The pattern of postglacial re-colonization of Europe and the present population structure are known for various plant and animal species. The reed beetle Macroplea mutica (Fabricius, 1792) has characteristics that should influence both aspects in a peculiar way and therefore complement the currently known scenarios: It is fully aquatic but cannot swim or fly. Samples from 25 European populations of M. mutica and five specimens from China were investigated using amplified fragment length polymorphism (AFLP, 251 loci). Assessment of error rates associated with this method showed that the data set contains a strong population genetic signal. As hypothesized pronounced population differentiation and signs of inbreeding were found. Italian populations are clearly differentiated from northern populations (and from each other), which underlines the role of the Alps as a major barrier. Specimens from Lake Balaton (Hungary) show some affiliation with the populations in the Baltic Sea, which are all relatively similar. Populations from the eastern part of Northern Germany are similar to the Baltic populations, while those from the western part are allied to the British populations. The hypothesis is that the recolonization of Europe was from both the Southeast and a western refugium in the area of present-day southern England or Ireland, which resulted in a suture zone in Northern Germany. The effect of passive dispersal by drift attached to host plant material (especially in the Baltic Sea) and by zoochory (migrating waterfowl) is discussed.
The behavioural response of an aphid-tending ant, the Argentine ant Linepithema humile, to semiochemicals related with spacing behaviour in the aphid Rhopalosiphum padi (L.) was evaluated. The compounds involved were 6-methyl-5-hepten-2-one (MHO), 6-methyl-5-hepten-2-ol (MHOH), and 2-tridecanone (2-T). Hexane solutions of these semiochemicals either singly or mixed, and extracts obtained by trapping volatile compounds from wheat seedlings either alone or infested with two different densities of aphids were used as stimuli in olfactometric bioassays. Ants showed attraction to volatile extracts from plants infested at both densities, and slightly preferred volatile compounds from lightly over heavily infested plants in a choice test. On the other hand, while a dose-dependent repellence response was elicited by the naturally-occurring mixture of MHO, MHOH and 2-T, single compounds did not elicit significant responses in olfactometric bioassays. The function of these semiochemicals as indicators of quality of the aphid colonies as trophic resource to ants is discussed.
Aquatic Coleoptera in shallow lakes associated with the Canal de Castilla (Palencia Province, Spain) in the northern Iberian Meseta were sampled over the course of a year (spring 1998-winter 1999). These waterbodies are typical plateau wetlands with dense vegetation and vary in permanence and area (from 3.3 ha to 29.35 ha). Oxygen concentration, conductivity and pH were recorded at the time of sampling. Lake area, depth, water permanence and type of vegetation were also taken into account. Ninety two species were collected. Species richness was high in comparison with other wetlands in Spain. The assemblage structure was assessed in terms of three community parameters: richness, abundance and diversity (Shannon index). Their relationships with environmental variables were explored using correlation coefficients. The assemblage composition was analysed by multivariate techniques. First, the sites were classified by means of TWINSPAN. The presence of each species in the different TWINSPAN groups was used to assess their habitat preferences. Second, the sites and species were ordinated by Detrended Correspondence Analysis (DCA) using the CANOCO statistical package. Richness was significantly correlated with water permanence, conductivity and aquatic macrophyte cover. The first DCA axis was significantly correlated with water permanence and conductivity, but not with any of the other parameters. Conductivity was significantly inter-correlated with permanence. Therefore, water permanence and aquatic vegetation cover seem to be the main factors influencing richness, but only water permanence appears to determine species composition.
A personalized antidiabetic therapy is not yet part of the official guidelines of professional societies for clinical practice. The aim of this study was to evaluate the serum C-peptide and plasma glucose levels in patients with type 2 diabetes mellitus (T2DM) after oral administration of whey proteins. Sixteen overweight T2DM Caucasians with good glycemic control and with preserved fasting serum C-peptide levels (>200 nmol/l) were enrolled in this study. Two oral stimulation tests – one with 75 g of glucose (OGTT) and the other with 75 g of whey proteins (OWIST) – were administered for assessing serum C-peptide and plasma glucose levels in each participant. Both oral tests induced similar pattern of C-peptide secretion, with a peak at 90 min. The serum C-peptide peak concentration was 2.91±0.27 nmol/l in OWIST, which was 22 % lower than in OGTT. Similarly, the C-peptide iAUC0-180 were 32 % lower in the OWIST than in the OGTT (p<0.01). Contrary to OGTT the OWIST did not cause a significant increase of glycemia (p<0.01). Our study showed that the OWIST represents a useful tool in estimation of stimulated serum C-peptide levels in patients with T2DM.
