WorldWideScience

Sample records for product migration studies

  1. [The productive structure and migration].

    Science.gov (United States)

    Fernandez, M

    1980-01-01

    The author discusses the possibility of determining the proper approach to the study of migration, with a focus on the importance of global, structural, and historical analysis of the phenomenon. A general theoretical outline is presented that tends to show migration as an integral part of the process of social change. The sociological focus on modernization as a theoretical guide influencing the study of migration in Latin America is evaluated. The concept of overpopulation is explained in relation to the migratory process, with reference to capitalist and non-capitalist forms of production.

  2. Burn-Up Determination by High Resolution Gamma Spectrometry: Fission Product Migration Studies

    Energy Technology Data Exchange (ETDEWEB)

    Forsyth, R S; Blackadder, W H; Ronqvist, N

    1967-04-15

    The migration of solid fission products, in particular caesium and ruthenium, in high temperature oxide fuel can create a severe problem during the application of non-destructive burn-up methods employing gamma spectrometry, since caesium-137 is otherwise the most convenient long-lived burn-up monitor and ruthenium-106 can be used to distinguish between fissions in U-235 and Pu-239. As part of an experimental programme to develop burn-up methods, gamma scanning experiments have been performed on slices of irradiated UO{sub 2} pellets using a lithium-drifted germanium detector. The usefulness of the technique for migration studies has been demonstrated by comparing the fission product distribution curves across the specimen diameters with the microstructure of the specimens after polishing and etching.

  3. [Internal migration studies].

    Science.gov (United States)

    Stpiczynski, T

    1986-10-01

    Recent research on internal migration in Poland is reviewed. The basic sources of data, consisting of censuses or surveys, are first described. The author discusses the relationship between migration studies and other sectors of the national economy, and particularly the relationship between migration and income.

  4. Migration studies of fission product nuclides in rocks. Pt.5: Diffusion and permeability of nuclide 125I in marble

    International Nuclear Information System (INIS)

    Wen Ruiyuan; Gao Hongcheng; Wang Xiangyun

    1996-01-01

    The migration behaviour of nuclide 125 I, as a simulation of the long lived fission product 129 I, in marble is studied in self-designed cells. A series of the most important parameters of diffusion and permeability (e.g., intrinsic diffusion coefficient, dispersion coefficient and interstitial flow velocity, etc.) are determined. Based on the differential equation of the nuclide migration, the distribution function and numerical solution of 125 I in marble are presented. The results show that the migration velocity of 125 I in marble is fast, indicating that it is not suitable to dispose nuclear waste in marble

  5. Simulated Leaching (Migration) Study for a Model Container-Closure System Applicable to Parenteral and Ophthalmic Drug Products.

    Science.gov (United States)

    Jenke, Dennis; Egert, Thomas; Hendricker, Alan; Castner, James; Feinberg, Tom; Houston, Christopher; Hunt, Desmond G; Lynch, Michael; Nicholas, Kumudini; Norwood, Daniel L; Paskiet, Diane; Ruberto, Michael; Smith, Edward J; Holcomb, Frank; Markovic, Ingrid

    2017-01-01

    A simulating leaching (migration) study was performed on a model container-closure system relevant to parenteral and ophthalmic drug products. This container-closure system consisted of a linear low-density polyethylene bottle (primary container), a polypropylene cap and an elastomeric cap liner (closure), an adhesive label (labeling), and a foil overpouch (secondary container). The bottles were filled with simulating solvents (aqueous salt/acid mixture at pH 2.5, aqueous buffer at pH 9.5, and 1/1 v/v isopropanol/water), a label was affixed to the filled and capped bottles, the filled bottles were placed into the foil overpouch, and the filled and pouched units were stored either upright or inverted for up to 6 months at 40 °C. After storage, the leaching solutions were tested for leached substances using multiple complementary analytical techniques to address volatile, semi-volatile, and non-volatile organic and inorganic extractables as potential leachables.The leaching data generated supported several conclusions, including that (1) the extractables (leachables) profile revealed by a simulating leaching study can qualitatively be correlated with compositional information for materials of construction, (2) the chemical nature of both the extracting medium and the individual extractables (leachables) can markedly affect the resulting profile, and (3) while direct contact between a drug product and a system's material of construction may exacerbate the leaching of substances from that material by the drug product, direct contact is not a prerequisite for migration and leaching to occur. LAY ABSTRACT: The migration of container-related extractables from a model pharmaceutical container-closure system and into simulated drug product solutions was studied, focusing on circumstances relevant to parenteral and ophthalmic drug products. The model system was constructed specifically to address the migration of extractables from labels applied to the outside of the

  6. Pilot batch production of specific-structured lipids by lipase-catalyzed interesterification: preliminary study on incorporation and acyl migration

    DEFF Research Database (Denmark)

    Xu, Xuebing; Balchen, Steen; Høy, Carl-Erik

    1998-01-01

    Effects of water content, reaction time and their relationships in the production of two types of specific-structured lipids (sn-MLM- and sn-LML-types: L-long chain fatty acids; M-medium chain fatty acids) by lipase-catalyzed interesterification in a solvent-free system were studied...... of two totally position-opposed lipids can be observed. Presumably these are caused by the different chain length of the fatty acids. The relationships between reaction time and water content are inverse and give a quantitative prediction of incorporation and acyl migration in selected reaction...

  7. Study of the HTGR fission product migration at the Osiris experimental reactor

    International Nuclear Information System (INIS)

    Homme, A. l'; Lucot, M.

    1977-01-01

    A program of study on accidents in HTR reactor operation is presented: blowdown of primary coolant circuit, water inlet into the primary circuit, fuel element overheating by pipe logging or loss of cooling. These studies will be made in Aida irradiation loop in the pool of the Osiris reactor [fr

  8. Analytical protocol to study the food safety of (multiple-)recycled high-density polyethylene (HDPE) and polypropylene (PP) crates: Influence of recycling on the migration and formation of degradation products

    NARCIS (Netherlands)

    Coulier, L.; Orbons, H.G.M.; Rijk, R.

    2007-01-01

    An analytical protocol was set up and successfully applied to study the food safety of recycled HDPE and PP crates. A worst-case scenario was applied that focused not only on overall migration and specific migration of accepted starting materials but also on migratable degradation products of

  9. Fluid migration studies in salt

    International Nuclear Information System (INIS)

    Shefelbine, H.C.; Raines, G.E.

    1980-01-01

    This discussion will be limited to the migration of water trapped in the rock salt under the influence of the heat field produced by nuclear waste. This is of concern because hypotheticl scenarios have been advanced in which this fluid movement allows radionuclides to escape to the biosphere. While portions of these scenarios are supported by observation, none of the complete scenarios has been demonstrated. The objectives of the present fluid migration studies are two-fold: 1. determine the character of the trapped fluid in terms of quantity, habitat and chemical constituents; and 2. define the mechanisms that cause the fluid to migrate toward heat sources. Based on the observations to date, fluid migration will not have a major impact on repository integrity. However, the above objectives will be pursued until the impacts, if any, can be quantified

  10. Youth Migration and Agricultural Production

    African Journals Online (AJOL)

    PROF. MADUKWE

    The study investigated the causes and examined the effects of youth ... poverty and search for better education in the cities were the major causes of .... and women from farming (rural) communities engenders urban nuisance and .... Frequency Percentage Mean. St.Dev. Age. <30 years. 31-60 years. 61 years and above.

  11. Studies on the biosynthesis of macrophage migration inhibitory factor in delayed hypersensitivity, 1. Effects of inhibitors of nucleic acid and protein synthesis on the production of macrophage migration inhibitory factor

    Energy Technology Data Exchange (ETDEWEB)

    Mizoguchi, Y; Yamamoto, S; Morisawa, S [Osaka City Univ. (Japan). Faculty of Medicine

    1973-03-01

    Specific antigenic stimulation of sensitized lymphocytes leads to the production of macrophage migration inhibitory factor (MIF). Production of MIF is inhibited by mitomycin C, actinomycin D, and puromycin. These inhibition effects are studied by using thymidine-/sup 3/H. The first two of these antibiotics only inhibit MIF production when added to the culture medium at a very early stage of antigenic stimulation. In contrast, puromycin exerts its inhibitory effect several hours after the antigenic stimulation, but not at an earlier stage. MIF behaves like a protein, so it seems likely that synthesis of RNA is necessary for MIF formation and MIF synthesis may start as early as a few hours after specific antigenic activation of the sensitized lymphocytes. The inhibitory effects of the antibiotics are discussed in relation to the kinetics of MIF production.

  12. Studies of Migration in Ecuador: From National Development to Mobilities

    OpenAIRE

    María Mercedes Eguiguren

    2017-01-01

    The article presents a review of the studies on migration in Ecuador during the period 1960-2016. It addresses the main debates that have marked these studies, the contexts of academic production, and the way in which migrations and their social and economic conditions have influenced the constitution and orientations of the field. Three stages go through the academic production: a first one where the internal migrations are approached from a spatial phenomena analysis; a second that deals wi...

  13. Radionuclide migration studies in soil

    International Nuclear Information System (INIS)

    Marumo, J.T.

    1989-01-01

    In this work a brief description about retention and migration parameters of radionuclides in soil, including main methods to determine the distribution coefficient (K) are given. Some of several factors that can act on the migration are also mentioned. (author) [pt

  14. Studies of Migration in Ecuador: From National Development to Mobilities

    Directory of Open Access Journals (Sweden)

    María Mercedes Eguiguren

    2017-05-01

    Full Text Available The article presents a review of the studies on migration in Ecuador during the period 1960-2016. It addresses the main debates that have marked these studies, the contexts of academic production, and the way in which migrations and their social and economic conditions have influenced the constitution and orientations of the field. Three stages go through the academic production: a first one where the internal migrations are approached from a spatial phenomena analysis; a second that deals with the links between agricultural transformations and migration; and a third that shows a transition from a resurgence of migration in the literature to recent studies on the diversification of mobilities in the country.

  15. Suppression of acyl migration in enzymatic production of structured lipids through temperature programming

    DEFF Research Database (Denmark)

    Yang, Tiankui; Fruekilde, Maj-Britt; Xu, Xuebing

    2005-01-01

    Acyl migration in the glycerol backbone often leads to the increase of by-products in the enzymatic production of specific structured lipids. Acyl migration is a thermodynamic process and is very difficult to stop fully in actual reactions. The objective of this study was to investigate...

  16. Liquid chromatography in migration studies

    International Nuclear Information System (INIS)

    Carlsen, L.; Batsberg, W.

    1982-01-01

    Liquid chromatography ahs been suggested as a facile experimental technique to determine important physico-chemical properties, as permeability, porosity, dispersion-, diffusion-, and sorption charcteristics for geological material as chalk samples. The feasibility of the trechnique as a rapid method to evaluate the possible influence of changes in ground water composition on the migration behavior of radionuclides has been demonstrated

  17. Japanese Migration and the Americas: An Introduction to the Study of Migration.

    Science.gov (United States)

    Mukai, Gary; Brunette, Rachel

    This curriculum module introduces students to the study of migration, including a brief overview of some categories of migration and reasons why people migrate. As a case study, the module uses the Japanese migration experience in the United States, Peru, Brazil, Canada, Mexico, Argentina, Bolivia, and Paraguay. The module introduces students to…

  18. Migration Studies and Academic Research on International Migration Policies in Argentina

    Directory of Open Access Journals (Sweden)

    Eduardo Domenech

    2017-05-01

    Full Text Available This article approaches the historical development of the field of migratory studies in Argentina and makes a review of the academic production around the so - called "migratory policies." The systematization of these studies, historically placed on migration policies, aims to highlight some of the most significant contributions of the research during the last 30 years, to understand or explain various aspects and dimensions of the Argentinean migration policy. To achieve this, texts were selected that derived from empirical research that explicitly assume the migratory policies as the object of study, or whose themes and research problems adopt as a framework for discussion the policies and practices aimed at regulating migration and mobility in Argentina. The organization and presentation of these selected texts consider issues related to the interests and thematic concerns, disciplinary and analytical approaches, distinct periods, scales of analysis and sources of information.

  19. MIGRATION '03: 9th International Conference on Chemistry and Migration Behavior of Actinides and Fission Products in the Geosphere

    International Nuclear Information System (INIS)

    Kim, Geon Young; Hahn, Pil Soo; Kang, Moon Ja; Baik, Min Hoon; Kim, Seung

    2003-12-01

    The objectives of this report are overview of the chemistry and migration behavior of actinide for the HLW disposal safety assessment and to summarise the present status of actinide science and future developments. Actinides in HLW are very toxic and long-life time radionuclides. Therefore, the understanding of their characteristics and reaction behaviors in the deep subsurface environment is necessary for improving the reliability of HLW disposal safety assessment. This report presents an overview of the recent developments in the fundamental chemistry of actinides and fission products in natural aquifer systems, their interactions and migration in the geosphere, and the processes involved in modeling their geochemical behavior for the high level radioactive waste management. In addition, the thesis presented in MIGRATION '03 conference were described briefly. Actinide science in relation to the HLW disposal management can be classified into three main subjects; aquatic chemistry of actinides and fission products, migration behavior of radionuclides and geochemical and transport modeling. The radionuclides leached from waste forms are intruded into human environment along the groundwater flowing in the fracture around the waster disposal facility. To analyze and predict such radionuclide migration phenomena, the data that were obtained from well defined condition are required. Data obtained from studies on the chemical behaviors of actinide elements and fission products in the groundwater are essential in the safety assessment of HLW management. This report is intended to suggest the direction of R and D in actinide chemistry for the national program of HLW management in future

  20. MIGRATION '03: 9th International Conference on Chemistry and Migration Behavior of Actinides and Fission Products in the Geosphere

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Geon Young; Hahn, Pil Soo; Kang, Moon Ja; Baik, Min Hoon; Kim, Seung

    2003-12-15

    The objectives of this report are overview of the chemistry and migration behavior of actinide for the HLW disposal safety assessment and to summarise the present status of actinide science and future developments. Actinides in HLW are very toxic and long-life time radionuclides. Therefore, the understanding of their characteristics and reaction behaviors in the deep subsurface environment is necessary for improving the reliability of HLW disposal safety assessment. This report presents an overview of the recent developments in the fundamental chemistry of actinides and fission products in natural aquifer systems, their interactions and migration in the geosphere, and the processes involved in modeling their geochemical behavior for the high level radioactive waste management. In addition, the thesis presented in MIGRATION '03 conference were described briefly. Actinide science in relation to the HLW disposal management can be classified into three main subjects; aquatic chemistry of actinides and fission products, migration behavior of radionuclides and geochemical and transport modeling. The radionuclides leached from waste forms are intruded into human environment along the groundwater flowing in the fracture around the waster disposal facility. To analyze and predict such radionuclide migration phenomena, the data that were obtained from well defined condition are required. Data obtained from studies on the chemical behaviors of actinide elements and fission products in the groundwater are essential in the safety assessment of HLW management. This report is intended to suggest the direction of R and D in actinide chemistry for the national program of HLW management in future.

  1. Production of freely-migrating defects during irradiation

    International Nuclear Information System (INIS)

    Rehn, L.E.; Okamoto, P.R.

    1986-09-01

    During irradiation at elevated temperatures, vacancy and interstitial defects that escape can produce several different types of microstructural changes. Hence the production rate of freely-migrating defects must be known as a function of irradiating particle species and energy before quantitative correlations can be made between microstructural changes. Our fundamental knowledge of freely-migrating defect production has increased substantially in recent years. Critical experimental findings that led to the improved understanding are reviewed in this paper. A strong similarity is found for the dependence of freely-migrating defect production on primary recoil energy as measured in a variety of metals and alloys by different authors. The efficiency for producing freely-migrating defects decreases much more strongly with increasing primary recoil energy than does the efficiency for creating stable defects at liquid helium temperatures. The stronger decrease can be understood in terms of additional intracascade recombination that results from the nonrandom distribution of defects existing in the primary damage state for high primary recoil energies. Although the existing data base is limited to fcc materials, the strong similarity in the reported investigations suggests that the same dependence of freely-migrating defect production on primary recoil energy may be characteristic of a wide variety of other alloy systems as well. 52 refs., 4 figs

  2. Migration of fission products in UO2. Final report

    International Nuclear Information System (INIS)

    Prussin, S.G.; Olander, D.R.

    1995-01-01

    Results of an experimental and calculational effort to examine the fundamental mechanisms of fission product migration in and release from polycrystalline uranium dioxide are reported. The experiments were designed to provide diffusion parameters for the representative fission products tellurium, iodine, xenon, molybdenum and ruthenium under both reducing and oxidizing conditions. The calculational effort applied a new model of fission product release from reactor fuel that incorporates grain growth as well as grain boundary and lattice diffusion

  3. Challenging issues in the study of fiscally-induced migration.

    Science.gov (United States)

    Winer, S L

    1986-01-01

    This paper reviews Shaw's book, INTERMETROPOLITAN MIGRATION IN CANADA, which provides new evidence concerning the link between fiscal structure and internal migration. Shaw bases his work on a valuable new migration series he has put together from census data: intermetropolitan flows from 1956-1981. The existence of censua data at 5-year intervals permits Shaw enough data to estimate migration equations separately for the periods before and after 1971. A comparison of the role of fiscal variables before and after 1971 is interesting because unemployment insurance, equalization payments, and provincial natural resource revenues probably became more important in determining regional differences in incomes after 1971 than in the 20 years prior to that. Shaw suspects that migration behavior has become less sensitive to traditional market variables such as wage differentials and more sensitive to other factors, including quality of life indicators since 1950. The author thinks that Shaw's conclusion cannot rest comfortably on estimating equations that omit fiscal variables. The overall role of wage differentials in determining observed migration patterns is the product of the coefficient on wage variables and the actual evolution of wages over the estimation period. Another problem with the methodology used to contrast pre- and post-1971 migration equations is the apparent neglect of statistical testing for shifts in coefficients on the traditional economic variables and for shifts in the coefficients on the fiscal variables. The strongest of the useful results from the study concern the role of unemployment insurance. The evidence that these have an influence on internal migration is now compelling. Shaw's book adds substantial weight to the view that variation in fiscal structure plays a significant role in determining internal migration patterns.

  4. Agricultural productivity, household poverty and migration in the Indian Sundarban Delta

    Directory of Open Access Journals (Sweden)

    Rituparna Hajra

    2018-01-01

    Full Text Available Deltas are highly sensitive to erosion, flooding, and salinization with consequential agricultural productivity losses and out-migration, which is a preferred adaptive measure for the inhabitants of deltaic islands. This study investigates the associations between agricultural productivity decrease, household poverty and the probability of out-migration in the Indian Sundarban Delta (ISD. Using newly collected survey data from randomly selected households within the ISD, we analysed these relationships by means of descriptive statistics and regression modeling. Results suggest the significant positive association between a decrease in agricultural productivity and out-migration. The results further show that ceteris paribus, out-migration is negatively associated with household poverty, which is likely to be explained by the effect of remittances. The results yield important policy implications at the local level and can contribute to the progress towards sustainable livelihoods in these deltaic islands.

  5. Gendered histories: garment production and migration in Mexico

    OpenAIRE

    F Wilson

    1999-01-01

    The author's impetus to write this paper stems from reflections on the history of clothing production in a mosaic of localities in western-central Mexico. In the 1990s, in addition to generating the largest flows of, mostly male, transnational migrants, these areas have become the most important garment producers in Mexico. Exploring the interconnectedness of industrial change, gendered patterns of migration, and gendered relations of production, the author provides a short history of garment...

  6. THE IMPACT OF AGRICULTURAL PRODUCTIVITY ON RURAL TO URBAN MIGRATION IN JAVA, INDONESIA

    Directory of Open Access Journals (Sweden)

    Renata Fauzia

    2013-11-01

    Full Text Available This paper investigates if the improvement of agricultural productivity will decrease rural to urban migration. Since rural to urban migration occurs due mainly to disparity between urban and agricultural wage, we assume that boosting agricultural income will reduce migration to urban areas. It is hypothesized that increase in agricultural productivity would result in a rise in agricultural wage, and hence income, ceteris paribus, reduces rural-urban migration. The data used in this study is the 2010 provincial statistics in West Java, Central Java, and East Java, Indonesia. The agricultural productivity and migration equations were estimated by using Ordinary Least Squares (OLS. The research findings may offer the suggestion to reduce rural to urban migration by boosting rural income through focusing the policy on agricultural productivity. Enhancing investment in agricultural sector such as increasing the number of subsidized fertilizer, adding agricultural labor and livestock, increasing education of rural people, and utilizing agricultural land resource are expected to increase agricultural output.Thus, it would also minimize the wage differential between urban and rural area.

  7. Refugee and Forced Migration Studies Online

    DEFF Research Database (Denmark)

    Andersson, Vibeke

    developments in communications technologies and the Internet and the proliferation of websites such as the CARFMS – Online Research and Teaching Tool and Practitioners Forum (ORTT & PF) and the Refugee Research Network (RRN), as examples, have contributed to the accessibility of information, knowledge......IASFM 14: Contested Spaces and Cartographic Challenges Kolkata, India, January 6-9, 2013 ABSTRACT for a Roundtable on the topic of Refugee and Forced Migration Studies Online: Harnessing “the Cloud” for Knowledge Generation, Instruction, and Mobilization With the advent of the Internet...... and the proliferation of websites and online instruments on refugee and forced migration studies the nature of research and information gathering, analysis, and dissemination, along with advocacy, has altered fundamentally both in its range, depth and scope. This Roundtable will seek to review how the latest...

  8. Study of radionuclide migration in clay formations

    International Nuclear Information System (INIS)

    Antonioli, F.; Bocola, W.

    1985-01-01

    This paper reports the studies on the migration of Cs, Sr and I in clay formations, which are presently considered for the geological disposal of radioactive wastes. The distribution and diffusion coefficients were evaluated by means of experimental techniques and computer procedures, which are presented in this report. The natural clays tested in the laboratory experiments were sampled from the most representative italian basins and from the zone of Mol (Belgium). In addition tests were performed on monomineral clays artificially remade in edometer. The experimental results are in accordance with data found in the literature and show the existence of a good correlation between the observed migration properties and the granulometric and mineralogic characteristics of the natural clays

  9. Theoretical foundations of international migration process studies: analysis of key migration theories development

    Directory of Open Access Journals (Sweden)

    Shymanska K.V.

    2017-03-01

    Full Text Available The need for transformation of Ukraine's migration policy based on globalized world development trends and in response to the challenges of European integration transformations causes the need of researching the theoretical and methodological basis of migration studies, and the regulations of existing theories of international migration. The bibliometric analysis of scientific publications on international migration in cites indexes found that the recent researches on these problems acquire interdisciplinary character. It necessitates the transformation of migration study approaches basing on economic, social, institutional theories and concepts synthesis. The article is devoted to the study of theoretical regulations of existing international migration theories in the context of the evolution of scientists’ views on this phenomenon. The author found that the existing theories of international migration should be divided into three categories (microeconomic, macroeconomic, globalizational that contributes to their understanding in the context of implementation possibilities in migrational public administration practice. It allows to determine the theories which should be used for Ukrainian state migration policy constructing and eliminating or reducing the external migration negative effects.

  10. Effects of diel vertical migration on ephippia production in Daphnia

    Directory of Open Access Journals (Sweden)

    Victor ALEKSEEV

    2004-09-01

    Full Text Available Fish presence in experimentally simulated temperature conditions (limno-towers led to diel vertical migration and resulted in a decrease of ephippia production in Daphnia pulicaria. Diel fluctuation of food, temperature and day length similar to those experienced by migrating Daphnia were tested in laboratory experiments with flow-through-systems. Daphnids were kept under these conditions for 15 days and the proportions of females producing an ephippium were determined. In addition, maturation time, survival to maturation, size of the first clutch and female dry weight (without eggs on day 15 were traced. The most important factor affecting ephippia production in migrating Daphnia was photoperiod change, and when mother and embryo are exposed to alternating light conditions, these are thought to have the effect on the mother of acting as a signal to stop ephippia production. Such effects might be explained by the different sensitiveness to light intensity in females carrying an embryo and an embryo itself in broods. Fish presence forced Daphnia to stay in low-light conditions during daytime hours, to avoid attacks by fish. The Daphnia were able to check light intensity constantly by short vertical jumps above a light-threshold that was confirmed experimentally in limno-towers. The dim conditions were possibly light enough for adults to check day length, but were too dark for embryos shaded by the mother's body. Food conditions played a relatively small role in the process, and no effects of temperature on ephippia production were found. As expected, food affected the size of the first clutch, and temperature controlled the time to maturation. Photoperiod had a marginally significant influence on the time to maturation in Daphnia. A hypothesis on the role of photoperiod as the key factor for Daphnia life cyclic recurrence and other seasonal adaptations is proposed.

  11. Laboratory studies of radionuclide migration in tuff

    International Nuclear Information System (INIS)

    Rundberg, R.S.; Mitchell, A.J.; Ott, M.A.; Thompson, J.L.; Triay, I.R.

    1989-01-01

    The movement of selected radionuclides has been observed in crushed tuff, intact tuff, and fractured tuff columns. Retardation factors and dispersivities were determined from the elution profiles. Retardation factors have been compared with those predicted on the basis of batch sorption studies. This comparison forms a basis for either validating distribution coefficients or providing evidence of speciation, including colloid formation. Dispersivities measured as a function of velocity provide a means of determining the effect of sorption kinetics or mass transfer on radionuclide migration. Dispersion is also being studied in the context of scaling symmetry to develop a basis for extrapolating from the laboratory scale to the field. 21 refs., 6 figs., 2 tabs

  12. Why Migrate: For Study or for Work?

    Directory of Open Access Journals (Sweden)

    Elise S. Brezis

    2016-08-01

    Full Text Available Over the past decades, globalization has led to a huge increase in the migration of workers, as well as students. This paper develops a simple two-step model that describes the decisions of an individual vis-à-vis education and migration, and presents a unified model, wherein the two migration decisions are combined into a single, unique model. This paper shows that under the plausible assumption that costs of migration differ over the human life cycle, the usual brain drain strategy is sub-optimal. With an increase in globalization, the brain drain strategy will be replaced by the strategy of migration of students.

  13. Migration aspirations and migration cultures : A case study of Ukrainian migration towards the European Union

    NARCIS (Netherlands)

    Van Mol, C.; Snel, Erik; Hemmerechts, Kenneth; Timmerman, Christiane

    2018-01-01

    An abundant body of research focused on macrolevel, mesolevel, and microlevel factors explaining why individuals move across international borders. In this paper, we aim to complement the existing literature by exploring how, within a single country, mesolevel factors differently impact migration

  14. Overall and specific migration from multilayer high barrier food contact materials - kinetic study of cyclic polyester oligomers migration.

    Science.gov (United States)

    Úbeda, Sara; Aznar, Margarita; Vera, Paula; Nerín, Cristina; Henríquez, Luis; Taborda, Laura; Restrepo, Claudia

    2017-10-01

    Most multilayer high barrier materials used in food packaging have a polyurethane adhesive layer in their structures. In order to assess the safety of these materials, it is important to determine the compounds intentionally added to the adhesives (IAS) as well as those non-intentionally added substances (NIAS). During the manufacture of polyurethane adhesives, some by-products can be formed, such as cyclic polyester oligomers coming from the reaction between dicarboxylic acids and glycols. Since these compounds are not listed in the Regulation 10/2011/EU, they should not be found in migration above 0.01 mg/kg of simulant. In this study two flexible multilayer packaging materials were used and migration was evaluated in simulant A (ethanol 10% v/v), simulant B (acetic acid 3% w/v) and simulant ethanol 95% v/v during 10 days at 60ºC. Identification and quantification of non-volatile compounds was carried out by UPLC-MS-QTOF. Most of migrants were oligomers such as cyclic polyesters and caprolactam oligomers. Overall migration and specific migration of adipic acid-diethylene glycol and phthalic acid-diethylene glycol were monitored over time and analysed by UPLC-MS-TQ. In most cases, ethanol 95% v/v was the simulant with the highest concentration values. Overall migration kinetics followed a similar pattern than specific migration kinetics.

  15. Migration of radionuclides in the soil-crop-food product system and assessment of agricultural countermeasures

    International Nuclear Information System (INIS)

    Bogdevitch, I.; Ageyets, V.

    1996-01-01

    Studies on dynamics of redistribution of radionuclides through of profile of the different soils on uncultivated agricultural lands of Belarus during the 1986-1995 period show that vertical migration occurs with low rate. In arable soils the radionuclides are distributed in comparatively uniform way through the whole depth of the 25-30 cm cultivated layer. Investigations on migration of radionuclides with wind erosion on the drained series of wet sandy and peat soils and water erosion on sloping lands show that one should take into consideration the secondary contamination of soils while forecasting a possible accumulation of radionuclides in farm products

  16. Migration of methane into groundwater from leaking production wells near Lloydminster

    International Nuclear Information System (INIS)

    1995-03-01

    The problem of migration of methane from leaking oil and gas wells into aquifers in the Lloydminster area in Saskatchewan, was discussed. A study was conducted to determine if the methane in shallow aquifers near the leaking wells, came from the wells or occurred naturally. Migration rate in aquifers, concentration gradients and approximate flux rates of methane from leaking wells to shallow aquifers, were studied. The methods of investigation included drilling of test holes at selected sites, installation of monitoring wells, purging of wells, pumping tests and water level monitoring, sampling and analyses for dissolved methane. The relatively high methane concentrations in many of the monitoring wells indicated the presence of a methane plume that has migrated from the production well. It was suggested that other leaky well sites in the area should be investigated to determine if similar plumes were present. 18 refs., 5 tabs., 13 figs

  17. Hospitality as lens for migration studies

    DEFF Research Database (Denmark)

    Greve, Anni

    there are limits to its financial resources. What is more, the focus on claim-making and extended rights of the migrant produces a tendency for the language and practice of hospitality to ‘turn’ against the guest today, and notably the construction of the figure of guests who not only fail to fulfil their duties...... (welfare ‘parasites’) but even betray the host. Next, an enquiry of the concept of hospitality as possible lens for migration studies; it implies a twofold analyses with two levels, a macro level, to focus our attention to the modalities of hospitality given by the juridical status of the stranger and its...... influence on civil inclusion (Sassen 2007; Brenner 2011); and a meso level, to focus instead upon hospitality as an inter-subjective relationship between the host and the guest as a way to relate, as an experience and as an ethics (Derrida 2001). Finally the paper gives a short introduction into an on...

  18. Migration of Spanish nurses 2009-2014. Underemployment and surplus production of Spanish nurses and mobility among Spanish registered nurses: A case study.

    Science.gov (United States)

    Galbany-Estragués, Paola; Nelson, Sioban

    2016-11-01

    After the financial crisis of 2008, increasing numbers of nurses from Spain are going abroad to work. To examine the health and workforce policy trends in Spain between 2009 and 2014 and to analyze their correlation with the migration of nurses. Single embedded case study. We examined data published by: Health Statistics, Organization for Economic Cooperation and Development (1996 to 2013); Ministry of Education, Culture and Sports (2006 to 2013); Ministry of Employment and Social Security (2009 to 2014); Ministry of Health, Social Services and Equality (1997 to 2014); and National Institute of Statistics (1976 to 2014). In addition to reviewing the scholarly literature on the topic in Spanish and English, we also examined Spanish mobility laws and European directives. We used the Organization for Economic Cooperation and Development definition of "professionally active nurses" which defines practising nurses and other nurses as those for whom their education is a prerequisite for employment as a nurse. Moreover, we used the term "nursing graduate" as defined by Spanish Ministry of Education to describe those who have obtained a recognized qualification in nursing in a given year, the term "registered nurses" is defined by Spanish law as nurses registered in the Nurses Associations and "unemployed nurses" are those without work and registered as seeking employment. A transformation of the Spanish health system has reduced the number of employed nurses per capita since 2010. Moreover, reductions in public spending, labour market reforms and widespread unemployment have affected nurses in two ways: first by increasing the number of applicants per vacancy between 2009 and 2013, and second, by an increase in casual positions. However, despite the poor job market and decreasing job security, the number of registered nurses and nursing graduates in Spain per year has continued to grow, increasing the pressure on the labour market. Spain is transforming from a stable

  19. Allosuppressor T lymphocytes abolish migration inhibition factor production in autoimmune thyroid disease: evidence from radiosensitivity experiments

    International Nuclear Information System (INIS)

    Topliss, D.J.; Okita, N.; Lewis, M.; Row, V.V.; Volpe, R.

    1981-01-01

    The ability of normal T lymphocytes to abolish the production of migration inhibition factor by antigen-sensitized T lymphocytes of Graves' disease (GD) and Hashimoto's thyroiditis (HT) in response to thyroid antigen has been studied by a modified migration inhibition factor test using isolated T lymphocytes alone. The production of migration inhibition factor was consistently abolished when normal T lymphocytes were mixed with GD or HT T lymphocytes in various ratios (1:9, 2:8, 5:5) as reported previously (Okita et al., 1980b). However, prior in-vitro irradiation (1000 rad) of the normal T lymphocytes resulted in loss of their ability to abolish migration inhibition factor production by the antigen-sensitized T lymphocytes of GD and HT. The effect is consistent with the radiosensitivity of suppressor T lymphocytes and indicates that the effect of normal T lymphocytes on GD and HT T lymphocytes is one of allosuppression. The results support the view that there is a defect in suppressor T cell function in GD and HT. (author)

  20. Liraglutide attenuates the migration of retinal pericytes induced by advanced glycation end products.

    Science.gov (United States)

    Lin, Wen-Jian; Ma, Xue-Fei; Hao, Ming; Zhou, Huan-Ran; Yu, Xin-Yang; Shao, Ning; Gao, Xin-Yuan; Kuang, Hong-Yu

    2018-07-01

    Retinal pericyte migration represents a novel mechanism of pericyte loss in diabetic retinopathy (DR), which plays a crucial role in the early impairment of the blood-retinal barrier (BRB). Glucagon-like peptide-1 (GLP-1) has been shown to protect the diabetic retina in the early stage of DR; however, the relationship between GLP-1 and retinal pericytes has not been discussed. In this study, advanced glycation end products (AGEs) significantly increased the migration of primary bovine retinal pericytes without influencing cell viability. AGEs also significantly enhanced phosphatidylinositol 3-kinase (PI3K)/Akt activation, and changed the expressions of migration-related proteins, including phosphorylated focal adhesion kinase (p-FAK), matrix metalloproteinase (MMP)-2 and vinculin. PI3K inhibition significantly attenuated the AGEs-induced migration of retinal pericytes and reversed the overexpression of MMP-2. Glucagon-like peptide-1 receptor (Glp1r) was expressed in retinal pericytes, and liraglutide, a GLP-1 analog, significantly attenuated the migration of pericytes by Glp1r and reversed the changes in p-Akt/Akt, p-FAK/FAK, vinculin and MMP-2 levels induced by AGEs, indicating that the protective effect of liraglutide was associated with the PI3K/Akt pathway. These results provided new insights into the mechanism underlying retinal pericyte migration. The early use of liraglutide exerts a potential bebefical effect on regulating pericyte migration, which might contribute to mechanisms that maintain the integrity of vascular barrier and delay the development of DR. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Material Exchange and Migration between Pore Fluids and Sandstones during Diagenetic Processes in Rift Basins: A Case Study Based on Analysis of Diagenetic Products in Dongying Sag, Bohai Bay Basin, East China

    Directory of Open Access Journals (Sweden)

    W. Meng

    2018-01-01

    Full Text Available The exchange and migration of basin materials that are carried by pore fluids are the essence of diagenesis, which can alter physical properties of clastic rocks as well as control formation and distribution of favorable reservoirs of petroliferous basins. Diagenetic products and pore fluids, resulting from migration and exchange of basin materials, can be used to deduce those processes. In this study, 300 core samples from 46 wells were collected for preparation of casting thin sections, SEM, BSE, EDS, inclusion analysis, and isotope analysis in Dongying Sag, Bohai Bay Basin, East China. Combined with geochemical characteristics of pore fluids and geological background of the study area, the source and exchange mechanisms of materials in the pore fluids of rift basins were discussed. It was revealed that the material exchange of pore fluids could be divided into five stages. The first stage was the evaporation concentration stage during which mainly Ca2+, Mg2+, and CO32- precipitated as high-Mg calcites. Then came the shale compaction stage, when mainly Ca2+ and CO32- from shale compaction water precipitated as calcites. The third stage was the carboxylic acid dissolution stage featured by predominant dissolution of plagioclases, during which Ca2+ and Na+ entered pore fluids, and Si and Al also entered pore fluids and then migrated as clathrates, ultimately precipitating as kaolinites. The fourth stage was the organic CO2 stage, mainly characterized by the kaolinization of K-feldspar as well as dissolution of metamorphic lithic fragments and carbon cements. During this stage, K+, Fe2+, Mg2+, Ca2+, HCO3-, and CO32- entered pore fluids. The fifth stage was the alkaline fluid stage, during which the cementation of ferro-carbonates and ankerites as well as illitization or chloritization of kaolinites prevailed, leading to the precipitation of K+, Fe2+, Mg2+, Ca2+, and CO32- from pore fluids.

  2. Substrate Curvature Regulates Cell Migration -A Computational Study

    Science.gov (United States)

    He, Xiuxiu; Jiang, Yi

    Cell migration in host microenvironment is essential to cancer etiology, progression and metastasis. Cellular processes of adhesion, cytoskeletal polymerization, contraction, and matrix remodeling act in concert to regulate cell migration, while local extracellular matrix architecture modulate these processes. In this work we study how stromal microenvironment with native and cell-derived curvature at micron-meter scale regulate cell motility pattern. We developed a 3D model of single cell migration on a curved substrate. Mathematical analysis of cell morphological adaption to the cell-substrate interface shows that cell migration on convex surfaces deforms more than on concave surfaces. Both analytical and simulation results show that curved surfaces regulate the cell motile force for cell's protruding front through force balance with focal adhesion and cell contraction. We also found that cell migration on concave substrates is more persistent. These results offer a novel biomechanical explanation to substrate curvature regulation of cell migration. NIH 1U01CA143069.

  3. The challenge of product development and tariff migration; Herausforderung Produktentwicklung und Tarifmigration

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Thomas [Simon-Kucher und Partners, Strategy und Marketing Consults, Wien (Austria); Stiller, Michael [Simon-Kucher und Partners, Bonn (Germany); Cerna, Daniela [Simon-Kucher und Partners, Frankfurt am Main (Germany)

    2011-01-15

    Power supply companies in German-speaking countries expect a marked shortening of product life cycles over the next five years. This means that new products will need to be developed at ever shorter time intervals. However, opinions on the success of newly introduced products are mediocre. While there is an understanding that the product portfolio should meet customers' needs, the importance of the conceptualisation phase in developing suitable products is systematically underestimated. A study performed by a reputed strategic consultancy firm has shown that at least when it comes to tariff migration there is a failure to address customers in a differentiated manner. A rethink in conceptualising product portfolios is needed if the success of new product launches is to be driven by other criteria than merely the price.

  4. Migration study of americium in porous medium

    International Nuclear Information System (INIS)

    Tanaka, Tadao; Ogawa, Hiromichi

    1999-01-01

    Migration experiments of 241 Am 3+ had been performed by a column system, to investigate migration behavior of 241 Am through a column packed porous sedimentary materials: a coastal sandy soil and a reddish soil. Most 241 Am loaded into the column packed the reddish soil sorbed on the influent edge of the column. In the case of the sandy soil, however, considerable amount of 241 Am was passed through the column. This shows that there is colloidal 241 Am species which may move without effective interaction with the sandy soil. Such a migration behavior of colloidal 241 Am in the sandy soil column could be evaluated by a sorption model based on filtration theory. Sorption mechanisms of 241 Am on the sedimentary materials were examined by a chemical extraction method, for 241 Am sorbed on the sandy soil and the reddish soil at any sections in the column. The 241 Am sorbed on the reddish soil was mainly controlled by a reversible ion exchange reaction. On the other hand, the 241 Am sorbed on the sandy soil ws controlled by irreversible reactions, such as the selective chemical sorptions onto Fe and Mn oxyhydroxide/oxide. The experimental results support that the migration of 241 Am in the reddish soil layer can be estimated by using the K d , whereas that in the sandy soil can not be explained by the K d concept. (author)

  5. Subseabed radionuclide migration studies and preliminary repository design concepts

    International Nuclear Information System (INIS)

    Brush, L.H.

    1982-01-01

    Geochemical research carried out by the US Subseabed Disposal Program is described. Data from studies of high-temperature interactions between sediments and pore water (seawater) and from studies of sorption and diffusion of radionuclides in oxidized, deep-sea sediments are used, along with results from heat transfer studies, to predict migration rates of raionuclides in a subseabed repository. Preliminary results for most radionuclides in oxidized sediments are very encouraging. Fission products with moderate K/sub D/ values (10 2 to 10 5 ml/g) and actinides with high K/sub D/ values (10 3 to 10 6 ml/g) would not migrate significant distances before decaying to innocuous concentrations. Among this group are 137 Cs, 90 Sr, and 239 Pu. The results for anionic species in oxidized sediments are less encouraging. Planning for field verification of these laboratory and modeling studies is currently under way. Conceptual repository designs and emplacement options are also described. 33 references, 15 figures, 1 table

  6. Abnormal neuronal migration: radiologic-clinic study

    International Nuclear Information System (INIS)

    Martinez Fernandez, M.; Menor Serrano, F.; Bordon Ferre, F.; Garcia Tena, J.; Esteban Hernandez, E.; Sanguesa Nebot, C.; Marti Bonnati, L.

    1994-01-01

    We present our experience in 18 pediatric patients with abnormal neuronal migration. Seven cases of heterotopia of the gray matter, 7 agyria-pachygyria complexes, 1 case of polymicrogyria, 2 cases of schizencephaly and 1 case of hemimegalencephaly were diagnosed by means of ultrasonography, computed tomography and magnetic resonance. The clinical picture was reviewed in each case, with special attention to the occurrence of convulsions, psycho motor development and visual changes. In general, the greater the morphological change, the greater the neurological involvement in these patients. However, the two cases of schizencephaly presented mild clinical expression. Magnetic resonance increases the diagnostic yield in neuronal migration disorders. Nevertheless, either ultrasonography or, especially, computed tomography is useful as a first diagnostic approach in these malformative disorders. (Author)

  7. Migration to Earth Observation Satellite Product Dissemination System at JAXA

    Science.gov (United States)

    Ikehata, Y.; Matsunaga, M.

    2017-12-01

    JAXA released "G-Portal" as a portal web site for search and deliver data of Earth observation satellites in February 2013. G-Portal handles ten satellites data; GPM, TRMM, Aqua, ADEOS-II, ALOS (search only), ALOS-2 (search only), MOS-1, MOS-1b, ERS-1 and JERS-1 and archives 5.17 million products and 14 million catalogues in total. Users can search those products/catalogues in GUI web search and catalogue interface(CSW/Opensearch). In this fiscal year, we will replace this to "Next G-Portal" and has been doing integration, test and migrations. New G-Portal will treat data of satellites planned to be launched in the future in addition to those handled by G - Portal. At system architecture perspective, G-Portal adopted "cluster system" for its redundancy, so we must replace the servers into those with higher specifications when we improve its performance ("scale up approach"). This requests a lot of cost in every improvement. To avoid this, Next G-Portal adopts "scale out" system: load balancing interfaces, distributed file system, distributed data bases. (We reported in AGU fall meeting 2015(IN23D-1748).) At customer usability perspective, G-Portal provides complicated interface: "step by step" web design, randomly generated URLs, sftp (needs anomaly tcp port). Customers complained about the interfaces and the support team had been tired from answering them. To solve this problem, Next G-Portal adopts simple interfaces: "1 page" web design, RESTful URL, and Normal FTP. (We reported in AGU fall meeting 2016(IN23B-1778).) Furthermore, Next G-Portal must merge GCOM-W data dissemination system to be terminated in the next March as well as the current G-Portal. This might arrise some difficulties, since the current G-Portal and GCOM-W data dissemination systems are quite different from Next G-Portal. The presentation reports the knowledge obtained from the process of merging those systems.

  8. Farming or seasonal migration? - Potential futures of reindeer husbandry in Fennoscandia studied with Social-Ecological System (SES) approach, co-production of knowledge, and scenarios

    Science.gov (United States)

    Käyhkö, Jukka; Horstkotte, Tim; Vehmas, Jarmo; Forbes, Bruce

    2017-04-01

    The area allocated for reindeer husbandry in Finland, Sweden and Norway covers approximately 40 % of each country. As the livelihood requires large, relatively unfragmented territories while being marginal in terms of direct income, land-use conflicts between various livelihoods and activities, such as forestry, agriculture, mining, energy production, tourism, and nature protection are common phenomena in the region. Simultaneously, rapid societal change, urban exodus and fading traditions as well as climate warming and subsequent ecosystem change may put the livelihood at stake. We have probed potential futures of reindeer husbandry in Northern Fennoscandia using the Social-Ecological System (SES) approach, knowledge co-production in stakeholder-scientist workshops in all three countries, and scenario building based on quantitative data and narratives. Regarding the future of the livelihood, we have identified some crucial components in the SES that are influential in determining the direction of development. We produced four potential pathways of future development and demonstrate that important factors controlling the direction of development include governance and actor relations. Governance is often considered distant and opaque by local stakeholders, fostering conflicts in land allocation, while unclear regulations at local level reinforce emerging conflict situations leading to distrust and restrained communication between the actors. Regionally, these conflicts may lead to decreased resilience and threaten the future of the livelihood altogether. Therefore, research should focus on supporting the reform process of institutional arrangements and governance mechanisms, and fostering co-design and co-production processes that ease distrust and improve resilience of the livelihood in multifunctional landscapes.

  9. Subsurface migration of petroleum hydrocarbons: A case study of immiscible migration and chromatographic separation

    International Nuclear Information System (INIS)

    Dawson, H.E.

    1991-01-01

    The subsurface distribution of a leaked crude oil illustrates the combined influence of both the chemical and physical properties of soil and free product on the migration of petroleum hydrocarbons. Immiscible phase behavior was observed, as well as chromatographic-like separation of the lighter constituents of the crude oil from the heavier constituents. After downward migration through approximately 50 ft of unsaturated, heterogeneous alluvial sediments, the crude oil formed a horizontal plume on top of a perched, saturated zone. Immiscible phase trapping is evident from the occurrence of very high concentration of hydrocarbons in both the vertical and horizontal plumes. Samples taken from the vertical zone of contamination indicate a transition from heavier hydrocarbons near the surface to lighter hydrocarbons at depth. This phenomenon is attributed to chromatographic-like separation of the heavier hydrocarbons by the soil, possibly due to preferential solubility of the lighter hydrocarbons in percolating ran water

  10. Predictive modelling of migration from packaging materials into food products for regulatory purposes

    NARCIS (Netherlands)

    Helmroth, E.; Rijk, R.; Dekker, M.; Jongen, W.

    2002-01-01

    Migration of low-molecular weight compounds is one of the most important problems of packaging plastics and other plastics intended to come into contact with food products. Since migration experiments are time consuming and expensive, predictive modelling has been introduced as a promising

  11. Labour migration and rural development in Egypt. A study of return migration in six villages.

    Science.gov (United States)

    Reichert, C

    1993-01-01

    An analysis of the impact of labor migration on social change in 6 rural villages (Shanawan and Kafr Shanawan north of Cairo, Kafr Yusuf and Tambul el Kubra near Simbalaween, and Abu Girg and Bani Walims in Minya governate) in Egypt was conducted in 1987-88. Since the 1991 Gulf war, the political environment, the labor markets, and the structure of migration opportunities have changed. An estimated 5% of rural households might have been directly affected by migrants' departure from Kuwait and Iraq. Data collection involved a household census survey of 8620 households, of which 2483 were migrants, including 1765 return migrants. A sample of return migrant (639) was interviewed about their migration experiences. Participant observation was also conducted among migrants and nonmigrants, and case studies were developed. Villages were demographically and socioeconomically very different; migration ranged from 18.5-434.2%. Structural change was measured on a scale of 1 to 6 in terms of population size, literacy of household heads, share of agricultural occupations, share of new red brick houses, and availability of infrastructural or institutional facilities. The probability of having a household with a migrant member increased with the rural character of the village. Landholdings or other major household variables were unrelated to migration. Rural outmigration was almost exclusively male, the average age was 29.6 years, and the average stay was 2.6 years. Migration destination was specific to individuals but affected by occupation and family or village resources. Professionals were overrepresented in Saudi Arabia, and farm and unskilled laborers or the unemployed were overrepresented in Iraq. Remittances from international migration have contributed along with the economic reforms of Sadat to new, private initiatives from all strata in rural society. 74.3% of returnees stated that improvement in income and living standards was the motivation for migration; many motives

  12. Using Single-Protein Tracking to Study Cell Migration.

    Science.gov (United States)

    Orré, Thomas; Mehidi, Amine; Massou, Sophie; Rossier, Olivier; Giannone, Grégory

    2018-01-01

    To get a complete understanding of cell migration, it is critical to study its orchestration at the molecular level. Since the recent developments in single-molecule imaging, it is now possible to study molecular phenomena at the single-molecule level inside living cells. In this chapter, we describe how such approaches have been and can be used to decipher molecular mechanisms involved in cell migration.

  13. Performance limits of coated particle fuel. Part III. Fission product migration in HTR fuel

    Energy Technology Data Exchange (ETDEWEB)

    Nabielek, H.; Hick, H.; Wagner-Loffler, M.; Voice, E. H.

    1974-06-15

    A general introduction and literature survey to the physics and mathematics of fission product migration in HTR fuel is given as well as a review of available experimental results and their evaluation in terms of models and materials data.

  14. The glass block site radionuclide migration study

    International Nuclear Information System (INIS)

    Killey, R.W.D.; Champ, D.R.

    1990-01-01

    In 1960 25 nepheline syenite glass blocks containing 14 TBq of mixed fission products in 50 kg of glass were placed below the water table in a shallow sand aquifer at Chalk River Laboratories. Experimental studies undertaken at the site since 1960 have included detailed mapping of the plume of 90 Sr in 1963, 1966 and 1971. Mathematical modeling studies have employed the radiostrontium plume data in determining the split between ion exchange and chemisorption of 90 Sr, and in obtaining reaction rate data for chemisorption. The distribution of 137 Cs on downgradient soils was mapped in 1963 and 1979. An extended plume of low-level 137 Cs contamination observed in the 1979 study prompted an investigation of the role of particulate materials in radionuclide transport. IN 1983, large volume groundwater sampling and separation of cationic, anionic, and neutral dissolved species, as well as particulates, detected anionic and cationic dissolved europium isotopes (154 and 155), and again encountered particulate 137 Cs. A variety of investigations of cesium and strontium sorption have provided a data base on sediment mineralogy, particle surface features, and information on sorption sites and processes. The year 1990 saw the inauguration of a three-year program to update investigations of radionuclide release, transport, and sorption at the glass block site. The first stage of the program has been a detailed definition and simulation of the hydrogeologic setting. Plume mapping and aqueous speciation studies are in progress. This paper summarizes past investigations, reviews the status of the current program, and discusses components of future studies, including investigations of sediment sorption mechanisms. (Author) (17 refs., 8 figs.)

  15. Introduction to Dossier. International Migrations in Latin America: Critical Views on the Production of a Field of Knowledge

    Directory of Open Access Journals (Sweden)

    Gioconda Herrera

    2017-05-01

    Full Text Available This article presents a reflection from three dimensions on epistemological and political logics that crosscut the studies on migrations in Latin America: 1 the increasing heterogeneity of flows and the need to rethink the conceptual categories from which migrations are addressed; 2 the dialogue and appropriation of analytical frameworks produced in other regions in Latin American studies; and 3 the political agendas of the States in the region and in the North, and their selective influence on the production of knowledge. The objective is to offer a general reflection on the production of the field of studies on migrations in Latin America to serve as a context for the analysis of the five articles presented in this dossier of Íconos. Revista de Ciencias Sociales.

  16. Religion and International Migration: A Case Study of Ukraine

    Directory of Open Access Journals (Sweden)

    Wadim Strielkowski

    2016-06-01

    Full Text Available This paper studies the relationships between religion and migration in modern-day Ukraine. We focus on Ukraine’s numerous churches and their attitude toward the phenomenon of emigration, their relevant activities with regard to the outward migration from the country, and the migration experiences and intentions of the believers. We find that the Greek Catholic Church has put special attention on the emigration phenomenon in its social doctrine, while the doctrines of other churches have been less elaborate, both in general terms and with regard to the issue of external migration in particular. Moreover, we demonstrate that worshippers belonging to the different churches have very similar growing concerns about the negative effects of Ukraine’s economic development—social divide and unemployment in particular.

  17. Effects of photoperiodism on the metabolism of carbon compounds and the migration of these products in tobacco

    International Nuclear Information System (INIS)

    Farineau, Jack

    1961-01-01

    This research thesis addressed the influence of photoperiodism on migrations. The author more particularly studied migrations of carbon-compound metabolism products by using a tobacco leaf in presence of "1"4CO_2, and which thus contained a high quantity of radioactive compounds. Some experiments were performed on short durations (few hours), and others on longer durations (15 days). As far as the first ones were concerned, the author studied the content of the petiole and of the terminal bud, and the first reactions of integration of carbon 14 compounds of the sap in the leaf. As far as the second type of experiments is concerned, the author measured the quantities of radioactive products migrating towards the terminal bud [fr

  18. A study on the radiometric method for evaluating element migration from plastic packagings to its contents

    International Nuclear Information System (INIS)

    Soares, Eufemia Paez

    2008-01-01

    Over the past few years, problems related to food contamination by substances or elements that can be a risk to human health have became a concern, not only to government authorities, but to the general population as well. Within this context, plastic packaging can constitute a source of food contamination since plastic manufacturing processes involve the use of catalysts and different types of additives that may contain toxic elements. When food comes into contact with this packaging, components of the package may migrate to the food. In order to control the material used as food packaging, the National Health Surveillance Agency (ANVISA) in Brazil, has established boundary values of migrant substances and procedures to determine migration from plastic packagings to food. In this study the radiometric method was evaluated for element migration determination from plastic packaging to food simulating or to the food itself. This radiometric method consisted in irradiating plastic packaging samples with a thermal neutron flux from the IEA-R1 nuclear research reactor in order to produce radionuclides of elements present in the packagings. The irradiated plastic was then exposed to food simulant or food for element migration. Gamma ray spectrometry was used to measure radioactivity in the simulant or food in order to quantify the migration. The food simulating types and experimental conditions were established according to the ANVISA regulations. Element migration was studied for plastic packaging used for soft drinks, drinking water, milk, dairy products, juices and fatty foods. In the instrumental neutron activation analysis of these packagings the presence of As, Cd, Cr, Co and Sb II was verified. Results obtained from the migration experiments by the radiometric method indicated that Cd, Co, Cr and Sb present in these plastics migrated to the simulant or to the food. In some packagings, the migration of only some of these elements was observed. In these cases the

  19. Protocols for Migration and Invasion Studies in Prostate Cancer.

    Science.gov (United States)

    van de Merbel, Arjanneke F; van der Horst, Geertje; Buijs, Jeroen T; van der Pluijm, Gabri

    2018-01-01

    Prostate cancer is the most common malignancy diagnosed in men in the western world. The development of distant metastases and therapy resistance are major clinical problems in the management of prostate cancer patients. In order for prostate cancer to metastasize to distant sites in the human body, prostate cancer cells have to migrate and invade neighboring tissue. Cancer cells can acquire a migratory and invasive phenotype in several ways, including single cell and collective migration. As a requisite for migration, epithelial prostate cancer cells often need to acquire a motile, mesenchymal-like phenotype. This way prostate cancer cells often lose polarity and epithelial characteristics (e.g., expression of E-cadherin homotypic adhesion receptor), and acquire mesenchymal phenotype (for example, cytoskeletal rearrangements, enhanced expression of proteolytic enzymes and other repertory of integrins). This process is referred to as epithelial-to-mesenchymal transition (EMT). Cellular invasion, one of the hallmarks of cancer, is characterized by the movement of cells through a three-dimensional matrix, resulting in remodeling of the cellular environment. Cellular invasion requires adhesion, proteolysis of the extracellular matrix, and migration of cells. Studying the migratory and invasive ability of cells in vitro represents a useful tool to assess the aggressiveness of solid cancers, including those of the prostate.This chapter provides a comprehensive description of the Transwell migration assay, a commonly used technique to investigate the migratory behavior of prostate cancer cells in vitro. Furthermore, we will provide an overview of the adaptations to the Transwell migration protocol to study the invasive capacity of prostate cancer cells, i.e., the Transwell invasion assay. Finally, we will present a detailed description of the procedures required to stain the Transwell filter inserts and quantify the migration and/or invasion.

  20. Freely-migrating-defect production during irradiation at elevated temperatures

    Science.gov (United States)

    Hashimoto, T.; Rehn, L. E.; Okamoto, P. R.

    1988-12-01

    Radiation-induced segregation in a Cu-1 at. % Au alloy was investigated using in situ Rutherford backscattering spectrometry. The amount of Au atom depletion in the near surface region was measured as a function of dose during irradiation at 350 °C with four ions of substantially different masses. Relative efficiencies for producing freely migrating defects were evaluated for 1.8-MeV 1H, 4He, 20Ne, and 84Kr ions by determining beam current densities that gave similar radiation-induced segregation rates. Irradiations with primary knock-on atom median energies of 1.7, 13, and 79 keV yielded relative efficiencies of 53, 7, and 6 %, respectively, compared to the irradiation with a 0.83-keV median energy. Despite quite different defect and host alloy properties, the relative efficiencies for producing freely migrating defects determined in Cu-Au are remarkably similar to those found previously in Ni-Si alloys. Hence, the reported efficiencies appear to offer a reliable basis for making quantitative correlations of microstructural changes induced in different alloy systems by a wide variety of irradiation particles.

  1. Adaptation as by-product: migration and environmental change in Nguith, Senegal

    Directory of Open Access Journals (Sweden)

    Romankiewicz, Clemens

    2016-06-01

    Full Text Available In the debate about the nexus between environmental change, climate and migration much attention has been given to a changing climate as a push factor for migration. A more recent strand of academic work focuses on migration as a means to enhance adaptation capacities and resilience. This article questions these intentional attributions and starts from the observation that migration is occurring regardless of environmental or climatic change and connects people and places through shared social and cultural identities and the flow of ideas and resources. Drawing on a case study of Nguith, a village in the Senegalese Sahel with a long and complex migration history, it is shown how migration and material and non-material remittances have led (in a way accidentally to an increased independence from local agro-ecological conditions. Therefore, we investigate the social, cultural and historical background of the people of Nguith with regard to their mobility and trace the continents-traversing migration network and connected translocal spaces. Finally, we explain the cohesive forces of this community that perpetuate and reinforce migration and show the effects of migration on everyday life, economic development in the village and resulting land-use change.

  2. Migrations of theory, method and practice: a reflection on themes in migration studies (Review article)

    OpenAIRE

    Palmary, Ingrid

    2009-01-01

    In this review article, I offer some reflection on three themes in migration research, namely, the categorisation and quantification of migration, the role of trauma and distress in such categorisation, and the feminisation of migration. I was prompted to explore these three themes after reading a recent publication on migration in southern Africa (edited by Kok, Gelderblom, Oucho and Van Zyl, 2006). In this paper I raise these as three areas that appear to be determining the boundaries of th...

  3. Environmental degradation and migration: the U.S.-Mexico case study.

    Science.gov (United States)

    1998-01-01

    This article provides a detailed account of the conclusions and policy recommendations of a study of environmental degradation and migration between the US and Mexico. Key recommendations and findings were included in the official US Congressional Commission on Immigration Reform report (September 1997). The Congressional report urges Congress to consider environment and development root causes of migration in establishing foreign policies with Mexico and other countries. It appears that the root cause of Mexican migration is rural land degradation or desertification. The study suggests feasible solutions, and not additional border security and employment-related sanctions. The US has the technology and expertise to facilitate programs that address environmental and development issues in targeted and integrated ways. The recommendations serve as a framework for policy reform and debate on rural development and agricultural productivity. Mexican states should be targeted that are new migration-sending states with extensive poverty and soil erosion problems and well-established migration states. Environment, population, and migration are all housed in the Global Affairs Office in the US Department of State, but there is little program integration. The USAID bureaucracy separates agricultural and environmental programs. Solutions include, for example, reducing the costs of remittances from the US to Mexico, conducting research on integrated solutions, and contributing to improved land and water management practices, forest management and land tenure, and the competitiveness of smallholders.

  4. Research Study on the Migration of Clients on Banking Market

    Directory of Open Access Journals (Sweden)

    Cornelia Tureac

    2013-02-01

    Full Text Available In this paper we present the relevancy and importance of knowing the reasons on clients’migration to competitive banking institutions. The main reason of being the client of several banks isdue to the fierce competition between credit institutions,thusthe banking market has changed. Basedon a case study within the Raiffeisen Bank we researched and presented the reasons fordiscontinuation of banking tiesand the migration of clients to other banks. The used researchmethodology consisted of the application of analysis point of contact by sending a questionnairethrough which there could have been identified 105 migrating clients, out of which 89 were formerclients of Raiffeisen Bank. Since both in the specialized literatureand in practice there is very littleinformation about migration behavior of banking clients-especially in the category of small andmedium enterprises-the present research was not limited to the Raiffeisen Bank clients, but to all 105respondents whodiscontinued totally or partially their connection with the bank. It can be concludedthat the attitude of the bank clients has a considerable influence on the migration behavior. The most“infidel” banking clients are considered in the category of “clients oriented towards the conditions.”

  5. Does Migration Make You Happy? A Longitudinal Study of Internal Migration and Subjective Well-Being (discussion paper)

    NARCIS (Netherlands)

    Nowok, B.; Van Ham, M.; Findlay, A.; Gayle, V.

    2011-01-01

    The majority of modelling studies on consequences of internal migration focus almost exclusively on the labour market outcomes and the material well-being of migrants. We investigate whether individuals who migrate within the UK become happier after the move than they were before it and whether the

  6. Tritium migration studies at the Nevada Test Site

    International Nuclear Information System (INIS)

    Schulz, R.K.; Weaver, M.O.

    1993-05-01

    Emanation of tritium from waste containers is a commonly known phenomenon. Release of tritium from buried waste packages was anticipated; therefore, a research program was developed to study both the rate of tritium release from buried containers and subsequent migration of tritium through soil. Migration of tritium away from low-level radioactive wastes buried in Area 5 of the Nevada Test Site was studied. Four distinct disposal events were investigated. The oldest burial event studied was a 1976 emplacement of 3.5 million curies of tritium in a shallow land burial trench. In another event, 248 thousand curies of tritium was disposed of in an overpack emplaced 6 m below the floor of a low-level waste disposal pit. Measurement of the emanation rate of tritium out of 55 gallon drums to the overpack was studied, and an annual doubling of the emanation rate over a seven year period, ending in 1990, was found. In a third study, upward tritium migration in the soil, resulting in releases in the atmosphere were observed in a greater confinement disposal test. Releases of tritium to the atmosphere were found to be insignificant. The fourth event consisted of burial of 2.2 million curies of tritium in a greater confinement disposal operation. Emanation of tritium from the buried containers has been increasing since disposal, but no significant migration was found four years following backfilling of the disposal hole

  7. Automated estimation of hip prosthesis migration: a feasibility study

    Science.gov (United States)

    Vandemeulebroucke, Jef; Deklerck, Rudi; Temmermans, Frederik; Van Gompel, Gert; Buls, Nico; Scheerlinck, Thierry; de Mey, Johan

    2013-09-01

    A common complication associated with hip arthoplasty is prosthesis migration, and for most cemented components a migration greater than 0.85 mm within the first six months after surgery, are an indicator for prosthesis failure. Currently, prosthesis migration is evaluated using X-ray images, which can only reliably estimate migrations larger than 5 mm. We propose an automated method for estimating prosthesis migration more accurately, using CT images and image registration techniques. We report on the results obtained using an experimental set-up, in which a metal prosthesis can be translated and rotated with respect to a cadaver femur, over distances and angles applied using a combination of positioning stages. Images are first preprocessed to reduce artefacts. Bone and prosthesis are extracted using consecutive thresholding and morphological operations. Two registrations are performed, one aligning the bones and the other aligning the prostheses. The migration is estimated as the difference between the found transformations. We use a robust, multi-resolution, stochastic optimization approach, and compare the mean squared intensity differences (MS) to mutual information (MI). 30 high-resolution helical CT scans were acquired for prosthesis translations ranging from 0.05 mm to 4 mm, and rotations ranging from 0.3° to 3° . For the translations, the mean 3D registration error was found to be 0.22 mm for MS, and 0.15 mm for MI. For the rotations, the standard deviation of the estimation error was 0.18° for MS, and 0.08° for MI. The results show that the proposed approach is feasible and that clinically acceptable accuracies can be obtained. Clinical validation studies on patient images will now be undertaken.

  8. Technological challenges of addressing new and more complex migrating products from novel food packaging materials.

    Science.gov (United States)

    Munro, Ian C; Haighton, Lois A; Lynch, Barry S; Tafazoli, Shahrzad

    2009-12-01

    The risk assessment of migration products resulting from packaging material has and continues to pose a difficult challenge. In most jurisdictions, there are regulatory requirements for the approval or notification of food contact substances that will be used in packaging. These processes generally require risk assessment to ensure safety concerns are addressed. The science of assessing food contact materials was instrumental in the development of the concept of Threshold of Regulation and the Threshold of Toxicological Concern procedures. While the risk assessment process is in place, the technology of food packaging continues to evolve to include new initiatives, such as the inclusion of antimicrobial substances or enzyme systems to prevent spoilage, use of plastic packaging intended to remain on foods as they are being cooked, to the introduction of more rigid, stable and reusable materials, and active packaging to extend the shelf-life of food. Each new technology brings with it the potential for exposure to new and possibly novel substances as a result of migration, interaction with other chemical packaging components, or, in the case of plastics now used in direct cooking of products, degradation products formed during heating. Furthermore, the presence of trace levels of certain chemicals from packaging that were once accepted as being of low risk based on traditional toxicology studies are being challenged on the basis of reports of adverse effects, particularly with respect to endocrine disruption, alleged to occur at very low doses. A recent example is the case of bisphenol A. The way forward to assess new packaging technologies and reports of very low dose effects in non-standard studies of food contact substances is likely to remain controversial. However, the risk assessment paradigm is sufficiently robust and flexible to be adapted to meet these challenges. The use of the Threshold of Regulation and the Threshold of Toxicological Concern concepts may

  9. Gas migration through cement slurries analysis: A comparative laboratory study

    Directory of Open Access Journals (Sweden)

    Arian Velayati

    2015-12-01

    Full Text Available Cementing is an essential part of every drilling operation. Protection of the wellbore from formation fluid invasion is one of the primary tasks of a cement job. Failure in this task results in catastrophic events, such as blow outs. Hence, in order to save the well and avoid risky and operationally difficult remedial cementing, slurry must be optimized to be resistant against gas migration phenomenon. In this paper, performances of the conventional slurries facing gas invasion were reviewed and compared with modified slurry containing special gas migration additive by using fluid migration analyzer device. The results of this study reveal the importance of proper additive utilization in slurry formulations. The rate of gas flow through the slurry in neat cement is very high; by using different types of additives, we observe obvious changes in the performance of the cement system. The rate of gas flow in neat class H cement was reported as 36000 ml/hr while the optimized cement formulation with anti-gas migration and thixotropic agents showed a gas flow rate of 13.8 ml/hr.

  10. A study of elemental migration from poly(ethylene terephthalate) of food packagings to simulated solutions by radiometric method

    International Nuclear Information System (INIS)

    Soares, Eufemia Paez; Saki, Mitiko; Silva, Leonardo G.A.

    2007-01-01

    Brazilian plastic production for food packagings, in recent years, has grown in the same proportion as food consumption. Considering that the plastic manufacturing involves catalytic processes and the use of additives, when the foods are in direct contact with these materials, the components present in plastics may migrate to the food. The Brazilian Health Surveillance Agency (ANVISA) has established boundary-values of migrants as well as procedures to evaluate migration of elements and substances from plastic packaging to food. In this study elemental composition of poly (ethylene terephthalate) - PET - packaging and results of elemental migration were obtained. Instrumental Neutron Activation Analysis (INAA) was used to determine elemental concentrations in PET packagings and the radiometric method was applied for elemental migration determination. This radiometric method consisted of irradiating the PET samples with neutrons, followed by migration exposition and radioactivity measurement in food-simulated solution. Experimental conditions used for migration were 10 days exposure period at 40 deg C. Migration was evaluated for soft drink, juice and water PET packaging. The analytical results indicated that PET packagings contain Co and Sb and those elements are transferred to the simulated solutions. However, these migration results were lower than the maximum tolerance values established by ANVISA. The migration detection limits also indicated high sensitivity of the radiometric method. (author)

  11. Studies of alkaline mediated phosphate migration in synthetic phosphoethanolamine l-glycero-d-manno-heptoside derivatives

    International Nuclear Information System (INIS)

    Stewart, A.; Martin, A.; Richards, J.C.; Bernlind, C.; Oscarson, S.; Schweda, E.K.H.

