932 resultados para Replacing strikers


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We estimated the effect on growth and nutrient efficiency of replacing fishmeal with silage incorporated with rice bran in diets for fingerling red tilapia (Oreochromis mossambicus × Oreochromis niloticus × Oreochromis aureus) over 12 weeks. Isonitrogenous (300 g kg−1 protein dry matter basis) and isoenergetic (4450 Kcal gross energy kg−1) feed formulations with increasing levels of tilapia silage as a replacement for fishmeal were prepared: Diet 1 with no silage (0 g Kg−1), Diet 2 (250 g Kg−1), Diet 3 (500 g Kg−1), and Diet 4 (750 g Kg−1). Feed intake was similar among Diets 1, 2, and 3, while Diet 4 had a significantly lower intake. There was no significant difference (P > 0.05) in weight gain or specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency ratio (PER), among fish fed Diets 1, 2, and 3. Fish fed with Diet 4 had significantly lower weight gain; SGR and PER and significantly higher FCR. Organoleptic properties of the fish were not affected by the diets. The results of this study indicate that less expensive dried fish silage with rice bran is an alternative protein source for tilapia feed up to 50% of fishmeal replacement.

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This paper compares the structural performance between thin-walled timber and FRP-timber composite Cee-sections. While, thin-walled composite timber structures have been proven to be efficient and ultra-light structural elements, their manufacturing is difficult and labour intensive. Significant effort and time is required to prevent the cracking of the transverse timber veneers, bent in the grain direction, when forming the cross-sectional shape. FRP-timber structures overcome this disadvantage by replacing the transverse veneers with flexible, unidirectional FRP material and only keeping the timber veneers which are bent in their natural rolling direction. The Cee-sections investigated in this study were 210 mm deep × 90 mm wide × 500 mm high and manufactured from five plies. For both section types, the three internal plies were thin (1 mm thick) softwood Hoop pine (Araucaria cunninghamii) veneers, orientated along the section longitudinal axis. The two outer layers, providing bending stiffness to the walls, were Hoop pine veneers (1 mm thick) for the timber sections and glass fibre reinforced plastic (0.73 mm thick) for the FRP-timber sections orientated perpendicular to the inner layers. The manufacturing process is briefly introduced in this paper. The profiles were fitted with strain gauges and tested in compression. Linear Variable Displacement Transducers also recorded the buckling along one flange. The test results are presented and discussed in this paper in regards to their structural behaviour and performance. Results showed that the use of FRP in the sections increases both the elastic local buckling load and section capacity, the latter being increased by about 24 percent. The results indicate that thin-walled FRP-timber can ultimately be used as a sustainable alternative to cold-formed steel profiles.

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We discuss three approaches to the use of technology as a teaching and learning tool that we are currently implementing for a target group of about one hundred second level engineering mathematics students. Central to these approaches is the underlying theme of motivating relatively poorly motivated students to learn, with the aim of improving learning outcomes. The approaches to be discussed have been used to replace, in part, more traditional mathematics tutorial sessions and lecture presentations. In brief, the first approach involves the application of constructivist thinking in the tertiary education arena, using technology as a computational and visual tool to create motivational knowledge conflicts or crises. The central idea is to model a realistic process of how scientific theory is actually developed, as proposed by Kuhn (1962), in contrast to more standard lecture and tutorial presentations. The second approach involves replacing procedural or algorithmic pencil-and-paper skills-consolidation exercises by software based tasks. Finally, the third approach aims at creating opportunities for higher order thinking via "on-line" exploratory or discovery mode tasks. The latter incorporates the incubation period method, as originally discussed by Rubinstein (1975) and others.

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An analytical solution of the heat transfer problem with viscous dissipation for non-Newtonian fluids with power-law model in the thermal entrance region of a circular pipe and two parallel plates under constant heat flux conditions is obtained using eigenvalue approach by suitably replacing one of the boundary conditions by total energy balance equation. Analytical expressions for the wall and the bulk temperatures and the local Nusselt number are presented. The results are in close agreement with those obtained by implicit finite-difference scheme. It is found that the role of viscous dissipation on heat transfer is completely different for heating and cooling conditions at the wall. The results for the case of cooling at the wall are of interest in the design of the oil pipe line.

