bluuebunny/crossref_metadata_2025 huggingface dataset:
Policy and Management Work within International Agricultural Research
Authors: Anderson Jock R.
Published: March 2003

The diversity of players in the field of agricultural (and, more generally, rural) policy and management research is sketched in a global overview of relevant research resources, and the small but important part played by the CGIAR Centres in this is explored, particularly where it has maximum value in terms of international public goods, and for strategic links to other parts of the CGIAR portfolio. The patchy and often slender (and perhaps diminishing in specific cases) capacity of national agricultural policy research and analysis units in the less‐developed world to deliver the needed research products is examined.
Principles of Australian Quarantine
Authors: Tanner Carolyn
Published: March 2003

This article provides an overview of the report on Australia’s quarantine policies and procedures, Australian Quarantine. The Report proposes fundamental changes to Australia’s approach to quarantine and recommends: the development of a partnership between industry, governments and the general public; the establishment of a statutory authority to develop Australia’s quarantine policy and to ensure national delivery of quarantine services; acknowledgment of the importance of maintaining Australia’s unique natural environment; the need to redress the imbalance between the plant and animal sectors; development of a more formally structured process for conducting risk analyses; and expanding the scope of quarantine beyond the ‘barrier’ to cover pre‐border, border and post‐border activities.
Financing agricultural R&D in rich countries: what’s happening and why
Authors: Alston Julian M. , Pardey Philip G. , Smith Vincent H.
Published: March 2003

Governments everywhere are trimming their support for agricultural R&D, giving greater scrutiny to the support that they do provide, and reforming the public agencies that fund, oversee, and carry out the research. This represents a break from previous patterns, which had consisted of expansion in the public funds for agricultural R&D. Private‐sector spending on agricultural research has slowed along with the growth of public spending in recent years, but the balance continues to shift towards the private sector. This article presents a quantitative review of these funding trends and the considerable institutional changes that have accompanied them. We discuss new data for 22 OECD countries, providing institutional details for five of these countries, and conclude with an assessment of policy developments.
Greenhouse abatement policy: insights from the G‐cubed multi‐country model
Authors: McKibbin Warwick J.
Published: March 2003

The third meeting of the Conference of the Parties of the Framework Convention on Climate Change held in Japan last December was a lost opportunity to set a realistic policy framework for addressing climate change in the coming decades. A number of countries proposed targets for greenhouse emissions, to be reached by a target date. The outcome was a range of different targets for each country. Analysis with the G‐cubed multi‐country model suggests that fixed targets are a costly way to address climate change. The extent of potential cost suggests the agreement will eventually fail. A better way to address climate change is to focus on uniformity in policy instruments that deliver differentiated outcomes rather than focus on differentiated policy settings.
Lease allocation systems, risk aversion and the resource rent tax
Authors: Fraser Rob
Published: March 2003

This article examines the case of a risk‐averse mining firm facing a resource rent tax in order both to incorporate the role of the risk‐sharing quality of such a tax and to assess its implications given a government’s lease allocation system. The model develops the conditions required for an investment‐neutral RRT characterised by a threshold rate of return (r) and a rate of tax (t) and suggests that for an auction system of lease allocation, government revenue could be maximised by setting the tax rate below 100 per cent, but that for a discretionary system, it is in the government’s interest to introduce an RRT which is effectively rate‐of‐return regulation.
An economic evaluation of bushfire prevention and suppression
Authors: Bennetton Julia , Cashin Paul , Jones Darren , Soligo James
Published: March 2003

The Fire Management Program (FMP) of the Victorian Department of Natural Resources and Environment is responsible for the prevention and suppression of fires on public land in the State of Victoria. This article reports on an economic evaluation of the net benefits of these fire management activities for a representative year. The FMP is calculated to yield high net benefits to Victoria from its investment in fire suppression and prevention, through a reduction in the value of agricultural, capital and forest assets which would otherwise be lost to bushfires.
A quarter of a century of Australian agricultural economics — some personal reflections
Authors: Gruen Fred
Published: March 2003

The late Fred Gruen (1921–1997) was asked to write these previously unpublished reflections for the twenty‐eighth Annual Conference of the Australian Agricultural Economics Society in 1984; they were circulated in working paper format as Gruen (1986). In this paper, Fred, who made the transition from agricultural to general economics later in his career, offers a modest perspective on his contributions to agricultural analysis and policy. The unifying theme in this outstandingly productive life was his focus on public policy issues whose resolution would impact importantly on the lives of many — that is, his intellectual curiosity was driven ultimately by his philanthropy.
Impacts of risk aversion on whole‐farm management in Syria
Authors: Pannell David J. , Nordblom Thomas L.
Published: March 2003

This article reports on a study of the impact of risk on farm management practices in northern Syria, focusing particularly on how these are affected by risk aversion and farm size. The study is based on production data from an eight‐year field trial and on prices from market surveys. A large linear programming model is built, representing the eight years as observations from a discrete probability distribution. Risk aversion is modelled by inclusion of a utility function with constant relative risk aversion, represented using the DEMP/UEP approach.
Examining long‐run relationships between Australian beef prices
Authors: Chang Hui‐Shung (Christie) , Griffith Garry
Published: March 2003

