256 research outputs found

    Growth of Chlorella vulgaris and Chlamydomonas reinhardtii for biodiesel production and carbon dioxide capture

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    The growth of two strains of green microalgae, Chlorella vulgaris (UTEX 2714) and Chlamydomonas reinhardtii (UTEX 90) was tested in three types of media; Tris Acetate Phosphate (TAP), Bushnell Haas Broth (BHB), and Wright\u27s Cryptophytes (WC buffered with either glycylglycine or Tris-base). Also, initial medium pH is ranging from 4 to 10, light intensity ranging from 100 to 600 micromol photons/m 2s, and CO2 concentrations ranging from 0.038% (ambient) to 12%, were tested. WC medium at pH 8 buffered with glycylglycine sustained the highest yield and best buffering capacity for growth of both C. vulgaris and C. reinhardtii. A light intensity of 200 micromol photons m-2s-1 provided for both good growth and electron transport rate (ETR). Both C. vulgaris and C. reinhardtii produced highest final yields when grown with 6% CO2. Also, lipid content increased with increasing CO2 concentration. Myristoleic acid (C14:1), palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1n9), linoleic acid (C18:2), and docosahexaenoic acid (DHA) were found in higher content when C. vulgaris was grown on 12% CO2, while the content of palmitoleic acid (C16:1), elaidic acid (C18:1t9), vaccenic acid (C18:1n7) were similar among all CO 2 concentration tested. CO2 capture was explored using two approaches: consumption of known quantities of CO2 in sealed serum bottles, and consumption of CO2 flowing through immobilized algal beads. In both cases, fixation rate decreased with increasing CO2 concentration. CO2 consumption generally decreased over the five day experiment. The rate observed using immobilized algae was 20% of the maximum obtained in liquid culture, indicating the need to future optimize this novel method for CO2 capture

    Research subjects studied by the Cluj accounting school in the „Brasov period”

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    This article focuses on the works published in the field of accounting during the Second World War and in the post-war period in Transylvania. More exactly, this work presents the research themes studied when the Academy of High Commercial and Industrial Studies, which was the first form of Higher education in the economic field in Transylvania, functioned in Brasov. We wanted to surprise in this paper the apparition of the Academy in Cluj, the reason of moving in Brasov and the “Brasov period”

    The Role of Oxidation Compounds in Biofilm Growth on Polyethylene Geomembrane Barriers Used in Landfill

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    In a model study, polyethylene was preoxidized and incubated for a period of 7 months at 40°C in two different municipal solid waste leachates. During the postexperimental analyses, specific attention was paid to the carbonyl species and carboxylic acid depletion during the environmental exposure because it is well known that carboxylic acids are believed to be a potential substrate for the development of microorganisms. The results showed that the carbonyl as well as the carboxylic acid depletion observed follows first-order kinetics. The biofilm formation was characterized using a suite of analytical techniques, and its formation was compared with the carboxylic acid and carbonyl depletion profil

    A High Density of Human Communication-Associated Genes in Chromosome 7q31-q36: Differential Expression in Human and Non-Human Primate Cortices

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    The human brain is distinguished by its remarkable size, high energy consumption, and cognitive abilities compared to all other mammals and non-human primates. However, little is known about what has accelerated brain evolution in the human lineage. One possible explanation is that the appearance of advanced communication skills and language has been a driving force of human brain development. The phenotypic adaptations in brain structure and function which occurred on the way to modern humans may be associated with specific molecular signatures in today’s human genome and/or transcriptome. Genes that have been linked to language, reading, and/or autism spectrum disorders are prime candidates when searching for genes for human-specific communication abilities. The database and genome-wide expression analyses we present here revealed a clustering of such communication-associated genes (COAG) on human chromosomes X and 7, in particular chromosome 7q31-q36. Compared to the rest of the genome, we found a high number of COAG to be differentially expressed in the cortices of humans and non-human primates (chimpanzee, baboon, and/or marmoset). The role of X-linked genes for the development of human-specific cognitive abilities is well known. We now propose that chromosome 7q31-q36 also represents a hot spot for the evolution of human-specific communication abilities. Selective pressure on the T cell receptor beta locus on chromosome 7q34, which plays a pivotal role in the immune system, could have led to rapid dissemination of positive gene variants in hitchhiking COAG

