bluuebunny/crossref_metadata_2025 huggingface dataset:
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

Aim:  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.
The Effect of Natural Cheddar Cheese Ripening on the Functional and Textural Properties of the Processed Cheese Manufactured Therefrom
Authors: Brickley C.A. , Auty M.A.E. , Piraino P. , McSweeney P.L.H.
Published: October 2007

ABSTRACT:  Cheddar cheese ripened at 8 °C was sampled at 7, 14, 28, 56, 112, and 168 d and subsequently used for the manufacture of processed cheese. The cheddar cheese samples were analyzed throughout ripening for proteolysis while the textural and rheological properties of the processed cheeses (PCs) were studied. The rate of proteolysis was the greatest in the first 28 d of cheddar cheese ripening but began to slow down as ripening progressed from 28 to 168 d. A similar trend was observed in changes to the texture of the PC samples, with the greatest decrease in hardness and increase in flowability being in the first 28 d of ripening. Confocal scanning laser microscopy showed that the degree of emulsification in the PC samples increased as the maturity of the cheddar cheese ingredient increased from 7 to 168 d. This increased emulsification resulted in a reduction in the rate of softening in the PC in samples manufactured from cheddar cheese bases at later ripening times. Multivariate data analysis was performed to summarize the relationships between proteolysis in the cheddar cheese bases and textural properties of the PC made therefrom. The proportion of αs1‐casein (CN) in the cheddar cheese base was strongly correlated with hardness, adhesiveness, fracturability, springiness, and storage modulus values for the corresponding PC. Degradation of αs1‐CN was the proteolytic event with the strongest correlation to the softening of PC samples, particularly those manufactured from cheddar cheese in the first 28 d of ripening.
Sensory and Instrumental Analysis for Slipperiness and Compliance of Food during Swallowing
Authors: Seo H.‐S. , Hwang I.K. , Han T.R. , Kim I.S.
Published: October 2007

ABSTRACT:  In spite of its importance, there have been few attempts to evaluate the sensory attributes of the food bolus during swallowing. In the current study, the slipperiness, the degree of slide for the food bolus through the mucosal surface of the oro‐pharynx, and the compliance, how easily the shape of a food bolus can be transformed for automatic and comfortable swallowing, were derived among several sensory attributes related to the swallowing. Therefore, the study aims were twofold: (1) to develop the methods of sensory and instrumental analyses for determining the slipperiness and compliance of the food bolus during swallowing and (2) to examine the appropriateness of the newly designed devices by correlating the data between the sensory and instrumental analyses. Six commercial food products were evaluated by 10 trained panelists for each attribute. The devices for assessing each attribute were developed in consideration of the oro‐pharyngeal movements. The sensory and instrumental analyses showed high correlation and regression coefficients as well as intensity differences of the 6 samples for each attribute. In conclusion, the slipperiness and the compliance were suitable for acquiring a better understanding of the sensory attributes of the food bolus during swallowing, and the newly developed devices showed a high potential for determining those attributes.
Minerals, Phenolic Compounds, and Antioxidant Capacity of Citrus Peel Extract by Hot Water
Authors: Xu G.H. , Chen J.C. , Liu D.H. , Zhang Y.H. , Jiang P. , Ye X.Q.
Published: October 2007

