88 research outputs found
Estrategias de desarrollo: visión de un grupo étnico Huilliche
El grupo Huilliche estudiado se encuentra ubicado en la localidad de Yaldad-Incopullo. El objetivo del estudio es detectar las aspiraciones y expectativas del grupo de jóvenes
de la comunidad, y su visión
Metabolic and enzymatic changes associated with carbon mobilization, utilization and replenishment triggered in grain amaranth (Amaranthus cruentus) in response to partial defoliation by mechanical injury or insect herbivory
Background: Amaranthus cruentus and A. hypochondriacus are crop plants grown for grain production in subtropical countries. Recently, the generation of large-scale transcriptomic data opened the possibility to study representative genes of primary metabolism to gain a better understanding of the biochemical mechanisms underlying tolerance to defoliation in these species. A multi-level approach was followed involving gene expression analysis, enzyme activity and metabolite measurements. Results: Defoliation by insect herbivory (HD) or mechanical damage (MD) led to a rapid and transient reduction of non-structural carbohydrates (NSC) in all tissues examined. This correlated with a short-term induction of foliar sucrolytic activity, differential gene expression of a vacuolar invertase and its inhibitor, and induction of a sucrose transporter gene. Leaf starch in defoliated plants correlated negatively with amylolytic activity and expression of a β-amylase-1 gene and positively with a soluble starch synthase gene. Fatty-acid accumulation in roots coincided with a high expression of a phosphoenolpyruvate/phosphate transporter gene. In all tissues there was a long-term replenishment of most metabolite pools, which allowed damaged plants to maintain unaltered growth and grain yield. Promoter analysis of ADP-glucose pyrophosphorylase and vacuolar invertase genes indicated the presence of cis-regulatory elements that supported their responsiveness to defoliation. HD and MD had differential effects on transcripts, enzyme activities and metabolites. However, the correlation between transcript abundance and enzymatic activities was very limited. A better correlation was found between enzymes, metabolite levels and growth and reproductive parameters.
Conclusions: It is concluded that a rapid reduction of NSC reserves in leaves, stems and roots followed by their long-term recovery underlies tolerance to defoliation in grain amaranth. This requires the coordinate action of genes/enzymes that are differentially affected by the way leaf damage is performed. Defoliation tolerance in grain is a complex process that can’t be fully explained at the transcriptomic level only
The novel and taxonomically restricted Ah24 gene from grain amaranth (Amaranthus hypochondriacus) has a dual role in development and defense
Grain amaranths tolerate stress and produce highly nutritious seeds. We have identified several (a)biotic stress-responsive genes of unknown function in Amaranthus
hypochondriacus, including the so-called Ah24 gene. Ah24 was expressed in young or developing tissues; it was also strongly induced by mechanical damage, insect herbivory
and methyl jasmonate and in meristems and newly emerging leaves of severely defoliated plants. Interestingly, an in silico analysis of its 1304 bp promoter region showed a predominance of regulatory boxes involved in development, but not in defense. The Ah24 cDNA encodes a predicted cytosolic protein of 164 amino acids, the localization of which was confirmed by confocal microscopy. Additional in silico analysis identified
several other Ah24 homologs, present almost exclusively in plants belonging to the Caryophyllales. The possible function of this gene in planta was examined in transgenic Ah24 overexpressing Arabidopsis thaliana and Nicotiana tabacum plants. Transformed Arabidopsis showed enhanced vegetative growth and increased leaf number with no penalty in one fitness component, such as seed yield, in experimental conditions. Transgenic tobacco plants, which grew and reproduced normally, had increased insect
herbivory resistance. Modified vegetative growth in transgenic Arabidopsis coincided with significant changes in the expression of genes controlling phytohormone synthesis or signaling, whereas increased resistance to insect herbivory in transgenic tobacco coincided with higher jasmonic acid and proteinase inhibitor activity levels, plus the accumulation of nicotine and several other putative defense-related metabolites. It is
proposed that the primary role of the Ah24 gene in A. hypochondriacus is to contribute to a rapid recovery post-wounding or defoliation, although its participation in defense against insect herbivory is also plausible
