931 resultados para blocking


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The effect of injecting agonistic and antagonistic analogues of gonadotropin releasing hormone analogues on serum testosterone levels was checked in adult and immature male bonnet monkeys. Of the agonistic analogues Buserelin, Ovurelin and D-Phe6 Gln8 GnRH were found to be most potent in increasing serum testosterone levels in the adult male bonnet monkeys. While 27-month-old monkeys responded well to des Gly10 GnRH, only marginal response was observed in the case of 15-month-old monkeys. Studies carried out with Ovurelin indicated that it was not effective in causing desensitization in adult monkeys. The antagonistic analogue was effective in blocking nocturnal surge of serum testosterone. Based on these studies it is suggested the adult male bonnet monkeys can be effectively used for testing the activity of GnRH analogues.

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We show that the ratio of matched individuals to blocking pairs grows linearly with the number of propose–accept rounds executed by the Gale–Shapley algorithm for the stable marriage problem. Consequently, the participants can arrive at an almost stable matching even without full information about the problem instance; for each participant, knowing only its local neighbourhood is enough. In distributed-systems parlance, this means that if each person has only a constant number of acceptable partners, an almost stable matching emerges after a constant number of synchronous communication rounds. We apply our results to give a distributed (2 + ε)-approximation algorithm for maximum-weight matching in bicoloured graphs and a centralised randomised constant-time approximation scheme for estimating the size of a stable matching.

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Many next-generation distributed applications, such as grid computing, require a single source to communicate with a group of destinations. Traditionally, such applications are implemented using multicast communication. A typical multicast session requires creating the shortest-path tree to a fixed number of destinations. The fundamental issue in multicasting data to a fixed set of destinations is receiver blocking. If one of the destinations is not reachable, the entire multicast request (say, grid task request) may fail. Manycasting is a generalized variation of multicasting that provides the freedom to choose the best subset of destinations from a larger set of candidate destinations. We propose an impairment-aware algorithm to provide manycasting service in the optical layer, specifically OBS. We compare the performance of our proposed manycasting algorithm with traditional multicasting and multicast with over provisioning. Our results show a significant improvement in the blocking probability by implementing optical-layer manycasting.

