cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Economic Incentives for Global Conservation of Wildlife: New International Policy Directions
Creators: name: Tisdell, Clement A.
name: Tisdell, Clement A.
Publisher: name: Unknown
Year: 2005
Subjects: Environmental Economics and Policy
Resource /Energy Economics and Policy

description: Growing economic globalisation by extending the operation of markets is a two-edged sword as far as nature conservation is concerned. In some circumstances, it threatens the conservation of nature and in other cases, it provides economic incentives that foster the conservation of biodiversity. This article shows how global policy directions have altered in that regard. Initially the World Conservation Union (IUCN) favoured bans on trade in endangered species. This view was enshrined in the Convention on International Trade in Endangered Species (CITES). Subsequently, with the upsurge of support for market-based economic liberalism, IUCN recognised that economic and market incentives, if linked to appropriate property rights, could foster biodiversity conservation. This is reflected in the International Convention on Biological Diversity. While there is conflict between this convention and CITES, its extent has been exaggerated. As explained, in certain cases, trade restrictions of the type adopted in CITES are appropriate for nature conservation whereas the market-oriented policy of the Convention on Biological Diversity can be effective in some different situations. Whether or not the extension of markets in wildlife and wildlife products and growing economic globalisation favours nature conservation varies according to the circumstances.
Resource Entitlements of Indigenous Minorities, Their Poverty and Conservation of Nature: Status of Australian Aborigines, Comparisons with India's Tribals, Theory and Changing Policies Globally
Creators: name: Tisdell, Clement A.
name: Tisdell, Clement A.
Publisher: name: Unknown
Year: 2005
Subjects: Environmental Economics and Policy
Resource /Energy Economics and Policy

description: Considers the relevance of A.K. Sen’s theory of entitlements to the situation facing indigenous tribal people, its relationship to institutionalism, and to theories of property rights. Changing world views about the resource entitlements that should be given to local communities are outlined concentrating on the views expressed by the World Conservation Union (IUCN). These changing views have relevance for the resource entitlements of indigenous tribal communities and are reflected in differences in the policy approaches inherent in the Convention on International Trade in Endangered Species (CITES) and the more recent Convention on Biological Diversity. The latter embodies the view that provision of greater resource entitlements to local communities can provide economic incentives for nature conservation. There is a case for Indigenous Australians to be given greater rights to market the natural produce from their lands. Despite progress with land rights, they are not entitled to market much of the natural produce from their land. The socioeconomic status of Australian Aborigines is outlined. Their standard of living and their life expectancy are low by world standards and in comparison to other Australians. This is partly a result of historical events that have restricted their rights. These events are outlined briefly. Views differ about the appropriate development paths for Indigenous Australians and these are assessed. Concern on environmental and economic grounds is expressed about the view that the economic development of Australian Aboriginal communities would be accelerated by replacing their communal land titles by private land titles and encouraging Western-style agriculture and commercial development of their lands. Some comparisons are also made with the situation of India’s Tribals.
title: المكتبات في مدينة عجمان منذ مطلع القرن العشرين حتى قيام الاتحاد/ علي محمد المطروشي.
Creators: name: المطروشي، علي محمد
Publisher: name: الأرشيف والمكتبة الوطنية
Year: 2017
Subjects: الإمارات العربية المتحدة - تاريخ.

- يتناول هذا البحث تاريخ الكتب والمكتبات في إمارة عجمان قبل قيام الاتحاد، فيسلط الباحث الضوء على الحياة الثقافية في الإمارات في حقبة الغوص على اللؤلؤ، والفئات الواعية والمثقفة في المجتمع في تلك الحقبة، ثم يتناول بالتفصيل مراحل الحياة العلمية والثقافية في إمارة عجمان قبل الاتحاد.
Unusual Galactic HII Regions at the Intersection of the Central Molecular Zone and the Far Dust Lane
Creators: name: Anderson, Loren D.
name: Sormani, Mattia C.
name: Ginsburg, Adam
name: Glover, Simon C. O.
name: Heywood, Ian
name: Rammala, Isabella
name: Schuller, Frederic
name: Csengeri, Timea
name: Urquhart, James S.
name: Bronfman, Leonardo J.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Sgr E is a massive star formation complex found toward the Galactic center that consists of numerous discrete, compact HII regions. It is located at the intersection between the Central Molecular Zone (CMZ) and the far dust lane of the Galactic bar, similar to "hot spots" seen in external galaxies. Compared with other Galactic star formation complexes, the Sgr E complex is unusual because its HII regions all have similar radio luminosities and angular extents, and they are deficient in ~10micron emission from their photodissociation regions (PDRs). Our Green Bank Telescope (GBT) radio recombination line observations increase the known membership of Sgr E to 19 HII regions. There are 43 additional HII region candidates in the direction of Sgr E, 26 of which are detected for the first time here using MeerKAT 1.28GHz data. Therefore, the true HII region population of Sgr E may number >60. Using APEX SEDIGISM 13CO 2-1 data we discover a 3.0x10^5 Solar mass molecular cloud associated with Sgr E, but find few molecular or far-infrared concentrations at the locations of the Sgr E HII regions. Comparison with simulations and an analysis of its radio continuum properties indicate that Sgr E formed upstream in the far dust lane of the Galactic bar a few Myr ago and will overshoot the CMZ, crashing into the near dust lane. We propose that the unusual infrared properties of the Sgr E HII regions are caused by their orbit about the Galactic center, which have possibly stripped their PDRs.
description: Accepted to ApJ
The Epsilon Calculus and Herbrand Complexity
Creators: name: Moser, Georg
name: Zach, Richard
Publisher: name: arXiv
Year: 2005
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 03F03 (Primary), 03F05, 03F07 (Secondary)

