Effects of Boron Purity, Mg Stoichiometry and Carbon Substitution on Properties of Polycrystalline MgB2_{2}

By synthesizing MgB$_{2}$ using boron of different nominal purity we found values of the residual resistivity ratio ($RRR = R(300 K) / R(42 K)$) from 4 to 20, which covers almost all values found in literature. To obtain high values of $RRR$, high purity reagents are necessary. With the isotopically pure boron we obtained the highest $RRR \sim$ 20 for the stoichiometric compound. We also investigated Mg$_{x}$$^{11}$B$_{2}$ samples with 0.8 $< x <$ 1.2. For the range Mg$_{0.8}$$^{11}$B$_{2}$ up to Mg$_{1.2}$$^{11}$B$_{2}$ we found average values of $RRR$ between 14 and 24. For smaller variations in stoichiometry ($x=1\pm 0.1$) $RRR = 18 \pm 3$. All of our data point to the conclusion that high $RRR$ ($\sim 20$) and low $\rho_{0}$ ($\leq 0.4 \mu \Omega cm$) are intrinsic material properties associated with high purity MgB$_{2}$. In addition we have performed initial work on optimizing the formation of carbon doped MgB$_{2}$ via the use of B$_{4}$C. Nearly single phase material can be formed by reaction of nominal Mg(B$_{0.8}$C$_{0.2}$)$_{2}$ for 24 hours at $1200^{\circ}C$. The $T_{c}$ for this composition is between $21.9 K$ and $22.7 K$ (depending on criterion).Comment: accepted to Physica C, special MgB2 issu

Segregation Effects According to the Evolutionary Stage of Galaxy Groups

We study segregation phenomena in 57 groups selected from the 2PIGG catalog of galaxy groups. The sample corresponds to those systems located in areas of at least 80% redshift coverage out to 10 times the radius of the groups. The dynamical state of the galaxy systems was determined after studying their velocity distributions. We have used the Anderson-Darling test to distinguish relaxed and non-relaxed systems. This analysis indicates that 84% of groups have galaxy velocities consistent with the normal distribution, while 16% of them have more complex underlying distributions. Properties of the member galaxies are investigated taking into account this classification. Our results indicate that galaxies in Gaussian groups are significantly more evolved than galaxies in non-relaxed systems out to distances of about 4R200, presenting signficantly redder (B-R) color. We also find evidence that galaxies with M_R < -21.5 in Gaussian groups are closer to the condition of energy equipartition.Comment: 5 pages, 4 figures, accepted for publication in the MNRAS Letter

Apparent diffusion coefficient in the analysis of prostate cancer

The multiparametric magnetic resonance imaging (MPMRI) approach, has allowed the diagnostic performance in the detection and characterization of prostate cancer (PCa). Diffusion-weighted imaging (DWI), is an important technique in the MPMRI, that provides qualitative and quantitative biological information regarding water diffusivity in a non-invasive manner. The apparent diffusion coefficient (ADC) measures water mobility and can be quantified from the signal intensity loss between two or more b-values. Different studies reported that ADC values are directly associated with microvessel density and cellularity. One of the main aspects that is in discussion is the b-values that must be used in the DWI sequence in order to compute ADC.info:eu-repo/semantics/publishedVersio

Functional and Immunological Relevance of Anaplasma marginale Major Surface Protein 1a Sequence and Structural Analysis.

Bovine anaplasmosis is caused by cattle infection with the tick-borne bacterium, Anaplasma marginale. The major surface protein 1a (MSP1a) has been used as a genetic marker for identifying A. marginale strains based on N-terminal tandem repeats and a 5'-UTR microsatellite located in the msp1a gene. The MSP1a tandem repeats contain immune relevant elements and functional domains that bind to bovine erythrocytes and tick cells, thus providing information about the evolution of host-pathogen and vector-pathogen interactions. Here we propose one nomenclature for A. marginale strain classification based on MSP1a. All tandem repeats among A. marginale strains were classified and the amino acid variability/frequency in each position was determined. The sequence variation at immunodominant B cell epitopes was determined and the secondary (2D) structure of the tandem repeats was modeled. A total of 224 different strains of A. marginale were classified, showing 11 genotypes based on the 5'-UTR microsatellite and 193 different tandem repeats with high amino acid variability per position. Our results showed phylogenetic correlation between MSP1a sequence, secondary structure, B-cell epitope composition and tick transmissibility of A. marginale strains. The analysis of MSP1a sequences provides relevant information about the biology of A. marginale to design vaccines with a cross-protective capacity based on MSP1a B-cell epitopes

Antibiosis in Ascia monuste orseis Godart (Lepidoptera: Pieridae) caused by kale genotypes

