Investigation of young water inflow in karst aquifers using SF6–CFC–3H/He–85Kr–39Ar and stable isotope components

Karst aquifers are known for their wide distribution of water transfer velocities. From this observation, a multiple geochemical tracer approach seems to be particularly well suited to provide a significant assessment of groundwater flows, but the choice of adapted tracers is essential. In this study, several common tracers in karst aquifers such as physicochemical parameters, major ions, stable isotopes, and d13C to more specific tracers such as dating tracers – 14C, 3H, 3H–3He, CFC-12, SF6 and 85Kr, and 39Ar – were used, in a fractured karstic carbonated aquifer located in Burgundy (France). The information carried by each tracer and the best sampling strategy are compared on the basis of geochemical monitoring done during several recharge events and over longer time periods (months to years). This study’s results demonstrate that at the seasonal and recharge event time scale, the variability of concentrations is low for most tracers due to the broad spectrum of groundwater mixings. The tracers used traditionally for the study of karst aquifers, i.e., physicochemical parameters and major ions, efficiently describe hydrological processes such as the direct and differed recharge, but require being monitored at short time steps during recharge events to be maximized. From stable isotopes, tritium, and Cl� contents, the proportion of the fast direct recharge by the largest porosity was estimated using a binary mixing model. The use of tracers such as CFC-12, SF6, and 85Kr in karst aquifers provides additional information, notably an estimation of apparent age, but they require good preliminary knowledge of the karst system to interpret the results suitably. The CFC-12 and SF6 methods efficiently determine the apparent age of baseflow, but it is preferable to sample the groundwater during the recharge event. Furthermore, these methods are based on different assumptions such as regional enrichment in atmospheric SF6, excess air, and flow models among others. 85Kr and 39Ar concentrations can potentially provide a more direct estimation of groundwater residence time. Conversely, the 3H–3He method is inefficient in the karst aquifer for dating due to 3He degassing.

From stellar nebula to planets: The refractory components

Context. To date, calculations of planet formation have mainly focused on dynamics, and only a few have considered the chemical composition of refractory elements and compounds in the planetary bodies. While many studies have been concentrating on the chemical composition of volatile compounds (such as H2O, CO, CO2) incorporated in planets, only a few have considered the refractory materials as well, although they are of great importance for the formation of rocky planets. Aims. We computed the abundance of refractory elements in planetary bodies formed in stellar systems with a solar chemical composition by combining models of chemical composition and planet formation. We also considered the formation of refractory organic compounds, which have been ignored in previous studies on this topic. Methods. We used the commercial software package HSC Chemistry to compute the condensation sequence and chemical composition of refractory minerals incorporated into planets. The problem of refractory organic material is approached with two distinct model calculations: the first considers that the fraction of atoms used in the formation of organic compounds is removed from the system (i.e., organic compounds are formed in the gas phase and are non-reactive); and the second assumes that organic compounds are formed by the reaction between different compounds that had previously condensed from the gas phase. Results. Results show that refractory material represents more than 50 wt % of the mass of solids accreted by the simulated planets with up to 30 wt % of the total mass composed of refractory organic compounds. Carbide and silicate abundances are consistent with C/O and Mg/Si elemental ratios of 0.5 and 1.02 for the Sun. Less than 1 wt % of carbides are present in the planets, and pyroxene and olivine are formed in similar quantities. The model predicts planets that are similar in composition to those of the solar system. Starting from a common initial nebula composition, it also shows that a wide variety of chemically different planets can form, which means that the differences in planetary compositions are due to differences in the planetary formation process. Conclusions. We show that a model in which refractory organic material is absent from the system is more compatible with observations. The use of a planet formation model is essential to form a wide diversity of planets in a consistent way.

Callings in career: A typological approach to essential and optional components

A sense of calling in career is supposed to have positive implications for individuals and organizations but current theoretical development is plagued with incongruent conceptualizations of what does or does not constitute a calling. The present study used cluster analysis to identify essential and optional components of a presence of calling among 407 German undergraduate students from different majors. Three types of calling merged: “negative career self-centered”, “pro-social religious”, and “positive varied work orientation”. All types could be described as vocational identity achieved (high commitment/high self-exploration), high in career confidence and career engagement. Not defining characteristics were centrality of work or religion, endorsement of specific work values, or positivity of core self-evaluations. The results suggest that callings entail intense self-exploration and might be beneficial because they correspond with identity achievement and promote career confidence and engagement while not necessarily having pro-social orientations. Suggestions for future research, theory and practice are suggested.

Demonstration of species-specific and cross-reactive components of Taenia solium metacestode antigens.

