974 resultados para Problems increased


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Lipeä on vahva emäs, jonka on havaittu lisäävän hemiselluloosan ja ligniinin hydrolyysiä pötsissä. Näin ollen lipeäkäsittelyllä on mahdollista korvata viljan mekaaninen litistys ja jauhatus. Seosrehuruokinnalla, jonka osana on lipeäkäsitelty vilja, on mahdollista vähentää liiallisesta tärkkelyksestä aiheutuvia metabolisia ongelmia pötsissä. Tämän tutkielman tarkoituksena oli selvittää lipeäkäsitellyn vehnän vaikutusta lypsylehmien syöntiin ja tuotokseen ad libitum seosrehuruokinnoilla. Ruokinnoissa korvattiin kuivaa murskattua vehnää asteittain kokonaisella lipeäkäsitellyllä vehnällä. Kontrollina oli perinteisesti käytetty kuiva, murskattu ohra-kaura seos. Koe tehtiin Ruotsin maatalousyliopiston (SLU) maataloustieteiden laitoksella Uumajassa. Koe alkoi syyskuussa ja päättyi joulukuussa 2010. Kokeessa oli 17 useamman kerran poikinutta lehmää ja 6 ensikkoa (Ruotsin punainen -rotu). Lehmät olivat lämpimässä pihattonavetassa, jossa seosrehun syöntiä mitattiin vaakakuppien avulla. Koekäsittelyt olivat murskattu ohra-kaura seos (1:1), murskattu kuiva vehnä (1:0), murskatun kuivan vehnän ja kokonaisen lipeävehnän seos (1:1) ja kokonainen lipeävehnä (1:0). Ruokintojen kuiva-ainepitoisuudeksi asetettiin 370 g/kg ja raakavalkuaispitoisuudeksi 180 g/kg kuiva-ainetta. Näennäinen ravintoaineen sulavuus määritettiin happoon liukenemattoman tuhkan avulla. Typen hyväksikäyttöä arvioitiin laskennallisen typpitaseen avulla. Koe toteutettiin 4x4 latinalaisen neliön koemallin mukaisesti ja käsittelyjen väliset tilastolliset erot testattiin kontrastien avulla. Kuiva-aineen (PQ=0,02) ja orgaanisen aineen (PQ=0,02) syönnit lisääntyivät, samalla kun niiden sulavuudet paranivat korvattaessa puolet kuivasta vehnästä lipeävehnällä. Ruokintojen välillä ei ollut tilastollisesti merkitsevää eroa maitotuotoksessa eikä energiakorjatussa maitotuotoksessa. Maidon rasvatuotos lisääntyi vähän (PQ=0,04) ja rasvapitoisuus selvästi (PQ=0,004), kun kuivasta vehnästä korvattiin puolet lipeävehnällä. Kun kaikki kuiva vehnä korvattiin lipeävehnällä, maidon valkuaispitoisuus väheni (PL<0,001). Samoin kävi maidon ureapitoisuudelle (PL=0,002). Lipeäkäsittely ei tuottanut tässä kokeessa taloudellisesti kannattavaa tulosta, sillä maidon valkuaispitoisuus väheni ja syönti lisääntyi maitotuotoksen pysyessä samana. Vehnäruokinnoista paras tuotosvaste saatiin kuivan vehnän ja lipeävehnän seoksella.

