Scots-Irish Women and the Southern Culture of Violence: The Influence of Scots-Irish Females on High Rates of Southern Violence

Prior research has documented a higher rate of violent crime within the South relative to other U.S. regions. Some scholars argue that higher rates of violence in the South are due to the lasting effect of the unique culture of the Scots-Irish immigrants that came into the U.S. in the mid-1700\u27s. Though there is a large body of literature examining the link between culture and violence in the South, an implicit assumption of this line of study is that the cultural effect occurs largely within the white male population in rural Southern areas. No study, to our knowledge, has extended this thesis to females. We address this omission in prior analyses by empirically testing the Southern Culture of Violence thesis using female arrest rates. Drawing on countylevel ancestry data from the 2000 Census and UCR Supplementary Homicide Report data, we estimate a series of negative binomial regression models. A conclusion and discussion of the results follow

3D-printed system optimizing dissolution of hyperpolarized gaseous species for micro-sized NMR

International audienceDissolution of hyperpolarized species in liquids of interest for NMR is often hampered by the presence of bubbles that degrade the field homogeneity. Here a device constituted by a bubble pump and a miniaturized NMR cell fitting both inside the narrow bore of an NMR magnet is built by 3D printing. 129Xe NMR experiments performed with hyperpolarized xenon reveal high and homogeneous dissolution of the gas in water

Ice Formation on Kaolinite: Insights from Molecular Dynamics Simulations

The formation of ice affects many aspects of our everyday life as well as technologies such as cryotherapy and cryopreservation. Foreign substances almost always aid water freezing through heterogeneous ice nucleation, but the molecular details of this process remain largely unknown. In fact, insight into the microscopic mechanism of ice formation on different substrates is difficult to obtain even via state-of-the-art experimental techniques. At the same time, atomistic simulations of heterogeneous ice nucleation frequently face extraordinary challenges due to the complexity of the water-substrate interaction and the long timescales that characterize nucleation events. Here, we have investigated several aspects of molecular dynamics simulations of heterogeneous ice nucleation considering as a prototypical ice nucleating material the clay mineral kaolinite, which is of relevance in atmospheric science. We show via seeded molecular dynamics simulations that ice nucleation on the hydroxylated (001) face of kaolinite proceeds exclusively via the formation of the hexagonal ice polytype. The critical nucleus size is two times smaller than that obtained for homogeneous nucleation at the same supercooling. Previous findings suggested that the flexibility of the kaolinite surface can alter the time scale for ice nucleation within molecular dynamics simulations. However, we here demonstrate that equally flexible (or non flexible) kaolinite surfaces can lead to very different outcomes in terms of ice formation, according to whether or not the surface relaxation of the clay is taken into account. We show that very small structural changes upon relaxation dramatically alter the ability of kaolinite to provide a template for the formation of a hexagonal overlayer of water molecules at the water-kaolinite interface, and that this relaxation therefore determines the nucleation ability of this mineral

Variability in energy cost of running at the end of a triathlon and a marathon

International audienceThe aim of this study was to investigate the increase in energy cost of running occurring at the end of a triathlon and a marathon event and to link them to the metabolic and hormonal changes, as well as to variations in stride length. Seven subjects took part in 3 experimental situations: a 2 h 15 min triathlon (30 min swimming, 60 min cycling and 45 min running), a 2 h 15 min marathon (MR) were the fast 45 min were run at the same speed as the triathlon run (TR), and a 45 min isolated run (IR) done at triathlon speed. The results show that energy cost during MR was higher than during TR (p < 0.01) (+ 8.9 %). Similar observations were made for pulmonary ventilation (+ 7.9 %) and heart rate (+ 6.3 %). Moreover, the values were significantly greater than the values obtained during the IR. TR and MR lead to greater weight loss (p < 0.01) (2.4±0.3 kg) than IR (1 ± 0.2 kg). The triathlon and the marathon produced a large decrease in plasma volume (respectively 19.6 ± 1.4 % and 12.9 ± 1.1 %) compared to IR (2 ± 0.4 %). Plasma renin activity was higher for the triathlon and the marathon than for the IR (p < 0.01). MR produces a significantly greater increase in plasma free fatty acids (F.F.A.) than TR (p < 0.05) and IR (p < 0.01). In addition, the F.F.A. at the end of TR were significantly higher than IR (p < 0.05). At the end of the trial the mean stride lengths for TR and IR were greater (+ 15 %) (p <0.01) than for MR. This study, carried out with subjects running overground, confirms the decrease in running efficiency previously shown at the end of a laboratory triathlon, and demonstrates that this decrease is lower than that occurring during a marathon

The derivation of performance expressions for communication protocols from timed Petri net models

Petri Net models have been extended in a variety of ways and have been used to prove the correctness and evaluate the performance of communication protocols. Several extensions have been proposed to model time. This work uses a form of Timed Petri Nets and presents a technique for symbolically deriving expressions which describe system performance. Unlike past work on performance evaluation of Petri Nets which assumes a priori knowledge of specific time delays, the technique presented here applies to a wide range of time delays so long as the delays satisfy a set of timing constraints. The technique is demonstrated using a simple communication protocol

Ion track grafting: A way of producing low-cost and highly proton conductive membranes for fuel cell applications

International audienceKeywords: Ion track grafting Radiografting Swift heavy ions Proton conductivity Polymer electrolyte membrane Proton exchange membrane fuel cell a b s t r a c t Proton conductive individual channels through a poly(vinyl di-fluoride) PVDF matrix have been designed using the ion track grafting technique. The styrene molecules were radiografted and further sulfonated leading to sulfonated polystyrene (PSSA) domains within PVDF. The grafting process all along the cylindrical ion tracks creates after functionalisation privileged paths perpendicular to the membrane plane for proton conduction from the anode to the cathode when used in fuel cells. Such ion track grafted PVDF-g-PSSA membranes have low gas permeation properties against H 2 and O 2. A degree of grafting (Y w) of 140% was chosen to ensure a perfect coverage of PSSA onto PVDF-g-PSSA surface minimizing interfacial ohmic losses with the active layers of the Membrane Electrolyte Assembly (MEA). A three-day fuel cell test has been performed feeding the cell with pure H 2 and O 2 , at the anode and cathode side respectively. Temperature has been progressively increased from 50 to 80 • C. Polarisation curves and Elec-trochemical Impedance Spectroscopy (EIS) at different current densities were used to evaluate the MEA performance. From these last measurements, it has been possible to determine the resistance of the MEA during the fuel cell tests and, thus the membrane conductivity. The proton conductivities of such membranes estimated during fuel cell tests range from 50 mS cm −1 to 80 mS cm −1 depending on the operating conditions. These values are close to that of perfluorosulfonated membrane such as Nafion ® in similar conditions