description: Hilbert's epsilon-calculus is based on an extension of the language of predicate logic by a term-forming operator $ε_{x}$. Two fundamental results about the epsilon-calculus, the first and second epsilon theorem, play a role similar to that which the cut-elimination theorem plays in sequent calculus. In particular, Herbrand's Theorem is a consequence of the epsilon theorems. The paper investigates the epsilon theorems and the complexity of the elimination procedure underlying their proof, as well as the length of Herbrand disjunctions of existential theorems obtained by this elimination procedure.
description: 23 pp
Environmentally Induced Entanglement -- Anomalous Behavior in the Adiabatic Regime
Creators: name: Hartmann, Richard
name: Strunz, Walter T.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Considering two non-interacting qubits in the context of open quantum systems, it is well known that their common environment may act as an entangling agent. In a perturbative regime the influence of the environment on the system dynamics can effectively be described by a unitary and a dissipative contribution. For the two-spin Boson model with (sub-) Ohmic spectral density considered here, the particular unitary contribution (Lamb shift) easily explains the buildup of entanglement between the two qubits. Furthermore it has been argued that in the adiabatic limit, adding the so-called counterterm to the microscopic model compensates the unitary influence of the environment and, thus, inhibits the generation of entanglement. Investigating this assertion is one of the main objectives of the work presented here. Using the hierarchy of pure states (HOPS) method to numerically calculate the exact reduced dynamics, we find and explain that the degree of inhibition crucially depends on the parameter $s$ determining the low frequency power law behavior of the spectral density $J(ω) \sim ω^s e^{-ω/ω_c}$. Remarkably, we find that for resonant qubits, even in the adiabatic regime (arbitrarily large $ω_c$), the entanglement dynamics is still influenced by an environmentally induced Hamiltonian interaction. Further, we study the model in detail and present the exact entanglement dynamics for a wide range of coupling strengths, distinguish between resonant and detuned qubits, as well as Ohmic and deep sub-Ohmic environments. Notably, we find that in all cases the asymptotic entanglement does not vanish and conjecture a linear relation between the coupling strength and the asymptotic entanglement measured by means of concurrence. Further we discuss the suitability of various perturbative master equations for obtaining approximate entanglement dynamics.
description: minor changes due to the reviewing process by the Quantum Journal
Le contrôle de gestion au service du pilotage de la performance de l'entreprise
Creators: name: CHEGRI, Meryem
name: TORRA, Mohamed
Publisher: name: Zenodo
Year: 2024
Subjects: Contrôle de gestion ; Performance ; Calcul de coût ; Tableau de bord ; Budgétisation.

description: Dans un monde en constante évolution et de plus en plus compétitif, l’amélioration de la performance des entreprises est une préoccupation cruciale pour chacun. L'une des fonctions clés au sein d'une entreprise est le contrôle de gestion, qui est un système conçu pour optimiser la performance des différents services. Pour y parvenir, les contrôleurs de gestion utilisent divers outils et instruments, dont le tableau de bord, le calcul de coût et ses différentes méthodes.  

Dans cet article, notre objectif est de procéder à un examen théorique des différents outils de performance utilisés par les contrôleurs de gestion et de déterminer les objectifs et les fonctions qu'ils remplissent.
Agroindústria canavieira no Brasil: intervencionismo, desregulação e neocorporativismo
Creators: name: Shikida, Pery Francisco Assis
name: Moraes, Marcia Azanha Dias Ferraz De
name: Alves, Lucilio Rogerio Aparecido
name: Shikida, Pery Francisco Assis
name: Moraes, Marcia Azanha Dias Ferraz De
name: Alves, Lucilio Rogerio Aparecido
Publisher: name: Unknown
Year: 2004
Subjects: subject: Institutional and Behavioral Economics
subject: Sugar cane agroindusty
subject: State
subject: Neo-corporatism
subject: Self-management

