14,230 research outputs found
O significado do trabalho da alegria em ambiente hospitalar de pediatria :: transformando o ritmo, reacendendo o brilho /
No full textDissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Saúde
Lyman break galaxies and the star formation rate of the Universe at z ~ 6
No full textWe determine the space density of UV-luminous starburst galaxies at z≈ 6 using deep HST ACS SDSS-i′ (F775W) and SDSS-z′ (F850LP) and VLT ISAAC J and Ks band imaging of the Chandra Deep Field South. We find eight galaxies and one star with (i′−z′) > 1.5 to a depth of z′AB= 25.6 (an 8σ detection in each of the 3 available ACS epochs). This corresponds to an unobscured star formation rate of ≈15 h−270 M⊙ yr−1 at z= 5.9, equivalent to L* for the Lyman-break population at z= 3–4 (ΩΛ= 0.7, ΩM= 0.3). We are sensitive to star-forming galaxies at 5.6 ≲z≲ 7.0 with an effective comoving volume of ≈1.8 × 105h−370 Mpc3 after accounting for incompleteness at the higher redshifts due to luminosity bias. This volume should encompass the primeval subgalactic-scale fragments of the progenitors of about a thousand L* galaxies at the current epoch. We determine a volume-averaged global star formation rate of (6.7 ± 2.7) × 10−4h70 M⊙ yr−1 Mpc−3 at z∼ 6 from rest-frame UV selected starbursts at the bright end of the luminosity function: this is a lower limit because of dust obscuration and galaxies below our sensitivity limit. This measurement shows that at z∼ 6 the star formation density at the bright end is a factor of ∼6 times less than that determined by Steidel et al. for a comparable sample of UV-selected galaxies at z= 3–4, and so extends our knowledge of the star formation history of the Universe to earlier times than previous work and into the epoch where reionization may have occurred
A diluent for prolonged motility of ocean pout (Macrozoarces americanus L.) sperm
No full textThe present study describes a new semen diluent (diluent C) which prolongs the sustained motility of ocean pout sperm, a distinguishing feature of the sperm of internally fertilizing teleosts. Sperm motilities were compared in the new diluent (C), based on the ionic composition of ocean pout seminal plasma, vs. four other semen diluents (A, B, D and E) ordinarily used for extending the semen of external fertilizers. While sperm retained motility after extension of ocean pout semen in all of these diluents, motility was significantly reduced following sperm resuspension in diluents B and D. Since sperm motility remained high in diluent C, formulated to closely mimic the composition of ocean pout seminal plasma, it was selected for additional experimentation. Negative effects were observed on sperm motility after dilution (> 1:10) of ocean pout semen with diluent C, but sperm motility could be restored by replacement of the seminal plasma. Of practical importance for storage of ocean pout sperm at 4 degrees C, it was shown that semen dilution 1:3 in diluent C preserved sperm motility beyond 5 days. Although ocean pout sperm tolerate a fairly wide range of K+ levels (0-30 mmol/l), the best motility was observed from 10-20 mmol/l [K+], similar to the ionic levels found in seminal plasma. Finally, since no change in fertility of ocean pout sperm occurred following 1:3 dilution of semen in diluent C, we conclude that diluent C is an effective medium for in vitro artificial egg insemination and prolonged motility of ocean pout sperm. (C) 1999 Elsevier Science B.V. All rights reserved.PT: J; CR: BAYNES SM, 1981, J FISH BIOL, V19, P259 BILLARD R, 1992, J EXP ZOOL, V261, P122 BILLARD R, 1993, AQUAT LIVING RESOUR, V6, P67 CHAMBEYRON F, 1990, AQUACULTURE, V90, P345 CHAUVAUD L, 1995, ENVIRON BIOL FISH, V43, P341 COBB JLS, 1973, J FISH BIOL, V5, P587 ERDAHL AW, 1987, AQUACULTURE, V60, P311 ERDAHL AW, 1987, AQUACULTURE, V60, P323 GALLANT RK, 1993, THERIOGENOLOGY, V40, P479 GATTI JL, 1990, J CELL PHYSIOL, V143, P546 GOODALL JA, 1989, AQUACULTURE, V77, P243 OHTA H, 1996, AQUACULTURE, V142, P107 PAVLOV DA, 1994, AQUACULTURE, V122, P295 STOSS J, 1983, AQUACULTURE, V30, P229 SUQUET M, 1993, J FISH BIOL, V42, P509 WANG Z, 1997, FISH PHYSIOL BIOCHEM, V16, P77 YAO Z, 1995, MOL REPROD DEV, V42, P58 YAO Z, 1995, P 5 INT S REPR PHYS YAO ZX, 1995, AQUACULTURE, V130, P361 YAO ZX, 1995, J FISH BIOL, V47, P171; NR: 20; TC: 6; J9: AQUACULTURE; PG: 11; GA: 182MLSource type: Electronic(1
