Aestivo-hibernal reproductive diapause in Drosophila moriwakii: flight as a controlling factor

Drosophila moriwakii Okada & Kurokawa (Diptera; Drosophilidae) generally has only one generation per year and enters aestivo-hibernal reproductive diapause in Sapporo, northern Japan, but a small fraction of the population produced a second generation in summer at a place where breeding resources were abundant. In this species, diapause seems to be controlled by flight activity. When flies were cultured in cages in which they were able to fly freely, they entered diapause irrespective of photoperiod, but they did not do so at long daylengths when cultured in small vials in which they were prevented from flying. Furthermore, flies with wings removed did not enter diapause at long daylengths even if they were cultured in the cages.     

Meeting threats to global health: a call for American leadership

Although the application of major biomedical advances has yielded spectacular results for individual health, there has been little improvement in the health of whole populations. There is a "back to the future" irony in the fact that at the inception of the 21st century, the eruption and spread of a multitude of "old" and "new" infectious diseases has become the most serious global threat to the health of humankind. At this historical juncture, the United States is the country with the most potential for favorably influencing global health and health care. Although there are historical, cultural, economic, and political factors that impede the United States from rising to this challenge, there is both a moral imperative and a rational long-term self-interest basis for the U.S. medical profession and government to exercise leadership in facing the health challenges of tragic and genocidal proportions that threaten everyone in an increasingly interdependent world.     

Conference summary: diet as an environmental factor in development of insulin-dependent diabetes mellitus.

An international symposium on diet as an environmental factor in development of insulin-dependent diabetes mellitus (IDDM) was held in Ottawa, Ont., Canada, September 1989. Several environmental factors such as viruses and chemicals, as well as diet modifications per se, were reviewed in both human and animal diabetes. Although the pathophysiology in the BB rat and nonobese diabetic (NOD) mouse may have different immunological mechanisms, both these animal syndromes of spontaneous IDDM are markedly affected by diet. In them, cereal-based rodent diets are the most diabetogenic and hydrolyzed casein-based purified diets are least diabetogenic. In two different NOD mouse colonies, diabetogenicity of cereal-based diets can be markedly decreased by extracting the diet with chloroform-methanol or water, reflecting either the different composition of the diets used in each colony or the chemical extraction and (or) alteration of certain diabetogenic agents. Thus, dietary lipids can be potent immune system modulators in several systems and the role of chloroform-methanol soluble agents in initiation and (or) promotion of the disease process is being studied. Attention was focused on protein sources previously identified by some groups as diabetogenic such as skim milk powder and wheat products, both of which can be found in natural ingredient rodent feeds. Circulating antibodies to dietary antigens such as bovine serum albumin and (crude) wheat gliadin may be elevated in diabetes-prone rodents and newly diagnosed patients, but their relationship to the pathogenesis of IDDM remains to be established. Because diet components can clearly influence the expression of the diabetic syndromes in the BB rat and NOD mouse, it will be crucial to identify the chemical nature of such components as a first step in understanding their mode of action.(ABSTRACT TRUNCATED AT 250 WORDS)     

Asian river fishes in the Anthropocene: threats and conservation challenges in an era of rapid environmental change

This review compares and contrasts the environmental changes that have influenced, or will influence, fishes and fisheries in the Yangtze and Mekong Rivers. These two rivers have been chosen because they differ markedly in the type and intensity of prevailing threats. The Mekong is relatively pristine, whereas the Three Gorges Dam on the Yangtze is the world's largest dam representing the apotheosis of environmental alteration of Asian rivers thus far. Moreover, it is situated at the foot of a planned cascade of at least 12 new dams on the upper Yangtze. Anthropogenic effects of dams and pollution of Yangtze fishes will be exacerbated by plans to divert water northwards along three transfer routes, in part to supplement the flow of the Yellow River. Adaptation to climate change will undoubtedly stimulate more dam construction and flow regulation, potentially causing perfect storm conditions for fishes in the Yangtze. China has already built dams along the upper course of the Mekong, and there are plans for as many as 11 mainstream dams in People's Democratic Republic (Laos) and Cambodia in the lower Mekong Basin. If built, they could have profound consequences for biodiversity, fisheries and human livelihoods, and such concerns have stalled dam construction. Potential effects of dams proposed for other rivers (such as Nujiang-Salween) are also cause for concern. Conservation or restoration measures to sustain some semblance of the rich fish biodiversity of Asian rivers can be identified, but their implementation may prove problematic in a context of increasing Anthropocene alteration of these ecosystems.     

