A survey of recent estimates of price elasticities of demand for transport

This paper reviews 70 estimates of the price elasticity of demand for many different transport modes and market situations. The paper presents figures separately for passenger and freight transport and include estimates of both own-price and mode choice elasticities. It also presents some elasticity estimates on demand for gasoline, together with selected cross-price elasticities. In addition, it includes a brief exposition on the different concepts of elasticity - compensated, uncompensated, price, cross-price and mode choice - and discusses the relations between them. This paper shows that, since transportation is a derived demand, it tends to be inelastic. Although the review is confined to estimates of price elasticities, it notes that quality variables are often more important than price, particularly in the air, motor freight, and container markets. Finally, most of the estimates relate to developed countries, reflecting the availabilty of data, research resources, and domicile of the researchers. The elasticity estimates are nevertheless thought to be relevant to developing countries as well. But since intermodal competition is generally less intense in developing countries, this tends to make transport demand more inelastic, although the lower income levels in such countries may partly offset this effect.Environmental Economics&Policies,Economic Theory&Research,Access to Markets,Markets and Market Access,Consumption

State-of-the-art Approaches for Sequencing, Assembling and Annotating Naphthenic Acid Degrading Bacterial Metagenomes

Naphthenic acids (NAs) are the main toxic component of oil refinery wastewater and require special processes to be removed. Harnessing bacterial biodegradation for NA removal has the potential to be effective, yet NA-degrading bacteria and pathways are poorly understood and uncharacterized. To improve our understanding of NA degradation, I characterize the metagenomes of novel NA-degrading bacterial communities seeded in NA-enriched granulated activated carbon (GAC) filters. I demonstrate methods that maximize the throughput of extraction, sequencing, and annotation of novel metagenomes - producing 72 MAGs and other 5432 circular contigs - 226 of which were putative phages. I also include state-of-the-art protein structure prediction and structure homology search tools, which greatly enrich annotations of novel sequences that are below the threshold for homology finding by sequence alone. Overall, these approaches unveiled a diverse and constantly changing consortium of novel bacteria and many potential NA-degrading genes

Classically time-controlled quantum automata

In this paper we introduce classically time-controlled quantum automata or CTQA, which is a slight but reasonable modification of Moore-Crutchfield quantum finite automata that uses time-dependent evolution operators and a scheduler defining how long each operator will run. Surprisingly enough, time-dependent evolutions provide a significant change in the computational power of quantum automata with respect to a discrete quantum model. Furthermore, CTQA presents itself as a new model of computation that provides a different approach to a formal study of “classical control, quantum data” schemes in quantum computing.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Trends in sexual activity and demand for and use of modern contraceptive methods in 74 countries: a retrospective analysis of nationally representative surveys.

BACKGROUND: A quarter of a century ago, two global events-the International Conference on Population and Development in Cairo, and the Fourth World Conference on Women in Beijing-placed gender equality and reproductive health and rights at the centre of the development agenda. Progress towards these goals has been slower than hoped. We used survey data and national-level indicators of social determinants from 74 countries to examine change in satisfaction of contraceptive need from a contextual perspective. METHODS: We searched for individual-level data from repeated nationally representative surveys that included information on sexual and reproductive health, and created a single dataset by harmonising data from each survey to a standard data specification. We described the relative timings of sexual initiation, first union (cohabitation or marriage), and first birth and used logistic regression to show the change in prevalence of sexual activity, demand for contraception, and modern contraceptive use. We used linear regression to examine country-level associations between the gender development index and the expected length of time in education for women and the three outcomes: sexual activity, demand for contraception, and modern contraceptive use. We used principal component analysis to describe countries using a combination of social-structural and behavioural indicators and assessed how well the components explained country-level variation in the proportion of women using contraception with fractional logistic regression. FINDINGS: In 34 of the 74 countries examined, proportions of all women who were sexually active, not wanting to conceive, and not using a modern contraceptive method decreased over time. Proportions of women who had been sexually active in the past year changed over time in 43 countries, with increases in 30 countries; demand for contraception increased in 42 countries, and use of a modern method of contraception increased in 37 countries. Increases over time in met need for contraception were correlated with increases in gender equality and with women's time in education. Regression analysis on the principal components showed that country-level variation in met contraceptive need was largely explained by a single component that combined behavioural and social-contextual variables. INTERPRETATION: Progress towards satisfying demand for contraception should take account of the changing context in which it is practised. To remove the remaining barriers, policy responses-and therefore research priorities-could require a stronger focus on social-structural determinants and broader aspects of sexual health. FUNDING: UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction

