Showing papers by "University of Aberdeen published in 1991"
TL;DR: Evidence is extended with evidence suggesting that both the particular configuration of features, and some aspects of the features themselves, are important for preferential tracking in the first hour of life.
1,243 citations
TL;DR: There was no interaction between task difficulty as measured by number of alternatives and rate of deterioration, suggesting that the progressive deterioration in performance shown by AD patients is a function of whether single or dual task performance is required, and is not dependent on simple level of task difficulty.
Abstract: A previous study (Baddeley et al., 1986) explored the hypothesis that patients suffering from dementia of the Alzheimer type (AD) are particularly impaired in the functioning of the central executive component of working memory. It showed that, when patients are required to perform 2 concurrent tasks simultaneously, the AD patients are particularly impaired, even when level of performance on the individual tasks is equated with that of age-matched controls. Although the results were clear, interpretation was still complicated by 2 issues: first, the question of comparability of performance on the separate tests between AD and control patients; secondly, the question of whether our results could be interpreted simply in terms of a limited general processing capacity being more taxed by more difficult dual tasks than by the individual tasks performed alone. The present study followed up the AD and control patients after 6 and 12 mths. We were able to allow for the problem of comparability of performance by using patients as their own control. Under these conditions, there is a very clear tendency for dual task performance to deteriorate while single task performance is maintained. A second experiment varied difficulty within a single task in which patients and controls were required to categorize words as belonging to 1, 2 or 4 semantic categories. There was a clear effect of number of categories on performance and a systematic decline in performance over time. There was, however, no interaction between task difficulty as measured by number of alternatives and rate of deterioration, suggesting that the progressive deterioration in performance shown by AD patients is a function of whether single or dual task performance is required, and is not dependent on simple level of task difficulty. Implications for the analysis of the central executive component of working memory are discussed.
651 citations
TL;DR: This second generation reshaped human monoclonal antibody cross-reacted with all clinical isolates of RSV tested and both prevented disease and cured mice even when administered four days after infection.
Abstract: We transferred the complementarity determining regions from a murine monoclonal antibody that neutralizes infection by respiratory syncytial virus (RSV) to a human IgG1 monoclonal antibody. The resulting reshaped human antibody lost affinity for RSV, but an additional alteration to one of the framework regions restored binding affinity and specificity. This second generation reshaped human monoclonal antibody cross-reacted with all clinical isolates of RSV tested and both prevented disease and cured mice even when administered four days after infection. We expect the antibody will prove useful in the management of this major childhood disease.
366 citations
TL;DR: Only complement activity was compromised in these vitamin E depleted fish, as determined by the ability of their serum to opsonize bacteria and cause haemolysis of antibody-coated sheep red blood cells.
273 citations
TL;DR: This study reports the results of an unusual opportunity to follow up a group of police officers who were involved in body-handling duties following the Piper Alpha disaster, and for whom there were available data from pre-disaster assessments.
Abstract: This study reports the results of an unusual opportunity to follow up a group of police officers who were involved in body-handling duties following the Piper Alpha disaster, and for whom there were available data from pre-disaster assessments. In addition, after these duties, the officers were compared with a matched control group of officers who had not been involved in such work. The comparisons failed to demonstrate high levels of post-traumatic distress or psychiatric morbidity. The results are interpreted in terms of issues such as the officers' own coping strategies, and major organisational and managerial factors.
245 citations
TL;DR: The energy costs of flight in two species of small echolocating Microchiroptera were measured using a novel combination of respirometry and doubly-labelled water and flight energy expenditure was not significantly different between echoling bats and non-echolocating bats and birds.
Abstract: ECHOLOCATION has evolved in relatively few animal species1. One constraint may be the high cost of producing pulses, the echoes of which can be detected over useful distances2. The energy cost of echolocation in a small (6 g) insectivorous bat, when hanging at rest, was recently measured at 0.067 Joules per pulse3, implying a mean cost for echolocation in flight of 9.5 × basal metabolic rate (range 7 to 12×). Because flight is very costly4, whether the costs of echolocation and flying are additive is an important question. We measured the energy costs of flight in two species of small echolocating Microchiroptera using a novel combination of respirometry and doubly-labelled water5. Flight energy expenditure (adjusted for body mass) was not significantly different between echolocating bats and non-echolocating bats and birds. The low cost of echolocation for flying vertebrates may have been a significant factor favouring its evolution in these groups.
