Genetic salivary protein polymorphism in Mexican population

Genetic polymorphism is the major contributor that affects human salivary composition. In order to determine the molecular phenotypes in saliva, it is important to know the distribution of proteins with specific functions which allows the clinical diagnosis of specific diseases. Unstimulated human whole saliva samples from 120 subjects were subjected to sodium dodecyl sulfate polyacrylamide slab gel electrophoresis (SDS-PAGE). The phenotype distribution of several molecules including MG1, MG2, alpha-Amylase, PRP-I and cystatins were similar. Qualitative and quantitative characteristics were specific in each subject.     

Sequence and mutational analysis of the common nodBCIJ region of Rhizobium sp. (Oxytropis arctobia) strain N33, a nitrogen-fixing microsymbiont of both arctic and temperate legumes

By heterologous hybridization, we have identified the common nodulation genes nodBCIJ of Rhizobium sp. strain N33 within a 8.2-kb PstI fragment. The nodBCIJ genes are located within a 4,620-bp region which also included a consensus nod box promoter. The four open reading frames coding for the nodBCIJ genes contain 657, 1,353, 915, and 789 nucleotides, respectively. We found that the nodA gene was not adjacent to the nodB gene, unlike the situation in many rhizobia. The DNA of the nodBCIJ genes of Rhizobium sp. strain N33 were found to be homologous to the corresponding genes of other rhizobia except for the 3'-coding region of the nodC gene. The deduced NodC protein was the longest of the rhizobia except Bradyrhizobium japonicum. Tn5 mutagenesis of the common nod region of strain N33 revealed that the nodBC genes were essential for nodulation on their temperate hosts Onobrychis viciifolia and Astragalus cicer. By contrast, mutations in the nodI and nodJ genes produced a Nod+ phenotype with a reduced number of nodules on the temperate hosts. Nodules formed on Onobrychis viciifolia by either nodI or nodJ mutants were approximately 10 times smaller than nodules formed by the wild type strain: this reduction in nodule size was not observed on Astragalus cicer.     

Severity-of-illness scores for neutropenic cancer patients in an intensive care unit: Which is the best predictor? Do multiple assessment times improve the predictive value?

C57BL/6 mice genetically deficient in interleukin-5 (IL-5-/-) and normal C57BL/6 (IL-5+/+) mice were infected with larvae of a homogonic strain of the nematode Strongyloides ratti. In primary infections both male and female IL-5-/- mice released two to four times more eggs and larvae than IL-5+/+ mice. IL-5-/- mice harboured about 60% more intestinal worms, which were more fecund, than IL-5+/+ mice. The duration of the infection was similar in normal and IL-5-deficient mice. Both IL-5-/- and IL-5+/+ mice resisted a secondary infection. IL5-/- mice lost more weight during the infection than normal mice and took longer to regain their initial weight after expelling the worms. The number of eosinophils increased in the bone marrow, peritoneal cavity and small intestine of IL-5+/+ mice, but not IL-5-/- mice, following infection. No significant differences between infected IL-5+/+ and IL-5-/- mice in mast cells or other leucocytes were observed in the peritoneal cavity. Thus, IL-5 functions to protect the host in a primary infection of S. ratti by limiting the number and fecundity of worms establishing in the small intestine. This protection is correlated with elevated blood and tissue eosinophilia which occurs in normal mice but not in IL-5-/- mice.     

Biological system for improving the availability of Tilemsi phosphate rock for wheat (Triticum aestivum L.) cultivated in Mali

The Tilemsi phosphate rock (TPR) of Mali is a good and cheaper alternative to imported phosphate fertilizers. Many soil microorganisms can also mobilize sparingly soluble inorganic phosphates, and several have a good potential to improve plant growth. With the aim of improving the response of wheat cultivated in Mali to fertilization with TPR, in this work we describe the isolation and selection from four different Malian soils of TPR-solubilizing microorganisms (TSM) with high P-mobilization activities. When the rhizosphere of three wheat cultivars (Alkama Beri, Hindi Tossom and Tetra) was used to isolate TSM, only bacterial isolates were selected. TPR-solubilizing fungi were only obtained by soil enrichment in liquid medium containing TPR as sole P source. In the rhizosphere a significant correlation was observed between the total microbial population and the number of microorganisms solubilizing TPR. No such correlation was observed in the rhizoplane. Initially 44 bacteria and 18 fungi were selected, but after 10 subcultures on agar plates and a liquid medium, only 6 bacteria and 2 fungi retained their high P solubilizing trait. A field inoculation trial was established during the growing season 2000–2001 in Koygour. Wheat cv. Tetra was inoculated with the 8 selected TSM (6 bacteria and 2 fungi) and fertilized with 30 kg ha⁻¹ P added as TPR or diammonium phosphate. The growth parameters measured were plant height at 30 and 60 days, the number of leaves per main stem at 60 days, and root and shoot dry matter yields 60 days after planting. Root colonization by indigenous arbuscular mycorrhizas (AM) was also measured in 45 day-old plants. Significant interactions were observed between TSM inoculation and P-fertilization for root colonization with AM, plant height at 30 days and root dry matter yield. The bacterial isolate Pseudomonas sp. BR2, which appeared to be a mycorrhiza helper bacterium, significantly enhanced wheat seedling emergence very early (5 days after planting) under field condition, and caused 128% increase in root dry matter yield. The two TPR-solubilizing fungal isolates Aspergillus awamori Nakazawa C1 and Penicillium chrysogenum Thom C13 also caused respectively 60 and 44% increases in root dry matter yields. The choice of the TSM BR2, C1 and C13 for further field trials is discussed. This article was previously published in Nutrient Cycling in Agroecosystems Volume 72/2 pages 147–157. The online version of the original article can be found at .     

