cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Improving Production and Marketing to Enhance Food Security in Mozambique
Creators: name: Tschirley, David L.
name: Abdula, Danilo Carimo
name: Weber, Michael T.
name: Tschirley, David L.
name: Abdula, Danilo Carimo
name: Weber, Michael T.
Publisher: name: Unknown
Year: 2005
Subjects: subject: Food Security and Poverty
subject: Marketing
subject: FOS: Economics and business
subject: food security
subject: food policy
subject: Mozambique
subject: maize

description: Food system challenges are examined from the standpoint of the country’s principal staple food: maize. Steps are identified that the country could take in the short-run to improve the situation, and also emphasize the long-term challenges the country faces. The focus is principally on the Center and South of the country because, with South Africa, they form a natural market area due to production patterns and transport costs; maize north of the Zambezi River flows almost entirely to northern cities or to Malawi, or feeds net buyers in the North.
description: Research Results of the Policy Analysis Department, Ministry of Agriculture, Directorate of Economics
The Speciality Index as invariant indicator in the BKL Mixmaster Dynamics
Creators: name: Cherubini, Christian
name: Bini, Donato
name: Bruni, Marco
name: Perjes, Zoltan
Publisher: name: arXiv
Year: 2004
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The speciality index, which has been mainly used in Numerical Relativity for studying gravitational waves phenomena as an indicator of the special or non-special Petrov type character of a spacetime, is applied here in the context of Mixmaster cosmology, using the Belinski-Khalatnikov-Lifshitz map. Possible applications for the associated chaotic dynamics are discussed.
Mudanças no Mercado e na Produção para Melhorar a Segurança Alimentar em Moçambique
Creators: name: Tschirley, David L.
name: Abdula, Danilo Carimo
name: Weber, Michael T.
name: Tschirley, David L.
name: Abdula, Danilo Carimo
name: Weber, Michael T.
Publisher: name: Unknown
Year: 2005
Subjects: subject: Food Security and Poverty
subject: Marketing
subject: FOS: Economics and business
subject: food security
subject: food policy
subject: Mozambique
subject: maize

description: Food system challenges are examined from the standpoint of the country’s principal staple food: maize. Steps are identified that the country could take in the short-run to improve the situation, and also emphasize the long-term challenges the country faces. The focus is principally on the Center and South of the country because, with South Africa, they form a natural market area due to production patterns and transport costs; maize north of the Zambezi River flows almost entirely to northern cities or to Malawi, or feeds net buyers in the North.
description: Resultados de pesquisa do Departmento de Análise de Políticas, MINAG, Direcção de Economia
2D mobile breather scattering in a hexagonal crystal lattice
Creators: name: Bajars, J.
name: Eilbeck, J. C.
name: Leimkuhler, B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences
subject: 82D25, 35Q82

description: We describe, for the first time, the full 2D scattering of long-lived breathers in a model hexagonal lattice of atoms. The chosen system, representing an idealized model of mica, combines a Lennard-Jones interatomic potential with an "egg-box" harmonic potential well surface. We investigate the dependence of breather properties on the ratio of the well depths associated to the interaction and on-site potentials. High values of this ratio lead to large spatial displacements in adjacent chains of atoms and thus enhance the two dimensional character of the quasi-one-dimensional breather solutions. This effect is further investigated during breather-breather collisions by following the constrained energy density function in time for a set of randomly excited mobile breather solutions. Certain collisions lead to 60$^\circ$ scattering, and collisions of mobile and stationary breathers can generate a rich variety of states.
description: 4 pages, 5 figures
Effect of dietary zinc intake on N-methyl-N-nitrosourea-induced mammary tumorigenesis and tumor histology in sexually mature female Sprague-Dawley rats
Creators: name: Lee, Samantha
Publisher: name: University of British Columbia
Year: 2009

description: Breast cancer is influenced by many factors such as reproductive history, hormonal, genetic and dietary factors. Zinc is vital to many physiological processes including DNA synthesis and cell proliferation. Increasing evidence has linked zinc exposure to mammary tumorigenesis. The hypothesis of this project was that dietary zinc levels have an effect on chemical carcinogen-induced mammary tumorigenesis in rats. The overall objective was to determine the effects of dietary zinc intake on the induction of mammary tumorigenesis by N-methyl-N-nitrosourea in sexually mature rats. Twenty one-day old female Sprague- Dawley rats were assigned to one of the following dietary treatment groups: low zinc (3 mg zinc/kg diet), adequate zinc (12 mg zinc/kg diet; ad libitum control) or high zinc (155 mg zinc/kg diet) group. In addition, two pair-fed control groups: pair-fed-to the-adequate-zinc and pair-fed-to-the-high-zinc groups, were also included. The rats were fed assigned diets from 21-days. At 50-days of age, all rats were injected with N-methyl-N-nitrosourea (50 mg/kg body weight). Starting from six weeks post-N-methyl-N-nitrosourea injection, rats were palpated weekly to monitor the development of mammary tumors. The experiment was terminated 14 weeks post-N-methyl-N-nitrosourea injection. Mammary tumorigenesis was assessed by tumor incidence, numbers, size, burden, multiplicity and latency of both palpable and total tumors. Tumor grade was assessed histologically. Incidence and number of both palpable and total tumors, and multiplicity of total tumors were lower in marginally low zinc rats than in the ad libitum and pair-fed control rats. Multiplicity of palpable tumors, latency, size and burden were lower in the marginally low zinc and pair-fed rats than in the ad libitum control rats. High zinc intake had no effect on all parameters used to assess the N-methyl-N nitrosourea-induced rat mammary tumorigenesis. Dietary zinc intake had no effect on tumor histological characteristics as only malignant tumors were observed regardless of dietary zinc intake. In summary, marginally low zinc intake reduced N-methyl-N-nitrosourea-induced mammary tumorigenesis in sexually mature female rats. Some of the inhibitory effects of marginally low zinc intake on N-methyl-N-nitrosourea-induced rat mammary tumorigenesis were due to reduced feed intake associated with low zinc intake, rather than low zinc intake per se. Zinc supplementation, however, had no effect on N-methyl-N-nitrosourea-induced rat mammary tumorigenesis.
Sup. Mat. S3 from Big dairy data to unravel effects of environmental, physiological and morphological factors on milk production of mountain-pastured Braunvieh cows
Creators: name: Duruz, Solange
name: Vajana, Elia
name: Burren, Alexander
name: Flury, Christine
name: Joost, Stéphane
Publisher: name: The Royal Society
Year: 2020
Subjects: Environmental Science
Computational Biology

