24 research outputs found
Cucurbitacin I Inhibits Cell Motility by Indirectly Interfering with Actin Dynamics
Cucurbitacins are plant natural products that inhibit activation of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway by an unknown mechanism. They are also known to cause changes in the organization of the actin cytoskeleton. actin depolymerization experiments, cucurbitacin I had no effect on the rate of actin filament disassembly at the nanomolar concentrations that inhibit cell migration. At elevated concentrations, the depolymerization rate was also unaffected, although there was a delay in the initiation of depolymerization. Therefore, cucurbitacin I targets some factor involved in cellular actin dynamics other than actin itself. Two candidate proteins that play roles in actin depolymerization are the actin-severing proteins cofilin and gelsolin. Cucurbitacin I possesses electrophilic reactivity that may lead to chemical modification of its target protein, as suggested by structure-activity relationship data. However, mass spectrometry revealed no evidence for modification of purified cofilin or gelsolin by cucurbitacin I.Cucurbitacin I results in accumulation of actin filaments in cells by a unique indirect mechanism. Furthermore, the proximal target of cucurbitacin I relevant to cell migration is unlikely to be the same one involved in activation of the JAK2/STAT3 pathway
Transnational social networks, health, and care : a systematic narrative literature review
While transnational social ties and exchanges are a core concern within migration studies, health researchers have often overlooked their importance. Continuous and circular exchanges of information within transnational networks, also defined as social remittances, facilitate the diffusion of innovations, potentially driving contemporary social and cultural change. Influences on health, wellbeing, and care-seeking are important, but under-researched, dimensions for consideration. We undertook a systematic narrative evidence synthesis to describe the current state of knowledge in this area and to identify gaps and future directions for health researchers to take. Between April 2017 and May 2019, an iterative series of searches in Medline, Embase, PsycINFO and PubMed, plus backward and forward citation searches identified 1,173 potential papers. Screening resulted in 36 included papers, eighteen focused on migrant populations and eighteen on those who remain behind. The top three health topics were health-seeking strategies, sexual and reproductive health issues, and healthcare support. And, while not always explicitly identified, mental health and wellbeing was a further prominent, cross-cutting theme. Articles on migrant populations were all conducted in the global North and 13 out of 18 used qualitative methods. Five main themes were identified: therapeutic effect of the continuing social relationships, disrupted social relationships, hybridisation of healthcare, facilitation of connections to healthcare providers, and factors encouraging or undermining transnational social exchanges. Papers concerned with those who remain behind were mainly focused on the global South and used a mix of qualitative and quantitative approaches. Four main themes were identified: transnational transfer of health-related advice, norms, and support; associations between migrant linkages and health behaviours/outcomes; transnational collective transfer of health knowledge; and power and resistance in exchanges. Findings suggest that transnational social exchanges can both support and undermine the health of migrants and those who remain behind. This review confirms that the volume and quality of research in this area must be increased so that health policy and practice can be informed by a better understanding of these important influences on the health of both migrants and those who remain behind
African and Latin American family reunifications in Mediterranean Spain: dynamics and socio-demographic structures
Los extranjeros autorizados en 2006-2009 a residir en España por motivos de reagrupación familiar, muestran la importancia que ha alcanzado esta forma de inmigración en el total de nuevos extranjeros empadronados. La investigación se basa en una encuesta específica a reagrupantes africanos y latinoamericanos, que también informan sobre sus familiares reagrupados, hayan utilizado, o no, las leyes de reagrupación. Africanos y latinoamericanos ofrecen dinámicas y estructuras sociodemográficas muy diferentes, a resultas, entre otras causas, de la antigüedad de sus flujos, su fecundidad, su dominio del idioma español, su nivel de instrucción, sus posibilidades de ingresos, su estructura por sexo y edad, tamaño de las familias reagrupadas, etc. Se ofrece información para los dos colectivos continentales y para los subgrupos familiares —reagrupantes, cónyuges, hijos, progenitores y otros familiares—, y se utilizan escalas del conjunto estudiado y de ámbitos territoriales —Cataluña litoral, Comunidad Valenciana, Murcia-Almería—. Los africanos concentran los aspectos estructurales más negativos —idioma español, instrucción, ingresos,…—, pero también son los que declaran intenciones más firmes y generalizadas de permanencia en España. Las conclusiones orientan sobre el futuro de estos flujos.The amount of foreigners authorised to live in Spain as residents between 2006 and 2009 due to family reunification reflects the significance of this type of immigration in the number of new registered foreigners. This research is based on a specific survey carried out on Africans and Latin Americans, who also provide information on the family members who have joined them here, in accordance with reunification laws or not. Africans and Latin Americans have very different dynamics and socio-demographic structures due, amongst other reasons, to the antiquity of their flows, their fertility rates, their command of Spanish, their level of education, their possibility of income, their structure by sex and age, the size of the reunited families, etc. Information is provided on both continental groups and family subgroups —those who reunite the family, spouses, children, parents and other family members— using scales for the group studied and for the geographical area —coastal Catalonia, the Region of Valencia, Murcia and Almeria—. Africans report the most negative structural aspects —Spanish language, education, income, etc.—; nevertheless it is this group that claim to have more firm and generalised intentions of staying in Spain. The conclusions in this paper give an indication of future flows for these two groups.Investigación realizada dentro del Proyecto «La reagrupación familiar de los inmigrantes africanos y latinoamericanos en la España mediterránea», Ref. CSO2008-01796, financiado por el Ministerio de Ciencia e Innovación
Group conflict theory in a longitudinal perspective: analyzing the dynamic side of ethnic competition
One of the most established approaches to explain attitudes toward immigration is group conflict theory. However, even though the theory was articulated in dynamic terms, previous research has almost exclusively tested it through cross‐sectional analyses. The aim of this study is to disentangle the dynamic character of ethnic competition from more permanent determinants of ethnic threat. The findings show that a remarkable variation of concern over immigration, usually attributed to permanent positions of economic vulnerability, disappears when within‐person variation is modeled. In line with a dynamic approach of ethnic competition, becoming unemployed or being laid off increases concern over immigration. This effect is independent of social class
Micro/Mesoporous Activated Carbons Derived from Polyaniline: Promising Candidates for CO2 Adsorption
A series of activated carbons were prepared by carbonization of polyaniline at different temperatures, using KOH or K2CO3 as activating agent. Pure microporous or micro/mesoporous activated carbons were obtained depending on the preparation conditions. Carbonization temperature has been proven to be a key parameter to define the textural properties of the carbon when using KOH. Low carbonization temperatures (400–650 °C) yield materials with a highly developed micro- and mesoporous structure, whereas high temperatures (800 °C) yield microporous carbons. Some of the materials prepared using KOH exhibit a BET surface area superior to 4000 m2/g, with total pore volume exceeding 2.5 cm3/g, which are among the largest found for activated carbons. On the other hand, microporous materials are obtained when using K2CO3, independently of carbonization temperature. Some of the materials were tested for CO2 capture due to their high microporosity and N content. The adsorption capacity for CO2 at atmospheric pressure and 0 °C achieves a value of ∼7.6 mmol CO2/g, which is among the largest reported in the literature. This study provides guidelines for the design of activated carbons with a proper N/C ratio for CO2 capture at atmospheric pressure.Authors acknowledge financial support from BroadBit industry (BroadBit Slovakia s.r.o. Eötvösova ul. 12. 945 01, Komárno, Slovakia)