754 resultados para 857


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An approach to nonlinearity management in optical transmission lines with periodic dispersion compensation and distributed Raman amplification was presented. The optimization of a three-step dispersion map with forward and backward pumped distributed amplification was examined. The optimization was performed using the analytical solution obtained under the assumption of undepleted pumps and without inclusion of double Rayleigh Scattering (DRS), and by means of a full numerical approach accounting for all important effects. It was found that both procedures led to the same final solution.

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Our research explores the possibility of categorizing webpages and webpage genre by structure or layout. Based on our results, we believe that webpage structure could play an important role, along with textual and visual keywords, in webpage categorization and searching.

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This article proposes a Bayesian neural network approach to determine the risk of re-intervention after endovascular aortic aneurysm repair surgery. The target of proposed technique is to determine which patients have high chance to re-intervention (high-risk patients) and which are not (low-risk patients) after 5 years of the surgery. Two censored datasets relating to the clinical conditions of aortic aneurysms have been collected from two different vascular centers in the United Kingdom. A Bayesian network was first employed to solve the censoring issue in the datasets. Then, a back propagation neural network model was built using the uncensored data of the first center to predict re-intervention on the second center and classify the patients into high-risk and low-risk groups. Kaplan-Meier curves were plotted for each group of patients separately to show whether there is a significant difference between the two risk groups. Finally, the logrank test was applied to determine whether the neural network model was capable of predicting and distinguishing between the two risk groups. The results show that the Bayesian network used for uncensoring the data has improved the performance of the neural networks that were built for the two centers separately. More importantly, the neural network that was trained with uncensored data of the first center was able to predict and discriminate between groups of low risk and high risk of re-intervention after 5 years of endovascular aortic aneurysm surgery at center 2 (p = 0.0037 in the logrank test).

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A kameralizmus a 16-18. századi német gyakorlati államtudomány és egyetemi tantárgy volt, amely összefoglalta a hivatalnokok képzéséhez szükséges elméleti és gyakorlati gazdasági ismereteket. Felfogása szerint az alattvalók jóléte és boldogsága feltétele az uralkodó gazdagságának, de az alattvalók önmaguktól nem képesek utat találni ehhez a boldogsághoz, szükség van az állandó külső irányításra. Igazgatásközpontúsága és egyetemi intézményesülése miatt nem tekinthető a merkantilizmus helyi változatának. Az 1840 és 1945 közötti német történeti iskola hagyományos ábrázolása több mint egy évszázadon át a német és a neoklasszikus tradíció szembenállását hangsúlyozta, kiemelve az organicizmus, a fejlődésgondolat és az egyediség jelentőségét, a szociális kérdés fontosságát, illetve a deduktív módszer és a gazdaság változatlan törvényeinek tagadását. A modern rekonstrukciók a történeti iskolát a posztklasszikus válságra adott egyik európai válaszként fogják fel, amely a történelemből levont, empirikusan megalapozott induktív alternatívát kínált. Az 1871-től kialakult osztrák iskola a neoklasszikus paradigmának egyszerre volt alkotórésze és versenytársa. A módszertani individualizmus, a szubjektivizmus, az idő fontossága, a tudás szerepe, az alternatív költségek elmélete stb. ugyan beépültek a mainstream közgazdaságtanba, de hangsúlyos kiemelésük lehetővé tette, hogy a társadalomelméleti magyarázat igényét őrző osztrák iskola megtartson valamit önálló beszédmódjából. / === / Cameralism was a practical political science and university subject in 16th–18th century Germany, summarizing the theoretical and practical economic knowledge required in the training of officials. The assumption was that the prosperity of the ruler depended on the welfare and happiness of the subjects, but the subjects themselves were not capable of achieving this happiness without permanent directions from above. Cameralism’s emphasis on administration and university institutionalization means that this approach cannot be seen as a local variant of mercantilism. The traditional account of the German historical school from 1840 to 1945 emphasized for over a century the contrast between the German and the Neoclassical traditions. It underlined the significance of the organic approach, the concept of development and individuality, the importance of the social question, and the denial of the deductive method and unalterable laws of the economy. Modern reconstructions see the historical school as one European response to the post-Classical crisis, offering an inductive alternative grounded empirically on history. The Austrian school formed in 1871 was at once a constituent of the Neoclassical paradigm and a rival to it. Methodological individualism, subjectivism, the importance of time, the role of knowledge, the theory of alternative costs etc. were absorbed into mainstream economics, but the focusing on these issues allowed the Austrian school, in keeping alive its demand for a social-theoretical explanation, to preserve something of an alternative discourse.

