3,135 research outputs found
Gender-From-Iris or Gender-From-Mascara?
Predicting a person's gender based on the iris texture has been explored by
several researchers. This paper considers several dimensions of experimental
work on this problem, including person-disjoint train and test, and the effect
of cosmetics on eyelash occlusion and imperfect segmentation. We also consider
the use of multi-layer perceptron and convolutional neural networks as
classifiers, comparing the use of data-driven and hand-crafted features. Our
results suggest that the gender-from-iris problem is more difficult than has so
far been appreciated. Estimating accuracy using a mean of N person-disjoint
train and test partitions, and considering the effect of makeup - a combination
of experimental conditions not present in any previous work - we find a much
weaker ability to predict gender-from-iris texture than has been suggested in
previous work
The Value of Life Near its End and Terminal Care
Medical care at the end of life, which is often is estimated to contribute up to a quarter of US health care spending, often encounters skepticism from payers and policy makers who question its high cost and often minimal health benefits. It seems generally agreed upon that medical resources are being wasted on excessive care for end-of-life treatments that often only prolong minimally an already frail life. However, though many observers have claimed that such spending is often irrational and wasteful, little explicit and systematic analysis exists on the incentives that determine end of life health care spending. There exists no positive theory that attempts to explain the high degree of end-of life spending and why differences across individuals, populations, or time occur in such spending. This paper attempts to provide the first rational and systematic analysis of the incentives behind end of life care. The main argument we make is that existing estimates of the value of a life year do not apply to the valuation of life at the end of life. We stress the low opportunity cost of medical spending near ones death, the importance of keeping hope alive in a terminal care setting, the larger social value of a life than estimated in private demand settings, as well as the insignificance in quality of life in lowering its value. We derive how an ex-ante perspective in terms of insurance and R&D alters some of these conclusions.
Human Capital: A Theoretical and Empirical Analysis with Special Reference to Education (3rd Edition)
An analytical high value target acquisition model
An Analytical High Value Target (HVT) acquisition model is developed for a generic anti-ship cruise missile system. the target set is represented as a single HVT within a field of escorts. The HVT's location is described by a bivariate normal probability distribution. the escorts are represented by a spatially homogeneous Poisson random field surrounding the HVT. Model output consists of the probability that at least one missile of a salvo acquires the HVT, conditioned on the number of missiles in the salvo which penetrate the HVT area defense. In addition, the fall of multiple penetrators is modeled using a conditional multinomial probability distribution. the model's equations are used to solve for an optimal missiles seeker range gate, given a probability distribution describing the location of the HVT within the targeted formation at the time the missile commences its search. Included in an appendix is a time-dependent model describing HVT location which provides for HVT movement during missile time of flight up to the moment of active search.http://archive.org/details/analyticalhighva00beckLieutenant, United States NavyApproved for public release; distribution is unlimited
Human Capital: A Theoretical and Empirical Analysis with Special Reference to Education (3rd Edition)
An Empirical Analysis of Cigarette Addiction
We use a framework suggested by a model of rational addiction to analyze empirically the demand for cigarettes. The data consist of per capita cigarettes sales (in packs) annually by state for the period 1955 through 1985. The empirical results provide support for the implications of a rational addiction model that cross price effects are negative (consumption in different periods are complements), that long-run price responses exceed short-run responses, and that permanent price effects exceed temporary price effects. A 10 percent permanent increase in the price of cigarettes reduces current consumption by 4 percent in the short run and by 7.5 percent in the long run. In contrast, a 10 percent increase in the price for only one period decreases consumption by only 3 percent. In addition, a one period price increase of 10 percent reduces consumption in the previous period by approximately .7 percent and consumption in the subsequent period by 1.5 percent. These estimates illustrate the importance of the intertemporal linkages in cigarette demand implied by rational addictive behavior.
