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PubMed2005

Evolutionary relationships of the limnochromini, a tribe of benthic deepwater cichlid fish endemic to Lake Tanganyika, East Africa.

Lake Tanganyika harbors an enormous diversity of cichlid fish that stem from eight distinct ancestral lineages, which colonized the lake after its formation 9 to 12 million years ago. Six of twelve currently described tribes are assigned to the "H-lineage," an assemblage of exclusively mouthbrood-ing cichlids, all of which evolved during a short period of time during the course of the primary radiation of lacustrine species. Our study focuses on the deepwater tribe Limnochromini, comprising bi-parental mouthbrooders, and is based on phylogenetic analysis of two mitochondrial gene segments. We confirm the polyphyletic origin of the Limnochromini as they are defined to date, in that Gnathochromis pfefferi is placed among the Tropheini, whereas the genus Benthochromis is presented as an independent lineage. The remaining nine species were unambiguously resolved as monophyletic and should be redefined as the tribe Limnochromini. Concerning generic assignments, the genus Greenwoodochromis appeared as monophyletic, Limnochromis as paraphyletic, and the genera Reganochromis and Baileychromis as monophyletic sister genera. The linearized tree analysis and the comparison of average sequence divergences to that of the remaining tribes of the H-lineage revealed a relatively recent but simultaneous proliferation of the Limnochromini, suggesting that the same environmental changes triggered the radiation of particular deepwater, benthic, pelagic, and littoral lineages. By using a preliminary calibration of a molecular clock based on gamma-corrected amino acid distances of the NADH2 gene, the diversification of the Limnochromini could tentatively be dated to 2.9-3.5 MYA, coinciding with a period of aridification in East Africa between 2.5 and 3 MYA. The lack of geographic color morphs and the structural uniformity and resource scarcity of deepwater habitats suggest that competition and resource partitioning leading to differential trophic specialization promoted speciation within the Limnochromini, rather than an allopatric model.

Animals↗
PubMed1996

A long-range physical map of human chromosome 21q22.1 band from the YAC continuum.

The human Chromosome (Chr) 21q22.1 region contains several genes for cytokines and neurotransmitters and the gene for superoxide dismutase (mutant forms of which can cause familial amyotrophic lateral sclerosis). A region of approximately 5.8 Mb encompassing D21S82 and the glycinamide ribonucleotide transformylase (GART) loci was covered by overlapping YAC clones, which were contiguously ordered by clone walking with sequence-tagged site (STSs). A total of 76 markers, including 29 YAC end-specific STSs, were unambiguously ordered in this 5.8-Mb region, and the average interval between markers was 76 kb. Restriction maps of the YAC clones with rare-cutting enzymes were simultaneously prepared, and the restriction sites were aligned to obtain a consensus restriction map of the proximal region of the 21q22.1 band. The restriction map made from 44 overlapping YACs contains 54 physically assigned STSs. By integrating the consensus map of the adjacent 1.8-Mb region, we obtained a fine physical map spanning 6.5 Mb of human Chr 21q22.1. This map contains 24 precisely positioned end-specific STSs and 12 NotI-linking markers. More than 39 potential CpG islands were identified in this region and were found to be unevenly distributed. This physical map and the YACs should be useful as a reference map and as a resource for further structural analysis of the Giemsa-negative band (R-band) of Chr 21q22.1.

Base Sequence↗
PubMed2003

Seasonal shift from bottom-up to top-down impact in phytophagous insect populations.

