bluuebunny/crossref_metadata_2025 huggingface dataset:
Postural stability in altered and unaltered sensory environments following fatiguing exercise of lower extremity joints
Authors: Dickin D. C. , Doan J. B.
Published: July 2010

Investigations of postural recovery following controlled external perturbations have provided models for healthy and pathological balance behavior. Less work, however, has investigated postural responses related to internal perturbations of the balance system. In this study, lower extremity joint (knee, or ankle) and overall fatigue of the dominant leg provided the internal perturbations to the balance system. Postural sway was examined during unilateral dominant leg standing before and immediately following fatiguing exercise, as well as at 10, 20, and 30 min post‐fatigue activity. Sway was measured in both firm and sway‐referenced support surface (external perturbation) conditions. Both joint‐localized fatigue and overall fatigue were found to induce impairments in postural control, which were further exacerbated by external postural perturbations. Follow‐up pairwise comparisons indicated that these impairments persisted at 10 and 30 min post‐fatigue. No differences in postural sway were found between fatigue locations or across any interactions between sway and fatigue location. The results indicated that muscular fatigue imposed a prolonged internal perturbation to postural control, regardless of any individual or combined joint fatigue localization. This global effect, combined with the prolonged impairment in postural response, provides support for critical contributions from a central mechanism to postural deficits due to fatigue.
Competitive and seasonal oxidative stress in elite alpine ski racers
Authors: Schippinger G. , Fankhauser F. , Abuja P. M. , Winklhofer‐Roob B. M. , Nadlinger K. , Halwachs‐Baumann G. , Wonisch W.
Published: July 2010

We investigated competitive‐ and long‐term oxidative stress during a competition season in eight top‐ranked members of the Austrian Men's Alpine Ski Team. Serum total peroxides, antibody titers against oxidized LDL (oLAb) and lag time of the degradation of the fluorophore 1‐palmitoyl‐2‐((2‐(4‐(6‐phenyl‐trans‐1,3,5‐hexatrienyl)phenyl)ethyl)‐carbonyl)‐sn‐glycero‐3‐phosphocholine were measured, along with plasma concentrations of ascorbate, α‐ and γ‐tocopherol, β‐carotene, uric acid and the lipid status. Competitive stress was indicated through an increased post‐race uric acid level (286 ± 50 μM pre‐race vs 456 ± 77 μM post‐race, P<0.001) in December. Long‐term effects were already apparent in November, with the highest concentrations of total peroxides (680 ± 458 μM H2O2 equivalents vs December 47 ± 58 μM H2O2 equivalents and January 15 ± 28 μM H2O2 equivalents, P<0.001) and a concomitant decrease in oLAb titers with an antibody trough in December (439 ± 150 mU/mL vs baseline 1036 ± 328 mU/mL; P=0.003). In January, after recovery, they attained nearly pre‐season levels of oxidative stress biomarkers. This study indicates midseason oxidative stress in top‐level skiers, which was associated with the performance in these athletes.
Effects of functional exercise training on performance and muscle strength after meniscectomy: a randomized trial
Authors: Ericsson Y. B. , Dahlberg L. E. , Roos E. M.
Published: July 2010

Muscular deficits and functional limitations have been found years after meniscectomy of the knee. The purpose of this randomized controlled trial was to examine the effect of functional exercise training on functional performance and isokinetic thigh muscle strength in middle‐aged patients subsequent to meniscectomy for a degenerative tear. Four years after meniscectomy, 45 patients (29 men, 16 women) were randomized to functional exercise training, supervised by a physical therapist, three times weekly for 4 months or to no intervention. The exercise program comprised of postural stability training and functional strength and endurance exercises for leg and trunk muscles. Outcomes were three functional performance tests and isokinetic muscle strength. Thirty patients (16 exercisers/14 controls) completed the study. Compared with control patients, the exercise group showed significant improvement in one‐leg hop (change 8 vs 2 cm; P=0.040), hamstrings strength 60°/s (P=0.033), and quadriceps endurance 180°/s (P=0.001). Functional exercise training was well tolerated and improved functional performance and thigh muscle strength in this group of middle‐aged subjects with a previous degenerative meniscal injury and partial meniscectomy.
Inflammatory factors, physical activity, and physical fitness in young people
Authors: Thomas N. E. , Williams D. R. R.
Published: July 2010

Cardiovascular disease (CVD) remains one of the leading causes of morbidity and mortality in developed countries. Over the past decade there has been much focus on the role of inflammation in the pathogenesis of atherosclerosis; to this end, there is increasing research on inflammatory factors such as C‐reactive protein (CRP), interleukin‐6 (IL‐6), and fibrinogen (Fg). There is compelling evidence that physical activity (PA) and physical fitness (PF) protect against chronic disease. More recently, research has shown that exercise reduces CRP, IL‐6, and Fg concentration in adults, and that this is often independent of adiposity. Although there are some data to suggest that this is similarly true for young people, there is inconsistency in the literature. The following review aims to illustrate what is known about the effects of PA and PF on inflammatory factors in young people aged 5–18 years.
Intermittent hypoxia at rest for improvement of athletic performance
Authors: Bärtsch P. , Dehnert C. , Friedmann‐Bette B. , Tadibi V.
Published: July 2010

