Metabolic response of horses to a high soluble carbohydrate diet: effects of low-intensity submaximal exercise and sodium bicarbonate supplementation.

Four mares fed a low fiber, high soluble carbohydrate diet were used in a crossover design to evaluate the effects of dietary sodium bicarbonate (NaHCO3) supplementation during daily low-intensity submaximal working conditions. Mares were fed the diet at 1.7 times the maintenance energy requirement for mature horses at work. The horses tolerated the diet well and had no clinical abnormalities. Resting venous blood bicarbonate (HCO3), standard HCO3, and base excess (BE) concentrations significantly (P less than 0.05) increased with NaHCO3 supplementation, but no significant changes in resting venous blood pH or carbon dioxide tension (PCO2) were recorded. Venous blood HCO3, standard HCO3, BE, hemoglobin, and heart rate were significantly (P less than 0.05) increased and plasma lactate concentration was significantly (P less than 0.05) decreased in the control horses and in the horses given the NaHCO3 supplement during low-intensity submaximal exercise. There were no significant changes in venous blood pH, PCO2, or plasma protein concentration with exercise. Venous blood HCO3, standard HCO3, and BE concentrations were significantly (P less than 0.05) greater during submaximal exercise in horses given the NaHCO3 supplement. There were no significant differences in plasma lactate or total protein concentrations, blood pH, PCO2, or hemoglobin concentration between the 2 groups during exercise.     

Bound xenobiotic residues in food commodities of plant and animal origin

The following are extended summaries of Technical Reports which are produced at intervals by the International Union of Pure and Applied Chemistry (IUPAC). They are entirely the responsibility of IUPAC/the authors and do not necessarily reflect the views of the Editorial Board of Pest Management Science. Copyright © 2002 Society of Chemical Industry     

New techniques for the assessment and optimal management of growth and standing crop variation in the cultured freshwater prawn, Macrobrachium rosenbergii

The current ‘traditional’ prawn pond management system really does not ‘manage’, but rather accommodates prawn production characteristics and was instituted with a minimum knowledge of prawn biology and husbandry. As such, the traditional system is not optimal because it does not rely on a strong empirical knowledge base. Prawn culture has succeeded up until now because Macrobrachium rosenbergii is easily cultured and will give 500–1000 kg ha⁻¹ year⁻¹ without much effort. This is sufficient in many areas of the world but not in others where economic conditions have break-even production requirements of nearly 1 tonne greater than this. The traditional system relying on selective harvesting with large seine nets is seriously inefficient which not only leads to lost revenue but under-manages pond growth since unculled large animals suppress the growth of unculled smaller ones. The degree to which this occurs was not known to the designers of the traditional system who had no way of knowing (as we do now from our research results) the extremely large compensatory growth capability of small prawns in the absence of large ones. The traditional system also does not manage sexual dimorphic growth because no technology exists which can be used to create monosex broods or manipulate the sex ratio in ponds. Accurate production models are not available because traditional ponds are rarely sampled and/or rarely drained. This, along with inefficient harvests, results in a co-mingling of cohort stocking classes. It is impossible to get accurate survival and growth data because of this and because it is so time consuming to sample commercial ponds and process the data on a regular basis. This paper describes four new engineering and ‘bioengineering’ techniques which are under development and can overcome all the drawbacks of the traditional system: (1) surgical sex reversal to create monosex broods; (2) genetic tagging of stocking and resident cohorts to assess survival and growth; (3) size grading and 100% efficient harvesting using pond draining and a machine grader-harvester; and (4) a semi-automated computer assisted prawn sample data management system which uses sonic digitization of prawn sample data.     

The development ofRhizoctonia solani Kühn on the underground parts of the potato plant

Summary The development of the sclerotia (black scurf) ofRhizoctonia solani Kühn, on potato tubers is related to tuber maturity and the health of the root and stolon systems. Few sclerotia formed on tubers from untreated plants until the onset of plant senescence when, as the tubers matured and roots and stolons decayed, sclerotia developed both rapidly and extensively. Application of acid to haulms in early August led to an increase in black scurf on tubers, initially related to the increase in root and stolon infection, but especially after later harvests, to the degree of tuber maturity. Later in August, scurf increases were paralleled both by tuber changes and root and stolon infection. My mid-September, when acid application was to plants becoming senescent, there was little difference between patterns of infection found on treated and check plants.