    1998-01-01

    Synthetic 2-, 3-, 4- and 6-monophosphate derivatives of methyl α-d-mannopyranosides, the 4-, 6- and 7-monophosphate derivatives of methyl l-glycero-α-d-manno-heptopyranosides and the corresponding phosphoethanolamine derivatives and a 6,7-cyclic phosphate analogue of methyl l-glycero-α-d-manno-heptopyranoside were used to study phosphate migration and hydrolysis when subjected to strong alkaline conditions (4 M KOH, 120 C, 18 h). The resulting products were analyzed by 1 H NMR spectroscopy and electrospray mass spectrometry. It was found that phosphate substituents were stable under these conditions and neither migration nor hydrolysis was observed except for the heptose 7-phosphate, which gave a substantial amount of phosphate hydrolysis. In phosphoethanolamine-substituted compounds migration to adjacent positions with concomitant loss of ethanolamine was found together with hydrolysis. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. Oklo natural reactor. Study of uranium and rare earths migration on a core drilled through a reaction zone. Application to determination of the date of the nuclear reaction by measurement of fission products

    International Nuclear Information System (INIS)

    Ruffenach, J.C.

    1977-01-01

    Isotopic and chemical analysis of uranium and five rare earths: neodymium, samarium, europium, gadolinium and dysprosium were effected on fourteen samples taken in the same core drilled through a reaction zone of the Oklo uranium deposit. This study points out the general stability of uranium and fission rare earths; spatial distributions of these elements are quite analogous. Migrations have affected about 5% only of fission neodymium in the core of the reaction zone; corresponding values for samarium and gadolinium are slightly higher. These migration phenomena have carried rare earths to no more than 80 cm out of the core. By study of the europium it is shown that nuclear reactions have stayed in the ground since the time of reactions. On the other hand it is shown by analysis of the dysprosium that rare earths have not undergone an important movement. This study allow also the datation of nuclear reactions from the measurement of the quantity of fission neodymium produced. A value of 1.98x10 9 years is obtained slightly higher than the value obtained by geochronology [fr

  13. Study on the chloride migration coefficient obtained following different Rapid Chloride Migration (RCM) test guidelines

    NARCIS (Netherlands)

    Spiesz, P.R.; Brouwers, H.J.H.; Uzoegbo, H.C.; Schmidt, W.

    2013-01-01

    This work presents the differences in the available Rapid Chloride Migration (RCM) test guidelines, and their influence on the values of the chloride migration coefficients DRCM, obtained following these guidelines. It is shown that the differences between the guidelines are significant and concern

  14. Sustainability and Productivity Indicators with Sensitivity Truth Table for Unskilled Thai Labour Reverse Migration

    Science.gov (United States)

    Panaingvait, Poj; Chakpitak, Nopasit; Yodmongkol, Pitipong; Sureephong, Paradorn; Nimmonrat, Acrapol

    2014-01-01

    Thailand, a developing country, had labours migrating from the agriculture into the industrial due to higher pay in the past. However the economic force has made the government policy to focus on creativity and developing technology towards automatic production. Unskilled Thai labours are facing a big challenge after retirement, which is called…

  15. Migrating to learn and learning to migrate: a study of the experiences and intentions of international student migrants.

    Science.gov (United States)

    Li, F L; Findlay, A M; Jowett, A J; Skeldon, R

    1996-03-01

    "The research reported here evaluates whether students come to the UK mainly for educational reasons, and therefore perceive their stay as temporary, or whether emigration for study is being used as part of a conscious strategy by people intending to become future labour migrants.... The simplest interpretation of the results appears to be that migration, experienced as a result of international moves for study purposes, does not influence planning of further migration moves. But the research also indicates that migration for education is closely tied to other types of population redistribution and should be treated by population geographers as an integral part of international migration systems." Data were collected by questionnaire survey from 349 engineering students at Hong Kong universities and 82 Hong Kong students studying engineering in the UK. excerpt

  16. Human migration activities drive the fluctuation of ARGs: Case study of landfills in Nanjing, eastern China.

    Science.gov (United States)

    Sun, Mingming; Ye, Mao; Schwab, Arthur P; Li, Xu; Wan, Jinzhong; Wei, Zhong; Wu, Jun; Friman, Ville-Petri; Liu, Kuan; Tian, Da; Liu, Manqiang; Li, Huixin; Hu, Feng; Jiang, Xin

    2016-09-05

    Landfills are perfect sites to study the effect of human migration on fluctuation of antibiotic resistance genes (ARGs) as they are the final destination of municipal waste. For example, large-scale human migration during the holidays is often accompanied by changes in waste dumping having potential effects on ARG abundance. Three landfills were selected to examine fluctuation in the abundance of fifteen ARGs and Intl1 genes for 14 months in Nanjing, eastern China. Mass human migration, the amount of dumped waste and temperature exerted the most significant effects on bimonthly fluctuations of ARG levels in landfill sites. As a middle-sized cosmopolitan city in China, millions of college students and workers migrate during holidays, contributing to the dramatic increases in waste production and fluctuation in ARG abundances. In line with this, mass migration explained most of the variation in waste dumping. The waste dumping also affected the bioaccessibility of mixed-compound pollutants that further positively impacted the level of ARGs. The influence of various bioaccessible compounds on ARG abundance followed the order: antibiotics>nutrients>metals>organic pollutants. Concentrations of bioaccessible compounds were more strongly correlated with ARG levels compared to total compound concentrations. Improved waste classification and management strategies could thus help to decrease the amount of bioaccessible pollutants leading to more effective control for urban ARG dissemination. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Study of test methods for radionuclide migration in aerated zone

    International Nuclear Information System (INIS)

    Li Shushen; Guo Zede; Wang Zhiming

    1993-01-01

    Aerated zone is an important natural barrier against transport of radionuclides released from disposal facilities of LLRW. This paper introduces study methods for radionuclide migration in aerated zone, including determination of water movement, laboratory simulation test, and field tracing test. For one purpose, results obtained with different methods are compared. These methods have been used in a five-year cooperative research project between CIRP and JAERI for an establishment of methodology for safety assessment on shallow land disposal of LLRW

  18. Estimating freshwater productivity, overwinter survival, and migration patterns of Klamath River Coho Salmon

    Science.gov (United States)

    Manhard, Christopher V.; Som, Nicholas A.; Perry, Russell W.; Faukner, Jimmy; Soto, Toz

    2018-01-01

    An area of great importance to resource management and conservation biology in the Klamath Basin is balancing water usage against the life history requirements of threatened Coho Salmon. One tool for addressing this topic is a freshwater dynamics model to forecast Coho Salmon productivity based on environmental inputs. Constructing such a forecasting tool requires local data to quantify the unique life history processes of Coho Salmon inhabiting this region. Here, we describe analytical methods for estimating a series of sub-models, each capturing a different life history process, which will eventually be synchronized as part of a freshwater dynamics model for Klamath River Coho Salmon. Specifically, we draw upon extensive population monitoring data collected in the basin to estimate models of freshwater productivity, overwinter survival, and migration patterns. Our models of freshwater productivity indicated that high summer temperatures and high winter flows can both adversely affect smolt production and that such relationships are more likely in tributaries with naturally regulated flows due to substantial intraannual environmental variation. Our models of overwinter survival demonstrated extensive variability in survival among years, but not among rearing locations, and demonstrated that a substantial proportion (~ 20%) of age-0+ fish emigrate from some rearing sites in the winter. Our models of migration patterns indicated that many age-0+ fish redistribute in the basin during the summer and winter. Further, we observed that these redistributions can entail long migrations in the mainstem where environmental stressors likely play a role in cueing refuge entry. Finally, our models of migration patterns indicated that changes in discharge are important in cueing the seaward migration of smolts, but that the nature of this behavioral response can differ dramatically between tributaries with naturally and artificially regulated flows. Collectively, these analyses

  19. Reinventing US Internal Migration Studies in the Age of International Migration.

    Science.gov (United States)

    Ellis, Mark

    2012-03-01

    I argue that researchers have sidelined attention to issues raised by US internal migration as they shifted focus to the questions posed by the post-1960s rise in US immigration. In this paper, I offer some reasons about why immigration has garnered more attention and why there needs to be greater consideration of US internal migration and its significant and myriad social, economic, political, and cultural impacts. I offer three ideas for motivating more research into US internal geographic mobility that would foreground its empirical and conceptual connections to international migration. First, there should be more work on linked migration systems investigating the connections between internal and international flows. Second, the questions asked about immigrant social, cultural, and economic impacts and adaptations in host societies should also be asked about internal migrants. Third, and more generally, migration researchers should jettison the assumption that the national scale is the pre-eminent delimiter of migration types and processes. Some groups can move easily across borders; others are constrained in their moves within countries. These subnational scales and constraints will become more visible if migration research decentres the national from its theory and empirics.

  20. Study of health human resource migration in India

    Directory of Open Access Journals (Sweden)

    Panneer Sigamani

    2015-01-01

    Full Text Available Background Human Resource for Health (HRH migration is an emerging concern in the development paradigm due to the critical importance to sustainability of health system in India. Being the largest human resource supplier to the world, it is important to analyze the consequences of the migration of HRH in the delivery of healthcare services to the country’s population. The study evidences limited to examine the size, distribution of the existing human resources or trends or patterns in migration. The consequences of migration have its implications to the healthcare delivery mechanism which needed to be critically analyzed. Review Methodology The methodology adopted in the paper is descriptive design. The critical review used to evaluate the existing evidence and to develop conceptual framework. The process involved the setting of the inclusion and exclusion criteria to select the articles. It included wide range of articles from the world development reports to specific studies oriented on the HRH scenario of the country. The search strategy comprised both form of studies qualitative and quantitative. The study utilizes the official data set published as report form. Main Findings The data on the migration in context of India, not systematically updated in the existing evidences. The availability of data on migration limits to few reports i.e.(World Health Organization WHO’s Joint Learning Initiatives and studies which combines census data of Organization for Economic Cooperation and Development (OECD and results in the number of foreign born health professionals. 1. A major proportion of the research studies reviewed describes the disparity in distribution of HRH between rural-urban and public-private. Few researches focused towards the policy environment of the source and destination country for the migration. 2. There is pool of literature explaining the factors of migration but it margins when to analyze the significant implications to

  1. Analytical study in 1D nuclear waste migration

    International Nuclear Information System (INIS)

    Perez Guerrero, Jesus S.; Heilbron Filho, Paulo L.; Romani, Zrinka V.

    1999-01-01

    The simulation of the nuclear waste migration phenomena are governed mainly by diffusive-convective equation that includes the effects of hydrodynamic dispersion (mechanical dispersion and molecular diffusion), radioactive decay and chemical interaction. For some special problems (depending on the boundary conditions and when the domain is considered infinite or semi-infinite) an analytical solution may be obtained using classical analytical methods such as Laplace Transform or variable separation. The hybrid Generalized Integral Transform Technique (GITT) is a powerful tool that can be applied to solve diffusive-convective linear problems to obtain formal analytical solutions. The aim of this work is to illustrate that the GITT may be used to obtain an analytical formal solution for the study of migration of radioactive waste in saturated flow porous media. A case test considering 241 Am radionuclide is presented. (author)

  2. Migration and religious (intolerance: Contribution to the studies regarding the impact of international migration and the perception of religious diversity

    Directory of Open Access Journals (Sweden)

    Olga Odgers Ortiz

    2005-07-01

    Full Text Available Mexicans migrating to the United Status confront a very different social space which forces them to re-elaborate multiple identity references, among which religious beliefs and practices stand out. A number of studies have shown that among those who migrate, some on occasion turn to practices of popular religiosity in order to create bridges and maintain links with their communities of origin, in other cases, the migratory experience favors the processes of religious conversion. The subject is reopened in this article in order to bring up a third expression of the impact of migration on religious conversion: the transformation of the idea of religious diversity among those who migrate and consequently, the modification of some attitudes of religious tolerance and intolerance.

  3. Nopal I uranium deposit: A study of radionuclide migration

    International Nuclear Information System (INIS)

    Wong, V.; Anthony, E.; Goodell, P.

    1996-01-01

    This summary reports on activities of naturally-occurring radionuclides for the Nopal I uranium deposit located in the Pena Blanca Uranium District, Chihuahua, Mexico. Activities were determined using gamma-ray spectroscopy. In addition, data reduction procedures and sample preparation (for Rn retention) will be discussed here. Nopal I uranium deposit has been identified as one of the most promising sites for analogue studies to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. The objective of this research is to study the potential for radionuclide migration by testing whether any portion of the deposit is in secular equilibrium

  4. Nopal I uranium deposit: A study of radionuclide migration

    Energy Technology Data Exchange (ETDEWEB)

    Wong, V.; Anthony, E.; Goodell, P. [Univ. of Texas, El Paso, TX (United States)

    1996-12-01

    This summary reports on activities of naturally-occurring radionuclides for the Nopal I uranium deposit located in the Pena Blanca Uranium District, Chihuahua, Mexico. Activities were determined using gamma-ray spectroscopy. In addition, data reduction procedures and sample preparation (for Rn retention) will be discussed here. Nopal I uranium deposit has been identified as one of the most promising sites for analogue studies to the proposed high-level nuclear waste repository at Yucca Mountain, Nevada. The objective of this research is to study the potential for radionuclide migration by testing whether any portion of the deposit is in secular equilibrium.

  5. Molecular orbital studies on the Wagner-Meerwein migration in ...

    Indian Academy of Sciences (India)

    Meerwein migration of various groups during the pinacol-pinacolone rearrangement of some acyclic systems. Pinacol first protonates and dehydrates to form a carbocation that undergoes a 1,2-migration to form a protonated ketone, which then ...

  6. Modeling Studies to Constrain Fluid and Gas Migration Associated with Hydraulic Fracturing Operations

    Science.gov (United States)

    Rajaram, H.; Birdsell, D.; Lackey, G.; Karra, S.; Viswanathan, H. S.; Dempsey, D.

    2015-12-01

    The dramatic increase in the extraction of unconventional oil and gas resources using horizontal wells and hydraulic fracturing (fracking) technologies has raised concerns about potential environmental impacts. Large volumes of hydraulic fracturing fluids are injected during fracking. Incidents of stray gas occurrence in shallow aquifers overlying shale gas reservoirs have been reported; whether these are in any way related to fracking continues to be debated. Computational models serve as useful tools for evaluating potential environmental impacts. We present modeling studies of hydraulic fracturing fluid and gas migration during the various stages of well operation, production, and subsequent plugging. The fluid migration models account for overpressure in the gas reservoir, density contrast between injected fluids and brine, imbibition into partially saturated shale, and well operations. Our results highlight the importance of representing the different stages of well operation consistently. Most importantly, well suction and imbibition both play a significant role in limiting upward migration of injected fluids, even in the presence of permeable connecting pathways. In an overall assessment, our fluid migration simulations suggest very low risk to groundwater aquifers when the vertical separation from a shale gas reservoir is of the order of 1000' or more. Multi-phase models of gas migration were developed to couple flow and transport in compromised wellbores and subsurface formations. These models are useful for evaluating both short-term and long-term scenarios of stray methane release. We present simulation results to evaluate mechanisms controlling stray gas migration, and explore relationships between bradenhead pressures and the likelihood of methane release and transport.

  7. A lean and mean strategy: a data migration industrial study

    NARCIS (Netherlands)

    Razavian, M.; Lago, P.

    2014-01-01

    Many companies have legacy assets to be integrated or modernized. Like today's software developments, migration projects are faced with steadily increasing demands for efficiency: migration has to be carried out faster, better, and cheaper. At the same time, migration complexity increases, and

  8. Studies on Tagged Clay Migration Due to Water Movement

    Energy Technology Data Exchange (ETDEWEB)

    Scharpenseel, H. W. [Institut fuer Bodenkunde der Universitaet Bonn, Federal Republic of Germany (Germany); Kerpen, W. [Arbeitsgruppe, Institut fuer Landwirtschaft der KFA Juelich, Bonn, Federal Republic of Germany (Germany)

    1967-11-15

    {sup 55}Fe-tagged clay minerals, produced by hydrothermal synthesis, serve to clarify the question whether clay migration or clay formation in situ is the predominating mechanism in the B{sub t}-development of Parabraunerde (sol brun lessive, grey brown podsolic, hapludalf, dernopodsol). They further indicate the possibilities of clay transportation caused by water percolation. Suitable experimental approaches, such as thin-layer chromatography and autoradiography, translocation tests in columns filled with monotypical textural fractions or with undisturbed soil profiles, and synchronous hydrothermal treatment of {sup 55}Fe-con raining material from different horizons of Parabraunerde, to reveal the specific readiness of the different profile zones for {sup 55}Fe-clay production, are described. The possibilities of clay percolation are discussed. (author)

  9. Studies on Tagged Clay Migration Due to Water Movement

    International Nuclear Information System (INIS)

    Scharpenseel, H.W.; Kerpen, W.

    1967-01-01

    55 Fe-tagged clay minerals, produced by hydrothermal synthesis, serve to clarify the question whether clay migration or clay formation in situ is the predominating mechanism in the B t -development of Parabraunerde (sol brun lessive, grey brown podsolic, hapludalf, dernopodsol). They further indicate the possibilities of clay transportation caused by water percolation. Suitable experimental approaches, such as thin-layer chromatography and autoradiography, translocation tests in columns filled with monotypical textural fractions or with undisturbed soil profiles, and synchronous hydrothermal treatment of 55 Fe-con raining material from different horizons of Parabraunerde, to reveal the specific readiness of the different profile zones for 55 Fe-clay production, are described. The possibilities of clay percolation are discussed. (author)

  10. Mechanistic studies of copper(I)-catalyzed 1,3-halogen migration.

    Science.gov (United States)

    Van Hoveln, Ryan; Hudson, Brandi M; Wedler, Henry B; Bates, Desiree M; Le Gros, Gabriel; Tantillo, Dean J; Schomaker, Jennifer M

    2015-04-29

    An ongoing challenge in modern catalysis is to identify and understand new modes of reactivity promoted by earth-abundant and inexpensive first-row transition metals. Herein, we report a mechanistic study of an unusual copper(I)-catalyzed 1,3-migration of 2-bromostyrenes that reincorporates the bromine activating group into the final product with concomitant borylation of the aryl halide bond. A combination of experimental and computational studies indicated this reaction does not involve any oxidation state changes at copper; rather, migration occurs through a series of formal sigmatropic shifts. Insight provided from these studies will be used to expand the utility of aryl copper species in synthesis and develop new ligands for enantioselective copper-catalyzed halogenation.

  11. Grading system for migrated lumbar disc herniation on sagittal magnetic resonance imaging. An agreement study

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Y.; Jeong, T.S. [Gachon University Gil Medical Center, Department of Neurosurgery, Incheon (Korea, Republic of); Lim, T.; Jeon, J.Y. [Gachon University Gil Medical Center, Department of Radiology, Incheon (Korea, Republic of)

    2018-01-15

    Migrated lumbar disc herniations (LDHs) in the sagittal plane are common. Disc migration grading can be applied as a useful measurement tool in the diagnosis, treatment, and outcome evaluation of migrated LDH. No study has evaluated the reliability of migrated LDH grading. We evaluated the reliability and functionality of the current magnetic resonance imaging (MRI) grading system for migrated LDH. We assessed a six-level grading system developed based on sagittal MRI and graded according to the direction (rostral and caudal) and degree (low, high, and very high) of disc migration. One-hundred and one migrated LDHs treated with minimally invasive endoscopic discectomy were analyzed independently by two experienced radiologists. Intraobserver and interobserver agreements were assessed by kappa statistics. The most common migrated LDH grade was grade 4 (30.94%; caudal, low-grade migration). Rostral and caudal migrations were more common in the upper and lower lumbar levels, respectively. Interobserver agreement in the grading of migrated LDH was good at both the first (kappa = 0.737) and second assessment (kappa = 0.657). The intraobserver agreement for reader 1 was very good (kappa = 0.827) and for reader 2 was good (kappa = 0.620). The current grading system for migrated LDH was found to be reliable and functional with good interobserver and intraobserver agreement. It may be useful in the interpretation of disc migration patterns and outcomes of various minimally invasive surgical procedures. (orig.)

  12. Radionuclide migration studies at the Nevada Test Site

    International Nuclear Information System (INIS)

    Thompson, J.L.

    1989-01-01

    The United States government routinely tests nuclear devices at the Nevada Test Site (NTS) in southern Nevada. A significant amount of radioactive material exists underground at the NTS with no containers or engineered barriers to inhibit its subsequent migration. The Department of Energy has sponsored for many years a research program on radionuclide movement in the geologic media at this location. Goals of this research program are to measure the extent of movement of radionuclides away from underground explosion sites and to determine the mechanisms by which such movement occurs. This program has acquired significance in another aspect of nuclear waste management because of the Yucca Mountain Project. Yucca Mountain at the NTS is being intensively studied as the possible site for a mined repository for high level nuclear waste. The NTS provides a unique setting for field studies concerning radionuclide migration; there is the potential for greatly increasing our knowledge of the behavior of radioactive materials in volcanogenic media. This review summarizes some of the significant findings made under this research program at the NTS and identifies reports in which the details of the research may be found. 36 refs., 4 figs

  13. Migration of DEHP and DINP into dust from PVC flooring products at different surface temperature.

    Science.gov (United States)

    Jeon, Seunghwan; Kim, Ki-Tae; Choi, Kyungho

    2016-03-15

    Phthalates are important endocrine disrupting chemicals that have been linked to various adverse human health effects. Phthalates are ubiquitously present in indoor environment and could enter humans. Vinyl or PVC floorings have been recognized as one of important sources of phthalate release to indoor environment including house dust. In the present study, we estimated the migration of di(2-ethylhexyl)phthalate (DEHP) and di-isononyl phthalate (DINP) from the flooring materials into the dust under different heating conditions. For this purpose, a small chamber specifically designed for the present study and a Field and Laboratory Emission Cell (FLEC) were used, and four major types of PVC flooring samples including two UV curing paint coated, an uncoated residential, and a wax-coated commercial type were tested. Migration of DEHP was observed for an uncoated residential type and a wax-coated commercial type flooring. After 14 days of incubation, the levels of DEHP in the dust sample was determined at room temperature on average (standard deviation) at 384 ± 19 and 481 ± 53 μg/g, respectively. In contrast, migration of DINP was not observed. The migration of DEHP was strongly influenced by surface characteristics such as UV curing coating. In the residential flooring coated with UV curing paint, migration of DEHP was not observed at room temperature. But under the heated condition, the release of DEHP was observed in the dust in the FLEC. Migration of DEHP from flooring materials increased when the flooring was heated (50 °C). In Korea, heated flooring system, or 'ondol', is very common mode of heating in residential setting, therefore the contribution of PVC flooring to the total indoor DEHP exposure among general population is expected to be greater especially during winter season when the floor is heated. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Waste migration studies at the Savannah River Plant burial ground

    International Nuclear Information System (INIS)

    Stone, J.A.; Oblath, S.B.; Hawkins, R.H.; Grant, M.W.; Hoeffner, S.L.; King, C.M.

    1985-01-01

    The low-level radioactive waste burial ground at the Savannah River Plant is a typical shallow-land-burial disposal site in a humid region. Studies of waste migration at this site provide generic data for designing other disposal facilities. A program of field, laboratory, and modeling studies for the SRP burial ground has been conducted for several years. Recent results of lysimeter tests, soil-water chemistry studies, and transport modeling are reported. The lysimeter experiments include ongoing tests with 40 lysimeters containing a variety of defense wastes, and recently concluded lysimeter tests with tritium and plutonium waste forms. The tritium lysimeter operated 12 years. In chemistry studies, measurements of soil-water distribution coefficients (K/sub d/) were concluded. Current emphasis is on identification of trace organic compounds in groundwater from the burial site. Development of the dose-to-man model was completed, and the computer code is available for routine use. 16 refs., 2 figs., 2 tabs

  15. Production of structured lipids: acyl migration during enzymatic interesterification and downstream processing

    DEFF Research Database (Denmark)

    Xu, Xuebing

    1997-01-01

    Production of structured lipids by lipase-catalyzed interesterification attracts great interests recently. Structured lipids are defined, in this article, as triacylglycerols which contain both medium or short chain fatty acids and long chain fatty acids, each groups locating specifically in the sn......-2 position or sn-1,3 positions of glycerol backbone. These kinds of lipids are reported to be promising for both enteral and parenteral nutrition. However, acyl migration occurs in the reaction stage and downstream purification process. This side-reaction causes by-products which are harmful...

  16. A study for the environmental impact assessment of the leachate migration in landfills

    International Nuclear Information System (INIS)

    Hwang, Y. S.

    1999-12-01

    In Korea there are hundreds of landfill sites all over the peninsula and the leachate problem is one of the national concern. Heavy precipitation especially during hot summers creates the fast degradation of waste products in the site which accelerates the migration of the leachate. To assess the source term, in the second year study, the computational modeling to predict the potential infiltration rate of groundwater into the landfill were developed and tested for different geomembrane sets. These results shall be used to assess the total risk of the landfill site if combined with the results in the first year R and D and potential future R and D on the biosphere. In addition the generation, migration of LFG were studied and then approaches for the monitoring and controlling of LFG were discussed. (author)

  17. Environmental degradation, global food production, and risk for large-scale migrations

    International Nuclear Information System (INIS)

    Doeoes, B.R.

    1994-01-01

    This paper attempts to estimate to what extent global food production is affected by the ongoing environmental degradation through processes, such as soil erosion, salinization, chemical contamination, ultraviolet radiation, and biotic stress. Estimates have also been made of available opportunities to improve food production efficiency by, e.g., increased use of fertilizers, irrigation, and biotechnology, as well as improved management. Expected losses and gains of agricultural land in competition with urbanization, industrial development, and forests have been taken into account. Although estimated gains in food production deliberately have been overestimated and losses underestimated, calculations indicate that during the next 30-35 years the annual net gain in food production will be significantly lower than the rate of world population growth. An attempt has also been made to identify possible scenarios for large-scale migrations, caused mainly by rapid population growth in combination with insufficient local food production and poverty. 18 refs, 7 figs, 6 tabs

  18. Fundamental aspects on ion-beam surface modification: defect production and migration processes

    International Nuclear Information System (INIS)

    Rehn, L.E.; Averback, R.S.; Okamoto, P.R.

    1984-09-01

    Ion-beam modification of metals is generating increasing scientific interest not only because it has exciting technological potential, but also because it has raised fundamental questions concerning radiation-induced diffusion processes. In addition to the implanted species, several defect production and migration mechanisms contribute to changes in the near-surface composition of an alloy during ion bombardment, e.g., atoms exchange positions via displacements and replacement sequences; preferential sputtering effects arise; radiation-enhanced diffusion and radiation-induced segregation occur. The latter two defect migration mechanisms are of particular significance since they can alter the composition to depths which are much greater than the implanted ion range. By altering various parameters such as irradiation temperature, ion mass, energy, and current density, and initial alloying distributions, a rich variety of near-surface composition profiles can be created. We have utilized changes in ion mass and energy, and irradiation temperature to distinguish defect production from defect migration effects. Experimental results are presented which provide a guide to the relative efficiencies of different mechanisms under various irradiation conditions. 46 references

  19. Securitization of Migration: an Australian case study of global trends

    Directory of Open Access Journals (Sweden)

    Michael Humphrey

    2014-08-01

    Full Text Available Post September 11 migration has increasingly been framed as a security problem. In the 2010 Australian election campaign migration was connected to security (defense of our borders, terrorism and social cohesion and to related issues of insecurity about the future (population size,sustainability and economic growth. Thisframing of migration as a national security issue overlooks the reality that Australian immigration is part of the global flow of population. Migration is an international issue experienced by states as a national question of border control and sovereignty seeking to manage the consequences of global inequality and mobility. This paper analyses the 'security turn' in migration debates in Australia and the North and the way the securitization of migration signifies the transformation of security from the problem of producing national order to the problem of managing global disorder resulting in the merging of national and international security strategies.

  20. Register-based studies on migration, ethnicity, and health

    DEFF Research Database (Denmark)

    Norredam, Marie; Kastrup, Marianne; Helweg-Larsen, Karin

    2011-01-01

    INTRODUCTION: Researchers in Denmark have unique possibilities of register-based research in relation to migration, ethnicity, and health. This review article outlines how these opportunities have been used, so far, by presenting a series of examples. RESEARCH TOPICS: We selected six registers...... it discriminatory. Although, we do not register ethnicity in relation to use of health care in Denmark, our possibilities of linkage between population registers and registers on diseases and healthcare utilisation appear to render the same potentials....... to highlight the process of how migrant study populations have been established and studied in relation to different registers: The Danish Cancer Registry, the Danish Central Psychiatric Research Register, the Danish National Patient Register, the Danish National Health Service Register, the Danish Injury...

  1. Program Plan: field radionuclide migration studies in Climax granite

    International Nuclear Information System (INIS)

    Isherwood, D.; Raber, E.; Coles, D.; Stone, R.

    1980-01-01

    This Program Plan describes the field radionuclide migration studies we plan to conduct in the Climax granite at the Nevada Test Site. Laboratory support studies are included to help us understand the geochemical and hydrologic processes involved in the field. The Program Plan begins with background information (Section 1) on how this program fits into the National Waste Terminal Storage Program Plan and discusses the needs for field studies of this type. The objectives stated in Section 2 are in direct response to these needs, particularly the need to determine whether laboratory studies accurately reflect actual field conditions and the need for field testing to provide a data base for verification of hydrologic and mass transport models. The technical scope (Section 3) provides a work breakdown structure that integrates the various activities and establishes a base for the technical approach described in Section 4. Our approach combines an interactive system of field and laboratory migration experiments with the use of hydrologic models for pre-test predictions and data interpretation. Section 5 on program interfaces identifies how information will be transferred to other related DOE projects. A schedule of activities and major milestones (Section 6) and the budget necessary to meet the project objectives (Section 7) are included in the Program Plan. Sections 8 and 9 contain brief descriptions of how the technical and program controls will be established and maintained and an outline of our quality assurance program. This program plan is an initial planning document and provides a general description of activities. An Engineering Test Plan containing detailed experimental test plans, an instrumentation plan and equipment design drawings will be published as a separate document

  2. Livelihood Diversification through Migration among a Pastoral People: Contrasting Case Studies of Maasai in Northern Tanzania.

    Science.gov (United States)

    McCabe, J Terrence; Smith, Nicole M; Leslie, Paul W; Telligman, Amy L

    2014-01-01

    This paper brings together over two decades of research concerning the patterns and processes of livelihood diversification through migration among Maasai pastoralists and agro-pastoralists of northern Tanzania. Two case studies, one from the Ngorongoro Conservation Area and the other from the Simanjiro plains, jointly demonstrate the complexity of migration within a single ethnic group. We analyze the relationship between wealth and migration and examine some of the consequences of migration for building herds, expanding cultivation, and influencing political leadership. We further argue that migration in Maasai communities is becoming a cultural norm and not only a response to economic conditions.

  3. Study of an API migration for two XML APIs

    NARCIS (Netherlands)

    T.T. Bartholomei; K. Czarnecki; R. Lämmel (Ralf); T. van der Storm (Tijs); M.G.J. van den Brand (Mark); D. Gasevic; J. Gray

    2010-01-01

    htmlabstractAPI migration refers to adapting an application such that its dependence on a given API (the source API) is eliminated in favor of depending on an alternative API (the target API) with the source and target APIs serving the same domain. One may attempt to automate API migration by code

  4. Migration study of actinides and lanthanides in compacted bentonite

    International Nuclear Information System (INIS)

    Sastrowardoyo, P.B.; Susilowati, D.; Suganda, D.

    1998-01-01

    Migration study of actinide and lanthanide elements in compacted bentonite has been conducted. Data of these elements mobilities have been shown, and it is showed that the diffusion coefficient was varied as the function of solution phase condition as well as the origin/composition of bentonite. It is showed that the diffusion coefficient decreased by the increasing of density, as well as the increasing of montmorillonite content in bentonite. The ratio of bentonite/silica-sand used was related to the increasing of elements mobility. In many case the difference of diffusion coefficient was related to the variation of pH and redox condition, as well as the presence of complexant in solution phase. The Lower diffusion coefficient could give the higher retardation factor, which is a favourable factor to retard the radionuclides release from a disposal facility to geosphere. (author)

  5. Migration as a form of workforce attrition: a nine-country study of pharmacists.

    Science.gov (United States)

    Wuliji, Tana; Carter, Sarah; Bates, Ian

    2009-04-09

    There is a lack of evidence to inform policy development on the reasons why health professionals migrate. Few studies have sought to empirically determine factors influencing the intention to migrate and none have explored the relationship between factors. This paper reports on the first international attempt to investigate the migration intentions of pharmacy students and identify migration factors and their relationships. Responses were gathered from 791 final-year pharmacy students from nine countries: Australia, Bangladesh, Croatia, Egypt, Portugal, Nepal, Singapore, Slovenia and Zimbabwe. Data were analysed by means of Principal Components Analysis (PCA) and two-step cluster analysis to determine the relationships between factors influencing migration and the characteristics of subpopulations most likely and least likely to migrate. Results showed a significant difference in attitudes towards the professional and sociopolitical environment of the home country and perceptions of opportunities abroad between those who have no intention of migrating and those who intend to migrate on a long-term basis. Attitudes of students planning short-term migration were not significantly different from those of students who did not intend to migrate. These attitudes, together with gender, knowledge of other migrant pharmacists and past experiences abroad, are associated with an increased propensity for migration. Given the influence of the country context and environment on migration intentions, research and policy should frame the issue of migration in the context of the wider human resource agenda, thus viewing migration as one form of attrition and a symptom of other root causes. Remuneration is not an independent stand-alone factor influencing migration intentions and cannot be decoupled from professional development factors. Comprehensive human resource policy development that takes into account the issues of both remuneration and professional development are necessary

  6. Migration to Alma/Primo: A Case Study of Central Washington University

    Directory of Open Access Journals (Sweden)

    Ping Fu

    2015-12-01

    Full Text Available This paper describes how Central Washington University Libraries (CWUL interacted and collaborated with the Orbis Cascade Alliance (OCA Shared Integrated Library System’s (SILS Implementation Team and Ex Libris to process systems and data migration from Innovative Interfaces Inc.’s Millennium integrated library system to Alma/Primo, Ex Libris’ next-generation library management solution and discovery and delivery solution. A chronological review method was used for this case study to provide an overall picture of key migration events, tasks, and implementation efforts, including pre-migration cleanup, migration forms, integration with external systems, testing, cutover, post-migration cleanup, and reporting and fixing outstanding issues. A three-phase migration model was studied, and a questionnaire was designed to collect data from functional leads to determine staff time spent on the migration tasks. Staff time spent on each phase was analyzed and quantitated, with some top essential elements for the success of the migration identified through the case review and data analysis. An analysis of the Ex Libris’ Salesforce cases created during the migration and post-migration was conducted to be used for identifying roles of key librarians and staff functional leads during the migration.

  7. Studies on the biosynthesis of macrophage migration inhibitory factor in delayed hypersensitivity, 1

    International Nuclear Information System (INIS)

    Mizoguchi, Yasuhiro; Yamamoto, Sukeo; Morisawa, Seiji

    1973-01-01

    Specific antigenic stimulation of sensitized lymphocytes leads to the production of macrophage migration inhibitory factor (MIF). Production of MIF is inhibited by mitomycin C, actinomycin D, and puromycin. These inhibition effects are studied by using thymidine- 3 H. The first two of these antibiotics only inhibit MIF production when added to the culture medium at a very early stage of antigenic stimulation. In contrast, puromycin exerts its inhibitory effect several hours after the antigenic stimulation, but not at an earlier stage. MIF behaves like a protein, so it seems likely that synthesis of RNA is necessary for MIF formation and MIF synthesis may start as early as a few hours after specific antigenic activation of the sensitized lymphocytes. The inhibitory effects of the antibiotics are discussed in relation to the kinetics of MIF production. (author)

  8. Radionuclide sorption and migration studies of getters for backfill barriers

    International Nuclear Information System (INIS)

    Nowak, E.J.

    1980-07-01

    Bentonite and hectorite clay minerals were chosen for study and development as potential backfill materials for testing in the proposed Waste Isolation Pilot Plant (WIPP), a radioactive waste repository and test facility in bedded salt. This choice of materials was based on initial screening results which are presented and on the predicted physical properties of these materials. These properties were verified experimentally in concentrated brines specific to the WIPP site. Distribution coefficients, K/sub d/, were calculated from batch sorption measurements on bentonite and hectorite in the nearly saturated brines A and B. The resulting K/sub d/ values were in the range of (1 to 5) x 10 3 ml/g for europium; (2 to 40) x 10 3 ml/g for plutonium(IV); and (4 to 16) x 10 3 ml/g for americium(III). A silica- and calcite-containing sand mixed with bentonite and hectorite acted as a sorber of americium(III) but was merely an inert diluent for plutonium(IV). Pertechnetate anions (TcO 4 - ) sorbed on activated charcoal with K/sub d/ values in the range of (0.2 to 0.4) x 10 3 ml/g. Pertechnetate, cesium, and strontium ions in brine were not sorbed appreciably by bentonite or hectorite. Although experimental evidence is given for a possible role of solubility in the sorption of europium on getters, other data presented here and evidence from the literature are inconsistent with a simple single reaction sorption mechanism. It is concluded that a backfill containing bentonite on hectorite and activated charcoal is potentially an effective barrier to the migration of Eu(III), Pu(IV), and Am(III) cations and, with further development, to the migration of TcO 4 - anions as well

  9. Feminist Ethnography on International Migration: From Acculturation Studies to Gender Studies

    Directory of Open Access Journals (Sweden)

    Ethel V. Kosminsky

    2007-09-01

    Full Text Available This article intends to analyze the book Italianos no mundo rural paulista, by João Baptista Borges Pereira (1974, one of the earliest Brazilian ethnographic international migration researches, based on the acculturation theory, in order to corroborate its contribution to the feminist ethnography. We focus on the use of gender as a central category on the international migration studies, thus empowering the Feminist Ethnography.

  10. Preliminary study of depleted uranium aerosol migration in soils

    International Nuclear Information System (INIS)

    Guo Zhiying; Yu Shui; Zheng Yonghong; Liang Yueqin; Liu Liping; Song Zhanjun; Zhao Fa

    2007-01-01

    Objective: To explore the depth of depleted uranium (DU) migration in six main kinds of Chinese soils and the pollution of the groundwater made by DU migration. Methods: With the circulating column model and the inductively coupled plasma-mass spectrometry (ICP-MS), concentration of uranium and the ratio of 235 U/ 238 U in different depth soils and in the corresponding filter liquids had been determined. Results: In the acid rain of pH 3.0, the migration depth of DU in the washed soil and brown soil were 6-8 cm and 4-6 cm, respectively. And with the increment of the acidity of the acid rain, the migration depth of DU in the soils was increased. The migration depth of DU in the 6 types soils was 0-4 cm. The distributed factor between the liquids and soils was lower than 0.004, and the concentration of uranium in the filter liquids was 0.05-10.33 μg/L. Conclusions: The migration depth of DU in soils can be increased by the acid rain, and the majority of DU was stayed in the upper soils and DU pollution might exist for long time, but the probability of groundwater pollution was low. The migration capability of DU was interrelated with the concentration of organic compound in the soils. (authors)

  11. Production of specific-structured lipids by enzymatic interesterification: elucidation of acyl migration by response surface design

    DEFF Research Database (Denmark)

    Xu, Xuebing; Skands, Anja; Høy, Carl-Erik

    1998-01-01

    Production of specific-structured lipids (SSL) by lipase-catalyzed interesterification has been attracting more and more attention recently. However, it was found that acyl migration occurs during the reaction and causes the production of by-products. In this paper, the elucidation of acyl...

  12. A preliminary study of international migration of the Chinese people.

    Science.gov (United States)

    Zhu, G

    1994-01-01

    International Chinese migration has spanned five periods: 1) an initial period of random and short-term migration dating back to the Qing and Han dynasties; 2) a spontaneous period since the Sui and Tang dynasties along trade routes; 3) a transition period during the Ming dynasty and the early Qing dynasty with war, poverty, and population growth as push factors; 4) peak migration during the Opium War period due to economic depression, population pressure, and the "coolie" trade; and 5) continuous development between the 1920s and 1949. Migration tended to occur between Guangdong and Fujian provinces and other southeast Asian countries. Four factors were identified as necessary for international migration to occur: the origin of migration, the destination factor, the middle link factor, and the immigrant characteristics. The origins of early Chinese migration appeared in a country of political corruption, population pressure, a backward economy, and social chaos. The pull factors at destination end were demand for labor. The middle link was the short distance between Guangdong and Fujian provinces and southeast Asian countries and longstanding nongovernmental exchanges. Other links were the similarity of climate, similar racial features, cultural lifestyle similarities, and convenient transportation. The people in these two provinces had a history of migration and a personality suitable for the spirit of adventure. Peak migration occurred during the late Qing dynasty and during the continuous development period. Between 1840 and 1911 there were about 10 million Chinese immigrants and during 1911 and 1949 there were about 6 million. In general, over 20 million immigrated prior to 1949, of which about 50% migrated during the peak period, 33% during the continuous period, and 20% before 1840. This amounted to about 33% of European migration and two times African migration. 60% were from Guangdong, and 30% were from Fujian province, of whom most were from counties

  13. Phthalate Migration Study from PVC Grafted by Gamma Radiation

    International Nuclear Information System (INIS)

    Manzoli, J.E.; Duarte, C.; Somesari, E.; Silveira, C.; Paes, H.A.; Manzoli, J.E.; Araujo, F.D.C.; Panzarini, L.C.G.A.

    2009-01-01

    PVC is a useful polymer used for many applications, as packaging of food, blood and in contact with body fluids. The most widely-used plasticizer, to make it flexible, is the phthalate DEHP, and its toxicity is a problem. A special radiation grafting of PVC allows an important reduction of thrombogenic properties, and it could cause changes in the DEHP migration too. In this work it is presented the methodology using gas chromatography and numerical simulation for the measurement of DEHP migration from PVC grafted with monomer DMAEMA. The grafting could be an interesting way to reduce DEHP migration

  14. First-principles study on migration of vacancy in tungsten

    International Nuclear Information System (INIS)

    Oda, Yasuhiro; Ito, Atsushi M.; Takayama, Arimichi; Nakamura, Hiroaki

    2014-03-01

    We calculated di-vacancy binding energies and migration energies of mono-vacancy and di-vacancy in tungsten material using DFT calculation. The mono-vacancy diffuses in [111] direction easily rather than in [001] direction. The migration energies of di-vacancies are almost the same value of the mono-vacancy. The migration of di-vacancy is approximately the same as the migration of mono-vacancy. The di-vacancy binding energies are almost zero or negative. The interactions between two vacancies in tungsten material are repulsive from the second to fifth nearest-neighbor. The vacancies are difficult to aggregate since di-vacancy is less stable than mono-vacancy. (author)

  15. Investigation of the Feasibility of Utilizing Gamma Emission Computed Tomography in Evaluating Fission Product Migration in Irradiated TRISO Fuel Experiments

    International Nuclear Information System (INIS)

    Harp, Jason M.; Demkowicz, Paul A.

    2014-01-01

    In the High Temperature Gas-Cooled Reactor (HTGR) the TRISO particle fuel serves as the primary fission product containment. However the large number of TRISO particles present in proposed HTGRs dictates that there will be a small fraction (~10"-"4 to 10"-"5) of as manufactured defects and in-pile particle failures that will lead to some fission product release. The matrix material surrounding the TRISO particles in fuel compacts and the structural graphite holding the TRISO particles in place can also serve as sinks for containing any released fission products. However data on the migration of solid fission products through these materials is lacking. One of the primary goals of the AGR-3/4 experiment is to study fission product migration from intentionally failed TRISO particles in prototypic HTGR components such as structural graphite and compact matrix material. In this work, the potential for a Gamma Emission Computed Tomography (GECT) technique to non-destructively examine the fission product distribution in AGR-3/4 components and other irradiation experiments is explored. Specifically, the feasibility of using the Idaho National Laboratory (INL) Hot Fuels Examination Facility (HFEF) Precision Gamma Scanner (PGS) system for this GECT application was considered. Previous experience utilizing similar techniques, the expected activities in AGR-3/4 rings, and analysis of this work indicate using GECT to evaluate AGR-3/4 will be feasible. The GECT technique was also applied to other irradiated nuclear fuel systems currently available in the HFEF hot cell, including oxide fuel pins, metallic fuel pins, and monolithic plate fuel. Results indicate GECT with the HFEF PGS is effective. (author)

  16. Two types of population migration in China: a comparative study.

    Science.gov (United States)

    Gu, S

    1992-01-01

    The patterns, extent of, and trends in permanent and temporary migration in China are presented. Permanency is determined by a household registration transfer. Floaters are considered temporary migrants. The regulatory history of migration is given: restrictions prior to 1978 on temporary migration and relaxation of restrictions after 1978. Permanent migration was greatest in the 1950s. Between 1949 and 1960, there were 73.37 million permanent migrants to urban areas from rural areas out of an urban population increase of 105.83 million. During the 1960 and 1970s, urban population was lowered. During the Cultural Revolution, emigration surpassed immigration and the nonagricultural population increased in cities and towns. Between 1976 and 1987, the natural growth of the urban population declined, and nonagricultural population increased from 57.65 million to 204.057 million in cities and towns (1949-88). The trends in the floating population show the lowest ratio of temporary migrants to permanent migrants between 1984 and 1987 to be in Shenyang (15:100); the highest was in Guangzhou (33:100) with an average of 23:100. When the ratio is considered as 20:100 in cities, the average floating population is calculated at 52.87 million in 1987 out of 264.354 million total urban population. 70% were from rural areas. In a comparison of six provinces, Hebei had the lowest percentage of floaters (19%) and Shandong the highest (40%). In country-governed towns, and estimated temporary in-migrants numbered 9.48 million; 8/86 million were floaters. During peak migration, temporary migration averages 50 million/day and permanent migration averages 50,000/day. The primary difference between floaters and permanent migrants is that floaters keep their ties to the land. Surplus labor drives temporary migration, and as such is a release valve. Permanent migration, which is government-controlled, does not allow as much flexibility in adapting to socioeconomic conditions. The sectors

  17. Migration among individuals with leprosy: a population-based study in Central Brazil

    Directory of Open Access Journals (Sweden)

    Christine Murto

    2014-03-01

    Full Text Available This study investigates social and clinical factors associated with migration among individuals affected by leprosy. A cross-sectional study was conducted among those newly diagnosed with leprosy (2006-2008, in 79 endemic municipalities in the state of Tocantins, Brazil (N = 1,074. In total, 76.2% were born in a municipality different from their current residence. In the five years before diagnosis 16.7% migrated, and 3.6% migrated after leprosy diagnosis. Findings reflect aspects associated with historical rural-urban population movement in Brazil. Indicators of poverty were prominent among before-diagnosis migrants but not after-diagnosis migrants. Migration after diagnosis was associated with prior migration. The association of multibacillary leprosy with migration indicates healthcare access may be an obstacle to early diagnosis among before-diagnosis migrants, which may also be related to the high mobility of this group.

  18. A study on the migration policy in ancient China.

    Science.gov (United States)

    Wang, Y

    1995-01-01

    During the Chinese dynasties of Sui and Tang, neighboring minority groups were forced to migrate to less settled areas of China. During the Song dynasty (960-1279) the Han government lost control of neighboring ethnic groups. Ethnically dominated states on their own expanded to the hinterlands, formed the national governments of Yuan and Qing, and established the local power of Liao and Jin in Han-dominated areas. During the Han dynasty the movement of minorities fulfilled the purpose of helping cultivate undeveloped land. The Han governments of feudal China held compulsory migration policies and policies encouraging minorities to move to less inhabited places. Han governments prior to the Tang and Song dynasties held policies favorable to minority settlements. During the Tang dynasty land was given to minority settlers. During the Song dynasty the Han government held a policy which prohibited taxation and harassment of new minority settlers. Minorities gained improved living conditions and the government achieved pacification. Resettlement of minorities either from forced or voluntary migration facilitated communication with the Han and promoted the exchange of culture, but also intensified ethnic conflict. The reason for the ethnic conflict was a question of control. Ethnic governments encouraged in-migration and adopted policies of compulsory and voluntary migration. Ethnic minorities in the north and west practiced mainly compulsory migration. Ethnic conflict in the Qin and Han dynasties occurred between the Han and the Huns. During the Eastern Jin and Northern dynasties minority governments captured Han and other ethnic groups. The rule of minority government was strengthened by voluntary migration. The frequent power shifts in ancient China contributed to the blending of Chinese nationalities.

  19. Iodine 125 seed migration after prostate brachytherapy: a study of 170 patients

    International Nuclear Information System (INIS)

    Chauveinc, L.; Osseili, A.; Rosenwald, J.C.; Cosset, J.M.; Flam, T.; Thiounn, N.; Savignoni, A.

    2004-01-01

    Purpose. To study the number of migrating seeds, the anatomical site of migration and possible predictive parameters of migration, after prostate cancer brachytherapy using a loose-seed (I125) implantation technique. Patients and methods. The charts of the 170 patients consecutively treated by the Institut Curie/Hospital Cochin/Hospital Necker Group between September 1, 2001 and August 31, 2002, were analysed. All seeds having migrated to the lungs and seen on the chest X-ray systematically performed at 2 months, have been recorded, as well as the seeds lost by the urines (after sieving) or in the sperm (condom). Results. Among 12,179 implanted seeds, 44 were found to have migrated (0.36%). Most of the migrating seeds (32/44; 73%), were found in the lungs. Overall, one or several seed migrations were observed in 35 patients (21% of the total number of patients in this series). In the majority of cases (77< r i. only one seed migrated. A significant relationship (P = 0.04) vs as found between the number of migrating seeds and the number of implanted ones (or with the prostate volume, but those two parameters were closely linked in our series). More specifically, a significant relationship (P = 0.02) could be demonstrated between the number of seeds implanted at the periphery of the prostate and the number of seeds migrating to the lungs. Conclusion. The percentage of migrating seeds observed in this series is low. actually one of the lowest found in the literature when using the loose-seed technique. There was no clinical consequences and the loss of-usually only one seed is very unlikely to alter the quality of the dose distribution. However, the predominance of pulmonary migrations in our series led us to slightly modify our implantation technique. We now try to avoid too 'peripheral' seed implantations, due to the risk of migration towards the peri-prostatic veins, and subsequently to the lungs. (author)

  20. Exploring the factors influencing the cloud computing adoption: a systematic study on cloud migration.

    Science.gov (United States)

    Rai, Rashmi; Sahoo, Gadadhar; Mehfuz, Shabana

    2015-01-01

    Today, most of the organizations trust on their age old legacy applications, to support their business-critical systems. However, there are several critical concerns, as maintainability and scalability issues, associated with the legacy system. In this background, cloud services offer a more agile and cost effective platform, to support business applications and IT infrastructure. As the adoption of cloud services has been increasing recently and so has been the academic research in cloud migration. However, there is a genuine need of secondary study to further strengthen this research. The primary objective of this paper is to scientifically and systematically identify, categorize and compare the existing research work in the area of legacy to cloud migration. The paper has also endeavored to consolidate the research on Security issues, which is prime factor hindering the adoption of cloud through classifying the studies on secure cloud migration. SLR (Systematic Literature Review) of thirty selected papers, published from 2009 to 2014 was conducted to properly understand the nuances of the security framework. To categorize the selected studies, authors have proposed a conceptual model for cloud migration which has resulted in a resource base of existing solutions for cloud migration. This study concludes that cloud migration research is in seminal stage but simultaneously it is also evolving and maturing, with increasing participation from academics and industry alike. The paper also identifies the need for a secure migration model, which can fortify organization's trust into cloud migration and facilitate necessary tool support to automate the migration process.

  1. Human migration activities drive the fluctuation of ARGs : Case study of landfills in Nanjing, eastern China

    OpenAIRE

    Sun, Mingming; Ye, Mao; Schwab, Arthur P; Li, Xu; Wan, Jinzhong; Wei, Zhong; Wu, Jun; Friman, Ville-Petri; Liu, Kuan; Tian, Da; Liu, Manqiang; Li, Huixin; Hu, Feng; Jiang, Xin

    2016-01-01

    Landfills are perfect sites to study the effect of human migration on fluctuation of antibiotic resistance genes (ARGs) as they are the final destination of municipal waste. For example, large-scale human migration during the holidays is often accompanied by changes in waste dumping having potential effects on ARG abundance. Three landfills were selected to examine fluctuation in the abundance of fifteen ARGs and Intl1 genes for 14 months in Nanjing, eastern China. Mass human migration, the a...

  2. Fracture mapping for radionuclide migration studies in the Climax granite

    International Nuclear Information System (INIS)

    Thorpe, R.; Springer, J.

    1981-05-01

    As part of LLNL's program on radionuclide migration through fractured rock, major geologic discontinuities have been mapped and characterized at the 420 m level in the Climax Stock, adjacent to LLNL's Spent Fuel Test. Persistence or continuity of features was the principal sampling criterion, and ninety major fractures and faults were mapped in the main access and tail drifts. Although the purpose and nature of this study was different from previous fracture surveys in the Climax Stock, the results are generally consistent in that three predominant fracture sets are identified: NW strike/vertical, NE strike/vertical, NW strike/subhorizontal. The frequency of major features in the main access drift is somewhat higher than in the tail drift. Those mapped in the main access drift are generally braided, stepped, or en echelon, while those in the tail drift appear to be more distinct and planar. Several of the fractures in the tail drift lie in the NE/vertical set, while most form an entirely different set oriented N5E/55NW. Subhorizontal fractures were common to both drifts. An area of seepage associated with some of these low-angle features was mapped in the main access drift

  3. Tungsten migration studies by controlled injection of volatile compounds

    Energy Technology Data Exchange (ETDEWEB)

    Rubel, M., E-mail: rubel@kth.se [Royal Institute of Technology (KTH), Association EURATOM-VR, Stockholm (Sweden); Coenen, J. [IEK-4, Plasma Physics, Forschungszentrum Jülich, Association EURATOM-FZJ, Jülich (Germany); Ivanova, D. [Royal Institute of Technology (KTH), Association EURATOM-VR, Stockholm (Sweden); Möller, S. [IEK-4, Plasma Physics, Forschungszentrum Jülich, Association EURATOM-FZJ, Jülich (Germany); Petersson, P. [Royal Institute of Technology (KTH), Association EURATOM-VR, Stockholm (Sweden); Brezinsek, S.; Kreter, A.; Philipps, V.; Pospieszczyk, A.; Schweer, B. [IEK-4, Plasma Physics, Forschungszentrum Jülich, Association EURATOM-FZJ, Jülich (Germany)

    2013-07-15

    Volatile tungsten hexa-fluoride was locally injected into the TEXTOR tokamak as a marker for material migration studies. The injection was accompanied by puffing N-15 rare isotope as a nitrogen tracer in discharges with edge cooling by impurity seeding. The objective was to assess material balance by qualitative and quantitative determination of a global and local deposition pattern, material mixing effects and fluorine residence in plasma-facing components. Spectroscopy and ex situ ion beam analysis techniques were used. Tungsten was detected on all types of limiter tiles and short-term probes retrieved from the vessel. Over 80% of the injected W was identified. The largest tungsten concentration, 1 × 10{sup 18} cm{sup −2}, was in the vicinity of the gas inlet. Co-deposits contained tungsten and a mix of light isotopes: H, D, He-4, B-10, B-11, C-12, C-13, N-14, N-15, O-16 and small quantities of F-19 thus showing that both He and nitrogen are trapped following wall conditioning (He glow) and edge cooling.

  4. Experimental and modelling studies of radionuclide migration from contaminated groundwaters

    International Nuclear Information System (INIS)

    Tompkins, J. A.; Butler, A. P.; Wheater, H. S.; Shaw, G.; Wadey, P.; Bell, J. N. B.

    1994-01-01

    Lysimeter-based studies of radionuclide uptake by winter wheat are being undertaken to investigate soil-to-plant transfer processes. A five year multi-disciplinary research project has concentrated on the upward migration of contaminants from near surface water-tables and their subsequent uptake by a winter wheat crop. A weighted transfer factor approach and a physically based modelling methodology, for the simulation and prediction of radionuclide uptake, have been developed which offer alternatives to the traditional transfer factor approach. Integrated hydrological and solute transport models are used to simulate contaminant movement and subsequent root uptake. This approach enables prediction of radionuclide transport for a wide range of soil, plant and radionuclide types. This paper presents simulated results of 22 Na plant uptake and soil activity profiles, which are verified with respect to lysimeter data. The results demonstrate that a simple modelling approach can describe the variability in radioactivity in both the harvested crop and the soil profile, without recourse to a large number of empirical parameters. The proposed modelling technique should be readily applicable to a range of scales and conditions, since it embodies an understanding of the underlying physical processes of the system. This work constitutes part of an ongoing research programme being undertaken by UK Nirex Ltd., to assess the long term safety of a deep level repository for low and intermediate level nuclear waste. (author)

  5. Cubans abroad: a gendered case study on international migrations.

    Science.gov (United States)

    Núñez-Sarmiento, Marta

    2010-01-01

    Cubans who have migrated since the 1990s after living for two decades or more in their country of origin left with an embedded gender ideology that they acquired in a society where gender relations were undergoing radical transformations. As a result, Cuban feminization of migrations has its peculiarities. In this context, there are three issues to consider: explaining how gender relations attained in Cuba, as part of the overall attitudes gained since childhood, influenced Cuban migrants who have left the island permanently since 1990, introduced uniqueness in their migration processes, and made up a different feminization of migration; identifying the features of Cuban social structure that shaped the gender ideology of Cuban migrants; and producing new knowledge about Cuban international migration processes by using a gender perspective and by analyzing the gender relations prevailing in the years before the crisis of the 1990s, as well as since the beginning of the twenty-first century. The first part of this article focuses on gender distinctiveness of recent Cuban migrants, and the second summarizes some traits of the Cuban social structure—mainly referred to female employment—that could explain the gender training of the migrants.

  6. A computer model for DNAPL potential migration study

    International Nuclear Information System (INIS)

    Yan, S.; Landry, G.R.; Tate, T.

    1994-01-01

    A computer model, named DNAPMIG (DNAPL Potential Migration), was developed to calculate the dense nonaqueous phase liquid (DNAPL) critical length required to initiate movement and direction of potential migration at locations within an area of interest. The model takes into consideration the potentiometric gradient, bottom structure elevation, DNAPL density, interfacial tension, contact angle, soil grain size, partitioning coefficient, effective solubility, and water saturation. The model is interfaced with SURFER graphics software to use vectors to indicate the DNAPL critical length and the potential migration direction. The potential for DNAPL existence and migration at a specific site can be estimated by relating chemical concentration in the ground water to its solubility limit and the DNAPL critical length. The possibility of vertical migration can also be determined. This model can be used to determine and compare the effectiveness of existing or alternative recovery well systems to capture a DNAPL plume or arrest its movement; to help determine optimum locations and pumping rates of recovery wells; and to help determine the optimum location of environmental borings to locate DNAPL. This paper presents two hypothetical examples and two site applications in south Louisiana

  7. A STUDY ON THE INTERNAL MIGRATION FLOWS IN TURKEY: LOWRY HYPOTHESIS

    Directory of Open Access Journals (Sweden)

    FERHAT TOPBAŞ

    2013-06-01

    Full Text Available The purpose of this study is to re-examine Lowry hypothesis that were examined for Turkey in period of 1965–1980 by Gedik (1992 and period of 1985–1990 by Yamak and Küçükkale (2001 by using The Census of Population 1975, 1980, 1985, 1990 and 2000 in Turkey. For this reason, the relationships between in-migration and out-migration and net migration have investigated with population size, net migration rate and per capita income factors. Analysis that involve in all provinces called general model is not considered in social, economic and urban development factors. In addition, estimated restriction models that are considered urban development are involved population, net migration rate and per capita income factors. In conclusion we have exposed comparatively relationship between internal migration flows and urban development frame of estimated models.

  8. Gendered Migration and the Urban Informal Sector: A Case Study of ...

    African Journals Online (AJOL)

    This study examined gendered migration patterns in Mwanza City, Tanzania as well as the impacts of differentials of men's and women's migration on their absorption in the urban informal sector, their access to assets, adaptation to city life and their livelihood and also their role in development of origin areas. The study ...

  9. A comparative study of species migration and diffusion mechanisms in all-vanadium redox flow batteries

    International Nuclear Information System (INIS)

    Oh, Kyeongmin; Won, Seongyeon; Ju, Hyunchul

    2015-01-01

    Highlights: • Migration effects on crossover phenomena is examined. • Crossover and migration model is newly implemented. • Totally opposite crossover trend is observed with migration during charging. • During discharging, the crossover is enhanced due to migration. - ABSTRACT: According to the Nernst–Planck equation, the transport of charged species in porous electrodes is mainly driven by diffusion and migration. Although a number of all-vanadium redox flow battery (VRFB) models have been developed by several VRFB modeling groups, a comparative study of these two ion transport mechanisms has not been clearly reported in the literature. In this study, we develop a three-dimensional (3-D), transient VRFB model that rigorously accounts for both diffusion and migration mechanisms of charged species, including V 2+ , V 3+ , VO 2+ ,VO 2 + and H + . The VRFB model relies upon five principles of conservation: mass, momentum, species, electric charge, and thermal energy. Due to the general form of the conservation equations, both species migration effects on species transport and species diffusion effects on charge transport are considered in the source terms of the model equations. The model calculates species migration and diffusion fluxes through the membrane and compares their relative magnitudes under various charging and discharging stages. This paper clearly elucidates the role of species migration on vanadium crossover and the subsequent capacity losses, demonstrating that the present VRFB model is a valuable tool for optimizing the component design and operation of VRFBs.

  10. Mercury migration into ground water, a literature study

    Energy Technology Data Exchange (ETDEWEB)

    Carlton, W.H.; Carden, J.L.; Kury, R.; Eichholz, G.G.

    1994-11-01

    This report presents a broad review of the technical literature dealing with mercury migration in the soil. The approach followed was to identify relevant articles by searching bibliographic data bases, obtaining the promising articles and searching these articles for any additional relevant citations. Eight catagories were used to organize the literature, with a review and summary of each paper. Catagories used were the following: chemical states of mercury under environmental conditions; diffusion of mercury vapor through soil; solubility and stability of mercury in environmental waters; transport of mercury on colloids; models for mercury migration through the environment; analytical techniques; retention of mercury by soil components; formation of organomecurials.

  11. Low-Dose Radiation Promotes Dendritic Cell Migration and IL-12 Production via the ATM/NF-KappaB Pathway.

    Science.gov (United States)

    Yu, Nan; Wang, Sinian; Song, Xiujun; Gao, Ling; Li, Wei; Yu, Huijie; Zhou, Chuanchuan; Wang, Zhenxia; Li, Fengsheng; Jiang, Qisheng

    2018-04-01

    For dendritic cells (DCs) to initiate an immune response, their ability to migrate and to produce interleukin-12 (IL-12) is crucial. It has been previously shown that low-dose radiation (LDR) promoted IL-12 production by DCs, resulting in increased DC activity that contributed to LDR hormesis in the immune system. However, the molecular mechanism of LDR-induced IL-12 production, as well as the effect of LDR on DC migration capacity require further elucidation. Using the JAWSII immortalized mouse dendritic cell line, we showed that in vitro X-ray irradiation (0.2 Gy) of DCs significantly increased DC migration and IL-12 production, and upregulated CCR7. The neutralizing antibody against CCR7 has been shown to abolish LDR-enhanced DC migration, demonstrating that CCR7 mediates LDR-promoting DC migration. We identified nuclear factor kappaB (NF-κB) as the central signaling pathway that mediated LDR-enhanced expression of IL-12 and CCR7 based on findings that 0.2 Gy X-ray irradiation activated NF-κB, showing increased nuclear p65 translocation and NF-κB DNA-binding activity, while an NF-κB inhibitor blocked LDR-enhanced expression of IL-12 and CCR7, as well as DC migration. Finally, we demonstrated that 0.2 Gy X-ray irradiation promoted ATM phosphorylation and reactive oxygen species generation; however, only the ATM inhibitor abolished the LDR-induced NF-κB-mediated expression of IL-12 and CCR7. Altogether, our data show that exposure to LDR resulted in a hormetic effect on DCs regarding CCR7-mediated migration and IL-12 production by activating the ATM/NF-κB pathway.

  12. Comparative studies on dyeing rate migration and wash fastness ...

    African Journals Online (AJOL)

    Migration and diffusion properties of synthesized azo dyes from 2-aminothiazole derivatives applied on commercial grade undyed cellulose acetate (CA) and cellulose triacetate (CTA) were investigated using dyeing conditions of 2% on weight of fabric (owf), 50:1 liquor ratio and subjected to ISO3 and ISO4 standard wash ...

  13. Migration, Trauma, PTSD: A Gender Study in Morrison's Jazz

    Science.gov (United States)

    Motlagh, Leila Tafreshi; Yahya, Wan Roselezam Wan

    2014-01-01

    Toni Morrison is an acknowledged master of trauma literature, however trauma theory and a gender response to trauma remain largely unaccounted for her migration literature, specifically "Jazz" (1992). In her novel, two migrant women are affected by the same trauma, a crime of passion. But they choose different reactions and coping…

  14. An Introduction to International Migration Studies: European Perspectives

    NARCIS (Netherlands)

    Martiniello, M.; Rath, J.; Martiniello, M.; Rath, J.

    2012-01-01

    No country in Europe is unaffected by migration, although its impact varies from place to place. Immigration is often associated with undermined social cohesion, urban crime, domestic insecurity and public health issues. Immigrants are increasingly regarded as a liability for the welfare state, for

  15. Acoustic effects of oil-production activities on bowhead and white whales visible during spring migration near Pt. Barrow, Alaska-1990 phase: sound propagation and whale responses to playbacks of continuous drilling noise from an ice platform, as studied in pack ice conditions. Final report

    International Nuclear Information System (INIS)

    Richardson, W.J.; Greene, C.R.; Koski, W.R.; Smultea, M.A.; Cameron, G.

    1991-10-01

    The report concerns the effects of underwater noise from simulated oil production operations on the movements and behavior of bowhead and white whales migrating around northern Alaska in spring. An underwater sound projector suspended from pack ice was used to introduce recorded drilling noise and other test sounds into leads through the pack ice. These sounds were received and measured at various distances to determine the rate of sound attenuation with distance and frequency. The movements and behavior of bowhead and white whales approaching the operating projector were studied by aircraft- and ice-based observers. Some individuals of both species were observed to approach well within the ensonified area. However, behavioral changes and avoidance reactions were evident when the received sound level became sufficiently high. Reactions to aircraft are also discussed

  16. Use of Invasion Percolation Models To Study the Secondary Migration of Oil and Related Problems

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, G.

    1997-12-31

    This thesis studies simulations of the slow displacement of a wetting fluid by a non-wetting fluid in porous media and in a single fracture. The simulations are based on the invasion percolation model. New modified versions of the model are presented that simulate migration, fragmentation and coalescence processes of the clusters of non-wetting fluid. The resulting displacement patterns are characterized by scaling laws. In particular, simulations of the secondary migration of oil through porous homogeneous rock are discussed. Fractured rocks are extreme cases of inhomogeneous porous media. Simulations of the slow displacement of a wetting fluid by a non-wetting fluid in a single fracture using the standard invasion model are presented. There is a discussion of a scenario in which a cluster of non-wetting fluid migrates through a porous medium that was saturated with a wetting fluid. The migration is driven by continuously driven buoyancy forces. Both experiments and simulations are described. The same scenario is also studied theoretically and by simulations using a simplified percolation model of fluid migration in one dimension. The migration model in two dimensions, with constant buoyancy forces, is also discussed. Simulations of fluid migration, such as the secondary migration of oil, in two- and three-dimensional media are examined, the media having multi-affine properties rather than being homogeneous. Slow immiscible displacement processes in single fractures are studied using fractal geometries to model single fractures. 167 refs., 123 figs.

  17. Advanced glycation end products promote the proliferation and migration of primary rat vascular smooth muscle cells via the upregulation of BAG3.