description: Evolution of fat percentage over a lactation cycle
Generic Lie Color Algebras
Creators: name: Price, Kenneth L.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Representation Theory (math.RT)
subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics
subject: 17B75; 17B35

description: We describe a type of Lie color algebra, which we call generic, whose universal enveloping algebra is a domain with finite global dimension. Moreover, it is an iterated Ore extension. We provide an application and show Grobner basis methods can be used to study universal enveloping algebras of factors of generic Lie color algebras.
description: 9 pages, submitted
Learning from the 2002/03 Food Crisis in Southern Africa: Lessons for the Current Year
Creators: name: Tschirley, David L.
name: Arlindo, Pedro
name: Nijhoff, Jan J.
name: Mwiinga, Billy
name: Weber, Michael T.
name: Jayne, Thomas S.
name: Tschirley, David L.
name: Arlindo, Pedro
name: Nijhoff, Jan J.
name: Mwiinga, Billy
name: Weber, Michael T.
name: Jayne, Thomas S.
Publisher: name: Unknown
Year: 2005
Subjects: subject: Food Security and Poverty
subject: food security
subject: food policy
subject: food crisis
subject: southern Africa
subject: trade

description: This paper examines the efficiency and effectiveness of emergency response in Southern Africa through the lens of the 2002/03-food crisis in the region. It outlines improvements in information and operational procedures needed to enhance the response to future events. Also discussed are national and regional trade regime changes that would reduce the need for emergency response, and consider what lessons the 2002/03 crisis may have for the role of Strategic Grain Reserves.
description: Research Results of SIMA (Market Information ) DEST (Statistics Department)t and DAP (Policy Analysis Department) of MINAG (the Ministry of Agriculture of Mozambique), Directorate of Economics
Sup. Mat. S2 from Big dairy data to unravel effects of environmental, physiological and morphological factors on milk production of mountain-pastured Braunvieh cows
Creators: name: Duruz, Solange
name: Vajana, Elia
name: Burren, Alexander
name: Flury, Christine
name: Joost, Stéphane
Publisher: name: The Royal Society
Year: 2020
Subjects: Environmental Science
Computational Biology

description: Evolution of protein percentage over a lactation cycle
Sup. Mat. S4 from Big dairy data to unravel effects of environmental, physiological and morphological factors on milk production of mountain-pastured Braunvieh cows
Creators: name: Duruz, Solange
name: Vajana, Elia
name: Burren, Alexander
name: Flury, Christine
name: Joost, Stéphane
Publisher: name: The Royal Society
Year: 2020
Subjects: Environmental Science
Computational Biology

description: Effect of influencing factors on protein yield
Cell signalling in response to Coxsackievirus B3 infection
Creators: name: White, Michaela
Publisher: name: University of British Columbia
Year: 2009