description: The purpose of this work is to analyze, on the way of the theoretical reference of the neo-corporatism, the new institutional paradigm of the sugar cane mill and the new ways of management and political articulation after the sector deregulation. With the end of the state intervention, there is the explanation of the process of the economical and social differences of the sector between and inside of the productive regions North/Northeast and Center/South. The productive segment is divided in two: the ones with capacity for facing new requests and the ones that don’t have that attribute. It is indispensable to recognize that for its own improvement and growth – considering the institutional limits – the need of self-management rules, whose main challenges is to attempter the interest of players of the own productive chain and the others that are connected each other and with society.
Physical Modeling and Performance of Spatial-Spectral Filters for CT Material Decomposition
Creators: name: Tivnan, Matthew
name: Tilley, Steven
name: Stayman, J. Webster
Publisher: name: arXiv
Year: 2020
Subjects: subject: Medical Physics (physics.med-ph)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Material decomposition for imaging multiple contrast agents in a single acquisition has been made possible by spectral CT: a modality which incorporates multiple photon energy spectral sensitivities into a single data collection. This work presents an investigation of a new approach to spectral CT which does not rely on energy-discriminating detectors or multiple x-ray sources. Instead, a tiled pattern of K-edge filters are placed in front of the x-ray to create spatially encoded spectra data. For improved sampling, the spatial-spectral filter is moved continuously with respect to the source. A model-based material decomposition algorithm is adopted to directly reconstruct multiple material densities from projection data that is sparse in each spectral channel. Physical effects associated with the x-ray focal spot size and motion blur for the moving filter are expected to impact overall performance. In this work, those physical effects are modeled and a performance analysis is conducted. Specifically, experiments are presented with simulated focal spot widths between 0.2 mm and 4.0 mm. Additionally, filter motion blur is simulated for a linear translation speeds between 50 mm/s and 450 mm/s. The performance differential between a 0.2 mm and a 1.0 mm focal spot is less than 15% suggesting feasibility of the approach with realistic x-ray tubes. Moreover, for reasonable filter actuation speeds, higher speeds are shown to decrease error (due to improved sampling) despite motion-based spectral blur.
Evaluation of environmental impacts of riverbed dredging : a proposed project on the lower Caroni River, Venezuela
Creators: name: Sandoval, Maria Claudia
Publisher: name: University of British Columbia
Year: 2009

description: The purpose of this research thesis is to identify social, economic and environmental impacts associated with dredging in riverbed settings and potential preventive actions. This project uses a mining dredging project (Caroni Project), currently at an early stage, as a case study. Increases in river water turbidity, changes in drinking water quality for the nearby cities, and increased mercury mobilization are the main environmental impacts this thesis project evaluates. A diversity of non-environmental factors also influence the feasibility of the Caroni Project, and for that reason an integrated environmental, social and economic approach is required. It was found that increases in river water turbidity during dredging operations can be prevented by using a combination of pneumatic high density suction dredging methods and an underwater crusher or a cutterhead dredger where hard pan layers are located. Regardless of the low fines content expected in the river, these procedures must be accompanied by preventive measures against turbidity like turbidity curtains and low impact cutterheads, due to the extreme sensitivity of the dredging area. It was also found that the main potential environmental impacts are linked to mercury recovery, waste water and sludge treatment. The removal of metallic mercury contained in the sediments can be achieved during the processing stage by gravity concentration and retorting. The residual mercury is expected to be associated with fine concentrates that could be treated by electrochemical methods if required. Encapsulation of metallic mercury and organic mercury bearing sludge is possible by commercially available methods. The development of a Sustainable Business Case and the implementation of the Mining, Minerals and Sustainable Development - Seven Questions Methodology as a tool for monitoring sustainability would both contribute to better foreseen opportunities to negotiate mutually beneficial agreements among stakeholders of the Caroni Project, and reduce the risk of land use conflict with hydro-electric company (EDELCA), former artisanal miners and other potential actors not yet identified. This research project provides an opportunity to propose specific sustainable practices not only applicable to the mineral dredging industry but also to junior mining company project.
RT01_3_04_Zembrzuski.pdf
Creators: name: Michał Zembrzuski
Publisher: name: figshare
Year: 2020
Subjects: subject: Philosophy
subject: FOS: Philosophy, ethics and religion

description: "Rocznik Tomistyczny", 1 (2012), s. 249-254
Search for long-lived heavy neutral leptons in proton-proton collision events with a lepton-jet pair associated with a secondary vertex at $\sqrt{s}$ = 13 TeV
Creators: name: CMS Collaboration
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: A search for long-lived heavy neutral leptons (HNLs) using proton-proton collision data corresponding to an integrated luminosity of 138 fb$^{-1}$ collected at $\sqrt{s}$ = 13 TeV with the CMS detector at the CERN LHC is presented. Events are selected with a charged lepton originating from the primary vertex associated with the proton-proton interaction, as well as a second charged lepton and a hadronic jet associated with a secondary vertex that corresponds to the semileptonic decay of a long-lived HNL. No excess of events above the standard model expectation is observed. Exclusion limits at 95% confidence level are evaluated for HNLs that mix with electron and/or muon neutrinos. Limits are presented in the mass range of 1-16.5 GeV, with excluded square mixing parameter values reaching as low as 2 $\times$ 10$^{-7}$. For masses above 11 GeV, the presented limits exceed all previous results in the semileptonic decay channel, and for some of the considered scenarios are the strongest to date.
description: Replaced with the published version. Added the journal reference and the DOI. All the figures and tables, including additional supplementary figures, can be found at http://cms-results.web.cern.ch/cms-results/public-results/publications/EXO-21-011 (CMS Public Pages)
Questão agrária e desenvolvimento econômico e social nas regiões Norte e Noroeste fluminense
Creators: name: Souza, Paulo Marcelo De
name: Ponciano, Niraldo Jose
name: Mata, Henrique Tome Da Costa
name: Detmann, Edenio
name: Souza, Paulo Marcelo De
name: Ponciano, Niraldo Jose
name: Mata, Henrique Tome Da Costa
name: Detmann, Edenio
Publisher: name: Unknown
Year: 2004
Subjects: subject: Community/Rural/Urban Development
subject: Agrarian structure
subject: Economic and social development
subject: Royalties

