944 resultados para National Broadband Network
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Semisupervised learning is a machine learning approach that is able to employ both labeled and unlabeled samples in the training process. In this paper, we propose a semisupervised data classification model based on a combined random-preferential walk of particles in a network (graph) constructed from the input dataset. The particles of the same class cooperate among themselves, while the particles of different classes compete with each other to propagate class labels to the whole network. A rigorous model definition is provided via a nonlinear stochastic dynamical system and a mathematical analysis of its behavior is carried out. A numerical validation presented in this paper confirms the theoretical predictions. An interesting feature brought by the competitive-cooperative mechanism is that the proposed model can achieve good classification rates while exhibiting low computational complexity order in comparison to other network-based semisupervised algorithms. Computer simulations conducted on synthetic and real-world datasets reveal the effectiveness of the model.
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Too Big to Ignore (TBTI; www.toobigtoignore.net) is a research network and knowledge mobilization partnership established to elevate the profile of small-scale fisheries (SSF), to argue against their marginalization in national and international policies, and to develop research and governance capacity to address global fisheries challenges. Network participants and partners are conducting global and comparative analyses, as well as in-depth studies of SSF in the context of local complexity and dynamics, along with a thorough examination of governance challenges, to encourage careful consideration of this sector in local, regional and global policy arenas. Comprising 15 partners and 62 researchers from 27 countries, TBTI conducts activities in five regions of the world. In Latin America and the Caribbean (LAC) region, we are taking a participative approach to investigate and promote stewardship and self-governance in SSF, seeking best practices and success stories that could be replicated elsewhere. As well, the region will focus to promote sustainable livelihoods of coastal communities. Key activities include workshops and stakeholder meetings, facilitation of policy dialogue and networking, as well as assessing local capacity needs and training. Currently, LAC members are putting together publications that examine key issues concerning SSF in the region and best practices, with a first focus on ecosystem stewardship. Other planned deliverables include comparative analysis, a regional profile on the top research issues on SSF, and a synthesis of SSF knowledge in LAC
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Maternal aggression is under the control of a wide variety of factors that prime the females for aggression or trigger the aggressive event. Maternal attacks are triggered by the perception of sensory cues from the intruder, and here we have identified a site in the hypothalamus of lactating rats that is highly responsive to the male intruder—the ventral premammillary nucleus (PMv). The PMv is heavily targeted by the medial amygdalar nucleus, and we used lesion and immediate-early gene studies to test our working hypothesis that the PMv signals the presence of a male intruder and transfers this information to the network organizing maternal aggression. PMv-lesioned dams exhibit significantly reduced maternal aggression, without affecting maternal care. The Fos analysis revealed that PMv influences the activation of hypothalamic and septal sites shown to be mobilized during maternal aggression, including the medial preoptic nucleus (likely to represent an important locus to integrate priming stimuli critical for maternal aggression), the caudal two-thirds of the hypothalamic attack area (comprising the ventrolateral part of the ventromedial hypothalamic nucleus and the adjacent tuberal region of the lateral hypothalamic area, critical for the expression of maternal aggression), and the ventral part of the anterior bed nuclei of the stria terminalis (presently discussed as being involved in controlling neuroendocrine and autonomic responses accompanying maternal aggression). These findings reveal an important role for the PMv in detecting the male intruder and how this nucleus modulates the network controlling maternal aggression.