Cointegration and impulse response analyses are used to investigate the short‐run and long‐run dynamics of the Australian beef market. The aim of this study is to determine whether long‐run relationships existed between Australian beef prices at the farm, wholesale and retail levels. Based on monthly data from 1971 to 1994, the results show that all three prices considered are cointegrated. Furthermore, the wholesale price is found to be weakly exogenous. The latter result might be an indication of market inefficiency due in part to price levelling often practised in the beef marketing system.
Attenuating indigenous property rights: land policy after the Wik decision
Authors: Godden David
Published: March 2003

In December 1996, the High Court of Australia handed down its judgement in the Wik case finding, by a 4:3 majority, that pastoral leases did not necessarily extinguish native title. An intense political campaign by both pastoral and indigenous interests, and their political representatives, was aimed, in the case of the former, at legislative extinguishment of native title on pastoral leases and, in the case of the latter, at defending property rights which the High Court found had never been extinguished. In this article it is argued that an efficient re‐allocation of property rights is unlikely to result from extinguishment, but requires Coasian‐type bargains between pastoral and indigenous interests.
Technological change and agricultural household income distribution: theory and evidence from China
Authors: Yifu Justin
Published: March 2003

This article applies a general equilibrium model to analyse the impact of new rice technology on household income and uses agricultural household survey data from China to test the implications of this model. It is shown that, when a new rice technology becomes available, the adopting household will reallocate resources to increase rice production and reduce the production of other goods. Meanwhile, the non‐adopting households will do the opposite. Thus, the income from rice becomes increasingly concentrated in the adopting households and income from non‐rice becomes increasingly concentrated in the non‐adopting households. If only one source of income is examined, the introduction of new rice technology increases the inequality of income distribution in rural areas. But, if the total household income is examined, the distributional inequality is mitigated.
How Different is Mining from Mineral Processing? A General Equilibrium Analysis of New Resources Projects in Western Australia
Authors: Qiang Ye
Published: March 2003

Western Australia has experienced an investment surge in the minerals sector of the economy in recent years. Unlike previous surges, this one involves a large proportion of mineral‐processing projects. In this study, the differential effects on the WA economy of 25 mining and 10 mineral‐processing projects are analysed using an economy‐wide model of WA. The results indicate that: (i) both the mining and mineral‐processing projects will have substantial flow‐on benefits to the WA economy as a whole; (ii) on an A$1‐million‐invested basis, mineral processing has larger flow‐on effects on employment and generates more export revenue than does mining once the projects are operational.
The Travel Cost Method: an Empirical Investigation of Randall’s Difficulty
Authors: Common M. , Bull T. , Stoeckl N.
Published: March 2003

Randall (1994) argued that the Travel Cost Method (TCM) cannot generate monetary measures of recreation site benefits for use in Cost Benefit Analysis. Randall argues that what is relevant to recreational decision‐making is the subjective, and unobservable, price of travel, whereas TCM uses the observer‐assessed cost of travel. Hence, TCM can at best give ordinally measurable welfare estimates. ‘Randall’s Difficulty’ is formulated as an estimation problem and results are derived for that problem. The meaning of, prospects for, and usefulness of ordinal measurement are explored, and the existence of a solution to Randall’s Difficulty is considered.
Imposing regularity conditions on a system of cost and factor share equations
Authors: Griffiths William E. , O’Donnell Christopher J. , Cruz Agustina Tan
Published: March 2003

Systems of equations comprising cost functions and first‐order derivative equations are often used to estimate characteristics of production technologies. Unfortunately, many estimated systems violate the regularity conditions implied by economic theory. Sampling theory methods can be used to impose these conditions globally, but these methods destroy the flexibility properties of most functional forms. We demonstrate how Bayesian methods can be used to maintain flexibility by imposing regularity conditions locally. The Bayesian approach is used to estimate a system of cost and share equations for the merino wool‐growing sector. The effect of local imposition of monotonicity and concavity on the signs and magnitudes of elasticities is examined.
The Government/Democrats’ package of changes in indirect taxes
Authors: Dixon Peter B. , Rimmer Maureen T.
Published: March 2003

Australia is faced with a comprehensive package of changes to its indirect tax system, including the introduction of a GST. The Government’s only quantitative analysis in formulating the package employed PRISMOD, an archaic input‐output price model. PRISMOD sheds dim light on a very limited range of policy‐relevant variables. This article explains how PRISMOD works; this is of continuing relevance because PRISMOD results are a benchmark in negotiations concerning the price effects of the tax package. Then an assessment of the package is made using MONASH, a comprehensive dynamic general equilibrium model. Overall, the conclusions are negative: the package is welfare‐reducing and unnecessary.
Dichotomous choice contingent valuation probability distributions
Authors: Kerr Geoffrey N.
Published: March 2003

