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The goal of the present paper is to search for natural trajectories that can be used to place a spacecraft to observe the triple asteroid 2001SN263. For a first set of observations mid-range distance orbits are ideal. To model this triple asteroid from a mid-range distance, it is considered that it can be modeled as a single ellipsoid body, which gives a simple mathematical model that allows on-board computation of trajectories. The mass is assumed to be equal to the sum of the masses of the three bodies and its dimensions are calculated considering the size of the orbits of Beta and Alpha. The objective is to search for orbits that can be used at the arrival time of the spacecraft in the vicinity of the triple asteroid to observe the bodies to make a better evaluation of their dimensions and dynamics before a good choice for a final orbit can be made. The two-dimensional elliptic restricted three-body problem is used as the mathematical model with the addition of the perturbations coming from the asteroid and the Sun irregular gravity fields (J2). It is also considered the disturbance caused by the solar radiation pressure, a major force near asteroids. [ABSTRACT FROM AUTHOR]

This paper has the goal of searching for natural trajectories that can be used for a particle or a spacecraft coming from a region of the space far from Jupiter system to be captured into this system by making close approaches with the Galilean satellites of the planet. The opposite situation is also possible and escape trajectories can also be found. This type of maneuver is called 'Swing-By' and it is usual in astrodynamics. It was used in many space missions to reduce the fuel consumption by gaining or loosing energy from the gravity of a celestial body. Several famous examples are the Voyager, Cassini, Galileo and other missions. The idea of the present research is to study this type of maneuver using the Galilean satellites of Jupiter, to search for trajectories that change the two-body energy (particle or spacecraft)-(Jupiter) from positive to negative (a capture trajectory) or from negative to positive (an escape trajectory). Those trajectories can be used for a spacecraft going or leaving the planet Jupiter or to explain how particles can be captured or escape from Jupiter system by close approaches with the Galilean satellites. Initial conditions are varied to cover the whole possible alternatives and then small regions of captures and escapes are identified. After that, a study is made to see the accuracy of the Tisserand's method when applied to those close approach trajectories. [ABSTRACT FROM AUTHOR]

We analyzed two West African samples (Guinea-Bissau: n=289 cases and 322 controls; The Gambia: n=240 cases and 248 controls) to evaluate single-nucleotide polymorphisms (SNPs) in Epiregulin (EREG) and V-ATPase (T-cell immune regulator 1 (TCIRG1)) using single and multilocus analyses to determine whether previously described associations with pulmonary tuberculosis (PTB) in Vietnamese and Italians would replicate in African populations. We did not detect any significant single locus or haplotype associations in either sample. We also performed exploratory pairwise interaction analyses using Visualization of Statistical Epistasis Networks (ViSEN), a novel method to detect only interactions among multiple variables, to elucidate possible interaction effects between SNPs and demographic factors. Although we found no strong evidence of marginal effects, there were several significant pairwise interactions that were identified in either the Guinea-Bissau or the Gambian samples, two of which replicated across populations. Our results indicate that the effects of EREG and TCIRG1 variants on PTB susceptibility, to the extent that they exist, are dependent on gene-gene interactions in West African populations as detected with ViSEN. In addition, epistatic effects are likely to be influenced by inter- and intra-population differences in genetic or environmental context and/or the mycobacterial lineages causing disease. [ABSTRACT FROM AUTHOR]

To assess easily monitored predictors for tuberculosis mortality. Risk factors for tuberculosis mortality were assessed during the 8-month treatment in 440 men and 269 women diagnosed with confirmed or presumed intrathoracic tuberculosis included prospectively in Guinea-Bissau from May 1996 to April 2001. A civil war occurred in the study area from June 1998 to May 1999. 12% were HIV-1 positive, 16% HIV-2 positive and 7% were HIV dually infected. Case fatality rates for HIV positive were higher during (35% [22/63]) and after the war (29% [27/92]) compared to before the war (17% [15/88]). The war did not have an effect on the case fatality rate in HIV negative (10% [13/135] before the war). HIV-1-infected patients had higher mortality than HIV-2 infected, mortality rate ratio (MRR) = 2.28 (95% confidence interval 1.17–4.46). Men had higher mortality than women but only among the HIV negative (MRR = 2.09 [0.95–4.59]). Hence, the negative impact of HIV infection on mortality was stronger in women (MRR = 6.51 [2.98–14.2]) than in men (MRR = 2.64 [1.67–4.17]) (test of homogeneity, p = 0.051). Anergy to tuberculin was associated with death in HIV positive (MRR = 2.77 [1.38–5.54]) but not in HIV negative (MRR = 1.14 [0.52–2.53]). Signs of immune deficiency, such as oral candida infection or leukoplakia (MRR = 4.25 [1.92–9.44]) and diarrhea (MRR = 2.15 [1.29–3.58] was associated with mortality in HIV positive. Tendencies were similar among HIV negative. HIV-positive relapse cases were at increased risk of dying (MRR = 2.42 [1.10–5.34]). Malnutrition, measured through mid-upper arm circumference (MUAC), increased the risk of death. Easily monitored predictors for mortality in tuberculosis patients include clinical signs of immune deficiency and low MUAC. [ABSTRACT FROM AUTHOR]

