bluuebunny/crossref_metadata_2025 huggingface dataset:
First Report of Tomato chlorosis virus Infecting Tomato Crops in Brazil
Authors: Barbosa J. C. , Teixeira A. P. M. , Moreira A. G. , Camargo L. E. A. , Filho A. Bergamin , Kitajima E. W. , Rezende J. A. M.
Published: November 2008

During 2006 and 2007 in the region of Sumaré, state of São Paulo, Brazil, surveys were done on tomato (Solanum lycopersicum L.) virus diseases in three open field-grown crops. The data revealed low incidence (0.25 to 3.42%) of randomly distributed plants exhibiting interveinal chlorosis and some necrosis on the basal leaves. Symptoms were only observed on old fruit-bearing plants. Preliminary analysis of thin sections of symptomatic leaves from one plant by transmission electron microscopy revealed the presence of aggregates of thin, flexible, and elongated particles in some phloem vessels, suggesting infection with a member of the genus Crinivirus, family Closteroviridae. Total RNA was extracted separately from leaves of 10 symptomatic plants and used for one-step reverse transcription (RT)-PCR using the HS-11/HS-12 primer pair, which amplifies a fragment of 587 bp from the highly conserved region of the heat shock protein (HSP-70) homolog gene reported for Tomato infectious chlorosis virus (TICV) and Tomato chlorosis virus (ToCV) (1). The RT-PCR product was subsequently tested by nested-PCR for single detection of TICV and ToCV using primer pairs TIC-3/TIC-4 and ToC-5/ToC-6, respectively (1). Only one fragment of approximately 463 bp was amplified from 7 of the 10 plants with the primer pair specific for ToCV. No amplification was obtained with the primers specific for TICV. Two amplicons of 463 bp were purified and directly sequenced in both directions. Sequence comparisons of the 463-bp consensus sequence (GenBank Accession No. EU868927) revealed 99% identity with the reported sequence of ToCV from the United States (GenBank Accession No. AY903448) (3). Virus-free adults of Bemisia tabaci biotype B confined on symptomatic tomato leaves for a 24-h acquisition access period were able to transmit the virus to healthy tomato plants, which reproduced the original symptoms on the bottom leaves 65 days after inoculation under greenhouse conditions. Infection from transmission was confirmed by RT-PCR using the HS-11/HS-12 primer pair. In addition to B. tabaci biotype B, the greenhouse whitefly, Trialeurodes vaporariorum, has also been reported as a vector of ToCV, although it is less efficient than the B. tabaci biotype B in transmission of this virus (4). T. vaporariorum, which was previously considered limited to greenhouses, was recently reported in tomato and green bean (Phaseolus vulgaris L.) crops under field conditions in São Paulo State (2). Therefore, it might also contribute to the spread of ToCV in tomato crops in São Paulo. To our knowledge, this is the first report of ToCV in Brazil and South America.

References: (1) C. I. Dovas et al. Plant Dis.86:1345, 2002. (2) A. L. Lourenção et al. Neotrop. Entomol. 37:89, 2008. (3) W. M. Wintermantel et al. Arch. Virol. 15:2287, 2005. (4) W. M. Wintermantel and G. C. Wisler. Plant Dis. 90:814, 2006.
Circum-menopausal effects on women's judgements of facial attractiveness
Authors: Vukovic Jovana , Jones Benedict C , DeBruine Lisa M , Little Anthony C , Feinberg David R , Welling Lisa L.M
Published: November 2008

The marked change in a woman's hormonal profile that happens at menopause affects many aspects of behaviour. We investigated circum-menopausal women's preferences for femininity in the faces of young adult men and women. Post-menopausal women demonstrated stronger preferences for femininity in same-sex faces than pre-menopausal women did. This effect was independent of possible effects of participant's age and suggests that dislike of feminine (i.e. attractive) same-sex competitors decreases as fertility decreases. No significant difference between pre- and post-menopausal women was observed for men's faces, potentially because circum-menopausal women do not necessarily view young adult men as potential mates. To our knowledge, this is the first study to demonstrate circum-menopausal changes in women's face preferences.
Mating behaviour inLymnaea stagnalispond snails is a maternally inherited, lateralized trait
Authors: Davison Angus , Frend Hayley T , Moray Camile , Wheatley Hannah , Searle Laura J , Eichhorn Markus P
Published: November 2008

Lateralization of the brain has traditionally been considered a specialization that is confined to the vertebrates, but recent studies have revealed that a range of invertebrates also have a brain that is structurally asymmetric and/or each side performs a different set of functions. Here, we show that the precopulatory mating behaviour of the pond snailLymnaea stagnalisis lateralized. We present evidence that the asymmetry of the behaviour corresponds to the sinistral or dextral shell coil, or chirality, of the snail, and is apparently also controlled by a maternal effect locus. As sinistral snails also tend to have mirror image brains, these findings suggest that the lateralized sexual behaviour ofL. stagnalisis set up early in development, and is a direct consequence of the asymmetry of the entire body.
A glycosylated peptide in the West Nile virus envelope protein is immunogenic during equine infection
Authors: Hobson-Peters Jody , Toye Philip , Sánchez Melissa D. , Bossart Katharine N. , Wang Lin-Fa , Clark David C. , Cheah Wai Yuen , Hall Roy A.
Published: November 2008