200 citations
01 Jan 1991
TL;DR: The aim of this chapter is to review the data which have recently become available on the rates of protein synthesis in ectotherms and attempt to integrate them with the likely energy cost of synthesising these proteins.
Abstract: The regulation of the rate of synthesis of tissue proteins is of the utmost importance to the energetic cost of the maintenance and growth of the whole animal. After water, protein is the largest component of the body mass and minimal theoretical estimates of the cost of synthesising proteins indicate that they represent the most expensive molecules to produce (e.g. Kiorboe et al. 1987; Jorgensen 1988). Studies on mammals have indicated that whole body protein metabolism is closely correlated with basal energy metabolism (Garlick et al. 1976; Waterlow 1980; Meier et al. 1981), and the indications are that similar correlations exist for ectotherms (Hawkins et al. 1989). The aim of this chapter is to review the data which have recently become available on the rates of protein synthesis in ectotherms and attempt to integrate them with the likely energy cost of synthesising these proteins.
194 citations
01 Jan 1991
TL;DR: In this article, a computer model of the saltation cloud is described and the importance of momentum exchange in determining the number of ejected grains from a collision is demonstrated, and a modification of the wind velocity profile is discussed and a realistic wind profile is calculated.
Abstract: A computer model of the saltation cloud is described. Experimental results from high speed films are used to characterise the grain/bed collision. The importance of momentum exchange in determining the number of ejected grains from a collision is demonstrated. The modification of the wind velocity profile is discussed and a realistic wind profile is calculated. Also the mass flux profiles calculated compare well to their expected shape. The model attains a steady state, characterised by a steady wind and a stationary grain population, after roughly 2 seconds. The response of the total mass flux to shear velocity is approximately cubic. Finally, potential uses of the model in studying ripple formation and dust emission are discussed.
191 citations
01 Jan 1991
TL;DR: A review of recent progress in the understanding of aeolian sediment transport can be found in this paper, with emphasis on work published since 1985 and the current conceptual model of sediment transport discussed at length, with attention given to problems of definition that have arisen.
Abstract: We review recent progress in our understanding of aeolian sediment transport, with emphasis on work published since 1985. The current conceptual model of sediment transport is discussed at length, with attention given to problems of definition that have arisen. We discuss in depth the collision (grain impact) and aerodynamic entrainment (initial motion) processes. The effect of the evolving population of moving grains on the wind (the wind feedback mechanism) is treated in the context of recent modelling of the self-regulating saltation process. The link between saltation and suspension is discussed briefly. We conclude by outlining future research directions that must involve a greater symbiosis of experimentalists and theoreticians, working both at the grain and the bedform scales.
180 citations
TL;DR: The suitability of the food-frequency questionnaire for determining dietary intake of antioxidant vitamins in epidemiological studies was investigated in 196 Scottish men and appeared to be an adequate tool for assigning individuals into tertiles of serum antioxidant vitamins with the main exception of β-carotene for smokers.
Abstract: ~~ ~ ~ ~ ~ ~ The increasing interest in the possible role of antioxidant vitamins in many disease states means that methods of assessing vitamin intakes which are suitable for large-scale investigations are now required. The suitability of the food-frequency questionnaire, which was developed by the Medical Research Council - Cardiff Group, for determining dietary intake of antioxidant vitamins in epidemiological studies was investigated in 196 Scottish men. The validity of the dietary data was assessed by comparison with serum vitamin concentrations, and separate analyses were performed for current smokers and nonsmokers. The results showed that total energy intake and the percentage of energy derived from sugar were higher in smokers, and that both dietary and serum values of vitamin C, /I-carotene and vitamin E were lower in smokers than non-smokers. After adjustment for serum lipids, energy intake and body mass index, correlation coefficients between dietary and serum vitamins C and E were similar for smokers (r 0555 and 0.25 respectively) and non-smokers (r 0.58 and 0.32 respectively). Correlation between dietary and serum carotenes was reduced from 0.28 in non-smokers to 0.09 in smokers and correlations for retinol and total vitamin A were weakly significant only for non-smokers. The food-frequency questionnaire assigned > 70% of subjects correctly into the upper or lower plus adjacent tertiles of serum vitamin values, with the exception of @-carotene and total vitamin A for smokers. Thus, the foodfrequency questionnaire appeared to be an adequate tool for assigning individuals into tertiles of serum antioxidant vitamins with the main exception of &carotene for smokers. Marked differences do occur between the vitamins and between the smoking groups which may reflect reduced accuracy of reporting on the food-frequency questionnaire or differential absorption and metabolism of the vitamins. Dietary antioxidant vitamins: Biochemical markers: Smoking
177 citations
TL;DR: The relationship between cellular growth mechanisms and vegetative growth in both filamentous fungi and actinomycetes is discussed, the conceptual and theoretical models applicable to both groups, and the significance of such models in industrial fermentation processes are discussed.
