Estimation of Treatment Time for Microbial Preprocessing of Biomass

Biochemical conversion of lignocellulosic biomass to ethanol involves size reduction, preprocessing, pretreatment, enzyme hydrolysis, and fermentation. In recent years, microbial preprocessing has been gaining attention as a means to produce labile biomass for lessening the requirement of pretreatment severity. However, loss of sugars due to microbial consumption is a major consequence, suggesting its minimization through optimization of nutrients, temperature, and preprocessing time. In this work, we emphasized estimation of fungal preprocessing time, at which higher sugar yields can be achieved after preprocessing and enzyme hydrolysis. The estimation is based on the enzymatic activity profile obtained by treating switchgrass with Phanerochaete chrysosporium for 28 days. Enzyme assays were conducted once in every 7 days for 28 days, for activities of phenol oxidase, peroxidase, β-glucosidase, β-xylosidase, and cellobiohydrolase. We found no activity for phenol oxidase and peroxidase, but the greatest activities for cellulases on the seventh day. We then treated switchgrass for 7 days with P. chrysosporium and observed that the preprocessed switchgrass had higher glucan (39%), xylan (17.5%), and total sugar yields (25.5%) than the unpreprocessed switchgrass (34%, 37.5%, and 20.5%, respectively, p < 0.05). This verifies the utility of using enzyme assays for initial estimation of preprocessing time to enhance sugar yields.     

The diffraction of elastic waves by an imperfect fusion bond

We consider diffraction by a semi-infinite crack located alonga fusion interface between two differing elastic media. Twotypes of crack, namely open and partially closed cracks, areinvestigated. An open crack is modelled by a stress-free contactboundary condition and a partially closed crack is modelledby a spring contact boundary condition. For the latter, thejump in the stress across the crack is assumed to be proportionalto the jump in the displacement across the crack. This situationarises in, for example, a K-weld where the fine grain of theparent material (for example, ferritic or forged austeniticsteel) is in stark contrast with the coarse-grained weld metal(for example, austenitic weld metal). In the metal weld thedirection of the grain axis varies through the metal. However,diffraction is a local phenomenon and so the austenitic steelis assumed to have a zonal axis so that it may be modelled bya transversely isotropic composite. The ferritic or forged austeniticsteel will be modelled as an isotropic material.     

Involvement of central noradrenaline, serotonin and dopamine system in the antidepressant activity of fruits of Solanum torvum (Solanaceae)

The methanolic extract (ME) of Solanum torvum seeds and its ethyl acetate fraction (EAF) were investigated for their antidepressant activity using behavioral (forced swim test, FST and tail suspension test, TST) and biochemical (monoamine oxidase, MAO reduced activity) tests. ME (10, 30 and 100?mg?kg(-1)) and EAF (10 and 30?mg?kg(-1)) dose dependently inhibited the immobility period, increased noradrenaline, serotonin and dopamine levels and inhibited the MAO enzymes in FST and TST using mice. Furthermore, we have observed antagonism between the threshold dose of ME (30 and 100?mg?kg(-1)) and EAF (10 and 30?mg?kg(-1)) with antagonists on behaviour mediated by neurotransmitters noradrenaline, serotonin and dopamine. MAO-A inhibition was more prominent as compared to MAO-B inhibition. The study provides evidence for antidepressant actions of S. torvum.     

NMR structure and dynamic studies of an anion-binding, channel-forming heptapeptide

The synthetic peptide (C(18)H(37))(2)NCOCH(2)OCH(2)CON-(Gly)(3)-Pro-(Gly)(3)-OCH(2)Ph forms chloride-selective channels in liposomes and exhibits voltage-gating properties in planar phospholipid bilayers. The peptide fragment of the channel is based on a conserved motif in naturally occurring chloride transporters. Membrane-anchoring residues at the N- and C-terminal ends augment the peptide. NMR spectra (1D and 2D) of the channel in CDCl(3) showed significant variation in the absence and presence of stoichiometric tetrabutylammonium chloride (Bu(4)NCl). One-dimensional solution-state NMR titration studies combined with computational molecular simulation studies indicate that the peptide interacts with the salt as an ion pair and H-bonds chloride. To our knowledge, this is the first structural analysis of any synthetic anion-channel salt complex.     

ON AVOIDANCE ACTIVITIES IN FISHERY ENFORCEMENT MODELS

Compliance and enforcement in fisheries are important issues from an economic point of view since management measures are useless without a certain level of enforcement. These conclusions come from the well‐established theoretical literature on compliance and enforcement problems within fisheries and a common result is that, it is efficient to set fines as high as possible and monitoring as low as possible, when fines are costless and offenders are risk neutral. However, this result is sensitive to the assumption that fishermen cannot engage in avoidance activities, e.g., activities to reduce the likelihood of being detected when noncomplying. The paper presents a model of fisheries that allows the fishermen to engage in avoidance activities. The conclusions from the model are that, under certain circumstances, fines are costly transfers to society since they not only have a direct positive effect on the level of deterrence, but also an indirect negative effect in the form of increased avoidance activities to reduce the probability of detection. The paper contributes to the literature on avoidance activities by introducing the externality from the illegal behavior as an endogenous effect on other offenders. For an externality, that has an exogenous effect on other actors, Malik shows that fines are only costly transfers for conditional deterrence (when one actor is deterred while another actor is not). For fisheries, we show that fines are also costly transfers under no deterrence (when no agents are deterred).     

Orthogonal Polynomials and Second-order Differential Equations

We show that a sequence of polynomials can be eigenfunctionsof a second-order differential operator only under severe restrictions.     

焙烧硼钠钙石在高固液比氯化铵溶液中的溶解动力学

Boron is available in the form of metal borates, especially of sodium and calcium, in nature[1]. The production of boron compounds has substantially increased recently due to increasing uses of these compounds in nuclear technology, in rocket engines as f…