MULTIDIMENSIONAL OUTPUT INDICES

This abstract describes alternative output aggregates that provide both cross-sectional and temporal comparisons appropriate for the analysis of panel data sets. Several of these multidimensional output indices are constructed using detailed data on agricultural production to illustrate the effects of fixing price weights over time, employing sample average price weights, and choosing between alternative approximations of Divisia indices.Research Methods/ Statistical Methods,

PATTERNS OF AGRICULTURAL DEVELOPMENT IN THE UNITED STATES

International Development,

U.S. AGRICULTURAL RESEARCH DEFLATORS: 1890-1985

Using newly developed time series on U.S. public sector agricultural research expenditures, two new deflators for agricultural research are constructed. These deflators differ from others currently used in the literature in that factor level price indices are weighted with time varying weights which capture the shifting factor mix of research spending by the state agricultural experiment stations (SAES). The substantial differences in measuring real resource allocation to agricultural research using these deflators and alternatives found in the literature, including that used by the National Science Foundation to report official R&D statistics, are demonstrated. In addition, the factor level expenditure series are used to contrast measurement of resource allocation in agricultural research from 1890 to the present using real research service flows as opposed to real research expenditures.Research and Development/Tech Change/Emerging Technologies,

INTERNATIONAL AGRICULTURAL PRODUCTIVITY PATTERNS

In this paper we present measures of land and labor productivity for a group of 98 developed and developing countries using an entirely new data set with annual observations spanning the past three decades. The substantial cross-country and intertemporal variation in productivity in our sample is linked to both natural and economic factors. We extend previous work by dealing with multiple sources of measurement error in conventional agricultural inputs when accounting for observed differences in productivity. In addition to the mix of conventional inputs in agriculture, we find that indicators of quality change in these inputs and the amount of publicly provided infrastructure are significant in explaining cross-sectional differences in productivity patterns.Productivity Analysis,

Agricultural science policy

Technological advances developed through R&D have supplied the world with not only more food, but better food. This report looks at issues raised by this changing environment for agricultural productivity, agricultural R&D, and natural resource management.Agriculture and state ,

Research returns redux: a meta-analysis of the returns to agricultural R&D

A total of 294 studies of returns to agricultural R&D (including extension) were compiled and these studies provide 1,858 separate estimates of rates of return. This includes some extreme values, which are implausible. When the highest and lowest 2.5 percent of the rates of return were set aside, the estimated annual rates of return averaged 73 percent overall–88 percent for research only, 45 percent for research and extension, and 79 percent for extension only. But these averages reveal little meaningful information from a large and diverse body of literature, which provides rate-of-return estimates that are often not directly comparable. The purpose of this study was to go behind the averages, and try to account for the sources of differences, in a meta-analysis of the studies of returns to agricultural R&D. The results conform with the theory and prior beliefs in many ways. Several features of the methods used by research evaluators matter, in particular assumptions about lag lengths and the nature of the research-induced supply shift.Rate of return., Agricultural research.,

A meta-analysis of rates of return to agricultural R & D: ex pede Herculem?

IFPRI has long argued that spending on agricultural research constitutes a sound investment in poverty reduction and agricultural and economic growth, through improvements in productivity. This argument is based partly on the reported evidence of high rates of return to agricultural research, typically believed to be in the range of 40–60 percent per year. Yet there continues to be controversy over whether these figures are to be believed, and over what they actually indicate. This study represents the first attempt to take a comprehensive look at all the available evidence on rates of return to investments in agricultural R&D since 1953, and the only attempt to do so in a formal statistical fashion. This report has compiled and documented the literature in ways that make it more accessible and more useful to other researchers and policymakers, as well as others interested in the evidence. The analysis reveals some systematic patterns and some sources of biases that make it easier to interpret the evidence and draw meaningful conclusions. (Excerpted from Summary by Per Pinstrup-Andersen)Development projects Evaluation., Agricultural research, Statistics., Agricultural economics and policies,

