Assessment of the potential in vivo ecotoxicity of Double-Walled Carbon Nanotubes (DWNTs) in water, using the amphibian Ambystoma mexicanum

Because of their specific properties (mechanical, electrical, etc), carbon nanotubes (CNTs) are being assessed for inclusion in many manufactured products. Due to their massive production and number of potential applications, the impact of CNTs on the environment must be taken into consideration. The present investigation evaluates the ecotoxic potential of CNTs in the amphibian larvae (Ambystoma mexicanum). Acute toxicity and genotoxicity were analysed after 12 days of exposure in laboratory conditions. The genotoxic effects were analysed by scoring the micronucleated erythrocytes in the circulating blood of the larvae according to the French standard micronucleus assay. The results obtained in the present study demonstrated that CNTs are neither acutely toxic nor genotoxic to larvae whatever the CNTs concentration in the water, although black masses of CNTs were observed inside the gut. In the increasing economical context of CNTs, complementary studies must be undertaken, especially including mechanistic and environmental investigations

Search For Heavy Pointlike Dirac Monopoles

We have searched for central production of a pair of photons with high transverse energies in $p\bar p$ collisions at $\sqrt{s} = 1.8$ TeV using $70 pb^{-1}$ of data collected with the D\O detector at the Fermilab Tevatron in 1994--1996. If they exist, virtual heavy pointlike Dirac monopoles could rescatter pairs of nearly real photons into this final state via a box diagram. We observe no excess of events above background, and set lower 95% C.L. limits of $610, 870, or 1580 GeV/c^2$ on the mass of a spin 0, 1/2, or 1 Dirac monopole.Comment: 12 pages, 4 figure

Live Imaging at the Onset of Cortical Neurogenesis Reveals Differential Appearance of the Neuronal Phenotype in Apical versus Basal Progenitor Progeny

The neurons of the mammalian brain are generated by progenitors dividing either at the apical surface of the ventricular zone (neuroepithelial and radial glial cells, collectively referred to as apical progenitors) or at its basal side (basal progenitors, also called intermediate progenitors). For apical progenitors, the orientation of the cleavage plane relative to their apical-basal axis is thought to be of critical importance for the fate of the daughter cells. For basal progenitors, the relationship between cell polarity, cleavage plane orientation and the fate of daughter cells is unknown. Here, we have investigated these issues at the very onset of cortical neurogenesis. To directly observe the generation of neurons from apical and basal progenitors, we established a novel transgenic mouse line in which membrane GFP is expressed from the beta-III-tubulin promoter, an early pan-neuronal marker, and crossed this line with a previously described knock-in line in which nuclear GFP is expressed from the Tis21 promoter, a pan-neurogenic progenitor marker. Mitotic Tis21-positive basal progenitors nearly always divided symmetrically, generating two neurons, but, in contrast to symmetrically dividing apical progenitors, lacked apical-basal polarity and showed a nearly randomized cleavage plane orientation. Moreover, the appearance of beta-III-tubulin–driven GFP fluorescence in basal progenitor-derived neurons, in contrast to that in apical progenitor-derived neurons, was so rapid that it suggested the initiation of the neuronal phenotype already in the progenitor. Our observations imply that (i) the loss of apical-basal polarity restricts neuronal progenitors to the symmetric mode of cell division, and that (ii) basal progenitors initiate the expression of neuronal phenotype already before mitosis, in contrast to apical progenitors

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events at \sqrt{s} = 1.8 TeV

We present limits on anomalous WWZ and WW-gamma couplings from a search for WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p -> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron Collider during the 1992-1995 run. The data sample corresponds to an integrated luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling parameters, the 95% CL limits on the CP-conserving couplings are -0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also presented.Comment: 11 pages, 2 figures, 2 table

A Measurement of the W Boson Mass

We report a measurement of the W boson mass based on an integrated luminosity of 82 pb$^{-1}$ from \ppbar collisions at $\sqrt{s}=1.8$ TeV recorded in 1994--1995 by the \Dzero detector at the Fermilab Tevatron. We identify W bosons by their decays to $e\nu$ and extract the mass by fitting the transverse mass spectrum from 28,323 W boson candidates. A sample of 3,563 dielectron events, mostly due to Z to ee decays, constrains models of W boson production and the detector. We measure \mw=80.44\pm0.10(stat)\pm0.07(syst)~GeV. By combining this measurement with our result from the 1992--1993 data set, we obtain \mw=80.43\pm0.11 GeV.Comment: 11 pages, 5 figure

Zgamma Production in pbarp Collisions at sqrt(s)=1.8 TeV and Limits on Anomalous ZZgamma and Zgammagamma Couplings

We present a study of Z +gamma + X production in p-bar p collisions at sqrt{S}=1.8 TeV from 97 (87) pb^{-1} of data collected in the eegamma (mumugamma) decay channel with the D0 detector at Fermilab. The event yield and kinematic characteristics are consistent with the Standard Model predictions. We obtain limits on anomalous ZZgamma and Zgammagamma couplings for form factor scales Lambda = 500 GeV and Lambda = 750 GeV. Combining this analysis with our previous results yields 95% CL limits |h{Z}_{30}| < 0.36, |h{Z}_{40}| < 0.05, |h{gamma}_{30}| < 0.37, and |h{gamma}_{40}| < 0.05 for a form factor scale Lambda=750 GeV.Comment: 17 Pages including 2 Figures. Submitted to PR

