cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
CT-duality as a local property of the world-sheet
Creators: name: Sazdovic, Branislav
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In the present article, we study the local features of the world-sheet in the case when probe bosonic string moves in antisymmetric background field. We generalize the geometry of surfaces embedded in space-time to the case when the torsion is present. We define the mean extrinsic curvature for spaces with Minkowski signature and introduce the concept of mean torsion. Its orthogonal projection defines the dual mean extrinsic curvature. In this language, the field equation is just the equality of mean extrinsic curvature and extrinsic mean torsion, which we call CT-duality. To the world-sheet described by this relation we will refer as CT-dual surface.
description: Latex, 15 pages, 2 Figures
VERTICAL AND HORIZONTAL COORDINATION IN THE AGRO-BIOTECHNOLOGY INDUSTRY: EVIDENCE AND IMPLICATIONS
Creators: name: Kalaitzandonakes, Nicholas G.
name: Bjornson, Bruce
name: Kalaitzandonakes, Nicholas G.
name: Bjornson, Bruce
Publisher: name: Unknown
Year: 1997
Subjects: subject: Industrial Organization
subject: Research and Development/Tech Change/Emerging Technologies
subject: Acquisitions
subject: Agricultural biotechnology
subject: FOS: Agricultural biotechnology
subject: Firm strategy
subject: Industry consolidation
subject: Industry structure
subject: Mergers

description: Agro-biotechnology is evolving from a pre-commercial phase dominated by basic research science to a commercial phase oriented around marketing products. In pursuing innovation rents in the commercial phase, firms are reorienting their strategies around complementary marketing and distribution assets. This is impacting vertical and horizontal industry structure. Conversely, industry structure is also impacting firm strategies. Horizontal alliances and consolidation continue from the pre-commercial phase into the commercial phase, while vertical coordination and integration strategies are accelerating rapidly. Interplay between firm strategy and industry structure is too complex for firms to anticipate early in the pre-commercial phase for long-term strategy formulation.
Matérn Gaussian Processes on Graphs
Creators: name: Borovitskiy, Viacheslav
name: Azangulov, Iskander
name: Terenin, Alexander
name: Mostowsky, Peter
name: Deisenroth, Marc Peter
name: Durrande, Nicolas
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Gaussian processes are a versatile framework for learning unknown functions in a manner that permits one to utilize prior information about their properties. Although many different Gaussian process models are readily available when the input space is Euclidean, the choice is much more limited for Gaussian processes whose input space is an undirected graph. In this work, we leverage the stochastic partial differential equation characterization of Matérn Gaussian processes - a widely-used model class in the Euclidean setting - to study their analog for undirected graphs. We show that the resulting Gaussian processes inherit various attractive properties of their Euclidean and Riemannian analogs and provide techniques that allow them to be trained using standard methods, such as inducing points. This enables graph Matérn Gaussian processes to be employed in mini-batch and non-conjugate settings, thereby making them more accessible to practitioners and easier to deploy within larger learning frameworks.
Stochastic control of inter-switch handoff and location update in wireless cellular networks
Creators: name: Wong, Wai-Shuen Vincent
Publisher: name: University of British Columbia
Year: 2009

description: One of the issues in mobility management is to support handoff. When the mobile user moves from one location to another, the network should ensure that all ongoing connections are rerouted to another access point in a seamless manner. Part of our work focuses on connection rerouting due to inter-switch handoff in wireless ATM networks. Although fast local connection rerouting minimizes handoff delay, the end-to-end path after rerouting may become "suboptimal", which implies an inefficient use of network resources. Path optimization may be necessary afterwards. Our research begins with the following question: "How often should path optimization be performed?" To this end, we propose three path optimization schemes (namely: exponential, periodic, and Bernoulli), which are simple to implement. Closed-form solutions of the optimal operating point are derived for each scheme. We further investigate this problem and propose a stochastic model to determine the optimal time to initiate path optimization. Link cost and signaling cost functions are introduced to capture the trade-off between the network resources utilized by a connection and the signaling and processing load incurred on the network. Results indicate that the optimal policy derived from our model has a better performance compared to other heuristics. Another issue in mobility management is to track the location of the users between call arrivals. Although it has been shown that the distance-based location update algorithm has a better performance than the movement and timer based schemes, the determination of the optimal distance threshold is often based on certain unrealistic assumptions. We propose a stochastic model to study the distance-based update algorithm. Our model is applicable to arbitrary cell topologies and the cell residence time can follow general distributions. We consider Markovian movement patterns in which the probability that the mobile user moves to a particular neighboring cell can depend on the location of the current cell or a list of cells recently visited. Results indicate that the distance thresholds determined from our model have a better performance than those derived from a hexagonal cell configuration with random walk movement pattern.
THE ROLE OF THE STATE IN PROMOTING MICROFINANCE INSTITUTIONS
Creators: name: Lapenu, Cecile
name: Lapenu, Cecile
Publisher: name: Unknown
Year: 2000
Subjects: Financial Economics

