DETERMINATION OF GUSTATORY SUCROSE THRESHOLD IN WATER BY USE OF A LINEAR SUCROSE GRADIENT

A novel experimental method was developed which allows the determination of the threshold concentration of sucrose by use of a linear sucrose gradient in water. With this method a continuous tasting of the test-liquid is possible. A panel of 15 persons experienced in taste-testing was used. Three gradients of different steepness were applied: 0 to 1.5% (w/w) sucrose in 2 min (I), 3 min (II) and 4 min (III). The results of the new method were compared with those of the standard method (DIN). With gradients I and II we found values which were significantly higher than those of the standard method (I: 0.49% (w/w); II: 0.46% (w/w); DIN: 0.31% (w/w)), whereas with gradient III the same threshold value was found as with the DIN-Method (III: 0.32% (w/w)).     

Effect of neurotensin on pancreatic function in man

The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs.     

Delimitation of the maritime boundary in the gulf of Maine area

The compulsory dispute settlement regime included in the 1982 Law of the Sea Convention is recognized as one of the most comprehensive in a modern international convention. Yet, in the recent application of this regime, the question has arisen as to whether the procedural prerequisites associated with the LOS Convention's compulsory dispute settlement mechanism are so arduous as to avoid binding and compulsory jurisdiction in most instances. This article addresses that question by examining, in particular, the reasoning of the Southern Bluefin Tuna arbitration tribunal, which found Article 281 of Section 1 of the LOS Convention to bar jurisdiction to the compulsory dispute settlement mechanism prescribed by the Convention, and offers suggestions as to how states might distinguish or overcome the barriers imposed by the Southern Bluefin Tuna tribunal in future cases.     

Inorganic pyrophosphatase: a new polymorphic allozyme locus in Pacific salmon

Genetic polymorphism of inorganic pyrophosphatase was investigated in 2799 individuals in four species of Pacific salmon: chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch), kokanee (O. nerka), and steelhead (O. mykiss), using horizontal starch gel electrophoresis. This enzyme system appears to be an isolocus system with electrophoretically indistinguishable allozymes encoded by two loci (PP-1,2*) expressed in retinal tissue. Mendelian inheritance was observed with a breeding study in three family crosses. Population variability in four species was characterized in 44 populations from the U.S. Pacific coast. Three alleles were found in chinook salmon; two alleles each were found in coho salmon, kokanee, and steelhead. Chinook salmon and kokanee populations differed enough with respect to PP-1,2* frequencies that this isolocus is useful for genetic stock identification in these species.     

A spatial analytical approach for selecting reintroduction sites for burbot in English rivers

1. Availability of suitable habitat is a prerequisite for species reintroduction success, and to ensure population persistence, investigations of a species’ habitat utilisation throughout its life history should be conducted as part of a feasibility study. 2. Habitat utilisation models for burbot, Lota lota, developed using data from field studies conducted in France and Germany and information from the literature were used to assess the feasibility of reintroducing burbot into rivers of its former native range in eastern England. 3. Per cent tree roots, aquatic vegetation and flow types were important predictors of adult burbot abundance. Furthermore, the habitat utilisation models were supplemented with information from the literature, which suggested that off‐channel habitat such as wetlands and backwaters is important for spawning and nursery stages. 4. An assessment of the habitat availability in the rivers of the burbot’s former native range using variables related to spawning and nursery and adult life stages showed that although adult habitat was widely distributed, the availability of spawning and nursery habitat was less abundant, potentially limiting successful reestablishment. 5. Potential suitable habitat was concentrated in the central and southern areas of the species’ former English distribution. Overall, rivers of the burbot’s former range potentially afford suitable habitat to sustain a reintroduced population. However, sites should be preferentially selected on the basis of having appropriate spawning and nursery areas.     

Two Reproductive Life History Types of Kokanee, Onchorynchus nerka, Exhibit Multivariate Morphometric and Protein Genetic Differentiation

Two reproductive types of kokanee are found in Okanagan Lake, British Columbia: one form that spawns in streams, and another that spawns approximately 2–4 weeks later along beaches of the lake. We examined the levels and patterns of genetic and morphometric variation among three populations (1 beach and 2 stream populations) to better understand life history differentiation. We assayed allozyme variation at 74 loci and identified 15 P_0.095 loci. Average F_ST was 0.041 among the three samples; the two stream-spawning populations grouped together in genetic distance analyses. We examined multivariate morphometric variation and fin size/shape variation using 35 truss characters. Populations did not sort morphologically by spawning type in principal component and relative warp analyses. Instead both analyses indicated that one stream-spawning population (Peachland Creek) was significantly more robust and had shallower caudal fins in comparison to the other samples. Second, clear multivariate shape differences between males and females were identified involving jaw size, mid-body dimensions, and caudal fin shape. A simple bivariate plot of tail `forkness' against fork length demonstrated that males had more forked tails and females had flattened tails. Level of differentiation of secondary sexual characteristics did not vary between the spawning types, although the beach-spawning population and one stream-spawning population did not show the strong, gender-discriminating variability in tail forkness. Although these two reproductive life history types of kokanee form discrete genetic groups, environmental differences are apparently insufficient to effect consistent differences in body shape, or fin size and shape between stream and beach-spawning morphs.     

Assessment of Oxidative Damage to Proteins and DNA in Urine of Newborn Infants by a Validated UPLC-MS/MS Approach

The assessment of oxidative stress is highly relevant in clinical Perinatology as it is associated to adverse outcomes in newborn infants. This study summarizes results from the validation of an Ultra Performance Liquid Chromatography–tandem Mass Spectrometry (UPLC-MS/MS) method for the simultaneous quantification of the urinary concentrations of a set of endogenous biomarkers, capable to provide a valid snapshot of the oxidative stress status applicable in human clinical trials, especially in the field of Perinatology. The set of analytes included are phenylalanine (Phe), para-tyrosine (p-Tyr), ortho-tyrosine (o-Tyr), meta-tyrosine (m-Tyr), 3-NO₂-tyrosine (3NO₂-Tyr), 3-Cl-tyrosine (3Cl-Tyr), 2′-deoxyguanosine (2dG) and 8-hydroxy-2′-deoxyguanosine (8OHdG). Following the FDA-based guidelines, appropriate levels of accuracy and precision, as well as adequate levels of sensitivity with limits of detection (LODs) in the low nanomolar (nmol/L) range were confirmed after method validation. The validity of the proposed UPLC-MS/MS method was assessed by analysing urine samples from a clinical trial in extremely low birth weight (ELBW) infants randomized to be resuscitated with two different initial inspiratory fractions of oxygen.