24 research outputs found
Modulation of inositol polyphosphate levels regulates neuronal differentiation
The binding of neurotrophins to tropomyosin receptor kinase receptors initiates several signaling pathways, including the activation of phospholipase C-γ, which promotes the release of diacylglycerol and inositol 1,4,5-trisphosphate (IP3). In addition to recycling back to inositol, IP3 serves as a precursor for the synthesis of higher phosphorylated inositols, such as inositol 1,3,4,5,6-pentakisphosphate (IP5) and inositol hexakisphosphate (IP6). Previous studies on the effect of neurotrophins on inositol signaling were limited to the analysis of IP 3 and its dephosphorylation products. Here we demonstrate that nerve growth factor (NGF) regulates the levels of IP5 and IP6 during PC12 differentiation. Furthermore, both NGF and brain-derived neurotrophic factor alter IP5 and IP6 intracellular ratio in differentiated PC12 cells and primary neurons. Neurotrophins specifically regulate the expression of IP5-2 kinase (IP5-2K), which phosphorylates IP5 into IP6. IP5-2K is rapidly induced after NGF treatment, but its transcriptional levels sharply decrease in fully differentiated PC12 cells. Reduction of IP5-2K protein levels by small interfering RNA has an effect on the early stages of PC12 cell differentiation, whereas fully differentiated cells are not affected. Conversely, perturbation of IP5-2K levels by overexpression suggests that both differentiated PC12 cells and sympathetic neurons require low levels of the enzyme for survival. Therefore maintaining appropriate intracellular levels of inositol polyphosphates is necessary for neuronal survival and differentiation. © 2013 Loss et al
Preparation of Quality Inositol Pyrophosphates
Myo-inositol is present in nature either unmodified or in more complex phosphorylated derivates. Of the latest, the two most abundant in eukaryotic cells are inositol pentakisphosphate (IP5) and inositol hexakisphosphate (phytic acid or IP6). IP5 and IP6 are the precursors of inositol pyrophosphate molecules that contain one or more pyrophosphate bonds1. Phosphorylation of IP6 generates diphoshoinositolpentakisphosphate (IP7 or PP-IP5) and bisdiphoshoinositoltetrakisphosphate (IP8 or (PP)2-IP4). Inositol pyrophosphates have been isolated from all eukaryotic organisms so far studied. In addition, the two distinct classes of enzymes responsible for inositol pyrophosphate synthesis are highly conserved throughout evolution2-4
Concurrent Security of Anonymous Credentials Light, Revisited
We revisit the concurrent security guarantees of the well-known Anonymous Credentials Light (ACL) scheme (Baldimtsi and Lysyanskaya, CCS\u2713). This scheme was originally proven secure when executed sequentially, and its concurrent security was left as an open problem.
A later work of Benhamouda et al. (EUROCRYPT\u2721) gave an efficient attack on ACL when executed concurrently, seemingly resolving this question once and for all.
In this work, we point out a subtle flaw in the attack of Benhamouda et al. on ACL and show, in spite of popular opinion, that it can be proven concurrently secure.
Our modular proof in the algebraic group model uses an ID scheme as an intermediate step and leads to a major simplification of the complex security argument for Abe\u27s Blind Signature scheme by Kastner et al. (PKC\u2722)
Entanglement distillation using particle statistics
We extend the idea of entanglement concentration for pure states(Phys. Rev.
Lett. {\bf 88}, 187903) to the case of mixed states. The scheme works only with
particle statistics and local operations, without the need of any other
interactions. We show that the maximally entangled state can be distilled out
when the initial state is pure, otherwise the entanglement of the final state
is less than one. The distillation efficiency is a product of the diagonal
elements of the initial state, it takes the maximum 50%, the same as the case
for pure states.Comment: 3 pages, 1 figur
Generation and Evolution of Spin Entanglement in NRQED
A complete analysis on the generation of spin entanglement from NRQED is
presented. The results of entanglement are obtained with relativistic
correction to the leading order of (v/c)^2. It is shown that to this order the
degree of entanglement of a singlet state does not change under time evolution
whereas the triplet state can change.Comment: 8 pages, 1 figure, to appear in Phys. Rev.
