bluuebunny/crossref_metadata_2025_split huggingface dataset:
Farm Economics of Bird Flu
Authors: Beach Robert H. , Poulos Christine , Pattanayak Subhrendu K. 
Published: October 2007

Outbreaks of infectious animal diseases represent a major threat to agriculture and can impose significant social and economic costs. The potential for devastating epidemics, such as the recent outbreaks of highly pathogenic avian influenza (HPAI) in Asia, Europe, and Africa, has prompted major global investments in animal disease prevention and control, both public and private. However, there has been little research into the effects of alternative public policies on farm‐level actions to prevent and control HPAI and the implications for disease impacts. Animal disease management involves both ex ante investments to reduce the probability of infection and ex post actions to contain the spread of disease once introduced. The public sector can play an important part in disease mitigation through provision of public disease prevention and control. Another vital role for government in mitigating the potential impacts of HPAI is in the development of well‐designed policies to induce socially optimal ex ante private investment while providing incentives for truthful disclosure of disease status. This study employs an economic epidemiology framework to examine the effects of farmer behavior on disease introduction and transmission and to analyze the effects of public policy decisions under alternative scenarios. Les éclosions de maladies animales infectieuses représentent une menace importante pour l’agriculture et peuvent entraîner des coûts socio‐économiques considérables. L’éventualité d’épidémies dévastatrices, telles que les récentes flambées d’influenza aviaire hautement pathogène (IAHP) en Asie, en Europe et en Afrique, a suscité d’importants investissements publics et privés à l’échelle mondiale pour prévenir et lutter contre ces maladies. Cependant, peu de recherches se sont penchées sur les effets des politiques publiques de rechange sur les mesures prises à la ferme pour prévenir et lutter contre l’IAHP et les répercussions des maladies. La gestion des maladies animales nécessite des investissements ex ante pour diminuer la probabilité d’infection et des mesures ex poste pour contenir la propagation d’une maladie une fois introduite. Le secteur public peut jouer un rôle important dans l’atténuation d’une maladie en instaurant des programmes publics de prévention et de lutte. Pour atténuer les conséquences potentielles de l’IAHP, le gouvernement peut élaborer des politiques efficaces pour inciter des investissements privés ex ante socialement optimaux tout en offrant des stimulants pour encourager la divulgation véridique de la situation zoosanitaire. Dans la présente étude, nous avons utilisé un cadre épidémiologique et économique pour examiner les conséquences du comportement de l’exploitant agricole sur l’introduction et la transmission des maladies et pour analyser les conséquences des décisions de politique publique selon divers scénarios.
The Mediterranean Fruit Fly and the United States: Is the Probit 9 Level of Quarantine Security Efficient?
Authors: Livingston Michael J. 
Published: October 2007