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The impacts of fragmentation and recreational use on the hemiboreal urban forest understorey vegetation and the microbial community of the humus layer (the phospholipid fatty acid (PLFA) pattern, microbial biomass and microbial activity, measured as basal respiration) were examined in the greater Helsinki area, southern Finland. Trampling tolerance of 1) herb-rich OMT, 2) mesic MT, and 3) sub-xeric VT forests (in decreasing order of fertility) was studied by comparing relative understorey vegetation cover (urban/untrampled reference ratio) of the three forest types. The trampling tolerance of forest vegetation increased with the productivity of the site (sub-xeric < mesic < herb-rich). Wear of understorey vegetation correlated positively with the number of residents (i.e., recreational pressure) around the forest patch. An increase of 15000 residents within a radius of 1 km around a forest patch was associated with ca. 30% decrease in the relative understorey vegetation cover. The cover of dwarf shrub Vaccinium myrtillus in particular decreased with increasing levels of wear. The cover of mosses in urban forests was less than half of that in untrampled reference areas. Cover of tree saplings, mainly Sorbus aucuparia, and some resilient herbs was higher than in the reference areas. In small urban forest fragments, broad-leaved trees, grasses and herbs were more abundant and mosses were scarcer than in larger urban forest areas. Thus, due to trampling and edge effects, resilient herb and grass species are replacing sensitive dwarf shrubs, mosses and lichens in urban forests. Differences in the soil microbial community structure were found between paths and untrampled areas and the effects of paths extended more than one meter from the paths. Paths supported approximately 25-30% higher microbial biomass with a transition zone of at least 1 m from the path edge. However, microbial activity per unit of biomass was lower on paths than in untrampled areas. Furthermore, microbial biomass and activity were 30-45% lower at the first 20 m into the forest fragments, due to low moisture content of humus near the edge. The decreased microbial activity detected at forest edges and paths implies decreased litter decomposition rates, and thus, a change in nutrient cycling. Changes in the decomposition and nutrient supply may in turn affect the diversity and function of plant communities in urban forests. Keywords: boreal forest vegetation, edge effects, phospholipid fatty acids, trampling, urban woodlands, wear

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Aggregation of the microtubule associated protein tau (MAPT) within neurons of the brain is the leading cause of tauopathies such as Alzheimer's disease. MAPT is a phospho-protein that is selectively phosphorylated by a number of kinases in vivo to perform its biological function. However, it may become pathogenically hyperphosphorylated, causing aggregation into paired helical filaments and neurofibrillary tangles. The phosphorylation induced conformational change on a peptide of MAPT (htau225−250) was investigated by performing molecular dynamics simulations with different phosphorylation patterns of the peptide (pThr231 and/or pSer235) in different simulation conditions to determine the effect of ionic strength and phosphate charge. All phosphorylation patterns were found to disrupt a nascent terminal β-sheet pattern (226VAVVR230 and 244QTAPVP249), replacing it with a range of structures. The double pThr231/pSer235 phosphorylation pattern at experimental ionic strength resulted in the best agreement with NMR structural characterization, with the observation of a transient α-helix (239AKSRLQT245). PPII helical conformations were only found sporadically throughout the simulations. Proteins 2014; 82:1907–1923. © 2014 Wiley Periodicals, Inc.

