2,661 research outputs found
The effect of exposure to radiofrequency fields on cancer risk in the general and working population: a protocol for a systematic review of human observational studies
BACKGROUND: The World Health Organization (WHO) has an ongoing project to assess potential health effects of exposure to radiofrequency electromagnetic fields (RF-EMF) in the general and working population. Here we present the protocol for a systematic review of the scientific literature on cancer hazards from exposure to RF-EMF in humans, commissioned by the WHO as part of that project. OBJECTIVE: To assess the quality and strength of the evidence provided by human observational studies for a causal association between exposure to RF-EMF and risk of neoplastic diseases. ELIGIBILITY CRITERIA: We will include cohort and case-control studies investigating neoplasia risks in relation to three types of exposure to RF-EMF: near-field, head-localized, exposure from wireless phone use (SR-A); far-field, whole body, environmental exposure from fixed-site transmitters (SR-B); near/far-field occupational exposures from use of handheld transceivers or RF-emitting equipment in the workplace (SR-C). While no restriction on tumour type will be applied, we will focus on selected neoplasms of the central nervous system (brain, meninges, pituitary gland, acoustic nerve) and salivary gland tumours (SR-A); brain tumours and leukaemias (SR-B, SR-C). INFORMATION SOURCES: Eligible studies will be identified through Medline, Embase, and EMF-Portal. RISK-OF-BIAS ASSESSMENT: We will use a tailored version of the OHAT's tool to evaluate the study's internal validity. DATA SYNTHESIS: We will consider separately studies on different tumours, neoplasm-specific risks from different exposure sources, and a given exposure-outcome pair in adults and children. When a quantitative synthesis of findings can be envisaged, the main aims of the meta-analysis will be to assess the strength of association and the shape of the exposure-response relationship; to quantify the degree of heterogeneity across studies; and explore the sources of inconsistency (if any). When a meta-analysis is judged inappropriate, we will perform a narrative synthesis, complemented by a structured tabulation of results and appropriate visual displays. EVIDENCE ASSESSMENT: Confidence in evidence will be assessed in line with the GRADE approach. FUNDING: This project is supported by the World Health Organization. Co-financing was provided by the New Zealand Ministry of Health; the Istituto Superiore di Sanita in its capacity as a WHO Collaborating Centre for Radiation and Health; ARPANSA as a WHO Collaborating Centre for Radiation Protection. REGISTRATION: PROSPERO CRD42021236798
Aspirin for the older person: report of a meeting at the Royal Society of Medicine, London, 3rd November 2011
On November 23rd 2011, the Aspirin Foundation held a meeting at the Royal Society of Medicine in London to review current thinking on the potential role of aspirin in preventing cardiovascular disease and reducing the risk of cancer in older people. The meeting was supported by Bayer Pharma AG and Novacyl
Neutrino Parameters, Abelian Flavor Symmetries, and Charged Lepton Flavor Violation
Neutrino masses and mixings have important implications for models of fermion
masses, and, most directly, for the charged lepton sector. We consider
supersymmetric Abelian flavor models, where neutrino mass parameters are
related to those of charged leptons and sleptons. We show that processes such
as \tau to \mu\gamma, \mu to e\gamma and \mu-e conversion provide interesting
probes. In particular, some existing models are excluded by current bounds,
while many others predict rates within reach of proposed near future
experiments. We also construct models in which the predicted rates for charged
lepton flavor violation are below even the proposed experimental sensitivities,
but argue that such models necessarily involve loss of predictive power.Comment: 27 pages, refs added, published versio
Observation of CP Violation in K(L)->pi+pi-e+e- Decays
We report the first observation of a manifestly CP violating effect in the
K(L)->pi+pi-e+e- decay mode. A large asymmetry was observed in the distribution
of these decays in the CP-odd and T-odd angle phi between the decay planes of
the e+e- and pi+pi- pairs in the K(L) center of mass system. After acceptance
corrections, the overall asymmetry is found to be 13.6+-2.5 (stat) +-1.2
(syst)%. This is the largest CP-violating effect yet observed integrating over
the entire phase space of a mode and the first such effect observed in an
angular variable.Comment: 4 pages 4 figures submitted to pr
Neutrino masses and mixings in a seesaw framework
Assuming the seesaw mechanism for hierarchical neutrino masses, we calculate
the heavy neutrino masses under the hypotheses that the mixing in the Dirac
leptonic sector is similar to the quark mixing () and that
or , where is the Dirac mass matrix of
neutrinos. As a result we find that for the vacuum
oscillation solution of the solar neutrino problem leads to a scale for the
heavy neutrino mass well above the unification scale, while for the MSW
solutions there is agreement with this scale. For the vacuum
solution is consistent with the unification scale, and the MSW solutions with
an intermediate scale. The mass of the lightest heavy neutrino can be as small
as GeV.Comment: 13 pages RevTex, no figures. Revised versio
Neutrino Masses and Lepton-Flavor Violation in Supersymmetric Models with lopsided Froggatt-Nielsen charges
We analyze in detail lepton-flavor violation (LFV) in the charged-lepton
sector such as , , and the
conversion in nuclei, within the framework of supersymmetric models
with lopsided Froggatt--Nielsen charges, in which the large mixing in the
neutrino sector as well as small mixings in the quark sector can be naturally
accommodated. We show that the present experimental limits on the LFV processes
already exclude some of the models. The future proposed search for LFV,
especially in muon processes, can provide a significant probe to this
framework. We also stress the importance of the measurement of
in neutrino experiments, and the fact that the KamLAND experiment could play a
significant role to test a certain class of models.Comment: 33 pages, 20 figure
Sun exposure and melanoma risk at different latitudes: a pooled analysis of 5700 cases and 7216 controls
Background Melanoma risk is related to sun exposure; we have investigated risk variation by tumour site and latitude
A Calculable Toy Model of the Landscape
Motivated by recent discussions of the string-theory landscape, we propose
field-theoretic realizations of models with large numbers of vacua. These
models contain multiple U(1) gauge groups, and can be interpreted as
deconstructed versions of higher-dimensional gauge theory models with fluxes in
the compact space. We find that the vacuum structure of these models is very
rich, defined by parameter-space regions with different classes of stable vacua
separated by boundaries. This allows us to explicitly calculate physical
quantities such as the supersymmetry-breaking scale, the presence or absence of
R-symmetries, and probabilities of stable versus unstable vacua. Furthermore,
we find that this landscape picture evolves with energy, allowing vacua to
undergo phase transitions as they cross the boundaries between different
regions in the landscape. We also demonstrate that supergravity effects are
crucial in order to stabilize most of these vacua, and in order to allow the
possibility of cancelling the cosmological constant.Comment: 49 pages, LaTeX, 13 figures, references adde
Don't Stop Thinking About Leptoquarks: Constructing New Models
We discuss the general framework for the construction of new models
containing a single, fermion number zero scalar leptoquark of mass GeV which can both satisfy the D0/CDF search constraints as well as
low energy data, and can lead to both neutral and charged current-like final
states at HERA. The class of models of this kind necessarily contain new
vector-like fermions with masses at the TeV scale which mix with those of the
Standard Model after symmetry breaking. In this paper we classify all models of
this type and examine their phenomenological implications as well as their
potential embedding into SUSY and non-SUSY GUT scenarios. The general coupling
parameter space allowed by low energy as well as collider data for these models
is described and requires no fine-tuning of the parameters.Comment: Modified text, added table, and updated reference
- …