Intestinal flora of animal models of human diseases as an environmental factor

Genetically-engineered animals are known to be useful in clarifying the functions of many genes and as animal models for human diseases. However, it has been widely reported that pathophysiology is not expressed in these animals when they become germfree or SPF animals, i.e., the pathophysiology is not the result of genes alone and a combination of gene function and intestinal flora as an environmental factor are necessary. It is important to determine the roles of each of these two factors by pathophysiological analysis. Gnotobiotic mice were produced by establishment of specified bacterial species in germfree animals to form the intestinal flora of SPF animals and they were placed in barrier facilities. Measures have been taken against infections by bacteria such as Pseudomonas aeruginosa and Enterobacter cloacae. In addition, gnotobiotic mice with a highly normal physiology are required. Analysis of the effects of each bacterial species and combinations of bacteria on in vivo functions, i.e., the cross-talk between the host and intestinal flora, is essential in the creation of better laboratory animals. Monitoring of the intestinal flora, a key factor in the colonies produced, is a topic for future research.     

The conference on reproductive behavior: a history

The Society for Behavioral Neuroendocrinology was, in part, an outgrowth of the Conference on Reproductive Behavior, which was, in turn, an outgrowth of the West Coast Sex Meetings. In this article I trace the history of these organizations. The West Coast meetings provided an opportunity for free and informal exchange among west coast researchers studying sexual behavior. The 29 meetings of the Conference on Reproductive Behavior began with a similar format that evolved as success and growth forced numerous changes. With time, the meetings became more structured and more dependent on time limits, and added invited addresses, symposia, workshops, roundtables, posters, tours, and papers presented by abstract only. The administrative structure was kept as simple as possible. With changing times, these informal meetings eventually were superseded by the Society for Behavioral Neuroendocrinology.     

Gender as a factor in an environmental assessment of the consumption of animal and plant-based foods in Germany

Purpose

Due to their production intensity, different foods of animal or plant origin play a crucial role in the assessment of the environmental impacts of human nutrition and diets. Based on a representative nutrition survey in Germany from the year 2006, a life cycle assessment (LCA) was conducted to quantify nutrition-related emissions of animal and plant-based foods (excluding beverages), with a special focus on the socio-demographic factor gender.

Materials and methods

For the study, representative data sets concerning German food production and consumption were used. These were complemented by the Danish LCA Food database and other LCA data to analyse the impact of food imports. As regards environmental impact assessment, global warming potential (GWP) was assessed, which included emissions from direct land use change and land use (dLUC, LU), along with three inventory indicators (ammonia emissions, land use, blue water use). The following food groups were analysed from cradle-to-store and their impacts were evaluated and compared with each other: animal-based foods (meat products, milk products, egg products and fish products), plant-based foods (grain products, vegetables, fruits, potato products, margarine/oils, sugar/sweets). The reference year in the study is the year 2006.

Results and discussion

For all indicators, the results show strong variation between the genders. Even if the physiologically different consumption patterns among men and women are adjusted on a weight basis, men show a higher impact in terms of GWP (CO₂ eq. +25%), ammonia emissions (+30%) and land use (+24%). In contrast, women demonstrate a higher water demand (+11%). These differences are primarily caused by a higher share of meat and meat products in the usual diet of men (+28%) as well as of fruit and vegetables in the diet of women (+40%). If men were to shift qualitatively to the usual diet of women, then 14.8 Mt CO₂ eq. and 60.1 kt ammonia emissions could be saved annually. Within the system boundaries of our study, this would translate into a reduction of 12% of CO₂ eq. and 14% of ammonia emissions. With regard to land use, this equals an area of 15,613?km²?year^?1 (?11%), whereas the total blue water demand would be increased by 94?Mm³?year^?1 (+7%). Limitations within this study are caused by the system boundaries cradle-to-store and are also due to the restricted set of environmental indicators which were analysed. Nonetheless, our results for GWP and land use are in keeping with previous studies. The results concerning ammonia and blue water use are limited when compared with other study results.