Using a monoclonal antibody directed to domain I of the West Nile virus (WNV) envelope (E) protein, we identified a continuous (linear) epitope that was immunogenic during WNV infection of horses. Using synthetic peptides, this epitope was mapped to a 19 aa sequence (WN19: E147–165) encompassing the WNV NY99 E protein glycosylation site at position 154. The inability of WNV-positive horse and mouse sera to bind the synthetic peptides indicated that glycosylation was required for recognition of peptide WN19 by WNV-specific antibodies in sera. N-linked glycosylation of WN19 was achieved through expression of the peptide as a C-terminal fusion protein in mammalian cells and specific reactivity of WNV-positive horse sera to the glycosylated WN19 fusion protein was shown by Western blot. Additional sera collected from horses infected with Murray Valley encephalitis virus (MVEV), which is similarly glycosylated at position E154 and exhibits high sequence identity to WNV NY99 in this region, also recognized the recombinant peptide. Failure of most WNV- and MVEV-positive horse sera to recognize the epitope as a deglycosylated fusion protein confirmed that the N-linked glycan was important for antibody recognition of the peptide. Together, these results suggest that the induction of antibodies to the WN19 epitope during WNV infection of horses is generally associated with E protein glycosylation of the infecting viral strain.
Vaccinia virus: shedding and horizontal transmission in a murine model
Authors: Ferreira Jaqueline Maria Siqueira , Abrahão Jônatas Santos , Drumond Betânia Paiva , Oliveira Fernando Meireles , Alves Pedro Augusto , Pascoal-Xavier Marcelo Antônio , Lobato Zélia Inês Portela , Bonjardim Cláudio Antônio , Ferreira Paulo César Peregrino , Kroon Erna Geessien
Published: November 2008

Vaccinia virus (VACV) has been associated with several bovine vaccinia outbreaks in Brazil, affecting cattle and humans. There are no available data about VACV environmental circulation or the role of wildlife in the emergence of an outbreak. Since VACV was isolated from rodents in Brazil, we investigated shedding and transmission of VACV strains in mice. The VACV excretion profile was assessed by PCR and chicken chorioallantoic membrane infection, revealing viral DNA and infectious virus in the faeces and urine of intranasally infected mice. Horizontal transmission was assessed by exposure of sentinel mice to wood shavings contaminated with excrement, to mimic a natural infection. Sentinel mice showed orthopoxvirus antibodies, and VACV DNA and infectious virus were detected in their faeces and intestines, even after six rounds of natural transmission. Together, these data suggest that murine excrement could play a relevant role in VACV spread and transmission, perhaps helping to explain how these viruses circulate between their natural hosts.
Hepatitis B virus genotype G epidemiology and co-infection with genotype A in Canada
Authors: Osiowy Carla , Gordon Diane , Borlang Jamie , Giles Elizabeth , Villeneuve Jean-Pierre
Published: November 2008

Hepatitis B virus (HBV) genotype G (HBV/G) is an unusual variant, and little is known about its epidemiology and natural history, particularly the requirement for a co-infecting HBV genotype and their relationship during infection. This study investigated the quasispecies nature of co-infecting genotypes in 39 samples collected over a 6 year period from 13 HBV/G-infected patients. HBV/G infections were found to occur predominantly in males (92 %) and were primarily associated with male homosexual sex (67 %). All patients were infected with HBV/G and HBV/A, or a recombinant HBV/A/G strain. Co-infecting genotypic prevalence was often observed to fluctuate over time, with periods of HBV/G monoinfection in some patients. The average sequence divergence among Canadian HBV/G strains was 1.57±0.62 %. Thus, all HBV/G infections in Canada occur in the context of co-infection or recombination with HBV/A, and strains display increased sequence divergence compared with all known HBV/G sequences described to date.
Blufensin1Negatively Impacts Basal Defense in Response to Barley Powdery Mildew
Authors: Meng Yan , Moscou Matthew J. , Wise Roger P.
Published: November 2008

Plants have evolved complex regulatory mechanisms to control the defense response against microbial attack. Both temporal and spatial gene expression are tightly regulated in response to pathogen ingress, modulating both positive and negative control of defense. BLUFENSIN1 (BLN1), a small peptide belonging to a novel family of proteins in barley (Hordeum vulgare), is highly induced by attack from the obligate biotrophic fungus Blumeria graminis f. sp. hordei (Bgh), casual agent of powdery mildew disease. Computational interrogation of the Bln1 gene family determined that members reside solely in the BEP clade of the Poaceae family, specifically, barley, rice (Oryza sativa), and wheat (Triticum aestivum). Barley stripe mosaic virus-induced gene silencing of Bln1 enhanced plant resistance in compatible interactions, regardless of the presence or absence of functional Mla coiled-coil, nucleotide-binding site, Leu-rich repeat alleles, indicating that BLN1 can function in an R-gene-independent manner. Likewise, transient overexpression of Bln1 significantly increased accessibility toward virulent Bgh. Moreover, silencing in plants harboring the Mlo susceptibility factor decreased accessibility to Bgh, suggesting that BLN1 functions in parallel with or upstream of MLO to modulate penetration resistance. Collectively, these data suggest that the grass-specific Bln1 negatively impacts basal defense against Bgh.
Incidence of bleeding lesions within reach of conventional upper and lower endoscopes in patients undergoing double‐balloon enteroscopy for obscure gastrointestinal bleeding
Authors: FRY L. C. , BELLUTTI M. , NEUMANN H. , MALFERTHEINER P. , MÖNKEMÜLLER K.
Published: November 2008

Background  Double‐balloon enteroscopy (DBE) is a useful method for evaluation of obscure gastrointestinal bleeding (OGIB).

