A Biodegradable, Bio-Based Polymer for the Production of Tools for Aquaculture: Processing, Properties and Biodegradation in Sea Water

Bio-based, biodegradable polymers can dramatically reduce the carbon dioxide released into the environment by substituting fossil-derived polymers in some applications. In this work, prototypes of trays for aquaculture applications were produced via injection molding by using a biodegradable polymer, Mater-Bi-(R). A characterization carried out via calorimetric, rheological and mechanical tests revealed that the polymer employed shows properties suitable for the production of tools to be used in aquaculture applications. Moreover, the samples were subjected to a biodegradation test in conditions that simulate the marine environment. The as-treated samples were characterized from gravimetrical, morphological and calorimetric point of views. The obtained data showed a relatively low biodegradation rate of the thick molded samples. This behavior is of crucial importance since it implies a long life in marine water for these manufacts before their disappearing

Physical and biological properties of electrospun poly(d,l-lactide)/nanoclay and poly(d,l-lactide)/nanosilica nanofibrous scaffold for bone tissue engineering

Electrospun scaffolds exhibiting high physical performances with the ability to support cell attachment and proliferation are attracting more and more scientific interest for tissue engineering applications. The inclusion of inorganic nanoparticles such as nanosilica and nanoclay into electrospun biopolymeric matrices can meet these challenging requirements. The silica and clay incorporation into polymeric nanofibers has been reported to enhance and improve the mechanical properties as well as the osteogenic properties of the scaffolds. In this work, for the first time, the physical and biological properties of polylactic acid (PLA) electrospun mats filled with different concentrations of nanosilica and nanoclay were evaluated and compared. The inclusion of the particles was evaluated through morphological investigations and Fourier transform infrared spectroscopy. The morphology of nanofibers was differently affected by the amount and kind of fillers and it was correlated to the viscosity of the polymeric suspensions. The wettability of the scaffolds, evaluated through wet contact angle measurements, slightly increased for both the nanocomposites. The crystallinity of the systems was investigated by differential scanning calorimetry highlighting the nucleating action of both nanosilica and nanoclay on PLA. Scaffolds were mechanically characterized with tensile tests to evaluate the reinforcing action of the fillers. Finally, cell culture assays with pre-osteoblastic cells were conducted on a selected composite scaffold in order to compare the cell proliferation and morphology with that of neat PLA scaffolds. Based on the results, we can convince that nanosilica and nanoclay can be both considered great potential fillers for electrospun systems engineered for bone tissue regeneration

Complex organic molecules in protostellar environments in the SKA era

Molecular complexity builds up at each step of the Sun-like star formation process, starting from simple molecules and ending up in large polyatomic species. Complex organic molecules (COMs; such as methyl formate, HCOOCH$_3$, dymethyl ether, CH$_3$OCH$_3$, formamide, NH$_2$CHO, or glycoaldehyde, HCOCH$_2$OH) are formed in all the components of the star formation recipe (e.g. pre-stellar cores, hot-corinos, circumstellar disks, shocks induced by fast jets), due to ice grain mantle sublimation or sputtering as well as gas-phase reactions. Understanding in great detail the involved processes is likely the only way to predict the ultimate molecular complexity reached in the ISM, as the detection of large molecules is increasingly more difficult with the increase of the number of atoms constituting them. Thanks to the recent spectacular progress of astronomical observations, due to the Herschel (sub-mm and IR), IRAM and SMA (mm and sub-mm), and NRAO (cm) telescopes, an enormous activity is being developed in the field of Astrochemistry, extending from astronomical observatories to chemical laboratories. We are involved in several observational projects providing unbiased spectral surveys (in the 80-300 and 500-2000 GHz ranges) with unprecedented sensitivity of templates of dense cores and protostars. Forests of COM lines have been detected. In this chapter we will focus on the chemistry of both cold prestellar cores and hot shocked regions, (i) reviewing results and open questions provided by mm-FIR observations, and (ii) showing the need of carrying on the observations of COMs at lower frequencies, where SKA will operate. We will also emphasize the importance of analysing the spectra by the light of the experimental studies performed by our team, who is investigating the chemical effects induced by ionising radiation bombarding astrophysically relevant ices.Comment: 18 pages, 8 figure

Identifying Youth at Clinical High Risk: What’s the Emotional Impact?

