2,528 research outputs found

    Augmented Sparse Reconstruction of Protein Signaling Networks

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    The problem of reconstructing and identifying intracellular protein signaling and biochemical networks is of critical importance in biology today. We sought to develop a mathematical approach to this problem using, as a test case, one of the most well-studied and clinically important signaling networks in biology today, the epidermal growth factor receptor (EGFR) driven signaling cascade. More specifically, we suggest a method, augmented sparse reconstruction, for the identification of links among nodes of ordinary differential equation (ODE) networks from a small set of trajectories with different initial conditions. Our method builds a system of representation by using a collection of integrals of all given trajectories and by attenuating block of terms in the representation itself. The system of representation is then augmented with random vectors, and minimization of the 1-norm is used to find sparse representations for the dynamical interactions of each node. Augmentation by random vectors is crucial, since sparsity alone is not able to handle the large error-in-variables in the representation. Augmented sparse reconstruction allows to consider potentially very large spaces of models and it is able to detect with high accuracy the few relevant links among nodes, even when moderate noise is added to the measured trajectories. After showing the performance of our method on a model of the EGFR protein network, we sketch briefly the potential future therapeutic applications of this approach.Comment: 24 pages, 6 figure

    Sustainable Recycling of Insoluble Rust Waste for the Synthesis of Iron-Containing Perovskite-Type Catalysts

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    Insoluble rust waste from the scraping of rusted iron-containing materials represents a cheap, eco-friendly, and available source of iron. LaFeO3 perovskite-type powders were successfully prepared by solution combustion synthesis using rust waste from an electricity transmission tower manufacturer. Solution combustion synthesis enabled introduction of this insoluble iron precursor directly into the final product, bypassing complex extraction procedures. Catalytic activity in the propylene oxidation of the waste-derived LaFeO3 with stoichiometric Fe/La ratio was almost identical to the commercial iron nitrate-derived LaFeO3 , thus demonstrating the viability of this recycling solution. The amount of waste iron precursor was varied and its effect on the powder properties was investigated. A lesser stoichiometric amount of precursor produced a LaFeO3 -La2O3 binary system, whereas a higher stoichiometric amount led to a LaFeO3 -Fe2O3 binary system. Catalytic activity of iron-rich compositions in the propylene oxidation was only slightly lower than the stoichiometric one, whereas iron-poor compositions were much less active. This eco-friendly methodology can be easily extended to other iron perovskites with different chemical compositions and to other iron-containing compounds

    Sustainable Chemistry: Reversible reaction of CO2 with amines

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    The reaction of primary and secondary amines with CO2 has been successfully leveraged to develop sustainable processes. In this article, we review specific examples that use the reversible reaction of CO2 with amines to synergistically enhance reaction and recovery of the products.  The three cases of interest highlighted herein are:  (i) reversible protection of amines, (ii) reversible ionic liquids for CO2 capture and chemical transformations, and (iii) reversible gels of ethylene diamine. These examples demonstrate that the reversible reaction of amines with CO2 is one of the tools in the sustainable technology’s toolbox.

    Effect of lairage duration on some blood constituents and beef quality in bulls after long journey