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Sydämen krooninen vajaatoiminta on merkittävä maailmanlaajuinen ongelma. Se on erilaisten sydän- ja verisuonisairauksien aiheuttama monimuotoinen oireyhtymä. Sydämen vasemman kammion hypertrofia eli sydämen seinämien paksuuntuminen on yksi keskeinen tekijä, joka voi olla sydämen vajaatoiminnan taustalla. Kohonnut verenpaine on yleisin syy, joka johtaa sydänlihaksen paksuuntumiseen. Tämä johtaa sydämen pumppaustoiminnan häiriintymiseen, erilaisten neurohormonaalisten mekanismien aktivaatioon ja edelleen sydämen vajaatoimintaan. Sydämen vajaatoiminnan neurohormonaalisista mekanismeista tärkeimmät ovat reniini-angiotensiini-aldosteroni-järjestelmän ja sympaattisen hermoston aktivaatio, sydämen rakenteiden uudelleenmuovautuminen, sydänlihassolujen apoptoosi ja systeeminen tulehdustila. Sydämen hypertrofiaa ja sen syntymistä pyritään estämään kohonneen verenpaineen lääkehoidolla. Reniini-angiotensiini-aldosteronijärjestelmällä on keskeinen merkitys sydämen vajaatoiminnassa. Sydämen vajaatoiminnan ennusteeseen vaikuttavista lääkeaineista angiotensiinikonvertasin estäjät (ACEestäjät) ovat säilyttäneet johtoasemansa jo vuosikymmenten ajan. Angiotensiinireseptoreiden salpaajien (AT1-salpaajien) odotettiin syrjäyttävän ACE-estäjät sydämen vajaatoiminnan hoidossa, mutta toistaiseksi niitä pidetään vain vaihtoehtoisina lääkkeinä. Sympaattisen hermoston aktivaatiota vähentävät β-salpaajat ovat vakiinnuttaneet asemansa toiseksi tärkeimpänä lääkeryhmänä. Diureetit ovat paljon käytetty lääkeaineryhmä sydämen vajaatoiminnan hoidossa, mutta niistä ainoastaan aldosteroniantagonisteilla on tutkitusti ennustetta parantavaa vaikutusta. Kroonisen vajaatoiminnan hoidossa käytetään edelleen myös digoksiinia. Tulevaisuudessa sydämen vajaatoiminnan ennusteeseen vaikuttavia lääkeaineita voivat olla reniinin estäjät, neutraaliendopeptidaasin estäjät, vasopressiinin antagonistit tai inflammatroisiin sytokiineihin vaikuttavat molekyylit. Erikoistyön kokeellisessa osiossa tarkoituksena oli tutkia sydämen hypertrofian kehittymistä vatsa-aortta kuristetuilla rotilla ja kalsiumherkistäjä levosimendaanin sekä AT1-salpaaja valsartaanin vaikutuksia hypertrofian kehittymiseen. Kokeellisessa osiossa arvioitiin myös sydämen hypertrofian ja vajaatoiminnan jyrsijämallina käytetyn vatsa-aortan kuristuksen (koarktaation) toimivuutta ja vaikutuksia ultraäänen avulla määritettyihin kardiovaskulaarisiin parametreihin. Vatsa-aortta kuristettiin munuaisvaltimoiden yläpuolelta. Kuristus saa aikaan verenpaineen kohoamisen ja sydämen työtaakan lisääntymisen. Pitkittyessään tila johtaa sydänlihaksen hypertrofiaan ja vajaatoimintaan. 64 eläintä jaettiin ryhmiin, siten että jokaiseen ryhmään tuli kahdeksan eläintä. Ryhmistä kolmelle annettiin lääkeaineena levosimendaania kolmella eri päiväannoksella (0,01 mg/kg; 0,10 mg/kg; 1,00 mg/kg) ja kolmelle valsartaania kolmella eri päiväannoksella (0,10 mg/kg; 1,00 mg/kg; 10,00 mg/kg) juomaveden mukana. Lääkitys aloitettiin leikkauksen jälkeen ja jatkettiin kahdeksan viikon ajan. Kardiovaskulaariset parametrit, kuten isovolumetrinen relaksaatioaika (IVRT), vasemman kammion läpimitta systolessa ja diastolessa sekä seinämäpaksuudet, ejektiofraktio (EF), supistuvuusosuus (FS), minuuttitilavuus (CO) ja iskutilavuus (SV) määritettiin kahdeksan viikon kuluttua leikkauksesta ultraäänitutkimuksen avulla. Lisäksi määritettiin eläinten sydämen paino suhteessa ruumiin painoon. Tuloksia verrattiin ilman lääkehoitoa olleeseen koarktaatioryhmään. Eläinmallin toimivuutta arvioitiin vertaamalla koarktaatioryhmän tuloksia sham-operoidun ryhmän tuloksiin. Levosimendaanilla havaittiin työssä sydämen systolista toimintaa parantava vaikutus. Tämä näkyi tendenssinä parantaa ejektiofraktioita ja vasemman kammion supistuvuusosuuksia. Sydämen diastoliseen toimintaan ei kummallakaan lääkeaineella ollut merkittävää vaikutusta. Diastolista toimintaa arvioitiin isovolumetrisen relaksaatioajan muutoksilla. Sydämen hypertrofian kehittymiseen ei kummallakaan lääkeaineella ollut merkittävää vaikutusta. Eläinmallin todettiin mallintavan hyvin sydämen hypetrofiaa ihmisellä, mutta ei niinkään sydämen vajaatoimintaa.

