bluuebunny/crossref_metadata_2025 huggingface dataset:
Long term Changes in the Relative Abundances of Birds in Kings Park, Perth, Western Australia
Authors: RECHER H. F. , SERVENTY D. L.
Published: July 2005

Abstract. D. L. Serventy censused birds in Kings Park, Perth, between 1928 and 1937 and again between 1952 and 1955. Abundance was estimated by the frequency with which species were detected on censuses. The counts were repeated in 1986 by H. F. Recher. A total of 44 species were recorded during censuses. Since the first counts, were made, 14 species decreased in abundance by more than 15%, and 9 species went locally extinct. Eleven species increased in abundance by more than 20% (5 by more than 50%), and the abundance of 19 remained unchanged (frequency of occurrence changed by less than 15%).

Although nearly 300 ha of the park's 400 ha area remains as native vegetation, this vegetation has been degraded by logging, changed fire regimes, construction of trails, and invasion by exotic weeds. Changes in the ground vegetation have had a particularly significant impact. Nine of the 16 species that declined in abundance are ground foragers. Of the species that increased in abundance, a number benefit from the greater availability of nectar, fruits, and water in the suburban gardens that have developed around the park The Australian Raven (Corvus coronoides) has become particularly abundant and predation by ravens on nests was contribute to the decline of some species Changes to tbe park vegetation, suburban development of the park's immediate surroundings, and the extensive clearing of vegetation throughout southwestem Australia appear to have had a more signifcant effect on the park's avifauna than the sire of the park or its isolation in an urban environment. Poor management has seriously reduced the capacity of Kings Park to support native wildliye. Changes in park management designed to mbabilitate native vegetation, control weeds, and control ravens are necessary to prevent the further loss of species from the park's avifauna.
Measurement of Genetic Variation in Endangered Populations: Bandicoots (Marsupialia: Peramelidae) as an Example
Authors: SHERWIN WILLIAM B. , MURRAY NEIL D. , GRAVES JENNIFER A. MARSHALL , BROWN PETER R.
Published: July 2005

Abstract. Attempts to monitor the genetic variation of endangered populations by the use of blood protein electrophoresis often suffer from three drawbacks: a small sample of loci, lack of control populations with “normal” variation, and, sometimes, difficulty in confirming inheritance of electromorphs.

An endangered isolate (Hamilton, Victoria) of the eastern barred bandicoot, Perameles gunnii, was compared with a widespread, dense, conspecific population in Tasmania. A previous study of the effective size of the siolate suggested that the loss of variation should be detectable by protein electrophoresis if average heterozygosity (h̄) was approximately 0.057 in widespread, dense populations and 20 to 50 individuals from each population were analysed for 25 or more loci. However, no genetic variation was detected within or between samples.

Similar studies proposed as a baseline for monitioring genetic variation could be equally powerless to detect changes in variation, even with quite high h̄ values. The analysis of variation in DNA is expected to avoid many of the problems associated with blood protein studies.

This study highlights the importance of a control population. Analysis of the Hamilton population alone might have led us to concludce that the recent population crash has been responsible for the low variation; however, this conclusion is not warranted, because h̄= 0 in the much larger Tasmania population.
Approximations and Heuristics for the “Cause‐Modified” Life Table
Authors: Brand Kevin P.
Published: July 2005

Life‐table analysis can help to gauge the lifetime impacts that accrue from modifications to (age‐specific) baseline mortality. Modifications of interest include those stemming from risk‐factor‐related exposures or from interventions. The specific algorithm used in these analyses can be called a cause‐modified life table (a generalization of the cause‐deleted life table). The author presents an approach for approximating that algorithm and uses it to obtain remarkably simplified expressions for approximating three indices of common interest: life‐years lost (LYL), excess lifetime risk ratio (ELRR), and risk of exposure‐induced death (REID). These efforts are restricted to the special case of multiplicative increases to baseline mortality (modeled as an excess rate ratio, ERR). The simplified expressions effectively “break open” what is often treated as a “black‐box” calculation. Several insights result. For a practical range of risk factor impacts (ERRs), each index can be related to the ERR as a function of a baseline summary statistic and a “characteristic number” specific to the population and cause of interest. Conveniently, those numbers help form “rules of thumb” for translating among the three indices and suggest heuristics for extrapolating indices across populations and causes of death.
Bioengineered tissues: the science, the technology, and the industry
Authors: Ahsan T , Nerem RM
Published: July 2005

Structured Abstract

Authors –  Ahsan T, Nerem RM

Objective –  The bioengineering of tissues and organs, sometimes called tissue engineering and at other times regenerative medicine, is emerging as a science, as a technology, and as an industry. The goal is the repair, replacement, and/or the regeneration of tissues and organs. The objective of this paper is to identify and discuss the major issues that have become apparent.

Results –  One of the critical issues is that of cell source, i.e. what will be the source of the cells to be employed? Another critical issue is the development of approaches for the fabrication of substitute tissues/organs and/or vehicles for the delivery of biological active molecules for use in the repair/regeneration of tissues. A third critical issue, one very much related to cell source, is that of immune acceptance. In addition, there are technological hurdles; there are additional issues such as the scale‐up of manufacturing processes and the preservation of living‐cell products for off‐the‐shelf availability. Although the initial products have been superficially applied skin substitutes, as this fledgling industry continues to evolve, it is beginning to focus on a wider range of more invasive and complicated products. From a public health perspective, the real opportunity may be in addressing chronic diseases, as well as the transplantation crisis (i.e. the tremendous disparity between patient need for vital organs and donor availability) and, equally important is the challenge of neural repair.

