bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolutionary repression of chondrogenic genes in the vertebrate osteoblast
Authors: Nguyen Jason K. B. , Eames B. Frank
Published: January 2020

Gene expression in extant animals might reveal how skeletal cells have evolved over the past 500 million years. The cells that make up cartilage (chondrocytes) and bone (osteoblasts) express many of the same genes, but they also have important molecular differences that allow us to distinguish them as separate cell types. For example, traditional studies of later‐diverged vertebrates, such as mouse and chick, defined the genesCol2a1and sex‐determining region Y‐box 9 as cartilage‐specific. However, recent studies have shown that osteoblasts of earlier‐diverged vertebrates, such as frog, gar, and zebrafish, express these ‘chondrogenic’ markers. In this review, we examine the resulting hypothesis that chondrogenic gene expression became repressed in osteoblasts over evolutionary time. The amphibian is an underexplored skeletal model that is uniquely positioned to address this hypothesis, especially given that it diverged when life transitioned from water to land. Given the relationship between phylogeny and ontogeny, a novel discovery for skeletal cell evolution might bolster our understanding of skeletal cell development.
Human proteinase 3 resistance to inhibition extends to alpha‐2 macroglobulin
Authors: N’Guessan Koffi , Grzywa Renata , Seren Seda , Gabant Guillaume , Juliano Maria A. , Moniatte Marc , van Dorsselaer Alain , Bieth Joseph G. , Kellenberger Christine , Gauthier Francis , Wysocka Magdalena , Lesner Adam , Sienczyk Marcin , Cadene Martine , Korkmaz Brice
Published: January 2020

Polymorphonuclear neutrophils contain at least four serine endopeptidases, namely neutrophil elastase (NE), proteinase 3 (PR3), cathepsin G (CatG), and NSP4, which contribute to the regulation of infection and of inflammatory processes. In physiological conditions, endogenous inhibitors including α2‐macroglobulin (α2‐M), serpins [α1‐proteinase inhibitor (α1‐PI)], monocyte neutrophil elastase inhibitor (MNEI), α1‐antichymotrypsin, and locally produced chelonianins (elafin, SLPI) control excessive proteolytic activity of neutrophilic serine proteinases. In contrast to human NE (hNE), hPR3 is weakly inhibited by α1‐PI and MNEI but not by SLPI. α2‐M is a large spectrum inhibitor that traps a variety of proteinases in response to cleavage(s) in its bait region. We report here that α2‐M was more rapidly processed by hNE than hPR3 or hCatG. This was confirmed by the observation that the association between α2‐M and hPR3 is governed by a kass in the ≤ 105 m−1·s−1 range. Since α2‐M‐trapped proteinases retain peptidase activity, we first predicted the putative cleavage sites within the α2‐M bait region (residues 690–728) using kinetic and molecular modeling approaches. We then identified by mass spectrum analysis the cleavage sites of hPR3 in a synthetic peptide spanning the 39‐residue bait region of α2‐M (39pep‐α2‐M). Since the 39pep‐α2‐M peptide and the corresponding bait area in the whole protein do not contain sequences with a high probability of specific cleavage by hPR3 and were indeed only slowly cleaved by hPR3, it can be concluded that α2‐M is a poor inhibitor of hPR3. The resistance of hPR3 to inhibition by endogenous inhibitors explains at least in part its role in tissue injury during chronic inflammatory diseases and its well‐recognized function of major target autoantigen in granulomatosis with polyangiitis.
A novel risk score to predict early and late recurrence in solitary fibrous tumour
Authors: Georgiesh Tatiana , Boye Kjetil , Bjerkehagen Bodil
Published: January 2020

Aims

Solitary fibrous tumours (SFTs) are rare mesenchymal neoplasms with recurrence rates of 10–30%. Current risk stratification systems for extrameningeal SFTs are based on cohorts with limited follow‐up and are not suitable for prediction of late recurrences. In this study we aimed to develop a prognostic model accounting for both early and late recurrences using a relatively large patient cohort with long‐term follow‐up.

Methods and results

Clinicopathological factors were analysed in a cohort of 100 extrameningeal, STAT6‐positive SFTs. Median follow‐up for overall survival (OS) and recurrence‐free interval (RFi) were 121 and 84 months, respectively. Disease relapse occurred in 31% of patients and median time to recurrence was 63 months. In univariate analysis mitotic count, necrosis, male gender and presence of severe atypia and pleomorphism were associated with inferior RFi. Mitotic count, necrosis and male gender were independent predictors of recurrence in multivariate analysis. Previously published risk models were also statistically associated with RFi in our cohort, but failed to reliably identify low‐risk patients due to poor prediction of late recurrences. A novel risk score based on mitotic count, necrosis and gender was able to stratify patients into low‐, intermediate‐ and high‐risk groups for both early and late recurrences.

