Home About us Contact
|
Home About us Contact | ||
|
|
||
Migration Process (migration + process)
Selected AbstractsCaveolin-1 polarization in migrating endothelial cells is directed by substrate topology not chemoattractant gradientCYTOSKELETON, Issue 11 2006Virginie Santilman Abstract Polarization is a hallmark of migrating cells, and an asymmetric distribution of proteins is essential to the migration process. Caveolin-1 is highly polarized in migrating endothelial cells (EC). Several studies have shown caveolin-1 accumulation in the front of migrating EC while others report its accumulation in the EC rear. In this paper we address these conflicting results on polarized localization of caveolin-1. We find evidence for the hypothesis that different modes of locomotion lead to differences in protein polarization. In particular, we show that caveolin-1 is primarily localized in the rear of cells migrating on a planar substrate, but in the front of cells traversing a three-dimensional pore. We also show that a chemoattractant, present either as a gradient or ubiquitously in the medium, does not alter caveolin-1 localization in cells in either mode of locomotion. Thus we conclude that substrate topology, and not the presence of a chemoattractant, directs the polarization of caveolin-1 in motile ECs. Cell Motil. Cytoskeleton 2006. © 2006 Wiley-Liss, Inc. [source] THE INTERSECTIONS OF GENDER AND GENERATION IN ALBANIAN MIGRATION, REMITTANCES AND TRANSNATIONAL CAREGEOGRAFISKA ANNALER SERIES B: HUMAN GEOGRAPHY, Issue 1 2009Russell King ABSTRACT. The Albanian case represents the most dramatic instance of post-communist migration: about one million Albanians, a quarter of the country's total population, are now living abroad, most of them in Greece and Italy, with the UK becoming increasingly popular since the late 1990s. This paper draws on three research projects based on fieldwork in Italy, Greece, the UK and Albania. These projects have involved in-depth interviews with Albanian migrants in several cities, as well as with migrant-sending households in different parts of Albania. In this paper we draw out those findings which shed light on the intersections of gender and generations in three aspects of the migration process: the emigration itself, the sending and receiving of remittances, and the care of family members (mainly the migrants' elderly parents) who remain in Albania. Theoretically, we draw on the notion of ,gendered geographies of power' and on how spatial change and separation through migration reshapes gender and generational relations. We find that, at all stages of the migration, Albanian migrants are faced with conflicting and confusing models of gender, behavioural and generational norms, as well as unresolved questions about their legal status and the likely economic, social and political developments in Albania, which make their future life plans uncertain. Legal barriers often prevent migrants and their families from enjoying the kinds of transnational family lives they would like. [source] BRAZILIAN IMMIGRATION TO THE UNITED STATES AND THE GEOGRAPHICAL IMAGINATION,GEOGRAPHICAL REVIEW, Issue 4 2009ALAN P. MARCUS ABSTRACT. In the late 1980s more than 1 million Brazilians left Brazil without returning. Today an estimated 2 million Brazilians live abroad, 1.2 million of them in the United States. In this article I show that Brazilians migrate for a variety of reasons, including the geographical imagination. Why are so many Brazilians leaving for the United States? What are their geographical imaginations, and how are they described in their migration process? Using primary and secondary data and multiple methods, I address these questions by providing insights into Brazilian migrants' place perceptions, experiences, and reasons for migrating, focusing on the geographical imagination. Those migrants who end up returning to Brazil are more likely to cite financial and curiosity reasons for having migrated. A web of transnational religious and social networks sustains those immigrants who remain in the United States. Reasons for migrating are not economic alone; rather, they are based on interrelated and complex factors that range from adventure to curiosity, the cultural influence of the United States, family members, education, and escape. [source] Nurses on the Move: A Global OverviewHEALTH SERVICES RESEARCH, Issue 3p2 2007Mireille Kingma Objective. To look at nurse migration flows in the light of national nursing workforce imbalances, examine factors that encourage or inhibit nurse mobility, and explore the potential benefits of circular migration. Principal Findings. The number of international migrants has doubled since 1970 and nurses are increasingly