Showing papers by "University of Aberdeen published in 1996"

Free histidine as a metal chelator in plants that accumulate nickel

Abstract: A NUMBER of terrestrial plants accumulate large quantities of metals such as zinc, manganese, nickel, cobalt and copper in their shoots1. The largest group of these so-called 'metal hyperaccumulators' is found in the genus Alyssum, in which nickel concentrations can reach 3% of leaf dry biomass2,3. Apart from their intrinsic interest, plants exhibiting this trait could be of value in the decontamination of metal-polluted soils4–6. However, the biochemical basis of the capacity for metal accumulation has not been elucidated. Here we report that exposing hyperaccumu-lator species of Alyssum to nickel elicits a large and proportional increase in the levels of free histidine, which is shown to be coordinated with nickel in vivo. Moreover, supplying histidine to a non-accumulating species greatly increases both its nickel tolerance and capacity for nickel transport to the shoot, indicating that enhanced production of histidine is responsible for the nickel hyperaccumulation phenotype in Alyssum.

Reduced bone density and osteoporosis associated with a polymorphic Sp1 binding site in the collagen type I alpha 1 gene.

Abstract: Osteoporosis is a common disease with a strong genetic component1–3, characterized by reduced bone mass and increased fracture risk4 Current evidence suggests that the inheritance of bone mass is under polygenic control5 but the genes responsible are poorly defined Type I collagen is the major protein of bone encoded by the COLIA1 and COLIA2 genes While these are strong candidates for the genetic regulation of bone mass, no abnormality of either gene has so far been defined in osteoporosis6 In this study, we describe a novel G→T polymorphism in a regulatory region of COLIA1 at a recognition site for the transcription factor Sp17 that is significantly related to bone mass and osteoporotic fracture G/T heterozygotes at the polymorphic Sp1 site (Ss) had significantly lower bone mineral density (BMD) than G/G homozygotes (SS) in two populations of British women and BMD was lower still in T/T homozygotes (ss) The unfavourable Ss and ss genotypes were over-represented in patients with severe osteoporosis and vertebral fractures (54%), as compared with controls (27%), equivalent to a relative risk of 297 (95% confidence interval 163–956) for vertebral fracture in individuals who carry the ‘s’ allele While the mechanisms that underlie this association remain to be defined, the COLIA1 Sp1 polymorphism appears to be an important marker for low bone mass and vertebral fracture, raising the possibility that genotyping at this site may be of value in identifying women who are at risk of osteoporosis

Matrix metalloproteinase–1 is associated with poor prognosis in colorectal cancer

Abstract: Colorectal cancer is one of the commonest malignant tumors and has a relatively poor prognosis. The outcome depends on the extent of local and particularly metastatic tumor spread. The matrix metalloproteinases (MMPs) are a family of closely related enzymes that degrade the extracellular matrix and are considered to be important in facilitating tumor invasion and spread (1-3). Using immunohistochemistry we have investigated the occurrence in colorectal cancer of MMP-1 (interstitial collagenase). Our monoclonal antibody was prepared against a synthetic peptide corresponding to an amino acid sequence specific for MMP-1 and was selected to react in formalin-fixed wax-embedded sections, thus allowing use in diagnostic histopathology and also enabling access to archival material. We found that the presence of MMP-1 in colorectal cancer is associated with a poor prognosis (P = 0.006) and has prognostic value independent of Dukes stage. One MMP inhibitor that strongly inhibits MMP-1 has already been shown to inhibit growth of human colon cancer xenografts in nude mice (4). Our results suggest that treatment of those individuals whose colon tumors produce MMP-1 with MMP inhibitors is a therapeutic strategy worth pursuing.

Natural killer cells and cancer.

Abstract: BACKGROUND Natural cytotoxicity, mediated by natural killer (NK) cells and cells with lymphokine-activated killer (LAK) activity, is believed to play an important role in host anti-cancer defense mechanisms. METHODS The authors critically review recent publications on the role of natural cytotoxicity in patients with cancer. RESULTS In patients with cancer, several studies have noted variations in the numbers and activity of NK and cells with LAK activity in different body compartments. NK cell activity in the peripheral blood lymphocytes (PBLs) is higher than that found in lymph nodes and within tumors, and this appears to be due to the presence of suppressor factors. The natural cytotoxicity of PBLs in patients with different types of cancers varies. However, there appears to be a trend for natural cytotoxicity to be reduced in certain cancer patients, possibly related to tumor volume or dissemination. Anti-cancer treatments (e.g., surgery, hormonal modulation, radiotherapy and chemotherapy) can also result in suppression of natural cytotoxicity, although the long-term effect on response to treatment and development of metastases is at present unknown. CONCLUSIONS NK and LAK cells, through the use of immune biologic modifiers, have been demonstrated to have a therapeutic role in the treatment of human cancers. Further studies are required to determine the optimal dosages and combinations of chemotherapeutic agents, the timing of surgery, and the adjuvant use of immune biologic response modifiers. An increasing awareness and understanding of this field, may allow for the future development of anti-cancer therapies. Cancer 1996;77:1226-43.