description: In a context of liberalized financial systems, microfinance allows millions of households, usually excluded from classical financial services, to begin or reinforce their own activities and become microentrepreneurs. Yet, in spite of the success of numerous microfinance institutions (MFI), many difficulties remain which must be urgently resolved in view of their ambitious objectives. First, a large number of the rural households still lack access to financial services. Second, most of the existing MFI are not yet financially sustainable. Finally, while funds from governments and donors are rapidly increasing, financial institutions still need solid foundations to avoid management failures. These issues raise questions of the role of the state to promote MFI including (1) which state-owned institutions may be necessary? (2) which level and type of subsidization of the financial institutions can be accepted? (3) what can be the choice for the state between alternative investments in financial institutions or complementary services? (4) what are the necessary conditions for creating a favorable environment? This paper presents the evolution of views on the role of the state in the financial system including theoretical and empirical points of view from the interventionist period of the 1960s and 1970s to the current period of liberalization. Based on country case studies illustrating the divergent role of the state in the development of the rural financial system, the paper reviews the respective role of the state, the NGO and the private commercial banks in increasing their outreach and in adopting microfinance innovations. It also analyzes different issues regarding regulation of MFI. The paper concludes with a discussion of the necessary roles of the state to promote MFI. The role of the state encompasses insuring a minimum banking structure in the rural areas, subsidizing microfinance start-up capital and innovations, and investing in complementary services such as infrastructure, health, and education. The state must also develop a clear and flexible regulatory framework for MFI with the means to enforce the rules for the supervisory bodies. The paper also concludes that efficient governance is more of a determinant than the distinction of ownership by the private or the public sector for the performances of the MFI.
PUBLIC SPENDING AND POVERTY IN MOZAMBIQUE
Creators: name: Heltberg, Rasmus
name: Simler, Kenneth R.
name: Tarp, Finn
name: Heltberg, Rasmus
name: Simler, Kenneth R.
name: Tarp, Finn
Publisher: name: Unknown
Year: 2003
Subjects: Food Security and Poverty
Public Economics

description: Poverty reduction strategies often highlight public spending to improve health and education, focusing on investments in human capital among poorer members of society. In addition, debt relief programs such as the enhanced Highly Indebted Poor Countries (HIPC) initiative often require increased spending on health and education in return for debt cancellation. Mozambique's poverty reduction strategy is closely integrated with the government expenditure program, yet up to now little is known about the extent to which public spending is targeted toward the poor in Mozambique. This paper assesses whether public expenditures on education and health are successful at reaching the poorer segments of the Mozambican population. Standard nonbehavioral benefit-incidence methodology is applied, combining individual client information from survey data with provincial-level data on the cost of service provision. Most of the public services we are able to measure are moderately progressive, although some of the instruments we could not measure are probably less equally distributed. In Mozambique, it appears that regional and gender imbalances in health and education are more significant than income-based differences. Nevertheless, increased public expenditures on health and education-such as that related to the HIPC initiative-are likely to have significant poverty-reducing effects.
TARGETING THE POOR IN MEXICO: AN EVALUATION OF THE SELECTION OF HOUSEHOLDS FOR PROGRESA
Creators: name: Skoufias, Emmanuel
name: Davis, Benjamin
name: De La Vega, Sergio
name: Skoufias, Emmanuel
name: Davis, Benjamin
name: De La Vega, Sergio
Publisher: name: Unknown
Year: 2001
Subjects: Food Security and Poverty

description: This report reevaluates PROGRESA’s targeting methods since the program began adding beneficiary households through a process called “densification.” The authors first evaluate PROGRESA’s accuracy in targeting both at the community and household levels. Second, they evaluate the targeting in terms of its impact on poverty alleviation relative to other feasible methods assuming the same total budget. The first step is accomplished by comparing PROGRESA’s method to an alternative selection method based on household consumption. For the second task, the costs associated with different schemes are compared for their effects on the budget available for poverty alleviation. Schemes considered include uniform transfers that involve no targeting, targeting based on consumption, and targeting at the locality rather than the household. The authors find that PROGRESA’s marginality index performs quite well when contrasted to a consumption-based model of locality selection. The consumption-based model results in a more precise categorization of poverty, which implies that geographic targeting based on the marginality index is more likely to result in leakage rather than undercoverage. The fit between the two methods is particularly tight for the low and very high marginality categories, and is more diffuse in the middle categories. This suggests that the PROGRESA marginality index loses its power of distinction between medium-marginality localities. The analysis also showed that PROGRESA’s targeting appears to accurately identify extremely poor households, but makes more errors identifying moderately poor households. This finding raises serious concerns about PROGRESA’s current targeting method for the less-poor areas. However, in comparison to other schemes, PROGRESA’s targeting appears to miss fewer extremely poor households. In addition, households that are included erroneously in the list of beneficiaries appear to be closer to the poverty line than households that are included incorrectly by other methods. In short, the errors of exclusion and inclusion occurring with PROGRESA’s targeting are less serious than those occurring with other feasible target and transfer schemes. Finally, the authors performed a number of simulations comparing PROGRESA’s targeting in terms of its impact on poverty alleviation relative to other schemes assuming the same total budget. For the social objectives of reducing the depth of poverty, PROGRESA’s targeting appears to be the second most effective scheme to “perfect” targeting based on consumption. However, it should be noted that the reduction in the higher-order measures of poverty accomplished by household targeting over and above those accomplished by simply including all the households in the locality are relatively small.
THE IMPACT OF PROGRESA ON FOOD CONSUMPTION
Creators: name: Hoddinott, John
name: Skoufias, Emmanuel
name: Hoddinott, John
name: Skoufias, Emmanuel
Publisher: name: Unknown
Year: 2003
Subjects: Food Consumption/Nutrition/Food Safety

