Energy evaluation of forest residues originated from pine in Galicia

Pine residues originated from cuts and forestry tasks were studied with the main objective of using them as an alternative source of energy. Calorific values were measured using a static bomb calorimeter in an oxygen atmosphere. From these measurements a value of 7500 kJkg(-1) for the mean lower heating value of these kind of residues was found. A rational and sustainable exploitation of the calorific energy contained in these residues can yield a gross benefit of 2.8 x 10(8) per year through its transformation in electric energy. The study was made along one year, using samples collected in different previously characterized zones. Some other parameters such as: elementary composition, heavy metal content, flammability, and bioclimatic properties were also determined.     

Bioengineered chondrocyte sheets may be potentially useful for the treatment of partial thickness defects of articular cartilage

Some treatments for full thickness defects of articular cartilage, such as cultured chondrocyte transplantation, have already been done. However, to overcome osteoarthritis, we must further study the partial thickness defect of articular cartilage. It is much more difficult to repair a partial thickness defect because few repairing cells can address such injured sites. We herein show that bioengineered layered chondrocyte sheets using temperature-responsive culture dishes may be a potentially useful treatment for partial thickness defects. We evaluated the property of these sheets using real-time PCR and histological findings, and allografted these sheets to evaluate the effect of treatment using a rabbit partial model. In conclusion, layered chondrocyte sheets were able to maintain the cartilageous phenotype, and could be attached to the sites of cartilage damage which acted as a barrier to prevent a loss of proteoglycan from these sites and to protect them from catabolic factors in the joint.     

中国青少年劳累尔指数发育曲线的地区差异分析

在１９８５年全国学生体质与健康调查资料基础上运用多元分析方法作再分析。首先利用因子分析集中概括男女各５６个地区,城乡青少年群体劳累尔指数发育曲线上的主要差异;再利用Ｑ聚类分析,将这些样本按不同发育特点归纳成若干类;利用多项式拟合方程,绘制各类劳累尔指数发育曲线,为不同地区制订营养评价标准提供科学依据。     

Gene expression in response to multiple nutrient-starvation conditions in Salmonella typhimurium

Abstract In nature, bacteria encounter a variety of environmental conditions, among the most frequent of these is the limitation or starvation of one or more essential nutrients. It is reasonable to assume, therefore, that bacteria have evolved mechanisms to enhance their survival over prolonged periods of nutrient starvation. We have identified eight genetic loci in the enteropathogen Salmonella typhimurium , using Mu d -directed lacZ operon fusion technology, that were induced in response to two or more different starvation conditions (sti) . In simultaneous studies, we also identified genetic loci, using Mu d-lac fusions, which respond to only phosphate-starvation conditions (psi) . We further characterized these loci as to their induction-characteristics, kinetics of induction, expression during growth on different carbon sources, and approximate location on the S. typhimurium genetic map. In concurrent studies, we analyzed whole cell extracts of S. typhimurium grown under a variety of nutrients oxydation conditions as well as under nonlimiting conditions, using two-dimensional polyacrylamide gel electrophoresis. Results from these studies correlated well with our gene fusion studies. In more recent studies, we have demonstrated a complex genetic regulation of a number of these starvation-inducible loci, and have implicated at least four of these loci in the long term starvation-survival of S. typhimurium .     

Contribution of the plasma membrane and central vacuole in the formation of autolysosomes in cultured tobacco cells

Autolysosomes accumulate in tobacco cells cultured under sucrose starvation conditions in the presence of a cysteine protease inhibitor. We characterized these plant autolysosomes using fluorescent dyes and green fluorescent protein (GFP). Observation using the endocytosis markers, FM4-64 and Lucifer Yellow CH, suggested that there is a membrane flow from the plasma membrane to autolysosomes. Using these dyes as well as GFP-AtVam3p, sporamin-GFP and gamma-VM23-GFP fusion proteins as markers of the central vacuole, we found transport of components of the central vacuole to autolysosomes. Thus endocytosis and the supply from the central vacuole may contribute to the formation of autolysosomes.     