Although many studies now examine how multiple factors influence the dynamics of herbivore populations, few studies explicitly attempt to document where and when each is important and how they vary and interact. In fact, how temporal variation in top-down (natural enemies) and bottom-up (host plant resources) factors affect herbivore dynamics has been suggested as a particularly important yet poorly understood feature of terrestrial food webs. In this study we examined how temporal changes in predator density (wolf spiders, sheet-web builders, and mirid egg predators) and host-plant resources (plant quality and structural complexity) influence the population dynamics of the dominant phytophagous insects on Atlantic-coast salt marshes, namely Prokelisia planthoppers (Homoptera: Delphacidae). We designed a factorial experiment in meadows of Spartina alterniflora to mimic natural variation in vegetation quality and structure by establishing two levels of plant nutrition (leaf nitrogen content) by fertilization, and two levels of habitat complexity by adding leaf litter (thatch). We then assessed seasonal changes in the strength of bottom-up (plant quality) and top-down (predator) impacts on planthopper populations. Planthopper populations responded positively to increased plant quality treatments in late summer. Despite the greater number of planthopper adults colonizing fertilized Spartina plots compared to unfertilized controls, the offspring of these colonists were much less abundant at the end of the season in fertilized plots, particularly those with thatch. The initial colonization effect was later erased because arthropod predators selectively accumulated in fertilized plots where they inflicted significant mortality on all stages of planthoppers. Predators rapidly colonized fertilized plots and reached high densities well in advance of planthopper colonization, a response we attribute to their rapid aggregation in complex-structured habitats with readily available alternative prey. Our results suggest that plant resources not only mediate the strength of predator impacts on herbivore populations, but they also promote the coupling of predator and prey populations and thus influence when enemy impacts are realized.

Animals↗
PubMed1992

Evaluation of maternal health programs: approaches, methods and indicators.

Evaluation of maternal health services is an essential function of any health system. Single or multiple aspects of a program can be evaluated but they must be clearly defined. To assess success of a program the dimensions of coverage, equity, quality, women's satisfaction, efficiency and cost-effectiveness must be considered. These can be measured according to some standard criteria, and various methods are described, including randomized clinical trials, randomized community trials, before and after studies, and observational studies, including the case-control approach and confidential inquiries into maternal deaths. Indicators to assess effectiveness of a maternal health program may relate to structure, i.e., available resources or organizational arrangement; process, including changes in quantity of services provided; or outcome indicators that measure maternal mortality or morbidity.

Female↗
PubMed1996

Profile of radiotherapy departments contributing to the Cooperative Group of Radiotherapy of the European Organization for Research and Treatment of Cancer.

PURPOSE: Since 1982, the Radiotherapy Group of the European Organization for Research and Treatment of Cancer (EORTC) is carrying out a Quality Assurance program that includes the evaluation of the structure and human resources of 50 centers actively participating in protocols of clinical research in radiotherapy. METHODS AND MATERIALS: One or two site visits were made by a team of radiation physicists and physicians. A detailed questionnaire was circulated to these radiotherapy centers to collect and update standardized figures on the status and activities of each center, to clarify some obscurities encountered during on-site visits, and to extend investigations to issues that were not addressed during local audits. RESULTS: This article reports on departmental infrastructure, staff and equipment workload, and quality control procedures carried out by single institutions. Large variations in equipment and staff are observed among participating centers. Comparisons between data collected in the early 1980s and during a recent update show no difference in workload per megavoltage equipment and per simulator. The number of cancer patients treated per year per radiotherapist seems to slightly diminish, especially in centers that experienced a considerable staff shortage a few years ago. The most significant improvement is observed for the number of cases treated per year per member of the radiation physics team. The radiographer's workload shows an opposite trend. CONCLUSIONS: Our database provides participating centers with strong comparative arguments to correct staff and equipment unbalances and to convince administrative authorities of priorities in decision making. The current analysis shows that the situation for equipment is unchanged in comparison with that observed 6 years ago. Efforts have to be put forth in some institutions to reduce the workload at simulators. A tentative profile and guidelines for minimum recommendations for European radiotherapy departments involved in clinical research are presented.

Cancer Care Facilities↗
PubMed2003

Introducing a problem-based unit into a lifespan nutrition class using a randomized design produces equivocal outcomes.

