bluuebunny/crossref_metadata_2025 huggingface dataset:
Plant macrofossils from the Lower Channel sediments at Marsworth, Buckinghamshire, UK
Authors: FIELD MICHAEL H.
Published: September 2010

Results from studies of sediments in the Pitstone No. 3 quarry near Marsworth, Buckinghamshire, England have raised the issue of a possible temperate episode between the Ipswichian and Hoxnian stages of the British Pleistocene. Plant macrofossils were studied from the fossiliferous Lower Channel muds, in which the probable temperate episode was represented, in an attempt to reconstruct the contemporary vegetation and to make inferences about the environment in which these sediments were deposited. Taxa recovered represented a treeless habitat with low growing herbs dominant. The assemblages may provide evidence of conditions cooler than those in southern England today. Only travertine incorporated into the Lower Channel muds and travertine made it impossible to determine the precise age of these sediments. The travertine could represent an additional temperate event between the Ipswichian and Hoxnian Stages. Alternatively, the travertine may have been deposited during the Hoxnian Stage and then reworked into the Lower Channel muds. This could have occurred at the beginning of the cold Wolstonian Stage or in an interstadial within this stage.
Survival and recovery of perennial forage grasses under prolonged Mediterranean drought: I. Growth, death, water relations and solute content in herbage and stubble
Authors: VOLAIRE FLORENCE , THOMAS HENRY , LELIÈVRE FRANÇOIS
Published: September 2010

Swards of Dactylis glomerata cultivars (cvs) KM2 and Lutetia and of Lolium perenne cvs Aurora and Vigor were grown under full irrigation or prolonged summer drought (80 d) in a field experiment in the South of France.

After irrigation was withheld, leaf extension rates of all cvs fell by 90% within 9–12 d, and rapid scorching of laminae followed. Tiller mortality at the end of the drought was very different in the cocksfoot cvs (4% for KM2 and 76% for Lutetia) and intermediate (41%) for both ryegrass cvs. Following re‐watering, rates of herbage regrowth were closely correlated with tiller survival. Measured minerals contributed c. 0·52 MPa to osmotic potential in all treatments, whereas water‐soluble carbohydrates (WSC) contributed 0·25 MPa under irrigation and 0·46 MPa during drought.

There was no systematic difference between the two species for summer survival under severe drought, but large differences between the cocksfoot cvs. The traits most strongly associated with superior survival were: (a) a deep root system and greater water uptake at depth; (b) low water and osmotic potentials in surviving laminae, i.e. better tolerance to dehydration; (c) large pool‐size of WSC reserves (fructans having degree of polymerization >4) in entire tiller bases (stubble); (d) low accumulation of proline in stubble; (e) rapid nitrogen uptake after rewatering.
Interactions between needles of Pinus resinosa and ectomycorrhizal fungi
Authors: KOIDE R. T. , SUOMI L. , STEVENS C. M. , McCORMICK L.
Published: September 2010

Relatively little is known about the factors controlling ectomycorrhizal fungal communities. One possible factor is forest litter chemistry. In a series of experiments we demonstrated that the growth of ectomycorrhizal fungi able to colonize red pine (Pinus resinosa Ait.) are differentially affected by red pine needles and needle chemical components. For example, water extracts of pine needles stimulated the growth of Suillus intermedius (Smith & Thiers) Smith & Thiers and inhibited the growth of Amanita rubescens Pers. Catechin and epicatechin gallate, components of the water extract, acted similarly to the extract. The volatile compounds α‐ and β‐pinene also had differential effects on the growth of the various species of ectomycorrhizal fungi. Our results suggest that forest litter chemistry has the potential differentially to affect the growth of ectomycorrhizal fungal species and so could affect the structure of ectomycorrhizal fungal communities.
Gibberellins: regulating genes and germination
Authors: RITCHIE SIAN , GILROY SIMON
Published: September 2010

The range of processes regulated by gibberellins (GAs) covers all aspects of the life history of the plant from seed germination to vegetative growth and flowering. In seeds there has been an intensive search, using the techniques of both biochemistry and cell biology, for the regulatory molecules linking GA perception to gene regulation and the events of germination. Although a GA receptor has yet to be identified, the site of perception has been localized to the plasma membrane. Calmodulin, Ca2+ and cGMP have also been identified as elements of the GA signal transduction pathway. These regulators parallel many of the signalling elements identified in the transduction of other signals such as phytochrome and ABA. Studies of GA‐regulated gene expression, principally of the α‐amylases of cereal aleurone, have identified core GA‐responsive promoter elements, such as the gibberellin response element (GARE), box‐1 and pyrimidine boxes, as well as elements that may lend specificity to GA‐regulated expression, such as the Opaque‐2‐similar element (O2S), and TRE and CRE motifs. One of the most striking features of all of these studies of the molecular basis of GA action is the interaction of GA‐dependent regulatory elements with those of other factors such as ABA. GA‐response elements also appear to be conserved between disparate GA‐response systems. For example, Myb transcription factors appear to regulate a multitude of GA‐induced genes in cereal aleurone as well as to alter GA responses when expressed in Arabidopsis. Thus the study of GA signal transduction and response systems is highlighting the conservation of regulatory elements used by plants. These common factors, used by distinct signal transduction systems, provide a molecular basis for the integration of the GA signal with other growth regulators that is the hallmark of plant growth and development.