Cold treatment periods, and associated levels of quarantine security, that maximize net US welfare under USDA's current medfly detection and control program are examined using a deterministic bioeconomic optimization model
. As anticipated, the efficient level of quarantine security is shown to increase with indices of medfly pressure (initial infestation rates) in areas in which the medfly is known to exist (the QCs)
. Efficient cold treatment periods and weighted mean medfly survival rates are 8, 11, and 12 days and 5.0 × 10–2, 1.7 × 10–3, and 5.2 × 10–4 under low, moderate, and high initial infestation rates, respectively. When model output is averaged across initial infestation rates, an 11‐day cold treatment period, resulting in a weighted mean medfly survival rate of 1.6 × 10–3, maximizes US welfare. These findings suggest that the current minimum cold treatment period of 14 days and the current objective of US cold treatment policy—the probit 9 level of quarantine security—are economically inefficient. Adopting the 11‐day cold treatment period is shown to increase US social surplus by an annual $24.9 million, of which $21.5 and $3.4 million would accrue to US consumers and producers, respectively, and QC producer surplus by an annual $24.8 million. Nous avons examiné, à l’aide d’un modèle déterministe d’optimisation bioéconomique, les périodes de traitement par le froid et les niveaux de quarantaine de sécurité connexes qui maximisent le bien‐être net des États‐Unis d’après le programme actuel de détection et de lutte contre la cératite, instauré par le USDA. Comme prévu, le degré de quarantaine de sécurité efficace augmente en fonction des indices de pression des ravageurs (indices d’infestation initiale) dans les pays où la cératite est présente (pays dont les produits sont soumis à une quarantaine). Selon qu’il s’agit d’un indice d’infestation initiale faible, moyen et élevé, les périodes de traitement par le froid efficaces sont de 8, 11 et 12 jours respectivement et les taux de survie moyens pondérés de la cératite de 5,0 × 10–2, 1,7 × 10–3, et 5,2 × 10–4 respectivement. Lorsque l’on établit la moyenne pondérée de la sortie du modèle par taux de survie, une période de traitement de 11 jours et un taux de survie moyen pondéré de 1,6 × 10–3 maximisent le bien‐être des États‐Unis. Ces résultats donnent à penser que la période minimale actuelle de traitement par le froid de 14 jours et la politique actuelle concernant le traitement par le froid (la norme probit 9) sont économiquement inefficaces. L’adoption d’une période de traitement par le froid de 11 jours augmenterait le surplus collectif des États‐Unis de 24,9 millions (M$) par année, dont 21,5 M$ et 3,4 M$ reviendraient aux consommateurs et aux producteurs des États‐Unis respectivement, et un surplus de 24,8 M$ par année aux producteurs des pays dont les produits sont soumis à une quarantaine.
Impacts of BSE on World Trade in Cattle and Beef: Implications for the Canadian Economy
Authors: Wigle Randall , Weerahewa Jeevika , Bredahl Maury , Samarajeewa Sudarma 
Published: October 2007

This paper evaluates the impact of BSE‐related trade restrictions on Canada using a general equilibrium model. It links selected results of the Global Trade Analysis Project (GTAP) approach, a global computable general equilibrium model, with Basic Model of Regional Trade (BMRT), a Canadian regional model. We find first, that while producers were hurt a lot, there are other general equilibrium considerations (gains to processors and/or consumers) and sectoral adjustments that at the regional level tend to partially offset the losses suffered by producers. We also assess the extent to which opening of the U.S. border is important relative to access to the rest of the world. Our results indicate that the losses to the Canadian economy are around $1 billion and they were reduced significantly when Canada resumed beef trade with the United States, as a result of various government allegations. Le présent article évalue, à l'aide d'un modèle d'équilibre général, les répercussions des restrictions commerciales imposées envers le Canada à la suite de la découverte d'un cas d'ESB. Il établit un lien entre les résultats sélectionnés du Projet d'analyse des échanges commerciaux (GTAP), un modèle d'équilibre général mondial et programmable, et ceux du Modèle de base des échanges régionaux (Basic Model of Regional Trade – BMRT), un modèle régional canadien. Bien que les producteurs aient été très touchés, il faut considérer d'autres éléments d'équilibre général (gains réalisés par les transformateurs et/ou les consommateurs) et des ajustements sectoriels qui, à l'échelle régionale, tendent à compenser partiellement les pertes subies par les producteurs. Nous avons évalué l'étendue de l'importance de l'ouverture des frontières des États‐Unis par rapport à l'accès au marché du reste du monde. Selon nos résultats, les pertes pour l'économie canadienne avoisinent le milliard de dollars et ont considérablement diminué lorsque le Canada a repris le commerce duf avec les États‐Unis à la suite de diverses allégations de la part du gouvernement.
An Evaluation of Economic Models to Provide Policy Advice in Response to the BSE Crisis in Canada
Authors: Le Roy Danny G. , Klein K. K. , Arbenser Lawrence Nii 
Published: October 2007

