Determination of the Cause of the Differing Ballistic Performance of 9mm DM11 Bullets from Two Manufacturers

In London, firearm threats faced by police during criminal activity include 9mm handguns and submachine guns. The UK Home Office body armour standards have included 9mm DM11 A1B2, manufactured originally by Dynamit Nobel under RWS branding, for over a decade. The recently published 2017 UK Home Office body armour standard continues to specify the 9mm DM11 A1B2, however, the specified manufacturer has changed to Metallwerk Elisenhütte GmbH (MEN). The DM11 A1B2 bullet comprises a copper coated steel full metal jacket with a lead core and bullets from both are specified to the same drawings and dimensional tolerances. However, during empirical testing against soft armour systems differences have been observed in the Vmean measured by CPA for the 2 bullets. As a result, body armour systems designed to pass the standard tests using the RWS 9mm DM11 A1B2 bullet manufactured may have a lesser safety margin when subject to impact with the equivalent MEN bullet. This paper reports on the results of an investigation in to the causes of the differing performance of the two sources of 9mm DM11 A1B2 bullets. It includes a study of the metallurgy of the steel jacket, dimensional and mass comparisons and a range of high strain rate testing to compare the properties and deformation behaviour of the two bullet types. Ballistic tests have been performed to demonstrate how the difference in performance may be related to the observed differences in the steel jacket metallurgy and the resulting differing deformation behaviour. The study has shown that the root cause of the differing performance is due primarily to differences in the steel used for the jackets by the different manufacturers. This work has important consequences for the UK body armour industry and others testing with the 9mm DM11 round

Inconsistency of threat level in soft armour standards, correlation of experimental tests to bullet X-ray 3D images

Fundamental to any ballistic armour standard is the reference projectile that is to be defeated. Typically, for certification, consistency of bullet geometry is assumed. Therefore, practical variations in bullet jacket dimensions can have far reaching consequences. Traditionally, internal dimensions have been analysed by physically sectioning bullets – an approach which rules out any subsequent ballistic assessment. The use of a non-destructive X-ray Computed Tomography (CT) method was demonstrated in [1]. Now, the authors apply this technique to correlate bullet impact response to jacket thickness variations. A set of 20 bullets (9 mm DM 11) was selected to analyse both intra and inter bullet variations using an image based analysis method to map the jacket thickness and measure the centre of gravity. Thickness variations of the order of 200μm were found commonly across all the bullets along the length and an angular variation of up to 50μm was found in a few bullets. The bullets were subsequently impacted against a rigid flat plate and re-scanned. The results of the experiments are shown and compared to the un-deformed bullet jacket thickness variations. The conclusions are relevant for future soft armour standards and provide important data for numerical model correlation and development

Authorised Firearms Officers’ body armour– can I perform my firearms role in it?

As litigation within the police body armour sector escalates, it is becoming increasingly important to have a robust evaluation and reporting method for evaluating ergonomic issues. This paper describes national differences in roles for Authorised Firearms Officers (AFOs). It identifies good practices learnt from previous ergonomic trials and makes recommendations for more complex assessments, such as those required to assess AFOs protection schemes. Furthermore it describes the use of police Subject Matter Experts (SMEs) to determine representative tasks and undertake a sensitivity exercise to identify the most important attributes of the AFO role. These formed the basis of the questionnaire, scoring scheme and analysis

Does wearing police body armour cause back issues?

Metvest body armour is worn by over 30,000 Metropolitan Police Officers patrolling the streets of London. Some officers have complained of lower back pain and have attributed the cause to wearing Metvest. This has raised the question as to whether or not wearing police body armour is related to low back pain issues. In order to investigate this, a study was carried out to determine the physiological effect of wearing body armour. This was assessed by measuring spinal torque / range of motion (RoM), muscle activity (EMG) during spinal flexion and extension, functional health score and subjective back pain, in both a Control Group and a non-specific Low Back Pain Group (LBP - identified by Occupational Health), to determine differences between these two groups. Additionally, the LBP group underwent an 8 week rehabilitation programme, devised and executed by Occupational Health, MPS. Functional and subjective assessments were taken group prior, mid and post rehabilitation. Data showed that wearing Metvest body armour did not have a significant effect on either spinal range of motion nor spinal muscle activity during forward flexion and backward extension in either the control or LBP subjects. Following completion of the MPS rehabilitation programme, the officers diagnosed with Low Back Pain exhibited improvements in spinal flexibility, control level spinal muscle activity, increased muscle power and physical capability and a significant decrease in subjective pain scores. It should be noted that during this rehabilitation period officers were still wearing MetVest whilst on normal duty. Finally, the technique used is simple, reproducible and may be applied to other body armour constructions

Inconsistency in 9mm bullets measured with non-destructive X-ray computed tomography

Fundamental to any ballistic armour standard is the reference projectile that is to be defeated. Typically, for certification, consistency of bullets is assumed. Therefore, practical variations in bullet jacket dimensions can have far reaching consequences. Traditionally, internal dimensions could only be analysed by cutting bullets which rules out any subsequent ballistic assessment. Therefore, the use of a non-destructive X-raycomputedtomography (CT) method is explored in this paper. A set of 10 bullets (9 mm DM11) was taken for analysing both intra and inter bullet jacket thickness variation. CT measurements of jacket thickness were validated with high resolution scanning electron microscope (SEM) images. An image based analysis methodology has been developed to extract the jacket thickness map and the centre of gravity. Thickness variations of the order of 200 μm were found commonly across all the bullets along the length and an angular variation of up to 100 μm was found in a few bullets. Jacket thickness and centre of gravity were also calculated for the same bullets after impact and the variations between the pre- and post-impacted bullets were compared, by establishing a common physical reference. The results show that the proposed CT scanning approach and subsequent image analysis method can bring out the statistical variations in bullet geometry pre- and post impact effectively