<Emphasis Type="Italic">Ab initio</Emphasis> gene identification: Prokaryote genome annotation with GeneScan and GLIMMER

We compare the annotation of three complete genomes using theab initio methods of gene identification GeneScan and GLIMMER. The annotation given in GenBank, the standard against which these are compared, has been made using GeneMark. We find a number of novel genes which are predicted by both methods used here, as well as a number of genes that are predicted by GeneMark, but are not identified by either of the nonconsensus methods that we have used. The three organisms studied here are all prokaryotic species with fairly compact genomes. The Fourier measure forms the basis for an efficient non-consensus method for gene prediction, and the algorithm GeneScan exploits this measure. We have bench-marked this program as well as GLIMMER using 3 complete prokaryotic genomes. An effort has also been made to study the limitations of these techniques for complete genome analysis. GeneScan and GLIMMER are of comparable accuracy insofar as gene-identification is concerned, with sensitivities and specificities typically greater than 0.9. The number of false predictions (both positive and negative) is higher for GeneScan as compared to GLIMMER, but in a significant number of cases, similar results are provided by the two techniques. This suggests that there could be some as-yet unidentified additional genes in these three genomes, and also that some of the putative identifications made hitherto might require re-evaluation. All these cases are discussed in detail.     

Expression Profile Analysis of Neurodegenerative Disease: Advances in Specificity and Resolution

Microarray technology has become a common tool for developing expression profiles. Initially used in the analysis of cells lines and homogeneous tissues, this platform has been applied to more diverse tissues, such as the brain. Several neural disorders have already been profiled by microarrays using relatively large amounts of tissue. This data has unveiled many genes with differential expression between normal and diseased tissue that could potentially be used as gene markers for these afflictions. Because of the heterogeneity of the CNS, it is likely that small differences between gene expression in these studies would be enhanced by the sampling of a subset of cells based on these newly characterized gene markers. Subtraction of normal, unaffected cells from the sample may also result in a more accurate profile of a diseased cell. Expression profile studies from several neuropathological states are presented, with emphasis placed on those studies using small samples of cellular material and those using specialized methods of cell isolation and RNA amplification.     

Lectin interactions with the variant surface glycoprotein from Trypanosoma brucei brucei incorporated into liposomes

The variant specific surface glycoprotein from Trypanosoma brucei brucei is incorporated into lipid vesicles using 8M urea as an unfolding reagent. Pronase treatment of these proteoliposomes removes most of the protein, leaving a glycophospholipopeptide which is the membrane attachment site. We show here that lectins, specific for mannose and galactose are able to recognize oligosaccharide residues on these proteoliposomes, using a straightforward aggregation assay. The relevance of these results obtained with the liposome model system to the accessibility of the surface antigens in living trypanosomes is discussed.     

Immunity to Onchocerca spp. in animal hosts

This review summarizes research using Onchocerca spp. in chimpanzees, cattle and mice to gain insight into the protective immune response to the filarial worm Onchocerca volvulus in humans. In addition, Acanthocheilonema viteae has been evaluated as a surrogate filarial worm for studying immunity to the infection. Immune mechanisms controlling these infections are described and initial success using recombinant antigen vaccines in these models is reviewed.     

Mechanical behavior of a new biphasic calcium phosphate bone graft

The aim of this study was to create a new porous calcium phosphate implant for use as a synthetic bone graft substitute. Porous bioceramic was fabricated using a foam-casting method. By using polyurethane foam and a slurry containing hydroxyapatite-dicalcium phosphate powder, water, and additives, a highly porous structure (66 ± 5%) was created. The porous specimens possess an elastic modulus of 330 ± 32 MPa and a compressive strength of 10.3 ± 1.7 MPa. The X-ray diffraction patterns show hydroxyapatite and beta-pyrophosphate phases after sintering. A rabbit model was developed to evaluate the compressive strength and elastic modulus of cancellous bone defects treated with these porous synthetic implants. The compressive mechanical properties became weaker until the second month post implantation. After the second month, these properties increased slightly and remained higher than control values. New bone formed on the outside surface and on the macropore walls of the specimens, as osteoids and osteoclasts were evident two months postoperatively. Considering these properties, these synthetic porous calcium phosphate implants could be applicable as cancellous bone substitutes.     

