295 research outputs found
Climate Change Enhances the Negative Effects of Predation Risk on an Intermediate Consumer
Predators are a major source of stress in natural systems because their prey must balance the benefits of feeding with the risk of being eaten. Although this \u27fear\u27 of being eaten often drives the organization and dynamics of many natural systems, we know little about how such risk effects will be altered by climate change. Here, we examined the interactive consequences of predator avoidance and projected climate warming in a three-level rocky intertidal food chain. We found that both predation risk and increased air and sea temperatures suppressed the foraging of prey in the middle trophic level, suggesting that warming may further enhance the top-down control of predators on communities. Prey growth efficiency, which measures the efficiency of energy transfer between trophic levels, became negative when prey were subjected to predation risk and warming. Thus, the combined effects of these stressors may represent an important tipping point for individual fitness and the efficiency of energy transfer in natural food chains. In contrast, we detected no adverse effects of warming on the top predator and the basal resources. Hence, the consequences of projected warming may be particularly challenging for intermediate consumers residing in food chains where risk dominates predator-prey interactions
Gold nanoparticles on nanodiamond for nanophotonic applications
We present here some recent results of a research focused on the prepn. of detonation nanodiamond/Au nanoparticles
hybrid materials. Two different exptl. routes are followed for the decoration of diamond nanoparticles by Au
nanoparticles, that are in turn prepd. by an innovative electroless approach. Structure and morphol. at the nanoscale
level of the Au-on-nanodiamond deposits have been deeply investigated by electron microscopy (FE-SEM, HR-TEM) and
diffraction (XRD) techniques. Optical properties of these systems have been detd. by performing scattering and UV-Vis
absorption measurements, and by comparing the exptl. data with simulated extinction spectra. The results highlighted
very interesting plasmonic and scattering behaviors, mainly related to the high refractive index of diamond
Nickel(II) 3,4;9,10-Perylenediimide bis-Phosphonate Pentahydrate: A MetalâOrganic Ferromagnetic Dye
The new metalâorganic compound nickel(II) 3,4;9,10-
perylenediimide bis-phosphonate pentahydrate, i.e. Ni2[(PDI-BP)-
(H2O)2]·3H2O (1), has been synthesized and its structural and magnetic
properties have been studied. Reaction of 3,4;9,10-perylenediimide bisphosphonate
(PDI-BP, hereafter) ligand and nickel chloride in water resulted
in the precipitation of a red and poorly crystalline solid (1). As the solid shows
a poor crystalline organization of aggregates, the energy dispersive X-ray
diffraction analysis (EDXD) technique has been used to obtain short-range
order structural information of the single nanoaggregates by radial distribution
function analysis. The overall structure of the compound is characterized by
layers containing perylene planes shifted in the direction perpendicular to the
stacking axes in such a way that only the outer rings overlap. The edges of the
perylene planes are connected to the phosphonate groups through an imido
group. The oxygen atoms of the [âPO3]2â group and those of the water
molecules are bonded to the nickel ions resulting in a [NiO6] octahedral coordination sphere. The NiâO bond lengths are 0.21
± 0.08 nm and the NiâOâNi angles of aligned moieties are 95 ± 2°. The oxygen atoms of the water molecules and the nickel
atoms are nearly planar and almost perpendicular to the perylene planes forming chains of edge-sharing octahedra. The magnetic
properties of (1) show the presence of intrachain ferromagnetic NiâNi interactions and a long-range ferromagnetic order below
21 K with a canting angle and with a spin glasslike behavior due to disorder in the inorganic layer. Hysteresis cycles show a
coercive field of ca. 272 mT at 2 K that decreases as the temperature is increased and vanishes at ca. 20 K
Hybrid Cnanotubes/Si 3D nanostructures by one-step growth in a dual-plasma reactor
Hybrid nanostructures consisting of Si polycrystalline nanocones, with an anemone-like termination coated with C-nanotubes bundles, have been generated on a (1 0 0) Si substrate in a dual mode microwave/radio-frequency plasma reactor.
The substrate is both heated and bombarded by energetic H ions during the synthesis process. The nanocones growth is explained considering pull of the growing Si nanocrystalline phase along the lines of the electrical field, likely via a molten/recrystallization mechanism. The one-step building of the achieved complex 3D architectures is described in terms of dynamic competition between Si and C nanotubes growth under the peculiar conditions of kinetically driven processes
Third workshop on full-body and multisensory experience
The workshop on "Full-Body and Multisensory Experience" aims at discussing the rich possibilities that the body offers to experience the external world and the prospects that arise for interaction designers when these often-neglected abilities are taken into account. In particular, the workshop will focus on the rediscovery of the human senses, either alone or in a multimodal combination, and of the perceptual-motor abilities of our body. The one-day workshop is divided in three steps: first phase is for the generation of ideas on multisensory interfaces, in the second phase, participants will have the possibilities to explore and rediscover their sensorimotor abilities through several exercises and games; in the third and last phase, there will be a further creative session in order to evaluate how the full body and multisensory activities have fostered people's creative processes. The aim of the whole experience is twofold: first, inspiring participants in designing novel concepts for multisensory interfaces; second, providing a preliminary study on the effect of these exercises in fostering creativity and supporting the design process of multisensory interfaces
Self-assembly of glycoprotein nanostructured filaments for modulating extracellular networks at long range