Ascia monuste orseis (Lepidoptera: Pieridae) is one of the main insect pests of kale. The study was done to  identify kale varieties resistant to A. monuste orseis by the antibiosis resistance mechanism. Kale genotypes (26) were evaluated in experiments performed at the Laboratory of Agricultural Entomology of Goiano Federal Institute - Campus Urutaí. A completely randomized experimental design with 50 replicates was used. The biological parameters evaluated were (a) larval stage: development time, instars, viability and larval weight 15 days after hatching; (b) pupal stage: development time, weight of 24-h-old pupae, viability; (c) larvae-adult stage: development time and viability. The genotypes Gigante I-915 and Pires 1 de Campinas have antibiosis resistance. Gigante I-915 caused high larval mortality and Pires 1 de Campinas resulted in low larval and pupal viability of A. monuste orseis.Key words: Brassica oleracea L. var. acephala, Brassicaceae, Great Southern White, host plant resistance, integrated pest management (IPM)

Tuberculose: limites e potencialidades do tratamento supervisionado

Objetivou-se analisar potencialidades e limites da estratégia do tratamento supervisionado (DOTS) para a tuberculose, sob a percepção de usuários em tratamento e de trabalhadores de saúde de uma supervisão técnica de saúde do município de São Paulo. Entrevistaram-se 4 usuários e 17 profissionais de saúde de nove unidades básicas de saúde, entre abril e junho de 2006, após consentimento livre e esclarecido. Os depoimentos foram decodificados segundo a técnica de análise de discurso. Adotou-se a teoria da determinação social do processo saúde/doença como referencial teórico. Foram potencialidades: criação de vínculo entre profissional/usuário e incentivos ao tratamento, o que favorece a adesão. Foram limites: restrito envolvimento dos profissionais no DOTS e conciliar horário de trabalho do usuário com a supervisão. Reitera-se que a adesão ao tratamento transcende o âmbito biológico, sendo fundamental que os trabalhadores de saúde reconheçam os usuários como portadores de necessidades, não se restringindo apenas à supervisão da tomada de medicamentos.Se objetivó analizar potencialidades y límites de la estrategia del Tratamiento Supervisado (DOTS) para la tuberculosis bajo la percepción de los usuarios en tratamiento y de los trabajadores de la salud de una Supervisión Técnica de Salud del Municipio de Sao Paulo. Se entrevistaron 4 usuarios y 17 profesionales de salud de nueve Unidades Básicas de Salud, entre abril y junio de 2006, después del consentimiento libre e informado. Las declaraciones fueron decodificadas según la técnica de análisis de discurso. Como marco teórico se adoptó la Teoría de la Determinación Social del Proceso Salud-Enfermedad. Las potencialidades encontradas fueron la creación de vínculo entre profesional/usuario y los incentivos al tratamiento, los que favorece la adhesión. Los límites fueron el reducido envolvimiento de los profesionales en el DOTS y el conciliar el horario de trabajo del usuario con la supervisión. Se reitera que la adhesión al tratamiento transciende el ámbito biológico, siendo fundamental que los trabajadores de la salud reconozcan a los usuarios como portadores de necesidades, que no se restringen a la supervisión de la ingesta de los medicamentos.This study analyzed the limitations and strengths of the Directly Observed Treatment Short-Course (DOTS) for tuberculosis from the perspective of patients and healthcare providers in a Technical Health Supervision unit in the city of São Paulo, SP, Brazil. Four patients and 17 healthcare providers from nine Primary Care Units were interviewed from April to June 2006, after signing free and informed consent forms. The reports were decoded according to the speech analysis technique. The Theory of the Social Determination of the Health-Disease Process was adopted as the theoretical framework. The strengths were: establishment of bonds between healthcare providers and patients and the introduction of incentives, which promotes treatment adherence. Limitations included: restricted involvement of DOTS' healthcare providers and reconciling patients' working hours with supervision. Treatment adherence goes beyond the biological sphere and healthcare providers should acknowledge patients' needs that go beyond the supervision of medication taken

Mantle-like Sr-Nd isotope composition of Fe-K subalkaline granites : the Peneda-Gerês Variscan massif (NW Iberian Peninsula)

The Peneda-Gerês massif is one of the most representative NW Iberian late- to post-orogenic Variscan granitic plutons. It resulted essentially from the subsynchronous emplacement, at 290-296 Ma, of two granitic magmas of Fe-K subalkaline affinity, with primitive isotopic composition: Sri = 0.703-0.707 and eNdi = -1.5 to -2.4. An origin by mantle input followed by mantle-crust interactions is proposed, implying the contribution of a less enriched mantle component than that involved in the genesis of syn-orogenic hybrid granitoids of Mg-K subalkaline affinity. A less voluminous aluminopotassic and isotopically more evolved magma (Sri = 0.708-0.709 and eNdi = -3.5 to –3.9) with little or no mantle input was also generated, suggesting the involvement of lower crust materials. Therefore, this study suggests an input of juvenile magmas in late-Variscan times, the mantle-like isotope signature of Fe-K granitic magmatism being clearly related to a geodynamic setting of extensional processes, large-scale uplift and thinning