    Science.gov (United States)

    Li, Cunshu; Chang, Ye; Li, Yuan; Chen, Shuang; Chen, Yintao; Ye, Ning; Dai, Dongxue; Sun, Yingxian

    2017-05-01

    The present study was aimed to investigate the role of reactive oxygen species (ROS) on advanced glycation end product (AGE)-induced proliferation and migration of vascular smooth muscle cells (VSMCs) and whether Bcl-2‑associated athanogene 3 (BAG3) is involved in the process. Primary rat VSMCs were extracted and cultured in vitro. Cell viability was detected by MTT assay and cell proliferation was detected by EdU incorporation assay. Cell migration was detected by wound healing and Transwell assays. BAG3 was detected using qPCR and western blot analysis. Transcriptional and translational inhibitors (actinomycin D and cycloheximide, respectively) were used to study the effect of AGEs on the expression of BAG3 in VSMCs. Lentiviral plasmids containing short hairpin RNA (shRNA) against rat BAG3 or control shRNA were transduced into VSMCs. Cellular ROS were detected by 2',7'-dichlorofluorescein diacetate (DCFH-DA) staining. Mitochondrial membrane potential was detected by tetramethylrhodamine methyl ester (TMRE) staining. AGEs significantly increased the expression of BAG3 in a dose-and time-dependent manner. Furthermore, AGEs mainly increased the expression of BAG3 mRNA by increasing the RNA synthesis rather than inhibiting the RNA translation. BAG3 knockdown reduced the proliferation and migration of VSMCs induced by AGEs. BAG3 knockdown reduced the generation of ROS and sustained the mitochondrial membrane potential of VSMCs. Reduction of ROS production by N-acetylcysteine (NAC), a potent antioxidant, also reduced the proliferation and migration of VSMCs. On the whole, the present study demonstrated for the first time that AGEs could increase ROS production and promote the proliferation and migration of VSMCs by upregulating BAG3 expression. This study indicated that BAG3 should be considered as a potential target for the prevention and/or treatment of vascular complications of diabetes.

  18. Microfluidic gradient device for studying mesothelial cell migration and the effect of chronic carbon nanotube exposure

    International Nuclear Information System (INIS)

    Zhang, Hanyuan; Sun, Jianbo; Li, Xiang; Liu, Yuxin; Lohcharoenkal, Warangkana; Rojanasakul, Yon; Wang, Liying; Wu, Nianqiang

    2015-01-01

    Cell migration is one of the crucial steps in many physiological and pathological processes, including cancer development. Our recent studies have shown that carbon nanotubes (CNTs), similarly to asbestos, can induce accelerated cell growth and invasiveness that contribute to their mesothelioma pathogenicity. Malignant mesothelioma is a very aggressive tumor that develops from cells of the mesothelium, and is most commonly caused by exposure to asbestos. CNTs have a similar structure and mode of exposure to asbestos. This has raised a concern regarding the potential carcinogenicity of CNTs, especially in the pleural area which is a key target for asbestos-related diseases. In this paper, a static microfluidic gradient device was applied to study the migration of human pleural mesothelial cells which had been through a long-term exposure (4 months) to subcytotoxic concentration (0.02 µg cm −2 ) of single-walled CNTs (SWCNTs). Multiple migration signatures of these cells were investigated using the microfluidic gradient device for the first time. During the migration study, we observed that cell morphologies changed from flattened shapes to spindle shapes prior to their migration after their sensing of the chemical gradient. The migration of chronically SWCNT-exposed mesothelial cells was evaluated under different fetal bovine serum (FBS) concentration gradients, and the migration speeds and number of migrating cells were extracted and compared. The results showed that chronically SWCNT-exposed mesothelial cells are more sensitive to the gradient compared to non-SWCNT-exposed cells. The method described here allows simultaneous detection of cell morphology and migration under chemical gradient conditions, and also allows for real-time monitoring of cell motility that resembles in vivo cell migration. This platform would be much needed for supporting the development of more physiologically relevant cell models for better assessment and characterization of the

  19. Microfluidic gradient device for studying mesothelial cell migration and the effect of chronic carbon nanotube exposure

    Science.gov (United States)

    Zhang, Hanyuan; Lohcharoenkal, Warangkana; Sun, Jianbo; Li, Xiang; Wang, Liying; Wu, Nianqiang; Rojanasakul, Yon; Liu, Yuxin

    2015-07-01

    Cell migration is one of the crucial steps in many physiological and pathological processes, including cancer development. Our recent studies have shown that carbon nanotubes (CNTs), similarly to asbestos, can induce accelerated cell growth and invasiveness that contribute to their mesothelioma pathogenicity. Malignant mesothelioma is a very aggressive tumor that develops from cells of the mesothelium, and is most commonly caused by exposure to asbestos. CNTs have a similar structure and mode of exposure to asbestos. This has raised a concern regarding the potential carcinogenicity of CNTs, especially in the pleural area which is a key target for asbestos-related diseases. In this paper, a static microfluidic gradient device was applied to study the migration of human pleural mesothelial cells which had been through a long-term exposure (4 months) to subcytotoxic concentration (0.02 µg cm-2) of single-walled CNTs (SWCNTs). Multiple migration signatures of these cells were investigated using the microfluidic gradient device for the first time. During the migration study, we observed that cell morphologies changed from flattened shapes to spindle shapes prior to their migration after their sensing of the chemical gradient. The migration of chronically SWCNT-exposed mesothelial cells was evaluated under different fetal bovine serum (FBS) concentration gradients, and the migration speeds and number of migrating cells were extracted and compared. The results showed that chronically SWCNT-exposed mesothelial cells are more sensitive to the gradient compared to non-SWCNT-exposed cells. The method described here allows simultaneous detection of cell morphology and migration under chemical gradient conditions, and also allows for real-time monitoring of cell motility that resembles in vivo cell migration. This platform would be much needed for supporting the development of more physiologically relevant cell models for better assessment and characterization of the

  20. Do more educated workers migrate more? Findings from the Korean Labor and Income Panel Study

    Directory of Open Access Journals (Sweden)

    Ye Seul Choi

    2015-11-01

    Full Text Available This paper examines the relationship of migration between capital regions and non-capital regions and the level of human capital in Korea using the method of multinomial logistic regression. This paper aims to show whether the high level of human capital of migrants who move to capital regions statistically differs from the other migrants. For analysis, this paper uses the 2006, 2008, 2010 and 2012 panel data from Korean Labor and Income Panel Study (KLIPS. The analysis is divided into two parts of migration based on the region of origin: the migration of individuals who live in non-capital regions and the migration of individuals who live in capital region. In this paper, we consider personal characteristics such as educational attainment and occupations as an indicator of human capital of individual, gender, age, and marriage status as explanatory variables. Our empirical finding is that the educational attainment of individual representing a level of human capital significantly affects the migration behavior moving from non-capital regions to capital regions. According to analysis of migration from Gyeonggi and Incheon to Seoul, the migration within capital regions, individuals who engage in occupation with high skilled and non-manual are more likely to move to Seoul capital regions where favorable conditions for workers in terms of higher wage and better job opportunities can provide. Those results can be understood in the context of human capital theory to maximize personal socioeconomic utilities by migrating to capital regions.

  1. Migration between the United States and Canada: a study of labour market adjustment.

    Science.gov (United States)

    Brox, J A

    1983-01-01

    "... The main purpose of this study is to examine population flows between Canada and the United States [from mid-1947 to mid-1972] in order to investigate the degree to which labour market adjustment is aided by such movements. [The author considers] several functional forms of the migration relationship in an attempt to empirically determine how the decision to migrate is formed. [He also compares the] results with those obtained by Courchene...for Canadian interprovincial migration in an effort to compare the effects of international and internal migration on labour market adjustment." It is found that "migration between the United States and Canada over the post-war period is an economic variable. In fact, [a] simple model employing differences in income levels and unemployment rates has been able to explain nearly ninety-five per cent of the variation in the migration rate." The author also notes that "although migration between Canada and the United States does occur in such a way as to aid labour market adjustment, it is not as efficient as internal migration." (summary in FRE, SPA) excerpt

  2. Associations Between Sociodemographic Characteristics, Pre Migratory and Migratory Factors and Psychological Distress Just After Migration and After Resettlement: The Indian Migration Study.

    Science.gov (United States)

    Agrawal, Sutapa; Taylor, Fiona C; Moser, Kath; Narayanan, Gitanjali; Kinra, Sanjay; Prabhakaran, Dorairaj; Reddy, Kolli Srinath; Davey Smith, George; Ebrahim, Shah

    2015-01-01

    Migration is suspected to increase the risk for psychological distress for those who enter a new cultural environment. We investigated the association between sociodemographic characteristics, premigratory and migratory factors and psychological distress in rural-to-urban migrants just after migration and after resettlement. Data from the cross-sectional sib-pair designed Indian Migration Study (IMS, 2005-2007) were used. The analysis focused on 2112 participants aged ≥18 years from the total IMS sample ( n = 7067) who reported being migrant. Psychological distress was assessed based on the responses of the 7-questions in a five-point scale, where the respondents were asked to report about their feelings now and also asked to recall these feelings when they first migrated. The associations were analyzed using multiple logistic regression models. High prevalence of psychological distress was found just after migration (7.3%; 95% confidence interval [CI]: 6.2-8.4) than after settlement (4.7%; 95% CI: 3.8-5.6). Push factors as a reason behind migration and not being able to adjust in the new environment were the main correlates of psychological distress among both the male and female migrants, just after migration. Rural-urban migration is a major phenomenon in India and given the impact of premigratory and migratory related stressors on mental health, early intervention could prevent the development of psychological distress among the migrants.

  3. Why sub-Saharan African health workers migrate to European countries that do not actively recruit: a qualitative study post-migration.

    Science.gov (United States)

    Poppe, Annelien; Jirovsky, Elena; Blacklock, Claire; Laxmikanth, Pallavi; Moosa, Shabir; De Maeseneer, Jan; Kutalek, Ruth; Peersman, Wim

    2014-01-01

    Many studies have investigated the migration intentions of sub-Saharan African medical students and health professionals within the context of a legacy of active international recruitment by receiving countries. However, many health workers migrate outside of this recruitment paradigm. This paper aims to explore the reasons for migration of health workers from sub-Saharan Africa to Belgium and Austria; European countries without a history of active recruitment in sub-Saharan Africa. Data were collected using semistructured interviews. Twenty-seven health workers were interviewed about their migration experiences. Included participants were born in sub-Saharan Africa, had trained as health workers in sub-Saharan Africa, and were currently living in Belgium or Austria, though not necessarily currently working as a health professional. Both Austria and Belgium were shown not to be target countries for the health workers, who instead moved there by circumstance, rather than choice. Three principal reasons for migration were reported: 1) educational purposes; 2) political instability or insecurity in their country of origin; and 3) family reunification. In addition, two respondents mentioned medical reasons and, although less explicit, economic factors were also involved in several of the respondents' decision to migrate. These results highlight the importance of the broader economic, social, and political context within which migration decisions are made. Training opportunities proved to be an important factor for migration. A further development and upgrade of primary care might help to counter the common desire to specialize and improve domestic training opportunities.

  4. [Study of migration and distribution of bone marrow cells transplanted animals with B16 melanoma ].

    Science.gov (United States)

    Poveshchenko, A F; Solovieva, A O; Zubareva, K E; Strunkin, D N; Gricyk, O B; Poveshchenko, O V; Shurlygina, A V; Konenkov, V I

    2017-01-01

    Purpose. Reveal features migration and distribution of syngeneic bone marrow cells (BMC) and subpopulations (MSC) after transplantation into the recipient carrier B16 melanoma bodies. Methods. We used mouse male and female C57BL/6 mice. Induction of Tumor Growth: B16 melanoma cells implanted subcutaneously into right hind paw of female C57BL/6 mice at a dose of 2.5 x 105 cells / mouse. migration study in vivo distribution and BMC and MSC was performed using genetic markers - Y-chromosome specific sequence line male C57Bl/6 syngeneic intravenous transplantation in females using the polymerase chain reaction (PCR) in real time on Authorized Termal Cycler - Light Cycler 480 II / 96 (Roche). Introduction suspension of unseparated bone marrow cells, mesenchymal stem cells from donor to recipient male mice (syngeneic recipient female C57BL/6), followed by isolation of recipients of organs was performed at regular intervals, then of organ recipients isolated DNA. Results. It was shown that bone marrow cells positive for Y-chromosome in migrate lymphoid (lymph nodes, spleen, bone marrow) or in non-lymphoid organs (liver, heart, brain, skin) syngeneic recipients. In addition to the migration of cells from the bone marrow to other organs, there is a way back migration of cells from the circulation to the bone marrow. B16 melanoma stimulates the migration of transplanted MSCs and BMC in bone marrow. It is found that tumor growth enhanced migration of transplanted bone marrow cells, including populations of MSCs in the bone marrow. In the early stages of tumor formation MSC migration activity higher than the BMC. In the later stages of tumor formation undivided population of bone marrow cells migrate to the intense swelling compared with a population of MSCs. Conclusion. The possibility of using bone marrow MSCs for targeted therapy of tumor diseases, because migration of MSCs in tumor tissue can be used to effectively deliver anticancer drugs.

  5. Identification of intentionally and non-intentionally added substances in plastic packaging materials and their migration into food products.

    Science.gov (United States)

    García Ibarra, Verónica; Rodríguez Bernaldo de Quirós, Ana; Paseiro Losada, Perfecto; Sendón, Raquel

    2018-05-07

    Plastic materials are widely used in food packaging applications; however, there is increased concern because of the possible release of undesirable components into foodstuffs. Migration of plastic constituents not only has the potential to affect product quality but also constitutes a risk to consumer health. In order to check the safety of food contact materials, analytical methodologies to identify potential migrants are required. In the first part of this work, a GC/MS screening method was developed for the identification of components from plastic packaging materials including intentionally and "non-intentionally added substances" (NIAS) as potential migrants. In the second part of this study, the presence of seven compounds (bis (2-ethylhexyl) phthalate (DEHP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), butylated hydroxytoluene (BHT), acetyl tributyl citrate (ATBC), benzophenone (BP)) previously identified in packaging materials were investigated in food products (corn and potatoes snacks, cookies, and cakes). For this purpose, a suitable extraction method was developed and quantification was performed using GC-MS. The developed method was validated in terms of linearity, recovery, repeatability, and limits of detection and quantification. The spiked recoveries varied between 82.7 and 116.1%, and relative standard deviation (RSD) was in the range of 2.22-15.9%. The plasticizer ATBC was the most detected compound (94% samples), followed by DEP (65%), DEHP (47%), BP (44%), DBP (35%), DIBP (21%), and BHT (12%). Regarding phthalates, DEP and DEHP were the most frequently detected compounds in concentrations up to 1.44 μg g -1 . In some samples, only DBP exceeded the European SML of 0.3 mg kg -1 established in Regulation 10/2011. Graphical abstract Chemical migration from plastic packaging into food.

  6. Does migration make you happy? A longitudinal study of internal migration and subjective well-being

    NARCIS (Netherlands)

    Nowok, B.; Van Ham, M.; Findlay, A.M.; Gayle, V.

    2013-01-01

    Marie Curie programme under the European Union's Seventh Framework Programme (FP/2007-2013) / Career Integration Grant n. PCIG10-GA-2011-303728 (CIG Grant NBHCHOICE, Neighbourhood choice, neighbourhood sorting, and neighbourhood effects). The majority of quantitative studies on the consequences of

  7. Simulation study ε-Caprolactam monomer and metallic elements migration from irradiated polymeric packaging into food stimulants

    International Nuclear Information System (INIS)

    Rosa, Faena Machado Leite

    2008-01-01

    For decades migration study of chemical compounds from packaging into food, such as metals, residual monomers and additives, is a very important issue, concerning public health and minimize chemical contamination. In this work, it was done irradiations of packagings taken in contact with food simulant, and it was studied this migration through a mathematical model of the diffusion process, compiled in a computational simulation method in order to study the microscopic behavior of migration of metallic elements cadmium, chromium, antimony and cobalt, present in metallic plastics from dairy product packagings, and also the migration of - caprolactam monomer, present in nylon polymeric plastics used for package meat stuffs, to the food simulant acetic acid 3%. The results from simulations of the migration of -caprolactam monomer were compared with experimental results obtained from high resolution gas chromatography (HRGC) measurements, and the simulation of metallic elements migration were compared with the neutron activation analysis measurements (NAA). These experimental results were performed and kindly informed by another research groups, partners in this project. The food packaging system was discretized in one-dimension space and in time and the partial differential equation that defines the diffusive process, the second 'Fick's law', together with an equation of Arrhenius type dealing with the thermal influence, were solved using finite differences. The final step of the resolution was a tridiagonal linear system, solved using the Thomas algorithm. It was studied, and in some cases even foreseen, experimental quantities, like the diffusion coefficient, activation energy and concentration profile of migrant compounds, allowing the understanding of the diffusion process and the quantitative estimate of the migration of such compounds under ionizing radiation influence. Variation on the initial concentration levels (C 0 ) of the monomer inside the packaging

  8. "International Division of Labour and Migration as a Global Labour Supply---A Theoretical Perspective to Study International Migration---"

    OpenAIRE

    Masaki Takenouchi

    2001-01-01

    Why did not mass migration from the Third World to the highly-developed countries occur before the Second World War? This is a simple but important question, since the preponderance of the migration from the "South" to the "North" is a main characteristic of the contemporary international migration. The orthodox explanations of migration based on the concept of the national economy as a unit of analysis do not give us clues to answer this question. Neither do these by the world-system approac...

  9. Studies of nuclear-waste migration in geologic media. Annual report, October 1977-September 1978

    International Nuclear Information System (INIS)

    Seitz, M.G.; Rickert, P.G.; Fried, S.M.; Friedman, A.M.; Steindler, M.J.

    1979-07-01

    The first phenomenon studied is incomplete water-nuclide-rock reaction because of slow reaction kinetics. A kinetic factor derived from the experimental results for strontium migration through glauconite (a hydrous silicate) was expressed in terms of the linear flow rate of solution and can be used to predict migration due to solution flow at rates of 0 to about 12 cm/min (60 km/y). Continuous-flow infiltration experiments with americium in fissures gave results that are predicted by a migration model that includes kinetic factors measured in experiments with static fluids. The results suggest that kinetic factors are as important as equilibrium adsorption parameters in predicting nuclide migration. The second phenomenon studied was the amount of adsorbed nuclide not being proportional to the nuclide concentration in solution (nonlinear adsorption isotherm). For cesium adsorption on limestone, a nonlinear isotherm was found to occur in the range of initial cesium concentrations from about 10 -3 to 10 -9 M. This adsorption property was confirmed by results of column-infiltration experiments in which cesium migration through oolitic limestone was found to be sensitive to the amount of cesium in solution. The existence of a nonlinear isotherm precludes the use of a single partition value (K/sub D/) to describe cesium migration in limestone at cesium concentrations above about 10 -9 M. Therefore, the effects of nonlinear isotherms are germane to nuclide migration. 24 figures, 6 tables

  10. Freely-migrating defects: Their production and interaction with cascade remnants

    International Nuclear Information System (INIS)

    Rehn, L.E.; Wiedersich, H.

    1991-05-01

    Many microstructural changes that occur during irradiation are driven primarily by freely-migrating defects, i.e. those defects which escape from nascent cascades to migrate over distances that are large relative to typical cascade dimensions. Several measurements during irradiation at elevated temperatures have shown that the survival rate of freely-migrating defects decreases much more strongly with increasing primary recoil energy than does the survival rate for defects generated at liquid helium temperatures. For typical fission or fusion recoil spectra, and for heavy-ion bombardment, the fraction of defects that migrate long-distances is apparently only ∼1% of the calculated dpa. This small surviving fraction of freely-migrating defects results at least partially from additional intracascade recombination at elevated temperatures. However, cascade remnants, e.g., vacancy and interstitial clusters, also contribute by enhancing intercascade defect annihilation. A recently developed rate-theory approach is used to discuss the relative importance of intra- and intercascade recombination to the survival rate of freely-migrating defects. Within the validity of certain simplifying assumptions, the additional sink density provided by defect clusters produced directly within individual cascades can explain the difference between a defect survival rate of about 30% for low dose, low temperature irradiations with heavy ions, and a survival rate of only ∼1% for freely-migrating defects at elevated temperatures. The status of our current understanding of freely-migrating defects, including remaining unanswered questions, is also discussed. 33 refs., 5 figs

  11. INTERNATIONAL MIGRATION AND TECHNOLOGICAL MANAGEMENT IN COFFEE PRODUCTION IN TWO COMMUNITIES IN THE CENTRAL AREA OF VERACRUZ STATE

    Directory of Open Access Journals (Sweden)

    Martha Elena Nava-Tablada

    2011-07-01

    Full Text Available Veracruz comes third in terms of national coffee production; however this sector is facing a crisis because of the fall in prices in the international market which has resulted amongst other things in increased emigration to the United States. The aim of this study was to analyze the relationship between migration and the level of technology employed in coffee production in two communities in the central area of Veracruz State: Capulapa and Zapoapan. Information was obtained through observation and by interviewing the members of 46 family production units (FPU. In Zapoapan, the FPUs which presented the highest level of technological management in their coffee plantations were those with greatest access to capital, as they are more extensive, produce other crops than coffee, have more family members in the United States and receive greater remittances; investing 14% more in agriculture. In the case of the FPUs in Capulapa, no relationship was observed between the number of international emigrants, the amount of remittances received and the level of technological management. This may be because 83% of the FPUs cultivate solely coffee and are beholden to the ups and downs of the international market, thus their socio-economic situation is more precarious and 86% of remittances are directed towards family sustenance; with only 7% directed towards agricultural investment.

  12. Locostatin, a disrupter of Raf kinase inhibitor protein, inhibits extracellular matrix production, proliferation, and migration in human uterine leiomyoma and myometrial cells.

    Science.gov (United States)

    Janjusevic, Milijana; Greco, Stefania; Islam, Md Soriful; Castellucci, Clara; Ciavattini, Andrea; Toti, Paolo; Petraglia, Felice; Ciarmela, Pasquapina

    2016-11-01

    To investigate the presence of Raf kinase inhibitor protein (RKIP) in human myometrium and leiomyoma as well as to determine the effect of locostatin (RKIP inhibitor) on extracellular matrix (ECM) production, proliferation, and migration in human myometrial and leiomyoma cells. Laboratory study. Human myometrium and leiomyoma. Thirty premenopausal women who were admitted to the hospital for myomectomy or hysterectomy. Myometrial and leiomyoma tissues were used to investigate the localization and the expression level of RKIP through immunohistochemistry and Western blotting. Myometrial and leiomyoma cells were treated with locostatin (10 μM) to measure ECM expression by real-time polymerase chain reaction, GSK3β expression by Western blotting, cell migration by wound-healing assay, and cell proliferation by MTT assay and immunocytochemistry. The expression of RKIP in human myometrial and leiomyoma tissue; ECM components and GSK3β expression, migration, and proliferation in myometrial and leiomyoma cells. RKIP is expressed in human myometrial and leiomyoma tissue. Locostatin treatment resulted in the activation of the mitogen-activated protein kinase (MAPK) signal pathway (ERK phosphorylation), providing a powerful validation of our targeting protocol. Further, RKIP inhibition by locostatin reduces ECM components. Moreover, the inhibition of RKIP by locostatin impaired cell proliferation and migration in both leiomyoma and myometrial cells. Finally, locostatin treatment reduced GSK3β expression. Therefore, even if the activation of MAPK pathway should increase proliferation and migration, the destabilization of GSK3β leads to the reduction of proliferation and migration of myometrial and leiomyoma cells. Our results indicate that RKIP may be involved in leiomyoma pathophysiology. Copyright © 2016 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  13. Psychosocial Studies of Migration and Community: Introduction to the Special Issue

    OpenAIRE

    Douglas D. Perkins; Neal A. Palmer; Manuel García-Ramírez

    2011-01-01

    Introducing the special issue on psychosocial studies of migration and community, we briefly reflect on the global increase in, and issues related to, both international and domestic migration, particularly from rural areas of less developed countries, which has fueled rapid urbanization and intercultural tensions in both post-industrial and developing countries. Topics covered in the issue are summarized, including an Italian study of the emotional impact of discrimination against immigrant ...

  14. Study on experimental models to analyze radionuclide migration behaviors through porous geologic media

    International Nuclear Information System (INIS)

    Tanaka, Tadao; Mukai, Masayuki

    2012-08-01

    The migration phenomenon of radionuclide through geological media such as soils and porous rocks, which is important in underground disposal of radioactive wastes, can be described by the advection-dispersion of groundwater and the interactions of radionuclide with geological media. On the other hand, to understand the migration phenomenon, actual migration data are experimentally acquired by a batch test, a column test and field trial. In the present study, experimental models about the interactions of radionuclide between the solid phase and the liquid phase were discussed systematically to interpret the migration data acquired by the various techniques and conditions. Equilibrium, reversibility, linearity, mechanism and chemistry in the interactions were considered in discussion of the experimental models. A calculation program, which can analyze migration data obtained under various conditions by applying the selected 9 types of experimental models, was maintained. The calculation program makes it be able to predict the migration behavior of radionuclide under various conditions and to decide the important parameter by a fitting analysis of the migration data. (author)

  15. Pre-migration persecution, post-migration stressors and resources, and post-migration mental health: A study of severely traumatized U.S. Arab immigrant women

    Science.gov (United States)

    Norris, Anne E.; Aroian, Karen J.; Nickerson, David

    2015-01-01

    Background Competing theories exist regarding the importance of pre-migration trauma as compared to post-migration stressors and resources with respect to the risk to immigrant mental health. Objective To examine how type of pre-migration trauma, post-migration stressors, and post-migration resources differentially predict PTSD and MDD symptomatology in Arab immigrant women who have been exposed to pre-migration trauma. Design Descriptive; using multinomial logistic regression to explain membership in one of four groups: (a) PTSD only (n = 14); (b) major depressive disorder (MDD) (n = 162), (c) Co-Morbid PTSD-MDD (n = 148), (d) Subclinical Symptoms (n = 209). Results Post-immigration related stressors (as measured by the Demands of Immigration (DI)) had the strongest effect: Parameter estimates indicated that a unit increase in DI scores was associated with a nearly 17 fold increase in the likelihood of being in the Co-morbid relative to the Subclinical group, and a nearly 2.5 increase in the likelihood of being in the Co-Morbid relative to the MDD only group (p Arab immigrant women for depression and PTSD is important given high levels observed in this community based sample. PMID:21835819

  16. Experimental study on neptunium migration under in situ geochemical conditions

    Science.gov (United States)

    Kumata, M.; Vandergraaf, T. T.

    1998-12-01

    Results are reported for migration experiments performed with Np under in situ geochemical conditions over a range of groundwater flow rates in columns of crushed rock in a specially designed facility at the 240-level of the Underground Research Laboratory (URL) near Pinawa, Manitoba, Canada. This laboratory is situated in an intrusive granitic rock formation, the Lac du Bonnet batholith. Highly altered granitic rock and groundwater were obtained from a major subhorizontal fracture zone at a depth of 250 m in the URL. The granite was wet-crushed and wet-sieved with groundwater from this fracture zone. The 180-850-μm size fraction was selected and packed in 20-cm long, 2.54-cm in diameter Teflon™-lined stainless steel columns. Approximately 30-ml vols of groundwater containing 3HHO and 237Np were injected into the columns at flow rates of 0.3, 1, and 3 ml/h, followed by elution with groundwater, obtained from the subhorizontal fracture, at the same flow rates, for a period of 95 days. Elution profiles for 3HHO were obtained, but no 237Np was detected in the eluted groundwater. After terminating the migration experiments, the columns were frozen, the column material was removed and cut into twenty 1-cm thick sections and each section was analyzed by gamma spectrometry. Profiles of 237Np were obtained for the three columns. A one-dimensional transport model was fitted to the 3HHO breakthrough curves to obtain flow parameters for this experiment. These flow parameters were in turn applied to the 237Np concentration profiles in the columns to produce sorption and dispersion coefficients for Np. The results show a strong dependence of retardation factors ( Rf) on flow rate. The decrease in the retarded velocity of the neptunium ( Vn) varied over one order of magnitude under the geochemical conditions for these experiments.

  17. Chain Migration through Social Networks: Case Study of Vietnamese Migrants in Thailand

    Directory of Open Access Journals (Sweden)

    Anh Tuan NGUYEN

    2016-11-01

    Full Text Available The paper aims to investigate the relationship between the recent increasingly pattern of Vietnamese migrants in Thailand and migration networks. By surveying 50 Vietnamese migrants in Bangkok, Thailand, the study confirms that migration networks have played a critical role in facilitating migration flows, especially irregular flows from Vietnam to Thailand over the years. It can be reflected by reducing the cost of migration, coping with new working environment and risks during working in Thailand and ensuring the return process for Vietnamese migrants. Moreover, forms of social networks includes personal networks (kinship and friendship networks, and community network (ngườidẫnđường’s network, social media has been also discussed. The study also implies that the người dẫn đường’s networks might contribute to recently emerging issues such as human trafficking and smugglings, which require further research.

  18. MIGRATION AND CHANGING CONSUMER BEHAVIOUR: A STUDY OF BALASORE DISTRICT IN INDIA

    OpenAIRE

    Nihar Ranjan Rout; Reshma Senapati

    2013-01-01

    In an attempt to understand the association between migration and consumer behavior, a primary survey based. on 84 sample households was conducted in Balasore district of Orissa in India. It was well evident from the current study that not only migration was associated with the household article possession diffirential but also by one way or the other it could bring lots of changes in the perception, attitude and behavior of the individuals, related to consumption and market...

  19. Transnational Migration, Integration, and Identity:\\ud A Study of Kurdish Diaspora in London

    OpenAIRE

    Ata, Ayar

    2017-01-01

    To understand the Kurdish diaspora in London requires answering two interrelated questions of Kurdish forced migration history and Kurdish cultural identity. Thus, this study firstly examines the history of Kurdish forced migration and displacement, exploring a common historical argument which positions the Kurds as powerless victims of the First World War (WW1). To this end it looks critically at the post-WW1 era and the development of the modern nation state in the Middle East, namely Turke...

  20. Inpatient migration patterns in persons with spinal cord injury: A registry study with hospital discharge data

    Directory of Open Access Journals (Sweden)

    Elias Ronca

    2016-12-01

    Full Text Available This study investigated and compared patient migration patterns of persons with spinal cord injury, the general population and persons with morbid obesity, rheumatic conditions and bowel disease, for secondary health conditions, across administrative boundaries in Switzerland. The effects of patient characteristics and health conditions on visiting hospitals outside the residential canton were examined using complete, nationwide, inpatient health records for the years 2010 and 2011. Patients with spinal cord injury were more likely to obtain treatment outside their residential canton as compared to all other conditions. Facilitators of patient migration in persons with spinal cord injury and the general hospital population were private or accidental health insurances covering costs. Barriers of patient migration in persons with spinal cord injury were old age, severe multimorbidity, financial coverage by basic health insurance, and minority language region. Keywords: Spinal cord injury, Patient migration, Health services accessibility, Health care utilization, Inpatient hospital care

  1. Is there a step-wise migration in Nigeria? A case study of the migrational histories of migrants in Lagos.

    Science.gov (United States)

    Afolayan, A A

    1985-09-01

    "The paper sets out to test whether or not the movement pattern of people in Nigeria is step-wise. It examines the spatial order in the country and the movement pattern of people. It then analyzes the survey data and tests for the validity of step-wise migration in the country. The findings show that step-wise migration cannot adequately describe all the patterns observed." The presence of large-scale circulatory migration between rural and urban areas is noted. Ways to decrease the pressure on Lagos by developing intermediate urban areas are considered. excerpt

  2. Crosstalk between intracellular and extracellular signals regulating interneuron production migration and integration into the cortex

    Directory of Open Access Journals (Sweden)

    Elise ePeyre

    2015-04-01

    Full Text Available During embryogenesis, cortical interneurons are generated by ventral progenitors located in the ganglionic eminences of the telencephalon. They travel along multiple tangential paths to populate the cortical wall. As they reach this structure they undergo intracortical dispersion to settle in their final destination. At the cellular level, migrating interneurons are highly polarized cells that extend and retract processes using dynamic remodeling of microtubule and actin cytoskeleton. Different levels of molecular regulation contribute to interneuron migration. These include: 1/ Extrinsic guidance cues distributed along migratory streams that are sensed and integrated by migrating interneurons; 2/ Intrinsic genetic programs driven by specific transcription factors that grant specification and set the timing of migration for different subtypes of interneurons; 3/ Adhesion molecules and cytoskeletal elements/regulators that transduce molecular signalings into coherent movement. These levels of molecular regulation must be properly integrated by interneurons to allow their migration in the cortex. The aim of this review is to summarize our current knowledge of the interplay between microenvironmental signals and cell autonomous programs that drive cortical interneuron porduction, tangential migration, and intergration in the developing cerebral cortex.

  3. Crosstalk between intracellular and extracellular signals regulating interneuron production, migration and integration into the cortex.

    Science.gov (United States)

    Peyre, Elise; Silva, Carla G; Nguyen, Laurent

    2015-01-01

    During embryogenesis, cortical interneurons are generated by ventral progenitors located in the ganglionic eminences of the telencephalon. They travel along multiple tangential paths to populate the cortical wall. As they reach this structure they undergo intracortical dispersion to settle in their final destination. At the cellular level, migrating interneurons are highly polarized cells that extend and retract processes using dynamic remodeling of microtubule and actin cytoskeleton. Different levels of molecular regulation contribute to interneuron migration. These include: (1) Extrinsic guidance cues distributed along migratory streams that are sensed and integrated by migrating interneurons; (2) Intrinsic genetic programs driven by specific transcription factors that grant specification and set the timing of migration for different subtypes of interneurons; (3) Adhesion molecules and cytoskeletal elements/regulators that transduce molecular signalings into coherent movement. These levels of molecular regulation must be properly integrated by interneurons to allow their migration in the cortex. The aim of this review is to summarize our current knowledge of the interplay between microenvironmental signals and cell autonomous programs that drive cortical interneuron porduction, tangential migration, and intergration in the developing cerebral cortex.

  4. Seasonal PCB bioaccumulation in an arctic marine ecosystem: a model analysis incorporating lipid dynamics, food-web productivity and migration.

    Science.gov (United States)

    Laender, Frederik De; Oevelen, Dick Van; Frantzen, Sylvia; Middelburg, Jack J; Soetaert, Karline

    2010-01-01

    Primary production and species' lipid contents in Arctic ecosystems are notoriously seasonal. Additionally, seasonal migration patterns of fish may alter prey availability and thus diet. Taking the southern Barents Sea as a study region and PCBs as model contaminants, we examined to what extent each of these factors cause bioaccumulation in fish to change throughout the year. Data on physiology and standing stocks of multiple trophic levels were used to estimated season-specific carbon budgets and by inference also corresponding values for food ingestion and production of cod, capelin, and herring. When combining these values with Arctic lipid dynamics for bioaccumulation model parameter setting, we predicted bioaccumulation factors (BAFs) that were in good agreement with BAFs for cod and capelin observed between 1998 and 2008. BAFs in all fish were 10 times lower in summer than in spring and fall/winter and were mainly driven by lipid dynamics. Trophic magnification factors (TMFs: increase in BAF per unit increase in trophic level as derived from our carbon budgets) were highest for PCB 153 during spring (2.3-2.4) and lowest for PCB 52 in summer and fall/winter (1.5-1.6) and were driven by seasonal shifts in trophic level and lipid dynamics.

  5. Studies of nuclear waste migration in geologic media. Annual report, October 1978-September 1979

    International Nuclear Information System (INIS)

    Seitz, M.G.; Rickert, P.G.; Couture, R.A.; Williams, J.; Meldgin, N.; Fried, S.M.; Friedman, A.M.; Steindler, M.J.

    1980-01-01

    Experimental results obtained this year confirm the results obtained in previous years - that nuclides migrating by fluid flow in rock often exhibit complex behavior not predicted by simple chromatographic-type models. A phenomenon found previously to lead to complex behavior for leached radionuclides is that the amount of adsorbed nuclide was not proportional to the nuclide concentration in solution (nonlinear adsorption isotherm). For cesium adsorption on limestone and on basalt, nonlinear isotherms were found this year to occur in the range of cesium concentrations in the groundwater of about 10 -3 to 10 -9 M. Because cesium concentrations in this range can readily be attained by the leaching of solid waste by groundwater, the effects of nonlinear isotherms are germane to nuclide migration. This dependence of cesium migration on the leached concentration of cesium emphasizes the importance of treating the leaching and migration processes simultaneously such as is done in the leach-migration experiments performed in this work. The existence of nonlinear isotherms precludes the use of a single partition coefficient (K/sub d/) to describe cesium migration at an arbitrary cesium concentration above 10 -9 M. Nonetheless, nonlinear isotherms can be studied experimentally (e.g., to give K/sub d/ as a function of concentration) and effects of nonlinear adsorption can be predicted quantitatively. Comparison of results from column and batch tests indicate that, in addition to nonlinear adsorption, kinetic effects need to be considered in predicting nuclide migration from the partition coefficients measured in batch tests. Results of batch experiments of 2 weeks or longer duration pertained to migration expected only at the very lowest (< 50 m/y) groundwater flow rates of interest

  6. HPLC study of migration of terephthalic acid and isophthalic acid from PET bottles into edible oils.

    Science.gov (United States)

    Khaneghah, Amin Mousavi; Limbo, Sara; Shoeibi, Shahram; Mazinani, Somayeh

    2014-08-01

    Polyethylene terephthalate (PET) containers for food oil packaging were evaluated with a newly established determination method for terephthalic acid (TPA) and isophthalic acid (IPA). The analysis of monomers, TPA and IPA that migrate from PET bottles into oils was performed using high-pressure liquid chromatography with a diode array detector. Three types of commercial oils (sunflower oil, canola oil and blended oil which included sunflower oil, soy bean oil and cottonseed oil) were bottled in PET containers. These samples were incubated for 10 days at 49 °C as accelerated test condition. The means of recovery for this method varied from 70% to 72% and from 101% to 111% for TPA and IPA, respectively. The results showed that the amounts of specific migration of TPA and IPA into the samples conform to European Union legislation that identifies specific migration limits. More important, the results highlighted a different behavior of migration as a function of the fatty acid profile. Previous investigations have been performed with food simulants such as HB307 or 20% ethanol but our study used real food samples and determined trace amounts of the migrated compounds. Further investigation will be needed to better explain the influence of fatty acid conformation on migration of PET monomers. © 2013 Society of Chemical Industry.

  7. Study of migration behavior of technogenic radionuclides in the Yenisey River-Kara Sea aquatic system

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, Yu.; Legin, E.; Legin, V. [Khlopin Radium Institute, St. Petersburg (Russian Federation); Shishlov, A.; Savitskii, Yu. [Krasnoyarsk Mining and Chemical Combine, Krasnoyarsk (Russian Federation); Novikov, A.; Goryachenkova, T. [Russian Academy of Sciences, Institute of Geochemistry and Analytical Chemistry, Moscow (Russian Federation)

    2001-03-01

    For 35 years Krasnoyarsk Mining-Chemical Combine (MCC) manufactures weapon plutonium in single-pass production reactors cooled with water of the Yenisey River. Water discharge from these reactors is the major source of radioactive contamination of the Yenisey River. We have demonstrated that after putting the reactors out of operation (in late 1992) the contamination level of the Yenisey River with short-lived radionuclides considerably decreased, and now the radioactive contamination is caused essentially by Cs-137, Eu-152, Pu-239,240, Sr-90, and Am-241, whose concentration in the aqueous phase is lower than in bottom sediments and, particularly, flood-land deposits by several orders of magnitude (except for Sr-90). The flood-land deposits are classified with the most contaminated environmental objects in the territories under the impact of MCC: their radioactivity is comparable with that of low-level waste. Taking into account the considerable depth and area of the flood-land deposits, this allows their classification as a great technogenic radiation anomaly. Comparison of the maximal Cs-137 and Pu-239,240 levels in flood-land soils and bottom sediments of the Yenisey River with those in bottom sediments of the Pripyat' River and the Kiev reservoir shows that these values are close each to other. A direct correlation is found between the spatial distribution of Cs-137 on the one hand and Pu-239,240, Eu-152, and Am-241 on the other hand in the aqueous phase and bottom sediments, which is not the case for Sr-90. Data on the distribution coefficients of the indicated radionuclides between the deposits and aqueous phase (obtained with actual and model systems) and also on the radionuclide distribution throughout geochemical mobility forms suggest that the essential part of Cs, Pu, Eu, and Am migrates with fine-disperse suspended material, the transport and distribution of which is controlled by the hydrological regime of the Yenisey River. By contrast, strontium

  8. Study of migration behavior of technogenic radionuclides in the Yenisey River-Kara Sea aquatic system

    International Nuclear Information System (INIS)

    Kuznetsov, Yu.; Legin, E.; Legin, V.; Shishlov, A.; Savitskii, Yu.; Novikov, A.; Goryachenkova, T.

    2001-01-01

    For 35 years Krasnoyarsk Mining-Chemical Combine (MCC) manufactures weapon plutonium in single-pass production reactors cooled with water of the Yenisey River. Water discharge from these reactors is the major source of radioactive contamination of the Yenisey River. We have demonstrated that after putting the reactors out of operation (in late 1992) the contamination level of the Yenisey River with short-lived radionuclides considerably decreased, and now the radioactive contamination is caused essentially by Cs-137, Eu-152, Pu-239,240, Sr-90, and Am-241, whose concentration in the aqueous phase is lower than in bottom sediments and, particularly, flood-land deposits by several orders of magnitude (except for Sr-90). The flood-land deposits are classified with the most contaminated environmental objects in the territories under the impact of MCC: their radioactivity is comparable with that of low-level waste. Taking into account the considerable depth and area of the flood-land deposits, this allows their classification as a great technogenic radiation anomaly. Comparison of the maximal Cs-137 and Pu-239,240 levels in flood-land soils and bottom sediments of the Yenisey River with those in bottom sediments of the Pripyat' River and the Kiev reservoir shows that these values are close each to other. A direct correlation is found between the spatial distribution of Cs-137 on the one hand and Pu-239,240, Eu-152, and Am-241 on the other hand in the aqueous phase and bottom sediments, which is not the case for Sr-90. Data on the distribution coefficients of the indicated radionuclides between the deposits and aqueous phase (obtained with actual and model systems) and also on the radionuclide distribution throughout geochemical mobility forms suggest that the essential part of Cs, Pu, Eu, and Am migrates with fine-disperse suspended material, the transport and distribution of which is controlled by the hydrological regime of the Yenisey River. By contrast, strontium

  9. Selective extractions in uranium migration studies - Findings from a natural analogue study at Palmottu

    International Nuclear Information System (INIS)

    Suksi, J.; Saarinen, L.

    1994-01-01

    The usefulness of chemical extractions in the study on uranium migration is considered in the light of the results compiled at Palmottu. Chemical extractions provide a method for evaluating the mass transfer of U and its retardation in geochemical cycling. The present detailed study provides more specific information on the in situ fixation of U on rock materials. The many observations made at Palmottu show the potential of the method to fill the gap in interpretations between the natural partitioning of U in rock and the distribution of artificial tracers determined by the short-term laboratory experiments. (orig.) (20 refs., 4 figs., 1 tab.)

  10. Use of Invasion Percolation Models To Study the Secondary Migration of Oil and Related Problems

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, G.

    1997-09-01

    In oil reservoir engineering, multi-phase displacement processes are important. This doctoral thesis describes simulations of the slow displacement of a wetting fluid by a non-wetting fluid in a complex, random porous medium and in a single fracture. The study is restricted to two-phase flow in the quasi-static limit in which viscous forces can be neglected. The secondary migration of oil takes place in this regime, however, the discussion is broader in scope. The thesis connects the problem of slow two-phase flow to percolation theory and discusses the mechanisms that control immiscible displacements. A new, modified version of the invasion percolation model is used to simulate an imbibition process in a porous medium and the migration of a cluster of non-wetting fluid through a porous medium saturated with a wetting fluid. The simulations include the secondary migration of oil through porous homogeneous rock. Fluid migration through heterogeneous porous media is simulated qualitatively. Slow displacement of a wetting fluid by a non-wetting fluid in a single rock fracture is simulated by using the standard invasion percolation model. Experiments and simulations are performed to study the fragmentation of invasion percolation-like structures of non-wetting fluid in a porous medium saturated with a wetting fluid. A scenario is studied in which a cluster of non-wettable fluid migrates through a porous medium that is saturated with a wetting fluid, the migration being driven by continuously increasing buoyancy forces. There is a simulation of the secondary migration of oil in both two- and three-dimensional media. 361 refs., 115 figs.

  11. Novel device (AirWave) to assess endotracheal tube migration: a pilot study.

    Science.gov (United States)

    Nacheli, Gustavo Cumbo; Sharma, Manish; Wang, Xiaofeng; Gupta, Amit; Guzman, Jorge A; Tonelli, Adriano R

    2013-08-01

    Little is known about endotracheal tube (ETT) migration during routine care among critically ill patients. AirWave is a novel device that uses sonar waves to measure ETT migration and obstructions in real time. The aim of the present study is to assess the accuracy of the AirWave to evaluate ETT migration. In addition, we determined the degree of variation in ETT position and tested whether more pronounced migration occurs in specific clinical scenarios. After institutional review board approval, we included mechanically ventilated patients from February 2012 to May 2012. A chest radiography (CXR) was obtained at baseline and 24 hours when clinically indicated. The ETT distance at the lips was recorded at baseline and every 4 hours. The AirWave system continuously recorded ETT position changes from baseline, and luminal obstructions. A total of 42 patients (age: 61 [SD ±13] years, men: 52%) were recruited. A total of 19 patients had measurements of ETT migration at 24 hours by the 3 methodologies used in this study. The mean (SD) of the ETT migration at 24 hours was +0.04 (1.2), -0.42 (0.7) and +0.34 (1.81) cm when measured by portable CXR, ETT distance at the teeth and AirWave device, respectively. Bland-Altman analysis of tube migration at 24 hours comparing the AirWave with CXR readings showed a bias of 0.1 cm with 95% limit of agreement of -3.8 and +4.3 cm. Comparison of tube migration at 24 hours determined by AirWave with ETT distance at the lips revealed a bias of -0.4 with 95% limit of agreement -3.7 to +3 cm, similar to the values observed between CXR and ETT distance at the lips (bias of -0.3 cm, 95% limit of agreement of -3.4 to +2.8 cm). Factors associated with ETT migration at 24 hours were ETT size and initial measurement from ETT tip to carina by portable CXR. AirWave detected in eight patients some degree of ETT obstruction (30% ± 9.6%) that resolved with prompt ETT catheter suction. The AirWave may provide useful information regarding ETT

  12. Terminalia chebula Fructus Inhibits Migration and Proliferation of Vascular Smooth Muscle Cells and Production of Inflammatory Mediators in RAW 264.7

    Directory of Open Access Journals (Sweden)

    Hyun-Ho Lee

    2015-01-01

    Full Text Available Pathogenesis of atherosclerosis and neointima formation after angioplasty involves vascular smooth muscle cells (VSMCs migration and proliferation followed by inflammatory responses mediated by recruited macrophages in the neointima. Terminalia chebula is widely used traditional medicine in Asia for its beneficial effects against cancer, diabetes, and bacterial infection. The study was designed to determine whether Terminalia chebula fructus water extract (TFW suppresses VSMC migration and proliferation and inflammatory mediators production in macrophage (RAW 264.7. Our results showed that TFW possessed strong antioxidative effects in 1,1-diphenyl-2-picryl hydrazyl (DPPH scavenging and lipid peroxidation assays. In addition, TFW reduced nitric oxide (NO production, inducible nitric oxide synthase (iNOS, and cyclooxygenase-2 (COX-2 expression in RAW 264.7 cells. Also, TFW inhibited platelet-derived growth factor (PDGF-BB induced VSMC migration as determined by wound healing and Boyden chamber assays. The antimigratory effect of TFW was due to its inhibitory effect on metalloproteinase-9 (MMP-9 expression, focal adhesion kinase (FAK activation, and Rho-family of small GTPases (Cdc42 and RhoA expression in VSMCs. Furthermore, TFW suppressed PDGF-BB induced VSMC proliferation by downregulation of mitogen activated protein kinases (MAPKs signaling molecules. These results suggest that TFW could be a beneficial resource in the prevention of atherosclerosis.

  13. [Identification and sampling of people with migration background for epidemiological studies in Germany].

    Science.gov (United States)

    Reiss, K; Makarova, N; Spallek, J; Zeeb, H; Razum, O

    2013-06-01

    In 2009, 19.6% of the population of Germany either had migrated themselves or were the offspring of people with migration experience. Migrants differ from the autochthonous German population in terms of health status, health awareness and health behaviour. To further investigate the health situation of migrants in Germany, epidemiological studies are needed. Such studies can employ existing databases which provide detailed information on migration status. Otherwise, onomastic or toponomastic procedures can be applied to identify people with migration background. If migrants have to be recruited into an epidemiological study, this can be done register-based (e. g., data from registration offices or telephone lists), based on residential location (random-route or random-walk procedure), via snowball sampling (e. g., through key persons) or via settings (e. g., school entry examination). An oversampling of people with migration background is not sufficient to avoid systematic bias in the sample due to non-participation. Additional measures have to be taken to increase access and raise participation rates. Personal contacting, multilingual instruments, multilingual interviewers and extensive public relations increase access and willingness to participate. Empirical evidence on 'successful' recruitment strategies for studies with migrants is still lacking in epidemiology and health sciences in Germany. The choice of the recruitment strategy as well as the measures to raise accessibility and willingness to participate depend on the available resources, the research question and the specific migrant target group. © Georg Thieme Verlag KG Stuttgart · New York.

  14. A Study on the Nuclide Migration and Retardation Using Natural Barrier

    International Nuclear Information System (INIS)

    Baik, Min Hoon; Park, Chung Kyun; Kim, Seung Soo

    2010-02-01

    In this study, we investigated the properties of geochemical reactions and sorption of high-level radionuclides (U, Th, Am, and Np), constructed databases for the geochemical reactions and sorption of the high-level radionuclides, and developed application methodologies of the databases. For the investigation on the nuclide migration and retardation through fractured rocks in KURT, in-situ solute migration system and on-line monitoring system were installed. The migration and retardation behaviors of nuclides were investigated annually for non-sorbing, simply sorbing and multi-valent sorbing nuclides, respectively, and interactions with fracture-filling materials were also analyzed. Besides, researches difficult to perform in KURT were carried out in foreign underground research facilities as joint studies for nuclide and colloid migration. The results from domestic and foreign underground facilities were compared each other and the reliability of the domestic results were assured from this. Diffusion depths of high-level radionuclides into rock matrix were measured in KURT conditions and their diffusion properties were analyzed and evaluated. In addition, the effects of bio-mineralization and redox reactions of a nuclide and microbe on nuclide behaviors were carried out to study the effects of combined interactions between minerals and microbes on the radionuclide migration and retardation

  15. Assessment of toxic and endocrine potential of substances migrating from selected toys and baby products.

    Science.gov (United States)

    Szczepańska, Natalia; Namieśnik, Jacek; Kudłak, Błażej

    2016-12-01

    Analysis of literature data shows that there is limited information about the harmful biological effects of mixture of compounds from the EDC group that are released from the surface of toys and objects intended for children and infants. One of the tools that can be used to obtain such information is appropriate bioanalytical tests. The aim of this research involved determining whether tests that use living organisms as an active element (Vibrio fischeri-Microtox®, Heterocypris incongruens-Ostrocodtoxkit F™ and the XenoScreen YES/YAS™ test of oestrogenic/androgenic activity) can be a tool for estimating the combined toxic effects induced by xenobiotics released from objects intended for children. To reproduce the conditions to which objects are exposed during their use, liquids with a composition corresponding to that of human bodily fluids (artificial sweat and saliva) were used. This research focused on the main parameters influencing the intensification of the migration process (temperature, contact time and composition of the extraction mixture). The studies aimed to estimate the endocrine potential of the extracts showed that compounds released from the surface of studied objects exhibit antagonistic androgenic activity. While on the basis of the results of Microtox® test, one can state that the largest quantity of toxic compounds are released in the first 2 h of using the object. The FTIR spectra analyses confirmed that no degradation of polymeric material took place. On the basis of the results obtained, it was unanimously concluded that contact of the object with bodily fluids may result in the release of a large number of xenobiotics, which has disadvantageous effects on the metabolic processes of the indicator organisms.

  16. Pre-migration and post-migration factors associated with mental health in humanitarian migrants in Australia and the moderation effect of post-migration stressors: findings from the first wave data of the BNLA cohort study.

    Science.gov (United States)

    Chen, Wen; Hall, Brian J; Ling, Li; Renzaho, Andre Mn

    2017-03-01

    The process of becoming a humanitarian migrant is potentially damaging to mental health. We examined the association between pre-migration and post-migration potentially traumatic events and stressors and mental health, and assessed the moderating effect of post-migration stressors in humanitarian migrants in Australia. In this study, we used the first wave of data between 2013 and 2014 from the Building a New Life in Australia survey. The survey included 2399 migrants who had arrived in Australia holding a permanent humanitarian visa 3-6 months preceding the survey, with 77% and 23% of participants being granted visas through offshore and onshore humanitarian programmes, respectively. Post-traumatic stress disorder (PTSD) was measured with the Post-traumatic Stress Disorder 8 items (PTSD-8) and severe mental illness was measured with the Kessler Screening Scale for Psychological Distress (K6). Pre-migration potentially traumatic events and post-migration stressors related to asylum process and resettlement were measured with a self-reported questionnaire. Of the 2399 participants, 762 (31%; 95% CI 29·4-33·2) had PTSD and 394 (16%; 95% CI 14·2-17·2) had severe mental illness. The mean number of pre-migration potentially traumatic events was 2·1 (SD 1·4). 64%, 59%, 49%, and 18% of participants reported poor social integration, economic problems, worrying about family or friends overseas, and loneliness as post-migration stressors. Pre-migration potentially traumatic events and post-migration stressors were positively associated with PTSD and severe mental illness. Factors significantly modifying the association between pre-migration potentially traumatic events and mental health after controlling for confounding factors were resettlement related stressors, including loneliness (odds ratio 1·17, 95% CI 1·05-1·28 for PTSD and 1·28, 1·16-1·41 for severe mental illness) and the number of social integration stressors (1·10, 1·05-1·16 for PTSD). Our data

  17. Managing health worker migration: a qualitative study of the Philippine response to nurse brain drain

    Directory of Open Access Journals (Sweden)

    Dimaya Roland M

    2012-12-01

    Full Text Available Abstract Background The emigration of skilled nurses from the Philippines is an ongoing phenomenon that has impacted the quality and quantity of the nursing workforce, while strengthening the domestic economy through remittances. This study examines how the development of brain drain-responsive policies is driven by the effects of nurse migration and how such efforts aim to achieve mind-shifts among nurses, governing and regulatory bodies, and public and private institutions in the Philippines and worldwide. Methods Interviews and focus group discussions were conducted to elicit exploratory perspectives on the policy response to nurse brain drain. Interviews with key informants from the nursing, labour and immigration sectors explored key themes behind the development of policies and programmes that respond to nurse migration. Focus group discussions were held with practising nurses to understand policy recipients’ perspectives on nurse migration and policy. Results Using the qualitative data, a thematic framework was created to conceptualize participants’ perceptions of how nurse migration has driven the policy development process. The framework demonstrates that policymakers have recognised the complexity of the brain drain phenomenon and are crafting dynamic policies and programmes that work to shift domestic and global mindsets on nurse training, employment and recruitment. Conclusions Development of responsive policy to Filipino nurse brain drain offers a glimpse into a domestic response to an increasingly prominent global issue. As a major source of professionals migrating abroad for employment, the Philippines has formalised efforts to manage nurse migration. Accordingly, the Philippine paradigm, summarised by the thematic framework presented in this paper, may act as an example for other countries that are experiencing similar shifts in healthcare worker employment due to migration.

  18. Extracellular ATP drives breast cancer cell migration and metastasis via S100A4 production by cancer cells and fibroblasts.

    Science.gov (United States)

    Liu, Ying; Geng, Yue-Hang; Yang, Hui; Yang, Han; Zhou, Yan-Ting; Zhang, Hong-Quan; Tian, Xin-Xia; Fang, Wei-Gang

    2018-05-04

    Our previous work has demonstrated that extracellular ATP is an important pro-invasive factor, and in this study, we tapped into a possible mechanism involved. We discovered that ATP could upregulate both the intracellular expression and secretion of S100A4 in breast cancer cells and fibroblasts. Apart from stimulating breast cancer cell motility via intracellular S100A4, ATP enhanced the ability of breast cancer cells to transform fibroblasts into cancer-associated fibroblast (CAF)-like cells, which in turn secreted S100A4 to further promote cancer cell motility. Both apyrase and niclosamide treatments could inhibit metastasis of inoculated tumors to lung, liver and kidney in mice model, and CAFs from these treated tumors exhibited weakened migration-stimulating capacity for breast cancer cells. Collectively, our data indicate that extracellular ATP promotes the interactions between breast cancer cells and fibroblasts, which work collaboratively via production of S100A4 to exacerbate breast cancer metastasis. Copyright © 2018. Published by Elsevier B.V.

  19. Trend of different molecular markers in the last decades for studying human migrations.

    Science.gov (United States)

    Kundu, Sharbadeb; Ghosh, Sankar Kumar

    2015-02-10

    Anatomically modern humans are known to have widely migrated throughout history. Different scientific evidences suggest that the entire human population descended from just several thousand African migrants. About 85,000 years ago, the first wave of human migration was out of Africa, that followed the coasts through the Middle East, into Southern Asia via Sri Lanka, and in due course around Indonesia and into Australia. Another wave of migration between 40,000 and 12,000 years ago brought humans northward into Europe. However, the frozen north limited human expansion in Europe, and created a land bridge, "Bering land bridge", connecting Asia with North America about 25,000 years ago. Although fossil data give the most direct information about our past, it has certain anomalies. So, molecular archeologists are now using different molecular markers to trace the "most recent common ancestor" and also the migration pattern of modern humans. In this study, we have studied the trend of molecular markers and also the methodologies implemented in the last decades (2003-2014). From our observation, we can say that D-loop region of mtDNA and Y chromosome based markers are predominant. Nevertheless, mtDNA, especially the D-loop region, has some unique features, which makes it a more effective marker for tracing prehistoric footprints of modern human populations. Although, natural selection should also be taken into account in studying mtDNA based human migration. As per technology is concerned, Sanger sequencing is the major technique that is being used in almost all studies. But, the emergence of different cost-effective-and-easy-to-handle NGS platforms has increased its popularity over Sanger sequencing in studying human migration. Copyright © 2014. Published by Elsevier B.V.

  20. FUTURE STUDIES AT PENA BLANCA: RADIONUCLIDE MIGRATION IN THE VADOSE ZONE OF AN ALLUVIAL FAN

    Energy Technology Data Exchange (ETDEWEB)

    P. Goodell; J. Walton; P.J. Rodriguez

    2005-07-11

    The pathway to the accessible environment at Yucca Mountain contains volcanic rocks and alluvial fill. Transport properties in alluvial fill, specifically retardation and dispersivity, may be significant in determining the overall performance of the repository. Prior relevant studies, with the exception of the Nye County Tracer Test, are almost entirely in bedrock material. The proposed study will provide field data on radionuclide migration in alluvial material. High grade uranium ore was mined at the Nopal I deposit. This mined ore (60,000 tons) was moved in 1994 to its present site as open piles on an alluvial fan in the Boquilla Colorada Microbasin. Precipitation is approximately 20 cm/year, and has caused migration of radionuclides into the subsurface. We propose partial removal of an ore pile, excavation into the alluvial fan, sampling, and determination of radionuclide mobilities from the uranium decay chain. The proposed research would be taking advantage of a unique opportunity with a known time frame for migration.

  1. FUTURE STUDIES AT PENA BLANCA: RADIONUCLIDE MIGRATION IN THE VADOSE ZONE OF AN ALLUVIAL FAN

    International Nuclear Information System (INIS)

    Goodell, P.; Walton, J.; Rodriguez, P.J.

    2005-01-01

    The pathway to the accessible environment at Yucca Mountain contains volcanic rocks and alluvial fill. Transport properties in alluvial fill, specifically retardation and dispersivity, may be significant in determining the overall performance of the repository. Prior relevant studies, with the exception of the Nye County Tracer Test, are almost entirely in bedrock material. The proposed study will provide field data on radionuclide migration in alluvial material. High grade uranium ore was mined at the Nopal I deposit. This mined ore (60,000 tons) was moved in 1994 to its present site as open piles on an alluvial fan in the Boquilla Colorada Microbasin. Precipitation is approximately 20 cm/year, and has caused migration of radionuclides into the subsurface. We propose partial removal of an ore pile, excavation into the alluvial fan, sampling, and determination of radionuclide mobilities from the uranium decay chain. The proposed research would be taking advantage of a unique opportunity with a known time frame for migration

  2. Migration chemistry

    International Nuclear Information System (INIS)

    Carlsen, L.

    1992-05-01

    Migration chemistry, the influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour of pollutants in the environment, is an interplay between the actual natur of the pollutant and the characteristics of the environment, such as pH, redox conditions and organic matter content. The wide selection of possible pollutants in combination with varying geological media, as well as the operation of different chemical -, biochemical - and physico-chemical reactions compleactes the prediction of the influence of these processes on the mobility of pollutants. The report summarizes a wide range of potential pollutants in the terrestrial environment as well as a variety of chemical -, biochemical - and physico-chemical reactions, which can be expected to influence the migration behaviour, comprising diffusion, dispersion, convection, sorption/desorption, precipitation/dissolution, transformations/degradations, biochemical reactions and complex formation. The latter comprises the complexation of metal ions as well as non-polar organics to naturally occurring organic macromolecules. The influence of the single types of processes on the migration process is elucidated based on theoretical studies. The influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour is unambiguous, as the processes apparently control the transport of pollutants in the terrestrial environment. As the simple, conventional K D concept breaks down, it is suggested that the migration process should be described in terms of the alternative concepts chemical dispersion, average-elution-time and effective retention. (AB) (134 refs.)

  3. Migration, violence, and safety among migrant sex workers: a qualitative study in two Guatemalan communities.

    Science.gov (United States)

    Rocha-Jiménez, Teresita; Brouwer, Kimberly C; Silverman, Jay G; Morales-Miranda, Sonia; Goldenberg, Shira M

    2016-09-01

    Despite reports of high levels of violence among women migrants in Central America, limited evidence exists regarding the health and safety of migrant sex workers in Central America. This study is based on 16 months of field research (November 2012-February 2014), including ethnographic fieldwork, in-depth interviews, and focus groups conducted with 52 internal and international migrant female sex workers in Tecún Umán and Quetzaltenango, Guatemala, key transit and destination communities for both international and internal migrants. The analysis explored migration-related determinants of susceptibility to violence experienced by migrant sex workers across different phases of migration. Violence in home communities and economic considerations were key drivers of migration. Unsafe transit experiences (eg undocumented border crossings) and negative interactions with authorities in destination settings (eg extortion) contributed to migrant sex workers' susceptibility to violence, while enhanced access to information on immigration policies and greater migration and sex work experience were found to enhance agency and resilience. Findings suggest the urgent need for actions that promote migrant sex workers' safety in communities of origin, transit, and destination, and programmes aimed at preventing and addressing human rights violations within the context of migration and sex work.

  4. The Impact of International Migration on the Labor Market – A Case Study from Hungary

    Directory of Open Access Journals (Sweden)

    Judit Oláh

    2017-08-01

    Full Text Available The economic, political and social changes experienced globally in recent years have influenced international migration in various countries. The aim of our study is to present the economic and non-economic aspects which determine the quantitative evaluation of migration and to reveal which of the two main factor groups is more dominant. In January 2017, an online questionnaire survey was conducted on the subject of migration. The group of respondents consisted of 438 full-time BSc, MSc and PhD students in Hungarian higher education institutions. Based on these questionnaires, two independent samples t-test, and one-way ANOVA, factor analysis and binary logistic regression procedures were performed. Based on the findings obtained, it was concluded that anti-migration behaviour cannot be explicitly explained by its economic impacts on the labour market. The rejecting attitudes observed on behalf of certain respondents were not in significant correlation with their highest educational levels or their given social class. As a result of the statistical analysis performed, it was concluded that the integration of foreigners is hindered by the so-called socio-cultural barriers, which cannot be removed solely by economic policy measures. Social conflicts of interest have to be eliminated in order for migration to have an active and permanently positive impact on the economy.

  5. Migration and self-esteem: A qualitative study among internal migrant girls in Turkey

    NARCIS (Netherlands)

    Altinyelken, H.K.

    2009-01-01

    This article examining the impact of migration experience on self-esteem of girls enrolled at primary schools in Turkey. It is based on a broader study that explored edueational and coping strategies of internal migrant girls living in a suburban town in the western part of Turkey. The study showed

  6. Advanced glycation end products induce chemokine/cytokine production via activation of p38 pathway and inhibit proliferation and migration of bone marrow mesenchymal stem cells

    OpenAIRE

    Yang, Ke; Wang, Xiao Qun; He, Yu Song; Lu, Lin; Chen, Qiu Jing; Liu, Jing; Shen, Wei Feng

    2010-01-01

    Abstract Background Advanced glycation products (AGEs), as endogenous inflammatory mediator, compromise the physiological function of mesenchymal stem cells (MSCs). MSCs have a potential role in cell replacement therapy in acute myocardial infarction and ischemic cardiomyopathy. However, mechanisms of AGEs on MSCs are still not unveiled. Methods Reactive oxygen species (ROS), genes regulation, cell proliferation and migration have been detected by AGE-BSA stimulated MSCs. Results We found tha...

  7. Studies on Horizontal and Vertical Migration of 90Sr in Soil Systems

    International Nuclear Information System (INIS)

    Solecki, J.; Chibowski, S.

    2002-01-01

    Here are presented results of studies on vertical and horizontal migration of strontium 90 Sr isotope in soil systems of Bug river valleys. Mean radioactivity of strontium in these soils was 26.15 ± 22.2 Bq/kg. Atmospheric precipitation of strontium on this area was 0.35 kBq/m2/cm. Radioactivity in soil profiles ranged from 17 to 130 Bq/m2/cm and the isotope was detected even at 30 cm depth. Some tendency to vertical migration of strontium towards the river was noticed. Obtained results were compared with concentrations of calcium and strontium in the soil. Any clear influence of these elements on the migration of strontium 90 Sr was noticed. (author)

  8. Studies on the migration rule and mechanism of radon and its daughters

    International Nuclear Information System (INIS)

    Jia Wenyi; Fang Fang; Zhou Rongsheng; Ma Yingjie; Qiu Yuande; Hou Xinsheng; Wu Yunping; Zu Xiulan; Wang Xiaoqin

    2000-01-01

    By using very precise, highly sensitive, static accumulated, easily repeated CD-1 α-cup, the migration rule and mechanism of radon and its daughters was studied. Significant results were obtained: (1) Under laboratory conditions, the vertical component of migration of radon and its daughters was much greater than the horizontal component, the former was over 90% and the latter was less than 10%. (2) Despite the very big specific gravity of radon and its daughters, the descending component of migration was less than 45%, while the ascending component was more than 45%. (3) After α-particles (emitted from radon and its daughters) being slowed down. 4 He combined with the radon and its daughters to form clusters. When the density of the cluster was less than that of the air, the self-ascending would occur

  9. A panel study of migration, self-selection and household real income.

    Science.gov (United States)

    Axelsson, R; Westerlund, O

    1998-02-01

    "The impact of migration on income for Swedish multi-adult households is examined using panel data pertaining to a sample of stable household constellations during the period 1980-1990. In contrast to previous studies, data on household disposable income is employed in estimating the income function. The empirical results indicate no significant effect on real disposable income from migration. In addition, the hypothesis of no self-selection, or zero correlation between the errors in the decision function and the income function, cannot be rejected." excerpt

  10. Xenon migration in UO{sub 2} under irradiation studied by SIMS profilometry

    Energy Technology Data Exchange (ETDEWEB)

    Marchand, B. [Université de Lyon, CNRS/IN2P3, Université Lyon 1, Institut de Physique Nucléaire de Lyon, 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); AREVA, AREVA NP, 10 rue Juliette Récamier, F-69456 Lyon (France); Moncoffre, N. [Université de Lyon, CNRS/IN2P3, Université Lyon 1, Institut de Physique Nucléaire de Lyon, 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Pipon, Y., E-mail: pipon@ipnl.in2p3.fr [Université de Lyon, CNRS/IN2P3, Université Lyon 1, Institut de Physique Nucléaire de Lyon, 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Université de Lyon, Université Lyon 1, IUT Lyon 1, 43 bd du 11 novembre 1918, 69 622 Villeurbanne cedex (France); Bérerd, N. [Université de Lyon, CNRS/IN2P3, Université Lyon 1, Institut de Physique Nucléaire de Lyon, 4 rue Enrico Fermi, F-69622 Villeurbanne cedex (France); Université de Lyon, Université Lyon 1, IUT Lyon 1, 43 bd du 11 novembre 1918, 69 622 Villeurbanne cedex (France); Garnier, C. [AREVA, AREVA NP, 10 rue Juliette Récamier, F-69456 Lyon (France); Raimbault, L. [Ecole des Mines de Paris, Centre de Géosciences, 35 rue Saint Honoré, F-77305 Fontainebleau cedex (France); Sainsot, P. [Université de Lyon, Université Lyon 1, LaMCoS, INSA-Lyon, CNRS UMR5259, F-69621 Villeurbanne cedex (France); and others

    2013-09-15

    During Pressurized Water Reactor operation, around 25% of the created Fission Products (FP) are Xenon and Krypton. They have a low solubility in the nuclear fuel and can either (i) agglomerate into bubbles which induce mechanical stress in the fuel pellets or (ii) be released from the pellets, increasing the pressure within the cladding and decreasing the thermal conductivity of the gap between pellets and cladding. After fifty years of studies on the nuclear fuel, all mechanisms of Fission Gas Release (FGR) are still not fully understood. This paper aims at studying the FGR mechanisms by decoupling thermal and irradiation effects and by assessing the Xenon behavior for the first time by profilometry. Samples are first implanted with {sup 136}Xe at 800 keV corresponding to a projected range of 140 nm. They are then either annealed in the temperature range 1400–1600 °C, or irradiated with heavy energy ions (182 MeV Iodine) at Room Temperature (RT), 600 °C or 1000 °C. Depth profiles of implanted Xenon in UO{sub 2} are determined by Secondary Ion Mass Spectrometry (SIMS). It is shown that Xenon is mobile during irradiation at 1000 °C. In contrast, thermal treatments do not induce any Xenon migration process: these results are correlated to the formation of Xenon bubbles observed by Transmission Electron Microscopy.