Parametric distributions applied to dichotomous choice contingent valuation data invoke assumptions about the distribution of willingness to pay that may contravene economic theory. This article develops and applies distributions that allow the shape of bid distributions to vary. Alternative distributions provide little, if any, improvement in statistical fit from commonly used distributions. While median willingness to pay is largely invariant to distribution, estimates of mean consumer surplus diverge widely. Sensitivity analysis to determine benefit measure response to distributional assumptions is essential to prevent erroneous policy advice from applied dichotomous choice research.
Water markets as a vehicle for water reform: the case of New South Wales
Authors: Crase Lin , O’Reilly Leo , Dollery Brian
Published: March 2003

Water reform in NSW is being undertaken using an adaptive approach in recognition of the uncertainty and imperfect knowledge embodied in the riverine environment. However, the reform process also relies, in part, on the ability of markets for tradable water entitlements to develop and thereby assist in allocating scarce water resources to their highest value use. This article explores impediments to the formation of efficient markets in permanent tradable water entitlements in NSW. The article concludes that more attention should be paid to market failures and related problems which manifest themselves in thin markets for permanent water entitlements.
Competition in the food marketing chain
Authors: Griffith Garry
Published: March 2003

Competition in the Australian food marketing chain is of continuing concern, but little evidence is available to guide policy debate. In a search for broad guidelines, the theoretical and empirical evidence is reviewed and the recent report of the Joint Select Committee on the Retailing Sector is examined. Then publicly available data on several food groups are used to test for evidence of persistent market power. The purchasing behaviour of the grains and oilseeds processing sector is found to warrant more detailed attention. A possible research agenda and a call for greater attention to data requirements complete the article.
The impact of the Asian Crisis on Australia’s primary exports: why it wasn’t so bad
Authors: Duncan Ron , Yang Yongzheng
Published: March 2003

This article explores the modest impact of the Asian Crisis on Australia’s primary commodity exports. Simulations using a global general equilibrium model show: (i) as capital flees Asia, investment in Australia increases and the trade deficit grows; (ii) while terms of trade deteriorate in the short run, they improve in the medium run as import demand increases in the crisis countries; (iii) exports of primary commodities expand as the crisis countries try to export more; (iv) more income‐elastic primary commodities fare less well than the income‐inelastic foodstuffs as incomes decline in the crisis countries; (v) Australia’s relatively low dependence on manufactured exports was a buffer as manufactured exports came under heavy pressure from exports from the crisis countries.
Future developments in global livestock and grains markets: the impacts of livestock productivity convergence in Asia‐Pacific
Authors: Rae Allan N. , Hertel Thomas W.
Published: March 2003

Increasing livestock product consumption in many Asian countries has been accompanied by growth in some countries’ imports of feedgrains for their domestic livestock sectors. This contributes to debate over future levels of grain imports. Yet projections often pay little attention to developments in livestock production. The impacts of technological catch‐up in livestock production on trade in livestock and grains products among countries in the Asia‐Pacific region are assessed. Tests are conducted of the hypothesis that productivity levels in the Asia‐Pacific region are converging. Projections of livestock productivity are made and incorporated in a modified GTAP model. The consequences for regional and global trade in livestock and grains products are explored.
Updating an input–output table for use in policy analysis
Authors: Buetre Benjamin L. , Ahmadi‐Esfahani Fredoun Z.
Published: March 2003

The long lag in the publication of input–output tables is one of the central constraints in applied general equilibrium analysis. Model builders often use out‐dated databases leading to analyses that are inappropriate for the policy questions being addressed. This occurs particularly when there exists a significant structural change in the economy. We discuss the updating of an input–output table of the Philippines by simulation technique. A detailed computable general equilibrium model of the Philippine economy with comparative static and forecasting capabilities is utilised. The data are drawn from known percentage changes of macroeconomic variables such as those in the national accounts and structural variables such as employment and output by industry.
Agricultural Extension Policy in Australia: Public Funding And Market Failure
Authors: Mullen John D. , Vernon Don , Fishpool Ken I.
Published: March 2003

Trends in public expenditure on agricultural extension are examined for Agriculture Departments in four States. There is little evidence that the share of public resources going to extension has declined. However, new demands have meant that the nature of extension has changed. A strategic approach to examining issues, such as land degradation, for the source of market failure may better guide the use of scarce public resources than the traditional focus on the public goods characteristics of research and extension. The case for evaluating broad functions such as research and extension is becoming more questionable as these functions become more diverse.
Farm‐level efficiency and productivity measurement using panel data: wool production in south‐west Victoria
Authors: Fraser Iain , Hone Phillip
Published: March 2003

In this article we explore some issues surrounding the use of farm‐level efficiency and productivity estimates for benchmarking studies. Using an eight‐year balanced panel of Victorian wool producers we analyse annual variation between estimates of farm‐level technical efficiency derived using Data Envelopment Analysis and Malmquist estimates of Total Factor Productivity. We find that farms change their relative rank in terms of efficiency across years. Also, unlike aggregate studies of Total Factor Productivity, we find at best erratic and modest growth, a worrying result for this industry. However, caution is needed when interpreting these results, and for that matter, benchmarking analysis as currently practised when using frontier estimation techniques like Data Envelopment Analysis.
Determination of yield and erosion damage functions using subjectively elicited data: application to smallholder tea in Sri Lanka
Authors: Ananda Jayanath , Herath Gamini , Chisholm Anthony
Published: March 2003

