bluuebunny/crossref_metadata_2025 huggingface dataset:
Annual Rhythm of Human Reproduction: I. Biology, Sociology, or Both?
Authors: Roenneberg Till , Aschof Jürgen
Published: March 2007

The annual rhythm of human reproduction was analyzed on the basis of more than 3000 years of monthly birth rates covering 166 regions of the globe. The following variables were used to characterize the annual rhythm of human conception (birth minus 9 months): amplitude, phase of maximum and minimum, phase and length of the time span when rates are above the annual mean (α), and the steepest upward slope (δmax) of the curve fitted to the rates. The waveform of the annual rhythm is characteristic for geographical regions (e.g., unimodal or bimodal) and persists as such for many years. In most countries, the onset of α coincides with δ max and lies close to the spring equinox. This phase of the rhythm is the most stable over time. In many populations, the rhythm has changed in recent years, specifically in amplitude and phase. The phase of the rhythm depends on latitude, with a 6-month difference between the Northern and Southern Hemispheres. The latitudinal distribution of amplitudes is less systematic. In spite of the many social influences on timing of conceptions, we conclude that the seasonal component in human reproduction is based on biological factors.
The Quail's Eye: A Biological Clock
Authors: Underwood Herbert , Barrett R. Keith , Siopes Thomas
Published: March 2007

The site (intraocular vs. extraocular) of the biological clock driving a rhythm in melatonin content in the eyes of Japanese quail was investigated by alternately patching the left and right eyes of individual birds, otherwise held in constant light, for 12-hr periods. This patching protocol, therefore, exposed each eye to a light-dark cycle (LD 12:12) 180° (12 hr) out of phase with the LD cycle experienced by the other eye. The optic nerves to both eyes were transected prior to initiating the patching protocol. The ocular melatonin rhythm (OMR) of the left eyes of quail could be entrained by this procedure 180° out of phase with the rhythm expressed by the right eyes. Since optic nerve section would have deprived any putative extraocular clocks of photic entrainment information, the results show conclusively that the clock driving the OMR is located within the eye itself. In addition, the OMR of Japanese quail is remarkably unaffected by removing two potential neural inputs to the eye (sympathetic innervation from the superior cervical ganglia, and input from the isthmo-optic nucleus of the midbrain); this suggests that these inputs are not required to maintain the OMR. Finally, the clock driving the OMR of one eye does not appear to be coupled to the clock driving the OMR in the other eye, since permanently patching one eye abolished the ability of the patched eye to re-entrain to an 8-hr shift in the phase of an LD 12:12 cycle, whereas the exposed eye rapidly re-entrained to the phase-shifted cycle.
Effects of Daily Schedules of Forced Activity on Free-Running Rhythms in the Rat
Authors: Mistlberger R.E.
Published: March 2007

Circadian rhythms of hamsters can be phase-shifted or entrained by single or daily sessions of induced wheel running. In contrast, observations of rats under restricted-feeding schedules suggest that their free-running rhythms are not readily entrainable by a daily bout of intense activity. A formal test of this idea was made by subjecting rats to daily 2-hr or 3-hr sessions of forced treadmill activity. None of 18 rats entrained to a daily treadmill schedule when tested in constant dim light, but 1 of 16 did entrain when tested after blinding, when the period of its free-running activity rhythm was very close to the period of the treadmill schedule and when the onset of its daily active phase overlapped with the treadmill sessions. These conditions were recreated in a final group of eight rats; the rats were trained in a light-dark cycle, blinded, and subjected to a treadmill schedule with a period of 23.91 hr that was initiated at the onset of the rats' active phase on day 1. Six of these rats entrained. The mechanism for entrainment by activity schedules clearly exists in rats, but the conditions under which this occurs are highly constrained, suggesting that activity is a very weak zeitgeber in this species. It is argued that the evolution of functionally separable food- and light-entrainable oscillators in the rat demands a very low sensitivity to feedback effects of activity.
Evidence of Multiple Circadian Oscillators in Bean Plants
Authors: Hennessey Timothy L. , Field Christopher B.
Published: March 2007

Circadian rhythms in stomatal opening and photosynthesis had shorter free-running periods than circadian rhythms in leaflet movement in bean plants ( Phaseolus vulgaris L.) transferred from 12-hr photoperiods to constant conditions. The rhythm in leaflet movement had a period close to 27 hr, whereas the rhythm in stomatal opening, measured as conductance to water vapor, had a period close to 24 hr. Photosynthesis, measured as net assimilation of CO2, also oscillated with a period close to 24 hr. The periods of these rhythms did not vary with increasing temperature, demonstrating temperature compensation of the controlling oscillators. The difference in free-running periods displayed by these rhythms is evidence that multiple oscillators with different intrinsic frequencies operate in bean plants.
The Statistical Analysis of Circadian Phase and Amplitude in Constant-Routine Core-Temperature Data
Authors: Brown Emery N. , Czeisler Charles A.
Published: March 2007