Whole-genome sequencing reveals host factors underlying critical COVID-19

Altres ajuts: Department of Health and Social Care (DHSC); Illumina; LifeArc; Medical Research Council (MRC); UKRI; Sepsis Research (the Fiona Elizabeth Agnew Trust); the Intensive Care Society, Wellcome Trust Senior Research Fellowship (223164/Z/21/Z); BBSRC Institute Program Support Grant to the Roslin Institute (BBS/E/D/20002172, BBS/E/D/10002070, BBS/E/D/30002275); UKRI grants (MC_PC_20004, MC_PC_19025, MC_PC_1905, MRNO2995X/1); UK Research and Innovation (MC_PC_20029); the Wellcome PhD training fellowship for clinicians (204979/Z/16/Z); the Edinburgh Clinical Academic Track (ECAT) programme; the National Institute for Health Research, the Wellcome Trust; the MRC; Cancer Research UK; the DHSC; NHS England; the Smilow family; the National Center for Advancing Translational Sciences of the National Institutes of Health (CTSA award number UL1TR001878); the Perelman School of Medicine at the University of Pennsylvania; National Institute on Aging (NIA U01AG009740); the National Institute on Aging (RC2 AG036495, RC4 AG039029); the Common Fund of the Office of the Director of the National Institutes of Health; NCI; NHGRI; NHLBI; NIDA; NIMH; NINDS.Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care or hospitalization after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes-including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)-in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Measurement of the double-differential inclusive jet cross section in proton-proton collisions at s\sqrt{s} = 5.02 TeV

International audienceThe inclusive jet cross section is measured as a function of jet transverse momentum $p_\mathrm{T}$ and rapidity $y$. The measurement is performed using proton-proton collision data at $\sqrt{s}$ = 5.02 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 27.4 pb$^{-1}$. The jets are reconstructed with the anti-$k_\mathrm{T}$ algorithm using a distance parameter of $R$ = 0.4, within the rapidity interval $\lvert y\rvert$$\lt$ 2, and across the kinematic range 0.06 $\lt$$p_\mathrm{T}$$\lt$ 1 TeV. The jet cross section is unfolded from detector to particle level using the determined jet response and resolution. The results are compared to predictions of perturbative quantum chromodynamics, calculated at both next-to-leading order and next-to-next-to-leading order. The predictions are corrected for nonperturbative effects, and presented for a variety of parton distribution functions and choices of the renormalization/factorization scales and the strong coupling $\alpha_\mathrm{S}$

Two-particle Bose-Einstein correlations and their Lévy parameters in PbPb collisions at sNN\sqrt{s_\mathrm{NN}} = 5.02 TeV

Two-particle Bose-Einstein momentum correlation functions are studied for charged-hadron pairs in lead-lead collisions at a center-of-mass energy per nucleon pair of $\sqrt{s_\mathrm{NN}}$ = 5.02 TeV. The data sample, containing 4.27$\times10^{9}$ minimum bias events corresponding to an integrated luminosity of 0.607 nb$^{-1}$, was collected by the CMS experiment in 2018. The experimental results are discussed in terms of a L\'evy-type source distribution. The parameters of this distribution are extracted as functions of particle pair average transverse mass and collision centrality. These parameters include the L\'evy index or shape parameter ($\alpha$), the L\'evy scale parameter ($R$), and the correlation strength parameter ($\lambda$). The source shape, characterized by $\alpha$, is found to be neither Cauchy nor Gaussian, implying the need for a full L\'evy analysis. Similarly to what was previously found for systems characterized by Gaussian source radii, a hydrodynamical scaling is observed for the L\'evy $R$ parameter. The $\lambda$ parameter is studied in terms of the core-halo model.Comment: Submitted to Physical Review C. All figures and tables can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/HIN-21-011 (CMS Public Pages

Measurement of the double-differential inclusive jet cross section in proton-proton collisions at s\sqrt{s} = 5.02 TeV

International audienceThe inclusive jet cross section is measured as a function of jet transverse momentum $p_\mathrm{T}$ and rapidity $y$. The measurement is performed using proton-proton collision data at $\sqrt{s}$ = 5.02 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 27.4 pb$^{-1}$. The jets are reconstructed with the anti-$k_\mathrm{T}$ algorithm using a distance parameter of $R$ = 0.4, within the rapidity interval $\lvert y\rvert$$\lt$ 2, and across the kinematic range 0.06 $\lt$$p_\mathrm{T}$$\lt$ 1 TeV. The jet cross section is unfolded from detector to particle level using the determined jet response and resolution. The results are compared to predictions of perturbative quantum chromodynamics, calculated at both next-to-leading order and next-to-next-to-leading order. The predictions are corrected for nonperturbative effects, and presented for a variety of parton distribution functions and choices of the renormalization/factorization scales and the strong coupling $\alpha_\mathrm{S}$