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We investigated the seasonal patterns of Amazonian forest photosynthetic activity, and the effects thereon of variations in climate and land-use, by integrating data from a network of ground-based eddy flux towers in Brazil established as part of the ‘Large-Scale Biosphere Atmosphere Experiment in Amazonia’ project. We found that degree of water limitation, as indicated by the seasonality of the ratio of sensible to latent heat flux (Bowen ratio) predicts seasonal patterns of photosynthesis. In equatorial Amazonian forests (5◦ N–5◦ S), water limitation is absent, and photosynthetic fluxes (or gross ecosystem productivity, GEP) exhibit high or increasing levels of photosynthetic activity as the dry season progresses, likely a consequence of allocation to growth of new leaves. In contrast, forests along the southern flank of the Amazon, pastures converted from forest, and mixed forest-grass savanna, exhibit dry-season declines in GEP, consistent with increasing degrees of water limitation. Although previous work showed tropical ecosystem evapotranspiration (ET) is driven by incoming radiation, GEP observations reported here surprisingly show no or negative relationships with photosynthetically active radiation (PAR). Instead, GEP fluxes largely followed the phenology of canopy photosynthetic capacity (Pc), with only deviations from this primary pattern driven by variations in PAR. Estimates of leaf flush at three
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The need for high bandwidth, due to the explosion of new multi\-media-oriented IP-based services, as well as increasing broadband access requirements is leading to the need of flexible and highly reconfigurable optical networks. While transmission bandwidth does not represent a limit due to the huge bandwidth provided by optical fibers and Dense Wavelength Division Multiplexing (DWDM) technology, the electronic switching nodes in the core of the network represent the bottleneck in terms of speed and capacity for the overall network. For this reason DWDM technology must be exploited not only for data transport but also for switching operations. In this Ph.D. thesis solutions for photonic packet switches, a flexible alternative with respect to circuit-switched optical networks are proposed. In particular solutions based on devices and components that are expected to mature in the near future are proposed, with the aim to limit the employment of complex components. The work presented here is the result of part of the research activities performed by the Networks Research Group at the Department of Electronics, Computer Science and Systems (DEIS) of the University of Bologna, Italy. In particular, the work on optical packet switching has been carried on within three relevant research projects: the e-Photon/ONe and e-Photon/ONe+ projects, funded by the European Union in the Sixth Framework Programme, and the national project OSATE funded by the Italian Ministry of Education, University and Scientific Research. The rest of the work is organized as follows. Chapter 1 gives a brief introduction to network context and contention resolution in photonic packet switches. Chapter 2 presents different strategies for contention resolution in wavelength domain. Chapter 3 illustrates a possible implementation of one of the schemes proposed in chapter 2. Then, chapter 4 presents multi-fiber switches, which employ jointly wavelength and space domains to solve contention. Chapter 5 shows buffered switches, to solve contention in time domain besides wavelength domain. Finally chapter 6 presents a cost model to compare different switch architectures in terms of cost.
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The study defines a new farm classification and identifies the arable land management. These aspects and several indicators are taken into account to estimate the sustainability level of farms, for organic and conventional regimes. The data source is Italian Farm Account Data Network (RICA) for years 2007-2011, which samples structural and economical information. An environmental data has been added to the previous one to better describe the farm context. The new farm classification describes holding by general informations and farm structure. The general information are: adopted regime and farm location in terms of administrative region, slope and phyto-climatic zone. The farm structures describe the presence of main productive processes and land covers, which are recorded by FADN database. The farms, grouped by homogeneous farm structure or farm typology, are evaluated in terms of sustainability. The farm model MAD has been used to estimate a list of indicators. They describe especially environmental and economical areas of sustainability. Finally arable lands are taken into account to identify arable land managements and crop rotations. Each arable land has been classified by crop pattern. Then crop rotation management has been analysed by spatial and temporal approaches. The analysis reports a high variability inside regimes. The farm structure influences indicators level more than regimes, and it is not always possible to compare the two regimes. However some differences between organic and conventional agriculture have been found. Organic farm structures report different frequency and geographical location than conventional ones. Also different connections among arable lands and farm structures have been identified.
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Surface based measurements systems play a key role in defining the ground truth for climate modeling and satellite product validation. The Italian-French station of Concordia is operative year round since 2005 at Dome C (75°S, 123°E, 3230 m) on the East Antarctic Plateau. A Baseline Surface Radiation Network (BSRN) site was deployed and became operational since January 2006 to measure downwelling components of the radiation budget, and successively was expanded in April 2007 to measure upwelling radiation. Hence, almost a decade of measurement is now available and suitable to define a statistically significant climatology for the radiation budget of Concordia including eventual trends, by specifically assessing the effects of clouds and water vapor on SW and LW net radiation. A well known and robust clear sky-id algorithm (Long and Ackerman, 2000) has been operationally applied on downwelling SW components to identify cloud free events and to fit a parametric equation to determine clear-sky reference along the Antarctic daylight periods (September to April). A new model for surface broadband albedo has been developed in order to better describe the features the area. Then, a novel clear-sky LW parametrization, based on a-priori assumption about inversion layer structure, combined with daily and annual oscillations of the surface temperature, have been adopted and validated. The longwave based method is successively exploited to extend cloud radiative forcing studies to nighttime period (winter). Results indicated inter-annual and intra-annual warming behaviour, i.e. 13.70 W/m2 on the average, specifically approaching neutral effect in summer, when SW CRF compensates LW CRF, and warming along the rest of the year due prevalentely to CRF induced on the LW component.
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Theory predicts the water hexamer to be the smallest water cluster with a three-dimensional hydrogen-bonding network as its minimum energy structure. There are several possible low-energy isomers, and calculations with different methods and basis sets assign them different relative stabilities. Previous experimental work has provided evidence for the cage, book, and cyclic isomers, but no experiment has identified multiple coexisting structures. Here, we report that broadband rotational spectroscopy in a pulsed supersonic expansion unambiguously identifies all three isomers; we determined their oxygen framework structures by means of oxygen-18–substituted water (H218O). Relative isomer populations at different expansion conditions establish that the cage isomer is the minimum energy structure. Rotational spectra consistent with predicted heptamer and nonamer structures have also been identified.