part of the migratory stream. Critical nursing shortages in industrialized countries are generating a demand that is fueling energetic international recruitment campaigns. Structural adjustments in the developing countries have created severe workforce imbalances and shortfalls often coexist with large numbers of unemployed health professionals. A nurse's motivation to migrate is multifactorial, not limited to financial incentives, and barriers exist that discourage or slow the migration process. The migration flows vary in direction and magnitude over time, responding to socioeconomic factors present in source and destination countries. The dearth of data on which to develop international health human resource policy remains. There is growing recognition, however, that migration will continue and that temporary migration will be a focus of attention in the years to come. Conclusions. Today's search for labor is a highly organized global hunt for talent that includes nurses. International migration is a symptom of the larger systemic problems that make nurses leave their jobs. Nurse mobility becomes a major issue only in a context of migrant exploitation or nursing shortage. Injecting migrant nurses into dysfunctional health systems,ones that are not capable of attracting and retaining staff domestically,will not solve the nursing shortage. [source] Best Practice in Temporary Labour Migration for Development: A Perspective from Asia and the PacificINTERNATIONAL MIGRATION, Issue 5 2009Graeme Hugo The dominant mode of international migration in Asia and the Pacific is temporary contract migration of low-skilled workers. The potential for such migration to deliver significant development dividends to origin communities is substantial because of its large scale and the fact that most migrant workers return to their home community. However, there are a number of barriers that are intervening to dampen these potential positive effects, such as high transaction costs, high costs of sending remittances, and the fact that some areas of origin lack the infrastructure and potential for productive investment. Moreover, destination countries have been very welcoming of high skill temporary migrants but highly restrictive in their attitudes toward their low skill counterparts. This paper discusses the lessons of best practice in temporary labour migration programmes in the region, which can help to overcome these obstacles reducing the positive development impacts of migration. It assesses, in turn, best practice separately for each stage of the labour migration process -- recruitment and selection, and pre-departure preparation -- at the destination and on return. In conclusion, a number of the barriers which impinge on Asian Pacific countries' ability to introduce and sustain best practice are discussed. These include the need for capacity building, lack of cooperation between origin and destination countries, lack of data, poor governance of labour migration a failure among governments to recognise the significance of migration and the need for more "development friendly" migration policies in destinations. [source] Highly Skilled and Business Migrants: Information Processes and Settlement OutcomesINTERNATIONAL MIGRATION, Issue 2 2003Maureen Benson-Rea Summary This paper reports on a research programme that has investigated the migration experiences of highly skilled professional and business migrants to New Zealand. Over a four-year period, five separate studies have been conducted on the stages in the process of migration. The paper sets out a model of the stages of the migration process and the data and analysis which it has guided. Of particular interest are the information sources available to potential migrants and employers, the cultural sensitivity of settlement processes and the migrants' subsequent ease of access to the labour market. The paper analyses information flows available to migrants at crucial phases in the migration process based on a stages model of the migration process. The model indicates some of the critical steps, interactions, and decisions in the migration process from the individual's point of view. Crucial information gaps are identified and implications are drawn for actors involved at the different stages. [source] The State Connection in China's Rural-Urban Migration,INTERNATIONAL MIGRATION REVIEW, Issue 2 2005Lei Guang This study explores the role of China's rural local state-owned and urban state-owned units in its rural-urban migration process. Most studies on Chinese migration have focused on migrants moving from rural to urban areas through informal mechanisms outside of the state's control. They therefore treat the Chinese state as an obstructionist