Conclusion –  These are the grand challenges, and the scientific community, business/private sector, and federal government must mobilize itself together in this emerging area to translate the benchtop science to the patient bedside.
The efficacy of mesenchymal stem cells to regenerate and repair dental structures
Authors: Shi S , Bartold PM , Miura M , Seo BM , Robey PG , Gronthos S
Published: July 2005

Structured Abstract

Authors –  Shi S, Bartold PM, Miura M, Seo BM, Robey PG, Gronthos S

Objectives –  Identification, characterization, and potential application of mesenchymal stem cells (MSC) derived from human dental tissues.

Methods –  Dental pulp and periodontal ligament were obtained from normal human impacted third molars. The tissues were digested in collagenase/dispase to generate single cell suspensions. Cells were cultured in α‐MEM supplemented with 20% fetal bovine serum, 2 mM l‐glutamine, 100 μM l‐ascorbate‐2‐phosphate. Magnetic and fluorescence activated cell sorting were employed to characterize the phenotype of freshly isolated and ex vivo expanded cell populations. The developmental potential of cultured cells was assessed following co‐transplantation with hydroxyapetite/tricalcium phosphate (HA/TCP) particles into immunocompromised mice for 8 weeks.

Results –  MSC were identified in adult human dental pulp (dental pulp stem cells, DPSC), human primary teeth (stem cells from human exfoliated deciduous teeth, SHED), and periodontal ligament (periodontal ligament stem cells, PDLSC) by their capacity to generate clongenic cell clusters in culture. Ex vivo expanded DPSC, SHED, and PDLSC populations expressed a heterogeneous assortment of makers associated with MSC, dentin, bone, smooth muscle, neural tissue, and endothelium. PDLSC were also found to express the tendon specific marker, Scleraxis. Xenogeneic transplants containing HA/TCP with either DPSC or SHED generated donor‐derived dentin‐pulp‐like tissues with distinct odontoblast layers lining the mineralized dentin‐matrix. In parallel studies, PDLSC generated cementum‐like structures associated with PDL‐like connective tissue when transplanted with HA/TCP into immunocompromised mice.

Conclusion –  Collectively, these data revealed the presence of distinct MSC populations associated with dental structures with the potential of stem cells to regenerate living human dental tissues in vivo.
Non‐viral‐mediated gene therapy approaches for bone repair
Authors: Winn SR , Chen JC , Gong X , Bartholomew SV , Shreenivas S , Ozaki W
Published: July 2005

Structured Abstract

Authors –  Winn SR, Chen JC, Gong X, Bartholomew SV, Shreenivas S, Ozaki W

Objectives –  Bone repair strategies continue to be developed for alternatives to autografting, allogeneic implants of banked bone, and other bone substitutes. Efforts have included the delivery of potent growth and/or differentiation factors and the use of gene therapy. For bone regeneration, gene therapy is the delivery, uptake and expression of DNA that has been localized to a wound bed. The objective of the current study is to investigate methods to enhance non‐viral‐mediated means of gene uptake and expression for use in bone regeneration.

Methods –  Several types of DNA‐polymer complexes, either applied directly to baby hamster kidney (BHK) cells, or released from a porous, resorbable gene‐activated matrix (GAM), were evaluated in vitro for their ability to transfect cells with a circular plasmid DNA construct expressing green fluorescent protein. Complexes included conjugates containing a lipophilic reagent, liposomes, poly‐ethyl‐oxazoline, and poly‐ethyleneimine (PEI). Data were subjected to analysis of variance and Fisher's protected least significant difference for multiple comparisons with significance established at p < 0.05.

Results –  Transfection efficiencies of the liposome and PEI complexes improved in vitro when released from resorbable GAMs. The lipophilic reagent FuGene 6 demonstrated abundant uptake and expression in the initial 1‐ and 2‐day evaluation periods. In contrast, the DNA‐liposome and PEI GAM complexes demonstrated a sustained release, uptake and expression by the BHK cells at the 2‐, 4‐, and 7‐day, and 4‐ and 7‐day evaluation intervals, respectively.

Conclusion –  GAM technology appears to improve the functional stability and release duration of incorporated DNA‐polymer complexes in the present in vitro studies. The ongoing objective of our research is to develop a localized treatment to improve the uptake and expression of plasmid DNA by non‐viral‐mediated gene therapy.
Erfahrungen mit der neuen American Joint Committee on Cancer (AJCC)‐Klassifikation des kutanen malignen Melanoms
Authors: Eigentler Thomas K. , Radny Peter , Kamin Anne , Weide Benjamin , Caroli Ulrich M. , Garbe Claus
Published: July 2005