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Neonatal sepsis causes high mortality and morbidity in preterm infants, but less is known regarding the long-term outcome after sepsis. This study aimed to determine the impact of sepsis on neurodevelopment at 2 years' corrected age in extremely preterm infants.
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Background While survival rates of extremely preterm infants have improved over the last decades, the incidence of neurodevelopmental disability (ND) in survivors remains high. Representative current data on the severity of disability and of risk factors associated with poor outcome in this growing population are necessary for clinical guidance and parent counselling. Methods Prospective longitudinal multicentre cohort study of preterm infants born in Switzerland between 240/7 and 276/7 weeks gestational age during 2000–2008. Mortality, adverse outcome (death or severe ND) at two years, and predictors for poor outcome were analysed using multilevel multivariate logistic regression. Neurodevelopment was assessed using Bayley Scales of Infant Development II. Cerebral palsy was graded after the Gross Motor Function Classification System. Results Of 1266 live born infants, 422 (33%) died. Follow-up information was available for 684 (81%) survivors: 440 (64%) showed favourable outcome, 166 (24%) moderate ND, and 78 (11%) severe ND. At birth, lower gestational age, intrauterine growth restriction and absence of antenatal corticosteroids were associated with mortality and adverse outcome (p < 0.001). At 360/7 weeks postmenstrual age, bronchopulmonary dysplasia, major brain injury and retinopathy of prematurity were the main predictors for adverse outcome (p < 0.05). Survival without moderate or severe ND increased from 27% to 39% during the observation period (p = 0.02). Conclusions In this recent Swiss national cohort study of extremely preterm infants, neonatal mortality was determined by gestational age, birth weight, and antenatal corticosteroids while neurodevelopmental outcome was determined by the major neonatal morbidities. We observed an increase of survival without moderate or severe disability.
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Since the turbulence of 1989, the countries of Central and Eastern Europe have striven to "return to Europe". Agreements have been signed with ten post-communist countries, beginning in 1991 with Czechoslovakia (before its division), Hungary and Poland. Since that time several countries have expressed a desire to become members of the EU. In 1997 the European Commission announced its opinion on the applications for EU membership of the Czech Republic, Hungary, Poland, Slovakia, and seven other applicant countries. The Commission recommended the commencement of negotiations on accession with the Czech Republic, Estonia, Hungary, Poland, and Slovenia. Mr. Kucia's report, presented in the form of a series of manuscripts totalling 91 pages, written in English and Polish and including many pages of tables and graphs, presents the results of a study of public opinion on European integration in four countries of Central Europe (CE): the Czech Republic (CZ), Hungary (H), Poland (PL), and Slovakia (SK). The research results are primarily based on a public-opinion survey known as the Central and Eastern Eurobarometer (CEEB). CEEB has been conducted on behalf of the European Commission in the Central and Eastern European countries each year in autumn since 1990. Below is a very small selection of Mr. Kucia's research findings. Throughout the 90s people in the four countries increasingly saw their countries' future tied up with the EU, since economic and political connections to the EU were growing and prospects for EU membership were increasing. Regional co-operation within CE did not gain much popular recognition. However, initially high levels of enthusiasm for the EU were gradually superseded by a more realistic approach or even scepticism. Poland was the exception in this respect; its population was more positive about the EU in 1996 than ever before. Mr. Kucia concludes that, since the political "elites" in CE are more positive about the EU than the people they serve, they should do their best to bring people round to their beliefs, lest the project of European integration become purely the business of the elites, as Mr. Kucia claims it has been in the EU up till now. He accuses the governments of the region, the EU authorities and the media of failing to provide appropriate information, especially about the two subjects which most affect them, association with the EU and the PHARE assistance programme. Respondents were asked to rank in order the countries or regions they saw their country's future most closely tied up with. In the period 92-96 the EU received the highest ratings in all of CE. The ratings were highest in CZ in 92 and 93 (46%) and in Poland in 96 (46%). They were the lowest in Hungary (22% in 94). After the EU came "Other Western European countries (non EU)", that is Austria, Sweden and Finland (before they joined the EU in 1995), Switzerland and Norway. Mr. Kucia puts the high ratings of these countries down to historical connections and geographical proximity, particularly in the case of Austria. The USA always came second in Poland, and in Hungary too its standing has always been higher than in CZ or SK. Indeed Mr. Kucia suggests that the USA's standing is disproportionately low in especially the CZ. Germany was nominated frequently by Hungarians, though in the CZ and SK, figures have been consistently low (1-2%). "Other CE/EE countries" increased their ratings in all of CE except Poland between 92 and 96. With regard to these last figures, Mr. Kucia makes an interesting note. Assuming that for the respondents