Aim To determine the incidence of lesions within reach of conventional upper and lower endoscopes as the cause of OGIB in patients referred for DBE.

Methods All patients undergoing DBE for OGIB during a 3.5‐year period at a university hospital were studied. OGIB was defined according to American Gastroenterological Association (AGA) guidelines.

Results One hundred and forty‐three DBEs were performed in 107 patients for obscure overt (n = 85) and obscure occult (n = 22) GIB. Lesions outside the SB as possible sources of GIB were found in 51 patients (47.6%) and a definite source of bleeding outside the small bowel (SB) was detected in 26 patients (24.3%). Lesions considered to explain a definite source of GIB were: gastric ulcer (n = 3), duodenal ulcer (n = 3), Cameron’s lesions (n = 2), gastric antral vascular ectasias (n = 4), radiation proctitis (n = 1), radiation ileitis (n = 2), duodenal angiodysplasias (n = 1), haemorrhoids with stigmata of recent bleed (n = 1), colon angiodysplasias (n = 3), colon diverticulosis (n = 3), colonic Crohn’s disease (n = 1), anastomotic ulcers (n = 1).

Conclusions The frequency of non‐SB lesions definitely explaining the source of GIB in patients referred for DBE was 24.3%. Therefore, repeat esophago‐gastroduodenoscopy (EGD) and ileocolonoscopy should be taken into consideration before DBE.
Predictors of insulin resistance among Hispanic adults infected with or at risk of infection with the human immunodeficiency virus and hepatitis C virus
Authors: Castaneda‐Sceppa C. , Bermudez O. I. , Wanke C. , Forrester J. E.
Published: November 2008

Summary.  Both the human immunodeficiency (HIV) and hepatitis C (HCV) viruses have been associated with insulin resistance (IR). However, our understanding of the prevalence of IR, the underlying mechanisms and predisposing factors is limited, particularly among minority populations. We conducted a study of 333 Hispanic adults including: 76 HIV monoinfected, 62 HCV monoinfected, 97 HIV/HCV co‐infected and 98 uninfected controls with a specific focus on HCV infection and liver injury as possible predictors of IR. IR was measured using the Quantitative Insulin Sensitivity Check Index (QUICKI). The majority (55–69%) of participants in all groups had QUICKI values <0.350. Body mass index was associated with IR in all groups. Triglycerides were associated with IR in the uninfected control group only (−1.83, SE = 0.58, P = 0.0022). HCV was associated with IR in participants infected with HIV (−0.012, SE = 0.0046, P = 0.010). Liver injury, as measured by score to assess liver injury (FIB‐4) score, was significantly associated with IR independently of HCV infection (−0.0035, SE = 0.0016, P = 0.027). In the HIV/HCV co‐infected group, treatment with nucleoside reverse‐transcriptase (RT) inhibitors plus non‐nucleoside RT inhibitors (−0.021, SE = 0.080, P = 0.048), but not protease inhibitors (−0.000042, SE = 0.0082, P = 0.96) was associated with IR. HCV infection and antiretroviral agents, including nucleoside RT inhibitor plus non‐nucleoside RT inhibitor treatment are contributors to IR in HIV infection. Liver injury, as measured by the FIB‐4 score, is a predictor of IR independently of HCV infection.
Investigating the selectivity of weed harrowing with new methods
Authors: RASMUSSEN J , BIBBY B M , SCHOU A P
Published: November 2008

In six field experiments on post‐emergence weed harrowing in spring barley, the effects of row spacing, timing, direction and orientation on crop/weed selectivity were investigated. The efficacies of increasing intensities of harrowing generated either by increasing number of passes or increasing driving speed were also tested. Selectivity was defined as the relationship between crop burial in soil immediately after treatment and weed control. To estimate crop burial, digital image analysis was used in order to make objective estimations. The study showed that narrow row spacing decreased selectivity in a late crop growth stage, whereas row spacing in the range 5.3–24 cm had no effects at an early growth stage. Harrowing across rows decreased selectivity in one out of two experiments. Whether repeated passes with the harrow were carried out in the same orientation along the rows or in alternative orientations forth and back was unimportant. There were indications that a high harrowing intensity produced by a single pass at high speed gave a lower selectivity than a similar intensity produced by several passes at a low speed. Impacts on selectivity, however, were small and only significant at high degrees of weed control. Timing had no significant impact on selectivity.
Assessment of Sperm DNA Fragmentation in Stallion (Equus caballus) and Donkey (Equus asinus) Using the Sperm Chromatin Dispersion Test
Authors: Cortés‐Gutiérrez EI , Crespo F , Serres‐Dalmau C , Gutiérrez de las Rozas AL , Dávila‐Rodríguez MI , López‐Fernández C , Gósalvez J
Published: November 2008