    Bullying homofóbico no contexto escolar em Portugal

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    O presente estudo pretendeu explorar o fenómeno do bullying homofóbico em Portugal relativamente à sua prevalência, consequências e formas de agressão. Mediante um questionário online, distribuído pelos núcleos locais da Associação rede ex aequo e preenchido por 184 estudantes, verificou­?se que, à semelhança de resultados internacionais, o recinto escolar é o local privilegiado para a ocorrência deste fenómeno. Os resultados indicam que prevalece a violência psicológica e a vitimização de rapazes; os comportamentos de agressão são desvalorizados; subsiste uma não intervenção nas situações presenciadas; existem consequências psicológicas significativas para as vítimas de bullying homofóbico, em comparação com as não­?vítimas. Defende­?se a importância de conceber programas de sensibilização, de criar medidas de protecção para as vítimas, e ainda de aprofundar a investigação desta temática.info:eu-repo/semantics/publishedVersio

    The cohesin ring concatenates sister DNA molecules

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    Sister chromatid cohesion, which is essential for mitosis, is mediated by a multi-subunit protein complex called cohesin whose Scc1, Smc1, and Smc3 subunits form a tripartite ring structure. It has been proposed that cohesin holds sister DNAs together by trapping them inside its ring. To test this, we used site-specific cross-linking to create chemical connections at the three interfaces between the ring’s three constituent polypeptides, thereby creating covalently closed cohesin rings. As predicted by the ring entrapment model, this procedure produces dimeric DNA/cohesin structures that are resistant to protein denaturation. We conclude that cohesin rings concatenate individual sister minichromosome DNAs

    Comparison of different methods for delayed post-mortem diagnosis of falciparum malaria

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    <p>Abstract</p> <p>Background</p> <p>Between 10,000 and 12,000 cases of imported malaria are notified in the European Union each year. Despite an excellent health care system, fatalities do occur. In case of advanced autolysis, the post-mortem diagnostic is impaired. Quicker diagnosis could be achieved by using rapid diagnostic malaria tests.</p> <p>Methods</p> <p>In order to evaluate different methods for the post-mortem diagnosis of <it>Plasmodium falciparum </it>malaria in non-immunes, a study was performed on the basis of forensic autopsies of corpses examined at variable intervals after death in five cases of fatal malaria (with an interval of four hours to five days), and in 20 cases of deaths unrelated to malaria. Detection of parasite DNA by PCR and an immunochromatographic test (ICT) based upon the detection of <it>P. falciparum </it>histidine-rich protein 2 (PfHRP2) were compared with the results of microscopic examination of smears from cadaveric blood, histopathological findings, and autopsy results.</p> <p>Results</p> <p>In all cases of fatal malaria, post-mortem findings were unsuspicious for the final diagnosis, and autoptic investigations, including histopathology, were only performed because of additional information by police officers and neighbours. Macroscopic findings during autopsy were unspecific. Histopathology confirmed sequestration of erythrocytes and pigment in macrophages in most organs in four patients (not evaluable in one patient due to autolysis). Microscopy of cadaveric blood smears revealed remnants of intraerythrocytic parasites, and was compromised or impossible due to autolysis in two cases. PCR and ICT performed with cadaveric blood were positive in all malaria patients and negative in all controls.</p> <p>Conclusion</p> <p>In non-immune fatalities with unclear anamnesis, ICT can be recommended as a sensitive and specific tool for post-mortem malaria diagnosis, which is easier and faster than microscopy, and also applicable when microscopic examination is impossible due to autolysis. PCR is more expensive and time-consuming, but may be used as confirmatory test. In highly endemic areas where asymptomatic parasitaemia is common, confirmation of the diagnosis of malaria as the cause of death has to rely on histopathological findings.</p
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