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991.
The K+/H+ antiporter LeNHX2 increases salt tolerance by improving K+ homeostasis in transgenic tomato 总被引:1,自引:0,他引:1
RAÚL HUERTAS LOURDES RUBIO OLIVIER CAGNAC MARÍA JESÚS GARCÍA‐SÁNCHEZ JUAN DE DIOS ALCHÉ KEES VENEMA JOSÉ ANTONIO FERNÁNDEZ MARÍA PILAR RODRÍGUEZ‐ROSALES 《Plant, cell & environment》2013,36(12):2135-2149
The endosomal LeNHX2 ion transporter exchanges H+ with K+ and, to lesser extent, Na+. Here, we investigated the response to NaCl supply and K+ deprivation in transgenic tomato (Solanum lycopersicum L.) overexpressing LeNHX2 and show that transformed tomato plants grew better in saline conditions than untransformed controls, whereas in the absence of K+ the opposite was found. Analysis of mineral composition showed a higher K+ content in roots, shoots and xylem sap of transgenic plants and no differences in Na+ content between transgenic and untransformed plants grown either in the presence or the absence of 120 mm NaCl. Transgenic plants showed higher Na+/H+ and, above all, K+/H+ transport activity in root intracellular membrane vesicles. Under K+ limiting conditions, transgenic plants enhanced root expression of the high‐affinity K+ uptake system HAK5 compared to untransformed controls. Furthermore, tomato overexpressing LeNHX2 showed twofold higher K+ depletion rates and half cytosolic K+ activity than untransformed controls. Under NaCl stress, transgenic plants showed higher uptake velocity for K+ and lower cytosolic K+ activity than untransformed plants. These results indicate the fundamental role of K+ homeostasis in the better performance of LeNHX2 overexpressing tomato under NaCl stress. 相似文献
992.
Thijl Sunier 《Ethnic and racial studies》2013,36(6):1138-1155
The attacks on the Twin Towers in New York in September 2001 and subsequent events not only ignited a ‘war on terror’, but also marked a crucial change in the policies on integration of migrants of Islamic background in Europe. Most countries departed from integration policies based on some sort of recognition of cultural diversity and emphasized national culture as the only legitimate format for citizenship. The result is a strengthening of a frame of governance with the aim to regulate Islamic practices and to mould outlooks, institutional settings and legal arrangements into the nation-state format. This has been referred to as the ‘domestication of Islam’. One of the consequences is the narrowing down of research agendas and academic knowledge production. In this article I explore this process and address important fields of study that tend to be neglected in the study of Islam in Europe. 相似文献
993.
Using the National Longitudinal Survey of Freshmen (NLSF), we examine both between- and within-group differences in the odds of feeling intraracially harassed. Specifically, we investigate the effects of colleges’ and universities’ racial composition as well as the nature of students’ associations with non-group members, including involvement in racially homogeneous campus organizations, ethnoracial diversity of friendship networks, and interracial dating. Our findings suggest that although college racial composition appears to have little effect on experiencing intraracial harassment, the nature of students’ involvement with other-race students matters a great deal. For all groups, interracial dating increased odds of harassment. Among black and white students, more diverse friendship networks did as well. And among Asian and Latino students, involvement in any racially homogeneous campus organization was associated with increases in reports of intraracial harassment. Thus, we propose a baseline theoretical model of intraracial harassment that highlights the nature of students’ associations with outgroups. 相似文献
994.
The making of an ‘ideal’ live-in migrant care worker: recruiting,training, matching and disciplining
Li-Fang Liang 《Ethnic and racial studies》2013,36(11):1815-1834
This essay investigates the contested processes through which gender and racial ideologies are practised and thereby place specific groups of women in particular gendered and racialized labour markets. The migration of female live-in care workers to Taiwan exemplifies how gender and racial ideologies are embodied in everyday practices that justify the paid care work done by these women and that produce their subordinate status. In this essay, I take the problematic of representation of ‘migrant care workers’ as a point of entry, to investigate how a gendered-racialized ideology is utilized to legitimate and naturalize the gendered-racialized division of care labour within the global capitalist context. 相似文献
995.
The number of people with a ‘mixed’ ethnicity heritage is growing in contemporary Britain. Research in this area has largely focused on implications for cultural and racialized identities, and little is known about associated economic and social factors. Data from the Millennium Cohort Study, a representative panel survey of children born in 2000–2001, are used to examine the circumstances of mixed ethnicity children in comparison with their non-mixed and white counterparts. Findings suggest a cultural location between ‘white’ and minority identities, and socio-economic advantage in comparison with non-mixed counterparts. For example, households of non-mixed white children had poorer economic profiles than households of both mixed white and mixed Indian children. This effect is associated with the presence of a white parent, and the factors underlying it are examined. Although the statistical approach used bypasses a consideration of the dynamics of identity, it provides important evidence on stratification and inequality, and the factors driving this. 相似文献
996.