Accurate estimation of the phases and amplitude of the endogenous circadian pacemaker from constant-routine core-temperature series is crucial for making inferences about the properties of the human biological clock from data collected under this protocol. This paper presents a set of statistical methods based on a harmonic-regression-plus-correlated-noise model for estimating the phases and the amplitude of the endogenous circadian pacemaker from constant-routine core-temperature data. The methods include a Bayesian Monte Carlo procedure for computing the uncertainty in these circadian functions. We illustrate the techniques with a detailed study of a single subject's core-temperature series and describe their relationship to other statistical methods for circadian data analysis. In our laboratory, these methods have been successfully used to analyze more than 300 constant routines and provide a highly reliable means of extracting phase and amplitude information from core-temperature data.
Does the Circadian Pacemaker Act through Cyclic AMP to Drive the Melatonin Rhythm in Chick Pineal Cells?
Authors: Zatz Martin
Published: March 2007

Cyclic AMP is a key regulator of melatonin production in the chick pineal gland. Agents that raise cyclic AMP levels (such as forskolin), or cyclic AMP analogues (such as 8-bromocyclic AMP), increase melatonin synthesis and release, whereas agents that lower cyclic AMP levels (including light) decrease melatonin synthesis and release. A circadian oscillator in these cells also raises and lowers melatonin output. We have been investigating the relationships between cyclic AMP and the circadian pacemaker in the regulation of melatonin production. In the chick pineal (unlike certain neuronal systems), the weight of the evidence indicates that cyclic AMP is not on an entrainment pathway to the circadian pacemaker. Instead, cyclic AMP appears to act downstream from the pacemaker. The pacemaker might itself act directly through cyclic AMP, regulating melatonin content by raising and lowering cyclic AMP levels. If this were the case, and if the effects of cyclic AMP levels on melatonin output are saturable (as they must be), then, in the face of such saturating levels of cyclic AMP, the pacemaker should no longer raise or lower melatonin output. To test this prediction, maximally effective concentrations of forskolin and 8-bromocyclic AMP were determined. Both agents markedly increased melatonin output. After 36 hr, cells were refractory to additional stimulation of melatonin output by addition of both agents together, or by higher concentrations of forskolin (although cyclic AMP levels could still be raised further). Nonetheless, the circadian pacemaker continued to raise and lower melatonin output: The rhythm persisted in the face of saturating levels of cyclic AMP. It is therefore suggested that the circadian pacemaker in chick pineal cells acts with, not through, cyclic AMP to regulate melatonin synthesis. Cyclic AMP and the pacemaker act synergistically to regulate serotonin N-acetyltransferase activity and the melatonin rhythm, with cyclic AMP mediating acute effects and amplitude regulation.
Light Pulses Induce "Singular" Behavior and Shorten the Period of the Circadian Phototaxis Rhythm in the CW15 Strain of Chlamydomonas
Authors: Johnson Carl Hirschie , Kondo Takao
Published: March 2007

While measuring action spectra for phase-shifting the circadian clock of Chlamydomonas, we observed that light pulses started near the phase response curve (PRC) "breakpoint" caused a reduction of the amplitude of the phototactic rhythm and two unexpected effects: (1) nonmonotonic fluence response curves (FRCs), and (2) shortening of the period of the subsequent free-running rhythm. The reduction of the rhythm's amplitude is dependent upon both the fluence and wavelength of the light pulse. The results are consistent with the amplitude being dependent upon the perceived "strength" of the stimulus, and with the nonmonotonic FRCs and reduced amplitude reflecting a light-induced change of the pacemaker's state variables to a region of the phase plane close to the "singularity." The period change that is evoked by single stimuli exhibits novel characteristics: large changes in period and a phase specificity that correlates with "singular" behavior. These period changes also appear to be a function of the stimulus strength, but indirectly; the magnitude of the period change is most strongly correlated with the magnitude of the light-induced phase shift. These results are interpreted in the context of limit cycle models of circadian clocks, and are used to suggest new tactics for measuring action spectra of light-induced clock resetting.
Serotonin and the Mammalian Circadian System: II. Phase-Shifting Rat Behavioral Rhythms with Serotonergic Agonists
Authors: Edgar Dale M. , Miller Joseph D. , Prosser Rebecca A. , Dean Robin R. , Dement William C.
Published: March 2007

The suprachiasmatic nuclei (SCN) receive primary afferents from the median and dorsal raphe, but the role of these projections in circadian timekeeping is poorly understood. Studies of the SCN in vitro suggest that quipazine, a general serotonin (5-HT) receptor agonist, can produce circadian time-dependent phase advances and phase delays in circadian rhythms of neuronal activity. The present study addresses whether quipazine and the selective 5-HT 1A receptor agonist 8-OH-DPAT are similarly effective in vivo. Drinking and wheel-running patterns of male Wistar rats individually housed in constant darkness were monitored before and after subcutaneous administration of quipazine (5-10 mg/kg) at either circadian time (CT) 6 or CT 18, with and without running wheels available. Dose-dependent phase advances (20-180 min) were produced at CT 6. Significant phase shifts were not observed at CT 18. CT 6 quipazine-treated animals also showed a sustained and significant shortening of rhythm period (τ) following treatment (-0.28 hr; p < 0.002). τ shortening was inconsistently observed in CT 18 quipazine-treated rats. Neither quipazine-induced phase shifts nor τ effects were dependent on wheel-running activity per se. 8-OH-DPAT delivered via intracerebral ventricular treatment into the third ventricle (5 μl at 100 μM in saline) produced slightly smaller phase advances (20-90 min) at CT 6, but did not produce phase delays at CT 18 or changes in τ. These findings support in vitro evidence that 5-HT-ergic agonists can phase-shift the circadian pacemaker.
Animal Issues Statement of the Society for Research on Biological Rhythms
Authors: Morin Lawrence P.
Published: March 2007