Effects of high-pass and low-pass spatial filtering on face identification

Abstract: If face images are degraded by block averaging, there is a nonlinear decline in recognition accuracy as block size increases, suggesting that identification requires a critical minimum range of object spatial frequencies. The identification of faces was measured with equivalent Fourier low-pass filtering and block averaging preserving the same information and with high-pass transformations. In Experiment 1, accuracy declined and response time increased in a significant nonlinear manner in all cases as the spatial-frequency range was reduced. However, it did so at a faster rate for the quantized and high-passed images. A second experiment controlled for the differences in the contrast of the high-pass faces and found a reduced but significant and nonlinear decline in performance as the spatial-frequency range was reduced. These data suggest that face identification is preferentially supported by a band of spatial frequencies of approximately 8-16 cycles per face; contrast or line-based explanations were found to be inadequate. The data are discussed in terms of current models of face identification.

Impedance Spectroscopy of Undoped BaTiO3 Ceramics

Abstract: The electrical properties of ceramic BaTiO3 were investigated by ac impedance spectroscopy over the ranges 25°-330°C and 0.03 Hz-1 MHz. Results are compared with those obtained from fixed-frequency measurements, at 1 kHz and 100 kHz. Fixed-frequency Curie-Weiss plots show deviations from linearity at temperatures well above tc. The ac measurements show that grain boundary impedances influence Curie-Weiss plots in two ways: at high temperatures, they increasingly dominate the fixed-frequency permittivities; at lower temperatures, closer to Tc, the high-frequency permittivity contains a contribution from grain boundary effects. Methods for extraction of bulk and grain boundary capacitances from permittivity and electric modulus complex plane plots are discussed. The importance of selecting the appropriate equivalent circuit to model the impedance response is stressed. A constriction impedance model for the grain boundary in BaTiO3 ceramics is proposed: the grain boundary capacitance is neither temperature-independent, nor shows Curie-Weiss behavior. The grain boundary is ferroelectric, similar to the grains, but its impedance is modified by either air gaps or high-impedance electrical inhomogeneity in the region of the necks between grains; the activation energy of the constriction grain boundary impedance differs from that of the bulk, suggesting differences in defect states or impurity levels.

Borrowing Constraints and the Tenure Choice of Young Households

Abstract: In this paper we analyze the factors that affect the tenure choice of young adults, highlighting the impact of mortgage lender imposed borrowing constraints The data set is a panel of youth age 20-33 for the years 1985-90 Our methods differ from most prior studies in many ways including consideration of possible sample selection bias, a richer model of the stochastic error structure, better measurement of which households are bound by borrowing constraints, and a fuller consideration of the endogeneity of wealth and income Once all changes are implemented, we find ownership tendencies to be quite sensitive to economic variables Specifically, potential earnings, the relative cost of owning a home, and especially borrowing constraints affect the tendency to own a home In our sample of youth, 37% of households are constrained even after choosing their loan-to-value ratio to minimize the impact of the separate wealth and income requirements The constraints reduce the probability of ownership of these households by 10 to 20 percentage points (a third to a half) depending on the particular characteristics of the household

The social and reproductive biology of Humpback Whales: an ecological perspective