Abstract: Filamentous microorganisms are of major biotechnological importance, being responsible for production of the majority of secondary metabolites, particularly antibiotics. Two main groups are involve...
TL;DR: In this paper, root penetration resistance and elongation of maize seedling roots were measured directly in undisturbed cores of two sandy loam soils, and it was shown that root elongation rate was negatively correlated with root penetration resistant, and was reduced to about 50 to 60% of that of unimpeded controls by a resistance of between 0.26 and 0.47 MPa.
Abstract: Root penetration resistance and elongation of maize seedling roots were measured directly in undisturbed cores of two sandy loam soils. Root elongation rate was negatively correlated with root penetration resistance, and was reduced to about 50 to 60% of that of unimpeded controls by a resistance of between 0.26 and 0.47 MPa. Resistance to a 30° semiangle, 1 mm diameter penetrometer was between about 4.5 and 7.5 times greater than the measured root penetration resistance. However, resistance to a 5° semiangle, 1 mm diameter probe was approximately the same as the resistnace to root penetration after subtracting the frictional component of resistance. The diameter of roots grown in the undisturbed cores was greater than that of roots grown in loose soil, probably as a direct result of the larger mechanical impedance in the cores.
TL;DR: In this paper, the bone collagen derived pyridinium cross-links were measured in 19 patients (4 M:15 F) with untreated thyrotoxicosis, and 20 pre-, and 20 postmenopausal women taking T4 100-200 μg daily for autoimmune hypothyroidism.
Abstract: Urinary excretion of the bone collagen derived pyridinium cross-links pyridinoline (PYD) and deoxypyridinoline (DPD) was measured in 19 patients (4 M:15 F) with untreated thyrotoxicosis, and 20 pre-, and 20 postmenopausal women taking T4 100–200 μg daily for autoimmune hypothyroidism. Both PYD and DPD excretion (nanomoles per mmol creatinine) was elevated in the thyrotoxic patients compared to 287 controls; median 131 vs. 26 and 37.5 vs. 7.2, respectively, P < 0.0001. In premenopausal women mean urinary pyridinium cross-link excretion and serum osteocalcin levels were similar in both T4-treated and matched control groups, despite suppression of serum TSH concentrations to below 0.1 mU/L in 14 of the20 taking T4. In postmenopausal women mean (±1 SE) urinary PYD excretion (nanomoles per mmol creatinine) was raised in those taking T4, relative to euthyroidcontrols; 40.0 ± 2.7 vs. 32.1 ± 2.3, P < 0.05. DPD excretion and serum osteocalcin levels were also higher, but not significantly. When only the T...
TL;DR: PAI-1 occurred throughout the body; its concentration and activity differed considerably from organ to organ, but the activity of the inhibitor was much higher in liver than in spleen: the liver may be a source of plasma PAI- 1.
Abstract: Extracts of human tissue were analysed for plasminogen activator inhibitor (PAI-1) antigen and activity. PAI-1 was localised in tissues by an immunochemical method, using monoclonal antibodies. PAI-1 occurred throughout the body; its concentration and activity differed considerably from organ to organ. Extracts of liver and spleen had the greatest abundance of PAI-1, but the activity of the inhibitor was much higher in liver than in spleen: the liver may be a source of plasma PAI-1. Immunochemical staining for PAI-1 was observed in endothelium, platelets and their precursor cells, the megakaryocytes, and locations central to the process of haemostasis. PAI-1 also occurred in neutrophil polymorphs and macrophages, cells important in inflammatory and immune processes, but not in lymphocytes. Other cell types, in particular, vascular smooth muscle cells and mesangial cells, also stained positively for PAI-1 and such cells seem to represent an important reservoir of PAI-1.
TL;DR: The role played by predation of birds in the mortality of British bats is assessed and the annual number of bats which die each year as a result of predation was estimated.
