Cuantificación de los flujos de asistencia: un nuevo enfoque

(Disponible en idioma inglés únicamente) La discusión sobre la eficacia de la asistencia externa se ha intensificado en los últimos años, en la medida en que la asistencia ha venido experimentando cada vez más presiones presupuestarias en los países donantes. Independientemente de los méritos de los argumentos en contra, el problema de fondo surge de si las medidas de asistencia que se emplean convencionalmente, tales como la ODA, que agrupa las donaciones y los préstamos, reflejan con precisión los flujos de asistencia reales. En este trabajo se analizan las deficiencias metodológicas de las medidas convencionales de la asistencia y se propone un nuevo enfoque de valoración que cuantifique los flujos de asistencia oficial como la suma de las donaciones y los equivalentes de donaciones de los préstamos oficiales. Esta medición de la asistencia, conceptualmente superior, puede distanciarse considerablemente de los agregados convencionales y dar una idea muy distinta de las principales tendencias de la asistencia.

Measuring aid flows : a new approach

Debate about the effectiveness of foreign aid has intensified in recent years, as budgetary pressures on aid have increased in donor countries. Whatever the merits of opposing arguments, the question is: do conventional measures of aid (such as OECD's Net ODA), which lump together grants and loans, accurately reflect true aid flows? The authors analyze the methodological shortcomings of conventional measures of aid and propose a new approach, which measures official aid flows as the sum of grants and the grant-equivalents of official loans (in a new aggregate they call"Effective Development Assistance,"or EDA). They show how results using this conceptually superior measure may differ significantly from conventional aggregates, providing a quite different view on major aid trends. They implement their approach empirically using data on some 40,000 official loans from the World Bank's DRS database--virtually all of the official loans to 133 developing countries from 1975 to 1995. The numerical results underscore several points: 1) The conventional approach has led to systematic overestimates of the concessionality of official loans. This overestimate has increased significantly since the mid-1980s. Conventional methods show a rising trend; the new method shows the opposite. 2) Net ODA increasingly overstates the true aid content of official flows, although the divergence between the two approaches is somewhat muted by the rising relative importance of grants over loans in total official flows.Strategic Debt Management,Economic Adjustment and Lending,Banks&Banking Reform,Payment Systems&Infrastructure,Economic Theory&Research,Economic Adjustment and Lending,Banks&Banking Reform,Strategic Debt Management,Economic Theory&Research,Payment Systems&Infrastructure

Architecture of the Short External Rotator Muscles of the Hip.

BackgroundMuscle architecture, or the arrangement of sarcomeres and fibers within muscles, defines functional capacity. There are limited data that provide an understanding of hip short external rotator muscle architecture. The purpose of this study was thus to characterize the architecture of these small hip muscles.MethodsEight muscles from 10 independent human cadaver hips were used in this study (n = 80 muscles). Architectural measurements were made on pectineus, piriformis, gemelli, obturators, quadratus femoris, and gluteus minimus. Muscle mass, fiber length, sarcomere length, and pennation angle were used to calculate the normalized muscle fiber length, which defines excursion, and physiological cross-sectional area (PCSA), which defines force-producing capacity.ResultsGluteus minimus had the largest PCSA (8.29 cm2) followed by obturator externus (4.54 cm2), whereas superior gemellus had the smallest PCSA (0.68 cm2). Fiber lengths clustered into long (pectineus - 10.38 cm and gluteus minimus - 10.30 cm), moderate (obturator internus - 8.77 cm and externus - 8.04 cm), or short (inferior gemellus - 5.64 and superior gemellus - 4.85). There were no significant differences among muscles in pennation angle which were all nearly zero. When the gemelli and obturators were considered as a single functional unit, their collective PCSA (10.00 cm2) exceeded that of gluteus minimus as a substantial force-producing group.ConclusionsThe key findings are that these muscles have relatively small individual PCSAs, short fiber lengths, and low pennation angles. The large collective PCSA and short fiber lengths of the gemelli and obturators suggest that they primarily play a stabilizing role rather than a joint rotating role

A Statistical Comparison of Zonal Mean and Tidal Signatures in FORMOSAT-3/COSMIC and Ground-Based GPS TECs

