121 research outputs found
Recent Searches for Exotic Physics at the BaBar/PEP-II B-factory
I present three recent results from searches for exotic physics at the
BaBar/PEP-II B-factory. These results span many of the samples produced at the
B-factory, including B mesons, tau leptons, and Upsilon(3S) mesons. We have
searched for CPT-violation in B mixing and find no significant deviation from
the no-violation hypothesis. We have also searched for lepton-flavor-violating
decays of the tau using tau- -> omega l- and tau- -> l+ l- l+ and their charge
conjugates. We find no evidence for these processes and set upper limits on
their branching fractions. Finally, we have searched for a low-mass Higgs boson
in the decay Upsilon(3S) -> gamma A0, where the Higgs decays invisibly. We find
no evidence for such a decay and set upper limits across a range of possible
Higgs masses.Comment: Parallel session talk at ICHEP08, Philadelphia, USA, July 2008. 4
pages, 5 Postscript figure
Higgs Production and at a Future Muon-Ion Collider
We investigate the production of Higgs bosons in neutral- and charged-current
interactions at a future Muon-Ion Collider (MuIC) with emphasis on decay. In particular, we focus on the leading production
mechanisms and explore the impact of a range of Parton Distribution Function
(PDF) scenarios, with emphasis on the role of heavy intrinsic quark flavor. We
emphasize estimates of non-resonant di-charm background production and explore
the impact of this background on a possible future measurement of at a future Muon-Ion Collider facility.Comment: 40 pages,38 figure
Design choices for observational studies of the effect of exposure on disease incidence.
The purpose of this paper is to help readers choose an appropriate observational study design for measuring an association between an exposure and disease incidence. We discuss cohort studies, sub-samples from cohorts (case-cohort and nested case-control designs), and population-based or hospital-based case-control studies. Appropriate study design is the foundation of a scientifically valid observational study. Mistakes in design are often irremediable. Key steps are understanding the scientific aims of the study and what is required to achieve them. Some designs will not yield the information required to realise the aims. The choice of design also depends on the availability of source populations and resources. Choosing an appropriate design requires balancing the pros and cons of various designs in view of study aims and practical constraints. We compare various cohort and case-control designs to estimate the effect of an exposure on disease incidence and mention how certain design features can reduce threats to study validity
Pseudo-nitzschia physiological ecology, phylogeny, toxicity, monitoring and impacts on ecosystem health
This paper is not subject to U.S. copyright. The definitive version was published in Harmful Algae 14 (2012): 271-300, doi:10.1016/j.hal.2011.10.025.Over the last decade, our understanding of the environmental controls on Pseudo-nitzschia blooms and domoic acid (DA) production has matured. Pseudo-nitzschia have been found along most of the world's coastlines, while the impacts of its toxin, DA, are most persistent and detrimental in upwelling systems. However, Pseudo-nitzschia and DA have recently been detected in the open ocean's high-nitrate, low-chlorophyll regions, in addition to fjords, gulfs and bays, showing their presence in diverse environments. The toxin has been measured in zooplankton, shellfish, crustaceans, echinoderms, worms, marine mammals and birds, as well as in sediments, demonstrating its stable transfer through the marine food web and abiotically to the benthos. The linkage of DA production to nitrogenous nutrient physiology, trace metal acquisition, and even salinity, suggests that the control of toxin production is complex and likely influenced by a suite of environmental factors that may be unique to a particular region. Advances in our knowledge of Pseudo-nitzschia sexual reproduction, also in field populations, illustrate its importance in bloom dynamics and toxicity. The combination of careful taxonomy and powerful new molecular methods now allow for the complete characterization of Pseudo-nitzschia populations and how they respond to environmental changes. Here we summarize research that represents our increased knowledge over the last decade of Pseudo-nitzschia and its production of DA, including changes in worldwide range, phylogeny, physiology, ecology, monitoring and public health impacts
Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector
A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
Erratum to: Methods for evaluating medical tests and biomarkers
[This corrects the article DOI: 10.1186/s41512-016-0001-y.]
Concurrent Exposure of Bottlenose Dolphins (Tursiops truncatus) to Multiple Algal Toxins in Sarasota Bay, Florida, USA
Sentinel species such as bottlenose dolphins (Tursiops truncatus) can be impacted by large-scale mortality events due to exposure to marine algal toxins. In the Sarasota Bay region (Gulf of Mexico, Florida, USA), the bottlenose dolphin population is frequently exposed to harmful algal blooms (HABs) of Karenia brevis and the neurotoxic brevetoxins (PbTx; BTX) produced by this dinoflagellate. Live dolphins sampled during capture-release health assessments performed in this region tested positive for two HAB toxins; brevetoxin and domoic acid (DA). Over a ten-year study period (2000–2009) we have determined that bottlenose dolphins are exposed to brevetoxin and/or DA on a nearly annual basis (i.e., DA: 2004, 2005, 2006, 2008, 2009; brevetoxin: 2000, 2004, 2005, 2008, 2009) with 36% of all animals testing positive for brevetoxin (n = 118) and 53% positive for DA (n = 83) with several individuals (14%) testing positive for both neurotoxins in at least one tissue/fluid. To date there have been no previously published reports of DA in southwestern Florida marine mammals, however the May 2008 health assessment coincided with a Pseudo-nitzschia pseudodelicatissima bloom that was the likely source of DA observed in seawater and live dolphin samples. Concurrently, both DA and brevetoxin were observed in common prey fish. Although no Pseudo-nitzschia bloom was identified the following year, DA was identified in seawater, fish, sediment, snails, and dolphins. DA concentrations in feces were positively correlated with hematologic parameters including an increase in total white blood cell (p = 0.001) and eosinophil (p<0.001) counts. Our findings demonstrate that dolphins within Sarasota Bay are commonly exposed to two algal toxins, and provide the impetus to further explore the potential long-term impacts on bottlenose dolphin health
Sketching women in court: The visual construction of co-accused women in court drawings
This paper explores the visual construction and representation of co-accused women offenders in court drawings. It utilises three case studies of female co-defendants who appeared in the England and Wales court system between 2003 and 2013. In doing so this paper falls into three parts. The first part considers the emergence of the sub-discipline, visual criminology and examines what is known about the visual representation of female offenders. The second part presents the findings of an empirical investigation, which involved engaging in a critical, reflexive visual analysis of a selection of court drawings of three female co-offenders. The third part discusses the ways in which the court artists' interpretation, the conventions of court sketching, and motifs of female offenders as secondary actors, drew on existing myths and prejudices by representing the women as listening, remorseless ‘others’
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