ABSTRACT: Some dried citrus peels, more familiar aschenpiin China, have been widely used in traditional Chinese medicines from ancient times. This paper reports the efficiency of infusion cooking on extracting minerals and phenolic compounds (flavanone glycosides [FGs], polymethoxylated flavones [PMFs], and phenolic acids), and also antioxidant activity of hot water extract of citrus peels. Peels of 2 citrus varieties, namely, Satsuma mandarin (C. unshiuMarc.) and Ponkan (C. poonensisHort. ex Tanaka), which belong toC. reticulata, were selected. As a result, hot water extraction was efficient in extracting phenolic acids and some minerals. As for citrus flavonoids, narirutin, nobiletin, and tangeretin were easier to extract than hesperidin. The result of antioxidant capacity assays indicated that for citrus peels, hot water extract had almost the same capacity as the methanol extract. We suggested that Ponkan was more suitable as the source ofchenpi, since its hot water extract had much higher content of phenolic acids, FGs and PMFs, and higher antioxidant capacity than those of Satsuma mandarin. Generally, to raise the extraction temperature or to prolong the time could not yield higher content of phenolic compounds and stronger antioxidant capacity, though the content of minerals increased to some extent. Furthermore, a 2nd‐time extraction seemed necessary since considerable minerals and phenolic compounds could be obtained by doing so. Finally, we suggested that 2 times extraction at 100 °C for 30 min was proper to extract the minerals and phenolic compounds inchenpi.
Production of β‐Glucosidase and Hydrolysis of Isoflavone Phytoestrogens byLactobacillus acidophilus,Bifidobacterium lactis, andLactobacillus caseiin Soymilk
Authors: Donkor O.N. , Shah N.P.
Published: October 2007

ABSTRACT: The study determined β‐glucosidase activity of commercial probiotic organisms for hydrolysis of isoflavone to aglycones in fermenting soymilk. Soymilk made with soy protein isolate (SPI) was fermented withLactobacillus acidophilusLAFTI®L10,Bifidobacterium lactisLAFTI®B94, andLactobacillus caseiLAFTI®L26 at 37 °C for 48 h and the fermented soymilk was stored for 28 d at 4 °C. β‐Glucosidase activity of organisms was determined using ρ‐nitrophenyl β‐D‐glucopyranoside as a substrate and the hydrolysis of isoflavone glycosides to aglycones by these organisms was carried out. The highest level of growth occurred at 12 h forL. caseiL26, 24 h forB. lactisB94, and 36 h forL. acidophilusL10 during fermentation in soymilk. Survival after storage at 4 °C for 28 d was 20%, 15%, and 11% greater (P< 0.05) than initial cell counts, respectively. All the bacteria produced β‐glucosidase, which hydrolyzed isoflavone β‐glycosides to isoflavone aglycones. The decrease in the concentration of β‐glycosides and the increase in the concentration of aglycones were significant (P< 0.05) in the fermented soymilk. Increased isoflavone aglycone content in fermented soymilk is likely to improve the biological functionality of soymilk.
Characterization of a Thermostable and Acidic‐Tolerable β‐Glucanase from Aerobic Fungi Trichoderma koningii ZJU‐T
Authors: Wang J.‐L. , Ruan H. , Zhang H.‐F. , Zhang Q. , Zhang H.‐B. , He G.‐Q. , Shen S.‐R.
Published: October 2007

ABSTRACT:  An extreme thermostable and acidic tolerable β‐glucanase was isolated and characterized from aerobic fungi Trichoderma koningii ZJU‐T. The optimal reaction temperature and pH for the β‐glucanase were 100 °C and pH 2.0, respectively. The β‐glucanase showed increased stability at higher temperatures and lower pH values when compared to other β‐glucanases. The optimum conditions for the β‐glucanase stability were found to be pH 4.0 and 80 °C. Even subjected to 100 °C for 3 h, β‐glucanase activity did not show significant reduction. Moreover, K+ significantly enhanced β‐glucanase activity at the concentration of 1 mM, while EDTA and other metal ions such as Mg2+, Mn2+, Zn2+, Ca2+, Fe2+, Pb2+, and Fe3+ inhibited β‐glucanase activity. Denaturants, including sodium dodecyl sulfate (SDS) and mercaptoethanol, also inhibited β‐glucanase activity at a concentration of 5%. However, in the presence of 7 M urea, residual activity of the β‐glucanase still remained 14.5%.
An Integrated Approach to Evaluate Food Antioxidant Capacity
Authors: Sun T. , Tanumihardjo S.A.
Published: October 2007