Eu jogo, tu jogas, nós aprendemos: experiências culturais eletrolúdicas no contexto do ciberespaço
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Educação. Programa de Pós-Graduação em Educação.No decorrer das últimas décadas, inúmeras pesquisas têm envidado esforços no intento de superar a crença de que os jogos digitais são apenas como formas vazias de entretenimento. Quanto a isso, percebe-se que tais iniciativas vêm modificando o imaginário acadêmico e social, dando visibilidade às variadas funções inerentes aos videogames, entre as quais, estão as de natureza educacional. Não obstante, mesmo adquirindo crescente atenção, o debate sobre a aprendizagem através dos jogos ainda parece excessivamente focado nas experiências provenientes do jogar propriamente dito, deixando de lado as vivências que mesmo nas "imediações" dessa atividade, orbitam em torno dela. Buscando agregar densidade às ponderações sobre a educação baseada em games, este trabalho discute sobre as experiências culturais construídas no âmbito das comunidades virtuais de jogadores, atentando para os limites e possibilidades de suas qualidades formativas. Para isso, recorre às noções de alegria, mídia-educação, cultura participativa, letramento, jogo e gaming. Em termos metodológicos, inspira-se nas perspectivas da (n)etnografia e da etnoarqueologia, constituindo-se como um estudo de caso sobre a comunidade virtual UOL Jogos. A construção dos dados ocorreu mediante o acompanhamento dos conteúdos veiculados pela seção Videogames do site principal, pelo fórum e pela página oficial no Facebook. Por se tratarem de ambientes on-line alinhados aos pressupostos da web 2.0, este exame levou em conta tanto as iniciativas dos administradores do espaço, quanto de seus usuários, no intuito de identificar as maneiras pelas quais essas comunidades se constituem como zonas de consumo, produção e circulação cultural a serviço dos jogos eletrônicos. Nesse sentido, verificou-se que as experiências socioculturais dos jogadores com este tipo de inserção detêm caráter ambivalente: de um lado, oferecem recursos capazes de contribuir com os processos de ensino e aprendizagem desenvolvidos no âmbito da educação formal; e de outro, demandam a formulação e implementação de ações específicas capazes de preparar os sujeitos para os desafios suscitados pelas formas participativas críticas, criativas e estético-artísticas da cultura digital. Por fim, conclui que a conversão da diversão provocada pelos jogos digitais em alegrias culturais depende da mobilização por parte instituições de ensino, por meio da qual, estes estabelecimentos devem estreitar seus laços com as práticas e vivências inscritas no gaming, dispondo-se a enriquecê-las com a cultura elaborada sob a sua responsabilidade - nesse caso, emoldurada aos princípios da mídia-educação e dos letramentos digitai
Auswirkungen der Einbringung von Buche (Fagus sylvatica L.) auf die Artendiversität und Naturnähe von Nadelholzbeständen in Niedersachsen