Two modalities of applying hypoxia at rest are reviewed in this paper: intermittent hypoxic exposure (IHE), which consists of hypoxic air for 5–6 min alternating with breathing room air for 4–5 min during sessions lasting 60–90 min, or prolonged hypoxic exposure (PHE) to normobaric or hypobaric hypoxia over up to 3 h/day. Hypoxia with IHE is usually in the range of 12–10%, corresponding to an altitude of about 4000–6000 m. Normobaric or hypobaric hypoxia with PHE corresponds to altitudes of 4000–5500 m. Five of six studies applying IHE and all four well‐controlled studies using PHE could not show a significant improvement with these modalities of hypoxic exposure for sea level performance after 14–20 sessions of exposure, with the exception of swimmers in whom there might be a slight improvement by PHE in combination with a subsequent tapering. There is no direct or indirect evidence that IHE or PHE induce any significant physiological changes that might be associated with improving athletic performance at sea level. Therefore, IHE and PHE cannot be recommended for preparation of competitions held at sea level.
Preparation for football competition at moderate to high altitude
Authors: Gore C. J. , McSharry P. E. , Hewitt A. J. , Saunders P. U
Published: July 2010

Analysis of ∼100 years of home‐and‐away South American World Cup matches illustrate that football competition at moderate/high altitude (>2000 m) favors the home team, although this is more than compensated by the likelihood of sea‐level teams winning at home against the same opponents who have descended from altitude. Nevertheless, the home team advantage at altitudes above ∼2000 m may reflect that traditionally, teams from sea level or low altitude have not spent 1–2 weeks acclimatizing at altitude. Despite large differences between individuals, in the first few days at high altitude (e.g. La Paz, 3600 m) some players experience symptoms of acute mountain sickness (AMS) such as headache and disrupted sleep, and their maximum aerobic power (VO2max) is ∼25% reduced while their ventilation, heart rate and blood lactate during submaximal exercise are elevated. Simulated altitude for a few weeks before competition at altitude can be used to attain partial ventilatory acclimation and ameliorated symptoms of AMS. The variety of simulated altitude exposures usually created with enriched nitrogen mixtures of air include resting or exercising for a few hours per day or sleeping ∼8 h/night in hypoxia. Preparation for competition at moderate/high altitude by training at altitude is probably superior to simulated exposure; however, the optimal duration at moderate/high altitude is unclear. Preparing for 1–2 weeks at moderate/high altitude is a reasonable compromise between the benefits associated with overcoming AMS and partial restoration of VO2max vs the likelihood of detraining.
Parental, socio and cultural factors associated with adolescents' sports participation in four Danish municipalities
Authors: Toftegaard‐Støckel J. , Nielsen G. A. , Ibsen B. , Andersen L. B.
Published: July 2010

Despite the well‐documented health effects of physical activity, few studies focus on the correlates of leisure‐time sports and exercise participation. The present study examined correlations between adolescent sports participation and demographic factors, socioeconomic status (SES) and sociocultural factors. A school‐based cross‐sectional cluster sample including 6356 Danish fifth‐ and ninth‐grade adolescents from four municipalities were included. Age (younger) and gender (boy) were associated with adolescents' sports participation. Girls were half as likely [odds ratio (OR) 0.49 95% confidence interval (CI): 0.44–0.55] to participate in sports than boys. Adolescents were more likely to participate in sports if they perceived their parents as active in exercise or sports. Adolescents with one or two unemployed parents were 0.75 (95% CI: 0.62–0.89) and 0.75 (95% CI: 0.56–1.00), respectively, less likely to participate in sports than adolescents with two employed parents. In a gender‐stratified analysis, parents' occupational status was only a predictor of sports participation in girls. Differences between municipalities in adolescents' sports participation remained significant when controlled for individual factors such as gender, age, parents' background or parents' physical activity. The association between sociocultural and SES was stronger for girls than boys. In conclusion, demographics, SES and sociocultural factors were the best determinants of adolescent sport participation.
New Danish reference values for height, weight and body mass index of children aged 0–5 years
Authors: Nielsen AM , Olsen EM , Juul A
Published: July 2010

Aim:  To derive new reference values for height, weight and body mass index (BMI) of children aged 0–5 years in Denmark and to compare them with the national reference from the 1970s and the 2006 WHO standard.

Methods:  The height and weight of 4105 healthy singleton children born in 1995 were obtained from a cohort study. Children were measured at birth and at seven regular health examinations by a general practitioner up to 5 years of age. Generalized additive models for location, scale and shape were used to construct percentile curves.

Results:  Mean length, weight and BMI at birth and during the first months of life increased significantly, but the differences diminished thereafter, and at 1 year BMI had decreased. In boys, weight and BMI had decreased by 2 years of age but had increased, together with height, at 5 years. Children were taller, heavier and had a higher BMI than that referred to in the WHO standard.