Tea has been Sri Lanka’s major export earner for several decades. However, soil erosion on tea‐producing land has had considerable on‐site and off‐site effects. This study quantifies soil erosion impacts for smallholder tea farms in Sri Lanka by estimating a yield damage function and an erosion damage function using a subjective elicitation technique. The Mitscherlich‐Spillman type of function was found to yield acceptable results. The study indicates that high rates of soil erosion require earlier adoption of soil conservation measures than do low rates of erosion. Sensitivity analysis shows the optimum year to change to a conservation practice is very sensitive to the discount rate but less sensitive to the cost of production and price of tea.
Modelling socially optimal land allocations for sugar cane growing in North Queensland: a linked mathematical programming and choice modelling study
Authors: Mallawaarachchi Thilak , Quiggin John
Published: March 2003

A modelling framework is developed to determine the joint economic and environmental net benefits of alternative land allocation strategies. Estimates of community preferences for preservation of natural land, derived from a choice modelling study, are used as input to a model of agricultural production in an optimisation framework. The trade‐offs between agricultural production and environmental protection are analysed using the sugar industry of the Herbert River district of north Queensland as an example. Spatially‐differentiated resource attributes and the opportunity costs of natural land determine the optimal trade‐offs between production and conservation for a range of sugar prices.
Evaluating improvements in irrigation efficiency as a salinity mitigation option in the South Australian Riverland
Authors: Heaney Anna , Beare Stephen , Bell Rosalyn
Published: March 2003

A modelling framework incorporating relationships between agricultural production and groundwater hydrology was developed to estimate the benefits of improved irrigation efficiency in the Riverland of South Australia. Increased irrigation efficiency can generate external benefits to downstream users through reduced discharge of saline groundwater. In the Riverland these benefits are large in comparison to the direct value of the irrigation water. However, the non‐exclusive and site‐specific nature of these benefits makes it difficult to fully internalise them through market instruments such as salinity credits. Achieving optimal irrigation efficiency is likely to require institutional arrangements that promote collective investment and public expenditure.
Empirical properties of duality theory
Authors: Lusk Jayson L. , Featherstone Allen M. , Marsh Thomas L. , Abdulkadri Abdullahi O.
Published: March 2003

This research examines selected empirical properties of duality relationships. Monte Carlo experiments indicate that Hessian matrices estimated from the normalised unrestricted profit, restricted profit and production functions yield conflicting results in the presence of measurement error and low relative price variability. In particular, small amounts of measurement error in quantity variables can translate into large errors in uncompensated estimates calculated via restricted and unrestricted profit and production functions. These results emphasise the need for high quality data when estimating empirical models in order to accurately determine dual relationships implied by economic theory.
Determinants of non‐farm labour participation rates among farmers in Australia
Authors: Lim‐Applegate Hazel , Rodriguez Gil , Olfert Rose
Published: March 2003

In recent decades, non‐farm employment has become prevalent and an important source of income for Australian farm families. However, models identifying the relative significance of the socioeconomic variables influencing non‐farm employment participation rates have never been estimated in Australia. In this paper, a bivariate probit model of non‐farm employment participation rates was estimated, using information from the Australian Bureau of Agricultural Resource Economics (ABARE) 1994–1995 surveys. It was found that the participation decision of the farm operator and spouse is likely to be jointly determined, that non‐farm employment participation increased at a declining rate with age among farmers and that university education enhances the participation rates particularly among spouses. Participation rates were also higher among spouses with lower other income and with no dependent children.
Water flow risks and stakeholder impacts on the choice of a dam site
Authors: Biçak Hasan Ali , Jenkins Glenn P. , Özdemirag Ali
Published: March 2003

This study evaluates three alternative locations for building a fresh water dam in the Yeşilirmak Valley of North Cyprus. Each of the three sites has different investment costs, water storage capabilities and socio‐political repercussions. These kinds of trade‐offs have in recent years characterised much of the worldwide debate surrounding the construction of electricity and irrigation dams. Another issue raised in this paper is the appropriate treatment of the risk and variability associated with the availability of water to fill the dam through time. This paper demonstrates how an integrated financial‐economic‐stakeholder analysis can provide the inputs needed by decision‐makers in such situations to make rational political and economic choices.
Productivity Gains from Farmer Education in China
Authors: Nguyen Tin , Cheng Enjiang
Published: March 2003

Regression results for five Chinese provinces provide stronger empirical support than hitherto for the role of farmer education in productivity gains. However, these results are largely due to the inclusion of two small groups of outliers: one consists of very poor households whose heads have no education and the other, relatively well‐off households whose heads have only three years of education. This article illustrates the need for a cautious interpretation of the regression results of earlier studies, because they could be affected by problems of outliers, multicollinearity and omitted variable bias.
Savings and technology choice for risk averse farmers
Authors: Brennan Donna
Published: March 2003

