470 research outputs found

    Evaluating Children’s Advocacy Centers’ Response to Child Sexual Abuse

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    Children’s Advocacy Centers (CACs) play an increasingly significant role in the response to child sexual abuse and other child maltreatment in the United States. First developed in the 1980s, CACs were designed to reduce the stress on child abuse victims and families created by traditional child abuse investigation and prosecution procedures and to improve the effectiveness of the response. According to several experts (Fontana, 1984; Pence and Wilson, 1992; Whitcomb, 1992), child victims were subjected to multiple, redundant interviews about their abuse by different agencies, and were questioned by professionals who had no knowledge of children’s developmental limitations or experience working with children. Child interviews would take place in settings like police stations that would further stress already frightened children. Moreover, the response was hampered because the multiple agencies involved did not coordinate their investigations, and children’s need for services could be neglected

    The uncertainty in stiffness and damping of an automotive vehicle's trim-structure mounts and its effect on the variability of the vibration transfer function

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    A large number of plastic clips are used in an automotive vehicle to connect the trim to the structure. These are small clips with very small masses compared to the structural elements that they connect together; however, the uncertainty in their properties can affect the dynamic response. The uncertainty arises out of their material and manufacturing tolerances and more importantly the boundary conditions. A test rig has been developed that can model the mounting condition of the clips. This allows measurement of the range of their effective stiffness and damping. Initially, the boundary condition at the structure side is replicated. The variability is found to be 7% for stiffness and 8% for damping. In order to simulate the connection of the trim side, a mount is built using a 3D printer. The variability due to the boundary condition on both sides was as large as 40% for stiffness and 36% for damping. A Monte Carlo simulation is used in order to assess the effect of the uncertainty of the clips’ properties on the vibration transfer functions of a door assembly. A simplified connection model is used in this study where only the axial degree of freedom is considered in connecting the trim to the door structure. The uncertainty in the clip stiffness and damping results in a variability in the vibration transfer function which is frequency dependent and can be as high as 10% at the resonant peaks with higher values at some other frequencies. It is shown that the effect of the uncertainty in the clips effective damping is negligible and the variability in the dynamic response is mainly due to the uncertainty in the clip’s stiffness. Furthermore, it is shown that the variability would reduce either by increasing or decreasing the effective stiffness of the clips

    Quantifying the variability in stiffness and damping of an automotive vehicle's trim-structure mounts

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    Small plastic clips are used in large numbers in automotive vehicles to connect interior trims to vehicle structures. The variability in their properties can contribute to the overall variability in noise and vibration response of the vehicle. The variability arises due to their material and manufacturing tolerances and more importantly due to the boundary condition. To measure their stiffness and damping, a simple experimental rig is used where a mass is supported by the clip which is modelled as a single degree of freedom system. The rig is designed in a way that it simulates the boundary condition as those of the real vehicle. The variability in clip and also due to the boundary condition at the structure side is first examined which is 7% for stiffness and 8% for damping. To simulate the connection of the trim side, a mount is built using a 3D printer. Rattling occurs in the response of the clips with loose connections, however by preloading the mount the effective stiffness increases and the rattling is eliminated. The variability due to the boundary condition at the trim side was as large as 40% for stiffness and 52% for damping

    The prediction of measurement variability in an automotive application by the use of a coherence formulation

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    Variability between nominally identical vehicles is an ever present problem in automotive vehicle design. In this paper it is shown that it is possible to quantify and, therefore, separate the measurement variability arising from a number of tests on an individual vehicle from the vehicle to vehicle variability arising from the manufacturing process from a series of controlled experiments. In this paper the coherence data is used to identify the measurement variability and, thus, to separate these two variability sources. In order to illustrate the methodology a range of nominally identical automotive vehicles have been tested for NVH (noise, vibration and harshness) variability by exciting the engine mount with an impact hammer and measuring the excitation force and corresponding velocity responses at different points on the vehicle. Normalised standard deviations were calculated for the transfer mobility data, giving variability values of 25.3 %, 33.5 % and 37.3 % for the responses taken at the suspension Strut, Upper A Pillar and B Pillar respectively. The measurement variability was determined by taking repeat measurements on a single vehicle, and was found to be 2.9 %. The measurement variability predicted by the coherence data on the multi-vehicle tests was compared with the directly taken repeat measurements taken on a single vehicle and was shown to agree well with one another over the frequency range of interest

    A study of vehicle and measurement NVH variability

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    A range of nominally identical automotive vehicles have been tested for NVH variability by exciting the engine mount with an impact hammer and measuring the responses at different points on the vehicle. Normalised standard deviations were calculated from the mobility, which fell well within the boundaries of previous comparable measurements. The measurement variability was determined by taking repeat measurements on a single vehicle, which were found to be very repeatable, varying by up to 2.9%. A function that uses the coherence to determine the random error was applied to the data to determine the variability due to the measurement taking process. This was compared with repeat measurements taken on a single vehicle and was shown to agree well with one another. A design of experiments has also been created that determines the effect of each variable such as the temperature and angle of impact on the overall vehicle to vehicle variability