Conclusions

In this cohort of patients with extrameningeal SFT and long‐term follow‐up mitotic count, necrosis and gender were independent prognostic markers of recurrence. We propose a novel risk score based on these factors and accounting for late recurrences, which should be validated in external cohorts with sufficient follow‐up time.
Hyponatraemia aggravates cardiac susceptibility to ischaemia/reperfusion injury
Authors: Oniki Takahiro , Teshima Yasushi , Nishio Satoru , Ishii Yumi , Kira Shintaro , Abe Ichitaro , Yufu Kunio , Takahashi Naohiko
Published: January 2020

Hyponatraemia is defined as a serum sodium concentration of <135 mEql/L and is the most common electrolyte disturbance in patients with chronic heart failure. We hypothesize that hyponatraemia may induce Ca2+ overload and enhance reactive oxygen species (ROS) production, which will exacerbate myocardial injury more than normonatraemia. We investigated the effect of hyponatraemia on the ability of the heart to recover from ischaemia/reperfusion episodes. Cardiomyocytes were obtained from 1‐ to 3‐day‐old Sprague Dawley rats. After isolation, cardiomyocytes were placed in Dulbecco's modified Eagle's medium (DMEM) containing low sodium concentration (110, 120, or 130 mEq/L) or normal sodium concentration (140 mEq/L) for 72 hours. Exposure of cardiomyocytes to each of the low‐sodium medium significantly increased both ROS and intracellular Ca2+ levels compared with the exposure to the normal‐sodium medium. In vivo, 8‐week‐old male Sprague Dawley rats were divided into four groups: control group (Con), furosemide group (Fur), low‐sodium diet group (Lsd) and both furosemide and low‐sodium diet group (Fur + Lsd). The hearts subjected to global ischaemia exhibited considerable decrease in left ventricular developed pressure during reperfusion, and the size of infarcts induced by ischaemia/reperfusion significantly increased in the Fur, Lsd and Fur + Lsd compared with that in the Con. Hyponatraemia aggravates cardiac susceptibility to ischaemia/reperfusion injury by Ca2+ overload and increasing in ROS levels.
Genre‐specific persuasion in oral presentations: Adaptation to the audience through multimodal persuasive strategies
Authors: Valeiras‐Jurado Julia
Published: January 2020

Product pitches, research dissemination talks and conference presentations are three oral genres that share important characteristics. Previous literature has described them as multimodal and persuasive oral genres and has shown that speakers resort to multimodal persuasive strategies to achieve their communicative goals. However, they are used in different contexts, which is likely to affect their use of multimodal persuasion, and raises questions as to how genre‐specific persuasion is. The aim of this paper is to explore how speakers adapt their multimodal persuasive efforts to the communicative situation established in each genre, and how this is reflected multimodally. This study combines multimodal discourse analysis and ethnographic methods. The results suggest that speakers multimodally convey a different relationship with the audience in each genre.
A theory of heterogeneous city growth
Authors: Ghiglino Christian , Nishimura Kazuo , Venditti Alain
Published: January 2020

We consider an economy with three cities producing different outputs. Two cities produce intermediate goods, a type 1 city producing an intermediate “agricultural” good with capital and labor only, and a type 2 city producing an intermediate “industrial” good with capital, labor, and human capital. A type 3 city produces the final good which is obtained from the two intermediate goods and labor. The asymmetric introduction of human capital allows us to prove that the three cities experience, at equilibrium, heterogeneous endogenous growth rates which are proportional to the growth rate of human capital. We show that the “industrial” type 2 city is characterized by the larger growth rate while the “agricultural” type 1 city experiences the lower growth rate, and thus the type 3 city is characterized by a growth rate which is a convex combination of the two former growth rates. This implies that the relative size in terms of output of the “agricultural” city decreases over time. This property allows us to recover the empirical fact that most non‐agricultural production occurs in growing metropolitan areas. But, simultaneously, as we prove that total labor employed in each city is proportional to the total population, the relative population size distribution of cities is constant over time, as shown in empirical studies.
Comparison of the effects of oral iron treatment every day and every other day in female patients with iron deficiency anaemia
Authors: Düzen Oflas Nur , Demircioğlu Sinan , Yıldırım Doğan Narin , Eker Elife , Kutlucan Ali , Doğan Ali , Aslan Mehmet , Demir Cengiz
Published: January 2020

Background

It is known that daily divided doses and high doses of iron increase hepcidin and reduce iron absorption.

Aim

To compare treatments of iron replacement every other day at low doses, once a day and twice a day in terms of their effectiveness and frequencies of side‐effects.

Methods

For 1 month, Group I received 270 mg ferrous sulphate twice a day (total elemental iron dose: 160 mg/day), Group II received 270 mg ferrous sulphate once a day (total elemental iron dose: 80 mg/day), and Group III received 270 mg ferrous sulphate every other day (total elemental iron dose: 80 mg/every other day). Intragroup and intergroup statistical analyses were carried out.