CONTENTS

Summary
363

I.
Introduction
364

II.
Responses of cereal aleurone to GA
364

III.
GA and genes
370

IV.
Conclusions and perspectives
378

Acknowledgments
379

References
379
Evolution of the type III secretion system and its effectors in plant–microbe interactions
Authors: McCann Honour C. , Guttman David S.
Published: September 2010

Many bacterial plant pathogens require the type III secretion system (T3SS) and its effector proteins (T3SEs) to invade and extract nutrients from their hosts successfully. While the molecular function of this system is being studied intensively, we know comparatively little about the evolutionary and ecological pressures governing its fate over time, and even less about the detailed mechanisms underlying and driving complex T3SS‐mediated coevolutionary dynamics. In this review we summarize our current understanding of how host–pathogen interactions evolve, with a particular focus on the T3SS of bacterial plant pathogens. We explore the evolutionary origins of the T3SS relative to the closely related flagellar system, and investigate the evolutionary pressures on this secretion and translocation apparatus. We examine the evolutionary forces acting on T3SEs, and compare the support for vertical descent with modification of these virulence‐associated systems (pathoadaptation) vs horizontal gene transfer. We address the evolutionary origins of T3SEs from the perspective of both the evolutionary mechanisms that generate new effectors, and the mobile elements that may be the source of novel genetic material. Finally, we propose a number of questions raised by these studies, which may serve to guide our thinking about these complex processes.

Contents

Summary
33

I.
Introduction
34

II.
The type III secretion system and the plant immune system
34

III.
The evolution of the type III secretion apparatus
36

IV.
The evolution of type III secreted effectors
39

V.
The origin of type III secreted effectors
41

VI.
Conclusion and future directions
43

Acknowledgements
44

References
44
Development and physiology of the brown alga Ectocarpus siliculosus: two centuries of research
Authors: Charrier Bénédicte , Coelho Susana M. , Le Bail Aude , Tonon Thierry , Michel Gurvan , Potin Philippe , Kloareg Bernard , Boyen Catherine , Peters Akira F. , Cock J. Mark
Published: September 2010

Brown algae share several important features with land plants, such as their photoautotrophic nature and their cellulose‐containing wall, but the two groups are distantly related from an evolutionary point of view. The heterokont phylum, to which the brown algae belong, is a eukaryotic crown group that is phylogenetically distinct not only from the green lineage, but also from the red algae and the opisthokont phylum (fungi and animals). As a result of this independent evolutionary history, the brown algae exhibit many novel features and, moreover, have evolved complex multicellular development independently of the other major groups already mentioned. In 2004, a consortium of laboratories, including the Station Biologique in Roscoff and Genoscope, initiated a project to sequence the genome of Ectocarpus siliculosus, a small filamentous brown alga that is found in temperate, coastal environments throughout the globe. The E. siliculosus genome, which is currently being annotated, is expected to be the first completely characterized genome of a multicellular alga. In this review we look back over two centuries of work on this brown alga and highlight the advances that have led to the choice of E. siliculosus as a genomic and genetic model organism for the brown algae.

Contents

Summary
319

I.
Introduction
320

II.
Diversity and taxonomy, distribution and ecology
321

III.
Development
321

IV.
Metabolism
326

V.
Interactions with the environment
327

VI.
Conclusion
328

Acknowledgements
329

References
329
The physicochemical and sensory properties of milk supplemented with ascorbic acid‐soluble nano‐chitosan during storage
Authors: SEO MI HWA , CHANG YOON‐HYUK , LEE SEONG , KWAK HAE‐SOO
Published: September 2010

This study was carried out to assess the feasibility of adding the ascorbic acid‐soluble nano‐chitosan (AANC) into the milk for improving the functionality of milk and to determine the effects of such addition on the physicochemical and sensory properties of the product during storage. The pH and titratable acidity of the AANC milks were not changed significantly when stored at 4°C for 15 days. The addition of the nano‐chitosan solution (1∼9%, v/v) into the milk samples led to an increase in the amounts of L‐ascorbic acid, thereby indicating an enhancement in health benefits. The sensory test revealed that astringency scores increased and colour scores decreased when the highest concentration of the nano‐chitosan solution (9%, w/w) was added into the milk samples The colour values, L‐ and a‐, in the milks were not significantly influenced by adding the nano‐chitosan solution (1∼9%, v/v); whereas the b‐values significantly increased with the addition of the nano‐chitosan solution (5∼9%, v/v). Based on the data obtained from this study, it is concluded that the low concentrations (1∼3%, v/v) of the nano‐chitosan solution could be used to produce a nanopowdered chitosan‐added milk without the significantly adverse effects on the physicochemical and sensory properties.
The effects of date syrup and guar gum on physical, rheological and sensory properties of low fat frozen yoghurt dessert
Authors: MILANI ELNAZ , KOOCHEKI ARASH
Published: September 2010

