A dynamical model exploring sensory integration in the insect central complex substructures.

It is imperative that an animal has the ability to contextually integrate received sensory information to formulate appropriate behavioral responses. Determining a body heading based on a multitude of ego-motion cues and visual landmarks is an example of such a task that requires this context dependent integration. The work presented here simulates a sensory integrator in the insect brain called the central complex (CX). Based on the architecture of the CX, we assembled a dynamical neural simulation of two structures called the protocerebral bridge (PB) and the ellipsoid body (EB). Using non-spiking neuronal dynamics, our simulation was able to recreate in vivo neuronal behavior such as correlating body rotation direction and speed to activity bumps within the EB as well as updating the believed heading with quick secondary system updates. With this model, we performed sensitivity analysis of certain neuronal parameters as a possible means to control multi-system gains during sensory integration. We found that modulation of synapses in the memory network and EB inhibition are two possible mechanisms in which a sensory system could affect the memory stability and gain of another input, respectively. This model serves as an exploration in network design for integrating simultaneous idiothetic and allothetic cues in the task of body tracking and determining contextually dependent behavioral outputs.

Benthic bioaccumulation and bioavailability of polybrominated diphenyl ethers from surficial Lake Ontario sediments near Rochester, New York, USA.

Polybrominated diphenyl ethers in Lake Ontario watershed sediments were assessed for benthic bioavailability through the use of biota-sediment accumulation factors. Sediments from lake and Rochester Harbor (lower Genesee River) areas were investigated. Congeners 47, 66, 85, 99 and 100 were detected in tissues of the oligochaete Lumbriculus variegatus. Biota-sediment accumulation factors ranged from 3.95 (congener 154) to 19.5 (congener 28) and were higher at the Lake Ontario area. The lower biota-sediment accumulation factors for the Rochester Harbor sediment may result from a higher fraction of black carbon generally expected in highly urbanized rivers. Degree of bromination may reduce bioavailability.

A subtle governance: 'soft' medical leadership in English primary care.

In many countries governments are recruiting the medical profession into a more active, transparent regulation of clinical practice. Consequently the medical profession adapts the ways it regulates itself and its relationship to health system managers changes. This paper uses empirical research in English Primary Care Groups (PCGs) and Primary Care Trusts (PCTs) to assess the value of Courpasson's concept of soft bureaucracy as a conceptualisation of these changes. Clinical governance in PCGs and PCTs displays important parallels with governance in soft bureaucracies, but the concept of soft bureaucracy requires modification to make it more applicable to general practice. In English primary care, governance over rank-and-file doctors is exercised by local professional leaders rather than general managers, harnessing their colleagues' perception of threats to professional autonomy and self-regulation rather than fears of competition as the means of 'soft coercion'.

Implementing clinical governance in English primary care groups/trusts: reconciling quality improvement and quality assurance.

OBJECTIVES: To investigate the concept of clinical governance being advocated by primary care groups/trusts (PCG/Ts), approaches being used to implement clinical governance, and potential barriers to its successful implementation in primary care. DESIGN: Qualitative case studies using semi-structured interviews and documentation review. SETTING: Twelve purposively sampled PCG/Ts in England. PARTICIPANTS: Fifty senior staff including chief executives, clinical governance leads, mental health leads, and lay board members. MAIN OUTCOME MEASURES: Participants' perceptions of the role of clinical governance in PCG/Ts. RESULTS: PCG/Ts recognise that the successful implementation of clinical governance in general practice will require cultural as well as organisational changes, and the support of practices. They are focusing their energies on supporting practices and getting them involved in quality improvement activities. These activities include, but move beyond, conventional approaches to quality assessment (audit, incentives) to incorporate approaches which emphasise corporate and shared learning. PCG/Ts are also engaged in setting up systems for monitoring quality and for dealing with poor performance. Barriers include structural barriers (weak contractual levers to influence general practices), resource barriers (perceived lack of staff or money), and cultural barriers (suspicion by practice staff or problems overcoming the perceived blame culture associated with quality assessment). CONCLUSION: PCG/Ts are focusing on setting up systems for implementing clinical governance which seek to emphasise developmental and supportive approaches which will engage health professionals. Progress is intentionally incremental but formidable challenges lie ahead, not least reconciling the dual role of supporting practices while monitoring (and dealing with poor) performance.

