1,213,535 research outputs found
L'aritmetica del dolore
No full textpostfazione di A. Tarantino e I. Both a L'evasione silenziosa, edizione italiana del diario dal carcere di L. Constante, Evaderea tacta, curata da Angela Tarantin
The vanishing author in computer-generated works: a critical analysis of recent Australian case law
No full textAbstract
The use of software is ubiquitous in the creation of many copyright works, yet the requirement in copyright law that every work have a human author who engages in independent intellectual effort means that its use may prevent copyright subsistence. Several recent Australian cases have refocused attention on authorship as an essential criterion of copyright subsistence, and these cases suggest that much computer-produced output may be authorless and thus lack copyright protection. This article, the first in a two-part series, analyses how each case deals with the question of authorship of computer-produced works and why the use of software diminishes copyright protection for a significant number of computer-generated works. The article critiques the application of conventional notions of human authorship developed in the pre-computer age to modern productions and suggests alternative approaches to authorship that satisfy both the major objectives of copyright policy and the need to adapt to the computer age. The article argues that, without a broader judicial approach to authorship of computer-generated works, Parliament must remedy the lacuna in protection for these ‘authorless’ works. Possible solutions for reform are suggested. In a forthcoming article, the author comprehensively examines those reform proposals
Experimental evidence for density dependence of reproduction in great tits
No full text1. Density dependence of avian reproduction has often been analysed using correlations between annual mean reproductive output and population density. Experiments are necessary to prove that density is the cause of the observed patterns, but so far, three out of four experimental studies do not support a direct causal effect of density on reproduction. 2. This paper presents experimental evidence that reproductive decisions in great tits, Parus major L., are causally affected by breeding density. The breeding density of great tits was manipulated by providing nest-boxes at different densities in an ecologically homogeneous area. 3. Within years the densities in the high and low density plots differed approximately 8-fold. During the 11 years of the experiment, clutch size, nestling mass and the proportion of birds starting a second brood were all lower in the high density plot. In 5 years with equal breeding densities in both parts, clutch size did not differ between the plots. The patterns found were consistent with the density effects as predicted from the non-experimental data. [KEYWORDS: clutch size; density dependence; density manipulation; Parus major; reproduction Flycatcher ficedula-hypoleuca; clutch-size; parus-major; interspecific competition; population fluctuations; food; survival; habitat; fitness; winter]
No experimental evidence for local competition in the nestling phase as a driving force for density-dependent avian clutch size
No full text1. In birds, local competition for food between pairs during the nestling phase may affect nestling growth and survival. A decrease in clutch size with an increase in breeding density could be an adaptive response to this competition. To investigate whether breeding density causally affected the clutch size of great tits (Parus major), we manipulated breeding density in three out of eight study plots by increasing nest-box densities. We expected clutch size in these plots to be reduced compared to that in control plots.
2. We analysed both the effects of variation in annual mean density (between-year comparisons) and experimental density (within-year comparison between plots) on clutch size variation, the occurrence of second broods and nestling growth. We examined within-female variation in clutch size to determine whether individual responses explain the variation over years.
3. Over the 11 years, population breeding density increased (from 0·33 to 0·50 pairs ha–1) while clutch size and the occurrence of second broods decreased (respectively from 10·0 to 8·5 eggs and from 0·39 to 0·05), consistent with a negative density-dependent effect for the whole population. Nestling growth showed a declining but nonsignificant trend over years.
4. The decline in population clutch size over years was primarily explained by changes occurring within individuals rather than selective disappearance of individuals laying large clutches.
5. Within years, breeding density differed significantly between manipulated plots (0·16 pairs ha–1 vs. 0·77 pairs ha–1) but clutch size, occurrence of second broods and nestling growth were not affected by the experimental treatment, resulting in a discrepancy between the effects of experimental and annual variation in density on reproduction.