Abstract: The role played by predation of birds in the mortality of British bats is assessed. A review of dietary studies and anecdotal accounts revealed eleven species of bird which occasionally feed on bats–Herring Gull Larus argentatus, Black-headed Gull Larus ridibundus, Rook Corvus frugilegus, Carrion Crow Corvus corone, Little Owl Athene noctua, Short-eared Owl Asio flammeus, Kestrel Falco tinnunculus, Hobby Falco subbuteo, Merlin Falco columbarius, Peregrine Falco peregrinus and Sparrowhawk Accipiter nisus. A further three species feed more frequently on bats–Barn Owl Tyto alba, Tawny Owl Strix aluco and Long-eared Owl Asio otus. Rates of predation were very low accounting for only 00034oo of items taken by small hawks and falcons (n items = 29 519) but 0035o, of prey taken by owls (n items = 99 479). By multiplying together the average annual prey capture rates of the predators, assessed from their energetic food requirements and direct observations of prey intake rates, the British populations of the predators and the contribution to the diet made by bats, the annual number of bats which die each year as a result of predation was estimated. The total losses of bats to predation might amount to about 201 400 bats/annum. The most significant predators are Tawny Owl (c. 168 850 bats/annum), Barn Owl (c. 8800 bats/ annum), Long-eared Owl (c. 10 200 bats/annum) and Kestrels (c. 8400 bats/annum). This predation by avian predators would account for about 11 % of the annual mortality of British bats. An assessment of the biases involved in this calculation suggests it is probably a minimum estimate. Despite the apparent low representation of bats in the diets of predatory birds, the effects of this predation on bat behaviour and population dynamics cannot be ignored.
TL;DR: In this paper, the authors report findings from a survey of in-migrants in Aberdeen in 1986, finding that consideration relating to male partner's occupational career was the main factor accounting for the inmigration of married women, but single women were more likely to come for educational or employment reasons.
Abstract: Although it has become almost axiomatic in much contemporary sociology that geographical mobility for husband's career reasons is disruptive of wives' labour market careers, there have been few systematical empirical inquiries into the issue. This study reports findings from a survey of in-migrants in Aberdeen in 1986. Considerations relating to male partner's occupational career were the main factor accounting for the in-migration of married women, but single women were more likely to come for educational or employment reasons. Levels of grievance among in-migrant partnered women about the consequences of this move for their employment were low but there was some evidence that women in-migrant for such reasons saw the move as less helpful careerwise than other in-migrant women. More, however, saw the move as helpful or making no difference, rather than being a hindrance. Many respondents were able to find what they regarded as suitable new employment and others saw themselves at the time of the move prim...
TL;DR: Long-term data sets on Corophium abundance in the Ythan suggest that this species has declined dramatically throughout those parts of the estuary affected by weed mats, and are dominated by species characteristic of organically enriched, low oxygen environments such as Capitella capitata.
Abstract: One of the most obvious effects of eutrophication in sheltered coastal areas and estuaries is enhanced growth of opportunistic macroalgae, which may form extensive mats over intertidal mudflats during the spring and summer. In the Ythan estuary, densities of the amphipod Corophium volutator (Pallas) in the sediment underlying weed mats were significantly lower than those in weed-free sediments, and are dominated by species characteristic of organically enriched, low oxygen environments such as Capitella capitata. Long-term data sets on Corophium abundance in the Ythan suggest that this species has declined dramatically throughout those parts of the estuary affected by weed mats.
TL;DR: From the files of the Scottish Melanoma Group, 100 cases of subungual malignant melanoma (melanoma arising in the nailbed) are identified, and this represents 2.8% of the total melanomas registered during the period 1979–1989.
Abstract: From the files of the Scottish Melanoma Group, we have identified 100 cases of subungual malignant melanoma (melanoma arising in the nailbed), and this represents 2.8% of the total melanomas registered during the period 1979-1989. Almost equal numbers arose on the foot as on the hand, with the thumb and big toe as the commonest digit affected. More than 80% were greater than 1.5 mm, with the mean Breslow depth 4.7 mm, and 70% were Clark level IV or V. Approximately half of the cases were of acral lentiginous type. At 5-year follow-up (54 cases), 26 have died of melanoma, six have died of an unrelated disease, four are alive with recurrence and 18 are alive and well. Features related to clinical outcome at 3 years were Breslow depth, mitotic count and the presence of vascular invasion.