Conclusion:  New references for length or height, weight and BMI by age were constructed for children in Denmark. Since the 1970s, weight, length and BMI at birth increased, and growth during the first year of life appears to be healthier.
SQUAMOSA Promoter‐Binding Protein‐Like Transcription Factors: Star Players for Plant Growth and Development
Authors: Chen Xiaobo , Zhang Zenglin , Liu Danmei , Zhang Kai , Li Aili , Mao Long
Published: July 2010

SQUAMOSA Promoter‐Binding Protein‐Like (SPL) genes encode plant‐specific transcription factors that play important roles in plant phase transition, flower and fruit development, plant architecture, gibberellins signaling, sporogenesis, and response to copper and fungal toxins. In Arabidopsis, many SPL genes are post‐transcriptionally regulated by the microRNA (miRNA) miR156, among which AtSPL9 in turn positively regulates the expression of the second miRNA miR172. This miR156‐AtSPL9‐miR172 regulatory pathway plays critical roles during juvenile to adult leaf development and the miR156‐SPLs feedback interaction persists all through the plant development, which may be conserved in other plants. In the present paper, we provide a concise review on the most recent progress in the regulatory mechanisms associated with plant SPL transcription factors, especially in relation to miRNAs. The potential application of these discoveries in agriculture is briefly discussed.
FARM MANAGEMENT RESEARCH DATA NEEDED FOR EXTENSION1
Authors: CLARK J. H.
Published: July 2010

Extension is a method of education for farm people who are already operating farm businesses. Farm management extension is the teaching of the facts and concepts of business management.

Interest must be created in a subject so that an extension programme may be planned. Economic conditions now make it more important for farmers to consider the business concepts of farming and thus create interest in farm management. Farm account book studies, survey studies and enterprise studies help to provide a basis for continuing this interest.

Farm extension workers must have both the basic facts of operation of the farms in their area and the basic input‐output data in order to indicate the way of profit maximization of farms and enterprises of the area. The facts can be obtained from farm account book studies, cost studies and special enterprise survey studies. Input‐output data can be provided by studies which include all relevant physical facts of production, by other studies designed to obtain factor‐product curves and by controlled experiments carried on in co‐operation with technical agricultural research workers. Price outlook information and other special information on particular phases of the management of the farm which may affect management decisions are also needed by the extension workers.

Farm management extension workers teach decision‐making. Research work which provides simple methods of evaluating the present farm business position and of budgeting for profit maximization are useful in teaching this subject. Linear programming provides a method of evaluating budgets and is useful for establishing standards, but the presentation should be simple and recommendations should also be based on the experience of the extension worker.
ECONOMIC GUIDELINES FOR MOBILIZING LABOUR AND MANAGEMENT IN CANADIAN AGRICULTURE1
Authors: Plaunt Darrel
Published: July 2010

This paper examines the role of management in stimulating economic growth. It sees the adjustment problem as the fundamental problem in Canadian agriculture and suggests ways of speeding the process. Recognizing that the individual farmer is the focal point of the adjustment process, the paper reviews the many kinds of adjustments possible, and suggests a new rural counselling service to help achieve the adjustment potentials.

LIGNES DIRECTRICES ÉCONOMIQUES POUR LA MOBILISATION DE ľEMPLOYÉ ET DE ľEMPLOYEUR DANS ľAGRICULTURE CANADIENNE –Le présent mémoire examine le rôle de la gestion dans la stimulation de ľaccroissement économique. II considère le problème ďajustement comme le problème fondamental dans ľagriculture canadienne et suggère des moyens ďaccélérer le processus. Reconnaissant que ľagriculteur lui‐même est le point tournant du processus ďajustement, le mémoire passe en revue les nombreux genres ďajustements possibles et suggère un nouveau service rural ďorientation pour aider à atteindre les possibilités ďajustement.
AN APPLICATION OF THE STAPLE THEORY TO SONORA, MEXICO*
Authors: Hicks W. Whitney
Published: July 2010

The role of primary exports in the economic development of a country or region has been subject to much debate. The “staple theory” has been proposed as an explanation of the beneficial effect of primary exports on the economic development of Canada and the United States. However, one authority argues that the staple theory is applicable only to the special case of a new underpopulated country. This paper shows that primary exports have stimulated development in the state of Sonora, Mexico. Data showing the increase in primary production and exports between 1950 and 1960 are linked to the increase in manufacturing employment in industries producing inputs for primary production, industries processing primary products, and industries producing products to satisfy increases in final demand. The role of government policies, institutional arrangements, and the nature of the production functions for primary products are examined in an effort to determine the impact of primary exports on manufacturing activity. This study illustrates that the staple theory provides insight into the development or lack of development of all countries exporting primary products.

L'IMPORTANCE DES EXPLOITATIONS DE BASE DANS LE DEVELOPPEMENT ECONOMQUE: ľAPPLICATION DE LA “THEORIE DES DENREES PRINCIPALES” DANS ľETAT DE SONORA AU MEXIQUE ‐ Le rôle des exportations de base dans le développement économique ďun pays ou ďune région a fait le sujet de bien des débats, La “théorie des denrées principales” a été proposée comme une explication de ľeffet avantageux des exportations de base sur le développement économique du Canada et des États‐Unis. Toutefois, une autorité prétend que la théorie des denrées principales ne s'applique qu'au cas particulier ďun nouveau pays sous‐peuplé. Le présent exposé démontre quelles exportations de baseont stimulilé développement de ľétal de Sonora au Mexique. Des données indiquant ľaugmen tation de la production et des exportations de base entre 1950 et 1960 sont liées àľavance de ľemploi manufacturier dans les industries produisant des intrants pour la production de base, pour les industries qui préparent des produits de base et pour les industries qui produisent des marchandises pour satisfaire aux demandes accrues de produits finis. Le rôle des politique! gouvemementales, des accords institutionnels et la nature des fonctions de la production pour les produits de base sont examinés afin de déterminer ľeffet des exportations de base sur ľactivité manufacturière. Cette étude démontre que la théorie des denrées principales fournit un aperçu du développement ou du manque de développement des pays qui exponent des produits de base.
Economic Guidelines for Present and Future Capital use in Canadian Agriculture*
Authors: Andal Melvin E.
Published: July 2010

Capital requirements for typical farms are expected to be $200,000 to $300,000 by 1980. This will necessitate substantial increases in credit and provide conditions more attractive to private investors than in the past for all types of credit as well as equity capital. Form operators' equity in the farm business is expected to decline substantially.