force and dismiss its facilitative role in the migration process. By documenting rural local states' "labor export" strategies and urban state units' employment of millions of peasants, this article provides a corrective to the existing literature. It highlights and explains the state connection in China's rural-urban migration. Labor is , a special kind of commodity. What we do is to fetch a good price for this special commodity. Labor bureau official from Laomei county, 1996 If we want efficiency, we have to hire migrant workers. Party secretary of a state textile factory in Shanghai, 1997 [source] Immigration and femininity in Southern Europe: A gender-based psychosocial analysisJOURNAL OF COMMUNITY & APPLIED SOCIAL PSYCHOLOGY, Issue 5 2008J. M. González-González Abstract Despite the growing presence of female immigrants in Western countries, research on the subject highlights two important biases that hinder appropriate explanation of the migratory phenomenon and hence prevent adequate intervention. First, most of the research studies conducted so far focus on male migration; second, the macro-social perspective has prevailed in these areas of study since socio-economic and political aspects have taken centre stage in analyses on migratory phenomena, From a gender-based psychosocial perspective, this study addresses the migration project of 53 women from different South American countries, the Maghreb region and Eastern Europe now living in Southern Spain. For this purpose we conducted 23 in-depth interviews, and staged six discussion groups with the aim of elucidating to what extent gender-based psychosocial beliefs,stereotypes, ideology and identity,determine women's migration process. Our results suggest that the main stages in the process,deciding to emigrate, itinerary for social and labour integration in the host country, and general assessment of the migration experience,are strongly influenced by psychosociological constructs which arise as a result of female gender-typing or female profile. Copyright © 2008 John Wiley & Sons, Ltd. [source] Staying or returning: Pre-migration influences on the migration process of German migrants to New ZealandJOURNAL OF COMMUNITY & APPLIED SOCIAL PSYCHOLOGY, Issue 4 2008Petra T. Bürgelt Abstract Changes in migrants' backgrounds and societies sending and receiving migrants might increase adaptation issues and reduce retention. To enhance migrants' well-being/health and their likelihood of staying it is necessary to gain an understanding of psychological and social factors that contribute to resilience and adaptation. This paper presents findings from a qualitative study that investigated the experiences, interpretations and actions of German migrant couples to New Zealand throughout the whole migration process to identify these factors. In depth, episodic interviews were conducted with four couples who decided to stay in New Zealand and four couples who decided to return to Germany. Interview data were complemented with participant observation. This paper provides insights into how the pre-migration experiences, interpretations and actions of German migrants to New Zealand influenced their establishment, their interpretations and actions and consequently adaptation, well-being/health and the decision whether to stay in New Zealand or to return to Germany. The findings illuminate the influence of psychological and social factors on migration experiences, interpretations and actions throughout the migration process. The paper offers some solutions for addressing the identified barriers to successful migration and integration into host societies. Copyright © 2008 John Wiley & Sons, Ltd. [source] PETROLEUM MIGRATION, FAULTS AND OVERPRESSURE, PART I: CALIBRATING BASIN MODELLING USING PETROLEUM IN TRAPS , A REVIEWJOURNAL OF PETROLEUM GEOLOGY, Issue 3 2006D.A. Karlsen This paper considers the principles of deciphering basin-scale hydrocarbon migration patterns using the geochemical information which is present in trapped petroleum. Petroleum accumulations in subsiding basins can be thought of as "data archives" within which stored information can help us to understand aspects of hydrocarbon formation and migration. This information can impart a time-resolved picture of hydrocarbon migration in a basin in response to processes associated with progressive burial, particularly in the context of the occurrence and periodic activity of faults. This review, which includes a series of tentative models of migration-related processes in the extensional Halten Terrace area, offshore mid-Norway, illustrates how we can use information from the migrating mobile hydrocarbon phase to improve our knowledge of the static geological system. Of