ABSTRACT:  Many methods are available for determining food antioxidant capacity, which is an important topic in food and nutrition research and marketing. However, the results and inferences from different methods may vary substantially because each complex chemical reaction generates unique values. To get a complete and dynamic picture of the ranking of food antioxidant capacity, relative antioxidant capacity index (RACI), a hypothetical concept, is created from the perspective of statistics by integrating the antioxidant capacity values generated from different in vitro methods. RACI is the mean value of standard scores transformed from the initial data generated with different methods for each food item. By comparing the antioxidant capacity of 20 commonly consumed vegetables in the U.S. market that were measured with 7 chemical methods, we demonstrated that the RACI correlated strongly with each method. The significant correlation of RACI with an independent data set further confirmed that RACI is a valid tool to assess food antioxidant capacity. The key advantage of this integrated approach is that RACI is in a numerical scale with no units and has consistent agreement with chemical methods. Although it is a relative index and may not represent a specific antioxidant property of different food items, RACI provides a reasonably accurate rank of antioxidant capacity among foods. Therefore, it can be used as an integrated approach to evaluate food antioxidant capacity.
Utilization of Electron Beam Irradiated Almond Skin Powder as a Natural Antioxidant in Ground Top Round Beef
Authors: Prasetyo M. , Chia M. , Hughey C. , Were L.M.
Published: October 2007

ABSTRACT:  Defatted Carmel variety almond skin powder (ASP) irradiated at 0, 10, 20, and 30 kGy was mixed with ground top round beef at 0.5% (w/w) and stored at 4 °C. Color stability, peroxide values (PV), conjugated dienes (CD), thiobarbituric acid reactive species (TBARS), and hexanal were determined periodically over a 2‐wk period. The L values were not affected by time or treatment. Initially, the redness (a value) was higher for both the negative control with no ASP (a value of 21.83) and positive control with 0.01% BHT (a value of 22.33) compared to samples that contained the ASP (a values from 17.70 to 20.17) on day 1. This decrease in redness was attributed to the presence of the ASP. Similar to day 1, the a values were not significantly different between the 2 controls over the duration of the study. All the samples with ASP exhibited lower lipid oxidation when compared to the negative control, with greatest oxidation retardation observed at 20 and 30 kGy. Over the treatment period, a 13% to 85% reduction in PV and a 40% to 80% reduction in TBARS were observed in the sample with 30 kGy ASP compared to the negative control. Generally, PV and TBARS of samples with ASP decreased with an increase in irradiation dose. While a difference due to irradiation dose was not observed in CD and hexanal content, the values were significantly lower (P < 0.05) than the controls over time. This study demonstrates that almond skin power could be used to extend the shelf life of refrigerated ground raw beef.
UV‐induced Immunosuppression in the Balance†
Authors: De Gruijl Frank R.
Published: October 2007

Around 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

Both 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

The 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

The 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.
Educators’ Views on the Role of Neuroscience in Education: Findings From a Study of UK and International Perspectives
Authors: Pickering Susan J. , Howard‐Jones Paul
Published: October 2007

ABSTRACT— This report summarizes findings from a study of educators’ views on the role of the brain in education. Responses were sought using questionnaires (n= 189), followed by a smaller number of in‐depth interviews (n= 11). Results show a high level of enthusiasm for attempts to interrelate neuroscience and education, although conceptualizations about what this entails differ widely. Findings suggest that communication with practitioners may become a key factor influencing the success of attempts to enrich classroom practice with scientific understanding about the brain and mind.
Educational Neuroscience: Defining a New Discipline for the Study of Mental Representations
Authors: Szűcs Dénes , Goswami Usha
Published: October 2007

ABSTRACT— Is educational neuroscience a “bridge too far”? Here, we argue against this negative assessment. We suggest that one major reason for skepticism within the educational community has been the inadequate definition of the potential role and use of neuroscience research in education. Here, we offer a provisional definition for the emerging discipline of educational neuroscience as the study of the development of mental representations. We define mental representations in terms of neural activity in the brain. We argue that there is a fundamental difference between doing educational neuroscience and using neuroscience research results to inform education. While current neuroscience research results do not translate into direct classroom applications, educational neuroscience can expand our knowledge about learning, for example, by tracking the normative development of mental representations. We illustrate this briefly via mathematical educational neuroscience. Current capabilities and limitations of neuroscience research methods are also considered.
Visual Learning and the Brain: Implications for Dyslexia
Authors: Schneps Matthew H. , Rose L. Todd , Fischer Kurt W.
Published: October 2007