description: The research has as objective to analyze the evolution of the agrarian structure, and the behavior of the economic and social development indicators, for the North and Northwest regions of the Rio de Janeiro state. Moreover, it searchs to verify if the land distribution is an important variable in the explanation of the divergences between the degree of economic development of the cities. The results show that, for the considered regions, the differences in the agrarian structure, separately, can not explain the differences in the degree of economic and social development. The size of the population, in turn, seems to be an important variable in this process. This can be associated to the greater potential demand, what is attractive the private investments. Another reason is, possibly, the greatest politics power, due to the size of the electorate, what can influence in the destination of the public investments.
A Gravitational Effective Action on a Finite Triangulation
Creators: name: Ko, Albert
name: Rocek, Martin
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Geometric Topology (math.GT)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We construct a function of the edge-lengths of a triangulated surface whose variation under a rescaling of all the edges that meet at a vertex is the defect angle at that vertex. We interpret this function as a gravitational effective action on the triangulation, and the variation as a trace anomaly.
description: 5 pages; clarifications, acknowledgements, references added
Determinantes do desmatamento em pequenas propriedades na Amazônia: um estudo de caso em Uruará - PA
Creators: name: Pereira, Ritaumaria De J.
name: Vieira, Wilson Da Cruz
name: Lima, Joao Eustaquio De
name: Caldas, Marcellus Marques
name: Pereira, Ritaumaria De J.
name: Vieira, Wilson Da Cruz
name: Lima, Joao Eustaquio De
name: Caldas, Marcellus Marques
Publisher: name: Unknown
Year: 2004
Subjects: subject: Environmental Economics and Policy
subject: Brasilian Amazon
subject: Deforestation
subject: Colonization
subject: Tobit model

description: The main objective of this paper was to analyse the factors that influence deforestation in small rural farms of a colonization area in Brazil’s Amazon Region. It was used data from 138 small farms distribuited over the transamazonic road in the municipality of Uruará, PA. The data was collected during july and august of 2002. A Tobit model with sample selectivity with etimation in two stages (Heckman) was used. In the first stage, the probability of deforestation was explained mainly by the presence of cattle in the farm. In the second stage, the deforestation area was modeled as a function of various factors. The results showed that the main determinants of deforestation are the amount paid for lired labor, the distance from the main road, the number of cattle heads and the number of people that live in the lot of land.
Vantagens comparativas reveladas e orientação regional das exportações agrícolas brasileiras para a União Européia
Creators: name: Waquil, Paulo Dabdab
name: Alvim, Augusto Mussi
name: Silva, Leonardo Xavier Da
name: Trapp, Glaucilene P.
name: Waquil, Paulo Dabdab
name: Alvim, Augusto Mussi
name: Silva, Leonardo Xavier Da
name: Trapp, Glaucilene P.
Publisher: name: Unknown
Year: 2004
Subjects: subject: International Relations/Trade
subject: Regional integration
subject: International trade
subject: Comparative advantages
subject: Agriculture

