Scalable grid resource allocation for scientific workflows using hybrid metaheuristics

Grid infrastructure is a valuable tool for scientific users, but it is characterized by a high level of complexity which makes it difficult for them to quantify their requirements and allocate resources. In this paper, we show that resource trading is a viable and scalable approach for scientific users to consume resources. We propose the use of Grid resource bundles to specify supply and demand combined with a hybrid metaheuristic method to determine the allocation of resources in a market-based approach. We evaluate this through the application domain of scientific workflow execution on the Grid

The dune size distribution and scaling relations of barchan dune fields

Barchan dunes emerge as a collective phenomena involving the generation of thousands of them in so called barchan dune fields. By measuring the size and position of dunes in Moroccan barchan dune fields, we find that these dunes tend to distribute uniformly in space and follow an unique size distribution function. We introduce an analyticalmean-field approach to show that this empirical size distribution emerges from the interplay of dune collisions and sand flux balance, the two simplest mechanisms for size selection. The analytical model also predicts a scaling relation between the fundamental macroscopic properties characterizing a dune field, namely the inter-dune spacing and the first and second moments of the dune size distribution.Comment: 6 pages, 4 figures. Submitted for publicatio

Climate Benefits Tenure Costs: The Economic Case for Securing Indigenous Land Rights in the Amazon

A new report offers evidence that the modest investments needed to secure land rights for indigenous communities will generate billions in returns—economically, socially and environmentally—for local communities and the world's changing climate. The report, Climate Benefits, Tenure Costs: The Economic Case for Securing Indigenous Land Rights, quantifies for the first time the economic value of securing land rights for the communities who live in and protect forests, with a focus on Colombia, Brazil, and Bolivia

A method for dense packing discovery

The problem of packing a system of particles as densely as possible is foundational in the field of discrete geometry and is a powerful model in the material and biological sciences. As packing problems retreat from the reach of solution by analytic constructions, the importance of an efficient numerical method for conducting \textit{de novo} (from-scratch) searches for dense packings becomes crucial. In this paper, we use the \textit{divide and concur} framework to develop a general search method for the solution of periodic constraint problems, and we apply it to the discovery of dense periodic packings. An important feature of the method is the integration of the unit cell parameters with the other packing variables in the definition of the configuration space. The method we present led to improvements in the densest-known tetrahedron packing which are reported in [arXiv:0910.5226]. Here, we use the method to reproduce the densest known lattice sphere packings and the best known lattice kissing arrangements in up to 14 and 11 dimensions respectively (the first such numerical evidence for their optimality in some of these dimensions). For non-spherical particles, we report a new dense packing of regular four-dimensional simplices with density $\phi=128/219\approx0.5845$ and with a similar structure to the densest known tetrahedron packing.Comment: 15 pages, 5 figure

The impact of emotions on polarization. Anger polarizes attitudes towards vaccine mandates and increases affective polarization

When does anger lead to greater polarization? As societal polarization and political polarization increase so does academic interest in its antecedents. One important cause of polarization appears to be anger. However, existing research linking anger and political polarization has focused primarily on the context of partisanship and did not distinguish between different types of anger nor different forms of polarization. To address this gap in the literature, we analyze how generalized versus issue-specific anger amplify issue-based and affective polarization in the highly charged context of the COVID-19 pandemic. We test these relationships through a survey experiment embedded in a national German sample (n = 2857) and show that anger is linked to polarization. However, we also show that different forms of anger influence different aspects of polarization. Issue polarization is driven primarily by generalized anger, while corona-specific anger increases affective polarization. Together, these results underline the importance of understanding the emotional nuances of polarization. More generally, the results illustrate the problems policy makers face when navigating heavily contested and emotionally charged topics. While increased anger may be helpful for mobilizing support among already supportive citizens, it does little to convince skeptical citizens and carries the cost of increasing societal polarization

The hidden majority/minority consensus: Minorities show similar preference patterns of immigrant support as the majority population

The acceptance of new arrivals has become an important topic regarding the social cohesion of the receiving countries. However, previous studies focused only on the native population's drivers of attitudes towards immigrants, disregarding that immigrant-origin inhabitants now form a considerable part of the population. To test whether the drivers for the willingness to support immigrants are the same for natives and immigrants and their descendants, we rely on a vignette study conducted in a representative German online panel (N = 3149) which contains an overrepresentation of immigrant-origin respondents. We presented participants with three vignettes of potential immigrants, varying, amongst other factors, economic prospects, safe and war-ridden countries of origin (to capture deservingness), as well as religious identity. While we find that minority members are generally slightly more welcoming towards immigrants than majority members, at their core are the same factors that drive attitudes to immigrants in both groups: economic cost, cultural similarity, and deservingness. However, we observe differences at the margins: Immigrant-origin respondents take into account economic prospects to a lesser degree than majority members do, and by trend, they are less likely to distinguish between immigrants from war-ridden and safe countries of origin. Furthermore, we can show that the preference for immigrants with the same religious identities not only occurs among majority members but also among minority members

Harpacticoida (Copepoda) in the plankton of Ushuaia and Golondrina Bays, Beagle Channel, Argentina

Harpacticoid copepods form a diverse and abundant group of the meiofauna in marine benthic habitats. Moreover, harpacticoids are frequently found in planktonic samples particularly in shallow and algae-covered coastal waters. Despite their high abundance, little is known about their taxonomy and importance as a component of the food web in the Southern bays of Argentina. Mesozooplankton samples and environmental data were obtained seasonally from Ushuaia and Golondrina Bays (August 2004 to June 2005) and analyzed for the composition and abundance of harpacticoid copepods. Remarkable seasonal changes in the harpacticoid communities were observed. In Ushuaia Bay, nitrogenated nutrients, chlorophyll a, salinity, and temperature were the prevailing environmental parameters that influenced the harpacticoid community, giving rise to different harpacticoid assemblages. The results highlight the importance of the community of Harpacticoida in both bays and provide background data for further studies on zooplankton communities and monitoring programs in marine systems.Fil: Biancalana, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Veit Köhler, G.. German Centre for Integrative Biodiversity Research; AlemaniaFil: Fricke, Anna Lena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina. Leibniz Centre for Tropical Marine Research; AlemaniaFil: Berasategui, Anabela Anhi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentin

Chiral dynamics in the presence of bound states: kaon-nucleon interactions revisited

We study the S-wave kaon-nucleon interactions for strangeness S=-1 in a novel relativistic chiral unitary approach based on coupled channels. Dispersion relations are used to perform the necessary resummation of the lowest order relativistic chiral Lagrangian. A good description of the data in the K^- p, \pi \Sigma and \pi \Lambda channels is obtained. We show how this method can be systematically extended to higher orders, emphasizing its applicability to any scenario of strong self-interactions where the perturbative series diverges even at low energies. Discussions about the differences to existing approaches employing pseudo-potentials in a regulated Lippmann-Schwinger equation are included. Finally, we describe the resonance content of our meson-baryon amplitudes and discuss its nature.Comment: 12 pp, LaTeX2e, FZJ-IKP(TH)-2000-2