description: As exemplified by the Millennium Declaration of the United Nations, the reduction of poverty and hunger are now seen as central objectives of international development. Yet the modalities for attaining these goals are contested. Further, while it might be assumed that interventions that alleviate poverty will automatically reduce hunger, a number of studies of the relationship between income and the acquisition of food suggest that this assumption may be incorrect. This paper contributes to this debate through an analysis of a Mexican antipoverty program called PROGRESA (the Programa de Educacion, Salud y Alimentacion). PROGRESA provides cash transfers linked to children’s enrollment and regular school attendance and to clinic attendance. By 2000, it reached approximately 2.6 million families, about 40 percent of all rural families and about one-ninth of all families in Mexico. We use a longitudinal sample of approximately 24,000 households from 506 communities. A distinguishing characteristic of this sample was that communities were randomly selected for participation in PROGRESA, while the rest were introduced into the program at later phases. Exploiting this feature in our analysis, we find that households receiving PROGRESA benefits increased caloric acquisition compared to comparable households not receiving these benefits. By November 1999, beneficiary households in treatment localities obtained 7.1 percent more calories than did comparable households in control localities. Perhaps more significantly, we find that the impact is greatest on dietary quality as measured by the acquisition of calories from vegetable and animal products—a finding consistent with the view of respondents themselves that PROGRESA was enabling them to “eat better.”
Dilaton Dynamics from Production of Tensionless Membranes
Creators: name: Cremonini, Sera
name: Watson, Scott
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this paper we consider classical and quantum corrections to cosmological solutions of 11D SUGRA coming from dynamics of membrane states. We first consider the supermembrane spectrum following the approach of Russo and Tseytlin for consistent quantization. We calculate the production rate of BPS membrane bound states in a cosmological background and find that such effects are generically suppressed by the Planck scale, as expected. However, for a modified brane spectrum possessing enhanced symmetry, production can be finite and significant. We stress that this effect could not be anticipated given only a knowledge of the low-energy effective theory. Once on-shell, inclusion of these states leads to an attractive force pulling the dilaton towards a fixed point of S-duality, namely $g_s=1$. Although the SUGRA description breaks down in this regime, inclusion of the enhanced states suggests that the center of M-theory moduli space is a dynamical attractor. Morever, our results seem to suggest that string dynamics does indeed favor a vacuum near fixed points of duality.
description: 39 pages, 7 figures, minor corrections and reference added
The $P_{cs}(4459)$ pentaquark from a combined effective field theory and phenomenological perspective
Creators: name: Peng, Fang-Zheng
name: Yan, Mao-Jun
name: Sánchez, Mario Sánchez
name: Valderrama, Manuel Pavon
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The observation of the $P_{cs}(4459)$ by the LHCb collaboration adds a new member to the set of known hidden-charm pentaquarks, which includes the $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$. The $P_{cs}(4459)$ is expected to have the light-quark content of a $Λ$ baryon ($I=0$, $S=-1$), but its spin is unknown. Its closeness to the $\bar{D}^* Ξ_c$ threshold -- $4478\,{\rm MeV}$ in the isospin-symmetric limit -- suggests the molecular hypothesis as a plausible explanation for the $P_{cs}(4459)$. While in the absence of coupled-channel dynamics heavy-quark spin symmetry predicts the two spin-states of the $\bar{D}^* Ξ_c$ to be degenerate, power counting arguments indicate that the coupling with the nearby $\bar{D} Ξ_c'$ and $\bar{D} Ξ_c^*$ channels might be a leading order effect. This generates a hyperfine splitting in which the $J=\tfrac{3}{2}$ $\bar{D}^* Ξ_c$ pentaquark will be lighter than the $J=\tfrac{1}{2}$ configuration, which we estimate to be of the order of $5-15\,{\rm MeV}$. We also point out an accidental symmetry between the $P_{cs}(4459)$ and $P_c(4440/4457)$ potentials. Finally, we argue that the spectroscopy and the $J/ψΛ$ decays of the $P_{cs}(4459)$ might suggest a marginal preference for $J = \tfrac{3}{2}$ over $J = \tfrac{1}{2}$.
description: 16 pages, 1 figure; includes discussions on power counting, the J=1/2,3/2 hyperfine splitting, saturation, phenomenological relation between the Pcs(4459) and Pc(4440/4457) potentials, decay to $J/\psi \Lambda$, etc
EMPIRICAL MEASUREMENTS OF HOUSEHOLDS' ACCESS TO CREDIT AND CREDIT CONSTRAINTS IN DEVELOPING COUNTRIES: METHODOLOGICAL ISSUES AND EVIDENCE
Creators: name: Diagne, Aliou
name: Zeller, Manfred
name: Sharma, Manohar P.
name: Diagne, Aliou
name: Zeller, Manfred
name: Sharma, Manohar P.
Publisher: name: Unknown
Year: 2000
Subjects: Financial Economics