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Genetic engineering of Bacillus thuringiensis (Bt) Cry proteins has resulted in the synthesis of various novel toxin proteins with enhanced insecticidal activity and specificity towards different insect pests. In this study, a fusion protein consisting of the DI–DII domains of Cry1Ac and garlic lectin (ASAL) has been designed in silico by replacing the DIII domain of Cry1Ac with ASAL. The binding interface between the DI–DII domains of Cry1Ac and lectin has been identified using protein–protein docking studies. Free energy of binding calculations and interaction profiles between the Cry1Ac and lectin domains confirmed the stability of fusion protein. A total of 18 hydrogen bonds was observed in the DI–DII–lectin fusion protein compared to 11 hydrogen bonds in the Cry1Ac (DI–DII–DIII) protein. Molecular mechanics/Poisson–Boltzmann (generalized-Born) surface area [MM/PB (GB) SA] methods were used for predicting free energy of interactions of the fusion proteins. Protein–protein docking studies based on the number of hydrogen bonds, hydrophobic interactions, aromatic–aromatic, aromatic–sulphur, cation–pi interactions and binding energy of Cry1Ac/fusion proteins with the aminopeptidase N (APN) of Manduca sexta rationalised the higher binding affinity of the fusion protein with the APN receptor compared to that of the Cry1Ac–APN complex, as predicted by ZDOCK, Rosetta and ClusPro analysis. The molecular binding interface between the fusion protein and the APN receptor is well packed, analogously to that of the Cry1Ac–APN complex. These findings offer scope for the design and development of customized fusion molecules for improved pest management in crop plants.

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The DAYCENT biogeochemical model was used to investigate how the use of fertilizers coated with nitrification inhibitors and the introduction of legumes in the crop rotation can affect subtropical cereal production and {N2O} emissions. The model was validated using comprehensive multi-seasonal, high-frequency dataset from two field investigations conducted on an Oxisol, which is the most common soil type in subtropical regions. Different N fertilizer rates were tested for each N management strategy and simulated under varying weather conditions. DAYCENT was able to reliably predict soil N dynamics, seasonal {N2O} emissions and crop production, although some discrepancies were observed in the treatments with low or no added N inputs and in the simulation of daily {N2O} fluxes. Simulations highlighted that the high clay content and the relatively low C levels of the Oxisol analyzed in this study limit the chances for significant amounts of N to be lost via deep leaching or denitrification. The application of urea coated with a nitrification inhibitor was the most effective strategy to minimize {N2O} emissions. This strategy however did not increase yields since the nitrification inhibitor did not substantially decrease overall N losses compared to conventional urea. Simulations indicated that replacing part of crop N requirements with N mineralized by legume residues is the most effective strategy to reduce {N2O} emissions and support cereal productivity. The results of this study show that legumes have significant potential to enhance the sustainable and profitable intensification of subtropical cereal cropping systems in Oxisols.

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Solvothermal treatment of an equimolar mixture of Co(NO3)(2)center dot 6H(2)O, HCONH2 and NaN3 in MeOH at 100 degrees C yielded a three-dimensional NaCl type network Co(HCOO)(2)(HCONH2)(2) center dot HCONH2 (1a) containing formamides in the pores of the structure. Solvated pink 1a undergoes single crystal-to-single crystal (SCSC) transformation at 215 degrees C to form the desolvated dark brown product Co(HCOO)(2)-( HCONH2)(2) (1b) with the retention of the original framework. Reversible single crystal-to-single crystal transformation of 1b (brown) to 1a (pink) in the presence of excess formamide was also established at room temperature. The coordination environment around Co(II) in both 1a and 1b is octahedral with a CoN2O4 coordination composition. A similar reaction replacing Co(II) by Cr(III) produced a heterometallic 3D extended network Na[Cr(HCOO)(4)(HCONH2)(2)]center dot 2H(2)O (2a) at 100 degrees C. An increase in reaction temperature to 150 degrees C produced a simple mononuclear complex Cr(HCOO)(3)(HCONH2)(3) center dot 3H(2)O (2b). Variable temperature magnetic studies revealed the presence of a canting phenomena in both 1a and 1b, and hysteresis loop in the field dependent magnetisation plot at 2 K whereas complex 2a is simply paramagnetic in nature.