Contents

Sperm DNA fragmentation (sDF) is an important parameter to assessing sperm quality. Information about sperm quality is not available for donkeys, especially in some breeds at risk of extinction. The objectives of this research were to test the four commercial variants of sperm chromatin dispersion test (SCD; sperm Halomax test), originally developed to assess sDF in boars, bulls, rams and stallions, in order to scrutinize their applicability in the study of sDF in a donkey breed at risk of extinction (Zamorano‐Leonesa), for which there is no specific test available to analyze sperm at present. Only the SCD test, originally developed for stallions, produced stable and consistent results, and was deemed suitable to assess DNA fragmentation in sperm samples from donkeys. Image analysis was used to compare differences between the SCD methodology applied to stallion and donkey semen samples processed under the same experimental conditions. The extent of SCD in the SCD test was approximately 20% lower in donkey sperm than in stallion sperm. Yet, the ratio of chromatin sperm dispersion achieved in fragmented and unfragmented nuclei did not differ significantly between species. These data suggest that a similar protein depletion treatment can cause differences in protein removal in equivalent cells from different species and that sperm chromatin may be organized differently in stallions and donkeys.
Ultrasonographic and Endocrine Evaluation of Three Regimes for Oestrus and Ovulation Synchronization for Sheep in the Subtropics
Authors: Ali A , Hayder M , Saifelnaser EOH
Published: November 2008

Contents

This study aimed to evaluate three regimes for oestrus and ovulation synchronization in Farafra ewes in the subtropics. During autumn, 43 ewes were assigned to (i) controlled internal drug releasing (CIDR)‐eCG group, treated with CIDR for 12 days and eCG at insert withdrawal, n = 13; (ii) PGF2α‐PGF2α group, treated with two PGF2α injections at 11 days interval, n = 14; and (iii) GnRH‐PGF2α‐GnRH group, treated with GnRH, followed 5 days later with PGF2α and 24 h later with a second GnRH, n = 16. Oestrus‐mating detection was carried out at 4 h intervals starting on day 0 [the day of CIDR withdrawal (CIDR‐eCG group), the day of second PGF2α treatment (PGF2α‐PGF2α group) and the day of PGF2α treatment (GnRH‐PGF2α‐GnRH group)]. Ovarian dynamics was monitored by ultrasound every 12 h beginning on day 0 and continued for 4 days. Blood samples were obtained daily for progesterone (P4) and oestradiol 17β (E2) estimation starting on day 0 and continued for 4 days. The obtained results showed that, oestrus expression, ovulation and conception were greater (p < 0.05) in CIDR‐eCG and PGF2α‐PGF2α groups than in GnRH‐PGF2α‐GnRH group. All ewes of PGF2α‐PGF2α group presented, on day of second PGF2α injection with mature CL (P4 > 2.0 ng/ml), compared to 42.9% in GnRH‐PGF2α‐GnRH group (p = 0.01). The peak of oestrus occurred 32–52, 48–60 and 28–96 h after the end of treatment in CIDR‐eCG, PGF2α‐PGF2α and GnRH‐PGF2α‐GnRH groups, respectively. Ovulation started 48 h after treatment in all groups and extended for 24, 36 and 48 h for CIDR‐eCG, PGF2α‐PGF2α and GnRH‐PGF2α‐GnRH groups, respectively. Results demonstrated that oestrus and ovulation synchronization could be efficiently achieved in Farafra ewes using either CIDR‐eCG or PGF2α‐PGF2α regimes; however, the GnRH‐PGF2α‐GnRH treatment induced a more spread oestrus and ovulation that may make the protocol inadequate for timed artificial insemination.
Local effect of topical FP‐receptor agonists on retinal vessels of the ipsilateral posterior retina in normal rabbit eyes
Authors: Ohashi Masaaki , Mayama Chihiro , Ishi Kiyoshi , Araie Makoto
Published: November 2008

Abstract

Purpose:  To determine whether a topically instilled prostaglandin analogue inhibits endothelin‐1 (ET‐1)‐induced vasoconstrictive effects in the posterior retina by its local effects, and the duration of the effect in normal rabbit eyes.

Methods:  Travoprost, a potent selective FP‐agonist, or unoprostone, a prostone that also has a weak non‐selective FP‐agonistic activity, solution was instilled once, or once daily (travoprost) or twice daily (unoprostone) for 7 days in one randomly chosen Dutch rabbit eye, and vehicle in the contralateral eye. ET‐1 was intravitreously injected in both eyes 30 min after a single instillation of a test drug or its vehicle, or just after, 30, 60, 90 or 180 min after the final instillation of a 7‐day instillation, and fundus photographed before, 30 and 60 min after the injection to study whether difference was seen in the ET‐1‐induced constriction of retinal vessels between the drug‐ and vehicle‐instilled eyes. The same experimental procedures were conducted with indomethacin pretreatment.

Results:  In the rabbit eyes where travoprost was instilled for 7 days, the ET‐1‐induced constriction of retinal vessels was significantly inhibited only on the drug‐treated side, when ET‐1 was injected 30 or 60 min after the final instillation (P = 0.026–0.005), which was abolished by indomethacin pretreatment. A single instillation of travoprost or unoprostone and 7‐day instillation of unoprostone showed no effect.

Conclusions:  After a 7‐day instillation in normal rabbit eyes, topical travoprost suppressed ET‐1‐induced vasoconstrictive effects only in the ipsilateral posterior retina by its local effect; this effect was maintained at least for 30 min and mediated by endogenous prostaglandins.
Complications and failure of uterine artery embolisation for intractable postpartum haemorrhage
Authors: Maassen MS , Lambers MDA , Tutein Nolthenius RP , van der Valk PHM , Elgersma OE
Published: November 2008

Objective  Primary postpartum haemorrhage (PPH) is a major cause of maternal morbidity and mortality around the world. Most patients can be managed conservatively, but patients with intractable bleeding require more aggressive treatment. In these cases uterine artery embolisation (UAE) has proven to be a useful tool to control PPH. The reported success rate of UAE is over 90% with only minor complications. In this case series we studied the effectiveness and complications of UAE.