The effect of adding date syrup (0%, 25% and 50% as sugar replacement) and guar gum (0%, 0.1%, 0.2% and 0.3% as fat replacement) was examined in respect of physicochemical, rheological and sensory properties of low fat frozen yoghurt. Increasing date syrup and guar gum concentration increased the mixture viscosity and acidity. Guar gum softened the frozen yoghurt whereas date syrup increased the hardness of the product. The control yoghurt was less sticky than samples containing the gum, but date syrup had no significant effect on the samples stickiness. Melt‐down stability of the samples also increased with increase in gum and date syrup concentration. The low fat orange flavoured frozen yoghurt dessert prepared in this study also had good sensory properties.
The Ties Made in the Harvest: Nicaraguan Farm‐worker Networks in Costa Rica's Agricultural Exports
Authors: LEE SANG E.
Published: September 2010

Traditional and nontraditional export agriculture expansion dramatically changed the social and economic landscapes in the global south. An examination of one aspect of south–south international migration, Nicaraguan migrant economic integration into Costa Rica's export agriculture sector, reveals how production systems in the traditional and nontraditional agricultural sectors shape migrant social networks in distinct ways in the global south and its significance for both migrant workers and the agricultural sectors they work in. The rapid expansion of nontraditional export agriculture – the essence of agricultural development in Costa Rica – depends on the traditional crop production structure of coffee farms. The experiences of Nicaraguan migrant workers and their social ties to each other in nontraditional export agriculture and the coffee farms in Costa Rica demonstrate how different production structures call for distinct fragile and conflicted social networks ties between migrants. The economic integration of migrant workers relies on opportunistic and weak ties that are both gendered and contradictory.
Is Bt Cotton a Pro‐Poor Technology? A Review and Critique of the Empirical Record
Authors: GLOVER DOMINIC
Published: September 2010

Policy makers, journalists and other commentators have hailed genetically modified (GM) crops as a ‘pro‐poor’ success in the developing world. Their confidence appears to be justified by the encouraging conclusions reached by academic studies on the performance and impacts of GM crops, which seem to provide convincing evidence of substantial benefits for smallholders in developing countries. However, a detailed, critical examination of studies on transgenic, insect‐resistant cotton in China, India and South Africa demonstrates that the technology's impacts have been evaluated and represented in selective and misleading ways. The performance and impacts of GM crops have in fact been highly variable, socio‐economically differentiated and contingent on a range of agronomic, socio‐economic and institutional factors. The shortcomings of the GM crop‐impacts literature have done a disservice to public and policy debates about GM crops in international development and impeded the development of sound, evidence‐based policy.
Replication of an association of variation in the FOXO3A gene with human longevity using both case–control and longitudinal data
Authors: Soerensen Mette , Dato Serena , Christensen Kaare , McGue Matt , Stevnsner Tinna , Bohr Vilhelm A. , Christiansen Lene
Published: September 2010

Genetic variation in FOXO3A has previously been associated with human longevity. Studies published so far have been case–control studies and hence vulnerable to bias introduced by cohort effects. In this study we extended the previous findings in the cohorts of oldest old Danes (the Danish 1905 cohort, N = 1089) and middle‐aged Danes (N = 736), applying a longitudinal study design as well as the case–control study design. Fifteen SNPs were chosen in order to cover the known common variation in FOXO3A. Comparing SNP frequencies in the oldest old with middle‐aged individuals, we found association (after correction for multiple testing) of eight SNPs; 4 (rs13217795, rs2764264, rs479744, and rs9400239) previously reported to be associated with longevity and four novel SNPs (rs12206094, rs13220810, rs7762395, and rs9486902 (corrected P‐values 0.001–0.044). Moreover, we found association of the haplotypes TAC and CAC of rs9486902, rs10499051, and rs12206094 (corrected P‐values: 0.01–0.03) with longevity. Finally, we here present data applying a longitudinal study design; when using follow‐up survival data on the oldest old in a longitudinal analysis, we found no SNPs to remain significant after the correction for multiple testing (Bonferroni correction). Hence, our results support and extent the proposed role of FOXO3A as a candidate longevity gene for survival from younger ages to old age, yet not during old age.
Chronic Care Improvement in Primary Care: Evaluation of an Integrated Pay‐for‐Performance and Practice‐Based Care Coordination Program among Elderly Patients with Diabetes
Authors: Fagan Peter J. , Schuster Alyson B. , Boyd Cynthia , Marsteller Jill A. , Griswold Michael , Murphy Shannon M. E. , Dunbar Linda , Forrest Christopher B.
Published: September 2010

Objective.To examine the effects of an intervention comprising (1) a practice‐based care coordination program, (2) augmented by pay for performance (P4P) for meeting quality targets, and (3) complemented by a third‐party disease management on quality of care and resource use for older adults with diabetes.