description: The paper analyses the Brazilian agricultural trade with the European Union (EU), in the context of the negotiations for a commercial agreement between Mercosur and the EU. We calculate indexes of revealed comparative advantages (RCA) and regional orientation (RO), for the period from 1991 to 2001. We selected the following products: soybeans, orange juice, tobacco, chicken meat, bovine meat, sugar and coffee. Altogether, these products corresponded to more than 20% of total Brazilian exports in that period. The products that show the highest Brazilian participation in world trade are soybeans, orange juice and coffee. Except for sugar, all the analyzed products had the EU as an important destiny for the exports. The results indicate comparative advantages for the Brazilian products, showing stable or increasing indexes along the decade. Besides, there is a high orientation of Brazilian exports to the EU, except for chicken meat and sugar, but with no increases in the period. Thus, an agreement between the blocs, reducing or eliminating tariff and non-tariff barriers, may result in a trade creation, in favor of Brazilian agricultural exports to the EU.
The Canis Major Dwarf Galaxy
Creators: name: Lewis, Geraint F.
name: Ibata, Rodrigo A.
name: Irwin, Michael J.
name: Martin, Nicolas F.
name: Bellazzini, Michele
name: Conn, Blair
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Recent observational evidence suggests that the Sagittarius dwarf galaxy represents the only major ongoing accretion event in the Galactic halo, accounting for the majority of stellar debris identified there. This paper summarizes the recent discovery of another potential Milky Way accretion event, the Canis Major dwarf galaxy. This dwarf satellite galaxy is found to lie just below the Galactic plane and appears to be on an equatorial orbit. Unlike Sagittarius, which is contributing to the Galactic halo, the location and eventual demise of Canis Major suggests that it represents a building block of the thick disk.
description: Refereed contribution to "Structure & Dynamics in the Local Universe, a workshop to honour Brent Tully's 60th birthday", Nov 2003. 4 pages + 2 figures (quality reduced due to size restrictions). To appear in PASA
Magnetic Field Structure in Spheroidal Star-Forming Clouds. II. Estimating Field Structure from Observed Maps
Creators: name: Myers, Philip C.
name: Stephens, Ian W.
name: Auddy, Sayantan
name: Basu, Shantanu
name: Bourke, Tyler L.
name: Hull, Charles L. H.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: This paper presents models to estimate the structure of density and magnetic field strength in spheroidal condensations, from maps of their column density and their polarization of magnetically aligned dust grains. The density model is obtained by fitting a column density map with an embedded p = 2 Plummer spheroid of any aspect ratio and inclination. The magnetic properties are based on the density model, on the Davis-Chandrasekhar-Fermi (DCF) model of Alfvénic fluctuations, and on the Spheroid Flux Freezing (SFF) model of mass and flux conservation in Paper I. The field strength model has the resolution of the column density map, which is finer than the resolution of the DCF estimate of field strength. The models are applied to ALMA observations of the envelope of the protostar BHR71 IRS1. Column density fits give the density model, from (2.0 +- 0.4) x 10^5 cm^-3 to (7 +- 1) x 10^7 cm^-3 . The density model predicts the field directions map, which fits the polarization map best within 1100 au, with standard deviation of angle differences 17°. In this region the DCF mean field strength is 0.7 +- 0.2 mG and the envelope mass is supercritical, with ratio of mass to magnetic critical mass 1.5 +- 0.4. The SFF field strength profile scales with the DCF field strength, from 60 x 10μG to 4+-1 mG. The spatial resolution of the SFF field strength estimate is finer than the DCF resolution by a factor ~7, and the peak SFF field strength exceeds the DCF field strength by a factor ~5.
description: Accepted for publication in The Astrophysical Journal
Predisposing Factors And Oral Findings Of Oral Cancer Patients In Egypt
Creators: name: Omara, Maisa
name: Mostafa, Salah
name: Norhan Abdalwahab
name: Ezzat, Amr
Publisher: name: figshare
Year: 2020
Subjects: subject: 110599 Dentistry not elsewhere classified
subject: FOS: Clinical medicine

description: Cancer is one of the leading causes of death worldwide. Oral cancer, the most common cancer of the head and neck region, ranks eighth among the most prevalent cancers in the world. In Egypt in 1991 the adjusted death rates for malignant neoplasm of the lip, oral cavity and pharynx were 0.3 per 100,000 person-years for males and 0.2 per 100,000 person-years for females. The etiology of oral cancer is multifactorial, the most important risk factors being tobacco, excess consumption of alcohol and betel quid usage, factors which act separately and synergistically. Much oral and other cancer therefore is potentially preventable by lifestyle change. This study aimed to describe predisposing factors & oral findings of oral cancer patients. A total sample of 89 patients, fulfilling the inclusion criteria were enrolled in the study at university hospitals in Cairo, Alexandria and El Menia during the study period (2011-2012). The result of the study revealed that the majority of sample was males and more than half of the sample (52.5%) belonged to 41-60years age group, also about two thirds of them were illiterate or read and write (62.5%). Regarding cancer location, about half of the sample (40%) had naso-pharyngeal cancer. Most of the sample smoked tobacco products (71.4%) and Cigarettes were the most common type followed by shisha. The majority of the sample had a history of dental problem (76.3%), about half (52.6%) never used tooth brush and only 5.3% visited dentist every 6-12 month.
On The Development of Multidimensional Progenitor Models For Core-collapse Supernovae
Creators: name: Fields, C. E.
name: Couch, S. M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Multidimensional hydrodynamic simulations of shell convection in massive stars suggest the development of aspherical perturbations that may be amplified during iron core-collapse. These perturbations have a crucial and qualitative impact on the delayed neutrino-driven core-collapse supernova explosion mechanism by increasing the total stress behind the stalled shock. In this paper, we investigate the properties of a 15 \msun model evolved in 1-,2-, and 3-dimensions (3D) for the final $\sim$424 seconds before gravitational instability and iron core-collapse using MESA and the FLASH simulation framework. We find that just before collapse, our initially perturbed fully 3D model reaches angle-averaged convective velocity magnitudes of $\approx$ 240-260 km s$^{-1}$ in the Si- and O-shell regions with a Mach number $\approx$ 0.06. We find the bulk of the power in the O-shell resides at large scales, characterized by spherical harmonic orders ($\ell$) of 2-4, while the Si-shell shows broad spectra on smaller scales of $\ell\approx30-40$. Both convective regions show an increase in power at $\ell=5$ near collapse. We show that the 1D \texttt{MESA} model agrees with the convective velocity profile and speeds of the Si-shell when compared to our highest resolution 3D model. However, in the O-shell region, we find that \texttt{MESA} predicts speeds approximately \emph{four} times slower than all of our 3D models suggest. All eight of the multi-dimensional stellar models considered in this work are publicly available.
description: Accepted for publication in ApJ. 21 pages, 19 figures, all eight CCSN progenitor models available publicly at https://doi.org/10.5281/zenodo.3976246
Discriminação da função de produção e elasticidades de substituição de fatores na agropecuária do estado de Minas Gerais
Creators: name: Baptista, Antonio Jose Medina Dos Santos
name: Castro, Eduardo Rodrigues De
name: Teixeira, Erly Cardoso
name: Baptista, Antonio Jose Medina Dos Santos
name: Castro, Eduardo Rodrigues De
name: Teixeira, Erly Cardoso
Publisher: name: Unknown
Year: 2004
Subjects: Production Economics