Bifurcated homeland and diaspora politics in China and Taiwan towards the Overseas Chinese in Southeast Asia
The conventional literature on diaspora politics tends to focus on one ‘homeland’ state and its relations with ‘sojourning’ diaspora around the world. This paper examines an instance of ‘bifurcated homeland:’ the People's Republic of China and the Republic of China (Taiwan) since 1949. The paper investigates the changing dynamics of China's and Taiwan's diaspora policies towards Overseas Chinese communities in Southeast Asia throughout the Cold War and post-Cold War periods. They were affected by their ideological competition, the rise of Chinese nationalism, and the ‘indigenisation’ of Taiwanese identity. Illustrating such changes through the case of the KMT Yunnanese communities in Northern Thailand, this paper makes two interrelated arguments. First, we should understand relations through the lens of interactive dynamics between international system-level changes and domestic political transformations. Depending on different normative underpinnings of the international system, the foundations of regime legitimacy have changed. Subsequently, the nature of relations between the diaspora and the homeland(s) transformed from one that emphasises ideological differences during the Cold War, to one infused with nationalist authenticity in the post-Cold War period. Second, the bifurcated nature of the two homelands also created mutual influences on their diaspora policies during periods of intense competition
Sending Country Policies
This chapter explores the twin central questions of how and why countries of origin reach out to expatriate populations. It first outlines basic concepts and typologies related to sending country policies, focusing particularly on key countries of origin of migrants settled within the European Union. Second, the chapter reviews central explanations for the emergence of sending country policies. However, sending countries do not reach out to their emigrants in equal measure. Differences are therefore examined in the outreach policies of sending countries and in sending countries' transnational relations with diasporas. The last part of the chapter discusses the nexus between sending country policies and migrant integration in the country of residence. On the basis of existing research, the chapter argues that sending country policies may intersect with migrants' integration in a number of ways. For example, migrant sending countries may seek to strengthen the upward mobility of their expatriate citizens in their place of residence abroad, and they may call for greater protection of migrant workers in precarious labour situations. Little is currently known about how migrants and diasporas respond to these policies and how they are perceived by political actors of countries of residence. This is an area for further study. More analysis is also needed to determine the extent that sending country outreach policies aimed at bonding with and supporting citizens abroad challenge territorial policy sovereignty and the strength of receiving countries in agenda-setting in international cooperation on migration and migrant settlement
Governing migration through death in Europe and the US: Identification, burial and the crisis of modern humanism
Comparing and theorizing state-diaspora relations
Abstract not availableAlexandra Délano, Alan Gamle
Comparing and theorizing state-diaspora relations
Published in Chinese and English本文评论、综合和拓宽现有祖籍国与离散族裔关系研究的理论基础,强调该领域现有大多数研究存在碎片化、个案研究倾向和非理论化的现象,指出在这一领域进行比较和理论化研究的必要性,并提出可行的研究主题和研究方法。本文首先描述了所考察祖籍国与离散族裔关系现象的范围,评论了此领域研究的各层次的文献,之后讨论了《政治地理》杂志2014年第41卷"祖籍国与离散族裔关系"专栏对这一领域作出的贡献,并指出未来的研究议题,包括比较的视角、定量和定性的方法、关于政策扩散理论的争论、治理以及规范的形成等。 = This article reviews,synthesizes,and extends the theoretical underpinnings of existing research on state-diaspora relations,highlighting the fragmented,case-study oriented and a-theoretical nature of most existing work in this area,emphasizing the need to compare and theorize state-diaspora relations and suggesting topics and methods through which this can be done. First we describe the range of phenomena under examination and review the various strands of literature informing this area of research. From there we discuss the contribution of this special section of Political Geography and point the way towards a future research agenda that includes a comparative dimension,employs quantitative and qualitative methods,and engages theoretical debates in relation to policy diffusion,governance and norm formation.亚历山大·德拉诺 艾伦·加姆伦 罗发龙 = Alexandra Délano, Alan Gamlen, Luo Falon
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