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Programed cell death (PCD) is a fundamental biological process that is as essential for the development and tissue homeostasis as cell proliferation, differentiation and adaptation. The main mode of PCD - apoptosis - occurs via specifi c pathways, such as mitochondrial or death receptor pathway. In the developing nervous system, programed death broadly occurs, mainly triggered by the defi ciency of different survival-promoting neurotrophic factors, but the respective death pathways are poorly studied. In one of the best-characterized models, sympathetic neurons deprived of nerve growth factor (NGF) die via the classical mitochondrial apoptotic pathway. The main aim of this study was to describe the death programs activated in these and other neuronal populations by using neuronal cultures deprived of other neurotrophic factors. First, this study showed that the cultured sympathetic neurons deprived of glial cell line-derived neurotrophic factor (GDNF) die via a novel non-classical death pathway, in which mitochondria and death receptors are not involved. Indeed, cytochrome c was not released into the cytosol, Bax, caspase-9, and caspase-3 were not involved, and Bcl-xL overexpression did not prevent the death. This pathway involved activation of mixed lineage kinases and c-jun, and crucially requires caspase-2 and -7. Second, it was shown that deprivation of neurotrophin-3 (NT-3) from cultured sensory neurons of the dorsal root ganglia kills them via a dependence receptor pathway, including cleavage of the NT- 3 receptor TrkC and liberation of a pro-apoptotic dependence domain. Indeed, death of NT-3-deprived neurons was blocked by a dominant-negative construct interfering with TrkC cleavage. Also, the uncleavable mutant of TrkC, replacing the siRNA-silenced endogeneous TrkC, was not able to trigger death upon NT-3 removal. Such a pathway was not activated in another subpopulation of sensory neurons deprived of NGF. Third, it was shown that cultured midbrain dopaminergic neurons deprived of GDNF or brainderived neurotrophic factor (BDNF) kills them by still a different pathway, in which death receptors and caspases, but not mitochondria, are activated. Indeed, cytochrome c was not released into the cytosol, Bax was not activated, and Bcl-xL did not block the death, but caspases were necessary for the death of these neurons. Blocking the components of the death receptor pathway - caspase-8, FADD, or Fas - blocked the death, whereas activation of Fas accelerated it. The activity of Fas in the dopaminergic neurons could be controlled by the apoptosis inhibitory molecule FAIML. For these studies we developed a novel assay to study apoptosis in the transfected dopaminergic neurons. Thus, a novel death pathway, characteristic for the dopaminergic neurons was described. The study suggests death receptors as possible targets for the treatment of Parkinson s disease, which is caused by the degeneration of dopaminergic neurons.

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1. The rat brain type IIA Na+ channel alpha-subunit was stably expressed in Chinese hamster ovary (CHO) cells. Current through the expressed Na+ channels was studied using the whole-cell configuration of the patch clamp technique. The transient Na+ current was sensitive to TTX and showed a bell-shaped peak current vs. membrane potential relation. 2. Na+ current inactivation was better described by the sum of two exponentials in the potential range -30 to +40 mV, with. a dominating fast component and a small slower component. 3. The steady-state inactivation, h(infinity), was related to potential by a Boltzmann distribution, underlying thr ee states of the inactivation gate. 4. Recovery of the channels from inactivation at different potentials in the range -70 to -120 mV were characterized by al? initial delay which decreased with hyperpolarization. The time course was well fitted by the sum of two exponentials. In this case the slower exponential was the major component, and both time constants decreased with hyperpolarization. 5. For a working description of the Na+ channel inactivation in this preparation, with a minimal deviation from the Hodgkin-Huxley model, a three-state scheme of the form O reversible arrow I-1 reversible arrow I-2 was proposed, replacing the original two-state scheme of the Hodgkin-Huxley model, and the rate constants are reported. 6. The instantaneous current-voltage relationship showed marked deviation from linearity and was satisfactorily fitted by the constant-field equation. 7. The time course of activation was described by an m(x) model. However, the best-fitted value of x varied with the membrane potential and had a mean value of 2. 8. Effective gating charge was determined to be 4.7e from the slope of the activation plot, plotted on a logarithmic scale. 9. The rate constants of activation, alpha(m) and beta(m), were determined. Their functional dependence on the membrane potential was investigated.

