Trace and rare earth elements determination in milk whey from the Veneto region, Italy

Multi-element analyses determine the content of 17 trace elements (Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Sr, Cd, Cs, Ba, Pb, U) and 14 rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, Lu, Y) in whey samples from cow and goat milk by inductively coupled plasma mass spectrometry and inductively coupled plasma-sector field mass spectrometry. A total of 261 milk whey samples were collected from four locations in the Veneto region of northeastern (NE) Italy. These samples contain a wide range concentration of 17 trace elements (0.06–1530 μg kg−1) and 14 rare earth elements (0.16–28.2 ng kg−1) in whey samples, but do not reach toxic concentrations. Elemental fingerprinting of trace and rare earth elements in cow and goat milk whey provide information on the dairy quality and, as they reflect the local environmental conditions, result in an excellent indicator of their geographical origin

Switcher-random-walks: a cognitive-inspired mechanism for network exploration

Semantic memory is the subsystem of human memory that stores knowledge of concepts or meanings, as opposed to life specific experiences. The organization of concepts within semantic memory can be understood as a semantic network, where the concepts (nodes) are associated (linked) to others depending on perceptions, similarities, etc. Lexical access is the complementary part of this system and allows the retrieval of such organized knowledge. While conceptual information is stored under certain underlying organization (and thus gives rise to a specific topology), it is crucial to have an accurate access to any of the information units, e.g. the concepts, for efficiently retrieving semantic information for real-time needings. An example of an information retrieval process occurs in verbal fluency tasks, and it is known to involve two different mechanisms: -clustering-, or generating words within a subcategory, and, when a subcategory is exhausted, -switching- to a new subcategory. We extended this approach to random-walking on a network (clustering) in combination to jumping (switching) to any node with certain probability and derived its analytical expression based on Markov chains. Results show that this dual mechanism contributes to optimize the exploration of different network models in terms of the mean first passage time. Additionally, this cognitive inspired dual mechanism opens a new framework to better understand and evaluate exploration, propagation and transport phenomena in other complex systems where switching-like phenomena are feasible.Comment: 9 pages, 3 figures. Accepted in "International Journal of Bifurcations and Chaos": Special issue on "Modelling and Computation on Complex Networks

Synergistic use of Sentinel-2 and UAV-derived data for plant fractional cover distribution mapping of coastal meadows with digital elevation models

Coastal wetlands provide a range of ecosystem services, yet they are currently under threat from global change impacts. Thus, their monitoring and assessment is vital for evaluating their status, extent and distribution. Remote sensing provides an excellent tool for evaluating coastal ecosystems, whether with small-scale studies using drones or national-/regional-/global-scale studies using satellite-derived data. This study used a fine-scale plant community classification of coastal meadows in Estonia derived from a multispectral camera on board unoccupied aerial vehicles (UAVs) to calculate the plant fractional cover (PFC) in Sentinel-2 MultiSpectral Instrument (MSI) sensor grids. A random forest (RF) algorithm was trained and tested with vegetation indices (VIs) calculated from the spectral bands extracted from the MSI sensor to predict the PFC. Additional RF models were trained and tested after adding a digital elevation model (DEM). After comparing the models, results show that using DEM with VIs can increase the prediction accuracy of PFC up to 2 times (R2 58%-70%). This suggests the use of ancillary data such as DEM to improve the prediction of empirical machine learning models, providing an appropriate approach to upscale local studies to wider areas for management and conservation purposes

General Methodology for the Identification of Reduced Dynamic Models of Barge-Type Floating Wind Turbines

Floating offshore wind turbines (FOWT) are designed to overcome some of the limitations of offshore bottom-fixed ones. The development of computational models to simulate the behavior of the structure and the turbine is key to understanding the wind energy system and demonstrating its feasibility. In this work, a general methodology for the identification of reduced dynamic models of barge-type FOWTs is presented. The method is described together with an example of the development of a dynamic model of a 5 MW floating offshore wind turbine. The novelty of the proposed identification methodology lies in the iterative loop relationship between the identification and validation processes. Diversified data sets are used to select the best-fitting identified parameters by cross evaluation of every set among all validating conditions. The data set is generated for different initial FOWT operating conditions. Indeed, an optimal initial condition for platform pitch was found to be far enough from the system at rest to allow the dynamics to be well characterized but not so far that the unmodeled system nonlinearities were so large that they affected significantly the accuracy of the model. The model has been successfully applied to structural control research to reduce fatigue on a barge-type FOWT