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Zusammenfassung In diesem Artikel wird der Fortlauf der Infektion durchRhizoctonia solani Kühn an Wurzeln. Stolonen und Knollen beschrieben. Ferner wird der Einfluss der Krautvernichtung und des zeitlichen Abstandes zwischen ihr und der Ernte auf diese Infektion untersucht. Pflanzknollen der Sorte Majestic wurden am Kronenende direkt vor dem Auspflanzen mit vier Isolaten vonR. solani (aus Sklerotien von Kartoffelknollen) inokuliert. An den ausgelesenen Knollen war keine Pockenkrankheit sichtbar. Das Kraut wurde an einem von fünf Daten gespritzt resp, nicht gespritzt und die Pflanzen nachher in Intervallen geerntet (Tabelle 1). Wurzel- und Stolonenteile wurden gewaschen, dann auf Leitungswasseragar, das 50 mg Neomycin und Chloramphenicol proliter enthielt, gebracht und vor der Beurteilung auf Rhizoctoniabefall w?hrend 48 Stunden bei Zimmertemperatur bebrütet. Die Pflanzknollen wurden gem?ss Tabelle 2 auf Sklerotienbefall beurteilt. Zur Reifesch?tzung wurde jede Knolle der L?nge nach geschnitten und der Prozentsatz des Periderms notiert, das mit einer Pinzette entfernt werden konnte, wenn man am Kronenende begann. Die Kontrollpflanzen hatten bis Mitte September bei nur beschr?nkter lokaler Infektion durchR. solani (Abb. 1 und 2) relativ gesunde Untergrundsysteme. In den folgenden drei Wochen reiften die Knollenperiderme. Wurzeln und Stolonen wurden weitgehend vom Pilz besiedelt. Folglich ?nderte sich die N?hrstoffversorgung des Pilzes, eine Situation, von der man weiss, dass sie die Entwicklung zur Sklerotienbildung f?rdert. Mitte September widerspiegelt sich die ?nderung in der Ern?hrung in einem Ansteigen der Anzahl von Knollen mit Pocken und in deren Ausdehnung auf den Knollen (Abb. 3 und 4). Krautvernichtung mit S?ure Anfang August führte zu einer Zunahme der Pockenkrankheit, was anf?nglich auf eine Zunahme der Wurzel- und Stoloneninfektion, sp?ter aber auf den Grad der Knollenreife (Abb. 5) in Beziehung stand.: Sp?ter, im August, wurden die Krankheitszunahmen mit Knollen?nderungen wie mit Wurzel- und Stoloneninfektion gleichlaufend. Die S?ureanwendung Mitte September geschah an alternden Pflanzen und ?nderte das an Kontrollpflanzen beobachtete Infektionsbild wenig.

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Résumé Cet article décrit l'évolution de la contamination, parRhizoctonia solani Kühn, des racines, stolons et tubercules de pommes de terre, et examine l'influence du défanage et de l'intervalle défanagerécolté sur une telle contamination. Des tubercules de la variété Majestic n'étant pas visuellement porteurs de sclérotes ont été inoculés à la couronne, juste avant la plantation, avec 4 souches deR. solani provenant de sclérotes sur tubercules de pommes de terre. Les tiges ont été ou n'ont pas été défanées à 5 dates différentes et on a récolté ensuite les tubercules à intervalles réguliers (tableau 1). Les fragments de racines et de stolons ont été lavés, placés sur une gelose à l'eau du robinet, contenant 50 mg de néomycin et de chloramphénicol par litre, et mis à incuber 48 heures à température ambiante avant notation de l'infection parR. solani. La notation des sclérotes sur tuberculesfils a été effectuée comme cela est indiqué dans le tableau 2. Comme estimation de la ‘maturité’ chaque tubercule a été coupé selon l'axe longitudinal et on a noté le pourcentage de périderme, en partant de la couronne qui a pu être enlevé avec des pinces. Les plantes témoins ont eu leurs systémes souterrains relativement sains jusqu'à la mi-septembre avec des contaminations locales parR. solani, limitées (figures 1 & 2). Les trois semaines suivantes, la maturité des tubercules a augmenté et les racines et stolons ont été fortement contaminés par le champignon. Le support nutritionnel du champignon a donc été altéré, cet élément connu permet de stimuler la maturité des sclérotes en cours de formation. Vers la mi-septembre, des changements nutritionnels se sont soldés par une augmentation du nombre de tubercules porteurs de sclérotes et par l'extension de ces derniers (figures 3 & 4). Le défanage aux colorants nitrés début ao?t a entrainé une augmentation des sclérotes, qui s'était manifestée initialement par une augmentation de la contamination des racines et stolons, et plus tard au niveau du degré de maturité du tubercule (figure 5). Plus tardivement en ao?t, l'augmentation des sclérotes allait de paire avec le changement de tubercule et avec la contamination des racines et stolons. Vers la mi-septembre, le défanage sur des plantes proches de la senescence a eu un léger effet sur la contamination des plantes témoins.