ABSTRACT— The central and peripheral visual fields are structurally segregated in the brain and are differentiated by their anatomical and functional characteristics. While the central field appears well suited for tasks such as visual search, the periphery is optimized for rapid processing over broad regions. People vary in their abilities to make use of information in the center versus the periphery, and we propose that this bias leads to a trade‐off between abilities for sequential search versus contemporaneous comparisons. The parameter of periphery‐to‐center ratio (PCR) describes the degree of peripheral bias, which evidence suggests is high in many people with dyslexia. That is, many dyslexics favor the peripheral visual field over the center, which results in not only search deficits but also (more surprisingly) talents for visual comparison. The PCR framework offers a coherent explanation for these seemingly contradictory observations of both deficit and talent in visual processing. The framework has potential implications for instructional support in visually intensive domains such as science and mathematics.
How Educational Theories Can Use Neuroscientific Data
Authors: Willingham Daniel T. , Lloyd John W.
Published: October 2007

ABSTRACT— Although many articles have addressed the relationship of neuroscience and education at a theoretical level, none has considered as a practical matter how one integrates neuroscientific data into a behavioral theory that uses hypothetical constructs. We describe 4 techniques by which researchers may do so: (a) direct observation of hypothetical constructs in the brain, (b) validation of hypothetical constructs through brain imaging, (c) using neural architecture to infer a behavioral architecture, and (d) using well‐developed knowledge of brain function to select among competing behavioral theories. A detailed examination of these 4 techniques indicates that they are amenable to educational research and, indeed, have been used to inform research and theory. We argue that these techniques are not applicable to all educational research problems, but rather they are appropriate to relatively low‐level behaviors (e.g., reading) rather than complex behaviors (e.g., classroom management).
Changing trends in gastrointestinal disease in the Asia–Pacific region
Authors: GOH KL
Published: October 2007

The new millennium has seen distinct changes in the pattern of gastrointestinal disease in the Asia–Pacific region. These changes are important as more than half of the world's population come from the region and therefore impact significantly on the global disease burden. The highest incidence of gastric cancer (GCA) has been reported from Asia and GCA remains a very important cancer. However time‐trend studies have shown a decrease in GCA incidence in several countries in Asia. A rise in cardio‐esophageal cancers as seen in the West has not been reported. On the other hand, colorectal cancer has been steadily increasing in Asia with age‐standardized incidence rates of some countries approaching that of the West. The pattern of acid‐related diseases has also changed. Gastroesophageal reflux disease is a fast emerging disease with an increasing prevalence of reflux esophagitis and reflux symptoms. The prevalence of peptic ulcer disease has at the same time declined in step with a decrease in H. pylori infection. Many of the changes taking place mirror the Western experience of several decades ago. Astute observation of the epidemiology of emerging diseases combined with good scientific work will allow a clearer understanding of the key processes underlying these changes. With rapid modernization, lifestyle changes have been blamed for an increase in several diseases including gastroesophageal reflux disease, nonalcoholic fatty liver disease and colorectal cancer. A worrying trend has been the increase in obesity among Asians, which has been associated with an increase in metabolic diseases and various gastrointestinal cancers. Conversely, an improvement in living conditions has been closely linked to the decrease in GCA and H. pylori prevalence.
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.
The efficacy of bismuth containing quadruple therapy as a first‐line treatment option for Helicobacter pylori
Authors: UYGUN Ahmet , KADAYIFCI Abdurrahman , SAFALI Mukerrem , ILGAN Seyfettin , BAGCI Sait
Published: October 2007

BACKGROUND:  Helicobacter pylori eradication rates have tended to decrease recently, mostly due to increasing antibiotic‐resistance. The present study aimed to compare the efficacy of bismuth‐based quadruple regimen with proton pump inhibitor‐based triple regimen for eradication of H. pylori.

