The Adler Function for Light Quarks in Analytic Perturbation Theory

The method of analytic perturbation theory, which avoids the problem of ghost-pole type singularities and gives a self-consistent description of both spacelike and timelike regions, is applied to describe the "light" Adler function corresponding to the non-strange vector channel of the inclusive decay of the $\tau$ lepton. The role of threshold effects is investigated. The behavior of the quark-antiquark system near threshold is described by using a new relativistic resummation factor. It is shown that the method proposed leads to good agreement with the ``experimental'' Adler function down to the lowest energy scale.Comment: 13 pages, one ps figure, REVTe

Molecular mechanisms for photosynthetic carbon partitioning into storage neutral lipids in Nannochloropsis oceanica under nitrogen-depletion conditions

Polysaccharides are a major carbon/energy-reservoir in microalgae, yet their relationship with another form of carbon/energy storage, triacylglycerol (TAG), is poorly understood. Here employing oleaginous microalga Nannochloropsis oceanica as a model, we probed the crosstalk between carbohydrate metabolism and TAG accumulation by tracking the temporal dynamics of lipidomes, monosaccharides and polysaccharides and transcripts of selected genes over 14 days under nitrogen-depleted (N-) and nitrogen-replete (N+) conditions. Glucose, galactose and mannitol were the main monosaccharides in IMET1, and laminarin may be the storage polysaccharide that competes for carbon precursors with TAG. Transcriptional expression analysis revealed that the beta-1,3-glucan degradation and pyruvate dehydrogenases pathways were the main regulatory components involved in driving carbon flow to TAG synthesis. Furthermore, temporal changes of lipidomes and transcripts of glycerolipid metabolism genes were indicative of possible conversion of membrane lipids to TAG, especially under an early stage of nitrogen deprivation conditions. A carbon partitioning model for Nannochloropsis oceanica was proposed, in which beta-1,3-glucan metabolism, acetyl-CoA synthesis and membrane lipid turnover/degradation, in addition to de novo fatty acid synthesis, all contributed to TAG synthesis. (C) 2014 Elsevier B.V. All rights reserved

Image method in the calculation of the van der Waals force between an atom and a conducting surface

Initially, we make a detailed historical survey of van der Waals forces, collecting the main references on the subject. Then, we review a method recently proposed by Eberlein and Zietal to compute the dispersion van der Waals interaction between a neutral but polarizable atom and a perfectly conducting surface of arbitrary shape. This method has the advantage of relating the quantum problem to a corresponding classical one in electrostatics so that all one needs is to compute an appropriate Green function. We show how the image method of electrostatics can be conveniently used together with the Eberlein and Zietal mehtod (when the problem admits an image solution). We then illustrate this method in a couple of simple but important cases, including the atom-sphere system. Particularly, in our last example, we present an original result, namely, the van der Waals force between an atom and a boss hat made of a grounded conducting material.Comment: This is a pedagogical and introductory paper on van der Waals forces between an atom and a conducting surfac

Effect of photon flux densities on regulation of carotenogenesis and cell viability of Haematococcus pluvialis (Chlorophyceae)

The green alga Haematococcus pluvialis produces large amounts of the pink carotenoid astaxanthin under high photon flux density (PFD) and other oxidative stress conditions. However, the regulation and physiological role of carotenogenesis leading to astaxanthin formation is not well understood. Comparative transcriptional expression of five carotenoid genes along with growth and pigment composition as a function of PFD was studied using a wild-type and an astaxanthin-overproduction mutant of H. pluvialis NIES144. The results indicate that astaxanthin biosynthesis was mainly under transcriptional control of the gene encoding carotenoid hydroxylase, and to a lesser extent, the genes encoding isopentenyl isomerase and phytoene desaturase, and to the least extent, the genes encoding phytoene synthase and carotenoid oxygenase. The expression of a plastid terminal oxidase (PTOX) gene ptox2 underwent transient up-regulation under elevated PFDs, suggesting that PTOX may be functionally coupled with phytoene desaturase through the plastoquinone pool and may play a role in reducing redox-potential-dependent and oxygen-concentration-dependent formation of reactive oxygen species in the chloroplast. Over-expression of both the carotenogenic and PTOX genes confers to the astaxanthin-overproduction mutant more effective photoprotective capability than that of the wild type under photooxidative stress

First-principles flocculation as the key to low energy algal biofuels processing.

This document summarizes a three year Laboratory Directed Research and Development (LDRD) program effort to improve our understanding of algal flocculation with a key to overcoming harvesting as a techno-economic barrier to algal biofuels. Flocculation is limited by the concentrations of deprotonated functional groups on the algal cell surface. Favorable charged groups on the surfaces of precipitates that form in solution and the interaction of both with ions in the water can favor flocculation. Measurements of algae cell-surface functional groups are reported and related to the quantity of flocculant required. Deprotonation of surface groups and complexation of surface groups with ions from the growth media are predicted in the context of PHREEQC. The understanding of surface chemistry is linked to boundaries of effective flocculation. We show that the phase-space of effective flocculation can be expanded by more frequent alga-alga or floc-floc collisions. The collision frequency is dependent on the floc structure, described in the fractal sense. The fractal floc structure is shown to depend on the rate of shear mixing. We present both experimental measurements of the floc structure variation and simulations using LAMMPS (Large-scale Atomic/Molecular Massively Parallel Simulator). Both show a densification of the flocs with increasing shear. The LAMMPS results show a combined change in the fractal dimension and a change in the coordination number leading to stronger flocs