Im Jahr 2001 wurde eine neue AJCC/UICC‐Klassifikation und Stadieneinteilung des malignen Melanoms publiziert, die seitdem für die Eingruppierung des malignen Melanoms gültig ist. Im Vergleich zu der vorherigen für einen Zeitraum von etwa 15 Jahren gültigen Klassifikation wurden erhebliche Änderungen eingeführt. Die Klassifikation des Primärtumors stützt sich jetzt auf neue Klassenbildungen für die Tumordicke nach Breslow (0 – 1,0 mm; 1,01 – 2,0 mm, 2,01 – 4,0 mm; > 4,0 mm). Zusätzlich wird eine histopathologisch diagnostizierte Ulzeration mit zur Einteilung herangezogen, die zur Eingruppierung in die nächsthöhere T‐Kategorie führt. Der Invasionslevel nach Clark hat nur noch für Tumoren mit einer Tumordicke bis 1 mm Bedeutung, hier führt Level IV und V zur Einordnung in die nächsthöhere T‐Kategorie. Die Einteilung der regionären Lymphknotenmetastasierung basiert auf der Unterscheidung zwischen nur mikroskopisch erkennbarer Metastasierung in der Wächterlymphknotenbiopsie oder makroskopisch‐klinisch erkennbarer Metastasierung, weiterhin gehen in die Einteilung die Zahl der befallenen Lymphknoten und das Auftreten von Satelliten‐ und In‐transit‐Metastasen mit ein. Bei Fernmetastasierung spielt die Art des Organbefalls (nur Haut und Lymphknoten vs. Lunge vs. andere Organe) sowie der LDH‐Wert eine Rolle, bei dessen Erhöhung eine Eingruppierung in die ungünstigste Kategorie erfolgt. Kritisch bleibt anzumerken, dass die starke Rolle, die der Ulzeration des Primärtumors zukommt, anhand der Daten des deutschen Zentralregisters malignes Melanom nicht bestätigt werden konnte. Weiter ist es ungünstig, dass das Stadium IIC eine signifikant ungünstigere Prognose aufweist als das Stadium IIIA, hier ist die Klassifikation inkonsistent. Die neue Stadieneinteilung sollte dennoch, insbesondere in klinischen Studien, um eine internationale Vergleichbarkeit der Daten zu ermöglichen, verwendet werden.
Liability Versus Property Rule Protection for Surface Entitlements
Authors: Wilman Elizabeth A.
Published: July 2005

The relative legal protection for the surface entitlement versus the mineral entitlement has traditionally favored the mineral owner or lessee with property rule protection, while allowing the agricultural surface owner only liability rule protection. A case is made for changing the system to allow property rule protection for the surface owner.
Quantitative Assessment of U.S. Wheat Performance for Quality Characteristics
Authors: Pick Daniel , Webb Alan , Dusch Erin , Gudmunds Karl
Published: July 2005

Quality of U. S. grain exports has been a contentious issue over the past decade. Nowhere is the issue more hotly debated than for wheat. At the core of the debate has been the ability of Canada to command a premium for its wheat in foreign markets. Buyers' perceptions of quality have been suggested as an explanation, but empirical evidence on the quality attributes responsible for this country‐of‐origin premium has been limited to hedonic pricing studies. This paper quantifies purchasers' perceptions of the relative importance of quality characteristics for the world's major importing countries. This is done by calculating three indices. The attainment index measures how well buyers' perceptions of the importance of the characteristic matches buyers' perceptions of how well it is being supplied. The supply index measures buyers' perceptions on how well a characteristic is being supplied. The demand index measures how important the buyers perceive a particular characteristic to be. Then buyers' perceptions of the performance of U.S. and Canadian wheats are evaluated, given the perceived importance of each characteristic, and related to previous empirical results. Finally, these results are compared for alternative groupings of importing countries.
Consumer Demand for New Reduced‐fat Foods: An Analysis of Cheese Expenditures
Authors: Gould Brian W. , Cornick Jorge , Cox Thomas
Published: July 2005

The dairy products industry is adjusting the types of products being marketed by increasing the availability of reduced‐fat foods. The desire of consumers to purchase foods with lower fat content is affecting the cheese market with the introduction of recently developed reduced‐fat cheese varieties. Econometric models of cheese expenditures for three specific cheese types are estimated, which incorporate censoring of cheese expenditures and the interrelationship between expenditures of full and reduced‐fat varieties.
A Comparative Evaluation of Yield Risk Reductions with Alternative Crop Insurance Programs in Manitoba
Authors: Ye Yongsheng , Yeh Martin H.
Published: July 2005

Three crop insurance programs are evaluated in terms of their effectiveness of yield risk reductions for 371 Manitoba farms. The examination is first conducted with a proposed index method, with which the relative yield risk reduction magnitude is calculated and compared for each farm under each alternative program. The generalized stochastic dominance (GSD) methodology is also used to provide an alternative analytical framework in analyzing producers’relative preferences among those alternatives by comparing the net yield distributions generated by each program for each farm. The results suggest that, given an actuarially sound basis, the filly individualized crop insurance (FI) program is the most favorable choice for risk‐averse producers. The area coverage and individual indemnity program (IA) is generally the second best option. The full area crop insurance program (FA) is least preferred by risk‐averse farmers.
Factors Influencing Productivity Enhancing and Environmental Husbandry on Rented Land
Authors: van Vuuren W. , Larue B. , Ketchabaw E. H.
Published: July 2005

Logistic regression analysis is used to determine what impact tenant, contract and land characteristics have on farm practices enhancing productivity and the environment. The results of the study indicate that contract terms play an important role in environmental husbandry on rented land.

