Stabbing segments with rectilinear objects

Given a set S of n line segments in the plane, we say that a region R R2 is a stabber for S if R contains exactly one endpoint of each segment of S. In this paper we provide optimal or near-optimal algorithms for reporting all combinatorially di erent stabbers for several shapes of stabbers. Speci cally, we consider the case in which the stabber can be described as the intersection of axis-parallel halfplanes (thus the stabbers are halfplanes, strips, quadrants, 3-sided rectangles, or rectangles). The running times are O(n) (for the halfplane case), O(n log n) (for strips, quadrants, and 3-sided rectangles), and O(n2 log n) (for rectangles).Junta de Andalucía PAI FQM-0164Ministerio de Economía y Competitividad MTM2014-60127-

THE BIOAVAILABILITY OF SEDIMENT BOUND TRIBUTYLTIN (TBT)

Merged with duplicate record 10026.1/591 on 12.04.2017 by CS (TIS)Tributyltin is arguably the most toxic compound ever to be deliberately introduced into the marine environment as an ingredient of antifouling paints. It has had widespread toxic effects on a range of marine organisms, with some gastropod species being particularly sensitive. Effects of TBT on non-target species have resulted in partial bans on its use in many countries, so that new inputs to the water column have decreased in most areas. One of the physicochemical features of TBT is that it is readily sequestered by suspended particulates due to its low solubility and its hydrophobicity, therefore becoming incorporated into estuarine sediments. The availability of this sediment-bound TBT has been investigated through its potential for re-release back to the water column, and directly from the sediment using the sediment dwelling gastropod Hinia reticulata. The sorption process itself has been investigated using natural components to determine the sediment-water partition coefficient (Kd) together with factors affecting its magnitude. Sorption by sediments has been shown to be rapid (minutes), although the achievement of equilibrium may take longer (hours), and exhibits a Freundlich-like dependence on the TBT concentration due to the variable energies of TBT sorption sites on sediment particles. The major determinant of Kd is sediment type, greater adsorption occurring in fine-grained organic rich sediments compared to low organic sands; although both salinity and pH modify the degree of adsorption. The sorption process has been shown to be reversible, so that previously contaminated sediments may act as reservoirs of TBT, releasing the compound back to the overlying water for many years. Hinia reticulata has been shown to be an effective and quantitative accumulator of both dissolved and sediment-bound TBT, principally acquiring TBT from water across the respiratory surfaces. When additionally exposed to sediments, significantly higher body burdens were accumulated, with up to 80% of the total attributable to the sediment. Uptake of TBT across the surface of the head/foot appears to be an important pathway for sediment-exposed Hinia reticulata, while the ingestion of contaminated sediment does not appear to occur. Hinia reticulata is capable of metabolising TBT to lesser butylated and presumably less toxic products which are excreted, making its accumulated body burdens responsive to changing environmental TBT levels, and increasing its value as a biomonitor. When exposed to a range of TBT contaminated sediments, Hinia reticulata showed there to be greater TBT availability from sediments with a low sorptive capacity (sands), principally through desorption of TBT to the overlying water. Fine-grained organic-rich muds, which have a greater capacity for TBT, produced lower accumulated burdens in Hinia reticulata, but may represent more important long-term sources of TBT to benthic organisms in estuaries.Plymouth Marine Laborator

Understanding key parameters affecting needle-free skin penetration by a parenteral drug delivery system

This thesis seeks to resolve difficulties in the development of a parenteral needle-free drug delivery system. Analysis of the penetration performance of Glide Pharma’s Solid Dose Injector in two clinical trials on man has shown that skin, and likely its inherent variation, was the cause of incomplete deliveries. As indicated by the literature and issues with previous needle-free technologies, a more complete understanding of skin penetration is required before such systems are capable of ensuring delivery across a patient population. Exploratory skin experiments led to the justification, design and build of a novel skin penetration test rig capable of simulating the delivery of a solid dose implant. This test rig, the Penetrometer, required significant software development to both stabilise and validate its performance before use on the in vivo porcine model, an established non-clinical model for drug delivery through human skin. Two non-clinical studies have been performed using the Penetrometer to capture force displacement profiles, using a metal probe equivalent to an implant, for penetration events on multiple test sites on multiple models. Significant levels of variation in key parameters were shown to be present intra- and inter-test site, as well as intra- and inter-model. It is likely that this variation, as detected in the porcine model, was the cause of problematic system performance during human clinical trials. Penetration experiments have also been performed to establish the validity of using in vitro skin or silicone rubber as an alternative test bed to in vivo models. The key parameters measured are the peak force during penetration, the displacement of the skin at penetration and the work required to penetrate the skin, with variations observed of the order of 30%, 100% and 140%, respectively. The results indicate how challenging it will be to reliably administer drugs using needle-free injection. This information should be used to better specify the device design and implant formulation to ensure delivery success. Prior to this thesis there was no quantitative data available, either published or within the collaborator, describing the magnitude and variation of the key parameters affecting needle-free skin penetration. This thesis has used the porcine model, further work must determine the parameters for the breadth of a human patient population