Atmospheric tidal components in the ionosphere can reflect either the in-situ generated quiet-time variation in the ionosphere, or vertically propagating tidal components generated through coupling to lower or middle atmosphere phenomena. Frequency-wavenumber tidal decomposition is a valuable tool for isolating the primary tidal components that drive the dynamics of the middle and upper atmosphere, allowing temporal and spatial variability to be quantified in a systematic manner, provided sufficient local time sampling. To date, two commonly used data sources for such tidal studies in the ionosphere are the FORMOSAT-3/COSMIC (F3/C) satellite constellation and ground-based GPS-derived Global Ionosphere Maps (GIMs). In this study, the migrating diurnal and semidiurnal tidal components, the nonmigrating diurnal eastward 3 (DE3) component, as well as the zonal mean component that dominate quiet-time ionospheric variability are extracted from 2008 F3/C and GIM Total Electron Content (TEC) data, using integration times of 20 days. We find that the zonal mean and tidal TEC components in F3/C and ground-based GIM data show qualitatively similar seasonal variability and spatial structure. However, the maximum amplitudes of the zonal mean and migrating tidal components computed from F3/C are consistently smaller than those from the ground-based GIMs, revealing a systematic difference between the two datasets. Conversely, the DE3 amplitudes are generally larger in F3/C compared to GIM, potentially due to the higher zonal wavenumber of that component

Evaluating Firm-Level Expected-Return Proxies

We develop and implement a rigorous analytical framework for empirically evaluating the relative performance of firm-level expected-return proxies (ERPs). We show that superior proxies should closely track true expected returns both cross-sectionally and over time (that is, the proxies should exhibit lower measurement-error variances). We then compare five classes of ERPs nominated in recent studies to demonstrate how researchers can easily implement our two-dimensional evaluative framework. Our empirical analyses document a tradeoff between time-series and cross-sectional ERP performance, indicating the optimal choice of proxy may vary across research settings. Our results illustrate how researchers can use our framework to critically evaluate and compare a growing body of ERPs

Processes for removing acid components from gas streams

The present disclosure relates to improved processes for treating acid gases to remove acid gas components therefrom. Processes in accordance with the present invention include preparing a calcium silicate hydrate sorbent in the form of a semi-dry, free-flowing powder, and treating the gas with the powdery sorbent, such as by injecting the sorbent into a stream of the gas. The powdery sorbents may be prepared by slurrying/drying or pressure hydration techniques. Examples disclosed herein demonstrate the utility of these processes in achieving improved acid gas-absorbing capabilities in both lab-scale and pilot plant studies. Additionally, disclosure is provided which illustrates preferred plant design configurations for employing the present processes using conventional dry sorbent injection equipment. Retrofit application to existing plants is also addressed.Board of Regents, University of Texas Syste

Inhibition in multiclass classification

The role of inhibition is investigated in a multiclass support vector machine formalism inspired by the brain structure of insects. The so-called mushroom bodies have a set of output neurons, or classification functions, that compete with each other to encode a particular input. Strongly active output neurons depress or inhibit the remaining outputs without knowing which is correct or incorrect. Accordingly, we propose to use a classification function that embodies unselective inhibition and train it in the large margin classifier framework. Inhibition leads to more robust classifiers in the sense that they perform better on larger areas of appropriate hyperparameters when assessed with leave-one-out strategies. We also show that the classifier with inhibition is a tight bound to probabilistic exponential models and is Bayes consistent for 3-class problems. These properties make this approach useful for data sets with a limited number of labeled examples. For larger data sets, there is no significant comparative advantage to other multiclass SVM approaches

Spontaneous Symmetry Breaking at Infinite Momentum without P+ Zero-Modes

The nonrelativistic interpretation of quantum field theory achieved by quantization in an infinite momentum frame is spoiled by the inclusion of a mode of the field carrying p+=0. We therefore explore the viability of doing without such a mode in the context of spontaneous symmetry breaking (SSB), where its presence would seem to be most needed. We show that the physics of SSB in scalar quantum field theory in 1+1 space-time dimensions is accurately described without a zero-mode.Comment: LaTeX, 8 pages, 3 eps figure