description: Coxsackievirus B3 is a member of the Picornaviridae, genus Enterovirus. The virus is non-enveloped with a positive sense RNA genome of approximately 7.4kb. CVB3 is the most common etiologic agent associated with acute viral myocarditis and chronic dilated cardiomyopathy, and this importance of CVB3 as a human pathogen makes its mode of infection an area of intense interest for study in the development of antivirals. Recent studies have demonstrated an important role for the Src family kinase (SFK) Lck in CVB3 infection in mice and Jurkat T cells. In Lck-/- mice CVB3 infection is severely attenuated and replication in JCaM cells, a Jurkat cell line that lacks Lck, occurs at levels several log-fold lower than in Lck-expressing Jurkat cells. This study aimed to identify whether HeLa and Mouse Embryonic Fibroblasts (MEF) cells, which express little or no Lck, also require SFK for efficient CVB3 replication and to elucidate which of the SFK are required. HeLa cells expressing dominant negative (DN) or wild-type (wt) Fyn or Src were infected with CVB3 and viral yields were measured. The results found that CVB3 replication was not inhibited in the presence of DN Fyn or Src relative to wt cDNA. Treatment of HeLa and MEF cells with the SFK inhibitor PP2 also did not inhibit CVB3 infection, however, replication was inhibited in Jurkat cells by PP2, as previously shown. To elucidate whether SFK were involved in infection of MEF cells, CVB3 replication was measured in knockout MEF cell lines with triple mutations in Src, Yes and Fyn (SYF). Viral titers measured at 0-24 hours post infection in MEF and SYF cells displayed no reduction in titer in the knockout cell lines, indicating that the SFK Fyn, Src and Yes are dispensable during CVB3 infection in these cell lines. The results have demonstrated that SFK are not required in HeLa or MEF cells during CVB3 infection. This study also sought to establish whether PI3K was required for CVB3 infection. Treatment of HeLa cells with PI3K inhibitors wortmannin or LY294002 did not cause any decrease in viral titer, indicating that PI3K function is not required for CVB3 infection. Treatment of HeLa cells with cytochalasin D, or with RhoGTPase inhibitor Clostridium difficile toxin A had no effect on CVB3 replication. These results show that the actin network plays no function in CVB3 replication. Our conclusions are that CVB3 uptake into HeLa and MEF cells differs from the pathways shown for either Adenovirus (which like CVB3 also uses CAR as its primary receptor) or echo virus (which utilizes DAF, the CVB3 secondary receptor), where actin rearrangements are required.
Friedmann cosmology with decaying vacuum density
Creators: name: Borges, H. A.
name: Carneiro, S.
Publisher: name: arXiv
Year: 2005
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Among the several proposals to solve the incompatibility between the observed small value of the cosmological constant and the huge value obtained by quantum field theories, we can find the idea of a decaying vacuum energy density, leading from high values at early times of universe evolution to the small value observed nowadays. In this paper we consider a variation law for the vacuum density recently proposed by Schutzhold on the basis of quantum field estimations in the curved, expanding background, characterized by a vacuum density proportional to the Hubble parameter. We show that, in the context of an isotropic and homogeneous, spatially flat model, the corresponding solutions retain the well established features of the standard cosmology, and, in addition, are in accordance with the observed cosmological parameters. Our scenario presents an initial phase dominated by radiation, followed by a dust era long enough to permit structure formation, and by an epoch dominated by the cosmological term, which tends asymptotically to a de Sitter universe. Taking the matter density equals to half of the vacuum energy density, as suggested by observation, we obtain a universe age given by Ht = 1.1, and a decelerating parameter equals to -1/2.
description: Accepted for publication in General Relativity and Gravitation
Discovery of Water Maser Emission in Eight AGN with 70-m Antennas of NASA's Deep Space Network
Creators: name: Kondratko, P. T.
name: Greenhill, L. J.
name: Moran, J. M.
name: Lovell, J. E. J.
name: Kuiper, T. B. H.
name: Jauncey, D. L.
name: Cameron, L. B.
name: Gomez, J. F.
name: Garcia-Miro, C.
name: Moll, E.
name: de Gregorio-Monsalvo, I.
name: Jimenez-Bailon, E.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the discovery of water maser emission in eight active galactic nuclei (AGN) with the 70-m NASA Deep Space Network (DSN) antennas at Tidbinbilla, Australia and Robledo, Spain. The positions of the newly discovered masers, measured with the VLA, are consistent with the optical positions of the host nuclei to within 1 sigma (0.3 arcsec radio and 1.3 arcsec optical) and most likely mark the locations of the embedded central engines. The spectra of two sources, NGC 3393 and NGC 5495, display the characteristic spectral signature of emission from an edge-on accretion disk, with orbital velocities of ~600 and ~400 km s^-1, respectively. In a survey with DSN facilities of 630 AGN selected from the NASA Extragalactic Database, we have discovered a total of 15 water maser sources. The resulting incidence rate of maser emission among nearby (v_sys < 7000 km s^-1) Seyfert 1.8-2.0 and LINER systems is ~10 percent for a typical rms noise level of ~14 mJy over 1.3 km s^-1 spectral channels. As a result of this work, the number of nearby AGN (v_sys < 7000 km s^-1) observed with <20 mJy rms noise has increased from 130 to 449.
description: 7 pages, 1 figure, 2 tables, to appear in the 2006 February 10 issue of the Astrophysical Journal, uses twocolumns.cls
The quantum measurement process in an exactly solvable model
Creators: name: Allahverdyan, Armen E.
name: Balian, Roger
name: Nieuwenhuizen, Theo M.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Other Condensed Matter (cond-mat.other)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: An exactly solvable model for a quantum measurement is discussed which is governed by hamiltonian quantum dynamics. The $z$-component $\hat s_z$ of a spin-1/2 is measured with an apparatus, which itself consists of magnet coupled to a bath. The initial state of the magnet is a metastable paramagnet, while the bath starts in a thermal, gibbsian state. Conditions are such that the act of measurement drives the magnet in the up or down ferromagnetic state according to the sign of $s_z$ of the tested spin. The quantum measurement goes in two steps. On a timescale $1/\sqrt{N}$ the off-diagonal elements of the spin's density matrix vanish due to a unitary evolution of the tested spin and the $N$ apparatus spins; on a larger but still short timescale this is made definite by the bath. Then the system is in a `classical' state, having a diagonal density matrix. The registration of that state is a quantum process which can already be understood from classical statistical mechanics. The von Neumann collapse and the Born rule are derived rather than postulated.
description: 7 pages revtex, 2 figures
Sup. Mat. S1 from Big dairy data to unravel effects of environmental, physiological and morphological factors on milk production of mountain-pastured Braunvieh cows
Creators: name: Duruz, Solange
name: Vajana, Elia
name: Burren, Alexander
name: Flury, Christine
name: Joost, Stéphane
Publisher: name: The Royal Society
Year: 2020
Subjects: Environmental Science
Computational Biology