Electron enrichment in 3d transition metal oxide hetero-nanostructures

Direct experimental observation of spontaneous electron enrichment of metal d orbitals in a new transition metal oxide heterostructure with nanoscale dimensionality is reported. Aqueous chemical synthesis and vapor phase deposition are combined to fabricate oriented arrays of high-interfacial-area hetero-nanostructures comprised of titanium oxide and iron oxide nanomaterials. Synchrotron-based soft X-ray spectroscopy techniques with high spectral resolution are utilized to directly probe the titanium and oxygen orbital character of the interfacial region's occupied and unoccupied densities of states. These data demonstrate the interface to possess electrons in Ti 3d bands and an emergent degree of orbital hybridization that is absent in parent oxide reference crystals. The carrier dynamics of the hetero-nanostructures are studied by ultrafast transient absorption spectroscopy, which reveals the presence of a dense manifold of states, the relaxations from which exhibit multiple exponential decays whose magnitudes depend on their energetic positions within the electronic structure.     

Driving in an urban environment,the stress response and effects of exercise

Driving may be detrimental to health, with one hypothesis suggesting that driving may elicit an acute stress response and, with repeated exposures, may become a chronic stressor. The present study examined the stress response to driving and the effectiveness of a prior exercise bout in dampening this response. Twenty healthy adults performed three tasks: control, driving and exercise plus driving. Heart rate (HR), heart rate variability (HRV), blood pressure (BP) and cortisol were measured to quantify the acute stress response to each condition. Data indicated a stress response to driving: HR was elevated and HRV was reduced during the driving task compared with control. HR was elevated and HRV was reduced comparing the exercise plus driving with the driving condition. BP and cortisol were not different among conditions. The potential of interventions, such as exercise, to counter daily stressors should be evaluated to safeguard long-term health.

Practitioner Summary: this study confirms that driving induces a stress response, with the exercise intervention providing mixed results (an increase in cardiovascular measures and a decrease in cortisol measure trending significance). Given the known consequences of stress and evidence that exercise can mitigate acute stress, further evaluation of exercise interventions is recommended.     

Synthesis and electrical conductivity of AsF5-doped poly(arylene vinylenes)

Summary A series of polymers containing 2,5-disubstituted phenylene vinylene units, and the polymer containing 1,4-naphthalene vinylene units, were prepared by polymerization of their bis(sulfonium salts) through a base elimination reaction in solution. Films of these polymers were cast from aqueous solution and chemically treated (doped) with AsF₅ vapor. The electrically conductivities of the doped films varied greatly with changes in polymer structure, with the highest value obtained of 1.8 ohm^–1 cm^–1 for poly (2,5-dimethoxyphenylene vinylene).     

Zirconia matrix composite dispersed with stainless steel particles: Processing and oxidation behavior

Materials with non uniform properties are being developed to optimize several functions of industrial components in severe atmospheres at high temperature. These composites called M(p)-CMC(s): “ceramic matrix composites dispersed with metal particles” are candidates for high-temperature structure materials as functionally graded materials (FGMs) such as intermediate components between electrolyte and interconnecting components in SOFC.Preparation of a model composite M(p)-CMC(s) is described. Powder metallurgy process is used to obtain a dense composite (98% of the theoretical density) based on yttrium stabilized zirconia for the ceramic part and on 304L stainless steel for the metallic part. The characteristics of this material as well as its behavior under oxidation at high temperature are reported.     

Numerical simulation of cloud rise phenomena associated with nuclear bursts

We present numerical simulations of cloud evolution from nuclear explosions using high-resolution numerical methods. Our numerical approach includes a fluid mechanical model that is a combination of a compressible code (GEODYN) and a low Mach code (LMC). Early stages of nuclear explosions that are characterized by the blust wave propagation are simulated with an explicit code (GEODYN) that solves the compressible Navier–Stokes equations via a high-order Godunov scheme. As soon as the blust wave weakens (≈10 s) the subsequent cloud rise due to buoyancy forces can be effectively simulated by the LMC code. LMC is an implicit code based on a pressure projection technique, and derived from the compressible Navier–Stokes equations using an asymptotic analysis in Mach number. It analytically eliminates time step restrictions based on sound wave propagation and it is computationally efficient and accurate for simulations of cloud rise dynamics at later stages. We perform a series of cloud rise scenarios ranging from an idealized bubble rise problem to realistic air bursts. We analyze effects of compressible dynamics on cloud evolution at different stages. It is found that in a realistic configuration, interaction of the reflected shock wave from the ground with the fireball significantly affects cloud evolution, in contrast to the equivalent idealized bubble rise simulations. We validate the code predictions against available experimental data. It is demonstrated that, by providing the initial source from the compressible GEODYN code, late time flow evolution can be successfully simulated with the fast, efficient and accurate LMC code.     

Thermotropic Liquid Crystalline Polyesters with Rigid or Flexible Spacer Groups

Several different series of rigid and flexible polyesters with main chain liquid crystalline units were prepared and their properties were examined in relation to their structures. The first group of polymers were rigid aromatic copolyesters with mesogenic groups based on either chloro or methyl hydroquinone terephthalate units combined with varying amounts of different types of bisphenol terephthalate units The bisphenol comonomers used contained the structure: in which X was none, ? C(CH₃)₂? , ? CH₂? , ? O? , ? S? , and ? So₂? . It was observed that the bisphenols with the bulkier X group were more efficient in destroying thermotropic liquid crystallinity of the resulting copolymers. The second group of polymers studied were flexible polyesters consisting of various types of mesogenic units which were connected together by different lengths of polymethylene flexible spacers. The liquid crystalline behaviours of these polymers, particularly their transition temperatures, were correlated with their structures. A brief review of previous studies on the synthesis of thermotropic liquid crystalline polyesters is included.