Farmers in developing countries have limited opportunities for borrowing to even out variability associated with risky farm income, but they can save. A dynamic programming model of savings is presented in the current paper which examines optimal savings strategies for farmers, using a case study of integrated rice–shrimp farms in Vietnam. It is shown that when savings are accounted for, the expected utility ranking of different risky farm choices may not differ that much between farmers with different levels of risk aversion.
Price elasticities, joint products, and international trade
Authors: Piggott Nicholas E. , Wohlgenant Michael K.
Published: March 2003

This paper extends the basic results of Houck's insight for derived demand elasticities for the case of joint products by allowing for the possibility of the joint and raw products being traded. Theoretical relationships between individual demands for a set of jointly–produced commodities that are traded and composite demand for the raw product from which the joint products originate are derived. It is shown that while the derived price elasticity of domestic demand retains the same form as Houck's original formula, the relevant price elasticities of demand to include in the formula are elasticities of total demand instead of domestic demand elasticities. Using the USA soybean industry as an example, this generalised formula that takes into account trade is implemented to calculate the elasticity of total demand for USA soybeans. The usefulness of this formula for policy–makers to trace out the impacts of changes in market conditions and trade policy in the joint–products, and how it will impact the price elasticity of domestic and total demand for the raw product, is demonstrated.
Public Sector Priority Setting Using Decision Support Tools
Authors: Mabin Victoria , Menzies Malcolm , King Graeme , Joyce Karen
Published: March 2003

The public sector is in transition in many countries, including New Zealand, and many government departments have been restructured so as to increase transparency and accountability in their decision‐making by implementing fundamental changes to governance, accountability regimes and information systems. New frameworks are also needed for tasks such as priority setting, and this paper describes the framework developed to assist the then NZ Ministry of Agriculture (MAF) in setting priorities for the allocation of research funds. This comprised a participative process including a series of workshops using both GroupSystems software for electronic meeting support and Visual Interactive Sensitivity Analysis (VISA) software to facilitate a multi‐criteria decision analysis.
Rural Policy Assumptions and Policy Failure: The Case of the Re‐establishment Grant
Authors: Botterill Linda Courtenay
Published: March 2003

For 30 years successive Commonwealth governments have offered grants to encourage marginal farmers to quit farming. The grants have increased in generosity over time but there has only ever been a limited uptake of the program. This paper considers the assumptions policy‐makers have made about farmers’ behaviour in formulating these programs and compares these with sociological evidence about farmers’ incentive structures. This case study provides an example of how the failure to take account of a sufficiently broad range of values when formulating policy can undermine policy objectives from the outset.
Knowing and Skilling in Contemporary Public Administration
Authors: Hess Michael , Adams David
Published: March 2003

Knowledge is the latest buzzword in public administration, yet contemporary debates demonstrate a poor understanding of how knowledge is constructed and valued and of how public administration knowledge frames are changing in response to major structural shifts in political imperatives. In particular the retreat from economic rationalism and the embracing of social and human capital ideas with the search for ‘third ways’ and ‘triple bottom lines’ are bringing more constructivist knowledge frames back into play. In this way centralised ‘rational/expert’ knowledge is being challenged by knowledge arising from cooperative, local inquiry and multiple knowledge frames are now being brought to bear in public administration. Yet public administration, as a profession, seems unsure of whether this is an elegant finesse implying little real change or an exposure of the naked pretension of previously dominant unitary frameworks. This article uses a historical comparison to show how changes in the ontology and epistemology of public administration are demanding new skills of contemporary public administrators.
GAUGE THEORIES ON OPEN LIE ALGEBRA NONCOMMUTATIVE SPACES
Authors: AGARWAL A. , AKANT L.
Published: March 2003

It is shown that noncommutative spaces, which are quotients of associative algebras by ideals generated by highly nonlinear relations of a particular type, admit extremely simple formulae for deformed or star products. Explicit construction of these star products is carried out. Quantum gauge theories are formulated on these spaces, and the Seiberg–Witten map is worked out in detail.
VERY HIGH-ENERGY NEUTRINOS FROM SLOWLY DECAYING, MASSIVE DARK MATTER AS A SOURCE OF EXPLOSIVE ENERGY FOR GAMMA-RAY BURSTS
Authors: BARSHAY SAUL , KREYERHOFF GEORG
Published: March 2003

We consider a speculative model for gamma-ray bursts (GRB), which predicts that the total kinetic energy in the ejected matter is less than the total energy in the gamma rays. There is also secondary energy in X-rays, which are emitted contemporaneously with the gamma rays. The model suggests that bremsstrahlung and Compton up-scattering by very energetic electrons, are important processes for producing the observed burst radiation. The dynamics naturally allows for the possibility of a moderate degree of beaming of matter and radiation in some gamma-ray bursts. GRB are predicted to have an intrinsically wide distribution in total energies, in particular, on the low side. They are predicted to occur at large redshifts, z ~ 8, in local regions of dense matter.
Heparin-Coated Stent Placement for the Treatment of Stenoses in Small Coronary Arteries of Symptomatic Patients
Authors: Haude Michael , Konorza Thomas F.M. , Kalnins Uldis , Erglis Andrejs , Saunamäki Kari , Glogar Helmut D. , Grube Eberhard , Gil Robert , Serra Antonio , Richardt Hans G. , Sick Peter , Erbel Raimund
Published: March 2003

Background—

The role of stents, especially of heparin-coated stents for the treatment of stenoses in small coronary arteries, is still unclear. Therefore, we performed this prospective, randomized trial to evaluate the angiographic and clinical outcome after treatment of stenoses in small coronary arteries (2.0 to 2.6 mm) of symptomatic patients.