    Testing the Impact of Group Offending on Behavioural Similarity in Serial Robbery

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    Behavioural case linkage assumes that offenders behave in a similar way across their crimes. However, group offending could impact on behavioural similarity. This study uses robbery data from two police forces to test this by comparing the behavioural similarity of pairs of lone offences (LL), pairs of group offences (GG) and pairs of offences where one crime was committed alone and the other in a group (GL). Behavioural similarity was measured using Jaccard’s coefficients. Kruskal–Wallis tests were used to examine differences between the three categories within the linked samples. No statistically significant differences were found for linked GG compared to linked LL pairs. However, differences emerged between GL and the other categories for some behaviours (especially control) suggesting caution should be applied when linking group and lone offences committed by the same perpetrator. Differences between linked and unlinked pairs were assessed using receiver operating characteristic. The results suggest it is possible to distinguish between linked and unlinked pairs based on behaviour especially within the GG and LL categories. There were, however, fewer significant findings for the GL sample, suggesting there may be issues linking crimes where the offender commits one crime as part of a group and the other alone

    Assembly line enzymology by multimodular nonribosomal peptide synthetases: the thioesterase domain of E. coli EntF catalyzes both elongation and cyclolactonization

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    BackgroundEntF is a 142 kDa four domain (condensation-adenylationpeptidyl carrier protein-thioesterase) nonribosomal peptide synthetase (NRPS) enzyme that assembles the Escherichia coli N-acyl-serine trilactone siderophore enterobactin from serine, dihydroxybenzoate (DHB) and ATP with three other enzymes (EntB, EntD and EntE). To assess how EntF forms three ester linkages and cyclotrimerizes the covalent acyl enzyme DHB-Ser-S-PCP (peptidyl carrier protein) intermediate, we mutated residues of the proposed catalytic Ser-His-Asp triad of the thioesterase (TE) domain.ResultsThe Ser1138→Cys mutant (kcat decreased 1000-fold compared with wild-type EntF) releases both enterobactin (75%) and linear (DHB-Ser)2 dimer (25%) as products. The HiResultThe Ser1138→Cys mutant (kcat decreased 1000-fold compared with wild-type EntF) releases both enterobactin (75%) and linear (DHB-Ser)2 dimer (25%) as products. The His1271→Ala mutant (kcat decreased 10,000-fold compared with wild-type EntF) releases only enterobactin, but accumulates both DHB-Ser-O-TE and (DHB-Ser)2-O-TE acyl enzyme intermediates. Electrospray ionization and Fourier transform mass spectrometry of proteolytic digests were used to analyze the intermediates.71→Ala mutant (kcat decreased 10,000-fold compared with wild-type EntF) releases only enterobactin, but accumulates both DHB-Ser-O-TE and (DHB-Ser)2-O-TE acyl enzyme intermediates. Electrospray ionization and Fourier transform mass spectrometry of proteolytic digests were used to analyze the intermediates.ConclusionsThese results establish that the TE domain of EntF is both a cyclotrimerizing lactone synthetase and an elongation catalyst for ester-bond formation between covalently tethered DHB-Ser moieties, a new function for chain-termination TE domains found at the carboxyl termini of multimodular NRPSs and polyketide synthases

    The East Midlands Knee Pain Multiple Randomised Controlled Trial Cohort Study: Cohort Establishment and Feasibility study protocol

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    Introduction: Knee pain and osteoarthritis (OA) are a common cause of disability. The UK National Institute of Health and Care Excellence (NICE) OA guidelines recommend education, exercise and weight-loss advice (if overweight) as core interventions before pharmacological adjuncts. However, implementation of these in primary care is often suboptimal. This study aims to develop a complex intervention with non-pharmacological and pharmacological components that can be delivered by nurses. The feasibility and acceptability of the intervention, and feasibility of undertaking a future cohort-randomised controlled trial (RCT) will be explored. Methods and analysis: In phase 1, we will develop a training programme for nurses and evaluate the fidelity and acceptability of the non-pharmacological element of the intervention. Fidelity checklists completed by the nurse will be compared to video-analysis of the treatment sessions. Patients and nurses will be interviewed to determine the acceptability of the intervention and explore challenges to intervention delivery. The non-pharmacological component will be modified based upon the findings. In phase 2, we will assess the feasibility of conducting a cohort RCT comprising of both the pharmacological and modified non-pharmacological components. We will compare three groups: group A will receive the non-pharmacological components delivered before pharmacological components; group B will receive pharmacological components followed by the non-pharmacological components; and group C (control arm) will continue to receive usual care. Study outcomes will be collected at 3 time points: baseline and weeks 13 and 26 after randomisation. Qualitative interviews will be conducted with a sample of participants from each of the two active intervention arms. Ethics and dissemination: This protocol was approved by the East Midlands-Derby Research Ethics Committee (18/EM/0288) and registered at clinicaltrials.gov (NCT03670706). The study will be reported in accordance with the CONSORT guidance and standards. The results will be submitted for publication in peer-reviewed academic journals
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