38 research outputs found
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
Identifying an indoor air exposure limit for formaldehyde considering both irritation and cancer hazards
Formaldehyde is a well-studied chemical and effects from inhalation exposures have been extensively characterized in numerous controlled studies with human volunteers, including asthmatics and other sensitive individuals, which provide a rich database on exposure concentrations that can reliably produce the symptoms of sensory irritation. Although individuals can differ in their sensitivity to odor and eye irritation, the majority of authoritative reviews of the formaldehyde literature have concluded that an air concentration of 0.3 ppm will provide protection from eye irritation for virtually everyone. A weight of evidence-based formaldehyde exposure limit of 0.1 ppm (100 ppb) is recommended as an indoor air level for all individuals for odor detection and sensory irritation. It has recently been suggested by the International Agency for Research on Cancer (IARC), the National Toxicology Program (NTP), and the US Environmental Protection Agency (US EPA) that formaldehyde is causally associated with nasopharyngeal cancer (NPC) and leukemia. This has led US EPA to conclude that irritation is not the most sensitive toxic endpoint and that carcinogenicity should dictate how to establish exposure limits for formaldehyde. In this review, a number of lines of reasoning and substantial scientific evidence are described and discussed, which leads to a conclusion that neither point of contact nor systemic effects of any type, including NPC or leukemia, are causally associated with exposure to formaldehyde. This conclusion supports the view that the equivocal epidemiology studies that suggest otherwise are almost certainly flawed by identified or yet to be unidentified confounding variables. Thus, this assessment concludes that a formaldehyde indoor air limit of 0.1 ppm should protect even particularly susceptible individuals from both irritation effects and any potential cancer hazard
Analysis of different preferences for the EU's regulatory options for endocrine disruptor identification criteria using argumentation theory
What criteria are most suitable to identify endocrine disrupting substances (EDSs) for regulatory purposes in the EU? The results of the European Commission's public consultation, as part of the process to establish identification criteria for EDSs, show that different regulatory options are supported. Some respondents prefer an option including hazard characterization considerations, whereas others prefer an option that avoids these considerations and introduces several hazard-identification based weight-of-evidence categories. In this study, the argumentation underlying the different preferences for identification criteria are analyzed and compared using pragma-dialectical argumentation theory (PDAT). All responses of non-anonymous, national governments that submitted a response in English (n = 17) were included. Responses of other stakeholder organizations were included if a Google News search returned an opinionated presence in the media on the subject (n = 9). Five topical themes and 21 underlying issues were identified. The themes are 1) mechanistic understanding of EDSs, 2) regulatory considerations related to the identification of EDSs, 3) consistency with existing regulatory frameworks, and 4) evaluations of specific issues related to a category approach and 5) related to including potency. We argue that two overarching (implicit) ‘advocacy coalitions’ can be discerned, that adopted contrasting positions towards the identified themes and issues. Among these ‘coalitions’, there appears to be consensus about the necessity of having ‘science-based’ criteria, though different perspectives exist as to what the most accurate mechanistic understanding of EDSs entails. To move the discussion forward, we argue that a societal dialogue would be beneficial, where EDS science and regulation are discussed as interrelated themes
Individual variation in temporal relationships between exposure to radiofrequency electromagnetic fields and non-specific physical symptoms: A new approach in studying 'electrosensitivity'.
Everyday exposure to radiofrequency electromagnetic fields (RF-EMF) emitted from wireless devices such as mobile phones and base stations, radio and television transmitters is ubiquitous. Some people attribute non-specific physical symptoms (NSPS) such as headache and fatigue to exposure to RF-EMF. Most previous laboratory studies or studies that analyzed populations at a group level did not find evidence of an association between RF-EMF exposure and NSPS