in the four countries this category covered the Visegrad 4, least support was found in Poland, whose government was the most in favour of close political co-operation within the V4, while most support was in evidence in CZ and SK, for whose governments V4 was simply not a priority. Again, there is evidence of a divide between the political elites and the people. Russia has occupied a consistently modest rank. It was the highest in PL, fairly low in H and SK and the lowest in CZ. The Slovak government's policy of closer ties with Russia is reflected in a growth in the figures from 2% in 93 to 6% in 95. Every year the spontaneous answer "we should depend on ourselves" appeared, which Mr. Kucia interprets as either a sign of isolationism and disillusionment or as a call for self-reliance. Unfortunately he regards both these tendencies as unfeasible in the uniting Europe. Moving to more general conclusions, Mr. Kucia finds that the concept "Central Europe" does not have much meaning for Central Europeans. He believes that this is probably due to the failure to establish a viable regional co-operation network. Group discussions also revealed that people thought themselves European as a consequence of being Czech or Polish etc. Thus European identity is based on national identities. Generally within the surveyed period, the numbers of those who said they often think themselves European decreased, while the numbers of those who said they never think themselves European increased from 41% in PL, 36% in CZ, and 30% in H in 1990, to 67% in CZ, 58% in PL, and 51% in H in 1995.
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PURPOSE: There is a need for valid and reliable short scales that can be used to assess social networks and social supports and to screen for social isolation in older persons. DESIGN AND METHODS: The present study is a cross-national and cross-cultural evaluation of the performance of an abbreviated version of the Lubben Social Network Scale (LSNS-6), which was used to screen for social isolation among community-dwelling older adult populations in three European countries. Based on the concept of lack of redundancy of social ties we defined clinical cut-points of the LSNS-6 for identifying persons deemed at risk for social isolation. RESULTS: Among all three samples, the LSNS-6 and two subscales (Family and Friends) demonstrated high levels of internal consistency, stable factor structures, and high correlations with criterion variables. The proposed clinical cut-points showed good convergent validity, and classified 20% of the respondents in Hamburg, 11% of those in Solothurn (Switzerland), and 15% of those in London as at risk for social isolation. IMPLICATIONS: We conclude that abbreviated scales such as the LSNS-6 should be considered for inclusion in practice protocols of gerontological practitioners. Screening older persons based on the LSNS-6 provides quantitative information on their family and friendship ties, and identifies persons at increased risk for social isolation who might benefit from in-depth assessment and targeted interventions.
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The first part of the lecture details a study of how receding glaciers and snowfields in Montana, New Zealand and Scotland affect the alpine plants that grow along and near their edges. Measuring and monitoring techniques are included. The second part describes the Global Observation Research Initiative in Alpine Environments (GLOBAL) whose purpose is "to establish and maintain a world-wide long-term observation network in alpine environments. Vegetation and temperature data collected at the GLORIA sites will be used for discerning trends in species diversity and temperature."
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The number of large research networks and programmes engaging in knowledge production for development has grown over the past years. One of these programmes devoted to generating knowledge about and for development is National Centre of Competence in Research (NCCR) North–South, a cross-disciplinary, international development research network funded by the Swiss Agency for Development and Cooperation and the Swiss National Science Foundation. Producing relevant knowledge for development is a core goal of the programme and an important motivation for many of the participating researchers. Over the years, the researchers have made use of various spaces for exchange and instruments for co-production of knowledge by academic and non-academic development actors. In this article we explore the characteristics of co-producing and sharing knowledge in interfaces between development research, policy and NCCR North–South practice. We draw on empirical material of the NCCR North–South programme and its specific programme element of the Partnership Actions. Our goal is to make use of the concept of the interface to reflect critically about the pursued strategies and instruments applied in producing and sharing knowledge for development across boundaries.
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OBJECTIVE: This report presents data from the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network on care of and morbidity and mortality rates for very low birth weight infants, according to gestational age (GA). METHODS: Perinatal/neonatal data were collected for 9575 infants of extremely low GA (22-28 weeks) and very low birth weight (401-1500 g) who were born at network centers between January 1, 2003, and December 31, 2007. RESULTS: Rates of survival to discharge increased with increasing GA (6% at 22 weeks and 92% at 28 weeks); 1060 infants died at CONCLUSION: Although the majority of infants with GAs of >or=24 weeks survive, high rates of morbidity among survivors continue to be observed.