A 'Third Way' for lay involvement: what evidence so far?

AIMS AND OBJECTIVES: This article considers evidence regarding lay involvement in the NHS, following the White Paper's commitment to rebuild public confidence in an NHS 'accountable to patients and open to the public and shaped by their views'. It looks at two aspects of lay involvement: the lay board member's involvement in primary care group (PCG) decision-making and the engagement of the PCG with the wider public. METHODS: The paper analyses data from the first sweep of the annual Tracker Survey of a sample of PCGs in England, led by the National Primary Care Research and Development Centre in collaboration with the King's Fund between September and December 1999. It draws specifically from the postal questionnaires sent to lay members. Firstly, however, it contextualizes this data by reviewing the history of lay involvement before 1997 in the NHS and particularly in primary care. CONCLUSIONS: The paper concludes that, during the first 6 months of their operation, the lay voice was faintly heard in PCGs. The lay member's role in decision-making at board-level was peripheral. The majority rated their involvement in key aspects of decision-making as low and their influence on decision-making below that of other board members including the Chief Officer, the chair and the GP board members. Beyond the arena of the board, what little contact there was with the lay voice has taken the shape of informing rather than consulting. Mitigating factors include the early stage at which the survey was completed and the lack of precedents for lay involvement in primary care in a broad sense on which PCGs can draw.

Fitting contraceptive diaphragms: can laywomen provide quality training for doctors?

OBJECTIVE: To test the feasibility of training laywomen as professional patients to teach doctors to fit the contraceptive diaphragm. DESIGN: Semi-structured interviews with instructing doctors and questionnaires to DFFP trainees. These documented current teaching practice and the acceptability of professional patients. The Delphi technique was used to establish a curriculum for the professional patients' training programme. RESULTS: The results show that there is currently a lack of standardisation in teaching methods and content with respect to diaphragm fitting. All instructing doctors and DFFP trainees involved had experienced difficulties in recruiting women for training, and the majority would be happy to work with professional patients. After three rounds of the Delphi procedure, consensus was reached and a curriculum developed. Five women were recruited on to a training programme, and four successfully completed it. CONCLUSION: Lack of standardisation and difficulty recruiting patients are current problems when training doctors to fit diaphragms. Our study shows that the use of professional patients would be acceptable to both DFFP trainees and instructing doctors, and that it is possible to recruit and train women for this purpose.

Decreased health care use among patients with silent myocardial ischemia: support for a generalized rather than cardiac-specific silence.

OBJECTIVE: The absence of angina among patients with silent myocardial ischemia (SMI) may be a cardiac phenomenon or may reflect a generalized lack of bodily awareness and symptom reporting. We tested the hypothesis that the silence is generalized, and, therefore, that patients with SMI would make fewer health care visits for noncardiac/chest-pain problems than patients with symptomatic ischemia. METHODS: We counted all out-patient visits to our medical system for the prior 18 months for 95 patients who demonstrated ischemia during treadmill exercise testing and subsequent nuclear scanning: 62 of the patients had SMI during exercise, and 33 of the patients had symptomatic ischemia. RESULTS: Patients with SMI made were significantly less likely to have sought emergency care or primary care and had significantly fewer primary care visits than patients with symptomatic ischemia. Group differences remained after controlling for demographics and health status variables. The two groups did not differ on utilization of specialty care. CONCLUSION: The reduced use of emergency and primary care among patients with SMI suggests that they have a generalized rather than cardiac-specific reduction in somatic awareness and/or symptom reporting.