Results

Haemoglobin (Hb) increased significantly in all three groups (P = 0.00). The increase in Hb levels was similar among the groups (P = 0.09). Ferritin significantly increased in all three groups after the treatment (P = 0.00). The increase in ferritin in Group I was significantly higher than those in Groups II and III (P < 0.05). Gastrointestinal tract (GIS) side‐effects were also significantly higher in Group I in comparison to the others (P = 0.001).

Conclusions

A low dosage of iron treatment every other day may be used in the place of providing iron once or twice every day with similar effectiveness and lower rates of GIS side‐effects.
Performance of simple serum‐based tests to exclude cirrhosis prior to hepatitis C treatment in non‐hospital settings in Australia
Authors: Burrage Lauren , Zimmerman Henry , Higgins Sarah , Param Kerrin , Orme Clare , Mitchell Jonathan , O'Beirne James
Published: January 2020

Background

Current guidelines suggest using transient elastography (TE) or aspartate aminotransferase to platelet ratio index (APRI) score <1 to exclude cirrhosis prior to commencing treatment for hepatitis C virus (HCV). Recently, fibrosis‐4 (FIB‐4) <0.93 has been shown to have a high negative predictive value (NPV) for the presence of cirrhosis.

Aims

To assess FIB‐4 and APRI in a cohort of HCV patients and to validate FIB‐4 <0.93 in populations of HCV‐infected individuals with differing cirrhosis prevalence, including secondary care, primary care and prisons.

Methods

From our treatment database, we identified patients with complete data (n = 793). We calculated FIB‐4 and APRI and correlated this with the presence of cirrhosis, determined by TE. We analysed the performance of FIB‐4 and APRI using area under the receiver operating curve analysis. We calculated sensitivity, specificity, positive predictive value, NPV and number of patients misclassified using published cut‐offs in populations with varying cirrhosis prevalence.

Results

FIB‐4 was superior to APRI for the diagnosis of cirrhosis (area under the receiver operating curve 0.868 vs 0.802). In secondary care (cirrhosis prevalence 32%), APRI <1 had a NPV of 80% and misclassified 14% of patients. FIB‐4 <0.93 had a NPV of 97% and misclassified 1%. In primary care and prison (cirrhosis prevalence 13% and 8%), the NPV for APRI <1 was 93% and 96%, respectively, but 5% of patients with cirrhosis were misclassified. FIB‐4 <0.93 had excellent NPV in both primary care (97%) and prisoners (100%).

Conclusions

FIB‐4 <0.93 is highly efficient at ruling out cirrhosis in HCV patients and allows TE to be appropriately avoided, thereby streamlining treatment algorithms.
Persistent Underinvestment in Public Agricultural Research
Authors: Oehmke James F.
Published: January 2020

It is often argued that public support of agricultural research is inadequate. However, the empirical papers that support this hypothesis rarely reflect formal behavioral theory capable of explaining this phenomenon. This paper presents a theory that explains underfunding, namely, that funding agencies respond too slowly to secular changes in the value of research. A model of farmer and funding agency behavior is presented, and shown to imply that actual research funding will be consistently smaller than optimal funding. The assumptions and results of the model are explained in terms of the institutional literature on public agricultural research agencies.
An Evaluation of Indian Government Rice Policy in Tamil Nadu
Authors: Chellaraj G. , Brorsen B. Wade
Published: January 2020

The Indian government procures rice from wholesalers or producers at a price below the market price and then distributes it to low‐income consumers at a subsidized price. This paper uses a simulataneous equations econometric model to evaluate the effects of this policy on supply/demand of rice in the state of Tamil Nadu, between 1956 and 1985. Results show that production is more responsive to power for irrigation and fertilizer prices than to output prices. Because supply is inelastic, producers bear the burden of the ‘tax’ imposed by procurement even though rice is procured from the wholesaler. Rice distributed by the government displaces rice demanded in the open market, and thus the government distribution of rice has not increased the total consumption of rice.
Issues relating to Agricultural Pricing Policies and their Analysis in Developing Countries
Authors: Lutz Ernst , Saadat Yasmin
Published: January 2020

Agricultural pricing policies in developing countries are often the result of complex interactions between producer, consumer and merchant groups and their relative effectiveness in influencing government decision making. Even within governments, various ministries often have opposing views. In this environment one of the contributions a policy analyst can make is to attempt to quantify the effects of different policy options. This permits a more informed discussion which hopefully leads to better decision‐making and an improved incentive environment.

Many analyses of agricultural pricing policies have used the standard partial equilibrium analysis where no linkages between commodity markets were considered. In this paper we have considered cross‐price effects. Also, we have discussed issues relating to other adjustments/refinements of the standard method so that a practitioner not familiar with the various methods can form an opinion of what the options are and what adjustments may be appropriate for a particular case in question. The adjustments relate to overvaluation of currencies, input price distortions, differences in the degree of distortions between producers and consumers, and variability of border prices.

