Gravitational wave recoils in non-axisymmetric Robinson-Trautman spacetimes

We examine the gravitational wave recoil waves and the associated net kick velocities in non-axisymmetric Robinson-Trautman spacetimes. We use characteristic initial data for the dynamics corresponding to non-head-on collisions of black holes. We make a parameter study of the kick distributions, corresponding to an extended range of the incidence angle $\rho_0$ in the initial data. For the range of $\rho_0$ examined ($3^{\circ} \leq \rho_0 \leq 110^{\circ}$) the kick distributions as a function of the symmetric mass parameter $\eta$ satisfy a law obtained from an empirical modification of the Fitchett law, with a parameter $C$ that accounts for the non-zero net gravitational momentum wave fluxes for the equal mass case. The law fits accurately the kick distributions for the range of $\rho_0$ examined, with a rms normalized error of the order of $5 \%$. For the equal mass case the nonzero net gravitational wave momentum flux increases as $\rho_0$ increases, up to $\rho_0 \simeq 55^{\circ}$ beyond which it decreases. The maximum net kick velocity is about $190 {\rm km/s}$ for for the boost parameter considered. For $\rho_0 \geq 50^{\circ}$ the distribution is a monotonous function of $\eta$. The angular patterns of the gravitational waves emitted are examined. Our analysis includes the two polarization modes present in wave zone curvature.Comment: 10 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:1403.4581, arXiv:1202.1271, arXiv:1111.122

The development impact of the illegality of drug trade

This paper reviews the unintended consequences of the war on drugs, particularly for developing countries, and weighs them against the evidence regarding the efficacy of prohibition to curb drug use and trade. It reviews the available evidence and presents new results that indicate that prohibition has limited effects on drug prevalence and prices, most likely indicating a combination of inelastic drug demand (due to its addictive properties) and elastic supply responses (due to black markets). This should turn the focus to the unintended consequences of drug prohibition. First, the large demand for drugs, particularly in developed countries, generates the possibility of massive profits to potential drug providers. This leads to the formation of organized crime groups, which use violence and corruption as their means of survival and expansion and which, in severe cases, challenge the state and seriously compromise public stability and safety. Second, prohibition and its derived illegal market impose greater costs on farmers than on drug traffickers. In many instances, this entails the transfer of wealth from poor peasants to rich (and ruthless) traders. Third, criminalization can exacerbate the net health effects of drug use. These consequences are so pernicious that they call for a fundamental review of drug policy around the world.Health Monitoring&Evaluation,Crime and Society,Economic Theory&Research,Post Conflict Reconstruction,Markets and Market Access

The mathematical description of the electrosynthesis of composites of oxy-hydroxycompounds cobalt with polypyrrole overooxidazed

The electrosynthesis of the composite with of the overoxidized polypyrrole with cobalt oxy-hydroxide in strongly acidic media has been described mathematically, using linear stability theory and bifurcation analysis. The steadystates stability conditions and oscillatory and monotonic instability requirements have been described too. The system´s behavior was compared with behavior of other systems with overoxidation, electropolymerization of heterocyclic compounds and electrosynthesis of the cobalt oxy-hydroxides

Population expansion in the North African Late Pleistocene signalled by mitochondrial DNA haplogroup U6

Background <br/> The archaeology of North Africa remains enigmatic, with questions of population continuity versus discontinuity taking centre-stage. Debates have focused on population transitions between the bearers of the Middle Palaeolithic Aterian industry and the later Upper Palaeolithic populations of the Maghreb, as well as between the late Pleistocene and Holocene. <br/> Results Improved resolution of the mitochondrial DNA (mtDNA) haplogroup U6 phylogeny, by the screening of 39 new complete sequences, has enabled us to infer a signal of moderate population expansion using Bayesian coalescent methods. To ascertain the time for this expansion, we applied both a mutation rate accounting for purifying selection and one with an internal calibration based on four approximate archaeological dates: the settlement of the Canary Islands, the settlement of Sardinia and its internal population re-expansion, and the split between haplogroups U5 and U6 around the time of the first modern human settlement of the Near East. <br/> Conclusions <br/> A Bayesian skyline plot placed the main expansion in the time frame of the Late Pleistocene, around 20 ka, and spatial smoothing techniques suggested that the most probable geographic region for this demographic event was to the west of North Africa. A comparison with U6's European sister clade, U5, revealed a stronger population expansion at around this time in Europe. Also in contrast with U5, a weak signal of a recent population expansion in the last 5,000 years was observed in North Africa, pointing to a moderate impact of the late Neolithic on the local population size of the southern Mediterranean coast

Lead toxicity in Saccharomyces cerevisiae : the role of glutathione

Lead is a non-essential metal for biological functions and is classified by the International Agency for Research on Cancer (IARC) as a probable human carcinogen. S. cerevisiae is a suitable model for studying Pb toxic effects since it is an eukaryote cell that can be easily manipulated and has a completely sequenced genome. In the present work, the role of reduced glutathione (GSH) as a defense mechanism against Pbinduced toxicity in S. cerevisiae was investigated. Yeast cells exposed to Pb (3h) lost cell viability (quantified by a clonogenic assay), accumulated intracellular reactive oxygen species (ROS) (evaluated by 2′,7′-dichlorodihydrofluorescein diacetate, H2 DCFDA) and decreased GSH level (assessed by monochlorobimane, mBCl). Yeast cells lacking the GSH1 (Dgsh1) or GSH2 (Dgsh2) genes were compared with wild type (WT) cells for loss of cell viability and Pb-induced ROS accumulation. We verified that Dgsh1 and Dgsh2 cells did not exhibit an increased loss of viability and did not experience ROS accumulation compared with WT cells. However, the treatment of WT cells with iodoacetamide (an alkylating agent which binds covalently to thiol groups) enhanced sensitivity to Pb. Incubation of WT cells with an amino acid mixture constituting GSH (L-glutamic acid, L-cysteine and glycine) reduced oxidative stress and loss of Pb-induced proliferation capacity. Together, the results suggest that intracellular GSH is involved in the defense against Pb-induced toxicity; however, it seems insufficient to sustain the oxidative stress and Pb-induced loss of cell viability

A comparison of mass parameters determination using capacitive and optical sensors

AbstractThis paper presents a comparison study between the use of 1mm resolution capacitive and optical sensors for the determination of yarn mass parameters. A parallel plate capacitive sensor to determine yarn mass variations and a yarn diameter and hairiness determination solution using optical sensors and integrating optical signal processing based on Fourier analysis are described. As there is a high correlation between yarn diameter and yarn mass, it is possible to determine yarn mass and infer variations in yarn diameter and vice-versa. Moreover, by optically detecting the degree of yarn hairiness, one can quantify its influence on the capacitive sensor mass variation measurements. Here we present the results of a signal processing analysis and statistical description of measurements carried out on a 100% cotton 295 g/km linear mass yarn. We conclude that an accurate yarn characterization can be carried out using optical sensors alone, reducing systems cost, complexity and increasing efficiency