Prevalence and correlates of preventive care among adults with diabetes in Kansas.

OBJECTIVE: To assess the prevalence and correlates of recommended preventive care among adults with diabetes in Kansas. RESEARCH DESIGN AND METHODS: A cross-sectional telephone survey was conducted among a sample of adults (> or = 18 years of age) with self-reported diabetes. Recommended preventive care was defined based on four criteria: number of health-care provider (HCP) visits per year (> or = 4 for insulin users and > or = 2 for nonusers), number of foot examinations per year (> or = 4 for insulin users and > or = 2 for nonusers), an annual dilated eye examination, and a blood pressure measurement in the past 6 months. RESULTS: The mean age of the 640 respondents was 61 years, 58% were women, and 86% were white. In the preceding year, 62% of respondents reported the appropriate number of visits to a HCP 27% the appropriate number of foot examinations, 65% an annual dilated eye examination, and 89% a blood pressure measurement in the preceding 6 months. Only 17% (95% CI 14-20) met all four criteria for recommended care. The adjusted odds of receiving recommended care were higher for males than for females (odds ratio [OR] 1.6; 95% CI 1.1-2.5), higher for people whose HCP scheduled follow-up appointments than for those who self-initiated follow-up (OR 2.7; 95% CI 1.6-4.8), and higher for former smokers than for current smokers (OR 3.1; 95% CI 1.6-6.9). CONCLUSIONS: Preventive care for people with diabetes is not being delivered in compliance with current guidelines, especially for women and current smokers. Scheduling follow-up visits for patients, targeting certain high-risk populations, and developing protocols to improve foot care may be effective in improving care.

Primary care groups and NHS rationing: implications of the Child B Case.

Implementing The new NHS and the 1997 NHS (Primary Care) Act will gradually extend cash-limiting into primary health care, especially general practice. UK policy-makers have avoided providing clear, unambivalent direction about how to 'ration' NHS resources. The 'Child B' case became an epitome of public debate about NHS rationing. Among many other decision-making processes which occurred, Cambridge and Huntingdon Health Authority applied an ethical code to this rationing decision. Using new data this paper analyses the rationing criteria NHS managers and clinicians used at local level in the Child B case; and the organisational structures which confronted them with such decisions. Primary Care Groups are likely to confront similar rationing decisions in respect of 'gate-kept' NHS services. However, such rationing processes are not so easily transposed to open-access services such as general practice. NHS rationing decisions, especially in PCGs, will require a much more specific ethical code than hitherto used.

The increased need for a permanent pacemaker after reoperative cardiac surgery.

OBJECTIVE: The requirement for permanent pacemaker implantation after most initial cardiac surgical procedures generally is less than 3%. To identify the incidence and factors related to permanent pacemaker need after repeat cardiac surgery, we retrospectively studied 558 consecutive patients undergoing at least one repeat cardiac operation. METHOD: Univariable and multivariable analyses of comorbidity, preoperative catheterization values, and operative data were performed to identify factors related to pacemaker implantation. RESULTS: In this group, 54 patients (9.7%) required a permanent pacemaker. A multivariable model showed a relationship between a permanent pacemaker and tricuspid valve replacement/annuloplasty associated with aortic/mitral valve replacement, preoperative endocarditis, increasing number of reoperations, the degree of hypothermia during cardiopulmonary bypass, and advanced age. Additional univariable predictors of pacemaker need included multiple valve replacement, increased cardiopulmonary bypass and aortic crossclamp times, and aortic valve replacement. Over 90% of patients who have or have not received permanent pacemaker implantation were in New York Heart Association class I to II, with a mean follow-up time of 6 years. Kaplan-Meier survival curves were statistically similar for both groups at 5 and 10 years after the operation. CONCLUSION: Permanent pacemaker implantation was required in 9.7% of patients undergoing repeat cardiac surgery. This represented approximately a fourfold increase compared with similar primary operations reported in other series. Factors strongly related to this need included valve replacement, preoperative endocarditis, number of reoperations, advanced age, and degree of hypothermia during cardiopulmonary bypass. The need for a permanent pacemaker after reoperations did not result in significant long-term impairment of functional status or longevity compared with those who did not require a permanent pacemaker.

