Balancing Act: An Interdisciplinary Exploration of Trade-offs in Reproducing Females.

Trade-offs resulting from the high demand of offspring production are a central focus of many subdisciplines within the field of biology. Yet, despite the historical and current interest on this topic, large gaps in our understanding of whole-organism trade-offs that occur in reproducing individuals remain, particularly as it relates to the nuances associated with female reproduction. This volume of Integrative and Comparative Biology (ICB) contains a series of papers that focus on reviewing trade-offs from the female-centered perspective of biology (i.

Seasonal patterns of body temperature in response to experimental photoperiod variation in a non-hibernating ground squirrel.

Unlike numerous other members of the holarctic Tribe Marmotini of the squirrel family (Sciuridae) that typically exhibit spontaneous bouts of torpor that progress into an annual season of hibernation, members of the genus Ammospermophilus (antelope ground squirrels) do not enter torpor, and they remain active throughout the year in nature. We have experimentally evaluated seasonal patterns of variation in the circadian rhythm of body temperature in captive A. leucurus over a two-and-a-half-year period by exposing groups to either a constant daily photoperiod of 12 h light or a seasonally changing photoperiod that cycled between a summer maximum of 16 h per day and a winter minimum of 8 h; ambient air temperature was maintained at 26 °C.

Exploring the association between quality of homecare services and older adults' well-being.

Homecare services play an important role in enabling older adults with chronic illness or functional impairment to continue living in their homes and communities. Previous research on homecare services has not fully explored the potential psychological benefits of homecare services. This study investigates the association between quality of homecare services and psychological well-being by analyzing two surveys.

Exploring determinants of behavioral chronotype in a diurnal-rodent model of human physiology.

Numerous studies conducted with human participants have shown that differences in chronotype, defined as individual patterns of early or late beginning of daily activity, have implications for many biobehavioral processes, such as cognitive performance, mood, impulsivity, academic achievement of college students, and mental health. However, the determinants of individual variation in chronotype have not been investigated. Basic research on circadian rhythms has provided a basis for investigating the causes of chronotype variation, but experimental tests of pertinent hypotheses are difficult to conduct with human subjects.

Diurnally active rodents for laboratory research.

Although inbred domesticated strains of rats and mice serve as traditional mammalian animal models in biomedical research, the nocturnal habits of these rodents make them inappropriate for research that requires a model with human-like diurnal activity rhythms. We conducted a literature review and recorded locomotor activity data from four rodent species that are generally considered to be diurnally active, the Mongolian gerbil ( Meriones unguiculatus), the degu ( Octodon degus), the African (Nile) grass rat ( Arvicanthis niloticus), and the antelope ground squirrel ( Ammospermophilus leucurus). Our data collected under 12-hour light/dark cycles confirmed and expanded the existing literature in showing that the activity rhythms of antelope ground squirrels and African grass rats are stronger and more concentrated in the light phase of the light/dark cycle than the activity rhythms of Mongolian gerbils and degus, making the former two species preferable and more reliable as models of consistent diurnal activity in the laboratory.