description: This paper presents a new methodological framework for measuring the level of household access to credit. It provides an analytical framework for examining the determinants of household credit limits and derives implications on information needed to examine the extent to which households are credit constrained. Empirical application of this method involves directly eliciting credit limit information in household surveys. Illustrations are provided using data from Bangladesh and Malawi.
Exactness of mean-field equations for open Dicke models with an application to pattern retrieval dynamics
Creators: name: Carollo, Federico
name: Lesanovsky, Igor
Publisher: name: arXiv
Year: 2020
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Open quantum Dicke models are paradigmatic systems for the investigation of light-matter interaction in out-of-equilibrium quantum settings. Albeit being structurally simple, these models can show intriguing physics. However, obtaining exact results on their dynamical behavior is challenging, since it requires the solution of a many-body quantum system, with several interacting continuous and discrete degrees of freedom. Here, we make a step forward in this direction by proving the validity of the mean-field semi-classical equations for open multimode Dicke models, which, to the best of our knowledge, so far has not been rigorously established. We exploit this result to show that open quantum multimode Dicke models can behave as associative memories, displaying a nonequilibrium phase transition towards a pattern-recognition phase.
description: 16 pages, 5 figures
THE CONSTRAINTS TO GOOD CHILD CARE PRACTICES IN ACCRA: IMPLICATIONS FOR PROGRAMS
Creators: name: Armar-Klemesu, Margaret
name: Ruel, Marie T.
name: Maxwell, Daniel G.
name: Levin, Carol E.
name: Morris, Saul Sutkover
name: Armar-Klemesu, Margaret
name: Ruel, Marie T.
name: Maxwell, Daniel G.
name: Levin, Carol E.
name: Morris, Saul Sutkover
Publisher: name: Unknown
Year: 2000
Subjects: Labor and Human Capital

description: Life in urban areas presents special challenges for maternal child care practices. Data from a representative survey of households with children less than 3 years of age in Accra were used to test a number of hypothesized constraints to child care, including various maternal (education, employment, marital status, age, health, ethnic group, migration status) and household-level factors (income, calorie availability, quality of housing and asset ownership, availability of services, household size, and crowding). An age-specific child care index was created using recall data on maternal child feeding practices and use of preventive health services. A hygiene index was created from spot check observations of proxies of hygiene behaviors. Multivariate analyses showed that maternal schooling was the most consistent constraint to both the care and the hygiene index. None of the household-level characteristics were associated with the care index, but better housing quality and access to garbage collection services were associated with better hygiene. Female head of household and larger family size were associated with poorer hygiene. The programmatic implications of these findings for nutrition education and behavior change interventions in Accra are discussed. The focus is on using the information to target the right practices to be modified as well as the main constraints to their adoption.
On Statistical Lensing and the Anti-Correlation Between 2dF QSOs and Foreground Galaxies
Creators: name: Myers, A. D.
name: Outram, P. J.
name: Shanks, T.
name: Boyle, B. J.
name: Croom, S. M.
name: Loaring, N. S.
name: Miller, L.
name: Smith, R. J.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We cross-correlate APM and SDSS galaxies with background QSOs from the 2dF QSO Redshift Survey, and detect a significant (2.8sigma) anti-correlation. The lack of a signal between 2dF stars and our galaxy samples suggests the anti-correlation is not due to a systematic error. The possibility that dust in the foreground galaxies could produce the anti-correlation is marginally rejected, at the 2sigma level through consideration of QSO colours. It is possible that dust that obscures QSOs without reddening them, or preferentially discards reddened QSOs from the 2QZ sample, could produce such an anti-correlation, however, such models are at odds with the positive QSO-galaxy correlations found at bright magnitudes by other authors. Our detection of a galaxy-QSO anti-correlation is consistent with statistical lensing theory. When combined with earlier results that have reported a positive galaxy-QSO correlation, a consistent, compelling picture emerges that spans faint and bright QSO samples showing positive or negative correlations according to the QSO N(m) slope. We find that galaxies are highly anti-biased on small scales. We consider two models that use different descriptions of the lensing matter and find they yield consistent predictions for the strength of galaxy bias on 0.1Mpc/h scales of b~0.1 (for LCDM). Whilst the slope of our power-law fit to the QSO-galaxy cross-correlation does not rule out linear bias, when we compare our measurement of b on 100 kpc/h scales to independent methods that determine b~1 on Mpc/h scales, we conclude that bias, on these small scales, is scale-dependent. These results indicate more mass, at least on the 100 kpc/h scales probed, than predicted by simple LCDM biasing prescriptions, and can thus constrain halo occupation models of the galaxy distribution.
description: 15 pages, 10 figures, accepted for publication in MNRAS
INCOME DIVERSIFICATION IN ZIMBABWE: WELFARE IMPLICATIONS FROM URBAN AND RURAL AREAS
Creators: name: Ersado, Lire
name: Ersado, Lire
Publisher: name: Unknown
Year: 2003
Subjects: Consumer/Household Economics

