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While our understanding of the way single neurons process chromatic stimuli in the early visual pathway has advanced significantly in recent years, we do not yet know how these cells interact to form stable representations of hue. Drawing on physiological studies, we offer a dynamical model of how the primary visual cortex tunes for color, hinged on intracortical interactions and emergent network effects. After detailing the evolution of network activity through analytical and numerical approaches, we discuss the effects of the model's cortical parameters on the selectivity of the tuning curves. In particular, we explore the role of the model's thresholding nonlinearity in enhancing hue selectivity by expanding the region of stability, allowing for the precise encoding of chromatic stimuli in early vision. Finally, in the absence of a stimulus, the model is capable of explaining hallucinatory color perception via a Turing-like mechanism of biological pattern formation., (© 2023 Massachusetts Institute of Technology.)

Background: Neonatal mortality (death within 0-28 d of life) in Kenya is high despite strong evidence that newborn care recommendations save lives. In public healthcare facilities, nurses counsel caregivers on term newborn care, but knowledge about the content and quality of nurses' recommendations is limited., Purpose: To describe the term newborn care recommendations provided at a tertiary-level, public referral hospital in Western Kenya, how they were provided, and related content taught at a university nursing school., Methods: A rapid, focused ethnographic assessment, guided by the culture care theory, using stratified purposive sampling yielded 240 hours of participant observation, 24 interviews, 34 relevant documents, and 268 pages of field notes. Data were organized using NVivo software and key findings identified using applied thematic analysis., Results: Themes reflect recommendations for exclusive breastfeeding, warmth, cord care, follow-up examinations, and immunizations, which were provided orally in Kiswahili and some on a written English discharge summary. Select danger sign recommendations were also provided orally, if needed. Some recommendations conflicted with other providers' guidance. More recommendations for maternal care were provided than for newborn care., Implications for Practice: There is need for improved consistency in content and provision of recommendations before discharge. Findings should be used to inform teaching, clinical, and administrative processes to address practice competency and improve nursing care quality., Implications for Research: Larger studies are needed to determine whether evidence-based recommendations are provided consistently across facilities and other populations, such as community-born and premature newborns, who also experience high rates of neonatal mortality in Kenya., (Copyright © 2021 by The National Association of Neonatal Nurses.)

Background: Maternal mortality is a critical global public health concern, especially in low- and middle-income countries in sub-Saharan Africa. Although maternal mortality rates have declined by approximately 39% in sub-Saharan Africa over the last decade, maternal deaths during pregnancy and in childbirth remain high. Interventions to improve mothers' use of skilled birth attendants may decrease maternal mortality in sub-Saharan African countries., Objectives: This systematic literature review examines components of and evaluates the effectiveness of interventions to increase use of skilled birth attendants in sub-Saharan Africa., Methods: Guided by the PRISMA model for systematic reviews, the PubMed, Web of Science, and CIHNAL databases were searched for studies from years 2003 through June 2020., Results: The 28 articles included in this review reported on interventions incorporating community health workers, phone or text messages, implementation of community-level initiatives, free health care, cash incentives, an international multi-disciplinary volunteer team, and a group home for pregnant women, which improved use of skilled birth attendants to varying degrees. Only one study reported improved outcomes with the use of community health workers. All of the interventions using text messages increased hospital utilization for births., Conclusions: Interventions implemented in sub-Saharan Africa hold promise for improving maternal health. Multi-level interventions that involve community members and local leaders can help address the multi-faceted issue of poor maternal health outcomes and mortality. Interventions should focus on capacity building and on training and mentoring of formally-trained health care providers and community health workers in order to expand access., Competing Interests: Declaration of Competing Interest None., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Aims: To (1) identify formal and informal healthcare provider knowledge and counselling on newborn care recommendations; (2) identify care guidelines used; and (3) determine healthcare provider training regarding recommendations., Background: In sub-Saharan Africa, many newborn deaths occur in the community between days two to 42 of life., Introduction: Formal and informal healthcare providers, including nurses and community health workers, counsel newborn caregivers but little is known about their recommendations., Methods: Integrative review of studies conducted 2000-2018 after search of PubMed, CINAHL, Embase, and African healthcare journals. Study quality was assessed and findings synthesized., Findings: Twelve qualitative, quantitative, or mixed-methods studies (quality good to poor) from seven countries were included. Eleven reported on one to three recommendations; one study reported on eight recommendations. Knowledge or counselling on feeding, cord care, recognizing illness, referrals, informal treatment, home visits, immunizations, follow-up examinations, thermal care, low birthweight, and bed net usage were reported. Formal healthcare providers gave recommendations in only two studies. Four studies documented use of guidelines. Six studies reported on training., Discussion: Studies were primarily descriptive, limiting quality. Feeding and cord care recommendations were prioritized. Care guidelines were underutilized. Additional training on recommendations is needed. These findings regarding healthcare providers align with other regions with high neonatal mortality., Conclusion: Research is needed to improve and sustain knowledge, counselling, and guideline usage among providers to address neonatal mortality., Implications for Nursing: The unique role of nurses to promote newborn health appears under-researched. Nurse professionalization and specialization may contribute to sustained knowledge of and counselling on newborn recommendations., Implications for Health Policy: As countries adopt universal health care, policies that enable formal providers to encourage maternal-newborn engagement in newborn health promotion before transition to the community are needed. Collaboration between formal and informal providers may improve dissemination of recommendations and contribute to gains in newborn health., (© 2019 International Council of Nurses.)