The days following the discovery of BSE in Canada were characterized by considerable uncertainty for both policy makers and industry stakeholders. This paper develops eight criteria for economic systems models that would provide information on the impacts of border closures and the effects of programs designed to alleviate some of the financial strain on industry stakeholders. The eight criteria provide a framework to evaluate two economic models used extensively by policy makers in Canada to provide policy guidance in addition to a survey of published economics literature related to the Canadian beef industry prior to the discovery of the BSE case in May 2003. The results suggest a need to improve the combination of knowledge and modeling skills and techniques before another tragedy strikes the agricultural industry in Canada. Les jours qui ont suivi la découverte d'un cas d'ESB au Canada ont semé beaucoup d'incertitude chez les décideurs et les acteurs de l'industrie. Dans la présente étude, nous avons élaboré huit critères pour des modèles de systèmes économiques qui fourniraient de l'information sur les répercussions de la fermeture des frontières et sur les effets des programmes visant à atténuer une partie des contraintes financières auxquelles sont confrontés les acteurs de l'industrie. Les huit critères offrent un cadre pour évaluer deux modèles économiques que les décideurs au Canada utilisent fréquemment pour déterminer une orientation politique, en plus d'un tour d'horizon de la littérature économique sur l'industrie bovine au Canada avant la découverte du premier cas d'ESB en mai 2003. Les résultats ont montré la nécessité d'améliorer la combinaison connaissances, compétences et techniques de modélisation avant qu'une autre tragédie ne frappe l'industrie agricole canadienne.
Influence of falling height on the excitability of the soleus H‐reflex during drop‐jumps
Authors: Leukel C. , Taube W. , Gruber M. , Hodapp M. , Gollhofer A. 
Published: October 2007

AbstractAim:  The stretch‐shortening cycle (SSC) is characterized by stretching of the target muscle (eccentric phase) prior to a subsequent shortening in the concentric phase. Stretch reflexes in the eccentric phase were argued to influence the performance of short lasting SSCs. In drop‐jumps, the short latency component of the stretch reflex (SLR) was shown to increase with falling height. However, in jumps from excessive heights, the SLR was diminished. So far, it is unclear whether the modulation of the SLR relies on spinal mechanisms or on an altered fusimotor drive. The present study aimed to assess the spinal excitability of the soleus Ia afferent pathway at SLR during jumps from low height (LH – 31 cm) and excessive height (EH – 76 cm).Methods:  In 20 healthy subjects (age 25 ± 3 years), H‐reflexes were timed to occur at the peak of the SLR during drop‐jumps from LH and EH.Results:  H‐reflexes were significantly smaller at EH than at LH (P < 0.05). Neither soleus and tibialis anterior background EMG nor the size of the maximum M‐wave changed with falling height.Conclusion:  Differences in the H‐reflex between EH and LH indicate that spinal mechanisms are involved in the modulation of the SLR. A decreased excitability of the H‐reflex pathway at EH compared with LH is argued to serve as a ‘prevention strategy’ to protect the tendomuscular system from potential injuries caused by the high load. It is argued that pre‐synaptic inhibition of Ia afferents is most likely responsible for the change in H‐reflex excitability between the two jump conditions.
UV‐induced Immunosuppression in the Balance†
Authors: De Gruijl Frank R. 
Published: October 2007

AbstractAround 1980, experiments with hairless mice showed us that UV‐induced actinic keratoses (AK) and ensuing skin carcinomas did not arise independently: the rate of occurrence in one skin area was increased considerably if AKs had already been induced separately in another distant skin area, i.e. a systemic effect. The ground laying work of Margaret Kripke in the 1970s provided a fitting explanation: UV‐induced immunosuppression and tolerance toward the UV‐induced tumors. From Kripke’s work a new discipline arose: “Photoimmunology.” Enormous strides were made in exploring and expanding the effects from UV carcinogenesis to infectious diseases, and in elucidating the mechanisms involved. Stemming from concerns about a depletion of the ozone layer and the general impact of ambient UV radiation, the groups I worked in and closely collaborated with explored the anticipated adverse effects of UV‐induced immunosuppression on healthy individuals. An important turning point was brought about in 1992 when the group of Kevin Cooper reported that immunosuppression could be induced by UV exposure in virtually all human subjects tested, suggesting that this is a normal and sound physiological reaction to UV exposure. This reaction could actually protect us from illicit immune responses against our UV‐exposed skin, such as observed in idiopathic polymorphic light eruption. This premise has fruitfully rekindled the research on this common “sun allergy,” affecting to widely varying degrees about one in five Europeans with indoor professions.
Waveband and Dose Dependency of Sunlight‐induced Immunomodulation and Cellular Changes†
Authors: Halliday Gary M. , Rana Sabita 
Published: October 2007