description: The paper examines, taking into account the urban-rural divides, the changes and welfare implications of income diversification in Zimbabwe following macroeconomic policy changes and droughts of the early 1990s. Data from two comparable national income, consumption, and expenditure surveys in 1990/91 and 1995/96 show that the percentage of households earning income from private and informal sources grew considerably while that from government and formal sources declined. In general, rural households tend to have a more diversified portfolio of income compared to urban and the degree of income diversification decreases with the level of urbanization. However, there are important differences in the level of diversification within the rural and urban areas, depending on wealth: while the relatively better-off households have a more diversified income base in rural areas, it is the poor that pursue multiple income sources in urban areas. A decomposition of changes in welfare indicates that the total contribution of income diversification is large and increased between 1990/91 and 1995/96 in both urban and rural areas. On the other hand, there were significant declines in returns to human and physical capital assets during the same period. The findings suggest that households with a more diversified income base are better able to withstand the unfavorable impacts of the policy changes and weather shocks. The fact that relatively better-off households have a more diversified income base following the shocks implies that the poor are more vulnerable to economic changes unaccompanied by well-designed safety nets.
Unifying the Fixed Order Evolution of Fragmentation Functions with the Modified Leading Logarithm Approximation
Creators: name: Albino, S.
name: Kniehl, B. A.
name: Kramer, G.
name: Ochs, W.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: An approach which unifies the Double Logarithmic Approximation at small x and the leading order DGLAP evolution of fragmentation functions at large x is presented. This approach reproduces exactly the Modified Leading Logarithm Approximation, but is more complete due to the degrees of freedom given to the quark sector and the inclusion of the fixed order terms. We find that data from the largest x values to the peak region can be better fitted than with other approaches.
Kiaeroceras undefined-A
Creators: name: Kröger, Björn
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Mollusca
Cephalopoda
Cyrtogomphoceratidae
Kiaeroceras
Kiaeroceras undefined-A

description: Kiaeroceras sp. A
Fig. 40A, D
Material examined
ESTONIA • 1 spec.; Hiumaa Island, Kõrgessaare quarry; Kõrgessaare Formation, Vormsi Regional Stage; TUG 895-69.
Description
The specimen is a fragment of a mature body chamber and phragmocone. The conch height and width at the base of the body chamber are 41 mm and 37 mm, respectively (CHI = 1.1). The conch is nearly straight. The conch cross section is elliptical. The length of the body chamber is not fully preserved, it was longer than 37 mm. In lateral view, margins of the body chamber are slightly convex; the body chamber reaches its greatest height of 42 mm ca 23 mm from the base. At the base of the body chamber, a ca 3 mm thin band of oncomyarian muscle scars is preserved. Five chambers of the phragmocone are preserved, indicating a low angle of expansion, which cannot be measured because of the incomplete preservation. Septal crowding of the adoral-most septa indicates maturity of the specimen. The sutures form very shallow lateral lobes. The siphuncle is located close to the conch margin and expands between the septal foramens toward a width of ca 5 mm. The width of the septal foramen is ca 4 mm where the conch height is 38 mm (RSH = 0.11, RSS = 1.25), and the septal distance is 5 mm (RCL = 0.13, SCR = 1).
Remarks
This fragment differs from K. kaebliki sp. nov. in its larger in adult size, and less compressed, more equally rounded conch cross section.
description: Published as part of Kröger, Björn, 2025, The Lyckholm acme of cephalopods - Review of the late Katian (Vormsi-Pirgu regional stages) Ordovician cephalopods of Estonia, pp. 1-169 in European Journal of Taxonomy 978 on page 111, DOI: 10.5852/ejt.2025.978.2801, http://zenodo.org/record/14988376
Numbers, Distribution, Composition, and Employment Status of the Farm Labor Group in the United States
Creators: name: Ham, William T.
name: Folsom, Josiah C.
Publisher: name: Unknown
Year: 1940
Subjects: Labor and Human Capital