description: For each criterion and calving month, the between-group difference in milk production in the alp and over the total lactation cycle is reported, together with the Δd (reflecting how differently the two groups are impacted by alping) and its associated significance.
Comerciantes de Pequena Escala Esperam Boas Colheitas, Mas Preços ao Produtor São Baixos nas Zonas de Difícil Acesso: O Que Fazer para Incentivar a Produção e a Comercialização Agrícolas?
Creators: name: Equipe Tecnica Do SIMA
name: Equipe Tecnica Do SIMA
Publisher: name: Unknown
Year: 2006
Subjects: subject: Crop Production/Industries
subject: Marketing
subject: FOS: Economics and business
subject: food security
subject: food policy

description: This document provides the information about commercialization dynamics collected in some areas of Central and Northern Mozambique. In addition, it provides some policy actions that could promote the agricultural products commercialization. The results show that the maize production varies in the studied areas. However, most of the interviewees think that agricultural production, especially maize production, improved in 2005/06 season when compared to the previous season. In addition, an increase in prices is expected. It was found that the measures to limit trade with neighboring countries must balance the hunger alleviation in short term with the long term benefits of trade with neighboring countries. Moreover, there is a need to rehabilitate some roads, especially in areas with high agricultural potential, in order to enable market access.
description: Resultados das Investigações do SIMA- Departamento de Estatística e Departamento de Análise de Políticas MINAG - Direcção de Economia
Modeling the Effects of Pasture Expansion on Emissions from Land-Use Change
Creators: name: Dumortier, Jerome
name: Hayes, Dermot J.
name: Carriquiry, Miguel A.
name: Dong, Fengxia
name: Du, Xiaodong
name: Elobeid, Amani E.
name: Fabiosa, Jacinto F.
name: Mulik, Kranti
name: Dumortier, Jerome
name: Hayes, Dermot J.
name: Carriquiry, Miguel A.
name: Dong, Fengxia
name: Du, Xiaodong
name: Elobeid, Amani E.
name: Fabiosa, Jacinto F.
name: Mulik, Kranti
Publisher: name: Unknown
Year: 2010
Subjects: subject: Land Economics/Use
subject: Resource /Energy Economics and Policy
subject: pasture expansion
subject: greenhouse gas emissions
subject: land-use change
subject: pasture extensification

description: We present a global agricultural greenhouse gas model that assesses emissions from land-use change. In addition to evaluating shifts in and out of crop production, we develop a pasture model to assess extensification and intensification of global livestock production based on herd size and stocking rate. We apply the model to a scenario that introduces a tax on methane emissions from cattle in the United States. The resulting expansion of pasture in the rest of the world leads to substantially higher emissions than without the tax. The yearly average emissions from the tax are 260 metric tons of CO2-equivalent.
description: Replaced with revised version of paper 12/14/2010.
Polar domains in lead titanate films under tensile strain
Creators: name: Catalan, G.
name: Janssens, A.
name: Rispens, G.
name: Csiszar, S.
name: Seeck, O.
name: Rijnders, G.
name: Blank, D. H. A.
name: Noheda, B.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Thin films of PbTiO3, a classical ferroelectric, have been grown under tensile strain on single-crystal substrates of DyScO3. The films, of only 5nm thickness, grow fully coherent with the substrate and show no crystallographic twin domains, as evidenced by synchrotron x-ray diffraction. A mapping of the reciprocal space reveals intensity modulations (satellites) due to regularly-spaced polar domains in which the polarization appears rotated away from the substrate normal, characterizing a low symmetry phase not observed in the bulk material. This could have important practical implications since these phases are known to be responsible for ultrahigh piezoelectric responses in complex systems.
description: Nature of changes: Slightly modified abstract, introduction and conclusion paragraphs to make it more accessible to the general reader. Corrected a typo in the value of the domain period. These changes do not affect the content and results. To be published in PRL
Will Consumers Pay a Premium for Clone-free labeled Meat products? Evidence from the 2009 Sunbelt Agricultural Exposition
Creators: name: Jones, Ghangela
name: Jennings, Shauntez
name: Ibrahim, Mohammed
name: Whitehead, Jackie
name: Jones, Ghangela
name: Jennings, Shauntez
name: Ibrahim, Mohammed
name: Whitehead, Jackie
Publisher: name: Unknown
Year: 2010
Subjects: subject: Food Consumption/Nutrition/Food Safety
subject: Food Security and Poverty
subject: Willingness to pay
subject: clone-free
subject: label

description: This paper examines consumer willingness to pay (WTP) for clone-free meat labels. Data were collected at the Sunbelt Agricultural Exposition (Ag Expo) in Moultrie, Georgia using a consumer survey instrument. Survey results show that majority (59.45%) of the respondents said they were willing to pay for clone-free labels. Results suggest that bid amount, gender and education are factors that influence WTP for clone-free labels.
Análisis de la metodología de los puntos de corte para la identificación de las respuestas “inconsistentes” en los modelos de elección discreta
Creators: name: Colombo, Sergio
name: Hanley, Nick
name: Bush, Glenn
name: Colombo, Sergio
name: Hanley, Nick
name: Bush, Glenn
Publisher: name: Unknown
Year: 2009
Subjects: subject: Agricultural and Food Policy
subject: Experimento de elección
subject: inconsistencias en la elección
subject: puntos de corte.