A group of four efficient mine rescuers 25 to 35 years old were exposed to a load of a cyclo-ergometer (stages A and B) and a hand ergometer (stage E) in a climate chamber. The total 120 min period of work was divided into four work intervals, 30 min each. There were 5-min breaks between the individual intervals. The load on the ergometer was selected in the range of 25 to 150 W, Tg = 20 to 40 °C, rh = 40 to 80 % and va = 0.2 to 1.5 m. s-1. The thermal resistance of the working suit was 0.65 clo at stage A, 1.07 clo at stage B and 0.81 clo at stage E. A total of 200 experiments with 50 combinations of the work and climate loads were made. The heart rate, oxygen consumption, carbon dioxide production, body temperature, skin temperature, water loss by sweating and perspiration, dry and wet bulb air temperature, air velocity and globe temperature were measured during the experiments. The expected production of sweat (SR) and the amount of accumulated heat in the body (Qmax) were calculated for each combination of the work-climate conditions by a computing program ISO 7933:1989 as well as by our own program. Good agreement was reached between the measured and predicted SR values, calculated by the ISO program (r = 0.871) as well as between the values calculated by the two programs, respectively (r = 0.985). The experimental results have shown good agreement between the predicted and actually measured values of temperature of the body core as an index of short-term tolerable climate load. The values of short-term tolerable time of work calculated at the level of accumulated heat in the body of 50 W.h.m-2 resulted in an increase of body core temperature by 0.8 to 1.0 K. The values of heart rate did not mostly exceed 140 beats/min, reaching in exceptional (three) cases values above 150 beats/min. The authors recommend to limit the long-term work-heat (climatic) load during a higher metabolic rate (M>80 W.m-2 including the basal metabolic rate) of acclimatized males and females at a sweat rate SR = 270 g.h-1.m-2, of non-acclimatized persons at SR = 206 g.h-1.m-2. The limit for low metabolic rates (M<80 W.m-2) for non-acclimatized and acclimatized persons is proposed for long-term tolerable loads of SR = 147 g.h-1.m-2. The short-term tolerable load by heat storage within the organism for all categories is proposed as Qmax-50 W.h.m-2.
An oxidant/antioxidant imbalance is thought to play an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). We hypothesized that antioxidant capacity reflected by erythrocyte glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) activities, and serum levels of the lipid peroxidation product malondialdehyde (MDA), may be related to the severity of obstructive lung impairment in patients with COPD. Erythrocyte GPx, SOD and CAT activities, and serum levels of MDA were measured in 79 consecutive patients with stable COPD. Pulmonary functional tests were assessed by bodyplethysmography. Moderate COPD (FEV1 50-80 %) was present in 23, and severe COPD (FEV1 < 50 %) in 56 patients. Erythrocyte GPx activity was significantly lower, and serum MDA levels were significantly higher in patients with severe COPD compared to patients with moderate COPD (GPx: 43.1±1.5 vs. 47.7±2.9 U/gHb, p<0.05, MDA: 2.4±0.1 vs. 2.1±0.1 nmol/ml, p<0.05). Linear regression analysis revealed a significant direct relationship between FEV1 and erythrocyte GPx activity (r = 0.234, p<0.05), and a significant inverse relationship between FEV1 and serum MDA levels (r = -0.239, p<0.05). However, no differences were observed in the erythrocyte SOD and CAT activities between the two groups of patients with different severity of COPD. Findings of the present study suggest that antioxidant capacity reflected by erythrocyte GPx activity and serum levels of the lipid peroxidation product MDA are linked to the severity of COPD., Z. Kluchová, D. Petrášová, P. Joppa, Z. Dorková, R. Tkáčová., and Obsahuje bibliografii a bibliografické odkazy
We examined whether dispersal was associated with body and wing morphology and individual quality, and whether such an association was sex-specific, in the Glanville fritillary butterfly Melitaea cinxia (L.) in Paldiski on the north coast of Estonia. Body weight, size and shape of both fore- and hindwing, wing aspect ratio and wing loading were used as measures of body and wing morphology. Fluctuating asymmetry (FA) of wing shape was used as a measure of individual quality. Males and females did not differ in dispersal rates, despite large differences in overall morphology and FA. Females had a significantly higher wing loading and aspect ratio, but a lower FA than males. Females, but not males, that dispersed differed in forewing shape from those that did not disperse. The sex-specifity of the covariation between dispersal and forewing shape is most probably due to wing shape being associated with different life-history traits in both sexes, resulting in different selection pressures on wing shape in each of the sexes.