Background: Early intervention in major mental illness promises to improve the lives of those identified. • But could identifying youth as at clinical high risk (CHR) for psychosis also do harm given that the majority never develop a psychotic disorder? • Could telling someone they are at risk for psychosis activate internalized stigma that has been associated with increased emotional distress, social withdrawal, non-engagement in treatment, and suicide risk in CHR youth? • Within the context of a larger study of stigma in CHR, we compared emotional responses to the CHR concept assessed before and after clinical feedback by study clinicians. • Some participants had been told of their risk prior to study entry; others had not

The second Palomar Sky Survey

We describe the main characteristics of the second Palomar Observatory Sky Survey, currently being taken using the Oschin telescope on Palomar Mountain. The limiting magnitudes of the POSS II plates are directly comparable with those of the SERC/ESO southern surveys, at Β_j = 22.5 mag, R_c = 20.8 mag, and I_c = 19.5 mag. We discuss the main modifications made to the telescope and the photographic methods employed in the course of the survey and compare the POSS I and POSS II plates

Overview of the results of the organics PET Study of the cometary samples returned from comet Wild 2 by the Stardust mission

This presenation will provide an overview of the efforts and results produced by the Organics Preliminary Examination Team during their studies of the samples returned from comet Wild 2 by the Stardust spacecraft

The USNO-B Catalog

USNO-B is an all-sky catalog that presents positions, proper motions, magnitudes in various optical passbands, and star/galaxy estimators for 1,042,618,261 objects derived from 3,643,201,733 separate observations. The data were obtained from scans of 7,435 Schmidt plates taken for the various sky surveys during the last 50 years. USNO-B1.0 is believed to provide all-sky coverage, completeness down to V = 21, 0.2 arcsecond astrometric accuracy at J2000, 0.3 magnitude photometric accuracy in up to five colors, and 85% accuracy for distinguishing stars from non-stellar objects. A brief discussion of various issues is given here, but the actual data are available from http://www.nofs.navy.mil and other sites.Comment: Accepted by Astronomical Journa

Early fluid migration and alteration fronts in the CM chondrite Reckling Peak 17085

Reckling Peak (RKP) 17085 is a newly classified Antarctic CM chondrite that preserves a complex alteration history characterized by mild aqueous alteration (CM2.7), overprinted by a short‐lived thermal metamorphic event (heating stage III [<750°C]), and affected by low‐grade terrestrial weathering. This meteorite contains abundant Fe‐rich bands within the fine‐grained matrix, composed of micron‐scale Fe‐oxyhydroxide minerals. They are interpreted as “alteration fronts” arising due to the dissolution and transport of Fe (typically <500 μm) before being abruptly deposited. This alteration texture is relatively rare among hydrated carbonaceous chondrites, with only five reported instances to date (Murchison, Murray, Allan Hills 81002, Miller Range 07687, and Northwest Africa 5958). Evidence from RKP 17085 suggests that early aqueous alteration operated as multiple geochemically isolated microenvironments, which moved outwards from local point sources within the matrix. Low permeability fine‐grained rims on chondrules appear to have acted as barriers to fluid flow, controlling the migration of fluid across the parent body. Furthermore, the higher porosity regions within the altered fine‐grained matrix represent either void space generated by the dehydration of hydrated minerals during post‐hydration metamorphism and/or sites of ice accretion (water‐ice or C‐bearing ices) preserved within a mildly altered primitive matrix

Prefigurative politics between ethical practice and absent promise

'Prefigurative politics' has become a popular term for social movements' ethos of unity between means and ends, but its conceptual genealogy has escaped attention. This article disentangles two components: an ethical revolutionary practice, chiefly indebted to the anarchist tradition, which fights domination while directly constructing alternatives; and prefiguration as a recursive temporal framing, unknowingly drawn from Christianity, in which a future radiates backwards on its past. Tracing prefiguration from the Church Fathers to politicised re-surfacings in the Diggers and the New Left, I associate it with Koselleck's 'process of reassurance' in a pre-ordained historical path. Contrasted to recursive prefiguration are the generative temporal framings couching defences of means-ends unity in the anarchist tradition. These emphasised the path dependency of revolutionary social transformation and the ethical underpinnings of anti-authoritarian politics. Misplaced recursive terminology, I argue, today conveniently distracts from the generative framing of means-ends unity, as the promise of revolution is replaced by that of environmental and industrial collapse. Instead of prefiguration, I suggest conceiving of means-ends unity in terms of Bloch's 'concrete utopia', and associating it with 'anxious' and 'catastrophic' forms of hope

Supermassive Black Holes in Galactic Nuclei: Past, Present and Future Research

This review discusses the current status of supermassive black hole research, as seen from a purely observational standpoint. Since the early '90s, rapid technological advances, most notably the launch of the Hubble Space Telescope, the commissioning of the VLBA and improvements in near-infrared speckle imaging techniques, have not only given us incontrovertible proof of the existence of supermassive black holes, but have unveiled fundamental connections between the mass of the central singularity and the global properties of the host galaxy. It is thanks to these observations that we are now, for the first time, in a position to understand the origin, evolution and cosmic relevance of these fascinating objects.Comment: Invited Review, 114 pages. Because of space requirements, this version contains low resolution figures. The full resolution version can be downloaded from http://www.physics.rutgers.edu/~lff/publications.htm