description: The objective of this study was to analyze the aggregate agriculture production function for the state of Minas Gerais. The analysis was accomplished in two phases. First, we separate the municipalities in terms of the productive efficiency, using the non-parametric approach of data envelopment analysis. In a second phase, a translog production function was adjusted for the efficient groups and for the inefficient ones, whose parameters were obtained by the ordinary least square method. This article indicates an analytic procedure that can subsidize the estimate of production functions more coherent with the reality, in the sense that relaxes the neoclassical assumptions that the firms are efficient. The results were coherent, once it was possible to separate the relatively inefficient municipal districts, to identify the difference in the partial elasticity of output and the elasticity of substitution between inputs in different groups. The conclusions indicated that is necessary to discriminate the production function in agreement with the level of productive efficiency and to calculate the elasticity of substitution in each point of the sample to test the regularity conditions in the production function.
Comércio exterior de produtos agrícolas do estado do Paraná de 1989 a 2001: análise de vantagens comparativas e do padrão de comércio
Creators: name: Rosa, Tatiana Diair Lourenzi Franco
name: Alves, Alexandre Florindo
name: Rosa, Tatiana Diair Lourenzi Franco
name: Alves, Alexandre Florindo
Publisher: name: Unknown
Year: 2004
Subjects: subject: International Relations/Trade
subject: Agricultural exports
subject: Comparative advantages
subject: Intraindustry trade

description: This paper discusses the evolution of agricultural products comparative advantages in the state of Paraná foreign trade from 1989-2001, and verifies the predominant type of trade for those products. The methodology is based on calculation of indicators of Revealed Comparative Advantage (Balassa, 1965), Covering Tax and Intraindustry Trade (Grubel & Lloyd, 1975). Results regarding comparative advantages of agricultural products that belong to the Section II of NBM-NCM, showed that the chapters Coffee, tea, mate and spices and Oilseeds and oleaginous fruits, grains etc., are “strong points” of Paraná economy. Although the section Vegetal Products has been characterized by the predominance of intraindustry trade, Grubel and Lloyd indexes showed that, for all chapters from that section, interindustry trade prevails.
Determinantes do uso de mercados futuros pelos produtores de soja no município de Cascavel - PR
Creators: name: Marques, Romao Honorio Serpa
name: Aguiar, Danilo Rolim Dias De
name: Marques, Romao Honorio Serpa
name: Aguiar, Danilo Rolim Dias De
Publisher: name: Unknown
Year: 2004
Subjects: subject: Marketing
subject: FOS: Economics and business
subject: Risk management
subject: Futures markets
subject: Soybean market
subject: Marketing

description: This study compares the producers who use future markets with those that don’t use this strategy to figure out the principal characteristics that differentiate them. Moreover there were studied the methods and strategies that farmers use for reducing price risk of soybeans. Besides identifying the strategies adopted by the producers, they were identified the key factors related to the choice of futures markets strategies. The methodological approach adopted is based on the estimate of a logit model. Based on the results, it is verified that the variables “education”, “gross income” and “work out of the property” were decisive on the use of in the adoption of futures markets.
The Impacts of Trade Barriers and Market Interventions on Maize Price Predictability: Evidence from Eastern and Southern Africa
Creators: name: Chapoto, Antony
name: Jayne, Thomas S.
name: Chapoto, Antony
name: Jayne, Thomas S.
Publisher: name: Unknown
Year: 2009
Subjects: subject: Food Security and Poverty
subject: International Relations/Trade
subject: Marketing
subject: FOS: Economics and business
subject: africa
subject: food security
subject: maize
subject: trade
subject: markets