The inclusion of cross‐price elasticities was important for assessing production, consumption and trade effects for Argentina, but for the other countries it resulted in only somewhat improved accuracy. The adjustment for exchange rates had a large impact in Egypt and was important for other countries as well. This underlines the importance of exchange rates as key variables for agricultural pricing policies in general. The numbers show that the traditional taxation policies of agricultural products in the sample of developing countries is somewhat less widespread than in the past. These policies, however, continue to favor consumers over producers, with significant losses for some of the latter. The large size of welfare losses, especially compared to efficiency losses, highlights the importance of correcting distorted prices that adversely affect the poorest sections of society. Also, the usual government objective of taxing producers to raise revenues is frequently defeated by the large subsidies provided to consumers.

For the partitioner, for whom time is often of the essence, the assessment of welfare effects using the partial equilibrium method may provide reasonably good ‘first cut’ estimates of the order of magnitude of the impact of distortions. But often, these 'base case estimates' can and should be adjusted for a number of possible factors. The analyst needs to determine how important accurate estimates of key variables are to the policy makers; he or she then needs to compare the costs involved in generating or gathering the data and doing the calculations with the benefits of a broader and more accurate analysis of the distortionary effects of the particular case in question.
Principles of Dynamic Optimization in Resource Management
Authors: Kennedy John O.S.
Published: January 2020

The type of resource problem amenable to static analysis is distinguished from that requiring dynamic analysis. Possibly due to the apparent complexity of optimal control theory methods, often dynamic models have not been applied where they would be appropriate. In this article dynamic programming arguments are used to derive optimality conditions directly and simply. They are derived for a renewable resource such as a fishery, but they have application to resource management in general. The approach is illustrated by examples to the extraction of a depletable resource, to feeding for weight gain, and to applying fertilizer when some fertilizer carriers over from one crop season to another. Conditions for the optimal replacement of biological units are also considered.
A Linear Programming Algorithm for Determining Mean‐Gini Efficient Farm Plans
Authors: Okunev John , Dillon John L.
Published: January 2020

A linear programming algorithm is presented for determination of farm plans that are efficient under the mean‐Gini criterion. Use of the algorithm is illustrated by applying it to a standard problem from the literature. The set of efficient plans is compared with those based on mean‐variance and MOTAD analysis of the same problem.
A Note on Private Farm Management Consulting Services: The Case of Argentina
Authors: Gallacher Marcos
Published: January 2020

The paper discusses the evolution and perspectives of private farm management consulting in Argentina. In the first part, recent developments in consulting services are presented. Because of its importance, particular emphasis is placed in the evolution of consulting work done in the framework of the CREA (Consorcios Regionales de Experimentación Agricola) association of farm producers. Rough estimates show that: (a) private consulting represents 10‐15% of total manpower devoted to direct farmer advice, and (b) demand for consulting work has grown considerably faster in areas where farms have mixed (crop‐livestock) production systems.

The possible incentives for farmers hiring consulting services are summarized. The widespread (in Argentina) opinion that consultants allow higher yields from a given input mix is not fully supported by the empirical data presented in this paper: there is evidence that yield differences found on farms are caused not only by the presence or absence of consultants but also (and perhaps primarily) by differences in land quality. The fact that the average farmer may be (at least on a yield basis) as efficient as the ‘top’ farmers should be further studied, as it has important implications from a policy point of view.
Malawi's Agricultural Development: A Success Story?
Authors: Sofranko Andrew J. , Fliegel Frederick C.
Published: January 2020

At a time when attention was focused on Africa's poor agricultural performance, Malawi demonstrated a capacity not only to feed itself, but to produce a surplus for export. During the periods covered in this paper, its agricultural growth exceeded that of most African countries and compared favorably with 'success stories' on the continent. This research focuses on Malawi's recent performance, with particular attention on trends in the provision of essential agro‐support services: credit; extension and farmer training; and input supply and marketing. Trends in these services are examined first at the national level and then at the district level. While overall trends indicate substantial progress, district level data reveal extensive unevenness. Moreover, at the farm level, census data on farmer training and technology utilization show fewer benefits to female operators and smaller farmers.

