Is the tetraneutron a bound dineutron-dineutron molecule?

In light of a new experiment which claims a positive identification, we discuss the possible existence of the tetraneutron. We explore a novel model based on a dineutron-dineutron molecule. We show that this model is not able to explain the tetraneutron as a bound state, in agreement with other theoretical models already discussed in the literature.Comment: 9 pages, 3 figures, J. Phys. G, in pres

The CAT Imaging Telescope for Very-High-Energy Gamma-Ray Astronomy

The CAT (Cherenkov Array at Themis) imaging telescope, equipped with a very-high-definition camera (546 fast phototubes with 0.12 degrees spacing surrounded by 54 larger tubes in two guard rings) started operation in Autumn 1996 on the site of the former solar plant Themis (France). Using the atmospheric Cherenkov technique, it detects and identifies very high energy gamma-rays in the range 250 GeV to a few tens of TeV. The instrument, which has detected three sources (Crab nebula, Mrk 421 and Mrk 501), is described in detail.Comment: 24 pages, 15 figures. submitted to Elsevier Preprin

Digital behaviour change interventions to increase vegetable intake in adults: A systematic review

Background: Digital interventions may help address low vegetable intake in adults, however there is limited understanding of the features that make them effective. We systematically reviewed digital interventions to increase vegetable intake to 1) describe the effectiveness of the interventions; 2) examine links between effectiveness and use of co-design, personalisation, behavioural theories, and/or a policy framework; and 3) identify other features that contribute to effectiveness. Methods: A systematic search strategy was used to identify eligible studies from MEDLINE, Embase, PsycINFO, Scopus, CINAHL, Cochrane Library, INFORMIT, IEEE Xplore and Clinical Trial Registries, published between January 2000 and August 2022. Digital interventions to increase vegetable intake were included, with effective interventions identified based on statistically significant improvement in vegetable intake. To identify policy-action gaps, studies were mapped across the three domains of the NOURISHING framework (i.e., behaviour change communication, food environment, and food system). Risk of bias was assessed using Cochrane tools for randomized, cluster randomized and non-randomized trials. Results: Of the 1,347 records identified, 30 studies were included. Risk of bias was high or serious in most studies (n = 25/30; 83%). Approximately one quarter of the included interventions (n = 8) were effective at improving vegetable intake. While the features of effective and ineffective interventions were similar, embedding of behaviour change theories (89% vs 61%) and inclusion of stakeholders in the design of the intervention (50% vs 38%) were more common among effective interventions. Only one (ineffective) intervention used true co-design. Although fewer effective interventions included personalisation (67% vs 81%), the degree of personalisation varied considerably between studies. All interventions mapped across the NOURISHING framework behaviour change communication domain, with one ineffective intervention also mapping across the food environment domain. Conclusion: Few digital interventions identified in this review were effective for increasing vegetable intake. Embedding behaviour change theories and involving stakeholders in intervention design may increase the likelihood of success. The under-utilisation of comprehensive co-design methods presents an opportunity to ensure that personalisation approaches better meet the needs of target populations. Moreover, future digital interventions should address both behaviour change and food environment influences on vegetable intake

The role of emergency department HIV care in resource-poor settings: lessons learned in western Kenya

The human immunodeficiency virus (HIV) pandemic in sub-Saharan Africa and other high prevalence regions continues to overwhelm health care systems. While there has been a global response to improve the delivery of antiretroviral therapy in these high prevalence regions, there are few models that have developed an adequate plan to deal with HIV specifically in resource-poor emergency department settings. In this manuscript, we report on the experience scaling up HIV care at one emergency department in a large referral hospital located in western Kenya. Specifically, we describe how rapid bedside HIV testing helps to narrow the differential diagnosis of disease processes in acute care patients and how HIV screening of patients discharged from the emergency department can detect HIV-infected individuals

Sociological stalking? Methods, ethics and power in longitudinal criminological research

Scholarship on criminal careers and desistance from crime employing longitudinal methodologies has paid scant attention to sociological and anthropological debates regarding epistemology, reflexivity and researcher positionality. This is surprising in light of a recent phenomenological turn in desistance research wherein (former) lawbreakers’ identity, reflexivity, and self-understanding have become central preoccupations. In this article I interrogate aspects of the methodological ‘underside’ (Gelsthorpe, 2007) of qualitative longitudinal research with criminalised women through an examination of the surveillant position of the researcher. Focusing on methods, ethics and power, I examine some contradictions of feminist concerns to ‘give women voice’ in research involving re-tracing an over-surveilled and highly stigmatised population. I reflect on the effects of researcher positionality through a conceptualisation of re-tracing methods as, at worst, a form of sociological stalking

Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated

Survey of Canadian Animal-Based Researchers' Views on the Three Rs: Replacement, Reduction and Refinement

The ‘Three Rs’ tenet (replacement, reduction, refinement) is a widely accepted cornerstone of Canadian and international policies on animal-based science. The Canadian Council on Animal Care (CCAC) initiated this web-based survey to obtain greater understanding of ‘principal investigators’ and ‘other researchers’ (i.e. graduate students, post-doctoral researchers etc.) views on the Three Rs, and to identify obstacles and opportunities for continued implementation of the Three Rs in Canada. Responses from 414 participants indicate that researchers currently do not view the goal of replacement as achievable. Researchers prefer to use enough animals to ensure quality data is obtained rather than using the minimum and potentially waste those animals if a problem occurs during the study. Many feel that they already reduce animal numbers as much as possible and have concerns that further reduction may compromise research. Most participants were ambivalent about re-use, but expressed concern that the practice could compromise experimental outcomes. In considering refinement, many researchers feel there are situations where animals should not receive pain relieving drugs because it may compromise scientific outcomes, although there was strong support for the Three Rs strategy of conducting animal welfare-related pilot studies, which were viewed as useful for both animal welfare and experimental design. Participants were not opposed to being offered “assistance” to implement the Three Rs, so long as the input is provided in a collegial manner, and from individuals who are perceived as experts. It may be useful for animal use policymakers to consider what steps are needed to make replacement a more feasible goal. In addition, initiatives that offer researchers greater practical and logistical support with Three Rs implementation may be useful. Encouragement and financial support for Three Rs initiatives may result in valuable contributions to Three Rs knowledge and improve welfare for animals used in science