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The aim of the study was to investigate if scale morphology could be used to discriminate fish populations at a local scale. To this aim, 168 rostrum dace (Leuciscus leuciscus burdigalensis) were collected at 3 sites in the River Viaur (SW France), distributed along 82 Km of stream. Seventy-one measurements were taken from scales: 2 shape factors and 69 Fourier coefficients. A stepwise discriminant analysis revealed that fish from the 3 sites showed morphological differences (p<0.001), with an average of 75.6% correct discrimination of the scales (65.5% after the cross-validation procedure). These results reveal that scale morphology can detect spatial structure in fish populations at a fine scale, which has implications for riverine fish conservation. [ABSTRACT FROM AUTHOR]

Simple mathematical models have illustrated the relationship between human carrying capacity and population growth. In this study, food supply is proposed as the variable which best accounts for the human carrying capacity. The logistic equation, using food supply data as a variable carrying capacity, yields population estimates which are in accord with actual population numbers. That food supply data adequately fits the logistic model of human population dynamics provides evidence that, consistent with ecological notions typically applied only to nonhuman species, human population increases are a function of increased food availability. [ABSTRACT FROM AUTHOR]

Summary. Neuropeptide Y (NPY) is a member of the pancreatic polypeptide family. It plays a critical role in the regulation of satiety, reproduction, the central endocrine and cardiovascular systems. The T1128C polymorphism of human NPY gene has been shown to be associated with many cardiovascular diseases. The allele frequency of the 1128C was investigated in 6626 subjects from Europe, North-America, South-America, Asia and the Middle-East. The 1128C allele was observed in all populations of European descent and the Israeli population, with a mean frequency of about 4%. The allele frequency showed a geographical north to south gradient of decreasing frequency. The highest allele frequencies were found in Nordic countries. The NPY 1128C allele might originate in the north of Europe, and then spread to neighboring regions. [ABSTRACT FROM AUTHOR]

Aims/hypothesis. The insulin resistance syndrome is related to arterial stiffness in diabetic subjects. Whether the insulin resistance syndrome is also related to arterial stiffness in non-diabetic subjects is less clear. We studied the association between variables of the insulin resistance syndrome in relation to arterial distensibility in healthy middle-aged non-diabetic women. Methods. This study was done in 180 non-diabetic women, aged 43–55, selected from the general population. Arterial distensibility was assessed in the carotid artery. The associations were evaluated using linear regression analyses. Results. Strong associations were found between arterial distensibility and the variables of the insulin resistance syndrome: body mass index, waist-to-hip ratio, high-density-lipoprotein-cholesterol, triglycerides, glucose, insulin, apolipoprotein A1, plasminogen activator inhibitor-1-antigen and tissue-type plasminogen activator-antigen. After additional adjustment for mean arterial pressure, common carotid arterial distensibility remained associated with body mass index: β-coefficient (95 % confidence interval) per kg/m2: –0.24 (–0.42; –0.06); waist-to-hip ratio: –26.62 (–40.59; –12.65) per m/m; triglycerides: –1.42(–2.77; –0.08) per mmol/l; plasminogen activator inhibitor–1-antigen: –0.01 (–0.02; –0.00) per ng/ml and borderline significant associated with high-density-lipoprotein-cholesterol: 1.93 (–0.01; 3.87; p = 0.07) per mmol/l. Clustering of variables of the insulin resistance syndrome was strongly related to decreased arterial distensibility which remained after adjustment for mean arterial pressure. No association was found between arterial distensibility and variables that are not part of the insulin resistance syndrome: total cholesterol, LDL-cholesterol and apolipoprotein B. Conclusion/interpretation. The results of this study show that variables of the insulin resistance syndrome are associated with decreased arterial distensibility of the common carotid artery in healthy non-diabetic subjects. [Diabetologia (2000) 43: 665–672] [ABSTRACT FROM AUTHOR]

We have studied the degree of genetic variation at a variable Mhc class II β gene in four populations of Atlantic salmon Salmo salar by using RFLPs. The class II β gene encodes the part of the Mhc class II molecule that contains the antigen binding region and is therefore essential for disease resistance. There was extensive genetic variation in all four populations; the expected heterozygosity (HSi) varied between 0.50 and 0.81. Heterozygosity tended to be higher in broods surviving a syndrome causing high mortalities (60–95%) in Swedish salmon hatcheries. Populations that had experienced more incidences of genetic bottlenecks (years when fewer than 60 adults had been used for breeding) and had a lower average effective population size (Ne), had a lower degree of heterozygosity. The four populations differed significantly in allele frequencies as measured by FST=0.13 and Nei's genetic distance (D=0.09-∞). Pairwise FST values varied between 0.01 and 0.23, all but one being highly significant, indicating a differentiation between the populations in Mhc class II β. This study shows that the four populations of Atlantic salmon have a high degree of polymorphism in the Mhc class II β gene. However, there was great variation between different hatcheries, both in heterozygosity levels and allele frequencies. [ABSTRACT FROM AUTHOR]

Microalbuminuria is a strong predictor of cardiovascular disease. The aim of this study was to investigate whether microalbuminuria is part of a cluster of risk factors, the insulin resistance syndrome (IRS), or whether it is only associated with, and presumably a complication of, hypertension and non-insulin-dependent diabetes mellitus (NIDDM). An age-, sex- and glucose tolerance-stratified random sample from a 50–75 year old general population ( n = 622) was investigated. The urinary albumin-to-creatinine ratio was measured in an early morning spot urine sample. Microalbuminuria was defined as an albumin-to-creatinine ratio greater than 2.0 mg/mmol. We considered, as IRS-related variables, fasting hyperinsulinaemia, insulin resistance (IR; calculated from the formula of the homeostasis model assessment), dyslipidaemia, glucose intolerance, hypertension and waist-to-hip ratio (WHR). Dyslipidaemia was defined as levels of HDL-cholesterol in the lowest and / or levels of triglyceride in the highest tertile. Fasting insulin levels, IR and WHR were divided into tertiles; the highest tertiles were compared to the lowest tertiles. Age-, sex- and glucose tolerance-adjusted analyses showed microalbuminuria to be significantly associated with hypertension, NIDDM and WHR. In multiple logistic regression analyses, microalbuminuria showed independent associations with hypertension, NIDDM and WHR, with odds ratios (ORs [95 % confidence interval]) of 3.33 (1.86–5.96), 2.26 (1.14–4.48) and 2.49 (1.09–5.70), respectively. No associations were found with impaired glucose tolerance, hyperinsulinaemia, IR or dyslipidaemia. Multiple logistic regression analyses in diabetic and non-diabetic subjects separately showed that microalbuminuria was independently associated only with hypertension (ORs 4.31 and 2.69). In this Caucasian population, microalbuminuria was associated with hypertension, NIDDM and WHR and not with other variables of the IRS. It is therefore likely that microalbuminuria is a complication of hypertension and NIDDM, and not an integral part of the IRS. [Diabetologia (1998) 41: 694–700] [ABSTRACT FROM AUTHOR]