Important elements of developmentally oriented infrastructure and services have been put in place and are functioning better than in most African countries. This is important in terms of longer‐term agricultural development prospects. There is ample evidence, however, that Malawi's progress has not spread across different segments of the farm population or Agriculture Development Districts. Both the unevenness and overall progress have been heavily influenced by donor‐support.
Evaluating Agricultural Energy Policies Under Uncertainty: The Case of Electricity in South India
Authors: Babu Suresh Chandra , Hallam Arne
Published: January 2020

Farmers' attitude towards risk associated with the availability of energy inputs will influence their investment behavior and demand for energy inputs. In order to analyze policies that reduce the risk in energy availability, some modifications in methods are required. This study, using a mean‐variance framework, demonstrates how cross‐sectional data and time‐series data on crop yields and prices can be used to analyze agricultural energy policies under uncertainty in a developing country context. It is argued that the farmers risk attitudes, their crop allocation behavior, changes in the demand for energy inputs and the stochastic relationship between various forms of energy inputs can be explained by the various energy constraints faced by them. Furthermore, using the same methods the impact of policies which affect these constraints, can be analyzed.
Derivation of Long‐run Factor Demands from Short‐run Responses
Authors: Guyomard Hervé , Vermersch Dominique
Published: January 2020

The concept of the restricted cost function provides a dual approach to the analysis of short‐run technology. It allows also, under curvature restrictions, inference of the different possible equilibria, according to constraints on the firms. Moreover, in this paper, the properties of the restricted cost function are spelled out. Substitution possibilities related to the different regimes are also derived from the restricted cost function.

This theoretical framework is applied to characterize the French cereal‐producing sector by using a cross‐section of farms.
Does Agricultural Growth in Poor Countries Harm Agricultural‐Exporting Rich Countries?
Authors: Anderson Kym
Published: January 2020

The commonly held view that agricultural‐exporting developed countries would lose from agricultural growth in less‐developed countries (LDCs) is shown to be based on an incomplete argument. It considers only the effects on LDC agricultural supply, or at best only that and the first‐round effects of increased farmer incomes on the demand for tradables. What also needs to be considered is the effect on the demand for nontradables and hence the second‐round effects of increased spending by producers of nontradables. When all these effects are considered, the positive correlations obtained between agricultural output growth in LDCs and agricultural imports from developed countries is not surprising. It is then shown that selling or giving away agricultural research and management skills to developing countries can be beneficial to developed countries, including agricultural exporters: by setting out to do good, they may end up also doing well.
An econometric choice for extension‐teaching methods: the Ilorin and Oyo North Agricultural Development Projects' experience
Authors: Umeh J. Chinedu
Published: January 2020

The appropriate combination of extension‐teaching methods for rapid farm‐technology diffusion and sustained productivity growth in the World‐Bank‐Assisted Agricultural Development Project in rural Nigeria is examined. The multiple extension‐teaching methods in the Ilorin and Oyo North Projects have led to self‐defeating and counterproductive results. Using principal‐components analysis, the ten extension‐teaching methods (variables) are transformed into a linear equation by allocating relative weights to each variable. These weights (coefficients of the equation), which are reasonably unique to each variable, measure the relative importance of the variables and therefore facilitate their ranking in each of the project districts.

The usefulness of the principal component model in the World‐Bank‐Assisted Agricultural Development Projects in particular, and the rural Nigerian agricultural industry in general, are briefly discussed.
Developing country debt: implications for agricultural trade
Authors: Gunasekera H. Don B.H. , Bowen Bruce , Andrews Neil
Published: January 2020

There has been a sharp decline in the rate of economic growth in many developing countries in the 1980s compared with the 1970s. Reduced availability of external finance following the international debt crisis has been identified as one of the most important factors responsible for this decline. At the same time there has been a slowdown in the rate of growth of food imports to these countries, particularly to the highly indepted ones.

The focus in the paper is on the implications for international agricultural commodity markets of a dept write‐off in developing countries. To analyse these implications a world agricultural trade model is used. Specifically, the analysis covers the effect of existing debt on the permanent incomes of developing debtor countries and developed creditor countries, and hence the effect on agricultural commodity markets.

The results indicate that, if the debts of the developing countries were written off, prices would improve in consequence of the resulting rise in their permanent incomes. If the debt write‐off also led to growth in developing countries returning to the levels prevalent before the debt crisis, the improvements in world prices would be likely to be much larger.
Variability in wheat export demand elasticity: Policy implications
Authors: Devadoss S. , Meyers William H.
Published: January 2020

Agricultural economists and policy makers in the United States believe that the magnitude of the export demand elasticity is one of the most important parameters used in farm policy decisions. However, past empirical estimates show wide variation in the size of the U.S. export demand elasticity. Reasons for this wide variation go beyond differences in model specification, estimation methods, and period of estimation to involve factors such as trade policies and changes in the supply and demand conditions of foreign countries. In view of the continual variation in magnitude, the elasticity of export demand should be viewed as a variable rather than as a parameter. In this study, U.S. wheat export demand elasticities are computed using a world wheat trade model. The estimates show that the elasticities vary significantly over time. They also reveal that elimination of trade barriers would more than double wheat export demand elasticities.
Risk preference and optimal crop combinations in upland Java, Indonesia: an application of stochastic programming
Authors: Nanseki Teruaki , Morooka Yoshinori
Published: January 2020