Incorporated farm statistics are presented as well as an estimate of the aggregate farm capital and credit structure in 1981. A number of policy questions are examined in the light of the changed financial structure envisaged.

GUIDES ÉCONOM1QUES CONCERNANT L'USAGE ACTUEL ET FU‐TUR DU CAPITAL DANS L'AGRICULTURE CANADIENNE–On estime que la mise de fonds en capital d'une ferme typique sera de l'ordre de $200,000 à$300,000 vers 1980. Cette situation entraînera des accroissements sensibles au chapitre du crédit et créera des conditions plus attrayantes que par le passé pour les investisseurs privés, les amenant à offrir tous les genres de credit et mime a participer au capital effectif de mise de fonds. On estime que Vavoir des exploitants agricoles dans leurs ferme diminuera sensiblement.

On présente des statistiques agricoles incorporees de même qu'une estimation de la structure d'ensemble du crédit et du capital des fermes en 1981. Un certain nombre de questions de politiques sont etudiees a la lumiire des changements prevus a la structure financiere.
Guidelines for Agricultural Policy Over the Next Decade
Authors: Campbell D. R. , MacGregor M. A.
Published: July 2010

This paper discusses the need for developing consistent public agricultural policies for Canada. Six “realities” of today are discussed and are proposed as guidelines for public involvement in Canadian agriculture. The guidelines are indicated to be applicable not only to public policy for agriculture, but also to other sectors, and are believed to be relevant well beyond a decade.

QUELQUES LIGNES DIRECTRICES CONCERNANT LA POLITIQUE AGR1COLE DES DIX PROCHAINES ANNÉES – L'article qui suit analyse pour le Canada la nécessité d'une véritable politique agricole. Dans cet ordre d'idées. six “schémas” qui pourraient constituer les lignes directrices d'une intervention des pouvoirs publics dans l'agriculture canadienne sont discutes et proposés. Ce cadre d'analyse pourrait être appliquée non seulement aux politiques agricoles mais aussi à d'autres secteurs et nous croyons qu'il serait valable bien au‐delà d'une décade.
FROM WAR‐CHESS TO FARM MANAGEMENT GAMES*
Authors: Longworth John W.
Published: July 2010

Management games offer a new approach to management education, extension and research. This paper reviews the evolution of the gaming concept from war‐chess to business management games; discusses the three broad classes of business games now available; reviews the range of farm management games available in America; and outlines an Australian farm management game recently developed and successfully operated at the University of Sydney. DES JEUX D'ECHECS JUSQU'AUX JEUX D'ENTREPRISES AGRICOLES – Les jeux d'entreprises off rent une nouvelle approche pour la recherche, la diffusion et l'enseignement de la gestion. Cet article passe en revue l'évolution de ce concept à partir du jeu d'echecs jusqu'aux jeux d'entreprises; discute les trois grandes categories de jeux d'entreprises agricoles maintenant disponibles; analyse I'elendue des jeux d'entreprises agricoles disponibles en Amérique; et souligne un jeu d'entreprise agricole Australien récemment mis au point et utilise avec succès à l'Université de Sydney.
EFFECT OF TENURE RELATIONSHIPS ON RESOURCE EFFICIENCY*
Authors: Langemeier Larry N.
Published: July 2010

This article outlines a method for developing optimum landlord‐tenant relationships. The representative farm analysis indicates that resource efficiency is highest when the tenant's net return is maximized and production costs are shared equally between landlord and tenant. Maximizing returns to either lease participant, with the tenant paying all production costs, results in less efficient use of resources, negative capital accumulation over time, and/or an undesirable distribution of total farm returns. Resource efficiency is shown to be superior on owner‐operator farms as compared to landlord‐tenant operations. Nevertheless, similarities between owner‐operator and landlord‐tenant operations suggest that part ownership can continue to grow with only a small loss in resource efficiency when forward planning is employed.