AbstractBoth the UVB and UVA wavebands within sunlight are immunosuppressive. This article reviews the relationship between wavebands and dose in UV‐induced immunosuppression mainly concentrating on responses in humans. It also contrasts the effects of UVB and UVA on cellular changes involved in immunosuppression. Over physiological sunlight doses to which humans can be exposed during routine daily living or recreational pursuits, both UVA and UVB suppress immunity. While there is a linear dose relationship with UVB commencing at doses less than half of what is required to cause sunburn, UVA has a bell‐shaped dose response over the range to which humans can be realistically exposed. At doses too low for either waveband to be suppressive, interactions between UVA and UVB augment each other, enabling immunosuppression to occur. At doses beyond where UVA is immunosuppressive, it still contributes to sunlight‐induced immunosuppression via this interaction with UVB. While there is little research comparing the mechanisms by which UVB, UVA and their interactions can cause immunosuppression, it is likely that different chromophores and early molecular events are involved. There is evidence that both wavebands disrupt antigen presentation and effect T cell responses. Different individuals are likely to have different immunomodulatory responses to sunlight.
p53 Tumor Suppressor Gene: A Critical Molecular Target for UV Induction and Prevention of Skin Cancer†
Authors: Benjamin Cara L. , Ullrich Stephen E. , Kripke Margaret L. , Ananthaswamy Honnavara N. 
Published: October 2007

AbstractThe relationship between exposure to UV radiation and development of skin cancer has been well established. Several studies have shown that UVB induces unique mutations (C→T and CC→TT transitions) in the p53 tumor suppressor gene that are not commonly induced by other carcinogens. Our studies have demonstrated that UV‐induced mouse skin cancers contain p53 mutations at a high frequency and that these mutations can be detected in UV‐irradiated mouse skin well before the appearance of skin tumors. This observation suggested that it might be possible to use p53 mutations as a biologic endpoint for testing the efficacy of sunscreens in photoprotection studies. Indeed, application of SPF 15 sunscreens to mouse skin before each UVB irradiation resulted in reduction in the number of p53 mutations. Because p53 mutations represent an early essential step in photocarcinogenesis, these results imply that inhibition of this event may protect against skin cancer development. This hypothesis was confirmed by our finding that sunscreens used in p53 mutation inhibition experiments also protected mice against UVB‐induced skin cancer.
Photoprocesses of Molecules with 2‐Nitrobenzyl Protecting Groups and Caged Organic Acids
Authors: Bley Filiz , Schaper Klaus , Görner Helmut 
Published: October 2007

AbstractThe 308 nm photoinduced formation of the nitroso product and the intermediacy of the aci‐nitro form(s) were studied for a series of 2‐nitrobenzyl alkyl and aryl esters (1a–4e) and bis‐(nitrophenyl)methyl acetates (5a–6b) by time‐resolved UV‐vis spectroscopy. A triplet state appears as major transient, when 2‐nitrobenzyl derivatives 1 are substituted by 4,5‐dimethoxy (2) and 4,5‐methylenedioxy (3/4) groups. This triplet of charge transfer character is, however, not part of the route via the aci‐nitro into the 2‐nitroso form. The activation energy and preexponential factor of the longest lifetime component (τaci), i.e. the major part of the aci‐nitro decay, were determined. The carboxylic acids as leaving groups have rather small effects on τaci. An additional nitrated phenyl ring in α‐position (5) leads generally to shorter τaci value. Otherwise, the photogeneration of nitroso products is similar. The quantum yield (Φd) varies only moderately with structure, the yield of the aci‐nitro form and Φd are correlated and little affected by solvent properties.
Stent implantation through rendezvous technique of PTBD and ERCP: The treatment of obstructive jaundice
Authors: LIU Ying Di , WANG Zhi Qiang , WANG Xiang Dong , YANG Yun Sheng , LINGHU En Qiang , WANG Wei Feng , LI Wen , CAI Feng Chun 
Published: October 2007

