Macro shocks and micro outcomes: child nutrition during Indonesia’s crisis

A survey of households in rural Java is used to assess the nutritional impact of Indonesia's drought and financial crisis of 1997/1998. A time-age-cohort decomposition reveals significant nutritional impacts. However, child weight-for-age (WAZ) remained constant throughout the crisis, despite rapid increases in food prices and the consequent household consumption shock. The evidence is consistent with the hypothesis that within households, mothers buffered children's caloric intake, resulting in increased maternal wasting. However, reductions in the consumption of high-quality foods further resulted in increased prevalence of anemia for both mothers and children. The combined effects were particularly severe for cohorts conceived and weaned during the crisis.     

A registry for exposure and population health in the Altai region affected by fallout from the Semipalatinsk nuclear test site

A registry of the rural population in the Altai region exposed to fallout from nuclear tests at the Semipalatinsk test site (STS) was established more than four decades after the first Soviet nuclear explosion on August 29, 1949. Information about individuals living in an exposed and a control area was collected using all available local sources, such as kolkhoz documentation, school registries, medical treatment records and interviews with residents. As a result, a database comprising an exposed group of 39 179 individuals from 53 Altai region villages, 6769 external and 3303 internal controls was compiled. For several settlements, effective dose estimates reached the level of 1.5 Sv, while the average effective dose estimate in the exposed group was 340 mSv. Dosimetric data, vital status information and health records gathered at rayon and village medical facilities are held in the registry. Cause-of-death information for deceased residents is obtained from death registration forms archived at the Altai region vital statistics office. At present, a follow-up of approximately 40% of the population exposed in 1949 has been done. More will be added by searching for migrants to the larger towns of the Altai region, i.e. Barnaul, Rubtsovsk and Biisk. In order to assess the influence of radiation exposure, analytical studies with a case-control design for stomach and lung cancer are currently being prepared. The number of known cases is sufficient to detect an odds ratio of 1.5 at the 95% confidence level. Epidemiological studies in populations affected by fallout from STS may be equally important to the atomic bomb survivors’ study for the direct quantification of radiation effects. The range of exposure rates experienced will extend the acute high-dose-rate findings from Hiroshima/Nagasaki towards acute and protracted lower exposures, which are more relevant for radiation protection issues. Received: 3 March 1999 / Accepted in revised form: 8 June 1999     

Reproductive factors and breast cancer risk in Palestine: A case control study

BackgroundEarly age at menarche, late age at menopause, and late age at first full-term pregnancy are linked to a modest increase in the risk of developing breast cancer (breast ca). This study aims to investigate the reproductive determinants of breast cancer among women in the West Bank of Palestine.A structured questionnaire was used to collect data in a case-control study (237 registered cases and 237 controls). A multivariate analysis model was used to adjust for the association between women’s reproductive factors and breast ca risk. This study was approved by Al Quds University Ethical Research Committee and the Ministry of Health research unit.ResultsIn the multivariate analysis, menarche after 13 years of age, use of oral contraceptives for more than two months, and hormonal contraceptives use significantly doubled the risk for breast ca (Adjusted Odds Ratio (AOR) = 2.03, 95 % CI: 1.21–4.37, p < 0.011 and AOR = 2.2, 95 % CI: 1.24–4.01, p = 0.008, respectively). Women who used hormone replacement therapy (HRT) were significantly associated with higher odds (5 folds) of having breast ca versus those who did not use them (AOR 5.02, 95 % CI: 1.93–13.06, p = 0.001). Similarly, nulliparous women showed 6 times the odds of breast ca compared with women with one or more children (p = 0.005). Also, parental consanguinity marriage (AOR 2.59, 95 % CI: 1.53–4.36, p = 0.001) and positive family history (AOR 3.88, 95 % CI: 2.19–6.87, p = 0.001) of the condition can be strong determinants for breast ca in this study.ConclusionThis study provides clear evidence that the use of reproductive hormones, whether as a birth control tool or for therapeutic purposes, must be rationalized worldwide and in Palestine in particular.     

