Purification of Anthrax Toxin Protective Antigen Component and Characterization of its Binding Interaction with Bovine Kidney Cells

Protective antigen component of B. anthracis toxin was produced and purified to the \u3e99% level. Toxin was purified from culture supernatant utilizing concentration and liquid chromatography techniques. Purity was determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified protective antigen retained biological and antigenic activity as evidenced respectively by lethality in Fischer 344 rats when injected in combination with lethal factor, and by positive results on the Ouchterlony double diffussion assay. Radioiodinated protective antigen was used both in the in vivo and the in vitro experiments. In vivo distribution of labelled protective antigen was determined in Fischer 344 rats. Assay of organ tissues for labelled protective antigen aided in the decision to use Maden-Darby bovine kidney cells for the cell cultures in the protective antigen binding studies. Protective antigen binding studies, all performed at 37°C, evaluated criteria for receptor existence. Labelled protective antigen was found to bind specifically and reversibly to Maden-Darby bovine kidney cells. Receptors proved to be saturable. Scatchard analysis showed a relatively high dissociation constant (KD= 17 X 10-9M) compared to other toxins in similar studies. This indicated moderately low affinity for protective antigen. The receptor was also partially characterized. It was shown that cholera toxin subunit B blocked the binding of labelled protective antigen to Maden-Darby bovine kidney cells and that the protective antigen receptor was insensitive to trypsin treatment. Both of these observations suggest a ganglioside as the receptor for protective antigen

The R∞R_\infty property for nilpotent quotients of generalized solvable Baumslag-Solitar groups

We say a group $G$ has property $R_\infty$ if the number $R(\varphi)$ of twisted conjugacy classes is infinite for every automorphism $\varphi$ of $G$. For such groups, the $R_\infty$-nilpotency degree is the least integer $c$ such that $G/\gamma_{c+1}(G)$ has property $R_\infty$. In this work, we compute the $R_\infty$-nilpotency degree of all Generalized Solvable Baumslag-Solitar groups $\Gamma_n$. Moreover, we compute the lower central series of $\Gamma_n$, write the nilpotent quotients $\Gamma_{n,c}=\Gamma_n/\gamma_{c+1}(\Gamma_n)$ as semidirect products of finitely generated abelian groups and classify which integer invertible matrices can be extended to automorphisms of $\Gamma_{n,c}$.Comment: 11 page

Rapid weight gain predicts fight success in mixed martial arts - evidence from 1,400 weigh-ins

We aimed to analyze whether rapid weight gain (RWG) between the official weigh-in and the time of the fight was associated with fight success in MMA. A total of 700 professional MMA fights involving 1,400 weigh-ins from 21 MMA promotions regulated by the California State Athletic Commission were analyzed. Multilevel logistic regression accounting for individual (i.e. athlete) and cluster levels (i.e. fights) was used to analyze the association of all measures with a theoretical relationship with the dependent variable and without interdependency with one another (i.e. %RWG, sex, body mass division, competition level) with the fight outcome (i.e. win or loss). The odds ratios (OR) with 95% confidence intervals (95%CI) were calculated. The highest mean %RWG was found for the flyweight, bantamweight, featherweight, and lightweight divisions. The %RWG significantly predicted the fight outcome (ss = 0.044; OR = 1.045; 95%CI = 1.014-1.078; p = 0.005) so that for each 1% of additional RWG, the chance of winning increased by 4.5%. With the largest sample to date and in a "real-world" scenario, the present results suggest that the magnitude of RWG is linked to the chance of winning in MMA combats. It is suggested that regulatory commissions, confederations, and event organisers should consider regulating RWG, considering that, despite its detrimental impact on the athletes' health and performance, the potential advantage might stimulate athletes to invest in rapid weight loss, followed by gain after the official weigh-in to increase their chance of winning

3D thixo-printing : a novel approach for additive manufacturing of biodegradable Mg-Zn alloys

A simple and widely used additive manufacturing technique for polymeric materials is fused filament fabrication (FFF). In the semi-solid state, metallic materials may show rheological features comparable to those of polymers. Thus, they can be processed accordingly. The use of biodegradable Mg-based materials is an interesting approach to avoid removal surgeries and release of toxic corrosion products and wear debris. Therefore, in this study, the FFF technique was applied using a biodegradable Mg-Zn alloy in the semi-solid state. Some preliminary compositions were investigated through thermodynamic simulations to verify their compatibility with the process. Among them, Mg-38Zn was selected to be experimentally evaluated. Metallic filaments were produced via hot extrusion, which also aided in obtaining a globular microstructure in the semi-solid state. FFF was performed at 420 °C without any obstruction at the nozzle channel, which allowed the production of sound parts with acceptable welding between the deposited layers. This indicated that this technique (termed as “3D thixo-printing”) provides a promising additive manufacturing route to produce biodegradable Mg-based implants196CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP405054/2016-52018/10190-