description: Tables and charts presented at the hearings before the Subcommittee on Senate Resolution 266 (74th Congress), of the Senate Committee on Education and Labor, May 8, 1940, by William T. Ham, in charge of Labor and Tenancy Studies, and Josiah C. Folsom, Associate Agricultural Economist, Division of Farm Population and Rural Welfare.
Baur, Jörg / Goppelt, Leonhard / u.a., Die Verantwortung der Kirche in der Gesellschaft
Creators: name: Boeckler, Richard
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 22 Nr. 3 (1973): Ökumenische Rundschau, Band 22, Heft 3
Local fringe frequency estimation in synthetic aperture radar interferograms using a multiband pre-filtering approach
Creators: name: Perea-Vega, Diego E.
Publisher: name: University of British Columbia
Year: 2009

description: Synthetic aperture radar (SAR) interferometry is a technique for obtaining accurate elevation maps of the Earth from radar images. Local fringe frequency estimates are needed in several stages of the interferometry process. They are used to correct the effect of the topographic slope in the estimation of the interferogram coherence. They are needed to define the frequency center for adaptive band-pass filtering or to model the local phase in slope-correction filtering. Finally, accurate fringe frequency estimates facilitate the phase unwrapping process. In this work, I propose a new algorithm for local fringe frequency estimation in which the SAR interferogram signal is pre-filtered before the local frequency estimation is performed. This allows the use of a simpler and more efficient frequency estimator that operates at the pixel level. The proposed scheme shows advantages over other schemes because it achieves a better spacefrequency resolution and therefore tracks the topographic changes of the scene more accurately. The filters used in this work are modulated Gaussian functions with variable spatial aperture and bandwidth. In this way, the analysis window is adapted to the local characteristics of the signal at all samples. The variable-aperture filters are similar to the variable space-frequency domain filters used in wavelet analysis. I present results for synthetic and real SAR interferograms, as well as the performance of the proposed algorithm. An application of the frequency estimation method is developed for the noise filtering stage. A non-linear phase model is built to locally flatten the phase allowing the averaging of a higher number of samples without significant distortion. Simulations show that this alternative method achieves a better performance than two other reported methods when the interferogram coherence is moderately high. However, the alternative method does not solve the problem of phase discontinuities in the presence of topographically induced residues.
QUALITY OR QUANTITY? THE SUPPLY-SIDE DETERMINANTS OF PRIMARY SCHOOLING IN RURAL MOZAMBIQUE
Creators: name: Handa, Sudhanshu
name: Simler, Kenneth R.
name: Handa, Sudhanshu
name: Simler, Kenneth R.
Publisher: name: Unknown
Year: 2000
Subjects: Labor and Human Capital

description: The role of school quality in determining educational outcomes has received much research attention in the United States. However, in developing countries, where a significant part of the school age population never attends school, policymakers must consider both quality and quantity when deciding how to maximize the impact of scarce investments. Acknowledging this difference in the policy environment in developing countries, this paper provides comparative estimates of the impact of quality versus quantity investments in school supply in rural Mozambique, one of the world’s poorest countries. Policy simulations show that improving school quality (through the pupil-teacher ratio) increases grade attainment and efficiency by approximately 9 percent with no impact on overall enrollment rates. However, these same results can be generated by increasing starting enrollment probabilities through the establishment of new schools in all rural villages that currently do not have schools. Furthermore, similar rates of increase in school achievement indicators can be achieved by building schools in only 56 percent of all villages currently without schools, provided these schools are placed in those villages that also do not have a school nearby. When cost information is considered, the main policy implication is that the expansion of school quantity through well-targeted placement of new schools will provide the greatest increase in educational outcomes for Mozambique at this time.
Topological mass generation in gapless systems
Creators: name: Yamamoto, Naoki
name: Yokokura, Ryo
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Mass generation of gauge fields can be universally described by topological couplings in gapped systems, such as the Abelian Higgs model in $(3+1)$ dimensions and the Maxwell-Chern-Simons theory in $(2+1)$ dimensions. These systems also exhibit the spontaneous breaking of higher-form $\mathbb{Z}_k$ symmetries and topological orders for level $k \geq 2$. In this paper, we consider topological mass generation in gapless systems. As a paradigmatic example, we study the axion electrodynamics with level $k$ in $(3+1)$ dimensions in background fields that hosts both gapped and gapless modes. We argue that the gapped mode is related to those in fully gapped systems in lower dimensions via dimensional reduction. We show that this system exhibits the spontaneous breaking of a higher-form $\mathbb{Z}_k$ symmetry despite the absence of the conventional topological order. In the case of the background magnetic field, we also derive the low-energy effective theory of the gapless mode with the quadratic dispersion relation and show that it satisfies the chiral anomaly matching.
description: 30 pages; v2: minor errors corrected, references added, published version
On the role of interactions in trans-sonically flowing atomic condensates
Creators: name: Tettamanti, Manuele
name: Carusotto, Iacopo
name: Parola, Alberto
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We provide a joint numerical-analytical study of the physics of a flowing atomic Bose-Einstein condensate in the combined presence of an external trap and a step potential which accelerates the atoms out of the condensate creating a pair of neighbouring black- and white- hole horizons. In particular, we focus on the rapidly growing density modulation pattern that appears in the supersonic region, an experimentally observed feature that was related to black-hole lasing phenomena. A direct assessment of the role of interactions in this process suggests an interpretation of the experimental data in terms of linear interference of atomic waves rather than collective effects. Our conclusions are further supported by an analytical solution of the Schrodinger equation in terms of Airy wavefunctions.
description: 10 pages, 5 figures. This version matches the published version
Health threat from cosmic radiation during a manned mission to Mars
Creators: name: Bloshenko, Alexandra D
name: Robinson, Jasmin M.
name: Colon, Rafael A.
name: Anchordoqui, Luis A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Popular Physics (physics.pop-ph)
subject: FOS: Physical sciences

