Network Exposure and Excessive Use of Force: Investigating the Social Transmission of Police Misconduct

Research Summary: In this study, we investigate how a police officer\u27s exposure to peers accused of misconduct shapes his or her involvement in excessive use of force. By drawing from 8,642 Chicago police officers named in multiple complaints, we reconstruct police misconduct ego‐networks using complaint records. Our results show that officer involvement in excessive use of force complaints is predicted by having a greater proportion of co‐accused with a history of such behaviors. Policy Implications: Our findings indicate officers’ peers may serve as social conduits through which misconduct may be learned and transmitted. Isolating officers that engage in improper use of force, at least until problematic behaviors are addressed, seems to be critical to reducing police misconduct and department‐wide citizen complaints. Future studies should be aimed at investigating how social networks shape police misconduct and the ways network analysis might be used to diffuse intervention strategies within departments

Global convergence of a non-convex Douglas-Rachford iteration

We establish a region of convergence for the proto-typical non-convex Douglas-Rachford iteration which finds a point on the intersection of a line and a circle. Previous work on the non-convex iteration [2] was only able to establish local convergence, and was ineffective in that no explicit region of convergence could be given

Assessing Uncertainty and Reliability of Connective Field Estimations From Resting State fMRI Activity at 3T

Connective Field (CF) modeling estimates the local spatial integration between signals in distinct cortical visual field areas. As we have shown previously using 7T data, CF can reveal the visuotopic organization of visual cortical areas even when applied to BOLD activity recorded in the absence of external stimulation. This indicates that CF modeling can be used to evaluate cortical processing in participants in which the visual input may be compromised. Furthermore, by using Bayesian CF modeling it is possible to estimate the co-variability of the parameter estimates and therefore, apply CF modeling to single cases. However, no previous studies evaluated the (Bayesian) CF model using 3T resting-state fMRI data. This is important since 3T scanners are much more abundant and more often used in clinical research compared to 7T scanners. Therefore in this study, we investigate whether it is possible to obtain meaningful CF estimates from 3T resting state (RS) fMRI data. To do so, we applied the standard and Bayesian CF modeling approaches on two RS scans, which were separated by the acquisition of visual field mapping data in 12 healthy participants. Our results show good agreement between RS- and visual field (VF)- based maps using either the standard or Bayesian CF approach. In addition to quantify the uncertainty associated with each estimate in both RS and VF data, we applied our Bayesian CF framework to provide the underlying marginal distribution of the CF parameters. Finally, we show how an additional CF parameter, beta, can be used as a data-driven threshold on the RS data to further improve CF estimates. We conclude that Bayesian CF modeling can characterize local functional connectivity between visual cortical areas from RS data at 3T. Moreover, observations obtained using 3T scanners were qualitatively similar to those reported for 7T. In particular, we expect the ability to assess parameter uncertainty in individual participants will be important for future clinical studies

Assessment of Trans-Environmental Transitions of Heavy Metals and Arsenic in Herbal Drugs and Herbal Medicinal Products of Valerian Rhizomes with Roots and Motherwort Herb

Scientific relevance. In the context of pharmacopoeial harmonisation, the available methods for quantifying the total heavy metal content in tinctures are not sufficient to demonstrate the safety of liquid dosage forms based on herbal drugs. However, the establishment of individual limits for the heavy metal content requires analysing the patterns of environmental toxicant transitions from plant raw materials to herbal medicinal products in finished dosage forms.Aim. This study aimed to analyse the trans-environmental transitions of heavy metals and arsenic from the soil through plants to herbal medicinal products using a case study of aqueous and alcoholic extracts of valerian and motherwort herbal drugs.Materials and methods. The study focused on motherwort herb and valerian rhizomes with roots, the corresponding herbal medicinal products, and the rhizospheric soil. The elemental composition of the studied samples was determined by inductively coupled plasma mass spectrometry.Results. The authors determined the content of 15 elements (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Cd, Sb, Hg, and Pb) in plant raw materials, the rhizosphere, and herbal drug infusions and tinctures. The concentrations of elements were 0.002–109.884 mg/kg in motherwort herb samples and 0.017–866.618 mg/kg in the samples of valerian rhizomes with roots. Pb, Cd, and As were detected in all plant raw materials, while Hg was found only in 25% of the study samples. The content of these elements was within acceptable limits. Valerian and motherwort infusions contained all elements, except for Hg; valerian tinctures were free from Fe and Hg; and motherwort tinctures included no Fe, Hg, Sr, Cd, and Pb. The concentrations of elements in the infusions did not exceed 3.169 mg/kg, while the concentrations of elements in the tinctures were below 1.27 mg/kg. In the tinctures, Zn, Cu, Mg, and Ti were the most abundant elements, and Sb and Cd were present in minimum amounts.Conclusions. Valerian and motherwort plants can concentrate Cu, Cr, Fe, and V from the soil. The transition of heavy metals and arsenic into infusions did not exceed 65% of the content of these elements in herbal drugs, while tinctures contained less than 30% of the content of heavy metals and arsenic in herbal drugs. Some elements passed into infusions 1.5–5 times more efficiently than into tinctures