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Ebben a tanulmányban részletesen bemutatjuk a 2009-es Versenyképesség felmérés etika és környezetvédelem vonatkozású témaköreit, valamint a vállalati interjúkon alapuló kutatásunk alapján a vállalati döntéshozatal azon jellemzőibe nyújtunk bepillantást, amelyek segítik, illetve gátolják a CSR és a fenntarthatóság vállalati érvényesülését. A vállalati etika és a vállalati környezetvédelem területein egyaránt egy-egy klasszikusnak számító intézmény, illetve rendszer terjedt el leginkább a vállalatok körében: az etikai kódex az etikai intézményesülés relatíve gyakori elemének számít, míg a környezetvédelmi eszközökre vonatkozó kérdéskörben a legjobb helyezést a minőségmenedzsment rendszer kapta. A felelős döntések hatótényezőinek vizsgálatakor azt tapasztaltuk, hogy szervezeti és egyéni jellemzők egyformán segítői és akadályai lehetnek a felelős vállalati működés terjedésének. Ugyanakkor azt is láttuk, hogy egy figyelemreméltó eszköztár a CSR explicit kifejeződéseként önmagában nem teremti meg az implicit felelősségvállalás terjedését, a reflektált, valamennyi vállalati döntésben mérlegelésre kerülő érintetti szempontok, morális, fenntarthatósági, felelősségi vonatkozások meglétét. ________ In this study we overview the findings of the Competitiveness Research Program in the fields of business ethics and environmental management, and we also introduce some of the results of our research on the Hungarian tendencies of corporate social responsibility based on qualitative research interviews. Both in the fields of business ethics and environmental management one dominant classic tool were identified. Code of conduct is the most prevailing instrument in the field of ethics and quality management still kept its popularity amongst the environmental management tools. It turned out that both organizational and individual characteristics can be enablers and burdens of the spread of corporate social responsibility. We also revealed that remarkable CSR initiatives and principles in a firm does not necessarily create the presence of implicit social responsibility, a reflexive decision making in the company that considers all stakeholders’ view and sustainability, ethical and responsibility issues.

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Mangrove forests are ecosystems susceptible to changing water levels and temperatures due to climate change as well as perturbations resulting from tropical storms. Numerical models can be used to project mangrove forest responses to regional and global environmental changes, and the reliability of these models depends on surface energy balance closure. However, for tidal ecosystems, the surface energy balance is complex because the energy transport associated with tidal activity remains poorly understood. This study aimed to quantify impacts of tidal flows on energy dynamics within a mangrove ecosystem. To address the research objective, an intensive 10-day study was conducted in a mangrove forest located along the Shark River in the Everglades National Park, FL, USA. Forest–atmosphere turbulent exchanges of energy were quantified with an eddy covariance system installed on a 30-m-tall flux tower. Energy transport associated with tidal activity was calculated based on a coupled mass and energy balance approach. The mass balance included tidal flows and accumulation of water on the forest floor. The energy balance included temporal changes in enthalpy, resulting from tidal flows and temperature changes in the water column. By serving as a net sink or a source of available energy, flood waters reduced the impact of high radiational loads on the mangrove forest. Also, the regression slope of available energy versus sink terms increased from 0.730 to 0.754 and from 0.798 to 0.857, including total enthalpy change in the water column in the surface energy balance for 30-min periods and daily daytime sums, respectively. Results indicated that tidal inundation provides an important mechanism for heat removal and that tidal exchange should be considered in surface energy budgets of coastal ecosystems. Results also demonstrated the importance of including tidal energy advection in mangrove biophysical models that are used for predicting ecosystem response to changing climate and regional freshwater management practices.

