707 research outputs found
Moisture in Untreated, Acetylated, and Furfurylated Norway Spruce Monitored During Drying Below Fiber Saturation Using Time Domain NMR
Using time domain-nuclear magnetic resonance spectroscopy, the moisture content (MC) in Norway spruce [Picea abies (L.) Karst.] sapwood, subjected to three different treatments (untreated, acetylated, and furfurylated), was studied during drying at 40°C at MCs below fiber saturation. Spin-spin relaxation time distributions were derived from Carr-Purcell-Meiboom-Gill relaxation curves using mulitexponential fitting (CONTIN). After conditioning for 6 wk at 100% RH, the modified wood samples had a MC of about 15%, whereas the MC of the untreated samples was about 30%. Two water populations with different relaxation times were found in all three sample types at this point: 1.1 ms and 0.15 ms (untreated), 0.5 ms and 0.15 ms (furfurylated), and 1.2 - 3.5 ms and 0.1 ms (acetylated). As the MC decreased, the relaxation time of the most slowly relaxing population decreased, whereas it remained more or less constant for the other population. For both the untreated and the furfurylated samples, the two populations merged at 5 - 10% MC, and relaxation times were identical for the two treatments at low MC. The two populations did not merge for the acetylated samples. These results indicate that while acetylation changed the interaction between water and the wood cell wall, furfurylation seemed to mostly affect the amount of water present within the cell wall at the beginning of the drying experiment
Moisture in Untreated, Acetylated, and Furfurylated Norway Spruce Studied During Drying Using Time Domain NMR1
Using time domain NMR, the moisture in Norway spruce (Picea abies (L.) Karst.) sapwood subjected to four different treatments (never-dried, dried and remoistened, acetylated, and furfurylated) was studied during drying at 40°C, at sample average moisture contents above fiber saturation. Spin-spin relaxation time distributions were derived from CPMG relaxation curves using multiexponential fitting (CONTIN), and the resulting water populations were assigned according to the literature and their behavior during drying. It was found that both acetylation and furfurylation increased the average spin-spin relaxation time of the lumen water in earlywood tracheids from about 80-100 ms to 200 and 300 ms, respectively. The average spin-spin relaxation time of the cell wall water was reduced from about 1.4 to 0.65 ms by furfurylation, while acetylation had less effect on this water. The relaxation times of both the earlywood lumen water and of the cell wall water were slightly longer for the never-dried samples than for the dried and remoistened samples
The Challenge for Women Academics: Reaching a Critical Mass in Research, Teaching, and Service
Contributions of academic women in Canadian universities are reviewed to determine whether their participation has reached a "critical mass." Specifically, scholarship about higher education, participation rates within academic ranks, and the frequency of administrative appointments are examined as illustrations of research, teaching and service, the traditional pillars that represent academic achievement. A fundamental assumption is that to achieve equity, a critical mass of women academics must promote and maintain gender sensitivity through these three pillars. Results indicate that, in a few instances, the minimum level of participation (35%) was attained, but generally, critical mass has not yet been reached.Les contributions des femmes dans les universités canadiennes ont été revisées à savoir si leur participation avait atteint la "masse critique." En utilisant les normes des Nations Unies, la "masse critique" est définie comme le pourcentage (35%) nécessaire qui affecte la prise de décision de haut-niveau et qui a des effets de changements permanents. Spécifiquement, les bourses d'études supérieures, les taux de participation à l'intérieur des rangs académiques et la fréquence des nominations administratives sont examinés comme des illustrations de recherche, d'enseignement et de service, soit les piliers traditionnels que représente la réussite académique. L'hypotèse fondamentale est que pour réaliser l'équité, la "masse critique" de femmes à l;université doit promouvoir et maintenir la sensibilité des genres à travers ces trois piliers. Les résultats indiquent que dans quelques exemples, le niveau minimum de participation a été atteint, mais généralement, la "masse critique" n'a pas encore été atteinte
Oxalate found in wood cell wall during incipient brown rot degradation