Abstract: Existing knowledge of the social organization, mating system and reproduction of Humpback Whales (Megaptera novaeangliae) is reviewed to assess how our current understanding of this wide-ranging marine mammal fits into the predictive framework developed from ecological studies of more accessible terrestrial taxa. The small unstable groups characteristic of this species on its summer feeding grounds appear to be a function of absence of predation and of the patchy, mobile nature of most prey; the absence of territoriality and the minimal importance of kinship in associations are also predictable consequences of the latter. The mating system is similar to both leks and to male dominance polygyny, in which males display (sing) or directly compete (perhaps sometimes in coalitions) for access to females. However, the rigid spatial structure characteristic of classic leks is absent. The mating system of this species is sufficiently different to merit a novel category, and ‘floating lek’ is proposed. The widespread distribution of females resulting from absence of both predation and resources during the breeding season preclude simultaneous monopolization by males of more than one potential mate. Furthermore, these factors, together with a male-biased operational sex ratio, minimize the possibility of competition among females. The intensity of intrasexual competition among males conforms to predictions derived from information on testis size and from expectation of future reproductive success. Female choice and, to a lesser extent, differential allocation of competitive effort by males, appears likely. Lack of interpopulation variation in social and mating behaviour, and in general reproductive biology, is likely a response to similarity of marine environmental conditions. Year-to-year variation in reproductive rates may be linked to variations in the abundance of prey. The invariably uniparous nature of female Humpback Whales is assumed to be related to the energetic demands of lactation, and the lower ratio of available energy partitioned to reproduction that is characteristic of larger mammals. The reversed sexual size dimorphism of this species may reflect different selective pressures on males and females. Finally, there is now evidence that, as in some other taxa, offspring sex ratio is related to maternal condition.

The Candida albicans HYR1 gene, which is activated in response to hyphal development, belongs to a gene family encoding yeast cell wall proteins.

Abstract: A hyphally regulated gene (HYR1) from the dimorphic human pathogenic fungus Candida albicans was isolated and characterized. Northern (RNA) analyses showed that the HYR1 mRNA was induced specifically in response to hyphal development when morphogenesis was stimulated by serum addition and temperature elevation, increases in both culture pH and temperature, or N-acetylglucosamine addition. The HYR1 gene sequence revealed a 937-codon open reading frame capable of encoding a protein with an N-terminal signal sequence, a C-terminal glycosylphosphatidylinositol-anchoring domain, 17 potential N glycosylation sites, and a large domain rich in serine and threonine (51% of 230 residues). These features are observed in many yeast cell wall proteins, but no homologs are present in the databases. In addition, Hyr1p contained a second domain rich in glycine, serine, and asparagine (79% of 239 residues). The HYR1 locus in C. albicans CAI4 was disrupted by "Ura-blasting," but the resulting homozygous delta hyr1/delta hyr1 null mutant displayed no obvious morphological phenotype. The growth rates for yeast cells and hyphae and the kinetics of germ tube formation in the null mutant were unaffected. Aberrant expression of HYR1 in yeast cells, when an ADH1-HYR1 fusion was used, did not stimulate hyphal formation in C. albicans or pseudohyphal growth in Saccharomyces cerevisiae. HYR1 appears to encode a nonessential component of the hyphal cell wall.

Cephalopod populations: definition and dynamics

Abstract: The study of cephalopod populations currently lacks the means to define populations adequately and to resolve basic systematic confusions Quantitative data are usually only available from indirect sources such as commercial fisheries and from estimates of consumption by higher predators Despite these methodological difficulties it is clear that cephalopods comprise a major component of biomass globally, throughout all fully marine habitats Life-cycle characteristics common to the coleoids - early and/or semelparous breeding, rapid growth, short lifespan, little overlap of generations, vulnerability to predation and environmental variables - result in wide inter-annual fluctuations in abundance Most of the pelagic forms also undertake large- or meso-scale migrations which, coupled to shifting patterns of oceanographic variables, contribute to the unpredictability of distribution and density associated with many cephalopod species Temporal and spatial patterns of breeding, seasonality, growth, recruitment and mortality are clearly evident in most of the better-studied species But exceptions to pattern (eg variable growth rates, extended breeding, complex recruitment) also seem to be important intrinsic characteristics Levels of genetic variation in cephalopods are relatively low, and their population dynamics appear to be influenced principally by phenotypic plasticity in response to environmental variability In such universally short-lived species the maintenance of this diversity balances the risks of mortality factors combining at any one time to cause periodic local extinction The extent and scale of the interactions between cephalopod populations and other trophic levels suggests that major ecological perturbations such as environmental shifts, or imposed effects such as commercial fishing, whether directed at cephalopods or other species, are likely to have an impact on their populations As short-lived species with high turnover of generations, plastic growth and reproductive characteristics, high mobility and catholic predatory habits, they are always poised to respond to changed balances in their environment Studies on cephalopod populations have expanded considerably in numbers and scope in the last 25 years, driven by increased interest in and recognition of their roles in the marine ecology, as well as their increasing value as globally exploited resources Despite these recent advances, the information and concepts arising from their study is only slowly entering mainstream biological thought and becoming accommodated in broad-scale models of the marine ecosystem