  11. Highly skilled international labour migration: a qualitative study of migrant Pakistani professionals in London's big four accounting firms

    OpenAIRE

    Rahim, Aisha

    2014-01-01

    Current Migration Studies literature in Europe can broadly be divided into two major strands. First is dominated by studies on the East-West migration of working class or asylum seeking, postcolonial ethnic groups and problems associated with their subsequent integration/assimilation into the host society. The second, more recent, strand of migration research is that of highly skilled professional migrants, usually hypermobile white men moving across highly-developed countries (for example wi...

  12. Migration of phthalates on culture plates - an important challenge to consider for in vitro studies.

    Science.gov (United States)

    Frohnert Hansen, Juliana; Boas, Malene; Møller Brorson, Marianne; Frederiksen, Hanne; Hartoft-Nielsen, Marie-Louise; Krogh Rasmussen, Åse; Main, Katharina M; Feldt-Rasmussen, Ulla

    2016-01-01

    Phthalates are endocrine disruptors of the reproductive system and suspected to influence many other organ and hormone systems. They are also semi-volatile organic compounds present in the gas phase in the environment. Their mode of action has been investigated in numerous in vitro studies. Multi-well culture plates are typically used to study phthalates in cell cultures. In a pilot study, we observed evidence of phthalate migration in 24-well culture plates. As this has not previously been described, we investigated the phenomenon in more detail. Primary human thyroid epithelial cell cultures (n = 8 cultures) were exposed to either di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), mono-n-butyl phthalate (MnBP) or di-(2-ethylhexyl) phthalate (DEHP). Measurement of phthalate metabolites by mass spectrometry demonstrated that the short-branched DEP was able to migrate to adjacent wells when added to cell culture plates. DnBP also seemed to be able to migrate, unlike the long-branched DEHP or the monoester MnBP which did not seem to have this ability. High background levels of phthalate metabolites were also observed, which might compromise results from low dose phthalate studies. In conclusion, the migration of phthalates which is probably caused by their volatile properties might lead to false interpretation of study results.

  13. Migrating Toward Fully 4-D Geodynamical Models of Asthenospheric Circulation and Melt Production at Mid-Ocean Ridges

    Science.gov (United States)

    van Dam, L.; Kincaid, C. R.; Pockalny, R. A.; Sylvia, R. T.; Hall, P. S.

    2017-12-01

    Lateral migration of mid-ocean ridge spreading centers is a well-documented phenomenon leading to asymmetric melt production and the surficial expressions thereof. This form of plate motion has been difficult to incorporate into both numerical and analogue geodynamical models, and consequently, current estimates of time-dependent flow, material transport, and melting in the mantle beneath ridges are lacking. To address this, we have designed and built an innovative research apparatus that allows for precise and repeatable simulations of mid-ocean ridge spreading and migration. Three pairs of counter-rotating belts with adjustable lateral orientations are scaled to simulate spreading at, and flow beneath, three 600km wide ridge segments with up to 300km transform offsets. This apparatus is attached to a drive system that allows us to test a full range of axis-parallel to axis-normal migration directions, and is suspended above a reservoir of viscous glucose syrup, a scaled analogue for the upper mantle, and neutrally buoyant tracers. We image plate-driven flow in the syrup with high-resolution digital cameras and use particle image velocimetry methods to obtain information about transport pathlines and flow-induced anisotropy. Suites of experiments are run with and without ridge migration to determine the overall significance of migration on spatial and temporal characteristics of shallow mantle flow. Our experiments cover an expansive parameter space by including various spreading rates, migration speeds and directions, degrees of spreading asymmetry, transform-offset lengths, and upper mantle viscosity conditions. Preliminary results highlight the importance of modeling migratory plate forces. Mantle material exhibits a significant degree of lateral transport, particularly between ridge segments and towards the melt triangle. Magma supply to the melting region is highly complex; parcels of material do not necessarily move along fixed streamlines, rather, they can

  14. The Caenorhabditis elegans Q neuroblasts: A powerful system to study cell migration at single-cell resolution in vivo.

    Science.gov (United States)

    Rella, Lorenzo; Fernandes Póvoa, Euclides E; Korswagen, Hendrik C

    2016-04-01

    During development, cell migration plays a central role in the formation of tissues and organs. Understanding the molecular mechanisms that drive and control these migrations is a key challenge in developmental biology that will provide important insights into disease processes, including cancer cell metastasis. In this article, we discuss the Caenorhabditis elegans Q neuroblasts and their descendants as a tool to study cell migration at single-cell resolution in vivo. The highly stereotypical migration of these cells provides a powerful system to study the dynamic cytoskeletal processes that drive migration as well as the evolutionarily conserved signaling pathways (including different Wnt signaling cascades) that guide the cells along their specific trajectories. Here, we provide an overview of what is currently known about Q neuroblast migration and highlight the live-cell imaging, genome editing, and quantitative gene expression techniques that have been developed to study this process. © 2016 Wiley Periodicals, Inc.

  15. Rural-to-Urban Migration, Strain, and Juvenile Delinquency: A Study of Eighth-Grade Students in Guangzhou, China.

    Science.gov (United States)

    Lo, Celia C; Cheng, Tyrone C; Bohm, Maggie; Zhong, Hua

    2018-02-01

    This examination of minor and serious delinquency among eighth graders in a large southern Chinese city, Guangzhou, also compared groups of these students, observing differences between the delinquency of migrants and that of urban natives. Data used were originally collected for the study "Stuck in the City: Migration and Delinquency Among Migrant Adolescents in Guangzhou." The present study asked whether and how various sources of strain and social control factors explained students' delinquency, questioning how meaningfully migration status moderated several of the observed delinquency relationships. Of students in the sample, 741 reported being natives of Guangzhou, and 497 reported migrating to Guangzhou from a rural area. The study conceptualized internal migration as a strain factor leading to delinquency, but the analyses did not suggest direct association between internal migration and delinquency. Results generally supported Agnew's theory, and, what's more, they tended to confirm that migration status moderated juvenile delinquency.

  16. Crosstalk between intracellular and extracellular signals regulating interneuron production, migration and integration into the cortex

    OpenAIRE

    Peyre, Elise; Silva, Carla G.; Nguyen, Laurent

    2015-01-01

    During embryogenesis, cortical interneurons are generated by ventral progenitors located in the ganglionic eminences of the telencephalon. They travel along multiple tangential paths to populate the cortical wall. As they reach this structure they undergo intracortical dispersion to settle in their final destination. At the cellular level, migrating interneurons are highly polarized cells that extend and retract processes using dynamic remodeling of microtubule and actin cytoskeleton. Differe...

  17. Cellular dysfunction in the diabetic fibroblast: impairment in migration, vascular endothelial growth factor production, and response to hypoxia.

    Science.gov (United States)

    Lerman, Oren Z; Galiano, Robert D; Armour, Mary; Levine, Jamie P; Gurtner, Geoffrey C

    2003-01-01

    Although it is known that systemic diseases such as diabetes result in impaired wound healing, the mechanism for this impairment is not understood. Because fibroblasts are essential for wound repair, we compared the in vitro behavior of fibroblasts cultured from diabetic, leptin receptor-deficient (db/db) mice with wild-type fibroblasts from mice of the same genetic background in processes important during tissue repair. Adult diabetic mouse fibroblast migration exhibited a 75% reduction in migration compared to normal fibroblasts (P under basal or hypoxic conditions, confirming that the results from db/db fibroblasts in mature mice resulted from the diabetic state and were not because of alterations in the leptin-leptin receptor axis. Markers of cellular viability including proliferation and senescence were not significantly different between diabetic and wild-type fibroblasts. We conclude that, in vitro, diabetic fibroblasts show selective impairments in discrete cellular processes critical for tissue repair including cellular migration, VEGF production, and the response to hypoxia. The VEGF abnormalities developed concurrently with the onset of hyperglycemia and were not seen in normoglycemic, leptin receptor-deficient db/db mice. These observations support a role for fibroblast dysfunction in the impaired wound healing observed in human diabetics, and also suggest a mechanism for the poor clinical outcomes that occur after ischemic injury in diabetic patients.

  18. A qualitative study of the factors influencing the global migration of ...

    African Journals Online (AJOL)

    2014-11-06

    Nov 6, 2014 ... the public sector upon qualifying, socio-economic and political instability in South Africa, ... that more work needs to be done on the human relations aspects of .... Case studies allowed for an in-depth, primarily qualitative ...... the Sponsorship and Temporary Migration of Skilled Workers to Australia',.

  19. Field studies about radionuclide migration natural analogues and faults in clays

    International Nuclear Information System (INIS)

    Williams, G.M.; Hooker, P.J.; Brightman, M.A.

    1990-01-01

    This report puts together final reports of CEC contracts about the following topics: in situ determination of the effects of organics on the mobility of radionuclides in controlled conditions of groundwater flow (Drigg site); natural analogue studies of radionuclide migration (Loch Lomond, Broubster, Needle's Eye); faults in clays: their detection and characterization (Down Ampney site)

  20. Towards healthy migration: an exploratory study on the resilience of migrant domestic workers from the Philippines

    NARCIS (Netherlands)

    van der Ham, A.J.; Ujano-Batangan, M.T.; Ignacio, R.; Wolffers, I.N.

    2014-01-01

    Domestic workers face many migration-related stressors that affect their mental health. Currently there is an emphasis in the literature on these workers' problems and vulnerability, while there is little insight into factors that positively affect their mental health. In this study, we describe a

  1. Researching Refugee and Forced Migration Studies: An Introduction to the Field and the Reference Literature.

    Science.gov (United States)

    Mason, Elisa

    1999-01-01

    Describes the evolution of refugee and forced migration studies, identifies factors that render it a challenging field to research, and highlights a variety of Internet-based and other electronic resources that can be used to locate monographs, periodicals, grey literature, and current information. Provides a bibliography of reference materials in…

  2. Migration and Multilingualism in Western Europe: A Case Study of the Netherlands.

    Science.gov (United States)

    Extra, Guus; Vallen, Ton

    1997-01-01

    Reviews demographic and linguistic consequences of recent processes of migration and minority group influx in Western Europe and describes the case of the Netherlands to illustrate these effects. Highlights first- and second-language studies of immigrant and ethnic minority groups and notes resulting major demographic trends in Dutch society and…

  3. (2008) SWJ:21-25 Comparative Studies On the Dying rate Migration

    African Journals Online (AJOL)

    Dr. Ahmed

    COMPARATIVE STUDIES ON DYEING RATE MIGRATION AND WASH FASTNESS PROPERTIES OF AZO DYES. DERIVED FROM ..... The dyeing of Cellulose Fibres Publication thrust,. London. Standard methods for determination of fastness properties of textiles and leather, 4th Edition. 1978. Soceity of dyers and ...

  4. Realization of a simulator for radon-222 underground migration studies

    International Nuclear Information System (INIS)

    Tidjani, A.; Seidel, J.L.; Monnin, M.; Isabelle, D.B.

    1987-01-01

    To study under controlled conditions the underground movements of radon gas a simulator has been built. It was designed in order to vary independently the different geophysical parameters such as pressure, temperature, humidity, type of soil and its granulometry, etc.. The first tests, described in this paper, have demonstrated the usefullness of such a simulator. (orig.)

  5. Cerebral migration of intraocular silicone oil: an MRI study

    DEFF Research Database (Denmark)

    Kiilgaard, Jens Folke; Milea, Dan; Løgager, Vibeke

    2011-01-01

    for retinal detachment. Methods: Nineteen patients included in this study were referred for silicone oil removal after uncomplicated retinal detachment surgery using internal silicone oil tamponade. Patients with a previous history of intraocular silicone oil, glaucoma or optic pit were excluded. After...

  6. Effects of Garlic Oil on the Migration of Neutrophil-Like Cell Studied by Using a Chemotactic Gradient Labchip

    Directory of Open Access Journals (Sweden)

    Po-Chen Shih

    2010-01-01

    Full Text Available We have designed and fabricated a novel chemotactic gradient Labchip for studying cell migration quantitatively. Owing to the great potential of garlic and its preparations in developing antiinflammatory drugs, the aim of the present study is to investigate the effect of garlic oil on the locomotion of a neutrophil-like cell by measuring the dynamic features of cell migration including migration direction, average migration speed, chemotactic index (CI, and motility index (MI with the newly designed Labchip. We found that garlic oil treatment lowered the values of CI and MI and reduced the average speed of cell migration from 13 to 8 μm/min. The results indicate that garlic oil is a potential inhibitor for neutrophil-like cell migration and chemotactic responsiveness. By comparing with the effects of nocodazole and cytochalasin B, we also suggest that the antiinflammatory activity exhibited by garlic oil was mainly through inhibiting the assembly-disassembly processes of the cytoskeleton.

  7. Study on the migration of radionuclide through geological media

    International Nuclear Information System (INIS)

    Park, Hun Hwee; Han, Kyung Won; Han, Pil Soo; Cho, Won Jin; Lee, Jae Owan; Park, Chung Kyun; Choi, Heui Joo; Lee, Youn Myoung; Yang, Ho Yeon

    1987-05-01

    In Korea, Two disposal alternatives such as shallow land burial and rock cavern disposal of low- and intermediate- level waste are most applaudable options currently receiving attention. For each disposal method, Safety assessment is necessary to estimate the performance of a disposal system and to predict probable radiological consequences. In the present study, rock cavern disposal method is proposed as a most favorable alternative in view of Korean situation

  8. Prenatal Characteristics of Infants with a Neuronal Migration Disorder: A National-Based Study

    Directory of Open Access Journals (Sweden)

    Estelle Naumburg

    2012-01-01

    Full Text Available The development of the central nervous system is complex and includes dorsal and ventral induction, neuronal proliferation, and neuronal migration, organization, and myelination. Migration occurs in humans in early fetal life. Pathogenesis of malformations of the central nervous system includes both genetic and environmental factors. Few epidemiological studies have addressed the impact of prenatal exposures. All infants born alive and included in the Swedish Medical Birth Register 1980–1999 were included in the study. By linkage to the Patient Register, 820 children with a diagnosis related to a neuronal migration abnormality were identified. Through copies of referrals for computer tomography or magnetic resonance imaging of the brain, the diagnosis was confirmed in 17 children. Median age of the mothers was 29 years. At the start of pregnancy, four out of 17 women smoked. Almost half of the women had a body mass index that is low or in the lower range of average. All infants were born at term with normal birth weights. Thirteen infants had one or more concomitant diseases or malformations. Two infants were born with rubella syndrome. The impact of low maternal body mass index and congenital infections on neuronal migration disorders in infants should be addressed in future studies.

  9. Electrokinetic migration studies on removal of chromium and uranyl ions from 904-A trench soil

    International Nuclear Information System (INIS)

    Bibler, J.P.; Meaker, T.F.; O'Steen, A.B.

    1992-01-01

    This report describes a laboratory-scale study, in which electrokinetic migration technology was used to remove chromium and uranium, as well as other ions, from soil taken from a bore hole adjacent to the 904-A trench at the Savannah River Technology Center. Imposition of an electric current on humid (not saturated) soil successfully caused cations to migrate through the pore water of the soil to the cathode, where they were captured in an ISOLOCKTm polymer matrix and in a cation exchange resin incorporated in the polymer. Chemicals circulated through the anode/polymer and cathode/polymer were able to control pH excursions in the electrokinetic-cells by reacting with the H + and OH - generated at the anode and cathode, respectively. The study indicates that ions adsorbed on the surface of the soil as well as those in the pores of soil particles can be caused to migrate through the soil to an appropriate electrode. After 10 days of operation at 20--25 V and 2 mA, approximately 65% of the chromium was removed from two 3.5 kg soil samples. A 57% removal of uranium was achieved. The study shows that electrokinetic migration, using the ISOLOCK trademark polymer will be effective as an in situ treatment method for the removal of metal ion contaminants in soil adjacent to the 904-A trench

  10. Studying the migration behaviour of radionuclides in boom clay by electromigration

    Energy Technology Data Exchange (ETDEWEB)

    Norbert Maes, H.; Moors, H.; Dierckx, A.; Aertsens, M.; Wang, L.; Canniere, P. de; Put, M. [SCK-CEN, Belgian Nuclear Research Centre, Waste and Disposal - R and D Geological Disposal Mol (Belgium)

    2001-07-01

    Migration studies are an important part in the assessment of the performance of the Boom Clay Formation as a candidate for geological disposal of High-Level radwaste in Belgium. However, classical diffusion experiments take a long time because of the excellent retention characteristics of the Boom Clay. Electrical fields can be used to move ionic species. Especially for low permeability soils/sediments (such as clays), this driving force is far more efficient than a hydraulic gradient. As a consequence, the experimental time can be reduced drastically. This paper gives an overview on the quantitative and qualitative use of electromigration as a powerful technique to study radionuclides migration in clays. The enormous time gain in the determination of migration parameters for strongly retarded radionuclides as {sup 137}Cs{sup +} and {sup 226}Ra{sup 2+} is first demonstrated. Secondly, we want to demonstrate that electromigration has some useful features to study the behaviour of radionuclides with a more complex chemistry like the redox sensitive element uranium and Am-Organic Matter (OM) complexes. In the case of uranium, electromigration provides information on the speciation of the migrating species while for the Am-organic Matter complexes the role of OM as a possible carrier of actinides is investigated. (orig.)

  11. Studying the migration behaviour of radionuclides in boom clay by electromigration

    International Nuclear Information System (INIS)

    Norbert Maes, H.; Moors, H.; Dierckx, A.; Aertsens, M.; Wang, L.; Canniere, P. de; Put, M.

    2001-01-01

    Migration studies are an important part in the assessment of the performance of the Boom Clay Formation as a candidate for geological disposal of High-Level radwaste in Belgium. However, classical diffusion experiments take a long time because of the excellent retention characteristics of the Boom Clay. Electrical fields can be used to move ionic species. Especially for low permeability soils/sediments (such as clays), this driving force is far more efficient than a hydraulic gradient. As a consequence, the experimental time can be reduced drastically. This paper gives an overview on the quantitative and qualitative use of electromigration as a powerful technique to study radionuclides migration in clays. The enormous time gain in the determination of migration parameters for strongly retarded radionuclides as 137 Cs + and 226 Ra 2+ is first demonstrated. Secondly, we want to demonstrate that electromigration has some useful features to study the behaviour of radionuclides with a more complex chemistry like the redox sensitive element uranium and Am-Organic Matter (OM) complexes. In the case of uranium, electromigration provides information on the speciation of the migrating species while for the Am-organic Matter complexes the role of OM as a possible carrier of actinides is investigated. (orig.)

  12. Psychosocial Studies of Migration and Community: Introduction to the Special Issue

    Directory of Open Access Journals (Sweden)

    Douglas D. Perkins

    2011-11-01

    Full Text Available Introducing the special issue on psychosocial studies of migration and community, we briefly reflect on the global increase in, and issues related to, both international and domestic migration, particularly from rural areas of less developed countries, which has fueled rapid urbanization and intercultural tensions in both post-industrial and developing countries. Topics covered in the issue are summarized, including an Italian study of the emotional impact of discrimination against immigrant adolescents; acculturation, integration and adaptation of Muslim immigrant youth in New Zealand; perceptions of human trafficking in Moldova; Chinese migrant workers´ social networks, life satisfaction and political participation; physician brain drain from sub-Saharan Africa; and a critical analysis of the oppressive and liberating impact of organizations on immigrants, multiculturalism, and social justice. The issue concludes with commentary articles by four leading international scholars of migration and community. The breadth of topics helps to address wide-ranging gaps in the literature, but more psychological and social research must connect ecologically across multiple levels and to cultural, political, economic, and environmental studies of migration and community.

  13. Study of strontium and cesium migration in fractured crystalline rock

    International Nuclear Information System (INIS)

    Gustafsson, E.; Klockars, C.E.

    1984-01-01

    The purpose of this investigation has been to study the retardation and dilution of non-active strontium and cesium relative to a non-absorbing substance (iodide) in a well-defined fracture zone in the Finnsjoen field research area. The investigation was carried out in a previously tracer-tested fracture zone. The study has encompassed two separate test runs with prolonged injection of strontium and iodide and of cesium and iodide. The test have shown that: - Strontium is not retarded, but rather absorbed to about 40% at equilibrium. - At injection stop, 36.3% of the injected mass of strontium has been absorbed and there is no deabsorption. -Cesium is retarded a factor of 2-3 and absorbed to about 30% at equilibrium. - At injection stop, 39.4% of the injected mass of cesium has been absorbed. Cesium is deabsorbed after injection stop (400h) and after 1300 hours, only 22% of the injected mass of cesium is absorbed. (author)

  14. A solid tissue phantom for photon migration studies

    International Nuclear Information System (INIS)

    Cubeddu, Rinaldo; Pifferi, Antonio; Taroni, Paola; Torricelli, Alessandro; Valentini, Gianluca

    1997-01-01

    A solid tissue phantom made of agar, Intralipid and black ink is described and characterized. The preparation procedure is fast and easily implemented with standard laboratory equipment. An instrumentation for time-resolved transmittance measurements was used to determine the optical properties of the phantom. The absorption and the reduced scattering coefficients are linear with the ink and Intralipid concentrations, respectively. A systematic decrease of the reduced scattering coefficient dependent on the agar content is observed, but can easily be managed. The phantom is highly homogeneous and shows good repeatability among different preparations. Moreover, agar inclusions can be easily embedded in either solid or liquid matrixes, and no artefacts are caused by the solid - solid or solid - liquid interfaces. This allows one to produce reliable and realistic inhomogeneous phantoms with known optical properties, particularly interesting for studies on optical imaging through turbid media. (author)

  15. Experimental Studies to Evaluate the Role of Colloids on the Radionuclide Migration in a Crystalline Medium

    International Nuclear Information System (INIS)

    Albarran, Nairoby; Missana, Tiziana; Alonso, Ursula; Garcia-Gutierrez, Miguel; Mingarro, Manuel; Lopez, Trinidad

    2008-01-01

    In a deep geological repository (DGR) of high level radioactive waste, all the possible phenomena affecting radionuclide migration have to be studied to assess its security over time. Colloids can play an important role for contaminant transport if the following conditions are fulfilled: colloids exist in a non negligible concentration, they are mobile and stable in the environment of interest, and they are able to adsorb radionuclides irreversibly. In this study, different transport experiments where performed to improve the knowledge on the main mechanisms affecting the radionuclide migration in the presence of colloids in a crystalline medium. Firstly, colloid stability was analysed and then transport experiments in an artificial granite longitudinal fracture were carried out. Synthetic colloids of different size and bentonite clay colloids were used to evaluate the effects of colloid size, charge, and water flow rate on their mobility. Results showed that both major importance of the water flow rate on the mobility of colloids and their recovery and a higher interaction of smaller particles with the surface. Finally, the migration behaviour of Sr, and Sr adsorbed onto bentonite colloids was compared. The elution curves of Sr adsorbed onto colloid were significantly different from the ones of Sr alone, pointing out that sorption/desorption mechanisms must be taken into account to understand the radionuclide migration in the fracture in the presence of colloids. (authors)

  16. A pilot study to assess adductor canal catheter tip migration in a cadaver model.

    Science.gov (United States)

    Leng, Jody C; Harrison, T Kyle; Miller, Brett; Howard, Steven K; Conroy, Myles; Udani, Ankeet; Shum, Cynthia; Mariano, Edward R

    2015-04-01

    An adductor canal catheter may facilitate early ambulation after total knee arthroplasty, but there is concern over preoperative placement since intraoperative migration of catheters may occur from surgical manipulation and result in ineffective analgesia. We hypothesized that catheter type and subcutaneous tunneling may influence tip migration for preoperatively inserted adductor canal catheters. In a male unembalmed human cadaver, 20 catheter insertion trials were divided randomly into one of four groups: flexible epidural catheter either tunneled or not tunneled; or rigid stimulating catheter either tunneled or not tunneled. Intraoperative patient manipulation was simulated by five range-of-motion exercises of the knee. Distance and length measurements were performed by a blinded regional anesthesiologist. Changes in catheter tip to nerve distance (p = 0.225) and length of catheter within the adductor canal (p = 0.467) were not different between the four groups. Two of five non-tunneled stimulating catheters (40 %) were dislodged compared to 0/5 in all other groups (p = 0.187). A cadaver model may be useful for assessing migration of regional anesthesia catheters; catheter type and subcutaneous tunneling may not affect migration of adductor canal catheters based on this preliminary study. However, future studies involving a larger sample size, actual patients, and other catheter types are warranted.

  17. Seizures, cysticercosis and rural-to-urban migration: the PERU MIGRANT study.

    Science.gov (United States)

    Gonzales, Isidro; Miranda, J Jaime; Rodriguez, Silvia; Vargas, Victor; Cjuno, Alfredo; Smeeth, Liam; Gonzalez, Armando E; Tsang, Victor C W; Gilman, Robert H; Garcia, Hector H

    2015-04-01

    To examine the prevalence of seizures, epilepsy and seropositivity to cysticercosis in rural villagers (cysticercosis-endemic setting), rural-to-urban migrants into a non-endemic urban shanty town and urban inhabitants of the same non-endemic shanty town. Three Peruvian populations (n = 985) originally recruited into a study about chronic diseases and migration were studied. These groups included rural inhabitants from an endemic region (n = 200), long-term rural-to-urban migrants (n = 589) and individuals living in the same urban setting (n = 196). Seizure disorders were detected by a survey, and a neurologist examined positive respondents. Serum samples from 981/985 individuals were processed for cysticercosis antibodies on immunoblot. Epilepsy prevalence (per 1000 people) was 15.3 in the urban group, 35.6 in migrants and 25 in rural inhabitants. A gradient in cysticercosis antibody seroprevalence was observed: urban 2%, migrant 13.5% and rural group 18% (P < 0.05). A similarly increasing pattern of higher seroprevalence was observed among migrants by age at migration. In rural villagers, there was strong evidence of an association between positive serology and having seizures (P = 0.011) but such an association was not observed in long-term migrants or in urban residents. In the entire study population, compared with seronegative participants, those with strong antibody reactions (≥ 4 antibody bands) were more likely to have epilepsy (P < 0.001). It is not only international migration that affects cysticercosis endemicity; internal migration can also affect patterns of endemicity within an endemic country. The neurological consequences of cysticercosis infection likely outlast the antibody response for years after rural-to-urban migration. © 2015 The Authors. Tropical Medicine & International Health Published by John Wiley & Sons Ltd.

  18. Study of the migration of metallic micropollutants in the soils by means of radioactive tracers

    International Nuclear Information System (INIS)

    Jacquemet, P.

    1995-01-01

    The aim of this work was to study the migration of metallic micropollutants using radioactive tracers. Three experimental techniques were employed to show the interaction phenomena linked to these migrations. First, a simple batch characterization allows the qualitative and quantitative evaluation of the sorption-desorption of the micropollutants on the soils. Next, an elution technique applied to soil columns was introduced to study the behavior of the pollutants in hydrodynamic conditions. Finally, a series of lysimetric pots were prepared to extend the experiment to systems which mimic a natural environment. The tests were conducted in a hot laboratory with five agricultural soils and seven pollutants ( 57 Co, 134 Cs, 123m Te, 109 Cd, 144 Ce, 85 Sr and 110m Ag). The batch measurements (kinetics, K d sorption ratio at equilibrium and isothermal measurements according to the Langmuir or Freundlich models) allowed for a better understanding of the sorption-desorption mechanisms of the micropollutants. Their migration on continuously percolated columns (breakthrough curves and determination of the radioactive profiles in the soils) was evaluated and expounded together with the results obtained from the batch characterization. The profiles of the radioactive tracers in the soils of the lysimeters (with or without vegetation) were also determined. All these observations were used to characterize the migration properties of the micropollutants in the investigated soils. A simple simulation model of the migration of interactive solutes in porous media based on dispersion and convection was also applied to the experimental data. The calculated profiles showed fairly good agreement with the experimental ones, especially in the case of unplanted systems. Several parametric adjustments were, however, necessary. It was shown, finally, that simulations, as perfect as they could be, can seldom replace the experimental studies of the behaviour of micropollutants in the

  19. State-of-the-art review of brine migration studies in salt. Technical memorandum report RSI-0075

    International Nuclear Information System (INIS)

    Gnirk, P.F.; Krause, W.B.; Fossum, A.F.

    1981-09-01

    This report provides a state-of-the-art review of brine migration studies in rock salt. Emphasis is placed on the review of literature relating to brine migration phenomena around nuclear waste canisters. This review includes experimental work which has been conducted in the laboratory and in the field. In addition to the literature review, some additional thoughts on brine migration are given and a series of laboratory experiments is proposed. The proposed laboratory experiments are designed to determine whether or not a relationship exists between brine migration and temperature, temperature gradient and stress in rock salt. 34 references, 9 figures, 3 tables

  20. Ab initio study of stability and migration of H and He in hcp-Sc

    International Nuclear Information System (INIS)

    Yang, L; Zu, X T; Peng, S M; Long, X G; Gao, F; Heinisch, H L; Kurtz, R J

    2011-01-01

    Ab initio calculations based on density functional theory have been performed to determine the relative stabilities and migration of H and He atoms in hcp-Sc. The results show that the formation energy of an interstitial H or He atom is smaller than that of a corresponding substitutional atom. The tetrahedral (T) interstitial position is more stable than an octahedral (O) position for both He and H interstitials. The nudged elastic band method has been used to study the migration of interstitial H and He atoms in hcp-Sc. It is found that the migration energy barriers for H interstitials in hcp-Sc are significantly different from those for He interstitials, but their migration mechanisms are similar. In addition, the formation energies of five different configurations of a H-H pair were determined, revealing that the most stable configuration consists of two H atoms located at the second-neighbor tetrahedral interstitial sites along the hexagonal direction. The formation and relative stabilities of some small He clusters have also been investigated.

  1. Differential S1P Receptor Profiles on M1- and M2-Polarized Macrophages Affect Macrophage Cytokine Production and Migration.

    Science.gov (United States)

    Müller, Jan; von Bernstorff, Wolfram; Heidecke, Claus-Dieter; Schulze, Tobias

    2017-01-01

    Introduction . Macrophages are key players in complex biological processes. In response to environmental signals, macrophages undergo polarization towards a proinflammatory (M1) or anti-inflammatory (M2) phenotype. Sphingosine 1-phosphate (S1P) is a bioactive lysophospholipid that acts via 5 G-protein coupled receptors (S1P 1-5 ) in order to influence a broad spectrum of biological processes. This study assesses S1P receptor expression on macrophages before and after M1 and M2 polarization and performs a comparative analysis of S1P signalling in the two activational states of macrophages. Methods . Bone marrow derived macrophages (BMDM) from C57 BL/6 mice were cultured under either M1- or M2-polarizing conditions. S1P-receptor expression was determined by quantitative RT-PCR. Influence of S1P on macrophage activation, migration, phagocytosis, and cytokine secretion was assessed in vitro. Results . All 5 S1P receptor subclasses were expressed in macrophages. Culture under both M1- and M2-polarizing conditions led to significant downregulation of S1P 1 . In contrast, M1-polarized macrophages significantly downregulated S1P 4 . The expression of the remaining three S1P receptors did not change. S1P increased expression of iNOS under M2-polarizing conditions. Furthermore, S1P induced chemotaxis in M1 macrophages and changed cytokine production in M2 macrophages. Phagocytosis was not affected by S1P-signalling. Discussion . The expression of different specific S1P receptor profiles may provide a possibility to selectively influence M1- or M2-polarized macrophages.

  2. Stratigraphic architecture of hydromagmatic volcanoes that have undergone vent migration: a review of Korean case studies

    Science.gov (United States)

    Sohn, Y.

    2011-12-01

    Recent studies show that the architecture of hydromagmatic volcanoes is far more complex than formerly expected. A number of external factors, such as paleohydrology and tectonics, in addition to magmatic processes are thought to play a role in controlling the overall characteristics and architecture of these volcanoes. One of the main consequences of these controls is the migration of the active vent during eruption. Case studies of hydromagmatic volcanoes in Korea show that those volcanoes that have undergone vent migration are characterized by superposition or juxtaposition of multiple rim deposits of partial tuff rings and/or tuff cones that have contrasting lithofacies characteristics, bed attitudes, and paleoflow directions. Various causes of vent migration are inferred from these volcanoes. Large-scale collapse of fragile substrate is interpreted to have caused vent migration in the Early Pleistocene volcanoes of Jeju Island, which were built upon still unconsolidated continental shelf sediments. Late Pleistocene to Holocene volcanoes, which were built upon a stack of rigid, shield-forming lava flows, lack features due to large-scale substrate collapse and have generally simple and circular morphologies either of a tuff ring or of a tuff cone. However, ~600 m shift of the eruptive center is inferred from one of these volcanoes (Ilchulbong tuff cone). The vent migration in this volcano is interpreted to have occurred because the eruption was sourced by multiple magma batches with significant eruptive pauses in between. The Yangpori diatreme in a Miocene terrestrial half-graben basin in SE Korea is interpreted to be a subsurface equivalent of a hydromagmatic volcano that has undergone vent migration. The vent migration here is inferred to have had both vertical and lateral components and have been caused by an abrupt tectonic activity near the basin margin. In all these cases, rimbeds or diatreme fills derived from different source vents are bounded by either

  3. Study of thermal-gradient-induced migration of brine inclusions in salt. Final report

    International Nuclear Information System (INIS)

    Olander, D.R.

    1984-08-01

    Natural salt deposits, which are being considered for high-level waste disposal, contain a small volume fraction of water in the form of brine inclusions distributed throughout the salt. Radioactive decay heating of the nuclear wastes will impose a temperature gradient on the surrounding salt which mobilizes the brine inclusions. Inclusions filled completely with brine (the all-liquid inclusions) migrate up the temperature gradient and eventually accumulate brine near the buried waste forms. The brine may slowly corrode or degrade the waste forms, which is undesirable. Therefore it is important to consider the migration of brine inclusions in salt under imposed temperature gradients to properly evaluate the performance of a future salt repository for nuclear wastes. The migration velocities of the inclusions were found to be dependent on temperature, temperature gradient, and inclusion shape and size. The velocities were also dictated by the interfacial mass transfer resistance at brine/solid interface. This interfacial resistance depends on the dislocation density in the crystal, which in turn, depends on the axial compressive loading of the crystal. At low axial loads, the dependence between the velocity and temperature gradient is nonlinear. At high axial loads, the interfacial resistance is reduced and the migration velocity depends linearly on the temperature gradient. All-liquid inclusions filled with mixed brines were also studied. For gas-liquid inclusions, helium, air and argon were compared. Migration studies were also conducted on single crystallites of natural salt as well as in polycrystalline natural salt samples. The behavior of the inclusions at large-ange grain boundaries was observed

  4. Study of thermal-gradient-induced migration of brine inclusions in salt. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Olander, D.R.

    1984-08-01

    Natural salt deposits, which are being considered for high-level waste disposal, contain a small volume fraction of water in the form of brine inclusions distributed throughout the salt. Radioactive decay heating of the nuclear wastes will impose a temperature gradient on the surrounding salt which mobilizes the brine inclusions. Inclusions filled completely with brine (the all-liquid inclusions) migrate up the temperature gradient and eventually accumulate brine near the buried waste forms. The brine may slowly corrode or degrade the waste forms, which is undesirable. Therefore it is important to consider the migration of brine inclusions in salt under imposed temperature gradients to properly evaluate the performance of a future salt repository for nuclear wastes. The migration velocities of the inclusions were found to be dependent on temperature, temperature gradient, and inclusion shape and size. The velocities were also dictated by the interfacial mass transfer resistance at brine/solid interface. This interfacial resistance depends on the dislocation density in the crystal, which in turn, depends on the axial compressive loading of the crystal. At low axial loads, the dependence between the velocity and temperature gradient is nonlinear. At high axial loads, the interfacial resistance is reduced and the migration velocity depends linearly on the temperature gradient. All-liquid inclusions filled with mixed brines were also studied. For gas-liquid inclusions, helium, air and argon were compared. Migration studies were also conducted on single crystallites of natural salt as well as in polycrystalline natural salt samples. The behavior of the inclusions at large-ange grain boundaries was observed.

  5. On The Possible Leakage of ET-RR1 Liquid Waste Tank: Hydrological and Migration Modes Studies

    Directory of Open Access Journals (Sweden)

    N. S. Mahmoud

    2005-01-01

    Full Text Available The first Egyptian (ET-RR1 research reactor has been in operation since 1961 at the Egyptian Atomic Energy Authority (EAEA Inshas site. Therefore, at present, it faces a serious problem due to aging equipment, especially those directly in contact with the environment such as the underground settling tanks of nuclear and radioactive waste. The possible leakage of radionuclides from these aging tanks and their migration to the aquifer was studied using instantaneous release.This study was done based on the geological and hydrological characteristics of the site, which were obtained from the hydrogeological data of 25 wells previously drilled at the site of the reactor[1]. These data were used to calculate the trend of water levels, hydraulic gradient, and formulation of water table maps from 1993–2002. This information was utilized to determine water velocity in the unsaturated zone.Radionuclides released from the settling tank to the aquifer were screened according to the radionuclides that have high migration ability and high activity. The amount of fission and activation products of the burned fuels that contaminated the water content of the reactor pool were considered as 10% of the original spent fuel. The radionuclides considered in this case were H-3, Sr-90, Zr-93, Tc-99, Cd-113, Cs-135, Cs-137, Sm-151, Pu-238, Pu-240, Pu-241, and Am-241.The instantaneous release was analyzed by theoretical calculations, taking into consideration the migration mechanism of the various radionuclides through the soil space between the tank bottom and the aquifer. The migration mechanism through the unsaturated zone was considered depending on soil type, thickness of the unsaturated zone, water velocity, and other factors that are specific for each radionuclide, namely retardation factor, which is the function of the specific distribution coefficient of each radionuclide. This was considered collectively as delay time. Meanwhile, the mechanism of

  6. MANAGING MIGRATION: TURKISH PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    İhsan GÜLAY

    2018-04-01

    Full Text Available Conducting migration studies is of vital importance to Turkey, a country which has been experiencing migration throughout history due to its “open doors policy”. The objective of this study is to evaluate the strategic management of migration in Turkey in order to deal with the issue of migration. The main focus of the study is Syrian migrants who sought refuge in Turkey due to the civil war that broke out in their country in April 2011. This study demonstrates the policies and processes followed by Turkey for Syrian migration flow in terms of the social acceptance and harmonisation of the migrants within a democratic environment. The study addresses some statistical facts and issues related to Syrian migration as it has become an integral part of daily life in Turkey. The study also reviews how human rights are protected in the migration process. The study will provide insights for developing sound strategic management policies for the migration issue.

  7. Human endogenous retrovirus W env increases nitric oxide production and enhances the migration ability of microglia by regulating the expression of inducible nitric oxide synthase.

    Science.gov (United States)

    Xiao, Ran; Li, Shan; Cao, Qian; Wang, Xiuling; Yan, Qiujin; Tu, Xiaoning; Zhu, Ying; Zhu, Fan

    2017-06-01

    Human endogenous retrovirus W env (HERV-W env) plays a critical role in many neuropsychological diseases such as schizophrenia and multiple sclerosis (MS). These diseases are accompanied by immunological reactions in the central nervous system (CNS). Microglia are important immunocytes in brain inflammation that can produce a gasotransmitter-nitric oxide (NO). NO not only plays a role in the function of neuronal cells but also participates in the pathogenesis of various neuropsychological diseases. In this study, we reported increased NO production in CHME-5 microglia cells after they were transfected with HERV-W env. Moreover, HERV-W env increased the expression and function of human inducible nitric oxide synthase (hiNOS) and enhanced the promoter activity of hiNOS. Microglial migration was also enhanced. These data revealed that HERV-W env might contribute to increase NO production and microglial migration ability in neuropsychological disorders by regulating the expression of inducible NOS. Results from this study might lead to the identification of novel targets for the treatment of neuropsychological diseases, including neuroinflammatory diseases, stroke, and neurodegenerative diseases.

  8. Migration to the GLUE 2.0 information schema in the LCG/EGEE/EGI production Grid

    International Nuclear Information System (INIS)

    Burke, Stephen; Field, Laurence; Horat, David

    2011-01-01

    The GLUE information schema has been in use in the LCG/EGEE production Grid since the first version was released in 2002. In 2008 a major redesign of GLUE, version 2.0, was defined in the context of the Open Grid Forum. The implementation of the publication and use of the new schema is a complex process which needs to be carefully managed to avoid any disruption to the production service, especially in the light of the end of the EGEE project and the transition to the new middleware and operational structures in EGI. In this paper we discuss the LDAP rendering of the schema, the upgrading of the Grid information system to allow both schemas to be used in parallel, the design and rollout of information providers, and the plans for migrating client software which uses the schema information. In particular we consider the implications for the specific requirements of the LCG project, especially regarding storage systems, accounting and monitoring.

  9. Programme of research into the management and storage of radioactive waste, nuclide migration studies, and mathematical modelling

    International Nuclear Information System (INIS)

    1982-01-01

    The progress of the work is reported under the headings: nuclide migration studies (nuclide-rock interactions; physico-chemical effects; field experiments; groundwater dating); mathematical modelling (calculation of steady groundwater flow using NAMMU; comparison of thermally and naturally driven flows near a radioactive waste repository; diffusion of radionuclides into a rock matrix; radionuclide migration). (U.K.)

  10. The Dynamics of Migration-Related Stress and Coping of Female Domestic Workers from the Philippines: An Exploratory Study

    NARCIS (Netherlands)

    van der Ham, A.J.; Ujano-Batangan, M.T.; Ignacio, R.; Wolffers, I.N.

    2015-01-01

    Female domestic workers face many migration-related stressors that affect their mental health, but we know little about the dynamics of stress and coping in different migration phases. This exploratory study aims to assess stress and coping of female migrant domestic workers from the Philippines in

  11. Long-term study of migration of volatile organic compounds from cross-linked polyethylene (PEX) pipes and effects on drinking water quality.

    Science.gov (United States)

    Lund, Vidar; Anderson-Glenna, Mary; Skjevrak, Ingun; Steffensen, Inger-Lise

    2011-09-01

    The objectives of this study were to investigate migration of volatile organic compounds (VOCs) from cross-linked polyethylene (PEX) pipes used for drinking water produced by different production methods, and to evaluate their potential risk for human health and/or influence on aesthetic drinking water quality. The migration tests were carried out in accordance with EN-1420-1, and VOCs were analysed by gas chromatography-mass spectrometry. The levels of VOC migrating from new PEX pipes were generally low, and decreasing with time of pipe use. No association was found between production method of PEX pipes and concentration of migration products. 2,4-di-tert-butyl phenol and methyl tert-butyl ether (MTBE) were two of the major individual components detected. In three new PEX pipes, MTBE was detected in concentrations above the recommended US EPA taste and odour value for drinking water, but decreased below this value after 5 months in service. However, the threshold odour number (TON) values for two pipes were similar to new pipes even after 1 year in use. For seven chemicals for which conclusions on potential health risk could be drawn, this was considered of no or very low concern. However, odour from some of these pipes could negatively affect drinking water for up to 1 year.

  12. The Rest of the Story: A Qualitative Study of Chinese and Indian Women's Graduate Education Migration

    Science.gov (United States)

    Yakaboski, Tamara

    2013-01-01

    Previous migration discourse views educational migration through narrowly defined push-pull forces, which ignores overseas graduate education as a path for maneuvering through restrictive gendered and cultural experiences. The purpose of this exploratory research is to expand migration research and view women's migration decisions as employing…

  13. Promotoras across the border: a pilot study addressing depression in Mexican women impacted by migration.

    Science.gov (United States)

    Edelblute, Heather B; Clark, Sandra; Mann, Lilli; McKenney, Kathryn M; Bischof, Jason J; Kistler, Christine

    2014-06-01

    The migration of working-aged men from Mexico to the United States fractures the family-centered support structures typical of Latin America and contributes to high levels of depression in women left behind in migratory sending communities in Mexico. Mujeres en Solidaridad Apoyandose (MESA) was developed to improve depression in women through social support in a resource poor setting. MESA is a promotora intervention that trains women in the community to lead social support groups over a five-week period. The MESA curriculum uses a combination of cognitive behavioral theory techniques, psychoeducation, and social support activities aimed at alleviating or preventing depression in women. Results from this pilot efficacy study (n = 39) show that depressed participants at baseline experienced declines in depression as measured by the Center for Epidemiologic Studies Depression Scale at follow-up. Other findings demonstrate the complexity behind addressing social support and depression for women impacted by migration in different ways.

  14. Critical look at studies of radionuclide migration in fractured granite cores

    Energy Technology Data Exchange (ETDEWEB)

    Isherwood, D.; Failor, R.

    1983-05-01

    A series of laboratory experiments studying radionuclide migration were conducted on eleven fractured granite cores from the Climax Stock at the Nevada Test Site. Failor et al (1982) discuss the equipment used, the preparation of the core, the experimental procedure, the data reduction, and the experimental results. They give estimates of the average fracture apertures, retardation values of /sup 85/Sr, /sup 95m/Tc, and /sup 137/Cs relative to /sup 3/H, and the percentage of each radionuclide retained in the core after each run. To determine the effect of fracture fill material and solution composition on radionuclide migration, they studied both natural and artificial fractures using either natural Climax ground water or distilled water. The results are summarized below along with a discussion of the problems inherent in the experiments and suggestions to minimize these problems.

  15. Critical look at studies of radionuclide migration in fractured granite cores

    International Nuclear Information System (INIS)

    Isherwood, D.; Failor, R.

    1983-05-01

    A series of laboratory experiments studying radionuclide migration were conducted on eleven fractured granite cores from the Climax Stock at the Nevada Test Site. Failor et al (1982) discuss the equipment used, the preparation of the core, the experimental procedure, the data reduction, and the experimental results. They give estimates of the average fracture apertures, retardation values of 85 Sr, /sup 95m/Tc, and 137 Cs relative to 3 H, and the percentage of each radionuclide retained in the core after each run. To determine the effect of fracture fill material and solution composition on radionuclide migration, they studied both natural and artificial fractures using either natural Climax ground water or distilled water. The results are summarized below along with a discussion of the problems inherent in the experiments and suggestions to minimize these problems

  16. Joint DOE/NRC field study of tracer migration in the unsaturated zone

    International Nuclear Information System (INIS)

    Nyhan, J.; Polzer, W.; Essington, E.; Cokal, E.; Lane, L.; Lopez, E.; Stallings, E.; Walker, R.

    1986-03-01

    The results of a joint DOE/NRC field experiment to evaluate leaching and transport of solutes in a sandy silt backfill used for shallow land burial operations at Los Alamos are presented for steady-state and unsteady-state flow conditions. The migration of iodide, bromide, and lithium through the backfill material is studied as functions of depth and time and they are compared with one another. The bromide and iodide tracer data are used to estimate the diffusion coefficient, the tortuosity factor, and dispersivity. These values are used to calculate effective dispersion coefficients for subsequent analyses of the retardation factor and the distribution coefficient for lithium using least squares procedures. The results of the tracer migration study are discussed relative to challenges facing the waste management community, and chemical transport modeling opportunities are presented for a modeling workshop to be held in FY86

  17. Application of centrifuge modelling and radiotracers to migration studies of buried toxic waste

    International Nuclear Information System (INIS)

    Villar, H.P.

    1995-01-01

    A new technique to study the migration of souble waste components in soils, based on the application of centrifugue modelling and of selected short-lived radiotracers, is presented. The technique is based on the acceleration of the migration proceses of a specific tracer in a soil model, with simple and well-established scaling laws being used to interpret the results. The use of radiotracers allows geat flexibility and the adoption of a wide range of concentrations. Demosntrations of the technique have been carried out with two elements of radically distinct behaviour: iodine noted for its mobility in soils, and thallium, which tends to be strongly sorbed. Two different soil types have been used. The results semed to confirm what is known about the behaviour of both elements, so that the feasibility of the technique for such studies has been concluded. (author). 7 refs, 4 figs, 1 tab

  18. Application of Geographic Information System (GIS) to Model the Hydrocarbon Migration: Case Study from North-East Malay Basin, Malaysia

    Science.gov (United States)

    Rudini; Nasir Matori, Abd; Talib, Jasmi Ab; Balogun, Abdul-Lateef

    2018-03-01

    The purpose of this study is to model the migration of hydrocarbon using Geographic Information System (GIS). Understanding hydrocarbon migration is important since it can mean the difference between success and failure in oil and gas exploration project. The hydrocarbon migration modeling using geophysical method is still not accurate due to the limitations of available data. In recent years, GIS has emerged as a powerful tool for subsurface mapping and analysis. Recent studies have been carried out about the abilities of GIS to model hydrocarbon migration. Recent advances in GIS support the establishment and monitoring of prediction hydrocarbon migration. The concept, model, and calculation are based on the current geological situation. The spatial data of hydrocarbon reservoirs is determined by its geometry of lithology and geophysical attributes. Top of Group E horizon of north-east Malay basin was selected as the study area due to the occurrence of hydrocarbon migration. Spatial data and attributes data such as seismic data, wells log data and lithology were acquired and processed. Digital Elevation Model (DEM) was constructed from the selected horizon as a result of seismic interpretation using the Petrel software. Furthermore, DEM was processed in ArcGIS as a base map to shown hydrocarbon migration in north-east Malay Basin. Finally, all the data layers were overlaid to produce a map of hydrocarbon migration. A good data was imported to verify the model is correct.

  19. Application of Geographic Information System (GIS to Model the Hydrocarbon Migration: Case Study from North-East Malay Basin, Malaysia

    Directory of Open Access Journals (Sweden)

    Rudini

    2018-01-01

    Full Text Available The purpose of this study is to model the migration of hydrocarbon using Geographic Information System (GIS. Understanding hydrocarbon migration is important since it can mean the difference between success and failure in oil and gas exploration project. The hydrocarbon migration modeling using geophysical method is still not accurate due to the limitations of available data. In recent years, GIS has emerged as a powerful tool for subsurface mapping and analysis. Recent studies have been carried out about the abilities of GIS to model hydrocarbon migration. Recent advances in GIS support the establishment and monitoring of prediction hydrocarbon migration. The concept, model, and calculation are based on the current geological situation. The spatial data of hydrocarbon reservoirs is determined by its geometry of lithology and geophysical attributes. Top of Group E horizon of north-east Malay basin was selected as the study area due to the occurrence of hydrocarbon migration. Spatial data and attributes data such as seismic data, wells log data and lithology were acquired and processed. Digital Elevation Model (DEM was constructed from the selected horizon as a result of seismic interpretation using the Petrel software. Furthermore, DEM was processed in ArcGIS as a base map to shown hydrocarbon migration in north-east Malay Basin. Finally, all the data layers were overlaid to produce a map of hydrocarbon migration. A good data was imported to verify the model is correct.

  20. Observations on the migration of bacillus spores outside a contaminated facility during a decontamination efficacy study

    Science.gov (United States)

    Silvestri, Erin E.; Perkins, Sarah; Lordo, Robert; Kovacik, William; Nichols, Tonya L.; Bowling, Charlena Yoder; Griffin, Dale W.; Schaefer, Frank W.

    2015-01-01

    The potential for an intentional wide-area or indoor release of Bacillus anthracis spores remains a concern, but the fate and transport of B. anthracis spores in indoor and outdoor environments are not well understood. Some studies have examined the possibility of spore transport within ventilation systems and in buildings and transport into a building following an outdoor release. Little research exists regarding the potential for spores to migrate to the outside of a building following an indoor release.

  1. Study of the migration of toxic metals in steelmaking waste using radioactive tracing

    International Nuclear Information System (INIS)

    Andre, C.; Jauzein, M.; Charentus, T.; Margrita, R.; Dechelette, O.

    1991-01-01

    The danger presented by toxic metals contained in steelmaking wastes put into slag piles may be neutralized by suitably chosen alternation of these wastes when they are deposited. Presentation of a study method using radioactive tracing of the migration of toxic metal (cadmium, zinc, chromium) in steelmaking wastes (slag, blast furnace sludge). This non destructive method was used in columns in the laboratory, but may be used in on-site slag piles [fr

  2. Radionuclide migration study in the case of a geological disposal site. Bibliographic research report

    International Nuclear Information System (INIS)

    Rio, Sophie

    1997-01-01

    The present bibliographic research deals with the study of radionuclide migration in the case of a geological disposal of spent fuel from PWR nuclear reactors. Bibliography was made with the DIALOG server on the following databases: INSPEC, NTIS, Ei Compendex Plus, SPIN, SciSearch, Pascal et Current Contents Search, and with the INIS and DocTheses CD-Roms. A synthesis based on a few documents is made in the second part of the report. (author) [fr

  3. Singapore Indian Eye Study-2: methodology and impact of migration on systemic and eye outcomes.

    Science.gov (United States)

    Sabanayagam, Charumathi; Yip, Wanfen; Gupta, Preeti; Mohd Abdul, Riswana Bb; Lamoureux, Ecosse; Kumari, Neelam; Cheung, Gemmy Cm; Cheung, Carol Y; Wang, Jie Jin; Cheng, Ching-Yu; Wong, Tien Yin

    2017-11-01

    Asian Indians are the fastest growing migration groups in the world. Studies evaluating the impact of migration on disease outcomes in this population are rare. We describe the methodology of the Singapore Indian Eye Study-2 (SINDI-2) aimed to evaluate the impact of migration status on diabetic retinopathy and other major age-related eye diseases in Asian Indians living in an urban environment. Population-based cohort study. A total of 2200 adults had participated in baseline SINDI (2007-2009, mean age [range] = 57.8 [42.7-84.1] years) and SINDI-2 (2013-2015, 56.5 [48.4-90.2] years). Participants were classified as 'first generation' if they were Indian residents born outside of Singapore and as 'second-generation' immigrants (59.7% in SINDI vs. 63.6% in SINDI-2) if they were born in Singapore. Response rate, participant characteristics and prevalence of systemic diseases were stratified by migration status. Of the 2914 eligible SINDI participants invited to participate, 2200 participated in SINDI-2 (response rate of 75.2%). In both SINDI and SINDI-2, compared with first-generation immigrants, second-generation immigrants were younger, less likely to have income <1000 SGD, had lower levels of pulse pressure, higher levels of high-density lipoprotein cholesterol, had lower prevalence of hypertension and chronic kidney disease and had higher prevalence of current smoking and obesity (all P < 0.05). In both SINDI and SINDI-2, second-generation immigrants had lower prevalence of cardiovascular risk factors except smoking and obesity compared with first-generation immigrants. The final report will confirm if these differences between generations are evident with regard to eye diseases. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

  4. Radionuclide migration experiments related to an underground nuclear test: II. modeling studies

    International Nuclear Information System (INIS)

    Tompson, A.; Carle, S.F.; Smith, D.K.; Hudson, G.B.; Bruton, C.J.

    2001-01-01

    Full text: The goal of this project is to improve our understanding of water and radionuclide migration in both saturated and unsaturated geologic media by coupling advanced simulation techniques, available characterization data, and radioanalytical measurements in the context of a remarkable field experiment. Between 1975 and 1991, groundwater was steadily pumped from a well adjacent to a 1965 underground test conducted in alluvium at the Nevada Test Site. The experiment was primarily conducted in order to elicit information on radionuclide migration through the saturated zone between the test and the well. The effluent was monitored. discharged to an unlined ditch, and allowed to infiltrate into the ground during flow towards a dry lake, about a kilometer away. The 16 years of pumping and infiltration created an unexpected second experiment in which the migration of the ditch effluent through the 200 meters of unsaturated media, back to the water table, could be studied. Pumping and effluent data are being utilized in conjunction with chemical measurements made in groundwater and a series of numerical models to better understand the movement of radionuclides in the system, both between the test and the well, and between the ditch and the water table. The release of radionuclides away from a testing area will be controlled by local groundwater flow rates, by their dissolution from solidified melt glass produced by the test, and by chemical sorption processes that retard their migration rates in chemically reactive geologic media. Only the more mobile and less reactive radionuclides (e.g.. tritium, 14 C, 36 Cl, 85 Kr, and 129 I) were measured in the well effluent. The movement of these radionuclides through the unsaturated media beneath the ditch will be affected additionally by the capillary nature of moisture movement under unsaturated conditions and by their interaction with and potential mass exchange with the gas (air) phase. Results of numerical simulations

  5. The Role of Organizations in Liberation Psychology: Applications to the Study of Migrations

    Directory of Open Access Journals (Sweden)

    Virginia Paloma

    2011-11-01

    Full Text Available The incorporation of an immigrant population in the receiving society often takes place in the context of asymmetrical power relationships between immigrants and other groups in society. This often reduces the chances of successfully fulfilling any goals or plans that immigrants may have for their lives in the new country. In this paper we analyze how the study of migration can be enriched by Liberation Psychology, a theoretical approach which calls for the transformation of society at all levels (structural, organizational and individual as a means to create social justice and conditions of well-being for all social groups. In addition, we analyze how the internal dynamics of several organizations working in the field of migration are actually helping to perpetuate the status quo. Finally, we highlight the potential role that organizations can play in the construction of a just multicultural society, using a Liberation Psychology approach.

  6. Two-Dimensional Numerical Study on the Migration of Particle in a Serpentine Channel

    Directory of Open Access Journals (Sweden)

    Yi Liu

    2018-01-01

    Full Text Available In this work, the momentum exchange scheme-based lattice Boltzmann method is adopted to numerically study the migration of a circular particle in a serpentine channel for the range of 20 ≤ Re ≤ 120. The effects of the Reynolds number, particle density, and the initial particle position are taken into account. Numerical results include the streamlines, particle trajectories, and final equilibrium positions. Close attention is also paid to the time it takes for the particle to travel in the channel. It has been found that the particle is likely to migrate to a similar equilibrium position irrespective of its initial position when Re is large. Furthermore, there exists a critical solid-to-fluid density ratio for which the particle travels fastest in the channel.

  7. Migration studies at the Savannah River Plant shallow land burial site

    International Nuclear Information System (INIS)

    Stone, J.A.; Oblath, S.B.; Hawkins, R.H.; Emslie, R.H.; Ryan, J.P. Jr.; King, C.M.

    1983-01-01

    Radionuclide migration from the Savannah River Plant low-level waste burial ground was studied in ongoing programs that provide generic data on a shallow land burial site in a humid region and support local waste disposal operations. Field, laboratory, and theoretical work continued in four areas. (1) Subsurface Monitoring: Groundwater around the burial ground was monitored for traces of radioactivity and mercury. (2) Lysimeter Tests: Gamma-emitting radionuclides were identified by sensitive methods in defense waste lysimeter percolate waters. Results from these and other lysimeters containing tritium, I-129, or Pu-239 sources are given. (3) Soil-Water Chemistry: Experiments on specific factors affecting migration of Cs-137 showed that potassium significantly increases cesium mobility, thus confirming observations with trench waters. Distribution coefficients for ruthenium were measured. (4) Transport Modeling: Efforts to refine and validate the SRL dose-to-man model continued. Transport calculations were made for tritium, Sr-90, Tc-99, and TRU radionuclides. 12 references, 3 tables

  8. Distance associated with marriage migration in a northern and a southern region of Bangladesh: an empirical study.

    Science.gov (United States)

    Rahman, Md Mizanur; Akter, Shamima; Rahman, Ataur

    2010-09-01

    This paper investigates the distribution of distance associated with marriage migration in the northern region of Rajshahi and the southern region of Khulna in Bangladesh. The study was conducted in 2007 on 2250 respondents who had migrated due to marriage. Of the wide variety of curves that fitted the distance-marriage/contact data, three are discussed: Pareto, exponential, and Pareto-exponential. Logistic regression models were used to identify the covariates of marriage distance migration. In general, the three functions work better for marriages, whereas Pareto-exponential functions are a superior fit for migrations and marriage distance. The models disclose that the distribution of distance is significantly associated with marriage migration (pPareto-exponential model was 100% stable and its shrinkage was 0.000000125. The main covariates associated with short-distance marriage migration were respondent's education, father's education and religion, whereas age at the time of marriage did not play a significant role in marriage migration. The risk of short-distance migration was greater in higher- than lower-educated Muslim families.

  9. TLR4 induces CREB-mediated IL-6 production via upregulation of F-spondin to promote vascular smooth muscle cell migration

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Guan-Lin [Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Graduate Institutes of Life Sciences, National Defense Medical Center, Taipei, Taiwan (China); Wu, Jing-Yiing [Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Yeh, Chang-Ching [Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Graduate Institutes of Life Sciences, National Defense Medical Center, Taipei, Taiwan (China); Kuo, Cheng-Chin, E-mail: kuocc@nhri.org.tw [Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan, Taiwan (China); Graduate Institutes of Life Sciences, National Defense Medical Center, Taipei, Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung, Taiwan (China)

    2016-05-13

    Toll-like receptor 4 (TLR4) is important in promoting inflammation and vascular smooth muscle cell (VSMC) migration, both of which contribute to atherosclerosis development and progression. But the mechanism underlying the regulation of TLR4 in VSMC migration remains unclear. Stimulation of VSMCs with LPS increased the cellular level of F-spondin which is associated with the regulation of proinflammatory cytokine production. The LPS-induced F-spondin expression depended on TLR4-mediated PI3K/Akt pathway. Suppression of F-spondin level by siRNA inhibited not only F-spondin expression but also LPS-induced phosphorylation of cAMP response element binding protein (CREB) and IL-6 expression, VSMC migration and proliferation as well as MMP9 expression. Moreover, suppression of CREB level by siRNA inhibited TLR4-induced IL-6 production and VSMC migration. Inhibition of F-spondin siRNA on LPS-induced migration was restored by addition of exogenous recombinant mouse IL-6. We conclude that upon ligand binding, TLR4 activates PI3K/Akt signaling to induce F-spondin expression, subsequently control CREB-mediated IL-6 production to promote VSMC migration. These findings provide vital insights into the essential role of F-spondin in VSMC function and will be valuable for developing new therapeutic strategies against atherosclerosis. -- Highlights: •LPS-induced F-spondin expression of VSMCs is via a TLR4/PI3K/Akt signaling. •F-spondin is pivotal for LPS-induced CREB-mediated IL-6 production. •F-spondin is required for LPS-induced VSMC migration and proliferation.

  10. TLR4 induces CREB-mediated IL-6 production via upregulation of F-spondin to promote vascular smooth muscle cell migration

    International Nuclear Information System (INIS)

    Lee, Guan-Lin; Wu, Jing-Yiing; Yeh, Chang-Ching; Kuo, Cheng-Chin

    2016-01-01

    Toll-like receptor 4 (TLR4) is important in promoting inflammation and vascular smooth muscle cell (VSMC) migration, both of which contribute to atherosclerosis development and progression. But the mechanism underlying the regulation of TLR4 in VSMC migration remains unclear. Stimulation of VSMCs with LPS increased the cellular level of F-spondin which is associated with the regulation of proinflammatory cytokine production. The LPS-induced F-spondin expression depended on TLR4-mediated PI3K/Akt pathway. Suppression of F-spondin level by siRNA inhibited not only F-spondin expression but also LPS-induced phosphorylation of cAMP response element binding protein (CREB) and IL-6 expression, VSMC migration and proliferation as well as MMP9 expression. Moreover, suppression of CREB level by siRNA inhibited TLR4-induced IL-6 production and VSMC migration. Inhibition of F-spondin siRNA on LPS-induced migration was restored by addition of exogenous recombinant mouse IL-6. We conclude that upon ligand binding, TLR4 activates PI3K/Akt signaling to induce F-spondin expression, subsequently control CREB-mediated IL-6 production to promote VSMC migration. These findings provide vital insights into the essential role of F-spondin in VSMC function and will be valuable for developing new therapeutic strategies against atherosclerosis. -- Highlights: •LPS-induced F-spondin expression of VSMCs is via a TLR4/PI3K/Akt signaling. •F-spondin is pivotal for LPS-induced CREB-mediated IL-6 production. •F-spondin is required for LPS-induced VSMC migration and proliferation.

  11. Employment status and psychological distress in a population-based cross-sectional study in Sweden: the impact of migration.

    Science.gov (United States)

    Sidorchuk, Anna; Engström, Karin; Johnson, Charisse M; Kayser Leeoza, Naima; Möller, Jette

    2017-04-07

    Unemployment and temporary employment are known to impact psychological health. However, the extent to which the effect is altered by migration-related and sociodemographic determinants is less clear. The purpose of this study was to investigate whether the association between employment status and psychological distress differs between immigrants and Swedish-born and to what extent, the association is modified by gender and reason for immigration. Cross-sectional survey study. Data from public health surveys undertaken in 2002, 2006 and 2010 from random samples of Stockholm County residents, Sweden, were used to analyse a weighted sample of 51 118 individuals aged 18-64 (43 444 Swedish-born, 4055 non-refugees, 3619 refugees). According to their activity in the labour market, the participants were categorised into permanently/self-employed, temporarily employed and unemployed. Associations between self-reported employment and psychological distress measured by a 12-item version of the General Health Questionnaire were explored across individuals with different migration status and reasons for immigration using logistic regression and pairwise comparisons. The analyses were stratified by gender and adjusted for age, socioeconomic characteristics and survey year. Unemployment was associated with elevated likelihood of psychological distress across the study population, regardless of migration status and gender. Fully adjusted models revealed nearly a 3-fold higher odds of distress in unemployed Swedish-born (OR 3.05, 95% CI 2.66 to 3.51), non-refugees (OR 3.51, 95% CI 2.44 to 5.05) and refugees (OR 2.91, 95% CI 2.20 to 3.85) when compared with permanently/self-employed. Temporary employment also increased the likelihood of distress, particularly among refugees and Swedish-born. The effect of unemployment on increased likelihood of poor psychological well-being overcomes gender-specific and migration-specific differences and is equally pronounced for Swedish

  12. Comparative study on the migration of di-2-ethylhexyl phthalate (DEHP) and tri-2-ethylhexyl trimellitate (TOTM) into blood from PVC tubing material of a heart-lung machine.

    Science.gov (United States)

    Eckert, Elisabeth; Münch, Frank; Göen, Thomas; Purbojo, Ariawan; Müller, Johannes; Cesnjevar, Robert

    2016-02-01

    Medical devices like blood tubing often consist of PVC material that requires the addition of plasticizers. These plasticizers may migrate into the blood leading to an exposure of the patients. In this study the migration behavior of three different blood tubing sets (PVC material with two different plasticizers and silicone as control material) applied on a heart-lung machine standardly used for cardiopulmonary bypass (CPB) in children was studied. We analyzed the total plasticizer migration by analysis of both, the parent compounds as well as their primary degradation products in blood. Additionally, the total mass loss of the tubing over perfusion time was examined. The PVC tubing plasticized with DEHP (di-2-ethylhexyl phthalate) was found to have the highest mass loss over time and showed a high plasticizer migration rate. In comparison, the migration of TOTM (tri-2-ethylhexyl trimellitate) and its primary degradation products was found to be distinctly lower (by a factor of approx. 350). Moreover, it was observed that the storage time of the tubing affects the plasticizer migration rates. In conclusion, the DEHP substitute TOTM promises to be an effective alternative plasticizer for PVC medical devices particularly regarding the decreased migration rate during medical procedures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. A report on intercomparison studies of computer programs which respectively model: i) radionuclide migration ii) equilibrium chemistry of groundwater

    International Nuclear Information System (INIS)

    Broyd, T.W.; McD Grant, M.; Cross, J.E.

