313 research outputs found
International Relations and the Global Politics of Health: A State of the Art?
Despite consistent political attention to health-related issues crossing national borders, public health and international relations have not engaged in a coherent dialogue. Public health scholars denounce studies of politics as not directly relevant to the governance of health, which they envisage as based on evidence and medical knowledge. The marginal place of the global politics of health in international relations is surprising given the richness of political interactions, diversity of actors involved, and the existential nature of health politics. This article outlines the main themes in the literature on global and public health politics, highlights the points of convergence and divergence, and discusses how we can build on the strengths and overcome the differences in search of a more comprehensive dialogue between the two disciplines
Unconditional convergence and invertibility of multipliers
In the present paper the unconditional convergence and the invertibility of
multipliers is investigated. Multipliers are operators created by (frame-like)
analysis, multiplication by a fixed symbol, and resynthesis. Sufficient and/or
necessary conditions for unconditional convergence and invertibility are
determined depending on the properties of the analysis and synthesis sequences,
as well as the symbol. Examples which show that the given assertions cover
different classes of multipliers are given. If a multiplier is invertible, a
formula for the inverse operator is determined. The case when one of the
sequences is a Riesz basis is completely characterized.Comment: 31 pages; changes to previous version: 1.) the results from the
previous version are extended to the case of complex symbols m. 2.) new
statements about the unconditional convergence and boundedness are added
(3.1,3.2 and 3.3). 3.) the proof of a preliminary result (Prop. 2.2) was
moved to a conference proceedings [29]. 4.) Theorem 4.10. became more
detaile
On sequence spaces for Fr\'echet frames
We analyze the construction of a sequence space , resp. a
sequence of sequence spaces, in order to have as a
-frame or Banach frame for a Banach space , resp.
pre--frame or -frame for a Fr\'echet space , where is a sequence of Banach spaces
Can any unconditionally convergent multiplier be transformed to have the symbol (1) and Bessel sequences by shifting weights?
Multipliers are operators that combine (frame-like) analysis, a
multiplication with a fixed sequence, called the symbol, and synthesis. They
are very interesting mathematical objects that also have a lot of applications
for example in acoustical signal processing. It is known that bounded symbols
and Bessel sequences guarantee unconditional convergence. In this paper we
investigate necessary and equivalent conditions for the unconditional
convergence of multipliers. In particular we show that, under mild conditions,
unconditionally convergent multipliers can be transformed by shifting weights
between symbol and sequence, into multipliers with symbol (1) and Bessel
sequences
Frame Theory for Signal Processing in Psychoacoustics
This review chapter aims to strengthen the link between frame theory and
signal processing tasks in psychoacoustics. On the one side, the basic concepts
of frame theory are presented and some proofs are provided to explain those
concepts in some detail. The goal is to reveal to hearing scientists how this
mathematical theory could be relevant for their research. In particular, we
focus on frame theory in a filter bank approach, which is probably the most
relevant view-point for audio signal processing. On the other side, basic
psychoacoustic concepts are presented to stimulate mathematicians to apply
their knowledge in this field
Effect of arsenic-phosphorus interaction on arsenic-induced oxidative stress in chickpea plants
Arsenic-induced oxidative stress in chickpea was investigated under glasshouse conditions in response to application of arsenic and phosphorus. Three levels of arsenic (0, 30 and 60 mg kg−1) and four levels of P (50, 100, 200, and 400 mg kg−1) were applied to soil-grown plants. Increasing levels of both arsenic and P significantly increased arsenic concentrations in the plants. Shoot growth was reduced with increased arsenic supply regardless of applied P levels. Applied arsenic induced oxidative stress in the plants, and the concentrations of H2O2 and lipid peroxidation were increased. Activity of superoxide dismutase (SOD) and concentrations of non-enzymatic antioxidants decreased in these plants, but activities of catalase (CAT) and ascorbate peroxidase (APX) were significantly increased under arsenic phytotoxicity. Increased supply of P decreased activities of CAT and APX, and decreased concentrations of non-enzymatic antioxidants, but the high-P plants had lowered lipid peroxidation. It can be concluded that P increased uptake of arsenic from the soil, probably by making it more available, but although plant growth was inhibited by arsenic the P may have partially protected the membranes from arsenic-induced oxidative stress
Preparation of iron(IV) nitridoferrate Ca<sub>4</sub>FeN<sub>4</sub> through azide-mediated oxidation under high-pressure conditions
Cancer Screening by Systemic Administration of a Gene Delivery Vector Encoding Tumor-Selective Secretable Biomarker Expression
Cancer biomarkers facilitate screening and early detection but are known for only a few cancer types. We demonstrated the principle of inducing tumors to secrete a serum biomarker using a systemically administered gene delivery vector that targets tumors for selective expression of an engineered cassette. We exploited tumor-selective replication of a conditionally replicative Herpes simplex virus (HSV) combined with a replication-dependent late viral promoter to achieve tumor-selective biomarker expression as an example gene delivery vector. Virus replication, cytotoxicity and biomarker production were low in quiescent normal human foreskin keratinocytes and high in cancer cells in vitro. Following intravenous injection of virus >90% of tumor-bearing mice exhibited higher levels of biomarker than non-tumor-bearing mice and upon necropsy, we detected virus exclusively in tumors. Our strategy of forcing tumors to secrete a serum biomarker could be useful for cancer screening in high-risk patients, and possibly for monitoring response to therapy. In addition, because oncolytic vectors for tumor specific gene delivery are cytotoxic, they may supplement our screening strategy as a “theragnostic” agent. The cancer screening approach presented in this work introduces a paradigm shift in the utility of gene delivery which we foresee being improved by alternative vectors targeting gene delivery and expression to tumors. Refining this approach will usher a new era for clinical cancer screening that may be implemented in the developed and undeveloped world
The nucleotide addition cycle of RNA polymerase is controlled by two molecular hinges in the Bridge Helix domain
Abstract Background Cellular RNA polymerases (RNAPs) are complex molecular machines that combine catalysis with concerted conformational changes in the active center. Previous work showed that kinking of a hinge region near the C-terminus of the Bridge Helix (BH-HC) plays a critical role in controlling the catalytic rate. Results Here, new evidence for the existence of an additional hinge region in the amino-terminal portion of the Bridge Helix domain (BH-HN) is presented. The nanomechanical properties of BH-HN emerge as a direct consequence of the highly conserved primary amino acid sequence. Mutations that are predicted to influence its flexibility cause corresponding changes in the rate of the nucleotide addition cycle (NAC). BH-HN displays functional properties that are distinct from BH-HC, suggesting that conformational changes in the Bridge Helix control the NAC via two independent mechanisms. Conclusions The properties of two distinct molecular hinges in the Bridge Helix of RNAP determine the functional contribution of this domain to key stages of the NAC by coordinating conformational changes in surrounding domains.</p
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