Design  Retrospective analysis of a case series.

Setting  Case series in a large peripheral hospital in the Netherlands.

Sample  Eleven patients who were treated with UAE for intractable PPH from November 2004 to February 2008.

Methods  In this paper we review the results of all patients treated with UAE for intractable PPH in our hospital and focus on the two cases with adverse outcomes.

Main outcome measures  Effectiveness, causes of failure of UAE, complications.

Results  Nine out of eleven patients were treated successfully with UAE. One patient needed an emergency hysterectomy for intractable bleeding. In the aftermath she developed a vesicovaginal fistula (VVF). Another patient suffered a major thrombo‐embolic event of the right leg, for which she underwent embolectomies and despite fasciotomy a necrotectomy.

Conclusions  UAE is a valuable tool in managing major PPH and in most cases it can replace surgery and thus prevent sacrification of the uterus. However, due to blood supply of the uterus by one of the ovarian or aberrant arteries, UAE might fail to control the bleeding. In addition, serious complications such as a thrombo‐embolic event or VVF may occur. We hereby present a case of migration of an embolus from the site of re‐embolisation into the femoral artery requiring immediate intervention to prevent the loss of the lower leg. This complication demonstrates that gelatine sponge particles could migrate from the internal iliac artery into the external iliac artery.
The right to remain silent: a qualitative study of the medical and social ramifications of pregnancy disclosure for Gambian women
Authors: Stokes E , Dumbaya I , Owens S , Brabin L
Published: November 2008

Objectives  Control of infectious diseases in developing countries often requires using drugs that are contraindicated during pregnancy. Avoiding inadvertent exposure to drugs involves women (a) recognising pregnancy early, (b) disclosing the pregnancy to health workers and (c) using medicines in an informed manner. We explored these factors to inform and improve the process by which health workers provide care and treatment to pregnant women.

Design  Qualitative study.

Setting  The Gambia.

Population  Rural women and men.

Methods  We conducted 41 interviews and 16 focus group discussions with women, adolescents, men and traditional birth attendants (TBAs).

Main outcome measure  Pregnancy disclosure.

Results  Most women recognised early signs and symptoms of pregnancy and believed other people could easily do so. To avoid gossip, women hid their pregnancies and delayed antenatal care, even though husbands and TBAs insisted on attendance. Women acutely ill in early pregnancy hoped health workers would recognise pregnancy without explicit disclosure. Women said that they knew, and sought to avoid, some contraindicated drugs, but their knowledge was rudimentary. Health workers stressed the benefits, not the risks of prescribed drugs.

Conclusions  Despite public health and clinical benefits of preventing and treating pregnancy infections, women were ill informed and pressurised into taking drugs. These ethical issues should be more widely addressed.
Varietal Licensing Standards and Canadian Wheat Exports
Authors: Carter C. A. , Loyns R. M. A. , Ahmadi‐Esfahani Z. F.
Published: November 2008

Canada's wheat grading system is largely based on visual criteria and it is based on relatively high quality standards. A strict varieties licensing system exists to maintain the integrity of the grade standards. One of the consequences of the licensing system is that higher yielding, lower or different quality wheats have not been grown in Canada until recently. The basic objective of this paper is to examine some of the consequences of the regulatory strategy of limiting wheat production to the traditional high quality wheats. This question is analyzed in the context of important changes in the international grain markets. Using a partial equilibrium trade model this paper estimates that if higher yielding wheats were permitted to be grown, annual producer gains would be 5 to 17 percent of current net farm income.

Le classement des blés au Canada est basé sur des critères visuels qui sont de hautes qualités. Le système actuel d'homologation des variétés est tel que l'intégrité de ce système est maintenue. En conséquent, ce système n'a pas encouragé la cultivation des blés de hauts rendements ou des varietés différentes que tout récemment. L'objectif principal de cette étude est d'examiner quelques unes des conséquences de la stratégic de la réglementation visant à limiter la production du blé aux variétés de hautes qualités. Cette question est adressée dans le contexte des changements importants qui ont eu lieu dans le marché international des grains. A l'aide d'un modèle d'équilibre partiel des échanges, la présente étude démontre gu'en permettant la production des blés de hauts rendements, le gain annuel aux producteurs serait de 5 à 17 pourcent du revenue agricole net.
Reducing the Cost of the Dairy Program
Authors: Short Cameron
Published: November 2008

The effects on farm incomes and consumer prices of elimination of the special export program and both an immediate and phased elimination of the direct subsidy with compensatory increases in support prices are examined.

The supply of milk is assumed to be verticle at a level determined by the amount of quota which in turn is set so that butter supplies and demand balance at the support price. The analysis then is concentrated on the demand side which is represented by the demands for 13 categories of dairy products at the consumer level. The demands are represented in a linear programming model to simulate changing relative prices of individual products caused by the changing support prices.

Dropping the special export program unambiguously leads to gains in Canadian welfare. Both an immediate and phased reduction of the direct subsidy requires either a large increase in consumer prices or decrease in farm income. All policy alternatives require a reduction of quota. Gradually eliminating the direct subsidy has the advantage that growth in demand due increases in population and per capita incomes will offset the reduction of quota due to the policy.

