cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Topological change and impedance spectrum of rat olfactory receptor I7: A comparative analysis with bovine rhodopsin and bacterior
Creators: name: Alfinito, Eleonora
name: Pennetta, Cecilia
name: Reggiani, Lino
Publisher: name: arXiv
Year: 2008
Subjects: subject: Biomolecules (q-bio.BM)
subject: FOS: Biological sciences

description: We present a theoretical investigation on possible selection of olfactory receptors (ORs) as sensing components of nanobiosensors. Accordingly, we generate the impedance spectra of the rat OR I7 in the native and activated state and analyze their differences. In this way, we connect the protein morphological transformation, caused by the sensing action, with its change of electrical impedance. The results are compared with those obtained by studying the best known protein of the GPCR family: bovine rhodopsin. Our investigations indicate that a change in morphology goes with a change in impedance spectrum mostly associated with a decrease of the static impedance up to about 60 % of the initial value, in qualitative agreement with existing experiments on rat OR I7. The predictiveness of the model is tested successfully for the case of recent experiments on bacteriorhodopsin. The present results point to a promising development of a new class of nanobiosensors based on the electrical properties of GPCR and other sensing proteins.
description: 6 pages, 8 figures
Device-independent dimension leakage null test on qubits at low operational cost
Creators: name: Rybotycki, Tomasz
name: Białecki, Tomasz
name: Batle, Josep
name: Bednorz, Adam
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We construct a null test of the two-level space of a qubit, which is both device independent and needs a small number of different experiments. We demonstrate its feasibility on IBM Quantum, with most qubits failing the test by more than 10 standard deviations. The robustness of the test against common technical imperfections, like decoherence and phase shifts, and supposedly negligible leakage, indicates that the origin of deviations is beyond known effects.
description: 7 pages, 4 figures
Loop quantum gravity and cosmological constant
Creators: name: Zhang, Xiangdong
name: Long, Gaoping
name: Ma, Yongge
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: An one-parameter regularization freedom of the Hamiltonian constraint for loop quantum gravity is analyzed. The corresponding spatially flat, homogenous and isotropic model includes the two well-known models of loop quantum cosmology as special cases. The quantum bounce nature is tenable in the generalized cases. For positive value of the regularization parameter, the effective Hamiltonian leads to an asymptotic de-Sitter branch of the Universe connecting to the standard Friedmann branch by the quantum bounce. Remarkably, by suitably choosing the value of the regularization parameter, the observational cosmological constant can emerge at large volume limit from the effect of quantum gravity, and the effective Newtonian constant satisfies the experimental restrictions in the meantime.
description: 6 pages, 1 figure; v2, accepted by PLB
Application of Copulas to Estimation of Joint Crop Yield Distributions
Creators: name: Vedenov, Dmitry V.
name: Vedenov, Dmitry V.
Publisher: name: Unknown
Year: 2008
Subjects: Crop Production/Industries

description: This paper presents a copula-based methodology for modeling joint yield distributions. Copulas have been used extensively in financial literature, but have not been widely used in agricultural economics and particularly risk management. The copula approach provides a powerful and flexible method to model multivariate distributions and thus go beyond joint normality, regressibility, and mean-variance criterion. Accurate estimation of joint distributions may help to improve the results in the area of risk management and insurance obtained under more limiting assumptions.
PointNetPGAP-SLC: A 3D LiDAR-based Place Recognition Approach with Segment-level Consistency Training for Mobile Robots in Horticulture
Creators: name: Barros, T.
name: Garrote, L.
name: Conde, P.
name: Coombes, M. J.
name: Liu, C.
name: Premebida, C.
name: Nunes, U. J.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Robotics (cs.RO)
subject: FOS: Computer and information sciences