Data Sources/Study Setting.Claims files of a managed care organization (MCO) for 20,943 adults aged 65 and older with diabetes receiving care in Alabama, Tennessee, or Texas, from January 2004 to March 2007.

Study Design.A quasi‐experimental, longitudinal study in which pre‐ and postdata from 1,587 patients in nine intervention primary care practices were evaluated against 19,356 patients in MCO comparison practices (>900). Five incentivized quality measures, two nonincentivized measures, and two resource‐use measures were investigated. We examined trends and changes in trends from baseline to follow‐up, contrasting intervention and comparison group member results.

Principal Findings.Quality of care generally improved for both groups during the study period. Only slight differences were seen between the intervention and comparison group trends and changes in trends over time.

Conclusions.This study did not generate evidence supporting a beneficial effect of an on‐site care coordination intervention augmented by P4P and complemented by third‐party disease management on diabetes quality or resource use.
Improving Timely Childhood Immunizations through Pay for Performance in Medicaid‐Managed Care
Authors: Chien Alyna T. , Li Zhonghe , Rosenthal Meredith B.
Published: September 2010

Objective. To evaluate the impact of a “piece‐rate” pay‐for‐performance (P4P) program aimed at rewarding up‐to‐date immunization delivery to 2‐year‐olds according to the recommended series.

Data Sources/Study Setting. Plan‐level data from New York State's Quality Assurance Reporting Requirement and claims data from Hudson Health Plan for 2003–2007. In 2003 Hudson Health Plan, a not‐for‐profit Medicaid‐focused managed care plan, introduced a U.S.$200 bonus payment for each fully immunized 2‐year‐old and provided administrative supports for identifying children who may need immunization. This represented a potential bonus of 15–25 percent above base reimbursement for eligible 2‐year‐olds.

Study Design. Case‐comparison and interrupted times series.

Principal Findings. Immunization rates within Hudson Health Plan rose at a significantly, albeit modestly, higher rate than the robust secular trend noted among comparison health plans. Supplementary analyses suggest that there was no significant change in preexisting disparities during the study period, and that children with chronic conditions have significantly greater odds of being fully immunized during the entire study period.

Conclusions. This study suggests that a piece‐rate P4P program with appropriate administrative supports can be effective at improving childhood immunization rates.
Piroxicam and carboplatin as a combination treatment of canine oral non‐tonsillar squamous cell carcinoma: a pilot study and a literature review of a canine model of human head and neck squamous cell carcinoma
Authors: De Vos J. P. , Burm A. G. D. , Focker A. P. , Boschloo H. , Karsijns M. , Van Der Waal I.
Published: September 2010

Results of the treatment with a combination of carboplatin and piroxicam in seven dogs with advanced non‐tonsillar oral squamous cell carcinoma (SCC) were retrospectively analysed. This multi‐agent protocol was well tolerated by all dogs and resulted in a complete regression of the tumour without additional surgery in four of seven patients. Additional surgery was necessary to remove a metastatic lymph node in one dog and residual tumour in a second dog, which achieved a partial response following medical therapy. Median follow‐up for all the dogs was 534 days, while the time‐to‐recurrence, time‐to‐progression and overall survival for this group of patients have not yet been reached. Our study, although limited in number of animals, suggests that this multiagent approach is a useful treatment option for oral non‐tonsillarSCC in dogs and warrants wider application.
The Utility of PCR for Antigen Receptor Rearrangement (PARR) in Staging and Predicting Prognosis in Canine Lymphoma
Authors: Lana S. E. , Jackson T. L. , Burnett R. C. , Morley P. , Avery A. C.
Published: September 2010

Introduction:  In lymphoid neoplasia, molecular assays to confirm clonality rely on the fact that lymphoid cells normally contain DNA regions that are unique in sequence, resulting from recombination of the V, D, and J genes. Based on the belief that malignancies are clonal, the presence of a single, clonal rearrangement can indicate neoplasia. In humans with lymphoid malignancies, PCR for antigen receptor rearrangement has been studied as a molecular staging test and a therapeutic monitoring tool. The purpose of this study was to determine the utility of PARR for molecular staging and predicting prognosis in canine lymphoma.

Methods:  Patients with lymphoma who had complete clinical staging were included in the study. All had PARR of pre treatment lymph node, blood and/or bone marrow. All were assigned a clinical stage (WHO 1–5) and a PCR stage (PS) where 0 indicated no clonal expansion in the blood, and 5 indicated the presence of a clonal expansion. In addition to stage, other factors that could affect prognosis were evaluated.

Results:  Eighty six patients were included. Clinical stage was distributed as follows: 3 = 44, 4 = 21, and 5 = 21. Sixty two patients had clonal rearrangements detected in the lymph node and were able to be PCR staged. Seventeen were PS 0 and 45 were PS 5. PCR stage was not prognostic for DFI or survival.