The molecular evolution of the allatostatin precursor in cockroaches

Allatostatins (ASTs) of the Tyr/Phe-Xaa-Phe-Gly Leu/Ile-NH2 family are a group of insect neuropeptides that inhibit juvenile hormone biosynthesis by the corpora allata. We have obtained genomic DNA sequences that specify the preproallatostatin precursor for the cockroaches, Blatta orientalis, Blattella germanica, Blaberus (cranufer and Supella longipalpa. The sequences obtained are similar to those of Diploptera punctata and Periplaneta americana reported previously. The precursors of all these cockroach species are similar in size, and the organization of the ASTs that they contain (there are 13 or 14, depending on the species) have been conserved. With the sequences of these precursors, and using the homologous sequence in the orthopteran Schistocera gregari as an outgroup, a phylogenetic analysis using parsimony was carried out. The dendrograms obtained from these analyses. using the amino acid as well as the nucleotide sequences, are comparable with current models for cockroach phylogeny. Parsimony analysis was also used to study the genealogy of the different ASTs within the same precursor. Results suggest that the AST sequences were generated through a process of internal gene duplication which occurred before these species diverged from each other in evolutionary time.     

Guard cell volume and pressure measured concurrently by confocal microscopy and the cell pressure probe

Guard cell turgor pressures in epidermal peels of broad bean (Vicia faba) were measured and controlled with a pressure probe. At the same time, images of the guard cell were acquired using confocal microscopy. To obtain a clear image of guard cell volume, a fluorescent dye that labels the plasma membrane was added to the solution bathing the epidermal peel. At each pressure, 17 to 20 optical sections (each 2 microm thick) were acquired. Out-of-focus light in these images was removed using blind deconvolution, and volume was estimated using direct linear integration. As pressure was increased from as low as 0.3 MPa to as high as 5.0 MPa, guard cell volume increased in a saturating fashion. The elastic modulus was calculated from these data and was found to range from approximately 2 to 40 MPa. The data allow inference of guard cell osmotic content from stomatal aperture and facilitate accurate mechanistic modeling of epidermal water relations and stomatal functioning.     

Artificial reproduction of the Yangtze field vole: in vitro embryo development and fertilization with fresh and freeze-thawed sperm

Several research groups are using the Yangtze field vole as a model for studying schistosome infection, but relatively little is known about the species's reproductive physiology. The authors examined the vole's in vivo and in vitro embryonic development as well as the efficacy of in vitro fertilization using either fresh or cryopreserved sperm to breed these rodents.     

Biodiesel production from waste cooking oil: 2. Economic assessment and sensitivity analysis

The economic feasibilities of four continuous processes to produce biodiesel, including both alkali- and acid-catalyzed processes, using waste cooking oil and the ‘standard’ process using virgin vegetable oil as the raw material, were assessed. Although the alkali-catalyzed process using virgin vegetable oil had the lowest fixed capital cost, the acid-catalyzed process using waste cooking oil was more economically feasible overall, providing a lower total manufacturing cost, a more attractive after-tax rate of return and a lower biodiesel break-even price. On the basis of these economic calculations, sensitivity analyses for these processes were carried out. Plant capacity and prices of feedstock oils and biodiesel were found to be the most significant factors affecting the economic viability of biodiesel manufacture.     

Infection in a dish: high-throughput analyses of bacterial pathogenesis

Diverse aspects of host-pathogen interactions have been studied using non-mammalian hosts such as Dictyostelium discoideum, Caenorhabditis elegans, Drosophila melanogaster and Danio rerio for more than 20 years. Over the past two years, the use of these model hosts to dissect bacterial virulence mechanisms has been expanded to include the important human pathogens Vibrio cholerae and Yersinia pestis. Innovative approaches using these alternative hosts have also been developed, enabling the isolation of new antimicrobials through screening large libraries of compounds in a C. elegans Enterococcus faecalis infection model. Host proteins required by Mycobacterium and Listeria during their invasion and intracellular growth have been uncovered using high-throughput dsRNA screens in a Drosophila cell culture system, and immune evasion mechanisms deployed by Pseudomonas aeruginosa during its infection of flies have been identified. Together, these reports further illustrate the potential and relevance of these non-mammalian hosts for modelling many facets of bacterial infection in mammals.     

