297 research outputs found
Studi di attivita’ biologica cosmeceutica di derivati di specie della zona sud orientale amazzonica ecuadoriana
No full textThe South American Natives, Shuar and Achuar people and their ethnomedical culture constituted the background subject of the PhD research, performed both in Ecuador (Salesian Politechnic University, Quito), and in Italy (Pharmaceutical biology labs, University of Ferrara). Based on ethnomedical and ethnocosmetic tradition, Oenocarpus bataua was chosen as Amazonian plant speciessubject of the research. Cosmetic plant derivatives were selected, extracted, characterized and studied.
AIMS
The research has been focused on:
. Botanical source identification;
. Selection and extraction of plant oil native of south eastern Ecuador;
. Chemical characterization of selected oil;
. Prototype development of cosmetic formulations employing Oenocarpus bataua oil;
. Bioactivity assays regarding cosmetic applications;
. Testing of alternatives extraction methods adequate to rural areas;
. ECOCERT cosmetic prototypes;
. GC-MS analysis of non-saponifiable fraction of O. bataua;
. Oil purification studies by supercritical fluids;
. Chemical and physical stability of ECOCERT cosmetic prototypes.
RESULTS
Oenocarpus bataua derivatives have potential cosmetic applications, in line with Natives Ecuadorian ethnocosmetic traditions. The oil extracted from the date pulp was chemically characterized and it showed a very similar composition to the olive oil. The extraction method does not influence significantly the oil composition and quality. Moreover the oil non-saponifiable fraction was investigated, together with the polar fraction. Cosmetic features were also studied; the O. bataua oil showed a high moisturizing property, while a low performance was recorded for cutaneous elasticity. Furthermore, 14 cosmetic products were developed and 3 emulsion products certifiable according to ECOCERT standards. The chemical and physical stability gave good results as well as the microbiological one achieved with preservatives permitted by the ECOCERT standards.
CONCLUSIONS
Many Amazonian species have a widespread ethnocosmetic potential. The studied species allowed us to isolate and chemically characterize the lipid fraction, one of the most interesting. The O. bataua oil showed a good moisturizing property and allows to produce diverse cosmetic formulations. In particular, the prototypes obtained following the ECOCERT standards have an important potential application for development of eco-friendly cosmetic supply chain from Amazonian origin
La questione del dialetto in Giuseppe Lombardo Radice
No full textFin dall’Unità, la questione linguistica costituisce in Italia un tema di fondamentale importanza nel processo di scolarizzazione-nazionalizzazione. A lungo rifiutato nella scuola come lingua 'cattiva' e 'imbrattante', è solo dai primi decenni del Novecento che il dialetto acquista nelle aule una dimensione nuova. Fra i principali sostenitori di questa svolta è Giuseppe Lombardo Radice, autore, in particolare, dei programmi per la scuola elementare del 1923. Il saggio ne ricostruisce il pensiero in materia e le novità da lui introdotte sul piano didattico
Characterization of the role of some members of the GH3 family of rice (Oryza sativa, L.) in the development of the primary root
No full textopenDurante questo progetto di tesi si è cercato di capire l’effetto delle citochinine nelle varietà di riso italiane Baldo e Vialone Nano, che presentano comportamento opposto, rispettivamente tollerante e sensibile, allo stress salino, e di identificare possibili geni candidati che possano aumentare la tolleranza allo stress salino, andando poi ad osservare il loro effetto sull’organismo modello A. thaliana.
All’inizio si è cercato di capire l’effetto di citochinine (trans-zeatina riboside, tRZ) e NaCl sulla crescita delle due varietà di riso, osservando come effettivamente tRZ diminuisca la lunghezza media della radice, mentre il sale influenzia solo Vialone Nano.
Dopo questo risultato, ci si è concentrati sui geni che sembrano regolare l’accrescimento della radice andando a legare in maniera irreversibile l’auxina: la famiglia di GH3. Per fare questo si è osservato il fenotipo di crescita di piante WT e gh3.17 o gh3.5 di A. thaliana. Si è paragonata la lunghezza della radice in condizioni normali ed esposte a CKs, osservando come la pianta WT risulti più corta, mentre le mutanti risultino insensibili alla condizione.
Dopo questa conferma, dove sia riso che pianta modello rispondono in maniera uguale, si è osservato il profilo di espressione genica dei geni candidati: OsGH3.8, OsGH3.9 e OsGH3.11, da piante di Vialone Nano in condizioni di controllo, NaCl e CKs. Dai risultati si vede che il sale diminuisce la produzione dei geni OsGH3.9 e OsGH3.11 mentre la tRZ sembra ridurre solo OsGH3.9. OsGH3.8 invece non sembra essere influenzato, ma dati gli errori alti sarebbe da eseguire nuovamente l’analisi per ottenere risultati più solidi. Questi risultati sono in contrasto con la letteratura trovata, possono essere spiegati con fenomeni di fluttuazione nelle tempistiche delle Cks o ai ritmi circadiani della pianta.
Infine, si sono trasformate le piante di Arabidopsis WT e gh3.17 con il vettore pGRHYG-35S-OsGH3.9-YFP creato per la selezione in batteri e piante. Le piante sono tuttora in fase di selezione. Al termine, avendo ottenuto i semi T2 omozigoti, si potrà osservare il fenotipo di overespressione e di complementazione.