6. We discuss two hypotheses that could explain this discrepancy: (i) the decline in breeding performance over time was not due to density, but resulted from other, unknown factors. (ii) Density did cause the decline in breeding performance, but this was not due to local competition in the nestling phase. Instead, we suggest that competition acting in a different phase (e.g. before egg laying or after fledgling) was responsible for the density effect on clutch size among years.
Density dependence of clutch size: habitat heterogeneity or individual adjustment?
No full text1. Two hypotheses have been proposed to explain density- dependent patterns in reproduction. The habitat heterogeneity hypothesis (HHH) explains density-dependent reproduction at the population level from poorer quality territories in heterogeneous environments only being occupied at high densities. No effect of population density is expected on reproduction within a given territory. If reproduction and territory quality are correlated, there will be a negative correlation between reproduction and density. Alternatively, density-dependent responses could be caused by variation in reproduction with population density. This will be referred to as the individual adjustment hypothesis (IAH). 2. The HHH predicts that individuals breeding on the same territory in years with different densities would show no response in reproduction to changes in population density. The response in reproduction of the population to changes in density would therefore be stronger than the within territory response. Under the IAH, the response of individuals on specific territories would be similar to the average response in the whole population. 3. This paper attempts to discriminate between these two hypotheses using data on clutch sizes of great tits Parus major L. from six different populations. In all populations the mean clutch size was negatively correlated with the population density. In four out of the six study populations individual females breeding on the same territory showed a negative correlation between the change in clutch size between years and the change in density. In none of the populations it was found that the response within territories was significantly smaller than the average response for the population. 4. These data suggest that density dependence of clutch size in great tits is not due to poorer quality territories being occupied more frequently at higher population densities. Within territories, individual females adjusted their clutch size to changes in density, and this was sufficient to explain the density dependence of clutch size in five of the six populations, In one population some evidence supporting the HHH was found. [KEYWORDS: clutch size; density dependence; habitat heterogeneity; individual adjustment; Parus major Tit parus-major; great tit]
Produção sustentável de pimenta-do-reino em tutor vivo de gliricídia no estado do Pará: bases econômicas e de qualidade.
No full textA pimenta-do-reino é a mais importante especiaria comercializada no mundo e como se trata de uma commodity, a tendência do mercado é a comercialização de produtos originados de sistemas de produção sustentáveis, com contribuição relevante do uso de tutor vivo de Gliricidia sepium L. em substituição ao estacão (tutor morto), na produção de pimenta-do-reino. Entretanto, a adoção desta tecnologia é limitada em decorrência da escassez de informações (irrigação, espaçamento, nutrição, manejo entre outros fatores de produção) sobre as interações entre o comportamento das cultivares de pimenteira-do-reino a esse tipo de tutor, para consolidação de um sistema de produção sustentável. Portanto, o estudo consiste em identificar as condições adequadas de irrigação e adubação em que a cultura da pimenteira-do-reino cultivada em tutor vivo tenha as exigências hídricas e nutricionais atendidas para a produção com qualidade e viabilidade econômica no Nordeste Paraense. Com o uso da irrigação, assinalou-se uma menor demanda hídrica com o uso de Gliricidia sepium no sistema de irrigação com duas linhas, e menor custo. A implantação do tutor vivo de gliricídia, com custos menores, comparados ao tutor morto, assegura recursos financeiros para a adoção de irrigação. No estabelecimento da cultura, referenda-se os níveis de adubação mínimos (60g de uréia, 40g de P2O5 e 70g de K2O por planta), que equivalem à recomendação de adubação na literatura. A qualidade da pimenta-do-reino produzida com o uso da gliricídia obteve incremento com relação aos índices de densidade, extrato etéreo e piperina. Os resultados desse estudo indicam evidentes contribuições do uso de tutor vivo de gliricídia na circularidade econômica da cadeia da pimenta-do-reino. Neste cenário, recomenda-se o estabelecimento de políticas públicas, voltadas ao desenvolvimento e validação de inovações tecnológicas que assegurem o incremento de produtividade, qualidade do produto e redução de riscos na cadeia produtiva da pimenta-do-reinoTese (Doutorado em Agronomia) - Universidade Federal Rural da Amazônia, Belém, PA. Orientador: Joaquim Alves de Lima Junior; Coorientador: Oriel Filgueira de Lemos, Embrapa Amazônia Oriental
