Roberto Refinetti

Bio: Roberto Refinetti is an academic researcher from Boise State University. The author has contributed to research in topics: Circadian rhythm & Thermoregulation. The author has an hindex of 32, co-authored 151 publications receiving 4296 citations. Previous affiliations of Roberto Refinetti include University of South Carolina & University of Virginia.

Procedures for numerical analysis of circadian rhythms.

Abstract: This article reviews various procedures used in the analysis of circadian rhythms at the populational, organismal, cellular and molecular levels. The procedures range from visual inspection of time plots and actograms to several mathematical methods of time series analysis. Computational steps are described in some detail, and additional bibliographic resources and computer programs are listed.

The circadian rhythm of body temperature.

Abstract: This article reviews the literature on the circadian rhythm of body temperature. It starts with a description of the typical pattern of oscillation under standard laboratory conditions, with consideration being given to intra- and interspecies differences. It then addresses the influence of environmental factors (principally ambient temperature and food availability) and biological factors (including locomotor activity, maturation and aging, body size, and reproductive state). A discussion of the interplay of rhythmicity and homeostasis (including both regulatory and heat-exchange processes) is followed by concluding remarks.

Daily and estrous rhythmicity of body temperature in domestic cattle

Abstract: Background Rhythmicity in core body temperature has been extensively studied in humans and laboratory animals but much less in farm animals. Extending the study of rhythmicity of body temperature to farm animals is important not only from a comparative perspective but also from an economic perspective, as greater knowledge of this process can lead to improvements in livestock production practices. In this study in cattle, we investigated the maturation of the daily rhythm of body temperature in newborn calves, characterized the parameters of the daily rhythm in young cows, and studied the oscillation in body temperature associated with the estrous cycle in adult cows.

Restricted feeding uncouples circadian oscillators in peripheral tissues from the central pacemaker in the suprachiasmatic nucleus

Abstract: In mammals, circadian oscillators exist not only in the suprachiasmatic nucleus, which harbors the central pacemaker, but also in most peripheral tissues. It is believed that the SCN clock entrains the phase of peripheral clocks via chemical cues, such as rhythmically secreted hormones. Here we show that temporal feeding restriction under light–dark or dark–dark conditions can change the phase of circadian gene expression in peripheral cell types by up to 12 h while leaving the phase of cyclic gene expression in the SCN unaffected. Hence, changes in metabolism can lead to an uncoupling of peripheral oscillators from the central pacemaker. Sudden large changes in feeding time, similar to abrupt changes in the photoperiod, reset the phase of rhythmic gene expression gradually and are thus likely to act through a clock-dependent mechanism. Food-induced phase resetting proceeds faster in liver than in kidney, heart, or pancreas, but after 1 wk of daytime feeding, the phases of circadian gene expression are similar in all examined peripheral tissues.

The Social Organization of Sexuality: Sexual Practices in the United States

Abstract: This survey of sexual practices in the United States has been combed by the media for items of interest to the public: monogamous sex is much more widespread in this country than has been thought; infidelity is less frequent than presumed; vaginal intercourse is the defining experience of heterosexual behavior; watching one's partner undress is stimulating to many people; married couples have more sex than single people (unmarried, cohabiting couples have the most sex of all); the majority of couples experience sex twice a week to several times a month; 2.8% of men identify themselves as homosexual and 1.4% of women do so, but a higher percentage of people consider a same-gender experience to have some appeal; 75% of men always experience orgasm compared with 28.6% of women, but more nearly equal numbers of men and women declare themselves satisfied with their sexual experiences. The book is, in fact, a

Central and Peripheral Circadian Clocks in Mammals

Abstract: The circadian system of mammals is composed of a hierarchy of oscillators that function at the cellular, tissue, and systems levels. A common molecular mechanism underlies the cell-autonomous circadian oscillator throughout the body, yet this clock system is adapted to different functional contexts. In the central suprachiasmatic nucleus (SCN) of the hypothalamus, a coupled population of neuronal circadian oscillators acts as a master pacemaker for the organism to drive rhythms in activity and rest, feeding, body temperature, and hormones. Coupling within the SCN network confers robustness to the SCN pacemaker, which in turn provides stability to the overall temporal architecture of the organism. Throughout the majority of the cells in the body, cell-autonomous circadian clocks are intimately enmeshed within metabolic pathways. Thus, an emerging view for the adaptive significance of circadian clocks is their fundamental role in orchestrating metabolism.

The Analysis of Time Series: An Introduction

Abstract: The Analysis of Time Series: An Introduction, 4th edn. By C. Chatfield. ISBN 0 412 31820 2. Chapman and Hall, London, 1989. 242 pp. £13.50.

Molecular components of the mammalian circadian clock

Abstract: Mammals synchronize their circadian activity primarily to the cycles of light and darkness in the environment. This is achieved by ocular photoreception relaying signals to the suprachiasmatic nucleus (SCN) in the hypothalamus. Signals from the SCN cause the synchronization of independent circadian clocks throughout the body to appropriate phases. Signals that can entrain these peripheral clocks include humoral signals, metabolic factors, and body temperature. At the level of individual tissues, thousands of genes are brought to unique phases through the actions of a local transcription/translation-based feedback oscillator and systemic cues. In this molecular clock, the proteins CLOCK and BMAL1 cause the transcription of genes which ultimately feedback and inhibit CLOCK and BMAL1 transcriptional activity. Finally, there are also other molecular circadian oscillators which can act independently of the transcription-based clock in all species which have been tested.