No full textThe promotion and extension of continuous cover mixed stands with a simultaneous reduction of conifer-monocultures play a major role in current silvicultural practices in Central Europe. It is assumed that the admixture of the natural dominant beech (Fagus sylvatica) in pure non site-specific conifer stands automatically indicates better conditions in terms of nature conservation and forest management. To test this hypothesis three different conifer-beech-comparisons of pure and mixed stands in Lower Saxony are studied, analyzing plant species diversity and naturalness of understory vegetation as one important indicator for the ecological status of forests. Each comparison includes pure coniferous stands (Picea abies, Pinus sylvestris, Pseudotsuga menziesii), mixed coniferous-beech-stands, and pure beech stands on similar acidic mineral soils where the potential natural vegetation will be an oligotrophic beech forest (L u z u l o - Fa g e t um). The age of stands varies between 50 and 150 years. To specify tree species influence on site conditions and vegetation, the study also includes light climate and soil data of the stands. It is observed that, with regard to all comparisons, the admixture of beech reduces plant species diversity but increases naturalness of the stands. The intensity of beech admixture effects differs. While in Scots pine stands the impact of admixed beech is very noticeable, with the mixed stands being nearly identical with pure beech stands, the species change in Douglas-fir and Norway spruce stands proceeds more slowly. Assuming that the status in nature conservation and forest management is improving with increasing plant species diversity and increasing naturalness, the results of this study show a contrary development on a stand scale, as the potential natural vegetation of the L u z u l o - F a g e t u m is in its self very species poor on vascular plants.Die Förderung und Ausweitung von Mischwäldern bei gleichzeitiger Reduktion reiner Nadelholz-Bestände spielt aktuell eine große Rolle im mitteleuropäischen Waldbau. Gemeinhin wird angenommen, dass die Beimischung der standortsgemäßen Buche (Fagus sylvatica) in standortsfremden Nadelholz Monokulturen die Bedingungen im Sinne des Naturschutzes und der Forstwirtschaft verbessert. Diese Hypothese wird auf der Grundlage von drei unterschiedlichen Nadelholz- Buchen-Versuchsreihen geprüft. Im Mittelpunkt steht dabei die Bodenvegetation als wichtiger und sensitiver Indikator für den ökologischen Zustand von Wäldern. Jede Versuchsreihe umfasst reine Nadelholz-Bestände (Picea abies, Pinus sylvestris, Pseudotsuga menziesii), Nadelholz-Buchen- Mischbestände und reine Buchen-Bestände auf sauren Mineralböden, auf denen von Natur aus nährstoffarme Buchenwälder (L u z u l o - Fa g e t um) vorherrschen würden. Das Alter der Bestände variiert zwischen 50 und 150 Jahren. Schwerpunkte der Analyse sind die Artenvielfalt und Naturnähe der Bodenvegetation. Um den Einfluss der Baumarten auf den Standort und die Vegetation zu bewerten, werden die Licht- und Bodenverhältnisse der Bestände charakterisiert. Es zeigt sich, dass mit der Beimischung der Buche in allen Versuchsreihen die Pflanzenartenvielfalt abnimmt und die Naturnähe zunimmt. Unterschiedlich ist dabei die Intensität der Veränderungen. Zwischen den Kiefern-Buchen-Mischbeständen und den Kiefern-Reinbeständen bestehen sehr deutliche Unterschiede im Aufbau der Bodenvegetation, so dass die Mischbestände den Buchen-Reinbeständen bereits sehr ähnlich sind. In den Douglasien- und Fichten-Versuchsreihen vollzieht sich der Artenwechsel vergleichsweise unauffällig und kontinuierlich. Wenn man davon ausgeht, dass der naturschutzfachliche und waldbauliche Status sich sowohl mit zunehmender Phytodiversität als auch bei zunehmender Naturnähe verbessert, so zeigen diese Ergebnisse auf Bestandesebene eine gegenläufige Entwicklung, da das in der Region der potenziell natürlichen Vegetation entsprechende L u z u l o - Fa g e tum von Natur aus sehr artenarm an Gefäßpflanzen ist
The Benefits of Being Economics Professor A (and not Z)