Des régressions avec variables dépendantes qualitatives sont utilisées pour analyser l'importance relative des caractéristiques des locataires, des contrats (de location), et des terres sur l'adoption de pratiques agricoles améliorant la productivité et la qualité de l'environnement. Les résultats indiquent que les clauses contractuelles jouent un rôle très important sur les aspects environnementaux liés à la gestion des terres louées.
Climatic Change and Canada's Boreal Forest: Socio‐economic Issues and Implications for Land Use
Authors: van Kooten G. Cornelis
Published: July 2005

This paper reviews the effect of climatic change and policies to sequester carbon on forest land use. Efficient mitigation strategies often require the conversion of agricultural land to forestry in order to sequester carbon, but such strategies could be wrong for Canada's boreal forest region if global warming is inevitable. It is argued that, from both an economic and a social perspective, conversion of the southern boreal forest to grassland or agriculture might be a better policy.

L'article passe en revue l'effet des changements climatiques et des politiques utilisées pour capter le gaz carbonique, sur l'utilisation des terres forestières. Pour être efficace, les stratégies d'atténuation nécessitent souvent la reconversion des terres agricoles à l'exploitation forestière afin de capturer le bioxyde de carbone mais, cette stratégie pourrait se révéler mauvaise pour la forêt boréale canadienne advenant l'inévitabilité d'un réchauffement planétaire. L'auteur estiment qu'autant dans la perspective économique que dans la perspective sociale, une meilleure solution serait plutôt de reconvertir le sud de la forêt boréale à la prairie ou à l'agriculture.
Quotas, Alternative Technologies and Immiserization
Authors: Hennessy David A.
Published: July 2005

This paper studies the relationships between technical change and welfare under a production quota regime. The conditions for producer impoverishment and quota owner impoverishment under technical change are identified. Whether the relative efficiency of a marketable quota regime is robust to the choice of technologies is also considered, as is the immiserization motive for banning a technology. The paper demonstrates that two or more technologies may exist in equilibrium and that the adoption of a technology may depend on the marketability of quota.
The Sharing of Risks and Returns in Prairie Special Crops: A Transaction Cost Approach
Authors: Weleschuk I. T. , Kerr William A.
Published: July 2005

The markets for special crops in western Canada are not yet mature. A farmer faces a choice of either signing a production contract with a buyer prior to planting the crop or selling the crop after harvest to a limited number of buyers. This paper examines both methods using a transaction cost approach. The evidence suggests that neither method will lead to an efficient level of investment in the production of special crops. As a result, the full potential for diversification into special crops may not have been realized in western Canada.
An Economic Analysis of Groundwater Contamination from Agricultural Nitrate Emissions in Southern Ontario
Authors: Giraldez Cesareo , Fox Glenn
Published: July 2005

This paper analyzes the costs and benefits of controlling groundwater pollution from agricultural use of nitrogen fertilizer in southwestern Ontario. The Village of Hensall, where nitrate concentrations have been observed above 10 mg/L in recent years, is selected as the study site.‘The CREAMS simulation model is used to estimate the effect of reducing nitrogen fertilizer on nitrate leaching and consequently on nitrate groundwater pollution. Estimates of the value of groundwater are obtained from the literature and are used to calculate the off‐farm cost of groundwater contamination. This procedure results in a wide range of values for the benefits of reducing nitrate pollution. Estimated annual benefits of improved ground‐water quality range from less than $1,000 to more than $30,000 for the village. The off‐farm benefits of nitrate groundwater pollution abatement outweigh the cost of using bottled water and also exceed the on‐farm cost of reducing nitrogen fertilizer application rates. Placing a tax on nitrogen fertilizer would reduce the level of nitrogen applications, but the farm cost of compliance to a nitrogen tax policy is substantially higher than the compliance cost under a regulatory policy that imposes a quantitative ceiling on nitrogen application rates over the part of the aquifer from which the village draws its water supply.
Comparaison de la rentabilité des systèmes conventionnels et biologiques en production laitière au Québec
Authors: Burgoyne Daniel , Levallois Raymond , Perrier Jean‐Philippe , Pellerin Doris , Paillat Et Nicolas
Published: July 2005

De la banque de données AGRITEL, 336 fermes conventionnelles et 16 fermes biologiques, spécialisées en production laitière, sont sélectionnées. Sept groupes (dont un est biologique) sont alors formés correspondant à des concepts de production différents. Les groupes defermes conventionnelles correspondent à des niveaux d'intrants particulièment élevés (haut niveau d'intrants) ou faibles (bas niveau d'intrants), ainsi qu'à des niveaux de production élevés @roduction intensive) oufaibles (production extensive), pour le troupeau ou pour l'ensemble de l'entreprise.

Les fermes biologiques parviennent à des résultats technico‐économiques et financiers au moins aussi bons que les fermes avec des rendements élevés (intensifs). En revanche, même si les concepts de production sont proches, les différences de rendement et de rentabilité sont assez nettes (souvent signcatives) entre le groupe biologique et les groupes extensifs ou à bas niveau d'intrants. Les entreprises biologiques sont plus équilibrtés et la prédominance de la production laitière est moindre. Les coûts de main‐d'œuvre sont toutefois plus élevés que la plupart des groupes d'entreprises conventionnelles.