Conclusion:  PARR is sensitive at detecting blood/bone marrow infiltration in canine lymphoma. It is not a useful prognostic tool in the diverse population in this study.
Proteins Involved in Glucose Recognition and Signaling are Expressed by Canine Insulinoma
Authors: Donley V. , Hiskett E. , Schermerhorn T.
Published: September 2010

Introduction:  Canine insulinoma is a functional neoplasia of insulin‐producing endocrine cells that produces hypoglycemia as a result of unregulated secretion of insulin. Knowledge of the molecular defects responsible for the observed functional abnormalities might help understand the clinical behavior of these tumors, predict the response to therapy, and identify potential targets for therapeutic intervention. We examined canine insulinomas to determine expression of beta‐cell proteins known to be important for glucose recognition and signaling.

Methods:  Tissue samples were obtained from naturally‐occurring canine insulinomas at the time of surgery or necropsy. A pancreatic beta cell line was used as control in functional studies. Normal canine pancreas served as control tissue for expression studies. For functional studies, glucose‐induced insulin secretion by cultured canine insulinoma cells was determined using radioimmunoassay. For mRNA expression studies, total RNA was isolated and reverse transcription performed using commercial reagents. The expression of proteins of interest was determined using PCR. Identities of PCR products were confirmed by automated sequence analysis. For protein expression studies, proteins were solubilized in detergent‐containing buffer, resolved by SDS‐PAGE, and detected by immunoblot analysis using specific antibodies.

Results:  Canine insulinoma cells exhibited a half‐maximal glucose response of 1.3 mM (23 mg/dL). Insulinomas were found to express proteins important for glucose responsiveness. Proteins expressed include those involved in glucose recognition (glucokinase, hexokinase), glucose signal transduction (Kir6.2, SUR1), and insulin exocytosis (SNAP 25, syntaxin 1A).

Conclusions:  Canine insulinomas express proteins similar to those found in the normal canine pancreas but exhibit an increased sensitivity to glucose.
The Utility of Flow Cytometry for the Diagnosis of Cranial Mediastinal Malignancy in Canine Patients
Authors: Plaza S. S. , Avery A. C. , Lana S. E.
Published: September 2010

Introduction:  The most common neoplasms located in the anterior mediastinum in the canine are thymoma and lymphoma. Distinguishing between the two is a diagnostic challenge. Treatment and prognosis for these diseases differs significantly. Thymomas contain a population of normally developing T cells. The majority of these T cells exhibit an immature phenotype, characterized by co‐expression of CD4 and CD8. This phenotype is rarely seen on neoplastic lymphocytes. The purpose of this study was to determine if analysis by flow cytometry could discriminate thymoma from lymphoma based on these cell surface markers.

Methods:  Fine needle aspirates were obtained from ten canine patients with mediastinal masses. Cells were analyzed by flow cytometry using a panel of T and B cell markers.

Results:  Six cases with 10% or greater CD4 + CD8+ cells were diagnosed with thymoma and were confirmed by histopathology. Four cases had fewer than 5% CD4 + CD8+ cells, having lymphocytes expressing CD4 only (3 cases) or CD21, a B cell marker(1 case). These were confirmed as lymphoma by cytology and/or a clonality assay. The sensitivity and specificity of this assay when used in the diagnostic work‐up for suspected thymoma was 100%.

Conclusion:  Flow cytometry may provide important, complementary information in the diagnostic work‐up of the canine patient with a mediastinal mass.
Analysis of the Determinants of Adoption of Organic Horticultural Techniques in the UK
Authors: Burton Michael , Rigby Dan , Young Trevor
Published: September 2010

The determinants of the decision to adopt organic production techniques are examined by applying binomial and multinomial logit techniques to a sample of 237 horticultural producers from the UK. The analysis indicates that organic horticultural producers are more likely to be younger, run smaller enterprises and be female than their conventional counterparts, and that there are significant non‐economic aspects to the decision to adopt organic techniques which may be missed in comparative profitability studies. In addition, the analysis indicates that the registered and unregistered organic producers should not be regarded as a homogenous group, with significant differences in terms of the influence of gender and information sources observed.
Assessing the Effects of Hazards and Interventions on Farm Household Liquidity in Sudan ‐ A Preliminary Accounting Model
Authors: Bright Geoff
Published: September 2010

The informed assessment of the effects of hazards on farm households and the design of appropriate interventions requires a knowledge of the pattern of household cash and asset stocks and flows. This paper uses the example of a poor farm household in Kordofan, Sudan to build a debt/savings model and then study the effects of environmental “shocks” and different forms of interventions. The results suggest that, in the absence of external injection in the form of technological improvement or worker remittances, over the period 1988–1992, households would have descended into a debt spiral, even with formal credit. With income improvements solvency would have only been ensured if formal credit had been available. Although more work needs to be done to increase the validity of such “accounting” models of farm household liquidity, this study has established a methodology which can be improved upon and applied elsewhere.
Area Allocation Under Price Uncertainty on Dutch Arable Farms
Authors: Lansink Alfons Oude
Published: September 2010