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Methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pneumoniae are major health problems worldwide, both found in symptomless carriage but also causing even life-threatening infections. The aim of this thesis was to characterise MRSA and S. pneumoniae in detail by using several molecular typing methods for various epidemiological purposes: clonality analysis, epidemiological surveillance, outbreak investigation, and virulence factor analysis. The characteristics of MRSA isolates from the strain collection of the Finnish National Infectious Disease Register (NIDR) and pneumococcal isolates collected from military recruits and children with acute otitis media (AOM) were analysed using various typing techniques. Antimicrobial susceptibility testing, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), spa typing, staphylococcal cassette chromosome mec (SCCmec) typing, and the detection of Panton-Valentine leukocidin (PVL) genes were performed for MRSA isolates. Pneumococcal isolates were analysed using antimicrobial susceptibility testing, serotyping, MLST, and by detecting pilus islet 1 (PI-1) and 2 (PI-2) genes. Several international community- and hospital-associated MRSA clones were recognised in Finland. The genetic diversity among MRSA FIN-4 isolates and among FIN-16 isolates was low. Overall, MRSA blood isolates from 1997 to 2006 were genetically diverse. spa typing was found to be a highly discriminatory, rapid and accurate typing method and it also qualifies as the primary typing method in countries with a long history of PFGE-based MRSA strain nomenclature. However, additional typing by another method, e.g. PFGE, is needed in certain situations to be able to provide adequate discrimination for epidemiological surveillance and outbreak investigation. An outbreak of pneumonia was associated with one pneumococcal strain among military recruits, previously healthy young men living in a crowded setting. The pneumococcal carriage rate after the outbreak was found to be exceptionally high. PI-1 genes were detected at a rather low prevalence among pneumococcal isolates from children with AOM. However, the study demonstrated that PI-1 has existed among pneumococcal isolates prior to pneumococcal conjugate vaccine and the increased antimicrobial resistance era. Moreover, PI-1 was found to associate with the serotype rather than the genotype. This study adds to our understanding of the molecular epidemiology of MRSA strains in Finland and the importance of an appropriate genotyping method to be able to perform high-level laboratory-based surveillance of MRSA. Epidemiological and molecular analyses of S. pneumoniae add to our knowledge of the characteristics of pneumococcal strains in Finland.

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This study aims at identifying the existing and potential resources, as well as recognizing the hinderances, for community-based ecotourism development in the Taita Hills in south-eastern Kenya. The indigenous mountain rain forests on the hills are rich in biodiversity, but severely degraded because of encroachment caused by the dynamics of increased population, socio-politics and economics. The research problems are based on the hypothesis that there is no tourism in the Taita Hills generating income for the local economy and high population density combined with poverty creates a need for alternative employment opportunities as well as for sustainable ways of forest resource management. The data for this study was gathered during two field trips in Kenya, in January-February 2004 and 2005, as a part of the Taita Project within the Department of Geography at the University of Helsinki. The qualitative methods used consist of RRA and PRA techniques, in-depth interviews, a structured questionnaire and literature analysis as well as attendance on excursions and a workshop with conservation experts and officials. Four case areas in the Taita Hills are studied. The study concludes that alternative livelihoods are needed among the Taita Hills´ rural population and community-based ecotourism is seen as a way of bringing financial benefits for households as well as reviving the fading cultural traditions and indigenous knowledge about forest use. The governmental policies, district level development plans and some NGOs support ecotourism development. The Forest Act 2005 forms base for local participation in forest management. The unique natural features, the welcoming Taita-culture and the location in the coastal tourism circle favour Taita Hills. However, this kind of development has its risks, such as too rapid change of sorest usage level and the exposure of communities to an ecotourism treadmill process. The costbenefit ration of marketing for hard ecotourists is generally low and the tourism infrastructure needs upgrading in the Taita Hills. More tight collaboration is important between the different level stakeholders working for conservation and development. Community-based ecotourism in Taita Hills, when carefully planned and managed, could be one opportunity for Kenya to diversify its tourism product supply and for forestadjacent communities to gain tangible benefits on a sustainable basis from forests.

