6809 research outputs found
Sort by
Sea ice phenology and primary productivity pulses shape breeding success in Arctic seabirds
No full textSpring sea ice phenology regulates the timing of the two consecutive pulses of marine autotrophs that form the base of the Arctic marine food webs. This timing has been suggested to be the single most essential driver of secondary production and the efficiency with which biomass and energy are transferred to higher trophic levels. We investigated the chronological sequence of productivity pulses and its potential cascading impacts on the reproductive performance of the High Arctic seabird community from Svalbard, Norway. We provide evidence that interannual changes in the seasonal patterns of marine productivity may impact the breeding performance of little auks and Br?nnich\u27s guillemots. These results may be of particular interest given that current global warming trends in the Barents Sea region predict one of the highest rates of sea ice loss within the circumpolar Arctic. However, local- to regional-scale heterogeneity in sea ice melting phenology may add uncertainty to predictions of climate-driven environmental impacts on seabirds. Indeed, our fine-scale analysis reveals that the inshore Br?nnich\u27s guillemots are facing a slower advancement in the timing of ice melt compared to the offshore-foraging little auks. We provide a suitable framework for analyzing the effects of climate-driven sea ice disappearance on seabird fitness
Action observation and motor imagery for rehabilitation in Parkinson\u27s disease: A systematic review and an integrative hypothesis
No full textThis article discusses recent evidence supporting the use of action observation therapy and motor imagery practice for rehabilitation of Parkinson\u27s disease. A main question that emerges from the review regards the different effectiveness of these approaches and the possibility of integrating them into a single method to enhance motor behaviour in subjects with Parkinson\u27s disease. In particular, the reviewed studies suggest that action observation therapy can have a positive effect on motor facilitation of patients and that a long-term rehabilitation program based on action observation therapy or motor imagery practice can bring some benefit on their motor recovery. Moreover, the paper discusses how the research on the combined use of action observation and motor imagery for motor improvements in healthy subjects may encourage the combined use of action observation therapy and motor imagery practice for therapeutic aims in Parkinson\u27s disease. To date, this hypothesis has been never experimented
Microinquinanti delle acque. Scoperti nuovi geni resistenti agli antibiotici
No full textNot availableNelle acque reflue vengono rilasciati in gran quantit? una serie di nuovi microinquinanti, come i geni di resistenza agli antibiotici, che gli impianti di depurazione non riescono a rimuovere in quanto non dispongono di alcun trattamento speciftco. L\u27Istituto per lo studio degli ecosistemi del Consiglio nazionale delle ricerche (Ise-Cnr) di Verbania Pallanza ha intrapreso una ricerca al fine di sviluppare sistemi di trattamento efftcienti,coordinata dal Gruppo di ecologia microbica (Meg) dell\u27Ise-Cnr in collaborazione con Universit? di Mons (Belgio) e Acqua Novara.Vco. I risultati sono pubblicati sulla rivista Water Research
Action observation therapy and Parkinson\u27s disease patients: a double blind controlled study
No full textNo abstract availabl
Photoacoustic spectroscopy for estimating nutritional indices in lepidopteran defoliators
No full textLymantria dispar L. and Malacosoma neustrium (L.) are the most serious defoliators of cork oak in the Mediterranean region. For this reason, information on their feeding behaviour are important in pest management. A non-destructive approach by using photoacoustic spectroscopy (PAS) combined with a partial least squares regression analyses (PLS), has been used to provide a rapid and cost-effective analysis to assess foliage chemistry and to estimate some nutritional indices of these insects. For testing the performance of larvae, cork oak leaves for chemical, spectroscopic analysis and bioassays were collected during the cork oak vegetational season. Leaves were analysed for their water content, polyphenols, tannins, condensed tannins, amid, nitrogen and carbon according to standard chemical protocols. Waldbauer\u27s method was applied to determine the following indices: Relative Growth Rate (RGR), Relative Consumption Rate (RCR), Efficiency of Conversion of Ingested food (ECI), Approximate Digestibility (AD), Efficiency of Conversion of Digested food (ECD). Chemometrics of PAS/PLS regression analysis produced adequate prediction algorithms for the studied chemico-physical and nutritional parameters. Multivariate analysis of data showed good relationships between the consumption and utilization of food by insects and nitrogen, condensed tannins, polyphenols, water content in foliage. Moreover, the relative based PAS/PLS models enabled the prediction of some chemico-physical constituents of foliage as nitrogen (R2=0.85), condensed tannins (R2=0.72), polyphenols (R2=0.84), water (R2=0.82) and ECD and ECI indices both for Lymantria (R2=0.82; R2=0.61, respectively) and Malacosoma (R2=0.71; R2=0.66, respectively). The proposed approach showed to be very useful for investigating the insects feeding behaviour and for obtaining leaf chemico-physical data and nutritional indices acquiring only the PAS spectra that can be collected quickly and at low cost
3D soil structure characterization of Biological Soil Crusts from Alpine Tarfala Valley