Habitat Exploitation by a Gleaning Bat, Plecotus auritus

Abstract: The brown long-eared bat, Plecotus auritus, differs from most other Palaearctic bats in having broad wings and long ears, which are linked to its slow flight, and its ability to hover and thus glean insects from surfaces. Previous studies have suggested a relation between interspecific variation in morphology of bats, particularly the shape of the wing, and differences in foraging behaviour. It might be predicted therefore that the foraging behaviour of P. auritus would differ from other Palaearctic species that have been studied. To examine activity patterns and habitat use, 16 P. auritus were radio-tracked from six roost sites in northeast Scotland. Differences in behaviour compared to other Palaearctic species were found in the nocturnal activity pattern, habitat use and distance travelled to foraging areas. Plecotus auritus emerged later than other sympatric species, at around 55 min after sunset, and remained active throughout the night, with a generally unimodal activity pattern. Individual bats used a series of feeding sites, to which they returned regularly, and sometimes shared with others from the same roost. Plecotus auritus foraged exclusively in woodland and around individual trees. The bats displayed a preference for deciduous over coniferous woodland, probably reflecting higher insect availability in the former. Hedgerows, tree lines and fence lines were used as commuting routes between roosts and feeding sites. Bats travelled up to 2.8 km from the roost site, but spent most time foraging within 0.5 km of the roost, although males foraged further from the roost than females. The foraging behaviour of P. auritus reflected the morphological specializations of this species, but displayed a degree of intraspecific flexibility. Deciduous woodland in the vicinity of roost sites appeared to be key foraging habitat for P. auritus.

The cost of rheumatoid arthritis

Abstract: This paper uses the Cost of Illness (COI) framework to estimate the cost of rheumatoid arthritis (RA) to society in the year 1992-93. By doing so, a clear insight is given into the many cost elements of RA treatment and monitoring. This paper estimates point prevalence rates of 2.06 and 6.94 1000 persons at risk for men and women, respectively, showing that prevalence is three times higher amongst women than men. Further to this, prevalence increases with age in both sexes, resulting in very high prevalence rates for RA amongst the elderly. The total economic impact of RA in England was estimated to be pounds 1.256 billion in 1992, of which 52% was a result of production loss caused by RA disability.

Further evidence for the presence of cannabinoid CB1 receptors in guinea-pig small intestine.

Abstract: 1. CP 50,556, CP 55,940, nabilone, CP 56,667, delta 9 -tetrahydrocannabinol (THC) and cannabinol each inhibited electrically-evoked contractions of the myenteric plexus-longitudinal muscle preparation of guinea-pig small intestine in a concentration-related manner. The IC50 values of these cannabinoids, respectively 3.45, 3.46, 30.61, 162.94, 214.63, and 3913.5 nM, correlate well with previously obtained potency values for displacement of [3H]-CP 55,940 from cannabinoid binding sites. 2. Electrically-evoked contractions of the myenteric plexus-longitudinal muscle preparation were also inhibited by AM 630 (6-iodo-pravadoline) and by WIN 55,212-2 (IC50 = 1923.0 and 5.54 nM, respectively). The present finding that AM 630 is an agonist, contrasts with a previous observation that it behaves as a cannabinoid receptor antagonist in the mouse isolated vas deferens. 3. SR141716A produced dose-related parallel rightward shifts in the log concentration-response curves of CP 55,940, WIN 55,212-2, THC and AM 630 for inhibition of electrically-evoked contractions of the myenteric plexus-longitudinal muscle preparation. SR141716A (1 microM) did not reverse the inhibitory effects of normorphine and clonidine on electrically-evoked contractions or potentiate the contractile response to acetylcholine. 4. Doses of naloxone and yohimbine that reversed the inhibitory effects of normorphine or clonidine on electrically-evoked contractions of the myenteric plexus-longitudinal muscle preparation did not affect the inhibitory response to WIN 55,212-2. 5. Electrically-evoked release of acetylcholine from strips of myenteric plexus-longitudinal muscle was decreased by 200 nM CP 55,940 and this inhibitory effect was almost completely reversed by 1 microM SR141716A. Acetylcholine-induced contractions were not affected by 200 nM CP 55,940. 6. These results support the hypothesis that guinea-pig small intestine contains prejunctional cannabinoid CB1 receptors through which cannabinoids act to inhibit electrically-evoked contractions by reducing release of the contractile transmitter, acetylcholine. 7. THC was found to be more susceptible to antagonism by SR141716A than CP 55,940 or AM 630, raising the possibility that guinea-pig small intestine contains more than one type of cannabinoid receptor. 8. At concentrations of 10 nM and above, SR141716A produced small but significant increases in the amplitude of electrically-evoked contractions of the myenteric plexus-longitudinal muscle preparation suggesting that this tissue may release an endogenous cannabinoid receptor agonist or that some cannabinoid receptors in this tissue are precoupled and that SR141716A can reduce the number of receptors in this state.