L'ÉTAT DES RELATIONS ENTRE FERMIERS ET PROPRIÉTAIRES SUR L'EFFICACITÉ DES RESSOURCES – Cet article souligne une méthode permettant d'optimiser les rapports entre le propriétaire et le fermier. L'ana‐lyse des fermes révèle que l'efficacité des ressources est la plus étevée quand d'une part le profit net du fermier est maximisé et quand d'autre part les coûts de production sont portagés équitablement entre le propriétaire et son fermier. Le fait de maximiser les rendements pour les parties prenantes du bail, avec le fermier payant tous les coûts de production, s'accompagne d'une moin‐dre efficacité dans l'utilisation des ressources, d'une desaccumulation du capital dans le temps et, ou d'une distribution inopportune des bénéfices totaux agricoles. L'efficacité des ressources est reconnue comme étant supérieure dans les exploitations gérées par leurs propriétaires que dans celles gérées pai des fermiers. Néanmoins, des similarités entre ces deux types de fermes suggèrent qu'une propriété partielle peut continuer à croître avec une perte sensible au niveau de l'efficacité des ressources quand une p/anification du futur est utilisée.
USER COST IN RENEWABLE NATURAL RESOURCES
Authors: Nautiyal J. C.
Published: July 2010

The development of the concept of user cost has been traced and its application in the economics of natural resources has been shown. The concept is useful in determining the optimum levels of investment and exploitation in a renewable natural resource like forestry. Application of user cost demonstrates that the rate at which a resource should be exploited is not the same at which it can be replenished, but the two are very much related to each other through the level of investment. It is not possible to say what the optimum rate of exploitation of a natural resource is without reference to the rate of investment.

LE COÛT D'USACE POUR LES RESSOURCES NATURELLES RENOU‐VELABLES – Le développement du concept du coût d'usage a été esquissé et son application dans l'économie des ressources naturelles a été montrée. Le concept est utile en déterminant les niveaux optimums d'inveslissement et d'exploitation pour des ressources naturelles comme la foret. L'application du coût d'usage démontre que le taux à partir duquel un bien pourrait‐être exploité n'est pas le même que le taux à partir duquel ce même bien peut‐être reconstitué, mais les deux sont étroitement reliés à‐travers le niveau des investissements. II est impossible de livrer le taux optimum d'exploitation des ressources naturelles sans faire référence au taux d'inveslissement.
MARKET SHARE ANALYSIS APPLIED TO CANADIAN WHEAT EXPORTS
Authors: Rigaux L. R.
Published: July 2010

This paper proposes a framework for market share analysis that provides for a distribution effect in addition to a competitive effect on a supplier's total sales of a commodity. The framework is applied to the change in Canadian wheat exports from 1963‐64 to 1967‐68. It is estimated that 3/5 of the reduction in export volume is attributable to the distribution effect, 1/5 to the competitive effect, and 1/5 to a smaller size of wheat market. The findings caution that scope may be limited for major improvements in Canadian wheat export policy. The paper concludes with an appraisal of the analytical technique and with proposals for its extension in further investigation.

Cet article expose les grandes lignes ďune méthode ďanalyse des parts de marché, faisant entrer en ligne de compte les effets de distribution et de compétition sur la rente ďun certain produit par un exporteur. La méthode est utilisee pour évaluer le changement des exportations cana‐diennes de blé, pour la période allant de 1963‐64 à 1967‐68. ďapres les estimations, on peut attribuer 3/5 de la réduction àľeffet de distribution, 1/5 à la compétition tandis que 1/5 est attribuable a la réduction du marché global du blé. Les résultats suggérent done une certaine prudence dans ľélaboration de nouvelles politiques ayant trait àľexportation de blé canadien. ľauteur termine par une évaluation de la méthode analytique, et fait quelques suggestions relatives à son usage pour des recherches futures.
THE IMPACT OF INPUT PRICE INFLATION ON THE UNITED STATES FARMING INDUSTRY*
Authors: Tweeten Luther , Quance Leroy
Published: July 2010

The impact of national inflation on net income of American farmers is expressed as the elasticity E of net income with respect to input prices. E is derived mathematically from a series of equations expressing productivity, revenue, costs, and elasticities of supply and demand. Empirical estimates of E are calculated for large input categories as well as for all purchased inputs for both the short and long run using estimates of the required parameters. Price inflation for cash operating inputs with an elastic demand such as fertilizer tends not to disadvantage farmers. But total use of inputs such as real estate, labor, and, durable inventories are relatively unresponsive to higher taxes, wages and interest rales, and thus farmers are seriously disadvantaged by inflation of these “prices.” In general, farmers benefit from input price increases if the price elasticity of demand for the input exceeds that of farm output. For all purchased inputs, this study reveals a small impact on net farm income from a once‐for‐all input price increment of one percent.

ľeffet de ľinflation nationale sur le revenu net des fermiers amériains s'exprime par la flexibilité E du revenu net par rapport au prix de revient. E est dérivé par calcul mathémalique d.une série ďéquations qui expriment la productivité, le rapport, les frais et la flexibilité de ľoffre el de la demande. On estime empiriquement la valeur de E pour des catégories ďinvestissement importantes de même que pour loutes les matières premières achelées, à tongue et à courte échéance, en se servant ďestimes des paramètres nécessaires. La hausse des prix des investissements achetés cast et dont le besoin est variable, tels que les engrais, tend a ne pas occasioner de perte pour le fermier. Mais ľemploi total ďinvestissements tels que biens immeubles, main ďoeuvre et invenlaires à longue durée sont relativemenl peu sensibles àľaugmentation du laux des impôts, des salaires, el ďintérêt. de sorte que les fermiers sont sérieusement handicapes par la hausse de ces “prix”. En général, les fermiers bénéficient de ľaugmentation des prix de revient si la flexibilityé de prix des ressources excede celle de la production fermiere. Pour toutes les ressources achetées, cette étude révèle qu'une augmentation de un pour‐cent dans les prix des investissements definitifsproduit un effet minime sur le revenufermier net.
SIMULATION OF THE GROWTH RESPONSE OF DRYLAND AND IRRIGATED CORN*
Authors: BIackie Malcolm J. , Schneeberger Kenneth C.
Published: July 2010

This paper studies the complex relationship between plant growth and the variables affecting that growth. The author has developed several growth models, with soil moisture being a primary explanatory variable in the models. The relationship of plant growth to moisture is demonstrated by the sensitivity of a corn plant to moisture at different periods in its growth.