Cette étuaè nous laisse croire qu'il est possible d'amtéliorer la rentabilité des fermes extensives et à bas niveau d'intrants, dont les concepts de production se rapprochent de ceux de l'agriculture biologique.
Testing for Chaos and Nonlinear Dynamics in Cattle Prices
Authors: Kohzadi Nowrouz , Boyd Milton S.
Published: July 2005

This study tests for the presence of chaos and nonlinear dynamics in monthly cattle prices for the period 1922–90. The Grassberger and Procaccia, BDS and Hurst Exponent tests show evidence of chaos and nonlinear dynamics for the above period.
Estimating Disequilibrium Cost Elasticities in Agricultural Production
Authors: Toichoa‐Buaha Gabriel , Apland Jeffrey
Published: July 2005

A restricted cost function is estimated using annual data for western Canadian agriculture over the period 1961–84. Using the parameter estimates, disequilibrium cost elasticities are calculated. The elasticities for the sector indicate that the ex ante market prices of quasi‐fixed inputs were higher than their shadow values. That is, quasi‐fixed factors were underutilized during the sample period. Excess agricultural land contributed most to the cost of disequilibrium.
Thinking Styles and Financial Characteristics of Selected Canadian Farm Managers
Authors: Howard Wayne H. , Brinkman George L. , Lambert Remy
Published: July 2005

The thinking styles of selected Canadian farm managers are identified using the life styles inventory (LSI). The farmers'LSI scores are compared with those of a base sample of nonfarmers, and correlations between the farmers'LSI scores and financial indicators are examined. Results indicate that farmers do thinking differently than nonfarmers and that there are significant correlations between thinking styles and financial measures.
Credit Risk and the Demand for Agricultural Loans
Authors: Turvey Calum G. , Weersink Alfons
Published: July 2005

This paper uses the lender–borrower relationship to provide insight into the impirical estimation of loan demand/contract curves for agricultural loans. Loan demand is shown to be determined partly by lenders’willingness to provide debt. The implicit solution to the loan contract curve in the lender–borrower relationship is derived from the cumulative probability distribution function of loan losses, which is the same measure used as the dependent variable in credit scoring models. Consequently, empirical estimation of loan demand can be obtained from credit scoring models. This paper presents the theory and then provides loan demand estimates and elasticities using Farm Credit Corporation cross‐sectional and time‐series data. Empirical estimates indicate the possibility of a backward‐bending loan demand curve, which may indicate some credit ationing in agriculture.
The Demand for Salmon in the European Union: The Importance of Product Form and Origin
Authors: Asche Frank , Bjørndal Trond , Salvanes Kjell G.
Published: July 2005

This paper addresses the importance of different product forms and their origin when considering the market structure in the European salmon market. The competition between farmed salmon and wild caught Pacific salmon has received some attention previously. However, this was before frozen Atlantic salmon emerged as an important product form in the market. This could be important as frozen Atlantic salmon is more likely to be a close substitute for Pacific salmon, which is mostly marketed frozen, than is fresh Atlantic salmon. In this paper, an almost ideal demand system is used to estimate the demand for fresh Atlantic salmon, frozen Atlantic salmon and frozen Pacific salmon in the European Union.
Use of Public Perceptions of Groundwater Quality Benefits in Developing Livestock Management Options
Authors: van Kooten G. Cornelis , Athwal Rita , Arthur Louise M.
Published: July 2005

In this study, a dichotomous choice model is used to determine the compensating welfare measure for water quality improvements stemming from livestock waste management in the Abbotsford region of southwestern British Columbia. The benefits of improving water quality are compared with the net costs of composting manure on a large scale, the option for handling livestock wastes preferred by the provincial government. The results indicate that the costs of composting manure exceed the revenue from selling manure (compost) plus the off‐site damages avoided.
Derived Demand for Refrigerated Truck Transport: A Gravity Model Analysis of Canadian Pork Exports to the United States
Authors: Prentice Barry E. , Wang Zhaokun , Urbina Hector J.
Published: July 2005

Gravity models have a long history in the empirical analysis of trade flows and market penetration, but lack a strong economic foundation. This paper demonstrates that the gravity model can be reconciled with existing economic theory within the framework of an interregional trade model. An empirical gravity model of interregional trade is specified for Canadian pork exports to the United States. The estimated results show that, among other things, demand for transport is highly elastic, suggesting that pork producers and truckers have a mutual interest in exploring means to lower freight costs. Finally, the gravity model is used to identify potential markets for each of the five major exporting provinces. The Canadian pork industry has its best opportunity for further penetration in Illinois, Texas, New York and New Jersey.
Optimal Markup Decisions under Demand Uncertainty
Authors: Lohr Luanne , Park Timothy A.
Published: July 2005

This article examines the consistency with economic theory of a rule of thumb in which a risk‐averse firm facing demand uncertaintly sets its price based on a percentage over the price paid to farmers. A testable set of comparative static results determines how the optimal markup is influenced by shifts in key parameters affecting the firm: expected demand, demand uncertainty and average variable costs. The model is tested using data from the wholesale markets for organic lettuce, broccoli and carrots. The results demonstrate that risk‐averse wholesalers raise markups as expected demand increases and reduce them as uncertainty increases, consistent with risk‐averse behavior. The empirical models show that produce marketing agents monitor shifts in expected demand and demand variability when adjusting markups. Expected demand has a greater impact on markups than demand variability.
Open Economy and Processor Oligopoly Power Effects of Beef Advertising in Canada
Authors: Cranfield John A. L. , Goddard Ellen W.
Published: July 2005

A North American beef industry model incorporating a hypothesized relationship between beef advertising and processor oligopoly power was estimated and used to evaluate various advertising options faced by Canadian cattle producers. Generic and branded advertising significantly increased Canadian and U.S. beef demand. As well, historic generic beef advertising expenditure in Canada returned a net profit to Canadian producers. However, additional Canadian producer investment in generic beef advertising in Canada lowered producer profits, while investment in Canadian or U.S. brand advertis‐ ing or U.S. generic advertising generated positive net returns.

