251 research outputs found
Urbanization effects on shoreline phytobenthos: A multiscale approach at lake extent
No full textTo understand how littoral biota respond to anthropogenic disturbances, limnologists seek to detect the scale at which patterns and processes occur. We conducted an extensive study on the shoreline phytobenthos of Lake Garda (Italy) with the following main objectives: (i) to examine the importance of urbanization for species distribution within a set of hierarchical spatial scales (101-104 m), and then (ii) to test the spatio-temporal interactions on a reduced set of scales (101-102 m, and 101-102 days). Results showed that most of the variation in most abundant species and habitat characteristics occurred at the spatial scale of 101-102 m. Species richness was positively related with microheterogeneity, but the relationship occurred only at low urbanization and not at highly-urbanized sites where artificial shores were less heterogeneous. The similarity of species assemblages was regulated by two interacting processes, one operating at a fine spatial scale (102 m), reflecting the physical-habitat requirements of the species, and the other one operating at a broader scale (104 m) in relation to the N-S nitrogen gradient. Overall, time explained 73 % of the total variation of species assemblages, space 7 %, and 20 % was explained by the interaction between space and time (the patch scale, 10s of m, and area scale, 100s of m, interacted with the finest temporal scale, 10s of days). This interaction might be explained by the process of species recruitment operating at different rates at the two spatial scales. Since the largest variation in species assemblages was at the temporal scale (due to the seasonal succession of phytobenthos), we recommend collecting at least one sample per season when monitoring littoral habitats. © 2013 Springer Basel
Bioavailability of carotenoids from spinach and tomatoes
No full textBackground and Aim: Few published studies have described the bioavailability of the different carotenoids in spinach. This was designed to evaluate the effects on plasma carotenoid concentrations of a daily consumption of spinach (rich in lutein and β-carotene), alone or together with lycopene-rich tomato puree. Methods and Results: Nine healthy young women consumed a standard low-carotenoid diet during the pre-study phase, the spinach diet (standard diet plus 150 g spinach: 9 mg lutein, 4 mg β-carotene) from day 0 to day 21, and then, after a wash-out period, the spinach-tomato diet (standard diet plus 150 g spinach and 25 g tomato puree: 9 mg lutein, 4.3 mg β-carotene and 7 mg lycopene) from day 35 to day 56. The spinach and spinach-tomato supplements were consumed together with 10 g olive oil. Fasting blood samples were collected on day -7, and every week thereafter. Plasma carotenoid concentrations significantly decreased during the standard low-carotenoid diet. Lutein levels gradually increased after spinach consumption from 0.36±0.05 to 1.59±0.19 μmol/L (p<0.0001), decreased during the wash-out period from 1.59±0.19 to 0.62±0.07 μmol/L (p<0.001), and rose again after the intake of spinach-tomato puree from 0.62±0.07 to 1.55±0.17 μmol/L (p<0.0001). β-carotene levels also increased during both dietary supplementation periods. Lycopene decreased during the spinach diet from 0.20±0.03 to 0.07±0.01 μmol/L (p<0.001) and increased during the spinach-tomato diet from 0.05±0.01 to 0.52±0.06 μmol/L (p<0.0001). Conclusions: The results of this study confirm that a regular intake of selected vegetables leads to a progressive increase in plasma carotenoid concentrations. The addition of tomato puree to spinach does not decrease lutein plasma concentrations. Furthermore, baseline plasma levels of lutein and lycopene are important variables affecting the relative increase in their levels after supplementation: ie more depleted subjects are expected to have a greater percent rise in plasma carotenoid concentrations
Bioelectrical impedance phase angle in sport: A systematic review
No full textBackground: Phase angle (PhA) is a raw BIA variable that has been gaining attention in recent years because it is supposed to be an index of the ratio between extracellular and intracellular water, body cell mass, and cellular integrity. The aim of this systematic review was to evaluate the variability of PhA between different sports and its relationships with sport performance. Additionally, we investigated whether PhA depends on gender or age, and analyzed the differences between athletes and controls. Methods: A systematic research using PubMed, Scopus and Web of Science up to June 2019 was performed. Selection criteria included studies on subjects who practice sports in planned and continuous modality at competitive or elite