Ce papier fail une études des relations complexes entre la croissance des plantes et les variables qui influent cette croissance. ľauteur a construit plusieurs modèles de croissance en se servant de ľhumidité du sol comme variable primaire explicalif La connexité entre la croissance des plantes el ľhumidilé est démonstée en utilisant une plante de blé d;inde ei en montrant comment sensible àľhumidité est cette plante à differentes étapes de sa maturation.
THE UK TOBACCO MARKET:POTENTIAL FOR INCREASED CANADIAN EXPORTS?
Authors: Smith Sheila M.
Published: July 2010

The recent decline in tobacco consumption in the UK may have serious implications for Canadian tobacco exports, which are heavily dependent upon the UK market. The latter market has been considered from the viewpoint of its overall market growth, and the potential substitutability of tobaccos from different sources of supply. From the viewpoint of market growth Canadian prospects do not appear to be favourable; however, a policy change involving a greater degree of export orientation might meet with success particularly because British purchasers seem to have become more flexible since the embargo on Rhodesian tobacco.

La baisse de la consommation du tabac au Royaume‐Uni peut avoir des conséquences pour les exportations canadiennes qui dépendent largement du marché britannique. Cetle étude considère ce marché sous deux aspects: premièrement, la croissance globale probable, et deuxièmement la possibilityé de changements dans ľimportance relative des fournisseurs. Si sous le premier aspect les perspectives canadiennes ne paraissent pas très favorables, en revanche sous le deuxième aspect elles semblenl être meilleures. Depuis ľinterruption des livraisons de la Rhodésie, fournisseur traditionnel du Royaume‐Uni, le marché britannique est devenu plus ouvert et les acheteurs choisissent librement entre les autres pays producteurs. ľauleur estime qu'un effort plus fori vers ľexportation par les producteurs canadiens pourrait avoir un succès considérable.
SUPPLY AREA OPTIMIZATION IN THE WESTERN CANADIAN HOG MARKET*
Authors: Jacobs P. C.
Published: July 2010

The study of marketing systems normally proceeds from an analysis of the existing structure. These post‐facto studies at best provide an evaluation of the system's efficiency and the areas in which improvements can be made. This study, however, was initiated in order to determine the optimal network of assembly points throughout the prairie provinces for the efficient marketing of hogs. This prior determination of the optimal size and location of assembly yards and the corresponding flows of hogs from the producing regions to the assembly points and then to the plants would then be available for use in designing changes in the existing systems or in implementing a new structure. The model used in this study was a modified transhipment model utilizing various truck transfer costs and per hog cost‐volume functions for the operation of the assembly yards. The model is readily amenable to further modifications to allow alternatives to be simulated. The use of this or similar techniques to evaluate various conditions should facilitate better design of structures within the Canadian agricultural industry

line étude des systèmes de distribution suit habituellement une analyse de la structure existame. Pour dire le mieux, ces etudes post‐facto nous donnent une évaluation de ľefficacité du système et des zones où on peut envisager des améliorations. Cette étude‐ci, cependant, a eté initiée avec ľintenlion de déterminer le réseau optime de lieux ďassemblage à travers les provinces de ľOuest pour la vente efficace de pores. On pourrait alors se servir de cette délimitation antérieure de la grandeur et de la location optimes de dépôts ďassemblage et du volume correspondent de pores provenant des régions producteurs et passant par les points ďassemblage pour arriver aux usines pour faire des changements dans les systèmes qui existent à présent ou pour mettre en oeuvre une structure nouvelle. Le modèle utilisé dans cette étude est un modèle modifyé de transbordement qui se sen de divers prix de transports en camion el des fonctions du prix par volume de pore pour ľopération des dépôts ďassemblage. Ce modèle peut facilement accommoder des modifications addition‐nelles pour permetlre la simulation d“alternatives. ľemploi de cette technique ou des techniques semblables pour évaluer divers conditions devrait faciliter une meilleure projection de structures dans I'industrie agricole canadienne.
AGRICULTURE IN ECONOMIC DEVELOPMENT THE COMPETITIVE APPROACH VERSUS SOVIET CONTROL
Authors: Yorgason Vernon W.
Published: July 2010

In an economy of full employment, economic growth largely occurs as a result of a transfer of resources from the agricultural to the industrial sector. Two different and opposing means of obtaining this transfer have been developed: the Soviet model, in which resources are shifted by command; and the competitive model, in which resources are shifted through the price mechanism. This study presents the two models in precise form and attempts to determine which is the most efficient in terms of encouraging long‐run growth. Difficulties with data allow only a historical statistical comparison, but certain tentative conclusions can be drawn