description: 3D LiDAR-based place recognition remains largely underexplored in horticultural environments, which present unique challenges due to their semi-permeable nature to laser beams. This characteristic often results in highly similar LiDAR scans from adjacent rows, leading to descriptor ambiguity and, consequently, compromised retrieval performance. In this work, we address the challenges of 3D LiDAR place recognition in horticultural environments, particularly focusing on inter-row ambiguity by introducing three key contributions: (i) a novel model, PointNetPGAP, which combines the outputs of two statistically-inspired aggregators into a single descriptor; (ii) a Segment-Level Consistency (SLC) model, used exclusively during training to enhance descriptor robustness; and (iii) the HORTO-3DLM dataset, comprising LiDAR sequences from orchards and strawberry fields. Experimental evaluations conducted on the HORTO-3DLM and KITTI Odometry datasets demonstrate that PointNetPGAP outperforms state-of-the-art models, including OverlapTransformer and PointNetVLAD, particularly when the SLC model is applied. These results underscore the model's superiority, especially in horticultural environments, by significantly improving retrieval performance in segments with higher ambiguity.
description: This preprint has been accepted for publication in IEEE Robotics and Automation Letters, 2024
The Evolution of the Water Distribution in a Viscous Protoplanetary Disk
Creators: name: Ciesla, Fred J.
name: Cuzzi, Jeffrey N.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: (Abridged) Astronomical observations have shown that protoplanetary disks are dynamic objects through which mass is transported and accreted by the central star. Age dating of meteorite constituents shows that their creation, evolution, and accumulation occupied several Myr, and over this time disk properties would evolve significantly. Moreover, on this timescale, solid particles decouple from the gas in the disk and their evolution follows a different path. Here we present a model which tracks how the distribution of water changes in an evolving disk as the water-bearing species experience condensation, accretion, transport, collisional destruction, and vaporization. Because solids are transported in a disk at different rates depending on their sizes, the motions will lead to water being concentrated in some regions of a disk and depleted in others. These enhancements and depletions are consistent with the conditions needed to explain some aspects of the chemistry of chondritic meteorites and formation of giant planets. The levels of concentration and depletion, as well as their locations, depend strongly on the combined effects of the gaseous disk evolution, the formation of rapidly migrating rubble, and the growth of immobile planetesimals. We present examples of evolution under a range of plausible assumptions and demonstrate how the chemical evolution of the inner region of a protoplanetary disk is intimately connected to the physical processes which occur in the outer regions.
description: 45 pages, 7 figures, revised for publication in Icarus
Wavefunctions, electronic localization and bonding properties for correlated materials beyond the Kohn-Sham formalism
Creators: name: James, A. D. N.
name: Harris-Lee, E. I.
name: Hampel, A.
name: Aichhorn, M.
name: Dugdale, S. B.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Many-body theories such as dynamical mean field theory (DMFT) have enabled the description of the electron exchange-correlation interactions that are missing in current density functional theory (DFT) calculations. However, there has been relatively little focus on the wavefunctions from these theories. We present the methodology of the newly developed Elk-TRIQS interface and how to calculate the DFT with DMFT (DFT+DMFT) wavefunctions, which can be used to calculate DFT+DMFT wavefunction dependent quantities. We illustrate this by calculating the electron localized function (ELF) in monolayer SrVO$_3$ and CaFe$_2$As$_2$, which provides a means of visualizing their chemical bonds. Monolayer SrVO$_3$ ELFs are sensitive to the charge redistribution between the DFT, one-shot DFT+DMFT and fully charge self-consistent DFT+DMFT calculations. In both tetragonal and collapsed tetragonal CaFe$_2$As$_2$ phases, the ELF changes weakly with correlation induced charge redistribution of the hybridized As-p and Fe-d states. Nonetheless, the interlayer As-As bond in the collapsed tetragonal structure is robust to the changes at and around the Fermi level.
Evaluation of Biorational Insecticides as Stand-alone Treatments for the Management of the Pigweed Flea Beetle, Disonycha glabrata (Coleoptera: Chrysomelidae), in Organic Production of Amaranthus spp.
Creators: name: Vorsah, Roger V.
name: Dingha, Beatrice N.
name: Sharma, Harmandeep
name: Jackai, Louis E.
name: Vorsah, Roger V.
name: Dingha, Beatrice N.
name: Sharma, Harmandeep
name: Jackai, Louis E.
Publisher: name: Unknown
Year: 2020
Subjects: subject: Crop Production/Industries
subject: Amaranthus spp.
subject: biorational insecticides
subject: Disonycha glabrata
subject: OMRI-approved, organic

description: The pigweed flea beetle, Disonycha glabrata, is the most damaging insect pest on Amaranthus spp. in the Piedmont zone of North Carolina (NC), United States. It is capable of causing severe yield loss on amaranth greens if uncontrolled. Field experiments were conducted over two growing seasons (Summer 2017 and 2018) in Greensboro, NC, to evaluate OMRI-approved biorational insecticides against D. glabrata in organic amaranth production. Insecticides evaluated included Azatin® O (azadiractin), Ecotec® (oils: rosemary, peppermint and geraniol), Entrust® (spinosad) and PyGanic® (pyrethrins) as stand-alone threshold-driven treatments applied at recommended label rates. Insecticide treatment action threshold (AT) was 2 (on a scale of 5) representing 20-40% leaf damage. The efficacy of the insecticides against D. glabrata population differed significantly within the amaranth varieties in comparison to their respective controls: treatments with Entrust® and PyGanic® on Green Callaloo and Red Leaf recorded 80% reduction in beetle population while Ecotec® gave only a 15% beetle reduction. The Azatin® O treatments recorded the highest D. glabrata population, sometimes greater than the control. Marketable fresh leaf yield from both Green Callaloo and Red Leaf amaranth was highest in the Entrust® and PyGanic® treatments. Hopi Red-Dye and Molten Fire amaranths showed some resistance to beetle damage; they are also intrinsically low yielding. These findings provide information that would make organic amaranth production possible with only limited and safe insecticide input using OMRI-approved insecticides in a threshold-driven manner, an important step towards the sustainable management of D. glabrata and amaranth production.
Gamma-Ray Bursts from quark stars
Creators: name: Paczynski, B.
name: Haensel, P.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Long gamma-ray bursts (GRBs) are believed to be related to the explosion of type Ic supernovae, which have been stripped of their hydrogen and helium envelopes. There appear to be two types of these explosions: those which are approximately spherical (GRB980425/1998bw), and which are associated with weak bursts, and the classical GRBs which generate ultrarelativistic jets (GRB030329/SN2003dh). If this bimodality is real Swift will provide a clear evidence for it. We propose that classical powerful GRBs, which generate ultrarelativistic outflows, are a result of a formation of quark stars. Quark stars may provide an additional energy for the explosion of SN Ic, but far more important is a creation of a surface which acts as a membrane which cannot be penetrated by baryons. A surface of a quark star allows only ultrarelativistic matter to escape: photons, neutrinos, electron -- positron pairs and magnetic fields. The formation of a quark star follows the initial core collapse in several minutes. Possible evidence for this time delay is provided by BATSE precursors to GRBs, as analyzed by Lazzati (2005).
description: 5 pages, (v3) MNRAS Letters, in press
Grass-Fed versus Organic Dairy Production: Southeastern US Willingness to Pay
Creators: name: Wong, Jonathan
name: Raghunathan, Uthra
name: Escalante, Cesar L.
name: Wolfe, Kent
name: Wong, Jonathan
name: Raghunathan, Uthra
name: Escalante, Cesar L.
name: Wolfe, Kent
Publisher: name: Unknown
Year: 2008
Subjects: subject: Livestock Production/Industries
subject: Grass-fed Dairy
subject: Heckman Probit Regression
subject: Organic Dairy
subject: WTP