This statement was prepared by an ad hoc committee on the Society for Research on Biological Rhythms, consisting of Lawrence P. Morin (Chair), Mark S. Bauer, John Dark, Donald I. McEachron, and Herbert Underwood. Dr. Charles C. Middleton, DVM, also assisted in the preparation of this report. This report represents the position of the Society with respect to the care and well-being of animals that are used in experiments involving the study of biological rhythms. The Executive Committee of the Society determined that such a report was necessary, because many experiments involving the study of biological rhythms require special husbandry and housing requirements that are often unique to such studies. Although National Institutes of Health (NIH) and U.S. Department of Agriculture (USDA) guidelines for housing animals are appropriate for animals not in experiments, quite often it is necessary to house animals under experimental conditions for many months in biological rhythms studies, and normal, routine care of these animals could interfere with and perhaps ruin the experiments. The report makes recommendations regarding cages, environmental chambers, rooms, recording devices, observing animals, cleanliness, feeding, lighting, temperature, ventilation, humidity, and safety alarms. The successful completion of experiments on biological rhythms in animals often requires special handling and care of animals on a day-to-day basis. Following the guidelines in this statement should enable investigators to collect meaningful data on biological rhythms, while at the same time ensuring that the animals are maintained in a healthy state and that they receive proper care. —Fred W. Turek, Past President, Society for Research on Biological Rhythms
Circadian Rhythm in the Visual System of the Lizard Anolis carolinensis
Authors: Shaw Andrew P. , Collazo C. Raul , Easterling Keith , Young Cheryl D. , Karwoski Chester J.
Published: March 2007

The electroretinogram (ERG) was recorded from free-moving Anolis lizards once per hour for 5 days. As in our previous work, the b-wave, but not the a-wave, showed a reliable circadian rhythm (CR) in amplitude, with an acrophase near projected noon. Both the a- and b-waves showed a CR in peak time (implicit time, or IT), with the a-wave IT being longest near midnight, and the b-wave IT at midday. Acrophases were shifted when animals were housed on a phase-shifted light-dark cycle. The ERG CR was unaffected by removal of the parietal organ, but it was virtually abolished by removal of the pineal gland, thus suggesting that pineal output (probably melatonin) modulates retinal responses. In addition to the ERG, the tectal light-evoked potential exhibited a CR—a finding compatible with a circadian variation in retinal output. Lastly, the amplitude of the ERG component waveforms showed a seasonal variation, but the ERG CR was constant across the year.
The Association between the Nocturnal Sleep Gate and Nocturnal Onset of Urinary 6-Sulfatoxymelatonin
Authors: Tzischinsky O. , Shlitner A. , Lavie P.
Published: March 2007

The present study investigated the relationship between the time of nocturnal onset of urinary 6-sulfatoxymelatonin (aMT6s) secretion, and the timing of the steepest increase in nocturnal sleepiness ("sleep gate"), as determined by an ultrashort sleep-wake cycle test (7 min sleep, 13 min wake). Twenty-nine men (mean age 23.8 ± 2.7 years) participated. The ultrashort sleep-wake paradigm started at 0700 hr after a night of sleep deprivation and continued for 24 hr until 0700 hr the next day. Electrophysiological recordings were carried out during the 7-min sleep trials, which were then scored conventionally for sleep stages. Urinary aMT6s was measured every 2 hr. The results showed that the timing of the sleep gate was significantly correlated with the onset of aMT6s secretion. These results are discussed in light of the possible role of melatonin in sleep-wake regulation.
The Effect of Short-Photoperiod Exposure on Tuberoinfundibular Dopamine Neurons in Male and Female Syrian Hamsters
Authors: Krajnak Kristine , Manzanares Jorge , Lookingland Keith J. , Nunez Antonio A.
Published: March 2007