Analysis of human serum reactivities to antigenic components of soluble Taenia solium metacestode proteins showed the predominant presence of determinants shared by T. solium, Echinococcus multilocularis and E. granulosus. Two polypeptides were demonstrated by SDS-PAGE and Western blot or enzyme-linked immunoelectrotransfer blot (EITB) assay to bind serum and CSF antibodies only from T. solium cysticercosis patients. These species-specific antigenic polypeptides focused between pH 4.6 and 3.9 after resolution by isoelectric focusing followed by EITB. The high species-specificity demonstrated by the present techniques offers the opportunity to confirm serologically an infection by T. solium metacestode.

Identification of Trypanosoma brucei components involved in trypanolysis by normal human serum

Normal human serum (NHS) confers human resistance to infection by the parasite Trypanosoma brucei owing to the trypanolytic activity of apolipoprotein L1 (APOL1), present in two serum complexes termed Trypanolytic Factors (TLF-1 and -2). In order to identify parasite components involved in the intracellular trafficking and activity of TLFs, an inducible RNA interference (RNAi) genomic DNA library constructed in bloodstream form T. brucei was subjected to RNAi induction and selection for resistant parasites under NHS conditions favouring either TLF-1 or TLF-2 uptake. While TLF-1 conditions readily selected the haptoglobin-haemoglobin (HP-HB) surface receptor TbHpHbR as expected, given its known ability to bind TLF-1, under TLF-2 conditions no specific receptor for TLF-2 was identified. Instead, the screen allowed the identification of five distinct factors expected to be involved in the assembly of the vacuolar proton pump V-ATPase and consecutive endosomal acidification. These data confirm that lowering the pH during endocytosis is required for APOL1 toxic activity.

Pelvic floor muscle activation and strength components influencing female urinary continence and stress incontinence: A systematic review

AIMS A better understanding of pelvic floor muscle (PFM) activation and strength components is a prerequisite to get better insight in PFM contraction mechanisms and develop more specific PFM-training regimens for female stress urinary incontinence (SUI) patients. The aim of this systematic review (2012:CRD42012002547) was to evaluate and summarize existing studies investigating PFM activation and strength components influencing female continence and SUI. METHODS PubMed, EMBASE, and Cochrane databases were systematically searched for literature from January 1980 to November 2013 for cross-sectional studies comparing female SUI patients with healthy controls and intervention studies with SUI patients reporting on the association between PFM activation and strength components and urine loss. Trial characteristics, evaluated PFM components, their definitions, measurement methods, study outcomes, as well as quality measures, based on the Cochrane risk of bias tool, were independently extracted. The high heterogeneity of the retrieved data made pooling of results impossible and therefore restricted the analysis to a systematic review. RESULTS Cross-sectional studies showed group differences in favor of the continent women compared to SUI patients for PFM activation or PFM maximal strength, mean strength or sustained contraction. All intervention studies showed an improvement of PFM strength and decrease in urine loss in SUI patients after physical therapy. CONCLUSIONS Higher PFM activation and strength components influence female continence positively. This systematic review underscored the need for a standardized PFM components' terminology (similar to rehabilitation and training science), standardized test procedures and well matched diagnostic instruments. Neurourol. Urodynam. © 2014 Wiley Periodicals, Inc.

Die Potsdamschen Schemmelbeen-Helden, jenannt Jardekohrs: Sie reiten hier sehr schön Parade, Doch is et um die Esel's Schade! En kleener Anhang zu den Armeebefehl: Jardekohrs! Panstrige Lümmels mit de Theekessels uf de Jrützköppe, hört mir an! ...

Welsch (Projektbearbeiter): Strafpredigt an das Gardekorps. Hintergrund: tätliche Angriffe von Soldaten des Gardekorps gegen Mitglieder des Potsdamer Politischen Klubs (wahrscheinlich 25. September 1848)

Numerical Magnitude Skills in 6-Years-Old Children: Exploring Specific Associations with Components of Executive Function

Little is known about how children learn to associate numbers with their corresponding magnitude and about individual characteristics contributing to performance differences on the numerical magnitude tasks within a relatively homogenous sample of 6-year-olds. The present study investigated the relationships between components of executive function and two different numerical magnitude skills in a sample of 162 kindergartners. The Symbolic Number Line was predicted by verbal updating and switching, whereas the Symbolic Magnitude Comparison was predicted by inhibition. Both symbolic tasks were predicted by visuo-spatial updating. Current findings suggest that visuo-spatial updating underlies young children’s retrieval and processing of numbers’ magnitude.