OBJECTIVE:  To study the technical method and clinical value of stent implantation through the rendezvous technique of percutaneous transhepatic biliary drainage (PTBD) and endoscopic retrograde cholangiopancreatography (ERCP) in patients with obstructive jaundice.METHODS:  Thirty‐six patients with obstructive jaundice underwent the rendezvous technique of PTBD and ERCP after initially unsuccessful ERCP.RESULTS:  The procedure of 36 cases were all successful. Sixteen cases underwent PTBD drainage from the bile duct through the right lobe approach and in 20 cases the left lobe approach was used. The one‐stage procedure involved in the rendezvous technique of PTBD and ERCP was successful in 23 cases, while the other 13 cases underwent PTBD first and then rendezvous ERCP the next time. The serum total bilirubin 4 days later had decreased by 44.75%, and direct bilirubin had decreased by 45.61%. The main complication was infection of the bile duct.CONCLUSION:  Stent implantation using the rendezvous technique of PTBD and ERCP is a new and feasible method to treat obstructive jaundice after initially unsuccessful ERCP. This may be of considerable value in clinical practice.
Increased prevalence of Helicobacter pylori infection in gastric cardia of patients with reflux esophagitis: A study from Jordan
Authors: ABDUL‐RAZZAK Khalid K , BANI‐HANI Kamal E 
Published: October 2007

BACKGROUND:  The role of H. pylori infection in GERD is highly controversial. Our aim was to investigate the relationship between reflux esophagitis and H. pylori infection in Jordanian subjects and to examine the gastric site for H. pylori that is most strongly associated with reflux esophagitis.METHODS:  During endoscopy two biopsies from the cardia and another two biopsies from the antrum were taken from 100 consecutive patients with reflux esophagitis (RE group) and from a sex‐ and age‐matched group of 50 patients, who were referred to the endoscopy unit for evaluation of upper gastrointestinal symptoms and whose endoscopic findings were normal (control group). The biopsies were examined histologically for the presence of gastritis and H. pylori.RESULTS:  Antral histological gastritis, Barrett's esophagus and hiatus hernia were significantly more common in the RE group than in the control group. Out of the 100 patients, 68 (68%) in the RE group and 26 of 50 (52%) in the control group were found to have H. pylori infection. The presence of H. pylori in both antral and cardiac biopsies was significantly more frequent in patients of the RE group. Forty‐four patients in the RE group had positive H. pylori in both antral and cardiac biopsies (44%), while only 12 out of 50 patients of the control group (24%) had positive H. pylori in both biopsies. In the control group the prevalence of H. pylori in the antrum was similar to that of patients of the RE group (52% vs. 59%), but colonization of H. pylori in the cardia was significantly much lower than that of the RE group (24% vs. 53%; P = 0.0007).CONCLUSIONS:  The increased prevalence of H. pylori colonization in the cardia is associated with reflux esophagitis and further controlled clinical study is required to show the impact of H. pylori eradication in patients with reflux esophagitis.
Evaluation of the monoclonal stool antigen test for Helicobacter pylori in an Asian population with dyspepsia
Authors: BHEWA Yusuf , HILMI Ida , CHEAH Phaik‐Leng , NAVARATNAM Parasakthi , GOH Khean‐Lee 
Published: October 2007

OBJECTIVE:  Although well established in the West, stool antigen tests (SAT) are not widely used in Asia. Data on the accuracy of this test in Asia is sparse and, to date, there have been no studies looking at the more refined monoclonal SAT. The aim of this study is to validate the diagnostic accuracy of a stool antigen test, Hp STAR, for the detection of Helicobacter pylori.METHODS:  Consecutive new patients with dyspepsia, referred to the endoscopy unit were recruited. At endoscopy, biopsies were taken for rapid urease tests and histology. Stool specimens were collected before any therapy was given and were tested for H. pylori using the monoclonal SAT HpSTAR test. Samples were collected from 90 patients. The stool antigen results were compared with the results of rapid urease tests and histopathology, which were used together as the gold standard test in the diagnosis of H. pylori.RESULTS:  Of the 90 patients tested, 45 were H. pylori positive and 45 were H. pylori negative. There was one false positive and one false negative test. The sensitivity, specificity, positive predictive value and negative predictive value for the Hp STAR were identical: 97.8% with a 95% confidence interval of 88.2–99.9%. The diagnostic accuracy was 97.8% with a 95% confidence interval of 92.2–99.7%.CONCLUSION:  The monoclonal stool antigen test, HpSTAR is a highly accurate test for the diagnosis of H. pylori.