Plants exude a variety of substances through their external surfaces and from germinating seeds, some of which have an inhibitory action against plant pathogens. The aim of this study was the investigation and characterization of defense proteins present in exudates from roots of cowpea seedlings (Vigna unguiculata(L.) Walp.). Root exudates were collected from seedlings that were grown hydroponically in three different media, including, 100 mM sodium acetate buffer pH 4.5, water pH 6.0 and 100 mM sodium phosphate buffer pH 7.5. The proteins from these exudates were analyzed by SDS-PAGE and SDS-Tricine-PAGE and the presence of antimicrobial proteins in the exudates was investigated by immunological and enzymatic assays. Results showed that roots from cowpea seedlings containedß-1,3-Glucanases, chitinases and lipid transfer proteins (LTPs), all of which may potentially function as plant defense proteins. Immunolocalization of one of these proteins, chitinase, revealed its presence in the xylem cell wall vessel elements. These exudates also demonstrated an inhibitory effect on the growth of the fungus,Fusarium oxysporum,in vitro. The results suggest that plant roots may exude a variety of proteins that may function to repress the growth of root pathogenic fungi. [ABSTRACT FROM AUTHOR]

A lectin with a high affinity for glucose/mannose was isolated from Annona muricata seeds (Annonaceae) by gel filtration chromatography on Sephacryl S-200, ion exchange chromatography on a DEAE SP-5 PW column, and molecular exclusion on a Protein Pak Glass 300 SW column. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (PAGE) yielded two protein bands of approximately 14 kDa and 22 kDa. However, only one band was seen in native PAGE. The Mr of the lectin estimated by fast-performance liquid chromatography-gel filtration on Superdex 75 was 22 kDa. The lectin was a glycoprotein with 8% carbohydrate (neutral sugar) and required divalent metal cations (Ca2+, Mg2+, and Mn2+) for full activity. Amino acid analysis revealed a large content of Glx, Gly, Phe, and Lys. The lectin agglutinated dog, chicken, horse, goose, and human erythrocytes and inhibited the growth of the fungi Fusarium oxysporum, Fusarium solani, and Colletotrichum musae. [ABSTRACT FROM AUTHOR]

Glass and glass ceramics were obtained using steelwork slag as a raw material. Glass was melted at 1500°C and heat treatments were performed at 720°C for nucleation and at 883°C for crystallization. Differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM), with energy dispersive X-ray spectrometer (EDX) were used to investigate glass and glass ceramics. The crystalline phases developed were diopside and augite. The final microstructure was made up of crystals uniformly distributed, with a size of 1 to 3.5 μm. [ABSTRACT FROM AUTHOR]

Two cases of mucoepidermoid carcinoma (MEC) of the larynx are reported. The peculiarities of both cases are emphasized, in particular the site of involvement and the young age of the former and the histological subtype ('clear cell' variant) of the latter. The microscopic differential diagnosis of MEC and its biological behavior according to the grade of differentiation is discussed. The available literature is reviewed. [ABSTRACT FROM AUTHOR]

Selenium (Se) is a contaminant of concern in environments affected by discharges from smelting and coal-burning industries. Experiments have been performed to investigate the phase associations of selenium in contaminated sediments under a range of controlled redox conditions. In this study, Se sediment associations were examined using the BCR sequential extraction technique after stabilisation at different redox states. It was shown that although most of the sediment-bound Se is associated with the operationally-defined 'organic/sulfide' fraction, as the measured redox potential of the system is increased, more Se moves into the 'exchangeable' and 'iron/manganese oxyhydroxide' fractions. In these fractions, contaminants can be expected to be more bioavailable. As the mass of Se absorbed to sediments is typically atleast an order of magnitude higher than the mass dissolved in porewaters, significant Se exposure may result from oxidative shifts in Se associations. [ABSTRACT FROM AUTHOR]