Per concludere, questo lavoro di tesi ha cercato di comprendere il nesso che è presente tra le Cks e la risposta della pianta, trovando che è presente una similarità tra riso e Arabidopsis. Inoltre, l’analisi di espressione dei geni candidati della famiglia di GH3 apre alla possibilità di capire il loro ruolo nell’allungamento della radice; infatti, nonostante la down regolazione non prevista, nuovi studi possono essere svolti per identificare le anomalie e trovare un nuovo meccanismo che riesca a spiegare anche queste incongruenze, Infine, la complementazione e overespressione per ottenere piante mutanti possono porre le basi per un’analisi dell’effetto dei geni selezionati sulla resistenza allo stress salino e sul meccanismo d’azione
On the relationship between experimental and numerical modelling of gravel-bed channel aggradation
No full textThis communication explores the use of numerical modelling to simulate the
hydro-morphologic response of a laboratory flume subject to sediment overloading. The numerical
model calibration was performed by introducing a multiplicative factor in the Meyer–Peter and Müller
transport formula, in order to achieve a correspondence with the bed and water profiles recorded
during a test carried out under a subcritical flow regime. The model was validated using a second
subcritical test, and then run to simulate an experiment during which morphological changes made
the water regime switch from subcritical to supercritical. The “relationship” between physical and
numerical modelling was explored in terms of how the boundary conditions for the two approaches
had to be set. Results showed that, even though the first two experiments were reproduced well,
the third one could not be modeled adequately. This was explained considering that, after the switch
of the flow regime, some of the boundary conditions posed into the numerical model turned out to be
misplaced, while others were lacking. The numerical modelling of hydro-morphologic processes
where the flow regime is trans-critical in time requires particular care in the position of the boundary
conditions, accounting for the instant at which the water regime changes
Letture gramsciane di Giuseppe Lombardo Radice (II parte)
No full textIn Gramsci’s intellectual development is not a place on the periphery is occupied by the figure of Lombrado Root. Prominent character of pedagogy idealism and importer in Italy, activist of instances (even American), socialist “romantic, sentimental, unscientific.” Lombardo Radice was a careful student of the drama of the South and Gramsci was always very interested in the work of the Sicilian and there are many similarities (apparent) between the two intellectuals: 1) the focus on popular culture, 2) the combination between educational and political problems, and 3) the reference to the figure of Leonardo and other similarities yet. The author has done a thorough research work and significant
A 45Gb/s PAM-4 transmitter delivering 1.3Vppd output swing with 1V supply in 28nm CMOS FDSOI
No full textA low-noise programmable-gain amplifier for 25 Gb/s multi-mode fiber receivers in 28nm CMOS FDSOI
No full textA High-Swing 45 Gb/s Hybrid Voltage and Current-Mode PAM-4 Transmitter in 28 nm CMOS FDSOI
No full text— Pushed by the ever-increasing demand of high-speed
connectivity, next generation 400 Gb/s electrical links are targeting
PAM-4 modulation to limit channel loss and preserve
link budget. Compared to NRZ, a higher amplitude is desirable
to counteract the 1/3 reduction of PAM-4 vertical eye opening.
However, linearity is also key, and PAM-4 levels must be precisely
spaced to preserve the horizontal eye opening advantage it has
over NRZ. This paper presents a 45 Gb/s PAM-4 transmitter
able to deliver a very large output swing with enhanced linearity
and state-of-the-art efficiency. Built around a hybrid combination
of current-mode and voltage-mode topologies, the driver is
embedded into a 4-taps 5-bits feed-forward equalizer (FFE),
and allows tuning the output impedance to ensure good source
termination. Implemented in 28 nm CMOS FDSOI process,
the full transmitter includes a half-rate serializer, duty-cycle
correction circuit, >> 2 kV HBM ESD diodes, and delivers a
full swing of 1.3 Vppd at 45 Gb/s, while drawing only 120 mA
from 1 V supply. The power efficiency is ∼ 2 times better than
previously reported PAM-4 transmitter
Two dimensional correlation Raman spectroscopy of perfluoropolyethers: Effect of peroxide groups
No full textPerfluoropolyethers (PFPEs) have been investigated with Raman spectroscopy and density functional theory (DFT) calculations. The two dimensional correlation spectroscopy (2DCOS) approach has been applied to a set of PFPEs containing different concentrations of peroxide (-OO-) groups, thus allowing to eval-
uate the effect on the Raman spectra due to the presence of oxygen–oxygen bonds in the molecular structure. Careful analysis of the vibrational normal modes obtained with DFT calculations supports the detailed interpretation of the 2DCOS maps
La questione del dialetto in Giuseppe Lombardo Radice
No full textSince Unification in 1861, the linguistic issue has been in Italy a topic of fundamental importance in the schooling-nationalization process. For a long time refused in school and considered as a “bad” and “dirty” language, it is only since the first decades of the twentieth century that dialect acquires a new dimension in the classroom. Among the main supporters of this new development is Giuseppe Lombardo Radice, author, in particular, of the programmes for elementary school of 1923. The essay reconstructs his thought on the matter and the new elements he introduced in the didactic field
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