METHODS:  Consecutive H. pylori‐positive patients with non‐ulcer dyspepsia were randomized into one of two regimens: (i) bismuth subsalicylate 300 mg q.i.d., lansoprazole 30 mg b.i.d., tetracycline 500 mg q.i.d. and metronidazole 500 mg t.i.d. (BLTM group) for 14 days; (ii) lansoprazole 30 mg b.i.d., amoxicillin 1 g b.i.d and clarithromycin 500 mg b.i.d. (LAC) for 14 days. Gastroscopy and 14C‐Urea breath test (UBT) were performed before enrollment, and UBT only was repeated for 6 weeks after treatment.

RESULTS:  A total of 240 patients were randomized into groups and 212 of them completed the protocols. The ‘intention‐to‐treat’ (ITT) and ‘per protocol’ (PP) H. pylori eradication rates were 70% (95%CI 61–78) and 82.3% (95%CI 74–89) in the BLTM group, and 57.5% (95%CI 48–66) and 62.7% (95%CI 53–71) in the LAC group. The BLTM treatment achieved a significantly better eradication rate compared with LAC treatment in PP analysis (82.3% vs. 62.7%, P = 0.002). Mild to severe side‐effects, which were more frequent in the BLTM group, were reported in 18.2% of the patients.

CONCLUSION:  The bismuth‐based quadruple regimen achieved a better eradication rate compared with proton pump inhibitor‐based triple regimens as a first‐line eradication option for H. pylori in our population.
Peritoneal mesothelioma presenting as an acute surgical abdomen due to jejunal perforation
Authors: SALEMIS Nikolaos S , TSIAMBAS Evangelos , GOURGIOTIS Stavros , MELA Ageliki , KARAMERIS Andreas , TSOHATARIDIS Efstathios
Published: October 2007

BACKGROUND:  Peritoneal mesothelioma is a rare disease associated with poor prognosis. Acute abdomen as the first presentation is an extremely rare occurrence. We report an exceptional case of a patient who was found to have a jejunal perforation due to infiltration of peritoneal mesothelioma.

METHODS:  A 62‐year‐old man was admitted with clinical signs of peritonitis. Computerized tomographic scans showed a mass distal to the ligament of Treitz, thickening of the mesentery and a small amount of ascites.

RESULTS:  Emergency laparotomy revealed a perforated tumor 15 cm distal to the ligament of Treitz and diffuse peritoneal disease. Segmental small bowel resection and suboptimal cytoreduction were performed. Histopathology and immunohistochemistry showed infiltration of malignant mesothelioma. During the postoperative period pleural mesothelioma was also diagnosed. Despite adjuvant chemotherapy, the patient died of disseminated progressive disease 7 months after surgery.

CONCLUSIONS:  Peritoneal mesothelioma is a rare malignancy with grim prognosis. Small bowel involvement is a poor prognostic indicator. Our case of a small bowel perforation due to direct infiltration by peritoneal mesothelioma appears to be the first reported in the English literature.
Basic research on inflammatory bowel disease in China
Authors: BAI Ai Ping , OUYANG Qin , HU Ren Wei
Published: October 2007

OBJECTIVE:  Since the etiology and the pathogenesis of inflammatory bowel disease (IBD) are still not well known, research on IBD often focuses on these topics. Investigative science papers about IBD in Chinese medical journals from 1989 to 2003 were viewed to understand the progress of basic IBD research in China.

MATERIALS AND METHODS:  The basic science investigative papers about IBD from 1989 to 2003 in Chinese periodicals (VIP and CMCC) were reviewed and analyzed; the key words used were as follows: inflammatory bowel disease, ulcerative colitis, Crohn's disease, basic science investigation, and literature review.

RESULTS:  There were 3454 articles about IBD published in Chinese medical journals from 1989 to 2003, and during these 15 years, 508 papers focused on basic scientific investigations. There were 463 papers investigating the pathogenesis of IBD, 287 papers on immunological mechanisms, and 176 papers about other mechanisms. There were 142 papers investigating the mechanisms of Chinese traditional medicine on IBD from 1989 to 2003, which included 117 papers related to animal experiments and 25 papers related to clinical studies.