description: This paper examines determinants of consumers’ willingness to pay a premium for grass-fed and organic dairy by using a survey data from the southeastern United States. We use ordered and Heckman probit regression techniques to estimate the impact of consumer characteristics on their willingness to pay premiums. The results suggest that some of relevant determinants are: age, income, gender, and geographical variables. This research has important implications for the large dairy industries in Florida and also as provides important information for the growing dairy industries in the rest of the southeastern United States.
Wholesale Price Discrimination: Inference and Simulation
Creators: name: Villas-Boas, Sofia Berto
name: Villas-Boas, Sofia Berto
Publisher: name: Unknown
Year: 2007
Subjects: subject: Demand and Price Analysis
subject: Uniform Wholesale Pricing
subject: Oligopoly models of multiple manufacturers and retailers
subject: Coffee Retail Market

description: This paper makes inferences about wholesale price discrimination and uniform wholesale pricing policy in a national grocery retail market where wholesale price discrimination occurs. I estimate demand and a supply model of multiple retailers’ and manufacturers’ oligopoly-pricing behavior where manufacturers may engage in wholesale price discrimination, which allows me to recover brand level marginal costs in this market. Then I simulate the welfare effects of no wholesale price discrimination via uniform price regulation given observed data on retail and input prices and retail quantities sold and not available data on wholesale prices. This approach uses retail level scanner data on coffee produced by multiple manufacturers sold at the largest retail outlets in Germany. The estimates of uniform wholesale pricing in this market suggest there to be positive welfare effects from preventing wholesale price discrimination, originating from positive effects on consumer surplus of the same magnitude as on joint vertical producer surplus. I show through simulations that estimated welfare decreases, due to higher retail prices under no wholesale price discrimination, for more collusive retail and manufacturer counterfactual scenarios. Finally, and in terms of counterfactual demand simulations, I find that banning wholesale price discrimination may be actually welfare improving the less heterogeneous and the more elastic demand is.
Fruit Waste as Natural Pectin Source for Jam Production in Rural Communities
Creators: name: Kluczkovski, Ariane M.
name: Kluczkovski-Junioer, Augusto
name: Lopes, Arine V.
name: Pinto, Samir C.B.
name: Monteiro, Diana C.
name: Kluczkovski, Ariane M.
name: Kluczkovski-Junioer, Augusto
name: Lopes, Arine V.
name: Pinto, Samir C.B.
name: Monteiro, Diana C.
Publisher: name: Unknown
Year: 2020
Subjects: subject: Crop Production/Industries
subject: Passiflora edulis
subject: Ananas comosus
subject: food waste

description: A study was carried out to elaborate and monitor the shelf life of a pineapple jam with ingredients using, as “gelatinizing agent”, the pectin extracted from passion fruit residues from a rural community of Amazonas State, Brazil. The product was always maintained at a temperature of 25 °C and studied for 4 months, with the results showing physical-chemical and microbiological stability. We concluded that passion fruit residue can be used in pineapple jam production while still meeting legal standards for commercialization, reducing environmental waste, and being an alternative source of income in rural communities.
A blind estimation of the power spectrum of CMB anisotropy from WMAP
Creators: name: Saha, Rajib
name: Jain, Pankaj
name: Souradeep, Tarun
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Accurate measurements of angular power spectrum of Cosmic Microwave Background (CMB) radiation has lead to marked improvement in the estimates of different cosmological parameters. This has required removal of foreground contamination as well as detector noise bias with reliability and precision. We present the estimation of CMB angular power spectrum from the multi-frequency observations of WMAP using a novel {\em model-independent} method. The primary product of WMAP are the observations of CMB in 10 independent difference assemblies (DA) that have uncorrelated noise. Our method utilizes maximum information available within WMAP data by linearly combining all the DA maps to remove foregrounds and estimating the power spectrum from cross power spectra of clean maps with independent noise. We compute 24 cross power spectra which are the basis of the final power spectrum. The binned average power matches with WMAP team's published power spectrum closely. A small systematic difference at large multipoles is accounted for by the correction for the expected residual power from unresolved point sources. The correction is small and significantly tempered. Previous estimates have depended on foreground templates built using extraneous observational input. This is the first demonstration that the CMB angular spectrum can be reliably estimated with precision from a *self contained analysis* of the WMAP data.
description: 4 pages, 3 figures, Matches version accepted to ApJ. Lett. Minor editing; Level of bias at low multipoles mentioned. Suppl. details at http://meghnad.iucaa.ernet.in/~tarun/sup0508383
Field-theoretical aspects of one-dimensional Bose and Fermi gases with contact interactions
Creators: name: Sekino, Yuta
name: Nishida, Yusuke
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate local quantum field theories for one-dimensional (1D) Bose and Fermi gases with contact interactions, which are closely connected with each other by Girardeau's Bose-Fermi mapping. While the Lagrangian for bosons includes only a two-body interaction, a marginally relevant three-body interaction term is found to be necessary for fermions. Because of this three-body coupling, the three-body contact characterizing a local triad correlation appears in the energy relation for fermions, which is one of the sum rules for a momentum distribution. In addition, we apply in both systems the operator product expansion to derive large-energy and momentum asymptotics of a dynamic structure factor and a single-particle spectral density. These behaviors are universal in the sense that they hold for any 1D scattering length at any temperature. The asymptotics for the Tonks-Girardeau gas, which is a Bose gas with a hardcore repulsion, as well as the Bose-Fermi correspondence in the presence of three-body attractions are also discussed.
description: 18 pages, 8 figures; published version
HOUSEHOLD TIME ALLOCATION AND ENDOGENOUS FARM STRUCTURE: IMPLICATIONS FOR THE DESIGN OF AGRICULTURAL POLICIES
Creators: name: Goodwin, Barry K.
name: Mishra, Ashok K.
name: Kimhi, Ayal
name: Goodwin, Barry K.
name: Mishra, Ashok K.
name: Kimhi, Ayal
Publisher: name: Unknown
Year: 2007
Subjects: Agricultural and Food Policy
Farm Management