level. Results: Thirty-five papers met the inclusion criteria (twenty-one cross-sectional data, fourteen longitudinal data). A few but convincing studies have shown that mean PhA is higher in athletes vs. controls. PhA increases with age and is likely to be higher in male than female athletes. A large variability in PhA is observed for the same sport, while it is still uncertain to what extent PhA differs between various sports. There are no clear relationships of PhA with sport performance or training/untraining. Conclusion: It is still to be defined to what extent PhA varies between different sports and changes with training/untraining. It can be argued that for a given sport much more data should be collected in a systematic way and for a period of time appropriate in order to determine changes and trends. This is even more crucial in the case of intervention studies
Niche partitioning, shape of species response, and diversity in the phytobenthos across the rocky shoreline of a large peri-Alpine lake
No full textBy colonizing a particular depth zone across the transition from aquatic to terrestrial habitats, littoral species may exhibit specific physiological and ecological adaptations, as well as characteristic responses to the gradient of conditions across the ecotone. The objectives of the study were: (i) to identify the depth zone (location in relation to average water level) where the replacement of species occurs most rapidly; (ii) to test whether and to what extent the occurrence of species, their abundance and their response to the gradient evolves over time; and (iii) to assess the shape of the species' response to the gradient, calculating the niche overlap of the dominant species. Results showed that the diversity of species peaked at a depth between 18 and 48. cm, in a zone thought to be of intermediate disturbance (the transect depth was, on average, 103. cm). The main macroalgal species (the red alga, Bangia atropurpurea and the green algae, Jaoa bullata, and Cladophora glomerata), showed a variety of response shapes to the gradient: monotonic, symmetrical and skewed, depending on the stage of seasonal growth. The efficient regulation of growth of B. atropurpurea along the fluctuating gradient was interpreted as an adaptive trait giving it an advantage over more slowly reacting species. The spatial and temporal niches of B. atropurpurea and Jaoa bullata overlapped widely only in early spring, whereas later their optimal habitats were clearly differentiated. This suggested partial niche segregation between these two species, and a potential seasonal interaction. © 2012 Elsevier B.V
Prediction of resting energy expenditure in healthy older adults: A systematic review
No full textBackground & aims: Estimates of energy requirements, based on measured or predicted resting energy expenditure (REE), are needed to avoid undernutrition or overnutrition (and their clinical consequences) in elderly subjects. The aims of this systematic review were to evaluate the prediction accuracy of REE in healthy elderly subjects and to ascertain which equation is more reliable at group level and/or individual level. Methods: Studies assessing prediction of REE in general elderly population were systematically searched using PubMed, EMBASE, Web of Science and CINAHL until March 2020. Prediction accuracy of REE was assessed at both group (bias) and individual (precision) level for each equation. Results: Fourteen studies met the inclusion criteria of this systematic review. Bias was reported in 8 papers and calculated in another 5 from absolute values. There was a prevalent tendency towards an overestimation of REE across the studies. The least bias was observed for the Mifflin (−0.3%) and Harris–Benedict (+2.6%) equations, with values above 5% for the FAO/WHO/UNU, Fredrix and Muller equations. Precision widely varied between studies for the same equation. The higher precision was observed using the Harris–Benedict equation (~70%), while the Henry and Mifflin equations provided estimates within 10% of measured values in 65% and 61% of elderly individuals, respectively. Conclusions: None of the prediction equations considered provides accurate and precise REE estimates in healthy older adults. However, the best prediction is given by the Mifflin equation at group level and by the Harris–Benedict equation at individual level. Further studies with strong quality design are needed to evaluate the variability and accuracy of REE in the elderly general population
Genetic variability of Italian southern Scots pine (Pinus sylvestris L.) populations: the rear edge of the range
No full textBrevi note in tema di "lesione del diritto di credito da parte di terzi" e di "responsabilità extracontrattuale da contratto"
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