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    Al fine di contribuire alla individuazione di un tempo adeguato di sosta al termine di un lungo trasporto, sono stati esaminati gli effetti di diverse durate della sosta al macello su alcuni parametri ematici e sulla qualit\ue0 della carne in bovini maschi interi sottoposti a viaggi commerciali di lunga durata. Lo studio \ue8 stato condotto su 39 vitelloni Limousine allevati nelle medesime condizioni presso un unica azienda situata nelle vicinanze di Saragoza (Spagna). Gli animali sono stati esaminati al termine di 5 viaggi commerciali dopo un tragitto di 2500 km, presso lo stabilimento di macellazione \u201cSan Giorgio\u201d di Gangi (Palermo). Il tempo di trasporto \ue8 stato pari a ore 53,6\ub110,9. Per i soggetti della prima, della terza e della quinta consegna, la durata della sosta \ue8 risultata compresa tra 24 e 36 ore, con una media pari a 31 ore (gruppo \u201cShort Lairage\u201d), mentre nella terza e nella quinta consegna la sosta \ue8 stata pari, rispettivamente, a 57 e 59 ore (gruppo \u201cLong Lairage\u201d). I risultati relativi all\u2019esame emocromo-citometrico, hanno evidenziato un effetto significativo (P>0,001) della durata della sosta pre-macellazione sia sul numero dei leucociti che sulle piastrine. La durata della sosta non ha mostrato avere nessun effetto significativo su globuli rossi, emoglobina ed ematocrito anche se l\u2019analisi della varianza per misure ripetute ha mostrato che, indipendentemente dalla durata della sosta, l\u2019ematocrito \ue8 variato significativamente dal momento dello scarico a quello della macellazione, aumentando durante tale periodo. L\u2019analisi statistica effettuata sui parametri ematochimici ha evidenziato un effetto significativo (P>0,05) della durata della sosta solo sull\u2019enzima CK e sul cortisolo. L\u2019enzima CK ha mostrato un incremento nel gruppo \u201cShort Lairage\u201d (33,2% vs 14,3%) mentre il Cortisolo ha mostrato una diminuzione nel gruppo \u201cLong Lairage\u201d (36,3% vs 3,8%). La durata della sosta non ha influenzato significativamente (P>0,05) l\u2019incidenza di lesioni lievi e gravi registrate sulle carcasse. Per quanto concerne la qualit\ue0 della carne, la durata della sosta ha influenzato significativamente il pHu, risultato pi\uf9 elevato (P>0,01) nel muscolo dei soggetti del gruppo \u201cLong Lairage\u201d; la luminosit\ue0 a 24h post mortem \ue8 risultata significativamente pi\uf9 elevata (P>0,05) nei soggetti del gruppo \u201cShort Lairage\u201d rispetto a quelli del gruppo \u201cLong Lairage\u201d, mentre gli indici del rosso e del giallo sono risultati essere maggiori in quest\u2019ultimo gruppo. Il calo peso dopo cottura \ue8 risultato significativamente minore (P>0,01) nel gruppo \u201cShort Lairage\u201d, lo stesso gruppo \u201cShort Lairage\u201d ha fatto registrare carni significativamente pi\uf9 tenere (P>0,01). Dai risultati ottenuti emerge come la durata della sosta pre-macellazione dopo un trasporto di lunga durata pu\uf2 influenzare il quadro ematologico e la qualit\ue0 della carne. Nel complesso \ue8 emerso che prolungare la sosta oltre le 36 ore non provoca alcun beneficio per il benessere dell\u2019animale e rischia di peggiorare la qualit\ue0 della carne. Nel caso di trasporti cos\uec lunghi come quelli esaminati sarebbe opportuno una migliore organizzazione della logistica al fine di ridurre il tempo di attesa degli animali prima della macellazione.With the aim to contribute to determine an adequate resting time for cattle after long transportation, the effects of different lairage time on some haematic parameters and meat quality of bulls subjected to long commercial journeys were investigated. Thirty-nine Limousine bulls supplied by one farm located near to Saragoza (Spain) were examined after 5 consignments at the final destination, after a journey of 2.550 km, of the \u201cSan Giorgio\u201d abattoir (Palermo, Italy). Transport time was of 53.6 \ub1 10.9 h; lairage duration for bulls of the 1st, 3rd and 5th consignments was of 31 h on average (\u201cShort Lairage\u201d group), whereas, for those of the 2nd and 4th consignments, was of 59 and 57 h, respectively (\u201cLong Lairage\u201d group). As regards the blood cell counts, data showed a significant effect (P< 0.001) of the lairage duration on leukocyte and platelet counts. No significant effect was observed for erythrocyte count, haemoglobin and hematocrit in relation to the lairage duration, even if the repeated measure analysis of variance showed that, irrespectively to the lairage duration, the hematocrit increased significantly from the unloading to the slaughter. Haematological parameters showed a significant (P< 0.05) effect of the lairage time only on CK and Cortisol. CK enzyme showed an increase in the \u201cShort Lairage\u201d group (33.2% vs. 14.3%) whereas, Cortisol showed a decrease in the \u201cLong Lairage\u201d group (36.3% vs. 3.8%). The different lairage duration did not significantly (P> 0.05) affect the incidence of slight and severe bruises of carcass. As regard meat quality, lairage duration has significantly influenced the pHu which was higher (P< 0.01) in the muscle of the animals of the \u201cLong Lairage\u201d group, the luminosity at 24h post mortem which was significantly higher (P< 0.05) in animals of the \u201cShort Lairage\u201d group and the red and yellow indices which were higher in the \u201cLong Lairage\u201d group. \u201cShort Lairage\u201d group showed lower (P< 0.01) value of cooking loss and higher (P< 0.01) value of tenderness. Data show that pre-slaughter lairage duration after a long transport may influence the blood parameters as well as meat quality. On the whole, the increase of the lairage duration over 36 h does not determine any benefit for the animal well-being whereas it can cause a reduction of the beef quality. For so long transports, it should be better an adequate organization of the facilities in order to diminish the pre-slaughter lairage duration

    Nero Siciliano pig: analysis of coat colour affecting genes and perspectives for breed traceability