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Nybildning av blodkärl från tidigare existerande kärl, angiogenes, är ett väsentligt skede vid tumörtillväxt. Denna process regleras av bland annat tillväxtfaktorer, var av den vaskulära endoteliala tillväxtfaktorn har en central roll. Hämning av angiogenes kan ske antingen extracellulärt med hjälp av humaniserade monoklonala antikroppar eller intracellulärt med hjälp av småmolekylära hämmaren. Sunitinib är en småmolekylär multikinashämmare och inhiberar flera tyrosinkinasreceptorer som påverkar tumörtillväxten och metastasutvecklingen vid cancer. Sunitinibs främsta indikationer är gastrointestinala stromacellstumörer, metastaserad njurcellscancer och neuroendokrina tumörer i bukspottskörteln. Behandling med tyrosinkinashämmare orsakar biverkningar som hypertension, kardiotoxicitet och njursvikt, vilka antas bero på de hämmande effekterna på mål som inte är väsentliga för anti-cancer-aktiviteten (”off-target” biverkningar). Bland annat AMP-aktiverat proteinkinas (AMPK), ett kinas som upprätthåller metabolisk homeostas i hjärtat, inhiberas av sunitinib och antas framkalla kardiovaskulära biverkningar. För att reducera ”off-target” biverkningar strävar man till att hitta alternativ som minskar de skadliga effekterna utan att den terapeutiska aktiviteten försvagas. Bland annat ett begränsat kaloriintag har uppvisat skyddande effekt på hjärtat via mekanismer sammankopplade till ökad resistens mot oxidativ stress, inflammation och mitokondriell dysfunktion, samt avtagande apoptos och autofagi. Detta sker delvis genom aktivering av enzymet Sirt1. Syftet med den här studien var att undersöka ifall kaloribegränsning skyddar mot kardiovaskulära och renala biverkningar inducerade av sunitinib hos råttor. Dessutom studerades vilka signalkedjor i cellen som medverkar. I studien användes 40 spontant hypertensiva råttor samt 10 normotensiva Wistar-Kyoto råttor. Försöksdjuren delades in i fem grupper beroende på behandling; I WKY kontroll, II SHR kontroll, III SHR + kaloribegränsning 70 %, IV SHR + sunitinib 3 mg/kg och V SHR + sunitinib 3 mg/kg + kaloribegränsning 70 %. Behandlingsperioden var åtta veckor. Blodtrycket mättes varje vecka med svansmanchett, urinutsöndringen undersöktes vecka 4 och vecka 8 med metabolismburar, ultraljudsundersökning av hjärtat utfördes sista veckan och blodkärlens respons till acetylkolin och natriumnitroprussid studerades i samband med avlivning. Proteinerna Sirt1 och AMPK analyserades i hjärtat med Western blotting samt förekomsten av makrofagmarkören ED1 i njurarna med immunhistokemi. Studien visade att sunitinibdosen 3 mg/kg är mycket väl tolererbar hos råttor eftersom sunitinib inte orsakade högre blodtryck, kraftigare hypertrofi eller mer omfattande njurskada jämfört med obehandlade SHR- grupper. Utgående från resultaten kan man också konstatera att kaloribegränsningen har positiva kardiovaskulära effekter.

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Finnish forest industry is in the middle of a radical change. Deepening recession and the falling demand of woodworking industry´s traditional products have forced also sawmilling industry to find new and more fertile solutions to improve their operational preconditions. In recent years, the role of bioenergy production has often been highlighted as a part of sawmills´ business repertoire. Sawmilling produces naturally a lot of by-products (e.g. bark, sawdust, chips) which could be exploited more effectively in energy production, and this would bring more incomes or maybe even create new business opportunities for sawmills. Production of bioenergy is also supported by government´s climate and energy policies favouring renewable energy sources, public financial subsidies, and soaring prices of fossil fuels. Also the decreasing production of domestic pulp and paper industry releases a fair amount of sawmills´ by-products for other uses. However, bioenergy production as a part of sawmills´ by-product utilization has been so far researched very little from a managerial point of view. The purpose of this study was to explore the relative significance of the main bioenergy-related processes, resources and factors at Finnish independent industrial sawmills including partnerships, cooperation, customers relationships and investments, and also the future perspectives of bioenergy business at these sawmills with the help of two resource-based approaches (resource-based view, natural-resource-based view). Data of the study comprised of secondary data (e.g. literature), and primary data which was attracted from interviews directed to sawmill managers (or equivalent persons in charge of decisions regarding bioenergy production at sawmill). While a literature review and the Delphi method with two questionnaires were utilized as the methods of the study. According to the results of the study, the most significant processes related to the value chain of bioenergy business are connected to raw material availability and procurement, and customer relationships management. In addition to raw material and services, the most significant resources included factory and machinery, personnel, collaboration, and geographic location. Long-term cooperation deals were clearly valued as the most significant form of collaboration, and especially in processes connected to raw material procurement. Study results also revealed that factors related to demand, subsidies and prices had highest importance in connection with sawmills´ future bioenergy business. However, majority of the respondents required that certain preconditions connected to the above-mentioned factors should be fulfilled before they will continue their bioenergy-related investments. Generally, the answers showed a wide divergence of opinions among the respondents which may refer to sawmills´ different emphases and expectations concerning bioenergy. In other words, bioenergy is still perceived as a quite novel and risky area of business at Finnish independent industrial sawmills. These results indicate that the massive expansion of bioenergy business at private sawmills in Finland is not a self-evident truth. The blocking barriers seem to be connected mainly to demand of bioenergy and money. Respondents´ answers disseminated a growing dissatisfaction towards the policies of authorities, which don´t treat equally sawmill-based bioenergy compared to other forms of bioenergy. This proposition was boiled down in a sawmill manager´s comment: “There is a lot of bioenergy available, if they just want to make use of it.” It seems that the positive effects of government´s policies favouring the renewables are not taking effect at private sawmills. However, as there anyway seems to be a lot of potential connected to emerging bioenergy business at Finnish independent industrial sawmills, there is also a clear need for more profound future studies over this topic.