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Industrial ecology is an important field of sustainability science. It can be applied to study environmental problems in a policy relevant manner. Industrial ecology uses ecosystem analogy; it aims at closing the loop of materials and substances and at the same time reducing resource consumption and environmental emissions. Emissions from human activities are related to human interference in material cycles. Carbon (C), nitrogen (N) and phosphorus (P) are essential elements for all living organisms, but in excess have negative environmental impacts, such as climate change (CO2, CH4 N2O), acidification (NOx) and eutrophication (N, P). Several indirect macro-level drivers affect emissions change. Population and affluence (GDP/capita) often act as upward drivers for emissions. Technology, as emissions per service used, and consumption, as economic intensity of use, may act as drivers resulting in a reduction in emissions. In addition, the development of country-specific emissions is affected by international trade. The aim of this study was to analyse changes in emissions as affected by macro-level drivers in different European case studies. ImPACT decomposition analysis (IPAT identity) was applied as a method in papers I III. The macro-level perspective was applied to evaluate CO2 emission reduction targets (paper II) and the sharing of greenhouse gas emission reduction targets (paper IV) in the European Union (EU27) up to the year 2020. Data for the study were mainly gathered from official statistics. In all cases, the results were discussed from an environmental policy perspective. The development of nitrogen oxide (NOx) emissions was analysed in the Finnish energy sector during a long time period, 1950 2003 (paper I). Finnish emissions of NOx began to decrease in the 1980s as the progress in technology in terms of NOx/energy curbed the impact of the growth in affluence and population. Carbon dioxide (CO2) emissions related to energy use during 1993 2004 (paper II) were analysed by country and region within the European Union. Considering energy-based CO2 emissions in the European Union, dematerialization and decarbonisation did occur, but not sufficiently to offset population growth and the rapidly increasing affluence during 1993 2004. The development of nitrogen and phosphorus load from aquaculture in relation to salmonid consumption in Finland during 1980 2007 was examined, including international trade in the analysis (paper III). A regional environmental issue, eutrophication of the Baltic Sea, and a marginal, yet locally important source of nutrients was used as a case. Nutrient emissions from Finnish aquaculture decreased from the 1990s onwards: although population, affluence and salmonid consumption steadily increased, aquaculture technology improved and the relative share of imported salmonids increased. According to the sustainability challenge in industrial ecology, the environmental impact of the growing population size and affluence should be compensated by improvements in technology (emissions/service used) and with dematerialisation. In the studied cases, the emission intensity of energy production could be lowered for NOx by cleaning the exhaust gases. Reorganization of the structure of energy production as well as technological innovations will be essential in lowering the emissions of both CO2 and NOx. Regarding the intensity of energy use, making the combustion of fuels more efficient and reducing energy use are essential. In reducing nutrient emissions from Finnish aquaculture to the Baltic Sea (paper III) through technology, limits of biological and physical properties of cultured fish, among others, will eventually be faced. Regarding consumption, salmonids are preferred to many other protein sources. Regarding trade, increasing the proportion of imports will outsource the impacts. Besides improving technology and dematerialization, other viewpoints may also be needed. Reducing the total amount of nutrients cycling in energy systems and eventually contributing to NOx emissions needs to be emphasized. Considering aquaculture emissions, nutrient cycles can be partly closed through using local fish as feed replacing imported feed. In particular, the reduction of CO2 emissions in the future is a very challenging task when considering the necessary rates of dematerialisation and decarbonisation (paper II). Climate change mitigation may have to focus on other greenhouse gases than CO2 and on the potential role of biomass as a carbon sink, among others. The global population is growing and scaling up the environmental impact. Population issues and growing affluence must be considered when discussing emission reductions. Climate policy has only very recently had an influence on emissions, and strong actions are now called for climate change mitigation. Environmental policies in general must cover all the regions related to production and impacts in order to avoid outsourcing of emissions and leakage effects. The macro-level drivers affecting changes in emissions can be identified with the ImPACT framework. Statistics for generally known macro-indicators are currently relatively well available for different countries, and the method is transparent. In the papers included in this study, a similar method was successfully applied in different types of case studies. Using transparent macro-level figures and a simple top-down approach are also appropriate in evaluating and setting international emission reduction targets, as demonstrated in papers II and IV. The projected rates of population and affluence growth are especially worth consideration in setting targets. However, sensitivities in calculations must be carefully acknowledged. In the basic form of the ImPACT model, the economic intensity of consumption and emission intensity of use are included. In seeking to examine consumption but also international trade in more detail, imports were included in paper III. This example demonstrates well how outsourcing of production influences domestic emissions. Country-specific production-based emissions have often been used in similar decomposition analyses. Nevertheless, trade-related issues must not be ignored.