description: En el método del experimento de elección se supone que el entrevistado es perfectamente racional, está informado y maximiza su utilidad siguiendo una regla de elección perfectamente compensatoria. Sin embargo, es posible que los individuos empleen otras reglas de decisión en sus elecciones para simplificar el esfuerzo cognitivo del ejercicio propuesto. En este trabajo se emplea la metodología de los valores de corte para incorporar en el experimento de elección reglas de decisión no compensatorias, y se amplia esta metodología para identificar respuestas inconsistentes. Los resultados indican que el empleo de los valores de corte mejora la capacidad descriptiva de los modelos de elección, y puede ser muy útil para la identificación de inconsistencias en la elección.
Rapid Transitions with Robust Accelerated Delayed Self Reinforcement for Consensus-Based Networks
Creators: name: Tiwari, Anuj
name: Devasia, Santosh
Publisher: name: arXiv
Year: 2020
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Rapid transitions are important for quick response of consensus-based, multi-agent networks to external stimuli. While high-gain can increase response speed, potential instability tends to limit the maximum possible gain, and therefore, limits the maximum convergence rate to consensus during transitions. Since the update law for multi-agent networks with symmetric graphs can be considered as the gradient of its Laplacian-potential function, Nesterov-type accelerated-gradient approaches from optimization theory, can further improve the convergence rate of such networks. An advantage of the accelerated-gradient approach is that it can be implemented using accelerated delayed-self-reinforcement (A-DSR), which does not require new information from the network nor modifications in the network connectivity. However, the accelerated-gradient approach is not directly applicable to general directed graphs since the update law is not the gradient of the Laplacian-potential function. The main contribution of this work is to extend the accelerated-gradient approach to general directed graph networks, without requiring the graph to be strongly connected. Additionally, while both the momentum term and outdated-feedback term in the accelerated-gradient approach are important in general, it is shown that the momentum term alone is sufficient to achieve balanced robustness and rapid transitions without oscillations in the dominant mode, for networks whose graph Laplacians have real spectrum. Simulation results are presented to illustrate the performance improvement with the proposed Robust A-DSR of 40% in structural robustness and 50% in convergence rate to consensus, when compared to the case without the A-DSR. Moreover, experimental results are presented that show a similar 37% faster convergence with the Robust A-DSR when compared to the case without the A-DSR.
description: 14 pages, 8 figures
Sup. Mat. S5 from Big dairy data to unravel effects of environmental, physiological and morphological factors on milk production of mountain-pastured Braunvieh cows
Creators: name: Duruz, Solange
name: Vajana, Elia
name: Burren, Alexander
name: Flury, Christine
name: Joost, Stéphane
Publisher: name: The Royal Society
Year: 2020
Subjects: Environmental Science
Computational Biology

description: Effect of influencing factors on fat yield
Effects of food prices and consumer income on nutrient availability: An application of the demand for dairy products in Tunisia
Creators: name: Dhehibi, Boubaker
name: Laajimi, Abderraouf
name: Dhehibi, Boubaker
name: Laajimi, Abderraouf
Publisher: name: Unknown
Year: 2009
Subjects: subject: Agricultural and Food Policy
subject: Dairy products demand
subject: health awareness
subject: nutrients
subject: price/quality index
subject: Tunisia

description: Number of Tunisian food demand studies have measured the influence of traditional variables, such as income and prices, and in some cases some socio-demographic variables. However, given increasing concerns about health, other important factors, such as the nutritious quality and the nutrient content of food, have also been shown to determine consumer choices. This paper analyses the effect of these factors on the demand for dairy products. The nutritious quality of dairy products is measured by an index that relates nutrient content of each product with the standards suggested by the National Academy of Science. A demand system is estimated and nutrient demand elasticities with respect to prices and expenditure are obtained. Results differ from traditional studies in the sense that higher prices do not indicate lower consumption but a shift to a higher quality demand.
Estimación del valor económico de la calidad del agua de un río mediante una doble aproximación: una aplicación de los principios económicos de la Directiva Marco del Agua
Creators: name: Del Saz Salazar, Salvador
name: Hernandez Sancho, Francesc
name: Sala Garrido, Ramon
name: Del Saz Salazar, Salvador
name: Hernandez Sancho, Francesc
name: Sala Garrido, Ramon
Publisher: name: Unknown
Year: 2009
Subjects: subject: Agricultural and Food Policy
subject: Beneficios sociales
subject: calidad del agua
subject: Directiva Marco del Agua
subject: ordenación contingente
subject: valoración contingente.

