1,003 research outputs found
Vaccines : A rapidly evolving technology - Are the hurdles being addressed?
AbstractVaccination usually works in infectious disease, why not in Cancer? Differences in the potency of microbial and cancer antigens, poor initiation of an immune response due to inadequate expression of tumour associated antigens, weak antigens or tolerance induction and local immune suppression were considered. There is a big difference between a therapeutic and a prophylactic vaccine.The opinion of the expert group was that an improved therapeutic efficacy can hardly be expected by further variation of types of vaccines, schedules, routes of administration and adjuvants alone. A major hurdle for developing therapeutic cancer vaccines is the need to effectively monitor the immune response and to be able to use this in an adaptive trial approach.End-points of assessment should be different from standard treatments as complete response or partial responses are usually low, unless combined with other therapies.In order to focus resources to overcome the hurdles of enhancing the therapeutic efficacy of cancer vaccines the Cancer Vaccine Clinical Trial Working Group, representing academia and the pharmaceutical and biotechnology industries has in a consensus process defined 'A clinical development paradigm for cancer vaccines and related biologics'
Two-Loop Polarization Contributions to Radiative-Recoil Corrections to Hyperfine Splitting in Muonium
We calculate radiative-recoil corrections of order
to hyperfine splitting in muonium generated by the
diagrams with electron and muon polarization loops. These corrections are
enhanced by the large logarithm of the electron-muon mass ratio. The leading
logarithm cubed and logarithm squared contributions were obtained a long time
ago. The single-logarithmic and nonlogarithmic contributions calculated here
improve the theory of hyperfine splitting, and affect the value of the
electron-muon mass ratio extracted from the experimental data on the muonium
hyperfine splitting.Comment: 15 pages, 11 figure
Single-Spin Observables and Orbital Structures in Hadronic Distributions
Within the light-quark sector of the standard model, P-odd observables are
generated from point-like electroweak processes while A_t- odd observables
(neglecting quark mass parameters) come from dynamic spin-orbit correlations
within hadrons or within larger composite systems, such as nuclei. The effects
of A_t-odd dynamics can be inserted into transverse-momentum dependent
constituent distribution functions and, in this paper, we construct the
contribution from an orbital quark to the A_t odd quark parton distribution.
Using this distribution, we examine the crucial role of initial- and
final-state interactions in the observation of the scattering asymmetries in
different hard-scattering processes. This construction provides a geometrical
and dynamical interpretation of the Collins conjugation relation between
single-spin asymmetries in semi-inclusive deep inelastic scattering and the
asymmetries in Drell-Yan production. Finally, our construction allows us to
display a significant difference between the calculation of a spin asymmetry
generated by a hard scattering mechanism involving color-singlet exchange (such
as a photon) and a calculation of an asymmetry with a hard-scattering exchange
involving gluons. This leads to an appreciation of the process dependence
inherent in measurements of single-spin observables.Comment: 35 pages, 6 figure
Producing valid statistics when legislation, culture, and medical practices differ for births at or before the threshold of survival: Report of a European workshop
To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Downloa
The compositional and evolutionary logic of metabolism
Metabolism displays striking and robust regularities in the forms of
modularity and hierarchy, whose composition may be compactly described. This
renders metabolic architecture comprehensible as a system, and suggests the
order in which layers of that system emerged. Metabolism also serves as the
foundation in other hierarchies, at least up to cellular integration including
bioenergetics and molecular replication, and trophic ecology. The
recapitulation of patterns first seen in metabolism, in these higher levels,
suggests metabolism as a source of causation or constraint on many forms of
organization in the biosphere.
We identify as modules widely reused subsets of chemicals, reactions, or
functions, each with a conserved internal structure. At the small molecule
substrate level, module boundaries are generally associated with the most
complex reaction mechanisms and the most conserved enzymes. Cofactors form a
structurally and functionally distinctive control layer over the small-molecule
substrate. Complex cofactors are often used at module boundaries of the
substrate level, while simpler ones participate in widely used reactions.
Cofactor functions thus act as "keys" that incorporate classes of organic
reactions within biochemistry.
The same modules that organize the compositional diversity of metabolism are
argued to have governed long-term evolution. Early evolution of core
metabolism, especially carbon-fixation, appears to have required few
innovations among a small number of conserved modules, to produce adaptations
to simple biogeochemical changes of environment. We demonstrate these features
of metabolism at several levels of hierarchy, beginning with the small-molecule
substrate and network architecture, continuing with cofactors and key conserved
reactions, and culminating in the aggregation of multiple diverse physical and
biochemical processes in cells.Comment: 56 pages, 28 figure
Twistors, Harmonics and Holomorphic Chern-Simons
We show that the off-shell N=3 action of N=4 super Yang-Mills can be written
as a holomorphic Chern-Simons action whose Dolbeault operator is constructed
from a complex-real (CR) structure of harmonic space. We also show that the
local space-time operators can be written as a Penrose transform on the coset
SU(3)/(U(1) \times U(1)). We observe a strong similarity to ambitwistor space
constructions.Comment: 34 pages, 3 figures, v2: replaced with published version, v3: Added
referenc
5-dim Superconformal Index with Enhanced En Global Symmetry
The five-dimensional supersymmetric gauge theory with Sp(N)
gauge group and SO(2N_f) flavor symmetry describes the physics on N D4-branes
with D8-branes on top of a single O8 orientifold plane in Type I' theory.