A five-year follow-up of 18 403 male British civil servants between the age of 40 and 64, who had been the subject of an earlier clinical survey found 277 deaths from coronary heart-disease (C.H.D.). After adjusting for age, current cigarette smoking, systolic and diastolic blood-pressure, and blood-cholesterol were shown to be related to both the prevalence of one or more indices of cardiac ischaemia and to the risk of cardiac death. Neither blood-glucose two hours after a 50 g load nor weight/height showed any such simple linear association with mortality. Multivariate analysis confirmed that the main risk factors were independently related to cardiac morbidity and mortality. Irrespective of blood-pressure or plasma-cholesterol, current cigarette smokers thus had a higher risk of C.H.D. death than those not smoking cigarettes.

A survey of the respiratory symptoms and smoking habits of a population of 20-year-olds- followed since birth- was repeated when they reached the age of 25. The association of cough prevalence with current smoking habits and with lower respiratory tract illness in childhood found in the survey at age 20 was confirmed and in each instance appears to have increased in strength over the 5 years. At age 25, however, the prevalence of cough was associated at a statistically significant level with fathers' occupation; and this association with social class of origin could not be explained by persisting differences in social status based on the educational levels attained by early adult life. The association with exposure to air pollution in childhood, although more obvious than before, could be due to chance. The prevalence of cough increased between the ages of 20 and 25 among those who smoked throughout or who started to smoke during this period. It declined for those who never smoked and for those who were smoking at 20 but had given up by 25. The implications of these changing patterns of respiratory disease behaviour at a crucial stage between adolescence and adult life are briefly discussed.

A total of 18 403 men aged between 40 and 64 years took part in a screening examination which included a self-administered version of the London School of Hygiene questionnaire on chest pain and intermittent claudication. The yield of positives for "angina" and "history of possible infarction" was about twice as high as with interviewers, but the positive groups obtained by the two techniques differed little in their association with electrocardiographic findings or in their ability to predict five-year coronary mortality risk. This risk ranged from 0-9% in men negative to questionnaire and electrocardiograms (ECG), to 4-3% for those with positive ECG but no symptoms, 4-5% for those with angina and negative ECG, up to 16% for those with angina and positive ECG. The self-administered version of this questionnaire provides a simple and convenient means of identifying individuals with a high risk of major coronary heart disease.

A screening examination including an electrocardiogram (limb leads only) coded by the Minnesota Code, using rigorous quality control was done on 18 403 male civil servants aged 40 to 64. The association of the findings with coronary heart disease has been tested in relation to age trends, symptomatic history, and coronary heart disease mortality rates in the ensuing five years. The results were positive for Q waves, left axis deviation, ST depression, and T wave changes (including minor T wave items as an isolated finding), ventricular conduction defects, and atrial fibrillation; but they were generally unimpressive for increased R amplitude and for lengthening or shortening of the PR interval, QT interval duration, premature beats, and extremes of heart rate. The prognosis of specific electrocardiographic findings discovered at screening is quite different from when they arise in clinical practice. Among the 6 per cent of men in this study with patterns suggesting ischaemia, the subsequent coronary heart disease mortality was little more than 1 per cent per year; and among those who were symptom free it was even less.

The design of the British-Norwegian Migrant Study afforded a unique opportunity for comparing in a large sample certain items of information on the same individual, as reported by himself some time before death, with the responses on the same points given after his death in a questionnaire addressed to his next-of-kin. This paper describes a comparison of the degree of agreement between these two methods of obtaining data and draws attention to possible sources and directions of bias involved in the use of information supplied after death by the next-of-kin. Validity, as measured by agreement with the subject's own replies, depends in part on the topic and nature of the information required and on the population included in the survey. A built-in check, such as that incorporated in the British-Norwegian Study, confers the advantage that such biases can be identified and the numerical effect of adjusting for them assessed with some confidence.

Mortality follow-up is now complete for 5 years in the 18 403 male civil servants aged 40-64 who were examined between 1967-69 in the Whitehall Study of British civil servants. During this period, 277 of them died of coronary heart-disease (C.H.D.); half of these deaths were in subjects in whom the findings at initial screening had suggested early myocardial ischaemia (angina or history of possible infarction according to standard questionnaire, or electrocardiographic evidence of ischaemia). The finding of suspect ischaemia had greater predictive power than the "primary" coronary risk factors, from which it was generally independent. At each level of the primary risk factors, the risk of death from C.H.D. was much greater in the presence of suspect ischaemia; and, with the possible exceptions of glucose tolerance and physical activity, the main risk factors still operated even at the stage of early ischaemia. These findings have implications for future studies of the effects of intervention.

The relationship between blood pressure and the blood sugar concentration measured two hours after a 50 g oral glucose load has been examined in two population surveys-the Whitehall and Bedford Surveys. In the Whitehall Survey, which was conducted in men above the age of 40, there was a positive, significant correlation between blood sugar and blood pressure (systolic and diastolic) which was independent of common associations with age, body mass index (BMI) and heart rate. In the Bedford Survey, systolic blood pressures were significantly higher in newly detected diabetics and borderline diabetics, both men and women, than in normoglycaemic controls after adjustment of blood pressures for age and BMI. However, in the stratified random sample of the cooperating Bedford population, only amongst women was the blood sugar significantly and independently correlated with the systolic blood pressure. Evidence is presented and discussed that autonomic, neurohumoral factors may play some part in the pathogenesis of maturity onset diabetes.