description: El principal objetivo de la Directiva Marco del Agua de la Unión Europea es logar un “buen estado” de las aguas europeas para el año 2015 mediante una combinación de diferentes medidas. En este estudio, dos métodos de preferencias declaradas, el método de valoración contingente y el método de ordenación contingente, han sido aplicados para obtener la valoración económica de una hipotética mejora de la calidad del agua de un río. La comparación de las dos metodologías muestra que las valoraciones obtenidas con el método de ordenación contingente son considerablemente mayores que las obtenidas con la valoración contingente. Por último, los valores estimados se agregan para obtener una aproximación cuantitativa a los beneficios sociales derivados de esta mejora ambiental.
Anomalous Hall effect in half-metallic Heusler compound Co$_{2}$Ti$X$ ($X$=Si, Ge)
Creators: name: Roy, Shubhankar
name: Singha, Ratnadwip
name: Ghosh, Arup
name: Pariari, Arnab
name: Mandal, Prabhat
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Though Weyl fermions have recently been observed in several materials with broken inversion symmetry, there are very few examples of such systems with broken time reversal symmetry. Various Co$_{2}$-based half-metallic ferromagnetic Heusler compounds are lately predicted to host Weyl type excitations in their band structure. These magnetic Heusler compounds with broken time reversal symmetry are expected to show a large momentum space Berry curvature, which introduces several exotic magneto-transport properties. In this report, we present systematic analysis of experimental results on anomalous Hall effect (AHE) in Co$_2$Ti$X$ ($X$=Si and Ge). This study is an attempt to understand the role of Berry curvature on AHE in Co$_2$Ti$X$ family of materials. The anomalous Hall resistivity is observed to scale quadratically with the longitudinal resistivity for both the compounds. The detailed analysis indicates that in anomalous Hall conductivity, the intrinsic Karplus-Luttinger Berry phase mechanism dominates over the extrinsic skew scattering and side-jump mechanism.
Geometrical approach to central molecular chirality: a chirality selection rule
Creators: name: Capozziello, S.
name: Lattanzi, A.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Chirality is of primary importance in many areas of chemistry and has been extensively investigated since its discovery. We introduce here the description of central chirality for tetrahedral molecules using a geometrical approach based on complex numbers. According to this representation, for a molecule having n chiral centres, it is possible to define an index of chirality. Consequently a chirality selection rule has been derived which allows the characterization of a molecule as achiral, enantiomer or diastereoisomer.
description: 10 pages
Non-Analytic Non-Equilibrium Field Theory: Stochastic Reheating of the Ising Model
Creators: name: Aron, Camille
name: Kulkarni, Manas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Many-body non-equilibrium steady states can be described by a Landau-Ginzburg theory if one allows non-analytic terms in the potential. We substantiate this claim by working out the case of the Ising magnet in contact with a thermal bath and undergoing stochastic reheating: It is reset to a paramagnet at random times. By a combination of stochastic field theory and Monte Carlo simulations, we unveil how the usual $φ^4$ potential is deformed by non-analytic operators of intrinsic non-equilibrium nature. We demonstrate their infrared relevance at low temperatures by a renormalization-group analysis of the non-equilibrium steady state. The equilibrium ferromagnetic fixed point is thus destabilized by stochastic reheating, and we identify the new non-equilibrium fixed point.
description: 16 pages, v2: minor edits
Propensity score weighting under limited overlap and model misspecification
Creators: name: Zhou, Yunji
name: Matsouaka, Roland A.
name: Thomas, Laine
Publisher: name: arXiv
Year: 2020
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Propensity score (PS) weighting methods are often used in non-randomized studies to adjust for confounding and assess treatment effects. The most popular among them, the inverse probability weighting (IPW), assigns weights that are proportional to the inverse of the conditional probability of a specific treatment assignment, given observed covariates. A key requirement for IPW estimation is the positivity assumption, i.e., the PS must be bounded away from 0 and 1. In practice, violations of the positivity assumption often manifest by the presence of limited overlap in the PS distributions between treatment groups. When these practical violations occur, a small number of highly influential IPW weights may lead to unstable IPW estimators, with biased estimates and large variances. To mitigate these issues, a number of alternative methods have been proposed, including IPW trimming, overlap weights (OW), matching weights (MW), and entropy weights (EW). Because OW, MW, and EW target the population for whom there is equipoise (and with adequate overlap) and their estimands depend on the true PS, a common criticism is that these estimators may be more sensitive to misspecifications of the PS model. In this paper, we conduct extensive simulation studies to compare the performances of IPW and IPW trimming against those of OW, MW, and EW under limited overlap and misspecified propensity score models. Across the wide range of scenarios we considered, OW, MW, and EW consistently outperform IPW in terms of bias, root mean squared error, and coverage probability.
description: 46 pages, 12 figures
A long-term platform for research outputs: a look at the impact of Monash University's Figshare implementation and engagement
Creators: name: Pearson, Beth
name: Groenewegen, David
name: Dickson, Neil
name: Harrison, Andrew
Publisher: name: figshare
Year: 2020
Subjects: subject: Library and Information Studies
subject: FOS: Media and communications

