3,819 research outputs found

    Location of Adult Children as an Attraction for Black and White Elderly Migrants in the United States

    Get PDF
    This research evaluates the location of adult children as a determinant of interstate primary migration for elderly (aged 60+) blacks and whites, over the 1985-90 period. We find that the location of adult children, as well as environmental amenities, affect the migration of both elderly blacks and whites but exert different redistribution influences on each race. Our results support the migration implications of Eugene Litwak's theory of the "modified extended family", which is considered to be more viable than the isolated nuclear family in a modern society.elderly migrants

    Reproductive Contributions of Foreign Wives in Taiwan: Similarities and Differences among Major Source Countries

    Get PDF
    In light of the entrenchment of sub-replacement fertility and the sharp increase in the stock of foreign wives in Taiwan in recent years, this research studies the reproductive contributions of Taiwan’s foreign wives from the top five source countries (China, Vietnam, Indonesia, Thailand, and the Philippines), based mainly on an application of a multinomial logit model to the micro data of the 2003 census of foreign wives. Our main findings are as follows. First, the overall fertility level of the foreign wives was probably somewhat higher than that of the native-born women and definitely lower than the replacement level. Second, among the five nationalities, those from China were much less reproductive than those from the other countries, mainly because the former were more prone to (1) having a rather old marriage age, (2) having a very large spousal age gap, (3) being separated or divorced, (4) having their current marriage being their second marriage, and (5) having a veteran as the husband. Third, among the four Southeast Asian nationalities, those from Indonesia and the Philippines were more reproductive than those from Thailand and Vietnam. This contrast was a muted reflection of the fertility difference in countries of origin. Fourth, for every nationality, marriage duration and marriage age were the most powerful explanatory factors and must be included in the model to avoid getting misleading estimated coefficients of other less powerful explanatory factors, whereas current age was a spurious factor that should not be used in the model. Fifth, in the context of marriage duration and marriage age, the explanatory factors with rather strong explanatory powers for at least one nationality included spousal age gap, marital status, remarriage status, co-residence with parent, and wife’s employment status. Sixth, the expected negative effect of wife’s educational attainment on lifetime fertility turned out to be either non-existent or modest. In particular, it had practically no effect on the probability of being childless. These findings implied that getting better educated foreign wives could increase the quality of their children with little or no reduction in the number of their children and in their probability of being childlessASEAN countries, China, international marriage, international migration, fertility, Taiwan

    Reproductive contributions of Taiwan´s foreign wives from the top five source countries

    Get PDF
    This research studies the reproductive contributions of Taiwan’s foreign wives from China, Vietnam, Indonesia, Thailand, and the Philippines, based on applications of the multinomial logit model to the micro data of the 2003 Census of Foreign Spouses. Wives from China are found to have the lowest lifetime fertility of 1.4 children, mainly because they were more prone to marry later, have a very large spousal age gap, be separated or divorced, and have their current marriage be their second marriage. The effect of wife’s educational attainment on lifetime fertility turned out to be either modest or nonexistent.fertility, international marriage, international migration, reproductive contribution, Taiwan

    Pediatric asthma and autism-genomic perspectives.

    Get PDF
    High-throughput technologies, ranging from microarrays to NexGen sequencing of RNA and genomic DNA, have opened new avenues for exploration of the pathobiology of human disease. Comparisons of the architecture of the genome, identification of mutated or modified sequences, and pre-and post- transcriptional regulation of gene expression as disease specific biomarkers are revolutionizing our understanding of the causes of disease and are guiding the development of new therapies. There is enormous heterogeneity in types of genomic variation that occur in human disease. Some are inherited, while others are the result of new somatic or germline mutations or errors in chromosomal replication. In this review, we provide examples of changes that occur in the human genome in two of the most common chronic pediatric disorders, autism and asthma. The incidence and economic burden of both of these disorders are increasing worldwide. Genomic variations have the potential to serve as biomarkers for personalization of therapy and prediction of outcomes

    Tetra-μ-benzoato-κ8 O:O′-bis­[(benzoic acid-κO)nickel(II)]

    Get PDF
    The title compound, [Ni2(C7H5O2)4(C7H6O2)2], is composed of two NiII ions, four bridging benzoate anions and two η1-benzoic acid mol­ecules. The [Ni2(PhCOO)4] unit adopts a typical paddle-wheel conformation. The center between the two NiII atoms represents a crystallographic center of inversion. In addition, each NiII ion also coordinates to one O atom from a benzoic acid mol­ecule. The crystal packing is realised by inter­molecular hydrogen-bonding inter­actions and π–π stacking inter­actions, with a centroid–centroid distance of 3.921 (1) Å