description: There is continuing debate in east and southern Africa about the effects of food market reform on the welfare of small-scale farmers and low-income consumers. At the center of this debate is the perception that food prices have become more unstable in countries that have liberalized their staple food markets, thereby exacerbating the plight of poor consumers and farmers. This perception has led many governments in the region to shun an open maize borders policy and pursue a variety of food marketing and trade policy tools to stabilize food prices. Unfortunately, there remains a dearth of empirical evidence on the effects of alternative food marketing and trade policies, including that of liberalization, on price stability and predictability. Assessments of this issue are complicated by the fact that market reform programs are not monolithic in their design or implementation – impacts of reform on price instability may depend on variations in implementation. It would be particularly important to compare the magnitude of food price instability in countries that have embraced relatively comprehensive staple food market reform policies over time versus those in which the state continues to influence and stabilize food prices through the operations of marketing boards and controls on trade. This study examines the amplitude of price instability and unpredictability between countries using trade barriers and marketing board operations to stabilize prices versus countries with relatively open trade policies. Instability is defined as the unconditional variance in food prices over time, whereas unpredictability is defined as the unanticipated component of price instability, i.e., the conditional variance from a price forecast model.
Active control of propeller aircraft run-up noise
Creators: name: Nakashima, Ann Marie
Publisher: name: University of British Columbia
Year: 2010

description: In 2000, the first phase of research on the feasibility of using active noise control (ANC) to control the noise from propeller aircraft run-up tests was completed by Germain. ANC is a noise cancellation technique that has been the focus of much research in recent years. It was of interest to extend the work by Germain, concentrating on the effects that phenomena such as atmospheric refraction and the ground impedance have on the performance of an ANC system. Furthermore, since propeller aircraft were found to have directional noise radiation, the studies must consider the effectiveness of an ANC system on complex noise sources. The effectiveness of an ANC system on a dipole noise source was investigated in a free-field environment through simulations and experiments. It was found that the performance of an ANC system depends on the orientation of the dipole noise source, and that the system is most effective when used to control noise in the direction of the strongest radiation of the source. Measurements of run-up noise from a Dash-8 were taken and analyzed to gain a better understanding of how it acts as a noise source. It was found that the full-power engine noise is strongly tonal, making it a possible candidate for ANC. The noise was also found to be strongly directional. The Green's function parabolic equation (GFPE) method for outdoor sound propagation was modified to include a single active control channel, and ANC predictions were performed in the case of reflective and soft grounds for different atmospheric conditions. The preliminary results show that atmospheric refraction causes fluctuations in the noise attenuation achieved by a single-channel control system, and has the overall effect of decreasing its performance. It is evident that multiple control channels must be used in order to achieve significant attenuation for realistic outdoor conditions. Further research is required to determine if multi-channel ANC is a realistic method for the control of propeller aircraft run-up noise in realistic situations.
A machine-learned kinetic energy model for light weight metals and compounds of group III-V elements
Creators: name: Lüder, Johann
name: Ihara, Manabu
name: Manzhos, Sergei
Publisher: name: arXiv
Year: 2024
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: We present a machine-learned (ML) model of kinetic energy for orbital-free density functional theory (OF-DFT) suitable for bulk light weight metals and compounds made of group III-V elements. The functional is machine-learned with Gaussian process regression (GPR) from data computed with Kohn-Sham DFT with plane wave bases and local pseudopotentials. The dataset includes multiple phases of unary, binary, and ternary compounds containing Li, Al, Mg, Si, As, Ga, Sb, Na, Sn, P, and In. A total of 433 materials were used for training, and 18 strained structures were used for each material. Averaged (over the unit cell) kinetic energy density is fitted as a function of averaged terms of the 4th order gradient expansion and the product of the density and effective potential. The kinetic energy predicted by the model allows reproducing energy-volume curves around equilibrium geometry with good accuracy. We show that the GPR model beats linear and polynomial regressions. We also find that unary compounds sample a wider region of the descriptor space than binary and ternary compounds, and it is therefore important to include them in the training set; a GPR model trained on a small number of unary compounds is able to extrapolate relatively well to binary and ternary compounds but not vice versa.
Generation of broadband circularly polarized deep-ultraviolet pulses in hollow capillary fibers
Creators: name: Lekosiotis, Athanasios
name: Belli, Federico
name: Brahms, Christian
name: Travers, John C.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We demonstrate an efficient scheme for the generation of broadband, high-energy, circularly polarized femtosecond laser pulses in the deep ultraviolet through seeded degenerate four-wave mixing in stretched gas-filled hollow capillary fibers. Pumping and seeding with circularly polarized 35 fs pulses centered at 400 nm and 800 nm, respectively, we generate idler pulses centered at 266 nm with more than 25 microjoule of energy and over 95% spectrally averaged ellipticity. Even higher idler energies and broad spectra (27 nm bandwidth) can be obtained at the cost of reduced ellipticity. Our system can be scaled in average power and used in different spectral regions, including the vacuum ultraviolet.
On the rational homotopical nilpotency index of principal bundles
Creators: name: Hao, Yanlong
name: Liu, Xiugui
Publisher: name: arXiv
Year: 2022
Subjects: subject: Algebraic Topology (math.AT)
subject: FOS: Mathematics
subject: 55P62, 55P10