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Sea floor dredging by the H.M.S. Challenger, the U.S.S. Albatross, the U.S.S. EPC(R) 857, and vessels of the Scripps Institution of Oceanography shows that extensive deposits of manganese nodules are on the deep sea floor and that crusts of manganese dioxide cover many seamounts. Sea floor photography reveals that in some places these crusts are quite continuous and the nodules are closely packed. These crusts and nodules are fully oxidized and hydrated mixtures of man¬ganese and iron plus earthy impurities. Also, relatively high concen¬trations of the trace elements nickel, copper, and cobalt are present.

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Extensive investigations of sedimentary barium were performed in the southern South Atlantic in order to assess the reliability of the barium signal in Antarctic sediments as a proxy for paleoproductivity. Maximum accumulation rates of excess barium were calculated for the Antarctic zone south of the polar front where silica accumulates at high rates. The correspondence between barium and opal supports the applicability of barium as a proxy for productivity. Within the Antarctic zone north of today's average sea ice maximum, interglacial vertical rain rates of excess barium are high, with a maximum occurring during the last deglaciation and early Holocene and during oxygen isotope chronozone 5.5. During these periods, the maximum silica accumulation was supposedly located south of the polar front. Glacial paleoproductivity, instead, was low within the Antarctic zone. North of the polar front, significantly higher barium accumulation occurs during glacial times. The vertical rain rates, however, are as high as in the glacial Antarctic zone. Therefore there was no evidence for an increased productivity in the glacial Southern Ocean.

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The development and progression of odontogenic tumors have been associated with an imbalance in the activity of growth factors, adhesion molecules, extracellular matrix proteins and their degradation enzymes, angiogenic factors and osteolytic. Some studies have shown that interaction relationships inductive epithelial / mesenchymal determinants of Odontogenesis are mimicked by these tumors. The objective of this research was to investigate the immunolocalization of growth factors (BMP-4 and FGF-8) and Sindecan-1 structural protein in a series of odontogenic tumors presenting different biological behaviors, to contribute to a better understanding of the role of these proteins in tumor development. The sample consisted of 21 of the solid ameloblastoma, odontogenic keratocysts 19 and 14 odontogenic adenomatoid tumors. Increased Sindecan-1 immunostaining was seen in the epithelium of the lesions when compared with mesenchyme. In ameloblastoma and odontogenic keratocysts, this expression was higher than in AOT. Epithelial expression of BMP4 showed quantitatively similar in the three studied lesions; however, when anlisada mesenchymal immunoreactivity, was detected significant higher expression when compared to the ameloblastoma keratocysts. In ameloblastoma, mesenchymal expression was predominantly (p = 0.008), while in keratocyst higher expression in the epithelium was observed (p = 0.046). In all injuries, strong or moderate correlation was observed in the BMP-4 immunoreactivity in the epithelium and mesenchyme. FGF-8, no injury was observed difference between the immunoreactivity in the epithelium or mesenchyme, however in ameloblastoma positive correlation was found (Spearman correlation, rho = 0.857, p <0.001). The results of this study suggest that the three evaluated biomarkers actively involved in the pathogenesis of lesions, especially the expression of ameloblastomas indicating a strong interaction between parenchymal and stromal cells which may contribute to its marked aggressiveness.

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In Western industrialized countries, it is well established that legally competent individuals may choose a surrogate healthcare decision-maker to represent their interests should they lose the capacity to do so themselves. There are few limitations on who they may select to fulfill this function. However, many jurisdictions place restrictions on or prohibit the patient's attending physician or other provider involved with an individual's care to serve in this role. Several authors have previously suggested that respect for the autonomy of patients requires that there be few (if any) constraints on whomever they may appoint as a proxy. In this essay we revisit this topic by first providing a survey of current state laws governing this activity. We then analyze the clinical and ethical circumstances in which potential difficulties could arise. We take a more nuanced and circumspect view of prior suggestions that patients should have virtually unfettered liberty to choose their healthcare proxies. We suggest a strategy to balance the freedom of patients' right to choose their surrogates with fiduciary duty of the state as regulator of medical practice. We identify six domains of possible concern with such relationships and suggest straightforward methods of mitigating their potential negative effects that could be plausibly be incorporated into physician practice.