Barriers and facilitators to learning and using first aid skills for road traffic crash victims in Nepal: a qualitative study

Data-sharing statement: The anonymised data for the study is available from the corresponding author on request.Background: Road traffic injuries are a major global public health problem despite being avoidable and preventable. In many low- and middle-income countries, the victims of road traffic crashes do not receive care at the scene and may die before reaching hospital. In low- and middle-income countries where prehospital emergency medical services are not well established, bystanders have the potential to save lives by providing first aid. Nepal has rising rates of road traffic injuries and emergency medical services are early in development. There is limited evidence on the factors that influence people in Nepal to become trained in first aid and to use their first aid skills. Objectives: To understand the barriers and facilitators to learning first aid and to applying those skills to help road traffic crash victims in Nepal. Design: Qualitative study using semistructured interviews. Setting: Kathmandu, Lalitpur, Bhaktapur, Kaski and Makwanpur districts in Nepal. Participants: We interviewed three groups of participants: (1) members of the public who had never been trained in first aid, (2) members of the public who had been trained in first aid and (3) first aid trainers. Data sources: Interviews explored reasons why people may be interested in being trained and factors that would inhibit being trained or applying their first aid skills. Interviews were transcribed, translated into English and analysed thematically. Results: Respect from the public, a desire to help those in need and confidence to apply skills were important factors in encouraging people to learn and apply first aid. Barriers included lack of time and financial implications of providing first aid. The fear of social and legal consequences if the patient had a poor outcome, a lack of confidence to apply skills and lack of trust shown to first aiders by some members of the community discouraged learning and using first aid skills. Limitations: Participants were mostly from urban and semiurban areas. People with more difficult access to health care may have held different views. People who were untrained in first aid and agreed to participate may hold different views to those who were not recruited, as they had interest in the topic. Conclusions: Members of the public can be encouraged to learn and apply first aid skills to help road traffic crash victims, but there are multiple barriers to engagement in first aid. Providing legal protection from prosecution for first aiders, raising public awareness of the value of first aid, addressing financial constraints and provision of refresher training may address these barriers. Future work: Research to address the barriers to the creation of a Good Samaritan law appears warranted. The perspectives of other groups often involved in the care and/or transport of road traffic crash victims, such as taxi drivers, would add to our understanding of factors affecting the application of first aid. The gendered stereotypes reported by female first aiders warrant further exploration. Funding: This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Global Health Research programme as award number 16/137/49.This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Global Health Research programme as award number 16/137/49 using UK aid from the UK Government to support global health research. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR or the UK government. Research is published in the NIHR Global Health Research Journal. See the NIHR Funding and Awards website for further award information. This article reports on one component of the research award Barriers and facilitators to learning and using first aid skills for road traffic crash victims in Nepal: a qualitative study. For more information about this research please view the award page (https://www.fundingawards.nihr.ac.uk/award/16/137/49

Prehospital emergency care for trauma victims in Nepal: a mixed-methods study

Data-sharing statement: All data requests should be submitted to the corresponding author for consideration. Access to anonymised data may be granted following review.Background: The prehospital care system in Nepal is poorly developed, with multiple providers, limited co-ordination of services and no national coverage. There is little published evidence reporting the prehospital care of patients with trauma, data which are important to inform the development of the prehospital care system. Objectives: In order to understand the challenges of providing prehospital care to trauma patients, the study aimed to explore the burden of trauma presenting to prehospital care providers and the experience of providing care to these patients. Design: We used a mixed-method study that included secondary data analysis and qualitative semistructured interviews. Setting: Nepal (Kathmandu Valley, Chitwan, Pokhara and Butwal). Participants: Staff employed by the Nepal Ambulance Service including ambulance drivers, emergency medical technicians, dispatch officers and service managers. Data sources: Data describing callouts by the Nepal Ambulance Service over 1 year. Callout data were anonymised and analysed descriptively. Semistructured interviews were audio-recorded, transcribed, translated and analysed using inductive thematic analysis. Results: Of 1408 trauma calls received, 48.4% (n = 682) resulted in prehospital care being provided. The most common mechanism of injury was falls (35.8%), followed by road traffic crashes (19.1%) and the commonest types of injuries were fractures (33.1%) and spinal injuries (10.1%). Mean time from call to arrival at hospital was 48 minutes (range 20 minutes–6 hours). Seventeen staff described factors facilitating effective prehospital care, including having adequate resources, systems and training. Barriers to delivering prehospital care included the expectations and behaviour of patients’ relatives and bystanders, a lack of public awareness of the role and provision of prehospital care, and poor road and traffic conditions. Limitations: For some data fields, data were missing, limiting the ability to precisely determine patient needs and response times. The qualitative data may have been subject to responder bias if participants felt uncomfortable reporting something that may have reflected badly on their employer. Conclusions: Trauma is a major reason for requesting prehospital care, which can be delivered in less than an hour from receiving a call to arrival at the hospital. Multiple factors impede the effective delivery of care which could be addressed through further development across the prehospital care system. Future work: Qualitative research to explore the perceptions and experiences of trauma victims, road users, emergency department staff, police officers, members of organisations involved in prehospital care, firefighters, and policy-makers would complement the findings from this study. Specific issues raised, such as the difficulties experienced when handing over patients between prehospital and hospital care providers, warrant further exploration.This article presents independent research funded by the National Institute for Health and Care Research (NIHR) Global Health Research programme as award number 16/137/49 using UK aid from the UK Government to support global health research