1,797 research outputs found
Non local lagrangians(I): the pion
We define a family of non local and chirally symmetric low energy lagrangians
motivated by theoretical studies on Quantum Chromodynamics. These models lead
to quark propagators with non trivial momentum dependencies. We define the
formalism for two body bound states and apply it to the pion. We study the
coupling of the photon and W bosons with special attention to the
implementation of local gauge invariance. We calculate the pion decay constant
recovering the Goldberger-Treiman and the Gell-Mann-Oakes-Renner relations. We
recover a form of the axial current consistent with PCAC. Finally we study the
pion form factor and we construct the operators involved in its parton
distribution.Comment: Latex, 25 pages with 15 figures; added references for introduction
and section
Does Enhancing Mind Perception Affect Conspiracy Belief?
This study was conducted to determine the effectiveness of a novel mind perception manipulation. Mind perception is currently theorized to be an essential aspect of a number of human social psychological processes. Thus, a successful manipulation would allow for the causal study of those processes. This manipulation was created in an attempt to explore the downstream impact of mind perception on the endorsement of conspiracy theories. Conspiracy theories are steadily becoming more and more prominent in social discourse. Endorsement of conspiracy theories are beginning to show real world ramifications such as a danger to human health (e.g., in the anti-vaccination movement). A sample of college students (valid N = 53) from a large rural institution in the southeastern United States participated for course credit. These participants completed a mind perception pretest, were randomly assigned to either the manipulation in question (in which participants are asked to consider the âmindâ of several targets and write their thoughts about them) or the control condition, and then they completed a posttest. The mixed ANOVA revealed that the interaction term between Time and Condition was not significant. Because the manipulation did not work, other analyses were aborted, in accord with the pre-registration. My Discussion focuses on the procedures and potential shortcomings of this manipulation, in an effort to lay the groundwork for a successful one
The topology of vitronectin: A complementary feature for neuroblastoma risk classification based on computerâaided detection
Tumors are complex networks of constantly interacting elements: tumor cells, stromal cells, immune and stem cells, blood/lympathic vessels, nerve fibers and extracellular matrix components. These elements can influence their microenvironment through mechanical and physical signals to promote tumor cell growth. To get a better understanding of tumor biology, cooperation between multidisciplinary fields is needed. Diverse mathematic computations and algorithms have been designed to find prognostic targets and enhance diagnostic assessment. In this work, we use computational digital tools to study the topology of vitronectin, a glycoprotein of the extracellular matrix. Vitronectin is linked to angiogenesis and migration, two processes closely related to tumor cell spread. Here, we investigate whether the distribution of this molecule in the tumor stroma may confer mechanical properties affecting neuroblastoma aggressiveness. Combining image analysis and graph theory, we analyze different topological features that capture the organizational cues of vitronectin in histopathological images taken from human samples. We find that the Euler number and the branching of territorial vitronectin, two topological features, could allow for a more precise pretreatment risk stratification to guide treatment strategies in neuroblastoma patients. A large amount of recently synthesized VN would create migration tracks, pinpointed by both topological features, for malignant neuroblasts, so that dramatic change in the extracellular matrix would increase tumor aggressiveness and worsen patient outcomes
The eta-photon transition form factor
The eta-photon transition form factor is evaluated in a formalism based on a
phenomenological description at low values of the photon virtuality, and a
QCD-based description at high photon virtualities, matching at a scale
. The high photon virtuality description makes use of a Distribution
Amplitude calculated in the Nambu-Jona-Lasinio model with Pauli-Villars
regularization at the matching scale , and QCD evolution from
to higher values of . A good description of the available
data is obtained. The analysis indicates that the recent data from the BaBar
collaboration on pion and eta transition form factor can be well reproduced, if
a small contribution of twist three at the matching scale is
included.Comment: 14 pages, 3 figures, revised version, minor corrections, references
added, conclusions unchanged. Accepted for publication in Phys. Rev.