Dans une économie de plain emploi, la croissance économique est largement at‐tribuable au transferi de ressources du secteur agricole au secteur industriel. Deux méthodes différenles et opposées ont été développées pour oblenir ce transfer!: le modèle soviétique, où les ressources sont déplacées par ordre du gouvernemenl, el le modèle de concurrence, où les ressources sont déplacées par moyen de contrôle de prix. Celte étude précise ces deux modèles et cherche à déterminer quelle méthode est la plus efficace en ce qui concerne la croissance économique à long terme. Des difficultés avec les données ne permettent qu'une comparaison siatistique historique mais certaines conclusions tentatives sont quand meme possibles
DISCRIMINATING CREDIT WORTHINESS OF CANADIAN PRAIRIE FARMERS
Authors: Kulshreshtha S. N.
Published: July 2010

Future agriculturists in Canada will rely more heavily on credit as a vehicle to attain income and equity objectives. In order that a lending institution may determine on an a priori basis the credit worthiness of a farm, knowledge of characteristics that determine financial performance of a farm operating with a long‐term loan, and the relative weights to be attached to them is required. This paper applies the technique of discriminant analysis in identifying the financially successful farms from others, in order to develop a guide for lending institutions to assess credit worthiness of farms. Prairie farms were stratified on the basis of province and enterprises, thereby leading to nine sub‐samples for which a discriminant function was estimated. Two characteristics which were indicated by the analysis to be unfavorable to the credit worthiness of farms are the debt‐assets ratio of the farm and the proportion of non‐productive debts to total liabilities. Characteristics which were found to be favorable to credit worthiness were the initial level of resources, owned area, and off‐farm income (particularly for grain farms)

A ľavenir les agriculteurs canadiens devront compter davantage sur le crédit comme moyen ďatteindre le revenu el le profit envisagés. Pour qu'une compagnie de prét puisse déterminer à priori le valeur de crédit ďune ferme, il est nécessaire ďêtre au courant des facteurs qui déterminent le rendemenl financier ďune ferme opérant àľaide ďun emprunt à long terme et de connaítre la valeur relative de chacun de ces facteurs. Cet article traite de la technique de ľanalyse différentieile ulilisée pour reconno tre les fermes qui réussissent ftnancierèment parmi les autres, en vue de dévélopper une marche à suivre àľintention des compagnies de prêt qui évaluent la valeur du crédit des fermes. On a classé les fermes des Prairies ďaprès la province et ľentreprise agricole, ce qui a donné naissance à neuf sous‐divisions pour lesquelles on a évalue une courbe différentieile. Deux caractéridliques, qui ďaprès ľanalyse, se sont révelées défavorables pour ľévaluation de la valeur du crédit des fermes sont les suivants: le rapport dettes‐actif de la ferme et le rapport enlre les denes non productives et le passif total. Les facteurs qui se sont avérés favorables àľévaluation du crédit étaient: le montant des ressources àľohgine, la superftcie possédée el le revenu provenanl de la ferme (particulièrement pour les fermes à grain)
OPTIMIZATION AND DECISION MODELS: THE USE OF STATISTICAL SEARCH PROCEDURES1
Authors: Boehlje Michael
Published: July 2010

This article identifies the basic elements of a decision model and the errors that can be made in the development of optimizing decision models–errors of specification and errors of exploration. Specification errors are defined as those errors that result from the use of inaccurate structural relationships and parameters, whereas exploration errors occur in the process of searching the decision space for the optimal response. A number of systematic search procedures that can be used to reduce the exploration error in simulation models are reviewed. These procedures include random search methods, experimental designs, “learning mechanisms,” and “hill climbing.” It is suggested that if the availability of these procedures is recognized, the choice of a particular empirical model can be based on its ability to accurately portray the decision problem rather than the availability of an error‐free optimizing algorithm.

Ľarticle traile des principes caraclerisliques fondamentaux concernant les modèles de norme ainsi que des erreurs possibles dans la mise au point de modèles de norme à réglage optimum, surtout des erreurs dues à la spécification et àľexploration. Les erreurs dites spécif ques proviennent de ľemploi de rapports el de paramèlres fonctionellement fauiifs ou inexacts, tandis que les erreurs ďexploration sont le résullat de calculs imprecis de ľespace denorme convenable pour obtenir une réponse optima. Ľauteur présente une serie ďexemples en vue de systématiser les procédes valables qui aboulissenl a une réduction des erreurs ďexploration àľaide de modèles‐simulaieurs. Parmi les procédes convenables on propose une méthode de déterminations au hasard, certains projets expérimentaux, des “mecanismes ďassimilalion intellectuelle” et des “expériences de tâtonnemenl progressif” L'auteur en conclut que si ľon reconnat et qu'on emploie les méthodes proposées, il est bien possible de mettre au pooint un modèle expérimental ou empirique capable de servir de modèle problemalique bien exact plutol que de s'appuyer foncieremenl sur ľemploi ďun algorithme optimum valable.
DEMAND PRICE, FISH SIZE AND THE PRICE OF FISH*
Authors: Gates J. M.
Published: July 2010

Despite considerable work in fisheries economics on the supply side, little attention has been devoted to theoretical aspects of the relationship between ex‐vessel price and landings. One of the widely recognized determinants of fish prices is fish size, yet virtually all empirical analyses of the demand for fish ignore fish size. In this paper a demand function is postulated which includes fish size as a continuous demand shift parameter and the implications of fish size to the relationship between price and quantity are examined. It is concluded that omission of fish size may result in confounded estimates of the steady state relationship between price and quantity. It is also concluded that bioeconomic models of the fishery which ignore fish size may yield policy conclusions which are quantitatively, and in some cases, qualitatively, inaccurate.