The disruption of mitochondrial axonal transport is an early event in neuroinflammation

Background: in brain inflammatory diseases, axonal damage is one of the most critical steps in the cascade that leads to permanent disability. Thus, identifying the initial events triggered by inflammation or oxidative stress that provoke axonal damage is critical for the development of neuroprotective therapies. Energy depletion due to mitochondrial dysfunction has been postulated as an important step in the damage of axons. This prompted us to study the effects of acute inflammation and oxidative stress on the morphology, transport, and function of mitochondria in axons. Methods: mouse cerebellar slice cultures were challenged with either lipopolysaccharide (LPS) or hydrogen peroxide (H2O2) ex vivo for 24 h. Axonal mitochondrial morphology was evaluated by transmission electron microscopy (TEM) and mitochondrial transportation by time-lapse imaging. In addition, mitochondrial function in the cerebellar slice cultures was analyzed through high-resolution respirometry assays and quantification of adenosine triphosphate (ATP) production. Results: both conditions promoted an increase in the size and complexity of axonal itochondria evident in electron microscopy images, suggesting a compensatory response. Such compensation was reflected at the tissue level as increased respiratory activity of complexes I and IV and as a transient increase in ATP production in response to acute inflammation. Notably, time-lapse microscopy indicated that mitochondrial transport (mean velocity) was severely impaired in axons, increasing the proportion of stationary mitochondria in axons after LPS challenge. Indeed, the two challenges used produced different effects: inflammation mostly reducing retrograde transport and oxidative stress slightly enhancing retrograde transportation. Conclusions: neuroinflammation acutely impairs axonal mitochondrial transportation, which would promote an inappropriate delivery of energy throughout axons and, by this way, contribute to axonal damage. Thus, preserving axonal mitochondrial transport might represent a promising avenue to exploit as a therapeutic target for neuroprotection in brain inflammatory diseases like multiple sclerosis

Retinal nerve fiber layer atrophy is associated with physical and cognitive disability in multiple sclerosis

Studying axonal loss in the retina is a promising biomarker for multiple sclerosis (MS). Our aim was to compare optical coherence tomography (OCT) and Heidelberg retinal tomography (HRT) techniques to measure the thickness of the retinal nerve fiber layer (RNFL) in patients with MS, and to explore the relationship between changes in the RNFL thickness with physical and cognitive disability. We studied 52 patients with MS and 18 proportionally matched controls by performing neurological examination, neuropsychological evaluation using the Brief Repetitive Battery-Neuropsychology and RNFL thickness measurement using OCT and HRT. RESULTS: We found that both OCT and HRT could define a reduction in the thickness of the RNFL in patients with MS compared with controls, although both measurements were weakly correlated, suggesting that they might measure different aspects of the tissue changes in MS. The degree of RNFL atrophy was correlated with cognitive disability, mainly with the symbol digit modality test (r=0.754, P<0.001). Moreover, temporal quadrant RNFL atrophy measured with OCT was associated with physical disability. CONCLUSION: In summary, both OCT and HRT are able to detect thinning of the RNFL, but OCT seems to be the most sensitive technique to identify changes associated with MS evolution

Fire, vegetation, and Holocene climate in a southeastern Tibetan lake: A multi-biomarker reconstruction from Paru Co

