The Importance of Spatial Effects for Environmental Health Policy and Research

Issues of spatial scale and resolution are intrinsic to efforts aimed at protecting and improving environmental health. Deciding on an appropriate policy or selecting a suitable research design implies a decision, either implicit or explicit, about spatial scale and resolution. This article looks at issues in the context of environmental health, reviews crucial problems and questions, and examines examples of spatial effects on analytical results related to causal inference, disease clustering, and analysis and interpretation of census data. The discussion focuses on the need to consider spatial issues as a key component of informed, well- reasoned decisions about safeguarding environmental health.     

国内脂肪酶研究状况分析

基于中国期刊全数据库(CJFD)1995～2001年中脂肪酶检索数据,从基础研究和应用研究两个方面对其进行了统计分析,客观地概述和评价了国内该领域的研究状况。着重分析了国内脂肪酶研究的现状、发展趋势。结果表明,中国脂肪酶研究多集中在基础研究领域,基础研究各方面发展不平衡,国内9个城市是脂肪酶研究的核心区域,高等学校是脂肪酶研究的主要机构。     

Wlassicsia,Bunops & Onchobunops (Anomopoda), three related genera

Comparison of the gross morphology and trunk limb ultrastructure of the macrothricid genera Wlassicsia, Bunops and Onchobunops by light and electron microscopy demonstrated their morphological similarity. We propose the synonymy of Onchobunops Fryer & Paggi with Bunops Birge on the basis of shared characteristics.     

Structural comparisons of TIM barrel proteins suggest functional and evolutionary relationships between beta-galactosidase and other glycohydrolases

Beta-galactosidase (lacZ) from Escherichia coli is a 464 kDa homotetramer. Each subunit consists of five domains, the third being an alpha/beta barrel that contains most of the active site residues. A comparison is made between each of the domains and a large set of proteins representative of all structures from the protein data bank. Many structures include an alpha/beta barrel. Those that are most similar to the alpha/beta barrel of E. coli beta-galactosidase have similar catalytic residues and belong to the so-called "4/7 superfamily" of glycosyl hydrolases. The structure comparison suggests that beta-amylase should also be included in this family. Of three structure comparison methods tested, the "ProSup" procedure of Zu-Kang and Sippl and the "Superimpose" procedure of Diederichs were slightly superior in discriminating the members of this superfamily, although all procedures were very powerful in identifying related protein structures. Domains 1, 2, and 4 of E. coli beta-galactosidase have topologies related to "jelly-roll barrels" and "immunoglobulin constant" domains. This fold also occurs in the cellulose binding domains (CBDs) of a number of glycosyl hydrolases. The fold of domain 1 of E. coli beta-galactosidase is closely related to some CBDs, and the domain contributes to substrate binding, but in a manner unrelated to cellulose binding by the CBDs. This is typical of domains 1, 2, 4, and 5, which appear to have been recruited to play roles in beta-galactosidase that are unrelated to the functions that such domains provide in other contexts. It is proposed that beta-galactosidase arose from a prototypical single domain alpha/beta barrel with an extended active site cleft. The subsequent incorporation of elements from other domains could then have reduced the size of the active site from a cleft to a pocket to better hydrolyze the disaccharide lactose and, at the same time, to facilitate the production of inducer, allolactose.     

Show Me Your Menu

This activity discusses a two-day unit on ecology implemented during the summer of 2004 using the project-based science instructional (PBSI) approach. Through collaborative fieldwork, group discussions, presentations, and reflections, students planned, implemented, and reported their own scientific investigations on the environmental health of their local park in the borough of Queens, New York City. Students' questions included a wide range of topics that dealt with plants, animals, soil and water, and the interactions and relationships between these variables. Findings from students' reports and presentations indicated that the pH of the soil and pond water system at the park, as well as the characteristics of terrestrial and aquatic organisms, differ by location. In addition, results of the unit of instruction demonstrated that it is possible to teach students science content and process in a reasonably short period using the PBSI approach.     

Parental Permission and Child Assent in Research on Children

Grounded on the ethical principle of respect for persons, parental permission andchild assent function together to protect the child and to foster thedevelopment of the child’s self-determination. Although both parental permissionand child assent involve the same components of information sharing,comprehension, and voluntariness, how these three components are understood andoperationalized should differ depending on the developmental level of the child.For example, the amount of information that a child must comprehend to providemeaningful and developmentally appropriate child assent (or dissent) should beallowed to vary with the age and maturity of the child. By understanding childassent together with the important protections of parental permission, childassent does not need to be burdened with the same informational and processrequirements. As a result, the age (as a proxy for developmental stage) at whicha child is deemed capable of assent would be lower (i.e., 5 to 7 years old). Byassuming a lack of capacity, the potential arises to dishonor and disregard achild’s wishes by failing to solicit meaningful assent or dissent. Furtherresearch needs to be done on how best to obtain truly informed and voluntaryparental permission and child assent for research participation.     

乳腺癌干细胞研究进展

乳腺癌在女性肿瘤相关性疾病的死亡中占有主要地位,乳腺癌干细胞在乳腺癌的发生、发展、治疗抵抗性、转移及复发中起到了关键作用。鉴于乳腺癌干细胞对治疗乳腺癌的重要意义,我们就乳腺癌干细胞的发现、研究意义、研究现状及研究中存在的问题做简要综述,以期为乳腺癌的研究开拓新的思路。     

Phenetic comparison of sevenEchinacea species based on immunomodulatory characteristics

The purpose of the present investigation was to compare similarities and differences in immune response among Echinacea species, which are commonly used to treat upper respiratory infections. The investigation involved two components: acquisition of immunomodulatory data reported here for the first time, and combined phenetic analysis of these data along with previous reports. Experimental data were obtained by stimulating human PBMC in vitro with extracts from Echinacea spp. and assaying production of three cytokines (interleukin-1β [IL-1β] interleukin-2 [IL-2], and tumor necrosis factor α [TNF-α]). Phenetic analyses were employed to compare responses across the entire data set, including UPGMA (Unweighted Pair Group Method with Arithmetic Mean) and neighbor-joining methods. In the immune experiments conducted for this investigation, E. angustifolia,E. paradoxa, E. purpurea, E. simulata, andE. tennesseensis extracts significantly augmented IL-1 β and TNF-α production, whereas no extracts significantly modulated IL-2. All phenetic methods produced similar dendrograms, revealing two species pairs (E. angustifolia + E. simulata and E. pallida + E.sanguinea) where both species cluster tightly and have similar immune-response profiles. These two species-pairs are maximally dissimilar from each other. The remaining species (E. paradoxa, E. purpurea, and E. tennesseensis) occupy intermediate positions in the dendrogram. Our results suggest that Echinacea spp. act heterogeneously on immune function. The utility of these data for science and industry is discussed.