particular importance is the role of sub-seismic heterogeneities and faults in controlling migration processes. We focus on how the secondary migration process can be enhanced in a multi-source rock basin such as the Halten Terrace, thereby increasing prospectivity. [source] Performance of hollow-fiber flow field-flow fractionation in protein separationJOURNAL OF SEPARATION SCIENCE, JSS, Issue 16 2005Ilyong Park Abstract Since hollow-fiber flow field-flow fractionation (HF FlFFF) utilizes a cylindrical channel made of a hollow-fiber membrane, which is inexpensive and simple in channel assembly and thus disposable, interests are increasing as a potential separation device in cells, proteins, and macromolecules. In this study, performance of HF FlFFF of proteins is described by examining the influence of flow rate conditions and length of fiber (polyacrylonitrile or PAN in this work) on sample recovery as well as experimental plate heights. The interfiber reproducibility in terms of separation time and recovery was also studied. Experiments showed that sample recovery was consistent regardless of the length of fiber when the effective field strength (equivalent to the mean flow velocity at the fiber wall) and the channel void time were adjusted to be equivalent for channels of various fiber lengths. This supported that the majority of sample loss in HF FlFFF separation of apoferritin and their aggregates may occur before the migration process. It is finally demonstrated that HF FlFFF can be applied for characterizing the reduction in Stokes' size of low density lipoproteins from blood plasma samples obtained from patients having coronary artery disease and from healthy donors. [source] Vascular adhesion protein-1 (VAP-1) is overexpressed in psoriatic patientsJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 1 2007A Madej Abstract Background, Vascular adhesion protein (VAP)-1 is an adhesion molecule with an enzymatic activity that partakes in the migration process of lymphocytes. Objectives, The aim of this study was to investigate the expression of VAP-1 in the skin and serum of psoriatic patients. Material and methods, Seventy-one patients suffering from psoriasis aged between 23 and 89 years were included in the study. The mean psoriasis severity assessed according to the psoriasis area and severity index was 14.2 ± 9.6 points. The soluble VAP-1 serum concentration was evaluated by ELISA and VAP-1 expression in the skin (nine patients) immunohistochemically. Results, The serum concentration of soluble VAP-1 was significantly higher in psoriatic patients than in healthy controls (403.4 ± 130.8 ng/mL vs. 246.4 ± 68.0 ng/mL; P < 0.0001). No significant relationships were found between sVAP-1 concentration and studied clinical parameters, except the presence of pruritus. Mean number of VAP-1 positive vessels in psoriatic skin, both lesional (19.8 ± 1.4) and non-lesional (9.4 ± 1.4), was significantly higher than in healthy skin (5.4 ± 1.5; P < 0.005). Lesional psoriatic skin demonstrated significantly more VAP-1 positive vessels than non-lesional skin (P < 0.01). Conclusions, Significant overexpression of VAP-1 in both lesional and non-lesional psoriatic skin and higher serum level of soluble VAP-1 in psoriatic patients may indicate the role of VAP-1 in chronic inflammation occurring in psoriasis. However, because of lack of correlation between soluble VAP-1 serum levels and psoriasis severity this hypothesis needs further investigation. [source] Metallicity, planetary formation and migrationMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2003Mario Livio ABSTRACT Recent observations show a clear correlation between the probability of hosting a planet and the metallicity of the parent star. As radial velocity surveys are biased, however, towards detecting planets with short orbital periods, the probability,metallicity correlation could merely reflect a dependence of migration rates on metallicity. We investigated the possibility, but find no basis to suggest that the migration process is sensitive to the metallicity. The indication is, therefore, that a higher metallicity results in a higher probability for planet formation. [source] Direction Sweden: migration fields and cognitive distances of Finland SwedesPOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 6 2007Charlotta Hedberg Abstract This article analyses migration fields and perceptions of distance in the context of the migration process of the Finland-Swedish minority group from Finland to Sweden between 1976 and 1999. The focus of investigation concerns whether the conceptualisation of distance, in terms of socio-historical migration fields and cognitive maps, can contribute to our understanding of