description: This case study looks at Monash University's six year Figshare journey, from launching monash.figshare for research data to the Bridges rebranding, widespread institutional use cases including an archive and open access journal, and one million downloads.
Electron transport through antiferromagnetic spin textures and skyrmions in a magnetic tunnel junction
Creators: name: Djavid, Nima
name: Lake, Roger K.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: An ideal layered $\hat{x}$-polarized antiferromagnet (AFM) between two antialigned $\pm \hat{z}$ polarized ferromagnetic (FM) contacts transmits no current due to a $π$ phase difference of the matrix elements coupling the spin degenerate states to the two FM contacts. The ratio of the two matrix elements coupling the two spin degenerate $\hat{x}$ AFM states to a $\hat{z}$ FM contact is determined by the exchange energy and the eigenstate energy. Inserting a normal metal layer or tunnel barrier layer between one FM contact and the AFM alters this phase difference, and, due to the unequal weighting of the two spins at the interface, it also breaks the spin degeneracy of the two AFM states. The broken symmetry of the matrix elements combined with the broken degeneracy of the AFM states, result in a Fano resonance in the transmission and a turn-on of the $T_{\uparrow,\downarrow}$ transmission channel. Such a magnetic tunnel junction geometry with two antialigned $\pm \hat{z}$ FM contacts can electrically detect an AFM skyrmion. The AFM skyrmion serves as an analogue of the oblique polarizer in the triple polarizer experiment. Resistances and resistance ratios are calculated and compared for FM and AFM skyrmions in a magnetic tunnel junction.
A reappraisal of the chemical composition of the Orion nebula based on VLT echelle spectrophotometry
Creators: name: Esteban, C.
name: Peimbert, M.
name: Garcia-Rojas, J.
name: Ruiz, M. T.
name: Peimbert, A.
name: Rodriguez, M.
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present VLT UVES echelle spectrophotometry of the Orion nebula in the 3100 to 10400 A range. We have measured the intensity of 555 emission lines, many of them corresponding to permitted lines of different heavy-element ions. This is the largest set of spectral emission lines ever obtained for a Galactic or extragalactic HII region. We have derived He+, C++, O+, O++ and Ne++ abundances from pure recombination lines. This is the first time that O+ and Ne++ abundances are obtained from this kind of lines in the nebula. We have also derived abundances from collisionally excited lines for a large number of ions of different elements. In all cases, ionic abundances obtained from recombination lines are larger than those derived from collisionally excited lines. We have obtained remarkably consistent independent estimations of the temperature fluctuations parameter, t2, from different methods, which are also similar to other estimates from the literature. This result strongly suggests that moderate temperature fluctuations -t2 between 0.02 and 0.03- are present in the Orion nebula. We have compared the chemical composition of the nebula with those of the Sun and other representative objects. The heavy element abundances in the Orion nebula are only slightly higher than the solar ones, a difference that can be explained by the chemical evolution of the solar vicinity.
description: 21 pages, 15 tables, 5 figures. Accepted for publication in MNRAS
Valoración económica de los beneficios ambientales de no mercado derivados de la mejora de la calidad del agua: una estimación en aplicación de la Directiva Marco del Agua al Guadalquivir
Creators: name: Martin-Ortega, Julia
name: Berbel, Julio
name: Brouwer, Roy
name: Martin-Ortega, Julia
name: Berbel, Julio
name: Brouwer, Roy
Publisher: name: Unknown
Year: 2009
Subjects: subject: Agricultural and Food Policy
subject: Beneficios ambientales
subject: costes desproporcionados
subject: Directiva Marco del Agua
subject: modelo Heckman
subject: valoración contingente