CONCLUSIONS:  There have been relatively few investigative scientific papers on IBD published in Chinese medical journals. However, the study of IBD has been emphasized in China. Research on the immunological mechanisms of IBD has been predominant. Furthermore, a large number of the research papers were about the mechanisms and effects of Chinese traditional medicine on IBD.
Characteristics of Flow Boiling Oscillations in Silicon Microchannel Heat Sinks
Authors: Muwanga R. , Hassan I. , MacDonald R.
Published: October 2007

Flow boiling oscillation characteristics in two silicon microchannel heat sink configurations are presented. One is a standard heat sink with 45 straight parallel channels, whereas the second is similar except with cross-linked paths at three locations. Data are presented over a flow range of 20–50ml∕min(91–228kg∕(m2s)) using distilled water as the working fluid. The heat sinks have a footprint area of 3.5cm2 and contain 269μm wide by 283μm deep reactive ion etching channels. Flow oscillations are found to be similar in characteristic trends between the two configurations, showing a decreasing frequency with increasing heat flux. The oscillation amplitudes are relatively large and identical in frequency for the inlet temperature, outlet temperature, inlet pressure, and pressure drop. Oscillation properties for the standard heat sink at two different inlet temperatures and various flow rates are correlated for different heat fluxes. This work additionally presents a first glimpse of the cross-linked heat sink performance under flow boiling instability conditions.
Heat Transfer Study in a Linear Turbine Cascade Using a Thermal Boundary Layer Measurement Technique
Authors: Han S. , Goldstein R. J.
Published: October 2007

An experimental system is designed, constructed, and operated to make local measurements of heat transfer from constant-temperature surfaces in a linear turbine cascade. The system includes a number of embedded heaters and a control system to maintain the turbine blades and end walls in the cascade at a uniform temperature. A five-axis measurement system is used to determine temperature profiles normal to the pressure and suction sides of the blades and to the end wall. Extrapolating these measurements close to the surface, the local heat transfer is calculated using Fourier’s law. The system has been tested in the laboratory, and results are shown for the temperature distributions above the surfaces and for the local variations in the Nusselt number on the different surfaces in the cascade. The system can also be used to study the heat and mass transfer analogy as considerable data are available for mass transfer results with similar geometries.
Spectral Element Approach for Coupled Radiative and Conductive Heat Transfer in Semitransparent Medium
Authors: Zhao J. M. , Liu L. H.
Published: October 2007

A spectral element method is presented to solve coupled radiative and conductive heat transfer problems in multidimensional semitransparent medium. The solution of radiative energy source is based on a second order radiative transfer equation. Both the second order radiative transfer equation and the heat diffusion equation are discretized by spectral element approach. Four various test problems are taken as examples to verify the performance of the spectral element method. The h-and the p-convergence characteristics of the spectral element method are studied. The convergence rate of p refinement for different values of Planck number follows the exponential law and is superior to that of h refinement. The spectral element method has good property to tolerate skewed meshes. The predicted dimensionless temperature distributions determined by the spectral element method agree well with the results in references. The presented method is very effective to solve coupled radiative and conductive heat transfer in semitransparent medium with complex configurations and demands little on the quality of mesh.
Natural-Convection Flow Along a Vertical Complex Wavy Surface With Uniform Heat Flux
Authors: Molla Mamun , Hossain Anwar , Yao Lun-Shin
Published: October 2007

A natural-convection boundary layer along a vertical complex wavy surface with uniform heat flux has been investigated. The complex surface studied combines two sinusoidal functions, a fundamental wave and its first harmonic. Using a method of transformed coordinates, the boundary-layer equations are mapped into a regular and stationary computational domain. The transformed equations can then be solved straightforwardly by any number of numerical methods designed for regular and stationary geometries. In this paper, an implicit finite-difference method is used. The results were readily obtained on a personal computer. The numerical results demonstrate that the additional harmonic substantially alters the flow field and temperature distribution near the surface. The induced velocity normal to the y axis can substantially thicken the boundary layer, implying that its growth is not due solely to the momentum and thermal diffusion normal to the y axis along a wavy surface.