Psychosocial factors related to noncardiac chest pain during treadmill exercise.

The authors examined historical, concurrent, and potentially secondary psychosocial problems related to noncardiac chest pain during exercise. The patients reporting chest pain during treadmill testing but who lacked cardiac ischemia (determined via nuclear scanning) were compared with the patients having both ischemia and chest pain, and with patients having neither ischemia nor chest pain. The noncardiac chest pain patients had the highest levels of 1) parental divorce and personal psychiatric treatment; 2) current depression, somatic awareness, and anger control; and 3) negative attitudes toward the health care system. The findings suggest that psychosocial problems predate, coexist with, and may result from noncardiac chest pain.

Correlates of unrecognized acute myocardial infarction detected via perfusion imaging.

Research using the electrocardiogram (ECG) indicates that about 1/3 of acute myocardial infarctions (AMIs) are unrecognized. To date, no studies of unrecognized AMIs have employed perfusion imaging, although it is more sensitive than the ECG and provides more information about infarct characteristics, such as size and location. In this study, 82 of 258 consecutive patients (31.8%) undergoing exercise testing with technetium-99m sestamibi perfusion imaging had fixed, nonartifactual perfusion defects, suggesting AMI. These patients were interviewed regarding their recognition of AMI; 27 patients (32.9%) had unrecognized AMI. Unrecognized AMI was significantly associated with (1) smaller infarcts, (2) infarcts not in the apical or septal regions, (3) diabetes mellitus, (4) lack of angina, (5) a negative family history for cardiac disease, and (6) being African-American. Many of these variables were significantly intercorrelated, and in multivariate analysis, unrecognized AMI remained significantly predicted by a smaller infarct and lack of angina. This study suggests that the incidence of unrecognized AMI detected via perfusion imaging on a clinic population is similar to that detected via electrocardiographic studies on community samples. This study also replicates prior findings of the medical history and demographic correlates of unrecognized AMI, and indicates that infarct size and location are also associated with unrecognized AMI.

Silent versus symptomatic myocardial ischemia: the role of psychological and medical factors.

This study examined the relationship of psychological, cardiac, and general medical history factors to asymptomatic (silent) versus symptomatic myocardial ischemia among 102 patients who underwent treadmill exercise testing and had perfusion imaging indicative of ischemia. During exercise, 68 patients exhibited silent ischemia, and 34 experienced chest pain. Patients with silent ischemia rated higher than symptomatic patients on anger control, externally oriented thinking, and somatosensory amplification, but did not differ on depression or global alexithymia. Anger control and externally oriented thinking remained independent correlates in multivariate analysis, controlling for demographic and cardiac factors. Groups did not differ on general medical or cardiac variables. Thus, this study suggests that affective and cognitive factors, but not biomedical factors, are associated with silent, as opposed to symptomatic, ischemia during exercise testing.

Paradoxes of GP fundholding: contracting for community health services in the British National Health Service.

The expansion of GP fundholding (GPFH) is central to the British government's attempt to maintain the revolution under way in the National Health Service (NHS). Evaluations of the NHS reforms have portrayed GPFH as an important mechanism for competition, and GPFH's bargaining power is reported to have secured significant changes in health service provision. However, these developments have been acknowledged to be less applicable in relation to community health services (CHS) than acute hospital services. On the basis of case studies of the process of contracting for CHS, GPFHs are shown to display ambivalent and sometimes contradictory views which have to be related to broader policy developments in general practice and primary care. Although this paper focuses on the British situation, many of the issues raised by reforms in primary and community health services have implications for developments in other Western health care systems.