Methods and Results—

We randomly assigned 588 patients to angioplasty (n=195), bare stenting (n=196), or heparin-coated stenting (n=197). The primary end point was minimal lumen diameter (MLD) at 6 months. With comparable baseline parameters, the two stent arms showed a larger postinterventional MLD, larger acute gain, and smaller residual percent diameter stenosis, although a residual stenosis of 12±16% was achieved in the angioplasty arm, including a 27% crossover rate to stenting. Eighty percent of patients had follow-up angiography, which documented a borderline significantly larger MLD and smaller percent diameter stenosis for the two stent groups (1.34±0.48 mm and 42±20% after angioplasty, 1.47±0.48 mm and 36±20% after bare stenting, and 1.45±0.54 mm and 38±23% after heparin-coated stenting;
P
=0.049 and
P
=0.038, respectively), but restenosis rates were not different (32%, 25%, and 30%). Thrombotic events occurred in 1.0% after angioplasty and 0.5% after bare or heparin-coated stenting. Survival without myocardial infarction or target vessel revascularization at 250 days was 84.6% (angioplasty), 88.3% (bare stenting), and 88.3% (heparin-coated stenting; log-rank
P
=0.39).

Conclusion—

Compared with angioplasty with provisional stenting, bare and heparin-coated stenting confer superior angiographic results and a nonsignificant 24% reduction in clinical events, with no difference between bare and heparin-coated stenting in the treatment of stenoses in small coronary arteries.
Bosentan for the Prevention of Overcirculation-Induced Experimental Pulmonary Arterial Hypertension
Authors: Rondelet Benoît , Kerbaul François , Motte Sophie , van Beneden Ronald , Remmelink Myriam , Brimioulle Serge , McEntee Kathleen , Wauthy Pierre , Salmon Isabelle , Ketelslegers Jean-Marie , Naeije Robert
Published: March 2003

Background—

The dual endothelin-receptor antagonist bosentan has been reported to improve pulmonary arterial hypertension, but the role of endothelins in the pathogenesis of the condition remains uncertain. We investigated the roles of endothelin-1 (ET-1), nitric oxide (NO), vascular endothelial growth factor (VEGF), and tenascin in overcirculation-induced pulmonary hypertension in piglets, as a model of early pulmonary arterial hypertension, with or without bosentan therapy.

Methods and Results—

Thirty 3-week-old piglets were randomized to placebo or to bosentan 15 mg/kg BID after the anastomosis of the left subclavian artery to the pulmonary arterial trunk or after a sham operation. Three months later, the animals underwent a hemodynamic evaluation followed by cardiac and pulmonary tissue sampling for morphometry, immunohistochemistry, and real-time quantitative PCR. Chronic systemic-to-pulmonary shunting increased circulating plasma ET-1, pulmonary mRNA for ET-1, ET
B
receptor, inducible NO synthase, VEGF, and pulmonary ET-1 and VEGF proteins. There were increases in myocardial mRNA for ET
A
receptor and VEGF and in myocardial VEGF protein. Pulmonary and myocardial tissue mRNA for tenascin did not change. Normalized-flow pulmonary artery pressure increased from 20 (2) to 33 (1) mm Hg [mean (SEM)], arteriolar medial thickness increased on average by 83%, and these changes were completely prevented by bosentan therapy. Right ventricular end-systolic elastance increased in proportion to pulmonary arterial elastance with or without bosentan.

Conclusions—

Experimental overcirculation-induced pulmonary arterial hypertension appears to be causally related to an activation of the pulmonary ET-1 system and as such is completely prevented by the dual endothelin receptor antagonist bosentan.
Angiopoietin-1 Protects Against the Development of Cardiac Allograft Arteriosclerosis
Authors: Nykänen Antti I. , Krebs Rainer , Saaristo Anne , Turunen Päivi , Alitalo Kari , Ylä-Herttuala Seppo , Koskinen Petri K. , Lemström Karl B.
Published: March 2003

Background—

Angiopoietin (Ang)–1 is an angiogenic growth factor that counteracts the permeability and proinflammatory effects of vascular endothelial growth factor and other proinflammatory cytokines. Recently, we demonstrated that vascular endothelial growth factor enhances cardiac allograft arteriosclerosis. Here, we studied the roles of Ang1, its natural antagonist Ang2, and their receptor Tie2 in rat cardiac allograft arteriosclerosis.

