Understanding Recent Spikes and Longer Trends in American Murders

On September 7, 2016, four of the nation’s newspapers of record weighed in on the connected crises in crime and policing. The New York Times revealed the tensions between the Mayor’s office in Chicago and several community and professional groups over a plan to overhaul Chicago’s police disciplinary board – a plan developed in the wake of the shooting of an unarmed teenager, Laquan McDonald, and the release of a video of that killing. The Wall Street Journal related a vigorous defense of New York City’s “broken windows” policing strategy – a strategy that has been a recurring source of tension between the city’s minority communities and the police, and whose value in crime reduction has been sharply debated. The Washington Post’s lead editorial decried Chicago’s “deadliest month in two decades” that left city officials at odds over the basic elements of public safety policy and strategic responses to the seemingly intractable violence. The Chicago Tribune weighed in as well. In it, Chicago Police Superintendent Eddie Johnson declared that the crisis is “not a police issue, it’s a society issue,” pointing to the need for stricter gun controls

The role of omnivory in mediating metacommunity robustness to habitat destruction

Omnivores have long been known to play an important role in determining the stability of ecological communities. Recent theoretical studies have suggested that they may also increase the resilience of their communities to habitat destruction, one of the major drivers of species extinctions globally. However, these outcomes were obtained for minimal food webs consisting of only a single omnivore and its prey species, while much more complex communities can be anticipated in nature. In this study, we undertake a systematic comparative analysis of the robustness of metacommunities containing various omnivory structures to habitat loss and fragmentation using a mathematical model. We observe that, in general, omnivores are better able to survive facing habitat destruction than specialist predators of similar trophic level. However, the community as a whole does not always benefit from the presence of omnivores, as they may drive their intraguild prey to extinction. We also analyze the frequency with which these modules occur in a set of empirical food webs, and demonstrate that variation in their rate of occurrence is consistent with our model predictions. Our findings demonstrate the importance of considering the complete food web in which an omnivore is embedded, suggesting that future study should focus on more holistic community analysis

Employee satisfaction and use of flexible working arrangements

This article considers the impact of flexible working arrangements (FWAs), using the British Household Panel Survey and Understanding Society, 2001–10/11. Results of panel logit, ANCOVA and change-score analysis are indicative of positive impacts from use of a number of FWAs, including homeworking having positive effects for men and women on job and leisure satisfaction. However, findings reveal gaps in availability and use of FWAs, and highlight the gendered nature of flexible employment. Flexi-time, the most common FWA among men, has positive effects as it facilitates management of household responsibilities while maintaining full-time employment. Part-time and homeworking are also positive, consistent with men using FWAs with a greater degree of choice. Women more often are constrained in their use of FWAs, often into working reduced hours. Consequently, FWAs have negative impacts for some women, on job (part-time when used for extended periods, flexi-time), leisure (job-share, flexi-time) and life satisfaction (job-share)

Changes in the volatile profile of skim milk powder prepared under different processing conditions and the impact on the volatile flavor profile of model white chocolate

The objective of this work is to determine the extent to which changes in the skim milk powder (SMP) manufacturing process alter the volatile profile of SMP, and whether these changes are carried through to a final product when the SMP is used as an ingredient and subjected to further processing. The manufacture of SMP is a multistage process involving a preliminary concentration step, heat treatment and a drying stage. However, the methods and conditions used by the industry are not standardized, and the inherent variability in the production of SMP has consequences for the end-users, such as the confectionery industry, where the SMP is used as an ingredient during the production of milk chocolate, white chocolate and caramel. This study investigates the impact of each stage of the manufacturing process on the concentration of reducing sugars and available amino groups (as precursors of the Maillard reaction) as well as on the volatile products of the Maillard reaction and lipid degradation. Eight types of SMP were produced using combinations of different processing conditions: concentration (by evaporation or reverse osmosis), heat treatment (low heat or high heat) and drying (spray-drying or freeze-drying). Maillard precursors were quantified after each processing stage and volatile compounds were extracted using solid-phase microextraction, and analyzed by GC-MS. The resulting SMPs were incorporated into a model white chocolate system, produced under varying conching conditions. We demonstrate not only that changes in the SMP manufacturing conditions affect the volatile profile of SMP, but also that these differences can be carried through to a final product when the SMP is used to prepare a model white chocolate. Understanding these differences is important to the industry for controlling the flavor of the end product

The Utility of Deformable Image Registration for Small Artery Visualisation in Contrast-Enhanced Whole Body MR Angiography

Purpose; An investigation was carried out into the effect of three image registration techniques on the diagnostic image quality of contrast-enhanced magnetic resonance angiography (CE-MRA) images. Methods Whole-body CE-MRA data from the lower legs of 27 patients recruited onto a study of asymptomatic atherosclerosis were processed using three deformable image registration algorithms. The resultant diagnostic image quality was evaluated qualitatively in a clinical evaluation by four expert observers, and quantitatively by measuring contrast-to-noise ratios and volumes of blood vessels, and assessing the techniques’ ability to correct for varying degrees of motion. Results The first registration algorithm (‘AIR’) introduced significant stenosis-mimicking artefacts into the blood vessels’ appearance, observed both qualitatively (clinical evaluation) and quantitatively (vessel volume measurements). The other two algorithms (‘Slicer’ and ‘SEMI’) based on the normalised mutual information (NMI) concept and designed specifically to deal with variations in signal intensity as found in contrast-enhanced image data, did not suffer from this serious issue but were rather found to significantly improve the diagnostic image quality both qualitatively and quantitatively, and demonstrated a significantly improved ability to deal with the common problem of patient motion. Conclusions This work highlights both the significant benefits to be gained through the use of suitable registration algorithms and the deleterious effects of an inappropriate choice of algorithm for contrast-enhanced MRI data. The maximum benefit was found in the lower legs, where the small arterial vessel diameters and propensity for leg movement during image acquisitions posed considerable problems in making accurate diagnoses from the un-registered images

Frequency and Severity Approaches to Indexing Exposure to Trauma: The Critical Incident History Questionnaire for Police Officers

The Critical Incident History Questionnaire indexes cumulative exposure to traumatic incidents in police by examining incident frequency and rated severity. In over 700 officers, event severity was negatively correlated (rs = -61) with frequency of exposure. Cumulative exposure indices that varied emphasis on frequency and severity-using both nomothetic and idiographic methods-all showed satisfactory psychometric properties and similar correlates. All indices were only modestly related to posttraumatic stress disorder (PTSD) symptoms. Ratings of incident severity were not influenced by whether officers had ever experienced the incident. Because no index summarizing cumulative exposure to trauma had superior validity, our findings suggest that precision is not increased if frequency is weighted by severity