    Effects of fully open-air [CO2] elevation on leaf photosynthesis and ultrastructure of Isatis indigotica Fort

    Get PDF
    Traditional Chinese medicine relies heavily on herbs, yet there is no information on how these herb plants would respond to climate change. In order to gain insight into such response, we studied the effect of elevated [CO2] on Isatis indigotica Fort, one of the most popular Chinese herb plants. The changes in leaf photosynthesis,chlorophyll fluorescence, leaf ultrastructure and biomass yield in response to elevated [CO2] (550619 mmol mol–1) were determined at the Free-Air Carbon dioxide Enrichment (FACE) experimental facility in North China. Photosynthetic ability of I. indigotica was improved under elevated [CO2]. Elevated [CO2] increased net photosynthetic rate (PN), water use efficiency (WUE) and maximum rate of electron transport (Jmax) of upper most fully-expended leaves, but not stomatal conductance (gs), transpiration ratio (Tr) and maximum velocity of carboxylation (Vc,max). Elevated [CO2] significantly increased leaf intrinsic efficiency of PSII (Fv’/Fm’) and quantum yield of PSII(WPSII), but decreased leaf non-photochemical quenching (NPQ), and did not affect leaf proportion of open PSII reaction centers (qP) and maximum quantum efficiency of PSII (Fv/Fm). The structural chloroplast membrane, grana layer and stroma thylakoid membranes were intact under elevated [CO2], though more starch grains were accumulated within the chloroplasts than that of under ambient [CO2]. While the yield of I. indigotica was higher due to the improved photosynthesis under elevated [CO2], the content of adenosine, one of the functional ingredients in indigowoad root was not affected

    Polytypism and Unexpected Strong Interlayer Coupling of two-Dimensional Layered ReS2

    Full text link
    The anisotropic two-dimensional (2D) van der Waals (vdW) layered materials, with both scientific interest and potential application, have one more dimension to tune the properties than the isotropic 2D materials. The interlayer vdW coupling determines the properties of 2D multi-layer materials by varying stacking orders. As an important representative anisotropic 2D materials, multilayer rhenium disulfide (ReS2) was expected to be random stacking and lack of interlayer coupling. Here, we demonstrate two stable stacking orders (aa and a-b) of N layer (NL, N>1) ReS2 from ultralow-frequency and high-frequency Raman spectroscopy, photoluminescence spectroscopy and first-principles density functional theory calculation. Two interlayer shear modes are observed in aa-stacked NL-ReS2 while only one interlayer shear mode appears in a-b-stacked NL-ReS2, suggesting anisotropic-like and isotropic-like stacking orders in aa- and a-b-stacked NL-ReS2, respectively. The frequency of the interlayer shear and breathing modes reveals unexpected strong interlayer coupling in aa- and a-b-NL-ReS2, the force constants of which are 55-90% to those of multilayer MoS2. The observation of strong interlayer coupling and polytypism in multi-layer ReS2 stimulate future studies on the structure, electronic and optical properties of other 2D anisotropic materials

    Sesquiterpenes from the marine red alga Laurencia composita.

    Get PDF
    Four new chamigrane derivatives, laurecomin A (1). laurecomin B (2), laurecomin C (3), and laurecomin D (4), one new naturally occurring sesquiterpene, 2,10-dibromo-3-chloro-7-chamigren-9-ol acetate (5), and three known halogenated structures, deoxyprepacifenol (6), 1-bromoselin-4(14),11-diene (7), and 9-bromoselin-4(14).11-diene (8), were isolated from the marine red alga Laurencia cornposita collected from Pingtan Island, China. The structures of these compounds were unambiguously established by 1D, 2D NMR and mass spectroscopic techniques. The bioassay results showed that 2 was active against both brine shrimp and fungus Colletotrichum lagenarium. (C) 2012 Elsevier B.V. All rights reserved.Four new chamigrane derivatives, laurecomin A (1). laurecomin B (2), laurecomin C (3), and laurecomin D (4), one new naturally occurring sesquiterpene, 2,10-dibromo-3-chloro-7-chamigren-9-ol acetate (5), and three known halogenated structures, deoxyprepacifenol (6), 1-bromoselin-4(14),11-diene (7), and 9-bromoselin-4(14).11-diene (8), were isolated from the marine red alga Laurencia cornposita collected from Pingtan Island, China. The structures of these compounds were unambiguously established by 1D, 2D NMR and mass spectroscopic techniques. The bioassay results showed that 2 was active against both brine shrimp and fungus Colletotrichum lagenarium. (C) 2012 Elsevier B.V. All rights reserved
    corecore