Alexis M. Silver 《Ethnic and racial studies》2013,36(5):824-840
The influx of Latin American immigrants into the US South since the early 1990s has changed the demographic face of the region, particularly among school-aged populations where the rate of growth among Latinos has been the fastest. Despite an emerging literature addressing changing racial and ethnic relations in the New US South, relatively little research has addressed the incorporation of Latino youths within southern schools. Relying on data from a four-year ethnographic and in-depth interview study in one North Carolina town, findings suggest powerful benefits of ethnic-identity based clubs for Latino youths in new immigrant destination schools. While both Latino and African American respondents faced discrimination within their community, Latino students received more formal support at school, which helped shield them from the negative impacts of discrimination. 相似文献
997.
Michael G. Hanchard 《Ethnic and racial studies》2013,36(8):1333-1340
This symposium on my book, The Specter of Race: How Discrimination Haunts Western Democracy (Princeton, 2018) provides an opportunity to engage specialists in classical and modern political theory and philosophy, comparative racial and ethnic politics, and political sociology who have provided commentary on different aspects of the two overarching arguments intertwined in The Specter of Race; how students of democracy have largely ignored how racial and ethno-national hierarchy has been historically tethered to its practice , and how students of comparative politics have, for the most part, ignored how these hierarchies have informed the very development of modern democracies. 相似文献
998.
Mylène Desorme Alexandra Montembault Jean-Michel Lucas Cyrille Rochas Thierry Bouet Laurent David 《Carbohydrate polymers》2013
We investigated the spinning of hydroalcoholic chitosan solutions. The dope composition was optimized in order to obtain a continuous alcogel fiber by water evaporation on heating the extruded hydroalcoholic solution. This alcogel fiber was then neutralized in aqueous alkali baths and washed in water to eliminate the residual alcohol and salts before final drying. Depending on the alcohol content in the filament at the neutralization step, on specific alcohol–chitosan interactions and on the nature and concentration of the coagulation base, the process yielded semicrystalline chitosan fibers with different proportions of anhydrous and hydrated allomorphs. Contrarily to the classical annealing method, the formation of mainly anhydrous crystals was obtained without significant molecular weight decrease by neutralizing the polymer in hydrophobic conditions. The control of allomorph content was shown to be related to the hydrophobicity of the solvent (alcohol fraction) at the neutralization step. 相似文献
999.
Based on our previous research, four sulfated polysaccharide (sPSs) from Tremella and Condonpsis pilosula, sTPStp, sTPS70c, sCPPStp and sCPPS50c, were prepared and their effects on splenic lymphocytes proliferation in vitro and the immune response of ND vaccine in chicken were compared taking the unmodified polysaccharide (uPS) TPStp as control. The results showed that four sPSs could significantly or numerically stimulate splenic lymphocyte proliferation singly or synergistically with LPS in vitro, sTPS70c and sCPPStp demonstrated better effect; promote peripheral lymphocytes proliferation and enhance serum HI antibody titer in chickens vaccinated with ND vaccine, the actions of sPSs were stronger than that of uPS, and sTPS70c at medium dosage presented the best efficacy. These indicated that sulfation modification could improve the immune-enhancing activity of TPS and CPPS, sTPS70c possessed the strongest activity and would be expected as a component of new-type immunopotentiator. 相似文献
1000.
Kristina L. Straub Wilhelm A. Schönhuber Berit E. E. Buchholz-Cleven Bernhard Schink 《Geomicrobiology journal》2013,30(6):371-378
In previous studies, three different strains (BrG1, BrG2, and BrG3) of ferrous iron-oxidizing, nitrate-reducing bacteria were obtained from freshwater sediments. All three strains were facultative anaerobes and utilized a variety of organic substrates and molecular hydrogen with nitrate as electron acceptor. In this study, analyses of 16S rDNA sequences showed that strain BrG1 was affiliated with the genus Acidovorax, strain BrG2 with the genus Aquabacterium, and strain BrG3 with the genus Thermomonas. Previously, bacteria similar to these three strains were detected with molecular techniques in MPN dilution series for ferrous iron-oxidizing, nitrate-reducing bacteria inoculated with different freshwater sediment samples. In the present study, further molecular analyses of these MPN cultures indicated that the ability to oxidize ferrous iron with nitrate is widespread amongst the Proteobacteria and may also be found among the Gram-positive bacteria with high GC content of DNA. Nitrate-reducing bacteria oxidized ferrous iron to poorly crystallized ferrihydrite that was suitable as an electron acceptor for ferric iron-reducing bacteria. Biologically produced ferrihydrite and synthetically produced ferrihydrite were both well suited as electron acceptors in MPN dilution cultures. Repeated anaerobic cycling of iron was shown in a coculture of ferrous iron-oxidizing bacteria and the ferric iron-reducing bacterium Geobacter bremensis. The results indicate that iron can be cycled between its oxidation states +II and +III by microbial activities in anoxic sediments. 相似文献