Conclusions

The study shows that within one society distinct diet profiles with markedly different environmental impacts are already established. Taking cultural and physiological considerations among the genders into account, these differences could be seen as offering potential opportunities to strengthen sustainable diet profiles. Further research should also consider health impact assessments to ensure that alterations in diet profiles due to environmental constraints do not lead to disadvantageous public health effects. Particular attention should be paid here to potentially undernourished subgroups (such as the elderly, sick people, pregnant women).     

Assessing the reproductive behavior of on- and off-reservation American Indian females: characteristics of two groups in Montana

Only limited fertility and general reproductive health data exist on American Indians. Using data from the 1987 Montana American Indian Health Risk Assessment, we found that the fertility of American Indians in Great Falls and on the Blackfeet Reservation was similar to blacks in the U.S. and relatively high when compared with fertility of whites in the United States. The influence of the direct determinants of fertility (nuptiality, contraceptive use, and lactation) was very different for the populations examined in this study. Great Falls American Indians and the U.S. black population were similar regarding age at first sexual intercourse (very young), breastfeeding (low prevalence and short duration), planning status of pregnancies (high unplanned), and contraceptive use (only moderate use). In contrast, Blackfeet women on the reservation and the U.S. white population married relatively late, had very high contraceptive use, used effective methods of contraception, and had moderately high levels of breastfeeding. However, Blackfeet fertility was much higher than that of whites. Three interrelated reasons are suggested as possible explanations. Blackfeet couples either wanted high fertility, were relatively poor users of family planning methods, or used less effective methods until they had exceeded their desired family size after which time they turned to sterilization. These finds raise numerous questions concerning the social and economic factors that may account for these group similarities and differences. Further studies with much larger data sets are needed to address these issues adequately.     

Mounting evidence for vitamin D as an environmental factor affecting autoimmune disease prevalence

Low vitamin D status has been implicated in the etiology of autoimmune diseases such as multiple sclerosis, rheumatoid arthritis, insulin-dependent diabetes mellitus, and inflammatory bowel disease. The optimal level of vitamin D intake required to support optimal immune function is not known but is likely to be at least that required for healthy bones. Experimentally, vitamin D deficiency results in the increased incidence of autoimmune disease. Mechanistically, the data point to a role for vitamin D in the development of self-tolerance. The vitamin D hormone (1,25-dihydroxy vitamin D(3)) regulates T helper cell (Th1) and dendritic cell function while inducing regulatory T-cell function. The net result is a decrease in the Th1-driven autoimmune response and decreased severity of symptoms. This review discusses the accumulating evidence pointing to a link between vitamin D and autoimmunity. Increased vitamin D intakes might decrease the incidence and severity of autoimmune diseases and the rate of bone fracture.     

Predator driven reproductive behavior in a tropical frog

Life history trade-offs in reproductive strategy are often invoked as ecological agents of evolutionary change, despite a limited amount of experimental data from the field. The larval deposition strategy of Allobates femoralis was tested in Southeastern Peru using a blocked, fully crossed experimental design. Arrays of four pools were used to test the effects of pool size and the presence of a predatory insect (Belostomatid) on the deposition behavior of A. femoralis. Further experiments investigated the colonization of insect predators into potential larval habitats and interactions between predatory insects. Results suggest that pool size, the presence of predatory aquatic insects, and interactions between predators, influence larval deposition in A. femoralis. Similar ecological interactions may have driven toxic dendrobatids to the use of arboreal phytotelmata and associated derived reproductive strategies.     

