463 research outputs found

    The Potential of Visible Spectroscopy as a Tool for the In-Line Monitoring of Lignin Methylolation

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    Out of the 50 to 70 million tons of lignin that are produced annually, only 1 to 2% are used for value-added products. Currently, 90% of the total market of this compound corresponds to lignosulphonates (LS). The most successful industrial attempts to use lignin for wood adhesives rely on using it as a partial substitute in phenolformaldehyde or ureaformaldehyde resins. However, lignins aromatic ring presents a low number of reactive sites. Several methods have been proposed to improve its reactivity, such as prior methylolation with formaldehyde. Off-line methods are commonly applied to monitor this reactions progress, but this introduces a significant delay in the analysis. This study proposes a new method for in-line monitoring of the methylolation reaction using visible spectroscopy. In order to monitor the reaction progress, principal component analysis was applied to the spectra, and the obtained scores were analyzed. When these results were plotted against those obtained by the off-line methods, a satisfactory regression was obtained at 50 °C (R2 = 0.97) and 60 °C (R2 = 0.98) for two different LS samples. Therefore, it was concluded that visible spectroscopy is a promising technique for studying lignin methylolation.</jats:p

    Climate change research and policy in Portugal

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    This article offers a review of research and policy on climate change in Portugal and is organized into three main themes: scientific knowledge and assessment of climate change; policy analysis and evaluation; and public engagement. Modern scientific research on meteorology and climatology started in Portugal in the 1950s and a strong community of researchers in climate science, vulnerabilities, impacts, and adaptation has since developed, particularly in the last decade. Nevertheless, there are still many gaps in research, especially regarding the economic costs of climate change in Portugal and costs and benefits of adaptation. Governmental policies with a strong emphasis on mitigation were introduced at the end of the 1990s. As greenhouse gas emissions continued to rise beyond its Kyoto target for 2012, the country had to resort to the Kyoto Flexibility Mechanisms in order to comply. Climate change adaptation policies were introduced in 2010 but are far from being fully implemented. Regarding public engagement with climate change, high levels of concern contrast with limited understanding and rather weak behavioral dispositions to address climate change. Citizens display a heavy reliance on the media as sources of information, which are dominated by a techno-managerial discourse mainly focused on the global level. The final part of the article identifies research gaps and outlines a research agenda. Connections between policy and research are also discussed

    Performance of Anaerobic Co‑digestion of Pig Slurry with Pineapple (Ananas comosus) Bio‑waste Residues

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    Agro-food industries produce large amounts of bio-waste, challenging innovative valorisation strategies in the framework of circular economy principles. Anaerobic digestion technology is an interesting route to stabilise organic matter and produce biogas as a renewable energy source. This paper aimed to study the optimal performance conditions for anaerobic co-digestion (AcoD) of pig slurry with pineapple (Ananas comosus) peel bio-waste. The anaerobic digestion (AD) trials were performed at lab scale, in a continuous stirred reactor, for 16 days’ hydraulic retention time in mesophilic conditions (37 ± 1 °C). Three hydraulic retention time were performed, one for the reference scenario ( T0) and two for AcoD trials ( T1, T2). Feeding mixtures (20:80; v:v) of pineapple peel liquor and pig slurry, with an OLR of 1.46 ± 0.04 g TVS L− 1 reactor day− 1 were used during AD/AcoD trials, presenting high values for soluble chemical oxygen demand and C/N ratio. This operational conditions highlight bioenergy recovery up to 0.58 L CH4 g TVSadded −1, in comparison with that obtained with pig slurry substrate (0.31 L CH4 g VSadded −1). The AD performance showed a total volatile solids and chemical oxygen demand removal efficiency of 23% to 47% and 26% to 48%, comparing T0 with the average of T1 and T2, respectively. The digester stability, evaluated by specific energetic loading rate, was below the limit (0.4 day−1) throughout the trials. Pig slurry co-digestion with pineapple peel liquor seems to be a promising approach for potential bioenergy recovery.info:eu-repo/semantics/publishedVersio

    Hydrolysis optimization and characterization study of preparing fatty acids from Jatropha curcas seed oil

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    <p>Abstract</p> <p>Background</p> <p>Fatty acids (FAs) are important as raw materials for the biotechnology industry. Existing methods of FAs production are based on chemical methods. In this study potassium hydroxide (KOH)-catalyzed reactions were utilized to hydrolysis <it>Jatropha curcas </it>seed oil.</p> <p>Results</p> <p>The parameters effect of ethanolic KOH concentration, reaction temperature, and reaction time to free fatty acid (FFA%) were investigated using D-Optimal Design. Characterization of the product has been studied using Fourier transforms infrared spectroscopy (FTIR), gas chromatography (GC) and high performance liquid chromatography (HPLC). The optimum conditions for maximum FFA% were achieved at 1.75M of ethanolic KOH concentration, 65°C of reaction temperature and 2.0 h of reaction time.</p> <p>Conclusions</p> <p>This study showed that ethanolic KOH concentration was significant variable for <it>J. curcas </it>seed oil hydrolysis. In a 18-point experimental design, FFA% of hydrolyzed <it>J. curcas </it>seed oil can be raised from 1.89% to 102.2%, which proved by FTIR and HPLC.</p