Revised “LEPS” Scores for Assessing Climate Model Simulations and Long-Range Forecasts

Abstract: The most commonly used measures for verifying forecasts or simulators of continuous variables are root-mean-squared error (rmse) and anomaly correlation. Some disadvantages of these measures are demonstrated. Existing assessment systems for categorical forecasts are discussed briefly. An alternative unbiased verification measure is developed, known as the linear error in probability space (LEPS) score. The LEPS scare may be used to assess forecasts of both continuous and categorical variables and has some advantages over rmse and anomaly correlation. The properties of the version of LEPS discussed here are reviewed and compared with an earlier form of LEPS. A skill-score version of LEPS may be used to obtain an overall measure of the skill of a number of forecasts. This skill score is biased, but the bias is negligible if the number of effectively independent forecasts or simulations is large. Some examples are given in which the LEPS skill score is compared with rmse and anomaly correlation.

Violent Interactions between Bottlenose Dolphins and Harbour Porpoises

Abstract: The majority (63%) of harbour porpoises stranded around the Moray Firth, Scotland, died from trauma characterized by multiple skeletal fractures and damaged internal organs. Surface injuries consisted of skin cuts resembling the teeth marks inflicted by one cetacean on another. The spacings between these matched those between teeth in bottlenose dolphins, of which there is a population in the Moray Firth. Four violent dolphin-porpoise interactions have been witnessed. Reasons for these interactions are unknown and similar documented examples between other mammals are extremely rare. These findings challenge the benign image of bottlenose dolphins and provide a hitherto unrecorded cause of mortality in porpoises.

Group aggregates and individual reliability: the case of verbal short-term memory.

Abstract: Two experiments examined the generalizability of the effects of word length and phonological similarity with visual and auditory presentation in immediate verbal serial ordered recall. In Experiment 1, data were collected from 251 adult volunteers drawn from a broad cross-section of the normal population. Word length and phonological similarity in both presentation modes significantly influenced the group means. However, 43% of the subjects failed to show at least one of the effects, and the likelihood that effects appeared was highly correlated with verbal memory span. In Experiment 2, 40 subjects of the original sample were retested, 20 of whom had failed to show one or more effects in Experiment 1. Whether or not an effect had appeared for individual subjects on the first test session was a poor predictor of whether the effect would appear on retest. Finally, an analysis of subject reports demonstrated that the patterns of experimental data could be accounted for in part by the strategies that subjects reported using, and the effect of strategy was independent of the effect of span. The implications of these findings for theories of verbal short-term memory are discussed.

Xanthine oxidase activity and free radical generation in patients with sepsis syndrome

Abstract: Objective : To determine xanthine oxidase activity, free radical concentrations, and lipid peroxidation in patients with sepsis syndrome compared with noninfected critically ill patients. Design : A prospective observational study. Setting : A nine-bed intensive care unit in a university teaching hospital trust. Patients : Fourteen consecutive patients who met the established criteria for sepsis syndrome with multiple organ dysfunction syndrome, and ten noninfected critically ill patients were studied. Interventions : None. Measurements and Main Results : Xanthine oxidase activity was increased in septic patients compared with both healthy volunteers (p <.01) and noninfected patients (p <.05), and was highest in the six patients who survived (p <.05). Lipid peroxides were increased in both septic patients (p <.001) and nonseptic controls (p <.001). Xanthine oxidase activity did not relate to the Acute Physiology and Chronic Health Evaluation (APACHE) II score or to the presence of organ dysfunction. The mean ascorbyl radical concentration (arbitrary units) determined by electron paramagnetic resonance following spin trapping was increased in patients compared with healthy subjects (p <.05). Conclusions : Patients with sepsis have xanthine oxidase activation, high free-radical concentrations, and evidence of free radical damage. The finding that xanthine oxidase activity was lower in those patients who died, coupled with increased lactate concentrations implies more severe ischemia with incomplete reperfusion resulting in less xanthine oxidase wash out into the circulation. Increased ascorbyl radical concentrations may be due to an increased radical generation and oxidant scavenging, but appears to be unrelated to xanthine oxidase activity within the circulation.