migration decision-making. A combination of methods has been employed. Firstly, a quantitative analysis took place of the migration fields of Finland Swedes originating in three case-study areas in Finland. The extension of their migration fields into Sweden is calculated relative to the internal migration pattern within Finland. Secondly, an interview study analysed perceptions of distance among migrants to Sweden. The article shows that a sizeable proportion of the Finland Swedes' migration fields were directed towards Sweden, but that their extension contained regional variations. Further, the decision to migrate to Sweden was strongly influenced by the migrants' perceptions of Sweden prior to migration. Thus, the migrants possessed cognitive maps, with particular sites in Sweden being regarded as distinct and ,close' locations, in contrast to alternative, ,remote' locations in Finland. The perceptions of distance were shaped by the migrants' social, cultural and economic links with Sweden, as well as by their ethnic identity, which included an ethnic affinity with Sweden. It is suggested that the Finland-Swedish migration process to Sweden should be seen as a case of transnational migration. Copyright © 2007 John Wiley & Sons, Ltd. [source] Balancing move and work: women's labour market exits and entries after family migrationPOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 1 2006William A. V. Clark Abstract A substantial literature has examined the nature of mobility and migration and the link to workforce participation. In general that literature has documented the disadvantages to women who move or migrate with a partner during the mobility or migration process, but it suggests, especially for the US, that the disadvantage is temporarily limited. This study of the same process in the British labour market reaffirms a temporary deficit-effect of two-worker migration for women, but unlike the US labour market the process of re-entry seems slower. There are modest monetary gains from mobility and migration, but these gains come for some families only when women enter the labour force after migration. The study reconfirms the importance of gender in the migration and mobility processes. Income, for women, recovers more slowly if a birth was registered in the migration interval. Copyright © 2006 John Wiley & Sons, Ltd. [source] A Novel Point Variant in NTRK3, R645C, Suggests a Role of this Gene in the Pathogenesis of Hirschsprung DiseaseANNALS OF HUMAN GENETICS, Issue 1 2009R. M. Fernández Summary Hirschsprung disease (HSCR) is a developmental disorder characterized by the absence of ganglion cells in the myenteric and submucosal plexuses due to a defect in the migration process of neural crest neuroblasts. Manifestation of the disease has been linked to the dysfunction of two principal signalling pathways involved in the enteric nervous system (ENS) formation: the RET-GDNF and the EDN3-EDNRB receptor systems. However, the NTF3/NTRK3 signalling pathway plays an essential role in the development of the ENS suggesting a potential role for those genes in the pathogenesis of HSCR. We have sought to evaluate the candidature of the NTRK3 gene, which encodes the TrkC receptor, as a susceptibility gene for Hirschsprung disease. Using dHPLC technology we have screened the NTRK3 coding region in 143 Spanish HSCR patients. A total of four previously described polymorphisms and 12 novel sequence variants were detected. Of note, the novel R645C mutation was detected in 2 affected siblings of a HSCR family also carrying a RET splicing mutation. Using bioinformatics tools we observed that the presence of an additional cysteine residue might implicate structural alterations in the mutated protein. We propose haploinsufficiency as the most probable mechanism for the NTRK3 R645C mutation. NTRK3 and RET mutations in this family only appear together in the HSCR patients, suggesting that they per se are necessary but not sufficient to produce the phenotype. In addition, it is quite probable that the contribution of other still unidentified modifier genes, may be responsible for the different phenotypes (length of aganglionosis) in the two affected members. [source] Branch-specific migration cues in the Drosophila tracheal systemBIOESSAYS, Issue 2 2002Dalia Rosin The Drosophila tracheal system forms by highly stereotyped migration of the tracheal cells, generating an elaborate network of interconnected tubes supplying oxygen to all tissues. A major guiding system in the migration process of all branches is the dynamic and localized expression of Branchless (Bnl), an FGF-like molecule. Bnl triggers the activation of the FGF receptor Breathless (Btl) locally in all tracheal cells. Is this