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Abstract: The karst ecosystem shows heterogeneity and variability of geology, hydrology, morphology and ecology in space and time. Chemical composition of water in karst plays a crucial role not only in dissolution of karst rocks and deposition but also in ecological processes. The heterogeneous nature of karst aquifers leads to difficulties in predicting groundwater flow and contaminant transport direction and travel times. For its position at the top of karst, epikarst represents the interface between surface and underground. Epikarst ecology, biodiversity and fauna have rarely been systematically studied. The typical absence of enterable passages makes necessary an indirect approach. In this research, epikarst biodiversity in relation to environmental conditions was studied in seven Alpine and Pre-Alpine caves, located at different altitudes, in Slovenia and in Italy: Snežna jama na planini Arto (1556 m a.s.l.), Jama pod Babjim zobom (860 m a.s.l.), Zadlaška jama (300 m a.s.l.) and Pološka jama (500 m a.s.l.), in Slovenian Alps and Pre-alps, and Grotta A del Ponte di Veja (600 m a.s.l.), Covolo della Croce (875 m a.s.l.) and Grotta di Roverè Mille (1005 m a.s.l.) in Lessinian Massif. In these caves, percolating water was monthly monitored for fauna in the period of one year. Temperature, discharge, conductivity and pH were measured at the same time, and water samples for the laboratory analyses of total hardness, concentrations of various ions (calcium, chlorine, nitrate, sulphate and phosphate) and dissolved organic carbon were taken. 66 aquatic and terrestrial, mostly hypogean, species were found. Aquatic fauna was dominant in all caves, with the exception of Covolo della Croce. Caves located at higher elevations harbour less diverse communities. No animals were found when discharge was very low and in correspondence of moonmilk formations. The most abundant and diverse group was Copepoda, with thirteen different species and 776 individuals at different maturity stadia, totally representing 61% of the community (between two and three copepod species per cave in Slovenia and between one and six per cave in Italy). The 62% of copepod species were stygobionts. Some copepod species (e.g. Speocyclops infernus) have wide ecological tolerance to environmental variables, other have more restricted tolerances (e.g. Lessinocamptus insoletus). With regard of copepods, there was a good agreement between the number of observed species and the total number of predicted species, confirming that the sampling method was appropriate and sampling complete. Correlations between the copepod community structure and measured parameters, obtained with Pearson correlation coefficient and principal component analysis (PCA) show different patterns. Presence of copepods was positively correlated with conductivity and dissolved organic carbon in Grotta di Roverè Mille, and with carbonate and nitrate in Pološka jama. In other caves not so high correlations were found between copepod species and measured parameters and between pairs of species. Investigations of the Alpine and Pre-alpine epikarst fauna can help to understand better the ecology of the epikarst fauna and its roles within the large range of different shallow subterranean habitats.
Keywords: Epikarst, Alpine and Pre-Alpine caves, percolating water, speleobiology, fauna.
Published in RUNG: 31.08.2016; Views: 5442; Downloads: 285
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Abstract: Obesity and MetS (Metabolic Syndrome) are both linked to persistent long-term hormonal and metabolic changes. In most of the studies, cortisol (C) and dehydroepiandrosterone (DHEA) concentrations have been measured in obese and normal-weight subjects, obtaining heterogeneous results. Plasma, saliva and urine, matrices that represent timepoint or short-term steroids exposure, were used for these studies. The aim was to study C, DHEA and C/DHEA ratio of mice pups in the hair, matrix capable of providing cumulative hormonal exposure. Sixty C57Bl/6 mice pups (30 males and 30 females) were housed in a temperature-controlled environment (22±2°C) and on a 12h light/dark schedule, under ad-libitum access to food and water for 16 weeks (welfare: Italian Law Decree 116-92 and EC Directive 86-609-EEC). Control and experimental diets were offered immediately after weaning (3 weeks old pups), for 16 weeks. Four experimental checkpoints were established (T1: 4 weeks, T2: 8 weeks, T3: 12 weeks and T4: 16 weeks of diet). T3 and T4 showed the hormonal concentrations of pubertal animals. Twentyseven pups (13 females and 14 males) were randomly group-housed in cages (6 for T1, 5 for T2, 6 for T3, 10 for T4) and assigned to control diet (CTRL: D12328, Research Diets, New Brunswick, NJ). 33 pups (17 females and 16 males) were randomly group-housed in cages (5 for T1, 6 for T2 and T3, 16 for T4) and assigned to the HFHC diet (HFHC: D12331, Research Diets, New Brunswick, NJ - plus 42g/L fructose/sucrose in drinking water). At each experimental checkpoint, all the animals of one cage for each experimental group were suppressed. Hair strands were carefully cut with scissors as close as possible to the skin from the back of the mice, paying attention to not to wound the animals. Hair was stored in an envelope at RT in a dry room until use. C and DHEA hair concentrations was measured by a solid-phase microtiter RIA assay (Peric et al., 2016 adapted in the mouse). Only at 8 weeks the HFHC group showed significantly higher C concentrations than the CTRL group (1.56±0.06 vs 1.92±0.130 pg/mg; P<0.05). DHEA concentrations were significantly reduced in the HFHC group than the CTRL group at 4 (114.64±13.93 vs 69.08±5.33 pg/mg; P<0.05), 8 (71.67±7.08 vs 50.38±4.74 pg/mg; P<0.05), 12 (73.27±8.29 vs 41.59±1.60 pg/mg; P<0.01) and 16 weeks (65.26±3.35 vs 55.05±1.84 pg/mg; P<0.05). The C/DHEA ratio was significantly increased in the HFHC than the CTRL group, at 8 (0.023±0.002 vs 0.040±0.005; P<0.01), 12 (0.024±0.003 vs 0.036±0.004; P<0.05) and 16 weeks (0.019±0.001 vs 0.025±0.002; P<0.01). The gender effect was not significant. Taking into account the lag time required for the hair emersion from the skin (about 1 week), the significant stimulation of the C at 8 weeks in the HFHC group refers to its chronic elevation from 5 to 7 weeks of treatment when the animals were not pubertal. Conversely, DHEA shows a chronic reduction in obese mice leading to consider an independent adrenal regulation of C and DHEA, both stimulated by ACTH. Research was supported by the Project CBM (MIUR DM60643). Peric et al. 2016 J Appl Anim Welf Sci 18:1-8.
Keywords: DIET, HAIR, CORTISOL, DHEA, MOUSE
Published in RUNG: 21.07.2016; Views: 5070; Downloads: 0
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Keywords: krave molznice, parklji, progesteron, kortizol
Published in RUNG: 16.06.2016; Views: 4099; Downloads: 17
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Keywords: krave molznice, dlake, kortizol
Published in RUNG: 16.06.2016; Views: 5003; Downloads: 142
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Keywords: činčile, hormoni, foziologija razmnoževanja, spolni ciklus
Published in RUNG: 16.06.2016; Views: 4110; Downloads: 24
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