    1985-01-01

    This report describes two intercomparison studies of computer programs which respectively model: i) radionuclide migration ii) equilibrium chemistry of groundwaters. These studies have been performed by running a series of test cases with each program and comparing the various results obtained. The work forms a part of the CEC MIRAGE project (MIgration of RAdionuclides in the GEosphere) and has been jointly funded by the CEC and the United Kingdom Department of the Environment. Presentations of the material contained herein were given at plenary meetings of the MIRAGE project in Brussels in March, 1984 (migration) and March, 1985 (equilibrium chemistry) respectively

  14. A DC-81-indole conjugate agent suppresses melanoma A375 cell migration partially via interrupting VEGF production and stromal cell-derived factor-1α-mediated signaling

    International Nuclear Information System (INIS)

    Hsieh, Ming-Chu; Hu, Wan-Ping; Yu, Hsin-Su; Wu, Wen-Chuan; Chang, Long-Sen; Kao, Ying-Hsien; Wang, Jeh-Jeng

    2011-01-01

    Pyrrolo[2,1-c][1,4]benzodiazepine (PBD) chemicals are antitumor antibiotics inhibiting nucleic acid synthesis. An indole carboxylate-PBD hybrid with six-carbon spacer structure (IN6CPBD) has been previously demonstrated to induce melanoma cell apoptosis and reduce metastasis in mouse lungs. This study aimed at investigating the efficacy of the other hybrid compound with four-carbon spacer (IN4CPBD) and elucidating its anti-metastatic mechanism. Human melanoma A375 cells with IN4CPBD treatment underwent cytotoxicity and apoptosis-associated assays. Transwell migration assay, Western blotting, and ELISA were used for mechanistic study. IN4CPBD exhibited potent melanoma cytotoxicity through interrupting G1/S cell cycle progression, increasing DNA fragmentation and hypodipoidic DNA contents, and reducing mitochondrial membrane potential. Caspase activity elevation suggested that both intrinsic and extrinsic pathways were involved in IN4CPBD-induced melanoma apoptosis. IN4CPBD up-regulated p53 and p21, thereby concomitantly derailing the equilibrium between Bcl-2 and Bax levels. Transwell migration assay demonstrated that stromal cell-derived factor-1α (SDF-1α) stimulated A375 cell motility, while kinase inhibitors treatment confirmed that Rho/ROCK, Akt, ERK1/2, and p38 MAPK pathways were involved in SDF-1α-enhanced melanoma migration. IN4CPBD not only abolished the SDF-1α-enhanced chemotactic motility but also suppressed constitutive MMP-9 and VEGF expression. Mechanistically, IN4CPBD down-regulated Akt, ERK1/2, and p38 MAPK total proteins and MYPT1 phosphorylation. In conclusion, beyond the fact that IN4CPBD induces melanoma cell apoptosis at cytotoxic dose, the interruption in the VEGF expression and the SDF-1α-related signaling at cytostatic dose may partially constitute the rationale for its in vivo anti-metastatic potency. - Research highlights: → A novel carboxylate-PBD hybrid as anti-melanoma drug. → IN4CPBD interrupts melanoma cell cycle progression

  15. Clonorchis sinensis excretory-secretory products promote the migration and invasion of cholangiocarcinoma cells by activating the integrin β4-FAK/Src signaling pathway.

    Science.gov (United States)

    Pak, Jhang Ho; Bashir, Qudsia; Kim, In Ki; Hong, Sung-Jong; Maeng, Sejung; Bahk, Young Yil; Kim, Tong-Soo

    2017-06-01

    Cholangiocarcinoma (CCA) is a slow-growing but highly metastatic cancer. Its metastatic potential largely explains its high mortality rate. A recognized risk factor for CCA development is infection with the liver flukes Opisthorchis viverrini and Clonorchis sinensis. We previously reported that the excretory-secretory products (ESPs) of C. sinensis promoted the three-dimensional aggregation and invasion of CCA cells. In the present study, a quantitative real-time PCR array of extracellular matrix (ECM) and adhesion molecules was used to examine the regulatory mechanism of ESP-mediated CCA cell migration and invasion. In particular, the expression levels of integrin α isoforms and β4 were upregulated in response to ESPs. Increased expression of integrin β4 was probably correlated with activation of focal adhesion kinase (FAK) and the steroid receptor coactivator (Src) family kinase and the subsequent activation of two downstream focal adhesion molecules, paxillin and vinculin. Moreover, inhibition of FAK/Src activation reduced paxillin and vinculin phosphorylation and attenuated ESP-induced CCA cell migration and invasion. These findings suggest that the integrin β4-FAK/Src signaling axis may play a crucial role in clonorchiasis-associated CCA metastasis during tumor progression. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Modeling of corrosion product migration in the secondary circuit of nuclear power plants with WWER-1200

    Science.gov (United States)

    Kritskii, V. G.; Berezina, I. G.; Gavrilov, A. V.; Motkova, E. A.; Zelenina, E. V.; Prokhorov, N. A.; Gorbatenko, S. P.; Tsitser, A. A.

    2016-04-01

    Models of corrosion and mass transfer of corrosion products in the pipes of the condensate-feeding and steam paths of the secondary circuit of NPPs with WWER-1200 are presented. The mass transfer and distribution of corrosion products over the currents of the working medium of the secondary circuit were calculated using the physicochemical model of mass transfer of corrosion products in which the secondary circuit is regarded as a cyclic system consisting of a number of interrelated elements. The circuit was divided into calculated regions in which the change in the parameters (flow rate, temperature, and pressure) was traced and the rates of corrosion and corrosion products entrainment, high-temperature pH, and iron concentration were calculated. The models were verified according to the results of chemical analyses at Kalinin NPP and iron corrosion product concentrations in the feed water at different NPPs depending on pH at 25°C (pH25) for service times τ ≥ 5000 h. The calculated pH values at a coolant temperature t (pH t ) in the secondary circuit of NPPs with WWER-1200 were presented. The calculation of the distribution of pH t and ethanolamine and ammonia concentrations over the condensate feed (CFC) and steam circuits is given. The models are designed for developing the calculation codes. The project solutions of ATOMPROEKT satisfy the safety and reliability requirements for power plants with WWER-1200. The calculated corrosion and corrosion product mass transfer parameters showed that the model allows the designer to choose between the increase of the correcting reagent concentration, the use of steel with higher chromium contents, and intermittent washing of the steam generator from sediments as the best solution for definite regions of the circuit.

  17. Study on water migration of tunnel surrounding rock in nuclear waste repository based on coupling theory

    International Nuclear Information System (INIS)

    Jiang Zhongming; Zhang Xinmin

    2008-01-01

    Excavation of tunnel changes not only the stresses and deformation of tunnel surrounding rock, but also disturbs the underground water environment in tunnel surrounding rock Water migration happens due to variation of pore water pressure and redistribution. Based on the mechanics of porous media, saturated and unsaturated hydro-mechanical coupling analysis method is employed to study the variation of the stresses, deformation and pore pressure of the surrounding rock. Case study indicates that the excavation of tunnel will induce redistribution of stress and pore water pressure. Redistribution of pore water pressure will seriously affect on evaluation of surrounding rock stability and diffusion of nucleon in the pore water. (authors)

  18. Migration and self-esteem: a qualitative study among internal migrant girls in Turkey.

    Science.gov (United States)

    Altinyelken, Hulya Kosar

    2009-01-01

    This article examining the impact of migration experience on self-esteem of girls enrolled at primary schools in Turkey. It is based on a broader study that explored educational and coping strategies of internal migrant girls living in a suburban town in the western part of Turkey. The study showed that students encountered a variety of challenges in their new school environment including adaptation, language, low socioeconomic background, peer relations, discrimination, and bullying. These challenges seemed to have a direct or indirect influence on the educational experiences of migrant girls, undermining their self-esteem in multiple and complex ways.

  19. Mid-term migration analysis of a femoral short-stem prosthesis: a five-year EBRA-FCA-study.

    Science.gov (United States)

    Freitag, Tobias; Fuchs, Michael; Woelfle-Roos, Julia V; Reichel, Heiko; Bieger, Ralf

    2018-05-01

    The objective of this study was to evaluate the mid-term migration pattern of a femoral short stem. Implant migration of 73 femoral short-stems was assessed by Ein-Bild-Roentgen-Analysis Femoral-Component-Analysis (EBRA-FCA) 5 years after surgery. Migration pattern of the whole group was analysed and compared to the migration pattern of implants "at risk" with a subsidence of more than 1.5 mm 2 years postoperative. Mean axial subsidence was 1.1 mm (-5.0 mm to 1.5 mm) after 60 months. There was a statistical significant axial migration until 2 years postoperative with settling thereafter. 2 years after surgery 18 of 73 Implants were classified "at risk." Nevertheless, all stems showed secondary stabilisation in the following period with no implant failure neither in the group of implants with early stabilisation nor the group with extensive early onset migration. In summary, even in the group of stems with more pronounced early subsidence, delayed settling occurred in all cases. The determination of a threshold of critical early femoral short stem subsidence is necessary because of the differing migration pattern described in this study with delayed settling of the Fitmore stem 2 years postoperatively compared to early settling within the first postoperative year described for conventional stems.

  20. The impact of economic factors on migration considerations among Icelandic specialist doctors: a cross-sectional study.

    Science.gov (United States)

    Solberg, Ingunn Bjarnadóttir; Tómasson, Kristinn; Aasland, Olaf; Tyssen, Reidar

    2013-12-18

    Globalization has facilitated the employability of doctors almost anywhere in the world. In recent years, the migration of doctors seems to have increased. However, we lack studies on doctors' migration from developed countries. Because the economic recession experienced by many countries might have affected the migration of doctors, research on this topic is important for the retention of doctors. Iceland was hit hard by the economic recession in 2008. Therefore, we want to explore how many specialist doctors in Iceland have considered migrating and whether economic factors at work and in private life, such as extensive cost-containment initiatives at work and worries about personal finances, are related to doctors' migration considerations. In 2010, all doctors in Iceland registered with the Icelandic Medical Association were sent an electronic cross-sectional survey by email. The 467 specialists who participated in this study represent 55% of all specialist doctors working in Iceland. Information on doctors' contemplation of migration was available from responses to the question: "Have you considered moving and working abroad?" The predictor variables in our logistic regression model are perceived cost-containment initiatives at work, stress related to personal finances, experience of working abroad during vacations, job dissatisfaction, job position, age, and gender. Sixty-three per cent of Iceland's specialist doctors had considered relocation abroad, 4% were moving in the next year or two, and 33% had not considered relocating. Logistic regression analysis shows that, controlling for age, gender, job position, job satisfaction, and experience of working abroad during vacations, doctors' migration considerations were significantly affected by their experiences of cost-containment initiatives at work (odds ratio (OR) = 2.0, p Economic factors affect whether specialist doctors in Iceland consider migration. More studies on the effect of economic recession

  1. Migration, unemployment and the urban labour market. A case study of the Sudan.

    Science.gov (United States)

    Oberai, A S

    1977-01-01

    Investigation of migration, unemployment, and the urban labor in Sudan was based on the Household Socioeconomic Survey of Greater Khartoum, conducted in October-November 1974. The survey sample consisted of 15,339 persons, 8904 of whom were natives of the 3 towns (Greater Khartoum) and 6435 were immigrants. Among the latter were 976 children below 12 years of age from whom no migration information was collected. Adult migrants were further subdivided into those who had migrated during the 5 years preceding the survey (947) and those who had migrated 5 or more years previously (4512). During the 5 years preceding the survey, the rate of migration into the 3 towns was of the order of 2.2% per annum. Over 80% of the migrants came from 9 of the 12 northern and central provinces. The 3 southern provinces contributed few migrants to the area. 47% of the recent migrants stated that their last place of residence had been a rural area; 53% reported an urban area. Among recent migrants, 69% of the males and 67% of the females were between the ages of 15-29. Only 4% of the males and 11% of the females were over 50. The migrants had a significantly higher level of education than the average population in the northern and central provinces where most of them originated, but this does not mean that they were necessarily better educated than the native population of the 3 towns. Of the 947 recent migrants, 354 had been working before the move. Of these the great majority, 73% had been in agriculture, 8% in services, 6% in trade, and 3% in construction. 18% of those working before the move were private employees, 6% government employees, and the remaining 76% either self employed or unpaid family workers. In this last category 82% of the self employed and 97% of the unpaid family workers had been in agriculture. The principal pull factors seemed to have been higher average annual earnings, job availability, better educational opportunities, and the low cost of migration due to the

  2. A validation study for the gas migration modelling of the compacted bentonite using existing experiment data

    International Nuclear Information System (INIS)

    Tawara, Y.; Mori, K.; Tada, K.; Shimura, T.; Sato, S.; Yamamoto, S.; Hayashi, H.

    2010-01-01

    Document available in extended abstract form only. After the field-scaled Gas Migration Test (GMT) was carried out at Grimsel Test Site (GTS) in Switzerland from 1997 through 2005, a study on advanced gas migration modelling has been conducted as a part of R and D programs of the RWMC (Radioactive Waste Management funding and Research Center) to evaluate long-term behaviour of the Engineered Barrier System (EBS) for the TRU waste disposal system in Japan. One of main objectives of this modelling study is to provide the qualified models and parameters in order to predict long-term gas migration behaviour in compacted bentonite. In addition, from a perspective of coupled THMC (Thermal, Hydrological, Mechanical and Chemical) processes, the specific processes which may have considerable impact to the gas migration behaviour are discussed by means of scoping calculations. Literature survey was conducted to collect experimental data related to gas migration in compacted bentonite in order to discuss an applicability of the existing gas migration models in the bentonite. The well-known flow rate controlled-gas injection experiment by Horseman, et al. and the pressure-controlled-gas injection test using several data with wide range of clay density and water content by Graham, et al, were selected. These literatures show the following characteristic behaviour of gas migration in high compacted and water-saturated bentonite. The observed gas flow rate from the outlet in the experiment by Horseman et al. was numerically reproduced by using the different conceptual models and computer codes, and then an applicability of the models and the identified key parameters such as relative permeability and capillary pressure were discussed. Helium gas was repeatedly injected into fully water-saturated and isotropically consolidated MX-80 bentonite (dry density: 1.6 Mg/m 3 ) in the experiment. One of the most important conclusions from this experiment is that it's impossible for

  3. Evidence of cormorant-induced mortality, disparate migration strategies and repeatable circadian rhythm in the endangered North Sea houting (Coregonus oxyrinchus ): A telemetry study mapping the postspawning migration

    DEFF Research Database (Denmark)

    Jensen, Lasse Fast; Rognon, Paul; Aarestrup, Kim

    2017-01-01

    constrained navigation through the lakes. The migration into the Wadden Sea correlated with temperature perhaps indicating osmoregulatory constraints of sea entry. Unlike most salmonid species, migration occurred both day and night. Moreover, fish exhibited repeatable individual differences in diel activity...

  4. Conflict-induced Migration of Composers: An Individual-level Study

    DEFF Research Database (Denmark)

    Borowiecki, Karol Jan

    2013-01-01

    Research on the causes of conflict-induced migration is hindered by the lack of adequately disaggregated data. The underlying study overcomes this problem by employment of historical data on 164 prominent classical composers born after 1800. We analyze the impact of war on the probability to emig...... responses to war based on individual’s quality. While the better composers are more likely to emigrate in times of peace, it is not so anymore if a war breaks out. In times of war, all artists are affected by war and are prone to emigrate....

  5. A study on the radionuclide migration by means of the code LISA

    International Nuclear Information System (INIS)

    Frenquellucci, F.; Deserti, M.

    1989-01-01

    LISA code (Long Term Isolation Safety Assessment) has been developed by J.R.C. EUROATOM Ispra (Radiochemistry Division) and it's utilized in order to study migration of radionuclides through porous media. Aim of the present work is to analyze LISA's input and output files. A brief description of the code is also performed. As LISA is a research and in development code, its structure is rather complex and an exhaustive description of input/output files is helpful for the user. Version 3 of LISA code, loaded on ENEA's IBM 3090, is avaylable by ENEA-VEL Bologna

  6. Studies of migration and dispersion of radionuclides from the storage of radioactive wastes

    International Nuclear Information System (INIS)

    Dlouhy, Z.

    1976-08-01

    Conditions were tested under which fixed low level liquid radioactive wastes could be safely stored in geological formations of Czechoslovakia. Geological models were constructed to yield relatively accurate information on the migration and dispersion properties of some soils and rock formation in both static and dynamic conditions. Based on results of the models further testing was conducted under field conditions. The principal radionuclides used during the tests were 90 Sr and 137 Cs. Relative transport and dispersion data are provided for various of the earth studied groups and an assessment of the various sites provided in the report

  7. An international labour migration to developing countries in Asia: a case study of Korea.

    Science.gov (United States)

    Kim, J K

    1996-12-01

    This study is based on a random sample of 431 temporary migrant workers from developing countries in Korea. Interviews were conducted from mid-October 1995 to mid-March 1996 with 105 Pakistanis, 77 Filipinos, 71 Sri Lankans, 67 Bangladeshi, 40 Indonesians, 26 individuals from Myanmar, 22 Chinese, 16 Nepalese, 2 Iranians, 2 Kazakstanians, 1 Malaysian, 1 Vietnamese, and 1 Ghanaian. Migration follows legal and illegal patterns. Legal trainee migrants leave before their contract time due to low pay, inadequate living conditions, forced overtime work, and lack of freedom. Trainees tend to be ethnic Koreans born in China and Chinese nationals. The number of illegal migrants is increasing. Foreign workers gain entry illegally through smuggling networks and legally through industrial work or tourist visas. Sample data reveal that the average age ranged from 26 to 32 years. Almost 70% were unmarried, and most were males. Filipinos tended to be older and show gender and marital balance. Age, marital status, religion, and education varied widely by ethnic group. Indonesians and Sri Lankans had lower household income than Pakistanis and Filipinos. Pakistanis tended to come from larger families. Total travel costs ranged from $3000 to $5000. Korea is one of four rapidly developing countries that shifted from being a major exporter of labor to a major importer of workers. Shortages of workers accompanied the shift. This case study illustrates that the traditional structural paradigm does not explain some unique features of international labor migration (ILM) in Asia, including the encouragement of illegal migration. The clandestine networks are different from those in developed countries. State policies mediate the flow of ILM.

  8. The dynamics of migration-related stress and coping of female domestic workers from the Philippines: an exploratory study.

    Science.gov (United States)

    van der Ham, Alida Joanna; Ujano-Batangan, Maria Theresa; Ignacio, Raquel; Wolffers, Ivan

    2015-01-01

    Female domestic workers face many migration-related stressors that affect their mental health, but we know little about the dynamics of stress and coping in different migration phases. This exploratory study aims to assess stress and coping of female migrant domestic workers from the Philippines in different phases of the migration process; prior to migration, in the country of destination and upon return to the Philippines. Data were collected in 2010 using questionnaires (N = 500). Validation of findings took place in a work shop (23 participants) and two focus groups (13 and 8 participants). Stress levels of women were significantly higher abroad than in the Philippines. Stress and coping in the Philippines was primarily related to financial issues, while stress and coping abroad related more strongly loneliness, working conditions and employers. Findings from this study provide insight in the phase-specific and transnational dimensions of stress and coping.

  9. Migration of persons between households in rural Alaska: considerations for study design

    Directory of Open Access Journals (Sweden)

    Dana Bruden

    2013-08-01

    Full Text Available Introduction. Recent epidemiologic research studies in rural Alaska have examined risk factors for infectious diseases collected at the household level. Examples include the health effects of in-home piped water and household air quality. Because the exposure is measured at the household level, it is necessary to determine if participants remained in the same house throughout the course of follow-up. Methods. We used data from a pneumococcal nasopharyngeal carriage study in 8 rural Alaska villages [3 regions; average number of persons: 642 (min 210, max 720 per village to quantify changes in household membership and individual movements from 2008 to 2010. We define a household as a group of individuals living in a home together. Because the same households participated in carriage surveys over several years, we could determine changes on an annual basis. We calculated the percentage of households with a ≥1 person change in household members from year to year. Additionally, we present the percentage of individuals that changed households during consecutive years. Results. In 3 regions of Alaska, the average household size was 5 persons. Between 2008 and 2009, 50% (250/497 of households had a change in their membership (≥1 person in-migrated or out-migrated. Fifty-three percent of households experienced some migration of their members between 2009 and 2010. A total of 27 and 15% of households had a change of ≥2 and ≥3 persons, respectively. The percentage of households with movement was similar among the 3 rural regions and varied from 42 to 63% between villages. At the individual level, an average of 11% of persons changed households between years. The group with the most movement between houses was persons 18–29 years of age (19%, and least movement was in 5–10 and 50–64 years of age (6%. There was no difference in movement by gender. Conclusions. In rural Alaska, 52% of households experienced movement of members between years and

  10. Transnationality and Social Integration within Lifestyle Migration. A comparative study of two cases in Mexico and Spain

    OpenAIRE

    Lizarraga, Omar; Mantecón Terán, Alejandro; Huete Nieves, Raquel

    2015-01-01

    International mobility in search of amenity spaces for long-stay tourism is a growing phenomenon. U.S. citizens have practiced this lifestyle migration for decades to Latin American countries, especially to Mexico. British citizens move to Spain for similar reasons. In this paper we make a comparative analysis of these two international contexts in order to gain greater insight into the diversity and breadth of this type of migration. The study uses quantitative surveys administered at each f...

  11. Migration from Mexico to the US and Conduct Disorder: A Cross-National Study

    Science.gov (United States)

    Breslau, Joshua; Borges, Guilherme; Saito, Naomi; Tancredi, Daniel J.; Benjet, Corina; Hinton, Ladson; Kendler, Kenneth S.; Kravitz, Richard; Vega, William; Aguilar-Gaxiola, Sergio; Medina-Mora, Maria Elena

    2013-01-01

    Context Twin studies suggest that Conduct Disorder (CD) is under substantial genetic influence, which is stronger for aggressive than for non-aggressive symptoms. Studies of migrating populations offer an alternative strategy for separating environmental and genetic influences on psychopathology. Objective To examine variation in the prevalence of CD associated with migration from Mexico to the US and whether this variation is similar for aggressive and non-aggressive CD symptoms and symptom profiles. Design The prevalence of CD, different types of CD symptoms and CD symptom profiles were compared across three generations of people of Mexican origin with increasing levels of exposure to American culture: families of origin of migrants (in Mexico), children of Mexican migrants raised in the US and Mexican-American children of US-born parents. Setting General population surveys conducted in Mexico and the US using the same diagnostic interview. Participants Adults age 18–44 in the household population of Mexico and the household population of people of Mexican descent in the US. Main Outcome Measures CD criteria assessed using the World Mental Health version of the Composite International Diagnostic Instrument (WMH-CIDI). Results Compared with families of origin of migrants, risk of CD is lower in the general population of Mexico (OR=0.54, 95% CI 0.19–1.51), higher in children of Mexican-born immigrants who are raised in the US (OR=4.12, 95% CI 1.47–11.52) and higher still in Mexican-American children of US-born parents (OR=7.64, 95% CI 3.20–18.27). The association with migration is markedly weaker for aggressive than for non-aggressive symptoms. Conclusions The prevalence of CD increases dramatically across generations of the Mexican-origin population following migration to the US. This increase is of larger magnitude for non-aggressive than for aggressive symptoms, consistent with the suggestion that non-aggressive symptoms are more strongly influenced by

  12. THE STUDY OF GAS MIGRATION IN CRYSTALLINE ROCK USING INJECTION TESTS

    Directory of Open Access Journals (Sweden)

    Jiří Svoboda

    2012-07-01

    Full Text Available The study of gas migration in crystalline rock using injection tests is being carried out in the frame of the FORGE (Fate of Repository Gases project. The Czech Technical University in Prague (CTU, Centre of Experimental Geotechnics (CEG is participating in WP4 which is focused on disturbed host rock formations with respect to radioactive waste deep repositories. A series of in-situ tests is being conducted at the Josef Underground Laboratory. The aim of the testing is to simulate and study phenomena that might lead to gas-driven radionuclide transport in fractured crystalline rock. The in-situ tests combine migration and large-scale gas injection measurements; gas injection tests are being employed for the study of gas transport. For the purposes of comparison of the behaviour of the rock mass with regard to air and water a series of water pressure tests are also being carried out. The quality of the rock mass is assessed using rock mass classification systems.

  13. In situ radionuclide migration studies in a shallow sand aquifer (Part 1)

    International Nuclear Information System (INIS)

    Williams, G.M.; Alexander, L.S.; Hitchman, S.P.; Hooker, P.J.; Noy, D.J.; Ross, C.A.M.; Stuart, A.; West, J.M.

    1985-07-01

    As a result of a study of the geology of the British Nuclear Fuels premises at Drigg, Cumbria, the British Geological Survey identified a shallow glacial sand deposit approximately 1.5m thick, interbedded between two clay horizons. An array of boreholes has been contructed in this sand in order to study the migration of radionuclides introduced into the formation under controlled conditions of groundwater flow. Conservative tracers used in the field test include chloride (as NaCl, detected using a specific ion electrode) and iodine-131 (as NaI, detected radiometrically using a NaI (T1) crystal). Strontium-85 (as the chloride) has been used as a chemically reactive tracer in conjuction with 131 I. The principal research objectives of the programme are as follows:- (1) to undertake laboratory batch sorption experiments using core material from the field site in order to choose those nuclides of radiological interest that would migrate sufficiently quickly for their behaviour to be studied in a field experiment within a reasonable time period. (2) to identify and quantify the mechanisms for nuclide/sediment interaction by determination of the geochemical distribution of 85 Sr in contaminated cores using a sequential leaching procedure. (3) to obtain appropriate data on the hydraulic characteristics of the sand formation in order to construct a mathematical model to describe groundwater flow and reactive mass transport. (author)

  14. Internal migration and regional differences of population aging: An empirical study of 287 cities in China.

    Science.gov (United States)

    Chen, Rong; Xu, Ping; Li, Fen; Song, Peipei

    2018-04-02

    In addition to birth and death, migration is also an important factor that determines the level of population aging in different regions, especially under the current context of low fertility and low mortality in China. Drawing upon data from the fifth and sixth national population census of 287 prefecture-level cities in China, this study explored the spatial patterns of population aging and its trends from 2000 to 2010 in China. We further examined how the large-scale internal migration was related to the spatial differences and the changes of aging by using multivariate quantitative models. Findings showed that the percentage of elder cities (i.e. proportion of individuals aged 65 and above to total population is higher than 7%) increased from 50% to 90% in the total 287 cities within the decade. We also found that regional imbalances of population aging have changed since 2000 in China. The gap of aging level between East zone and the other three zones (i.e. West, Central, and North-east) has considerably narrowed down. In 2000, Eastern region had the greatest number (65) of and the largest proportion (74.7%) of elder cities among all four regions. By 2010, the proportion (87.4%) of elder cities in the eastern region was slightly lower than Central (91.4%), Western (88.2%) and North-east sectors (91.2%). Results from multivariate quantitative models showed that the regional differences of population aging appear to be affected much more by the large-scale internal migration with clear age selectivity and orientation preference than by the impact of fertility and mortality. Population aging is expected to continue in China, which will in turn exacerbate regional imbalances. Policies and implications are discussed to face the challenges that the divergent aging population may present in China.

  15. Emotional Testimonies:An Ethnographic Study of Emotional Suffering Related to Migration from Mexico to Arizona

    Directory of Open Access Journals (Sweden)

    Rebecca eCrocker

    2015-07-01

    Full Text Available It is increasingly argued that social and economic inequity poorly affect overall health. One of the means through which these inequities are translated to the body is via negative emotions, which carry known psychological and physiological responses. This paper examines migration-related psychosocial stressors impacting first generation Mexican immigrants in southern Arizona, and reports on the primary emotional experiences immigrants associate with these stressors. Data were drawn from a qualitative, ethnographic study conducted over the course of 14 months during 2013-2014 with first generation Mexican immigrants (N=40 residing in Tucson Arizona and service providers working directly in the immigrant community (N=32. Results indicate that the primary structural vulnerabilities that cause emotional hardship amongst immigrants are pre-migration stressors and adversity, dangerous border crossings, detention and deportation, undocumented citizenship status, family separation, and extreme poverty. Many of these factors have intensified over the past decade due to increased border security and state level anti-immigrant legislation in Arizona. Immigrants connected these hardships to the emotions of trauma (50%, fear (65%, depression (75%, loneliness (75%, sadness (80%, and stress (85%, and most respondents reported suffering from three or more of these emotions. Given the heavy emotional toll of migration and the direct impact that regional legislation and border security had on well-being, this paper argues that emotion be considered an important mechanism for health declines in the immigrant community. In order to stem the frequency and intensity of emotional stress in the Mexican immigrant community in Tucson, it is imperative to support organizations and policies that promote community building and support networks and also expand access to and availability of mental health services for immigrants regardless of documentation status.

  16. Consideration for modelling studies of migration of accidentally released radionuclides in a river watershed

    International Nuclear Information System (INIS)

    Matsunaga, Takeshi; Tsuduki, Katsunori; Yanase, Nobuyuki; Hanzawa, Yukiko; Ueno, Takashi

    2004-01-01

    Concerning radionuclides that might be released in an event of an accident from a nuclear facility, much attention has been paid to the migration pathways including the atmospheric deposition and subsequent inflow to surface water bodies since the Chernobyl nuclear accident in 1986. In European countries, computer-coded systems for predicting the migration including those pathways and providing scientific supports for decision makers to manage the contamination have been developed. This report is a summary of presentations and discussion made at the occasion of the visit of Dr. Monte in order to have directions related to the current subject of research, development of a mathematical model of the behavior of radionuclides in a river watershed. Those presentations and discussions were made at JAERI and also at prominent universities and institutes of Japan involved in this study field. As a result of these discussions, distinct advantages and key issues in use of a mathematical model for prediction of the migration of radionuclides in a river watershed have been identified and analyzed. It was confirmed that the use of mathematical modeling has distinct advantages. Re-arrangement of the existing experimental knowledge on the environment in an ordered way according to a theory (a mathematical model) will lead to a new angle to consider a problem in that environment, despite several gaps in the data array. A model to assess the radionuclide behaviour in contaminated aquatic ecosystems is a basis of decision analysis tools for helping decision-makers to select the most appropriate intervention strategies for the ecosystems. Practical use of a mathematical model and continuous effort in its validation were recognized as crucial. (author)

  17. Emotional Testimonies: An Ethnographic Study of Emotional Suffering Related to Migration from Mexico to Arizona

    Science.gov (United States)

    Crocker, Rebecca

    2015-01-01

    It is increasingly argued that social and economic inequities poorly affect overall health. One of the means through which these inequities are translated to the body is via negative emotions, which carry known psychological and physiological responses. This paper examines migration-related psychosocial stressors impacting first-generation Mexican immigrants in southern Arizona, and reports on the primary emotional experiences immigrants associate with these stressors. Data were drawn from a qualitative, ethnographic study conducted over the course of 14 months during 2013–2014 with first-generation Mexican immigrants (N = 40) residing in Tucson Arizona and service providers working directly in the immigrant community (N = 32). Results indicate that the primary structural vulnerabilities that cause emotional hardship among immigrants are pre-migration stressors and adversity, dangerous border crossings, detention and deportation, undocumented citizenship status, family separation, and extreme poverty. Many of these factors have intensified over the past decade due to increased border security and state level anti-immigrant legislation in Arizona. Immigrants connected these hardships to the emotions of trauma (50%), fear (65%), depression (75%), loneliness (75%), sadness (80%), and stress (85%), and most respondents reported suffering from three or more of these emotions. Given the heavy emotional toll of migration and the direct impact that regional legislation and border security had on well-being, this paper argues that emotion be considered an important mechanism for health declines in the immigrant community. In order to stem the frequency and intensity of emotional stress in the Mexican immigrant community in Tucson, it is imperative to support organizations and policies that promote community building and support networks and also expand access to and availability of mental health services for immigrants regardless of documentation status. PMID

  18. Comparative Study on Migration, Urbanization and Development in the ESCAP Region (RAS/P13/79). Rev. version.

    Science.gov (United States)

    1982-01-01

    Development of a study project by the UN Economic and Social Commission for Asia and the Pacific (ESCAP) on migration, urbanization, and development in the following countries is described: Indonesia, Malaysia, Pakistan, Philippines, Republic of Korea, Sri Lanka, and Thailand. The project's immediate goal is to assist decision makers in formulating population redistribution policies. It was recommended that ESCAP develop and test a migration questionnaire to assist member countries in undertaking surveys to study the interrelationships of migration and development. Upon completion of survey manuals to assist in the survey implementation, it was suggested that ESCAP run a series of in-country workshops to discuss the applications of survey results for policy formulation. A national migration survey will be taken in each country in the early 1980s in order to discern pattern and type of population mobility, factors that cause people to move or not to move, and the consequences of migration on places of origin and destination. A sample of 14,000 households in each country will be selected and 1 person of age 15-64 will be chosen as the respondent for each household. the following are some items which will be studied: 1) volume of migration streams within and between metropolitan areas and urban-rural areas; 2) decision making factors; 3) interactions between population movement and family structure, chages in fertility levels, employment, and education; 4) impact of agricultural systems on seasonal movements; 5) contributions of migrants to the cities; and 6) implications of international migration to and from the country. Leading family planning agencies will use these results to develop policy relating to population distribution, industry location, migration laws, regional economic planning, modern technology, and rural education. The management framework of the project is presented. After these results are published, government agencies can utilize them by

  19. Migration and risk of HIV acquisition in Rakai, Uganda: a population-based cohort study.

    Science.gov (United States)

    Olawore, Oluwasolape; Tobian, Aaron A R; Kagaayi, Joseph; Bazaale, Jeremiah M; Nantume, Betty; Kigozi, Grace; Nankinga, Justine; Nalugoda, Fred; Nakigozi, Gertrude; Kigozi, Godfrey; Gray, Ronald H; Wawer, Maria J; Ssekubugu, Robert; Santelli, John S; Reynolds, Steven J; Chang, Larry W; Serwadda, David; Grabowski, Mary K

    2018-04-01

    In sub-Saharan Africa, migrants typically have higher HIV prevalence than non-migrants; however, whether HIV acquisition typically precedes or follows migration is unknown. We aimed to investigate the risk of HIV after migration in Rakai District, Uganda. In a prospective population-based cohort of HIV-negative participants aged 15-49 years in Rakai, Uganda, between April 6, 1999, and Jan 30, 2015, we assessed the association between migration and HIV acquisition. Individuals were classified as recent in-migrants (≤2 years in community), non-recent in-migrants (>2 years in community), or permanent residents with no migration history. The primary outcome was incident HIV infection. We used Poisson regression to estimate incidence rate ratios (IRRs) of HIV associated with residence status with adjustment for demographics, sexual behaviours, and time. Data were also stratified and analysed within three periods (1999-2004, 2005-11, and 2011-15) in relation to the introduction of combination HIV prevention (CHP; pre-CHP, early CHP, and late CHP). Among 26 995 HIV-negative people who participated in the Rakai Community Cohort Study survey, 15 187 (56%) contributed one or more follow-up visits (89 292 person-years of follow-up) and were included in our final analysis. 4451 (29%) were ever in-migrants and 10 736 (71%) were permanent residents. 841 incident HIV events occurred, including 243 (29%) among in-migrants. HIV incidence per 100 person-years was significantly increased among recent in-migrants compared with permanent residents, for both women (1·92, 95% CI 1·52-2·43 vs 0·93, 0·84-1·04; IRR adjusted for demographics 1·75, 95% CI 1·33-2·33) and men (1·52, 0·99-2·33 vs 0·84, 0·74-0·94; 1·74, 1·12-2·71), but not among non-recent in-migrants (IRR adjusted for demographics 0·94, 95% CI 0·74-1·19 for women and 1·28, 0·94-1·74 for men). Between the pre-CHP and late-CHP periods, HIV incidence declined among permanent resident men (p

  20. Characterizing and modelling river channel migration rates at a regional scale: Case study of south-east France.

    Science.gov (United States)

    Alber, Adrien; Piégay, Hervé

    2017-11-01

    An increased awareness by river managers of the importance of river channel migration to sediment dynamics, habitat complexity and other ecosystem functions has led to an advance in the science and practice of identifying, protecting or restoring specific erodible corridors across which rivers are free to migrate. One current challenge is the application of these watershed-specific goals at the regional planning scales (e.g., the European Water Framework Directive). This study provides a GIS-based spatial analysis of the channel migration rates at the regional-scale. As a case study, 99 reaches were sampled in the French part of the Rhône Basin and nearby tributaries of the Mediterranean Sea (111,300 km 2 ). We explored the spatial correlation between the channel migration rate and a set of simple variables (e.g., watershed area, channel slope, stream power, active channel width). We found that the spatial variability of the channel migration rates was primary explained by the gross stream power (R 2  = 0.48) and more surprisingly by the active channel width scaled by the watershed area. The relationship between the absolute migration rate and the gross stream power is generally consistent with the published empirical models for freely meandering rivers, whereas it is less significant for the multi-thread reaches. The discussion focused on methodological constraints for a regional-scale modelling of the migration rates, and the interpretation of the empirical models. We hypothesize that the active channel width scaled by the watershed area is a surrogate for the sediment supply which may be a more critical factor than the bank resistance for explaining the regional-scale variability of the migration rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. The 'global interconnectedness' of dentist migration: a qualitative study of the life-stories of international dental graduates in Australia.

    Science.gov (United States)

    Balasubramanian, Madhan; Brennan, David S; Spencer, A John; Short, Stephanie D

    2015-05-01

    The migration of dentists is a major challenge contributing to the oral health system crisis in many countries. This paper explores the origins of the dentist migration problem through a study on international dental graduates, who had migrated to Australia. Life-stories of 49 international dental graduates from 22 countries were analysed in order to discern significant themes and patterns. We focused on their home country experience, including stories on early life and career choice; dental student life; professional life; social and political life; travels; and coming to Australia. Our participants exhibited a commitment to excellence in earlier stages of life and had cultivated a desire to learn more and be involved with the latest technology. Dentists from low- and middle-income countries were also disappointed by the lack of opportunity and were unhappy with the local ethos. Some pointed towards political unrest. Interestingly, participants also carried prior travel learnings and unforgettable memories contributing to their migration. Family members and peers had also influenced participants. These considerations were brought together in four themes explaining the desire to migrate: 'Being good at something', 'Feelings of being let down', 'A novel experience' and 'Influenced by someone'. Even if one of these four themes dominated the narrative, we found that more than one theme, however, coexisted for most participants. We refer to this worldview as 'Global interconnectedness', and identify the development of migration desire as a historical process, stimulated by a priori knowledge (and interactions) of people, place and things. This qualitative study has enriched our understanding on the complexity of the dental migration experience. It supports efforts to achieve greater technical co-operation in issues such as dental education, workforce surveillance and oral health service planning within the context of ongoing global efforts on health professional

  2. Migration and Remittances : Recent Developments and Outlook - Transit Migration

    OpenAIRE

    World Bank Group

    2018-01-01

    This Migration and Development Brief reports global trends in migration and remittance flows, as well as developments related to the Global Compact on Migration (GCM), and the Sustainable Development Goal (SDG) indicators for volume of remittances as percentage of gross domestic product (GDP) (SDG indicator 17.3.2), reducing remittance costs (SDG indicator 10.c.1) and recruitment costs (SD...

  3. Laboratory and field studies related to the Hydrology/Radionuclide Migration Project

    International Nuclear Information System (INIS)

    Thompson, J.L.

    1991-05-01

    This annual report describes research conducted in FY 1990 by Los Alamos National Laboratory for the Hydrology/Radionuclide Migration Project. This multi-agency project measures the underground movement of radionuclides related to nuclear testing at the Nevada Test Site. This project continues the long-term experiment at the site of the Cambric nuclear test. Water pumped from a well adjacent to the explosion cavity continues to show decreasing amounts of tritium and Krypton 85 but no Cesium 139. Analyses of drillback debris shows a distinction between refractory and volatile materials in respect to both their location in the test cavity and their leachability with groundwater. We surveyed materials used during nuclear testing to evaluate any post-test hazard; we concluded that most such materials pose a minimal hazard. The Los Alamos drilling program provided an opportunity for us to sample a collapsed zone above the cavity of a test, which was fired 2 years ago. We continue our research in colloid characterization and in detection of low levels of Technetium 99 in Nevada Test Site water. During FY 1990, we drilled a new hole in the Yucca Flat area to study radionuclide migration. This report also describes Los Alamos management and planning activities in support of this project. 20 refs., 2 figs., 14 tabs

  4. Study of the Fixation and Migration of Radioactive Cations in a Natural Ion-Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Baetsle, L. [Centre d' Etudes de l' Energie Nucleaire, Mol (Belgium)

    1960-07-01

    The purpose of this study is to analyse the behaviour of Sr90 and Cs137 on natural ion-exchangers such as lignite and soil. Lignite is a substance which is found in large quantities near the Belgian Nuclear Energy Research Centre (CEN) at Mol and is particularly useful in the processing of radioactive liquid wastes because of its ion-exchange properties. The physical and chemical characteristics of lignite which have a bearing on ion exchange are given in section 1 of this paper. The various ion equilibria which affect the processing of.radioactive liquid wastes are studied in section 2, which also lists the basic factors required for calculating the rate of saturation of a lignite column. The speed of ion migration in the soil is studied along the same lines as for lignite.

  5. First-principles study of vacancy formation and migration in clean and Re-doped γ'-Ni3Al

    International Nuclear Information System (INIS)

    Zhang Xu; Wang Chongyu

    2009-01-01

    Using density functional theory calculations in conjunction with the climbing images nudged elastic band method, we studied the vacancy formation and migration in clean and Re-doped Ni 3 Al. Both the chemical potential of the species and the magnetic effect are considered to determine the vacancy formation energy. We also simulated the vacancy migration in a complete set of migration paths. The evaluated vacancy formation energy and activation energy for the motion of vacancy compared well with the experimental results. Also, the obtained migration ways for the diffusion of Ni and Al atoms are consistent with previous theoretical predictions and experimental observations. Magnetism is found to influence both the vacancy formation and migration. Our results reveal that Re doping can inhibit the formation of Ni vacancies but facilitate the formation of Al vacancies, and can also inhibit the migration of neighboring vacancies. While the doped Re atom on the Al site is stable, the Re atom on the Ni site can diffuse within the Ni-sublattice mediated by Ni vacancies

  6. A phase-field simulation study of irregular grain boundary migration during recrystallization

    DEFF Research Database (Denmark)

    Moelans, N.; Zhang, Yubin; Godfrey, A.

    2015-01-01

    We present simulation results based on a phase-field model that describes the migration of recrystallization boundaries into spatially varying deformation energy fields. Energy fields with 2-dimensional variations representing 2 sets of dislocation boundaries lying at equal, but opposite, angles......, highly asymmetrical protrusions and retrusions can develop on the migrating recrystallization front resulting in a migration velocity considerably larger than that expected from standard recrystallization models. It is also seen that, when the wavelength of the variations in a deformation microstructure...

  7. Migration into art

    DEFF Research Database (Denmark)

    Petersen, Anne Ring

    This book addresses a topic of increasing importance to artists, art historians and scholars of cultural studies, migration studies and international relations: migration as a profoundly transforming force that has remodelled artistic and art institutional practices across the world. It explores...... contemporary art's critical engagement with migration and globalisation as a key source for improving our understanding of how these processes transform identities, cultures, institutions and geopolitics. The author explores three interwoven issues of enduring interest: identity and belonging, institutional...

  8. Sib-recruitment for studying migration and its impact on obesity and diabetes

    Directory of Open Access Journals (Sweden)

    Prabhakaran Dorairaj

    2006-03-01

    Full Text Available Abstract Background Urban-rural comparisons are of limited relevance in examining the effects of urban migration in developing countries where urbanisation is due to growth of existing urban populations, expansion of urban boundaries, and rural in-migration. Cultural, genetic and life-style backgrounds of migrants and host populations further limit the value of rural-urban comparisons. Therefore we evaluated a sib-comparison design intended to overcome the limitations of urban-rural comparisons. Methods Using the framework of a current cardiovascular risk factor screening study conducted in Indian factories, we recruited the non-migrant rural sibs of migrant urban factory workers and the urban sibs of non-migrant factory workers. The response rate, completed interviews and examinations conducted were assessed. Adequacy of generic food frequency questionnaires and WHO quality of life questionnaire were assessed. Results All the urban factory workers and spouses approached agreed to be interviewed. Of the 697 participants interviewed, 293 (42% had at least one rural dwelling sibling. Twenty (22% siblings lived further than 100 km from the study site. An additional 21 urban siblings of non-migrant factory workers were also investigated to test the logistics of this element of the study. Obesity (BMI >25 kg/m2 was more common in rural sibs than urban factory workers (age adjusted prevalence: 21.1% (17.1 to 25.0 vs. 16.1% (11.9, 20.3. Diabetes prevalence (fasting plasma glucose greater than 126 mg/dl was higher than expected (age-adjusted prevalence: 12.5% (22 out of 93 in urban migrants and 4.5% (8 out of 90 in rural non-migrant sibs. Conclusion The sib-comparison design is robust and has been adopted in the main study. It is possible that simple urban-rural study designs under-estimate the true differences in diabetes risk between migrants and non-migrants.

  9. Area deprivation and its association with health in a cross-sectional study: are the results biased by recent migration?

    Directory of Open Access Journals (Sweden)

    Piro Fredrik

    2007-09-01

    Full Text Available Abstract Background The association between area deprivation and health has mostly been examined in cross-sectional studies or prospective studies with short follow-up. These studies have rarely taken migration into account. This is a possible source of misclassification of exposure, i.e. an unknown number of study participants are attributed an exposure of area deprivation that they may have experienced too short for it to have any influence. The aim of this article was to examine to what extent associations between area deprivation and health outcomes were biased by recent migration. Methods Based on data from the Oslo Health Study, a cross-sectional study conducted in 2000 in Oslo, Norway, we used six health outcomes (self rated health, mental health, coronary heart disease, chronic obstructive pulmonary disease, smoking and exercise and considered migration nine years prior to the study conduct. Migration into Oslo, between the areas of Oslo, and the changes in area deprivation during the period were taken into account. Associations were investigated by multilevel logistic regression analyses. Results After adjustment for individual socio-demographic variables we found significant associations between area deprivation and all health outcomes. Accounting for migration into Oslo and between areas of Oslo did not change these associations much. However, the people who migrated into Oslo were younger and had lower prevalences of unfavourable health outcomes than those who were already living in Oslo. But since they were evenly distributed across the area deprivation quintiles, they had little influence on the associations between area deprivation and health. Evidence of selective migration within Oslo was weak, as both moving up and down in the deprivation hierarchy was associated with significantly worse health than not moving. Conclusion We have documented significant associations between area deprivation and health outcomes in Oslo after

  10. Use of X-ray fluorescence analysis in studying vertical element migration in weathering zone

    International Nuclear Information System (INIS)

    Houdkova, Z.; Hally, J.

    1980-01-01

    The vertical migration of elements was studied in a model area of the Zelivka river basin. The VRS 2 Zeiss GDR analyzer, connected to automatic processor KSR 4 100, were used for the study of concentration variations. Soil samples were taken from bore holes drilled to a depth of the solid bedrock (0 to 6 m). The contents of SiO 2 , Al 2 O 3 , Fe 2 O 3 , K 2 O, CaO, TiO 2 , P 2 O 5 and MnO were determined in concentration ranges from 10 -2 to 10 1 %. The method was tested in comparative measurements against conventional methods of chemical analysis. (author)

  11. Standards for Instrument Migration When Implementing Paper Patient-Reported Outcome Instruments Electronically: Recommendations from a Qualitative Synthesis of Cognitive Interview and Usability Studies.

    Science.gov (United States)

    Muehlhausen, Willie; Byrom, Bill; Skerritt, Barbara; McCarthy, Marie; McDowell, Bryan; Sohn, Jeremy

    2018-01-01

    To synthesize the findings of cognitive interview and usability studies performed to assess the measurement equivalence of patient-reported outcome (PRO) instruments migrated from paper to electronic formats (ePRO), and make recommendations regarding future migration validation requirements and ePRO design best practice. We synthesized findings from all cognitive interview and usability studies performed by a contract research organization between 2012 and 2015: 53 studies comprising 68 unique instruments and 101 instrument evaluations. We summarized study findings to make recommendations for best practice and future validation requirements. Five studies (9%) identified minor findings during cognitive interview that may possibly affect instrument measurement properties. All findings could be addressed by application of ePRO best practice, such as eliminating scrolling, ensuring appropriate font size, ensuring suitable thickness of visual analogue scale lines, and providing suitable instructions. Similarly, regarding solution usability, 49 of the 53 studies (92%) recommended no changes in display clarity, navigation, operation, and completion without help. Reported usability findings could be eliminated by following good product design such as the size, location, and responsiveness of navigation buttons. With the benefit of accumulating evidence, it is possible to relax the need to routinely conduct cognitive interview and usability studies when implementing minor changes during instrument migration. Application of design best practice and selecting vendor solutions with good user interface and user experience properties that have been assessed in a representative group may enable many instrument migrations to be accepted without formal validation studies by instead conducting a structured expert screen review. Copyright © 2018 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  12. Why do some, but not all, tropical birds migrate? A comparative study of diet breadth and fruit preference

    Science.gov (United States)

    Boyle, W.A.; Conway, C.J.; Bronstein, Judith L.

    2011-01-01

    Annual migrations of birds profoundly influence terrestrial communities. However, few empirical studies examine why birds migrate, in part due to the difficulty of testing causal hypotheses in long-distance migration systems. Short-distance altitudinal migrations provide relatively tractable systems in which to test explanations for migration. Many past studies explain tropical altitudinal migration as a response to spatial and temporal variation in fruit availability. Yet this hypothesis fails to explain why some coexisting, closely-related frugivorous birds remain resident year-round. We take a mechanistic approach by proposing and evaluating two hypotheses (one based on competitive exclusion and the other based on differences in dietary specialization) to explain why some, but not all, tropical frugivores migrate. We tested predictions of these hypotheses by comparing diets, fruit preferences, and the relationships between diet and preference in closely-related pairs of migrant and resident species. Fecal samples and experimental choice trials revealed that sympatric migrants and residents differed in both their diets and fruit preferences. Migrants consumed a greater diversity of fruits and fewer arthropods than did their resident counterparts. Migrants also tended to have slightly stronger fruit preferences than residents. Most critically, diets of migrants more closely matched their preferences than did the diets of residents. These results suggest that migrants may be competitively superior foragers for fruit compared to residents (rather than vice versa), implying that current competitive interactions are unlikely to explain variation in migratory behavior among coexisting frugivores. We found some support for the dietary specialization hypothesis, propose refinements to the mechanism underlying this hypothesis, and discuss how dietary specialization might ultimately reflect past interspecific competition. We recommend that future studies quantify variation

  13. Evaluating the migration of ingredients from active packaging and development of dedicated methods: A study of two iron-based oxygen absorbers

    NARCIS (Netherlands)

    López-Cervantes, L.; Sánchez-Machado, D.I.; Pastorelli, S.; Rijk, R.; Paseiro-Losada, P.

    2003-01-01

    The behaviour of two commercial oxygen-scavenging products with respect to migration of active ingredients into foodstuffs was investigated. Migrants were identified, and by using appropriate analytical methods, migration was determined in a variety of liquid, solid or gelled food simulants and

  14. Post-graduation migration intentions of students of Lebanese medical schools: a survey study

    Directory of Open Access Journals (Sweden)

    Sakr Mazen

    2008-06-01

    Full Text Available Abstract Background The international migration of physicians is a global public health problem. Lebanon is a source country with the highest emigration factor in the Middle East and North Africa and the 7th highest in the World. Given that residency training abroad is a critical step in the migration of physicians, the objective of this study was to survey students of Lebanese medical schools about their intentions to train abroad and their post training plans. Methods Our target population consisted of all students of Lebanese medical schools in the pre-final and final years of medical school. We developed the survey questionnaire based on the results of a qualitative study assessing the intentions and motives for students of Lebanese medical schools to train abroad. The questionnaire inquired about student's demographic and educational characteristics, intention to train abroad, the chosen country of abroad training, and post-training intention of returning to Lebanon. Results Of 576 eligible students, 425 participated (73.8% response rate. 406 (95.5% respondents intended to travel abroad either for specialty training (330 (77.6% or subspecialty training (76 (17.9%. Intention to train abroad was associated with being single compared with being married. The top 4 destination countries were the US (301(74.1%, France (49 (12.1%, the United Kingdom (31 (7.6% and Canada (17 (4.2%. One hundred and two (25.1% respondents intended to return to Lebanon directly after finishing training abroad; 259 (63.8% intended to return to Lebanon after working abroad temporarily for a varying number or years; 43 (10.6% intended to never return to Lebanon. The intention to stay indefinitely abroad was associated male sex and having a 2nd citizenship. It was inversely associated with being a student of one of the French affiliated medical schools and a plan to train in a surgical specialty. Conclusion An alarming percentage of students of Lebanese medical schools

  15. Post-graduation migration intentions of students of Lebanese medical schools: a survey study.

    Science.gov (United States)

    Akl, Elie A; Maroun, Nancy; Major, Stella; Afif, Claude; Abdo, Abir; Choucair, Jacques; Sakr, Mazen; Li, Carl K; Grant, Brydon Jb; Schünemann, Holger J

    2008-06-02

    The international migration of physicians is a global public health problem. Lebanon is a source country with the highest emigration factor in the Middle East and North Africa and the 7th highest in the World. Given that residency training abroad is a critical step in the migration of physicians, the objective of this study was to survey students of Lebanese medical schools about their intentions to train abroad and their post training plans. Our target population consisted of all students of Lebanese medical schools in the pre-final and final years of medical school. We developed the survey questionnaire based on the results of a qualitative study assessing the intentions and motives for students of Lebanese medical schools to train abroad. The questionnaire inquired about student's demographic and educational characteristics, intention to train abroad, the chosen country of abroad training, and post-training intention of returning to Lebanon. Of 576 eligible students, 425 participated (73.8% response rate). 406 (95.5%) respondents intended to travel abroad either for specialty training (330 (77.6%)) or subspecialty training (76 (17.9%)). Intention to train abroad was associated with being single compared with being married. The top 4 destination countries were the US (301(74.1%)), France (49 (12.1%)), the United Kingdom (31 (7.6%)) and Canada (17 (4.2%)). One hundred and two (25.1%) respondents intended to return to Lebanon directly after finishing training abroad; 259 (63.8%) intended to return to Lebanon after working abroad temporarily for a varying number or years; 43 (10.6%) intended to never return to Lebanon. The intention to stay indefinitely abroad was associated male sex and having a 2nd citizenship. It was inversely associated with being a student of one of the French affiliated medical schools and a plan to train in a surgical specialty. An alarming percentage of students of Lebanese medical schools intend to migrate for post graduate training, mainly

  16. Toward healthy migration: an exploratory study on the resilience of migrant domestic workers from the Philippines.

    Science.gov (United States)

    van der Ham, Alida Joanna; Ujano-Batangan, Maria Theresa; Ignacio, Raquel; Wolffers, Ivan

    2014-08-01

    Domestic workers face many migration-related stressors that affect their mental health. Currently there is an emphasis in the literature on these workers' problems and vulnerability, while there is little insight into factors that positively affect their mental health. In this study, we describe a range of factors that potentially contribute to the resilience of female domestic workers from the Philippines, and explore their relation to stress and well-being. The study used an explorative, mixed-methods design. First, data were collected using questionnaires (n = 500) to assess self-perceived stress levels, well-being, personal resources, and social resources. Then, findings from the questionnaires were validated and elaborated on in a workshop (n = 23) and two focus groups (n = 13; n = 8). Results show that participants perceived their well-being abroad as relatively good, while they also experienced high levels of stress. Workers used a variety of resources in dealing with stress. Socially oriented coping strategies and spirituality seemed to play an important role as personal resources, while the influence of reasons for migration was less clear. Employers and (access to) social networks appeared important in determining social resources. Social resources were more often related to stress and well-being than were personal resources. Findings from this study can help to design strengths-based interventions aimed at improving the well-being of female domestic workers and preventing mental health problems. The environmental factors and structural constraints that provide the context for resilience should be further explored as they influence the ability to mobilize resources. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  17. Study of power peak migration due to insertion of control bars in a PWR reactor

    International Nuclear Information System (INIS)

    Affonso, Renato Raoni Werneck; Costa, Danilo Leite; Borges, Diogo da Silva; Lava, Deise Diana; Lima, Zelmo Rodrigues de; Moreira, Maria de Lourdes

    2014-01-01

    This paper aims to present a study on the power distribution behavior in a PWR reactor, considering the intensity and the migration of power peaks as is the insertion of control rods in the core banks. For this, the study of the diffusion of neutrons in the reactor was adopted by computer simulation that uses the finite difference method for numerically solving the neutron diffusion equation to two energy groups in steady state and in symmetry of a fourth quarter core. We decided to add the EPRI-9R 3D benchmark thermal-hydraulic parameters of a typical power PWR. With a new configuration for the reactor, the positions of the control rods banks were also modified. Due to the new positioning of these banks in the reactor, there was intense power gradients, favoring the occurrence of critical situations and logically unconventional for operation of a nuclear reactor. However, these facts have led interesting times for the study on the power distribution behavior in the reactor, showing axial migration of power peaks and mainly the effect of the geometry of the core on the latter. Based on the distribution of power was evident the increase of the power in elements located in the central region of the reactor core and, concomitantly, the reduction in elements of its periphery. Of course, the behavior exhibited by the simulated reactor is not in agreement with that expected in an actual reactor, where the insertion of control rods banks should lead to reduced power throughout the core as evenly as possible, avoiding sharp power peaks, standardizing the burning fuel, controlling reactivity deviations and acting in reactor shutdown

  18. In situ radionuclide migration studies in a shallow sand aquifer. Part. 1. Part. 2: appendices

    International Nuclear Information System (INIS)

    Williams, G.M.; Alexander, L.S.; Hitchman, S.P.; Hooker, P.J.; Noy, D.J.; Ross, C.A.M.; Stuart, A.; West, J.M.

    1986-01-01

    As a result of a study of the geology of the British Nuclear Fuels premises at Drigg, Cumbria, the British Geological Survey identified a shallow glacial sand deposit approximately 1.5m thick, interbedded between two clay horizons. An array of boreholes has been constructed in this sand in order to study the migration of radionuclides introduced into the formation under controlled conditions of groundwater flow. Conservative tracers used in the field test include chloride (as NaCl) and iodine-131 (as NaI). Strontium-85 (as the chloride) has been used as a chemically reactive tracer in conjunction with 131 I. The principal research objectives of the programme are as follows: (1) To undertake laboratory batch sorption experiments using core material from the field site in order to choose those nuclides of radiological interest that would migrate sufficiently quickly for their behaviour to be studied in a field experiment within a reasonable time period. (2) To identify and quantify the mechanisms for nuclide/sediment interaction by determination of the geochemical distribution of 85 Sr in contaminated cores using a sequential leaching procedure. (3) To obtain appropriate data on the hydraulic characteristics of the sand formation in order to construct a mathematical model to describe groundwater flow and reactive mass transport. Part 2 of this report contains the following appendices: (1) Calculation of sorption parameters. (2) A low-cost manifold system for use with multi-level samplers. (3) Radioactivity curves for 131 I and 85 Sr. (4) Results of particle size analysis for sand aquifers

  19. Migration patterns and influence of support networks: A case study of West Africans in the Netherlands

    NARCIS (Netherlands)

    Chelpi-den Hamer, M.

    2008-01-01

    This article explores the influence of support networks in the migration process of West African migrants to the Netherlands. Taking a case-oriented biographic approach, the article analyzes the migration stories of several West African migrants with a focus on the networks that facilitated their

  20. Parental migration patterns and risk of depression and anxiety disorder among rural children aged 10-18 years in China: a cross-sectional study.

    Science.gov (United States)

    Shen, Min; Gao, Jing; Liang, Zenzen; Wang, Youjie; Du, Yukai; Stallones, Lorann

    2015-12-29

    This study aims to explore the prevalence of depression and anxiety in left-behind children, and to identify patterns of parents' migration and relative factors associated with depression and anxiety risk in this population. A cross-sectional survey using a school-based sample was conducted in Puyang, Hebei, North China in December 2012. 2283 students aged 10-18 years. Parental migration status, depression and anxiety disorder. 61.2% of participants were left-behind children. The prevalence rate of depression among left-behind children with both parents migrating (14.2%) was higher than that of children with one parent migrating (11.7%) and no parent migrating (12.6%). The prevalence rate of anxiety disorder for children with no parent migrating (25.1%) was higher than that for children living with one or neither parent (22.2% and 22.0%). The risk factors for depression were low-level social support (OR=3.46, 95% CI 2.00 to 6.01), average academic performance (OR=2.37, 95% CI 1.7 to 3.3) and low academic performance (OR=3.01, 95% CI 1.92 to 4.72), staying up late (OR=1.67, 95% CI 1.17 to 2.39), having difficulty falling asleep (OR=2.04, 95% CI 1.48 to 2.82) and being an only child (OR=1.73, 95% CI 1.04 to 2.89). The factors associated with anxiety disorder were being female (OR=2.09, 95% CI 1.64 to 2.66), being in high school (OR=1.8, 95% CI 1.38 to 2.36), physical abuse (OR=1.5, 95% CI 1.04 to 2.15), having difficulty falling asleep (OR=1.67, 95% CI 1.33 to 2.10) and low-level social support (OR=2.17, 95% CI 1.44 to 3.28) and middle-level social support (OR=1.82, 95% CI 1.3 to 2.56). Parents' migration was not associated with depression and anxiety in rural children aged 10-18 years, but academic performance at school, sleep problems and lack of social support were associated with depression and anxiety. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  1. Generalization of some results of a vertical radionuclide migration study in soils of 30-km zone

    International Nuclear Information System (INIS)

    Ziborov, A.M.; Sadol'ko, I.V.; Sushchik, Yu.Ya.; Tikhanov, Eh.K.; Proskuryakov, A.G.; Kuz'michev, V.N.; Shcheglov, A.I.

    1992-01-01

    Results of radionuclide distribution study in a vertical profile of soils are presented under different landscape geochemical conditions in 1989-1991. It is ascertained that radionuclide migration process in geochemical profile of soils of 30-km zone is in early stage of development. More than 90% of radioactivity concentrates in the upper 5-10 cm layer whereas measurable radioactivity fixes at a depth up to 1 m. The process of deepening of radioactivity reserve center takes place in the surface soil layer. Now it equals 1,5-3 cm. Peculiarities of the vertical radionuclide distribution haven't brightly pronounced character depending on soil types and are at the formation stage. 12 figs.; 2 tabs

  2. In-Situ TEM Study of Interface Sliding and Migration in an Ultrafine Lamellar Structure

    Energy Technology Data Exchange (ETDEWEB)

    Hsiung, L M

    2005-12-06

    The instability of interfaces in an ultrafine TiAl-({gamma})/Ti{sub 3}Al-({alpha}{sub 2}) lamellar structure by straining at room temperature has been investigated using in-situ straining techniques performed in a transmission electron microscope. The purpose of this study is to obtain experimental evidence to support the creep mechanisms based upon the interface sliding in association with a cooperative movement of interfacial dislocations previously proposed to interpret the nearly linear creep behavior observed from ultrafine lamellar TiAl alloys. The results have revealed that both the sliding and migration of lamellar interfaces can take place simultaneously as a result of the cooperative movement of interfacial dislocations.

  3. Migration and Transculturation in the Digital Age: A Framework for Studying the “Space Between”

    Directory of Open Access Journals (Sweden)

    Padmini Banerjee

    2010-11-01

    Full Text Available Transnational immigrants today appear to live dual or even multiple lives across national borders, with help from a range of new technologies involving media and channels of communication such as Internet-based chat or telephony, mobile phones, and interactive online social networks. The authors explore the implications of accumulated findings on this aspect for researchers and scholars investigating the contemporary experience of global migration in relation to diasporas and their technology-enabled interconnections with home and host societies. Against the context of existing conceptual frameworks, the utility of the multi-dimensional construct of transculturalism (Ortiz, 1995 [1940], involving the three processes of acculturation, deculturation, and neo-culturation, is considered as a guiding concept in this emerging area of study.

  4. Natural analogues of radionuclide migration: reconnaissance study of sites (May 1985-March 1986)

    International Nuclear Information System (INIS)

    Hooker, P.J.; Ball, T.K.; Basham, I.R.; Bloodworth, A.J.; Roberts, P.D.; Ivanovich, M.

    1986-01-01

    Research into natural analogues of radionuclide migration provide data for supporting computer codes that describe the processes of transport and retardation. Such models are appropriate to the far-fields of shallow and deep radioactive waste repositories. The objective of this research project was to define locations within the UK and abroad worthy of detailed investigation. Site investigations and evaluations were carried out at a number of UK localities. The main focus of this survey has been on uraniferous veins in places at near surface where transport of uranium into sediments has occurred. Several uranium rich mineralisations associated with granite margins were visited in Cornwall, Devon and along the Solway Firth coast in Scotland; the disused U mine at South Terras in Cornwall and the coastal site at Needle's Eye near Dalbeattie are confirmed as future study sites. Results to hand from the sediments of Loch Lomand warrant further measurements of iodine and bromine in fresh cores. (author)

  5. Fundamental Studies of Charge Migration and Delocalization Relevant to Solar Energy Conversion

    Energy Technology Data Exchange (ETDEWEB)

    Michael J. Therien

    2012-06-01

    This program aimed to understand the molecular-level principles by which complex chemical systems carry out photochemical charge separation, transport, and storage, and how these insights could impact the design of practical solar energy conversion and storage devices. Towards these goals, this program focused on: (1) carrying out fundamental mechanistic and transient dynamical studies of proton-coupled electron-transfer (PCET) reactions; (2) characterizing and interrogating via electron paramagnetic resonance (EPR) spectroscopic methods novel conjugated materials that feature large charge delocalization lengths; and (3) exploring excitation delocalization and migration, as well as polaron transport properties of meso-scale assemblies that are capable of segregating light-harvesting antennae, nanoscale wire-like conduction elements, and distinct oxidizing and reducing environments.

  6. Studies of nuclear-waste migration in geologic media. Annual report, November 1976--October 1977

    International Nuclear Information System (INIS)

    Seitz, M.G.; Rickert, P.G.; Fried, S.M.; Friedman, A.M.; Steindler, M.J.

    1978-03-01

    The confinement of nuclear wastes in geologic formations is being considered as a method of permanently disposing of the waste. Laboratory experiments (column infiltration, static absorption, and batch partitioning experiments) were performed with nuclides of Cs, Pu, Np, and Am to examine the migratory characteristics of long-lived radionuclides that could be mobilized by groundwaters infiltrating a nuclear waste repository and the surrounding geologic body. In column infiltration experiments, the positions of peak concentrations of Cs in chalk or shale columns; Pu in limestone; Am in limestone, sandstone, or tuff; and Np in a limestone column did not move when the columns were infiltrated with water. However, fractions of each of the nuclides were seen downstream from the peaks, indicating that there was a large dispersion in the relative migration rates of each of the trace elements in the lithic materials studied. The results of static absorption experiments indicate that Pu and Am are strongly absorbed from solution by the common rocks studied and that their migration relative to ground-water flow is thereby retarded. In addition, the reaction rates of dissolved nuclides with rocks were found to vary considerably in different rock-element systems. Batch partitioning experiments were performed to test whether absorption processes are reversible. After granulated basalt and americium-bearing water were contacted in an absorption step, part of the water was replaced with water free of Am and the Am repartitioned between rock and solution. The distribution of Am after desorption was comparable to its distribution after absorption. In cntrast, when tablets of various rocks were allowed to dry between absorption and desorption tests, Pu and Am were not generally desorbed from the tablets. This suggests that reversible reactions of nuclides, between waters and rocks may be upset by treatments such as drying

  7. Competitive homing assays to study gut-tropic t cell migration.

    Science.gov (United States)

    Villablanca, Eduardo J; Mora, J Rodrigo

    2011-03-01

    In order to exert their function lymphocytes need to leave the blood and migrate into different tissues in the body. Lymphocyte adhesion to endothelial cells and tissue extravasation is a multistep process controlled by different adhesion molecules (homing receptors) expressed on lymphocytes and their respective ligands (addressions) displayed on endothelial cells (1 2). Even though the function of these adhesion receptors can be partially studied ex vivo, the ultimate test for their physiological relevance is to assess their role during in vivo lymphocyte adhesion and migration. Two complementary strategies have been used for this purpose: intravital microscopy (IVM) and homing experiments. Although IVM has been essential to define the precise contribution of specific adhesion receptors during the adhesion cascade in real time and in different tissues, IVM is time consuming and labor intensive, it often requires the development of sophisticated surgical techniques, it needs prior isolation of homogeneous cell populations and it permits the analysis of only one tissue/organ at any given time. By contrast, competitive homing experiments allow the direct and simultaneous comparison in the migration of two (or even more) cell subsets in the same mouse and they also permit the analysis of many tissues and of a high number of cells in the same experiment. Here we describe the classical competitive homing protocol used to determine the advantage/disadvantage of a given cell type to home to specific tissues as compared to a control cell population. We chose to illustrate the migratory properties of gut-tropic versus non gut-tropic T cells, because the intestinal mucosa is the largest body surface in contact with the external environment and it is also the extra-lymphoid tissue with the best-defined migratory requirements. Moreover, recent work has determined that the vitamin A metabolite all-trans retinoic acid (RA) is the main molecular mechanism responsible for inducing

  8. Regional Redistribution and Migration

    DEFF Research Database (Denmark)

    Manasse, Paolo; Schultz, Christian

    We study a model with free migration between a rich and a poor region. Since there is congestion, the rich region has an incentive to give the poor region a transfer in order to reduce immigration. Faced with free migration, the rich region voluntarily chooses a transfer, which turns out...... to be equal to that a social planner would choose. Provided migration occurs in equilibrium, this conclusion holds even in the presence of moderate mobility costs. However, large migration costs will lead to suboptimal transfers in the market solution...