Problem-based learning (PBL) is a tutorial, student-centered, problem-driven educational strategy adopted by medical and allied health educators to positively influence self-directed learning, critical thinking, and learning behavior. PBL was examined in dietetics education through random assignment of 32 undergraduate dietetics students for two weeks to either a problem-based or a lecture-based case format for the infant and elderly units of a 16-week lifespan nutrition course. Random assignment followed stratification for gender and earlier course examination performance. Expert validation of PBL curricular components and noted differences in discussion structure and information resources verified curriculum distinctiveness. Main outcome measures were pre- and post-Cognitive Behavior Survey scores for memorization, reflection, and positive learning experience scales, unit and course evaluations and unit examination scores. Students in problem-based modules demonstrated greater gains in reflective thinking with stable memorization, suggesting improved critical thinking skills. Tenets that problem-based learning promotes knowledge retention and provides a more positive learning experience were not upheld. Knowledge acquisition was not hindered by a problem-based approach. We conclude that gains in reflective thinking and evidence of increased self-directed learning argue for inclusion of PBL in dietetics curricula and that a problem-based education will help dietitians successfully respond to professional development needs.

Adult↗
PubMed2001

[Impact in the quality of health care and cost-effectiveness analysis of the reform of an emergency medicine service].

BACKGROUND: To determine the effects that the reform of an emergency department (ED) have on efficacy, health care quality and efficiency. MATERIAL AND METHOD: Reforms consisted of 50% and 34% increases in structural and human resources, respectively. Roles of each ED member were redetermined, new assistance pathways were implemented, and the relationship between ED and the remaining hospital departments was reassessed. As efficacy markers, we determined the number of patients waiting to be attended (Pesp), the waiting time of patients to receive medical assistance (T(esp)),and the total waiting time of patients staying in the ED (T(total)). As health-care quality markers, we determined the percentage of patients leaving ED without having been visited by a physician(IPNV), the percentage of patients who were visited again (IPR),and the percentage of mortality (IPF). We also quantified the number of visits to the ED. All these data were obtained daily over 3 weeks, before (February 1999) and after (February 2000)the reforms. Effectiveness was estimated from the ratio P(total)/T(esp)(E1) and P(total)/P(esp) (E2). Costs were recorded for both periods and a cost-effectiveness analysis was performed to study the efficiency. RESULTS: In 2000, the number of visits increased by +12% (CI 95%: 2% to 22%). Despite this increase, we observed an improvement of most efficacy and health-care quality markers after the ED reforms. E1 increased by 996% (CI 95%: 335% to 1,658%) and E2 increased by 186% (CI 95%: -23%to 395%). Cost-effectiveness analysis showed 70% (CI 95%: 33%to 107%) and 56% (CI 95%: 18% to 94%) increases regarding E1 and E2, respectively, after the reforms. CONCLUSIONS: Providing ED with the necessary resources leads to an objective improvement of its efficacy and health-care quality and, consequently, the service and quality perceived by users improve. Despite the total cost increase after the ED reforms, efficiency also improves.

Cost-Benefit Analysis↗
PubMed1987

Changing association between community occupational structure and ischaemic heart disease mortality in the United States.

The changing association between community occupational structure and ischaemic heart disease mortality in white men and women of the United States from 1968 to 1982 has been investigated. Occupational structure was represented by the proportion of workers in white-collar jobs. A negative association, with lower mortality in communities with higher levels of white-collar employment, emerged over the period in both men and women. The results for men may be interpreted as suggesting a recapitulation in the US of the changing association between social class and heart disease observed in Britain. Occupational structure, however, reflects resources and opportunities in a community derived from its contribution to the national and international economy. Thus the growing inequalities in heart disease mortality presented in this ecological study relate more appropriately to communities than to individual workers.

Adult↗
PubMed2001

Psychosocial challenges facing physicians of today.