This theory is known to be superconformal at the strong coupling limit with the
enhanced global symmetry for . In this work we calculate
the superconformal index on for the Sp(1) gauge theory by the
localization method and confirm such enhancement of the global symmetry at the
superconformal limit for to a few leading orders in the chemical
potential. Both perturbative and (anti)instanton contributions are present in
this calculation. For cases some issues related the pole structure of
the instanton calculation could not be resolved and here we could provide only
some suggestive answer for the leading contributions to the index. For the
Sp(N) case, similar issues related to the pole structure appear.Comment: 70 pages, references added, published versio
Learning through social spaces: migrant women and lifelong learning in post-colonial London
This article shows how migrant women engage in learning through social spaces. It argues that such spaces are little recognised, and that there are multiple ways in which migrant women construct and negotiate their informal learning through socialising with other women in different informal modes. Additionally, the article shows how learning is shaped by the socio-political, geographical and multicultural context of living in London, outlining ways in which gendered and racialised identities shape, construct and constrain participation in lifelong learning. The article shows that one way in which migrant women resist (post)colonial constructions of difference is by engaging in informal and non-formal lifelong learning, arguing that the benefits are (at least) two-fold. The women develop skills (including language skills) but also use their informal learning to develop what is referred to in this article as 'relational capital'. The article concludes that informal lifelong learning developed through social spaces can enhance a sense of belonging for migrant women
Transient increase in CSF GAP-43 concentration after ischemic stroke
Background: Cerebrospinal fluid (CSF) biomarkers reflect ongoing processes in the brain. Growth-associated
protein 43 (GAP-43) is highly upregulated in brain tissue shortly after experimental ischemia suggesting the CSF
GAP-43 concentration may be altered in ischemic brain disorders. CSF GAP-43 concentration is elevated in
Alzheimer’s disease patients; however, patients suffering from stroke have not been studied previously.
Methods: The concentration of GAP-43 was measured in longitudinal CSF samples from 28 stroke patients
prospectively collected on days 0–1, 2–4, 7–9, 3 weeks, and 3–5 months after ischemia and cross-sectionally in 19
controls. The stroke patients were clinically evaluated using a stroke severity score system. The extent of the brain
lesion, including injury size and degrees of white matter lesions and atrophy were evaluated by CT and magnetic
resonance imaging.
Results: Increased GAP-43 concentration was detected from day 7–9 to 3 weeks after stroke, compared to day 1–4
and to levels in the control group (P = 0.02 and P = 0.007). At 3–5 months after stroke GAP-43 returned to admission
levels. The initial increase in GAP-43 during the nine first days was associated to stroke severity, the degree of white
matter lesions and atrophy and correlated positively with infarct size (rs = 0.65, P = 0.001).
Conclusions: The transient increase of CSF GAP-43 is important to take into account when used as a biomarker for
other neurodegenerative diseases such as Alzheimer’s disease. Furthermore, GAP-43 may be a marker of neuronal
responses after stroke and additional studies confirming the potential of CSF GAP-43 to reflect severity and
outcome of stroke in larger cohorts are warranted
Male reproductive health and environmental xenoestrogens
EHP is a publication of the U.S. government. Publication of EHP lies in the public domain and is therefore without copyright.
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Use of any materials published in EHP should be acknowledged (for example, "Reproduced with permission from Environmental Health Perspectives") and a reference provided for the article from which the material was reproduced.Male reproductive health has deteriorated in many countries during the last few decades. In the 1990s, declining semen quality has been reported from Belgium, Denmark, France, and Great Britain. The incidence of testicular cancer has increased during the same time incidences of hypospadias and cryptorchidism also appear to be increasing. Similar reproductive problems occur in many wildlife species. There are marked geographic differences in the prevalence of male reproductive disorders. While the reasons for these differences are currently unknown, both clinical and laboratory research suggest that the adverse changes may be inter-related and have a common origin in fetal life or childhood. Exposure of the male fetus to supranormal levels of estrogens, such as diethlylstilbestrol, can result in the above-mentioned reproductive defects. The growing number of reports demonstrating that common environmental contaminants and natural factors possess estrogenic activity presents the working hypothesis that the adverse trends in male reproductive health may be, at least in part, associated with exposure to estrogenic or other hormonally active (e.g., antiandrogenic) environmental chemicals during fetal and childhood development. An extensive research program is needed to understand the extent of the problem, its underlying etiology, and the development of a strategy for prevention and intervention.Supported by EU Contract BMH4-CT96-0314
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