  9. A multidisciplinary study of significant migrations on the territory of Vojvodina in the 20th century

    Directory of Open Access Journals (Sweden)

    Bjeljac Željko

    2016-01-01

    Full Text Available Migrations of population in a particular area and/or at a particular time represent the phenomenon of global proportions. As such, they require multidisciplinary approach to research. The most common questions posed by the individual, but also multidisciplinary scientific disciplines are: Who is moving? Where are they going? Why do they go? What are the natural and economic conditions of migrations? Why do migrations occur and how they maintain over time? Multidisciplinary research of migrations is very important for a more complete understanding of this process, primarily from the physical, historical, economic, ethnographic, anthropological, legal, politicological, sociological, etc. The aim of the paper is to highlight the importance of multidisciplinary research through the representation of some major migrations in Vojvodina in the 20th century. As a subject of research the following has been singled out: colonization (immigration of population from 1919 to 1930, 1945-1948 (there are some similarities among them (population decline, new social and political conditions and legal regulation, difficulties to get used to new ways of life, mixing folklore and customs with the local population. The paper includes the emigration of the German population from Vojvodina, 1944-1950, as part of one of the largest (e migrations in Europe in the 20th century. This migration, seen from legal, economic, historical and political aspects has consequences today, during the approach of Serbia to the European Union. [Projekat Ministarstva nauke Republike Srbije, br. III47007 i br. III47027

  10. Internal migration and the health of the returned population: a nationally representative study of China.

    Science.gov (United States)

    Zhang, Luwen; Liu, Shuaishuai; Zhang, Guoying; Wu, Shaolong

    2015-07-28

    China had 236 million internal migrants in 2012 and the majority of them migrated from rural to urban areas. The research based on medical and epidemical records found that the migrants had worse health than the urban residents, but the household and working place investigations reported better health status. The sick or unhealthy migrants are likely to return to their hometowns, which in turn may cause a report bias or over-estimation of the health status of rural-to-urban migrants in China. This paper explores the association of migration status and the physical and psychological health of Chinese internal migrants. Nationally representative household survey data from the China Labor-force Dynamics Survey 2012 (CLDS) were used to analyze the association between the migration status and the health status of internal migrants in China. Migration status of the respondents was measured by hukou status and migration experience and all respondents were divided into four groups: returned population, migrant population, urban residents, and rural residents. Health status of respondents was measured by self-reported physical and psychological health. Migration experience was associated with the physical health of the returned population. The physical health of the returned population was worse than the migrant population and was distinguished by age and sex. The physical health status of migrant population was significantly better than rural residents, but not significantly better than urban residents. However, the association between migration status and psychological health was not statistically significant. Besides migration status, the socioeconomic status (SES) had a positive correlation with both physical and psychological health status, while occupational hazards exerted negative influence. The results indicate a tight association between migration experience and health status. The internal unhealthy migrants were more likely to return to their hometown and the

  11. Studies on migration behavior of radionuclides under reducing conditions in JNC

    International Nuclear Information System (INIS)

    Kitamura, A.; Sato, H.

    2002-01-01

    Japan Nuclear Cycle Development Institute (JNC) has performed extensive researches and developments to investigate the geochemistry and radionuclide migration in buffer materials and geosphere. Experimental and modeling studies have been carried out related to the geological disposal of high-level radioactive waste (HLW) as a link in the chair of a follow-up of the second progress report, which has explained in the technical feasibility of HLW geological disposal in Japan. In this paper, three experimental studies on solubility, sorption and diffusion of radionuclides under reducing conditions for assuring the reliability and for improving the quality of the databases are introduced. Solubility and sorption behavior of neptunium (Np) have been studied under reducing conditions in carbonate media. For the solubility study, thermodynamic equilibrium constants of carbonatohydroxo complexes of Np(IV) have been determined from a solubility measurement in alkaline solutions. For the sorption study, distribution coefficient (K d ) of Np onto smectite has been determined in weak alkaline solutions under reducing conditions in carbonate media. For the diffusion study, apparent diffusivity (D a ) of selenium (Se) in compacted bentonite have been determined under reducing conditions as a function of silica sand content and temperature

  12. The Impact of Forced Migration on Mortality: A Cohort Study of 242,075 Finns from 1939-2010.

    Science.gov (United States)

    Haukka, Jari; Suvisaari, Jaana; Sarvimäki, Matti; Martikainen, Pekka

    2017-07-01

    The stresses and life changes associated with migration may have harmful long-term health effects, especially for mental health. These effects are exceedingly difficult to establish, because migrants are typically a highly selected group. We examined the impact of migration on health using "naturally occurring" historical events. In this article, we use the forced migration of 11% of the Finnish population after WWII as such a natural experiment. We observed the date and cause of death starting from 1 January 1971 and ending in 31 December 2010 for the cohort of 242,075 people. Data were obtained by linking individual-level data from the 1950 and 1970 population censuses and the register of death certificates from 1971 to 2010 (10% random sample). All-cause and cause-specific mortalities were modeled using Poisson regression. Models with full adjustment for background variables showed that both all-cause mortality (RR 1.03, 95% CI 1.01, 1.05), and ischemic heart disease mortality (RR 1.11, 95% CI 1.08, 1.15) were higher in the displaced population than in the nondisplaced population. Suicide mortality was lower (RR 0.77, 95% CI 0.64, 0.92) in displaced than in the general population. In our long-term follow-up study, forced migration was associated with increased risk of death due to ischemic heart diseases. In contrast, lower suicide mortality was observed in association with forced migration 25 years or more.

  13. Migration studies of 3-chloro-1,2-propanediol (3-MCPD) in polyethylene extrusion-coated paperboard food packaging.

    Science.gov (United States)

    Pace, Gregory V; Hartman, Thomas G

    2010-06-01

    The manufacturing process of paperboard food packaging can produce small quantities of 3-chloro-1,2-propanediol (3-MCPD or 3-monochloropropane-1,2-diol) when wet-strength resins containing epichlorohydrin are used. 3-MCPD is from the same family as 1,3-dichloro-2-propanol (1,3-DCP), which is known to cause cancer in animals. 3-MCPD has been found in acid hydrolyzed vegetable protein, Asian sauces and paperboard for food contact. In this investigation, we conducted extraction studies to measure 3-MCPD migration into food simulant solvents from the food contact side of polyethylene extrusion-coated paperboard beverage cartons and aqueous extractions of cut pieces from the entire paperboard. We demonstrate that 3-MCPD confirmed present at concentrations up to 9.9 mg kg(-1) within the paperboard matrix does not migrate through the polyethylene-coated food contact surface. The aqueous extraction of the entire paperboard and food contact side extractions with aqueous/acidic food simulants were performed using US Food and Drug Administration (FDA) and European Commission (EU) migration testing protocols. We also show that no significant amount of 3-MCPD migrates through the unskived edges on the inside seam of the paperboard structure. The methodology for the aqueous and migration cell extractions using GC-MS analyses was validated with a limit of quantification (LOQ) of 0.009 mg kg(-1) and a limit of detection (LOD) of 0.005 mg kg(-1).

  14. Factors Associated with Migration in Individuals Affected by Leprosy, Maranhão, Brazil: An Exploratory Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    C. Murto

    2013-01-01

    Full Text Available In Brazil, leprosy is endemic and concentrated in high-risk clusters. Internal migration is common in the country and may influence leprosy transmission and hamper control efforts. We performed a cross-sectional study with two separate analyses evaluating factors associated with migration in Brazil’s Northeast: one among individuals newly diagnosed with leprosy and the other among a clinically unapparent population with no symptoms of leprosy for comparison. We included 394 individuals newly diagnosed with leprosy and 391 from the clinically unapparent population. Of those with leprosy, 258 (65.5% were birth migrants, 105 (26.6% were past five-year migrants, and 43 (10.9% were circular migrants. In multivariate logistic regression, three independent factors were found to be significantly associated with migration among those with leprosy: (1 alcohol consumption, (2 separation from family/friends, and (3 difficulty reaching the healthcare facility. Separation from family/friends was also associated with migration in the clinically unapparent population. The health sector may consider adapting services to meet the needs of migrating populations. Future research is needed to explore risks associated with leprosy susceptibility from life stressors, such as separation from family and friends, access to healthcare facilities, and alcohol consumption to establish causal relationships.

  15. Age at migration and future risk of psychotic disorders among immigrants in the Netherlands : a 7-year incidence study

    NARCIS (Netherlands)

    Veling, Wim; Hoek, Hans W; Selten, Jean-Paul; Susser, Ezra

    2011-01-01

    Objective: The purpose of this study was to examine whether the increased risk for developing a psychotic disorder among immigrants is related to their age at the time of migration. Method: In a 7-year first-contact incidence study, immigrants to the Netherlands and Dutch citizens, ages 15-54 years,

  16. Subject-3: Study on migration of radionuclides released into terrestrial and aquatic environment after nuclear accident

    International Nuclear Information System (INIS)

    Amano, H.; Matsunaga, T.; Ueno, T.; Nagao, S.; Yanase, N.; Tkachenko, Yu.

    2001-01-01

    Subject-3 has been focused on the migration behavior of long-lived radionuclides in the terrestrial surface environment, especially in connection with their chemical and physical forms. Migration behavior of radionuclides is strongly affected with their chemical and physical forms (for example; Gunten and Benes 1995). One of the two categories in Subject-3 consists of migration from surface soils including aging effects of hot particles, plant uptake from contaminated soils, and resuspension of radionuclides. The other is run off by river system, considering the role of organic materials. (author)

  17. Subject-3: Study on migration of radionuclides released into terrestrial and aquatic environment after nuclear accident

    Energy Technology Data Exchange (ETDEWEB)

    Amano, H.; Matsunaga, T.; Ueno, T.; Nagao, S.; Yanase, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Arkhipov, A.N. [Chernobyl Scientific and Technical Center for International Research (Ukraine); Tkachenko, Yu. [The State Enterprise Regional Monitoring and Domestic Control (RADEC) (Unknown)

    2001-03-01

    Subject-3 has been focused on the migration behavior of long-lived radionuclides in the terrestrial surface environment, especially in connection with their chemical and physical forms. Migration behavior of radionuclides is strongly affected with their chemical and physical forms (for example; Gunten and Benes 1995). One of the two categories in Subject-3 consists of migration from surface soils including aging effects of hot particles, plant uptake from contaminated soils, and resuspension of radionuclides. The other is run off by river system, considering the role of organic materials. (author)

  18. A study on the migration of students from Taiwan to the United States: a summary report.

    Science.gov (United States)

    Tsai, H C

    1989-06-01

    This study examines the general characteristics and differentials in the status trends, processes, and consequences of student migration to the US, emphasizing micro analysis. The study uses 2 methods to collect data: 1) examination of secondary statistical data and literature and 2) interviews (in 1987) of 435 family members and close friends of emigrating students. The results show the following demographic and socioeconomic characteristics of the emigrating students: 1) in 1988, about 6000 Taiwanese students were in the US; 2) the sex ratio has decreased in recent years to 6 males in every 10 students; and 3) in 1986, the return migration rate was about 20%. This study examines differentials in 1) motivation to study abroad; 2) employment and housing arrangements; 3) applications for permanent residence and citizenship; 4) marriage, family, and general socioeconomic conditions; and 5) interactions with family and society of origin. Major findings show that 1) the most important motivation to study abroad is to pursue professional knowledge, techniques, and advanced degrees, thereby to earn a high income; 2) about 40% receive doctoral degrees, while the rest obtain master's degrees; 3) most students experienced a time gap between graduation and finding a formal job; 4) more than 1/2 have worked no longer than 10 years; 5) most rent a room or share an apartment or house while in school; 6) after graduation, most attempt to buy a house; 7) most live in large cities; 8) most live in California; 9) about 1/2 have received US citizenship and 1/3 are permanent residents; 10) most who stay in the US are married and are satisfied with their socioeconomic conditions; 11) at 1st, most students receive financial assistance from their parents, but after graduation, over 1/2 send money to their parents; 12) only a few are offered permanent jobs in Taiwan. Suggestions for policy making include 1) developing a good graduate study program and residential environment in Taiwan to

  19. Correlation between self-diffusion in Si and the migration mechanisms of vacancies and self-interstitials: An atomistic study

    International Nuclear Information System (INIS)

    Posselt, M.; Gao, F.; Bracht, H.

    2008-01-01

    The migration of point defects in silicon and the corresponding atomic mobility are investigated by comprehensive classical molecular-dynamics simulations using the Stillinger-Weber potential and the Tersoff potential. In contrast to most of the previous studies both the point defect diffusivity and the self-diffusion coefficient per defect are calculated separately so that the diffusion-correlation factor can be determined. Simulations with both the Stillinger-Weber and the Tersoff potential show that vacancy migration is characterized by the transformation of the tetrahedral vacancy to the split vacancy and vice versa and the diffusion-correlation factor f V is about 0.5. This value was also derived by the statistical diffusion theory under the assumption of the same migration mechanism. The mechanisms of self-interstitial migration are more complex. The detailed study, including a visual analysis and investigations with the nudged elastic band method, reveals a variety of transformations between different self-interstitial configurations. Molecular-dynamics simulations using the Stillinger-Weber potential show that the self-interstitial migration is dominated by a dumbbell mechanism, whereas in the case of the Tersoff potential the interstitialcy mechanism prevails. The corresponding values of the correlation factor f I are different, namely, 0.59 and 0.69 for the dumbbell and the interstitialcy mechanisms, respectively. The latter value is nearly equal to that obtained by the statistical theory which assumes the interstitialcy mechanism. Recent analysis of experimental results demonstrated that in the framework of state-of-the-art diffusion and reaction models the best interpretation of point defect data can be given by assuming f I ≅0.6. The comparison with the present atomistic study leads to the conclusion that the self-interstitial migration in Si should be governed by a dumbbell mechanism

  20. Migration case studies and the implications of humic substances for the radiological performance assessment of radioactive waste repositories

    International Nuclear Information System (INIS)

    Bryan, N.D.; Bernhard, G.; Geipel, G.; Heise, K.H.; Schmeide, K.; Benes, P.

    2005-01-01

    Using the information obtained during the experimental and modelling tasks a series of migration case studies have been performed. These are not full performance assessment studies, but are merely intended to demonstrate the likely impact of humic substances upon the migration of radionuclides in the environment. Three separate sites have been investigated: (i) a shallow waste repository site at Dukovany in the Czech Republic; (ii) the formerly proposed, but now withdrawn, waste repository site at Gorleben in Germany; (iii) a large rock pile, consisting of tailings from a uranium mine, Schlema Alberode, near Dresden, Germany. To provide the maximum information, a variety of 'release scenarios' have been defined: continuous leakage in the Dukovany case study; a short pulsed release at Gorleben, and steady leaching in the case of the rock pile. The effects of the magnitudes of the chemical rate constants have been studied along with the effects of the initial distribution between exchangeable and non-exchangeable. Further, modelling during the HUPA project has shown that in certain lab column experiments the sorption of humic and humic-radionuclide complexes onto mineral surfaces could have an impact upon migration. Therefore, the likely impact of these processes on the field scale was investigated. In each of the three cases, humics are predicted to have a significant impact upon migration. However, whereas for the repository cases, it is the presence of the non-exchangeable fraction that results in migration, and the exchangeable fraction plays no significant part in transport, for the rock pile, the model predicts that the humic should promote migration even with the exchangeable interaction alone. Humic sorption may affect the degree of migration, but even in the case of maximum impact, the net effect of humic substances is still to enhance migration significantly. In fact, the initial distribution of radionuclide upon entry to the far-field is much more

  1. Laboratory and field studies related to the Radionuclide Migration project: Progress report, October 1, 1986-September 30, 1987

    International Nuclear Information System (INIS)

    Thompson, J.L.

    1988-02-01

    In this report we describe the research done by personnel of the Los Alamos National Laboratory in support of the Radionuclide Migration project during FY 1987. We are engaged in collecting data concerning the movement of radionuclides at three locations on the Nevada Test Site. We continue to monitor the elution of tritium and krypton from the RNM-2S well at the Cambric site and have described in detail the elution of 36 Cl from the same well. The data from this field study provide us with the opportunity to test the validity of several models of solute transport through geologic media. We have detected tritium and fission products in a water sample from the hole UE20n number1, which was drilled this year at the Cheshire site on Pahute Mesa. We are also continuing our efforts to learn how radionuclides have moved in test areas 3 and 4 near the Aleman site. Our laboratory work this year includes (1) a characterization of the size and density of two stable plutonium(IV) colloid suspensions prepared by different techniques and (2) a study of the transmission of colloidal-size polystyrene beads through crushed-rock columns. 18 refs., 7 figs., 9 tabs

  2. Not only moving bodies: contested and transforming concepts in migration studies

    Czech Academy of Sciences Publication Activity Database

    Uherek, Zdeněk

    2017-01-01

    Roč. 65, č. 2 (2017), s. 222-233 ISSN 1335-1303 Institutional support: RVO:68378076 Keywords : migration * transnationalism * cosmopolitanism * country of origin Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Antropology, ethnology

  3. Functionalization and migration of bromine adatoms on zigzag graphene nanoribbons: A first-principles study

    Science.gov (United States)

    Jaiswal, Neeraj K.; Kumar, Amit; Patel, Chandrabhan

    2018-05-01

    Tailoring the electronic band gap of graphene nanoribbons (GNR) through edge functionalization and understanding the adsorption of guest adatoms on GNR is crucial for realization of upcoming organic devices. In the present work, we have investigated the structural stability and electronic property of bromine (Br) termination at the edges of zigzag GNR (ZGNR). The migration pathways of Br adatom on ZGNR have also been discussed along four different diffusion paths. It is revealed that Br termination induces metallicity in ZGNR and caused upward shifting of Fermi level. Further, the migration is predicted to take place preferable along the ribbon edges whereas across the ribbon width, migration is least probable to take place due to sufficiently higher migration barrier of ˜160 meV.

  4. Turning points in international labor migration: a case study of Thailand.

    Science.gov (United States)

    Vasuprasat, P

    1994-01-01

    "This article describes the dynamics of the structural transformation of the Thai economy, labor migration and direct foreign investment and proposes an econometric model to explain the migration phenomenon. Though migration shifts have been significantly influenced by political factors such as the Gulf crisis and tensions with Saudi Arabia, economic factors such as the Thai government's liberalization of markets and the expansion of trade and direct foreign investment have contributed to changes in labor market needs. The economic conditions of a shift from net exporter to net importer for labor are posited in the model. The empirical results reveal a turning point in labor migration from Thailand and also confirm the contribution of commodity export in place of labor export in creating employment and income." excerpt

  5. Saponins extracted from by-product of Asparagus officinalis L. suppress tumour cell migration and invasion through targeting Rho GTPase signalling pathway.

    Science.gov (United States)

    Wang, Jieqiong; Liu, Yali; Zhao, Jingjing; Zhang, Wen; Pang, Xiufeng

    2013-04-01

    The inedible bottom part (~30-40%) of asparagus (Asparagus officinalis L.) spears is usually discarded as waste. However, since this by-product has been reported to be rich in many bioactive phytochemicals, it might be utilisable as a supplement in foods or natural drugs for its therapeutic effects. In this study it was identifed that saponins from old stems of asparagus (SSA) exerted potential inhibitory activity on tumour growth and metastasis. SSA suppressed cell viability of breast, colon and pancreatic cancers in a concentration-dependent manner, with half-maximum inhibitory concentrations ranging from 809.42 to 1829.96 µg mL(-1). However, SSA was more functional in blocking cell migration and invasion as compared with its cytotoxic effect, with an effective inhibitory concentration of 400 µg mL(-1). A mechanistic study showed that SSA markedly increased the activities of Cdc42 and Rac1 and decreased the activity of RhoA in cancer cells. SSA inhibits tumour cell motility through modulating the Rho GTPase signalling pathway, suggesting a promising use of SSA as a supplement in healthcare foods and natural drugs for cancer prevention and treatment. © 2012 Society of Chemical Industry.

  6. College Student Migration.

    Science.gov (United States)

    Fenske, Robert H.; And Others

    This study examines the background characteristics of two large national samples of first-time enrolled freshmen who (a) attended college within their state of residence but away from their home community, (b) migrated to a college in an adjacent state, (c) migrated to a college in a distant state, and (d) attended college in their home community.…

  7. Employment goals, expectations, and migration intentions of nursing graduates in a Canadian border city: a mixed methods study.

    Science.gov (United States)

    Freeman, Michelle; Baumann, Andrea; Akhtar-Danesh, Noori; Blythe, Jennifer; Fisher, Anita

    2012-12-01

    Internationally, nurse migration in border cities has received little attention. Nurses who graduate from nursing programs in Canadian border communities have the option of working in Canada or the United States. They are able to cross the international border each day as commuter migrants returning to their home country after work. Despite recent investment by Canada to increase the number of nursing students, the migration intentions of graduating nurses and the factors influencing their decision making has not been explored. The objective of this study is to explore the migration intentions of a graduating class of baccalaureate nursing students in a Canadian border community and the factors influencing their decision making. An explanatory sequential mixed methods design was used. In the first quantitative phase, data was collected by a web-based self-report survey. In the qualitative phase, semi-structured interviews were conducted. Data collection took place between February and July 2011. The response rate to the survey was 40.9% (n=115). Eighty-six percent of graduates preferred to work in Canada although two thirds identified that they were considering migrating for work outside of Canada. Knowing a nurse who worked in the US (Michigan) influenced intention to migrate and living in a border community was a strong predictor of migration. Migrants had significantly higher expectations that their economic, professional development, healthy work environment, adventure and autonomy values would be met in another country than Canada. Evidence from the interviews revealed that clinical instructors and clinical experiences played a significant role in framing students' perceptions of the work environment, influencing their choice of specialty, and where they secured their first job. The value-expectancy framework offered a novel approach to identifying job factors driving migration intentions. The study offered a snapshot of the graduates' perception of the work

  8. Pace studying worldwide coke production

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Pace Consultants Inc., Houston, has started a multiclient study of world-wide petroleum coke production, examining environmental initiatives and eventually forecasting prices of fuel grade coke. Pace expects coker expansions, increased operating severity, and reduced cycle times to boost coke supply to more than 50 million metric tons/year in 2000, compared with 39.7 million metric tons in 1992. Increased supply and tightened environmental rules in countries consuming large amounts of petroleum coke will be the main factors affecting coke markets. The paper discusses coke quality and the Japanese market

  9. Music Preferences and Family Language Background: A Computer-Supported Study of Children's Listening Behavior in the Context of Migration

    Science.gov (United States)

    Sakai, Winfried

    2011-01-01

    Turkish migrants are the largest national group in Germany. Nevertheless, neither in music psychology research nor in intercultural research can empirical data on the music preferences of Turkish-German primary schoolchildren in the migrational context be found. This study thus examined the music preference responses of children with Turkish…

  10. 78 FR 24425 - Assay Migration Studies for In Vitro Diagnostic Devices; Guidance for Industry and Food and Drug...

    Science.gov (United States)

    2013-04-25

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2008-D-0642] Assay Migration Studies for In Vitro Diagnostic Devices; Guidance for Industry and Food and Drug Administration Staff; Availability AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food...

  11. Bridging the Qualitative and Quantitative Divide in Comparative Migration Studies : Newspaper Data and Political Ethnography in Mixed Method Research

    NARCIS (Netherlands)

    Mügge, L.M.

    2016-01-01

    Newspaper data are popular in Comparative Migration Studies as they allow diachronic and cross-national comparison and are relatively easy and inexpensive to acquire. Critics, however, warn that newspaper data are hampered by selection, description and researcher bias. This article argues that

  12. A brain slice culture model for studies of endogenous and exogenous precursor cell migration in the rostral migratory stream

    DEFF Research Database (Denmark)

    Tanvig, Mette; Blaabjerg, Morten; Andersen, Rikke K

    2009-01-01

    The rostral migratory stream (RMS) is the main pathway by which newly born subventricular zone (SVZ) cells reach the olfactory bulb (OB) in rodents. This migration has been well studied in vivo, but an organotypic in vitro model would facilitate more experimental investigations. Here we introduce...

  13. Operating without a Safety Net: Gay Male Adolescents and Emerging Adults' Experiences of Marginalization and Migration, and Implications for Theory of Syndemic Production of Health Disparities

    Science.gov (United States)

    Bruce, Douglas; Harper, Gary W.

    2011-01-01

    Health disparities among gay men (HIV, substance use, depression) have been described as a mutually occurring "syndemic" that is socially produced through two overarching dynamics: marginalization and migration. Although the syndemic theory proposes a developmental trajectory, it has been largely based on epidemiological studies of adult gay men…

  14. Nutritional profile of Indian vegetarian diets – the Indian Migration Study (IMS)

    Science.gov (United States)

    2014-01-01

    Background The cardiovascular and other health benefits and potential harms of protein and micronutrient deficiency of vegetarian diets continue to be debated. Methods Study participants included urban migrants, their rural siblings and urban residents (n = 6555, mean age - 40.9 yrs) of the Indian Migration Study from Lucknow, Nagpur, Hyderabad and Bangalore. Information on diet (validated interviewer-administered semi-quantitative food frequency questionnaire), tobacco, alcohol, physical activity, medical histories, as well as blood pressure, fasting blood and anthropometric measurements were collected. Nutrient databases were used to calculate nutrient content of regional recipes. Vegetarians ate no eggs, fish, poultry and meat. Using multivariate linear regression with robust standard error model, we compared the macro- and micro-nutrient profile of vegetarian and non-vegetarian diets. Results Vegetarians, (32.8% of the population), consumed greater amounts of legumes, vegetables, roots and tubers, dairy and sugar, while non-vegetarians had a greater intake of cereals, fruits, spices, salt (p Vegetarians had a higher socioeconomic status, and were less likely to smoke, drink alcohol (p vegetarians consumed more carbohydrates (β = 7.0 g/day (95% CI: 9.9 to 4.0), p vegetarian diets were found to be adequate to sustain nutritional demands according to recommended dietary allowances with less fat. Lower vitamin B12 bio-availability remains a concern and requires exploration of acceptable dietary sources for vegetarians. PMID:24899080

  15. Nutritional profile of Indian vegetarian diets--the Indian Migration Study (IMS).

    Science.gov (United States)

    Shridhar, Krithiga; Dhillon, Preet Kaur; Bowen, Liza; Kinra, Sanjay; Bharathi, Ankalmadugu Venkatsubbareddy; Prabhakaran, Dorairaj; Reddy, Kolli Srinath; Ebrahim, Shah

    2014-06-04

    The cardiovascular and other health benefits and potential harms of protein and micronutrient deficiency of vegetarian diets continue to be debated. Study participants included urban migrants, their rural siblings and urban residents (n = 6555, mean age - 40.9 yrs) of the Indian Migration Study from Lucknow, Nagpur, Hyderabad and Bangalore. Information on diet (validated interviewer-administered semi-quantitative food frequency questionnaire), tobacco, alcohol, physical activity, medical histories, as well as blood pressure, fasting blood and anthropometric measurements were collected. Nutrient databases were used to calculate nutrient content of regional recipes. Vegetarians ate no eggs, fish, poultry and meat. Using multivariate linear regression with robust standard error model, we compared the macro- and micro-nutrient profile of vegetarian and non-vegetarian diets. Vegetarians, (32.8% of the population), consumed greater amounts of legumes, vegetables, roots and tubers, dairy and sugar, while non-vegetarians had a greater intake of cereals, fruits, spices, salt (p Vegetarians had a higher socioeconomic status, and were less likely to smoke, drink alcohol (p vegetarians consumed more carbohydrates (β = 7.0 g/day (95% CI: 9.9 to 4.0), p vegetarian diets were found to be adequate to sustain nutritional demands according to recommended dietary allowances with less fat. Lower vitamin B12 bio-availability remains a concern and requires exploration of acceptable dietary sources for vegetarians.

  16. Migration in the Face of Unemployment and Unemployment Risk: a Case Study of Temporal and Regional Effects

    Directory of Open Access Journals (Sweden)

    Stefanie Kley

    2013-03-01

    Full Text Available This article employs an elaborated model of migration decision-making and behaviour to analyse the influence of individually experienced unemployment and unemployment risk. Following a contrast group design, respondents from two cities inGermanywith different levels of economic prosperity are compared using event history data from a tailor-made panel study. According to a micro-economic approach to migration it is expected that respondents living in an economically deprived city are more likely to decide in favour of migration and actually move compared to those living in a prosperous city because they often perceive opportunities as better elsewhere than at their current place of residence. Moreover, perceiving a risk of becoming unemployed in the near future might trigger migration decision-making more in a deprived city because difficulties to find a new job at the place of residence are anticipated. On the other hand, the new household economics approach and the theory of social networks stress the importance of the meso level. Individuals seldom decide in favour or against migration solely; the family rather makes joint decisions. Former research revealed that for unemployed people social networks are a major source for social support and are therefore especially important. There is evidence that in deprived regions social networks deter individuals stronger from moving than in others. These theoretical considerations and findings lead to the expectation that once people are unemployed they seldom leave deprived regions, what is at odds with the expectations from micro-economic theory. The analyses reveal that the perceived risk of becoming unemployed indeed triggers migration decision-making, but exclusively in the deprived city, whereas people who are already unemployed do not consider or plan leaving the city more often than employed people. Nevertheless, having a partner, children and family at the place of residence might outweigh the

  17. Migrating Home Computer Audio Waveforms to Digital Objects: A Case Study on Digital Archaeology

    Directory of Open Access Journals (Sweden)

    Mark Guttenbrunner

    2011-03-01

    Full Text Available Rescuing data from inaccessible or damaged storage media for the purpose of preserving the digital data for the long term is one of the dimensions of digital archaeology. With the current pace of technological development, any system can become obsolete in a matter of years and hence the data stored in a specific storage media might not be accessible anymore due to the unavailability of the system to access the media. In order to preserve digital records residing in such storage media, it is necessary to extract the data stored in those media by some means.One early storage medium for home computers in the 1980s was audio tape. The first home computer systems allowed the use of standard cassette players to record and replay data. Audio cassettes are more durable than old home computers when properly stored. Devices playing this medium (i.e. tape recorders can be found in working condition or can be repaired, as they are usually made out of standard components. By re-engineering the format of the waveform and the file formats, the data on such media can then be extracted from a digitised audio stream and migrated to a non-obsolete format.In this paper we present a case study on extracting the data stored on an audio tape by an early home computer system, namely the Philips Videopac+ G7400. The original data formats were re-engineered and an application was written to support the migration of the data stored on tapes without using the original system. This eliminates the necessity of keeping an obsolete system alive for enabling access to the data on the storage media meant for this system. Two different methods to interpret the data and eliminate possible errors in the tape were implemented and evaluated on original tapes, which were recorded 20 years ago. Results show that with some error correction methods, parts of the tapes are still readable even without the original system. It also implies that it is easier to build solutions while original

  18. Specialist training in Fiji: Why do graduates migrate, and why do they remain? A qualitative study

    Directory of Open Access Journals (Sweden)

    Usher Kim

    2009-02-01

    Full Text Available Abstract Background Specialist training was established in the late 1990s at the Fiji School of Medicine. Losses of graduates to overseas migration and to the local private sector prompted us to explore the reasons for these losses from the Fiji public workforce. Methods Data were collected on the whereabouts and highest educational attainments of the 66 Fiji doctors who had undertaken specialist training to at least the diploma level between 1997 and 2004. Semistructured interviews focusing on career decisions were carried out with 36 of these doctors, who were purposively sampled to include overseas migrants, temporary overseas trainees, local private practitioners and public sector doctors. Results 120 doctors undertook specialist training to at least the diploma level between 1997 and 2004; 66 of the graduates were Fiji citizens or permanent residents; 54 originated from other countries in the region. Among Fiji graduates, 42 completed a diploma and 24 had either completed (21 or were enrolled (3 in a master's programme. Thirty-two (48.5% were working in the public sectors, four (6.0% were temporarily training overseas, 30.3% had migrated overseas and the remainder were mostly in local private practice. Indo-Fijian ethnicity and non-completion of full specialist training were associated with lower retention in the public sectors, while gender had little impact. Decisions to leave the public sectors were complex, with concerns about political instability and family welfare predominating for overseas migrants, while working conditions not conducive to family life or frustrations with career progression predominated for local private practitioners. Doctors remaining in the public sectors reported many satisfying aspects to their work despite frustrations, though 40% had seriously considered resigning from the public service and 60% were unhappy with their career progression. Conclusion Overall, this study provides some support for the view that

  19. Theoretical analysis and numerical modelling of heat transfer and fuel migration in underlying soils and constructive elements of nuclear plants during an accident release from the core

    International Nuclear Information System (INIS)

    Arutunjan, R.V.; Bolshov, L.A.; Vitukov, V.V.; Goloviznin, V.M.; Dykhne, A.M.; Kiselev, V.P.; Klementova, S.V.; Krayushkin, I.E.; Moskovchenko, A.V.; Pismennii, V.D.; Popkov, A.G.; Chernov, S.Y.; Chudanov, V.V.; Khoruzhii, O.V.; Yudin, A.I.

    1990-01-01

    Migration of fuel fragments and core fission products during severe accidents on nuclear plants is studied analytically and numerically. The problems of heat transfer and migration of volume heat sources in construction materials and underlying soils are considered

  20. Youth Labor Migration in Nepal

    OpenAIRE

    Bossavie, Laurent; Denisova, Anastasiya

    2018-01-01

    This descriptive study investigates internal and external labor migration by Nepalese youth. External labor migration is separated into the flow to India, which is unregulated, and the flow to other countries, which typically takes the form of temporary contract migration to countries with bilateral labor agreements with Nepal (referred to in Nepal as foreign employment). The study finds t...

  1. Risk of psychosis and internal migration: Results from the Bologna First Episode Psychosis study.

    Science.gov (United States)

    Tarricone, Ilaria; Boydell, Jane; Kokona, Arnisa; Triolo, Federico; Gamberini, Lisa; Sutti, Enrico; Marchetta, Michela; Menchetti, Marco; Di Forti, Marta; Murray, Robin M; Morgan, Craig; Berardi, Domenico

    2016-05-01

    Incidence of psychotic disorders is higher in many migrant groups; however little is known about internal migrants (IM). This study aims to describe the IR in natives (NA), IM and external migrants (EM). All patients aged 18-64years, with First Episode Psychosis (FEP), who made contact with the Bologna West psychiatric services, between 2002 and 2010, were included. 187 cases were included. Age and sex adjusted IR of psychosis per 100,000per year were: 12.6 for NA, 25.3 for IM and 21.4 for EM. The IRR was 1.93 (1.19-3.13, P=0.007) for IM and 1.79 (1.06-3.02, P=0.03) for EM compared to NA. Rates of psychosis were significantly elevated in IM as well as in EM. This result adds evidence as to the role of migration itself (versus ethnicity) on the risk of psychosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Study of rapid grain boundary migration in a nanocrystalline Ni thin film

    International Nuclear Information System (INIS)

    Kacher, Josh; Robertson, I.M.; Nowell, Matt; Knapp, J.; Hattar, Khalid

    2011-01-01

    Research highlights: → Abnormal growth is distributed randomly in the foil and initiates at different times. → Growth occurs from seemingly uncorrelated regions of the grain boundary. → Growth twins are created during all stages of abnormal grain growth. → Grain growth patterns are qualitatively similar to a vacancy diffusion model. → Grain boundaries and orientations evolve during growth to minimize system energy. - Abstract: Grain boundary migration associated with abnormal grain growth in pulsed-laser deposited Ni was studied in real time by annealing electron transparent films in situ in the transmission electron microscope. The resulting texture evolution and grain boundary types produced were evaluated by ex situ electron backscatter diffraction of interrupted anneals. The combination of these two techniques allowed for the investigation of grain growth rates, grain morphologies, and the evolution of the orientation and grain boundary distributions. Grain boundaries were found to progress in a sporadic, start/stop fashion with no evidence of a characteristic grain growth rate. The orientations of the abnormally growing grains were found to be predominately //ND throughout the annealing process. A high fraction of twin boundaries developed during the annealing process. The intermittent growth from different locations of the grain boundary is discussed in terms of a vacancy diffusion model for grain growth.

  3. Studies of Be migration in the JET tokamak using AMS with 10Be marker

    Science.gov (United States)

    Bykov, I.; Bergsåker, H.; Possnert, G.; Zhou, Y.; Heinola, K.; Pettersson, J.; Conroy, S.; Likonen, J.; Petersson, P.; Widdowson, A.

    2016-03-01

    The JET tokamak is operated with beryllium limiter tiles in the main chamber and tungsten coated carbon fiber composite tiles and solid W tiles in the divertor. One important issue is how wall materials are migrating during plasma operation. To study beryllium redistribution in the main chamber and in the divertor, a 10Be enriched limiter tile was installed prior to plasma operations in 2011-2012. Methods to take surface samples have been developed, an abrasive method for bulk Be tiles in the main chamber, which permits reuse of the tiles, and leaching with hot HCl to remove all Be deposited at W coated surfaces in the divertor. Quantitative analysis of the total amount of Be in cm2 sized samples was made with inductively coupled plasma atomic emission spectroscopy (ICP-AES). The 10Be/9Be ratio in the samples was measured with accelerator mass spectrometry (AMS). The experimental setup and methods are described in detail, including sample preparation, measures to eliminate contributions in AMS from the 10B isobar, possible activation due to plasma generated neutrons and effects of diffusive isotope mixing. For the first time marker concentrations are measured in the divertor deposits. They are in the range 0.4-1.2% of the source concentration, with moderate poloidal variation.

  4. A diffusion based study of population dynamics: Prehistoric migrations into South Asia.

    Directory of Open Access Journals (Sweden)

    Mayank N Vahia

    Full Text Available A diffusion equation has been used to study migration of early humans into the South Asian subcontinent. The diffusion equation is tempered by a set of parameters that account for geographical features like proximity to water resources, altitude, and flatness of land. The ensuing diffusion of populations is followed in time-dependent computer simulations carried out over a period of 10,000 YBP. The geographical parameters are determined from readily-available satellite data. The results of our computer simulations are compared to recent genetic data so as to better correlate the migratory patterns of various populations; they suggest that the initial populations started to coalesce around 4,000 YBP before the commencement of a period of relative geographical isolation of each population group. The period during which coalescence of populations occurred appears consistent with the established timeline associated with the Harappan civilization and also, with genetic admixing that recent genetic mapping data reveal. Our results may contribute to providing a timeline for the movement of prehistoric people. Most significantly, our results appear to suggest that the Ancestral Austro-Asiatic population entered the subcontinent through an easterly direction, potentially resolving a hitherto-contentious issue.

  5. Study of Stress Migration Failure in SiLKTM/SiO2 Hybrid Cu Interconnects

    International Nuclear Information System (INIS)

    Tsuchikawa, Haruo; Nakamura, Tomoji; Suzuki, Takashi; Mori, Hiroko; Shono, Ken

    2004-01-01

    Stress migration (SM) behavior is studied for a 130nm-node SiLK TM /SiO2 hybrid structure in which the interlevel dielectrics (ILD) consist of SiLK TM for trench levels and SiO2 for via levels. The failure rate dependence on the temperature, line width and circuit is examined in detail. Furthermore, an effect of dielectric deposition process on the reliability of the hybrid interconnects is investigated. It has been found that SM behavior is essentially similar to that reported in Cu/SiO2 systems. It has also been clarified that SiO2 PVD conditions at via level had a large impact on the failure rate. Therefore, the control of ILD deposition conditions is found to be one of the key factors in suppressing the SM failure. In order to examine the effect of the PVD conditions, the residual stress in vias were measured by using X-ray diffraction method. The results show that σx (the stress component parallel to the surface) in vias greatly depends on the PVD conditions. Then, the relationship between the PVD conditions and the SM failure rate is clarified

  6. Intertwined effects of gender and migration status on persistence in SET study programmes

    Science.gov (United States)

    Guenther, Elisabeth Anna; Koeszegi, Sabine Theresia

    2017-11-01

    This paper explores the intersectional interference of gender and migration status on students' persistence at an Austrian University of Technology. While controlling for the pre-university education and performance indicators, we estimate the odds for the persistence of male and female students, as well as of students with diverse migration statuses. We use the enrolment data of students from 1998 to 2010. The analysis reveals remarkable and significant effects of gender and migration status, as well as intersectional interference effects from both social categories on persistence. Female and students with immigration status are less likely to persist, even if performance and previous relevant experiences are controlled. A segregated analysis of the student population sheds further light on the interlocked and entangled effects of the social ascriptions underlying gender and migration status. The analysis supports the proposition of the accumulation of (dis-)advantages along students' careers. The profound quantification of gender and migration status effects can be utilised as basis for further research and purposeful policy measures to increase persistence in Science, Engineering and Technology for students with diverse backgrounds.

  7. Migration under irradiation of the I, Cs fission products in SiC; Migration sous irradiation des produits de fission I, Cs dans SiC

    Energy Technology Data Exchange (ETDEWEB)

    Benyagoub, A. [Paris-11 Univ., 91 - Orsay (France). Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse; Centre Interdisciplinaire de Recherche Ions Lasers (CIRIL), 14 - Caen (France)

    2007-07-01

    This work is a part of the CEA-CNRS program on the behaviour of materials under irradiation. Its aim is to contribute to scientifically base the predicting methods of the behaviour of ceramic materials under irradiation in using the important development of calculation means. In particular, its role has been 1)to develop the basic knowledge and the interactions physics and 2)to elaborate calculation models at relevant scales. The studied topics are until now, the damage mechanisms, the diffusion under irradiation, the micro-structural evolutions and the incidences on the mechanical properties. (O.M.)

  8. Phase-field simulation study of the migration of recrystallization boundaries

    DEFF Research Database (Denmark)

    Moelans, Nele; Godfrey, Andy; Zhang, Yubin

    2013-01-01

    We present simulation results based on a phase-field model that describes the local migration of recrystallization boundaries into varying deformation energy fields. An important finding from the simulations is that the overall migration rate of the recrystallization front can be considerably...... amplitudes, however, the velocity scales with the maximum of the deformation energy density along the variation, resulting in a considerably larger velocity than that obtained from standard recrystallization models. The shape of the migrating grain boundary greatly depends on the local characteristics...... of the varying stored deformation energy field. For different deformation energy fields, the simulation results are in good qualitative agreement with experiments and add information which cannot be directly derived from experiments....

  9. Rural to urban migration and changes in cardiovascular risk factors in Tanzania: a prospective cohort study

    Directory of Open Access Journals (Sweden)

    Tamin Bushiri

    2010-05-01

    Full Text Available Abstract Background High levels of rural to urban migration are a feature of most African countries. Our aim was to investigate changes, and their determinants, in cardiovascular risk factors on rural to urban migration in Tanzania. Methods Men and women (15 to 59 years intending to migrate from Morogoro rural region to Dar es Salaam for at least 6 months were identified. Measurements were made at least one week but no more than one month prior to migration, and 1 to 3 monthly after migration. Outcome measures included body mass index, blood pressure, fasting lipids, and self reported physical activity and diet. Results One hundred and three men, 106 women, mean age 29 years, were recruited and 132 (63.2% followed to 12 months. All the figures presented here refer to the difference between baseline and 12 months in these 132 individuals. Vigorous physical activity declined (79.4% to 26.5% in men, 37.8% to 15.6% in women, p -1 respectively, p -1, p = 0.01, and triglycerides fell (0.31 mmoll-1, p = 0.034. Blood pressure appeared to fall in both men and women. For example, in men systolic blood pressure fell by 5.4 mmHg, p = 0.007, and in women by 8.6 mmHg, p = 0.001. Conclusion The lower level of physical activity and increasing weight will increase the risk of diabetes and cardiovascular disease. However, changes in diet were mixed, and may have contributed to mixed changes in lipid profiles and a lack of rise in blood pressure. A better understanding of the changes occurring on rural to urban migration is needed to guide preventive measures.

  10. Impact of policies regulating foreign physician migration to Switzerland: a modelling case study in anaesthesia.

    Science.gov (United States)

    Haller, Guy; Combescure, Christophe; Mamie, Chantal; Zoccatelli, Davide; Clergue, François

    2015-05-22

    Several countries have developed policies that restrict or limit duration of stay, clinical privileges or the number of residency permits allocated to migrating physicians. Switzerland is currently preparing a new law limiting overall foreign immigration. The impact of such restrictive policies is currently unknown. In a case study of anaesthesia care in Switzerland we modelled, trends in the size of physicians' workforce until 2024, following the implementation of a strict quota policy for foreign medical trainees. We developed a computer-based Markov model with Monte-Carlo simulations to project, in the context of a strict quota policy for foreign trainees, supply and demand for anaesthesia positions until 2024. We used data from a cross-sectional study performed in the French- and Italian-speaking cantons of Switzerland and the Health dataset from the OECD. With 8 to 12 (95% CI 4-20) anaesthetists retiring per year, the implementation of strict quotas of foreign graduates would result in a 38% decrease in the number of anaesthetists in intermediary (senior registrars) positions by 2024. This decrease would be particularly important in district hospitals where nearly half (49%) of the non-Swiss anaesthetists are practising. Swiss graduates are unlikely to balance the shortage. Despite efforts by Swiss universities to increase the number of medical graduates, their number has dropped from 10.5 to 9.7/100 000 inhabitants between 2000 and 2012, due to the growth of the population. This case study in Latin Switzerland shows that a restrictive policy limiting foreign immigration of trainees would result in a major deficit in the number of anaesthetists available to meet population needs. These aspects should be carefully considered when countries develop restrictions and limitations of foreign immigration.

  11. Migration experiences, employment status and psychological distress among Somali immigrants: a mixed-method international study.

    Science.gov (United States)

    Warfa, Nasir; Curtis, Sarah; Watters, Charles; Carswell, Ken; Ingleby, David; Bhui, Kamaldeep

    2012-09-07

    The discourse about mental health problems among migrants and refugees tends to focus on adverse pre-migration experiences; there is less investigation of the environmental conditions in which refugee migrants live, and the contrasts between these situations in different countries. This cross-national study of two samples of Somali refugees living in London (UK) and Minneapolis, Minnesota, (USA) helps to fill a gap in the literature, and is unusual in being able to compare information collected in the same way in two cities in different countries. There were two parts to the study, focus groups to gather in-depth qualitative data and a survey of health status and quantifiable demographic and material factors. Three of the focus groups involved nineteen Somali professionals and five groups included twenty-eight lay Somalis who were living in London and Minneapolis. The quantitative survey was done with 189 Somali respondents, also living in London and Minneapolis. We used the MINI International Neuropsychiatric Interview (MINI) to assess ICD-10 and DSM-IV mental disorders. The overall qualitative and quantitative results suggested that challenges to masculinity, thwarted aspirations, devalued refugee identity, unemployment, legal uncertainties and longer duration of stay in the host country account for poor psychological well-being and psychiatric disorders among this group. The use of a mixed-methods approach in this international study was essential since the quantitative and qualitative data provide different layers and depth of meaning and complement each other to provide a fuller picture of complex and multi-faceted life situations of refugees and asylum seekers. The comparison between the UK and US suggests that greater flexibility of access to labour markets for this refugee group might help to promote opportunities for better integration and mental well-being.

  12. Migration experiences, employment status and psychological distress among Somali immigrants: a mixed-method international study

    Directory of Open Access Journals (Sweden)

    Warfa Nasir

    2012-09-01

    Full Text Available Abstract Background The discourse about mental health problems among migrants and refugees tends to focus on adverse pre-migration experiences; there is less investigation of the environmental conditions in which refugee migrants live, and the contrasts between these situations in different countries. This cross-national study of two samples of Somali refugees living in London (UK and Minneapolis, Minnesota, (USA helps to fill a gap in the literature, and is unusual in being able to compare information collected in the same way in two cities in different countries. Methods There were two parts to the study, focus groups to gather in-depth qualitative data and a survey of health status and quantifiable demographic and material factors. Three of the focus groups involved nineteen Somali professionals and five groups included twenty-eight lay Somalis who were living in London and Minneapolis. The quantitative survey was done with 189 Somali respondents, also living in London and Minneapolis. We used the MINI International Neuropsychiatric Interview (MINI to assess ICD-10 and DSM-IV mental disorders. Results The overall qualitative and quantitative results suggested that challenges to masculinity, thwarted aspirations, devalued refugee identity, unemployment, legal uncertainties and longer duration of stay in the host country account for poor psychological well-being and psychiatric disorders among this group. Conclusion The use of a mixed-methods approach in this international study was essential since the quantitative and qualitative data provide different layers and depth of meaning and complement each other to provide a fuller picture of complex and multi-faceted life situations of refugees and asylum seekers. The comparison between the UK and US suggests that greater flexibility of access to labour markets for this refugee group might help to promote opportunities for better integration and mental well-being.

  13. Determination of chemical parameters for the Schlema-Alberoda uranium tailings pile migration case study

    International Nuclear Information System (INIS)

    Bryan, N.; Vopalka, D.; Benes, P.; Stamberg, K.; Doubravova, K.

    2004-01-01

    A central aim of environmental chemistry is to develop an understanding of processes at the microscopic level, and to develop speciation models to simulate that behaviour, which may be used with transport codes to predict the fate of pollutants on the field scale. In fact, one objective of this HUPA project is to develop a coupled chemical transport computer code, which includes the effects of humic substances, and then apply it to three field scale test cases: 1. a deep hypothetical repository in a salt formation; 2. a shallow, sandy hypothetical repository; 3. a large pile of uranium mine tailings. This work concerns the third case study (U-tailings), which is based upon a real U-tailings pile at Schlema-Alberoda, near Dresden, Saxony, Germany. Environmental problems are inherently complex, and even apparently simple systems, such as a single metal ion interacting with a 'single' surface may be extremely complex. There have been considerable advances in computing power over the last few decades, unfortunately, in order to make calculations solvable in a reasonable time, the models used to simulate the chemistry of the system must be as simple as possible. The interaction between uranium and humic substances has been studied previously. However, the details of the interaction of uranyl cations with the material of the pile have not been modelled. Therefore, the objective here is to develop a simple model of this interaction, ready to use in the migration case study. Experiments were performed at the Czech Technical University, Prague and the data modelled at the University of Manchester. (orig.)

  14. International migration and the gender

    OpenAIRE

    Koropecká, Markéta

    2010-01-01

    My bachelor thesis explores the connection between international migration and gender. Gender, defined as a social, not a biological term, has a huge impact on the migration process. Statistics and expert studies that have been gender sensitive since 1970s demonstrate that women form half of the amount of the international migrants depending on the world region and representing a wide range of the kinds of international migration: family formation and reunification, labour migration, illegal ...

  15. COUP-TFI mitotically regulates production and migration of dentate granule cells and modulates hippocampal Cxcr4 expression.

    Science.gov (United States)

    Parisot, Joséphine; Flore, Gemma; Bertacchi, Michele; Studer, Michèle

    2017-06-01

    Development of the dentate gyrus (DG), the primary gateway for hippocampal inputs, spans embryonic and postnatal stages, and involves complex morphogenetic events. We have previously identified the nuclear receptor COUP-TFI as a novel transcriptional regulator in the postnatal organization and function of the hippocampus. Here, we dissect its role in DG morphogenesis by inactivating it in either granule cell progenitors or granule neurons. Loss of COUP-TFI function in progenitors leads to decreased granule cell proliferative activity, precocious differentiation and increased apoptosis, resulting in a severe DG growth defect in adult mice. COUP-TFI-deficient cells express high levels of the chemokine receptor Cxcr4 and migrate abnormally, forming heterotopic clusters of differentiated granule cells along their paths. Conversely, high COUP-TFI expression levels downregulate Cxcr4 expression, whereas increased Cxcr4 expression in wild-type hippocampal cells affects cell migration. Finally, loss of COUP-TFI in postmitotic cells leads to only minor and transient abnormalities, and to normal Cxcr4 expression. Together, our results indicate that COUP-TFI is required predominantly in DG progenitors for modulating expression of the Cxcr4 receptor during granule cell neurogenesis and migration. © 2017. Published by The Company of Biologists Ltd.

  16. Conservation physiology of animal migration

    Science.gov (United States)

    Lennox, Robert J.; Chapman, Jacqueline M.; Souliere, Christopher M.; Tudorache, Christian; Wikelski, Martin; Metcalfe, Julian D.; Cooke, Steven J.

    2016-01-01

    Migration is a widespread phenomenon among many taxa. This complex behaviour enables animals to exploit many temporally productive and spatially discrete habitats to accrue various fitness benefits (e.g. growth, reproduction, predator avoidance). Human activities and global environmental change represent potential threats to migrating animals (from individuals to species), and research is underway to understand mechanisms that control migration and how migration responds to modern challenges. Focusing on behavioural and physiological aspects of migration can help to provide better understanding, management and conservation of migratory populations. Here, we highlight different physiological, behavioural and biomechanical aspects of animal migration that will help us to understand how migratory animals interact with current and future anthropogenic threats. We are in the early stages of a changing planet, and our understanding of how physiology is linked to the persistence of migratory animals is still developing; therefore, we regard the following questions as being central to the conservation physiology of animal migrations. Will climate change influence the energetic costs of migration? Will shifting temperatures change the annual clocks of migrating animals? Will anthropogenic influences have an effect on orientation during migration? Will increased anthropogenic alteration of migration stopover sites/migration corridors affect the stress physiology of migrating animals? Can physiological knowledge be used to identify strategies for facilitating the movement of animals? Our synthesis reveals that given the inherent challenges of migration, additional stressors derived from altered environments (e.g. climate change, physical habitat alteration, light pollution) or interaction with human infrastructure (e.g. wind or hydrokinetic turbines, dams) or activities (e.g. fisheries) could lead to long-term changes to migratory phenotypes. However, uncertainty remains

  17. Scenario studies for algae production

    OpenAIRE

    Slegers, P.M.

    2014-01-01

    Microalgae are a promising biomass for the biobased economy to produce food, feed, fuel, chemicals and materials. So far, large-scale production of algae is limited and as a result estimates on the performance of such large systems are scarce. There is a need to estimate large-scale biomass productivity and energy consumption, while considering the uncertainty and complexity in such large-scale systems. In this thesis frameworks are developed to assess 1) the productivity during algae culti...

  18. Analysis of the Trinom Migration – FDI – Competitiveness. Case Study: Romania (2004-2015

    Directory of Open Access Journals (Sweden)

    Ana Maria Talmaciu (Banu

    2017-03-01

    Full Text Available In the context of a global economy, increasingly competitive, the battle for the competitive advantage has become harsh. The attractiveness of countries which influence the international migration, generate opposite or complementary effects in the countries of origin and destination. Labor migration among highly qualified people stirred controversy on the impact on the economies of the countries involved in the international transfer of human capital. Labor migration, highly qualified or not, produce a change in the investor’s behavior. They will be interested in investing in countries where the workforce is favoring either qualitatively, either financially, or both.The foreign direct investment fluctuates as the dynamics of migration increases. A country with a large number of highly skilled migrants can lose to foreign investors due to the lack of attractiveness of human capital, and, at the same time, a country with a large number of a trained environmental emigrant may be of interest to investors in search of cheap labor. This paper aims to examine the following hypothesis: to which extent the emigration influence the competitive level (measured by GDP and the foreign direct investments in the origin country. The results confirm the economic theory, showing a correlation, but not a significative one, for the analized years.

  19. Migration of diadromous and landlocked smelt populations studies by otolith geochemistry

    NARCIS (Netherlands)

    Phung, A.T.; Tulp, I.Y.M.; Baeyens, W.; Elskens, M.; Leermakers, M.; Gao, Y.

    2015-01-01

    Laser ablation inductively coupled mass spectrometry (LA-ICPMS) was used to determine Sr and Ba profiles along the growth axis of otholiths of European smelt caught in the Wadden Sea, the IJsselmeer and the Markermeer and to investigate the migration behaviour of the fish between the freshwater

  20. Intermingling and seasonal migrations of Greenland halibut ( Reinhardtius hippoglossoides ) populations determined from tagging studies

    DEFF Research Database (Denmark)

    Boje, Jesper

    2002-01-01

    A total of 7244 Greenland halibut (Reinhardtius hippoglossoides' Walbaum) were tagged in Greenland waters between 1986 and 1998 to increase information on stock delineations, to clarify migration routes, and to describe the seasonal movements of cord populations. At present 517 recaptured Greenla...

  1. Migration and Ethnic Group Disproportionality in Special Education: An Exploratory Study

    Science.gov (United States)

    Gabel, Susan L.; Curcic, Svjetlana; Powell, Justin J. W.; Khader, Khaled; Albee, Lynn

    2009-01-01

    Issues of educational equity and opportunity cannot be understood without regard to special education, as a key response to disabilities, disadvantages, and difficulties. Likewise, globalization cannot be understood without regard to cross-border migration and minority group status in society. Illuminating the nexus of these, research into…

  2. A novel method to measure femoral component migration by computed tomography: a cadaver study.

    Science.gov (United States)

    Boettner, Friedrich; Sculco, Peter; Lipman, Joseph; Renner, Lisa; Faschingbauer, Martin

    2016-06-01

    Radiostereometric analysis (RSA) is the most accurate technique to measure implant migration. However, it requires special equipment, technical expertise and analysis software and has not gained wide acceptance. The current paper analyzes a novel method to measure implant migration utilizing widely available computer tomography (CT). Three uncemented total hip replacements were performed in three human cadavers and six tantalum beads were inserted into the femoral bone similar to RSA. Six different 28 mm heads (-3, 0, 2.5, 5.0, 7.5 and 10 mm) were added to simulate five reproducible translations (maximum total point migration) of the center of the head. Implant migration was measured in a 3-D analysis software (Geomagic Studio 7). Repeat manual reconstructions of the center of the head were performed by two investigators to determine repeatability and accuracy. The accuracy of measurements between the centers of two head sizes was 0.11 mm with a CI 95 % of 0.22 mm. The intra-observer repeatability was 0.13 mm (CI 95 % 0.25 mm). The interrater-reliability was 0.943. CT based measurement of head displacement in a cadaver model were highly accurate and reproducible.

  3. International Student Migration: A Comparison of UK and Indian Students' Motivations for Studying Abroad

    Science.gov (United States)

    King, Russell; Sondhi, Gunjan

    2018-01-01

    This paper breaks new ground in its comparative analysis of two international student migration (ISM) streams, one from the Global South to the Global North (India to developed Anglophone countries), and the other within the Global North (UK to North America, Europe and Australia). These two ISM movements reflect different positionalities within…

  4. Labeling of Pest Insects Using Radioisotopes to Study Dispersal Pattern, Migration and Estimation of Population Density

    International Nuclear Information System (INIS)

    Singgih Sutrisno

    2008-01-01

    To study insects behaviour in their habitat such as dispersal, migration and flight range, insects are needed to be labelled to trace their movement. One of the most promising labeling methodology for internal labeling is the use of radioisotopes. Radioisotopes that have been used for labeling insects are 3 H, 32 P, 14 Ca, 45 K, 35 S, 59 Fe, 60 Co, and 14 C. Insect labeling with isotopes has more advantages as compared to dyes due to isotopes used for labeling is bonded to the tissue such as 3 H, 32 P, 14 Ca, K, 131 I. Several consideration have to be taken to determine isotopes that will be used in line with the time consuming for experiments. This have to be carried out due to the phenomenon that several isotopes are toxic to insects such as 45 Ca, 59 Fe, 86 Rb, 110 Ag, 115 Cd, and 131 J. Precautions have to be fulfilled for insect radiolabeling which are save to insects, environment, easy to apply, materials are available and acceptable to the public. Radioisotope 32 P with a correct dose is very convenience to be used in such experiments due to its relatively short half live, which is only 14.3 days. If it is an stable isotope it can be kept for a long time so the sample analyzed can be conducted convenience for long periods of time. Stable elements such as Rb can be changed to be radioisotopes by bombardment of neutrons in a nuclear reactor or accelerator. Then the element that has been activated can be identified using solid scintillation counter, multichannel analyzer or can be detected using autoradiography. (author)

  5. State policies and internal migration in Asia.

    Science.gov (United States)

    Oberai, A S

    1981-01-01

    The objective of this discussion is to identify policies and programs in Asia that are explicitly or implicitly designed to influence migration, to investigate why they were adopted and how far they have actually been implemented, and to assess their direct and indirect consequences. For study purposes, policies and programs are classified according to whether they prohibit or reverse migration, redirect or channel migration to specific rural or urban locations, reduce the total volume of migration, or encourage or discourage urban in-migration. Discussion of each type of policy is accompanied by a description of its rationale and implementation mechanism, examples of countries in Asia that have recourse to it, and its intended or actual effect on migration. Several countries in Asia have taken direct measures to reverse the flow of migration and to stop or discourage migration to urban areas. These measures have included administrative and legal controls, police registration, and direct "rustication" programs to remove urban inhabitants to the countryside. The availability of public land has prompted many Asian countries to adopt schemes that have been labeled resettlement, transmigration, colonization, or land development. These schemes have been designed to realize 1 or more of the following objectives: to provide land and income to the landless; increase agricultural production; correct spatial imbalances in the distribution of population; or exploit frontier lands for reasons of national security. 1 of the basic goals of decentralized industrialization and regional development policies has been the reduction of interregional disparities and the redirection of migrations from large metropolitan areas to smaller and medium sized towns. To encourage industry to move to small urban locations initial infrastructure investments, tax benefits, and other incentives have been offered. Policies to reduce the overall volume of migration have frequently included rural

  6. Indonesia's migration transition.

    Science.gov (United States)

    Hugo, G

    1995-01-01

    This article describes population movements in Indonesia in the context of rapid and marked social and economic change. Foreign investment in Indonesia is increasing, and global mass media is available to many households. Agriculture is being commercialized, and structural shifts are occurring in the economy. Educational levels are increasing, and women's role and status are shifting. Population migration has increased over the decades, both short and long distance, permanent and temporary, legal and illegal, and migration to and between urban areas. This article focuses specifically on rural-to-urban migration and international migration. Population settlements are dense in the agriculturally rich inner areas of Java, Bali, and Madura. Although the rate of growth of the gross domestic product was 6.8% annually during 1969-94, the World Bank ranked Indonesia as a low-income economy in 1992 because of the large population size. Income per capita is US $670. Indonesia is becoming a large exporter of labor to the Middle East, particularly women. The predominance of women as overseas contract workers is changing women's role and status in the family and is controversial due to the cases of mistreatment. Malaysia's high economic growth rate of over 8% per year means an additional 1.3 million foreign workers and technicians are needed. During the 1980s urban growth increased at a very rapid rate. Urban growth tended to occur along corridors and major transportation routes around urban areas. It is posited that most of the urban growth is due to rural-to-urban migration. Data limitations prevent an exact determination of the extent of rural-to-urban migration. More women are estimated to be involved in movements to cities during the 1980s compared to the 1970s. Recruiters and middlemen have played an important role in rural-to-urban migration and international migration.

  7. Modern Processes of Hydrocarbon Migration and Re-Formation of Oil and Gas Fields (Based on the Results of Monitoring and Geochemical Studies)

    Science.gov (United States)

    Plotnikova, Irina; Salakhidinova, Gulmira; Nosova, Fidania; Pronin, Nikita; Ostroukhov, Sergey

    2015-04-01

    important fundamental task of exceptional practical importance. The reservoir water monitoring has been conducted in five wells that have penetrated the water-saturated, loosely aggregated zones of the South Tatarstan Arch's basement. The long-term testing resulted in the production of reservoir water from the basement. The sedimentary cover in these wells is blocked by the column, which prevents water cross-flowing from the sedimentary cover. The observations have shown that the levels, gas saturation, mineralisation, density, and composition of reservoir waters from the loosely aggregated zones of the basement change with time. The varying characteristics of the water include its component composition, redox potential, and amount of chlorine and some other components and trace elements. Compositional changes in gases of the loosely aggregated zones of the basement, variations in the gas saturation of reservoir waters and of their composition, the decreasing density of oil in the sedimentary cover, - all result from one cause. This cause is the movement of fluids (solutions and gases dissolved in them) through the loosely aggregated zones and faults of the Earth's crust and the sedimentary cover. The fluids mainly move vertically in an upward direction, although their migration through subhorizontal, loosely aggregated zones of the crystalline basement is also possible. Fluid migration still takes place in the Earth's crust of ancient platforms. This phenomenon indicates that some portions of the platforms - primarily, their margins - periodically resume tectonic activities. The fluid dynamic activity of the crust define the processes in the sedimentary cover. It affects the development of the sedimentary basin during the sedimentation period, and the formation of mineral deposits. The monitoring of the present-day movement of fluid systems in the loosely aggregated zones of the basement will permit the more detailed study of the present-day fluid regime in the upper

  8. Patterning of Endothelial Cells and Mesenchymal Stem Cells by Laser-Assisted Bioprinting to Study Cell Migration

    Directory of Open Access Journals (Sweden)

    Jean-Michel Bourget

    2016-01-01

    Full Text Available Tissue engineering of large organs is currently limited by the lack of potent vascularization in vitro. Tissue-engineered bone grafts can be prevascularized in vitro using endothelial cells (ECs. The microvascular network architecture could be controlled by printing ECs following a specific pattern. Using laser-assisted bioprinting, we investigated the effect of distance between printed cell islets and the influence of coprinted mesenchymal cells on migration. When printed alone, ECs spread out evenly on the collagen hydrogel, regardless of the distance between cell islets. However, when printed in coculture with mesenchymal cells by laser-assisted bioprinting, they remained in the printed area. Therefore, the presence of mesenchymal cell is mandatory in order to create a pattern that will be conserved over time. This work describes an interesting approach to study cell migration that could be reproduced to study the effect of trophic factors.

  9. Patterning of Endothelial Cells and Mesenchymal Stem Cells by Laser-Assisted Bioprinting to Study Cell Migration.

    Science.gov (United States)

    Bourget, Jean-Michel; Kérourédan, Olivia; Medina, Manuela; Rémy, Murielle; Thébaud, Noélie Brunehilde; Bareille, Reine; Chassande, Olivier; Amédée, Joëlle; Catros, Sylvain; Devillard, Raphaël

    2016-01-01

    Tissue engineering of large organs is currently limited by the lack of potent vascularization in vitro . Tissue-engineered bone grafts can be prevascularized in vitro using endothelial cells (ECs). The microvascular network architecture could be controlled by printing ECs following a specific pattern. Using laser-assisted bioprinting, we investigated the effect of distance between printed cell islets and the influence of coprinted mesenchymal cells on migration. When printed alone, ECs spread out evenly on the collagen hydrogel, regardless of the distance between cell islets. However, when printed in coculture with mesenchymal cells by laser-assisted bioprinting, they remained in the printed area. Therefore, the presence of mesenchymal cell is mandatory in order to create a pattern that will be conserved over time. This work describes an interesting approach to study cell migration that could be reproduced to study the effect of trophic factors.

  10. International student mobility and highly skilled migration: a comparative study of Canada, the United States, and the United Kingdom.

    Science.gov (United States)

    She, Qianru; Wotherspoon, Terry

    2013-12-01

    Against the backdrop of demographic change and economic reconfiguration, recruiting international students, especially those at tertiary level, has drawn growing attention from advanced economies as part of a broad strategy to manage highly skilled migration. This comparative study focuses on three English speaking countries receiving international students: Canada, the United States, and the United Kingdom. International student policies, in particular entry and immigration regulations, and the trends in student mobility since the late 1990s are examined drawing on secondary data. By exploring the issue from the political economy perspectives, this study identifies distinct national strategies for managing student mobility, determines key factors shaping the environment of student migration in each nation, and addresses the deficiency of human capital theory in the analysis of global competition for high skills.

  11. Migration of dioctyladipate plasticizer from food-grade PVC film into chicken meat products: effect of gamma-radiation

    International Nuclear Information System (INIS)

    Goulas, A.E.; Kontominas, M.G.