A stochastic programming model was used to evaluate the economic performance of a soybean‐based farming system in upland Java. The model incorporates farmers' risk preferences, revenue fluctuations and resources restrictions. The results show that (1) changes in risk preference do affect the optimal crop combination, and (2) the typical cropping pattern is rational under the present level of the farmers' risk preference estimated in the study site.
Economic issues in tariffication: an overview
Authors: Moschini Giancarlo
Published: January 2020

The agricultural trade liberalization proposal known as ‘ tariffication’ aims at converting all existing non‐tariff barriers (NTBs) to trade into bound tariffs, and to reduce these tariffs over time. This is in tune with the original philosophy of the General Agreement on Tariffs and Trade (GATT) and it calls for a dramatic overhaul of existing agricultural policies in many developed countries. The main economic issues that arise with tariffication stem from the non‐equivalence of tariffs and NTBs in a number of scenarios. This paper analyzes non‐equivalence arising from the existence of: imperfect competition in importing countries; price instability in importing and exporting countries; and, inefficient allocation of quantitative restrictions. It is shown that in all these cases the definition of an appropriate 'equivalent tariff to be used in tariffication is not straightforward, and that in general this equivalent tariff cannot be computed on the basis of only observed price differences between countries. Tariff‐rate quotas, which are meant to be the main tool of implementation of tariffication according to the existing proposal, are analyzed in some detail. Concerning the relationship between tariffication and the other elements of the trade liberalization package, it is shown that tariffication would limit the scope of export subsidy policies. It is also shown that the existence of production and export subsidies makes observed price gaps between countries of questionable value in setting equivalent tariff levels. Finally, it is argued that the main focus of tariffication should be the conversion of NTBs to acceptable long‐run (bound) tariffs rates, and considerable flexibility in this conversion process could be exercised in the transition period.
Agricultural settlement with joint production services
Authors: Feinerman Eli , Kislev Yoav
Published: January 2020

A theory of settlement planning focussing on village‐level production services is presented, and settlement plans are compared. The analysis draws on the modern theory of local public goods. Conditions for optimal level of services and optimum settlement size are derived, together with rules of finance of collective operations. The value of the right to settle is calculated for the cases considered.
Capital accumulation and the growth of aggregate agricultural production
Authors: Haley Stephen L.
Published: January 2020

This report empirically examines the role which capital accumulation plays in the growth of agricultural production potential. The report assumes that the degree to which available technology can be implemented in a nation's agricultural sector depends on accumulated investments that have been made in the sector. Results from estimating aggregate agricultural production functions show the primary importance of rural labor in accounting for agricultural gdp and crop production. Capital accumulation is the dominant explainer of livestock production. Estimation results support the conjecture that capital tends to save scarce land resources (substitute relationship) and use rural labor (complementarity relationship). Output supply elasticities derived from the estimated equations tend to be large. The large elasticities imply that price distortions have had large impacts on resource use and production.
Urbanization and food imports in sub‐Saharan Africa
Authors: Tabi James , Howard Wayne H. , Phillips Truman
Published: January 2020

The Granger statistical test of causality was used to examine the relationship between total food imports and urbanization and between food aid and urbanization. Urbanization appears to have caused total food imports to increase in 13 of the 24 countries. Food imports appear to be a cause of urbanization in three countries. Food aid, however, apparently was a cause of urbanization in 16 of the 24 countries used in the analysis.
Institutional effects on changes in Chinese foodgrain production and its variability
Authors: Wan Guang H.
Published: January 2020

By applying variance decomposition technique to the regional data from China, this paper discusses possible impact on Chinese foodgrain production and its variations created by institutional changes, including imposition of procurement quota and the introduction of the agricultural production responsibility system (APRS). Despite the imperfection of the analytical tool used, the results are quite useful and imformative.
Canadian dairy policy and the returns to federal dairy cattle research
Authors: Fox Glenn , Roberts Bruce , Brinkman George L.
Published: January 2020

The economic surplus approach is used to estimate the returns to federal investments in dairy cattle research in Canada. A national supply function is estimated using time series data. Lagged research expenditures are included as explanatory variables in the model, facilitating the calculation of ***marginal as well as average benefits from research. Simulation analysis is used to study the effects of product market distortions associated with Canadian dairy policy as well as of the marginal excess burden on the rates of return to research and on the distribution of research benefits. Returns were found to be high at the margin. Distortions in the product market had a small effect on the overall returns to dairy cattle research but had a large impact on the distribution of research benefits. Rate of return estimates were found to be indicative of underinvestment even when the marginal excess burden was taken into account.
Impacts of capital and land constraints on the economics of new livestock technology in western Kenya
Authors: Nyaribo Fanny B. , Young Douglas L.
Published: January 2020