    Mycotic aneurysm of the femoral artery complicating Staphylococcus aureus bacteremia: a case report

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    INTRODUCTION: Staphylococcus aureus is the major cause of bacteremia, with the potential for some complications, namely mycotic aneurysms, defined as irreversible dilatation of an artery due to destruction of the vessel wall by infection. CASE PRESENTATION: The authors present the case of a 52 year-old-Caucasian male, admitted with Staphylococcus aureus bacteremia and mycotic aneurysm of the right superficial femoral artery, associated with advanced atherosclerotic process. CONCLUSION: Mycotic aneurysms are rare, and a high index of suspicion is needed, because appropriate treatment will certainly affect the outcome, as they are associated with high morbidity and mortality

    Domestication syndrome is investigated by proteomic analysis between cultivated cassava (Manihot esculenta Crantz) and its wild relatives

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    Cassava (Manihot esculenta Crantz) wild relatives remain a largely untapped potential for genetic improvement. However, the domestication syndrome phenomena from wild species to cultivated cassava remain poorly understood. The analysis of leaf anatomy and photosynthetic activity showed significantly different between cassava cultivars SC205, SC8 and wild relative M. esculenta ssp. Flabellifolia (W14). The dry matter, starch and amylose contents in the storage roots of cassava cultivars were significantly more than that in wild species. In order to further reveal the differences in photosynthesis and starch accumulation of cultivars and wild species, the globally differential proteins between cassava SC205, SC8 and W14 were analyzed using 2-DE in combination with MALDI-TOF tandem mass spectrometry. A total of 175 and 304 proteins in leaves and storage roots were identified, respectively. Of these, 122 and 127 common proteins in leaves and storage roots were detected in SC205, SC8 and W14, respectively. There were 11, 2 and 2 unique proteins in leaves, as well as 58, 9 and 12 unique proteins in storage roots for W14, SC205 and SC8, respectively, indicating proteomic changes in leaves and storage roots between cultivated cassava and its wild relatives. These proteins and their differential regulation across plants of contrasting leaf morphology, leaf anatomy pattern and photosynthetic related parameters and starch content could contribute to the footprinting of cassava domestication syndrome. We conclude that these global protein data would be of great value to detect the key gene groups related to cassava selection in the domestication syndrome phenomena

    Postcopulatory sexual selection

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    The female reproductive tract is where competition between the sperm of different males takes place, aided and abetted by the female herself. Intense postcopulatory sexual selection fosters inter-sexual conflict and drives rapid evolutionary change to generate a startling diversity of morphological, behavioural and physiological adaptations. We identify three main issues that should be resolved to advance our understanding of postcopulatory sexual selection. We need to determine the genetic basis of different male fertility traits and female traits that mediate sperm selection; identify the genes or genomic regions that control these traits; and establish the coevolutionary trajectory of sexes

    Haplotypes of the bovine IgG2 heavy gamma chain in tick-resistant and tick-susceptible breeds of cattle

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    Bovines present contrasting, heritable phenotypes of infestations with the cattle tick, Rhipicephalus (Boophilus) microplus. Tick salivary glands produce IgG-binding proteins (IGBPs) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. Allotypes that occur in the constant region of IgG may differ in their capacity to bind with tick IGBPs; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. In order to test this hypothesis, we investigated the frequency of haplotypes of bovine IgG2 among tick-resistant and tick-susceptible breeds of bovines. Sequencing of the gene coding for the heavy chain of IgG2 from 114 tick-resistant (Bos taurus indicus, Nelore breed) and tick-susceptible (B. t. taurus, Holstein breed) bovines revealed SNPs that generated 13 different haplotypes, of which 11 were novel and 5 were exclusive of Holstein and 3 of Nelore breeds. Alignment and modeling of coded haplotypes for hinge regions of the bovine IgG2 showed that they differ in the distribution of polar and hydrophobic amino acids and in shape according to the distribution of these amino acids. We also found that there was an association between genotypes of the constant region of the IgG2 heavy chain with phenotypes of tick infestations. These findings open the possibility of investigating if certain IgG allotypes hinder the function of tick IGBPs. If so, they may be markers for breeding for resistance against tick infestations
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