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Understanding how seafood will be influenced by coming environmental changes such as ocean acidification is a research priority. One major gap in knowledge relates to the fact that many experiments are not considering relevant end points related directly to production (e.g., size, survival) and product quality (e.g., sensory quality) that can have important repercussions for consumers and the seafood market. The aim of this experiment was to compare the survival and sensory quality of the adult northern shrimp (Pandalus borealis) exposed for 3 wk to a temperature at the extreme of its thermal tolerance (11°C) and 2 pH treatments: pH 8.0 (the current average pH at the sampling site) and pH 7.5 (which is out of the current natural variability and relevant to near-future ocean acidification). Results show that decreased pH increased mortality significantly, by 63%. Sensory quality was assessed through semiqualitative scoring by a panel of 30 local connoisseurs. They were asked to rate 4 shrimp (2 from each pH treatment) for 3 parameters: appearance, texture and taste. Decreased pH reduced the score significantly for appearance and taste, but not texture. As a consequence, shrimp maintained in pH8.0 had a 3.4 times increased probability to be scored as the best shrimp on the plate, whereas shrimp from the pH 7.5 treatment had a 2.6 times more chance to be scored as the least desirable shrimp on the plate. These results help to prove the concept that ocean acidification can modulate sensory quality of the northern shrimp P. borealis. More research is now needed to evaluate impacts on other seafood species, socioeconomic consequences, and potential options.

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The chemical composition of surface associated metabolites of two Fucus species (Fucus vesiculosus and Fucus serratus) was analysed by means of gas chromatography-mass spectrometry (GC-MS) to describe temporal patterns in chemical surface composition. Method: The two perennial brown macroalgae F. vesiculosus and F. serratus were sampled monthly at Bülk, outer Kiel Fjord, Germany (54°27'21 N / 10°11'57 E) over an entire year (August 2012 - July 2013). Per month and species six non-fertile Fucus individuals were collected from mixed stands at a depth of 0.5 m under mid water level. For surface extraction approx. 50 g of the upper 5-10 cm apical thalli tips were cut off per species. The surface extraction of Fucus was performed according to the protocol of de Nys and co-workers (1998) with minor modifications (see Rickert et al. 2015). GC/EI-MS measurements were performed with a Waters GCT premier (Waters, Manchester, UK) coupled to an Agilent 6890N GC equipped with a DB-5 ms 30 m column (0.25 mm internal diameter, 0.25 mM film thickness, Agilent, USA). The inlet temperature was maintained at 250°C and samples were injected in split 10 mode. He carrier gas flow was adjusted to 1 ml min-1. Alkanes were used for referencing of retention times. For further details (GC-MS sample preparation and analysis) see the related publication (Rickert et al. submitted to PLOS ONE).

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To better understand Holocene vegetation and hydrological changes in South Africa, we analyzed pollen and microcharcoal records of two marine sites GeoB8331 and GeoB8323 from the Namaqualand mudbelt offshore the west coast of South Africa covering the last 9900 and 2200 years, respectively. Our data corroborate findings from literature that climate developments apparently contrast between the summer rainfall zone (SRZ) and winter rainfall zone (WRZ) over the last 9900 years, especially during the early and middle Holocene. During the early Holocene (9900-7800 cal.yr BP), a minimum of grass pollen suggests low summer rainfall in the SRZ, and the initial presence of Renosterveld vegetation indicates relatively wet conditions in the WRZ. Towards the middle Holocene (7800-2400 cal. yr BP), a rather moist savanna/grassland rich in grasses suggests higher summer rainfall in the SRZ resulting from increased austral summer insolation and a decline of fynbos vegetation accompanied by an increasing Succulent Karoo vegetation in the WRZ possibly suggests a southward shift of the Southern Hemisphere westerlies. During the last 2200 years, a trend towards higher aridity was observed for the SRZ, while the climate in the WRZ remained relatively stable. The Little Ice Age (ca. 700-200 cal. yr BP) was rather cool in both rainfall zones and drier in the SRZ while wetter in the WRZ.