Effects of the Menopause Transition on Body Fatness and Body Fat Distribution

Objective : The menopause transition increases cardiovascular and metabolic disease risk, partly because of the adverse effects of estrogen deficiency on the plasma lipid-lipoprotein profile and cardiovascular function. This increased cardiovascular and metabolic disease risk may also be partially mediated by increased body fat, increased intraabdominal adipose tissue accumulation, or both. The objective of this mini-review is to summarize studies that have investigated the relationships among the menopause transition, body fatness, and body fat distribution. Research Methods and Procedures : A review of cross-sectional and longitudinal studies on menopause that examined body fatness and body fat distribution. Results : Cross-sectional reports show that the menopause transition is related to modest increases in body mass index or total fatness, although not all studies found significant effects. Increased central adiposity appears to be related to menopause, independent of advancing age, but these results are methodology dependent. An independent effect of menopause on central body fatness was noted by the use of techniques such as DEXA or computed tomography, whereas studies using circumference measures showed discrepant results. Longitudinal studies showed that the menopause transition accelerated the increase in central adiposity, although no studies quantified changes in intra-abdominal fat by imaging techniques. Discussion : Thus, additional longitudinal studies using more accurate measures of adiposity are needed to critically examine the effects of the menopause transition on total and central body fatness. Collectively, previous studies suggest that menopause is related to modest increase in total fatness and accelerated accumulation of central body fat that exceeds changes normally attributed to the aging process. These changes may increase the risk for cardiovascular and metabolic disease in aging women.     

From Orders to Borders: Toward a Sustainable Co-managed Lobster Fishery in Bonavista Bay, Newfoundland

Over the last two decades, demands by fish harvesters for greater input into policy-making, combined with government cutbacks to fisheries management agencies, have resulted in a proliferation of community-based fisheries comanagement projects in many countries. One such example is found on Newfoundland’s Eastport Peninsula, where a group of lobster harvesters have formed a unique partnership with federal government bureaucrats and university researchers in an effort to protect local lobster stocks from increasing fishing pressure. This paper draws upon interviews with lobster harvesters and others with close ties to the Eastport project in exploring the reasons for the development of this initiative and identifying existing and potential obstacles to its long-term success.

Animal Welfare and Livestock Production in a Postindustrial Milieu

Structural transformation, food safety, and environmental risks pose challenges to livestock producers. Adjustments to livestock production systems to improve animal welfare will be made in an economic and political milieu characterized by these challenges. However, competing assumptions about contemporary society provide different frameworks for formulating the problems faced by industry and government decision makers. The assumption that industrialization is the key problem in livestock production leads to an application of science that does not adequately address the role of public participation and trust.     

Menopause in Free-Ranging Rhesus Macaques: Estimated Incidence, Relation to Body Condition, and Adaptive Significance

We examined the question of whether the occurrence of menopause in rhesus macaque (Macaca mulatta) females approximates that found in women from a life history standpoint. We used data from two provisioned free-ranging populations of rhesus macaques to estimate the probability that a juvenile female not only will survive to the potentially postmenopausal age of 25 years but also will cease to experience menstrual cycles between 25 and 27 years. We used the same data to assess whether an age-related deterioration in body condition can predict whether females 25 years old will be acyclic. Our analyses indicate that, within our study populations, (1) 1 in every 10 juvenile females can be expected eventually to undergo the climacteric, and (2) being in poor condition is strongly associated with being acyclic in old age. Current theory regarding the evolution of senescence in species that do not reproduce by binary fission posits that aging is a consequence of the force of natural selection declining with age. Inasmuch as the proportion of female rhesus macaque juveniles that ultimately experience menopause is small, and inasmuch as reproductive senescence does not appear to outpace organismal aging in general (as indexed by an age-related decline in body condition), we conclude that the occurrence of menopause in rhesus females is parsimoniously explained by the general evolutionary theory of aging and that the invocation of a special adaptive explanation, such as the grandmother hypothesis or a variant thereof, is unnecessary.     