Disease resistance and spring phenological characteristics of Ribes L. germplasm

North American cultivation of Ribes L. may expand as small fruit growers seek species to diversify horticultural crops. The Ribes industry was suppressed for decades out of fear that cultivated black currants and gooseberries would intensify the fungal disease white pine blister rust (WPBR) on five-needle pine (Pinus L. section Quinquefoliae) species. These pines were historically vital to the timber industry. Today, plant breeders seek to strengthen the Ribes small fruit industry through production of material suitable for North American conditions. Paramount to this effort is the development of resistance against major pests and diseases. Growers must be able to recognize the attributes of available genotypes prior to field establishment. The objectives of this research were to determine disease resistance and phenological characteristics of Ribes selections at the United States Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository (NCGR) in Corvallis, Oregon. Since the early 1930's, plant breeders have used immune black currant (R. nigrum L.) germplasm as a control tactic against the exotic WPBR, caused by the basidiomycete fungus Cronartium ribicola J.C. Fischer. In 1999, a seedling population was generated at the NCGR from a cross involving susceptible pistillate R. nigrum 'Ben Lomond' and immune staminate parent R. ussuriense Jancz. x R. nigrum 'Consort.' To test the inheritance of resistance in the F₁ population, aeciospore and urediniospore treatments were applied in 2008 to single-leaf softwood cuttings under controlled conditions in a greenhouse. Resistant F₁ phenotypes segregated in a 1:1 ratio consistent with the pattern of simple dominant inheritance of a single gene. Artificial inoculations testing aeciospore and urediniospore infectivity produced equivalent disease severity in the experimental Ribes genotypes. Resistance to the native powdery mildew fungus, Podosphaera mors-uvae (Schwein.) U. Brown and S. Takamatsu, was also evaluated in the F₁ population. Individuals segregated for resistance in a 1:3 ratio after exposure to elevated disease pressure in the greenhouse. Fifteen F₁ genotypes were resistant to both fungal pathogens and are candidates for further breeding trials. In a second study, five years of spring phenological survey data were analyzed using a growing degree-day (GDD) model, with the objective to identify cultivars adapted to North American conditions. Ribes section Calobotrya was the earliest group to reach "first bloom," followed sequentially by R. [superscript]xnidigrolaria Bauer hybrid species, section Symphocalyx, section Grossularia, section Ribes, and lastly, section Botrycarpum. Early and late-flowering accessions were identified for each taxon

Reinforcement learning in large, structured action spaces: A simulation study of decision support for spinal cord injury rehabilitation

Reinforcement learning (RL) has helped improve decision-making in several applications. However, applying traditional RL is challenging in some applications, such as rehabilitation of people with a spinal cord injury (SCI). Among other factors, using RL in this domain is difficult because there are many possible treatments (i.e., large action space) and few patients (i.e., limited training data). Treatments for SCIs have natural groupings, so we propose two approaches to grouping treatments so that an RL agent can learn effectively from limited data. One relies on domain knowledge of SCI rehabilitation and the other learns similarities among treatments using an embedding technique. We then use Fitted Q Iteration to train an agent that learns optimal treatments. Through a simulation study designed to reflect the properties of SCI rehabilitation, we find that both methods can help improve the treatment decisions of physiotherapists, but the approach based on domain knowledge offers better performance. Our findings provide a "proof of concept" that RL can be used to help improve the treatment of those with an SCI and indicates that continued efforts to gather data and apply RL to this domain are worthwhile.Comment: 31 pages, 7 figure

The Mississippi River System Shallow Draft Barge Market – Perfectly Competitive or Oligopolistic?

Most transportation textbooks and articles on inland waterway navigation assume a perfectly competitive Mississippi River system barge industry. One study found the 1972 and 1977 grain barge industry to be oligopolistic. A second study of the U.S. barge industry found "intra industry competition for the barge industry on a day-to-day basis with easy entry and exit." Using the concentration ratio and the Herfindahl Index, this study found the Mississippi River barge industry to be oligopolistic. These results suggest that Mississippi River navigation infrastructure studies should not use long run marginal barge costs as a proxy for barge rates