Bioinformatics challenges of new sequencing technology

New DNA sequencing technologies can sequence up to one billion bases in a single day at low cost, putting large-scale sequencing within the reach of many scientists. Many researchers are forging ahead with projects to sequence a range of species using the new technologies. However, these new technologies produce read lengths as short as 35-40 nucleotides, posing challenges for genome assembly and annotation. Here we review the challenges and describe some of the bioinformatics systems that are being proposed to solve them. We specifically address issues arising from using these technologies in assembly projects, both de novo and for resequencing purposes, as well as efforts to improve genome annotation in the fragmented assemblies produced by short read lengths.     

Approaches to studying climatic change and its role on the habitat selection of antarctic pinnipeds

Top predators integrate resources over time and space, and depending on the particular species they represent, different components of the marine environment. The habitat utilization of top predators has been studied using electronic tags to follow their movements and foraging behavior. In addition, these tags provide information on the physical characteristics of the water column (temperature and salinity) at a scale and resolution that is coincident with the animals' behavior. In addition to data on the animals' behavior, these tags provide physical oceanographic data in regions or at times they cannot be collected using other currently available technologies. These data inform us on how these important top predators are likely to respond to climatic change, as well as about how the Southern Ocean is changing.     

Alcohol dehydrogenase expression as a biomarker of denitrification activity in activated sludge using methanol and glycerol as electron donors

Carbon sources such as methanol and glycerol are used for enhancing denitrification at wastewater treatment plants, which are required to meet increasingly stringent effluent nitrogen limits. Consequently, dosing strategies for these compounds could benefit from the development and application of molecular activity biomarkers to infer and distinguish between methanol- or glycerol-based denitrification in activated sludge. In this study, the applicability of genes coding for methanol dehydrogenase (mdh2 and mxaF) and glycerol dehydrogenase (dhaD) as potential biomarkers of denitrification activity using these specific substrates was explored and confirmed using a two-pronged approach. First, during short-term spikes of activated sludge biomass with glycerol, the ability of dhaD mRNA concentrations to closely track nitrate depletion profiles was demonstrated. Second, a high-degree of correlation of the mRNA concentrations of mdh2, mxaF and dhaD with methanol- and glycerol-based denitrification kinetics during long-term bioreactor operation using these substrates was also shown. Based on these results, expression of mdh2, mxaF and dhaD genes are promising biomarkers of in situ denitrification activity on methanol and glycerol, respectively, in mixed-culture engineered wastewater treatment processes.     

An evaluation of the reliability of the characterization of the porous structure of activated carbons based on incomplete nitrogen adsorption isotherms

The paper presents the results of research devoted to reliability evaluation of the analysis of results of the porous structure of activated carbons based on incomplete nitrogen adsorption isotherms using the BET, t-plot, and NLDFT methods, as well as the LBET method comprising the unique numerical fast multivariant procedure of adsorption system identification. The research involved the application of the nitrogen adsorption isotherms obtained for five samples of activated carbons produced from waste materials of organic origin by way of chemical activation with potassium hydroxide, sodium hydroxide, and potassium carbonate with the use of microwave heating. The analyses performed pointed to a good correlation between the results obtained using the BET, t-plot, NLDFT, and LBET methods. Moreover, the parameters of the porous structure determined using these methods based on incomplete adsorption isotherms of nitrogen are in fact as reliable as these methods allow.     

Studies on synthetic pathway of xylose-containing N-linked oligosaccharides deduced from substrate specificities of the processing enzymes in sycamore cells (Acer pseudoplatanus L.).

We measured the activities of alpha-1,3-mannosyl-glycoprotein beta-1,2-N-acetylglucosaminyltransferase, alpha-1,6-mannosyl-glycoprotein beta-1,2-N-acetylglucosaminyltransferase, beta-1,4-mannosyl-glycoprotein beta-1,2-xylosyltransferase and glycoprotein 3-alpha-L-fucosyltransferase in the Golgi fraction of suspension-cultured cells of sycamore (Acer pseudoplatanus L.) using fluorescence-labelled oligosaccharides as acceptor substrates for these transferase reactions. The structures of the pyridylaminated oligosaccharides produced by these reactions were analyzed by two-dimensional sugar mapping using high-performance liquid chromatography. We demonstrated that (formula; see text) was processed to produce by these in vitro reactions. On the basis of these results, we discuss a biosynthetic pathway for xylose containing N-linked oligosaccharides in plant glycoproteins.