No full textAlphabetic name ordering on multi-authored academic papers, which is the convention in the economics discipline and various other disciplines, is to the advantage of people whose last name initials are placed early in the alphabet. As it turns out, Professor A, who has been a first author more often than Professor Z, will have published more articles and experienced afaster growth rate over the course of her career as a result of reputation and visibility. Moreover, authors know that name ordering matters and indeed take ordering seriously: Several characteristics of an author group composition determine the decision to deviate from the default alphabetic name order to a significant extent.performance measurement, incentives, economists, name ordering
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Ultimate soil resistance of the laterally loaded pile in uniform sand
No full textPiles have been widely used as foundations to resist lateral loads. For the design of a laterally loaded pile, one of the most important inputs is the ultimate soil resistance (pult = KultDσv′,whereKult is the ultimate lateral soil resistance coefficient, D is the pile diameter, and σv′ is the vertical effective stress). However, great discrepancy can be found in the existing design equations for piles in sand. To provide new insights and clarify the discrepancy in previous studies, in this study, a series of numerical simulations were performed on piles of different configurations using the finite element model validated by centrifuge pile tests. The computed results suggest that Kult is a function of depth ratios z/D and z/L for the flexible and rigid piles, respectively (where z is the absolute depth and L is the embedded pile length), and all existing design equations failed to reproduce the magnitude and distribution of Kult . Additionally, the Kult of horizontally translated fixed-head rigid piles exhibits the same pattern as that of free-head flexible piles, suggesting that the difference between free-head flexible piles and rigid piles is caused by the change of failure modes.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work publicGeo-engineerin
Measurement of the ZZ production cross section and Z -> l(+)l(-)l '(+)l '(-) branching fraction in pp collisions at root s=13TeV
No full textFour-lepton production in proton-proton collisions, pp -> (Z/gamma*)(Z/gamma*)-> l(+)l(-)l '(+)l '(-), where l,l '(-) = e or mu, is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.6fb(-1). The ZZ production cross section, sigma(pp -> ZZ) = 14.6(-1.8)(+1.9)(stat)(-0.3)(+0.5) (syst) +/-0.2 (theo) +/-0.4 (lumi) pb, is measured for events with two opposite-sign, sameflavor lepton pairs produced in the mass region 60 < m(l+l-) m (l'+l'-) < 120GeV. The Z boson branching fraction to four leptons is measured to be B(Z -> l(+)l(-)l '(+)l '(-)) = 4.9(-0.7)(+0.8)(stat)(-0.2)(+0.3)(syst)(-0.1)(+0.2)(theo) +/- 0.1 (lumi) x10(-6) for the four-lepton invariant mass in the range 80 < m(l+)l-l'+l' < 100GeVand dilepton mass m(l+l-) > 4GeVfor all opposite-sign, same-flavor lepton pairs. The results are in agreement with standard model predictions. (C) 2016 The Author. Published by Elsevier B. V. This is an open access article under the CC BY licens
Self-archiving practice and the influence of publisher policies in the social sciences
No full textAuthors in different disciplines exhibit very different behaviours on the so-called ‘green’ road to open access, i.e. self-archiving. This study looks at the self-archiving behaviour of authors publishing in leading journals in six social science disciplines. It tests the hypothesis that authors are self-archiving according to the norms of their respective disciplines rather than following self-archiving policies of publishers, and that, as a result, they are self-archiving significant numbers of publisher PDF versions. It finds significant levels of
self-archiving, as well as significant self-archiving of
the publisher PDF version, in all the disciplines
investigated. Publishers’ self-archiving policies have
no influence on author self-archiving practice
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