    1996-01-01

    Food-grade PVC film containing 28.3% dioctyladipate (DOA) plasticizer was used to wrap chicken meat samples, with and without skin, contained in a polystyrene tray. Samples were then irradiated with gamma-radiation [60Co] at doses equal to 4 kGy and 9 kGy corresponding to ''cold pasteurization''. Irraddiation was carried out at 8-10 degrees C and samples were subsequently stored at 4-5 degrees C. Contaminated chicken meat samples were analysed for DOA at intervals between 7 h and 240 h of contact, using an indirect GC method. Identical non-irradiated (control) samples were also analysed for their DOA content. Results showed no statistically significant differences in migrated amounts of DOA between irradiated and non-irradiated samples. Neither were differences observed between samples irradiated at 4 kGy and 9 kGy. This was supported by identical IR spectra recorded for irradiated and non-irradiated samples and leads to the conclusion that, at such intermediate radiation doses ( < or = kGy), the migration characteristics of PVC film are not affected. DOA migration was found to be time dependent, approaching equilibrium after approximately 170 h for the chicken flesh plus skin samples and 120 h for the chicken flesh samples. The amount of DOA migrated into chicken flesh plus skin samples was significantly greater (3.2-22.3 mg/dm2) than that for chicken flesh samples (0.9-8.9 mg/dm2). After 240 h of sample/film contact under refrigeration, loss of DOA was approximately 35.6% for chicken flesh plus skin samples and 14.3% for chicken flesh samples. Sample spoilage, as demonstrated by off-odour development, occurred after approximately 120 h of refrigerated storage. Diffusion coefficients for DOA were calculated and were found to be lower for chicken flesh (1 x 10(-13) than for flesh plus skin (4.4 x 10(-13)) samples

  12. Effects of transnational migration on drug use: an ethnographic study of Nepali female heroin users in Hong Kong.

    Science.gov (United States)

    Tang, Wai-Man

    2015-01-01

    Past studies of female drug users in South Asia tend to focus on their plights, for instance, how they have been driven to drug use and encounter more problems than their male counterparts, such as HIV/AIDS and sexual abuse. Few studies focus on their active role--how they actively make use of resources in the external environment to construct their desired femininity through drug consumption. Furthermore, little is known about the situation of female South Asian drug users who are living overseas. This paper is a study of transnational migration, drug use and gender--how transnational migration influences the drug use of female transnational migrants. An 18-month ethnography has been carried out in a Nepali community in Hong Kong and 13 informants were interviewed. Data were coded and analyzed by using the grounded-theory approach. Themes related to the drug use of the female Nepali heroin users were identified. The findings show that there are three important themes that significantly affect the drug use of female Nepali heroin users, which include (1) their relationships with intimate partners, (2) their means of support, and (3) their legal status in migration. The findings are consistent with the concept of post-structuralism in gender and transnationalism theories. Female Nepali heroin users in Hong Kong are neither active agents nor passive victims; their active/passive role is largely dependent on their reconfigured opportunities and constraints in transnational migration. Thus, transnationalism should be taken as an important perspective to study the situation of female drug users in a globalized context. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Potential of qualitative network analysis in migration studies- Reflections based on an empirical analysis of young researchers' mobility aspirations

    OpenAIRE

    Elisabeth Scheibelhofer

    2011-01-01

    Based on the example of an empirical research study, the paper examines the strengths and limitations of a qualitative network approach to migration and mobility. The method of graphic drawings produced by the respondents within an interview setting was applied. With this method, we argue to be able to analyse migrants’ specific social embeddedness and its influence on future mobility aspirations. Likewise, connections between the migratory biography and the individuals’ various social relati...

  14. Laboratory and field studies related to the Radionuclide Migration Project: Progress report, October 1, 1985-September 30, 1986

    International Nuclear Information System (INIS)

    Thompson, J.L.

    1987-08-01

    In this report we describe the work done at Los Alamos in support of the Radionuclide Migration project during fiscal year 1986. We have continued to monitor the transport of tritium and 85 Kr from the Cambric explosion zone to the satellite well, which is pumped at 600 gal/min. Corresponding movement of cationic radionuclides such as 137 Cs and 90 Sr has not yet been observed after 12 yr of pumping, nor have we seen evidence that these strongly sorbing ions move in conjunction with colloids. We have analyzed more data from the Cheshire study site but have not resolved the uncertainties regarding the distribution and movement of radioactive materials at this location. Our attempts to improve our analytical capability for 36 Cl and 99 Tc have resulted in some progress. Similarly, we have increased our understanding of radionuclide transport phenomena such as channeling in fracture flow and anion exclusion in zeolites and clays. A sample exchange with Lawrence Livermore National Laboratory has helped us identify critical steps in our procedures for collecting and analyzing large-volume water samples. We have surveyed potential sites on Pahute Mesa at the Nevada Test Site for future radionuclide migration studies and conclude that there are none other than Cheshire presently available, and none are likely to be created in the near future. The Laboratory has engaged recently in radionuclide migration studies sponsored by our weapons program; we reviewed this work in an appendix to the annual report

  15. Studies of radiocaesium migration in soils with high organic matter content

    International Nuclear Information System (INIS)

    Zygmunt, J.; Chibowski, S.; Klimowicz, Z.

    1997-01-01

    This paper encloses results of field tests carried out on two types of organic soils. Activities of caesium, originating from global fallout as well as from Chernobyl power plant breakdown, were measured for these two soils. Radioactive caesium is present to a depth of 40 and 70 cm, in black soil and in peat, respectively, although the highest activity was found in the topmost layers. Caesium originating from the Chernobyl accident constitutes about 70% of the total activity in the 0-10 cm layers of soils. The vertical migration rates of caesium from both sources were also measured. In the case of peat soil the migration rate of the Chernobyl caesium as well as that from global fallout were found to be similar and amounted to 0.2 cm/year. In the case of black soil the differences were more pronounced (0.34 and 0.14 cm/year, respectively). (author)

  16. Abnormal neuronal migration: radiologic-clinic study. Alteraciones en la migracion neural: estudio clinico-radiologico

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Fernandez, M.; Menor Serrano, F.; Bordon Ferre, F.; Garcia Tena, J.; Esteban Hernandez, E.; Sanguesa Nebot, C.; Marti Bonnati, L. (Hospital Infantil La Fe, Valencia (Spain))

    1994-01-01

    We present our experience in 18 pediatric patients with abnormal neuronal migration. Seven cases of heterotopia of the gray matter, 7 agyria-pachygyria complexes, 1 case of polymicrogyria, 2 cases of schizencephaly and 1 case of hemimegalencephaly were diagnosed by means of ultrasonography, computed tomography and magnetic resonance. The clinical picture was reviewed in each case, with special attention to the occurrence of convulsions, psycho motor development and visual changes. In general, the greater the morphological change, the greater the neurological involvement in these patients. However, the two cases of schizencephaly presented mild clinical expression. Magnetic resonance increases the diagnostic yield in neuronal migration disorders. Nevertheless, either ultrasonography or, especially, computed tomography is useful as a first diagnostic approach in these malformative disorders. (Author)

  17. Population-level body condition correlates with productivity in an arctic wader, the dunlin Calidris alpina, during post-breeding migration.

    Science.gov (United States)

    Neubauer, Grzegorz; Pilacka, Lucyna; Zieliński, Piotr; Gromadzka, Jadwiga

    2017-01-01

    Weather and predation constitute the two main factors affecting the breeding success of those Arctic waders whose productivity is highly variable over the years. We tested whether reproductive success is associated with the post-breeding condition of adults, in which in 'good' years (with warm weather, plentiful food and low predation pressure) the condition of breeders and their productivity is high. To verify this hypothesis, we used a 10-year dataset comprising 20,792 dunlins Calidris alpina, trapped during migration at a stopover site on the southern Baltic Sea shore. Males were consistently in a slightly worse condition than females, likely due to male-biased parental investment in brood rearing. Annual productivity indices were positively correlated with the respective condition indices of breeders from the Eurasian Arctic, indicating that in 'good' years, despite great effort spent on reproduction, breeders leave the breeding grounds in better condition. The pattern did not hold for 1992: productivity was low, but the average condition of adults during migration was the highest noted over the decade. We suggest that the delayed effect of the Mount Pinatubo eruption in the Philippines in 1991, could be responsible for the unexpected high condition of Arctic breeders in 1992. High population-level average condition, coupled with the low productivity could stem from severe weather caused by the volcano eruption a year before and strong predation pressure, which in turn lead to a reduced investment in reproduction. The importance of large-scale episodic phenomena, like this volcano eruption, may blur the statistical associations of wildlife with local environmental drivers.

  18. Population-level body condition correlates with productivity in an arctic wader, the dunlin Calidris alpina, during post-breeding migration.

    Directory of Open Access Journals (Sweden)

    Grzegorz Neubauer

    Full Text Available Weather and predation constitute the two main factors affecting the breeding success of those Arctic waders whose productivity is highly variable over the years. We tested whether reproductive success is associated with the post-breeding condition of adults, in which in 'good' years (with warm weather, plentiful food and low predation pressure the condition of breeders and their productivity is high. To verify this hypothesis, we used a 10-year dataset comprising 20,792 dunlins Calidris alpina, trapped during migration at a stopover site on the southern Baltic Sea shore. Males were consistently in a slightly worse condition than females, likely due to male-biased parental investment in brood rearing. Annual productivity indices were positively correlated with the respective condition indices of breeders from the Eurasian Arctic, indicating that in 'good' years, despite great effort spent on reproduction, breeders leave the breeding grounds in better condition. The pattern did not hold for 1992: productivity was low, but the average condition of adults during migration was the highest noted over the decade. We suggest that the delayed effect of the Mount Pinatubo eruption in the Philippines in 1991, could be responsible for the unexpected high condition of Arctic breeders in 1992. High population-level average condition, coupled with the low productivity could stem from severe weather caused by the volcano eruption a year before and strong predation pressure, which in turn lead to a reduced investment in reproduction. The importance of large-scale episodic phenomena, like this volcano eruption, may blur the statistical associations of wildlife with local environmental drivers.

  19. Experimental study of fly-ash migration by using magnetic method

    Czech Academy of Sciences Publication Activity Database

    Kapička, Aleš; Kodešová, R.; Petrovský, Eduard; Hůlka, Z.; Grison, Hana; Kaška, M.

    2011-01-01

    Roč. 55, č. 4 (2011), s. 683-696 ISSN 0039-3169 R&D Projects: GA AV ČR IAA300120701 Grant - others:GA AV ČR(CZ) M100120901 Institutional research plan: CEZ:AV0Z30120515 Keywords : environmental magnetism * fly-ash migration * magnetic susceptibility * SM400 Kappameter Subject RIV: DK - Soil Contamination ; De-contamination incl. Pesticides Impact factor: 0.700, year: 2011

  20. Immunohistochemical study of macrophage migration inhibitory factor in rat liver fibrosis induced by thioacetamide

    OpenAIRE

    Y Hori; S Sato; J Yamate; M Kurasaki

    2009-01-01

    Macrophage migration inhibitory factor (MIF) is a molecule known to regulate macrophage accumulation at sites of inflammation. To elucidate the role of MIF in progression of liver fibrosis, the immunohistochemical localization of MIF and macrophages in the liver were examined. Male Wistar rats received thioacetamide (TA) injections (200 mg/kg, i.p.) for 1 or 6 weeks. In biochemical and histological tests, it was confirmed that liver fibrosis was induced. In immunohistochemical analyses, the e...

  1. Gulf migration study: Employment, wages and working conditions of Kerala emigrants in the United Arab Emirates

    OpenAIRE

    K.C. Zachariah; B.A. Prakash; S. Irudaya Rajan

    2002-01-01

    This is the fourth in a series of Working Papers published by the CDS on Kerala migration. Unlike the other three, this one is financed by the Kerala Government and the data were collected in UAE. The objectives of this Working Paper are to: document changes in the labour demand for different categories of emigrant workers, enumerate the emigration policies, examine employment and working conditions, wage levels and related problems of the Kerala emigrants, understand the education and traini...

  2. Product derivation in software product families : a case study

    NARCIS (Netherlands)

    Deelstra, S; Sinnema, M; Bosch, J

    2005-01-01

    From our experience with several organizations that employ software product families, we have learned that, contrary to popular belief, deriving individual products from shared software assets is a time-consuming and expensive activity. In this paper we therefore present a study that investigated

  3. Study on radionuclide migration through a buffer material of the repository for high level nuclear waste

    International Nuclear Information System (INIS)

    Tsukamoto, Masaki; Ohe, Toshiaki

    1989-01-01

    The present report discusses radionuclide migration through a buffer material from the view point of experimental and data analysis. Na-bentonite loosely compacted with dry density of 0.8 - 1 g/cm 3 was contacted with cesium chloride solution of about 100 ppb containing Cs-134 as a tracer at 40degC and at 70degC. After the experiments, the bentonite cake was sliced and cesium distribution in the cake was measured by gamma-spectrometry. Apparent diffusivities of 2∼5 x 10 -7 cm 2 /sec was determined through the analysis method where pore diffusion and adsorption were involved. Numerical solution well described the observed data. The pore diffusion would be clearfied to be a dominant mechanism of the radionuclide migration in the bentonite, through discussing the pore diffusion mechanism and activation energy of the diffusion. This report also discusses the capability of the chemical transport model CHEMTRN for long-term predictions of the radionuclide migration. (author)

  4. A column experiment for the study of colloidal radionuclide migration in Gorleben aquifer systems

    International Nuclear Information System (INIS)

    Kim, J.I.; Delakowitz, B.; Zeh, P.; Klotz, D.; Lazik, D.

    1994-01-01

    A column experiment is performed for the assessment of the migration behaviour of trivalent 152 Eu, 241 Am and tetra- and pentavalent 237 Np, 233 Pa in the presence of humic colloids. Groundwater of an organic rich aquifer from the geological site at Gorleben is chosen for the experiment, as this has been well characterized during the earlier work and contains a substantial amount of humic colloids. The chemical and mineralogical composition of the pleistocene quartz-sand used in the column experiment is characterized by various analytical and mineralogical methods. Prior to the actinide migration experiment, the hydraulic properties (flow velocity, effective porosity, longitudinal dispersion coefficient) are determined in order to ascertain stable conditions for the experiment. In addition, the microstructure parameters (sediment surface, pore size distribution) of the groundwater-sand system in the column are determined. Radiotracers used for the determination of the hydraulic properties are 3 HHO and 82 Br - . Results obtained to date indicate a relatively high mobility of the lanthanide and actinide ions loaded on aquatic humic colloids. The recovery of injected radiotracer ions in eluates is found to depend on the flow velocity of groundwater through the column. The results help to elucidate the actinide migration behaviour in the presence of natural humic colloids. (orig.)

  5. [Staying and working at home or considering migrating: Survey-based study of African ophthalmologists].

    Science.gov (United States)

    Nentwich, M M; Klauss, V; Wilhelm, F

    2015-05-01

    The shortage of ophthalmologists is a major obstacle in the struggle of fighting preventable blindness in sub-Saharan Africa. However, to date reasons affecting migration of ophthalmologists have not been completely understood. Evaluation of reasons reported by ophthalmologists for staying in their current work setting/country, of potential reasons for migration as well as of effects of German-African partnerships. In the years 2009-2011 and 2013 participants of continuous medical education courses in Ethiopia, Cameroon and Kenya were interviewed using a standardized questionnaire. A total of 106 ophthalmologists participated in this survey. In the years 2009/2010 participants were mainly board certified ophthalmologists, while the 2011/2013 surveys were answered mainly by residents. The main reasons for staying in their current region/country were good working conditions, commitment to help/patriotism, possibility of further training, good income and familial ties. Professional development elsewhere and better income abroad were named as the main reasons for considering migration followed by better technical equipment elsewhere and insecurity in the home country. Good working conditions and the possibility of further training were named as the top reasons for staying in the current region/country apart from commitment to help and familial ties. Therefore, international cooperation programs aiming at improving training of ophthalmologists and establishing an ophthalmic infrastructure may have a role in promoting ophthalmic care in Africa.

  6. An Empirical Study on the Migration Among Young Skilled and Creative People

    Directory of Open Access Journals (Sweden)

    Marta-Christina Suciu

    2017-08-01

    Full Text Available In the context of a knowledge and innovative-based society and economy, smart and creative cities are attracting an increasing number of young people, most of them being gifted, very talented students and high-skilled workforce, with multiple competences. These young people are pro-active and they involve themselves on enhancing the progress of the community in which they are living. Many cities are facing a higher rate of brain drain, as a consequence of the quality of life and the low level of wages considering also a reduce level of acceptance and implementation of innovative solutions. In the last decades migration phenomenon had been amplified and there is an increased young people migration from emergent countries to the innovation driven countries, witch assure more financial stability and favourable conditions to contribute to both personal and professional development for its residents. Through an empiric research, we have identified the most important factors which contribute to the amplified migration among youths. We have also highlighted the motivational elements for returning to homeland, when the socio-economic situation is favourable. The paper includes also a set of recommendations that could create a proper framework to attract talented, skilled and creative youth, regardless their origin country.

  7. Gremlin promotes retinal pigmentation epithelial (RPE) cell proliferation, migration and VEGF production via activating VEGFR2-Akt-mTORC2 signaling.

    Science.gov (United States)

    Liu, Yuan; Chen, Zhijun; Cheng, Haixia; Chen, Juan; Qian, Jing

    2017-01-03

    Retinopathy of prematurity (ROP) is characterized by late-phase pathologic retinal vasoproliferation. Gremlin is a novel vascular endothelial growth factors (VEGF) receptor 2 (VEGFR2) agonist and promotes angiogenic response. We demonstrated that gremlin expression was significantly increased in retinas of ROP model mice, which was correlated with VEGF upregulation. In retinal pigmentation epithelial (RPE) cells, gremlin activated VEGFR2-Akt-mTORC2 (mammalian target of rapamycin complex 2) signaling, and promoted cell proliferation, migration and VEGF production. VEGFR inhibition (by SU5416) or shRNA knockdown almost abolished gremlin-mediated pleiotropic functions in RPE cells. Further, pharmacological inhibition of Akt-mTOR, or shRNA knockdown of key mTORC2 component (Rictor or Sin1) also attenuated gremlin-exerted activities in RPE cells. We conclude that gremlin promotes RPE cell proliferation, migration and VEGF production possibly via activating VEGFR2-Akt-mTORC2 signaling. Gremlin could be a novel therapeutic target of ROP or other retinal vasoproliferation diseases.

  8. Optimization of mass spectrometry acquisition parameters for determination of polycarbonate additives, degradation products, and colorants migrating from food contact materials to chocolate.

    Science.gov (United States)

    Bignardi, Chiara; Cavazza, Antonella; Laganà, Carmen; Salvadeo, Paola; Corradini, Claudio

    2018-01-01

    The interest towards "substances of emerging concerns" referred to objects intended to come into contact with food is recently growing. Such substances can be found in traces in simulants and in food products put in contact with plastic materials. In this context, it is important to set up analytical systems characterized by high sensitivity and to improve detection parameters to enhance signals. This work was aimed at optimizing a method based on UHPLC coupled to high resolution mass spectrometry to quantify the most common plastic additives, and able to detect the presence of polymers degradation products and coloring agents migrating from plastic re-usable containers. The optimization of mass spectrometric parameter settings for quantitative analysis of additives has been achieved by a chemometric approach, using a full factorial and d-optimal experimental designs, allowing to evaluate possible interactions between the investigated parameters. Results showed that the optimized method was characterized by improved features in terms of sensitivity respect to existing methods and was successfully applied to the analysis of a complex model food system such as chocolate put in contact with 14 polycarbonate tableware samples. A new procedure for sample pre-treatment was carried out and validated, showing high reliability. Results reported, for the first time, the presence of several molecules migrating to chocolate, in particular belonging to plastic additives, such Cyasorb UV5411, Tinuvin 234, Uvitex OB, and oligomers, whose amount was found to be correlated to age and degree of damage of the containers. Copyright © 2017 John Wiley & Sons, Ltd.

  9. Studies on groundwater flow and radionuclide migration at underground environments. Final report of collaboration research between JAERI and AECL

    International Nuclear Information System (INIS)

    Ogawa, Hiromichi; Nagao, Seiya; Yamaguchi, Tetsuji

    2001-01-01

    The Japan Atomic Energy Research Institute (JAERI) conducted a collaboration program Phase II with the Atomic Energy of Canada Limited (AECL) from 1994 to 1998. The program was started to contribute the establishment of safety assessment methodology for the geological disposal of high-level radioactive wastes on the basis of the results from the Phase I program (1987-1993). The Phase II program consisted of following experimental items: (1) radionuclide migration experiments for quarried blocks (1m x 1m x 1m) of granite with natural fracture under in-situ geochemical conditions at 240 m level of Underground Research Laboratory of AECL; (2) study on the effects of dissolved organic materials extracted from natural groundwaters on radionuclide migration; (3) study on groundwater flow using environmental isotopes at two different geologic environments; (4) development of groundwater flow and radionuclide transport model for heterogeneous geological media. The mobility of radionuclides was retarded in the fracture by the deep geological conditions and the fracture paths. The groundwater humic substances with high molecular size were enhanced for the mobility of radionuclides in the sand and granitic media due to the complexation. The application of 36 Cl and 129 I for the analysis on the long-term groundwater flow can be validated on the basis of investigation at the URL site. Moreover, the geostatistical model for the analysis on groundwater flow and radionuclide migration was developed, and was able to describe the groundwater flow and the migration of environmental tracers at AECL sites. This report summaries the results of the Phase II program between JAERI and AECL. (author)

  10. Studies on groundwater flow and radionuclide migration at underground environments. Final report of collaboration research between JAERI and AECL

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Hiromichi; Nagao, Seiya; Yamaguchi, Tetsuji [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    2001-01-01

    The Japan Atomic Energy Research Institute (JAERI) conducted a collaboration program Phase II with the Atomic Energy of Canada Limited (AECL) from 1994 to 1998. The program was started to contribute the establishment of safety assessment methodology for the geological disposal of high-level radioactive wastes on the basis of the results from the Phase I program (1987-1993). The Phase II program consisted of following experimental items: (1) radionuclide migration experiments for quarried blocks (1m x 1m x 1m) of granite with natural fracture under in-situ geochemical conditions at 240 m level of Underground Research Laboratory of AECL; (2) study on the effects of dissolved organic materials extracted from natural groundwaters on radionuclide migration; (3) study on groundwater flow using environmental isotopes at two different geologic environments; (4) development of groundwater flow and radionuclide transport model for heterogeneous geological media. The mobility of radionuclides was retarded in the fracture by the deep geological conditions and the fracture paths. The groundwater humic substances with high molecular size were enhanced for the mobility of radionuclides in the sand and granitic media due to the complexation. The application of {sup 36}Cl and {sup 129}I for the analysis on the long-term groundwater flow can be validated on the basis of investigation at the URL site. Moreover, the geostatistical model for the analysis on groundwater flow and radionuclide migration was developed, and was able to describe the groundwater flow and the migration of environmental tracers at AECL sites. This report summaries the results of the Phase II program between JAERI and AECL. (author)

  11. Rationalization of the selectivity between 1,3- and 1,2-migration: a DFT study on gold(i)-catalyzed propargylic ester rearrangement.

    Science.gov (United States)

    Jiang, Jingxing; Liu, Yan; Hou, Cheng; Li, Yinwu; Luan, Zihong; Zhao, Cunyuan; Ke, Zhuofeng

    2016-04-14

    Gold catalyzed rearrangement of propargylic esters can undergo 1,3-acyloxy migration to form allenes, or undergo 1,2-acyloxy migration to access gold-carbenoids. The variation in migration leads to different reactivities and diverse cascade transformations. The effect of terminal substituents is very important for the rearrangement. However, it remains ambiguous how terminal substituents govern the selectivity of the rearrangement. This study presents a theoretical model based on the resonance structure of gold activated propargylic ester complexes to rationalize the rearrangement selectivity. Substrates with a major resonance contributor A prefer 5-exo-dig cyclization (1,2-migration), while those with a major resonance contributor B prefer 6-endo-dig cyclization (1,3-migration). This concise model would be helpful in understanding and tuning the selectivity of the metal catalyzed rearrangement of propargylic esters.

  12. Industrial Based Migration in India. A Case Study of Dumdum "Dunlop Industrial Zone"

    Science.gov (United States)

    Das, Biplab; Bandyopadhyay, Aditya; Sen, Jayashree

    2012-10-01

    Migration is a very important part in our present society. Basically Millions of people moved during the industrial revolution. Some simply moved from a village to a town in the hope of finding work whilst others moved from one country to another in search of a better way of life. The main reason for moving home during the 19th century was to find work. On one hand this involved migration from the countryside to the growing industrial cities, on the other it involved rates of migration, emigration, and the social changes that were drastically affecting factors such as marriage,birth and death rates. These social changes taking place as a result of capitalism had far ranging affects, such as lowering the average age of marriage and increasing the size of the average family.Migration was not just people moving out of the country, it also invloved a lot of people moving into Britain. In the 1840's Ireland suffered a terrible famine. Faced with a massive cost of feeding the starving population many local landowners paid for labourers to emigrate.There was a shift away from agriculturally based rural dwelling towards urban habitation to meet the mass demand for labour that new industry required. There became great regional differences in population levels and in the structure of their demography. This was due to rates of migration, emigration, and the social changes that were drastically affecting factors such as marriage, birth and death rates. These social changes taking place as a result of capitalism had far ranging affects, such as lowering the average age of marriage and increasing the size of the average family. There is n serious disagreement as to the extent of the population changes that occurred but one key question that always arouses debate is that of whether an expanding population resulted in economic growth or vice versa, i.e. was industrialization a catalyst for population growth? A clear answer is difficult to decipher as the two variables are so

  13. Study of reactive solutes transport and PAH migration in unsaturated soils

    International Nuclear Information System (INIS)

    Gujisaite, V.; Simonnot, M.O.; Gujisaite, V.; Morel, J.L.; Ouvrard, S.; Simonnot, M.O.; Gaudet, J.P.

    2005-01-01

    -silty uncontaminated soil or a sand and a model porous medium constituted of sand in which coal tar particles are dispersed. In a second time, column experiments will be carried out with a PAH contaminated soil from a former coking plant and with a multi-polluted industrial soil (PAH, heavy metals) to study PAH migration. For each studied soil, we will also determine the water retention curve in order to find the best operating conditions for our experiments with unsaturated flow. Modelling of solutes transfer in soils is also needed to improve understanding of the fate of contaminants and for risk assessment. However, it is difficult to take into account at the same time flow and interactions in models. Different models and numerical codes have been developed for solute transport. We have chosen to use the CXTFIT code, in order to model our results. This code allows indeed modelling of reactive solute transport in unsaturated porous media as well as under saturated conditions. It is usually used to estimate solute transport parameters using a nonlinear least-squares parameter optimization method. It may be used to solve the inverse problem by fitting a variety of mathematical solutions of theoretical transport models, based upon the one-dimensional convection-dispersion equation (CDE), to experimental results. The program may also be used to solve the direct or forward problem to determine concentrations as a function of time and/or position. This study at a bench scale will enable us at first to develop a methodology under unsaturated conditions and also to better understand the dominating mechanisms which control PAH transfer and availability in natural soils, especially by quantifying the impact of parameters like soil water content, water flow or the presence of plants. This is a first step before the change of scale (lysimeter). Modelling of the observed processes will also enable us to predict long term fate of PAH in soils

  14. Scenario studies for algae production

    NARCIS (Netherlands)

    Slegers, P.M.

    2014-01-01

    Microalgae are a promising biomass for the biobased economy to produce food, feed, fuel, chemicals and materials. So far, large-scale production of algae is limited and as a result estimates on the performance of such large systems are scarce. There is a need to estimate large-scale biomass

  15. Migrating Worker

    DEFF Research Database (Denmark)

    Hansen, Hans

    This is the preliminary report on the results obtained in the Migrating Worker-project. This project was initiated by the Danish Ministry of Finance with the aim of illustrating the effects of the 1408/71 agreement and the bilateral double taxation agreements Denmark has with the countries included...

  16. Dateline Migration.

    Science.gov (United States)

    Tomasi, Lydio E., Ed.

    1995-01-01

    Presents data on international migration and its effects in and between various countries in North America, Europe, and Africa. Discussions include refugee, immigrant, and migrant worker flows; the legal, political, and social problems surrounding immigrants; alien terrorism and law enforcement problems; and migrant effects on education, social…

  17. Migration from Mexico to the United States and subsequent risk for depressive and anxiety disorders: a cross-national study.

    Science.gov (United States)

    Breslau, Joshua; Borges, Guilherme; Tancredi, Daniel; Saito, Naomi; Kravitz, Richard; Hinton, Ladson; Vega, William; Medina-Mora, Maria Elena; Aguilar-Gaxiola, Sergio

    2011-04-01

    Migration is suspected to increase risk for depressive and anxiety disorders. To test the hypothesized increase in risk for depressive and anxiety disorders after arrival in the United States among Mexican migrants. We combined data from surveys conducted separately in Mexico and the United States that used the same diagnostic interview. Discrete time survival models were specified to estimate the relative odds of first onset of depressive disorders (major depressive episode and dysthymia) and anxiety disorders (generalized anxiety disorder, social phobia, panic disorder, and posttraumatic stress disorder) among migrants after their arrival in the United States compared with nonmigrant Mexicans who have a migrant in their immediate family. Population surveys in the United States and Mexico. Two thousand five hundred nineteen nonmigrant family members of migrants in Mexico and 554 Mexican migrants in the United States. First onset of any depressive or anxiety disorder. After arrival in the United States, migrants had a significantly higher risk for first onset of any depressive or anxiety disorder than did nonmigrant family members of migrants in Mexico (odds ratio, 1.42; 95% confidence interval, 1.04-1.94). Associations between migration and disorder varied across birth cohorts. Elevated risk among migrants relative to nonmigrants was restricted to the 2 younger cohorts (those aged 18-25 or 26-35 years at interview). In the most recent birth cohort, the association between migration and first onset of any depressive or anxiety disorder was particularly strong (odds ratio, 3.89; 95% confidence interval, 2.74-5.53). This is, to our knowledge, the first study to compare risk for first onset of psychiatric disorder between representative samples of migrants in the United States and nonmigrants in Mexico. The findings are consistent with the hypothesized adverse effect of migration from Mexico to the United States on the mental health of migrants, but only among

  18. Model studies of migration from paper and board into fruit and vegetables and into Tenax as a food simulant.

    Science.gov (United States)

    Bradley, E L; Castle, L; Speck, D R

    2014-01-01

    Four samples of paper and board (P/B) of a type used for packaging dry foods were subjected to migration tests using mushrooms, apples, potatoes and bananas, and using the polymeric powder Tenax as a food simulant. The P/B samples contained only low levels of diisopropylnaphthalene (DiPN) and diisobutyl phthalate (DiBP) and so the experiments were conducted after impregnating the P/B with added model substances. These were o-xylene, acetophenone, dodecane, benzophenone, DiPN and DiBP. Migration levels depended strongly on the nature of the substance and on the nature of the food and much less on the characteristics of the P/B, except insofar as they affected the contact area - flexible papers giving more extensive contact with the food than thick rigid board. Migration into Tenax was at least a factor of 10 higher than migration into the fresh fruit and vegetables. The food samples were placed in contact with the P/B and then overwrapped loosely with aluminium foil and so this correction factor will tend to be conservative compared with a more open storage of the packed foods. Washing, peeling or cooking the fruits and vegetables after contact with the P/B had a surprisingly small effect on contaminant levels in general, and no one processing step was effective in giving a significant reduction of all the types of chemicals studied. This was because either they had penetrated into the food (so resisting peeling), or were not freely water-soluble (so resisting washing) or were not particularly volatile (so resisting loss by evaporation during cooking).

  19. Luteolin inhibits the colon cancer HT-29 cell proliferation, migration and epithelial-mesenchymal transition: an experimental study

    Directory of Open Access Journals (Sweden)

    Xin Meng

    2017-11-01

    Full Text Available Objective: To study the regulating effect of luteolin on colon cancer HT-29 cell proliferation, migration and epithelial-mesenchymal transition. Methods: Colon cancer HT-29 cells were cultured and randomly divided into two groups, control group were treated with serum-free medium without drugs and LUT group were treated with serum-free medium containing luteolin. After 24 h of treatment, cells were collected to extract RNA, and then fluorescent quantitative PCR method was used to determine the mRNA expression of proliferation genes, migration genes and epithelial-mesenchymal transition genes. Results: After 24 h of luteolin treatment, Lrig1, TSPYL5, Bim, SOX15 and DLC1 mRNA expression in LUT group were significantly higher than those in control group while RPS15a, Bad, TRPV5, TRPV6, PLD2, IBP, SphK1, FAK, Vimentin and N-cadherin mRNA expression were significantly lower than those in control group. Conclusion: Luteolin has inhibiting effect on colon cancer HT-29 cell proliferation, migration and epithelial-mesenchymal transition.

  20. S1P Signalling Differentially Affects Migration of Peritoneal B Cell Populations In Vitro and Influences the Production of Intestinal IgA In Vivo.

    Science.gov (United States)

    Kleinwort, Annabel; Lührs, Felix; Heidecke, Claus-Dieter; Lipp, Martin; Schulze, Tobias

    2018-01-29

    Introduction: Sphingosine-1-phosphate (S1P) regulates the migration of follicular B cells (B2 cells) and directs the positioning of Marginal zone B cells (MZ B cells) within the spleen. The function of S1P signalling in the third B cell lineage, B1 B cells, mainly present in the pleural and peritoneal cavity, has not yet been determined. Methods: S1P receptor expression was analysed in peritoneal B cells by real-time polymerase chain reaction (qPCR). The chemotactic response to S1P was studied in vitro. The role of S1P signalling was further explored in a s1p₄ -/- mouse strain. Results: Peritoneal B cells expressed considerable amounts of the S1P receptors 1 and 4 (S1P₁ and S1P₄, respectively). S1P₁ showed differential expression between the distinct peritoneal B cell lineages. While B2 cells showed no chemotactic response to S1P, B1 B cells showed a migration response to S1P. s1p₄ -/- mice displayed significant alterations in the composition of peritoneal B cell populations, as well as a significant reduction of mucosal immunoglobulin A (IgA) in the gut. Discussion: S1P signalling influences peritoneal B1 B cell migration. S1P₄ deficiency alters the composition of peritoneal B cell populations and reduces secretory IgA levels. These findings suggest that S1P signalling may be a target to modulate B cell function in inflammatory intestinal pathologies.

  1. Study of heavy particle production

    International Nuclear Information System (INIS)

    1990-01-01

    The collaboration of Columbia University, Fermilab, University of Massachusetts, Mexico and Texas A ampersand M is working on installation of E690 at Fermilab and on analysis of data from the Brookhaven E766 experiment. All the major components of the E690 experiment are in place and final cabling and electronics check outs are being done. In addition to the Brookhaven set-up, the Fermilab set-up has a downstream spectrometer made up of five main ring magnets for detection of a fast 800 GeV proton. This allows us on-line to identify diffraction dissociation of the target proton and to select on the mass produced. We expect copious charm production and some bottom particles. This work should produce papers on charm production at Brookhaven, high mass diffraction dissociation, Lambda-Lambda correlations and polarization of Lamdas

  2. Thermal gradient brine inclusion migration in salt study: gas-liquid inclusions, preliminary model

    International Nuclear Information System (INIS)

    Olander, D.R.; Machiels, A.J.

    1979-10-01

    Natural salt deposits contain small cubical inclusions of brine distributed through the salt. Temperature gradients, resulting from storing heat-generating wastes in the salt, can cause the inclusions to move through the salt. Prediction of the rate and amount of brine-inclusion migration is necessary for the evaluation of bedded or domed salts as possible media for waste repositories. Inclusions filled exclusively with liquid migrate up the temperature gradient towards the heat source. The solubility of salt in the brine inclusion increases with temperature. Consequently, salt dissolves into the inclusion across the hot surface and crystallizes out at the cold surface. Diffusion of salt within the liquid phase from the hot to the cold faces causes the inclusions to move in the opposite direction. In so doing, they change shape and eventually become rectangular parallelipipeds with a width (dimension perpendicular to the thermal gradient) much larger than the thickness (dimension in the direction of the thermal gradient). The inclusions may also contain a gas phase predominantly consisting of water vapor. These entities are termed two-phase or gas-liquid inclusions. The two-phase inclusions usually migrate down the temperature gradient away from the heat source remaining more-or-less cubical. A two-phase inclusion also forms when an all-liquid inclusion reaches the waste package; upon opening up at the salt-package interface, the brine partially evaporates and the inclusion reseals with some insoluble gas trapped inside. These gas-liquid inclusions proceed to move down the temperature gradient, in the opposite sense of the all-liquid inclusions. The gas-liquid inclusions phenomenon provides a pathway by which radionuclides leached from the wasteform by the brine can be transported away from the waste package and thus might have greater access to the biosphere

  3. Tank Information System (tis): a Case Study in Migrating Web Mapping Application from Flex to Dojo for Arcgis Server and then to Open Source

    Science.gov (United States)

    Pulsani, B. R.

    2017-11-01

    Tank Information System is a web application which provides comprehensive information about minor irrigation tanks of Telangana State. As part of the program, a web mapping application using Flex and ArcGIS server was developed to make the data available to the public. In course of time as Flex be-came outdated, a migration of the client interface to the latest JavaScript based technologies was carried out. Initially, the Flex based application was migrated to ArcGIS JavaScript API using Dojo Toolkit. Both the client applications used published services from ArcGIS server. To check the migration pattern from proprietary to open source, the JavaScript based ArcGIS application was later migrated to OpenLayers and Dojo Toolkit which used published service from GeoServer. The migration pattern noticed in the study especially emphasizes upon the use of Dojo Toolkit and PostgreSQL database for ArcGIS server so that migration to open source could be performed effortlessly. The current ap-plication provides a case in study which could assist organizations in migrating their proprietary based ArcGIS web applications to open source. Furthermore, the study reveals cost benefits of adopting open source against commercial software's.

  4. TANK INFORMATION SYSTEM (TIS: A CASE STUDY IN MIGRATING WEB MAPPING APPLICATION FROM FLEX TO DOJO FOR ARCGIS SERVER AND THEN TO OPEN SOURCE

    Directory of Open Access Journals (Sweden)

    B. R. Pulsani

    2017-11-01

    Full Text Available Tank Information System is a web application which provides comprehensive information about minor irrigation tanks of Telangana State. As part of the program, a web mapping application using Flex and ArcGIS server was developed to make the data available to the public. In course of time as Flex be-came outdated, a migration of the client interface to the latest JavaScript based technologies was carried out. Initially, the Flex based application was migrated to ArcGIS JavaScript API using Dojo Toolkit. Both the client applications used published services from ArcGIS server. To check the migration pattern from proprietary to open source, the JavaScript based ArcGIS application was later migrated to OpenLayers and Dojo Toolkit which used published service from GeoServer. The migration pattern noticed in the study especially emphasizes upon the use of Dojo Toolkit and PostgreSQL database for ArcGIS server so that migration to open source could be performed effortlessly. The current ap-plication provides a case in study which could assist organizations in migrating their proprietary based ArcGIS web applications to open source. Furthermore, the study reveals cost benefits of adopting open source against commercial software's.

  5. Preliminary study of the migration of technetium in soil under hydrous conditions

    International Nuclear Information System (INIS)

    Sisson, D.H.; MacLean, S.C.; Schulz, R.K.; Borg, R.J.

    1979-01-01

    The sorption of technetium compared to sodium, cesium, and strontium by a common agricultural soil was measured using a column method. As expected, no sorption of Tc occurred under conditions that substantially removed Na + , Cs + , and Sr ++ . High radioactivity levels were used to establish absorption profiles over six orders of magnitude of tracer concentration. Behavior of initially dry columns was compared with that of initially water-saturated columns; the results were not quantitatively different although there was a qualitative difference in the appearance of the profiles. Technetium tracked the moisture content of the column and hence migrated at the veloccity of the aqueous medium

  6. A study on nuclide migration in buffer materials and rocks for geological disposal of radioactive waste

    International Nuclear Information System (INIS)

    Sato, Haruo

    1998-01-01

    This thesis summarizes the results investigated in order to establish a basic theory on the predictive method of diffusion coefficients of nuclides in compacted sodium bentonite which is a candidate buffer material and in representative rocks for the geological disposal of radioactive waste by measuring the pore structural factors of the compacted bentonite and rocks such as porosity and tortuosity, measuring diffusion coefficients of nuclides in the bentonite and rocks, acquiring basic data on diffusion and developing diffusion models which can quantitatively predict nuclide migration in long-term. (J.P.N.). 117 refs

  7. Seizures, cysticercosis and rural-to-urban migration: the PERU MIGRANT study

    Science.gov (United States)

    Gonzales, Isidro; Miranda, J Jaime; Rodriguez, Silvia; Vargas, Victor; Cjuno, Alfredo; Smeeth, Liam; Gonzalez, Armando E; Tsang, Victor C W; Gilman, Robert H; Garcia, Hector H

    2015-01-01

    Objectives To examine the prevalence of seizures, epilepsy and seropositivity to cysticercosis in rural villagers (cysticercosis-endemic setting), rural-to-urban migrants into a non-endemic urban shanty town and urban inhabitants of the same non-endemic shanty town. Methods Three Peruvian populations (n = 985) originally recruited into a study about chronic diseases and migration were studied. These groups included rural inhabitants from an endemic region (n = 200), long-term rural-to-urban migrants (n = 589) and individuals living in the same urban setting (n = 196). Seizure disorders were detected by a survey, and a neurologist examined positive respondents. Serum samples from 981/985 individuals were processed for cysticercosis antibodies on immunoblot. Results Epilepsy prevalence (per 1000 people) was 15.3 in the urban group, 35.6 in migrants and 25 in rural inhabitants. A gradient in cysticercosis antibody seroprevalence was observed: urban 2%, migrant 13.5% and rural group 18% (P grupos incluían habitantes rurales de una región endémica (n=200), inmigrantes de larga duración de zonas rurales a urbanas (n=589), e individuos que vivían en la misma zona urbana (n=196). Las convulsiones se detectaron mediante una encuesta y un neurólogo examinó a quienes habían respondido positivamente. Se procesaron muestras de suero de 981/985 individuos en busca de anticuerpos para cisticercosis mediante inmunoblot. Resultados La prevalencia de epilepsia (por 1,000 personas) era de 15.3 en el grupo urbano, 35.6 en inmigrantes y 25 en habitantes rurales. Se observó un gradiente en la seroprevalencia de los anticuerpos para cisticercosis: grupos urbano 2%, inmigrante 13.5% y rural 18% (p<0.05). Se observó un patrón de aumento similar de mayor seroprevalencia entre inmigrantes según la edad que tenían en el momento de emigrar. En pobladores rurales, había una evidencia importante de asociación entre tener una serología positiva y sufrir convulsiones (p=0

  8. Studying uranium migration in natural environment: experimental approach and geochemical modeling

    International Nuclear Information System (INIS)

    Phrommavanh, V.

    2008-10-01

    The present study deals with characterizing uranium migration in a limited zone of Le Bouchet site, a former uranium ore treatment facility, which is dismantled and the rehabilitation of which is under process. Some wastes are packed in a rehabilitated disposal nearby, called the Itteville site. In the framework of the monitoring of the deposit environment (air, water, sediment) set by prefectorial decrees, a piezometer (PZPK) located downstream to the latter, has shown total dissolved uranium peaks each winter since the 1990's. PZPK collects both the interstitial water of a calcareous peat formation, between the surface and 3 m, and an alluvial aquifer near 6 m of depth. Firstly, a hydrogeochemical characterization of the site has evidenced the uranium source term, which is present in the peat soil near 0.8 m, hence excluding any leaching from the waste disposal. Actually, a few microparticles of uranium oxide and mixed uranium-thorium oxide have been detected, but they do not represent the major part of the source term. Secondly, water chemistry of the peat soil water and PZPK has been monitored every two months from 2004 to 2007 in order to understand the reasons of the seasonal fluctuations of [U]tot.diss.. Completed with geochemical modeling and a bacterial identification by 16S rDNA sequence analysis, water chemistry data showed an important sulfate-reducing bacterial activity in summertime, leading to reducing conditions and therefore, a total dissolved uranium content limited by the low solubility of uraninite U IV O 2 (s). In wintertime, the latter bacterial activity being minimal and the effective pluviometry more important, conditions are more oxidant, which favors U(VI), more soluble, notably as the Ca 2 UO 2 (CO 3 ) 3 (aq) complex, evidenced by TRLFS. Finally, bacterial activity has been reproduced in laboratory in order to better characterize its impact on uranium solubility in the peat soil. Various parameters were tested (C sources, temperature

  9. Clonorchis sinensis excretory-secretory products regulate migration and invasion in cholangiocarcinoma cells via extracellular signal-regulated kinase 1/2/nuclear factor-κB-dependent matrix metalloproteinase-9 expression.

    Science.gov (United States)

    Pak, Jhang Ho; Shin, Jimin; Song, In-Sung; Shim, Sungbo; Jang, Sung-Wuk

    2017-01-01

    Matrix metalloproteinase-9 plays an important role in the invasion and metastasis of various types of cancer cells. We have previously reported that excretory-secretory products from Clonorchis sinensis increases matrix metalloproteinase-9 expression. However, the regulatory mechanisms through which matrix metalloproteinase-9 expression affects cholangiocarcinoma development remain unclear. In the current study, we examined the potential role of excretory-secretory products in regulating the migration and invasion of various cholangiocarcinoma cell lines. We demonstrated that excretory-secretory products significantly induced matrix metalloproteinase-9 expression and activity in a concentration-dependent manner. Reporter gene and chromatin immunoprecipitation assays showed that excretory-secretory products induced matrix metalloproteinase-9 expression by enhancing the activity of nuclear factor-kappa B. Moreover, excretory-secretory products induced the degradation and phosphorylation of IκBα and stimulated nuclear factor-kappa B p65 nuclear translocation, which was regulated by extracellular signal-regulated kinase 1/2. Taken together, our findings indicated that the excretory-secretory product-dependent enhancement of matrix metalloproteinase-9 activity and subsequent induction of IκBα and nuclear factor-kappa B activities may contribute to the progression of cholangiocarcinoma. Copyright © 2016 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.

  10. The study of the migration of the radionuclide Am-241 in unsaturated soil from in Saligny area

    International Nuclear Information System (INIS)

    Toma, Alexandru Dan

    2005-01-01

    The functioning of the Cernavoda Nuclear Power Plant will generate low and medium radioactive waste contaminated with long-lived fission products (from U, Pu, Np, Am fission or decay), radioactive carbon (C-14) and tritium (H-3), which by their radiochemical characteristics and their influence upon the environment and people, request special attention regarding their storage and disposal. Based on the geological and mineralogical researches regarding the location of a repository for low and medium active waste, Saligny area near the Cernavoda Nuclear Power Plant was chosen. The repository will be located in loess, seated on sedimentary formations with insertions of clay patches. The main target of the research is to obtain some experimental data necessary for the evaluation of the migration of the radionuclide Am-241 (resulted from Cernavoda Nuclear Power Plant) in unsaturated soils in Saligny area, which will be the host of the Final Repository for Low and Medium Active Waste. The analysis of the test data obtained in the laboratory for the determination of the migration parameters of the radionuclide Am-241 in the material of the geological formation of Saligny area showed that there is a direct correlation between the values of these parameters and the basic mineralogical component - clay - of the soil sample. (author)

  11. Laboratory and field studies related to the radionuclide migration project. Progress report, October 1, 1982-September 30, 1983

    International Nuclear Information System (INIS)

    Daniels, W.R.; Thompson, J.L.

    1984-04-01

    The FY 1983 laboratory and field studies related to the Radionuclide Migration project are described. Results are presented for radiochemical analyses of water samples collected from the RNM-1 well and the RNM-2S satellite well at the Cambric site. Data are included for tritium, 36 Cl, 85 Kr, 90 Sr, 129 I, and 137 Cs. Preliminary results from water collection at the Cheshire site are reported. Laboratory studies emphasize the sorptive behavior of tuff and its dependence on mineralogy. 18 references, 7 figures, 13 tables

  12. Family, Socialization and Migration in Norwegian-Pakistani Families: A Study of the First and the Second Generation

    OpenAIRE

    Shakari, Yasmine

    2013-01-01

    Summary Author s name: Yasmine Shakari Title: Family, Socialization and Migration in Norwegian-Pakistani Families: A Study of the First and the Second Generation Supervisor: Øystein Gullvåg Holter Co-supervisor: Thomas Walle Aim of study: This thesis seeks to obtain knowledge about 1) how the first generation of Norwegian-Pakistanis were raised in Pakistan in terms of socialization of gender roles, 2) how the second generation of Norwegian-Pakistanis have been raised here in Norway, and 3) if...

  13. Quantitative genetics of migration syndromes: a study of two barn swallow populations.

    Science.gov (United States)

    Teplitsky, C; Mouawad, N G; Balbontin, J; De Lope, F; Møller, A P

    2011-09-01

    Migration is a complex trait although little is known about genetic correlations between traits involved in such migration syndromes. To assess the migratory responses to climate change, we need information on genetic constraints on evolutionary potential of arrival dates in migratory birds. Using two long-term data sets on barn swallows Hirundo rustica (from Spain and Denmark), we show for the first time in wild populations that spring arrival dates are phenotypically and genetically correlated with morphological and life history traits. In the Danish population, length of outermost tail feathers and wing length were negatively genetically correlated with arrival date. In the Spanish population, we found a negative genetic correlation between arrival date and time elapsed between arrival date and laying date, constraining response to selection that favours both early arrival and shorter delays. This results in a decreased rate of adaptation, not because of constraints on arrival date, but constraints on delay before breeding, that is, a trait that can be equally important in the context of climate change. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

  14. Studying Strangeness Production with HADES

    Science.gov (United States)

    Schuldes, Heidi

    2018-02-01

    The High-Acceptance DiElectron Spectrometer (HADES) operates in the 1 - 2A GeV energy regime in fixed target experiments to explore baryon-rich strongly interacting matter in heavy-ion collisions at moderate temperatures with rare and penetrating probes. We present results on the production of strange hadrons below their respective NN threshold energy in Au+Au collisions at 1.23A GeV ( = 2.4 GeV). Special emphasis is put on the enhanced feed-down contribution of ϕ mesons to the inclusive yield of K- and its implication on the measured spectral shape of K-. Furthermore, we investigate global properties of the system, confronting the measured hadron yields and transverse mass spectra with a Statistical Hadronization Model (SHM) and a blastwave parameterization, respectively. These supplement the world data of the chemical and kinetic freeze-out temperatures.

  15. Studying uranium migration in natural environment: experimental approach and geochemical modeling; Etude de la migration de l'uranium en milieu naturel: approche experimentale et modelisation geochimique

    Energy Technology Data Exchange (ETDEWEB)

    Phrommavanh, V.

    2008-10-15

    The present study deals with characterizing uranium migration in a limited zone of Le Bouchet site, a former uranium ore treatment facility, which is dismantled and the rehabilitation of which is under process. Some wastes are packed in a rehabilitated disposal nearby, called the Itteville site. In the framework of the monitoring of the deposit environment (air, water, sediment) set by prefectorial decrees, a piezometer (PZPK) located downstream to the latter, has shown total dissolved uranium peaks each winter since the 1990's. PZPK collects both the interstitial water of a calcareous peat formation, between the surface and 3 m, and an alluvial aquifer near 6 m of depth. Firstly, a hydrogeochemical characterization of the site has evidenced the uranium source term, which is present in the peat soil near 0.8 m, hence excluding any leaching from the waste disposal. Actually, a few microparticles of uranium oxide and mixed uranium-thorium oxide have been detected, but they do not represent the major part of the source term. Secondly, water chemistry of the peat soil water and PZPK has been monitored every two months from 2004 to 2007 in order to understand the reasons of the seasonal fluctuations of [U]tot.diss.. Completed with geochemical modeling and a bacterial identification by 16S rDNA sequence analysis, water chemistry data showed an important sulfate-reducing bacterial activity in summertime, leading to reducing conditions and therefore, a total dissolved uranium content limited by the low solubility of uraninite U{sup IV}O{sub 2}(s). In wintertime, the latter bacterial activity being minimal and the effective pluviometry more important, conditions are more oxidant, which favors U(VI), more soluble, notably as the Ca{sub 2}UO{sub 2}(CO{sub 3}){sub 3}(aq) complex, evidenced by TRLFS. Finally, bacterial activity has been reproduced in laboratory in order to better characterize its impact on uranium solubility in the peat soil. Various parameters were tested

  16. Intra-household tensions and conflicts of interest in migration decision making: a case study of the Todgha valley, Morocco

    NARCIS (Netherlands)

    de Haas, H.; Fokkema, C.M.

    2009-01-01

    This paper explores the role of intra-household tensions and conflicts of interest in explaining the diverse return and pendulum migration strategies among Moroccan migrants who first migrated to Europe in the 1960s and 1970s. Migration strategies and motivations of migrants and their households are

  17. The Oklo natural nuclear reactors: neutron parameters, age and duration of the reactions, uranium and fission products migrations

    International Nuclear Information System (INIS)

    Ruffenach, J.-C.

    1979-09-01

    Mass spectrometry and isotopic dilution technique are used in order to carry out, on various samples from the fossil nuclear reactors at Oklo, Gabon, isotopic and chemical analyses of some particular elements involved in the nuclear reactions: uranium, lead, bismuth, thorium, rare gases (krypton, xenon), rare earths (neodymium, samarium, europium, gadolinium, dysprosium), ruthenium and palladium. Interpretations of these analyses lead to the determination of many neutron parameters such as the neutron fluence received by the samples, the spectrum index, the conversion coefficient, and also the percentages of fissions due to uranium-238 and plutonium-239 and the total number of fissions relative to uranium. All these results make it possible to determine the age of the nuclear reactions by measuring the amounts of fission rare earths formed, i.e. 1.97 billion years. This study brings some informations to the general problem of radioactive wastes storage in deep geological formations, the storage of uranium, plutonium and many fission products having been carried out naturally, and for about two billion years [fr

  18. Oxygen vacancy formation and migration in Sr- and Mg-doped LaGaO3: a density functional theory study

    International Nuclear Information System (INIS)

    Zhang Jie; Liang Er-Jun; Sun Qiang; Jia Yu

    2012-01-01

    Oxygen vacancy formation and migration in La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ (LSGM) with various crystal symmetries (cubic, rhombohedral, orthorhombic, and monoclinic) are studied by employing first-principles calculations based on density functional theory (DFT). It is shown that the cubic LSGM has the smallest band gap, oxygen vacancy formation energy, and migration barrier, while the other three structures give rise to much larger values for these quantities, implying the best oxygen ion conductivity of the cubic LSGM among the four crystal structures. In our calculations, one oxygen vacancy migration pathway is considered in the cubic and rhombohedral structures due to all the oxygen sites being equivalent in them, while two vacancy migration pathways with different migration barriers are found in the orthorhombic and monoclinic symmetries owing to the existence of nonequivalent O 1 and O 2 oxygen sites. The migration energies along the migration pathway linking the two O 2 sites are obviously lower than those along the pathway linking the O 1 and O 2 sites. Considering the phase transitions at high temperatures, the results obtained in this paper can not only explain the experimentally observed different behaviours of the oxygen ionic conductivity of LSGM with different symmetries, but also predict the rational crystal structures of LSGM for solid oxide fuel cell applications. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  19. Capitalist development and internal migration in Nigeria.

    Science.gov (United States)

    Akor, R I; Mou, D

    1986-12-01

    The authors analyze internal migration trends in Nigeria by examining individual household strategies and how they have adapted to structural changes brought about by colonial rule and capitalist development. The first section of this article describes the structural changes that started the process of labor migration. The second section deals with post-independence industrialization and the consequent rural-urban migration. The final section analyzes the consequences of these migration patterns for urban growth and rural productivity.

  20. A preference for migration

    OpenAIRE

    Stark, Oded

    2007-01-01

    At least to some extent migration behavior is the outcome of a preference for migration. The pattern of migration as an outcome of a preference for migration depends on two key factors: imitation technology and migration feasibility. We show that these factors jointly determine the outcome of a preference for migration and we provide examples that illustrate how the prevalence and transmission of a migration-forming preference yield distinct migration patterns. In particular, the imitation of...

  1. Studies of cesium and strontium migration in unconsolidated Canadian geological materials

    International Nuclear Information System (INIS)

    Gillham, R.W.; Lindsay, L.E.; Reynolds, W.D.; Kewen, T.J.; Cherry, J.A.; Reddy, M.R.

    1981-06-01

    Distribution coefficients (Ksub(d)) were measured for cesium and strontium in 16 samples of Canadian unconsolidated geological materials. The samples were collected to cover a wide range of grain size, clay-mineral composition, cation exchange capacity and carbonate mineral content. Distribution coefficients ranged between 10 2 and 2.0 x 10 4 ml/g for cesium and between 2.5 and 10 2 ml/g for strontium, indicating that most unconsolidated geological materials have a substantial ability to retard the migration of cesium, while strontium could generally be expected to be somewhat more mobile. The measured K values were not significantly correlated with the measured soil properties, but appeared to be significantly affected by the background concentration of stable isotopes of the respective radionuclides

  2. Dietary intake and rural-urban migration in India: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Liza Bowen

    Full Text Available Migration from rural areas of India contributes to urbanisation and lifestyle change, and dietary changes may increase the risk of obesity and chronic diseases. We tested the hypothesis that rural-to-urban migrants have different macronutrient and food group intake to rural non-migrants, and that migrants have a diet more similar to urban non-migrants.The diets of migrants of rural origin, their rural dwelling sibs, and those of urban origin together with their urban dwelling sibs were assessed by an interviewer-administered semi-quantitative food frequency questionnaire. A total of 6,509 participants were included. Median energy intake in the rural, migrant and urban groups was 2731, 3078, and 3224 kcal respectively for men, and 2153, 2504, and 2644 kcal for women (p<0.001. A similar trend was seen for overall intake of fat, protein and carbohydrates (p<0.001, though differences in the proportion of energy from these nutrients were <2%. Migrant and urban participants reported up to 80% higher fruit and vegetable intake than rural participants (p<0.001, and up to 35% higher sugar intake (p<0.001. Meat and dairy intake were higher in migrant and urban participants than rural participants (p<0.001, but varied by region. Sibling-pair analyses confirmed these results. There was no evidence of associations with time in urban area.Rural to urban migration appears to be associated with both positive (higher fruit and vegetables intake and negative (higher energy and fat intake dietary changes. These changes may be of relevance to cardiovascular health and warrant public health interventions.

  3. Demographic predictors of active tuberculosis in people migrating to British Columbia, Canada: a retrospective cohort study.

    Science.gov (United States)

    Ronald, Lisa A; Campbell, Jonathon R; Balshaw, Robert F; Romanowski, Kamila; Roth, David Z; Marra, Fawziah; Cook, Victoria J; Johnston, James C

    2018-02-26

    Canadian tuberculosis (TB) guidelines recommend targeting postlanding screening for and treatment of latent tuberculosis infection (LTBI) in people migrating to Canada who are at increased risk for TB reactivation. Our objectives were to calculate robust longitudinal estimates of TB incidence in a cohort of people migrating to British Columbia, Canada, over a 29-year period, and to identify groups at highest risk of developing TB based on demographic characteristics at time of landing. We included all individuals ( n = 1 080 908) who became permanent residents of Canada between Jan. 1, 1985, and Dec. 31, 2012, and were resident in BC at any time between 1985 and 2013. Multiple administrative databases were linked to the provincial TB registry. We used recursive partitioning models to identify populations with high TB yield. Active TB was diagnosed in 2814 individuals (incidence rate 24.2/100 000 person-years). Demographic factors (live-in caregiver, family, refugee immigration classes; higher TB incidence in country of birth; and older age) were strong predictors of TB incidence in BC, with elevated rates continuing many years after entry into the cohort. Recursive partitioning identified refugees 18-64 years of age from countries with a TB incidence greater than 224/100 000 population as a high-yield group, with 1% developing TB within the first 10 years. These findings support recommendations in Canadian guidelines to target postlanding screening for and treatment of LTBI in adult refugees from high-incidence countries. Because high-yield populations can be identified at entry via demographic data, screening at this point may be practical and high-impact, particularly if the LTBI care cascade can be optimized. © 2018 Joule Inc. or its licensors.

  4. An Explanatory Study of Lean Practices in Job Shop Production/ Special Job Production/ Discrete Production/ Batch Shop Production Industries

    OpenAIRE

    Lavlesh Kumar Sharma; Ravindra Mohan Saxena

    2014-01-01

    In this paper, the study explores the benefits and advantages of Lean Practices or Lean Thinking in Job shop production/ Special job production/ Discrete production/ Batch shop production industries. The Lean Practices have been applied more compatible in Job shop production than in the continuous/ mass production because of several barriers and hurdles in the industrial context that influence the whole processes again and again, this happens due to the lack of knowledge about...

  5. Simulation Study of a Vehicle Production Line for Productivity Improvement

    Directory of Open Access Journals (Sweden)

    M.F.F. Ab Rashid

    2015-06-01

    Full Text Available This paper presents the study of a motorcycle frame production line in a particular company in Malaysia. Due to the high demand, the company needs to increase its production by at least 12% compared with current output. In order to improve productivity, the production-floor data was collected and simulated using the discrete event simulation approach. Later, a number of suggestions for improvement were simulated to identify the effect of the suggestions on productivity. In addition, cost analysis was also undertaken to identify the profit margin for a particular period of time for each suggestion. Simulation results indicate that there are three suggestions that are able to fulfill the 12% volume increment. In the short term, the suggestion to hire an assistant line leader will give instant effect to the profit. Meanwhile, for the medium term, Poka-yoke will give higher profit compared with the others, while in the long term, SOP (standard operating procedure implementation will yield a better profit margin. In future, the simulation of a dynamic demand model for this product is suggested to cope with new trends in the market.

  6. Radionuclide migration studies at the Savannah River Plant humid shallow land burial site for low-level waste

    International Nuclear Information System (INIS)

    Stone, J.A.; Oblath, S.B.; Hawkins, R.H.; Emslie, R.H.; Hoeffner, S.L.; King, C.M.

    1984-01-01

    A program of field, laboratory, and modeling studies for the Savannah River Plant low-level waste burial ground has been conducted for several years. The studies provide generic data on an operating shallow land burial site in a humid region. Recent results from individual studies on subsurface monitoring, lysimeter tests, soil-water chemistry, and transport modeling are reported. Monitoring continues to show little movement of radionuclides except tritium. Long-term lysimeter tests with a variety of defense wastes measure migration under controlled field conditions. One lysimeter was excavated to study radionuclide distribution on the soil column beneath the waste. New soil-water distribution coefficients (K/sub d/) were measured for Co-60, Sr-90, Ru-106, Sb-125, and I-129. Laboratory and field data are integrated by means of the SRL dose-to-man model, to evaluate effects of alternative disposal practices. The model recently has been used to evaluate TRU disposal criteria and to predict migration behavior of tritium, Tc-99, and I-129. 14 references, 2 tables

  7. Evaluation of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ): a cross-sectional study.

    Science.gov (United States)

    Sullivan, Ruth; Kinra, Sanjay; Ekelund, Ulf; Bharathi, A V; Vaz, Mario; Kurpad, Anura; Collier, Tim; Reddy, K Srinath; Prabhakaran, Dorairaj; Ebrahim, Shah; Kuper, Hannah

    2012-02-09

    Socio-cultural differences for country-specific activities are rarely addressed in physical activity questionnaires. We examined the reliability and validity of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ) in urban and rural groups in India. A sub-sample of IMS participants (n = 479) was used to examine short term (≤ 1 month [n = 158]) and long term (> 1 month [n = 321]) IMS-PAQ reliability for levels of total, sedentary, light and moderate/vigorous activity (MVPA) intensity using intraclass correlation (ICC) and kappa coefficients (k). Criterion validity (n = 157) was examined by comparing the IMS-PAQ to a uniaxial accelerometer (ACC) worn ≥ 4 days, via Spearman's rank correlations (ρ) and k, using Bland-Altman plots to check for systematic bias. Construct validity (n = 7,000) was established using linear regression, comparing IMS-PAQ against theoretical constructs associated with physical activity (PA): BMI [kg/m2], percent body fat and pulse rate. IMS-PAQ reliability ranged from ICC 0.42-0.88 and k = 0.37-0.61 (≤ 1 month) and ICC 0.26 to 0.62; kappa 0.17 to 0.45 (> 1 month). Criterion validity was ρ = 0.18-0.48; k = 0.08-0.34. Light activity was underestimated and MVPA consistently and substantially overestimated for the IMS-PAQ vs. the accelerometer. Criterion validity was moderate for total activity and MVPA. Reliability and validity were comparable for urban and rural participants but lower in women than men. Increasing time spent in total activity or MVPA, and decreasing time in sedentary activity were associated with decreasing BMI, percent body fat and pulse rate, thereby demonstrating construct validity. IMS-PAQ reliability and validity is similar to comparable self-reported instruments. It is an appropriate tool for ranking PA of individuals in India. Some refinements may be required for sedentary populations and women in India.

  8. MIGRATION AND ITS ENVIROMENTAL EFFECTS

    OpenAIRE

    Rashid SAEED; Rana NADIR IDREES; Humna IJAZ; Marriam FURQANI; Raziya NADEEM

    2012-01-01

    Migration can be ongoing shifting of a particular person from one location to another. The reason of shifting depends on selected thought deficiency, shock, difficulties, hopes, enthusiasm. Case study ended up recognizing the extent to which in turn migration can be relying on the specifics especially natural environment. This particular document expects to research the actual linkages between the atmosphere as well as migration using secondary data. Lots of investigation may be completed wit...

  9. Nordic Migration and Integration Research

    OpenAIRE

    Pyrhönen, Niko; Martikainen, Tuomas; Leinonen, Johanna

    2017-01-01

    EXECUTIVE SUMMARY Migration and integration are currently highly contentious topics in political, public and scientific arenas, and will remain so in the near future. However, many common migration-related prejudices and inefficien¬cies in the integration of the migrant population are due to the lack of sound, tested and accessible scientific research. Therefore, the study of migration – by developing basic research and by properly resourcing novel methodological approaches and interventions ...

  10. Alcohol consumption and binge drinking in adolescents: comparison of different migration backgrounds and rural vs. urban residence - a representative study

    Directory of Open Access Journals (Sweden)

    Bleich Stefan

    2011-02-01

    Full Text Available Abstract Background Binge drinking is a constant problem behavior in adolescents across Europe. Epidemiological investigations have been reported. However, epidemiological data on alcohol consumption of adolescents with different migration backgrounds are rare. Furthermore representative data on rural-urban comparison concerning alcohol consumption and binge drinking are lacking. The aims of the study are the investigation of alcohol consumption patterns with respect to a urban-rural differences and b differences according to migration background. Methods In the years 2007/2008, a representative written survey of N = 44,610 students in the 9th. grade of different school types in Germany was carried out (net sample. The return rate of questionnaires was 88% regarding all students whose teachers respectively school directors had agreed to participate in the study. Weighting factors were specified and used to make up for regional and school-type specific differences in return rates. 27.4% of the adolescents surveyed have a migration background, whereby the Turkish culture is the largest group followed by adolescents who emigrated from former Soviet Union states. The sample includes seven large cities (over 500,000 inhabitants (12.2%, independent smaller cities ("urban districts" (19.0% and rural areas ("rural districts" (68.8%. Results Life-time prevalence for alcohol consumption differs significantly between rural (93.7% and urban areas (86.6% large cities; 89.1% smaller cities with a higher prevalence in rural areas. The same accounts for 12-month prevalence for alcohol consumption. 57.3% of the rural, re-spectively 45.9% of the urban adolescents engaged in binge drinking in the 4 weeks prior to the survey. Students with migration background of the former Soviet Union showed mainly drinking behavior similar to that of German adolescents. Adolescents with Turkish roots had engaged in binge drinking in the last four weeks less frequently than

  11. Study of rare earth elements, uranium and thorium migration in rocks from Espinharas uranium deposit, Paraiba - Brazil

    International Nuclear Information System (INIS)

    Conceicao, Cirilo C.S.

    2009-01-01

    The determination of rare earth elements as natural analogue in patterns geologic has grown as a tool for predicting the long-term safety of nuclear disposal in geological formation. Migration of natural radionuclides is one of the most serious problems in the waste deposit from nuclear fuel cycle. Rare earth elements show the same kinetic behavior in rocks as natural radionuclides. This similar property of the analogues allows perform studies and models on the subject of radionuclides migration. The aim of this study was to determine the distribution of rare earth elements in rocks located at Espinharas - Paraiba - Brazil, uranium deposit. In this work are presented the results from the study above the distribution of rare earth elements in function of the degree of mineralized rocks, composition and the conditions of radioactive equilibrium of the uranium and thorium in some fractures on the rocks from radioactive occurrence of Espinharas-Brazil. The results show that there is a correlation of heavy rare earth elements, uranium and Thorium concentrations to oxidation factor of the rocks. However this correlation was not observed for light rare earth elements. It means that heavy rare earth elements follow the natural radionuclides in oxidation process of rocks. The samples were analyzed by ICP-MS, alpha and gamma spectrometry, X-ray diffraction and fluorimetry. (author)

  12. Comparative study of bioethanol production from sugarcane ...

    African Journals Online (AJOL)

    The study was designed to compare the bioethanol production from Zymomonas mobilis and Saccharomyces cerevisiae using molasses as production medium. The focus was on the retention time at lab scale. Bioethanol and petroleum blend can be used in existing gasoline engines. Present study showed a more ...