description: Cosmic radiation is a critical factor for astronauts' safety in the context of evaluating the prospect of future space exploration. The Radiation Assessment Detector (RAD) on board the Curiosity Rover launched by the Mars Scientific Laboratory mission collected valuable data to model the energetic particle radiation environment inside a spacecraft during travel from Earth to Mars, and is currently doing the same on the surface of Mars itself. The Martian Radiation Experiment (MARIE) on board the Mars Odyssey satellite provides estimates of the absorbed radiation dose in the Martian orbit, which are predicted to be similar to the radiation dose on Mars' surface. In combination, these data provide a reliable assessment of the radiation hazards for a manned mission to Mars. Using data from RAD and MARIE we reexamine the risks for a crew on a manned flight to Mars and discuss recent developments in space exploration.
description: In Proceedings of the 37th International Cosmic Ray Conference ICRC2021, Berlin
Eguchi-Hanson Solitons in Odd Dimensions
Creators: name: Clarkson, R.
name: Mann, R. B.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present a new class of solutions in odd dimensions to Einstein's equations containing either a positive or negative cosmological constant. These solutions resemble the even-dimensional Eguchi-Hanson-(A)dS metrics, with the added feature of having Lorentzian signatures. They are asymptotic to (A)dS$_{d+1}/Z_p$. In the AdS case their energy is negative relative to that of pure AdS. We present perturbative evidence in 5 dimensions that such metrics are the states of lowest energy in their asymptotic class, and present a conjecture that this is generally true for all such metrics. In the dS case these solutions have a cosmological horizon. We show that their mass at future infinity is less than that of pure dS.
description: 26 pages, Latex
WEIGHING WHAT'S PRACTICAL: PROXY MEANS TESTS FOR TARGETING FOOD SUBSIDIES IN EGYPT
Creators: name: Ahmed, Akhter U.
name: Bouis, Howarth E.
name: Ahmed, Akhter U.
name: Bouis, Howarth E.
Publisher: name: Unknown
Year: 2002
Subjects: Food Security and Poverty

description: Despite achieving a significant cost reduction over the past two decades, the absolute cost of food subsidies in Egypt is still high relative to the benefits received by the poor. There is scope for better targeting food subsidies, in particular those for rationed cooking oil and sugar, both because reforms in this area are perceived to be far less politically sensitive than adjusting subsidy policies for bread and wheat flour and because higher income groups presently receive a significant percentage of the benefits. Targeting the high-subsidy green ration cards to the poor and the low-subsidy red ration cards to the nonpoor will require identification of both poor and nonpoor households. An International Food Policy Research Institute (IFPRI) research team in Egypt, in collaboration with the Egyptian Ministry of Trade and Supply, developed a proxy means test for targeting ration cards. This paper describes the process of moving from the optimal income-predicting model to the final model that was both administratively and politically feasible. An ex-ante evaluation of the levels of accuracy of the proxy means testing model indicates that the model performs quite well in predicting the needy and nonneedy households. An effective and full implementation of this targeting method would increase the equity in the ration card food subsidy system and, at the same time, lower the total budgetary costs of rationed food subsidies. Moreover, the experience gained under this reform would facilitate targeting future social interventions to reduce and prevent poverty in Egypt.
Phase-lag predicts nonlinear response maxima in liquid-sloshing experiments
Creators: name: Bäuerlein, Bastian
name: Avila, Kerstin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: Mass-spring models are essential for the description of sloshing resonances in engineering. By experimentally measuring the liquid's centre of mass in a horizontally oscillated rectangular tank, we show that low-amplitude sloshing obeys the Duffing equation. A bending of the response curve in analogy to a softening spring is observed, with growing hysteresis as the driving amplitude increases. At large amplitudes, complex wave patterns emerge (including wave-breaking and run up at the tank walls), competition between flow states is observed and the dynamics departs progressively from Duffing. We also provide a quantitative comparison of wave shapes and response curves to the predictions of a multimodal model based on potential flow theory (Faltinsen & Timokha 2009) and show that it systematically overestimates the sloshing amplitudes and the hysteresis. We find that the phase-lag between the liquid's centre of mass and the forcing is the key predictor of the nonlinear response maxima. The phase-lag reflects precisely the onset of deviations from Duffing dynamics and - most importantly - at resonance the sloshing motion always lags the driving by 90° (independently of the wave pattern). This confirms the theoretical 90°-phase-lag criterion (Cenedese & Haller 2020).
description: 29 pages, 15 figures; [v3]: accepted version in Journal of Fluid Mechanics; minor revision in {\S}8 [v2]: some structure changes; added comparison to multimodal modal from Faltinsen & Timokha 2009 in {\S}5, {\S}7.2 & appendix; new chapter {\S}8
Práticas acadêmico-pedagógica em tecnologias digitais com os docentes cariocas
Creators: name: Villas, Bruna
Publisher: name: Zenodo
Year: 2024