Brown rot fungi are a marvel and an enigma of Nature. They are capable of depolymerizing holocellulose within wood cell walls without significantly ineralizing lignin. The exact details behind this feat remain unknown, but a staggered mechanism has been identified: 1) an initial step characterized by oxidative degradation of the wood cell wall biopolymers and hypothesized to involve transport of Fe3+ chelated by oxalate into the cell wall, and 2) a second degradation step dominated by hydrolytic enzymes, primarily endoglucanase activity. We subjected spruce wood (Picea abies) to Rhodonia placenta and isolated xylem tissue in the initial stage of degradation. Confocal Raman microscopy revealed oxalate accumulation in the secondary cell wall of a tracheid having fungal hyphae within the lumen. This observation is the first in situ verification of oxalate accumulation within the cell wall during the first step of brown rot degradation.publishedVersio
Insulin-Responsive Transcription Factors
The hormone insulin executes its function via binding and activating of the insulin receptor,
a receptor tyrosine kinase that is mainly expressed in skeletal muscle, adipocytes, liver, pancreatic
β-cells, and in some areas of the central nervous system. Stimulation of the insulin receptor activates
intracellular signaling cascades involving the enzymes extracellular signal-regulated protein kinase 1/2 (ERK1/2), phosphatidylinositol 3-kinase, protein kinase B/Akt, and phospholipase Cγ as signal
transducers. Insulin receptor stimulation is correlated with multiple physiological and biochemical
functions, including glucose transport, glucose homeostasis, food intake, proliferation, glycolysis,
and lipogenesis. This review article focuses on the activation of gene transcription as a result of
insulin receptor stimulation. Signal transducers such as protein kinases or the GLUT4-induced influx
of glucose connect insulin receptor stimulation with transcription. We discuss insulin-responsive
transcription factors that respond to insulin receptor activation and generate a transcriptional network
executing the metabolic functions of insulin. Importantly, insulin receptor stimulation induces
transcription of genes encoding essential enzymes of glycolysis and lipogenesis and inhibits genes
encoding essential enzymes of gluconeogenesis. Overall, the activation or inhibition of insulin responsive transcription factors is an essential aspect of orchestrating a wide range of insulin-induced
changes in the biochemistry and physiology of insulin-responsive tissues
Correlating the ability of lignocellulosic polymers to constrain water with the potential to inhibit cellulose saccharification
BACKGROUND: Studies in bioconversions have continuously sought the development of processing strategies to overcome the “close physical association” between plant cell wall polymers thought to significantly contribute to biomass recalcitrance [Adv Space Res 18:251–265, 1996],[ Science 315:804–807, 2007]. To a lesser extent, studies have sought to understand biophysical factors responsible for the resistance of lignocelluloses to enzymatic degradation. Provided here are data supporting our hypothesis that the inhibitory potential of different cell wall polymers towards enzymatic cellulose hydrolysis is related to how much these polymers constrain the water surrounding them. We believe the entropy-reducing constraint imparted to polymer associated water plays a negative role by increasing the probability of detrimental interactions such as junction zone formation and the non-productive binding of enzymes. RESULTS: Selected commercial lignocellulose-derived polymers, including hemicelluloses, pectins, and lignin, showed varied potential to inhibit 24-h cellulose conversion by a mix of purified cellobiohydrolase I and β-glucosidase. At low dry matter loadings (0.5% w/w), insoluble hemicelluloses were most inhibitory (reducing conversion relative to cellulose-only controls by about 80%) followed by soluble xyloglucan and wheat arabinoxylan (reductions of about 70% and 55%, respectively), while the lignin and pectins tested were the least inhibitory (approximately 20% reduction). Low field nuclear magnetic resonance (LF-NMR) relaxometry used to observe water-related proton relaxation in saturated polymer suspensions (10% dry solids, w/w) showed spin-spin, T(2,) relaxation time curves generally approached zero faster for the most inhibitory polymer preparations. The manner of this decline varied between polymers, indicating different biophysical aspects may differentially contribute to overall water constraint in each case. To