Structure cristalline du spinelle CdEr2S4

The crystal structure of CdEr₂S₄ is solved from single crystal determinations. The R factor is 0.06 for 120 independent reflections. It is normal spinel, with regular occupancy of the sites. Interatomic distances are : 2.67 Å for ErS, and 2.57 Å for CdS.     

Sampling lesbian, gay, and bisexual populations.

Sampling has been the single most influential component of conducting research with lesbian, gay, and bisexual (LGB) populations. Poor sampling designs can result in biased results that will mislead other researchers, policymakers, and practitioners. Investigators wishing to study LGB populations must therefore devote significant energy and resources to choosing a sampling approach and executing the sampling plan. The authors describe probability and nonprobability sampling methods used in LGB populations and critically discuss the advantages and disadvantages of the sampling methods they review. The authors conclude that no single sampling methodology is correct or incorrect for use in LGB populations; rather, researchers must evaluate advantages and disadvantages of each sampling methodology in the context of the specific research question and the research design. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Requirement for homologous rabbit reticulocyte initiation factor 3 for initiation of alpha- and beta-globin mRNA translation in a crude protozoal cell-free system

Experimental evidence showing specificity of rabbit reticulocyte initiation factor 3 (EIF-3) for selective initiation of mRNA translation is presented. A new cell-free system was developed from Crithidia fasciculata. The crude postmitochondrial supernatant fluid was treated with puromycin and 0.5 M KCl to dissociate mRNA from polysomes and ribosomes into subunits. The drug and salt were removed by gel filtration on Sephadex G-25. Additions of amino acids and energy source initiate protein synthesis. All synthesis starts at the initiation site. This treatment brought about a shift in MgCl2 optimum from 6 to 3 mM. Exogenously supplied rabbit reticulocyte globin mRNA is faithfully translated in this system. However, crithidial EIF-3 has a low affinity for globin mRNA as evidenced by a 6-fold increase in the rate of globin synthesis after the addition of rabbit reticulocyte EIF-3 in the range at which globin synthesis is linear to the amount of globin mRNA added to the system. It is also shown that in a reconstituted system in which ribosomal subunits are depleted from initiation factors, EIF-3 from rabbit reticulocytes has a higher affinity for globin mRNA, as measured by the formation of polysomes during the linear time of amino acid incorporation. These results are taken to indicate that initiation factor EIF-3 action should be considered as an enzyme catalyzed reaction for which various mRNAs serve as different substrate analogs. Therefore, specificity is most likely to be expressed as an affinity of enzyme to substrate and would show as rate difference rather than an all-or-none phenomenon.     

Hybrid solar cells with prescribed nanoscale morphologies based on hyperbranched semiconductor nanocrystals

In recent years, the search to develop large-area solar cells at low cost has led to research on photovoltaic (PV) systems based on nanocomposites containing conjugated polymers. These composite films can be synthesized and processed at lower costs and with greater versatility than the solid state inorganic semiconductors that comprise today's solar cells. However, the best nanocomposite solar cells are based on a complex architecture, consisting of a fine blend of interpenetrating and percolating donor and acceptor materials. Cell performance is strongly dependent on blend morphology, and solution-based fabrication techniques often result in uncontrolled and irreproducible blends, whose composite morphologies are difficult to characterize accurately. Here we incorporate three-dimensional hyperbranched colloidal semiconductor nanocrystals in solution-processed hybrid organic-inorganic solar cells, yielding reproducible and controlled nanoscale morphology.     

贝丝哈罗契姆康复中心

正贝丝哈罗契姆康复中心坐落于贝尔谢巴市郊区,处于城市与荒漠(内格夫沙漠)的交界地带。这里是残疾退伍军人及其家属的安居所。沙漠的炽阳和景观是设计的灵感来源,建筑最终呈现出岩石般堆砌的形式,形成一个私密的保护空间。     

Reclaiming respectability? The class-cultural dynamics of crime, community and governance in inner-city Dublin

This paper critically examines developments in Irish urban governance through an ethnographic account of one community's historical memory and contemporary structure. During an era of rapid economic growth, the Irish state has courted previously excluded communities, offering them greater inclusion as partners in responding to urban decay and crime. The micro-governance structures this creates, however, become sites of contest between competing community factions and class-cultural imperatives. Tensions emerge between aspirational community leaders championing the aesthetics (if not the values) of respectability and residual residents who are presented as rough. The paper demonstrates that nuances of class-cultural identity dictate the character of partnership governance at the community level with particular implications for local regeneration and crime control agendas.     

Testing Periodicity

We study the string-property of being periodic and having periodicity smaller than a given bound. Let Σ be a fixed alphabet and let p,n be integers such that p ￡ \fracn2p\leq \frac{n}{2} . A length-n string over Σ, α=(α ₁,…,α _n ), has the property Period(p) if for every i,j∈{1,…,n}, α _i =α _j whenever i≡j (mod p). For an integer parameter g ￡ \fracn2,g\leq \frac{n}{2}, the property Period(≤g) is the property of all strings that are in Period(p) for some p≤g. The property Period( ￡ \fracn2)\mathit{Period}(\leq \frac{n}{2}) is also called Periodicity.     

Social ties,knowledge sharing and successful collaboration in globally distributed system development projects

Traditionally, the main focus of the information system (IS) literature has been on technical aspects related to system development projects. Furthermore, research in the IS field has mainly focused on co-located project teams. In this respect, social aspects involved in IS projects were neglected or scarcely reported. To fill this gap, this paper studies the contribution of social ties and knowledge sharing to successful collaboration in distributed IS development teams. Data were drawn from two successful globally distributed system development projects at SAP and LeCroy. Data collected were codified using Atlas.ti software. The results suggest that human-related issues, such as rapport and transactive memory, were important for collaborative work in the teams studied. The paper concludes by discussing the implications for theory and suggesting a practical guide to enhance collaborative work in globally distributed teams.     

Hierarchy Theorems for Property Testing

Referring to the query complexity of property testing, we prove the existence of a rich hierarchy of corresponding complexity classes. That is, for any relevant function q, we prove the existence of properties that have testing complexity Θ(q). Such results are proven in three standard domains often considered in property testing: generic functions, adjacency predicates describing (dense) graphs, and incidence functions describing bounded-degree graphs. While in two cases, the proofs are quite straightforward, and the techniques employed in the case of the dense graph model seem significantly more involved. Specifically, problems that arise and are treated in the latter case include (1) the preservation of distances between graph under a blow-up operation and (2) the construction of monotone graph properties that have local structure.