This paper uses a Mean‐Variance utility function to build a dual model that simultaneously determines area allocation and production/input levels under output price uncertainty. Regularity conditions of the indirect utility function (convexity) and producers risk preferences are tested. The framework is applied to a rotating sample of Dutch arable farms. Dutch arable farmers are found to be risk averse, with the size of the risk premium given by 3 per cent of annual profit. A bootstrap resampling method shows that curvature conditions are rejected. Price elasticities are compared for an unrestricted model and for a model with curvature conditions being imposed.
Irreversible Investment Under Uncertainty: Conservation Easements and the Option to Develop Agricultural Land
Authors: Tegene Abebayehu , Wiebe Keith , Kuhn Betsey
Published: September 2010

A landowner's decision to convert farmland to urban use is presented as an irreversible investment under uncertainty. This approach improves on conventional approaches to the valuation of conservation easements by incorporating option values. This approach also refines the calculation of compensation potentially due to landowners when use of their land is restricted by government policies to protect the environment.
Futures Markets and Spot Price Volatility: A Case Study
Authors: Morgan C. W.
Published: September 2010

Futures markets, where they exist, can play a crucial role in determining the storage decision in the underlying spot (physical) market. The futures market acts as a conduit for market information and is a gatherer of agents' expectations about the future prospects for the spot market. As such, it is able to provide both price insurance and price discovery roles, the latter of which generates information for spot market traders and allows them to make rational storage decisions. If this were to be the case, then the efficiency of storage is improved which can potentially lead to a reduction in the volatility of spot prices over the marketing season. The existing literature is ambiguous as to whether futures markets can help spot markets price more efficiently. This paper seeks to examine whether this is the case in the British maincrop potato market by evaluating the volatility of spot prices over the period 1969–96 in a “before‐after” analysis of the impact of the introduction of futures trading in 1980. The results suggest that the introduction of the futures market has led to a reduction in price volatility, despite some problems in the operation of the futures market itself.
The Role of Attitudes and Objectives in Farmer Decision Making: Business and Environmentally‐Oriented Behaviour in Scotland
Authors: Willock Joyce , Deary Ian J. , Edwards‐Jones Gareth , Gibson Gavin J. , McGregor Murray J. , Sutherland Alistair , Dent J. Barry , Morgan Oliver , Grieve Robert
Published: September 2010

Despite considerable effort to understand and represent decision making by farmers, there has been little attempt to integrate socio‐economic, psychological and farming variables within a comprehensive framework. This paper attempts to do this in the context of two types of farming behaviour ‐ business and environmental ‐for a sample of over 200 Scottish farmers. Using variables covering their attitudes, objectives and behaviours relevant to many aspects of farming, we proposed mediating variables models of business‐oriented and environmentally‐oriented farming behaviours. Structural equation modelling was used to test the adequacy of the proposed models. The results of the study emphasise the importance of psychological factors in the decision making of farmers.
Importance and Need for Rural Development Instruments Under the CAP: A Survey of Farmers' Attitudes in Marginal Areas of Greece
Authors: Dimara Efthalia , Skuras Dimitris
Published: September 2010

The present work assesses the attitudes towards importance and need for providing agricultural development instruments other than traditional grant aid mechanisms in rural areas. Assistance in marketing farm produce, provision of extension services on new agricultural technology, agricultural training and provision of quality standards are four of the instruments examined. The importance and need for providing these instruments depends upon producers' human capital accumulation and farm characteristics. The analysis indicates that different instruments may apply to different parts of the rural population and thus a flexible, multi‐instrument and selective rural development policy may be required.
A Note on the Adoption of Soil Conservation Measures in the Northern Province of South Africa
Authors: Anim Francis D. K.
Published: September 2010

This study attempts to expand the range of explanatory variables used in adoption studies. The results suggest that awareness of soil erosion problems and increases in long‐term profit are significant indicators of the probability of adopting silt traps and contour ploughing as methods of soil conservation. Factors such as age, security of land tenure, informal communication, size of land holding and difficulty of adopting a particular technology, do not appear to be significant determinants of the adoption of soil conservation measures.
The Use of Maximum Entropy to Estimate Input‐Output Coefficients From Regional Farm Accounting Data
Authors: Léony Yves , Peeters Ludo , Quinqu Maurice , Surry Yves
Published: September 2010

This paper proposes the use of the Generalised Maximum Entropy (GME) method to estimate input‐output coefficients, which reflect the unobserved allocation of farm input accounting costs to the various outputs produced. The GME method uses Shannon's information criterion as a basis for estimation. The performance of the GME method is compared with three other estimation techniques: Ordinary Least Squares (OLS), Bayesian estimation, and Linear Programming (LP). The various methods are applied to accounting data from a sample of beef‐dairy farms in Brittany, France. The analysis shows that the GME method offers an interesting alternative to “traditional” estimation methods. In contrast with the latter, though, the GME method is suitable to handle easily the problems of singularity, constrained estimation, and zero‐observations. Moreover, due to its flexibility, transparency and relative ease of implementation, the GME method is of great value to practitioners. However, the sensitivity of the GME estimates with respect to the design of the prior information set needs to be investigated further.
Compliance Monitoring and Agri‐Environmental Policy
Authors: Choe Chongwoo , Fraser Iain
Published: September 2010

