Improvements in Digestion Protocols for Trace Element and Isotope Determinations in Stream and Lake Sediment Reference Materials (JSd-1, JSd-2, JSd-3, JLk-1 and LKSD-1)

International audienceTotal dissolution is a critical step in geochemical analysis. Despite the number of published protocols, this issue still draws attention for sediment samples, which are particularly difficult to dissolve due to the common occurrence and high abundance of refractory phases such as zircon. We present tests of different chemical digestion procedures carried out on reference materials (RM) of stream (JSd-1, JSd-2 and JSd-3) and lake (JLk-1 and LKSD-1) sediments from the Geological Survey of Japan (GSJ) and the Canadian Certified Reference Material Programme (CCRPM). We demonstrate that the fusion technique is not appropriate for our studies as not all elements of interest were recovered and blank levels were too high to permit further Sr and Pb isotopic composition measurements. Similarly, conventional HF+HNO3 dissolution methods were not efficient enough for detrital samples. Our preferred method involved using high pressure Teflon® vessel bombs in association with HClO4. This protocol ensured a complete dissolution of the powder, as well as a complete recovery of trace elements. Moreover, blank levels were sufficiently low that Sr or Pb isotope compositions could be measured from the same mother solution. We also tested the homogeneity of RM powders by performing tests on various amount of powder

Ideal free streamline flow over a curved obstacle

AbstractIn the classical two-dimensional model the description of Helmholtz's (Kirchhoff) flow is a problem of complex analysis which can be solved analytically only for a few simple bodies or polygonal contours, using the Schwarz-Christoffel map. This paper presents a practical method for computing flows over arbitrary obstacles whose boundaries may be piecewise smooth curves, while the impinging flow may be an unbounded flow, a jet, or a semi-infinite stream, i.e. the ocean

Bouddhisme chinois

Les textes de formules cérémonielles (jiemo wen) Nous avons poursuivi le travail entamé l’année passée sur la pratique des cérémonies de jeûne (zhai) par les laïcs bouddhiques. Notre attention s’est portée cette fois sur un manuscrit découvert il y a quelques années dans la bibliothèque du Kongōji, monastère qui se trouve situé sur le mont Amanō, dans la préfecture d’Osaka. Le Kongōji fait partie de ces quelques monastères japonais anciens dont les bibliothèques ont fait, ou font encore comme..

Bouddhisme chinois

Programme de l’année 2006-2007 : I. Les rites bouddhiques dans la culture chinoise : les assemblées de jeûne — II. Textes et pratiques rituelles du bouddhisme chinois (iie-vie siècles

Political Places: Neighborhood Social Organization and the Ecology of Political Behaviors

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142536/1/ssqu12352.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142536/2/ssqu12352_am.pd

Hot spots policing of small geographic areas effects on crime

Background In recent years, crime scholars and practitioners have pointed to the potential benefits of focusing crime prevention efforts on crime places. A number of studies suggest that there is significant clustering of crime in small places, or “hot spots,” that generate half of all criminal events. Researchers have argued that many crime problems can be reduced more efficiently if police officers focused their attention to these deviant places. The appeal of focusing limited resources on a small number of high-activity crime places is straightforward. If crime can be prevented at these hot spots, then citywide crime totals could be reduced. Objectives To assess the effects of focused police crime prevention interventions at crime hot spots. The review also examined whether focused police actions at specific locations result in crime displacement (i.e., crime moving around the corner) or diffusion (i.e., crime reduction in surrounding areas) of crime control benefits. Search Methods A keyword search was performed on 15 abstract databases. Bibliographies of past narrative and empirical reviews of literature that examined the effectiveness of police crime control programs were reviewed and forward searches for works that cited seminal hot spots policing studies were performed. Bibliographies of past completed Campbell systematic reviews of police crime prevention efforts were reviewed and hand searches of leading journals in the field were completed. Experts in the field were consulted and relevant citations were obtained. Selection Criteria To be eligible for this review, interventions used to control crime hot spots were limited to police-led prevention efforts. Suitable police-led crime prevention efforts included traditional tactics such as directed patrol and heightened levels of traffic enforcement as well as alternative strategies such as aggressive disorder enforcement and problem-oriented policing. Studies that used randomized controlled experimental or quasiexperimental designs were selected. The units of analysis were limited to crime hot spots or high-activity crime “places” rather than larger areas such as neighborhoods. The control group in each study received routine levels of traditional police crime prevention tactics. Data Collection and Analysis Sixty-five studies containing 78 tests of hot spots policing interventions were identified and full narratives of these studies were reported. Twenty-seven of the selected studies used randomized experimental designs and 38 used quasiexperimental designs. A formal meta-analysis was conducted to determine the crime prevention effects in the eligible studies. Random effects models were used to calculate mean effect sizes. Results Sixty-two of 78 tests of hot spots policing interventions reported noteworthy crime and disorder reductions. The meta-analysis of key reported outcome measures revealed a small statistically significant mean effect size favoring the effects of hot spots policing in reducing crime outcomes at treatment places relative to control places. The effect was smaller for randomized designs but still statistically significant and positive. When displacement and diffusion effects were measured, a diffusion of crime prevention benefits was associated with hot spots policing. Authors\u27 Conclusions The extant evaluation research suggests that hot spots policing is an effective crime prevention strategy. The research also suggests that focusing police efforts on high-activity crime places does not inevitably lead to crime displacement; rather, crime control benefits may diffuse into the areas immediately surrounding the targeted locations

