were less likely to feel confident about achieving safe sex. These findings suggest that there are widespread opportunities for the sexual transmission of HIV from drug-using women to HIV-uninfected men, and that reasons vary by type of partnership. Multifaceted interventions that address personal, dyadic, and addiction problems are needed for HIV-positive injection drug-using women.

Adult↗

PubMed2001

Toward high-throughput genotyping: dynamic and automatic software for manipulating large-scale genotype data using fluorescently labeled dinucleotide markers.

To efficiently manipulate large amounts of genotype data generated with fluorescently labeled dinucleotide markers, we developed a Microsoft database management system, named. offers several advantages. First, it accommodates the dynamic nature of the accumulations of genotype data during the genotyping process; some data need to be confirmed or replaced by repeat lab procedures. By using, the raw genotype data can be imported easily and continuously and incorporated into the database during the genotyping process that may continue over an extended period of time in large projects. Second, almost all of the procedures are automatic, including autocomparison of the raw data read by different technicians from the same gel, autoadjustment among the allele fragment-size data from cross-runs or cross-platforms, autobinning of alleles, and autocompilation of genotype data for suitable programs to perform inheritance check in pedigrees. Third, provides functions to track electrophoresis gel files to locate gel or sample sources for any resultant genotype data, which is extremely helpful for double-checking consistency of raw and final data and for directing repeat experiments. In addition, the user-friendly graphic interface of renders processing of large amounts of data much less labor-intensive. Furthermore, has built-in mechanisms to detect some genotyping errors and to assess the quality of genotype data that then are summarized in the statistic reports automatically generated by. The can easily handle >500,000 genotype data entries, a number more than sufficient for typical whole-genome linkage studies. The modules and programs we developed for the can be extended to other database platforms, such as Microsoft SQL server, if the capability to handle still greater quantities of genotype data simultaneously is desired.

Alleles↗

PubMed1997

Worthwhile visits on the World Wide Web.

Using personal experience and recommendations from other users in compiling a selection of reviews, provides a taste of the diversity of resources available on the World Wide Web, looking at sites to visit and detailing what each site has to offer. Covers information sources, journals, management development, networking, skills and directories.

Computer Communication Networks↗

PubMed2003

Therapeutic treatment plan optimization with probability density-based dose prescription.

The dose optimization in inverse planning is realized under the guidance of an objective function. The prescription doses in a conventional approach are usually rigid values, defining in most instances an ill-conditioned optimization problem. In this work, we propose a more general dose optimization scheme based on a statistical formalism [Xing et al., Med. Phys. 21, 2348-2358 (1999)]. Instead of a rigid dose, the prescription to a structure is specified by a preference function, which describes the user's preference over other doses in case the most desired dose is not attainable. The variation range of the prescription dose and the shape of the preference function are predesigned by the user based on prior clinical experience. Consequently, during the iterative optimization process, the prescription dose is allowed to deviate, with a certain preference level, from the most desired dose. By not restricting the prescription dose to a fixed value, the optimization problem becomes less ill-defined. The conventional inverse planning algorithm represents a special case of the new formalism. An iterative dose optimization algorithm is used to optimize the system. The performance of the proposed technique is systematically studied using a hypothetical C-shaped tumor with an abutting circular critical structure and a prostate case. It is shown that the final dose distribution can be manipulated flexibly by tuning the shape of the preference function and that using a preference function can lead to optimized dose distributions in accordance with the planner's specification. The proposed framework offers an effective mechanism to formalize the planner's priorities over different possible clinical scenarios and incorporate them into dose optimization. The enhanced control over the final plan may greatly facilitate the IMRT treatment planning process.

Algorithms↗

PubMed1992

Digital speech processing for cochlear implants.