TL;DR: It is reported that the Kluyveromyces lactis toxin, a protein containing three subunits (alpha, beta and gamma) which causes sensitive yeast cells to arrest proliferation in the G1 phase of the cell cycle, is a potent exochitinase.
Abstract: The Kluyveromyces lactis toxin is a protein containing three subunits (α, β and γ) which causes sensitive yeast cells to arrest proliferation in the G1 phase of the cell cycle. Despite the toxin's complex structure, the γ subunit appears to be the only component required for it to arrest proliferation since intracellular expression of the γ polypeptide alone in a sensitive yeast strain mimics the effect of the exogenous native toxin. The toxin α subunit shows sequence similarity to a variety of chitinases and here we report that the toxin is a potent exochitinase. The exochitinase activity is absolutely required for its biological activity against sensitive Saccharomyces cerevisiae cells and allosamidin, a specific inhibitor of chitinases, abolishes the biological activity of the toxin. However, since the α subunit is not required for the G1 arrest induced by the toxin, the chitinase activity of the toxin cannot be directly responsible for the ultimate effect of the toxin and most likely plays a role in the initial interaction of the toxin with sensitive cells.
TL;DR: The complete (17159 bp) nucleotide sequence of the gene for the human C1 inhibitor has been determined, and the occurrence of 17 AluI repeats of all four ancestral subgroups indicates that the gene has been invaded during consecutive waves of Alu amplification, including a recent one.
Abstract: The complete (17159 bp) nucleotide sequence of the gene for the human C1 inhibitor has been determined. The transcription initiation site was examined by primer extension using human liver mRNA, and the messenger 5'-end sequence was determined on clones obtained by the anchored polymerase chain reaction. The gene of this serpin molecule is split by seven introns, with junctions of phases zero and one. An outstanding feature of the intron sequences is the occurrence of 17 AluI repeats of all four ancestral subgroups, indicating that the gene has been invaded during consecutive waves of Alu amplification, including a recent one. These Alu repeats form the sites of deletion and insertion in several known lesions in the C1-inhibitor gene. There is no obvious promoter site of the TATA-box type at the 5' end of the gene, but instead it contains a region of potential H-DNA structure similar to that found upstream of the human c-myc gene.
TL;DR: In this paper, the authors argue that Scottish fan behaviour in Italy was structured by two opposing forms of self-knowledge, relating to either expressions of violent machismo or instrumentally ambassadorial conduct.
Abstract: This short paper seeks to explain the activities of Scottish fans in Genoa and Turin, during the 1990 World Cup, by drawing on some key concepts offered by contemporary writers in the field of post-modernism and post-structuralism. These writers include Foucault, Derrida, Barthes and Baudrillard. All emphasize a re-empowerment of agency, evading more conventional forms of domination: Foucault within the domain of enabling discourse, Derrida on the open interpretation of the sign's apparent meaning, Barthes on the ‘nature’ of jouissance and the body principle, and Baudrillard on the public toying with their media representation. It is argued that Scottish fan behaviour in Italy was structured by two opposing forms of ‘self-knowledge’, relating to either expressions of violent machismo or instrumentally ambassadorial conduct. The eventual triumph of the latter is most clearly shown through an application of Goffman's conception of ‘impression management’, as the social interaction of Scottish fans with other ‘teams’ in Italy is detailed chronologically. The paper concludes with some recommendations aimed at the relevant authorities, with a view to maximizing the internationalism of Scottish fans at future competitions.
TL;DR: Bats were attracted by the fluttering sounds of moths, and it is suggested that they locate prey on surfaces by passive listening, and when gleaning, bats were more successful when attempting captures without echolocation.
TL;DR: The agreement between MRI and UWW estimates in both lean and overweight women suggests that MRI may be a satisfactory substitute for the more established methods of body fat estimation in adult women.