Nous avons construit un modèle mathématique pour le secteur nord‐américain de la viande de boeuf, incorporant un rapport hypothétique entre la publicité du produit et le pouvoir oligopolistique au niveau du secteur de la préparation‐transformation. Nous avons utilisé le modéle pour évaluer diverses options de publicité auxquelles font face les producteurs de bavins canadiens. La publicité générique et la publicité de marque ont procuré un accroissement de la demande de viande bovine tant au Canada qu'aux États‐Unis. De plus, les dépenses engagées au cours des années au chapitre de la publicité générique de la viande bovine au Canada ont valu aux producteurs canadiens un bénéfice net. En revanche tout accroissement des investissements consacrés à la publicité générique par ces producteurs s‘est soldé par une baisse des profits à la production, alors qu‘aux États‐Unis il se révélait en général rentable. Par aileurs, l'intensification de la publicité de marque s'est montrée rentable dans les deux pays.
Optimal Generic Advertising Decisions in Supply‐managed Industries: Clarification and Some Further Results
Authors: Kinnucan Henry W.
Published: July 2005

Supply control enhances the incentive to promote through its ancillary trade policies that protect the domestic industry from foreign competition. Incentives are intensified when supply control is coupled with a price discrimination scheme that renders the supply of the agricultural product to the higher‐priced (premium) market perfectly elastic. In this case, aper‐unit levy imposed on the premium market to finance the advertising is shifted entirely to consumers, which means that the producer cost of advertising the premium product is nil. This in essence is the situation for fluid milk in Canada, Taiwan and California, which explains in part why fluid milk dominates the generic advertising scene in these regions. This article investigates these and related issues in some detail, using an earlier analysis by Goddard and McCutcheon as the point of departure.

La gestion de l'offre amplifie les incitations à produire par le biais de ses politiques corrollaires de commerce extérieur qui mettent le secteur intérieur à I'abri de la concurrence étrangère. Les incitations sont defait intensifiées lorsque le contrôle de I'offre est coupléà un systéme de discrimination des prix qui rend I'offre d'unproduit agricole donné sur le marché les plus lucratifs parfaitement élastique. Dans ce cos, le droit unitaire imposé au marché le plus rentable pourfinancer la publicité est refilé entiérement aux consommateurs, de sorte que le coût à la production de la promotion duproduit vedette est nul. C'est essentiellement la situation qui prévaut pour le lait de consommation au Canada, à Taïwan et en Californie, ce qui en partie explique la prédominance de ce produit dans la publicité générique dans ces régions. Nous examinons ces questions plus ou moins en détail utilisant comme point de départ une analyse antérieure faite par Goddard et McCutcheon.
A Note on Asymmetry in Commodity Futures Markets
Authors: Gravelines Rony S. , Boyd Milton
Published: July 2005

This study tests for asymmetry in futures price changes using commodities from a variety of groups such as agricultural, metals, and financials. Tests are used to determine whether or not prices move up in the same fashion as they move down, over varying data frequencies. The results indicate that every commodity analyzed shows at least some degree of asymmetry.

Nous avons scruté les signes éventuels d'asymétrie dans l'évolution des prix à terme de certaines catégories de produits agricoles, industriels (pétrole et métaux) et boursiers. Des tests ont été utilisés pour déterminer si les prix moment de la même façon qu'ils descendent pour diverses fréquences d'établissement des prix (quotidien, hebdomadaire, mensuel). Il ressort de ces analyses que chaque type de produit comportait au mains un certain degré d'asymétrie.
The Future of European Union Dairy Policy
Authors: Benjamin Catherine , Gohin Alexandre , Guyomard Hervé
Published: July 2005

Even if the quota regime has been extended until 2007–08 as part of the Agenda 2000 reform adopted in March 1999, the European Union (EU) dairy sector is currently experiencing large uncertainty over future policy. This paper examines EU dairy policy issues and assesses their likely implications. It mainly addresses the central question of dismantling the quota and intervention support mechanisms. Simulation results illustrate how three factors (marginal costs of production, import tariffs on dairy products and compensatory payments granted to dairy producers) may affect the outcomes of a quota elimination scenario.

Même si le régime des quotas a été prolongé jusqu'en 2007–2008 à l'occasion de la réforme Agenda 2000 de mars 1999, le débat sur la nécessité d'une réforme plus importante de la politique laitiére européenne n'est pas clos. Dans ce papier, nous analysons les différentes contraintes auxquelles l'Union européenne doit faire face et ses implications pour le secteur laitier communautaire. L'attention est centrée sur les conséquences d'une suppression du régime des quotas et du mécanisme de l'intervention. Les résultats de simulation montrent comment les conséquences d'un tel scénario dépendent de trois facteurs, i.e., les coûts marginaux de production du lait, la protection tarifaire sur les importations européennes de produits laitiers et les mesures de compensation accordées aux producteurs de lait.
Policy Reform in the European Union Dairy Sector: Effects on Markets and Welfare
Authors: Mechemache Zohra Bouamra , Réquillart Vincent
Published: July 2005

This paper analyzes the impacts of policy reforms in the EU dairy sector. It is shown that the imple‐mentation of GATT agreements leads to a 4% decrease in the milk price. Prices of SMP and WMP decrease more than butter and cheese prices. EU welfare increases marginally, but distributive effects are large. The increase in quotas decided by the Berlin Agreement will cause a dramatic cut in the milk price (−10% to −15% depending on how EU demand will increase in the future). Moreover, because of the constraints on subsidized exports, the implicit price of protein will decrease much more than the price of fat. Finally, if demand expands sufficiently, then compensatory payments (including national envelopes) will cover about 90% of the loss in producer surplus due to the milk price cut. We also inves‐tigate the impact of a two‐tiered quota system and show that its impacts are similar to those generated by the implementation of GATT agreements.

