Glochidia are the larval stage of freshwater unionid mussels that parasitize the fins and gill apparatus of fish. A total of 22 fish species were examined for the presence of glochidia whose distribution on individual hosts was studied on three common fish species, the roach Rutilus rutilus (L.), perch Perca fluviatilis L. and bitterling Rhodeus sericeus (Pallas). Between 1997 and 1999, the fish were obtained from the rivers Morava and Kyjovka and surrounding water pools in the Czech Republic. The glochidia of two genera, Unio and Anodonta, were found. Anodonta glochidia were observed on 10 fish species, Unio glochidia on 17 fish species. There was a difference in spatial distribution of glochidia on the body of the host fish. Unio glochidia were predominantly located on the gills, whereas most Anodonta glochidia were found on the fins, with the highest numbers of glochidia were observed on the margin of the pectoral fins. For the gill apparatus, Unio glochidia were found predominantly on the second and third arch. Anodonta glochidia were predominantly found during winter and spring (November-May), whereas Unio glochidia were more abundant during May and June. The number of glochidia was positively correlated with fish length in perch highly infected by Anodonta glochidia and perch infected by Unio glochidia. Of the three fish species, the highest occurrence of parasites was found on perch with fewer observed on roach. In spite of the close relationship between bitterling and unionid mussels, glochidiosis was rare on this fish species.
We used a rat model to assess the role of nephrin, podocin, and desmin in the pathogenesis of IgA nephropathy (IgAN). A rat IgAN model was established by administration of BSA, CCl4, and lipopolysaccharide (LPS) and compared with healthy control rats. Urinary protein, urine red blood cells, and biochemical parameters were measured for 12 weeks. Renal morphology and ultrastructure were examined by light and electron microscopy. Immunofluorescence was used to assess IgA deposition in the glomeruli and to measure expression of nephrin, podocin, and desmin. Real-time quantitative PCR was used to measure expression of nephrin, podocin, and desmin mRNAs. IgAN rats developed proteinuria at week-6 and this worsened over time. Pathological changes were evident under light microscopy at week-8 and under electron microscopy at week-4. Immunofluorescence analysis showed deposition of IgA in the kidneys of IgAN rats, but not control rats. IgAN rats had increased expression of glomerular podocin, nephrin, and desmin mRNAs and proteins at week-4. The expression of nephrin, podocin and desmin proteins and the expression of podocin and desmin mRNAs preceded the increase in urinary protein. Taken together, our study of a rat model of IgAN indicates that changes in the expression and distribution of nephrin, podocin, and desmin precede and may cause foot process fusion and proteinuria., H.-Y. Lu, ... [et al.]., and Obsahuje seznam literatury
Main aim of the study was to determine the temporal and spatial patterns of relations between monthly and annual average river flow (RF) and water temperature (WT) for 53 rivers in Poland. The research made use of monthly and annual WT and RF for 88 water gauges for the period 1971–2015. Correlations were established using the Spearman’s rank correlation coefficient and the similarity of RF–WT relations was determined using the Ward’s hierarchical grouping. It was demonstrated that correlations between average annual RF and WT were negative (for >85% of water gauges) and statistically significant (p<0.05) only for 30% of water gauges. It was confirmed that the studied RF–WT relations underwent seasonal changes. Positive correlations were clearly predominant in the winter months, while from April to September these relations were negative and statistically significant. The RF–WT relations were also characterized by spatial differences and this had been confirmed by separation of seven groups of water gauge profiles distinguished with the help of the Ward's hierarchical grouping method. The strongest RF–WT relations were apparent in the case of mountainous rivers, for which snow melt supply and summer rainfall supply were predominant, and lakeland rivers, which had a considerable share of groundwater supply. These were classified as cold rivers, as opposed to the cool rivers in the lowland belt, for which the RF–WT relations were the weakest. The results obtained may contribute to the elaboration of an appropriate management strategy for river ecosystems, which are assigned important economic and environmental functions.
It is well known that rainfall causes soil erosion in sloping German vineyards, but little is known about the effect of age of plantation on soil erosion, which is relevant to understand and design sustainable management systems. In the Ruwer-Mosel valley, young (1- to 4-years) and old (35- to 38-years after the plantation) vineyards were selected to assess soil and water losses by using two-paired Gerlach troughs over three years (2013–2015). In the young vineyard, the overland flow was 107 L m–1 and soil loss 1000 g m–1 in the year of the plantation, and decreased drastically over the two subsequent years (19 L m–1; 428 g m–1). In the old vineyard, soil (from 1081 g m–1 to 1308 g m–1) and water (from 67 L m–1 to 102 L m–1) losses were 1.2 and 1.63 times higher, respectively, than in the young vineyard.
A four-year experiment with a total of 993 individually-tagged barbel, Barbus barbus, resulted in the assessment of survival and abundance. The mean annual survival rate was 0.862, but the partial values assessed separately for seasons (spring – autumn and autumn – spring) differed considerably and the possible reasons for this phenomenon are discussed. On the basis of known survival rate, the abundance was subsequently estimated (for the entire studied stretch and per hectare) using the Petersen capture-recapture method for the period spring 1999 to autumn 2002, and the mean value reached 303 ± 110 ind.ha-1 (minimum 195, maximum 498 ind.ha-1). The Jolly-Seber method was also used to estimate abundance from autumn 1999 to spring 2001 and gave a mean 425 ± 120 ind.ha-1 and a range 233–563 ind.ha1. These results were in autumn 2001 supported by another simultaneously conducted census following the removal method by Zippin (316 ind.ha-1). The abundance showed a significant tendency to increase during the four-year survey, which is in an accordance with the long-term changes observed in the dynamics of the fish community in this stream.