The introduction of new forages and milk marketing improvements was projected to permit even the smallest modeled farms in a western Kenya region to adopt dual‐purpose goats and thereby improve family income and nutrition. Expanded credit permitted modeled medium and large farms, especially, to vigorously exploit these innovations; credit also expanded income more than did goat management improvements. Because credit, extension assistance, marketing improvements, and new forages will leave projected incomes of small farmers below those of medium and large farmers in the study region, development of off‐farm jobs may still be necessary to supplement the incomes of this fast growing group. The marginal value of capital for medium and large farmers with new livestock technology was high. This suggests that government‐subsidized credit might be unnecessary. With proper infrastructural and legal support, private capital markets might develop as new livestock technology and marketing improvements expand the demand for borrowing.
Effects of subsidized wheat consumption by state in India
Authors: Chellaraj G. , Brorsen B. Wade , Farris Paul L.
Published: January 2020

This paper reports the results of a study of the effects of the Indian government's consumer subsidies on wheat demand. Results indicate consumption of subsidized wheat is higher in urban areas than in rural areas. The public distribution of wheat in most states had little effect on demand in the commercial market, which suggests the government is effective in targeting subsidized wheat to poor consumers.
Estimation and use of risk aversion coefficient for traditional dryland agriculture in western Sudan
Authors: Elamin Eltighani M. , Rogers LeRoy F.
Published: January 2020

This paper explores the importance of including risk when modeling subsistence‐oriented agriculture in a developing nation. The specific objective is to measure the degree of risk aversion for typical farmers in the smallholder traditional agriculture of the Sudan. The procedure followed is to impute the farmer's risk aversion coefficient through a mathematical risk programming technique. Imputed farmers' risk aversion coefficients were used to validate the model specified and identify, for further analysis, a single risk optimal farm plan for each of the different farm situations studied.
Cardinal criteria for ranking uncertain prospects
Authors: Bigman David
Published: January 2020

The purpose of this paper is to develop criteria for comparing and ranking uncertain prospects when we have some information on the extent to which agents are risk‐averse. The basis for these comparisons is the value of the certainty equivalent outcome of the corresponding uncertain prospects. Clearly, the ranking established by the values of the certainty equivalent outcome is identical to the ranking established by the expected utility of the outcome. By comparing the former values, however, we can determine not only the ranking of the uncertain prospects under consideration but we can also determined by how much one prospect would be more valuable than the other in terms of money – for that particular agent.

The paper develops expressions for approximating the values of the certainty equivalent outcomes on the basis of the central moments of their distribution and the value of the underlying coefficient of variation. These criteria are then applied for comparing alternative crop rotation and irrigation practices of wheat in Israel.
Labour on the family farm: a theory under uncertainty – an extension
Authors: Bar‐Shira Ziv , Finkelshtain Israel
Published: January 2020

In a framework developed by P.J. Dawson, the effects of output price risk on the family labour supply and its demand for hired labour are investigated. In particular, the effects of changes in autonomous income, expected output price, family composition, and farm size‐are studied. Comparative statics is used to sign these effects, revealing the importance of the behavior of the measures of absolute, relative and partial risk aversion in determining them. It is shown that some of the effects may be determined only via empirical research.
Livestock pricing policy in sub‐Saharan Africa: objectives, instruments and impact in five countries
Authors: Williams Timothy O.
Published: January 2020

Livestock pricing policies in many developing countries are often instituted without a good appreciation of the consequences of such policies for allocative efficiency, output and trade. This paper evaluates, in a comparative cross‐country context, the objectives and instruments of livestock pricing policy in five sub‐Saharan African countries: Ivory Coast, Mali, Nigeria, Sudan and Zimbabwe during the period 1970‐86. It assesses the extent to which pricing policy objectives have been attained, and also estimates the effects of price interventions on output, consumption, trade and government revenues in order to draw out lessons for the future.

The empirical results indicate that in comparison with real border prices, a certain degree of success was achieved in stabilising real domestic producer prices in the study countries. The results also show that since the early 1980s, there has been a gradual shift away from taxation of producers. However, consumers still appear to gain as much as producers in three of the study countries, with negative consequences for foreign exchange earnings and government revenues. The analysis reveals the importance of domestic inflation and exchange rates as key variables for livestock pricing policies and highlights the need to address the macroeconomic imbalances that cause exchange rate distortions and high domestic inflation at the same time that direct price distortions are being tackled.
Efficiency of U.S. conservation‐compliance program
Authors: Govindasamy Ramu , Huffman Wallace
Published: January 2020

Under the conservation‐compliance program, most of the individual producers are forced to cut their soil erosion to 7 t per acre annually irrespective of the marginal cost of controlling soil erosion. In a system where coupons to a ton of soil loss were issued to producers and traded, the marginal cost of controlling soil loss within each soil type and across different soil types would be equalized. An instrumental variable procedure was used to determine the effect of soil erosion on net profits. The results for Iowa show that there is considerable difference in the marginal opportunity cost of controlling soil erosion between soil types. By assigning one ton of erosion to Iowa soil type Downs (5‐10% slope) instead of Clarion (2‐5% slope), there is a savings of $5.00 per acre for the society as a whole. The tradable coupon system is not only efficient, but will also bring in more land under soil conservation.
Chile's agricultural diversification
Authors: Arnade Carlos , Sparks Amy
Published: January 2020

