69,988 research outputs found

    Stability estimates for the inverse boundary value problem by partial Cauchy data

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    In this paper we study the inverse conductivity problem with partial data in dimension n3n\geq 3. We derive stability estimates for this inverse problem if the conductivity has C1,σ(Ωˉ)H3/2+σ(Ω)C^{1,\sigma}(\bar\Omega)\cap H^{3/2+\sigma}(\Omega) regularity for 0<σ<10<\sigma<1

    Bobot minimal arborescence dari graph berarah dan aplikasinya

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    Graph berara,h G = ( V,E ) memuat suatu arbores¬cence /—= ( V,T ) dengan TCE dan mempunyai bobot w(T) Arborescence adalah suatu tree (pohon) yang mempunyai satu akar dan setiap titik lainnya (berbeda dengan akar) di da¬lam-G dapat dicapal hanya dengan satu lintasan saja lai dari akar tersebut. Melalui definisi dan teorema akan dicari suatu penyelesaian masalah untuk mendapatkan arbo rescence dengan bobot minimal. Serta dipakai suatu algorit ma dan flow chart untuk memahami langkah-langkah penyele¬saianny

    Behaviour of carbon dioxide and water vapour flux densities from a disturbed raised peat bog

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    Measurements of carbon dioxide and water vapour flux densities were carried out for a disturbed raised peat bog in the north of the Netherlands during an 18 month continuous experiment. Tussock grass (sp. Molinea caerulae) mainly dominated the vegetation of the bog area. The maximum leaf area index (LAI) of the vegetation reached a numerical value of about 1.7 in mid-August. When the LAI is large enough (LAI > 0.2), a mean net uptake of carbon dioxide is observed with a clear daily pattern. The total evapotranspiration consists of a soil, an open water, and a plant transpiration part. When the LAI is large enough (LAI > 0.2), plant transpiration dominates the total evapotranspiration. The mean daily transpiration pattern, however, is not similar to the carbon dioxide uptake pattern. During the summer months, the daytime carbon dioxide uptake shows a single early morning maximum value followed by a decline in uptake during the rest of the day. The evapotranspiration, however, follows more or less the incoming short-wave radiation pattern. Effects of the vapour pressure deficit are suggested as a possible cause of this discrepanc

    Determining fPAR and leaf area index of several land cover classes in the Pot River and Tsitsa River catchments of the Eastern Cape, South Africa

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    Determining the quantum (both annual maxima and minima) and the temporal variation in the leaf area index (LAI), and the fraction of photosynthetically active radiation (fPAR), are three fundamental biophysical characteristics of the plant canopy that should parameterise ecophysiological models of water use (evapotranspiration) and carbon sequestration. Although Earth observation provides values and time series for both these parameters, in-field validation of these values is necessary. Following a very wet summer season, we conducted field surveys of several land cover classes within two quaternary catchments in the Eastern Cape province, South Africa, to determine maximum values of LAI and fPAR that occur within each of these land cover classes. To assist in up-scaling these point measures to the landscape, we present a regression relationship between Landsat 8 NDVI and LAI measured using an Accupar Ceptometer (r2 = 0.92). Peak wet season LAI varied from extremely high (&gt;7.0) under the canopy of invasive black wattle (Acacia mearnsii) trees to ~2.0 under the canopy of a Eucalyptus plantation. Ungrazed native grassland displayed an intermediate LAI value of 3.84. The black wattle stand absorbed 97% of the available PAR, whereas the mature Eucalyptus plantation only absorbed 66% of PAR.Keywords: agroforestry, ecosystem ecology, remote sensin

    hμ+μh \to \mu^+\mu^- via gluon fusion at the LHC

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    We study the observability of the hμ+μh\to \mu^+\mu^- decay in the Standard Model and the MSSM at the LHC. The observation of the hμμh\mu\mu coupling is important to determine whether the Higgs particle that generates mass for the weak bosons is also responsible for mass generation of the second generation of fermions. We find that the signal via the gluon fusion channel is comparable to that from the weak-boson fusion. By combining these two channels, observing hμ+μh\to \mu^+\mu^- is feasible at the LHC with a delivered luminosity of 300fb1300 fb^{-1} at 3σ3\sigma statistical significance for 110 GeV <mh<140<m_h<140 GeV in the Standard Model. This corresponds to a hμμh\mu\mu coupling determination at about 15% accuracy assuming httˉ,hbbˉht\bar t, hb\bar b couplings SM-like. The observation becomes more promising in the MSSM for tanβ>8\tan\beta>8 and MA<130M_A<130.Comment: 7 pages, 3 figure