This paper examines the issue of compliance monitoring in agri‐environmental policy when a farmer is risk‐neutral and risk‐averse. The optimal contract model presented here significantly extends and generalises the results and conclusions of Choe and Fraser (1998). In this paper the environmental agency explicitly chooses monitoring accuracy and monitoring costs as well as rewards for farmers. It is found that, by modelling the environmental agency as being cost‐conscious optimal monitoring accuracy may or may not be higher for a risk‐averse farmer than for a risk‐neutral farmer. Essentially, the environmental agency faces an explicit trade‐off between monitoring costs and incentive payments as a means to ensure the desired behaviour from the farmer. The importance of the results derived are discussed in the context of agri‐environmental policy design and implementation
Modelling and Mapping Agricultural Output Values Using Farm Specific Details and Environmental Databases
Authors: Bateman Ian J. , Ennew Christine , Lovett Andrew A. , Rayner Anthony J.
Published: September 2010

Ongoing concerns regarding the economic losses associated with the CAP and the negative environmental impacts of present land use have led to calls for land use change and consequent efforts to identify areas which are, from both a financial and social perspective, most appropriate for such conversion. This paper develops and applies an output value modelling methodology in which site‐specific biophysical factors are combined with farm level data in order to predict input usage and, subsequently, farm profit. The spatial analytic capabilities of a geographical information system (GIS) are used to combine the variety of data employed to permit analysis of a large study area (the entirety of Wales) and yield models of both the market and shadow value of output from the two principal agricultural sectors of the area: dairying and sheep farming. The GIS is then used to produce readily interpretable maps of these values across the study area. The resulting maps are highly compatible both with value maps of alternative land uses given in the recent literature and with approaches to policy formulation currently under development by a range of UK agencies. Such maps may be used to assist estimation of the extent and location of farming response to land use policy change.
The Normative Analysis of Agricultural Policy: A General Framework and Review
Authors: Bullock David S. , Salhofer Klaus , Kola Jukka
Published: September 2010

The paper provides a general framework of normative agricultural policy analysis within which it is possible to unify forty years of literature. It is shown that the literature has gone from examining a very small set of simple policies to a much broader set of policies that combine policy instruments simultaneously. In ranking alternative policies agricultural economists have tried to consider distributive equity. While at a glance it may seem that many different methods have been used to consider distributive equity, we show that in general all these methods can be traced back to three alternative methods based on welfarism and Pareto efficiency.
Returns to Farm‐Level Soil Conservation on Tropical Steep Slopes: The Case of the Eritrean Highlands
Authors: Araya Bereket , Asafu‐Adjaye John
Published: September 2010

This study conducts an economic analysis of investment in simple soil conservation technologies in the highlands of Eritrea. The data used in the analysis were obtained from a farm survey and supplemented with data from secondary sources. Risk analysis techniques are used to take account of the uncertainties regarding the relationship between soil erosion and crop yield. The financial analysis reveals negative net present values (NPVs) and internal rates of return (IRRs) below 12 per cent for various slope categories. On the other hand, the economic analysis returns positive NPVs and IRRs of over 20 per cent. The results clearly indicate that investment in soil conservation technology may not be a viable short‐term proposition from the farmer's point of view and yet the net social benefits are positive. There is a strong case for government to provide incentives for soil conservation in view of the economic benefits.
Green Consumerism and Ecolabelling: A Strategic Behavioural Model
Authors: Hussain S. Salman
Published: September 2010

The ethos of “green” marketing is to affect tastes and perceptions so that those individuals for whom the attribute of environmental‐friendliness is significant can signal this preference by choosing the “green” alternative. This paper presents a strategic behavioural model of interactions between two agents, a firm and consumer, under conditions of incomplete information. The outcome of the model is that, unless some restrictive and (arguably) unrealistic conditions apply, some proportion of “green” marketing campaigns will be misleading; “green” marketing is not restricted to “green” products, and “green” consumers only adapt their purchasing habits some of the time. Ecolabelling schemes can be used as a means of ameliorating this inefficiency in information‐transfer. Whether state intervention to make ecolabelling mandatory for “green” products is welfare‐improving depends on the balance between the deadweight losses from the process and the gains in terms of facilitating the expression of “green” preferences.
Consumer Assessment of the Safety of Beef at the Point of Purchase: A Pan‐European Study
Authors: Henson Spencer , Northen James
Published: September 2010

The paper employs structural equation modelling to explore the process by which consumers assess the safety of beef at the point of purchase. The data employed in the analysis are collected through a telephone survey in six European Union member states. The results indicate differences in the process by which the safety of beef is assessed by consumers between the study countries. The implications of the results for policy within the European Union are discussed.
Optimal Hedging Ratios for Wheat and Barley at the LIFFE: A GARCH Approach
Authors: Dawson P. J. , Tiffin A. L. , White B.
Published: September 2010

