The temporal dynamics of voluntary emotion regulation

Background

Neuroimaging has demonstrated that voluntary emotion regulation is effective in reducing amygdala activation to aversive stimuli during regulation. However, to date little is known about the sustainability of these neural effects once active emotion regulation has been terminated.

Methodology/Principal Findings

We addressed this issue by means of functional magnetic resonance imaging (fMRI) in healthy female subjects. We performed an active emotion regulation task using aversive visual scenes (task 1) and a subsequent passive viewing task using the same stimuli (task 2). Here we demonstrate not only a significantly reduced amygdala activation during active regulation but also a sustained regulation effect on the amygdala in the subsequent passive viewing task. This effect was related to an immediate increase of amygdala signal in task 1 once active emotion regulation has been terminated: The larger this peak postregulation signal in the amygdala in task 1, the smaller the sustained regulation effect in task 2.

Conclusions/Significance

In summary, we found clear evidence that effects of voluntary emotion regulation extend beyond the period of active regulation. These findings are of importance for the understanding of emotion regulation in general, for disorders of emotion regulation and for psychotherapeutic interventions.     

细胞周期和调控因子

近期对细胞周期调控的研究获得了突破性进展.人们深入地研究了周期蛋白家族和pp³⁴蛋白家族在周期调控中的作用及二者之间的相互关系,同时还发现了很多与之相关的调控因子,它们彼此相互作用,形成了极为复杂的级联调控网络.     

Regulatory Network of the Initiation of Chromosomal Replication in Escherichia coli

ABSTRACT

The bacterial chromosome is replicated once during the division cycle, a process ensured by the tight regulation of initiation at oriC. In prokaryotes, the initiator protein DnaA plays an essential role at the initiation step, and feedback control is critical in regulating initiation. Three systems have been identified that exert feedback control in Escherichia coli, all of which are necessary for tight strict regulation of the initiation step. In particular, the ATP-dependent control of DnaA activity is essential. A missing link in initiator activity regulation has been identified, facilitating analysis of the reaction mechanism. Furthermore, key components of this regulatory network have also been described. Because the eukaryotic initiator complex, ORC, is also regulated by ATP, the bacterial system provides an important model for understanding initiation in eukaryotes. This review summarizes recent studies on the regulation of initiator activity.     

Genomics: shifts in metaphorical landscape between 2000 and 2003

Modern biotechnology has been characterized by being surrounded by scientific and public debate and by interest conflicts. An early Danish debate and regulation has been criticized for inhibiting or retarding development and thus growth. Though much regulation and debate have been transferred to the European arena, their role and extension are still an issue. In this paper, the often anticipated innovation-inhibiting effects of regulation are questioned by giving an account of regulations and debates in Denmark. An account which includes the shifting positions of industry, the research community, environmental groups, regulators and other interest groups. The paper indicates that the regulatory measures, introduced as a response to public and interest group critique, have generally reduced industrial uncertainty and promoted industrial Danish biotechnology development. It is further found that regulation and debate changed the rate and direction of new biotechnology development, contributing to technology acceptance, without however ensuring it. The paper thus questions the caricatured assumptions in economics and industrial policy that regulation restrict techno-economic growth. The paper further states regulation and controversies to have contributed actively to the specific technology development, but also states the difficulties in setting radically different technology development agendas.     

Evolution des acides amines libres intracellulaires

The influence of brackish waters on the isosmotic intracellular regulation has been studied on the abdominal muscle of Astacus leptodactylus. Parameters examined are hydratation and free amino acid concentration. Isosmotic intracellular regulation seems to be effective for this animal, some halophilous populations of which live in the Caspian Sea.     

Down-regulation of the M6P/IGF-II receptor increases cell proliferation and reduces apoptosis in neonatal rat cardiac myocytes

Background  

The mannose 6-phosphate/insulin-like growth factor-II receptor (M6P/IGF2R) is a multi-functional protein that has been implicated in regulation of cell growth and apoptosis. Cardiac myocytes express relatively high levels of M6P/IGF2R, and cardiomyocyte apoptosis has been identified in a variety of cardiovascular disorders, such as myocardial infarction and heart failure. However, involvement of M6P/IGF2R in the pathogenesis of these conditions has not been determined. Thus, the objective of this study was to determine the role of M6P/IGF2R in regulation of cardiac myocyte growth and apoptosis.     