the only guiding cue, or do additional local signals provide distinct inputs to each branch? Several recent papers identify such local signals, relying on contacts with specific cell types and with the matrix encountered by the migrating tracheal branches. In particular, the paper by Boube et al(1) demonstrates a role for PS integrins in promoting migration of a specific tracheal branch. BioEssays 24:110,113, 2002. © 2002 Wiley Periodicals, Inc. [source] Au-Catalyzed Tandem Cyclization/[1,2]-Alkyl Migration Reaction of Epoxy Alkynes: Synthesis of SpiropyranonesCHEMISTRY - A EUROPEAN JOURNAL, Issue 17 2008Xing-Zhong Shu Dr. Abstract A novel gold-catalyzed tandem cyclization/[1,2]-alkyl migration process of epoxy alkynes to spiropyranones has been discovered. From this process, the construction of adjacent multiple stereocenters with a new quaternary carbon atom is achieved. The gold-catalyzed domino process is stereospecific with respect to the migrating carbon atom. A type of unusual CC bond cleavage of epoxide systems has also been discovered, which can lead to the formation of two Z,alkenes and a carbonyl functional group in one step with excellent stereoselectivity. Furthermore, this efficient domino process could be achieved in the presence of the simplest and least expensive gold catalyst [NaAuCl4],2,H2O with a low catalyst loading. [source] Processes and forms of an unstable alluvial system with resistant, cohesive streambeds ,EARTH SURFACE PROCESSES AND LANDFORMS, Issue 7 2002Andrew Simon Abstract As a response to channelization projects undertaken near the turn of the 20th century and in the late 1960s, upstream reaches and tributaries of the Yalobusha River, Mississippi, USA, have been rejuvenated by upstream-migrating knickpoints. Sediment and woody vegetation delivered to the channels by mass failure of streambanks has been transported downstream to form a large sediment/debris plug where the downstream end of the channelized reach joins an unmodified sinuous reach. Classification within a model of channel evolution and analysis of thalweg elevations and channel slopes indicates that downstream reaches have equilibrated but that upstream reaches are actively degrading. The beds of degrading reaches are characterized by firm, cohesive clays of two formations of Palaeocene age. The erodibility of these clay beds was determined with a jet-test device and related to critical shear stresses and erosion rates. Repeated surveys indicated that knickpoint migration rates in these clays varied from 0·7 to 12 m a,1, and that these rates and migration processes are highly dependent upon the bed substrate. Resistant clay beds of the Porters Creek Clay formation have restricted advancement of knickpoints in certain reaches and have caused a shift in channel adjustment processes towards bank failures and channel widening. Channel bank material accounts for at least 85 per cent of the material derived from the channel boundaries of the Yalobusha River system. Strategies to reduce downstream flooding problems while preventing upstream erosion and land loss are being contemplated by action agencies. One such proposal involves removal of the sediment/debris plug. Bank stability analyses that account for pore-water and confining pressures have been conducted for a range of hydrologic conditions to aid in predicting future channel response. If the sediment/debris plug is removed to improve downstream drainage, care should be taken to provide sufficient time for drainage of groundwater from the channel banks so as not to induce accelerated bank failures. Published in 2002 John Wiley & Sons, Ltd. [source] Illegal Migration: What Can We Know And What Can We Explain?INTERNATIONAL MIGRATION REVIEW, Issue 3 2004The Case of Germany Methodological problems in the study of illegal migration as defined in this article relate to questions of indicators for illegal migration, with special reference to Germany. It is argued and demonstrated that illegal immigrants are traceable, to some degree, in official statistics and that these can be analyzed for trends. In present-day migration processes, illegal immigration frequently is undertaken with the support of human smugglers. The analysis of the social organization of different forms of smuggling is the other main focus of the article. From a methodological point of view, the literature and public discourse lack adequate concepts for describing and explaining the social organization of human smuggling. The theory of organized crime as a main actor in human smuggling is criticized. The study borrows concepts from market and networks theory and applies these to different forms of human smuggling and illegal migration. The social and technological