The intriguing capability of branched glycoprotein filaments to change their hierarchical organization, mediated by external biophysical stimuli, continues to expand understanding of self-assembling strategies that can dynamically rearrange networks at long range. Previous research has explored the corresponding biological, physiological and genetic mechanisms, focusing on protein assemblies within a limited range of nanometric units. Using direct microscopy bio-imaging, we have determined the morpho-structural changes of self-assembled filament networks of the zona pellucida, revealing controlled levels of structured organizations to join distinct evolved stages of the oocyte (Immature, Mature, and Fertilized). This natural soft network reorganizes its corresponding hierarchical network to generate symmetric, asymmetric, and ultimately a state with the lowest asymmetry of the outer surface roughness, and internal pores reversibly changed from elliptical to circular configurations at the corresponding stages. These elusive morpho-structural changes are regulated by the nanostructured polymorphisms of the branched filaments by self-extension/-contraction/-bending processes, modulated by determinate theoretical angles among repetitive filament units. Controlling the nanoscale self-assembling properties by delivering a minimum number of activation bio-signals may be triggered by these specific nanostructured polymorphic organizations. Finally, this research aims to guide this soft biomaterial into a desired state to protect oocytes, eggs, and embryos during development, to favour/prevent the fertilization/polyspermy processes and eventually to impact interactions with bacteria/virus at multiscale levels.The intriguing capability of branched glycoprotein filaments to change their hierarchical organization, mediated by external biophysical stimuli, continues to expand understanding of self-assembling strategies that can dynamically rearrange networks at long range
Morpho-chemical observations of human deciduous teeth enamel in response to biomimetic toothpastes treatment
Today, biomaterial research on biomimetic mineralization strategies represents a new challenge in the prevention and cure of enamel mineral loss on delicate deciduous teeth. Distinctive assumptions about the origin, the growth, and the functionalization on the biomimetic materials have been recently proposed by scientific research studies in evaluating the different clinical aspects of treating the deciduous tooth. Therefore, appropriate morpho-chemical observations on delivering specific biomaterials to enamel teeth is the most important factor for controlling biomineralization processes. Detailed morpho-chemical investigations of the treated enamel layer using three commercial toothpastes (Biorepair, F1400, and F500) were performed through variable pressure scanning electron microscopy (VP-SEM) and energy dispersive X-ray spectroscopy (EDS) on deciduous teeth in their native state. A new microscopy methodology allowed us to determine the behaviors of silicate, phosphate, and calcium contents from the early stage, as commercially available toothpastes, to the final stage of delivered diffusion, occurring within the enamel layer together with their penetration depth properties. The reported results represent a valuable background towards full comprehension of the role of organic-inorganic biomaterials for developing a controlled biomimetic toothpaste in biofluid media
Nanocarbon surfaces for biomedicine
The distinctive physicochemical, mechanical and electrical
properties of carbon nanostructures are currently gaining
the interest of researchers working in bioengineering and
biomedical fields. Carbon nanotubes, carbon dendrimers, graphenic
platelets and nanodiamonds are deeply studied aiming
at their application in several areas of biology and medicine.
Here we provide a summary of the carbon nanomaterials
prepared in our labs and of the fabrication techniques used to
produce several biomedical utilities, from scaffolds for tissue
growth to cargos for drug delivery and to biosensors
Constraints on the quantum gravity scale from kappa - Minkowski spacetime
We compare two versions of deformed dispersion relations (energy vs momenta
and momenta vs energy) and the corresponding time delay up to the second order
accuracy in the quantum gravity scale (deformation parameter). A general
framework describing modified dispersion relations and time delay with respect
to different noncommutative kappa -Minkowski spacetime realizations is firstly
proposed here and it covers all the cases introduced in the literature. It is
shown that some of the realizations provide certain bounds on quadratic
corrections, i.e. on quantum gravity scale, but it is not excluded in our
framework that quantum gravity scale is the Planck scale. We also show how the
coefficients in the dispersion relations can be obtained through a
multiparameter fit of the gamma ray burst (GRB) data.Comment: 9 pages, final published version, revised abstract, introduction and
conclusion, to make it clear to general reade
Translational control in the stress adaptive response of cancer cells: a novel role for the heat shock protein TRAP1
TNF receptor-associated protein 1 (TRAP1), the main mitochondrial member of the heat shock protein (HSP) 90 family, is induced in most tumor types and is involved in the regulation of proteostasis in the mitochondria of tumor cells through the control of folding and stability of selective proteins, such as Cyclophilin D and Sorcin. Notably, we have recently demonstrated that TRAP1 also interacts with the regulatory protein particle TBP7 in the endoplasmic reticulum (ER), where it is involved in a further extra-mitochondrial quality control of nuclear-encoded mitochondrial proteins through the regulation of their ubiquitination/degradation. Here we show that TRAP1 is involved in the translational control of cancer cells through an attenuation of global protein synthesis, as evidenced by an inverse correlation between TRAP1 expression and ubiquitination/degradation of nascent stress-protective client proteins. This study demonstrates for the first time that TRAP1 is associated with ribosomes and with several translation factors in colon carcinoma cells and, remarkably, is found co-upregulated with some components of the translational apparatus (eIF4A, eIF4E, eEF1A and eEF1G) in human colorectal cancers, with potential new opportunities for therapeutic intervention in humans. Moreover, TRAP1 regulates the rate of protein synthesis through the eIF2α pathway either under basal conditions or under stress, favoring the activation of GCN2 and PERK kinases, with consequent phosphorylation of eIF2α and attenuation of cap-dependent translation. This enhances the synthesis of selective stress-responsive proteins, such as the transcription factor ATF4 and its downstream effectors BiP/Grp78, and the cystine antiporter system xCT, thereby providing protection against ER stress, oxidative damage and nutrient deprivation. Accordingly, TRAP1 silencing sensitizes cells to apoptosis induced by novel antitumoral drugs that inhibit cap-dependent translation, such as ribavirin or 4EGI-1, and reduces the ability of cells to migrate through the pores of transwell filters. These new findings target the TRAP1 network in the development of novel anti-cancer strategies
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