description: Let $\rm{Aut}(p)$ denote the space of all self-fibre homotopy equivalences of a principal $G$-bundle $p: E\rightarrow X$ of simply connected CW complexes with $E$ finite. When $G$ is a compact connected topological group, we show that there exists an inequality $$n-{\rm N}(p)\leq {\rm Hnil}_{\mathbb{Q}}({\rm{Aut}}(p)_0)\leq n$$ for any space $X$, where $n$ is the number of non-trivial rational homotopy groups of $G$ and ${\rm N}(p)$ is defined in Section 2. In particular, ${\rm Hnil}_{\mathbb{Q}}({\rm{Aut}}(p)_{0})=n$ if $p$ is a fibre-homotopy trivial bundle and X is finite.
DigiGen Working Paper Series
Creators: name: Lorenz, Theresa
name: Kapella, Olaf
Publisher: name: figshare
Year: 2020
Subjects: subject: Sociology
subject: FOS: Sociology

description: Although digital technologies are an integral part of all areas of life, chil­dren and young people use ICT (Information and Communication Tech­nology) most frequently at home. The omnipresence of digital technol­ogies affects the social interactions in their homes and thus influences the family dynamics. Therefore, this working paper reviews the existing literature on the effect of new technologies on family life from the per­spective of the individual family members, but also looks at families as a whole. This review shows that the use of digital devices is becoming increas­ingly privatized and mobile. Still, families enjoy the joint use of digital technologies by actively engaging in ICT activities together or by appre­ciating the passive co-presence of other family members during their digital experiences. Individual ICT activities are a primary source for entertainment and a way to relax but are also a root cause of family conflicts. Unlike solitary ICT use, joint digital family activities can create a strong sense of ‘we-ness’ among family members which promotes family cohesion. As a result, digital technologies are part of the daily act of reproducing family and can thus be understood as a central element of the concept of ‘doing family’. The existing evidence suggests that the ways families engage with dig­ital technologies are complex, and so are their consequences. On the one hand, ICT offers unique opportunities for families and their diverse individual members. Digital technologies support the reproduction of family (doing family), assist the creation and maintenance of new and existing relationships, help children in the development of their identi­ty and skills. On the other hand, children – and also adults – face on­line risks and challenges, for example if they are exposed to harmful content or if their privacy is abused. Adequate parental mediation and essential digital competencies can help to mitigate the adverse effects of children’s and young people’s online activities. Hence, whether the overall impact on family life is positive or negative highly depends on the combination of digital behaviours families implement in their daily lives. In addition to families, the society – including its multiple institu­tions – is also essential to promote digital competencies and strengthen the resilience of children and young people.
Gapless deconfined phase in a $\mathbb{Z}_N$ symmetric Hamiltonian created in a cold-atom setup
Creators: name: Rakov, Mykhailo V.
name: Tagliacozzo, Luca
name: Lewenstein, Maciej
name: Zakrzewski, Jakub
name: Chanda, Titas
Publisher: name: arXiv
Year: 2024
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We investigate a quasi-two-dimensional system consisting of two species of alkali atoms confined in a specific optical lattice potential [Phys. Rev. A 95, 053608 (2017)]. In the low-energy regime, this system is governed by a unique $\mathbb{Z}_N$ gauge theory, where field theory arguments have suggested that it may exhibit two exotic gapless deconfined phases, namely a dipolar liquid phase and a Bose liquid phase, along with two gapped (confined and deconfined) phases. We address these predictions numerically by using large-scale density matrix renormalization group simulations. Our findings provide conclusive evidence for the existence of a gapless Bose liquid phase for $N \geq 7$. We demonstrate that this gapless phase shares the same critical properties as one-dimensional critical phases, resembling weakly coupled chains of Luttinger liquids. In the range of ladder and cylinder geometries and $N$ considered, the gapless dipolar phase predicted theoretically is still elusive and its characterization will probably require a full two-dimensional treatment.
description: 11 pages, 6 figures. Close to the published version
Superquasicrystals: selfsimilar ordered structures with non-crystallographic point symmetries
Creators: name: Niizeki, Komajiro
name: Fujita, Nobuhisa
Publisher: name: arXiv
Year: 2004
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We present a systematic method of constructing limit-quasiperiodic structures with non-crystallographic point symmetries. Such structures are different aperiodic ordered structures from quasicrystals, and we call them "superquasicrystals". They are sections of higher-dimensional limit-periodic structures constructed on "super-Bravais-lattices". We enumerate important super-Bravais-lattices. Superquasicrystals with strong selfsimilarities form an important subclass. A simplest example is a two-dimensional octagonal superquasicrystal.
description: 7 pages, 1 figure, Submitted to J. Phys. A
Confronting Einstein Yang Mills Higgs Dark Energy in light of observations
Creators: name: Adak, Debabrata
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study the observational aspects of Einstein Yang Mills Higgs Dark energy model and constrain the parameter space from the latest observational data from type Ia supernovae, observational Hubble data, baryon acoustic oscillation data and cosmic microwave background radiation shift parameter data. It is found from the analysis of data that the Higgs field in presence of gauge fields can successfully describe the present accelerated expansion of the universe consistent with the astrophysical observations.
description: 11 pages, 10 figures