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In recent years urban hydrology and individual urban streams have been in focus and subjects to research also in Helsinki. However, until now there has been lack of research covering simultaneously the whole area of the city of Helsinki. The aim of this study was to find out the general state of water quality in small urban streams in the city of Helsinki. 21 streams were studied: Mätäjoki, Korppaanoja, Mätäpuro, Näsinoja-Tuomarinkylänoja, Tuomarinkartanonpuro, Kumpulanpuro, Tapaninkylänpuro, Tapaninvainionpuro, Puistolanpuro, Longinoja, Säynäslahdenpuro, Viikinoja, Porolahdenpuro, Mustapuro, Marjaniemenpuro, Mellunkylänpuro, Vuosaarenpuro, Rastilanpuro, Ramsinkannaksenpuro, Skatanpuro and Yliskylänpuro. Water samples were collected from 48 sampling points, each stream having at least one point. Four water samples were collected from each point, sampling periods being 9.-11.2., 26.-28.4., 29.6.-1.7. and 25.-27.10.2004. Field measurements associated with water sampling included water temperature, oxygen concentration, pH and electrical conductivity. Water samples were analysed in the Laboratory of Physical Geography in the University of Helsinki and in the Environmental Laboratory of the City of Helsinki Environment Centre for following properties: suspended solids, dissolved substances, alkalinity, principal anions and cations (Na+, K+, Mg2+, Ca2+, F-, Cl-, NO3-, PO43- and SO42-), colour, turbidity, biological and chemical oxygen demand (BOD7 and CODMn-values), nutrient concentrations and bacterial indicators of hygienic quality. The main water quality issues found in this study were low oxygen levels in many streams and poor hygienic quality at least occasionally. E.g. in summer oxygen levels were under 60 % in every stream. Amount of total dissolved substances and nutrients were high in some of the streams studied. Compared to other Finnish streams the values of alkalinity and pH were higher. Although these problems were common, the variation between different streams and sampling points was significant. This was probably due to local conditions. Best overall water quality was found in Mätäpuro and Tuomarinkartanonpuro streams. Seasonal variation was evident in almost all water quality properties. For example the total amount of dissolved substances was largest in winter and decreased during the year. Colour and turbidity were smallest in winter and increased towards the end of the year. The same was true for suspended solids, which had smallest concentration in winter and greatest in autumn. It must be kept in mind that the spring samples were collected after the spring flood otherwise the largest suspended solid concentrations would have been expected in spring. Finnish general water quality classification was used to assess the quality of urban stream waters. Its suitability for small urban streams is not, however, completely trouble-free. This classification does not take into account the quick changes in such small streams but evaluates only the yearly mean values. This can oversimplify the picture of the water quality situation in the streams. Also in order to better reflect the urban environment the analysed water quality properties should also include total dissolved substances and e.g. concentrations of chloride and sodium.

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The set of attainable laws of the joint state-control process of a controlled diffusion is analyzed from a convex analytic viewpoint. Various equivalence relations depending on one-dimensional marginals thereof are defined on this set and the corresponding equivalence classes are studied.

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In this work, we present a new monolithic strategy for solving fluid-structure interaction problems involving incompressible fluids, within the context of the finite element method. This strategy, similar to the continuum dynamics, conserves certain properties, and thus provides a rational basis for the design of the time-stepping strategy; detailed proofs of the conservation of these properties are provided. The proposed algorithm works with displacement and velocity variables for the structure and fluid, respectively, and introduces no new variables to enforce velocity or traction continuity. Any existing structural dynamics algorithm can be used without change in the proposed method. Use of the exact tangent stiffness matrix ensures that the algorithm converges quadratically within each time step. An analytical solution is presented for one of the benchmark problems used in the literature, namely, the piston problem. A number of benchmark problems including problems involving free surfaces such as sloshing and the breaking dam problem are used to demonstrate the good performance of the proposed method. Copyright (C) 2010 John Wiley & Sons, Ltd.

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The plane stress solution for the interaction analysis of a framed structure, with a foundation beam, resting on a layered soil has been studied using both theoretical and photoelastic methods. The theoretical analysis has been done by using a combined analytical and finite element method. In this, the analytical solution has been used for the semi-infinite layered medium and finite element method for the framed structure. The experimental investigation has been carried out using two-dimensional photoelasticity in which modelling of the layered semi-infinite plane and a method to obtain contact pressure distribution have been discussed. The theoretical and experimental results in respect of contact pressure distribution between the foundation beam and layered soil medium, the fibre stresses in the foundation beam and framed structure have been compared. These results have also been compared with theoretical results obtained by idealizing the layered semi-infinite plane as (a) a Winkler model and (b) an equivalent homogeneous semi-infinite medium

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In linear elastic fracture mechanics (LEFM), Irwin's crack closure integral (CCI) is one of the signficant concepts for the estimation of strain energy release rates (SERR) G, in individual as well as mixed-mode configurations. For effective utilization of this concept in conjunction with the finite element method (FEM), Rybicki and Kanninen [Engng Fracture Mech. 9, 931 938 (1977)] have proposed simple and direct estimations of the CCI in terms of nodal forces and displacements in the elements forming the crack tip from a single finite element analysis instead of the conventional two configuration analyses. These modified CCI (MCCI) expressions are basically element dependent. A systematic derivation of these expressions using element stress and displacement distributions is required. In the present work, a general procedure is given for the derivation of MCCI expressions in 3D problems with cracks. Further, a concept of sub-area integration is proposed which facilitates evaluation of SERR at a large number of points along the crack front without refining the finite element mesh. Numerical data are presented for two standard problems, a thick centre-cracked tension specimen and a semi-elliptical surface crack in a thick slab. Estimates for the stress intensity factor based on MCCI expressions corresponding to eight-noded brick elements are obtained and compared with available results in the literature.