description: Este trabalho tem como objetivo desenvolver e propor um plano pedagógico para treinar e orientar professores cariocas em tecnologias digitais, a fim de potencializar seu trabalho em sala de aula e engajar seus alunos por meio de atividades e linguagem tecnológica. A utilização frequente de tecnologias educacionais permite ao professor maior familiaridade e agilidade com outras ferramentas pedagógicas, ampliando o uso desses recursos em outras atividades acadêmicas. Dessa forma, este trabalho busca contribuir para o desenvolvimento das habilidades dos docentes da rede pública e promover aulas com o uso de tecnologia.
Flavors of Astrophysical Neutrinos with Active-Sterile Mixing
Creators: name: Ahlers, Markus
name: Bustamante, Mauricio
name: Willesen, Niels Gustav Nortvig
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We revisit the flavor composition of high-energy astrophysical neutrinos observed at neutrino telescopes. Assuming unitary time evolution of the neutrino flavor states, the flavor composition observable at Earth is related to the initial composition at their sources via oscillation-averaged flavor transitions. In a previous study we derived general bounds on the flavor composition of TeV-PeV astrophysical neutrinos assuming three-flavor unitary mixing. We extend these bounds to the case of active-sterile neutrino mixing. Our bounds are analytical, derived based only on the unitarity of the mixing, and do not require sampling over the values of the unknown active-sterile mixing parameters. These bounds apply to any extended active-sterile neutrino mixing scenario where energy-dependent nonstandard flavor mixing dominates over the standard mixing observed in accelerator, reactor, and atmospheric neutrino oscillations.
description: 10+7 pages, 4 figures, extended version accepted for publication in JCAP
Algorithms for linear time reconstruction by discrete tomography II
Creators: name: Ceko, Matthew
name: Pagani, Silvia M. C.
name: Tijdeman, Rob
Publisher: name: arXiv
Year: 2020
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 68R05 (Primary) 52C05 (Secondary)

description: The reconstruction of an unknown function $f$ from its line sums is the aim of discrete tomography. However, two main aspects prevent reconstruction from being an easy task. In general, many solutions are allowed due to the presence of the switching functions. Even when uniqueness conditions are available, results about the NP-hardness of reconstruction algorithms make their implementation inefficient when the values of $f$ are in certain sets. We show that this is not the case when $f$ takes values in a field or a unique factorization domain, such as $\R$ or $\Z$. We present a linear time reconstruction algorithm (in the number of directions and in the size of the grid), which outputs the original function values for all points outside of the switching domains. Freely chosen values are assigned to the other points, namely, those with ambiguities. Examples are provided.
description: 26 pages, 7 figures, accepetd for publication in Discrete Applied Mathematics
Quantum Monte Carlo Study of Strongly Correlated Electrons: Cellular Dynamical Mean-Field Theory
Creators: name: Kyung, B.
name: Kotliar, G.
name: Tremblay, A. -M. S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We study the Hubbard model using the Cellular Dynamical Mean-Field Theory (CDMFT) with quantum Monte Carlo (QMC) simulations. We present the algorithmic details of CDMFT with the Hirsch-Fye QMC method for the solution of the self-consistently embedded quantum cluster problem. We use the one- and two-dimensional half-filled Hubbard model to gauge the performance of CDMFT+QMC particularly for small clusters by comparing with the exact results and also with other quantum cluster methods. We calculate single-particle Green's functions and self-energies on small clusters to study their size dependence in one- and two-dimensions.
description: 14 pages, 18 figures