L'article qui suit examine les consequences, aux revenus agricoles et aux consommateurs de l'élimination du programme spécial d'exportation ainsi que de l'élimination immédiate et progressive de la subvention directe avec compensation sur les prix d'indemnités.

On suppose que l'offre du lait est verticale à un niveau déterminé par le quota qui lui est établi de façon à ce que l'offre et la demandé du beurre soient en équilibre avec les subventions.

L'analyse, est done surtout du côté demande, et, est répresentée par les demandes de 13 catégories de produits laitiers au niveau du consommateur. Les demandes sont répresentées dans un modèle de programmation linéaire simulant le changement des prix relatifs des produits, causé par le changement des subventions.

Laisser tomber le programme spécial d'exportation mène éventuellement à une augmentation du bien‐être des canadiens. De toute façon l'élimination immédiate et progressive de la subvention directe requière soit une augmentation du prix aux consommateurs ou une diminution dans les revenus agricoles. Toutes alternatives requièrent une réduction du quota. L'avantage de l'élimination progressive est que la demande évoluant de la croissance de la population et des revenus per capita contrebalance la réduction des quotas.
A Review of Issues Pertaining to Soil Deterioration in Canada
Authors: Van Kooten G. C. , Furtan W. Hartley
Published: November 2008

In Canada, there exists a perception that the annual costs of soil deterioration to farmers are enormous and that, unless something is done quickly to ameliorate the problem of soil degradation, agricultural production potential could be threatened. In this paper, we argue that the on‐farm costs of soil degradation are grossly overstated and that Canada' s agricultural future is not on the verge of a catastrophe. Further, we argue that concern with conservation is a philosophical issue which is not readily analyzed in a neoclassical economic framework. However, where this framework has been employed by (primarily) physical scientists, the analysis has resulted in on‐farm loss estimates which are somewhat misleading.

Au Canada, on perçoit que les coûts annuels aux fermiers à cause de la détérioration du sol sont énormes et que, à moins que quelque chose soit faite bientôt pour améliorer le problème de dégradation du sol, la production potentielle agricole pourrait être menacée. Dans cette étude, nous avançons que les coûts sur la ferme de la dégradation du sol sont grandement exagérés et que le futur agricole au Canada n' est pas sur le point dse catastrophe. En plus, nous avançons que le souci de conservation est une issue philosophique qui n' est pas facilement analysée dans un cadre néoclassique économique. Cependant, là où ce cadre fut utilisé par (surtout) des spécialistes des sciences physiques, les estimations de l' analyse montraient une perte sur la ferme et ceci porte quelque peu à confusion.
Sustainable Rates of Return for Milk Quotas in Ontario
Authors: Moschini Giancarlo , Meilke Karl D.
Published: November 2008

This paper utilizes the capital asset pricing model, together with available econometric estimates of the cost function of Ontario dairy farms, to estimate rates of returns for three types of milk quotas. The estimated rates follow the trend of the interest rate in the economy, and the rate of return on fluid milk quota is higher than the rate of return on industrial milk quotas.

Cet article utilise un modèle de formation des prix des actifs, avec des estimées économetriques de la fonction de coûts des producteurs laitiers de ľOntario, pour estimer les taux de retour associés avec trois differents types de quotas laitiers. Les taux estimés suivent la même tendence que le taux ďintérêt dans ľéconomie, et le taux de retour du quota pour le lait fluide est plus elevée que les taux de retour du quotas pour le lait industriel.
Demand System Estimation with Upward‐Sloping Supply
Authors: Wahl Thomas I. , Hayes Dermot J.
Published: November 2008

This paper motivates the use of three‐stage least squares in demand systems estimation in which disaggregated data are used and supply adjustment costs exist. A system of Japanese meat expenditures is used as an example. It is shown that all but one of the meat prices are endogenous to the system. Correcting these prices for endogeneity has a significant effect on the calculated elasticities.

Cet ouvrage utilise la technique de minimisation des moindres carrés à trois étapes dans un système de demande utilisant des données désagrégées et où des coûts d'ajustement de l'offre existent. Un système de dépenses pour les viandes au Japon est utilisé comme exemple. Il est démontré que tous les prix des viandes sont endogènes à l'exception d'un seul. Les élasticités qui sont dérivées sont très sensibles à l'endogénization des prix.

There are three important implications of this work. First, demand systems estimates that overlook supply response are as subject to simultaneous equations bias as single ad hoc demand equations. Theil shows theoretically that assuming supply curves are perfectly elastic, when in fact they are not will underestimate price responsiveness in demand equations. An empirical example is presented that demonstrates that the price elasticities generally increase when upward‐sloping supplies are assumed.

Second, the iterative testing procedure presented may provide direction for model building when the true structure of the system is unknown. For example, the results of the Wu‐Hausman test indicate that assuming chicken supply is perfectly elastic in a model of the Japanese livestock industry is justified. The results also indicate that the supplies of Wagyu beef, dairy beef, pork and fish are upward‐sloping and therefore should be modeled as endogenous variables in the demand system.

Third, the results emphasize the sensitivity of projections of Japanese beef imports to the assumptions underlying the demand system. If perfectly elastic meat supplies are assumed for an analysis of reducing Japanese beef import liberalization, the results will likely underestimate the impacts on beef imports.