Observations of collisions of saltating grains with a granular bed from high‐speed cine‐film

Abstract: High-speed photography was used to record saltating sand grains colliding with a horizontal, noncohesive bed of similarly sized grains. Impacting grain/bed interaction is discussed in general. The process, as observed from the films, is then described in terms of the apparent bed contact length (ABCL) and various parameters of the impacting grains and any ejected grains. Examples are given of typical behaviour of bed grains in response to impacting grains of different sizes. Saltating grains that are large in comparison to the bed grains they encounter at collision can churn up the surface layers of soils and sediments, so that previously buried grains become available for entrainment. This process is discussed in relation to the potential release of dust particles into the airflow.

Restoration of fluid balance after exercise-induced dehydration: effects of food and fluid intake

Abstract: This study investigated the effects of post-exercise rehydration with fluid alone or with a meal plus fluid. Eight healthy volunteers (five men, three women) were dehydrated by a mean of 2.1 (SEM 0.0)% of body mass by intermittent cycle exercise in a warm [34 (SEM 0)°C], humid [55 (SEM 1)% relative humidity] environment. Over 60 min beginning 30 min after exercise, the subjects ingested a commercially-available sports drink (21 mmol · l−1 Na+, 3.4 mmol · l− K+, 12 mmol · l−1 Cl−1) on trials A and B; on trial C a standard meal [63 kJ · kg−1 body mass (53% CHO, 28%fat,19%protein; 0.118 mmol · kJ−1 Na+, 0.061 mmol · kJ−1 K+)] plus drink (1 mmol · l−1 Na+, 0.4 mmol · l−1 K+, 1 mmol · l−1 Cl−) were consumed. Water intake (in millilitres) was 150% of the mass loss (in grams). The trials took place after an overnight fast and were separated by 7 days. Blood and urine samples were collected at intervals throughout the study. Blood was analysed for haematocrit, haemoglobin concentration, serum osmolality, Na+, Ku+ and Cl− concentrations and plasma angiotensin II concentration. Urine volume, osmolality and electrolyte concentrations were measured. Dehydration resulted in a mean 5.2 (SEM 1.3)% reduction in plasma volume. With the exception of serum osmolality, which was higher on trial B than A at the end of the rehydration period, no differences were recorded for any of the measured parameters between trials A and B. Cumulative urine output following rehydration was lower (P < 0.01) on trial C [median 665 (range 396–1190) ml] than on trial B [median 934 (range 550–1403) ml] which was not different (P = 0.44) from trial A [median 954 (range 474–1501) ml]. Less urine was produced over the 1-h period ending 2 h after rehydration on trial C than on B (P = 0.01). On trials A and B the subjects were in net negative fluid balance by 337 (range 779-minus 306) ml and 373 (range 680-minus 173) ml, respectively (P < 0.01): on trial C the subjects were no different from their initial euhydrated state [median minus 29 (range minus 421−137) ml] 6 h after the end of rehydration (P = 1.00). A larger fraction of total water intake was retained when the standard meal plus drink was consumed. This may have been due to the larger quantities of Na+ and K+ ingested with the meal [mean 63 (SEM 4)mmol Na+, 21.3 (SEM 1.3)mmol K+] than with the drink [mean 42 (SEM 2) mmol Na+, 6.8 (SEM 0.4) mmol K+]. There was no difference between trials B and C in any of the measured blood parameters, but urinary Na+ and K+ excretion were both higher on trial C than B. These results suggest that post-exercise fluid replacement can be achieved by ingestion of water if consumed in sufficient volume together with a meal providing significant amounts of electrolytes.

Estimation of abundance of abyssal demersal fishes; a comparison of data from trawls and baited cameras

Abstract: The abundance of the macrourid Coryphaenoides (Nematonurus) armatus was investigated using a single warp trawl and baited camera at soundings from 2500 to 5000 m in the north-east Atlantic Ocean. There was no significant relationship between abundance (n km−2) as determined from swept area of the trawl and numbers of fish photographed at standard baits. However, timing of the first arrival (tarr s) of the first fish at bait correlated well with the trawl data through the relationship: It is concluded that by measurement of arrival times, the baited camera provides a cost-effective complement to trawl sampling for estimating abundance of deep-water fish including Synaphobranchus kaupi, Anlimora rostratu and C. (N). armatus. However, some abundant species such as the roundnose grenadier Coryphaenoides rupestris were not attracted to baited long-lines or baited cameras and therefore could be sampled only by trawl.