  13. Migration from Mexico to the US and Subsequent Risk for Depressive and Anxiety Disorders: A Cross-National Study

    Science.gov (United States)

    Breslau, Joshua; Borges, Guilherme; Tancredi, Daniel; Saito, Naomi; Kravitz, Richard; Hinton, Ladson; Vega, William; Medina-Mora, Maria Elena; Aguilar-Gaxiola, Sergio

    2013-01-01

    Objective To test the hypothesized increase in risk for depressive and anxiety disorders following arrival in the US among Mexican-origin migrants. Method Data from surveys conducted in Mexico and the US were combined. The surveys were conducted separately, but used the same structured diagnostic interview. Discrete time survival models were specified to estimate the relative odds of first onset of depressive (major depressive episode, dysthymia) and anxiety (generalized anxiety disorder, social phobia, panic disorder, posttraumatic stress disorder) disorders among migrants after their arrival in the US compared with non-migrant Mexicans who have a migrant in their immediate family. Results After arrival in the US, migrants had signficantly higher risk for first onset of any depressive or anxiety disorder than non-migrant family members of migrants in Mexico (OR=1.4, 95% CI =1.04–1.94). Associations between migration and disorder varied across birth cohorts. Elevated risk among migrants relative to non-migrants was restricted to the two younger cohorts, those 18–25 or 26–35 years old at interview. In the most recent cohort, the association between migration and first onset of any depressive or anxiety disorder was particularly strong (OR=3.89, 95% CI=2.74–5.53). Conclusions This is the first study to compare risk for first onset of psychaitric disorder between representative samples of migrants in the US and non-migrants in Mexico. The findings are consistent with the hypothesized adverse effect of migration from Mexico to the US on the mental health of migrants, but only among migrants in recent birth cohorts. PMID:21464367

  14. S1P Signalling Differentially Affects Migration of Peritoneal B Cell Populations In Vitro and Influences the Production of Intestinal IgA In Vivo

    Directory of Open Access Journals (Sweden)

    Annabel Kleinwort

    2018-01-01

    Full Text Available Introduction: Sphingosine-1-phosphate (S1P regulates the migration of follicular B cells (B2 cells and directs the positioning of Marginal zone B cells (MZ B cells within the spleen. The function of S1P signalling in the third B cell lineage, B1 B cells, mainly present in the pleural and peritoneal cavity, has not yet been determined. Methods: S1P receptor expression was analysed in peritoneal B cells by real-time polymerase chain reaction (qPCR. The chemotactic response to S1P was studied in vitro. The role of S1P signalling was further explored in a s1p4−/− mouse strain. Results: Peritoneal B cells expressed considerable amounts of the S1P receptors 1 and 4 (S1P1 and S1P4, respectively. S1P1 showed differential expression between the distinct peritoneal B cell lineages. While B2 cells showed no chemotactic response to S1P, B1 B cells showed a migration response to S1P. s1p4−/− mice displayed significant alterations in the composition of peritoneal B cell populations, as well as a significant reduction of mucosal immunoglobulin A (IgA in the gut. Discussion: S1P signalling influences peritoneal B1 B cell migration. S1P4 deficiency alters the composition of peritoneal B cell populations and reduces secretory IgA levels. These findings suggest that S1P signalling may be a target to modulate B cell function in inflammatory intestinal pathologies.

  15. The effects of low dose ionizing radiation on the development of rat cerebral cortex, (2); In vitro study with regards to neuronal migration

    Energy Technology Data Exchange (ETDEWEB)

    Matsushita, Koji [Kyoto Prefectural Univ. of Medicine (Japan)

    1993-03-01

    In order to study the molecular mechanisms of neuronal migration on developing rat cerebral cortex, we need a tissue culture system in which neuronal migration can be observed. We prepared a tissue culture system of embryonic rat cerebral cortex starting on embryonic day 16 and cultivating it for 48 hours. The autoradiographic study in this system revealed not only the migration of [sup 3]H-thymidine labeled neurons but also neuronal migration delays from low doses of ionizing radiation of more than 10 cGy. In addition, on immunohistochemical study, cell-cell adhesion molecule N-CAM staining was remarkably decreased in the matrix cell layer. In the tissue culture system where monoclonal anti-N-CAM antibodies were added, neuronal migration delay comparable to that of 20 cGy radiation was found. In conclusion, it was speculated that neuronal migration delay might be caused by disturbed N-CAM synthesis in matrix cells after low dose ionizing radiation. (author).

  16. HS-SPME-GC-MS analysis of antioxidant degradation products migrating to drinking water from PE materials and PEX pipes

    DEFF Research Database (Denmark)

    Lützhøft, Hans-Christian Holten; Waul, Christopher Kevin; Andersen, Henrik Rasmus

    2013-01-01

    degradation products may leach and enter drinking water. The aim of this investigation was to develop a method for measuring these degradation products with a performance meeting the drinking water quality criteria of 20 µg L−1. Using headspace solid phase microextraction coupled to a gas chromatograph......Polyethylene (PE) and cross-linked polyethylene (PEX) pipes are frequently used in water supply systems. Such pipes contain added antioxidants with phenolic structures, e.g. Irgafos 168, Irganox 1010 and 1076, in order to improve durability. However, phenol, ketone and quinone antioxidant...

  17. Register study of migrants' hospitalization in Norway: world region origin, reason for migration, and length of stay.

    Science.gov (United States)

    Elstad, Jon Ivar

    2016-07-26

    The proportion of migrants and refugees increase in many populations. Health planners have to consider how migration will influence demand for health care. This study explores how migrants' geographical origin, reason for migration, and duration of residence are associated with admission rates to somatic hospitals in Norway. Sociodemographic information on all individuals residing in Norway at the start of 2008 was linked to data on all admissions to somatic hospitals during 2008-2011. Migrants, age 30-69, who had come to Norway during 1970-2007 (N = 217,907), were classified into seven world region origins and compared with native Norwegians of the same age (N = 2,181,948). Any somatic hospital stay 2008-2011 and number of hospital admissions 2008-2011 per 1000 personyears for a set of somatic diagnoses were analyzed by age and gender standardized rates, linear probability models, and Poisson regression. In the native Norwegian sample, 28.7 % had at least one admission 2008-2011, and there were 116 admissions per 1000 personyears. Corresponding age and gender adjusted figures for the migrant sample were 27.0 % and 103 admissions. Admission rates varied with migrants' geographical origin, with relatively many admissions among migrants from West and South Asia and relatively few admissions among migrants from Western, East European, and Other Asian countries. Hospitalization varied strongly with reason for migration, with low admission rates for recent work migrants and high admission rates for recent refugees. Admission rates tended to move towards the level among native Norwegians with increasing length of stay. Among longstanding migrants (arrival period 1970-1989), admission rates were close to the levels of native Norwegians for most analyzed migrant categories. Both world region origin, reason for migration, and duration of residence are important sources for variations in migrants' utilization of somatic hospitals. Forecasts about migrants' use of

  18. A comparison of the migration process to an urban barrio and to a rural community: two case studies.

    Science.gov (United States)

    Flinn, W L; Cartano, D G

    1970-01-01

    The results of 2 case studies on migration in Colombia are outlined and compared. The 1st study examines inmigration to a shantytown, El Carmen, in Bogota. The 2nd study involves inmigration to a community in the eastern interior of Colombia, Granada. Migrants' motives, paths of migration, and personal characteristics are examined, suggesting hypotheses for future studies. Economic reasons were most often listed as motives for moving by both the residents of Granada and El Carmen. The type of economic motives varied greatly between the 2 communities. Reasons such as "looking for land," "establishing a business," or "to find a better life" ranked high in importance among Granada residents. These motives, along with the flight from violence, indicate that the independence provided by land and small business affords the inmigrants to Granada a certain security. Inmigrants to El Carmen were seeking employment. Only 34% of the migrants to El Carmen made 1 or more moves before settling in Bogota. 90% of the rural to rural migrants made 1 or more stops before moving to Granada. 68% of the migrants to El Carmen were born within 100 miles of Bogota while only 18% of the migrants to Granada were born within a 100 mile radius of the community. The usual pattern of the migrant to Granada was to move to a neighboring village, town, or city regardless of whether it was closer to Granada or not. The majority of inmigrants to Granada moved from distances greater than 100 miles. Over 70% of the inmigrants were born in towns and villages of more than 2000 population. If a nucleus of 10,000 inhabitants or more are considered urban, then 46% of the rural to rural migrants resided in urban areas prior to moving to Granada. This suggests that a sizable proportion of the migration to Granada is really urban to rural frontier. Studies done in Colombia and Brazil indicate that migrants to rural areas have a lower educational level than migrants to urban areas. Data from El Carmen and

  19. Immunohistochemical study of macrophage migration inhibitory factor in rat liver fibrosis induced by thioacetamide

    Directory of Open Access Journals (Sweden)

    Y Hori

    2009-06-01

    Full Text Available Macrophage migration inhibitory factor (MIF is a molecule known to regulate macrophage accumulation at sites of inflammation. To elucidate the role of MIF in progression of liver fibrosis, the immunohistochemical localization of MIF and macrophages in the liver were examined. Male Wistar rats received thioacetamide (TA injections (200 mg/kg, i.p. for 1 or 6 weeks. In biochemical and histological tests, it was confirmed that liver fibrosis was induced. In immunohistochemical analyses, the expression of MIF protein was seen in hepatocytes in the areas extending out from the central veins to the portal tracts. In particular, at 6 weeks, immunoreactivity was detected in degenerated hepatocytes adjacent to the fibrotic areas but hardly observed in the fibrotic areas. On the other hand, a number of exudate macrophages stained by antibody ED1 were seen in the areas from the central veins to the portal tracts at 1 week and in the fibrotic areas at 6 weeks. Macrophages also showed a significant increase in number as compared with controls. These results revealed that there was a close relationship between the appearance of MIF expression and ED1-positive exudate macrophages in degenerated hepatocytes during the progression of TA-induced liver fibrosis.

  20. Immunohistochemical study of macrophage migration inhibitory factor in rat liver fibrosis induced by thioacetamide.

    Science.gov (United States)

    Hori, Y; Sato, S; Yamate, J; Kurasaki, M; Nishihira, J; Hosokawa, T; Fujita, H; Saito, T

    2003-01-01

    Macrophage migration inhibitory factor (MIF) is a molecule known to regulate macrophage accumulation at sites of inflammation. To elucidate the role of MIF in progression of liver fibrosis, the immunohistochemical localization of MIF and macrophages in the liver were examined. Male Wistar rats received thioacetamide (TA) injections (200 mg/kg, i.p.) for 1 or 6 weeks. In biochemical and histological tests, it was confirmed that liver fibrosis was induced. In immunohistochemical analyses, the expression of MIF protein was seen in hepatocytes in the areas extending out from the central veins to the portal tracts. In particular, at 6 weeks, immunoreactivity was detected in degenerated hepatocytes adjacent to the fibrotic areas but hardly observed in the fibrotic areas. On the other hand, a number of exudate macrophages stained by antibody ED1 were seen in the areas from the central veins to the portal tracts at 1 week and in the fibrotic areas at 6 weeks. Macrophages also showed a significant increase in number as compared with controls. These results revealed that there was a close relationship between the appearance of MIF expression and ED1-positive exudate macrophages in degenerated hepatocytes during the progression of TA-induced liver fibrosis.

  1. A numerical study on the impact of nonlinear interactions on the amplitude of the migrating semidiurnal tide

    Directory of Open Access Journals (Sweden)

    C. M. Huang

    2006-12-01

    Full Text Available To quantitatively study the effects of nonlinear interactions on tide structure, a nonlinear numerical tidal model is developed, and the reliability and convergence of the adopted algorithm and coding are checked by numerical experiments. Under the same conditions as those employed by the GSWM-00 (Global Scale Wave Model 2000, our model provides the nonlinear quasi-steady solution of the migrating semidiurnal tide, which differs from the GSWM-00 result (the linear steady solution in the MLT region, especially above 100 km. Additionally, their amplitude difference displays a remarkable month-to-month variation, and its significant magnitudes occur during the month with strong semidiurnal tide. A quantitative analysis suggests that the main cause for the amplitude difference is that the initial migrating 12-h tide will interact with the mean flow as well as the nonlinearity-excited 6-h tide, and subsequently yield a new 12-h tidal part. Furthermore, our simulations also show that the mean flow/tidal interaction will significantly alter the background wind and temperature fields. The large magnitudes of the tidal amplitude difference and the background alteration indicate that the nonlinear processes involved in tidal propagations should be comprehensively considered in the description of global atmospheric dynamics in the MLT region. The comparisons among our simulations, the GSWMs and some observations of tides suggest that the nonlinearity-induced tidal structure variation could be a possible mechanism to account for some discrepancies between the GSWMs and the observations.

  2. Radioautographic study of the synthesis and migration of glycoproteins in the cells of the rat adrenal medulla

    International Nuclear Information System (INIS)

    Benchimol, Sarita; Cantin, Marc

    1978-01-01

    Rats were injected intravenously with ( 3 H) fucose to study the synthesis and migration of glycoproteins into adrenaline-storing and noradrenaline-storing cells of the adrenal medulla and to evaluate the fate of this radioactive sugar in both serum and adrenal-medulla at various time intervals. Radioactivity was decreased in serum by 50% between 5 and 20 min after the injection and by a hundred fold with 1 h. There was a sharp decrease in the radioactivity of the adrenal-medulla between 5 and 20 min after the injection and a slight, continuous decrease thereafter. The adrenal-medullae were fixed 5 min, 20 min, 1 h and 4 h after intravenous injection of [ 3 H] fucose, and radiautographs were analysed quantitatively after development in Microdol X. Kinetic analysis showed that, in both cell types, glycoprotein synthesis is completed in the Golgi complex and glycoproteins migrate subsequently to the secretory granules and to the cell coat. This analysis also revealed that [ 3 H] fucose moves much more rapidly in the Golgi complex of noradrenaline-storing cells than in that of adrenaline-storing cells and appears much earlier in the secretory granules of the former cell type [fr

  3. Experimental methodology to study radionuclide sorption and migration in geological formations and engineered barriers of waste repositories

    International Nuclear Information System (INIS)

    Rojo Sanz, H.

    2010-01-01

    In Spain, the waste management options include either the possibility of a final storage in a deep geological repository (DGR) or the centralized temporal surface disposal (CTS). DGRs are based in a multi-barrier concept with the geological barrier and including the vitrified waste, the metal containers and engineered barriers such as compacted bentonite and cement-based materials. On the other hand, CTS mainly considers concrete and cement to confine the metal canisters containing the waste. Radionuclide migration will mainly take place by the existence of chemical concentration gradients being thus diffusion the main transport mechanism or by the existence of hydraulic gradients due to the existence of water-conductive fractures. Radionuclide sorption/retention on the materials composing the natural and engineered barriers is the fundamental process controlling contaminant migration. The evaluation of sorption parameters and the understanding of the different mechanisms leading to radionuclide retention are very important issues. The study of diffusion processes is very relevant as well. This paper describes the main experimental methodologies applied to analyse radionuclide transport in the different barriers of radioactive repositories. Particularly we focused on obtaining of retention parameters as distribution coefficients, kd, or retardation factors, Rf, and diffusion coefficients of radionuclides. (Author) 6 refs.

  4. Studies of meson production at SIS energies

    International Nuclear Information System (INIS)

    Hartnack, Ch.; David, Ch.; Aichelin, J.

    1996-01-01

    IQMD results on kaon and pion data are presented. The influence of the equation of state and of the elementary kaon cross sections on the excitation function and on the system size dependence is analyzed. Effects of density dependent threshold reductions for the production of positive and negative kaons are studied. The influence of the Delta lifetime on the pion production is discussed. (author)

  5. Migrating for a Profession

    DEFF Research Database (Denmark)

    Olwig, Karen Fog

    2015-01-01

    a strong sense of agency and self-empowerment. In the post-WWII period, numerous Caribbean women trained in nursing at British hospitals that have been described as marred by race and gender related inequality and associated forms of exploitation. Yet, the nurses interviewed about this training emphasised......Youths from the Global South migrating for further education often face various forms of discrimination. This Caribbean case study discusses how conditions in the home country can provide a foundation for educational migration that helps the migrants overcome such obstacles and even develop...... in which it enabled these Caribbean women to stake out a new life for themselves....

  6. Evaluation of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Sullivan Ruth

    2012-02-01

    Full Text Available Abstract Background Socio-cultural differences for country-specific activities are rarely addressed in physical activity questionnaires. We examined the reliability and validity of the Indian Migration Study Physical Activity Questionnaire (IMS-PAQ in urban and rural groups in India. Methods A sub-sample of IMS participants (n = 479 was used to examine short term (≤1 month [n = 158] and long term (> 1 month [n = 321] IMS-PAQ reliability for levels of total, sedentary, light and moderate/vigorous activity (MVPA intensity using intraclass correlation (ICC and kappa coefficients (k. Criterion validity (n = 157 was examined by comparing the IMS-PAQ to a uniaxial accelerometer (ACC worn ≥4 days, via Spearman's rank correlations (ρ and k, using Bland-Altman plots to check for systematic bias. Construct validity (n = 7,000 was established using linear regression, comparing IMS-PAQ against theoretical constructs associated with physical activity (PA: BMI [kg/m2], percent body fat and pulse rate. Results IMS-PAQ reliability ranged from ICC 0.42-0.88 and k = 0.37-0.61 (≤1 month and ICC 0.26 to 0.62; kappa 0.17 to 0.45 (> 1 month. Criterion validity was ρ = 0.18-0.48; k = 0.08-0.34. Light activity was underestimated and MVPA consistently and substantially overestimated for the IMS-PAQ vs. the accelerometer. Criterion validity was moderate for total activity and MVPA. Reliability and validity were comparable for urban and rural participants but lower in women than men. Increasing time spent in total activity or MVPA, and decreasing time in sedentary activity were associated with decreasing BMI, percent body fat and pulse rate, thereby demonstrating construct validity. Conclusion IMS-PAQ reliability and validity is similar to comparable self-reported instruments. It is an appropriate tool for ranking PA of individuals in India. Some refinements may be required for sedentary populations and women in India.

  7. The Last Adventure: Retirement Migration, Climate and "Amenities"

    Directory of Open Access Journals (Sweden)

    Saša Božić

    2001-12-01

    Full Text Available The rising number of European retirement migrants on the Mediterranean coasts, especially in the EU countries shows that the practical and scientific relevance of the new forms of migration in Europe is on the rise. "Retirement migration" evolved from a descriptive term to a candidate for a scientific or a research concept, at least if the use of the term IRM (international retirement migration is considered. However, it is necessary to solve several problems before this term can really become a coherent concept, useful for the research and explanation of the "new" migration phenomena. The author claims that the studies usually do not distinguish clearly between the migration of the elderly and retirement migration. The naming of the concept in this case mixes the characteristics of the migrants with the reasons for migration. The author shows that the usually mentioned reasons for retirement migration cannot be clearly formulated as factors which explain retirement migration. Further on, retirement as such is not a pull, push or staying put factor. Migration rates of retired, although rising, are still lower than the migration rates of the working age population and the Mediterranean coasts are also a destination for professionals who have the means to detach the job from the working place. Only a combination of conditions that enable migration and migration decisions, as well as a combination of motives and perceptions of reasons for migration, can partially "explain" retirement migration. One of the problems that has to be solved before retirement migration is affirmed as a concept is the treatment of the temporal and spatial dimension of the mobility of the retirement migrants. The author shows that a clear positioning of retirement migration on the temporal scale of mobility is hardly possible. Retirement migration is too wide and too complex a phenomenon to be easily localised in the temporal continuum. A similar problem emerges when the

  8. Post-migration living difficulties as a significant risk factor for PTSD in immigrants: a primary care study

    Directory of Open Access Journals (Sweden)

    Massimilano Aragona

    2012-09-01

    Full Text Available

    Background: recent research shows that severe/very severe post-migration living difficulties (PMLD have a negative impact on the mental health and social integration of refugees and asylum seekers. This study focuses on the role of PMLD in primary care “ordinary” immigrants.

    Methods: 443 primary care immigrants were asked to complete a self-administered questionnaire measuring the number and severity of pre-migratory potentially traumatic events (PTE, PMLD, and the current prevalence of a post-traumatic stress disorder (PTSD. The frequency of PMLD was assessed in the whole sample and compared in patients with and without PTSD. The effect of the number of PMLD on the risk of having a PTSD was studied by means of a regression analysis, adjusted by the number of PTE.

    Results: 391 patients completed the questionnaire and were enrolled into the study. The prevalence of PTSD was 10.2%. In the whole sample the most frequent PMLD were “no permission to work” (38.6% and “poverty” (34.5%. All PMLD (except “communication difficulties” were more frequent in patients with a PTSD. The number of PMLD significantly increased the likelihood to have a PTSD independently from PTE. Conclusions: severe/very severe post-migration living difficulties (PMLD increase significantly the risk of PTSD in primary care “ordinary” migrants. Our hypothesis is that they have a retraumatizing effect on individuals who are already vulnerable and with a low capacity to handle resettlement stress due to their previous traumatic history. The implications in clinical practice and for immigration policies are discussed.

  9. Dispersal and migration

    Directory of Open Access Journals (Sweden)

    Schwarz, C.

    2004-06-01

    Full Text Available Ringing of birds unveiled many aspects of avian migration and dispersal movements. However, there is even much more to be explored by the use of ringing and other marks. Dispersal is crucial in understanding the initial phase of migration in migrating birds as it is to understand patterns and processes of distribution and gene flow. So far, the analysis of migration was largely based on analysing spatial and temporal patters of recoveries of ringed birds. However, there are considerable biases and pitfalls in using recoveries due to spatial and temporal variation in reporting probabilities. Novel methods are required for future studies separating the confounding effects of spatial and temporal heterogeneity of recovery data and heterogeneity of the landscape as well. These novel approaches should aim a more intensive and novel use of the existing recovery data by taking advantage of, for instance, dynamic and multistate modeling, should elaborate schemes for future studies, and should also include other marks that allow a more rapid data collection, like telemetry, geolocation and global positioning systems, and chemical and molecular markers. The latter appear to be very useful in the delineating origin of birds and connectivity between breeding and non–breeding grounds. Many studies of migration are purely descriptive. However, King and Brooks (King & Brooks, 2004 examine if movement patterns of dolphins change after the introduction of a gillnet ban. Bayesian methods are an interesting approach to this problem as they provide a meaningful measure of the probability that such a change occurred rather than simple yes/no response that is often the result of classical statistical methods. However, the key difficulty of a general implementation of Bayesian methods is the complexity of the modelling —there is no general userfriendly package that is easily accessible to most scientists. Drake and Alisauskas (Drake & Alisauskas, 2004 examine the

  10. Isotopic reconstruction of ancient human migrations: A comprehensive Sr isotope reference database for France and the first case study at Tumulus de Sables, south-western France

    Science.gov (United States)

    Willmes, M.; Boel, C.; Grün, R.; Armstrong, R.; Chancerel, A.; Maureille, B.; Courtaud, P.

    2012-04-01

    Strontium isotope ratios (87Sr/86Sr) can be used for the reconstruction of human and animal migrations across geologically different terrains. Sr isotope ratios in rocks are a product of age and composition and thus vary between geologic units. From the eroding environment Sr is transported into the soils, plants and rivers of a region. Humans and animals incorporate Sr from their diet into their bones and teeth, where it substitutes for calcium. Tooth enamel contains Sr isotope signatures acquired during childhood and is most resistant to weathering and overprinting, while the dentine is often diagenetically altered towards the local Sr signature. For the reconstruction of human and animal migrations the tooth enamel 87Sr/86Sr ratio is compared to the Sr isotope signature in the vicinity of the burial site and the surrounding area. This study focuses on the establishment of a comprehensive reference map of bioavailable 87Sr/86Sr ratios for France. In a next step we will compare human and animal teeth from key archaeological sites to this reference map to investigate mobility. So far, we have analysed plant and soil samples from ~200 locations across France including the Aquitaine basin, the western and northern parts of the Paris basin, as well as three transects through the Pyrenees Mountains. The isotope data, geologic background information (BRGM 1:1M), field images, and detailed method descriptions are available through our online database iRhum (http://rses.anu.edu.au/research/ee). This database can also be used in forensic studies and food sciences. As an archaeological case study teeth from 16 adult and 8 juvenile individuals were investigated from an early Bell Beaker (2500-2000 BC) site at Le Tumulus des Sables, south-west France (Gironde). The teeth were analysed for Sr isotope ratios using laser ablation ICP-MS. Four teeth were also analysed using solution ICP-MS, which showed a significant offset to the laser ablation results. This requires further

  11. STUDY ON PRODUCTIVITY INDICATORS IN EDUCATION

    Directory of Open Access Journals (Sweden)

    Andreea Fortuna SCHIOPU

    2014-06-01

    Full Text Available This paper aims to outline synthetically a set of indicators for the study of productivity in education and to critically analyze their suitability as input, output or outcome. References were made to the indicators available in the databases of Romania, World Bank, Eurostat, OECD relevant for measuring productivity in education, which opposed to usual reporting between effect / result and inputs elements consumed in the production process,in the case of educational services should be considered the quantitative, but also qualitative aspects - and especially - mediated effects, on long-term and very long term. The research results presented, emphasize the importance of the educational reform efforts to focus more on qualitative aspects in measuring productivity, more precisely on the abilities, competencies that have pupils /students and adults, on motivating teachers, to achieve educational outcomes which could increase students performance, productivity growth on long-term and very long term effects, with an impact at the macroeconomic level.

  12. The Caenorhabditis elegans Q neuroblasts : A powerful system to study cell migration at single-cell resolution in vivo

    NARCIS (Netherlands)

    Rella, Lorenzo; Fernandes Póvoa, Euclides E.; Korswagen, Hendrik C.

    2016-01-01

    During development, cell migration plays a central role in the formation of tissues and organs. Understanding the molecular mechanisms that drive and control these migrations is a key challenge in developmental biology that will provide important insights into disease processes, including cancer

  13. The Caenorhabditis elegans Q neuroblasts : A powerful system to study cell migration at single-cell resolution in vivo

    NARCIS (Netherlands)

    Rella, Lorenzo; Fernandes Póvoa, Euclides E; Korswagen, Hendrik C

    During development, cell migration plays a central role in the formation of tissues and organs. Understanding the molecular mechanisms that drive and control these migrations is a key challenge in developmental biology that will provide important insights into disease processes, including cancer

  14. A study of long-term (103-104Yr) elemental migration in saturated clays and sediments

    International Nuclear Information System (INIS)

    Mac Kenzie, A.B.; Scott, R.D.; Ridgway, I.M.; Mc Kinley, I.G.; West, J.M.

    1986-01-01

    This report presents the results of a project to investigate the use of elemental profiles in Scottisch sediments resulting from the Flandrian marine transgression as a natural analogue of radionuclide migration through argillaceous material. The work was carried out within Research Area no. 5 of the CEC project MIRAGE ''Natural Geological Migration Systems''

  15. Stage migration after introduction of sentinel lymph node dissection in breast cancer treatment in Denmark: a nationwide study

    DEFF Research Database (Denmark)

    Tvedskov, Tove Filtenborg; Jensen, Maj-Britt; Balslev, Eva

    2011-01-01

    To estimate the size and therapeutic consequences of stage migration after introduction of sentinel lymph node dissection (SLND) in breast cancer treatment in Denmark.......To estimate the size and therapeutic consequences of stage migration after introduction of sentinel lymph node dissection (SLND) in breast cancer treatment in Denmark....

  16. In the ideal condition an experimental study on migration of radon and its daughters in the atmosphere

    International Nuclear Information System (INIS)

    Zeng Bing; Zhang Jinzhao; Wang Qing

    2010-01-01

    According to the relevant theory of thermodynamics, this presentation which based on the radon migration of the cluster theory has deduced ordinarily the ideal velocity period and displacement. The purpose was to establish the theoretical model of migration of radon and its daughters in the atmosphere in the ideal case, which would provide a underlying theoretical basis for the further research. (authors)

  17. Radioautographic study of the proliferative activity and cell migration in the fetal and neonatal rat adrenal cortex

    International Nuclear Information System (INIS)

    Bertholet, J.-Y.; Idelman, Simon

    1978-01-01

    On the 20th day of fetal life the cell proliferation is higher in the zona glomerulosa. The fate of marked cells in each cell compartment shows centripetal migration. Their displacement, from the 20th day of pregnancy up to five days post-partum, while at that time the adrenal growth is slowered down, suggests a real migration [fr

  18. Engendering climate change-induced migration

    Science.gov (United States)

    Caretta, Martina Angela; Miletto, Michela

    2017-04-01

    Climate change leads to increased climate variability, which is manifest in extreme weather events such as floods and droughts. These put at stake agricultural productivity, forestry, inland fisheries, aquaculture, water supply and sanitation which in turn hamper poorest householdś self-sufficiency and capability to cope with risks. Due to the risk of losing or the actual loss of livelihood, farmers in the Global South must look for alternative strategies to diversify risk. Migration is one of those strategies, which that can be seen either as an adaptive measure or an indicator of limits to adaptation to environmental stress. 60% of young migrants live in the Global South (UN, 2013). Many internally displaced people in the world are under the age of 18, some move with their families, other, mostly in South Asia and West Africa, migrate alone. Youth, as all migrants, are seeking better economic opportunities to support themselves and their families. Migration is a gendered process which plays out differently in diverse societies depending on local cultural norms that do not only affect and are affected by gender roles, but also by age, class and ethnicity. Threats to water availability, access and water hazards have diverse impacts on men and women. The link gender and climate-induced migration is still under investigation and few studies provide concrete country specific examples of this phenomenon. Our paper will present a state of the art literature review around climate-induced migration in the Global South from a gender perspective showing how meńs and womeńs migratory decisions, patterns and outcomes differ at the stage pre-during post migration.

  19. KIN NETWORKS AND MIGRATION IN SAGBAMA LOCAL ...

    African Journals Online (AJOL)

    CIU

    Historically, migration process has been characterized and continues to be .... Mexican migration to the U.S (Massey, Arango, Hugo, Kouaouci, Pellegrino and .... the study destination (Sagbama) according to Independent National Electoral.

  20. Exploring the diet and lifestyle changes contributing to weight gain among Australian West African women following migration: A qualitative study.

    Science.gov (United States)

    Babatunde-Sowole, Olutoyin O; Power, Tamara; Davidson, Patricia; Ballard, Charlotte; Jackson, Debra

    2018-04-10

    This paper reports on women's experiences of weight gain and obesity as they became acculturated to the Australian diet and lifestyle. Migrants from sub-Saharan Africa have a much higher risk of obesity than the native population when settling in industrialised countries. Qualitative. Women in this study reported weight gain post-migration. This was attributed to increased access to a wide variety of food including takeaway food and more sedentary lifestyles. Obesity has long-term consequences for health and well-being. Further research is needed to support a healthy transition to life in Australia. Gaining insight into the underlying reasons that West African immigrants to Australia become obese could contribute to assisting health professionals design culturally appropriate interventions and health education programmes to support new arrivals.

  1. Evidence of surface migration and formation of catalytically inactive Pt in corrosion studies of Pt+ implanted Ti

    International Nuclear Information System (INIS)

    Appleton, B.R.; Kelly, E.J.; White, C.W.; Thompson, N.G.; Lichter, B.D.

    1980-08-01

    This investigation is part of an ongoing research project directed at applying the techniques of ion implantation doping and ion scattering analysis to identify the mechanisms associated with the anodic dissolution of Ti-Pt alloys. The Ti-Pt alloys produced by ion implantation were electrochemically examined in hydrogen saturated 1 N H 2 SO 4 by both potentiostatic polarization and open-circuit potential methods. In this study, Ti samples implanted to relatively high doses (5.4 x 10 15 to 2.9 x 10 16 atoms/cm 2 ) were examined by ion scattering analysis at various stages in the electrochemical measurements. Quantitative measurements showed that the majority of the implanted Pt accumulated on the surface during anodic dissolution and underwent large scale surface migration. Evidence is also presented for the transition of the Pt on the surface from a catalytically active to inactive state. Possible mechanisms for the observed catalytically inactive Pt are discussed

  2. The Introduction of Innovative Services in a State Owned Airline: A Case Study of an IT Migration Project

    Directory of Open Access Journals (Sweden)

    Konstantinos Malagas

    2013-03-01

    Full Text Available This study critically examines the transition process followed by a state-owned airline in a major IT migration project (introduction of novel electronic services. The change management process proposed by Kotter (1995 is examined in relation to the different phases identifed, based on an interview based qualitative research. Focusing on the project team leaders a set of results is identifed / determined, which provides signifcant insight into the key factors, defciencies and outcomes of the project, with reference to the characteristics of a state-owned company. Further elaboration of the proposed methodology is deemed to be applicable in the identifcation of the weak and strong points of similar change projects.

  3. Traumatic events, post-migration living difficulties and post-traumatic symptoms in first generation immigrants: a primary care study

    Directory of Open Access Journals (Sweden)

    Massimiliano Aragona

    2013-06-01

    Full Text Available OBJECTIVES: To study potentially traumatic events (PTE, post-traumatic stress disorder (PTSD, anxiety, depression, somatization and post-migration living difficulties (PMLD in primary care immigrants. DESIGN: Patients self-rated transculturally validated questionnaires. Those with and without PTSD were compared on all variables. The influence of the number of PTE and of PMLD on PTSD was measured. RESULTS: 391 patients completed the questionnaires. Prevalence of PTSD was 10.2%. PTE and PMLD were frequent in the whole sample but more common in PTSD subjects. Either the number of PTE and of PMLD significantly increased the likelihood to have a PTSD. CONCLUSIONS: PTE, PMLD, PTSD and related conditions (anxiety, depression and somatization are frequent among immigrants in primary care, and either PTE and PMLD significantly influence resulting psychopathology. The implications in clinical practice are discussed.

  4. Measuring International Migration in Azerbaijan

    Directory of Open Access Journals (Sweden)

    Serhat Yüksel

    2018-01-01

    Full Text Available International migration significantly affects economic, social, cultural, and political factors of the country. Owing to this situation, it can be said that the reasons of international migration should be analyzed in order to control this problem. The purpose of this study is to determine the influencing factors of international migration in Azerbaijan. In this scope, annual data of 11 explanatory variables for the period of 1995–2015 was analyzed via Multivariate Adaptive Regression Splines (MARS method. According to the results of this analysis, it was identified that people prefer to move other countries in case of high unemployment rates. In addition, the results of the study show that population growth and high mortality rate increases the migration level. While considering these results, it was recommended that Azerbaijan should focus on these aspects to control international migration problem.

  5. Does migration affect asthma, rhinoconjunctivitis and eczema prevalence? Global findings from the international study of asthma and allergies in childhood.

    Science.gov (United States)

    Garcia-Marcos, Luis; Robertson, Colin F; Ross Anderson, H; Ellwood, Philippa; Williams, Hywel C; Wong, Gary Wk

    2014-12-01

    Immigrants to Westernized countries adopt the prevalence of allergic diseases of native populations, yet no data are available on immigrants to low-income or low-disease prevalence countries. We investigated these questions using data from the International Study of Asthma and Allergies in Childhood. Standardized questionnaires were completed by 13-14-year-old adolescents and by the parent/guardians of 6-7-year-old children. Questions on the symptom prevalence of asthma, rhinoconjunctivitis and eczema, and a wide range of factors postulated to be associated with these conditions, including birth in or not in the country and age at immigration, were asked. Odds ratios for risk of the three diseases according to immigration status were calculated using generalized linear mixed models. These were adjusted for: world region; language and gross national income; and individual risk factors including gender, maternal education, antibiotic and paracetamol use, maternal smoking, and diet. Effect modification by gross national income and by prevalence was examined. There were 326 691 adolescents from 48 countries and 208 523 children from 31 countries. Immigration was associated with a lower prevalence of asthma, rhinoconjunctivitis and eczema in both age groups than among those born in the country studied, and this association was mainly confined to high-prevalence/affluent countries. This reduced risk was greater in those who had lived fewer years in the host country. Recent migration to high prevalence/affluent countries is associated with a lower prevalence of allergic diseases. The protective pre-migration environment quickly decreases with increasing time in the host country. © The Author 2014; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  6. A review of a field study of radionuclide migration from an underground nuclear explosion at the Nevada Test Site

    International Nuclear Information System (INIS)

    Hoffman, D.C.; Daniels, W.R.; Wolfsberg, K.; Thompson, J.L.; Rundberg, R.S.; Fraser, S.L.; Daniels, K.S.

    1984-01-01

    Results from a long-term (9 year) field study of the distribution of radionuclides around an underground nuclear explosion cavity at the Nevada Test Site are reviewed. The goals of this Radionuclide Migration project are to examine the rates of migration underground in various media and to determine the potential for movement, both on and off the Nevada Test Site, of radioactivity from such explosions, with particular interest in possible contamination of water supplies. Initial studies were undertaken near the site of the low-yield test Cambric, which was detonated 73 m beneath the water table in tuffaceous alluvium. Solid samples were obtained from just below ground surface to 50 m below the detonation point, and water was sampled from five different regions in the vicinity of the explosion. Ten years after the test, most of the radioactivity was found to be retained in the fused debris in the cavity region and no activity above background was found 50 m below. Only tritium and 90 Sr were present in water in the cavity at levels greater than recommended concentration guides for water in uncontrolled areas. A satellite well is being used to remove water 91 m from the detonation point. During seven years (7x10 6 m 3 ) of pumping, tritium, 85 Kr, 36 Cl and 129 I have been detected in the water. Approximately 40% of the total tritium from the cavity region has been removed by pumping at the satellite well, and the maximum in the tritium concentration is clearly defined. Use of sensitive analytical techniques has permitted measurement of the very low concentrations of 36 Cl and 129 I present in the water. The 36 Cl peak precedes the tritiated water, possibly as a result of anion exclusion. Additional analyses are in progress to better define the shape of the 129 I concentration curve. (author)

  7. Review of a field study of radionuclide migration from an underground nuclear explosion at the Nevada Test Site

    International Nuclear Information System (INIS)

    Hoffman, D.C.; Daniels, W.R.; Wolfsberg, K.; Thompson, J.L.; Rundberg, R.S.; Fraser, S.L.; Daniels, K.S.

    1983-01-01

    Results from a long-term (9 year) field study of the distribution of radionuclides around an underground nuclear explosion cavity at the Nevada Test Site are reviewed. The goals of this Radionuclide Migration project are to examine the rates of migration underground in various media and to determine the potential for movement, both on and off the Nevada Test Site, of radioactivity from such explosions, with particular interest in possible contamination of water supplies. Initial studies were undertaken near the site of the low-yield test Cambric, which was detonated 73 m beneath the water table in tuffaceous alluvium. Solid samples were obtained from just below ground surface to 50 m below the detonation point, and water was sampled from five different regions in the vicinity of the explosion. Ten years after the test, most of the radioactivity was found to be retained in the fused debris in the cavity region and no activity above background was found 50 m below. Only tritium and 90 Sr were presented in water in the cavity at levels greater than recommended concentration guides for water in uncontrolled areas. A satellite well is being used to remove water 91 m from the detonation point. During seven years (7 x 10 6 m 3 ) of pumping, tritium, 85 Kr, 36 Cl, and 129 I have been detected in the water. Approximately 40% of the total tritium from the cavity region has been removed by pumping at the satellite well, and the maximum in the tritium concentration is clearly defined. Use of sensitive analytical techniques has permitted measurement of the very low concentrations of 36 Cl and 129 I present in the water. The 36 Cl peak precedes the tritiated water, possibly as a result of anion exclusion. Additional analyses are in progress to better define the shape of the 129 I concentration curve

  8. Migration studies of the fission product nuclides in rocks: Pt. 1

    Energy Technology Data Exchange (ETDEWEB)

    Ruiyuan, Wen; Hongcheng, Gao; Chenghua, Jiang; Yuanfang, Liu [Beijing Univ., BJ (China). Dept. of Technical Physics

    1991-11-01

    A most promising way being considered for the disposal of radioactive waste is deep geological in rocks, such as granite and limestone. Different measurements have been made on granite and limestone sampled from the suburbs of Beijing. {sup 75}Se(SeO{sub 3}{sup 2-}) is used as a tracer simulating the long-lived {sup 79}Se. The diffusion experiment is carried out in a diffusion cell which is designed and fabricated in the laboratory of Department of Technical Physics, Peking University. Details of the experimental technique and method of analysis are described and the most important diffusion parameters, namely, intrinsic diffusion coefficient D{sub i9} rock capacity factor and sorption coefficient K are given. The implications of the results are discussed.

  9. Migration studies of the fission product nuclides in rocks: Pt. 1

    International Nuclear Information System (INIS)

    Wen Ruiyuan; Gao Hongcheng; Jiang Chenghua; Liu Yuanfang

    1991-01-01

    A most promising way being considered for the disposal of radioactive waste is deep geological in rocks, such as granite and limestone. Different measurements have been made on granite and limestone sampled from the suburbs of Beijing. 75 Se(SeO 3 2- ) is used as a tracer simulating the long-lived 79 Se. The diffusion experiment is carried out in a diffusion cell which is designed and fabricated in the laboratory of Department of Technical Physics, Peking University. Details of the experimental technique and method of analysis are described and the most important diffusion parameters, namely, intrinsic diffusion coefficient D i9 rock capacity factor and sorption coefficient K are given. The implications of the results are discussed

  10. Analysis of the role of strategic products in sustainable rural livelihoods (Case study: saffron production in the Roshtkhar rural district

    Directory of Open Access Journals (Sweden)

    Sadegh Asghari Lafmejani

    2017-09-01

    Full Text Available Saffron is the most expensive agricultural and pharmaceutical product in the world. It is significant for several reasons such as having high water productivity compared to other crops. It is providing rural employment and preventing their migration, having high medicinal and spice values, ease of maintenance and transportation. Most importantly, it is producing a high revenue compared to other agricultural products. On this basis, due to the suitability of some parts of Iran to saffron production and the role of this product in the livelihood of rural households, assessment of the sustenance impacts of saffron production in the active villages seems absolutely necessary. Therefore, the aim of the present study is to assess the status of saffron production and its role in the livelihood of rural households of the Roshtkhar Rural District. This research was done based on a descriptive-analytic approach. In this regard, the role of saffron cultivation in 355 households living in 13 villages with over 100 households in the study rural district was investigated. To this goal, after conducting documentary studies and initial field visits, a wide range of measures proportional to the circumstances of the study villages were adopted. Then, data collection was performed based on the selected indices and questionnaires were distributed to be filled by villagers and households... To analyze the data, the relevant statistical and spatial analyses were done through the application of Expert choice, SPSS, and ArcGIS software packages. The research findings indicated that the annual revenues derived from saffron production in 43.9% of the households under study were more than they obtained from other sources of income. Through the analysis of the study data, it can be concluded that saffron production has a significant effect on the improvement of the residents’ livelihood in the Roshtkhar Rural District and this fact has reinforced the households

  11. Migration Flows: Measurement, Analysis and Modeling

    NARCIS (Netherlands)

    Willekens, F.J.; White, Michael J.

    2016-01-01

    This chapter is an introduction to the study of migration flows. It starts with a review of major definition and measurement issues. Comparative studies of migration are particularly difficult because different countries define migration differently and measurement methods are not harmonized.

  12. Annual spatiotemporal migration schedules in three larger insectivorous birds

    DEFF Research Database (Denmark)

    Jacobsen, Lars Bo; Jensen, Niels Odder; Willemoes, Mikkel

    2017-01-01

    Background: Knowledge of spatiotemporal migration patterns is important for our understanding of migration ecology and ultimately conservation of migratory species. We studied the annual migration schedules of European nightjar, a large nocturnal insectivore and compared it with two other larger ...

  13. Study of Agricultural Product Options Pricing

    Science.gov (United States)

    HONG, Qiu

    2017-09-01

    China is a large agricultural country, and the healthy development of agriculture is related to the stability of the whole society. The agricultural production and management of agricultural products are confronted with many risks, especially the market risks. Option contract is the object of option market transaction, so it is very important to study the option contract of agricultural products. Option trading separates the risk and profit, so that the trader can avoid the risk while retaining the opportunity to obtain income. The option has the characteristics of low transaction cost, simple and efficient, so it is suitable for small and medium investors.

  14. Case study of establishing a clean production

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Kun; Nam, Yoon Mi [Korea Environment Institute, Seoul (Korea)

    1998-12-01

    This study was implemented to derive suggestions for improving policies in Korea through the examination and analysis on the present policies related to the clean production and its establishment in enterprises. The characters of concept on clean production presented in pollution prevention, waste minimization, zero emission, environmental friendly design, and industrial ecology were analyzed and the mechanism for implementing clean production and government policy were arranged comprehensively. The related policies of major countries with international organizations including UNEP (United Nations Environment Program) and EU (European Union) were reviewed and compared to those of Korea to propose future policy plan. 73 refs., 3 figs., 30 tabs.

  15. The Quiet Migration Redux: International Adoption, Race, and Difference.

    Science.gov (United States)

    Leinaweaver, Jessaca B

    2014-01-01

    Demographers frame international adoption primarily as an unusual kind of migration. This insight offers anthropologists new ways to think about kinship. Drawing on demographic scholarship and anthropological kinship and migration studies, this article develops a new and hybrid approach to international adoption as a complex social process that is both migratory and productive of kinship. Viewing international adoption as a form of migration reveals how the stated "push factors" and actual "pull factors" of international adoption do not align perfectly. Using an anthropological life course perspective, the article then explores how the experiences of these "migrants" and those close to them, over time, are better understood as racialization than solely the product of migration. Looking at adoptees' lives through a migration lens reveals some of the persistent discomforts that prevent open conversations about racial difference and minority status in an adoptive context, that is, one where children have been caused to migrate, recruited into families. This article draws on data from ethnographic fieldwork with Spanish parents who have adopted Peruvian children to argue that international adoption is a unique form of immigration that produces a minority category within a majority population.

  16. A novel, ring-connected stent versus conventional GI stents: comparative study of physical properties and migration rates in a canine colon obstruction model.

    Science.gov (United States)

    Park, Hong Suk; Choo, In Wook; Seo, Soowon; Hyun, Dongho; Lim, Sooyoun; Kim, Jae J; Hong, Saet-Byul; Min, Byung-Hoon; Do, Young Soo; Choo, Sung Wook; Shin, Sung Wook; Park, Kwang Bo; Cho, Sung Ki

    2015-01-01

    Migration of stents is one of the most common adverse events in covered stent placement in GI tract obstruction. To compare physical property and migration rates in a canine colon obstruction model among a novel stent and conventional stents. Comparative physical test and animal study. Medical device testing laboratory and animal laboratory. Mongrel dogs (N=26). Surgical colon obstruction followed by placement of a novel (n=13) or conventional (n=13) stent. Physical properties, migration, and adverse events. The novel stent showed better flexibility, as in a physical test of longitudinal compressibility and axial force, than did conventional stents, and it withstood the fatigue test for 10 days. In terms of radial force and tensile strength, the novel stent showed the same or better results than conventional stents. In a canine colon obstruction model, the migration rate of a novel stent was significantly lower than that of a conventional stent (2/13, 15.4% vs 8/13, 61.5%; P=.008). Animal study of limited size. The novel, ring-connected stent is more flexible and more resistant to migration than the conventional stents. Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.

  17. Development of a New Hanging-Type Esophageal Stent for Preventing Migration: A Preliminary Study in an Animal Model of Esophagotracheal Fistula

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Masayuki, E-mail: masay010@yahoo.co.jp; Kaminou, Toshio, E-mail: kaminout@med.tottori-u.ac.jp; Ohuchi, Yasufumi, E-mail: oyasu@med.tottori-u.ac.jp [Tottori University, Department of Radiology, Faculty of Medicine (Japan); Sugiura, Kimihiko, E-mail: kimihikosugiura@gmail.com [Yonago Medical Center, Department of Radiology (Japan); Yata, Shinsaku, E-mail: yata-s@med.tottori-u.ac.jp; Adachi, Akira, E-mail: july1st@med.tottori-u.ac.jp; Kawai, Tsuyoshi, E-mail: prgr-xxio@kuc.biglobe.ne.jp; Takasugi, Syohei, E-mail: stakasugi@med.tottori-u.ac.jp; Yamamoto, Shuichi, E-mail: yamamotoshu@med.tottori-u.ac.jp; Matsumoto, Kensuke, E-mail: matsumoto-k@v103.vaio.ne.jp [Tottori University, Department of Radiology, Faculty of Medicine (Japan); Hashimoto, Masayuki, E-mail: hashimotom@pref.tottori.jp [Tottori Prefectural Kosei Hospital, Department of Radiology (Japan); Ihaya, Takashi, E-mail: iahaya@orange.ocn.ne.jp [Sanin Rosai Hospital, Department of Radiology (Japan); Ogawa, Toshihide, E-mail: ogawa@med.tottori-u.ac.jp [Tottori University, Department of Radiology, Faculty of Medicine (Japan)

    2012-10-15

    Purpose: Covered, self-expandable metallic stents (SEMS) have been enthusiastically adopted for the treatment of esophagotracheal fistula, but problems with stent migration have yet to be resolved. To overcome this problem, we have developed a new hanging-type esophageal stent designed to prevent migration, and we conducted an animal study to assess the efficacy of our method. Methods: A total of six female pigs were used in this study. The main characteristic of our stent was the presence of a string tied to the proximal edge of the stent for fixation under the skin of the neck. The first experiment was performed to confirm technical feasibility in three pigs with esophagotracheal fistula. The second experiment was performed to evaluate stent migration and esophagotracheal fistula in three pigs. Results: Creation of the esophagotracheal fistula and stent placement were technically successful in all pigs. In the first experiment, esophagotracheal fistula was sealed by stent placement. In the second experiment, no stent migration was seen 11 or 12 days after stent placement. Gross findings showed no fistulas on the esophageal or tracheal wall. Conclusions: Our new hanging-type esophageal stent seems to offer a feasible method for preventing stent migration.

  18. Development of a New Hanging-Type Esophageal Stent for Preventing Migration: A Preliminary Study in an Animal Model of Esophagotracheal Fistula

    International Nuclear Information System (INIS)

    Endo, Masayuki; Kaminou, Toshio; Ohuchi, Yasufumi; Sugiura, Kimihiko; Yata, Shinsaku; Adachi, Akira; Kawai, Tsuyoshi; Takasugi, Syohei; Yamamoto, Shuichi; Matsumoto, Kensuke; Hashimoto, Masayuki; Ihaya, Takashi; Ogawa, Toshihide

    2012-01-01

    Purpose: Covered, self-expandable metallic stents (SEMS) have been enthusiastically adopted for the treatment of esophagotracheal fistula, but problems with stent migration have yet to be resolved. To overcome this problem, we have developed a new hanging-type esophageal stent designed to prevent migration, and we conducted an animal study to assess the efficacy of our method. Methods: A total of six female pigs were used in this study. The main characteristic of our stent was the presence of a string tied to the proximal edge of the stent for fixation under the skin of the neck. The first experiment was performed to confirm technical feasibility in three pigs with esophagotracheal fistula. The second experiment was performed to evaluate stent migration and esophagotracheal fistula in three pigs. Results: Creation of the esophagotracheal fistula and stent placement were technically successful in all pigs. In the first experiment, esophagotracheal fistula was sealed by stent placement. In the second experiment, no stent migration was seen 11 or 12 days after stent placement. Gross findings showed no fistulas on the esophageal or tracheal wall. Conclusions: Our new hanging-type esophageal stent seems to offer a feasible method for preventing stent migration.

  19. The Globalisation of migration

    OpenAIRE

    Milan Mesić

    2002-01-01

    The paper demonstrates that contemporary international migration is a constitutive part of the globalisation process. After defining the concepts of globalisation and the globalisation of migration, the author discusses six key themes, linking globalisation and international migration (“global cities”, the scale of migration; diversification of migration flows; globalisation of science and education; international migration and citizenship; emigrant communities and new identities). First, in ...

  20. The Development and Application of Reactive Transport Modeling Techniques to Study Radionuclide Migration at Yucca Mountain, NV

    International Nuclear Information System (INIS)

    Hari Selvi Viswanathan

    1999-01-01

    Yucca Mountain, Nevada has been chosen as a possible site for the first high level radioactive waste repository in the United States. As part of the site investigation studies, we need to make scientifically rigorous estimations of radionuclide migration in the event of a repository breach. Performance assessment models used to make these estimations are computationally intensive. We have developed two reactive transport modeling techniques to simulate radionuclide transport at Yucca Mountain: (1) the selective coupling approach applied to the convection-dispersion-reaction (CDR) model and (2) a reactive stream tube approach (RST). These models were designed to capture the important processes that influence radionuclide migration while being computationally efficient. The conventional method of modeling reactive transport models is to solve a coupled set of multi-dimensional partial differential equations for the relevant chemical components in the system. We have developed an iterative solution technique, denoted the selective coupling method, that represents a versatile alternative to traditional uncoupled iterative techniques and the filly coupled global implicit method. We show that selective coupling results in computational and memory savings relative to these approaches. We develop RST as an alternative to the CDR method for solving large two- or three-dimensional reactive transport simulations for cases in which one is interested in predicting the flux across a specific control plane. In the RST method, the multidimensional problem is reduced to a series of one-dimensional transport simulations along streamlines. The key assumption with RST is that mixing at the control plane approximates the transverse dispersion between streamlines. We compare the CDR and RST approaches for several scenarios that are relevant to the Yucca Mountain Project. For example, we apply the CDR and RST approaches to model an ongoing field experiment called the Unsaturated Zone

  1. The role of family decision in internal migration: the case of India.

    Science.gov (United States)

    Bhattacharyya, B

    1985-01-01

    This paper analyzes the effects of family decisions and individual decisions on rural-urban migration in India under 2 different rural institutions--family farm and wage labor systems. An analytical framework for explaining family migration decisions reveals that whenever a member of the extended family migrates, he gives up his share in the produce of the family farm. When this happens, the number of adult members on the farm goes down and the total product is affected. 3 case studies of Indian villages are analyzed for this study. 2 empirical relations are examined: 1) if individual migration decisions are predominant, and 2) if family decisions are important in determining the overall flow of migration. Relationships between migration decisions and other variables, such as: 1) number of males in urban areas; 2) urban wages; 3) daily wage rate; 4) average agricultural income; 5) railway distance between rural and urban areas; 6) size of the labor market in destination region; 7) probability that a migrant arriving in an urban area will find a job; and 8) comsumption expenditure, in urban areas estimated by working class consumer price index, are determined. Results show that: 1) the market determined wage variable does not play a very significant role in migration decisions; 2) distance is one of the most important variables in analyzing migration; and 3) the aggregate flow of migration is affected if migration decisions are predominantly family decisions. These findings have relevant policy implications for less developed countries (LDCs), especially because large flows of rural-urban migration in recent years have forced governments to adopt policies for controlling the flows to reduce the burden of unemployment in the urban areas. Government policies affecting rural institutions will have an impact on migration flow; those that lead to a reduction of uncertainty in agriculture will affect average per-capita consumption levels in family farms and hence

  2. Calmodulin promotes matrix metalloproteinase 9 production and cell migration by inhibiting the ubiquitination and degradation of TBC1D3 oncoprotein in human breast cancer cells.

    Science.gov (United States)

    Zhao, Huzi; Zhang, Lina; Zhang, Yongchen; Zhao, Lei; Wan, Qing; Wang, Bei; Bu, Xiaodong; Wan, Meiling; Shen, Chuanlu

    2017-05-30

    The hominoid oncoprotein TBC1D3 enhances growth factor (GF) signaling and GF signaling, conversely, induces the ubiquitination and subsequent degradation of TBC1D3. However, little is known regarding the regulation of this degradation, and the role of TBC1D3 in the progression of tumors has also not been defined. In the present study, we demonstrated that calmodulin (CaM), a ubiquitous cellular calcium sensor, specifically interacted with TBC1D3 in a Ca2+-dependent manner and inhibited GF signaling-induced ubiquitination and degradation of the oncoprotein in both cytoplasm and nucleus of human breast cancer cells. The CaM-interacting site of TBC1D3 was mapped to amino acids 157~171, which comprises two 1-14 hydrophobic motifs and one lysine residue (K166). Deletion of these motifs was shown to abolish interaction between TBC1D3 and CaM. Surprisingly, this deletion mutation caused inability of GF signaling to induce the ubiquitination and subsequent degradation of TBC1D3. In agreement with this, we identified lysine residue 166 within the CaM-interacting motifs of TBC1D3 as the actual site for the GF signaling-induced ubiquitination using mutational analysis. Point mutation of this lysine residue exhibited the same effect on TBC1D3 as the deletion mutant, suggesting that CaM inhibits GF signaling-induced degradation of TBC1D3 by occluding its ubiquitination at K166. Notably, we found that TBC1D3 promoted the expression and activation of MMP-9 and the migration of MCF-7 cells. Furthermore, interaction with CaM considerably enhanced such effect of TBC1D3. Taken together, our work reveals a novel model by which CaM promotes cell migration through inhibiting the ubiquitination and degradation of TBC1D3.

  3. Implementing Product Platforms: A Case Study

    DEFF Research Database (Denmark)

    Nielsen, Ole Fiil; Mortensen, Niels Henrik

    2006-01-01

    The paper describes a case study dealing with the process of creating and implementing a product platform. The paper espessially deals with the fact that to obtain the benefits of platforms a permanent change in behaviour in product development must be ensured. This change in behaviour requires...... acceptance and approval from the organisation in general and the commitment from management to enforce agreed-upon decisions. The case study itself was performed in the Danish company LEGO Group. The case study had two objectives: To create a technical architecture and align this architecture...

  4. Migration pathways in soils

    International Nuclear Information System (INIS)

    Gronow, J.R.

    1986-01-01

    This study looked at diffusive migration through three types of deformation; the projectile pathways, hydraulic fractures of the sediments and faults, and was divided into three experimental areas: autoradiography, the determination of diffusion coefficients and electron microscopy of model projectile pathways in clay. For the autoradiography, unstressed samples were exposed to two separate isotopes, Pm-147 (a possible model for Am behaviour) and the poorly sorbed iodide-125. The results indicated that there was no enhanced migration through deformed kaolin samples nor through fractured Great Meteor East (GME) sediment, although some was evident through the projectile pathways in GME and possibly through the GME sheared samples. The scanning electron microscopy of projectile pathways in clay showed that emplacement of a projectile appeared to have no effect on the orientation of particles at distances greater than two projectile radii from the centre of a projectile pathway. It showed that the particles were not simply aligned with the direction of motion of the projectile but that, the closer to the surface of a particular pathway, the closer the particles lay to their original orientation. This finding was of interest from two points of view: i) the ease of migration of a pollutant along the pathway, and ii) possible mechanisms of hole closure. It was concluded that, provided that there is no advective migration, the transport of radionuclides through sediments containing these defects would not be significantly more rapid than in undeformed sediments. (author)

  5. Use of 131I labelling to study distribution and migration of spermatozoa in the genital tract of female sheep, following artifical insemination. 1

    International Nuclear Information System (INIS)

    Brueckner, G.; Kaempfer, I.; Rummer, H.J.; Menger, H.; Schneider, G.; Karl-Marx-Universitaet, Leipzig

    1982-01-01

    Ram sperma, which had been sucessfully labelled with Na 131 I was followed up by means of a gamma camera up to 150 minutes from insemination while migrating through the genital tract of female sheep. The study had been undertaken primarily for the purpose of testing the method and the suitability of this radionuclide for sperm labelling without major impairment of spermatic motility. Also included in the study were comparisons between oestrus induction by means of fluorogestonacetate vaginal sponges plus pregnant mare serum gonadotrophin treatment and spontaneous oestrus or between fresh and liquid-preserved ram sperma for migration capacity as well as observation of passive migration of sperma in the genital tract of sheep. Rompun anesthesia was applied to sheep for sedation for gamma camera observation. (author)

  6. Extrusion product defects: a statistical study

    International Nuclear Information System (INIS)

    Qamar, S.Z.; Arif, A.F.M.; Sheikh, A.K.

    2003-01-01

    In any manufacturing environment, defects resulting in rework or rejection are directly related to product cost and quality, and indirectly linked with process, tooling and product design. An analysis of product defects is therefore integral to any attempt at improving productivity, efficiency and quality. Commercial aluminum extrusion is generally a hot working process and consists of a series of different but integrated operations: billet preheating and sizing, die set and container preheating, billet loading and deformation, product sizing and stretching/roll-correction, age hardening, and painting/anodizing. Product defects can be traced back to problems in billet material and preparation, die and die set design and maintenance, process variable aberrations (ram speed, extrusion pressure, container temperature, etc), and post-extrusion treatment (age hardening, painting/anodizing, etc). The current paper attempts to analyze statistically the product defects commonly encountered in a commercial hot aluminum extrusion setup. Real-world rejection data, covering a period of nine years, has been researched and collected from a local structural aluminum extrusion facility. Rejection probabilities have been calculated for all the defects studied. The nine-year rejection data have been statistically analyzed on the basis of (i) an overall breakdown of defects, (ii) year-wise rejection behavior, (iii) breakdown of defects in each of three cost centers: press, anodizing, and painting. (author)

  7. A study of electrolytic tritium production

    International Nuclear Information System (INIS)

    Storms, E.K.; Talcott, C.L.

    1990-01-01

    Tritium production is being investigated using cathodes made from palladium and its alloys with various surface treatments. Three anode materials have been studied as well as different impurities in the electrolyte. Tritium has been produced in about 10% of the cells studied but there is, as yet, no pattern of behavior that would make the effect predictable. 15 refs., 4 figs., 6 tabs

  8. Tilting Saturn without Tilting Jupiter: Constraints on Giant Planet Migration

    Science.gov (United States)

    Brasser, R.; Lee, Man Hoi

    2015-11-01

    The migration and encounter histories of the giant planets in our solar system can be constrained by the obliquities of Jupiter and Saturn. We have performed secular simulations with imposed migration and N-body simulations with planetesimals to study the expected obliquity distribution of migrating planets with initial conditions resembling those of the smooth migration model, the resonant Nice model and two models with five giant planets initially in resonance (one compact and one loose configuration). For smooth migration, the secular spin-orbit resonance mechanism can tilt Saturn’s spin axis to the current obliquity if the product of the migration timescale and the orbital inclinations is sufficiently large (exceeding 30 Myr deg). For the resonant Nice model with imposed migration, it is difficult to reproduce today’s obliquity values, because the compactness of the initial system raises the frequency that tilts Saturn above the spin precession frequency of Jupiter, causing a Jupiter spin-orbit resonance crossing. Migration timescales sufficiently long to tilt Saturn generally suffice to tilt Jupiter more than is observed. The full N-body simulations tell a somewhat different story, with Jupiter generally being tilted as often as Saturn, but on average having a higher obliquity. The main obstacle is the final orbital spacing of the giant planets, coupled with the tail of Neptune’s migration. The resonant Nice case is barely able to simultaneously reproduce the orbital and spin properties of the giant planets, with a probability ˜ 0.15%. The loose five planet model is unable to match all our constraints (probability <0.08%). The compact five planet model has the highest chance of matching the orbital and obliquity constraints simultaneously (probability ˜0.3%).

  9. In-situ study of migration and transformation of nitrogen in groundwater based on continuous observations at a contaminated desert site

    Science.gov (United States)

    Zuo, Rui; Jin, Shuhe; Chen, Minhua; Guan, Xin; Wang, Jinsheng; Zhai, Yuanzheng; Teng, Yanguo; Guo, Xueru

    2018-04-01

    The objective of this study was to explore the controlling factors on the migration and transformation of nitrogenous wastes in groundwater using long-term observations from a contaminated site on the southwestern edge of the Tengger Desert in northwestern China. Contamination was caused by wastewater discharge rich in ammonia. Two long-term groundwater monitoring wells (Wells 1# and 2#) were constructed, and 24 water samples were collected. Five key indicators were tested: ammonia, nitrate, nitrite, dissolved oxygen, and manganese. A numerical method was used to simulate the migration process and to determine the migration stage of the main pollutant plume in groundwater. The results showed that at Well 1# the nitrogenous waste migration process had essentially been completed, while at Well 2# ammonia levels were still rising and gradually transitioning to a stable stage. The differences for Well 1# and Well 2# were primarily caused by differences in groundwater flow. The change in ammonia concentration was mainly controlled by the migration of the pollution plume under nitrification in groundwater. The nitrification rate was likely affected by changes in dissolved oxygen and potentially manganese.

  10. Evaluation of Bernese periacetabular osteotomy: prospective studies examining projected load-bearing area, bone density, cartilage thickness and migration.

    Science.gov (United States)

    Mechlenburg, Inger

    2008-06-01

    mean thickness of the femoral cartilage was 1.18 mm, SD 0.06. The precision calculated as the error variance was estimated for the thickness of the acetabular cartilage to 0.01 and femoral cartilage 0.02. We suggest that the method can be advantageous for assessing the progression of osteoarthritis in dysplastic hips after periacetabular osteotomy. In study IV, 32 dysplastic hips, 27 females and 5 males were included in the study. Radiostereometric examinations (RSA) were done at one week, four weeks, eight weeks and six months. Data are presented as mean + SD. Six months postoperatively, the acetabular fragment had migrated 0.7 mm + 0.8 medially, and 0.7 mm + 0.5 proximally. Mean rotation in adduction was 0.5 degrees + 1.3. In other directions, mean migration was below 0.5 mm/degrees. There was no statistical difference between migration 8 weeks and 24 weeks postoperatively in translation or rotation. Due to the limited migration, we find our postoperative partial weight-bearing regime safe. In conclusion, the studies in the present PhD thesis indicate that the projected loadbearing area of the hip joint increases considerable in patients undergoing periacetabular osteotomy and a method to estimate this area was described. Bone density increases in the medial quadrants two years postoperative and a method is developed to precisely estimate bone density on CT images. Also a method to precisely estimate cartilage thickness was presented and we suggest that the method can be advantageous for assessing the progression of osteoarthritis in dysplastic hips after periacetabular osteotomy. Due to the very limited migration of the acetabular fragment fixated with two screws, we find our fixation sufficient and the postoperative partial weight-bearing regimen safe.

  11. A study on the radiation and environmental safety -Studies on radionuclide migration and distribution in terrestrial ecosystem-

    International Nuclear Information System (INIS)

    Lee, Jung Hoh; Lee, Hyun Duk; Kim, Sam Lang; Lee, Chang Woo; Choi, Yong Hoh; Kim, Sang Bok; Lee, Myung Hoh; Hong, Kwang Heui; Lee, Won Yoon; Park, Doo Won; Choi, Sang Doh

    1995-07-01

    In order to investigate the migrational behaviors of radionuclides deposited onto the farm-land during crop cultures, potato and red pepper were cultured on lysimeters installed in a greenhouse and the solution of mixed radionuclides such as Mn-54, Co-60, Sr-85 and Cs-137 was distributed over the land surface on different growth stages of the crops. For rice, soybean, Chinese cabbage and radish, the second or third year's radio-tracer experiments were carried out. Experimental results on Sr-85 and Cs-137 transfer factors for Chinese cabbage and radish were compared with their root-uptake concentrations calculated using existing methods. Samples of farm-land soils and crop plants were collected in the middle part of Korea and concentrations of several γ-emitters were measured. Soil-to-plant transfer factors of Cs-137 measured in outdoor fields were compared with those from greenhouse experiments. 20 figs, 35 tabs, 58 refs. (Author)

  12. Defective neuronal migration and inhibition of bipolar to multipolar transition of migrating neural cells by Mesoderm-Specific Transcript, Mest, in the developing mouse neocortex.

    Science.gov (United States)

    Ji, Liting; Bishayee, Kausik; Sadra, Ali; Choi, Seunghyuk; Choi, Wooyul; Moon, Sungho; Jho, Eek-Hoon; Huh, Sung-Oh

    2017-07-04

    Brain developmental disorders such as lissencephaly can result from faulty neuronal migration and differentiation during the formation of the mammalian neocortex. The cerebral cortex is a modular structure, where developmentally, newborn neurons are generated as a neuro-epithelial sheet and subsequently differentiate, migrate and organize into their final positions in the cerebral cortical plate via a process involving both tangential and radial migration. The specific role of Mest, an imprinted gene, in neuronal migration has not been previously studied. In this work, we reduced expression of Mest with in utero electroporation of neuronal progenitors in the developing embryonic mouse neocortex. Reduction of Mest levels by shRNA significantly reduced the number of neurons migrating to the cortical plate. Also, Mest-knockdown disrupted the transition of bipolar neurons into multipolar neurons migrating out of the sub-ventricular zone region. The migrating neurons also adopted a more tangential migration pattern upon knockdown of the Mest message, losing their potential to attach to radial glia cells, required for radial migration. The differentiation and migration properties of neurons via Wnt-Akt signaling were affected by Mest changes. In addition, miR-335, encoded in a Mest gene intron, was identified as being responsible for blocking the default tangential migration of the neurons. Our results suggest that Mest and its intron product, miR-335, play important roles in neuronal migration with Mest regulating the morphological transition of primary neurons required in the formation of the mammalian neocortex. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. The golden geese fly the internet: some research issues in the migration of Irish professionals

    OpenAIRE

    Wickham, James

    1998-01-01

    A new research agenda is needed for the study of Irish "middle class" emigrants. Globalisation and information technology fragment the identity of the nation state and society. The migration of skilled labour is first and foremost determined by new global economic networks, linked to new hierarchies of knowledge production. However, knowledges vary in the extent to which they are globally applicable. Migration also involves the relationship between knowledge production and the national eco...

  14. Protective effect of Galectin-9 in murine model of lung