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Neutral point clamped (NPC), three level converters with insulated gate bipolar transistor devices are very popular in medium voltage, high power applications. DC bus short circuit protection is usually done, using the sensed voltage across collector and emitter (i.e., V-CE sensing), of all the devices in a leg. This feature is accommodated with the conventional gate drive circuits used in the two level converters. The similar gate drive circuit, when adopted for NPC three level converter protection, leads to false V-CE fault signals for inner devices of the leg. The paper explains the detailed circuit behavior and reasons, which result in the occurrence of such false V-CE fault signals. This paper also illustrates that such a phenomenon shows dependence on the power factor of the supplied three-phase load. Finally, experimental results are presented to support the analysis. It is shown that the problem can be avoided by blocking out the V-CE sense fault signals of the inner devices of the leg.

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Nuclear import of proteins is mediated by the nuclear pore complexes in the nuclear envelope and requires the presence of a nuclear localization signal (NLS) on the karyophilic protein. In this paper, we describe studies with a monoclonal antibody, Mab E2, which recognizes a class of nuclear pore proteins of 60-76 kDa with a common phosphorylated epitope on rat nuclear envelopes. The Mab Ea-reactive proteins fractionated with the relatively insoluble pore complex-containing component of the envelope and gave a finely punctate pattern of nuclear staining in immunofluorescence assays. The antibody did not bind to any cytosolic proteins. Mab E2 inhibited the interaction of a simian virus 40 large T antigen NLS peptide with a specific 60-kDa NLS-binding protein from rat nuclear envelopes in photoaffinity labeling experiments. The antibody blocked the nuclear import of NLS-albumin conjugates in an in vitro nuclear transport assay with digitonin-permeabilized cells, but did not affect passive diffusion of a small nonnuclear protein, lysozyme, across the pore. Mab E2 may inhibit protein transport by directly interacting with the 60-kDa NLS-binding protein, thereby blocking signal-mediated nuclear import across the nuclear pore complex. (C) 1994 Academic Press, Inc.

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Beavers are often found to be in conflict with human interests by creating nuisances like building dams on flowing water (leading to flooding), blocking irrigation canals, cutting down timbers, etc. At the same time they contribute to raising water tables, increased vegetation, etc. Consequently, maintaining an optimal beaver population is beneficial. Because of their diffusion externality (due to migratory nature), strategies based on lumped parameter models are often ineffective. Using a distributed parameter model for beaver population that accounts for their spatial and temporal behavior, an optimal control (trapping) strategy is presented in this paper that leads to a desired distribution of the animal density in a region in the long run. The optimal control solution presented, imbeds the solution for a large number of initial conditions (i.e., it has a feedback form), which is otherwise nontrivial to obtain. The solution obtained can be used in real-time by a nonexpert in control theory since it involves only using the neural networks trained offline. Proper orthogonal decomposition-based basis function design followed by their use in a Galerkin projection has been incorporated in the solution process as a model reduction technique. Optimal solutions are obtained through a "single network adaptive critic" (SNAC) neural-network architecture.

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In this paper we consider an N x N non-blocking, space division ATM switch with input cell queueing. At each input, the cell arrival process comprises geometrically distributed bursts of consecutive cells for the various outputs. Motivated by the fact that some input links may be connected to metropolitan area networks, and others directly to B-ISDN terminals, we study the situation where there are two classes of inputs with different values of mean burst length. We show that when inputs contend for an output, giving priority to an input with smaller expected burst length yields a saturation throughput larger than if the reverse priority is given. Further, giving priority to less bursty traffic can give better throughput than if all the inputs were occupied by this less bursty traffic. We derive the asymptotic (as N --> infinity) saturation throughputs for each priority class.