In male hamsters, exposure to a short photoperiod results in a significant decrease in median eminence (ME) dopamine (DA) concentrations. The mechanism responsible for this decrease in DA is unknown. The experiments described in this paper were designed to examine the effects of photo period on DA metabolism and synthesis in the ME to determine if a change in these processes is responsible for the short-photoperiod-induced decrease in ME DA concentrations. In the first experi ment, the metabolism of DA in tuberoinfundibular dopamine (TIDA) neuronal terminals was determined by measuring ME concentrations of 3,4-dihydroxyphenylacetic acid (DOPAC; a major metabolite of DA) and DA in male and female hamsters housed in long and short photoperiods. In both males and females, exposure to the short photoperiod induced a collapse of the reproductive system and a reduction in circulating prolactin. In males, but not in females, exposure to the short photoperiod reduced ME DA concentrations; however, DOPAC concentrations were not affected by photoperiod. Thus, the decrease in ME DA seen in males is not the result of an increase in DA metabolism. In the second experiment, tyrosine hydroxylase (TH) activity in the ME of males was determined by injecting animals housed in long and short photoperiods with a L-aromatic amino acid decarboxylase inhibitor (NSD 1015) and measuring 3,4-dihydroxyphenylalanine (DOPA). Consistent with Experiment 1, ME DA concentrations were significantly decreased in gonadally regressed males housed in a short photoperiod; however, ME DOPA accumulation was not affected. Thus, the observed decrease in DA is not the result of a decrease in TH activity in the ME. The results of the experiments presented here indicate that (1) in males but not females, the decrease in circulating prolactin seen in animals housed in a short photoperiod for 12 weeks is associated with a decrease in ME DA concentrations, and (2) the decrease in ME DA seen in males housed in a short photoperiod is not the result of an increase in DA metabolism or a decrease in synthesis by TIDA neurons.
Circannual Alterations in the Circadian Rhythm of Melatonin Secretion
Authors: Thrun L.A. , Moenter S.M. , O'Callaghan D. , Woodfill C.J.I. , Karsch F.J.
Published: March 2007

To determine if a circadian rhythm known to be functionally related to the reproductive axis varies on a circannual basis, we monitored the circadian secretion of melatonin at monthly intervals for 2 years in four ovariectomized, estradiol-implanted ewes held in a constant short-day photoperiod. Prior to the study, ewes had been housed in a short-day (8L:16D) photoperiod for 4 years and were exhibiting circannual reproductive rhythms as assessed by serum luteinizing hormone (LH) levels. Three of the four sheep showed unambiguous deviations from the expected nocturnal melatonin secretion at two different times approximately 1 year apart. Nocturnal rises in melatonin, which usually last the duration of the dark phase, were delayed by 3-14 h or were missing. Altogether, five of the seven melatonin alterations observed in these three ewes occurred during the nadir of the circannual LH cycle. In the remaining ewe, we did not observe an altered melatonin secretory pattern during this period, and this ewe also failed to show a high amplitude circannual cycle of LH. The results provide evidence for a circannual change in the circadian rhythm of melatonin secretion. This alteration in melatonin secretion may serve as a "functional" change in daylength, and thereby may influence the expression of the circannual reproductive rhythm of sheep held in a fixed photoperiod for an extended time.
Circadian Aspect of Photoperiodic Time Measurement in a Female House Sparrow, Passer domesticus
Authors: Ravikumar G. , Senthilkumaran B. , Tewary P.D. , Goel A.K.
Published: March 2007

Endogenous circadian rhythms are involved in various photoperiodic responses of birds. Investigations involving the mechanisms of photoperiodic time measurement in birds have been confined mainly to temperate zone species using males exclusively. Due to the paucity of experimental evidence on sub tropical birds that have very wide distribution, the present study was performed using subtropical female house sparrows. Photoperiodic sparrows were sub jected to various T cycles for 60 days in which a fixed 3-h photophase was combined with scotophase in cycles of 20-30 h duration. Simultaneously, two groups of birds were also exposed to short days (light:dark = 8L:16D) or long days (15L:9D) as controls. Significant ovarian growth was found only in cycles of 3L:17D, 3L:23D, 3L:25D, and 3L:27D as well as in 15L:9D, whereas no positive response was detected in 3L:19D, 3L:21D, and 8L:16D. Plasma levels of estradiol showed a close relation to ovarian growth. The results indicate that photoperio dic time measurement in house sparrows involves an endogenous circadian rhythm.
The Effects of Anterior Hypothalamic Lesions on Short-Day Responses in Siberian Hamsters Given Timed Melatonin Infusions
Authors: Song C. Kay , Bartness Timothy J.
Published: March 2007

The suprachiasmatic nucleus (SCN) of the hypothalamus is an area of dense 2-[125I]Iodomelatonin binding in Siberian hamsters (Phodopus sungorus sungorus) that is suggestive of a possible role in the reception and/or relaying of melatonin (MEL) signals. Indeed, in pinealectomized male Siberian hamsters given short day (SD) MEL signals (long-duration MEL infusions), lesions of the SCN (SCNx) block testicular regression and decreases in body and fat pad masses seen in identically treated hamsters with sham lesions (SCNs). In similar studies using Syrian hamsters ( Mesocricetus auratus), anterior hypothalamic lesions (AHx), but not SCNx, blocked SD MEL signal-induced gonadal regression despite the similarity in the 2-[125I]Iodomelatonin binding pattern between the two species. The discrepancy between the ability of SCNx to block the reception of SD MEL signals between the two species is puzzling, given the similarity in the reproductive status of the Syrian and Siberian hamsters to systemically administered and timed MEL infusions. One possible way of reconciling the differences between these studies was that ancillary damage to areas neighboring the SCN, including the AH, may have occurred in our attempt to achieve complete SCNx in Siberian hamsters. Therefore, the purpose of the present study was to challenge AHx Siberian hamsters with SD MEL signals. Adult male hamsters were pinealectomized, fitted with subcutaneous catheters, and given daily timed infusions of MEL for 5 or 10 h (long day-like and short day-like, respectively) or the saline vehicle for 6 wk following bilateral electrolytic, or sham (AHs) lesions of the AH. Hamsters receiving 10 h MEL infusions that lacked evidence of anatomical or functional damage to the SCN showed SD-like gonadal regression, decreases in body and fat pad mass, and food intake similar to that observed in AHs animals. In contrast, 10 h MEL-infused SCNx hamsters did not exhibit SD-like responses, a finding confirming our previous report. These data suggest that interspecies differences exist between Syrian and Siberian hamsters in central nervous system sites and pathways involved in the reception/transmission of SD MEL signals.
Phase-Advanced Daily Rhythms of Melatonin, Body Temperature, and Locomotor Activity in Food-Restricted Rats Fed during Daytime
Authors: Challet E. , Pevet P. , Vivien-Roels B. , Malan A.
Published: March 2007