A rather general basic working hypothesis for cochlear implant research might be formulated as follows. Signal processing for cochlear implants should carefully select a subset of the total information contained in the sound signal and transform these elements into those physical stimulation parameters which can generate distinctive perceptions for the listener. Several new digital processing strategies have thus been implemented on a laboratory cochlear implant speech processor for the Nucleus 22-electrode system. One of the approaches (PES, pitch excited sampler) is based on the maximum peak channel vocoder concept whereby the spectral energy of a number of frequency bands is transformed into appropriate electrical stimulation parameters for up to 22 electrodes using a voice pitch synchronous pulse rate at any electrode. Another approach (CIS, continuous interleaved sampler) uses a maximally high pitch-independent stimulation pulse rate on a selected number of electrodes. As only one electrode can be stimulated at any instance of time, the rate of stimulation is limited by the required stimulus pulse widths (as determined individually for each subject) and some additional constraints and parameters which have to be optimized and fine tuned by psychophysical measurements. Evaluation experiments with 5 cochlear implant users resulted in significantly improved performance in consonant identification tests with the new processing strategies as compared with the subjects own wearable speech processors whereas improvements in vowel identification tasks were rarely observed. The pitch-synchronous coding (PES) resulted in worse performance compared to the coding without explicit pitch extraction (CIS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2000

A developmental model for the evolution of artificial neural networks.

We present a model of decentralized growth and development for artificial neural networks (ANNs), inspired by developmental biology and the physiology of nervous systems. In this model, each individual artificial neuron is an autonomous unit whose behavior is determined only by the genetic information it harbors and local concentrations of substrates. The chemicals and substrates, in turn, are modeled by a simple artificial chemistry. While the system is designed to allow for the evolution of complex networks, we demonstrate the power of the artificial chemistry by analyzing engineered (handwritten) genomes that lead to the growth of simple networks with behaviors known from physiology. To evolve more complex structures, a Java-based, platform-independent, asynchronous, distributed genetic algorithm (GA) has been implemented that allows users to participate in evolutionary experiments via the World Wide Web.

Algorithms↗

PubMed2000

Use of community support services by middle-aged and older patients with psychotic disorders.

OBJECTIVE: The study sought to determine the degree to which use of community services is related to predisposing, enabling, and need factors among older patients with psychotic disorders who live in the community and to assess whether high use of community services is associated with improving or declining psychopathology. METHODS: The sample consisted of 89 middle-aged and elderly community-dwelling patients with schizophrenia or other psychotic disorders. Assessments at baseline and two follow-ups at six-month intervals included measures of psychopathology, well-being, and social adjustment, in addition to the frequency of use of 17 formal community services in three categories-psychological, social, and daily living services. RESULTS: Ninety-two percent of patients reported use of community support services. The mean number of annual service contacts per patient was 36.6 for psychological services, 81 for social services, and 39.7 for daily living services. High users of psychological services were younger and experienced more severe positive psychotic symptoms and depressive symptoms. High users of social services were of higher socioeconomic status, more likely to be female, and had a longer history of psychosis, more cognitive deficits, and more severe negative psychotic and depressive symptoms. Patients who used daily living services were older, had poorer functional health status and more cognitive deficits, and had more severe negative psychotic and depressive symptoms. A trend was noted for high users of social services to experience relief from depressive symptoms over time. CONCLUSIONS: Use of community services is common among older outpatients with psychotic disorders, but its frequency varies as a function of patient characteristics.

Aged↗

PubMed2003

Life with an indwelling urinary catheter: the dialectic of stigma and acceptance.

The purpose of this hermeneutic phenomenology was to describe and interpret the lived experience of long-term users of urinary catheters. Living with a urinary catheter involved a dialectical swing between acknowledgment that the catheter was "a part of me" and feelings of alienation and vulnerability when it was experienced as a stigma. Themes include Adjusting to embodied changes by perceiving the catheter as a "part of me," Shame and responding to shame by normalizing, and Embarrassment and coping with embarrassment by humor. Providers can minimize stigma related to the visibility of the catheter by coaching patients in strategies to manage going out of the home with a minimum of urine accidents or by helping develop ways to conceal the urine bag.

Adaptation, Psychological↗