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    Nero Siciliano is an autochthonous pig breed reared in the internal areas of Sicily region mainly in the Nebrodi mountains. The animals are usually completely black with a dorsal stripe but a few present white portions mainly in the face or in the fore legs. According to the increased requests of the consumers for local and typical products, meat and cured products of Nero Siciliano pigs are sold at a higher price compared to other pig products. Thus there is the need to guarantee both consumers and the whole Nero Siciliano production chain from possible frauds. The identification and/or use of DNA markers that may be breed specific could make it possible to establish breed traceability and authenticity systems for the products obtained with this local pig breed. Mutations in coat colour genes have been already described and utilized for porcine breed traceability. In this trial we analysed mutations identified in two coat colour affecting genes, the melanocortin 1 receptor (MC1R) and the v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene (KIT), with the aim to characterize the Nero Siciliano pig at these loci and provide useful information to establish authenticity systems for the meat products. Fragment analysis of PCR products and PCRRFLP methods were used to identify the polymorphic sites that can distinguish known alleles at these two loci in 104 Nero Siciliano pigs. Four alleles were identified at the MC1R locus: the two dominant black alleles (ED2, frequency of 0.673; ED1, 0.187), allele EP (0.106) and the recessive e allele (0.034). The results showed that different alleles were observed at this locus, polymorphisms at the MC1R gene cannot be used for product traceability and authentication of this breed. As regards the KIT locus, all the animals were negative for the splice site mutation of exon/intron 17. Thus, meat of Nero Siciliano pigs can be distinguished from meat of white pigs that are positive for this polymorphic site. Moreover, at this locus only 4 pigs showed the 3'-5' duplication breakpoint suggesting that they carried the Ip allele. Studies are in progress to evaluate the effect of this allele on coat colour phenotypes in Nero Siciliano pig

    Strontium and iron-doped barium cobaltite prepared by solution combustion synthesis: exploring a mixed-fuel approach for tailored intermediate temperature solid oxide fuel cell cathode materials

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    Ba0.5Sr0.5Co0.8Fe0.2O3–δ (BSCF) powders were prepared by solution combustion synthesis using single and double fuels. The effect of the fuel mixture on the main properties of this well-known solid oxide fuel cell cathode material with high oxygen ion and electronic conduction was investigated in detail. Results showed that the fuel mixture significantly affected the area-specific resistance of the BSCF cathode materials, by controlling the oxygen deficiency and stabilizing the Co2+ oxidation state. It was demonstrated that high fuel-to-metal cations molar ratios and high reducing power of the combustion fuel mixture are mainly responsible for the decreasing of the area-specific resistance of BSCF cathode materials. Moreover, a new metastable monoclinic phase with Ba0.5Sr0.5CO3 composition was discovered in the as-burned BSCF powders, enlarging the existing information on the BSCF phase formation mechanis

    Leachate analyses of volcanic ashes from Stromboli volcano: A proxy for the volcanic gas plume composition?

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    Many volcanoes show a change in chemical composition of the gas phase prior to periods of eruptive activity. Fine‐grained tephra erupted from active vents and transported through volcanic plumes can adsorb, and therefore rapidly scavenge, volatile elements such as sulfur, halogens, and metal species in the form of soluble salts adhering to ash surfaces. Analysis of such water‐soluble surface materials is a suitable supplement for remote monitoring of volcanic gases at inaccessible volcanoes. In this work, ash samples of the 2004 to 2009 eruptive activity of Stromboli volcano were sampled, leached, and analyzed for major and trace elements. Data analysis and interpretation was focused on determining the relationship between chemical composition of water‐soluble components adhering to volcanic ash and the volcano’s activity state. First results show significant temporal variations in ash leachate compositions, reflecting changes in the eruptive style of the volcano. In particular, we reveal that ash leachates S/F and Mg/Na ratios showed marked increases prior to a large‐scale explosion on 15 March 2007.PublishedD172041.2. TTC - Sorveglianza geochimica delle aree vulcaniche attiveJCR Journalreserve

    Adhesive and Rheological Features of Ecofriendly Coatings with Antifouling Properties

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    In this work, formulations of "environmentally compatible" silicone-based antifouling, synthesized in the laboratory and based on copper and silver on silica/titania oxides, have been characterized. These formulations are capable of replacing the non-ecological antifouling paints currently available on the market. The texture properties and the morphological analysis of these powders with an antifouling action indicate that their activity is linked to the nanometric size of the particles and to the homogeneous dispersion of the metal on the substrate. The presence of two metal species on the same support limits the formation of nanometric species and, therefore, the formation of homogeneous compounds. The presence of the antifouling filler, specifically the one based on titania (TiO2) and silver (Ag), facilitates the achievement of a higher degree of cross-linking of the resin, and therefore, a better compactness and completeness of the coating than that attained with the pure resin. Thus, a high degree of adhesion to the tie-coat and, consequently, to the steel support used for the construction of the boats was achieved in the presence of the silver-titania antifouling
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