How we raise young children is one of today's most highly personalized and sharply politicized issues, in part because each of us can claim some level of "expertise." The debate has intensified as discoveries about our development-in the womb and in the first months and years-have reached the popular media. How can we use our burgeoning knowledge to assure the well-being of all young children, for their own sake as well as for the sake of our nation? Drawing from new findings, this book presents important conclusions about nature-versus-nurture, the impact of being born into a working family, the effect of politics on programs for children, the costs and benefits of intervention, and other issues. The committee issues a series of challenges to decision makers regarding the quality of child care, issues of racial and ethnic diversity, the integration of children's cognitive and emotional development, and more. Authoritative yet accessible, From Neurons to Neighborhoods presents the evidence about "brain wiring" and how kids learn to speak, think, and regulate their behavior. It examines the effect of the climate-family, child care, community-within which the child grows.

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From Neurons to Neighborhoods: The Science of Early Childhood Development

To determine whether the onset of myocardial infarction occurs randomly throughout the day, we analyzed the time of onset of pain in 2999 patients admitted with myocardial infarction. A marked circadian rhythm in the frequency of onset was detected, with a peak from 6 a.m. to noon (P<0.01). In 703 of the patients, the time of the first elevation in the plasma creatine kinase MB (CK-MB) level could be used to time the onset of myocardial infarction objectively. CK-MB—estimated timing confirmed the existence of a circadian rhythm, with a threefold increase in the frequency of onset of myocardial infarction at peak (9 a.m.) as compared with trough (11 p.m.) periods. The circadian rhythm was not detected in patients receiving beta-adrenergic blocking agents before myocardial infarction but was present in those not receiving such therapy. If coronary arteries become vulnerable to occlusion when the intima covering an atherosclerotic plaque is disrupted, the circadian timing of myocardial infarction ma...

Circadian variation in the frequency of onset of acute myocardial infarction

Bright artificial light suppressed nocturnal secretion of melatonin in six normal human subjects. Room light of less intensity, which is sufficient to suppress melatonin secretion in other mammals, failed to do so in humans. In contrast to the results of previous experiments in which ordinary room light was used, these findings establish that the human response to light is qualitatively similar to that of other mammals.

https://science.sciencemag.org/content/sci/210/4475/1267.full.pdf

Light Suppresses Melatonin Secretion in Humans

background Although sleep deprivation has been shown to impair neurobehavioral performance, few studies have measured its effects on medical errors. methods We conducted a prospective, randomized study comparing the rates of serious medical errors made by interns while they were working according to a traditional schedule with extended (24 hours or more) work shifts every other shift (an “every third night” call schedule) and while they were working according to an intervention schedule that eliminated extended work shifts and reduced the number of hours worked per week. Incidents were identified by means of a multidisciplinary, four-pronged approach that included direct, continuous observation. Two physicians who were unaware of the interns’ schedule assignments independently rated each incident. results During a total of 2203 patient-days involving 634 admissions, interns made 35.9 percent more serious medical errors during the traditional schedule than during the intervention schedule (136.0 vs. 100.1 per 1000 patient-days, P<0.001), including 56.6 percent more nonintercepted serious errors (P<0.001). The total rate of serious errors on the critical care units was 22.0 percent higher during the traditional schedule than during the intervention schedule (193.2 vs. 158.4 per 1000 patient-days, P<0.001). Interns made 20.8 percent more serious medication errors during the traditional schedule than during the intervention schedule (99.7 vs. 82.5 per 1000 patient-days, P = 0.03). Interns also made 5.6 times as many serious diagnostic errors during the traditional schedule as during the intervention schedule (18.6 vs. 3.3 per 1000 patientdays, P<0.001). conclusions Interns made substantially more serious medical errors when they worked frequent shifts of 24 hours or more than when they worked shorter shifts. Eliminating extended work shifts and reducing the number of hours interns work per week can reduce serious medical errors in the intensive care unit.

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Effect of reducing interns' work hours on serious medical errors in intensive care units.

Regulation of circadian period in humans was thought to differ from that of other species, with the period of the activity rhythm reported to range from 13 to 65 hours (median 25.2 hours) and the period of the body temperature rhythm reported to average 25 hours in adulthood, and to shorten with age. However, those observations were based on studies of humans exposed to light levels sufficient to confound circadian period estimation. Precise estimation of the periods of the endogenous circadian rhythms of melatonin, core body temperature, and cortisol in healthy young and older individuals living in carefully controlled lighting conditions has now revealed that the intrinsic period of the human circadian pacemaker averages 24.18 hours in both age groups, with a tight distribution consistent with other species. These findings have important implications for understanding the pathophysiology of disrupted sleep in older people.