description: We evaluate relationships among time allocation decisions for farm operators and their spouses and endogenous farm structure. We consider two aspects of farm structure{ farm scale, represented by acreage operated and harvested, and farm scope, which is represented by an index of diversification. We are particularly interested in the role of policy expectations as a factor influencing labor decisions and farm structure. Our results indicate that farm structure and household time allocations are significantly related to one another. Operators on larger and more diversified farms tend to work less off the farm. Size may be endogenous to off-farm work decisions in that farms tend to be smaller when farmers pursue off-farm work opportunities, though the converse is true for the operators' spouses. Direct (decoupled) payments tend to be associated with less off-farm work by spouses, a smaller scale of production, and more diversification. This result has relevance to the ongoing debate over the production neutrality of decoupled payments. Coupled payments tend to be associated with more off-farm work by spouses and larger farms, thus suggesting a positive effect on farm labor.
How do binaries affect the derived dynamical mass of a star cluster?
Creators: name: Kouwenhoven, M. B. N.
name: de Grijs, R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The dynamical mass of a star cluster can be derived from the virial theorem, using the measured half-mass radius and line-of-sight velocity dispersion of the cluster. However, this dynamical mass may be a significant overestimation of the cluster mass if the contribution of the binary orbital motion is not taken into account. In these proceedings we describe the mass overestimation as a function of cluster properties and binary population properties, and briefly touch the issue of selection effects. We find that for clusters with a measured velocity dispersion of sigma > 10 km/s the presence of binaries does not affect the dynamical mass significantly. For clusters with sigma < 1 km/s (i.e., low-density clusters), the contribution of binaries to sigma is significant, and may result in a major dynamical mass overestimation. The presence of binaries may introduce a downward shift of Delta log(L/Mdyn) = 0.05-0.4 in the log(L/Mdyn) vs. age diagram.
description: 6 pages, 5 figures, to appear in ``Young Massive Star Clusters - Initial Conditions and Environments'', 2008, Astrophysics & Space Science, eds. E. Perez, R. de Grijs, R. M. Gonzalez Delgado
On Random Walks with a General Moving Barrier
Creators: name: Zhang, Jun
name: Hui, Lam
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Random walks with a general, nonlinear barrier have found recent applications ranging from reionization topology to refinements in the excursion set theory of halos. Here, we derive the first-crossing distribution of random walks with a moving barrier of an arbitrary shape. Such a distribution is shown to satisfy an integral equation that can be solved by a simple matrix inversion, without the need for Monte Carlo simulations, making this useful for exploring a large parameter space. We discuss examples in which common analytic approximations fail, a failure which can be remedied using the method described here.
description: 6 pages, 7 figures, submitted to ApJ
LAND REFORM AND RURAL WELL BEING IN THE REPUBLIC OF GEORGIA: 1996-2003
Creators: name: Gogodze, Joseph
name: Kan, Iddo
name: Kimhi, Ayal
name: Gogodze, Joseph
name: Kan, Iddo
name: Kimhi, Ayal
Publisher: name: Unknown
Year: 2007
Subjects: Community/Rural/Urban Development
Land Economics/Use

description: Land reform was launched in the Republic of Georgia in 1992, about a year after the country gained its independence from the Soviet Union. While an impressive land individualization process has been in effect since then, the pace and the performance of this process are far from satisfactory. This is due to a combination of institutional and economic constraints. We use comparable survey data from 1996 and 2003 and show that the land reform has been progressing mainly through land leasing. This allows successful farm households to expand their farming operation and improve their well-being. Land documentation doesn’t seem to yield the expected results, and the blame may be on less than sufficient labor and credit opportunities. We conclude that there is scope for continuing the process of land reform in Georgia, but this has to be accompanied by measures to develop rural credit and labor markets.
Technical Efficiency of Wheat Producers in North Shewa Zone of Amhara Region, Central Ethiopia
Creators: name: Getachew, Tadesse
name: Metema, Mengistu
name: Goshu, Degye
name: Abebaw, Degnet
name: Getachew, Tadesse
name: Metema, Mengistu
name: Goshu, Degye
name: Abebaw, Degnet
Publisher: name: Unknown
Year: 2020
Subjects: subject: Crop Production/Industries
subject: Central Ethiopia
subject: stochastic frontier production function
subject: technical efficiency
subject: wheat productivity