Chile's fruit sector, both in production and exports, has grown significantly since 1974. At that time, Chile introduced structural reforms in its economy which assured that market principles would operate regarding land ownership. Also, the government began a ‘hands‐off’ policy which basically allowed free‐market principles to prevail. As a result of these conditions operating in the economy, Chile's agricultural sector diversified from producing largely annual crops and wool to also producing a significant amount of commercial fruit crops. A second round of diversification is currently underway within the fruit industry where pears and peaches are being produced and exported in addition to apples and table grapes.

In this paper we derive decision criteria when aggregate performance is evaluated from the perspective of maximizing a risk‐averse utility function. Empirical evidence on Chilean fruit exports indicates that, on an aggregate level, Chilean fruit exporters are following the path of utility maximization and validates the sequence by which Chilean producers introduced nontraditional crops over time. While on an individual level there may be complex factors and constraints involved in the planting decisions, the results of this study seem to indicate that the sum of producer behavior satisfies the conditions required for maximizing a risk‐averse utility function.
An application of Target MOTAD Model to crop production in Zambia: Gwembe Valley as a case study
Authors: Maleka Phiri
Published: January 2020

The Zambian Government encourages crop production in the Gwembe Valley without taking into consideration the risks involved. These risks mainly originate from the stochastic nature of rainfall. This paper, therefore, identifies optimal cropping patterns in the Gwembe Valley by using Target MOTAD Model. The results of the Target MOTAD Model indicate an optimal cropping pattern of growing sorghum, rice and soyabeans. This is different from the existing cropping pattern of sorghum, sunflower, cotton and maize. The overall policy implication of adopting the cropping pattern obtained from the model solution is that some resources allocated to the production of current crops have to be reallocated to the production of new crops. Moreover, since people in the Gwembe Valley are used to growing of cotton, sunflower and maize, the adoption of the suggested new crops will entail the education of the people (through extension services) in the crop husbandry of these crops.
Risk analysis of new maize technology in Zaire: a portfolio approach
Authors: Ames Glenn C.W. , Reid Donald W. , Hsiou Li‐Fang
Published: January 2020

Risk associated with the adoption of new maize technology and the impact of mandatory cotton production on traditional farmers in the Kasai Oriental Region of Zaire are evaluated within a portfolio context using a quadratic programming model. Seasonal net returns for farm plans including four levels of maize technology in combination with staple food crops are evaluated, with and without mandatory cotton production. The results indicate that cropping systems that include new maize technology are risk‐efficient relative to local maize varieties while mandatory cotton production is not risk‐efficient at the prevalent price and yield levels in the farming system.
Peasant household modelling: Farming systems evolution and sustainability in northern Zambia
Authors: Holden Stein T.
Published: January 2020

Chitemene slash‐and‐burn cultivation continues to be a dominating cropping system in northern Zambia even after the introduction of modern technologies such as hybrid maize and fertilizer. The rationale of farming systems evolution in northern Zambia where labour markets have been absent or highly imperfect, has been analyzed by goal programming based on the theories of Chayanov (1966) and Nakajima (1986). Carrying capacity estimation is incorporated in the models and discussed in relation to the sustainability of land use systems in the area.

The major changes in agricultural technologies in northern Zambia during this century has been the introduction of cassava, maize and fertilizer technologies. Cassava has had the most significant impact since the land could support much higher population densities and since the dependence on the chitemene system no longer was critical for the survival of peasants. By switching from finger‐millet to cassava as the main staple the peasants could reduce their total labour recquirement to meet their basic food needs by as much as 40%. The results also show that the maize‐fertilizer technology has been unable to replace the chitemene system because economic incentives to continue the system exist as long as there is suitable woodland available. Nevertheless, the introduction of the maize‐fertilizer technology may have resulted in reduced chitemene cultivation. The rapid expansion of maize production in northern Zambia from the late 70s to the late 80s depended critically on the government policy of equity pricing and input subsidisation. The models predicted that the removal of fertilizer subsidies would result in a dramatic reduction in maize production.
A generalized Armington trade model: Respecification
Authors: Yang Seung‐Ryong , Koo Won W.
Published: January 2020

Even if the original version of the Armington model is simple and plausible in estimation, the single CES and homotheticity assumptions are too restrictive for practical application and give biased price elasticities. This paper develops a generalized Armington model, which relaxes the single CES and homotheticity restrictions, and includes the Armington model as a special case. The Armington and generalized Armington trade models are applied to the Japanese meat import demand to demonstrate their performance. The empirical results rejected the two assumptions imposed on the Armington model. The generalized Armington model provides an alternative to the restrictive but indispensable Armington model.