The fire history of the Tibetan Plateau over centennial to millennial timescales is not well known. Recent ice core studies reconstruct fire history over the past few decades but do not extend through the Holocene. Lacustrine sedimentary cores, however, can provide continuous records of local environmental change on millennial scales during the Holocene through the accumulation and preservation of specific organic molecular biomarkers. To reconstruct Holocene fire events and vegetation changes occurring on the southeastern Tibetan Plateau and the surrounding areas, we used a multi-proxy approach, investigating multiple biomarkers preserved in core sediment samples retrieved from Paru Co, a small lake located in the Nyainqentanglha Mountains (29°47045.600N, 92°21007.200 E; 4845ma.s.l.). Biomarkers include n-alkanes as indicators of vegetation, polycyclic aromatic hydrocarbons (PAHs) as combustion proxies, fecal sterols and stanols (FeSts) as indicators of the presence of humans or grazing animals, and finally monosaccharide anhydrides (MAs) as specific markers of vegetation burning processes. Insolation changes and the associated influence on the Indian summer monsoon (ISM) affect the vegetation distribution and fire types recorded in Paru Co throughout the Holocene. The early Holocene (10.7- 7.5 cal kyr BP) n-alkane ratios demonstrate oscillations between grass and conifer communities, resulting in respective smouldering fires represented by levoglucosan peaks, and high-temperature fires represented by high-molecular-weight PAHs. Forest cover increases with a strengthened ISM, where coincident high levoglucosan to mannosan (L = M) ratios are consistent with conifer burning. The decrease in the ISM at 4.2 cal kyr BP corresponds with the expansion of regional civilizations, although the lack of human FeSts above the method detection limits excludes local anthropogenic influence on fire and vegetation changes. The late Holocene is characterized by a relatively shallow lake surrounded by grassland, where all biomarkers other than PAHs display only minor variations. The sum of PAHs steadily increases throughout the late Holocene, suggesting a net increase in local to regional combustion that is separate from vegetation and climate change

Diels-Alder-based thermo-reversibly crosslinked polymers:Interplay of crosslinking density, network mobility, kinetics and stereoisomerism

Polymers crosslinked through thermo-reversible furan/maleimide Diels-Alder chemistry have been widely explored, since they stand as an ingenious design for reprocessable and self-healing thermosets and elastomers. For these polymeric products, crosslinking density plays a key role on the polymer thermo-reversibility. However, how this degree of network interconnectivity influences the kinetics of thermal reversibility has not yet been addressed. In order to tackle this problem, furan-grafted polyketones crosslinked by a bi-functional maleimide were prepared with different ratios between maleimide and furan groups. The thermo-reversible dynamics of the prepared polymers were then studied by rheology and differential scanning calorimetry. Here we show that, the thermo-reversible process occurs faster and at lower temperatures in polymers with lower crosslinking densities. Network mobility is responsible for this effect. It allows the formulations to rearrange their polymer network differently through the heating-cooling cycles. The results also indicate that the crosslinking density rather than the stereoisomerism of the Diels-Alder adducts plays a larger role in the reversible behavior of the system. Additionally, the thermo-reversible features of the polymer were shown to be dependent on its thermal history. This work impacts the development of reprocessable and self-healing crosslinked polymers, and the design of the corresponding reprocessing and healing procedures

Characterisation of fatty acyl reductases of sunflower (Helianthus annuus L.) seed

Long and very long chain fatty alcohols are produced from their corresponding acyl-CoAs through the activity of fatty acyl reductases (FARs). Fatty alcohols are important components of the cuticle that protects aerial plant organs, and they are metabolic intermediates in the synthesis of the wax esters in the hull of sunflower (Helianthus annuus) seeds. Genes encoding 4 different FARs (named HaFAR2, HaFAR3, HaFAR4 and HaFAR5) were identified using BLAST, and studies showed that four of the genes were expressed in seed hulls. In this study, the structure and location of sunflower FAR proteins were determined. They were also expressed exogenously in Saccharomyces cerevisiae to evaluate their substrate specificity based on the fatty alcohols synthesized by the transformed yeasts. Three of the four enzymes tested showed activity in yeast. HaFAR3 produced C18, C20 and C22 saturated alcohols, whereas HaFAR4 and HaFAR5 produced C24 and C26 saturated alcohols. The involvement of these genes in the synthesis of sunflower seed wax esters was addressed by considering the results obtained