The Long-Term Public Health Impact of a Community-Based Participatory Research Project for Health Promotion Among Socially Disadvantaged Women—A Case Study Protocol
Introduction: Community-based participatory research (CBPR) is considered to be of high potential for health promotion among socially disadvantaged groups. However, the long-term implementation and transfer of these approaches remain challenging, and the public health impact they achieve is difficult to study. This also pertains to the potential health effects and cost-effectiveness of CBPR. This study protocol describes the follow-up case study (NU-BIG) after 15 years of the BIG project (movement as investment in health), a project to promote physical activity among socially disadvantaged women. Through a participatory approach, BIG empowers the addressed women to plan and implement low-threshold physical activity offers. Since the project started in 2005, it was transferred to 17 communities in Germany. Materials and Analysis: NU-BIG intends to examine the long-term effects, including economic aspects, of the BIG project on individual and structural levels at all project sites, as well as its long-term implementation and transfer. NU-BIG is a cross-sectional and longitudinal study using a mixed method approach. For the longitudinal section, we re-analyze existing data from former BIG evaluations. For cross-sectional data collection, we use questionnaires and conduct qualitative interviews and focus groups. Women who take part in BIG program offers are part of the research team and will use the photo-voice approach to report on the effects of BIG. The study population consists of about 800 women who participate in BIG project offers and 50 persons involved in the implementation of the BIG project at local sites. Discussion: The expected results from NU-BIG are highly relevant for studying the long-term public health impact of CBPR. In particular, this project intends to answer questions on how the transfer of such projects can succeed and which factors determine if a CBPR project can be sustained at the community level. Eventually, these results can contribute to the further development of participatory approaches to provide effective health promotion among socially disadvantaged groups. Conclusion: Although CBPR is seen of having the potential to reduce health disparities, there is still a lack of research on its long-term effects and public health impact. NU-BIG aims at generating knowledge about the economic effects, reach, efficacy, adoption, implementation, and maintenance of a CBPR project. The expected results could be of high interest for BIG and other CBPR-projects
The Long-Term Public Health Impact of a Community-Based Participatory Research Project for Health Promotion Among Socially Disadvantaged Women—A Case Study Protocol
Introduction: Community-based participatory research (CBPR) is considered to be of high potential for health promotion among socially disadvantaged groups. However, the long-term implementation and transfer of these approaches remain challenging, and the public health impact they achieve is difficult to study. This also pertains to the potential health effects and cost-effectiveness of CBPR. This study protocol describes the follow-up case study (NU-BIG) after 15 years of the BIG project (“movement as investment in health”), a project to promote physical activity among socially disadvantaged women. Through a participatory approach, BIG empowers the addressed women to plan and implement low-threshold physical activity offers. Since the project started in 2005, it was transferred to 17 communities in Germany.
Materials and Analysis: NU-BIG intends to examine the long-term effects, including economic aspects, of the BIG project on individual and structural levels at all project sites, as well as its long-term implementation and transfer. NU-BIG is a cross-sectional and longitudinal study using a mixed method approach. For the longitudinal section, we re-analyze existing data from former BIG evaluations. For cross-sectional data collection, we use questionnaires and conduct qualitative interviews and focus groups. Women who take part in BIG program offers are part of the research team and will use the photo-voice approach to report on the effects of BIG. The study population consists of about 800 women who participate in BIG project offers and 50 persons involved in the implementation of the BIG project at local sites.
Discussion: The expected results from NU-BIG are highly relevant for studying the long-term public health impact of CBPR. In particular, this project intends to answer questions on how the transfer of such projects can succeed and which factors determine if a CBPR project can be sustained at the community level. Eventually, these results can contribute to the further development of participatory approaches to provide effective health promotion among socially disadvantaged groups.
Conclusion: Although CBPR is seen of having the potential to reduce health disparities, there is still a lack of research on its long-term effects and public health impact. NU-BIG aims at generating knowledge about the economic effects, reach, efficacy, adoption, implementation, and maintenance of a CBPR project. The expected results could be of high interest for BIG and other CBPR-projects
Sub-Telomere Directed Gene Expression during Initiation of Invasive Aspergillosis
Aspergillus fumigatus is a common mould whose spores are a
component of the normal airborne flora. Immune dysfunction permits developmental
growth of inhaled spores in the human lung causing aspergillosis, a significant
threat to human health in the form of allergic, and life-threatening invasive
infections. The success of A. fumigatus as a pathogen is unique
among close phylogenetic relatives and is poorly characterised at the molecular
level. Recent genome sequencing of several Aspergillus species
provides an exceptional opportunity to analyse fungal virulence attributes
within a genomic and evolutionary context. To identify genes preferentially
expressed during adaptation to the mammalian host niche, we generated multiple
gene expression profiles from minute samplings of A. fumigatus
germlings during initiation of murine infection. They reveal a highly
co-ordinated A. fumigatus gene expression programme, governing
metabolic and physiological adaptation, which allows the organism to prosper
within the mammalian niche. As functions of phylogenetic conservation and
genetic locus, 28% and 30%, respectively, of the
A. fumigatus subtelomeric and lineage-specific gene
repertoires are induced relative to laboratory culture, and physically clustered
genes including loci directing pseurotin, gliotoxin and siderophore biosyntheses
are a prominent feature. Locationally biased A. fumigatus gene
expression is not prompted by in vitro iron limitation, acid,
alkaline, anaerobic or oxidative stress. However, subtelomeric gene expression
is favoured following ex vivo neutrophil exposure and in
comparative analyses of richly and poorly nourished laboratory cultured
germlings. We found remarkable concordance between the A.
fumigatus host-adaptation transcriptome and those resulting from
in vitro iron depletion, alkaline shift, nitrogen
starvation and loss of the methyltransferase LaeA. This first transcriptional
snapshot of a fungal genome during initiation of mammalian infection provides
the global perspective required to direct much-needed diagnostic and therapeutic
strategies and reveals genome organisation and subtelomeric diversity as
potential driving forces in the evolution of pathogenicity in the genus
Aspergillus
Perturbation of pH and calcium signalling as a means to prevent Aspergillus fumigatus infection
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