SOFHIA: a CAD environment to design digital control systems

"Series Title: IFIP - The International Federation for Information Processing, ISSN 1868-4238"Petri Nets (PNs) prove to be an e cient methodology to model discrete-event systems with parallel activities. The main advantages lie on the graphical interface and on the availability of a set of techniques for formal analysis, including the validation and the test of the modelled system. A proposal to modify the normal PN behaviour is presented, which aims a fast speci cation of synchronous parallel digital systems, including both the data path and the control unit. A CAD environment, SOFHIA, was developed to model digital systems, to validate their properties and to simulate their behaviour. The environment includes the automatic generation of VHDL code to allow simulation and synthesis on existing CAD tools

A Map-Reduce Parallel Approach to Automatic Synthesis of Control Software

Many Control Systems are indeed Software Based Control Systems, i.e. control systems whose controller consists of control software running on a microcontroller device. This motivates investigation on Formal Model Based Design approaches for automatic synthesis of control software. Available algorithms and tools (e.g., QKS) may require weeks or even months of computation to synthesize control software for large-size systems. This motivates search for parallel algorithms for control software synthesis. In this paper, we present a Map-Reduce style parallel algorithm for control software synthesis when the controlled system (plant) is modeled as discrete time linear hybrid system. Furthermore we present an MPI-based implementation PQKS of our algorithm. To the best of our knowledge, this is the first parallel approach for control software synthesis. We experimentally show effectiveness of PQKS on two classical control synthesis problems: the inverted pendulum and the multi-input buck DC/DC converter. Experiments show that PQKS efficiency is above 65%. As an example, PQKS requires about 16 hours to complete the synthesis of control software for the pendulum on a cluster with 60 processors, instead of the 25 days needed by the sequential algorithm in QKS.Comment: To be submitted to TACAS 2013. arXiv admin note: substantial text overlap with arXiv:1207.4474, arXiv:1207.409

Analysis of periosteal lesions from commingled human remains at the Xagħra Circle hypogeum reveals the first case of probable scurvy from Neolithic Malta

Abstract Objectives Palaeopathological analysis is key for characterising population health at the individual level and across large assemblages but is rarely exploited to unite the remains of disarticulated individuals. This study explores the potential for individual identification through differential diagnosis of periosteal lesions in a commingled deposit, both to ascertain the number of individuals represented and provide a differential diagnosis. Materials and Methods The late Neolithic Xag?ra Circle hypogeum on Gozo contains the remains of more than 800 individuals, most of which were transformed to a collective disarticulated assemblage. Across the excavated population, pathological observations are strikingly low. In one specific 1???1-m area in a single stratigraphic context, fragmented and disarticulated cranial and post-cranial non-adult bones were identified that displayed periosteal new bone formation. To aid differential diagnosis, macroscopic analysis, taphonomic analysis and micro-computed tomography (?CT) imaging were integrated. Results This approach, when combined with osteobiographical analyses, reveals that the elements most likely derive from one individual, a young child, who presents a probable case of scurvy. The potential for micronutrient co-morbidities are explored, but without further microscopic study it cannot be determined if this individual also experienced iron-deficiency anaemia and/or rickets. Discussion In the context of the Mediterranean and Europe in later prehistory, reported cases of scurvy are currently low and often reveal periods of environmental instability and resource insufficiency. Our finding of non-adult scurvy in late 3rd millennium BC Malta contributes to a developing picture of an increasingly unstable palaeoenvironment and declining population health at this time, although it may also indicate an individual case of poor childhood health within this broader context.1 Introduction 1.1 Archaeological context of the Xagħra Circle hypogeum 2 Materials and methods 2.1 Remains presenting periosteal lesions 2.2 Macroscopic and micro-CT analysis 3 Macroscopic and radiological observations of pathology 3.1 Frontal bone (FB0039, FB0040) and zygoma (FB0041) 3.2 Mandible (FB0042) 3.3 Left rib (FB0043) and right rib (FB0044) 3.4 Ulna (FB0045) 4 Differential diagnosis 4.1 Frontal bone (FB0039, FB0040) and zygoma (FB0041) 4.2 Mandible (FB0042) 4.3 Left rib (FB0043) and right rib (FB0044) 4.4 Ulna (FB0045) 5 Discussion 5.1 Scurvy: Causes, consequences and comorbidities 5.2 Scurvy in prehistory 5.3 The Maltese context 6 Conclusio