Properties of food loads delivered to nestlings in the pied flycatcher: effects of clutch size manipulation, year, and sex

Experimental manipulation of the number of altricial offspring is supposed to modify parental expenditure in birds. In addition to the observed increase in parental feeding rate, it is also possible that the choice of prey or the size of load may change with the changing demand for food. Sexual differences in the provisioning response are also expected, on the basis of earlier studies. We examined the effect of brood size manipulation on choice of prey brought to nestlings and load size in the pied flycatcher. The composition and size of loads differed between years, possibly depending on varying availability of different prey types. Males responded to brood size enlargement by gathering heavier loads, whereas females showed no response. The alteration of load size in males was not explained by a larger number of prey items or mean prey size, but was a combination of these components. It is likely that males also increased their work rate in response to increased food demand at the nest. The absence of response in females might be because they are unable to increase work rate any further, or because food delivery rate in females can not be optimized by changing load properties. Received: 18 December 1997 / Accepted: 1 March 1998     

Activation of human B lymphocytes. XVII. Synergy between nonspecific and specific signals in the antigen-specific responses of human B cells

The incubation of human peripheral blood lymphocytes (PBL) with the natural killer (NK)-sensitive MOLT-4 cell line results in PBL-target cell conjugate formation by certain lymphocyte subpopulations. Following velocity sedimentation, the PBL depleted of these conjugate-forming subpopulations are markedly diminished in the ability to mediate either antibody-dependent cellular cytotoxicity (ADCC) or NK activity. The immediate testing of highly pure PBL subpopulations isolated from the NK target conjugates does not reveal the expected recovery of augmented ADCC or NK levels. Following in vitro incubation, however, the PBL NK target-binding subpopulations do manifest augmented levels of both NK and ADCC, whereas the depleted PBL continue to display diminished NK and ADCC levels. In addition, the degree of augmented NK and ADCC levels recovered by the NK target-binding PBL subpopulations appears dependent on both the time and the temperature of in vitro incubation. Moreover, the ADCC recovery patterns are identical to those observed for NK activity regardless of the time and temperature of in vitro incubation. These results directly demonstrate that the PBL subpopulations isolated from certain NK target cells are functionally enriched in the ability to mediate from ADCC and NK activity.     

Pollination biology of a disjunct population of the endangered sandhills endemic <Emphasis Type="Italic">Penstemon haydenii</Emphasis> S. Wats. (Scrophulariaceae) in Wyoming,USA

We studied the breeding system and flower visitors of the endangered plant, Penstemon haydenii, at several south-central Wyoming, USA occurrences. In agreement with earlier studies of the species 300 km to the east in Nebraska, we found Wyoming plants to be self-incompatible and pollinator-dependent for sexual reproduction. Flower visitors were several species of native bees in the families Apidae (particularly bumblebees), Halictidae (small sweat bees), and Megachilidae (especially in the genus Osmia); and the masarid wasp Pseudomasaris vespoides. Especially important was Osmia brevis, an abundant megachilid bee, and one of only two species (the sweat bee Lasioglossum (Dialictus) pruinosum was the other) present at all five sites. As in Nebraska, fruit set did not differ between our experimental cross-pollination treatment and an open-pollinated control. However, unlike Nebraska, open-pollinated treatments in Wyoming produced significantly fewer seeds per fruit than the experimental out-crossing treatment. We discuss several possible explanations for seed limitation: (1) a scarcity of pollinators early in the flowering season; (2) resource competition for developing ovules on open-pollinated inflorescences but not on experimental inflorescences; (3) the deposition of self pollen through intra-inflorescence and intra-genet pollinator movements; (4) few S-alleles and mating types in the Wyoming metapopulation compared to the Nebraska metapopulation, from which it likely derives.     