This study was performed to investigate possible effects of a timed caloric restriction on the light-dark (LD) synchronization of four biological rhythms pair-studied in the same animals. In Experiment 1, food-restricted rats kept under a photoperiod of 12 h light:12 h dark received 50% of previous ad libitum food 2 h after the onset of light. Their daily rhythm of pineal melatonin and rhythms of plasma melatonin and corticosterone were examined and com pared to those of ad libitum control rats after 1 or 2 months of food restriction. A significant phase advance (about 2 h) was found for the pineal melatonin rhythm and for the daily onset of plasma melatonin. Timing of nocturnal peak of circulating corticosterone was unchanged, and a diurnal peak anticipated food presentation by about 2 h. In Experiment 2, effects of a timed caloric restriction under 12L:12D were studied on the expression of daily rhythms of body tem perature and locomotor activity. To discriminate between the effects of timed meal feeding and those of the added caloric restriction, these rhythms were analyzed in food-restricted rats, as in Experiment 1, and were compared to those in sham-restricted rats, concomitantly fed twice more than food-restricted rats (i.e., a timed meal feeding without caloric restriction). Acrophase of the nocturnal peak of body temperature rhythm reached the greatest phase advance (7 h) in food-restricted rats, in which it was close to LD transition. The nocturnal com ponent of locomotor activity rhythm also was markedly phase advanced (6 h) by caloric restriction, as indicated by wheel-running and general activity occur ring from early afternoon to midnight. A smaller 4-h phase advance of the nocturnal peak of body temperature also was observed in sham-restricted rats, although the onset of locomotor activity rhythm apparently was unaffected by meal feeding and the end of activity rhythm was phase advanced by 2 h. These results indicate that timed caloric restriction is a potent phase-shifting agent that interacts with the LD cycle zeitgeber. This nonphotic stimulus phase advances melatonin, corticosterone, body temperature, and activity rhythms to different extents and thus suggests a change in the internal synchronization of the cir cadian system.
Aftereffects of Entrainment on the Period of the Pacemaker in the Eye of the Mollusk Bulla gouldiana
Authors: Page Terry L. , Wassmer Gary T. , Fletcher Julia , Block Gene D.
Published: March 2007

The authors examined the "aftereffects" of entrainment of Bulla gouldi ana to 11 h light:11 h dark (LD 11:11) (T22) or LD 13:13 (T26) on the period (τ) of the circadian rhythm of impulse activity recorded in vitro from the eye in constant darkness. When both eyes remained attached to the cerebral ganglion, the average period was 23.9 ± 0.62 h (mean ± SD, n = 6) for animals from T22 and 24.9 ± 0.54 h for animals from T26. The 1-h difference between the periods of the T26 and the T22 animals was significant ( p < .01, t test). When eyes were isolated from the cerebral ganglion by severing the optic nerve, the difference in average period between eyes from T22 and eyes from T26 animals was 2.2 h (23.3 ± 0.72 h [ n = 7] vs. 25.5 ± 0.62 [ n = 6], p <.001). When eyes remained attached to the brain but uncoupled from the contralateral eye, the aftereffect of entrainment to non-24-h light cycles was intermediate. For T22 animals, τ was 23.9 ± 0.29 h ( n = 6), whereas for the T26 animals, τ = 25.2 ± 0.48 h ( n = 7). The results show that isolated eyes can express aftereffects and indicate that coupling between ocular pacemakers and efferent signals from the cerebral ganglion diminish the effects of entrainment on the free-running period of the rhythm from the eye.
Circadian Patterns of Locomotor Activity and Body Temperature in Blind Mole-Rats, Spalax ehrenbergi
Authors: Goldman B.D. , Goldman S.L. , Riccio A.P. , Terkel J.
Published: March 2007

