Pressure jump interface law for the Stokes-Darcy coupling: Confirmation by direct numerical simulations

It is generally accepted that the effective velocity of a viscous flow over a porous bed satisfies the Beavers-Joseph slip law. To the contrary, interface law for the effective stress has been a subject of controversy. Recently, a pressure jump interface law has been rigorously derived by Marciniak-Czochra and Mikeli\'c. In this paper, we provide a confirmation of the analytical result using direct numerical simulation of the flow at the microscopic level.Comment: 25 pages, preprin

Glacial dynamics in pre-Alpine narrow valleys during the Last Glacial Maximum inferred by lowland fluvial records (northeast Italy)

During the Last Glacial Maximum (LGM), most of the major glaciated basins of the European Southern Alps had piedmont lobes with large outwash plains; only a few glaciers remained within the valley. Piedmont glaciers have left well-preserved terminal moraines, which allow for investigations to be carried out and inferences to be made regarding their evolution and chronology. Valley glaciers\u2019 remnants, on the contrary, are often scantly preserved, and changes can only be detected through correlations with glaciofluvial deposits in downstream alluvial basins. The Brenta glacial system\u2019s dynamics in the glacier\u2019s terminal tract have been inferred through a wide range of sediment analysis techniques on an alluvial stratigraphic record of the Brenta megafan (northeast Italy), and via the mapping of in-valley glacial/glaciofluvial remnants. Glaciers flowing across narrow gorges could possibly be slowed/blocked by such morphology, and glacial/sediment fluxes may then be diverted to lateral valleys. Moreover, narrow valleys may induce glaciers to bulge and form icefalls at their front, preventing the formation of terminal moraines. The Brenta Glacier was probably slowed/blocked by the narrow Valsugana Gorge downstream of Primolano and was effectively diverted eastwards across a wind gap (Canal La Menor Valley), joining the Cismon/Piave glaciers near Rocca and ending 2 km downstream. The Cismon and Piave catchments started to contribute to the Brenta system just after 27 ka cal BP until at least 19:5 ka cal BP. After the glaciers collapsed, the Piave River once again flowed into its main valley, whilst the Cismon continued to merge with the Brenta. This investigation shows that glacial catchments may vary significantly over time during a single glaciation in rugged Alpine terrains. Sand petrography and the chemical/mineralogical composition of sediments are powerful proxies for tracing such variations, as they propagate through the glacial and glaciofluvial systems and can be recognized in the alluvial stratigraphic record far downstream from the glacier front

The Influence of the Galactic Bar on the Dynamics of Globular Clusters

We make use of recent estimates for the parameters of the Milky Way's halo globular clusters and study the influence of the galactic bar on the dynamics of these clusters by computing their orbits. We use both an axisymmetric and non-axisymmetric galactic potentials, which include the rotating elongated bar/bulge structure. We account for observational errors both in the positions and in the velocities of the globular clusters and explore the influence of the bar on cluster's evolution. This is contained in the angular momentum-total energy plane, (Lz,E), which is widely exploited as an indicator of the groups of globular clusters that originated from the same accretion event. Particular attention is devoted to the Gaia-Sausage/Enceladus and Pontus structures identified recently as two independent accretion events. Our study shows that it is not possible to identify GSE and Pontus as different merger events.Comment: 17 pages, 9 figure

Tuning the activity of a hybrid polymer–oxocluster catalyst: A composition—selectivity correlation

Zr-based oxoclusters M$_{x}$O$_{y}$(OR)$_{w}$(OOR’)$_{z}$ are promising catalysts for the activation of hydrogen peroxide. However, they need to be integrated into suitable matrices to increase their hydrolytic stability and allow for their recovery after use. Polymeric materials can be successfully employed for this aim, since they modify the properties of the resulting hybrid materials, in terms of polarity and chemical affinity for the substrates, improving the catalytic activity. Herein, we report the synthesis of different acrylic polymers based on various co-monomers (methyl methacrylate (MMA), 2,2,2-trifluoroethylmethacrylate (TFMA) and 3-methacryloxypropyltrimethoxylsilane (MAPTMS)) covalently cross-linked by a Zr$_{4}$-based oxocluster, whose composition was tuned to optimise the catalytic oxidation of methyl p-tolyl sulphide. To assess their properties and stability, the materials were characterised via Fourier Transform Infrared (FT-IR) and Raman spectroscopies, Thermogravimetric Analysis (TGA), Solid-State NMR (SS-NMR) and X-Ray Absorption Spectroscopies XAS, before and after catalytic turnover

High-Mobility Group Box-1 Protein and β-Amyloid oligomers promote neuronal differentiation of adult hippocampal neural progenitors via Receptor for Advanced Glycation Endproducts/Nuclear Factor-kB axis: Relevance for Alzheimer’s disease.