better compare the LF-NMR data to inhibitory potential, T(2) values from monocomponent exponential fits of relaxation curves were used as a measure of overall water constraint. These values generally correlated faster relaxation times (greater water constraint) with greater inhibition of the model cellulase system by the polymers. CONCLUSIONS: The presented correlation of cellulase inhibition and proton relaxation data provides support for our water constraint-biomass recalcitrance hypothesis. Deeper investigation into polymer-cellulose-cellulase interactions should help elucidate the types of interactions that may be propagating this correlation. If these observations can be verified to be more than correlative, the hypothesis and data presented suggest that a focus on water-polymer interactions and ways to alter them may help resolve key biological lignocellulose processing bottlenecks
Rapid and Specific Diagnosis of Extrapulmonary Tuberculosis by Immunostaining of Tissues and Aspirates With Anti-MPT64
Background: Extrapulmonary tuberculosis (EPTB) constitutes about 15% to 20% of all cases of tuberculosis (TB). The confirmation of EPTB has always been a challenge to laboratory personnel. We aim to evaluate the diagnostic potential of immunostaining with anti-MPT64 in various EPTB specimens. Materials and Methods: We studied a total of 51 TB cases and 38 non-TB control specimens comprising of fine-needle aspirates and formalin-fixed biopsies. These were investigated using a combination of the Ziehl-Neelsen method, the Lowenstein-Jensen culture, immunostaining with anti-MPT64 and anti-BCG, and nested-polymerase chain reaction (PCR) for IS6110. Results of all the tests were compared using nested-PCR as the gold standard. Results: Diagnostic validation of immunostaining for anti-MPT64 was performed using nested-PCR as the gold standard. The overall sensitivity, specificity, and positive and negative predictive values for immunostaining with anti-MPT64 were 100%, 97%, 97%, and 100%, respectively. Conclusions: Immunostaining using anti-MPT64 is a rapid and sensitive method for establishing an early and specific diagnosis of Mycobacterium tuberculosis infection. The technique is simple to be incorporated into routine pathology laboratories.publishedVersio
Pengaruh Bauran Promosi, Persepsi Harga dan Lokasi terhadap Keputusan Pembelian dan Kepuasan Konsumen pada Perumahan Tamansari Metropolitan Manado
Manajemen Perusahaan sangat penting untuk memahami bauran promosi yang digunakan, persepsi harga konsumen terhadap produk dan lokasi, terutama dalam hal menarik perhatian konsumen dan penentuan keputusan pembelian. Pasca keputusan pembelian maka akan ditinjau dari segi kepuasan konsumen yang merupakan aspek penting dan utama dari berjalannya pemasaran. Penelitian ini bertujuan untuk menganalisis pengaruh bauran promosi, persepsi harga dan lokasi terhadap keputusan pembelian dan kepuasan konsumen pada Perumahan Tamansari Metropolitan Manado. Metode Analisis yang digunakan adalah analisis jalur. Populasi penelitian berjumlah 218, sampel berjumlah 135 responden. Hasil penelitian menunjukkan bauran promosi berpengaruh positif dan signifikan terhadap keputusan pembelian dan kepuasan konsumen. Persepsi harga berpengaruh negatif terhadap keputusan pembelian dan kepuasan konsumen. Lokasi berpengaruh positif dan signifikan terhadap keputusan pembelian dan negatif terhadap kepuasan konsumen. Sebaiknya pihak manajemen memperhatikan dan meningkatkan bauran promosi Perusahaan terhadap keputusan pembelian untuk mempertahankan kepuasan konsumen
Four cases on market orientation of value chains in agribusiness and fisheries
This working paper presents results from the project ‘Supra-company level determinants of degree of market orientation of value chains in agriculture and fisheries’, which is carried out in cooperation between MAPP – Centre for Research on Customer Relations in the Food Sector, Aarhus School of Business, Denmark, the Norwegian College of Fisheries Science, University of Tromsø, Norway, and the Department of Marketing, University of Stirling, Scotland. It has benefited from grants from the Danish Social Science Research Council and from the Norwegian Research Council. The present working paper is the ‘long’ version of the empirical work in the first major phase of the project, where we study four examples of food value chains to get insight into their degree of market orientation and possible determinants. The insights gained here have been used in subsequent empirical work that is currently underwayMarket orientation;
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