We investigated the association between metamphetamine dependence and TaqI A polymorphism of the dopamine receptor D2 gene (DRD2), I/D polymorphism in angiotensin-converting enzyme (ACE) and M235T polymorphism of the angiotensinogen gene (AGT) in 93 unrelated metamphetamine-dependent subjects and 131 controls. Our results did not prove any association of TaqI A polymorphism of the DRD2 gene, I/D polymorphism of ACE gene, and M235T polymorphism of AGT gene with the metamphetamine dependence in Caucasians of Czech origin. However, a significant difference in allele I frequency between male and female control groups for the I/D ACE polymorphism (p<0.03) was found., O. Šerý, V. Vojtová, P. Zvolský., and Obsahuje bibliografii
Bradykinin can enhance skeletal muscle glucose uptake (GU), and exercise increases both br adykinin production and muscle insulin sensitivity, but bradykinin’s relationship with post-exercise insulin action is uncertain. Our primary aim was to determine if the B2 receptor of bradykinin (B2R) is essential for the post- exercise increase in GU by insulin-stimulated mouse soleus muscles. Wildtype (WT) and B2 R knockout (B2RKO) mice were sedentary or performed 60 minutes of treadmill exercise. Isolated soleus muscles were incubated with [ 3 H]-2-deoxyglucose ±insulin (60 or 100 μ U/ml). GU tended to be greater for WT vs. B2RKO soleus with 60 μ U/ml insulin (P=0.166) and was significantly greater for muscles with 100 μ U/ml insulin (P<0.05). Both genotypes had significant exercise-induced reductions (P<0.05) in glycemia and insulinemia, and the decrements for glucose (~14 %) and insulin (~55 %) were similar between genotypes. GU tended to be greater for exercised vs. sedentary soleus with 60 μ U/ml insulin (P=0.063) and wa s significantly greater for muscles with 100 μ U/ml insulin (P<0.05). There were no significant interactions between genotype and exercise for blood glucose, plasma insulin or GU. These results indicate that the B2R is not essential for the exerci se-induced decrements in blood glucose or plasma insulin or for the post-exercise increase in GU by insulin-stimulated mouse soleus muscle., G. G. Schweitzer ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
In this study, the 2n = 58 chromosomal race of blind mole rats,
Nannospalax xanthodon, from the Erzincan province in Turkey was investigated. Conventional chromosome staining, Ag-NOR staining and C-banding analysis were carried out in the specimens studied. The karyotype included three small or medium-sized meta/submetacentric pairs and twenty-five acrocentric pairs of autosomes of gradually diminishing size (NFa = 62). C-heterochromatin regions were found in centromeric and pericentromeric areas or in short arms of some bi-armed autosomal pairs and in pericentromeric areas of a few acrocentric autosomes. The X chromosome had a centromeric C-positive band and the short arm of the Y chromosome appeared to be C-positively stained. The NORs were
localized in distal heterochromatin areas of the short arms of two pairs of biarmed and one pair of acrocentric autosomes. Within the 58 chromosome populations reported from Turkey, two groups can be recognized differing by the presence or absence of a large submetacentric autosomal pair. The populations possessing this marker chromosome occur in central and northern Anatolia, whereas populations form eastern Anatolia have no similar chromosome in their karyotype.