Fundamental changes in the organization, financing, and delivery of health care have added new stressors or opportunities to the medical profession. These new potential stressors are in addition to previously recognized external and internal ones. The work environment of physicians poses both psychosocial, ergonomic, and physico-chemical threats. The psychosocial work environment has, if anything, worsened. Demands at work increase at the same time as influence over one's work and intellectual stimulation from work decrease. In addition, violence and the threat of violence is another major occupational health problem physicians increasingly face. Financial constraint, managed care and consumerism in health care are other factors that fundamentally change the role of physicians. The rapid deployment of new information technologies will also change the role of the physician towards being more of an advisor and information provider. Many of the minor health problems will increasingly be managed by patients themselves and by non-physician professionals and practitioners of complementary medicine. Finally, the economic and social status of physicians are challenged which is reflected in a slower salary increase compared to many other professional groups. The picture painted above may be seen as uniformly gloomy. In reality, that is not the case. There is growing interest in and awareness of the importance of the psychosocial work environment for the delivery of high quality care. Physicians under stress are more likely to treat patients poorly, both medically and psychologically. They are also more prone to make errors of judgment. Studies where physicians' work environment in entire hospitals has been assessed, results fed-back, and physicians and management have worked with focused improvement processes, have demonstrated measurable improvements in the ratings of the psychosocial work environment. However, it becomes clear from such studies that quality of the leadership and the physician team impact on the overall work atmosphere. Physicians unaware of the goals of the department as well as the hospital, that do not receive management performance feedback, and who do not get annual performance appraisals and career guidance, rate their psychosocial environment as more adverse than their colleagues. There is also a great need to offer personally targeted competence development plans. Heads of department and senior physicians rate their work environment as of higher quality than more junior and mid-career physicians. More specifically, less senior physicians perceive similar work demands as their senior colleagues but rate influence over work, skills utilization, and intellectual stimulation at work as significantly worse. In order to combat negative stressors in the physicians' work environment, enhancement initiatives should be considered both at the individual, group, and structural level. Successful resources used by physicians to manage the stress of everyday medicine should be identified. Physicians are a key group to ensure a well-functioning health care system. In order to be able to change and adapt to the ongoing evolution of the Western health care system, more focus needs to be put on the psychosocial aspects of physicians' work.

Humans↗
PubMed2000

Change counselling in diabetes: the development of a training programme for the diabetes team.

Skills in counselling for behaviour change may help staff working in diabetes care to facilitate self management in people with diabetes. A feasibility study was conducted to define the essential competencies (attitudes, knowledge and skills), training methods, and assess whether this approach was practicable in a diabetes resource centre. Semi structured interviews with staff were routinely conducted throughout the duration of the study. The findings suggest that the stages of change model, motivational interviewing and behavioural techniques are relevant to work in this area. Acquiring the competencies was harder to achieve than anticipated, though most were evident after one years training. The most valued training methods were individual supervision and video examples. However, the competencies were difficult to apply in the clinical setting given time constraints, the strength of existing staff routines and the patients' readiness to change. The lessons learned and suggestions for future work are presented.

Competency-Based Education↗
PubMed1999

Modelling with constructive backpropagation.

Neural network methods have proven to be powerful tools in modelling of nonlinear processes. One crucial part of modelling is the training phase where the model parameters are adjusted so that the model performs the desired operation as well as possible. Besides parameter estimation, an important problem is to select a suitable model structure. With a bad structure we potentially run into problems like underfitting, overfitting or wasting computational resources. One approach for structure learning is to use constructive methods, where training begins with minimal structure, and then more parameters are added when needed according to some predefined rule. This kind of constructive solution has also become more attractive in neural networks literature where one of the most well known constructive techniques is cascade-correlation (CC) learning. Inspired by CC we propose and study a similar technique called constructive backpropagation (CBP). We show that CBP is computationally just as efficient as the CC algorithm even though we need to backpropagate the error through no more than one hidden layer. Further, CBP has the same constructive benefits as CC, but in addition CBP benefits from simpler implementation and the ability to utilize stochastic optimization routines. Moreover, we show how CBP can be extended to allow addition of multiple new units simultaneously and how it can be used to perform continuous automatic structure adaptation. This includes both addition and deletion of units. The performance of CBP learning is studied with time series modelling experiments which demonstrate that CBP can provide significantly better modelling capabilities compared to CC learning.

Journal Article↗
PubMed1999

The challenges of employing performance monitoring in public health community-based efforts: a case study.