Malgré le nombre important ďétudes sur ľeconomique des pêcheries du point de vue des provisions, peu ďattention s'est consacre aux aspects théoriques du rapport entre le prix ex‐vaisseau et les débarquements. Un déterminant largement reconnu du prix des poissons, c'est leur taille, quoique presque toutes les analyses empiriques de la demande de poissons ne tiennent aucun compte de la taille des poissons. Ľouvrage présent poslule une fonction de la demande, qui lient compte de la taille des poissons comme paramètre des changements de demande; il examine aussi les implications de la taille des poissons dans le rapport entre prix et quantité. On conclut que ľomission de la taille des poissons puisse résulter en des évaluations confondues du rapport constant entre prix et quantité. On conclut également que les modèles bio‐économiques de la pêcherie qui ne tiennent aucun compte de la taille des poissons puissent produire des conclusions de politique qui sone inexactes du point de vue quantitatif, et parfois du point de vue qualitatif.
THE OPTIMAL CONCENTRATION OF CATTLE FEED SUPPLEMENTS
Authors: van de Panne C. , Srangeland D. N.
Published: July 2010

The paper deals with the optimal composition of cattle feed supplements which are prepared by feed mills and sold to cattle feeders. Two problems are distinguished. In the first problem the ratio in which supplement and main feed are utilised is considered as given, while in the second problem this ratio is optimally chosen.

The relationships between these two problems as well as their dual problems are analysed. It is indicated that feed mill profit margins for the supplement, based on the quantity of the supplement and the input costs, generally lead to supplements which are too concentrated. An application to a dairy ration is used as an example.

Cette étude s'occupe avec la composition optimale des suppléments fourragères préparés par des entreprises fourragères et vendus aux éleveurs de bétail. On distingue deux problèmes. Dans la première la proportion entre le supplément et le fourrage principal est prise pour donnée, et dans la seconde cette proportion est choisie optimalement.

Les relations entre les deux problèmes et les problèmes duales correspondantes sont analysées et on constate que des écarts bénéficiares des entreprises fourragères qui sont basés sur la quantité du supplément et les coûts des ingrédients en général out pour résultat des suppléments trop concentrés. Une application à une ration pour des vaches laitières est donnée pour exemple.
INCOME TAX DATA AND FARM FINANCIAL STATISTICS
Authors: Anderson Marvin S.
Published: July 2010

Tracing the income patterns of individual farm operators whose major source of income is generally derived from farming indicates that off‐farm income is becoming an increasingly important income component. The relative importance of off‐farm income has nearly quadrupled during the last 20 years, rising from about 10 percent of total income to about 37 percent of total income. Most of this off‐farm income can be traced to wages and salaries. These fractions are heavily dependent upon relative income levels. In 1970, very low income farmers posted an aggregate net farm loss whereas the $15,000 ‐ $20,000 class secured about three‐quarters of their total income from farm sources. In this same year, wages and salaries were generally the prime off‐farm income source for farmers with an assessed income of less than $20,000. Dividends and interest were more important to farmers with an income in excess of $20,000. These differences are faithfully reflected in the regional compilations. As a percent of total income, off‐farm income ranged from 41 percent in Ontario to about 29 percent in Quebec. The composition of off‐farm sources also varies considerably between regions.

In 1970 the income position of taxable unincorporated farm operators (who relied on the farm for their major source of income) remained relatively unfavorable. These farmers still had one of the lowest average incomes of any major occupational class in Canada, with an income distribution which was relatively equally distributed between income classes and not unlike that of the national average. These assessed income statistics, of course, are not necessarily indicative of the welfare position of the respective occupational classes. The calculations conducted are simply illustrative of how income tax statistics can be utilized to facilitate our understanding of the income structure in primary agriculture today. The exercise simply underlines the observation that:

The fact that there are conceptual differences between income tax data and other data sources should not detract from the usefulness of the income tax data …. Income tax statistics can stand as an independent data source for the analysis of a variety of issues [13].

For many purposes the tax definition of a farm operator may be more operational than the concept of a farmer as defined in the Census of Agriculture. We might profit considerably from further analyses which attempt to disaggregate Census farms into more homogeneous farm‐types using the tax statistics available.
An Evaluation of the Actuarial structure of manitoba crop Insurance Program and its Implications
Authors: Yeh Martin H. , Sun Shih‐ping
Published: July 2010

Very little research has been done in evaluating the basic principles and assumptions of the actuarial structure for premium ratemaking in crop insurance programs. Therefore, the objectives of this study are: (a) to examine the Pearson probability distribution of actual crop yields as compared with an application of normal‐curve theory to crop yields as compared with an application of normal‐curve theory to crop yield distributions and in turn to crop insurance ratemaking which was suggested by Botts and Boles in 1958 [1]; (b) to evaluate the pure premium rates derived from estimated Pearson probability distributions for wheat yields in 14 crop districts of the province of Manitoba; and to establish an experience rating system for the crop insurance program based upon the estimated Pearson distribution of actual crop yields on the individual farm.