Life Course Perspectives on Women's Autonomy and Health Outcomes

Gender inequality leads to negative demographic consequences in many societies. Patterns of household formation and inheritance strongly influence these consequences. Peasant societies of preindustrial northern Europe emphasized the conjugal bond, while intergenerational bonds were weak. The reverse is true in contemporary northern India. As a result, greater potential exists there for marginalizing women. The convergence of low autonomy due to youth as well as gender means that women's autonomy is at its lowest point during the peak of childbearing years. This has considerable implications for demographic and health outcomes in terms of poorer child survival, slower fertility decline, and poorer reproductive health.     

Partial Purification and Characterization of Naegleria fowleriβ-Glucosidase1

Naegleria fowleri cells, grown axenically, contain high levels of β-D-glucosidase which catalyzes the hydrolysis of 4-methylumbelliferyl-β-D-glucopyranoside (4MUGlc) (K_m, 0.9 mM), octyl-β-D-glucoside (K_m, 0.17 mM), and p-nitrophenyl-β-D-glucopyranoside at relative rates of 1.00, 2.88, and 1.16, respectively (substrate concentration, 3.0 mM). When the amebae are subjected to freeze-thawing, sonication, and centrifugation (100,000 g, 1 h), 85% of the β-glucosidase activity appears in the supernatant fraction. The β-glucosidase was purified 40-fold (34% yield) using a combination of chromatographic steps involving DE-52 cellulose, concanavalin A-Sepharose, and hydroxylapatite followed by isoelectric focusing. The predominant soluble β-D-galactosidase activity in the Naegleria extract copurifies with the β-D-glucosidase; the two activities have the same isoelectric point (pI, 6.9), similar heat stabilities, are both inhibited by lactobionic acid (K_i, 0.40 mM), and exhibit optima at pH 4.5, indicating that they are probably the same enzyme. The Naegleriaβ-D-glucosidase has an apparent molecular weight of 66,000, a Stokes radius of 25 Å, and a sedimentation coefficient of 4.2S. The β-glucosidase is not inhibited by conduritol β-epoxide or galactosylsphingosine but is completely inhibited by 1.25 mM bromo conduritol β-epoxide. The latter compound, when present in the growth medium, inhibits the growth of the organism and profoundly alters its ultrastructure, the main effect being the apparent inhibition of cytokinesis and the generation of multinucleate cells. The issue of the role of the β-glucosidase in the metabolism of the ameba and its possible role in pathogenic mechanisms are discussed.     

印度四种蝗科农业害虫的取食量定量测定及据此推测的亲缘关系

【目的】害虫的取食潜力反映了其生态学和经济学特性,这些知识有助于扩展其控制措施。能否将害虫物种按亲缘关系的远近进行分组,对它们在发育或成熟期的取食量进行定量排序？了解不同害虫种类的取食模式有助于这一问题的解答。 【方法】对印度4种蝗科农业害虫--等岐蔗蝗Hieroglyphus banian (Fab.), 暗翅剑角蝗Acrida exaltata (Walk.), 中华板胸蝗Spathosternum prasiniferum prasiniferum (Walk.) 和 Oxya fuscovittata (Mars.)的取食量进行了定量测定,估测了4种害虫雌雄各若虫龄期及整个成虫期的每日取食量和总取食量。【结果】基于其多食性特征和存在多种食物来源的情况,所有测试中均只提供最为偏好的寄主植物。在研究的4种害虫中,观察到相同的取食率模式,取食率随着若虫龄期的增加而逐步增加。4种害虫的雌虫取食量均显著高于雄虫,且成虫期害虫的取食量显著高于幼期。各龄若虫和成虫的取食量与对应的若虫或成虫历期明显相关。就整个生活期的取食量和平均存活率而言,暗翅剑角蝗A. exaltata 和中华板胸蝗S. pr. prasiniferum 的亲缘关系比其他两种昆虫略近。就整个生活期的取食量和平均存活率而言,单化性害虫（等岐蔗蝗H. banian）和二化性害虫（暗翅剑角蝗A. exaltata) 比另外两种近缘的多化性害虫（中华板胸蝗S. pr. prasiniferum 和 O. fuscovittata）的亲缘关系更近一些。【结论】寿命长的物种(每年可完成1~2个世代)在取食潜力方面比寿命短的物种（每年完成2代以上的世代）更具有可比性。通过对多个不同化性的害虫物种的研究,使我们在这方面能达到更全面的认识。     

Scaling body mass and use of space in three species of marsupials in the Atlantic Forest of Brazil

Abstract Body mass is considered a major determinant of home range size, but usually at a large scale of body mass variation. The exact scale where body size becomes more important than particular adaptations of each species is not clear, and uncertainty in the estimate of home range size is a possible cause of weak intraspecific scaling. We determine the scaling to body mass of two alternative movement measurements, daily home range (DHR) and its intensity of use (IU), in three species of didelphid marsupials, Didelphis aurita, Philander frenatus, and Metachirus nudicaudatus (Didelphimorphia, Didelphidae). The expected scaling exponents DHR ≈ M^0.5 and IU ≈ M^?0.25 were derived from the scaling to body mass of home range and daily movement distance. Animals were tracked in Serra dos Órgãos, Rio de Janeiro, Brazil, using a spool‐and‐line device. Individuals of the three species were compared combining intra and interspecific variation in a single analysis, with species, body mass, and thread tracked as covariates. The model best supported included only body mass as the independent variable, with DHR ≈ M^0.435 and IU ≈ M^?0.218, close to the expected values. The second best supported model included species identity, but with a non‐significant effect. It was surprising that body mass was more important than species identity in a comparison involving only three species, and considering the morphological and locomotory adaptations of the three species. Body mass may become more important than species identity when the scale of variation approaches one order of magnitude.     

Morphological and Biochemical Investigations on Ipomoea Seedlings and their Species Interrelationships

Studies on seedling morphology and the isozyme profile of 12species ofIpomoea , undertaken with a view to tracing the linkageand homology between the species, revealed the concordance ofmorphological findings with biochemical analysis. The trendof clustering in the dendrogram based on isozyme profiles revealedtwo broad clusters or groups. Interrelationships and homologybetween the species revealed by the phyletic tree constructedfrom seedling morphology and from the dendrogram on isozymedata were comparable, with only minor variations. Ipomoea spp.; seedlings; morphology; isozymes; dendrogram; phyletic tree     

Proportion of exotics and relatedness of host species mediate the positive effect of plant richness on the species richness of fruit flies

1. All else being equal, the greater the local species richness of plants, the greater the number of associated herbivore species. Because most herbivore insects feed on a subset of closely related plant species, plant phylogenetic diversity is expected to play a key role in determining the number of herbivore species. What is not well known, however, is how an increase in the species richness of exotic plants affects the species richness of herbivores. 2. In this study, we used plant–fruit fly interactions to investigate the influence of the proportion and species richness of exotic host plants on the species richness of herbivorous insects. We also tested whether the phylogenetic diversity of host plants increases when the number of exotic plant species increases. 3. We found that the species richness of fruit flies is more accurately predicted by the richness of native host plants than by total plant species richness (including both native and exotic species). The proportion of exotic host species and the phylogenetic diversity of host plants had negative and positive effects, respectively, on the species richness of fruit flies. 4. Our findings suggest that a positive effect of plant richness on herbivore richness occurs only when an increase in plant diversity involves plant species with which native herbivores share some evolutionary history.