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The present study focusses attention on the effects of blocking estrogen synthesis, during follicular phase, on follicular maturation in the adult female bonnet monkey (Macaca radiata). Administration of cycling females (n = 4) with an aromatase inhibitor CGS 16949A (AI) by Alzet mini-pump (2.5 mg/day) from day 3 of cycle resulted in significant reduction in basal (by 53%) and surge levels of estrogen (by 70%) but this had no effect on follicular maturation, ovulation and luteal function as assessed by serum hormone profiles as well as laparotomy. This lack of need for estrogen for completion of follicular maturation process was confirmed by administering cycling monkeys hFSH (25 IU/day) from day 3 till day 8 of the cycle along with (5 mg AI/day) or without Al (n = 3/group). Administration of Al resulted in suppression of FSH induced increase in serum estrogen (by 100%) and elevation in circulating androstenedione. Aromatase inhibitor treatment had no effect on either the number of follicles developed or their size relative to control. Testing the ability of both granulosa and thecal cells, removed on day 9 of treatment cycle, to respond to gonadotropins in vitro showed no change indicating that cellular development and maturation of follicular cells had occurred normally. It is concluded that follicular maturation in the primate can occur even when increase in estrogen synthesis is blocked.

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Wet chemical reaction of hydrated alumina gels, Al2O3.yH(2)O(80blocking defects and structural intergrowths. The metastable Ba-hexa-aluminates doped with Eu(II), exhibit predominantly the 436nm emission band for all the 'x' values. No deterioration in emission intensity is noticed on long term preservation of the phosphors. Differences prevailing in literature on the phase relations in Ba-hexa-aluminates can be attributed to preparative route dependent metastability.

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The integration of different wireless networks, such as GSM and WiFi, as a two-tier hybrid wireless network is more popular and economical. Efficient bandwidth management, call admission control strategies and mobility management are important issues in supporting multiple types of services with different bandwidth requirements in hybrid networks. In particular, bandwidth is a critical commodity because of the type of transactions supported by these hybrid networks, which may have varying bandwidth and time requirements. In this paper, we consider such a problem in a hybrid wireless network installed in a superstore environment and design a bandwidth management algorithm based on the priority level, classification of the incoming transactions. Our scheme uses a downlink transaction scheduling algorithm, which decides how to schedule the outgoing transactions based on their priority level with efficient use of available bandwidth. The transaction scheduling algorithm is used to maximize the number of transaction-executions. The proposed scheme is simulated in a superstore environment with multi Rooms. The performance results describe that the proposed scheme can considerably improve the bandwidth utilization by reducing transaction blocking and accommodating more essential transactions at the peak time of the business.

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The formation of molecular films of 2,9,16,23-tetraamino metal phthalocyanines [TAM(II)Pc; M (II) = Co, Cu, and TAM(III)Pc; M = Fe] by spontaneous adsorption on gold and silver surfaces is described. The properties of these films have been investigated by cyclic voltammetry, impedance, and FT-Raman spectroscopy. The charge associated with Co(II) and Co(I) redox couple in voltammetric data leads to a coverage of (0.35+/-0.05) x 10(-10) mol cm(-2), suggesting that the tetraamino cobalt phthalocyanine is adsorbed as a monolayer with an almost complete coverage. The blocking behavior of the films toward oxygen and Fe(CN)(6)(3-/4-) redox couple have been followed by cyclic voltammetry and impedance measurements. This leads to an estimate of the coverage of about 85 % in the case of copper and the iron analogs. FT-Raman studies show characteristic bands around 236 cm(-1) revealing the interaction between the metal substrate and the nitrogen of the -NH2 group on the phthalocyanine molecules.

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The TCP transcription factors control important aspects of plant development. Members of class I TCP proteins promote cell cycle by regulating genes directly involved in cell proliferation. In contrast, members of class II TCP proteins repress cell division. While it has been postulated that class II proteins induce differentiation signal, their exact role on cell cycle has not been studied. Here, we report that TCP4, a class II TCP protein from Arabidopsis that repress cell proliferation in developing leaves, inhibits cell division by blocking G1 -> S transition in budding yeast. Cells expressing TCP4 protein with increased transcriptional activity fail to progress beyond G1 phase. By analyzing global transcriptional status of these cells, we show that expression of a number of cell cycle genes is altered. The possible mechanism of G1 -> S arrest is discussed. (C) 2011 Elsevier Inc. All rights reserved.