217 research outputs found

    Simultaneous determination of natural and synthetic steroid estrogens and their conjugates in aqueous matrices by liquid chromatography / mass spectrometry

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    An analytical method for the simultaneous determination of nine free and conjugated steroid estrogens was developed with application to environmental aqueous matrices. Solid phase extraction (SPE) was employed for isolation and concentration, with detection by liquid chromatography/mass spectrometry (LC/MS) using electrospray ionisation (ESI) in the negative mode. Method recoveries for various aqueous matrices (wastewater, lake and drinking water) were determined, recoveries proving to be sample dependent. When spiked at 50 ng/l concentrations in sewage influent, recoveries ranged from 62-89 % with relative standard deviations (RSD) < 8.1 %. In comparison, drinking water spiked at the same concentrations had recoveries between 82-100 % with an RSD < 5%. Ion suppression is a known phenomenon when using ESI; hence its impact on method recovery was elucidated for raw sewage. Both ion suppression from matrix interferences and the extraction procedure has bearing on the overall method recovery. Analysis of municipal raw sewage identified several of the analytes of interest at ng/l concentrations, estriol (E3) being the most abundant. Only one conjugate, estrone 3-sulphate (E1-3S) was observe

    Immigrant community integration in world cities

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    As a consequence of the accelerated globalization process, today major cities all over the world are characterized by an increasing multiculturalism. The integration of immigrant communities may be affected by social polarization and spatial segregation. How are these dynamics evolving over time? To what extent the different policies launched to tackle these problems are working? These are critical questions traditionally addressed by studies based on surveys and census data. Such sources are safe to avoid spurious biases, but the data collection becomes an intensive and rather expensive work. Here, we conduct a comprehensive study on immigrant integration in 53 world cities by introducing an innovative approach: an analysis of the spatio-temporal communication patterns of immigrant and local communities based on language detection in Twitter and on novel metrics of spatial integration. We quantify the "Power of Integration" of cities --their capacity to spatially integrate diverse cultures-- and characterize the relations between different cultures when acting as hosts or immigrants.Comment: 13 pages, 5 figures + Appendi

    Assessing Immigrant Assimilation: New Empirical and Theoretical Challenges

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    This review examines research on the assimilation of immigrant groups. We review research on four primary benchmarks of assimilation: socioeconomic status, spatial concentration, language assimilation, and intermarriage. The existing literature shows that today's immigrants are largely assimilating into American society along each of these dimensions. This review also considers directions for future research on the assimilation of immigrant groups in new southern and midwestern gateways and how sociologists measure immigrant assimilation. We document the changing geography of immigrant settlement and review the emerging body of research in this area. We argue that examining immigrant assimilation in these new immigrant gateways is crucial for the development of theories about immigrant assimilation. We also argue that we are likely to see a protracted period of immigrant replenishment that may change the nature of assimilation. Studying this change requires sociologists to use both birth cohort and generation as temporal markers of assimilation.Sociolog

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Study of hadronic event-shape variables in multijet final states in pp collisions at √s=7 TeV

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    Peer reviewe

    Constraints on parton distribution functions and extraction of the strong coupling constant from the inclusive jet cross section in pp collisions at √s=7 TeV

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    Peer reviewe

    Combined Tevatron upper limit on gg->H->W+W- and constraints on the Higgs boson mass in fourth-generation fermion models

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    Report number: FERMILAB-PUB-10-125-EWe combine results from searches by the CDF and D0 collaborations for a standard model Higgs boson (H) in the process gg->H->W+W- in p=pbar collisions at the Fermilab Tevatron Collider at sqrt{s}=1.96 TeV. With 4.8 fb-1 of integrated luminosity analyzed at CDF and 5.4 fb-1 at D0, the 95% Confidence Level upper limit on \sigma(gg->H) x B(H->W+W-) is 1.75 pb at m_H=120 GeV, 0.38 pb at m_H=165 GeV, and 0.83 pb at m_H=200 GeV. Assuming the presence of a fourth sequential generation of fermions with large masses, we exclude at the 95% Confidence Level a standard-model-like Higgs boson with a mass between 131 and 204 GeV.We combine results from searches by the CDF and D0 collaborations for a standard model Higgs boson (H) in the process gg→H→W+W- in pp̅ collisions at the Fermilab Tevatron Collider at √s=1.96  TeV. With 4.8  fb-1 of integrated luminosity analyzed at CDF and 5.4  fb-1 at D0, the 95% confidence level upper limit on σ(gg→H)×B(H→W+W-) is 1.75 pb at mH=120  GeV, 0.38 pb at mH=165  GeV, and 0.83 pb at mH=200  GeV. Assuming the presence of a fourth sequential generation of fermions with large masses, we exclude at the 95% confidence level a standard-model-like Higgs boson with a mass between 131 and 204 GeV.Peer reviewe

    Identification and Filtering of Uncharacteristic Noise in the CMS Hadron Calorimeter

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    Performance of CMS hadron calorimeter timing and synchronization using test beam, cosmic ray, and LHC beam data

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    This paper discusses the design and performance of the time measurement technique and of the synchronization systems of the CMS hadron calorimeter. Time measurement performance results are presented from test beam data taken in the years 2004 and 2006. For hadronic showers of energy greater than 100 GeV, the timing resolution is measured to be about 1.2 ns. Time synchronization and out-of-time background rejection results are presented from the Cosmic Run At Four Tesla and LHC beam runs taken in the Autumn of 2008. The inter-channel synchronization is measured to be within ±2 ns

    Immigrant fertility in West Germany: is there a socialization effect in transitions to second and third births?

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    In this paper on immigrant fertility in West Germany, we estimate the transition rates to second and third births, using intensity-regression models. The data come from the German Socio-Economic Panel Study. We distinguish women of the first and the second immigrant generations originating from Turkey, the former Yugoslavia, Greece, Italy, and Spain, and compare their fertility levels to those of West German women. In the theoretical framework, we discuss competing hypotheses on migrant fertility. The findings support mainly the socialization hypothesis: the transition rates of first-generation immigrants vary by country of origin, and the fertility patterns of migrant descendants resemble more closely those of West Germans than those of the first immigrant generation. In addition, the analyses show that fertility differentials between immigrants and women of the indigenous population can largely, though not in full, be explained by compositional differences.Dans cet article relatif à la fécondité des immigrées en Allemagne, le passage du premier au deuxieme enfant et dans celui du deuxieme au troisieme enfant est estimé à partir de modèles de régression à risques instantanés. Les données utilisées proviennent de l’étude de Panel socio-économique allemand. On distingue les femmes immigrées de première ou de seconde génération originaires de Turquie, d’ex-Yougoslavie, de Grèce, d’Italie et d’Espagne, et leurs niveaux de fécondité sont comparés à ceux des femmes ouest-allemandes d’origine. Des hypothèses concurrentes sur la fécondité des immigrés sont discutées dans le cadre théorique. Les résultats vérifient principalement l’hypothèse de la socialisation : le passage au deuxieme et au troisieme enfant de la première génération d’immigrés varie selon le pays d’origine, et le profil de fécondité par âge des descendantes d’immigrées se rapproche plus de celui des femmes ouest-allemandes que de celui des immigrées de première génération. De plus, les analyses montrent que les différences de fécondité entre les immigrées et les femmes ouest-allemandes peuvent être en grande partie, mais pas totalement, expliquées par des différences de structure
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