Abstract: Body fat content of seven lean women (body mass index (BMI) 20.6 (SD 1.8) kg/m2) and seven overweight women (BMI 31.1 (SD 3.3) kg/m2) was estimated by six different methods: underwater weighing (UWW), body-water dilution (BWD), whole-body counting ('@K), skinfold thickness (SFT), bioelectrical impedance (BEI) and magnetic resonance imaging (MRI). Using UWW as the reference method, the differences between percentage fat by each other method and the percentage fat by UWW were calculated for each subject. The mean difference was lowest for SFT and highest for BWD. MRI showed the lowest variability in individual results, and '@K the highest. "K and BWD methods used in combination gave better agreement with UWW results than either "K or BWD methods alone. There was a weak negative correlation between the difference from the UWW results and percentage fat in the SFT measurements, but not in the BWD, QK, BE1 or MRI measurements, suggesting that for these methods the assumptions involved produced no greater inaccuracy in the overweight women than in the lean women. In all subjects the BE1 offered little improvement over the traditional SFT measurements. The agreement between MRI and UWW estimates in both lean and overweight women suggests that MRI may be a satisfactory substitute for the more established methods of body fat estimation in adult women. Body composition: Methodology : Obesity
TL;DR: The data suggest involvement of abnormal fatty acid metabolism in the etiology of diabetic neuropathy and myopathy in streptozocin-induced diabetic rats.
Abstract: Effects of essential fatty acids on nerve conduction, hypoxic resistance, skeletal muscle contractile properties, and capillary density were examined in streptozocin-induced diabetic rats. Nondiabetic and diabetic controls and three diabetic groups treated with 10% supplements of corn oil, evening primrose oil (Efamol), or a mixture of 80% evening primrose oil and 20% fish oil (Efamol Marine) for 2 mo were used. Efamol and Efamol Marine increased plasma gamma-linolenic acid levels, but arachidonic acid was elevated only with Efamol. Diabetes resulted in 15-29% reductions in sciatic motor and sensory saphenous nerve conduction velocity. Efamol prevented conduction deficits more effectively than Efamol Marine, and corn oil had no effect. In vitro measurement of sciatic nerve hypoxic resistance revealed a 49% increase in the time taken for action potential amplitude to decline by 50% with diabetes. Corn oil had no significant effect. With Efamol, hypoxic resistance was within the nondiabetic range. Efamol Marine produced intermediate results. Functional improvements may relate to enhanced vasa nervorum perfusion, because endoneurial capillary density increased by 22% with Efamol, angiogenesis perhaps resulting from eicosanoid production from arachidonic acid. Soleus muscle contractions were prolonged by diabetes. This was partially corrected by treatment, Efamol being most effective. Extensor digitorum longus muscle had reduced tetanic tension with diabetes, and this was prevented by all treatments. Soleus showed a modest increase in capillarization with Efamol, which may have contributed to reduced susceptibility to fatigue. The data suggest involvement of abnormal fatty acid metabolism in the etiology of diabetic neuropathy and myopathy.
TL;DR: It is concluded that vascular factors play an important role in the etiology of experimental diabetic neuropathy, and functional changes may be corrected by chronic vasodilator treatment.
Abstract: The effects of alpha-receptor blockade on nerve conduction, hypoxic resistance, ouabain-sensitive Na(+)-K(+)-ATPase, nerve polyols, and capillary density were examined in streptozocin-induced diabetic (STZ-D) rats. Nondiabetic and untreated diabetic control groups were used. Diabetes duration was 2 mo. There were two treated diabetic groups. A "prevention" group received 5 mg/kg prazosin for 2 mo from the induction of diabetes. A "reversal" group was untreated for the 1st mo and was given prazosin for the subsequent month. Conduction was measured in motor nerves supplying tibialis anterior and gastrocnemius muscles and sensory saphenous nerve. Diabetes resulted in 15-29% reductions in conduction velocity (P less than 0.01). In the prevention group, conduction deficits were minimal compared with untreated diabetes (P less than 0.01). In the reversal group, motor conduction was also substantially improved, although sensory conduction was not significantly affected. In vitro measurement of sciatic nerve hypoxic resistance revealed a 49% increase in the time taken for compound action potential amplitude to reach half its initial value with diabetes (P less than 0.01). This was largely prevented by prazosin treatment (P less than 0.01), although treatment had a lesser effect in the reversal group. Treatment had no effect on nerve polyol levels or Na(+)-K(+)-ATPase activity. Functional improvements with prazosin were probably based on increased vasa nervorum perfusion. There was a 20% elevation of endoneurial capillary density (P less than 0.01) in both prevention and reversal groups. We conclude that vascular factors play an important role in the etiology of experimental diabetic neuropathy, and functional changes may be corrected by chronic vasodilator treatment.
TL;DR: The regulation of glycolytic genes in response to carbon source in the yeast Saccharomyces cerevisiae has been studied and the relative levels of each gly colytic mRNA were compared during exponential growth on glucose or lactate, found to be induced to differing extents by glucose.