description: Esta investigación responde a la necesidad de información económica relativa a los beneficios derivados de la implementación de la Directiva Marco del Agua (DMA). Se plantea una definición práctica del concepto de beneficio ambiental y un escenario de valoración de los beneficios de la mejora de la calidad del agua que no tienen reflejo en el mercado. Esta valoración es necesaria, entre otros aspectos, para la evaluación de la desproporcionalidad de los costes de la DMA. La metodología se aplica a un caso práctico en el Guadalquivir en un ejercicio de valoración contingente y análisis estadístico mediante un modelo Heckman en dos etapas.
A novel 3D multi-path DenseNet for improving automatic segmentation of glioblastoma on pre-operative multi-modal MR images
Creators: name: Fu, Jie
name: Singhrao, Kamal
name: Qi, X. Sharon
name: Yang, Yingli
name: Ruan, Dan
name: Lewis, John H.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Medical Physics (physics.med-ph)
subject: Image and Video Processing (eess.IV)
subject: FOS: Physical sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Convolutional neural networks have achieved excellent results in automatic medical image segmentation. In this study, we proposed a novel 3D multi-path DenseNet for generating the accurate glioblastoma (GBM) tumor contour from four multi-modal pre-operative MR images. We hypothesized that the multi-path architecture could achieve more accurate segmentation than a single-path architecture. 258 GBM patients were included in this study. Each patient had four MR images (T1-weighted, contrast-enhanced T1-weighted, T2-weighted, and FLAIR) and the manually segmented tumor contour. We built a 3D multi-path DenseNet that could be trained to generate the corresponding GBM tumor contour from the four MR images. A 3D single-path DenseNet was also built for comparison. Both DenseNets were based on the encoder-decoder architecture. All four images were concatenated and fed into a single encoder path in the single-path DenseNet, while each input image had its own encoder path in the multi-path DenseNet. The patient cohort was randomly split into a training set of 180 patients, a validation set of 39 patients, and a testing set of 39 patients. Model performance was evaluated using the Dice similarity coefficient (DSC), average surface distance (ASD), and 95% Hausdorff distance (HD95%). Wilcoxon signed-rank tests were conducted to examine the model differences. The single-path DenseNet achieved a DSC of 0.911$\pm$0.060, ASD of 1.3$\pm$0.7 mm, and HD95% of 5.2$\pm$7.1 mm, while the multi-path DenseNet achieved a DSC of 0.922$\pm$0.041, ASD of 1.1$\pm$0.5 mm, and HD95% of 3.9$\pm$3.3 mm. The p-values of all Wilcoxon signed-rank tests were less than 0.05. Both 3D DenseNets generated GBM tumor contours in good agreement with the manually segmented contours from multi-modal MR images. The multi-path DenseNet achieved more accurate tumor segmentation than the single-path DenseNet.
description: 15 pages, 6 figures, review in progress
Gravitational dual of averaged free CFT's over the Narain lattice
Creators: name: Pérez, Alfredo
name: Troncoso, Ricardo
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: It has been recently argued that the averaging of free CFT's over the Narain lattice can be holographically described through a Chern-Simons theory for $U\left(1\right)^{D}\times U\left(1\right)^{D}$ with a precise prescription to sum over three-dimensional handlebodies. We show that a gravitational dual of these averaged CFT's would be provided by Einstein gravity on AdS$_{3}$ with $U\left(1\right)^{D-1}\times U\left(1\right)^{D-1}$ gauge fields, endowed with a precise set of boundary conditions closely related to the "soft hairy" ones. Gravitational excitations then go along diagonal $SL\left(2,\mathbb{R}\right)$ generators, so that the asymptotic symmetries are spanned by $U\left(1\right)^{D}\times U\left(1\right)^{D}$ currents. The stress-energy tensor can then be geometrically seen as composite of these currents through a twisted Sugawara construction. Our boundary conditions are such that for the reduced phase space, there is a one-to-one map between the configurations in the gravitational and the purely abelian theories. The partition function in the bulk could then also be performed either from a non-abelian Chern-Simons theory for two copies of $SL\left(2,\mathbb{R}\right)\times U\left(1\right)^{D-1}$ generators, or formally through a path integral along the family of allowed configurations for the metric. The new boundary conditions naturally accommodate BTZ black holes, and the microscopic number of states then appears to be manifestly positive and suitably accounted for from the partition function in the bulk. The inclusion of higher spin currents through an extended twisted Sugawara construction in the context of higher spin gravity is also briefly addressed.
description: 12 pages, no figures. Improved discussion about the density of states. Matches published version
Role of Elvira in Gioachino Rossini’s "L’Italiana in Algeri" ; Role of Esmeralda in Bedr̆ich Smetaná's "Prodaná Nevĕsta"
Creators: name: Farrell, Jennifer Heather
Publisher: name: University of British Columbia
Year: 2009

description: The thesis for the Master of Music in Opera consists of the performance of a major role in one full opera production, or of two supporting roles in two full opera productions in the first or second year. 1 performed the role of Elvira in Gioachino Rossini's "L'Italiana in Algeri" on November 2, 2002, and the role of Esmeralda in Bedřich Smetaná's "Prodaná Nevĕsta" on March 6 and March 8, 2003.
Implicaciones de NAFTA, TLCUEM y de la integración de China a la OMC en el mercado de la berenjena: una perspectiva de equilibrio espacial
Creators: name: Guajardo, Ramon
name: Rios, Maricela
name: Guajardo, Ramon
name: Rios, Maricela
Publisher: name: Unknown
Year: 2009
Subjects: subject: Agricultural and Food Policy
subject: Modelos de equilibrio espacial
subject: mercado de la berenjena
subject: programación cuadrática
subject: liberación comercial.

description: Este artículo estudia el impacto de NAFTA, TLCUEM y de la integración de China a la OMC en el mercado mundial de la berenjena. Los impactos son medidos en términos de cambios en los flujos comerciales y en los precios. Se especificó y estimó un modelo de equilibrio espacial con precios endógenos y se simularon escenarios alternativos: con y sin la operación de los tratados y la integración de China a la OMC. Los resultados mostraron que la operación de estos tratados crea desviación de comercio. Además, la integración de China a la OMC aun con libre comercio mundial no impacta al mercado mundial de la berenjena.
A broad iron line in the Chandra/HETG spectrum of 4U 1705-44
Creators: name: Di Salvo, T.
name: Iaria, R.
name: Mendez, M.
name: Burderi, L.
name: Lavagetto, G.
name: Robba, N. R.
name: Stella, L.
name: van der Klis, M.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results of a Chandra 30 ks observation of the low mass X-ray binary and atoll source 4U 1705-44. Here we concentrate on the study of discrete features in the energy spectrum at energies below 3 keV, as well as on the iron Kalpha line, using the HETG spectrometer on board of the Chandra satellite. Below 3 keV, three narrow emission lines are found at 1.47, 2.0, and 2.6 keV. The 1.47 and 2.6 keV are probably identified with Ly-alpha emission from Mg XII and S XVI, respectively. The identification of the feature at 2.0 keV is uncertain due to the presence of an instrumental feature at the same energy. The iron Kalpha line at ~6.5 keV is found to be intrinsically broad (FWHM ~ 1.2 keV); its width can be explained by reflection from a cold accretion disk extending down to 15 km from the neutron star center or by Compton broadening in the external parts of a hot (~2 keV) Comptonizing corona. We finally report here precise X-ray coordinates of the source.
description: 8 pages including 2 figures. ApJ Letters, in press