     

The role of flatfishes in the organization and structure of the eastern Bering Sea ecosystem

We evaluated the role of flatfishes in the organization and structure of the eastern Bering Sea ecosystem using the Ecopath/Ecosim approach. As basic input data for the Ecopath/Ecosim model, we used estimates of biomass from bottom trawl surveys and age-structured population models, production/biomass (P/B) ratio, consumption/biomass (Q/B) ratio, diet composition (DC), and fisheries harvests for each component of species or species groups. We estimated the trophic level of each component, niche overlaps among flatfishes, and the impacts of competition and predation on flatfish species in the eastern Bering Sea ecosystem. Based on those estimates, we developed the tropho-dynamic structure of the ecosystem, and the model was used to simulate ecological effects of fishery exploitation patterns. No single flatfish species appeared to have a profound and uniquely important role in the organization and structure of the ecosystem. Instead, the most important component among the guild of flatfish species appeared to be yellowfin sole Pleuronectes asper, which had greater biomass than other flatfish and a relatively diverse diet among the small flatfish species. Pacific halibut Hippoglossus stenolepis, Greenland turbot Reinhardtius hippoglossoides, and arrowtooth flounder Atheresthes stomias were important keystone predators in the eastern Bering Sea ecosystem together with some groups of marine mammals and sea birds. Intra flatfish complex cannibalism was not observed, however, substantial diet overlaps were common in the flatfish guild system.     

Synchronizing rock clocks of Earth history

Calibration of the geological time scale is achieved by independent radioisotopic and astronomical dating, but these techniques yield discrepancies of approximately 1.0% or more, limiting our ability to reconstruct Earth history. To overcome this fundamental setback, we compared astronomical and 40Ar/39Ar ages of tephras in marine deposits in Morocco to calibrate the age of Fish Canyon sanidine, the most widely used standard in 40Ar/39Ar geochronology. This calibration results in a more precise older age of 28.201 +/- 0.046 million years ago (Ma) and reduces the 40Ar/39Ar method's absolute uncertainty from approximately 2.5 to 0.25%. In addition, this calibration provides tight constraints for the astronomical tuning of pre-Neogene successions, resulting in a mutually consistent age of approximately 65.95 Ma for the Cretaceous/Tertiary boundary.     

Clinical Chemical Studies in Aleutian Disease of Mink

Clinical chemical determinations were carried out on blood removed by cardiac puncture from 49 mink affected with Aleutian disease and 25 normal animals and the respective differences tested for statistical significance. Blood urea nitrogen, serum total protein and globulin, thymol turbidity, glutamic oxalacetic and glutamic pyruvic transaminases and amylase were definitely elevated in the affected animals whereas serum calcium, albumin and A/G ratio were depressed. No statistically significant difference was apparent between the two groups in the comparison of inorganic phosphorus, alkaline and acid phosphatases, bilirubin, total cholesterol and esters, cephalin-cholesterol flocculation (3+ in each case), sodium, potassium, chloride, CO₂-combining power, leucine aminopeptidase and lactic dehydrogenase (means: over 2,000 u./ml.). For both the control and affected mink, the distribution of serum lactic dehydrogenase isozymes resembled that of human homologous serum hepatitis. Electrophoresis of serum proteins confirmed earlier findings of hypergammaglobulinemia in the diseased animals but a fast-moving or pre-albumin component, averaging 4% of the total protein, occurred in both the diseased and normal mink.     

Usefulness, completeness, and accuracy of Web sites providing information on osteoarthritis in dogs

OBJECTIVE: To evaluate the quality of information regarding osteoarthritis (OA) in dogs currently available on the World Wide Web. DESIGN: Survey study. PROCEDURE: 5 search engines were searched with the keywords "dog," "degenerative joint disease," "canine," and "osteoarthritis," and the first 50 sites listed by each search engine were analyzed. Unique Web site addresses were distributed to 3 diplomates of the American College of Veterinary Surgeons, who provided a standardized evaluation of each site. RESULTS: 30 unique Web sites were evaluated. Twenty (66%) provided information consistent with conventional knowledge as outlined in textbooks and peer-reviewed literature, 8 (27%) provided experimental or anecdotal information in addition to conventional knowledge, and 2 (7%) provided misleading information. Mean scores for overall usefulness of the information provided in regard to clinical features of and treatment for OA were 1.3 and 1.5, respectively (1 = information of minimal use; 5 = very useful information). Twenty-three (77%) sites encouraged pet owners to seek the advice of a veterinarian. Twenty-three (77%) sites were given overall quality scores < 2, and 7 (23%) were given scores between 2 and 3 (1 = site was counterproductive; 5 = site was very valuable). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the quality of information currently available on the Web that addresses OA in dogs is questionable. Although most of the sites conveyed some conventional information with reasonable accuracy, the information was incomplete, of minimal use, and often considered counterproductive.