Methods and Results—

Heterotopic cardiac allografts and syngrafts were transplanted from Dark Agouti (DA) to Wistar-Furth rats and from DA to DA rats, respectively. Immunohistochemistry disclosed that only a few mesenchymal cells expressed Ang1 in normal hearts and syngrafts, whereas no immunoreactivity was found in cardiac allografts undergoing chronic rejection. Ang2 and Tie2 immunoreactivity was induced mainly in capillaries and postcapillary venules in chronic allografts when compared with syngeneic controls, but no immunoreactivity was found in arterial endothelium. Intracoronary perfusion of cardiac allografts with a clinical-grade adenoviral vector encoding human Ang1 (Ad.Ang1) protected against the development of allograft arteriosclerosis. Ad.Ang1 perfusion reduced Ang2 expression in microcirculation, the numbers of graft-infiltrating leukocytes, and the level of immunoactivation and interstitial fibrosis, as well as both the incidence and intensity of intimal lesions. Ad.Ang1 perfusion also increased CD34
+
stem cell counts in peripheral blood.

Conclusions—

Our findings suggest that the antiinflammatory properties of Ang1 may offer an entirely new therapeutic approach to prevent cardiac allograft arteriosclerosis.
Hacia una evaluación de las nuevas formas del prejuicio racial: las actitudes sutiles del racismo
Authors: Rueda José Francisco , Navas Marisol
Published: March 2003

El objetivo de la investigación fue comprobar si las Escalas de Prejuicio Manifiesto vs. Sutil, presentadas por Meertens y Pettigrew (1992) resultaban válidas en la medición de las actitudes prejuiciosas, en nuestro entorno social. Seleccionamos tres exogrupos objeto de prejuicio: gitanos, magrebíes y negros. La muestra estuvo compuesta por 160 estudiantes de BUP y primeros cursos de Universidad. Los datos obtenidos muestran una fiabilidad aceptable de las escalas, así como una estructura factorial coincidente con la del estudio original. En cuanto a las indicaciones de validez, aparecen diferencias significativas en la expresión del prejuicio medido por ambas escalas, siendo el exogrupo gitano el peor evaluado. Finalmente, se analizan las diferencias encontradas entre sujetos igualitarios y sutiles con respecto a los sentimientos que les producen los exogrupos, las creencias sobre las ayudas estatales que éstos reciben y la política futura a seguir con ellos.
Análisis de la interacción grupal a través de medidas de observación en comunicación mediada
Authors: Orengo Virginia , Zornoza Ana , Acín Catherine , Prieto Fernando , Peiró José María
Published: March 2003

En la actualidad, las nuevas tecnologías están favoreciendo la formación de grupos de trabajo distribuidos. Estos grupos pueden tener un carácter relativamente permanente como un equipo editorial, o un equipo de diseño de distintos departamentos de una multinacional. Los Psicólogos del Trabajo y de las Organizaciones están retados a proporcionar teorías y modelos para el análisis y diseño de estos grupos. El presente estudio tiene como objetivo analizar el proceso de interacción de los grupos que se comunican a través de tecnologías de la información, centrándonos en aspectos que surgen o varían con mayor frecuencia a lo largo de ese proceso en función de la tecnología utilizadapara comunicarse (conducta desinhibiday gestión del conflicto en el grupo). Habitualmente, la metodología empleada para llevar a cabo este tipo de estudios ha adoptado una aproximación cuantitativa a partir de medidas de autoinforme. Sin embargo, en el presente estudio se emplea una metodología observacional basada en técnicas de análisis del proceso de interacción y sistemas de categorización de determinados tipos de conducta. El presente trabajo se ha llevado a cabo comparando tres medios de comunicación: cara a cara, videoconferenciay correo electrónico empleando una tarea de multidecisión («Supervivencia en la Luna»). Los resultados obtenidos muestran que el uso de una metodología observacional aporta una información muy valiosa del funcionamiento del grupo, del proceso de interacción y de algunos de sus aspectos relevantes, presentando un análisis diferencial en función de las tecnologías utilizadas por los grupos.
Componentes básicos del amor: algunas matizaciones al modelo de Sternberg
Authors: Yela Carlos
Published: March 2003

Entre los modelos teóricos presuntamente integradores sobre la estructura y dinámica del amor en las relaciones de pareja, uno de los más novedosos y plausibles es la Teoría Triangular de Sternberg (1986), quien propone la existencia de tres dimensiones básicas del amor, que denomina «Intimidad», «Pasión» y «Compromiso». Pero un detallado análisis de éste revela ciertas contradicciones entre la definición, evaluación y evolución de dichos componentes. Tratando de superarlas introdujimos una matización del modelo, dividiendo el componente pasional original en una «Pasión-Erótica» y una «Pasión-Romántica» (división planteada ya en la literatura especializada aunque no específicamente incorporada al modelo de Sternberg). Contrastamos dicho modelo teórico en una muestra de 412 sujetos, aplicando un cuestionario con items de las escalas de Sternbergy otros autores. El análisis de los datos ofrece cierto apoyo empírico a la estructurafactorial del modelo propuesto. Se sugiere la necesidad de posteriores confirmaciones, incorporando otro tipo de instrumentos y muestras, así como la contrastación de la parte dinámica del modelo: la evolución de los componentes a lo largo de la relación amorosa.
Differenza di genere e morale
Authors: Gius Erminio , Zamperini Adriano , Bocaccio Giorgia
Published: March 2003

Un análisis del problema del dualismo de género y el modo masculino o femenino de abordar la moralidad conduce, en la Psicología Social, a un examen cuidadoso del juicio moral de la mujer. Dos son las referencias principales en tal campo: los importantes estudios de Kohlberg y Piaget y la investigación de Carol Gilligan. Gilligan propone la existencia de dos orientaciones morales: la primera, que apela a la justicia y derechos, sería más apropiada para describir la perspectiva moral del hombre, y la segunda, que apela al afecto y cuidado, sería más adecuada para interpretar la visión femenina de la moral.