Over 100,000 futures contracts for cereals are traded annually on the London International Financial Futures Exchange. The proportion of the spot position held as futures contracts ‐ the hedging ratio ‐ is critical to traders and traditional estimates, using OLS, are constant over time. In this paper, we estimate time‐varying hedging ratios for wheat and barley contracts using a multivariate generalised autoregressive conditional heteroscedasticity (GARCH) model. Results indicate that GARCH hedging ratios do change through time. Moreover, risk using the GARCH hedge is reduced significantly by around 4 per cent for wheat and 2 per cent for barley relative to the no hedge position, and significantly by around 0.2 per cent relative to the constant hedge. The optimal, expected utility‐maximising, and the risk‐minimising hedging ratios are equivalent.
Back to Basics: Household Food Production in Russia
Authors: Caskie Paul
Published: September 2010

In this paper the increasing importance of household production to total food supply in Russia is analysed and its relevance to agricultural reform discussed. The structure and profile of production are described and its incidence amongst households quantified. Factors influencing production are identified, and distinguishing characteristics between urban and rural households are highlighted and given historical context. The market share of output traded is also estimated. Finally, it is argued that the relationship between rural household production and large‐scale farming operations has impacted on continuing attempts to re‐structure socialised agriculture.
Statistical Modelling of Incentive Design Under Limited Information ‐ The Case of Public Access to Farmland
Authors: Crabtree Bob , Potts Jacqueline , Smart Trevor
Published: September 2010

This paper explores the use of statistical modelling to aid efficient policy design for the provision of environmental goods on farms under conditions of adverse selection. The specific case of incentive‐based schemes to enhance the supply of public access to farmland is used as an example. A range of site willingness‐to‐pay (WTP) distributions are used to explore the benefits derived from policies designed under different levels of information. Where no individual farm information is available, low payment rates are optimal, but efficient market creation may not be possible. Increasing the information set allows discretion in pricing and entry: optimal payment rates and net benefits are higher and the pay‐off from procuring improved information can be substantial. Such benefits are reduced where there is a welfare cost associated with increased government expenditure. Optimal policies are sensitive to the skewness of the WTP distributions. Mechanisms for increasing the information set available to policy makers are discussed.
On Population Growth and Technological Change: Selectivity Bias in Historical Analysis
Authors: Chavas Jean‐Paul
Published: September 2010

This paper investigates the relationship between population growth and technological change. After an historical overview of the evolution of world population, alternative models of population growth are examined. They include a Malthusian model, a model of endogenous technological change, and a model of population growth that allows for switching regimes between Malthusian resource limitation and endogenous technological change. The regime‐switching model stresses the potential for a biased interpretation of historical data. While there is strong empirical evidence supporting endogenous technical change, it is argued that the Malthusian scenario should not be overlooked even if the odds of facing it are low.
Agricultural Growth and Inter‐Sectoral Linkages in a Developing Economy
Authors: Gemmell N. , Lloyd T. A. , Mathew M.
Published: September 2010

Does growth in the manufacturing sector of an economy spillover to agriculture, or do sectors share similar growth rates only when they share some common exogenous stimuli? The limited number of investigations of this issue, for cross‐sections of countries, have found some evidence in favour of spillovers, though the methodologies used cannot readily separate correlation from causation. Adapting the Feder (1982) model of sectoral externalities to a time‐series context, we examine how far agricultural output in Malaysia has been affected by inter‐sectoral spillovers. Our results suggest that expansion of manufacturing output, though associated with reduced agricultural output in the short‐run, is associated with agricultural expansion over the long‐run. Service output growth on the other hand seems to have been inimical to agricultural growth in both the short‐ and long‐runs, while causality testing supports the case for spillovers rather than “common causes”. Evidence on sectoral productivity is consistent with neoclassical arguments suggesting that the benefits of higher productivity in manufacturing tend to spill over to agriculture, encouraging productivity convergence.
Agricultural Comparative Advantage and Government Policy Interventions
Authors: Peterson E. Wesley F. , Valluru Siva Rama Krishna
Published: September 2010

International trade patterns are often explained by comparative advantage which is frequently thought to depend on variations in national factor endowments. Government intervention in agricultural markets may also have an impact on trade patterns. This study explores the relation between factor endowments and agricultural trade patterns and examines the impact of agricultural and environmental policies on trade flows. Measures of national endowments of capital, labour, land and energy reserves are computed for a sample of 40 countries and used to estimate Heckscher‐Ohlin‐Vanek equations with net trade in several agricultural commodities as the dependant variable. Variables measuring agricultural policy and environmental regulations are added to the equations and tested for significance. The variables representing government intervention do not contribute to the explanation of trade patterns while national factor endowments do account for much of the variation in trade patterns of grains, oilseeds, cotton, and, to a lesser extent, meat products and an aggregate of all agricultural goods. Commodities such as sugar, tropical products and fruits and vegetables do not appear to be well explained by factor endowments.