description: The aim of this study is to analyze technical efficiency of wheat producers and identifying the sources of inefficiency in North Shewa Zone of Amhara National Region State, Central Ethiopia. A multi-stage sampling technique was used to select sample respondent households. In the first phase, three potential wheat grower districts namely, Bassona Worrana, Siyadebrna Wayu, and Moretna Jiru were selected purposively. In the second stage, six potential kebeles (lowest administrative level), two from each of the three districts were selected. In the third phase, proportionally with population size, 374 sample households were selected using simple random sampling techniques from each of the selected kebeles. Cobb-Douglas Stochastic Frontier Production (SFP) function and inefficiency function were used to estimate the technical inefficiency level of wheat producers using a one-step maximum likelihood estimation procedure. The average productivity of wheat was found to be 32.60 quintals per hectare. Land size, fertilizer, seed, labor, and oxen power were important factors of production positively and significantly affecting wheat output. Age and education level of a farmer, off-farm income, extension contact, and credit services were found negatively and significantly affecting the technical inefficiency of wheat producing farmers. The inefficiency components contributed about 70.62% of the total deviation from the best possible production output. The average technical efficiency (TE) level of wheat producers was 72%. Overall, the provision of fertilizers, credit, and extension services would make wheat producers more productive and technically efficient in the study area.
Phase Transitions in Quantum Many-Body Scars
Creators: name: Larsen, Peter Græns
name: Nielsen, Anne E. B.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We propose a type of phase transition in quantum many-body systems, which occurs in highly excited quantum many-body scar states, while most of the spectrum is largely unaffected. Such scar state phase transitions can be realized by embedding a matrix product state, known to undergo a phase transition, as a scar state into the thermal spectrum of a parent Hamiltonian. We find numerically that the mechanism for the scar state phase transition involves the formation or presence of low-entropy states at energies similar to the scar state in the vicinity of the phase transition point.
description: 6 pages, 3 figures, v2: accepted version
Tight Approximation Guarantees for Concave Coverage Problems
Creators: name: Barman, Siddharth
name: Fawzi, Omar
name: Fermé, Paul
Publisher: name: arXiv
Year: 2020
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: Computational Complexity (cs.CC)
subject: FOS: Computer and information sciences

description: In the maximum coverage problem, we are given subsets $T_1, \ldots, T_m$ of a universe $[n]$ along with an integer $k$ and the objective is to find a subset $S \subseteq [m]$ of size $k$ that maximizes $C(S) := \Big|\bigcup_{i \in S} T_i\Big|$. It is a classic result that the greedy algorithm for this problem achieves an optimal approximation ratio of $1-e^{-1}$. In this work we consider a generalization of this problem wherein an element $a$ can contribute by an amount that depends on the number of times it is covered. Given a concave, nondecreasing function $φ$, we define $C^φ(S) := \sum_{a \in [n]}w_aφ(|S|_a)$, where $|S|_a = |\{i \in S : a \in T_i\}|$. The standard maximum coverage problem corresponds to taking $φ(j) = \min\{j,1\}$. For any such $φ$, we provide an efficient algorithm that achieves an approximation ratio equal to the Poisson concavity ratio of $φ$, defined by $α_φ := \min_{x \in \mathbb{N}^*} \frac{\mathbb{E}[φ(\text{Poi}(x))]}{φ(\mathbb{E}[\text{Poi}(x)])}$. Complementing this approximation guarantee, we establish a matching NP-hardness result when $φ$ grows in a sublinear way. As special cases, we improve the result of [Barman et al., IPCO, 2020] about maximum multi-coverage, that was based on the unique games conjecture, and we recover the result of [Dudycz et al., IJCAI, 2020] on multi-winner approval-based voting for geometrically dominant rules. Our result goes beyond these special cases and we illustrate it with applications to distributed resource allocation problems, welfare maximization problems and approval-based voting for general rules.
description: 33 pages. v3 minor corrections and added FPT hardness
Measuring topological descriptors of complex networks under uncertainty
Creators: name: Raimondo, Sebastian
name: De Domenico, Manlio
Publisher: name: arXiv
Year: 2020
Subjects: subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Dynamical Systems (math.DS)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Revealing the structural features of a complex system from the observed collective dynamics is a fundamental problem in network science. In order to compute the various topological descriptors commonly used to characterize the structure of a complex system (e.g. the degree, the clustering coefficient), it is usually necessary to completely reconstruct the network of relations between the subsystems. Several methods are available to detect the existence of interactions between the nodes of a network. By observing some physical quantities through time, the structural relationships are inferred using various discriminating statistics (e.g. correlations, mutual information, etc.). In this setting, the uncertainty about the existence of the edges is reflected in the uncertainty about the topological descriptors. In this study, we propose a novel methodological framework to evaluate this uncertainty, replacing the topological descriptors, even at the level of a single node, with appropriate probability distributions, eluding the reconstruction phase. Our theoretical framework agrees with the numerical experiments performed on a large set of synthetic and real-world networks. Our results provide a grounded framework for the analysis and the interpretation of widely used topological descriptors, such as degree centrality, clustering and clusters, in scenarios where the existence of network connectivity is statistically inferred or when the probabilities of existence $π_{ij}$ of the edges are known. To this purpose we also provide a simple and mathematically grounded process to transform the discriminating statistics into the probabilities $π_{ij}$ .
description: 15 pages, 6 figures. Manuscript updated after peer-review. Appendices added
THE SIMULTANEOUS EVOLUTION OF FARM SIZE AND SPECIALIZATION: DYNAMIC PANEL DATA EVIDENCE FROM ISRAELI FARM COMMUNITIES
Creators: name: Kimhi, Ayal
name: Rekah, Hila
name: Kimhi, Ayal
name: Rekah, Hila
Publisher: name: Unknown
Year: 2005
Subjects: Farm Management