Reduction and Acetylation of 2,4-Dinitrotoluene by a Pseudomonas aeruginosa Strain
Aerobic and anoxic biotransformation of 2,4-dinitrotoluene (DNT) was examined by using a Pseudomonas aeruginosa strain isolated from a plant treating propellant manufacturing wastewater. DNT biotransformation in the presence and absence of oxygen was mostly reductive and was representative of the type of cometabolic transformations that occur when a high concentration of an easily degradable carbon source is present. P. aeruginosa reduced both nitro groups on DNT, with the formation of mainly 4-amino-2-nitrotoluene and 2-amino-4-nitrotoluene and small quantities of 2,4-diaminotoluene. Acetylation of the arylamines was a significant reaction. 4-Acetamide-2-nitrotoluene and the novel compounds 2-acetamide-4-nitrotoluene, 4-acet-amide-2-aminotoluene, and 2,4-diacetamidetoluene were identified as DNT metabolites. The biotransformation of 2,4-diaminotoluene to 4-acetamide-2-aminotoluene was 24 times faster than abiotic transformation. 2-Ni-trotoluene and 4-nitrotoluene were also reduced to their corresponding toluidines and then acetylated. How-ever, the yield of 4-acetamidetoluene was much higher than that of 2-acetamidetoluene, demonstrating that acetylation at the position para to the methyl group was favored
Role of the environment in the stability of anisotropic gold particles
International audienceDespite the long-lasting interest in the synthesis control of nanoparticles (NPs) in both fundamental and applied nanosciences, the driving mechanisms responsible for their size and shape selectivity in an environment (solution) are not completely understood, and a clear assessment of the respective roles of equilibrium thermodynamics and growth kinetics is still missing. In this study, relying on an efficient atomistic computational approach, we decipher the dependence of energetics, shapes and morphologies of gold NPs on the strength and nature of the metalâenvironment interaction. We highlight the conditions under which the energy difference between isotropic and elongated gold NPs is reduced, thus prompting their thermodynamic coexistence. The study encompasses both monocrystalline and multi-twinned particles and extends over size ranges particularly representative of the nucleation and early growth stages. Computational results are further rationalized with arguments involving the dependence of facet and edge energies on the metalâenvironment interactions. We argue that by determining the abundance and diversity of particles nucleated in solution, thermodynamics may constitute an important bias influencing their final shape. The present results provide firm grounds for kinetic simulations of particle growth
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Metabolic network analysis reveals microbial community interactions in anammox granules.
Microbial communities mediating anaerobic ammonium oxidation (anammox) represent one of the most energy-efficient environmental biotechnologies for nitrogen removal from wastewater. However, little is known about the functional role heterotrophic bacteria play in anammox granules. Here, we use genome-centric metagenomics to recover 17 draft genomes of anammox and heterotrophic bacteria from a laboratory-scale anammox bioreactor. We combine metabolic network reconstruction with metatranscriptomics to examine the gene expression of anammox and heterotrophic bacteria and to identify their potential interactions. We find that Chlorobi-affiliated bacteria may be highly active protein degraders, catabolizing extracellular peptides while recycling nitrate to nitrite. Other heterotrophs may also contribute to scavenging of detritus and peptides produced by anammox bacteria, and potentially use alternative electron donors, such as H2, acetate and formate. Our findings improve the understanding of metabolic activities and interactions between anammox and heterotrophic bacteria and offer the first transcriptional insights on ecosystem function in anammox granules
Alternative Paradigms in Animal Health Decisions: A Framework for Treating Animals Not Only as Commodities
Zoonoses are diseases transmitted from (vertebrate) animals to humans in the environment. The control and prevention of these diseases require an appropriate way to measure health value for prudent and well-balanced decisions in public health, production costs, and market values. Currently, the impact of diseases and animal disease control measures are typically assessed in monetary values, thus lacking consideration of other values such as emotional, societal, ecological, among others. Therefore, a framework is proposed that aims to explore, understand, and open up a conversation about the non-monetary value of animals through environmental and normative ethics. This method might help us complement the existing metrics in health, which are currently DALY and zDALY, adding more comprehensive values for animal and human health to the âOne Healthâ approach. As an example of this framework application, participants can choose what they are willing to give in exchange for curing an animal in hypothetical scenarios selecting a human health condition to suffer, the amount of money, and lifetime as a tradeoff. Considering animals beyond their monetary value in public health decisions might contribute to a more rigorous assessment of the burden of zoonotic diseases, among other health decisions. This study is structured as follows: after a brief introduction of zoonoses, animal health, and health metrics, briefly, different environmental health perspectives are presented. Based on this, a framework for animal health decisions is proposed. This framework introduces the âanthropozoocentric interfaceâ based on anthropocentrism and zoocentrism perspectives
Production Budgets for Arkansas Wine and Juice Grapes
Production budgets are presented for wine and juice grapes suitable for cultivation in Arkansas. Varieties examined include V. labruscana, French-American and American hybrids, V. aestivalis, V. rotundifolia, and V. vinifera. Important production considerations specific to each of these varieties are summarized. Results indicate considerable variation in profit potential among varieties. However, one or more varieties can be profitably grown in most regions of the state. With the exception of Sunbelt, V. labruscana varieties showed the least profitability. V. rotundifolia (muscadine) varieties hold promise as a new crop for the warmer southern regions of Arkansas, while Chambourcin shows strong profit potential as a red wine grape in parts of the state with more temperate climates. Other promising varieties include Chardonel, Traminette, and Cynthiana. V. vinifera varieties also show strong profit potential, but are limited by their intense management requirements and can only be grown on the best sites
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