A simple chlorophyll fluorescence (CF) measuring system has been implemented to study temporal characteristics of chlorophyll fluorescence induction (CFI) in dark-adapted freshwater algal cultures of Chlorella emersonii. There were two different decay time constants describing the CF quenching: τ0 (the faster) and τ1 (the slower) with amplitudes A0 and A1, respectively. The relative amplitude of the faster quenching component decreased once the sample was subject to deprivation from dissolved oxygen (DO). The DO concentration of samples was monitored to validate the effects of deprivation from air contact for up to 7 d and to the effect of adding DCMU to the culture (herbicide for blocking electron transport of photosystem 2). CFI analysis and DO measurements showed that the relative amplitude of A0 to (A0 + A1) and the DO concentration can be used as an indication of relative photosynthetic activity, thus allowing for the possibility to classify the physiological state of algal blooms into active and inactive states. and N. E. El Khachia, E. O'Mongain, A. Collins.
The daily activity patterns of animals are modulated by external factors such as habitat selection, temporal niche selection, prey availability and predation risk. Furthermore, different species show a variety of responses to human disturbance; therefore, to understand the effects of human activities on wildlife, it is crucial to consider the disturbance characteristics (e.g. type, frequency, timing and location of human activity). Our objective was to evaluate whether vehicles on forest roads altered the daily temporal activity patterns of three apex predators; Eurasian lynx (Lynx lynx), the grey wolf (Canis lupus) and brown bear (Ursus arctos), using an extensive camera trap data set collected across a gradient of forest roads and wildlife trails in the Croatian part of the Dinaric mountains. We expected a low temporal overlap between humans and apex predators but predicted this even lower at sites where vehicles are present. Consistent with our expectations, the general overlap in temporal activity of all three apex predators and humans was low, the former being primarily active at night/dawn/dusk hours and the latter during daylight hours. In contrast, our results showed similarity in the temporal activity of all three predators on wildlife trails and forest roads where human activity was more frequent and diverse.
We studied the occurrence of apoptosis and secondary delayed cell death at various time points in the penumbra zone, which is the target for therapeutic intervention after stroke. A compression lesion was induced in the right sensory motor cortex of rat brains. At 0.5, 1, 3, 6, 12, 24, 48 and 72 h after lesioning, motor functions were evaluated by behavioral tests, and cortical layers IV and V were examined by electron microscopy. Behavioral recovery was observed at 48 h after lesioning. At 0.5-1 h in the lesioned area, the neuropil was expanded and contained affected cells. Apoptotic cells were found between 0.5-72 h, and at 12 h, 47.3 % of the total cell number was apoptotic cells. On the contralateral side, cells showed an enlarged endoplasmic reticulum at 3 h, indicating secondary delayed cell death. Our results show that a compression lesion is a useful model for studying ultrastructural changes in injured cells. The lesion results in the penumbra zone with apoptotic cell death between 0.5-72 h. As secondary delayed cell death occurred on the contralateral side at three hours after lesioning might be the time period during which injured, but still viable, neurons can be targets for acute treatment.
We compared the progression of lens opacification with the time course of oxidation of lens proteins under conditions of streptozotocin-induced experimental diabetes in rats. By the end of the 17th week, approx. 50 % of the diabetic animals developed mature cataracts. During the following month, 95 % of the eyes in the diabetic group became
cataractous. In the course of lens opacification we observed a time-dependent increase in the content of protein carbonyls and decrease in the concentration of protein sulfhydryls in the lenses of diabetic animals. Significantly higher protein carbonyl (p<0.01) and lower protein sulfhydryl (p<0.001) content was found in lenses with the advanced stage
of cataract when compared with the diabetic lenses still transparent. We showed that the values of protein carbonyls exceeding 1.2 nmol/mg protein and of sulfhydryls falling below 60 nmol/mg protein corresponded to an approximately 50 % incidence of mature cataract development. At the end of the 34th week, when all lenses of diabetic rats became cataractous, the corresponding values of protein carbonyls and sulfhydryls were 2.5 nmol/mg protein and 27 nmol/mg protein, respectively. The main finding of this study is the disclosure of quantitative relationship between the degree of protein oxidation and the rate of advanced cataract development in the widely used model of streptozotocin-induced experimental diabetes in rats.
Unusual climatic events are known to influence micro-evolutionary changes in birds through selection and directional evolution of body size. In NW Italy a notable climatic episode occurred from 1984–85 to 1986–87 when the winters were unusually severe. In the periods 1986–88 and 1997–2000 we measured the body size and mass of 808 adult hooded crows. Body size measurements of specimens collected from the same area but in two other periods (1950 and 1974) were also considered for comparison. In the 1986–88 sample (just after the unusual climatic period), there was a significant shift of body size, with a greater tarsus length than in the other three periods; body mass was also higher than in 1997–2000. The peak in tarsus length and body mass is discussed with regard to the severe weather in the winter which could have acted as a strong directional selective factor, favouring bigger birds, or may have prompted irruptive movements of Northern larger crows.