Zygoparity and sex steroid hormone profiles in bluemouth Helicolenus dactylopterus

Two hundred and seven individuals (103 females and 104 males) of bluemouth Helicolenus dactylopterus (Scorpaeniformes, Sebastidae), a commercially important deep-water species with an unusual reproductive strategy, from the eastern Atlantic Ocean ranging from 139 to 375 cm total length (L-T) were analysed from September 2011 to October 2012. The analysis included gonad maturity phases and blood-plasma levels of oestradiol-17 (E-2), 11-ketotestosterone (11-KT) and 17,20-dihydroxypregn-4-en-3-one (17,20-P). Results confirmed the existence of an annual reproductive cycle with asynchrony between females and males and a spawning season from January to May. A pronounced peak in 17,20-P in October for both sexes was associated with possible mating behaviour and recent copula. Levels of E-2 increased preceding the elevation of the gonado-somatic index during ovarian growth and were lower during regression and regeneration. The frequency distribution of oocyte-embryonic stages and variation of hormone levels suggest the existence of daily rhythms. Fertilization was detected between 2000-0000 and 0800-1200 h and spawning took place throughout the day peaking between 2000 and 0000 h. The cyclic pattern of sex steroids and ovarian recruitment provides a new insight into the reproductive strategy of this species.Fundacao para a Ciencia e a Tecnologia SFRH/BPD/108917/2015, SFRH/BD/92769/2013info:eu-repo/semantics/publishedVersio

Functional modeling of the MnCAT active site with a dimanganese(III) complex of an unsymmetrical polydentate N 3 O 3 ligand

A new diMn III complex, [Mn 2 L(OAc) 2 (H 2 O)](BPh 4 )·3H 2 O (1), obtained with the unsymmetrical N 3 O 3 -ligand H 3 L = 1-[N-(2-pyridylmethyl),N-(2-hydroxybenzyl)amino]-3-[N′-(2-hydroxybenzyl),N′-(benzyl)amino]propan-2-ol, has been prepared and characterized. The unsymmetrical hexadentate ligand L 3− leads to coordination dissymmetry (dissimilar donor atoms) around each Mn ion (N 2 O 4 and NO 4 (solvent), respectively) leaving one labile site on one of the two Mn ions that facilitates interaction of the metal center with H 2 O 2 , as in Mn catalase. 1 is able to catalyze H 2 O 2 disproportionation in acetonitrile, with second-order rate constant k cat = 23.9(2) M −1 s −1 . The accessibility of the Mn II 2 state and the closeness of the two one-electron reduction processes suggest 1 employs Mn III 2 /Mn II 2 oxidation states for catalysis.Fil: Ledesma, Gabriela Nanci. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Anxolabehere Mallart, Elodie. Université Paris Diderot - Paris 7; FranciaFil: Sabater, Laurent. Universite de Toulouse; FranciaFil: Hureau, Christelle. Universite de Toulouse; FranciaFil: Signorella, Sandra Rosanna. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; Argentin