A wide variety of organisms exhibit circadian rhythms, regulated by internal clocks that are entrained primarily by the alternating cycle of light and darkness. There have been few studies of circadian rhythms in fossorial species that inhabit a microenvironment where day-night variations in most environ mental parameters are minimized and where exposure to light occurs only infrequently. In this study, daily patterns of locomotor activity and body tem perature (Tb) were examined in adult blind mole-rats (Spalax ehrenbergi). These fossorial rodents lack external eyes but possess rudimentary ocular structures that are embedded in the Harderian glands and covered by skin and fur. Most individual mole-rats exhibited circadian rhythms of locomotor activity, but some animals were arrhythmic. Individuals that did exhibit robust rhythms of loco motor activity also showed rhythms of Tb. In most cases, Tb was highest during the phase of intense locomotor activity. Locomotor activity rhythms could be entrained to light:dark cycles, and several mole-rats exhibited entrainment to non-24-h light cycles (T-cycles) with period lengths ranging from T = 23 h to T = 25 h. Some individuals also showed entrainment to daily cycles of ambient temperature. There was considerable interindividual variation in the daily pat terns of locomotor activity among mole-rats in virtually all the conditions of environmental lighting and temperature employed in this study. Thus, whereas it appears likely that photic cues have a significant role in the entrainment of circadian rhythms in mole-rats, the amount of variability in rhythm patterns among individuals appears to be much greater than for most species that have been studied.
Sustainability and Planning: Diverse Concepts and Close Associations
Authors: Jepson Edward J.
Published: March 2007

Sustainability is a term that has received a significant amount of attention in the public policy arena. Within the planning profession, there has likewise been a growing recognition of its possible relevance in the areas of land use and general community development, and planners are increasingly finding themselves either leading or being expected to contribute to local “sustainable development” efforts. The purpose of this article is to provide an introduction to the sustainability framework in terms of its scientific basis and cultural interpretations and to identify and explore conceptual associations that tend to tie it to the planning profession.
Children Who Move
Authors: van Vliet Willem
Published: March 2007

According to the most recent census data, nearly eleven million children in the United States annually change their residence. Residential relocation can be a severely disruptive event for adults, but little is known about its effects on children. After a brief sketch of the ldimensions-a-nfdfiackground of the problem, this article reviews the extant literature to examine whether and how the mobility of children is related to their academic behavior, social relations, and general well-being. The importance of several contextual factors is noted. Finally, limitations of research and the implications for planning are discussed.
Feminist Planning Ethics
Authors: Hendler Sue
Published: March 2007

Feminist ethics-which examines women's values, experiences, and decision-making processes-is an area of moral philosophy that has been slow to attract the interest of planning ethicists. Feminist approaches to ethics share several commonalities, including an emphasis on care and empathy rather than rights and justice, and a balance between freedom and responsibility. Six approaches tofeminist ethics are critically analyzed here. The common themes are then applied to those areas of planning most amenable to ethical analysis: normative planning theory, planning techniques, administrative role definition, plan making, and professional ethics in everyday decision-making.
Provision of Community Residences for People with Developmental Disabilities
Authors: Miano Margaret M.
Published: March 2007

Although it is established public policy that people with developmental disabilities live in their communities, the degree to which this is true varies greatly among the states in this country. For community residential programs to be developed, funding must be real located from large institutions. This article provides a historical background including legislation and court decisions that mandated states to deinstitutionalize and establish community residential programs. It reviews the literature that addresses the major obstacles to institutional closure and establishment of community residences.
The Implications of the Nonlinear Paradigm for Integrated Environmental Design and Planning
Authors: Hwang Sang W.
Published: March 2007

The purpose of this article is to describe the potential implications of the "new sciences" such as chaos theory, self-organization theory, and complexity science to reconcile various different schools of philosophical thought in the environment development debate. Design, through the means of transdisciplinary analysis, here is conceived as a creative process that aids in the emergence of appropriate metaphors and models for the development of sophisticated environmental planning and policies. The epistemological and philosophical foundations of two broad paradigms of thought, the material and ecological paradigms, are examined to develop a more comprehensive approach to sustainable development. Surprisingly, this takes us into the terrain of Newtonian mechanics and principles of thermodynamics. The article then presents an alternative view of sustainability based on the emerging new science paradigm. Finally, the article examines some possible implicationsfor integrated environmental design and planning.
Older Women's Adjustment to Unemployment
Authors: Rife John C. , Toomey Beverly G. , First Richard J.
Published: March 2007

Few studies of unemployment have examined the impact of joblessness on older women. The exploratory study reported in this article examined the differences in adjustyriertt to unemployment of 72 women and 76 men, aged 50 and over. The results reflect the vulnerability and special challenges that older unemployed women face and the need for social work services that are targeted to this population.
Consequences of Sexual Harassment in the Workplace
Authors: Kaplan Sally J.
Published: March 2007

Numerous popular and scholarly articles have examined sexual harassment in the workplace, but have not addressed the existing or potential costs to business and society. This article examines the individual and societal costs of sexual harassment in the context of the necessity of competing in an international marketplace, projections of a labor shortage, and predictions that the decline in the productivity of workers will result in a lower standard of living for Americans. A discussion of the efficacy of current social policy in addressing the issue follows, as do recommendations to address the macroeconomic consequences.
International Adoption: The Exploitation of Women and Children
Authors: Herrmann Kenneth J. , Kasper Barbara
Published: March 2007

Although the adoption of Third World children by adults in developed nations may provide families for parentless children, it also exploits women and children in undeveloped countries, both politically and economically. The common practice of treating international adoption as a business has resulted in violations of standards and laws. To deal with this problem, human rights must be protected, community development programs must be expanded, and standards and laws must be strengthened.
Is Everything Women's Work?
Authors: Dinerman Miriam
Published: March 2007