No full textCyanobacteria filaments, microfungal hyphae, lichen rhizinae and anchoring rhizoids of bryophytes all together contribute to induce formation of structure in the thin soil layer beneath the Biological Soil Crusts (BSCs). Quantitative assessment of the soil structure beneath the BSCs is primarily hindered by the fragile nature of the crusts. Therefore, the role of BSCs in affecting such soil physical property has been rarely addressed using direct measurements. In this work we applied non-destructive X-ray microtomography imaging on five different samples of BSCs collected in the Alpine Tarfala Valley (northern Sweden), which have already been characterized in terms of fungal biodiversity in a previous work. We obtained images of the 3D spatial organization of the soil underneath the BSCs and characterized its structure by applying procedures of image analysis allowing to determine pore size distribution, pore connectivity and aggregate size distribution. Results has then been correlated with the different fungal assemblages of the samples
Synthesis of antioxidant carotenoids in microalgae in response to physiological stress
No full textCarotenoids act as potential antioxidants, quenching energy of excited singlet oxygen and scavenging free radicals. Among microalgae, Haematococcus, Chlamydomonas, Chlorella, Dunaliella and diatoms and dinoflagellates, such as Phaeodactylum and Isochrysis, are able to synthesize large amount of carotenoids. The main function of carotenoids consists in absorbing light to perform photosynthesis, and some of them are constitutively present in the cells (primary carotenoids). The main primary carotenoids usually found are neoxanthin, violaxanthin, lutein, and ?-carotene. To preserve cells from oxidative damage, their production may be increased, while other carotenoids may be synthesized de novo. In particular, under stress conditions such as high light exposure, nutrient starvation, change in oxygen partial pressure, and high or low temperatures, microalgal metabolism is altered and photosynthetic activity may be reduced. In these conditions, photosynthetic electrons transport is reduced, and the intracellular reduction level increase may be associated with the formation of free radicals and species containing singlet oxygen. In order to prevent damage from photooxidation, microalgae are able to adopt strategies to contrast these dangerous oxidant molecules. One of the most active mechanisms is to synthesize large amount of carotenoids, which can act as antioxidants
Comprehensive and coordinated approach of GEOSS to ecosystem challenges.
No full textNo abstract availabl
Ecosystem services in European protected areas: Ambiguity in the views of scientists and managers?.
No full textProtected Areas are a key component of nature conservation. They can play an important role in counterbalancing the impacts of ecosystem degradation. For an optimal protection of a Protected Area it is essential to account for the variables underlying the major Ecosystem Services an area delivers, and the threats upon them. Here we show that the perception of these important variables differs markedly between scientists and managers of Protected Areas in mountains and transitional waters. Scientists emphasise variables of abiotic and biotic nature, whereas managers highlight socio-economic, cultural and anthropogenic variables. This indicates fundamental differences in perception. To be able to better protect an area it would be advisable to bring the perception of scientists and managers closer together. Intensified and harmonised communication across disciplinary and professional boundaries will be needed to implement and improve Ecosystem Service oriented management strategies in current and future Protected Areas
An island view of endemic rarity-Environmental drivers and consequences for nature conservation
No full textAim: Rarity-an important measure for conservation biogeography-can vary over many orders of magnitude. However, it is unclear which regional-scale abiotic conditions drive processes affecting rarity of endemic species on islands. To support conservation efforts, we (1) assess the main abiotic drivers of endemic rarity, (2) determine how well existing protected areas (PAs) coincide with hotspots of endemic rarity and (3) introduce and evaluate a new hypervolume-based rarity estimator. Location: La Palma (Canary Islands). Methods: We recorded all present endemic vascular plant species in 1,212 plots covering the entire island. We calculated endemic rarity (corrected range-rarity richness for endemics) using a rarity estimation approach based on kernel density estimations (hypervolume approach). We performed a sensitivity analysis based on multiple linear regressions and relative importance estimations of environmental drivers to estimate the performance of the hypervolume-based rarity estimation compared to standard methods (occurrence frequency, convex hulls, alpha hulls). Results: Climate variables (mean annual temperature, climatic rarity, precipitation variability) best explained archipelago endemic (AE) and single-island endemic (SIE) rarity. Existing PAs covered the majority of AE and SIE rarity, especially national and natural parks as well as the Natura 2000 sites. In our study system, hypervolumes performe better than standard measures of range size. Main conclusion: Both AE and SIE rarity on La Palma show a clear spatial pattern, with hotspots of endemic rarity found at high elevations and in rare climates, presumably owing to geographical and climatic constraints and possibly anthropogenic pressure (e.g., land use, introduced herbivores, fire). Areas of high rarity estimates coincide with the distribution and extent of PAs on La Palma, especially since the recent addition of the Natura 2000 sites. The hypervolume approach is a promising tool to estimate species range sizes, and can be applied on all scales where point/plot data are available