On étudie les effets de différents scénarios de réforme de la politique laitiére européenne. La mise en oeuvre des accords du GATT implique une réduction du prix du lait de 4%. De plus, les baisses de prix des produits transformés sont plus importantes pour les poudres de lait que pour le beurre ou le fro‐mage. L'impact des accords sur le bien‐ětre est positif mais faible. Par contre les effets redistributifs sont importants. L'augmentation des quotas décidée lors de l'accord de Berlin entraľnera une baisse importante du prix du lait européen, de l'ordre de 10 %à 15 % selon l'évolution de la consommation intérieure. En raison des contraintes d'exportations qui portent principalement sur les produits pro‐téiques, le prix implicite de la protéine de lait diminue beaucoup plus que le prix implicite de la matiére grasse laitiére. Par ailleurs, on montre que si la demande européenne s'accroľt suffisamment, les paiements compensatoires prévus couvriront environ 90 % des pertes de revenus des producteurs liées à la baisse du prix du lait. Enfin, on montre que les effets d'un scénario de double prix double quota sont proches de ceux provoqués par la mise en application des accords du GATT.
Sanitary and Technical Regulations: Issues for Trade Liberalization in the Dairy Sector1
Authors: Bureau Jean‐Christophe , Doussin Jean‐Pierre
Published: July 2005

Sanitary and technical regulations can impede trade liberalization in dairy products. The World Trade Organization tackle regulatory trade barriers mainly through the Sanitary and Phytosanitary (SPS) and the Technical Barriers to Trade (TBT) agreements. The SPS and TBT agreements are presented, focusing on those provisions that are relevant for the dairy sector. Arbitration of recent SPS disputes clarified the right of a country to set a particular level of protection, as well as the role of international standards. Building on the recent jurisprudence of the disputes settled under the World Trade Organization, the practical scope of the SPS and TBT agreements is explained. Empirical consequences for trade in the dairy sector are presented on the basis of three examples, the Bst issue, the controversy on mandatory pasteurization of cheese and the definition and labeling of yogurts.

Les règlementations nationales sur le plan sanitaire ou technique peuvent créer des obstacles aux échanges. L'Organisation Mondiale du Commerce (OMC) traite ces problémes principalement à trovers l'Accord Sanitaire et phytosanitaire (SPS) et celui sur les Obstacles techniques aux échanges (OTE). Ces accords et leurs effets possibles sur le secteur laitier sont présentés. L'arbitrage des différends récents par l'OMC dans le domaine sanitaire et phytosanitaire a claifié le droit d'un pays àétablir son propre niveau de protection des consommateurs et a précisé la portée des normes internationales. En s'appuyant sur la jurisprudence récente, la portée pratique des accords SPS et OTE est expliquée. Les conséquences pratiques pour le commerce international des produits laitiers sont présentées sur la base de trois exemple, la Bst, la controverse sur la pasteurisation des fromages, et la définition et l'étiquetage des yaourts.
Alternative Trade Mechanisms in World Dairy Markets
Authors: Thompson Wyatt , Liapis Peter , Sckokai Paolo
Published: July 2005

Dairy remains among the most protected agricultural sectors within OECD countries. Trade implications of this protection are import barriers and policies to induce greater exports, all of which distort markets. The Uruguay Round Agreement on Agriculture (URAA) set limits on subsidized exports and tariff rates for dairy products in order to liberalize trade. Yet few of the nations engaged in dairy market support have quit their efforts since the agreement. Continued implementation of the URAA with its accompanying limits, or possibly expanded liberalization after future trade talks, may result in greater stress on domestic price support mechanisms. We investigate implications of the URAA limitations on world dairy markets and some alternative methods of dairy product trade intervention by examining cases of existing and potential trade distortion.

La filière du lait demeure le secteur agricole le plus protégé au sein des pays de l'OCDE. Sur le plan des échanges internationaux, cette protection se traduit par des barriéres à l'importation et par des politiques d'exportation agressives, autant de causes de distorsion du commerce mondial. Dans l'esprit de libéraliser les échanges commerciaux, l'Accord sur l'agriculture de l'Uruguay Round (AAUR) a fixé des limites aux exportations subventionnées et aux taux tarifaires imposés à l'importation des produits laitiers. Pourtant, quelques‐unes seulement des nations appliquant des mesures de soutien du marché laitier ont jusqu'ici relâché leurs efforts. La poursuite de la mise en application de l'AAUR et des limites qu'il impose, ou une libéralisation éventuelle plus grande survenant après les prochaines discussions commerciales, peut créer une pression accrue sur les mécanismes de soutien des marchés intérieurs. Nous analysons la portée des restrictions de l'AAUR sur les marchés laitiers mondiaux ainsi que quelques méthodes d'intervention sur le marché des produits laitiers, par l'examen de certains cas de distorsion actuels, et éventuels du commerce extérieur.
Estimating the Off‐farm Labor Supply in Canada
Authors: Howard Wayne , Swidinsky Michael
Published: July 2005