A majority of women work. Can the family manage the caring tasks while attaining equity among its members? Can women find equity in the workplace? Social work faces both issues as it deals with women clients and internally as a female-intensive occupation. Dimensions of the problems and an action agenda are presented.
Listening to Middle-Aged Homeless Women Talk About Their Lives
Authors: Butler Sandra Sue
Published: March 2007

Using a phenomenological research approach, the author interviewed 11 unattached middle-aged homeless women every few weeks over a six-month period. Four themes emerged from the stories the women told about their lives: relationships, resiliency, normalcy, and political awareness. These themes support the idea that middle-aged homeless women are similar to other middle-aged women in this society, al though their poverty and the shortage of low-income housing have made their lives more difficult.
Women, Welfare, and College: The Impact of Higher Education on Economic Well-Being
Authors: Thompson Joanne J.
Published: March 2007

Women on welfare can make effective use of higher education opportunities to improve their economic status and pursue new careers. The study reported in this article found that after graduation, most of the 103 women were employed and off welfare and that the women's perseverance, desire to get a job, and receipt of financial aid were the primary factors in their success. Implications for welfare policies and practice are discussed.
Mandatory HIV Testing of Newborns: The Debate and a Programmatic Response
Authors: Beckerman Nancy L. , Beder Joan , Gelman Sheldon R.
Published: March 2007

The U.S. Congress is considering legislation—H.R. 1872—that would require mandatory HIV testing of all newborns except those whose mothers were tested during pregnancy. This article presents a detailed analysis of the complex issues involved in the proposed legislation. It also describes the authors' programmatic response that incorporates feminist and social work values, given the likely passage of the bill. This response includes the anticipated social service needs (education and supportive counseling) of mothers whose HIV status is revealed through tests of newborns.
Mutuality in the Relationship of Homeless Women and Their Mothers
Authors: Goldberg Joan E.
Published: March 2007

This article describes the findings of a study in which homeless women who were living in a shelter explored their relationships with their mothers and the impact that these relationships had on them.
Abused Women in New Mexican Shelters: Factors That Influence Independence on Discharge
Authors: Hilbert Judith C. , Kolia Raiza , VanLeeuwen Dawn M.
Published: March 2007

The aim of the exploratory study discussed in this article was to distinguish between women who return to shelters and those who become independent from their abusers on discharge (disposition). The women's length of stay in the shelters and the severity of abuse were the strongest predictors, and suicidality and substance abuse were strongly associated with disposition. The findings suggest that cul turally sensitive mental health services and longer stays in shelters may foster women's independence from their abusers.
Female Survivors of Violence and Abuse
Authors: FRY PREM S. , BARKER LISA A.
Published: March 2007

Two hundred and eighty-six female survivors of violence and abuse were surveyed about their major regrets of action and inaction following the experience of violence. Two factor analyses, with varimax rotation, were conducted on the questionnaire data to identify recurrent themes underlying survivors' regrets. The factor analysis of regrettable actions yielded three factors centering on themes of isolation and alienation. Factor analyses of regrets about inaction, or failure to act, yielded four factors centering on themes of insufficient action for self-care and self-protection, and reluctance to seek a change of venue and identity. These factors accounted for a significant percentage of the total variance. Qualitative data derived from 32 in-depth interviews provided further confirmation of the presence of these same themes. As hypothesized, the number of regrets of inaction far exceeded those of action. Implications of the findings are discussed with respect to the changing role of professionals working with women's experience of violence.
Batterer Program Participants Who Repeatedly Reassault
Authors: GONDOLF EDWARD W. , WHITE ROBERT J.
Published: March 2007

Approximately 20% of batterer program participants repeatedly reassault their partners despite intervention. Previous typology and personality research suggests that these men tend to be antisocial and psychopathic. Using recommended criteria for the Millon Clinical Multiaxial Inventory, Version III (MCMI-III), the personality profiles of 580 men who did not reassault their partners, reassaulted once, and repeatedly reassaulted during a 15-month follow-up were grouped. The majority (60%) of the “repeat reassaulters” show no serious personality dysfunction or psychopathology. Only 11% have profiles suggesting conventional or primary psychopathic disorder. The broadest conception of psychopathy, including secondary psychopathy and both psychopathic disorder and style, applies to 54% of the repeaters. There is no significant difference among the reassault types for personality dysfunction, psychopathic disorder, or personality type, but a significantly greater portion of repeaters shows some psychopathic tendency. The findings contradict overgeneralizations about high risk batterers and imply that batterer counseling may be appropriate for many of them.
Risk of Crime Victimization Among Youth Exposed to Domestic Violence
Authors: MITCHELL KIMBERLY J. , FINKELHOR DAVID
Published: March 2007

This article explores the degree to which youth are at higher risk of crime victimization when they live in a household with an adult who has been the victim of domestic violence or another violent crime. Combined data from the 1996, 1997, and 1998 National Crime Victimization Surveys show a generally higher victimization risk for youth who live in households with a victimized adult. The risk is elevated for youth from households with adult victims of both domestic and other nondomestic violence. Girls living in households with an adult victim of domestic violence appear to be at particularly high risk for crime victimization. Some of the added risk for such youth appears to be from family members. These findings reinforce the need to direct crime prevention and detection efforts toward youth in households in which an adult has been victimized.
Perceptions of Rape and Sexual Assault Among Australian Adolescents and Young Adults
Authors: XENOS SOPHIA , SMITH DAVID
Published: March 2007