Heat kernel expansion: user's manual

The heat kernel expansion is a very convenient tool for studying one-loop divergences, anomalies and various asymptotics of the effective action. The aim of this report is to collect useful information on the heat kernel coefficients scattered in mathematical and physical literature. We present explicit expressions for these coefficients on manifolds with and without boundaries, subject to local and non-local boundary conditions, in the presence of various types of singularities (e.g., domain walls). In each case the heat kernel coefficients are given in terms of several geometric invariants. These invariants are derived for scalar and spinor theories with various interactions, Yang-Mills fields, gravity, and open bosonic strings. We discuss the relations between the heat kernel coefficients and quantum anomalies, corresponding anomalous actions, and covariant perturbation expansions of the effective action (both "low-" and "high-energy" ones).Comment: 113 pp, to be submitted to Phys.Repts, v2: added references and corrected typo

Proceedings of the 3rd Biennial Conference of the Society for Implementation Research Collaboration (SIRC) 2015: advancing efficient methodologies through community partnerships and team science

It is well documented that the majority of adults, children and families in need of evidence-based behavioral health interventionsi do not receive them [1, 2] and that few robust empirically supported methods for implementing evidence-based practices (EBPs) exist. The Society for Implementation Research Collaboration (SIRC) represents a burgeoning effort to advance the innovation and rigor of implementation research and is uniquely focused on bringing together researchers and stakeholders committed to evaluating the implementation of complex evidence-based behavioral health interventions. Through its diverse activities and membership, SIRC aims to foster the promise of implementation research to better serve the behavioral health needs of the population by identifying rigorous, relevant, and efficient strategies that successfully transfer scientific evidence to clinical knowledge for use in real world settings [3]. SIRC began as a National Institute of Mental Health (NIMH)-funded conference series in 2010 (previously titled the “Seattle Implementation Research Conference”; $150,000 USD for 3 conferences in 2011, 2013, and 2015) with the recognition that there were multiple researchers and stakeholdersi working in parallel on innovative implementation science projects in behavioral health, but that formal channels for communicating and collaborating with one another were relatively unavailable. There was a significant need for a forum within which implementation researchers and stakeholders could learn from one another, refine approaches to science and practice, and develop an implementation research agenda using common measures, methods, and research principles to improve both the frequency and quality with which behavioral health treatment implementation is evaluated. SIRC’s membership growth is a testament to this identified need with more than 1000 members from 2011 to the present.ii SIRC’s primary objectives are to: (1) foster communication and collaboration across diverse groups, including implementation researchers, intermediariesi, as well as community stakeholders (SIRC uses the term “EBP champions” for these groups) – and to do so across multiple career levels (e.g., students, early career faculty, established investigators); and (2) enhance and disseminate rigorous measures and methodologies for implementing EBPs and evaluating EBP implementation efforts. These objectives are well aligned with Glasgow and colleagues’ [4] five core tenets deemed critical for advancing implementation science: collaboration, efficiency and speed, rigor and relevance, improved capacity, and cumulative knowledge. SIRC advances these objectives and tenets through in-person conferences, which bring together multidisciplinary implementation researchers and those implementing evidence-based behavioral health interventions in the community to share their work and create professional connections and collaborations

Organic Contaminants in Urban Lake Sediments: A Preliminary Assessment

From the Proceedings of the 1989 Meetings of the Arizona Section - American Water Resources Association and the Hydrology Section - Arizona-Nevada Academy of Science - April 15, 1989, University of Nevada, Las Vegas, NevadaBottom sediments from several urban lakes located in the Phoenix metropolitan area were collected and analyzed for organic priority pollutants. The lakes selected for analysis were broadly representative of the diversity of lake characteristics found in the Phoenix area. That is, lakes were sampled that had different types of primary water sources and that were located in watersheds of differing degrees of urbanization. Preliminary results indicate that only nine of the 114 listed organic priority pollutants were found in measurable quantities in the sediments of the lakes surveyed. The pollutants detected were either phthalate esters or volatile or semi-volatile halogenated compounds. None of the pollutants were common to all the lakes sampled. Dibutyl phthalate was detected in three of the six lakes. A larger database is being developed and will be necessary to determine whether a statistical correlation exists between watershed characteristics and feedwater, and organic composition of lake sediments.This article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact [email protected]

Effect of Stream Discharge on Phosphorus Loading and Assimilation in the East Verde River

From the Proceedings of the 1984 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona-Nevada Academy of Science - April 7, 1984, Flagstaff, ArizonaThis article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact [email protected]

Accumulation of Heavy Metals and Petroleum Hydrocarbons in Urban Lakes: Preliminary Results

From the Proceedings of the 1988 Meetings of the Arizona Section - American Water Resources Association and the Hydrology Section - Arizona-Nevada Academy of Science - April 16, 1988, University of Arizona, Tucson, ArizonaA preliminary survey of several urban lakes in the Phoenix metropolitan area was undertaken to assess the degree of accumulation of priority pollutant metals and petroleum -based hydrocarbons in these impoundments. Three sediment samples were collected from each lake along a transect (from a probable point of stormwater addition to the opposite shore), and were composited on an equal weight basis prior to analysis. Total petroleum hydrocarbon concentrations ranged from 30 to 8000 mg /kg dry weight. The concentration ranges (mg /kg dry weight) of total metals were: arsenic 7-26, copper 25-2800, chromium 14-55, nickel 5-40, lead < 1-138, selenium < 0.5-1.1, and zinc 33-239. Silver and cadmium were undetectable (< 5.0 and < 0.5 mg /kg, respectively). Factors that may be associated with the magnitude of accumulation in urban lakes include lake age, primary source of influent, reception of stormwater runoff, mechanical aeration of the water, and direct chemical addition.This article is part of the Hydrology and Water Resources in Arizona and the Southwest collections. Digital access to this material is made possible by the Arizona-Nevada Academy of Science and the University of Arizona Libraries. For more information about items in this collection, contact [email protected]