organization of smuggling is under constant pressure to adapt to new conditions. The dynamism for this change results mainly from an "arms race" between smugglers and law enforcement. Since control over territory and population are central elements of state sovereignty, the state cannot simply withdraw from this race. [source] A major fish stranding caused by a natural hypoxic event in a shallow bay of the eastern South Pacific OceanJOURNAL OF FISH BIOLOGY, Issue 7 2010E. Hernández-Miranda A massive beaching and mortality of fishes occurred in Coliumo Bay, a shallow bay located along the coast of the eastern South Pacific Ocean on 3 January 2008. This stranding was a consequence of an abrupt decrease in the dissolved oxygen concentration throughout the whole water column, due to the effect of intense upwelling along the coast off central-southern Chile. The main objectives of this study were: (1) to characterize taxonomically and biologically the fish species assemblage present in this beaching; (2) to evaluate several physiological indicators for the condition of the beached species at the time of their death; and (3) to assess the possible cause,effect mechanisms involved in the fishes death and the changes that took place in the fish community throughout the time. In this beaching, 26 fish species were identified: 23 teleosts, one myxiniform and two elasmobranchs. Most beached specimens were juveniles. Haematological and histological evidence indicate that severe hypoxia that lasted for at least 48 h was the most plausible cause of death. The main conclusion of this study is that the presence of oxygen-poor equatorial sub-surface water in the shallow coastal zone due to intense regional-scale upwelling caused the fish stranding. Although the effect of the hypoxic event was severe for the fish assemblage of Coliumo Bay, the rapid recuperation observed suggests that hypoxic events at the local spatial scale can be buffered by migration processes from the fish community inhabiting close by areas non-affected by low oxygen conditions. The effect that severe hypoxic events may have on larger spatial scales remains unknown. [source] PETROLEUM MIGRATION, FAULTS AND OVERPRESSURE, PART I: CALIBRATING BASIN MODELLING USING PETROLEUM IN TRAPS , A REVIEWJOURNAL OF PETROLEUM GEOLOGY, Issue 3 2006D.A. Karlsen This paper considers the principles of deciphering basin-scale hydrocarbon migration patterns using the geochemical information which is present in trapped petroleum. Petroleum accumulations in subsiding basins can be thought of as "data archives" within which stored information can help us to understand aspects of hydrocarbon formation and migration. This information can impart a time-resolved picture of hydrocarbon migration in a basin in response to processes associated with progressive burial, particularly in the context of the occurrence and periodic activity of faults. This review, which includes a series of tentative models of migration-related processes in the extensional Halten Terrace area, offshore mid-Norway, illustrates how we can use information from the migrating mobile hydrocarbon phase to improve our knowledge of the static geological system. Of particular importance is the role of sub-seismic heterogeneities and faults in controlling migration processes. We focus on how the secondary migration process can be enhanced in a multi-source rock basin such as the Halten Terrace, thereby increasing prospectivity. [source] Investigations on local Ga and In incorporation of GaInN quantum wells on facets of selectively grown GaN stripesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 6 2006B. Neubert Abstract Multiple GaInN quantum wells (QWs) were grown on side facets with reduced piezoelectric fields (PFs) of selectively grown GaN stripes oriented along the ,100, and ,110, directions by metalorganic vapor phase epitaxy (MOVPE). The different luminescence wavelengths observed for the QWs on these facets can be explained by the reduced PFs, additionally the QW thickness depends on the facet type. Although stripes running along ,100, and ,110, develop similar triangular or trapezoidal shape, their detailed growth behaviour, electrical and luminescence properties differ significantly pointing to different adsorption/desorption and inter-facet migration processes of In, Ga and the p-type dopant Mg. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Immigration, employment relations, and health: Developing a research agendaAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 4 2010Joan Benach Abstract Background International migration has emerged as a global issue that has transformed the lives of hundreds of millions of persons. Migrant workers contribute to the economic growth of high-income countries often serving as the labour force performing dangerous, dirty and degrading work that nationals are reluctant to perform. Methods Critical examination of the scientific and "grey" literatures on immigration, employment relations and health. Results Both lay and scientific literatures indicate that public health researchers should be concerned about the health consequences of migration processes. Migrant workers are more represented in dangerous industries and in hazardous jobs, occupations and tasks. They are often hired as labourers in precarious jobs with poverty wages and experience more serious abuse and exploitation at the workplace. Also, analyses document migrant workers' problems of social exclusion, lack of health and safety training, fear of reprisals for demanding better working conditions, linguistic and cultural barriers that minimize the effectiveness of training, incomplete OHS surveillance of foreign workers and difficulty accessing care and compensation when injured. Therefore migrant status can be an important source of occupational health inequalities. Conclusions Available evidence shows that the employment conditions and associated work organization of most migrant workers are dangerous to their health. The overall impact of immigration on population health, however, still is poorly understood and many mechanisms, pathways and overall health impact are poorly documented. Current limitations highlight the need to engage in explicit analytical, intervention and policy research. Am. J. Ind. Med. 53:338,343, 2010. © 2009 Wiley-Liss, Inc. [source] Theoretical Characterization of Charge Transport in One-Dimensional Collinear Arrays of Organic Conjugated MoleculesCHEMPHYSCHEM, Issue 5 2010Lucas Viani Abstract A great deal of interest has recently focused on host,guest systems consisting of one-dimensional collinear arrays of conjugated molecules encapsulated in the channels of organic or inorganic matrices. Such architectures allow for controlled charge and energy migration processes between the interacting guest molecules and are thus attractive in the field of organic electronics. In this context, we characterize here at a quantum-chemical level the molecular parameters governing charge transport in the hopping regime in 1D arrays built with different types of molecules. We investigate the influence of several parameters (such as the symmetry of the molecule, the presence of terminal substituents, and the molecular size) and define on that basis the molecular features required to maximize the charge carrier mobility within the channels. In particular, we demonstrate that a strong localization of the molecular orbitals in push,pull compounds is generally detrimental to the charge transport properties. [source] CCR3-active chemokines influence eosinophil adhesion to endothelial cells under static and flow conditionsCLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 1 2007H. Tachimoto Summary We recently demonstrated that CCR3-active chemokines promote rapid detachment of eosinophils bound to vascular cell adhesion molecule-1 (VCAM-1) in vitro. Eosinophils adhered well to immobilized human recombinant VCAM-1 primarily via ,4,1 integrin. Eotaxin-2, a CCR3-specific chemokine, induced eosinophil de-adhesion from VCAM-1. In contrast, very few eosinophils spontaneously adhered to bovine serum albumin (BSA), and eosinophil adhesion to BSA was enhanced by eotaxin-2 over a similar nm range of concentrations. This enhancement of BSA adhesion was dependent on ,2 integrins. Eosinophil ,4,1 integrins can mediate rolling on VCAM-1 under physiological flow conditions. Although we observed a reduction of eosinophil accumulation on immobilized VCAM-1 in response to eotaxin-2 under physiological flow conditions, this reduction of adhesion was not observed when VCAM-1 and intercellular adhesion molecule-1 (ICAM-1) were co-immobilized. Based on antibody-blocking studies, this appears to be caused by a chemokine-induced shift in integrin usage away from ,1 integrin-dominated interactions with VCAM-1 towards ,2 integrin-dominated interactions with ICAM-1. Our results confirm the important role of integrins and chemokines in selective eosinophil migration processes. CCR3-active chemokines may be necessary to facilitate de-adhesion from luminal VCAM-1 and to facilitate the process of diapedesis by shifting integrin usage in eosinophils away from ,1 integrin-dominated interactions with VCAM-1 towards ,2 integrin-dominated interactions with ICAM-1. The critical importance of integrins and chemokines in eosinophilic inflammation lends support for targeting these molecules with novel therapeutic agents. [source] | |||||||||||||||||||||||||