The development of community-based coalitions has acquired great popularity as a health promotion strategy. The Institute of Medicine recommends that community-based health coalitions employ a performance monitoring process in their efforts. The results of the current study indicate that in the community setting, implementing a performance monitoring process and sustaining the specialized functions entailed in this strategy are challenging. Many of the challenges result from fundamental differences between the organizational environment of bureaucracies--in which these techniques are developed, supported, and greatly successful--and the realities of the loosely-structured and resource-limited community environment. The performance monitoring process is measurement-driven. One challenge of implementing this process at the community level is that public health problems of local concern are not always documented in current surveillance systems and thus a performance monitoring strategy is not always, or immediately, applicable. When data which document a health problem of local concern are available, a second challenge facing community-based coalitions is acquiring the resources, especially the wide-range of specialized expertise, required to fully implement and sustain the performance monitoring process. These issues are examined in the context of the Massachusetts Department of Public Health's Community Health Network Area (CHNA) Initiative which entails the formation of coalitions of local health service providers. The CHNA initiative is a statewide project in which health service providers in specified geographic regions work collaboratively on health improvement projects.

Adolescent↗
PubMed2002

Helping tomorrow's doctors to gain a population health perspective - good news for community stakeholders.

INTRODUCTION: The modernising agenda of the NHS and recommendations of professional bodies demand that all doctors achieve a basic understanding of a population health perspective. The principle of integrated learning and the logistics of provision make it inappropriate for such learning to be delivered solely by public health specialists, and community-based learning has been promoted as the best setting in which to assist this objective. However, there is little evidence from practice as to whether non-specialist staff are willing or able to play a role in orienting tomorrow's doctors to the needs of communities. METHODS: Semi-structured interviews, questionnaires and focus groups iterated the opinion of key stakeholders on their preferred contributions to community-oriented undergraduate medical education. Framework analysis was used to elicit key outcomes and process factors. RESULTS: There was consensus that community-based learning should be a core element of the medical curriculum as it can demonstrate the socioenvironmental context of care and the doctor's role in interagency working and preventive care. Effective academic/NHS partnerships were called for, with higher education leading the agenda on aims and objectives, creating collaborative structures, and reallocating resources to support new learning. Community-based stakeholders would offer the translation of theory into practice by demonstrating clinical and social diversity, models of teamworking, and a context for the application of prior learning. They also promoted recurrent contact with communities, and suggested an enhanced role in mentoring students through longer term relationships. CONCLUSION: Community-based personnel and NHS users are an under-used resource for medical education. Their proposed contributions strongly accord with the agenda for a population health perspective in basic training. Curriculum planners need to make long-term partnerships with community-based agencies, rather than using them as an intermittent provider of limited learning sessions with narrowly defined objectives.

Community Health Services↗
PubMed2004

Maternal resources, proximity of services, and curative care of boys and girls in Minya, Egypt 1995-97.

Despite declines in the risk of dying among children in Egypt, girls' excess mortality in early childhood persists. Using data from a representative sample of children in Minya, Egypt, I assess whether maternal resources, marital household structure, and proximity of services influence disparities by sex in curative care. The results show that boys visit any source of care marginally more often than girls. Among children who receive care, boys more often receive private care. Higher maternal education has no effect on the relative odds of private care, whereas maternal residence with marital relatives reduces the odds that girls receive private care. Having a public clinic in the neighbourhood, at which private services may be offered, increases girls' odds of receiving private care. Higher and more equitable levels of care-seeking at public and private services of higher quality may reduce differences in the survival of boys and girls in a highly sex-stratified setting.

Child↗
PubMedDate not supplied

Determinants of variability among nations in child growth.