Brain aromatase mRNA expression in two populations of the peacock blenny Salaria pavo with divergent mating systems

Aromatase, the key enzyme in the conversion of androgens to estrogens, regulates the availability of these hormones in tissues and controls many physiological and behavioral processes. In fish and other vertebrates, the regulation of aromatase expression in the brain has been implicated in the modulation of male sexual and aggressive behaviors. Here, the pattern of mRNA expression of the brain aromatase isoform (encoded by the CYP19A2 gene also referred as CYP19b) was quantified at the peak of spawning season in brain macroareas from males and females of the blenny Salaria pavo originated from two populations displaying male alternative reproductive tactics but differing in their mating systems. In Trieste (Adriatic) nesting males aggressively defend nests and take the initiative in courtship and perform sexual displays more often than females while in Ria Formosa (Southern Portugal) the pattern is reversed as a result of shortage of appropriate nesting sites. Nesting males from Ria Formosa had overall higher levels of brain aromatase mRNA expression than nesting males from Trieste, suggesting a higher brain estrogen synthesis in these males. Since in some fish species exogenous estradiol administration has been shown to decrease sexual and agonistic behaviors, the higher levels of brain aromatase in Ria Formosa nesting males may explain their reduced expression of sexual and aggressive displays when compared with nesting males from Trieste. Alternatively, the higher brain aromatase levels in nesting males from Ria Formosa could be a mechanism to decrease the putative androgen-induced activation of aggressive and sexual displays by reducing the local availability of androgens through their metabolization into estrogens. Although females and parasitic female-like males also differ in their displays between populations, the interpopulational pattern of brain aromatase mRNA expression was similar, suggesting that other neuroendocrine agents mediate the expression of female and female-like behaviors. In conclusion, brain aromatase availability seems like a probable mechanism to regulate the effects of steroids on the brain circuits underlying the expression of sexual and agonistic displays in S. pavo.     

Ecological character displacement caused by reproductive interference

We carried out a theoretical investigation of whether ecological character displacement can be caused by reproductive interference. Our model assumes that a quantitative character is associated with both resource use and species recognition, and that heterospecific mating incurs costs. The model shows that ecological character displacement can occur as a consequence of evolution of premating isolation; this conclusion is based on the premise that resource competition is less intense between species than within species and that the ecological character also contributes to premating isolation. When resource competition between species is intense, extinction of either species may occur by competitive exclusion before ecological character divergence. Some observational studies have shown that character displacement in body size is associated with not only resources use but also species recognition. We propose that body size displacement can occur as a consequence of evolution of premating isolation. Our results suggest that ecological character displacement results from reproductive character displacement.     

Ecological analyses of nesting success in evening grosbeaks

Summary We studied the nesting success of Evening Grosbeaks (Coccothraustes vespertinus) inhabiting two areas of the Front Range of the Rocky Mountains of Colorado from 1983–1987. Sixty-four nests were followed during building, incubating, brooding, and fledging; 54.7% were successful (young fledged). The largest number of nests failed during incubation. Nests started later were more successful than nests begun earlier in the season. Failure was most likely due to severe weather, abandonment during building, or predation. Specific habitat characteristics of grosbeak nesting sites and where nests were placed in trees were consistently associated with nesting success. Successful nests, when compared with nests that failed, were: (1) built in more open areas characterized by dispersed vegetation and a higher minimum canopy, (2) oriented in more southerly directions, (3) built closer to the main trunk of the nest tree, and (4) built in larger trees. Current ideas about whether or not birds actually select nest-sites are briefly discussed. We conclude that some grosbeaks optimally select nest sites where the likelihood of producing fledglings is higher than in other areas.     

细叶百合的生物量和营养分配

 以栽培的2年生细叶百合（Lilium pumilum）为材料,于2000年的生长季从蕾期至种子成熟期进行6次取样,对其各器官生物量和氮、磷元素的配置进行了动态研究。结果表明,细叶百合虽然以种子繁殖为主,但在整个生长季用于生殖器官的生物量投资的比例并不很大,大量干物质分配到地下器官鳞茎中（平均为60.17%）;茎、叶的生物量分配比例仅次于鳞茎;雄蕊生物量分配比例明显高于雌蕊。在叶萌动及展叶初期植株全氮百分含量最高;从春季萌动至秋季果实成熟,叶中的氮呈逐渐递减的趋势;茎和生殖器官的全氮含量在蕾期最大;生殖器官与叶、鳞茎的全氮含量相关显著。磷在生殖器官的含量较高,这与磷在植物有性生殖过程中的重要作用相一致;生殖器官与茎的全磷含量相关显著。地下器官全氮、全磷随季节变化有增多的趋势;地上各器官全氮、全磷相关显著,随季节变化有明显减少的趋势。