This study expands the empirical and theoretical understanding of attitudes toward rape victims. Six hundred and eight adolescents and young adults were given three brief questionnaires assessing attitudes toward rape victims, attitudes toward women, and sex-role orientation, in addition to three sexual coercion vignettes. The results demonstrated that a significant proportion of students held unfavorable attitudes toward rape victims, perceived the victims as being responsible for the rape, and perceived the victims as contributing to their assault. Negative stereotypes about rape were also related to conservative and traditional beliefs about women's social roles. Gender and educational level differences regarding rape victims were also found. The direct implications of these results for enhancing the efficacy of rape prevention and education programs is discussed in terms of both content and target group.
Cognitive Correlates of Reported Sexual Abuse in Eating-Disordered Women
Authors: WALLER GLENN , RUDDOCK ANGELA , CURETON SARA
Published: March 2007

It is important to understand the cognitive processes associated with sexual abuse experiences to target treatment for the victims. Evidence to date suggests that those correlates are not yet adequately understood. This study describes an information-processing task that assesses the degree of attentional bias toward words with abusive connotations. In a group of eating-disordered women, this instrument was used to demonstrate that reported sexual abuse was associated with a greater cognitive bias toward abuse-related information. This attentional bias was associated with a greater level of specific self-denigratory beliefs as a result of the abuse. There were no similar associations with beliefs about the motivation of the abuser or of the victim at the time of abuse, or with beliefs about the present-day motives of others. Treatment implications are discussed, although this information-processing measure requires wider validation.
Sexual Assault of Adult Males
Authors: STERMAC LANA , SHERIDAN PETER M. , DAVIDSON ALISON , DUNN SHEILA
Published: March 2007

The circumstances and characteristics of sexual assaults against adult males presenting to a crisis unit in a large metropolitan area were examined. Twenty-nine men, ranging in age from 18 to 65, who were victims of sexual assaults or attempted sexual assaults, were seen over a 16-month period. Information extracted from the unit database included client demographics and personal history, assault characteristics, and presentation information. Twenty-five (86%) of the reported assaults involved male perpetrators, one involved a single female perpetrator, and two involved both male and female perpetrators. Half the male-male assaults and all the female-male assaults were acquaintance sexual assaults. Only a minority of the stranger assaults were suggestive of antigay violence. Most victims were young gay men, many of whom had physical or cognitive disabilities making them particularly vulnerable. The results suggest a need for increased awareness of acquaintance sexual assault in adult males.
Childhood Abuse and Chronic Pain
Authors: TRIEF PAULA M.
Published: March 2007

This article presents a hypothesis developed from clinical practice for understanding the possible link between chronic pain and childhood abuse that has recently emerged in the literature. The model enables the treating psychotherapist to overcome common initial resistance to psychotherapy while helping the patients achieve better symptomatic control. A case report is presented that elaborates on this hypothesis and future research directions are presented.
Police Officers' Perceptions of Rape
Authors: CAMPBELL REBECCA , JOHNSON CAMILLE R.
Published: March 2007

This study examined how police officers (N = 91) define rape. In the past decade, most states have dramatically reformed their rape laws, shifting the emphasis from the behavior of the victim to that of the assailant. This study provides an exploratory picture of how such reforms have affected police by examining the degree to which there was consistency between officers' personal definitions of rape and state law. Officers were asked to define rape/sexual assault in their own words. These definitions were content analyzed, and hierarchical cluster analysis was performed. Three clusters of definitions emerged. Nineteen percent of the sample described many of the reformed legal factors when defining rape, such as the use or threat of force (Force Definition of Rape). Thirty-one percent focused primarily on penetration and consent (Consent Definition of Rape). Fifty-one percent of the officers provided definitions that mixed old legal definitions with some victim blaming views (Mixed Definition of Rape).
Responsible Mothers and Invisible Men
Authors: EDLESON JEFFREY L.
Published: March 2007

This commentary identifies critical issues regarding social interventions with families where both child maltreatment and woman battering are suspected. The author addresses several common assumptions of service providers and suggests changes in current practice.
The Moderating Effects of Parenting Stress on Children's Adjustment in Woman-Abusing Families
Authors: LEVENDOSKY ALYTIA A. , GRAHAM-BERMANN SANDRA A.
Published: March 2007

Research on the psychological effects of domestic violence on women and children has flourished in the past few years, concluding that both suffer increased adjustment problems and psychopathology. The current studies, however, have not provided an understanding of the processes or factors that can protect children from being detrimentally affected. The purpose of this study was to examine the potential moderating effects of maternal parenting stress on children's adjustment in homes with varying levels of domestic violence. The sample consisted of 60 sheltered battered women and their 7- to 12-year-old children, and 61 nonsheltered women and children from the same community. Results indicated that children's adjustment was significantly predicted by parenting stress after controlling for psychological and physical abuse of the mother. Results are discussed in light of protective and vulnerability factors for children's adjustment in high-risk families.