Tras diez años de investigación, la perspectiva de Gilligan ha abierto nuevas perspectivas en Psicología Social y generando un importante volumen de investigaciones con resultados contradictorios. La investigación empírica comentada en este artículo lleva a la reconsidereación de la conexión entre la moral y género, considerando ambos conceptos como no necesariamente relacionados.
Aspectos físicos y sociales en los lugares peligrosos. Miedo al delito en un espacio institucional
Authors: Fernández Baltasar , Corraliza José Antonio
Published: March 2003

Se propone el concepto de lugar peligrosopara unificar diversos resultados relacionados con las características sociofísicas de los espacios en que ocurre el miedo al delito. El concepto se refiere a la interpretación de los rasgos físicos ambientales como índices de las posibles actividades sociales esperadas en el lugar (bien delictivas, bien como apoyo social). Se realiza un estudio, mediante diapositivas, en un espacio institucional, para reafirmar la implicación de algunos rasgos físicos, como deterioro ambiental, rasgos de misterio y nocturnidad. La presencia de posibles ofensores ofrece resultados ambiguos que requieren investigaciones posteriores. Frente al escaso poder explicativo de variables personales previas relacionadas con el conocimiento del delito, se destaca la implicación de la percepción actual de amenaza y de variables referidas a competencias de afrontamiento del individuo.
Evaluación de la calidad ambiental urbana
Authors: García Ricardo , Sabucedo José Manuel , Arce Constantino
Published: March 2003

Esta investigación constituye un estudio centrado en la evaluación del ambiente urbano desde una perspectiva multidimensional. Se tuvieron en cuenta una multiplicidad de factores relacionados con la vida en la ciudad, así como la vivencia subjetiva que conforma la experiencia del ciudadano en este marco, como influyentes en la satisfacción y en las actitudes de las personas hacia el ambiente urbano. Así, se analizaron predictores de calidad ambiental como el ruído, la privacidad, la seguridad, el mantenimiento del barrio, la calidad del aire, las características de los vecinos y la accesibilidad a diferentes servicios. Se utilizó un procedimiento de análisis factorial y regresión múltiple para probar un modelo de relación entre la calidad ambiental residencialy la satisfacción de los usuarios, así como para proporcionar información sobre los aspectos de calidad que definen esa satisfacción.
Dynamic analysis of planar elastic mechanisms using the dyad method
Authors: Romdhane L , Dhuibi H , Salah H Bel Hadj
Published: March 2003

Based on graph representation of planar linkages, a new algorithm has been developed to identify the different dyads of a mechanism. A dyad, or class II group, is composed of two binary links connected by either a revolute (1) or a slider (0) pair, with provision for attachment of other links by lower pair connectors located at the end of each link. There are five types of dyad: D111, D101, D011, D001 and D010. The dyad analysis of a mechanism is predicated on the ability to construct the system from one or more of the five binary structure groups or class II groups. If the mechanism is complicated and several dyads are involved, the task of identifying these dyads, by inspection, can be difficult and time consuming for the user. This algorithm allows complete automation of this task. It is based on Dijkstra's algorithm for finding the shortest path in a graph. When compared with algorithmic methods, such as the Newton-Raphson method, the dyad method proved to be a very efficient one and requires as little as one-tenth of the time needed by the method using the Newton-Raphson algorithm.

The second part of this work presents an extension of the dyad method to non-rigid or elastic mechanisms. Here also, this method is predicated on the ability to subdivide the elastic mechanism into elastic dyads. The solution for each type of elastic dyad is derived and can be applied to each dyad in the mechanism. Therefore, a solution of the complete elastic mechanism is possible when the mechanism is made of dyads only. This method makes a powerful and simple tool for analysing complex elastic mechanisms. Moreover, the complexity of the model does not increase as the mechanism becomes more complex.

The D111 dyad is taken as an example to demonstrate this method. A finite element (FE) analysis was made for this type of dyad, and an experimental set-up was built to validate the analysis. The dyad-FE results were in good agreement with the experimental ones.
Matrix approach to deployment dynamics of an n-panel solar array
Authors: Balaji K , Nataraju B S , Sureshakumar H N
Published: March 2003

The equations of motion of a deploying solar array are derived using Lagrange's method and solved numerically. With increase in the number of panels, the mathematical modelling becomes complicated, involving the derivation of lengthy equations which can be error prone. A matrix approach has been adopted for automatic derivation of lengthy equations of motion. This facilitates the accommodation of n panel formulation by increasing the number of rows and columns. The complexity in derivation of the air drag and damper are discussed here.