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Stability, Precision, and Near-24-Hour Period of the Human Circadian Pacemaker

Two- to threefold variations in sleep length were observed in 12 subjects living on self-selected schedules in an environment free of time cues. The duration of polygraphically recorded sleep episodes was highly correlated with the circadian phase of the body temperature rhythm at bedtime and not with the length of prior wakefulness. Furthermore, the rate of REM (rapid eye movement) sleep accumulation , REM latency, bedtime selection, and self-rated alertness assessments were also correlated with the body temperature rhythm.

https://science.sciencemag.org/content/sci/210/4475/1264.full.pdf

Human sleep: its duration and organization depend on its circadian phase

Ten male subjects were studied for a total of 306 days on self-selected schedules Four of them developed bedrest-activity cycle period lengths very different from 24 hr (mean = 368 hr) despite the persistence of near-24-hr oscillations in other physiologic functions, including that of body temperature (mean = 246 hr) The percentage of sleep time spent in REM sleep varied significantly with the phase of that near-24-hr body temperature cycle The peak in REM sleep propensity (RSP) occurred on the rising slope of the average body temperature curve, coincident with the phase of peak sleep tendency This was associated with a significantly increased REM episode duration and shortened REM latency (including sleep-onset REM episodes), but without a significant change in the REM-NREM cycle length We conclude that there is an endogenous circadian rhythm of REM sleep propensity which is closely coupled to the body temperature rhythm and is capable of free-running with a period different from both 24 hr and the average period of the sleep-wake cycle

Timing of REM sleep is coupled to the circadian rhythm of body temperature in man.

was done by examining the correlation of life style, stress, and blood pressure within the categories of social support. Social support in terms of multiple matings and siblings in the community was protective of blood pressure. Persons with more social support remained unaffected by stress (as far as blood pressure was concerned) and those with high stress and with little social support had significantly higher blood pressure (multiple matings p < 0.05 and sibling p < 0.001). This is a well-written behavioral medical study carried out in the field with limited resources. It constitutes an effective pilot study pointing the way to future work. Despite an outward appearance of disorganization, i.e., disaster, migration, and social change, the idiosyncratic family and social system of St. Lucia can provide strong social support offsetting the lack of economic resources. The author generalizes that the "staying power" of a population depends on its ability to evolve stable institutional solutions meeting physical needs and demands of self-esteem. One expression of the grave economic pressure in these Caribbean islands may be the extraordinary incidence of high blood pressure, as has also been recorded for St. Kitts. The author presents challenging data suggesting that the exact structure of the social support system and the social and cultural resources unique to that particular society are of primary importance in determining the people's adaptation as measured by blood pressure. This book is well organized and has a good bibliography and index. It will interest those concerned with new developments in behavorial medicine.

The Clocks That Time Us: Physiology of the Circadian Timing System

We report here the development of a brief drug-free rescheduling treatment ("chronotherapy") for Delayed Sleep Phase (DSP) insomnia, a syndrome characterized by sleep-onset insomnia with difficulty in morning awakening. We postulated that patients with DSP insomnia had an inadequate capacity to achieve phase advance shifts of the circadian pacemaker which times the sleep-wake cycle. Chronotherapy was therefore designed to reset these patients' biological clocks by the phase delay route. This single 5-6 day treatment was tested in 5 patients with a 4-15 year history of DSP insomnia. All 5 patients reported a lasting resolution of their symptoms substantiated by systematic long-term self-reports and objective polygraphic recording before and after treatment (average follow-up of 260 days; range, 42-910 days). The average sleep onset advanced from 4:50 a.m. before treatment to 12:20 a.m. afterwards, and wake times advanced from 1:00 p.m. to 755 a.m. (for both, p less than 0.001), with no reduction in sleep efficiency. As a result, all 5 patients were able to end their chronic dependence on hypnotic medications.

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Chronotherapy: resetting the circadian clocks of patients with delayed sleep phase insomnia.

THE study of circadian (approximately 24-hour) rhythms has within the past decade evolved from a biologic curiosity to a science with enormous implications for clinical medicine The concurrent mat

Martin C. Moore-Ede

Papers

Human sleep: its duration and organization depend on its circadian phase

Timing of REM sleep is coupled to the circadian rhythm of body temperature in man.

The Clocks That Time Us: Physiology of the Circadian Timing System

Chronotherapy: resetting the circadian clocks of patients with delayed sleep phase insomnia.

Circadian timekeeping in health and disease. Part 1. Basic properties of circadian pacemakers.