description: This paper deals with structural changes that are observed in farm sectors in many developed economies: the increase in farm size and in farm specialization. Using panel data on Israeli farm communities for the years 1992-2001, we estimate a system of simultaneous equations in which these variables are determined jointly in a dynamic setting. We employ the Arellano and Bond dynamic panel GMM algorithm for each of the equations, treating the other variables as endogenous and allowing for unobserved heterogeneity and for time trends that depend on geographical and institutional factors. The results exhibit positive and statistically significant autoregressive effects in both size and specialization. Farm size depends negatively on specialization, while specialization does not depend significantly on size. This implies that opposite to what one may conclude from aggregate data, Israeli farms expand by diversifying into additional crops and/or livestock rather than by expanding existing enterprises. Simulations show that while specialization increases in all types of communities, farm size is increasing over time in cooperative villages and decreasing over time in collective farms. This implies a gradual process that leads, in the long run, to concentration of agricultural production in a small number of large, business-oriented, family farm enterprises.
Ghost Condensate Busting
Creators: name: Bilić, Neven
name: Tupper, Gary B.
name: Viollier, Raoul D.
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Applying the Thomas-Fermi approximation to renormalizable field theories, we construct ghost condensation models that are free of the instabilities associated with violations of the null-energy condition.
description: 9 pages, minor corrections, a reference added, the discussion on consistency of the Thomas-Fermi approximation expanded, to appear in JCAP
Concentration, Temperature and Storage duration Influence Chemical Stability of Compost Tea
Creators: name: Vehniwal, Sanjamveer S.
name: Ofoe, Raphael
name: Abbey, Lord
name: Vehniwal, Sanjamveer S.
name: Ofoe, Raphael
name: Abbey, Lord
Publisher: name: Unknown
Year: 2020
Subjects: subject: Crop Production/Industries
subject: organic amendment
subject: compost storage
subject: chemical stability
subject: shelf-life
subject: municipal solid waste

description: Chemical stability is one of the key quality control criterion for complex degradable materials with an active microbial community like compost tea, but largely understudied. A laboratory study was performed to assess the chemical stability of varying concentrations (0, 2.5, 5, 10, 15, 20, 30, 50 and 100%) of municipal solid waste (MSW) compost tea stored at different temperatures (4°, 10°, 22° and 35°C) and storage time (0, 13, 26 39 and 52 days). A 2-dimension principal component biplot confirmed close relationship amongst total dissolved solids (TDS), electric conductivity (EC) and salinity while pH was less related and turbidity was isolated. TDS in the MSW compost tea did not change at a storage temperature of 4oC or 10oC but was significantly (P<0.05) increased by 4.3% when the storage temperature was raised to 35oC. Also, TDS increased sharply from 93.25 mg/L on day 1 to 111.31 mg/L on day 26 after which it remained unchanged. EC increased by approximately 8% only when the MSW compost tea was stored at 35oC. The EC on the other hand increased by 19.4% from 131.28 µS/cm on day 1 when it peaked on day 26 and plateaued off to day 52. The change in pH was small and ranged from 7.44 to 7.67. Concentration had the strongest association with TDS, EC, salinity and turbidity and did not vary with storage time nor temperature. A multilinear regression (Y = αD + βC + γT + k) showed significant (P<0.05) coefficients for all the independent variables except the coefficients for temperature in the turbidity, salinity and pH regression models. In conclusion, the chemical stability of the MSW compost tea was dependent on the storage temperature and storage duration. Chemical stability was reached after 26 days of storage while cold storage at 4oC or 10oC reduced chemical alteration.
The complex multi-component outflow of the Seyfert galaxy NGC 7130
Creators: name: Comerón, S.
name: Knapen, J. H.
name: Almeida, C. Ramos
name: Watkins, A. E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: AGN are a key ingredient for understanding galactic evolution. AGN-driven outflows are one of the manifestations of feedback. The AO mode for MUSE at the VLT permits to study the innermost tens of parsecs of nearby AGN in the optical. We present a detailed analysis of the ionised gas in the central regions of NGC 7130, an archetypical composite Seyfert and nuclear starburst galaxy. We achieve an angular resolution of 0.17$^{\prime\prime}$ (50 pc). We performed a multi-component analysis of the main ISM lines and identified nine kinematic components, six of which correspond to the outflow. The outflow is biconic and has velocities of a few $100\,{\rm km\,s^{-1}}$ with respect to the disc. We decompose the approaching side of the outflow into a broad and a narrow component with typical velocity dispersions below and above $\sim200\,{\rm km\,s^{-1}}$, respectively. The blueshifted narrow component has substructure, in particular a collimated plume aligned with the radio jet, indicating that it may be jet-powered. The redshifted lobe is composed of two Narrow Components and a Broad Component. An additional redshifted component is seen outside the main outflow axis. Line ratio diagnostics indicate that the outflow gas in the main axis is AGN-powered whereas the off-axis component has LINER properties. The ionised gas mass outflow rate is $\dot{M}=1.2\pm0.7\,M_{\odot}\,{\rm yr^{-1}}$ and the kinetic power is $\dot{E}_{\rm kin}=(2.7\pm2.0)\times10^{41}\,{\rm erg\,s^{-1}}$, which corresponds to $F_{\rm kin}=0.12\pm0.09\%$ of the bolometric AGN power. The combination of high angular resolution integral field spectroscopy and a careful multi-component decomposition allows a uniquely detailed view of the outflow in NGC 7130, illustrating that AGN kinematics are more complex than traditionally derived from less sophisticated data and analyses. (abridged)
description: Published in A&A. This version of the preprint has been corrected with the modifications appearing in the A&A corrigendum
Chrysozyma fusiformis Q. M. Wang, F. Y. Bai & A. H. Li 2020, sp. nov.
Creators: name: Li, A. - H.
name: Yuan, F. - X.
name: Groenewald, M.
name: Bensch, K.
name: Yurkov, A. M.
name: Li, K.
name: Han, P. - J.
name: Guo, L. - D.
name: Aime, M. C.
name: Sampaio, J. P.
name: Jindamorakot, S.
name: Turchetti, B.
name: Inacio, J.
name: Fungsin, B.
name: Wang, Q. - M.
name: Bai, F. - Y.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Microbotryomycetes
Chrysozymaceae
Chrysozyma
Chrysozyma fusiformis