Adaptive parental feeding as a factor influencing the reproductive rate in the grey starling

1. Adaptive parental feeding of chicks is one of the factors influencing the reproductive rate of a local population.
2. The food resources in the rural and urban colonies in Tokyo were entirely different as proved by collar experiments of the chicks.
3. In the rural habitat the mole-cricket of fair size (1 g) and of a high nutritive value was the ‘key food' to all broods and only a few other items were added for larger broods.
4. In the urban habitat the food consisted of both animal and plant (fruits) items of various kinds, but the animal matter was mostly small and of poor nutritive value, and fruits are much less nutritive than animal matters as experimentally proved with captive chicks by using cherries which are the most abundant and favoured fruit.
5. Thus the food preference and the feeding ability of parents had more important effect upon growth rate and flying success of chicks in the urban colony than in the rural, especially in larger broods.
6. In the rural colony, the adaptive reaction of parents to a large brood size (experimentally increased) was evident in a pair which adequately switched the normal food, the secretive mole-cricket, to an easily obtainable kind, the small white pupae and caterpillars.
7. Such focussed or concentrated foraging was also shown to some other food items to be found in clustered condition and selection for large size was also suggested, since such large foods as the gecko or lizard were brought though they were disgorged by chicks in some cases.
8. Subject to various factors, there is the maximum possible feeding frequency for the parents and therefore, however hard the parents might work, there were limits of brood size they could successfully raise.
9. Such limits were 6 chicks for some parents or 7 for others, and a single parent could raise not more than 3 chicks.
10. Thus in the grey starling the broods of 5–6 chicks are of the most efficient size in reproductive rate and are most common, though are subject to difference of local food situation.

     

Interference between enterovirus and reovirus as a limiting factor in environmental virus detection

AIMS: Faecal material from raw sewage or other sources lacking effective treatment sometimes contaminates water for human consumption. The relevant Italian regulations therefore call for testing drinking and recreational water for the presence of enterovirus. METHODS AND RESULTS: Traditional methods of analysis are based on revealing the typical cytopathic effects of enterovirus on cell cultures. However, the presence in environmental samples of different types of virus may cause interference phenomena that mask such cytopathic effects. The paper reports on an experimental test of this interference hypothesis. Buffalo Green Monkey cell cultures were co-infected via mixed suspensions of the polio type 3 virus and reovirus type 1. Cytopathic effects were then sought and the presence of enterovirus tested for via RT-PCR. CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: The results obtained indicate that the normally high sensitivity of tests for the detection of enterovirus in samples is considerably decreased by the simultaneous presence of reovirus.     

Modeling territory attendance and preening behavior in a seabird colony as functions of environmental conditions

In previous studies we developed a general compartmental methodology for modeling animal behavior and applied the methodology to marine birds and mammals. In this study we used the methodology to construct a system of two differential equations to model the dynamics of territory attendance and preening in a gull colony on Protection Island, Strait of Juan de Fuca, Washington. We found that colony occupancy was driven primarily by abiotic environmental conditions, including tide height, time of day, solar elevation, and wind speed over open water. For birds in the colony, preening behavior was driven to some extent by abiotic environmental conditions (including time of day, solar elevation, humidity, and wind speed on the colony), but apparently was driven primarily by local and/or biotic effects not included in the model. In terms of R ² values, the model explained 65% and 37% of the variability in colony occupancy and preening data, respectively, as a function of these six abiotic environmental factors.     

Modeling territory attendance and preening behavior in a seabird colony as functions of environmental conditions

In previous studies we developed a general compartmental methodology for modeling animal behavior and applied the methodology to marine birds and mammals. In this study we used the methodology to construct a system of two differential equations to model the dynamics of territory attendance and preening in a gull colony on Protection Island, Strait of Juan de Fuca, Washington. We found that colony occupancy was driven primarily by abiotic environmental conditions, including tide height, time of day, solar elevation, and wind speed over open water. For birds in the colony, preening behavior was driven to some extent by abiotic environmental conditions (including time of day, solar elevation, humidity, and wind speed on the colony), but apparently was driven primarily by local and/or biotic effects not included in the model. In terms of R(2) values, the model explained 65% and 37% of the variability in colony occupancy and preening data, respectively, as a function of these six abiotic environmental factors.     

Social marketing campaigns as an instrument of influence on the attitude and behavior of youth in the area of sexual health

The principles and necessity of carrying out campaigns "Reasonable Man--Reasonable Choice" are presented. The sociological questioning among young people in Moscow (prior to the campaign) was found to be indicative of the discrepancy between their knowledge of protection from HIV/AIDS and their behavior. The development of the strategy of the campaign included sociological studies, the full set of publicity materials and drawing attention to the campaign itself. The results of the work for 8 months were summed up by means of sociological questioning which demonstrated the effectiveness of all arrangements of the campaign.