In summary, the supply curves for agricultural products tend to slope upward within the time periods used for traditional policy analysis and demand system estimation, which in turn implies that prices are determined endogenously within the system. Endogenous price determination is contrary to the assumptions that underlie the theoretical foundations and many empirical applications of demand systems. We present a methodology to test for and adjust demand systems for endogeneity. The importance of this adjustment is demonstrated by using an analysis of the liberalization of the Japanese beef market.
Value of Household and Farm Work: Evidence from Alberta Farm Family Data
Authors: Fast Janet E. , Munro Brenda
Published: November 2008

Estimates of the economic value of unpaid household and farm work of Alberta farm women and men are calculated using two common market alternative cost methods. Time use data for 1984 collected by Doherty and Keating (1985) from 414 Alberta grain farm families as well as Statistics Canada wage data are used. The average annual value of unpaid farm work ranges from $20,647.35 to $29,088.24 for men and from $5,017.54 to $6,604.19 for women. Conversely, unpaid household work performed by women has an average annual value of $17,460.98 to $34,617.66, while the value of men's unpaid household work ranges from $1,943.02 to $3,962.54 annually. When the values of farm and household production and the income generated by off‐farm work are accounted for, there is little difference between mend's and womend's total contributions to the economic well‐being of the farm family. These estimates illustrate the importance of family membersd' unpaid work to the economic well‐being of the family. They also suggest that there is little basis for the historic inequity of legal and other social systems that neglect the economic value of womend's contributions to family welfare.

On estime la valeur du travail domestique et agricole non rémunéré des agricultrices et des agriculteurs de l'Alberta au moyen de deux autres méthodes de calcul des coûts, dd'usage courant sur le marché. On se sert pour cela des données de 1984 sur le temps recueillies par Keating and Doherty (1985) auprès de 414 producteurs de céréales de l'Alberta et des données sur les salaires de Statistique Canada. La valeur annuelle moyenne du travail agricole non rémunéré varie de 20 647,35 $ à 29 088,24 $ pour les hommes et de 5 017,54 $ à 6 604,19 $ pour les femmes. Parallèlement, le travail domestique non rémunéré effectuÉ par les femmes vaut de 17 460,98 $ à 34 617,66 $ en moyenne par année, tandis que pour les hommes il varie entre 1 943,02 $ et 3 962,54 $. Lorsqud'on additionne la valeur de la production agricole et domestique et le revenu générÉ par le travail non agricole, on constate qud'il y a peu dd'écart entre la contribution totale de l'homme et celle de la femme au bien‐être économique de la famille rurale. Ces estimations prouvent 1d'importance du travail non rémunéré des membres de la famille pour la situation économique de cette derniÈre. Elles suggèrent également qud'il nd'existe pas de véritable fondement à l'injustice historique introduite par les systèmes juridiques et sociaux qui négligent la valeur de la contribution des femmes au bien‐être économique de la famille.
Testing for Asymmetric Pricing in the Alberta Pork Market
Authors: Punyawadee Varaporn , Boyd Milton S. , Faminow Merle D.
Published: November 2008

Asymmetry tests have been used by agricultural economists to determine if the effects of price changes in one region or level in the marketing channel are transmitted to other regions or levels in the marketing channel in an identical manner for price increases and decreases. Two tests are normally conducted: sum of coefficients tests and speed of adjustment tests. In this analysis, these two tests are conducted on weekly price response equations that relate Alberta and Ontario price changes. Six separate periods of analysis are used to reflect institutional changes in the Alberta market. Evidence of asymmetrical price response is detected for the period immediately preceding the establishment of the Alberta Pork Producers Marketing Board.

Les spécialistes en économie rurale vérifient i'asymétrie des prix pour voir si la fluctuation des cours dans une région ou un élément du circuit se transmet aux autres régions ou éléments de la même façon pour les hausses et les baisses de prix. On effectue habituellement deux épreuves: (1) somme des résultats des épreuves sur les coefficients et (2) vérification de la rapidité d'ajustement. Les auteurs ont appliqué ces deux épreuves aux équations qui mesurent la réaction des prix hebdomadaires et relient les fluctuations des prix entre l'Ontario et l'Alberta. lis se sont servis de six périodes d'analyse distinctes pour tenir compte des changements institutionnels survenus sur le marché albertain. Les résultats indiquent une réaction asymétrique des prix pour la période qui a immédiatement précédé la création de l'Office de commercialisation des producteurs de pores de l'Alberta.
Dynamics and Long‐run Structure in U.S. Meat Demand
Authors: Kesavan T. , Hassan Zuhair A. , Jensen Helen H. , Johnson Stanley R.
Published: November 2008

Empirical analysis, based on a general dynamic Almost Ideal Demand System, shows the commonly used autoregressive and partial adjustment processes are restrictive to meat demand data. This study derives a linear specification in levels form to investigate dynamics in a general framework. Merging a long‐run steady state structure with short‐run dynamics results in consistent and robust long‐run demand elasticities

Une analyse empirique, basée sur un systéme dynamique général de demande quasi optimale, montre que les mécanismes courants d'ajustement autorégressif et d'ajustement partiel ont un effect restrictif sur l'évaluation des données de la demande de viande. Les auteurs proposent une spécifcation linéaire par niveaux pour examiner la dynamique du cadre général. La combinaison d'une structure stable de longue durée avec une dynamique de courte période a produit des élasticités cohérentes et solides de la demande à long terme
Are Subsidies Capitalized into Land Values? Some Time Series Evidence from Saskatchewan
Authors: Clark J. Stephen , Klein K. K. , Thompson Shelley J.
Published: November 2008