Dysregulated hippocampal neurogenesis has been associated with neurodegenerative disorders, including Alzheimer's disease (AD), in which it may potentially represent an auto-reparatory mechanism that could counteract neuronal loss and cognitive impairment. We evaluated hippocampal neurogenesis in TgCRND8 mice and reported that, at 32 weeks of age, corresponding to an advanced AD-like neuropathology stage, increased numbers of proliferating cells, doublecortin-expressing progenitors/neuroblasts, and early postmitotic calretinin-expressing neurons were present compared with wild-type (WT) littermates. When hippocampal neural progenitor cells (NPCs) were isolated from TgCRND8 mice, we demonstrated that (1) their neurogenic potential was higher compared with WT NPCs; (2) medium conditioned by TgCRND8 NPC promoted neuronal differentiation of WT NPCs; and (3) the proneurogenic effect of TgCRND8-conditioned medium was counteracted by blockade of the receptor for advanced glycation end products (RAGE)/nuclear factor-\u3baB (NF-\u3baB) axis. Furthermore, we showed that \u3b2-amyloid 1-42 (A\u3b21-42) oligomers, but not monomers and fibrils, and the alarmin high-mobility group box-1 protein (HMGB-1) could promote neuronal differentiation of NPCs via activation of the RAGE/NF-\u3baB axis. Altogether, these data suggest that, in AD brain, an endogenous proneurogenic response could be potentially triggered and involve signals (A\u3b21-42 oligomers and HMGB-1) and pathways (RAGE/NF-\u3baB activation) that also contribute to neuroinflammation/neurotoxicity. A more detailed analysis confirmed no significant increase of new mature neurons in hippocampi of TgCRND8 compared with WT mice, suggesting reduced survival and/or integration of newborn neurons. Therapeutic strategies in AD should ideally combine the ability of sustaining hippocampal neurogenesis as well as of counteracting an hostile brain microenvironment so to promote survival of vulnerable cell populations, including adult generated neurons

Current evidence of antifungal prophylaxis and therapy in pediatric patients

Invasive fungal infections (IFI) are an important complication in pediatric haematological and oncological patients who undergo intensive chemotherapy for leukemia, solid tumour at advanced stage or relapsed, and hematopoietic stem cell transplantation. The incidence of IFI is lower than bacterial infection but mortality rate remains high. This review is designed to help paediatric oncologists in choosing the appropriate anti-fungal strategy and agents for prophylaxis, empirical, pre-emptive and specific therapy on the basis of published evidence

Cryptosporidium Oocyst Contamination in Drinking Water: A Case Study in Italy

The aim of this study was to evaluate the occurrence of Cryptosporidium oocysts in a drinking water treatment plant (DWTP) located in a rural area of northern Italy. Influent and effluent samples were collected at the DWTP over three years (2013–2016). In parallel, tap water samples from a public drinking fountain were collected as well. All samples were analyzed for the presence of Cryptosporidium spp. oocysts by a common method based on an immunomagnetic separation (IMS)/immunofluorescence assay (IFA), complemented by 4,6-diamidino-2-phenylindole (DAPI) staining. A reverse transcriptase-PCR (RT-PCR) protocol was added to evaluate oocyst viability. The results highlighted a high variability of oocyst concentrations across all samples (mean 4.3 ± 5.8/100 L) and a high variability in the percentage of DAPI-positive specimens (mean 48.2% ± 40.3%). Conversely, RT-PCR did not reveal the presence of viable C. parvum and C. hominis oocysts. A nested PCR targeting Cryptosporidium 18S ribosomal DNA, carried out in two water samples, confirmed the presence of a Cryptosporidium genotype associated with wild animals in the river and in tap water. The results obtained underline the vulnerability of the investigated surface water to Cryptosporidium spp. contamination. Although the recovered Cryptosporidium genotype is not a human pathogen, its presence demonstrates the existence of a potential pathogen Cryptosporidium spp. contamination risk. Moreover, these results underline the importance of also considering unconventional (not bacterial) biological contaminations (protozoa) in water resources in rural areas, including those of developed countries

Developing biodiversity assessment on a stand forest type management level in north-eastern Italy

This paper discusses a simple operative proposal, elaborated by a team of advisers to the Forestry Service of the Veneto administrative region (north-eastern Italy), concerning the definition of stand-level forest type biodiversity indicators and biodiversity oriented management provisions. Such tools are conceived to transfer biodiversity conservation understanding in current forest stand management practices. The developed assessment system is targeted to: maintenance and increase of the variability of forest landscape mosaic; conservation of species variability; creation of resource reservoirs. The following criteria and indicators are taken into consideration: spatial pattern (widespreadness, connectedness, species contagion potential), forest structure (uneven aged stands: percent of trees in three broad diameter classes; even aged stands: number of development stages and surface of each development stage), herbs/shrubs species (average, minimum and maximum number of species; average number of short-lived herb/ shrub species recorded in minimal anthropic disturbance conditions; dynamic trend in the number of herb/shrub species), bird species (average, minimum and maximum number of species); overall naturalistic quality (flora; vegetation; fauna). Such indicators are proposed as biodiversity reference standards for each forest type in the considered region: they provide practical baseline information with which forest stand management efficiency in achieving biodiversity targets can be compared