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The Modified Crack Closure Integral (MCCI) technique based on Irwin's crack closure integral concept is very effective for estimation of strain energy release rates G in individual as well as mixed-mode configurations in linear elastic fracture mechanics problems. In a finite element approach, MCCI can be evaluated in the post-processing stage in terms of nodal forces and displacements near the crack tip. The MCCI expressions are however, element dependent and require a systematic derivation using stress and displacement distributions in the crack tip elements. Earlier a general procedure was proposed by the present authors for the derivation of MCCI expressions for 3-dimensional (3-d) crack problems modelled with 8-noded brick elements. A concept of sub-area integration was proposed to estimate strain energy release rates at a large number of points along the crack front. In the present paper a similar procedure is adopted for the derivation of MCCI expressions for 3-d cracks modelled with 20-noded brick elements. Numerical results are presented for centre crack tension and edge crack shear specimens in thick slabs, showing a comparison between present results and those available in the literature.

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Progress in the development of contraceptive vaccines for males and females is reviewed. Based on the criteria which need to be met with, none of the proposed candidate antigens meets the requirements for use as a contraceptive vaccine for human application. One of the major problems is the need for periodic injections to maintain required titre and use of an alternate method until effective titres are obtained. Some of the problems associated with active immunization approach can be overcome by the use of preformed, highly specific, potent antibodies. Some progress has been achieved in this direction by the use of humanized single chain monoclonal antibodies to human chorionic gonadotropin.

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The Modified Crack Closure Integral (MCCI) technique based on Irwin's crack closure integral concept is very effective for estimation of strain energy release rates G in individual as well as mixed-mode configurations in linear elastic fracture mechanics problems. In a finite element approach, MCCI can be evaluated in the post-processing stage in terms of nodal forces and displacements near the crack tip. The MCCI expressions are however, element dependent and require a systematic derivation using stress and displacement distributions in the crack tip elements. Earlier a general procedure was proposed by the present authors for the derivation of MCCI expressions for 3-dimensional (3-d) crack problems modelled with 8-noded brick elements. A concept of sub-area integration was proposed to estimate strain energy release rates at a large number of points along the crack front. In the present paper a similar procedure is adopted for the derivation of MCCI expressions for 3-d cracks modelled with 20-noded brick elements. Numerical results are presented for centre crack tension and edge crack shear specimens in thick slabs, showing a comparison between present results and those available in the literature.

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Calcium/calmodulin dependent protein kinase II (CaMKII) is implicated to play a key role in learning and memory. NR2B subunit of N-methyl-D-aspartate receptor (NMDAR) is a high affinity binding partner of CaMKII at the postsynaptic membrane. NR2B binds to the T-site of CaMKII and modulates its catalysis. By direct measurement using isothermal titration calorimetry (ITC), we show that NR2B binding causes about 11 fold increase in the affinity of CaMKII for ATP gamma S, an analogue of ATP. ITC data is also consistent with an ordered binding mechanism for CaMKII with ATP binding the catalytic site first followed by peptide substrate. We also show that dephosphorylation of phospho-Thr(286)-alpha-CaMKII is attenuated when NR2B is bound to CaMKII. This favors the persistence of Thr(286) autophosphorylated state of CaMKII in a CaMKII/phosphatase conjugate system in vitro. Overall our data indicate that the NR2B- bound state of CaMKII attains unique biochemical properties which could help in the efficient functioning of the proposed molecular switch supporting synaptic memory.

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We illustrate the potential of using higher order critical points in the deeper understanding of several interesting problems of condensed matter science, e.g. critical adsorption, finite size effects, morphology of critical fluctuations, reversible aggregation of colloids, dynamics of the ordering process, etc.

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This paper presents a dan-based evolutionary approach for solving control problems. Three selected control problems, viz. linear-quadratic, harvest, and push-cart problems, are solved using the proposed approach. Results are compared with those of the evolutionary programming (EP) approach. In most of the cases, the proposed approach is successful in obtaining (near) optimal solutions for these selected problems.