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Efficient Solvers for Nonstandard Models for Flow and Transport in Unsaturated Porous Media
No full textWe study several iterative methods for fully coupled flow and reactive transport in porous media. The resulting mathematical model is a coupled, nonlinear evolution system. The flow model component builds on the Richards equation, modified to incorporate nonstandard effects like dynamic capillarity and hysteresis, and a reactive transport equation for the solute. The two model components are strongly coupled. On one hand, the flow affects the concentration of the solute; on the other hand, the surface tension is a function of the solute, which impacts the capillary pressure and, consequently, the flow. After applying an Euler implicit scheme, we consider a set of iterative linearization schemes to solve the resulting nonlinear equations, including both monolithic and two-splitting strategies. The latter include a canonical nonlinear splitting and an alternate linearized splitting, which appears to be overall faster in terms of number of iterations, based on our numerical studies. The (time discrete) system being nonlinear, we investigate different linearization methods. We consider the linearly convergent L-scheme, which converges unconditionally, and the Newton method, converging quadratically but subject to restrictions on the initial guess. Whenever hysteresis effects are included, the Newton method fails to converge. The L-scheme converges; nevertheless, it may require many iterations. This aspect is improved by using the Anderson acceleration. A thorough comparison of the different solving strategies is presented in five numerical examples, implemented in MRST, a toolbox based on MATLAB.The research of D. Illiano was funded by VISTA, a collaboration between the NorwegianAcademy of Science and Letters and Equinor, project number 6367, project name: adaptive model and solver simulation of enhanced oil recovery. The research of J.W. Both was supported by the Research Council of Norway Project 250223, as well as the FracFlow project funded by Equinor through Akademiaavtalen. The research of I.S. Pop was supported by the Research Foundation-Flanders (FWO), Belgium through the Odysseus programme (project G0G1316N) and Equinor through the Akademia grant
Efficient Solvers for Nonstandard Models for Flow and Transport in Unsaturated Porous Media
No full textWe study several iterative methods for fully coupled flow and reactive transport in porous media. The resulting mathematical model is a coupled, nonlinear evolution system. The flow model component builds on the Richards equation, modified to incorporate nonstandard effects like dynamic capillarity and hysteresis, and a reactive transport equation for the solute. The two model components are strongly coupled. On one hand, the flow affects the concentration of the solute; on the other hand, the surface tension is a function of the solute, which impacts the capillary pressure and, consequently, the flow. After applying an Euler implicit scheme, we consider a set of iterative linearization schemes to solve the resulting nonlinear equations, including both monolithic and two-splitting strategies. The latter include a canonical nonlinear splitting and an alternate linearized splitting, which appears to be overall faster in terms of number of iterations, based on our numerical studies. The (time discrete) system being nonlinear, we investigate different linearization methods. We consider the linearly convergent L-scheme, which converges unconditionally, and the Newton method, converging quadratically but subject to restrictions on the initial guess. Whenever hysteresis effects are included, the Newton method fails to converge. The L-scheme converges; nevertheless, it may require many iterations. This aspect is improved by using the Anderson acceleration. A thorough comparison of the different solving strategies is presented in five numerical examples, implemented in MRST, a toolbox based on MATLAB.The research of D. Illiano was funded by VISTA, a collaboration between the NorwegianAcademy of Science and Letters and Equinor, project number 6367, project name: adaptive model and solver simulation of enhanced oil recovery. The research of J.W. Both was supported by the Research Council of Norway Project 250223, as well as the FracFlow project funded by Equinor through Akademiaavtalen. The research of I.S. Pop was supported by the Research Foundation-Flanders (FWO), Belgium through the Odysseus programme (project G0G1316N) and Equinor through the Akademia grant
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
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