鞘氨醇单胞菌的研究进展

鞘氨醇单胞菌(Sphingomonas)不仅细胞膜含有比脂多糖更疏水的鞘糖脂,而且具有高效的代谢调控机制和基因调控能力,使其在威兰胶合成、环境修复和促进植物生长等方面具有巨大的应用潜力。目前国内在鞘氨醇单胞菌代谢机制方面的研究尚无新突破。本文主要综述了鞘氨醇单胞菌的系统分类、基因组学、基因调控机制及其应用等方面的研究,从基因层面分析鞘氨醇单胞菌产威兰胶的合成机制,为后续鞘氨醇单胞菌高密度发酵、工业化生产等研究提供理论基础,以便进一步发掘其在生物技术上的应用潜力。     

Identifying how bacterial cells find their middle: a new perspective

Bacterial cell division begins with the polymerization of the FtsZ protein to form a Z ring at the division site. This ring subsequently recruits the division machinery to allow cytokinesis. How the Z ring is positioned correctly remains a challenging question in biology and our knowledge in this area has been restricted to a few model species. Spatial regulation of division in these bacteria has been considered to be negatively controlled, with Z rings assembling in the area of least inhibition: the cell centre. An article in this issue of Molecular Microbiology reports the discovery of a new protein in Myxococcus xanthus, called PomZ (Positioning at midcell of FtsZ), that is required for the efficient recruitment of the Z ring to the division site. PomZ is a member of the Mrp/Min family of P loop ATPases that includes a diverse range of proteins involved in spatial regulation in bacteria. PomZ is the first positive regulator of Z ring positioning to be identified in vegetatively growing bacterial cells. Positive spatial regulation of division has previously been observed during sporulation in Streptomyces coelicolor and has been suggested to occur in Bacillus subtilis. Perhaps this will emerge as a common theme in the future.     

Glycine N-Methyltransferase and Regulation of S-Adenosylmethionine Levels

Methylation is a major biological process. It has been shown to be important in formation of compounds such as phosphatidylcholine, creatine, and many others and also participates in epigenetic effects through methylation of histones and DNA. The donor of methyl groups for almost all cellular methylation reactions is S-adenosylmethionine. It seems that the level of S-adenosylmethionine must be regulated in response to developmental stages and metabolic changes, and the enzyme glycine N-methyltransferase has been shown to play a major role in such regulation in mammals. This minireview will focus on the latest discoveries in the elucidation of the mechanism of that regulation.     

The role of apoptosis in regulating hematopoietic stem cell numbers

The importance of apoptosis, in combination with proliferation, in maintaining stable populations has become increasingly clear in the last decade. Perturbation of either of these processes can have serious consequences, and result in a variety of disorders. Moreover, as the players and pathways gradually emerge, it turns out that there are strong connections in the regulation of cell cycle progression and apoptosis. Apoptosis, proliferation, and the disorders resulting from aberrant regulation have been studied in a variety of cell types and systems. Hematopoietic stem cells (HSC) are defined as primitive mesenchymal cells that are capable of both self-renewal and differentiation into the various cell lineages that constitute the functioning hematopoietic system. Many (but certainly not all) mature hematopoietic cells are relatively short-lived, sometimes with a half-life in the order of days. Homeostasis requires the production of 10⁸ (mouse) to 10¹¹ (human) cells each day. All of these cells are ultimately derived from HSC that mostly reside in the bone marrow in adult mammals. The study of the regulation of HSC numbers has focussed mainly on the choice between self-renewal and differentiation, symmetric and asymmetric cell divisions. Recently, however, it has been directly demonstrated that apoptosis plays an important role in the regulation of hematopoietic stem cells in vivo.     

On the control of heat shock protein synthesis in Drosophila melanogaster and Ceratitis capitata

The regulation of heat shock protein synthesis has been studied in two dipteran species, Drosophila melanogaster and Ceratitis capitata. The synthesis of the heat shock proteins was studied in organ cultures and compared to the respective translatable mRNA levels determined by in vitro translation in cell-free system. The obtained results suggest regulation of these proteins at the level of translation.     

Tissue- and isoform-specific phytochrome regulation of light-dependent anthocyanin accumulation in Arabidopsis thaliana

Phytochromes regulate light- and sucrose-dependent anthocyanin synthesis and accumulation in many plants. Mesophyll-specific phyA alone has been linked to the regulation of anthocyanin accumulation in response to far-red light in Arabidopsis thaliana. However, multiple mesophyll-localized phytochromes were implicated in the photoregulation of anthocyanin accumulation in red-light conditions. Here, we report a role for mesophyll-specific phyA in blue-light-dependent regulation of anthocyanin levels and novel roles for individual phy isoforms in the regulation of anthocyanin accumulation under red illumination. These results provide new insight into spatial- and isoform-specific regulation of pigmentation by phytochromes in A. thaliana.Key words: anthocyanin, Arabidopsis, photomorphogenesis, photoreceptor, phytochrome