A simple capitalization formula model is used to determine whether subsidies are capitalized into land values. Using Saskatchewan annual data, it is found that while income by itself cannot support the secular growth in land values, income plus subsidies may. The results of this study indicate that income plus subsidies are mildly cointegrated with land values and the series are not too volatile. The evidence suggests that there is some support for the hypothesis that short‐term subsidies are capitalized into land values; however, the evidence is not strong

Un modèle à formule de capitalisation simple est utilisé pour établir si les subventions sont capitalisées dans les valeurs foncières. À partir de données annuelles recueillies en Saskatchewan, on constate que si le revenu à lui seul ne suffit pas à soutenir la croissance à long terme des valeurs foncières, il le peut lorsqu'il est complété par des subventions. Le résultat de l'étude montre que le revenu complété par les subventions est modérément coinégré avec la valeur de la terre et que les séries obtenues ne fluctuent pas outre mesure. Il semble que les subventions à court tenne soient Capitalisées dans la valeur des terres, encore que les preuves à l'appui ne soient pas des plus convaincantes
The Economics of a Single North American Barley Market
Authors: Carter Colin A.
Published: November 2008

On I August 1993, the Canadian government extended the dual feed barley market to all of North America and established a similar marketing system for malting barley. The 1993 policy reform removed the Canadian Wheat Board's (limited) ability to set monopoly prices. While the loss of the board's domestic monopoly power was negative for farmers, there were offsetting positive impacts. The new policy will lead to economic gains for farmers due to improved price signals and competitive discipline in grain handling. The author concludes that the gains to farmers from a move to a single North American market far ourneigh any associated losses.

Le 1er août 1993, le gouvernement canadien étendait le système de double marché de l'brge fourragère a toute l'Amérique du Nord et instaurait un régime semblable pour l'orge de brasserie. La réforme de 1993 retirait à la Commission canadienne du blé son quasi‐monopole sur l'établissement des prix. Bien que cette perte de monopole ait eu des effets négatifs pour les agriculteurs, elle a eu certaines incidences positives. La nouvelle politique apportera aux agriculteurs des gains économiques en leur envoyant des signalcx plus clairs sur les prix du marché, et aussi par l'instauration d'une discipline plus concurrentielle du réseau de manutention des céréales. L'auteur estime que les avantages pour les agriculteurs du passage à un marché unique pour l'Amérique du Nord compenseront largement les penes corollaires éventuelles que peuvent en découler.
First, Let's Assume We Have a Can Opener: An Analysis of the Economics of a Single North American Barley Market
Authors: Brooks Harvey G.
Published: November 2008

In summary, it has been shown that the results of the Carter paper are driven, not surprisingly, by the assumptions that were fed into the model used. In addition, it has been shown that many of the assumptions are highly questionable or unrelated to the problem, and therefore limit the applicability of the findings to any “real‐world” prescriptive analysis.

The Carter study does not model a change from a single‐desk selling structure to a multiple seller environment. It simply assumes:

feed barley yields increase,

U.S. demand for feed barley increases by 500,000 t and malting barley demand increases by 400,000 t,

all barley shipments to maltsters bypass the primary elevator system, and

malt selection rates are increased by 50%.

Any one of these assumptions would lead an economic model to a result of higher net producer income. Carter, however, fails to connect these assumptions to the institution of a CBM. Further, the modeling errors created in trying to “customize” the CRAM model for this use clearly invalidate the results. There are serious flaws in the structural modeling of how a competitive market for malting barley would operate in North America and they invalidate the Carter's results regarding the prices, producer returns and production of malting barley under the CBM scenario.

While it is an interesting academic exercise to examine the possible economic impacts of a policy change by “shocking” an economic model, it is quite another matter to represent the results of such an endeavor as being “an exhaustive and definitive analysis of the issues” (Carter 31 March 1993). Besides the questionable assumptions and modeling errors of this paper, the author clearly misrepresents the power and accuracy of mathematical economic modeling.
Predicting needs for nursing home admission – does sense of coherence delay nursing home admission in care dependent older people? A longitudinal study
Authors: Thygesen Elin , Saevareid Hans Inge , Lindstrom Torill Christine , Nygaard Harald A , Engedal Knut
Published: November 2008

Objectives.  This study examined predisposing, enabling and need variables (Andersen’s Behavioral Model) influencing the need for nursing home admission (NHA) in older people receiving home nursing care. In particular, the potential role of coping ability, measured as ‘sense of coherence’ (SOC), was studied.

Design, sample, and measurements.  A survey with baseline‐ and follow‐up data after a 2‐year period was undertaken with 208 patients aged 75+. The measures used were: gender, education, age, social visits, SOC, social provision scale (SPS), self‐rated health (SRH), general health questionnaire (GHQ), clinical dementia rating (CDR), Barthel activities of daily living (ADL) index, and registered illnesses (RI). A Cox proportional model was used to examine factors that could explain risk of NHA.

Results.  Measures with predictive properties were Barthel ADL index, SPS, SRH, and gender. SOC, along with subjective health complaints, general health questionnaire, RI and social visits did not predict NHA.

Conclusions.  It is concluded that the patients’ subjective evaluations of both their health and perceived social support were important predictors of future NHA needs, and should be seriously taken into consideration, along with the more commonly used objective measures of ADL and CDR.