description: Chrysozyma fusiformis Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828854. Fig. 19A, B.
 Etymology: the specific epithet fusiformis refers to the fusiform vegetative cells of the type strain.
 Culture characteristics: In YM broth, after 7 d at 17 °C, cells are ellipsoidal to fusiform, 3.0– 4.6 × 4.7– 8.2 μm and single, budding is polar (Fig. 19A), a sediment is present. After 1 mo at 17 °C, a ring and sediment are present. On YM agar, after 1 mo at 17 °C, the streak culture is cream, butyrous, smooth and dull surface. The margin is entire. In Dalmau plate culture on corn meal agar, pseudohyphae are not formed. Sexual structures are not observed on YM, PDA, V8 and CM agar. Ballistoconidia are ellipsoidal orallantoid, 2.9– 4.3 × 7.1 –11.4 μm (Fig. 19B).
 Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, sucrose, maltose, cellobiose, trehalose, melibiose, melezitose, ethanol, D-mannitol and succinate (delayed and weak) are assimilated as sole carbon sources. Galactose, L-sorbose, lactose, raffinose, inulin, soluble starch, D-xylose, L-arabinose, D-arabinose, D-ribose, L-rhamnose, Dglucosamine, methanol, glycerol, erythritol, ribitol, galactitol, Dglucitol, Methyl-α- D-glucoside, salicin, DL-lactate, citrate, myo-inositol and hexadecane are not assimilated. Ammonium sulfate, potassium nitrate, sodium nitrite, L-lysine, ethylamine hydrochloride and cadaverine dihydrochloride are assimilated as sole nitrogen sources. Maximum growth temperature is 24 °C. Growth in vitamin-free medium is negative. Starch-like substances are not produced. Growth on 50 % (w/w) glucose-yeast extract agar is negative. Urease activity is positive. Diazonium Blue B reaction is positive.
 Physiologically, Ch. fusiformis differs well from other Chrysozyma species in its assimilation of carbon and nitrogen sources (Table S1.34).
 Typus: China, Lulang county, Tibet, obtained from a leaf of an unidentified plant, Sep. 2004, F.-Y. Bai (holotype CGMCC 2.2765 T preserved in a metabolically inactive state, ex-type CBS 15458 = XZ33C2).
description: Published as part of Li, A. - H., Yuan, F. - X., Groenewald, M., Bensch, K., Yurkov, A. M., Li, K., Han, P. - J., Guo, L. - D., Aime, M. C., Sampaio, J. P., Jindamorakot, S., Turchetti, B., Inacio, J., Fungsin, B., Wang, Q. - M. & Bai, F. - Y., 2020, Diversity and phylogeny of basidiomycetous yeasts from plant leaves and soil: Proposal of two new orders, three new families, eight new genera and one hundred and seven new species, pp. 17-140 in Studies In Mycology 96 on page 129, DOI: 10.1016/j.simyco.2020.01.002
Lengsfeld, Peter / Stobbe, Heinz-Günther: Theologischer Konsens und Kirchenspaltung
Creators: name: Kg.
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 30 Nr. 4 (1981): Ökumenische Rundschau, Band 30, Heft 4
Local Spectral Density and Vacuum Energy near a Quantum Graph Vertex
Creators: name: Fulling, Stephen A.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Spectral Theory (math.SP)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 81Q10 (primary), 34B45 (secondary)