Abstract: The regulation of glycolytic genes in response to carbon source in the yeast Saccharomyces cerevisiae has been studied. When the relative levels of each glycolytic mRNA were compared during exponential growth on glucose or lactate, the various glycolytic mRNAs were found to be induced to differing extents by glucose. No significant differences in the stabilities of the PFK2, PGK1, PYK1, or PDC1 mRNAs during growth on glucose or lactate were observed. PYK::lacZ and PGK::lacZ fusions were integrated independently into the yeast genome at the ura3 locus. The manner in which these fusions were differentially regulated in response to carbon source was similar to that of their respective wild-type loci. Therefore, the regulation of glycolytic mRNA levels is mediated at the transcriptional level. When the mRNAs are ordered with respect to the glycolytic pathway, two peaks of maximal induction are observed at phosphofructokinase and pyruvate kinase. These enzymes (i) catalyze the two essentially irreversible steps on the pathway, (ii) are the two glycolytic enzymes that are circumvented during gluconeogenesis and hence are specific to glycolysis, and (iii) are encoded by mRNAs that we have shown previously to be coregulated at the translational level in S. cerevisiae (P. A. Moore, A. J. Bettany, and A. J. P. Brown, NATO ASI Ser. Ser. H Cell Biol. 49:421-432, 1990). This differential regulation of glycolytic mRNA levels might therefore have a significant influence upon glycolytic flux in S. cerevisiae.
TL;DR: It is concluded that conventional electrophysiological tests in the lower limb are reliable surrogate measures for structural abnormalities in early diabetic neuropathy.
Abstract: The morphological findings in sural nerve biopsy specimens from 15 diabetic patients with mild neuropathy were compared with control biopsies from eight non-neuropathic, non-diabetic subjects, and correlations were sought with electrophysiological studies and quantitative sensory tests for vibration, thermal, and current perception thresholds. Myelinated fibre density was reduced compared with control biopsies (4042 +/- 2090 (+/- SD) vs 6800 +/- 1100 mm-2; p less than 0.01). A strong correlation existed between myelinated fibre density and sural sensory conduction velocity (r = 0.84, p less than 0.001), sural action potential amplitude (r = 0.74, p less than 0.001), peroneal motor conduction velocity (r = 0.58, p less than 0.02), and median sensory amplitude (r = 0.64, p less than 0.01) but there was no correlation between myelinated fibre density and any quantitative sensory test. We conclude that conventional electrophysiological tests in the lower limb are reliable surrogate measures for structural abnormalities in early diabetic neuropathy.
TL;DR: In this article, the authors tracked the speeds and directions of departing deep demersal scavenging fishes by embedding acoustic transmitters in bait and deploying them together with an automatic tracking system and cameras on the sea floor.
Abstract: BAITED cameras on the deep ocean floor first revealed the presence of communities of scavengers, including deep demersal fishes capable of consuming food falls and thus dispersing surface-derived organic carbon1–3. By embedding acoustic transmitters in baits and deploying them together with an automatic tracking system and cameras on the sea floor4,5, we have now tracked the speeds and directions of departing deep demersal scavenging fishes. At a series of stations between 4,000 and 6,000 m deep in the Northern Hemisphere, in contrasting trophic regimes, we have found that two closely related species of fish, Coryphaenoides (Nematonurus) armatus and C.(N .) yaquinae have a significant role in bait dispersal. Even in remote oligotrophic locations, transmitters were consumed rapidly and were removed from the area of detection at a mean velocity of 0.11 m s−1. We find that these fish are active foragers, constantly moving independently of bottom currents. This result is contrary to previous speculation of passive or drifting strategies6 which might have been expected to conserve energy in a food-limiting environment.
TL;DR: In both age cohorts there was a higher incidence of spontaneous abortion among infertile women and a significantly higher proportion of younger women had sought medical help.
Abstract: A questionnaire-based study of infertility has been carried out in two age cohorts of women in a defined geographical region. Women were aged 36-40 years or 46-50 years at the time of the survey. The prevalence of infertility (no conception after 2 years of trying) was approximately 14% in both age cohorts. However, a significantly higher proportion of younger women had sought medical help. In both age cohorts there was a higher incidence of spontaneous abortion among infertile women. These findings suggest no significant increase in the prevalence of infertility over a decade but a considerable increase in the use of medical services.