Quality of Herbal Medicines: New Aspects and Solutions

Herbal drugs and herbal medicinal products remain of interest to Russian researchers both in terms of the development, efficacy, and safety of medicines, and in terms of the research methodology applicable to these medicine, as well as the use of new analytical methods expanding the boundaries of contemporary science and medicine. In this interview, Vladimir G. Luzhanin (Candidate of Sciences, Associate Professor, Rector of the Perm State Pharmaceutical Academy), Vladimir A. Kurkin (Doctor of Pharmaceutical Sciences, Full Professor, Chairman of the Department of Pharmacognosy with Botany and the Basics of Phytotherapy, Samara State Medical University), and Irina V. Gravel (Doctor of Pharmaceutical Sciences, Full Professor, Professor of the I.M. Sechenov First Moscow State Medical University) share their views on the application potential and future quality assessment of herbal medicines

Hamiltonians separable in cartesian coordinates and third-order integrals of motion

We present in this article all Hamiltonian systems in E(2) that are separable in cartesian coordinates and that admit a third-order integral, both in quantum and in classical mechanics. Many of these superintegrable systems are new, and it is seen that there exists a relation between quantum superintegrable potentials, invariant solutions of the Korteweg-De Vries equation and the Painlev\'e transcendents.Comment: 19 pages, Will be published in J. Math. Phy

Two-dimensional superintegrable metrics with one linear and one cubic integral

We describe all local Riemannian metrics on surfaces whose geodesic flows are superintegrable with one integral linear in momenta and one integral cubic in momenta. We also show that some of these metrics can be extended to the 2-sphere. This gives us new examples of Hamiltonian systems on the sphere with integrals of degree three in momenta, and the first examples of superintegrable metrics of nonconstant curvature on a closed surfaceComment: 35 page

Study of the Elemental Composition of Pectoral Species No. 2 and Its Components

INTRODUCTION. The influence of anthropogenic factors on the content of toxic elements in plants increases the need for monitoring the content of toxic elements in medicinal plant raw materials and the corresponding herbal medicinal products. In addition, studying the elemental composition of herbal medicinal products will help determine their potential in the treatment of elemental metabolism disorders (macroand micro-elementoses).AIM. This study aimed to determine the elemental composition and the heavy metal content in Pectoral Species No. 2 and its components.MATERIALS AND METHODS. The study used Pectoral Species No. 2 and its components, including common coltsfoot (Tussilago farfara L.) leaf, greater plantain (Plantago major L.) leaf, and liquorice (Glycyrrhiza glabra L., G. uralensis Fisch.) root. The samples were manufactured by Krasnogorskleksredstva JSC and purchased at Moscow pharmacies. To determine the elemental composition, the study samples were digested with concentrated nitric acid and analysed by inductively coupled plasma mass spectrometry (ICP-MS). The calibration involved using concentrations ranging from 0.5 to 1.5 times the maximum permissible concentration for each element.RESULTS. This study identified and quantified 26 elements in Pectoral Species No. 2 and its components. The content of heavy metals was within the permissible concentrations. The study established the predominant macronutrients (potassium, calcium, and magnesium), micronutrients (iron, aluminium, and strontium), and ultramicronutrients (barium, nickel, and chromium) in Pectoral Species No. 2. The authors evaluated the contributions of each herbal drug to the total element content in the medicinal product.CONCLUSIONS. Coltsfoot leaf exerts the greatest influence on the content of macro-, micro-, and ultramicronutrients in Pectoral Species No. 2. Greater plantain leaf contributes the most to the zinc, silver, and nickel content. Liquorice root has the highest strontium and molybdenum content

Room temperature Suzuki coupling of aryl iodides, bromides, and chlorides using a heterogeneous carbon nanotube-palladium nanohybrid catalyst

International audiencePalladium nanoparticles were immobilized on multi-walled carbon nanotubes by a layer-by-layer approach, resulting in a well-defined assembly. The nanohybrid was found effective in promoting Suzuki cross couplings of various halogenated aromatics, including chlorinated ones, with arylboronic acids under sustainable conditions. The heterogeneous catalyst could also easily be recovered from the reaction mixture and reused with no loss of activity over several cycles