A rapid fluorometric assay for the S-malonyltransacylase FabD and other sulfhydryl utilizing enzymes

The development of biorenewable chemicals will support green chemistry initiatives and supplement the catalog of starting materials available to the chemical industry. Bacterial fatty acid biosynthesis is being pursued as a source of protein catalysts to synthesize novel reduced carbon molecules in fermentation systems. The availability of methods to measure enzyme catalysis for native and engineered enzymes from this pathway remains a bottleneck because a simple quantitative enzyme assay for numerous enzymes does not exist. Here we present two variations of a fluorescence assay that is readily extendable to high-throughput screening and is appropriate for thiol consuming and generating enzymes including the Escherichia coli enzymes malonyl-coenzyme A transacylase (FabD) and keto-acylsynthase III (FabH). We measured KM values of 60 ± 20 µM (acetyl-CoA) and 20 ± 10 µM (malonyl-ACP) and a kcatof 7.4–9.0 s-1 with FabH. Assays of FabD included a precipitation step to remove the thiol-containing substrate holo-ACP from the reaction product coenzyme-A to estimate reaction rates. Analysis of initial velocity measurements revealed KM values of 60 ± 20 µM (malonyl-CoA) and 40 ± 10 µM (holo-ACP) and a kcat of 2100–2600 s-1for the FabD enzyme. Our data show similar results when compared to existing radioactive and continuous coupled assays in terms of sensitivity while providing the benefit of simplicity, scalability and repeatability. Fluorescence detection also eliminates the need for radioactive substrates traditionally used to assay these enzymes

Pioneering Extension Nutrition Education with iPad Apps: A Development Story

Technology can be an effective vehicle for Extension nutrition education. Body Quest: Food of the Warrior is a childhood obesity prevention initiative of the Alabama Cooperative Extension System that successfully incorporates technology in the classroom. With Body Quest, students learn about healthful eating through blended learning involving both classroom instruction and self-directed e-learning via apps. Seven iPad apps excite students and engage them in the learning process. Extension professionals can benefit from our lessons learned for creating a successful app

Evaluation of the Internal Consistency, Factor Structure, and Validity of the Depression Change Expectancy Scale

The psychometric properties and predictive validity of the Depression Change Expectancy Scale (DCES), a modification of an expectancy scale originally developed for patients with anxiety disorders, were examined in two studies. In Study 1, the 20-item scale was administered along with a battery of questionnaires to a sample of 416 dysphoric undergraduate students and demonstrated good internal consistency. A two-factor solution most parsimoniously accounted for the variance, with one factor containing all pessimistically worded items (DCES-P) and the second containing all optimistically worded items (DCES-O). The DCES-P showed patterns of correlations with other measures of related constructs consistent with hypothesized relationships; the DCES-O showed similar, but weaker, relationships with the other measures. Multilevel modeling was used to examine the predictive utility of the DCES in a clinical sample of 63 adults (Study 2). Improved depressive symptoms (over 6 weeks) were strongly associated with optimistic expectancies but were unrelated to pessimistic expectancies for change. The DCES appears to be a promising measure of expectancies for improvement among individuals with depressive symptoms

Coherent control of the cooperative branching ratio for nuclear x-ray pumping

Coherent control of nuclear pumping in a three level system driven by x-ray light is investigated. In single nuclei, the pumping performance is determined by the branching ratio of the excited state populated by the x-ray pulse. Our results are based on the observation that in ensembles of nuclei, cooperative excitation and decay leads to a greatly modified nuclear dynamics, which we characterize by a time-dependent cooperative branching ratio. We discuss prospects of steering the x-ray pumping by coherently controlling the cooperative decay. First, we study an ideal case with purely superradiant decay and perfect control of the cooperative emission. A numerical analysis of x-ray pumping in nuclear forward scattering with coherent control of the cooperative decay via externally applied magnetic fields is presented. Next, we provide an extended survey of nuclei suitable for our scheme, and propose proof-of-principle implementations already possible with typical M\"ossbauer nuclear systems such as $^{57}\mathrm{Fe}$. Finally, we discuss the application of such control techniques to the population or depletion of long-lived nuclear states.Comment: 11 pages, 8 figures; updated to the published versio

Алгоритм диагностики и лечения отравления грибами

Facultatea de Medicina “Victor Papilian”, Sibiu, România, Spitalul Militar de Urgenţă, Sibiu, România, Conferinţa Ştiinţifico-Practică „Medicina modernă, actualităţi şi perspective”, consacrată aniversării de 40 de ani ai Spitalului Clinic al Ministerului Sănătăţii, 27-28 mai, 2010, Chişinău, Republica MoldovaSince information about natural exposures is often insufficient and incorrect, a new syndromic classification of mushroom poisoning is recommended to guide clinicians in making earlier diagnoses – especially in cases where only advanced critical care, including liver transplantation, may be life saving. In 2005, Diaz proposed a classification system based on presentation timing and target organ systemic toxicity (14 major syndromes, 4 new syndromes). The diagnosis is based on clinical evaluation and urinary amatoxin evaluation. The treatment objectives are: to prevent absorption of the toxin from the gastrointestinal tract and to promote elimination from the systemic circulation (primary and secondary detoxification); regarding amatoxin poisoning, to lower the serum concentration of amanitin as soon as possible and thereby shorten the period of time that hepatocytes and renal tubular cells are exposed (extracorporeal detoxification and liver transplant).Отсутствие в настоящее время систематизированной информации об отравлении грибами вызвало необходимость разработки новой классификации для оказания помощи врачам в ранней диагностике. В 2005 году Диас предложил классификацию отравлений грибами на основе двух критериев: скорость проявления симптомов интоксикации и системная токсичность. Позитивная диагностика основывается на клинической оценке и определении мочевого аматоксина. Целью лечения является: предотвращение всасывания токсинов из желудочно-кишечного тракта, а также первичная и вторичная детоксикация системы кровообращения

Cooperative effects in nuclear excitation with coherent x-ray light

The interaction between super-intense coherent x-ray light and nuclei is studied theoretically. One of the main difficulties with driving nuclear transitions arises from the very narrow nuclear excited state widths which limit the coupling between laser and nuclei. In the context of direct laser-nucleus interaction, we consider the nuclear width broadening that occurs when in solid targets, the excitation caused by a single photon is shared by a large number of nuclei, forming a collective excited state. Our results show that for certain isotopes, cooperative effects may lead to an enhancement of the nuclear excited state population by almost two orders of magnitude. Additionally, an update of previous estimates for nuclear excited state population and signal photons taking into account the experimental advances of the x-ray coherent light sources is given. The presented values are an improvement by orders of magnitude and are encouraging for the future prospects of nuclear quantum optics.Comment: 22 pages, 4 figures, 5 tables; updated to the published version, one additional results tabl