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This case study has been carried out as a comparison between two different land-use strategies for climate change mitigation, with possible application within the Clean Development Mechanisms. The benefits of afforestation for carbon sequestration versus for bioenergy production are compared in the context of development planning to meet increasing domestic and agricultural demand for electricity in Hosahalli village, Karnataka, India. One option is to increase the local biomass based electricity generation, requiring an increased biomass plantation area. This option is compared with fossil based electricity generation where the area is instead used for producing wood for non-energy purposes while also sequestering carbon in the soil and standing biomass. The different options have been assessed using the PRO-COMAP model. The ranking of the different options varies depending on the system boundaries and time period. Results indicate that, in the short term (30 years) perspective, the mitigation potential of the long rotation plantation is largest, followed by the short rotation plantation delivering wood for energy. The bioenergy option is however preferred if a long-term view is taken. Short rotation forests delivering wood for short-lived non-energy products have the smallest mitigation potential, unless a large share of the wood products are used for energy purposes (replacing fossil fuels) after having served their initial purpose. If managed in a sustainable manner all of these strategies can contribute to the improvement of the social and environmental situation of the local community. (C) 2009 Elsevier Ltd. All rights reserved.

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We deal with a single conservation law with discontinuous convex-concave type fluxes which arise while considering sign changing flux coefficients. The main difficulty is that a weak solution may not exist as the Rankine-Hugoniot condition at the interface may not be satisfied for certain choice of the initial data. We develop the concept of generalized entropy solutions for such equations by replacing the Rankine-Hugoniot condition by a generalized Rankine-Hugoniot condition. The uniqueness of solutions is shown by proving that the generalized entropy solutions form a contractive semi-group in L-1. Existence follows by showing that a Godunov type finite difference scheme converges to the generalized entropy solution. The scheme is based on solutions of the associated Riemann problem and is neither consistent nor conservative. The analysis developed here enables to treat the cases of fluxes having at most one extrema in the domain of definition completely. Numerical results reporting the performance of the scheme are presented. (C) 2006 Elsevier B.V. All rights reserved.

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Differential Unitary Space-Time Block codes (STBCs) offer a means to communicate on the Multiple Input Multiple Output (MIMO) channel without the need for channel knowledge at both the transmitter and the receiver. Recently Yuen-Guan-Tjhung have proposed Single-Symbol-Decodable Differential Space-Time Modulation based on Quasi-Orthogonal Designs (QODs) by replacing the original unitary criterion by a scaled unitary criterion. These codes were also shown to perform better than differential unitary STBCs from Orthogonal Designs (ODs). However the rate (as measured in complex symbols per channel use) of the codes of Yuen-Guan-Tjhung decay as the number of transmit antennas increase. In this paper, a new class of differential scaled unitary STBCs for all even number of transmit antennas is proposed. These codes have a rate of 1 complex symbols per channel use, achieve full diversity and moreover they are four-group decodable, i.e., the set of real symbols can be partitioned into four groups and decoding can be done for the symbols in each group separately. Explicit construction of multidimensional signal sets that yield full diversity for this new class of codes is also given.