Quantum computation with devices whose contents are never read

In classical computation, a "write-only memory" (WOM) is little more than an oxymoron, and the addition of WOM to a (deterministic or probabilistic) classical computer brings no advantage. We prove that quantum computers that are augmented with WOM can solve problems that neither a classical computer with WOM nor a quantum computer without WOM can solve, when all other resource bounds are equal. We focus on realtime quantum finite automata, and examine the increase in their power effected by the addition of WOMs with different access modes and capacities. Some problems that are unsolvable by two-way probabilistic Turing machines using sublogarithmic amounts of read/write memory are shown to be solvable by these enhanced automata.Comment: 32 pages, a preliminary version of this work was presented in the 9th International Conference on Unconventional Computation (UC2010

Cardioprotective Effects of Selective Mitochondrial-Targeted Antioxidants in Myocardial Ischemia/Reperfusion (I/R) Injury

During myocardial ischemia, coronary blood flow interruption deprives cardiomyocytes of oxygen, glucose and fatty acids. Ischemic damage is exacerbated by a burst of reactive oxygen species (ROS) generated at reperfusion when oxygen interacts with damaged mitochondrial electron transport chains (ETC), especially uncoupled complexes I and III (Fig. 1,2). Nicotinamide adenine dinucleotide phosphate oxidase (Nox) activity can also release ROS, inducing additional tissue/organ damage. Surgical intervention or thrombolytic treatments can restore coronary blood flow. However, as blood flow reestablishes, oxidative stress leads to I/R injury. Clinical treatment remains a challenge as no pharmaceutical agents effectively limit I/R-induced damage. Mitochondria are implicated in I/R as a major source of ROS3,4,5. Excess ROS leads to mitochondrial and cardiac contractile dysfunction6. Conventional antioxidants have limited efficacy in myocardial I/R because they are not targeted selectively to where most I/R damage occurs, in mitochondria (Fig. 3)3,4,5. Mitoquinone (mitoQ, MW=600 g/mol), a coenzyme Q analog, easily crosses phospholipid bilayers and is driven by the large electrochemical membrane potential to concentrate mitoQ several hundred-fold within mitochondria. The respiratory chain reduces mitoQ to its active ubiquinol antioxidant form to limit myocardial I/R injury5. The SS-31 (Szeto-Schiller) peptide ((D-Arg)-Dmt-Lys-Phe-Amide, MW=640 g/mol, Genemed Synthesis, Inc., San Antonio, TX) is also of interest since it is cellpermeable, specifically targeted to inner mitochondrial membranes based on its alternating cationic aromatic residue sequence, with an antioxidant dimethyltyrosine moeity. SS peptides scavenge ROS in I/R models. Although mitochondrial-targeted antioxidant pretreatment can effectively limit I/R injury, pretreatment is not always possible in cases of myocardial infarction. Therefore, evaluating cardioprotective efficacy of mitochondrialtargeted antioxidants when given at reperfusion is of high significanc

Public and private enforcement of corporate and securities laws: An empirical comparison of Hong Kong and Singapore

Ministry of Education, Singapore under its Academic Research Funding Tier

Ganciclovir-Resistant Cytomegalovirus (CMV) Retinitis in a Patient with Wild-Type CMV in Her Plasma

A patient with systemic cytomegalovirus (CMV), including chorioretinitis, received localized and systemic ganciclovir, systemic cidofovir analog, and localized foscarnet. Mutations conferring ganciclovir and cidofovir resistance were detected in CMV from the aqueous fluid but not in CMV from plasma. Quantifying CMV from aqueous fluid was valuable for monitoring the clinical response and predicting resistance