The Pericentrion: Identification, Characterization, and Function of a Novel cPKC-Dependent Compartment
Members of the protein kinase C (PKC) superfamily transduce a myriad of transmembrane signals initiated by the formation of sn-l ,2-diacylglycerol (DAG). As the primary physiological agonist for C] domain containing PKC isoenzymes, DAG functions to regulate the spatial and temporal parameters of PKC activity. It is now recognized that cellular DAG levels can vary from minutes to hours and even days. These observations have suggested a division of PKC functions that correlate to the duration of the cellular DAG signal. In their classical role, cPKCs respond acutely to the short-lived (1-2 min) DAG generated at the plasma membrane by the phospholipase C-mediated turnover of phosphoinositides. In contrast, a more persistent DAG signal can be produced through a variety of physiologic as well as pathologic mechanisms, and this DAG has also been proposed to regulate PKC activity. Currently, there are conflicting data on this issue and the specific subcellular localization of cPKC during prolonged DAG is unknown. To investigate the target of PKC during sustained activation, green fluorescent protein (GFP) technology was utilized to monitor the subcellular traffic of various PKC isoenzymes in response to treatment with either DAG-mimicking phorbol esters or DAG-generating agonists (e.g. platelet-derived growth factor). In response to a persistent elevation of DAG, cPKC isoenzymes, α and βII, translocated to the plasma membrane and to a juxtanuclear location in a variety of cell lines examined. Characterization of this compartment revealed that it overlapped/co-localized with a rab II-positive subcompartment of recycling endosomes concentrated around the MTOC/centrosome. The cPKC compartment was distinguish from the rab II-positive compartment by several features including a requirement for kinase and phospholipase D activity, an enrichment of lipid raft components, and the independence of microtubules and temperature for maintenance of the structure. Investigation into the significance of this compartment revealed that cPKC translocation coincided with the attendant sequestration of membrane recycling components. Given these distinctions, it was proposed that this novel cPKC-compartment be named the pericentrion in order to distinguish it from the rab 11 subcompartment of recycling endosomes. Subsequent analysis of a disease model wherein cPKC is maintained in a persistently active state, in this case chronic hyperglycemia associated with type I and type II diabetes, revealed a possible role for cPKC in the dysregulation of GLUT4 trafficking in response to insulin. These studies identify a novel site for cPKC translocation and function in response to a physiological and pathological elevation of DAG
Biogeochemical significance and biomarker potential of novel glycerolipids and respiratory quinones in the marine environment
Microorganisms catalyze processes which shape the chemistry of the biosphere, drive global element cycles, and ultimately influence the composition of Earthâ s surface and interior on geological timescales. Microbial lipids provide crucial information about the distribution, activity, and adaptation of microbial communities in both modern and ancient environments. In this thesis, advanced chromatographic methods were developed that have significantly expanded the analytical window for microbial lipidomics in complex environmental sample matrices and have paved the way for the discovery of novel microbial biomarkers. Application of the novel protocols to samples from microbial cultures, the hypersaline Discovery Basin and the stratified water column and sediments of the Black Sea revealed an exceptional diversity of lipids. The combination of respiratory quinone and core and intact polar lipid analysis provided detailed information about microbial community composition and biogeochemical processes the microbes are mediating
The Economic Theory of Illegal Goods: The Case of Drugs
This paper concentrates on both the positive and normative effects of punishments that enforce laws to make production and consumption of particular goods illegal, with illegal drugs as the main example. Optimal public expenditures on apprehension and conviction of illegal suppliers obviously depend on the extent of the difference between the social and private value of consumption of illegal goods, but they also depend crucially on the elasticity of demand for these goods. In particular, when demand is inelastic, it does not pay to enforce any prohibition unless the social value is negative and not merely less than the private value. We also compare outputs and prices when a good is legal and taxed with outputs and prices when the good is illegal. We show that a monetary tax on a legal good could cause a greater reduction in output and increase in price than would optimal enforcement, even recognizing that producers may want to go underground to try to avoid a monetary tax. This means that fighting a war on drugs by legalizing drug use and taxing consumption may be more effective than continuing to prohibit the legal use of drugs.
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