This cross-national study aimed at understanding variability in growth among nations and its determinants. It examined the variability of growth among nations, the factors most important for explaining this variability, how these factors jointly determine growth, and the consistency of the patterns and relationships. A conceptual model was adapted from U. Jonsson. National data on height and weight of children, sex, ethnicity, and 15 social, economic, health, education, and political factors were combined from three secondary sources. A sequence of multiple linear regression models was used with three age groups: 1-2, 3-5, and 6-10 years. Substantial variability in growth among nations was seen in comparison to that within nations. Regression models with sex, ethnicity, food security, maternal and child care, and health services and environment explained a large percentage of this variability. Institutions, politics/ideology, economic structure, and potential resources contributed little additionally to the models. Ethnic differences among nations were observed and persisted even when models controlled for other factors, but should not necessarily be interpreted as genetic differences. Determinants for height, weight, and weight adjusted for height were somewhat different. Adjustment for only previous growth and sex explained about 90% of variability in growth, supporting the assumption that growth patterns are generally established early in life. As policy decisions and programmes addressing mild-to-moderate malnutrition are increasingly considered, the implications of cross-national variability in growth may assume greater importance. Future work should examine simultaneously the effects of national, community, family, and individual characteristics on growth using data from individuals in a number of nations.

Anthropometry↗
PubMedDate not supplied

Changes in the policies of the department of hematology, 1982-1998, designed to promote the mental health of children with leukemia and enhance their quality of life.

A perceived personal control (PPC) preventive intervention model that had earlier received empirical and theoretical verification was applied to a population of pediatric leukemia patients to promote their mental health and enhance their quality of life. The PPC model entails intervention on two complementary levels. On the personal interaction level, preventive intervention is administered by a network of natural and organized support systems, while the social action level leads to the introduction of changes in policies, structures, allocation of resources, and services. Preventive intervention in both domains is discussed with respect to changes in policies introduced between 1982 and 1998 in the hematology department of Rambam Medical Center in Haifa, Israel, as well as in other relevant departments catering to children with leukemia, to foster the positive mental health of these children.

Attitude of Health Personnel↗
PubMed2003

LOX-DB-- database on lipoxygenases.

SUMMARY: Lipoxygenases are a family of enzymes involved in a variety of human diseases like inflammation, asthma, artherosclerosis and cancer. The lipoxygenases database (LOX-DB) aims to be a web accessible compendium of information in particular on the mammalian members of this multigene family. This resource includes molecular structures, reference data, tools for structural and computational analysis as well as links to related information maintained by others. The data can be retrieved by the use of various search options and analyzed applying publicly available visualization tools. AVAILABILITY: LOX-DB is available at http://www.dkfz-heidelberg.de/spec/lox-db/

Database Management Systems↗
PubMed2004

A survey of medical ethics education at U.S. and Canadian medical schools.

PURPOSE: To assess the format, content, method, and placement of medical ethics education in medical schools; the faculty and curricular resources and institutional structure and support of medical ethics; and the perceptions of ethics education among deans of medical education and medical ethics course directors at U.S. and Canadian medical schools. METHOD: Two questionnaires were mailed to 125 U.S. medical schools and 16 Canadian schools: one to be completed by the deans of medical education and one to be completed by the medical ethics course director. Descriptive statistics were used to compare responses. RESULTS: In all, 123 (87%) deans and 91 (64%) course directors responded, providing information about 91 schools (six Canadian). All responding institutions offered some formal instruction in medical ethics, and among these, 71 (78%) incorporated ethics into required preclinical courses. The primary pedagogic course structure was small-group discussion and the primary pedagogic method was case discussions. One-fifth of schools provided no funding for ethics teaching, and 47 (52%) did not fund curricular development in ethics. Institutions with a dedicated ethics faculty member were twice as likely to have a mandatory introductory ethics course (64% versus 32%, p <.05). The primary obstacles to ethics education were thought to be a lack of time in the curriculum, a lack of qualified teachers, and a lack of time in faculty schedules. CONCLUSIONS: Within a few decades the number of U.S. and Canadian medical schools requiring medical ethics has increased. Nevertheless, significant variation in the content, method, and timing of ethics education suggests consensus about curricular content and pedagogic methods remains lacking. Further progress in ethics education may depend on institutions' willingness to devote more curricular time and funding to medical ethics.

Canada↗