    A phage-displayed peptide recognizing porcine aminopeptidase N is a potent small molecule inhibitor of PEDV entry

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    Three phage-displayed peptides designated H, S and F that recognize porcine aminopeptidase N (pAPN), the cellular receptor of porcine transmissible gastroenteritis virus (TGEV) were able to inhibit cell infection by TGEV. These same peptides had no inhibitory effects on infection of Vero cells by porcine epidemic diarrhea virus (PEDV). However, when PEDV, TGEV and porcine pseudorabies virus were incubated with peptide H (HVTTTFAPPPPR), only infection of Vero cells by PEDV was inhibited. Immunofluorescence assays indicated that inhibition of PEDV infection by peptide H was independent of pAPN. Western blots demonstrated that peptide H interacted with PEDV spike protein and that pre-treatment of PEDV with peptide H led to a higher inhibition than synchronous incubation with cells. These results indicate direct interaction with the virus is necessary to inhibit infectivity. Temperature shift assays demonstrated that peptide H inhibited pre-attachment of the virus to the cells

    A new method for extracting the bottom quark Yukawa coupling at the CERN Large Hadron Collider

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    We propose a new method for measuring the H -> bb rate at the CERN LHC in a manner which would allow extraction of the b quark Yukawa coupling. Higgs boson production in purely electroweak WHjj events is calculated. The Standard Model signal rate including decays W -> l nu and H -> bb is 11 fb for M_H = 120 GeV. It is possible to suppress the principal backgrounds, Wbbjj and ttjj, to approximately the level of the signal. As the top quark Yukawa coupling does not appear in this process, it promises a reliable extraction of g_Hbb in the context of the Standard Model or some extensions, such as the MSSM.Comment: added background, updated/added references, additional comment

    Modelling the recent historical impacts of atmospheric CO2 and climate change on Mediterranean vegetation

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    During the past century, annual mean temperature has increased by 0.75 degrees C and precipitation has shown marked variation throughout the Mediterranean basin. These historical climate changes may have had significant, but presently undefined, impacts on the productivity and structure of sclerophyllous shrubland, an important vegetation type in the region. We used a vegetation model for this functional type to examine climate change impacts, and their interaction with the concurrent historical rise in atmospheric CO2. Using only climate and soil texture as data inputs, model. predictions showed good agreement with observations of seasonal and regional variation in leaf and canopy physiology, net primary productivity (NPP), leaf area index (LAI) and soil water. Model simulations for shrubland sites indicated that potential NPP has risen by 25% and LAI by 7% during the past century, although the absolute increase in LAI was small. Sensitivity analysis suggested that the increase in atmospheric CO2 since 1900 was the primary cause of these changes, and that simulated climate change alone had negative impacts on both NPP and LAI. Effects of rising CO2 were mediated by significant increases in the efficiency of water-use in NPP throughout the region, as a consequence of the direct effect of CO2 on leaf gas exchange. This increase in efficiency compensated for limitation of NPP by drought, except in areas where drought was most severe. However, while water was used more efficiently, total canopy water loss rose slightly or remained unaffected in model simulations, because increases in LAI with CO2 counteracted the effects of reduced stomatal conductance on transpiration. Model simulations for the Mediterranean region indicate that the recent rise in atmospheric CO2 may already have had significant impacts on productivity, structure and water relations of sclerophyllous shrub vegetation, which tended to offset the detrimental effects of climate change in the region

    Genomic Dna Extraction Method From Mature Leaf Of Lai (Durio Kutejensis Becc.)

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    Lai (Durio kutejensis Becc.) is an indigeneous germplasm of Kalimantan which has some superiorities compared to its close-relative, durian (Durio zibethinus Murr.). Genetic exploration of lai is important to support its breeding program. According to rapid development in molecular biology, genetic exploration effort of lai will be easier. One of significant step in any molecular biology activities is DNA isolation to produce high quality DNA for further analysis. Leaves of lai, as other perennial crop, contain of high concen-tration of polysaccharides and polyphenol which will be co-extracted with the DNA. These compounds can interfere enzymes activities in subsequent molecular analysis. The aim of this study was to establish an optimal and effective DNA extraction method to obtain high-quality DNA from mature leaf of lai. An established extraction buffer and its modification were used in this study. The result showed that modification 4 could produce high quality DNA, and was considered to be the most effective DNA extraction method for mature leaf of lai
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