Off‐farm labor supply in Canada is modeled using separate off‐farm labor participation and off‐farm labor supply equations, which allows variables to affect participation and labor supply differently. The data used in this study are from Statistics Canada's Agriculture‐Population Linkage Database, which links the Population Census for 1986 to a 20% sample from the Census of Agriculture. Results indicate that age, education and wages have large, significant and opposite effects on participation and supply, and that government efforts to stabilize and supplement farm incomes through rural employment programs may have less effect on labor allocation decisions than do the underlying demographic factors and regional and farm characteristics.

Nous modélisons id les disponibilités d'emploi extérieur (hors‐ferme) pour les agriculteurs, utilisant des équations distinctes pour la participation aux emplois extérieurs et pour l'offre des emplois extérieurs, ce qui permet de laisser les variables influer différemment sur les deux éléments. Les donées utilisées proviennent de la base de données de Statistique Canada sur le couplage agriculture‐population, laquelle relie le recensement de la population de 1986 à un échantillon de 20 % prélevé sur le recensement de l'agriculture. Les résultats font voir que l'âge, le niveau de scolarisation et les salaires ont de grands effets, significatifs mais opposés, sur l'utilisation et sur les disponibilites d'emplois extérieurs et que les initiatives de‘État pour stabiliser et compléter le revenu agricole au moyen de programmes d'emploi rural auraient mains d'effets sur les décisions d'attribution des emplois que les facteurs sous‐jacents relevant de la démographie et des caractéristiques particulières de chaque région et exploitation.
Regional Climate Change: Trend Analysis of Temperature and Precipitation Series at Selected Canadian Sites
Authors: Clark J. Stephen , Yiridoe Emmanuel K. , Burns Nigel D. , Astatkie T.
Published: July 2005

Global climate change does not necessarily imply that temperature or precipitation is increasing at specific locations. The hypothesis of increasing temperature and precipitation trends associated with global climate change is tested using actual annual temperature and precipitation data for nine selected weather stations, spatially distributed across Canada. Vogelsang's (1998) partial sum and Woodward et al's (1997) bootstrap methods are used for testing for trend. Both methods suggest no warming in the Canadian temperature series except for Toronto, Ontario, which had significant increase over time, along with Moncton, New Brunswick, and Indian Head, Saskatchewan, which had marginal increases. There is no evidence of increasing trend in precipitation except for Moncton, New Brunswick, which had a significantly increasing trend. Thus, public policies designed to address the regional effects of climate change need to be adapted for a particular ecological zone, based on knowledge of the climate trends for that region, rather than on general global climate change patterns.

Les changements climatiques à l'échelle planétaire ne signifient pas nécessairement que la température et les précipitations sont en augmentation dans des emplacements donnés. Nous avons testé I'hypothèse d'une assoviation de la tendance à la hausse de la température et des précipitations avec les changements climatiques planétaires à partir des données réelles de température et de précipitations obtenues à 9 stations d'observation climatique réparties dans les diverses régions du Canada. Nous utilisons, pour cefaire, la méthode des sommes partielles de Vogelsang (1998) et celle de rééchantillonnage bootstrap de Woodward et al (1997). Les deux méthodes ne révèlent aucun réchauffement de la température dans les séries chronologiques, sauf pour Toronto, en Ontario, où l'on constate une hausse significative en fonction du temps, ainsi que pour Moncton au Nouveau‐Brunswick et Indian Head en Saskatchewan qui marquent de très légères augmentations. Rien n'indique une tendance à la hausse des précipitations, sauf à Moncton où se dessine une tendance significative dans ce sens. Les programmes publics destinés à faire face aux effets régionaux du changement climatique doivent donc être adaptés à chaque zone écologique particulière, à partir d”observations faites dans la région même, plutôt que de la configuration du changement climatique à l'échelle planétaire.
Macroeconomic Impact of Establishing a Large‐scale Fuel Ethanol Plant on the Canadian Economy
Authors: Thomassin Paul J. , Baker Laurie
Published: July 2005

This paper analyzes the macroeconomic impact of establishing a large‐scale fuel ethanol plant that uses com as its feedstock. An input‐output model of the Canadian economy is used to estimate the macroeconomic impact. The agricultural output data required for the input‐output analysis are generated using an econometric model. The macroeconomic impact of operating this plant is increases in industrial output of $328.6 million, in GDP at factor cost of $84.2 million and in employment of 1,390 jobs.

Ce document a pour but d'analyser l'impact macro‐économique de l'installation d'une grande usine productrice d'éthanol, utilisant le maï's comme matière première. Un modèle entrées‐sorties de l'économie canadienne est employé afin d'estimer l'impact macro‐économique. Les données de rendements agricole requises pour cette analyse sont générées à l'aide d'un modèle économétrique. Les impacts macro‐économique qui résultèrent suite à l'opération de cette usine sont: un augmentation de $328.6 millions du rendement industriel, une augmentation de $84.2 millions du PIB au coût des facteurs, ainsi qu'un gain de 1,390 emplois.