Strategic Ejaculation in the Black Scavenger Fly Sepsis cynipsea Revisited: Copula Duration as a Function of Sperm Depletion and Body Size

The massive numbers of sperm males transfer during a single mating are physiologically costly and the amount of sperm that can be stored is limited. Therefore, males can perform only a finite number of successive copulations without loss of fertility, and males should allocate sperm prudently. We investigated sperm availability and depletion in male black scavenger flies, Sepsis cynipsea (Diptera: Sepsidae), asking whether males adjust copula duration according to nutrition, their sperm stores, their own and their partner’s body size, as predicted by theory. We created a gradient of sperm limitation by restricting dung (their protein resource as adults) and subjecting males to a varying number of copulations. While male fertility did not depend on access to fresh dung (contrary to females), it did decline after three copulations, and more so when males were small. Larger females tended to lay more unfertilized eggs after copulating with previously mated males. However, copula duration was not influenced by a male’s number of previous copulations, and therefore apparently not by his current sperm stores. Nevertheless, copula duration varied with male size, with small males copulating longer, and with female size, as copulations lasted longer with larger females, suggesting that males are investing more sperm in larger, more fecund females. While male copula adjustments to their own nutrition and body size may be simple (proximate) physiological responses, responses to female size indicate more strategic and sophisticated sperm‐allocation strategies than previously thought.     

The Hypothesis on Function of Glycosphingolipids and ABO Blood Groups Revisited

Twenty-five years ago the author proposed new ideas of glycoprotein (GPs) and glycosphingolipid (GSLs) functions at the cell membrane. The GPs, apart from their glycan carrying capacity, were assumed to have specific, protein associated, functions. In contrast, GSLs such as those of globo and neolacto/lacto series, were considered to be energetically cheap membrane packing substances, filling in membrane spaces not covered with functional GPs. The terminal carbohydrate structures of the neolacto/lacto GSLs, i.e., sialic acid residues and ABH glycotopes, were postulated to have either regulatory or protective functions, respectively. A special active role was ascribed to terminal β-galactosyl residues of GSLs and GPs. Gangliosides were considered to be functional GSLs. In the present review the author discusses these old ideas in context of the contemporary knowledge and comes to the conclusion that they have not aged.     

Hypoxic Reptiles: Blood Gases, Body Temperature and Control of Breathing

Our contribution to this symposium is a review of recent modelsand experimental cdata on oxygen homeostasis in vertebrateswith normal intracardiac shunts; i.e., amphibians and reptiles.We focus on the interactions among hemoglobin function, bodytemperature regulation, and cardiovascular shunts under normalconditions (i.e., breathing fresh air at or near sea level)and during external hypoxia (e.g., altitude, burrows) and internalhypoxia (e.g., anemia, hemorrhage). Mathematical models andexperimental data suggest that animals with venous admixturefrom cardiovascular shunts will show biphasic arterial and mixedvenous Po₂ responses to warming; i.e., first increasing andthen, as the dissociation curve shifts too far to the right,decreasing. This has implications for many physiological functionsincluding oxygen consumption by tissues, control of breathing,as well as preferred body temperature and its regulation. Wepresent some of the recent experiments that have explored theseimplications.     

A Mathematical Model of a Fishery with Variable Market Price: Sustainable Fishery/Over-exploitation

We present a mathematical bioeconomic model of a fishery with a variable price. The model describes the time evolution of the resource, the fishing effort and the price which is assumed to vary with respect to supply and demand. The supply is the instantaneous catch while the demand function is assumed to be a monotone decreasing function of price. We show that a generic market price equation (MPE) can be derived and has to be solved to calculate non trivial equilibria of the model. This MPE can have 1, 2 or 3 equilibria. We perform the analysis of local and global stability of equilibria. The MPE is extended to two cases: an age-structured fish population and a fishery with storage of the resource.     

Rapid Blood Ketone Body Estimation in the Diagnosis of Diabetic Ketoacidosis

Different methods of assessing ketone body concentrations in blood and plasma of ketoacidotic patients have been compared. We confirmed that Ketostix reacts strongly with acetoacetate, giving a useful range of 0 to 10 mM for plasma acetoacetate, that acetone reacts weakly, and that 3-hydroxybutyrate does not react at all. Plasma Ketostix readings correlated only moderately well with enzymatically determined whole-blood acetoacetate. All samples giving a + + + reaction contained more than 1·6 mM acetoacetate while only 4 out of 21 samples showing 0 contained more than 0·4 mM. Comparison of Ketostix readings with total blood ketone body content showed poor correlation. One reason for this was the large variation in the ratio of 3-hydroxybutyrate to acetoacetate in ketoacidosis; another was that often Ketostix had been stored in such a way that they had become damp, which impairs their reliability. If the Ketostix reading and estimation of the blood pH show a discrepancy we suggest that an enzymatic assay should be used to determine the ketone bodies and lactate.     

Contesting Agriculture: Cooperativism and Privatization in the New Eastern Germany

Contesting Agriculture: Cooperativism and Privatization in the New Eastern Germany. Hans C. Buechler and Judith-Maria Buechler. Albany: State University of New York Press, 2002. 354 pp.