DNA Evidence: Probability, Population Genetics, and the Courts

To help meet the challenge of presenting properly performed DNA tests within the post-Daubert legal framework, this article outlines the statistical procedures that have been employed or proposed to provide judges and juries with quantitative measures of probative value, describes more fully how the courts have dealt with these procedures, and evaluates the opinions and the statistical analyses from the standpoint of the law of evidence. Specifically, the article outlines the procedure used to declare whether two samples of DNA match, and how shrinking the size of the match window, as some defendants have urged, will decrease the risk of false matches, but will also exclude highly probative evidence of identity. It also demonstrates that a defendant\u27s effort to show that a smaller match window would not permit the declaration of a match is irrelevant or misleading. Additionally, the article explains procedures for estimating the frequency of the incriminating genetic characteristics in various populations. These procedures have been the subject of an acrimonious debate, both in the courts and in the press, about the effect of population structure. The population structure objection, which has proved so effective in court, applies most strongly to only a limited class of case, and therefore, courts have erred in excluding DNA evidence on the theory that the scientific community advocates that the most conservative procedures must be used in all cases. Finally, the article identifies more fundamental problems in the use of population frequency estimates, and advocates supplementary and alternative procedures that are essential if quantitative statements of the probative value of DNA evidence are to be admissible

DNA Evidence: Probability, Population Genetics, and the Courts

To help meet the challenge of presenting properly performed DNA tests within the post-Daubert legal framework, this article outlines the statistical procedures that have been employed or proposed to provide judges and juries with quantitative measures of probative value, describes more fully how the courts have dealt with these procedures, and evaluates the opinions and the statistical analyses from the standpoint of the law of evidence. Specifically, the article outlines the procedure used to declare whether two samples of DNA match, and how shrinking the size of the match window, as some defendants have urged, will decrease the risk of false matches, but will also exclude highly probative evidence of identity. It also demonstrates that a defendant\u27s effort to show that a smaller match window would not permit the declaration of a match is irrelevant or misleading. Additionally, the article explains procedures for estimating the frequency of the incriminating genetic characteristics in various populations. These procedures have been the subject of an acrimonious debate, both in the courts and in the press, about the effect of population structure. The population structure objection, which has proved so effective in court, applies most strongly to only a limited class of case, and therefore, courts have erred in excluding DNA evidence on the theory that the scientific community advocates that the most conservative procedures must be used in all cases. Finally, the article identifies more fundamental problems in the use of population frequency estimates, and advocates supplementary and alternative procedures that are essential if quantitative statements of the probative value of DNA evidence are to be admissible

Assembling life : models, the cell, and the reformations of biological science, 1920-1960

Imperial Users onl

Live, Die, Buy, Eat

Live, Die, Buy, Eat. These words represent a chain of events which today is disconnected. In the past few years, controversies around meat have arisen around industrialization and globalization of meat production, often pivoting around health, environmental issues, and animal welfare. Although meat increasingly figures as a problem, most consumers’ knowledge of animal husbandry and meat production is more absent than ever. Tracing a historical process of alienation along three distinct axes, the authors show how the animal origin of meat is covered up, rationalized, forgotten, excused, neglected, and denied. How is meat produced today, and where? How do we consume meat, and how have our consumption habits changed? Why have these changes occurred, and what are the social and cultural consequences of these changes? Using Norway as a case study, this book examines the dramatic changes in meat production and consumption over the last 150 years. With a wide range of historical sources, together with interviews and observation at farms, slaughterhouses, and production units, as well as analyses of contemporary texts and digital sources, Live, Die, Buy, Eat explores the transformation of animal husbandry, meat production and consumption, together with its cultural consequences. It will appeal to scholars of anthropology, sociology, cultural studies, geography, and history with an interest in food, agriculture, environment, and culture