description: The delta interaction at a vertex generalizes the Robin (generalized Neumann) boundary condition on an interval. Study of a single vertex with N infinite leads suffices to determine the localized effects of such a vertex on densities of states, etc. For all the standard initial-value problems, such as that for the wave equation, the pertinent integral kernel (Green function) on the graph can be easily constructed from the corresponding elementary Green function on the real line. From the results one obtains the spectral-projection kernel, local spectral density, and local energy density. The energy density, which refers to an interpretation of the graph as the domain of a quantized scalar field, is a coefficient in the asymptotic expansion of the Green function for an elliptic problem involving the graph Hamiltonian; that expansion contains spectral/geometrical information beyond that in the much-studied heat-kernel expansion.
description: 12 pages. Paper presented at AMS-IMS-SIAM Joint Summer Research Conference on Quantum Graphs and Their Applications, Snowbird, June, 2005
Quasiprobability decompositions with reduced sampling overhead
Creators: name: Piveteau, Christophe
name: Sutter, David
name: Woerner, Stefan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum error mitigation techniques can reduce noise on current quantum hardware without the need for fault-tolerant quantum error correction. For instance, the quasiprobability method simulates a noise-free quantum computer using a noisy one, with the caveat of only producing the correct expected values of observables. The cost of this error mitigation technique manifests as a sampling overhead which scales exponentially in the number of corrected gates. In this work, we present a new algorithm based on mathematical optimization that aims to choose the quasiprobability decomposition in a noise-aware manner. This directly leads to a significantly lower basis of the sampling overhead compared to existing approaches. A key element of the novel algorithm is a robust quasiprobability method that allows for a tradeoff between an approximation error and the sampling overhead via semidefinite programming.
description: v2: 22 pages, 9 figures; published version
Chrysozyma sorbariae Q. M. Wang, F. Y. Bai & A. H. Li 2020, sp. nov.
Creators: name: Li, A. - H.
name: Yuan, F. - X.
name: Groenewald, M.
name: Bensch, K.
name: Yurkov, A. M.
name: Li, K.
name: Han, P. - J.
name: Guo, L. - D.
name: Aime, M. C.
name: Sampaio, J. P.
name: Jindamorakot, S.
name: Turchetti, B.
name: Inacio, J.
name: Fungsin, B.
name: Wang, Q. - M.
name: Bai, F. - Y.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Fungi
Basidiomycota
Microbotryomycetes
Chrysozymaceae
Chrysozyma
Chrysozyma sorbariae

description: Chrysozyma sorbariae Q.M. Wang, F.Y. Bai & A.H. Li sp. nov. MycoBank MB828855. Fig. 19C, D.
 Etymology: the specific epithet sorbariae refers to Sorbaria, the plant genus from which the type strain was isolated.
 Culture characteristics: In YM broth, after 7 d at 17 °C, cells are elongate ellipsoidal and cylindrical, 1.7–2.7 × 5.8–10.4 μm and single, budding is polar (Fig. 19C), a sediment is present. On YM agar, after 1 mo at 17 °C, the streak culture is cream, butyrous, smooth and semi-gloosy. The margin is entire. In Dalmau plate culture on corn meal agar, pseudohyphae are not formed. Sexual structures are not observed on YM, PDA, V8 and CM agar. Ballistoconidia are allantoid or falcate, 2.1–2.9 × 6.4–7.9 μm (Fig. 19D).
 Physiological and biochemical characteristics: Glucose fermentation is absent. Glucose, sucrose, maltose, trehalose, melezitose, inulin (delayed and weak), D-mannitol and D-glucitol are assimilated as sole carbon sources. Galactose, Lsorbose, cellobiose, lactose, melibiose, raffinose, soluble starch, D-xylose, L-arabinose, D-arabinose, D-ribose, L-rhamnose, D-glucosamine, methanol, ethanol, glycerol, erythritol, ribitol, galactitol, Methyl-α- D-glucoside, salicin, DL-lactate, succinate, citrate, myo-inositol and hexadecane are not assimilated. Ammonium sulfate, potassium nitrate (weak) and sodium nitrite are assimilated as sole nitrogen sources. Llysine, ethylamine hydrochloride and cadaverine dihydrochloride are not assimilated. Maximum growth temperature is 26 –27 Ί C. Growth in vitamin-free medium is variable. Starch-like substances are not produced. Growth on 50 % (w/w) glucose-yeast extract agar is negative. Urease activity is positive. Diazonium Blue B reaction is positive.
 Physiologically, Ch. sorbariae differs well from other Chrysozyma species in its assimilation of carbon and nitrogen sources (Table S1.34).
 Typus: China, Bomi county, Tibet, obtained from a leaf of Sorbaria arboricola, Sep. 2004, F.-Y. Bai (holotype CGMCC 2.2768 T preserved in a metabolically inactive state, ex-type CBS 15460 = XZ9D1).
description: Published as part of Li, A. - H., Yuan, F. - X., Groenewald, M., Bensch, K., Yurkov, A. M., Li, K., Han, P. - J., Guo, L. - D., Aime, M. C., Sampaio, J. P., Jindamorakot, S., Turchetti, B., Inacio, J., Fungsin, B., Wang, Q. - M. & Bai, F. - Y., 2020, Diversity and phylogeny of basidiomycetous yeasts from plant leaves and soil: Proposal of two new orders, three new families, eight new genera and one hundred and seven new species, pp. 17-140 in Studies In Mycology 96 on page 129, DOI: 10.1016/j.simyco.2020.01.002