1,721,094 research outputs found
Plastica D'A_mare
No full textUNICAM, su iniziativa dell'Associazione Culturale Biologi Nutrizionisti e della Scuola di Architettura e Design promuove un bando per un contest al fine di sensibilizzare la comunità Unicam e l'opinione pubblica sul grave problema della plastica nel mare e dei suoi effetti nefasti all'interno degli equilibri dell'ambiente marino.
L'iniziativa mira al massimo coinvolgimento della comunità universitaria, degli studenti e del personale nell'attività di promozione e valorizzazione del brand Unicam e della sua immagine nel territorio come Ateneo sostenibile ed attento alle problematiche ambientali.
La partecipazione è limitata esclusivamente agli studenti ed al personale Unicam.
Il concorso, che si articola in due sezioni, si concluderà con la premiazione dei primi due classificati di entrambe le sezioni.
L'iniziativa è svolta con il coinvolgimento della RUS (Rete delle Università per lo Sviluppo sostenibile) come esempio di buone pratiche
Rendere visibile l'invisibile ovvero esperienze didattiche al microscopio
No full textQuali sono le conoscenze necessarie a costruire una competenza minimale relativa al funzionamento del proprio corpo e alla sua cura? Come integrare le conoscenze già acquisite dal bambino in famiglia? Qual è il ruolo dei tanti input informativi extra-scolastici e come trattarli? Quale formazione è necessaria per il docente, perché possa svolgere un ruolo di mediazione culturale? Il testo costituisce uno sforzo di dare risposte a Quest'ordine d'interrogativi, ricorrendo a una metodologia interdisciplinare, non solo sul piano della collaborazione tra Autori di formazione diversa, ma anche nella ricerca condotta insieme a insegnanti e bambini all'interno della scuola.
Nel libro sono identificabili alcune piste di lettura: una è relativa alle metodologie di insegnamento in campo scientifico, in cui vengono offerte e commentate sia strategie di rilevazione dei saperi ingenui, sia proposte d'intervento del docente disciplinare; una seconda si riferisce al ruolo docente, in cui l'insegnante è considerato nella duplice e sinergica veste di esperto disciplinare e operatore culturale; una terza ha a che fare con prospettive linguistiche, giacché i processi di insegnamento-apprendimento, anche quando non gravano direttamente sull'area linguistica, si basano su tale tipo di competenze; una quarta con le strategie di ricerca scientifica, in cui l'osservatore è una componente essenziale per definire l'evento e un elemento necessario alla struttura della teoria; una quinta con l'organizzazione di esperienze nel laboratorio scientifico; una sesta delinea un possibile percorso dal 'visibile all'invisibile; l'ultima è specificamente legata al tema della digestione, processo preso a modello in quanto coinvolge il corpo nella sua interezza
Effects of 4-nonylphenol on hepatic gene expression of peroxisome proliferator-activated receptors and cytochrome P450 isoforms (CYP1A1 and CYP3A4) in juvenile sole (Solea solea)
Full text linkThe objective of the present study was to investigate the modulatory effects of the xenoestrogen 4-nonylphenol (4-NP) on hepatic peroxisome proliferator-activated receptor (PPAR) α and β gene expression patterns in relation to the detoxification pathways mediated by cytochrome P450 isoforms (CYP1A1 and CYP3A4). Waterborne 4-NP-induced effects were compared with those of 10−8 M 17β-estradiol (E2) by using in vivo dose–response experiments carried out with juvenile sole (Solea solea). Compared to the controls, significantly higher levels of PPARα mRNAs were found in fish treated with E2 or 4-NP (10−6 M) 3 d after exposure; the highest dose of 4-NP also caused up-regulation of retinoid X receptor α (RXRα) transcript levels. On the contrary, PPARβ gene expression was not modulated by E2 or 4-NP. Our data show that 4-NP-induced PPARα mRNA levels coincide with suppression of CYP1A1 and CYP3A4 expression similarly to E2. The results from these in vivo studies suggest the presence of cross-talk between nuclear receptor-mediated signaling pathways and PPARα that may result in modulation of CYP450 isoforms expression following 4-NP treatment in sole liver
TOXICOLOGICAL APPLICATION OF LOGGERHEAD SEA TURTLE (CARETTA CARETTA) CULTURED ERYTROCYTES
No full textJuvenile loggerhead turtles (Caretta caretta) can be considered a good indicator species for monitoring environmental contaminants that can mimic steroid hormone signaling. However, due to the legal constraints of their endangered status, the impact of environmental pollutants on nuclear steroid hormone receptor-mediated signaling is still poorly investigated in sea turtles. Here we describe the use of an in vitro toxicity testing for evaluating the effects of different environmental exogenous estrogens on the expression of C. caretta estrogen receptor (ER). In this regard, primary cultures of erythrocytes were exposed to increasing concentrations of 4-nonylphenol (4-NP), Diisodecyl phthalate (DiDP) and Tri-m-cresyl phosphate (TMCP) for 48 h. A real time quantitative PCR assay, optimized in the loggerhead turtles red blood cells (RBCs), showed significantly increased levels of ER mRNA in a dose-dependent manner after 48 h exposure to both 4-NP and TMCP. Interestingly, the dosage-dependent effects of DiDP on ER expression were opposite in comparison to that obtained following exposure to the other tested compounds. Our work demonstrates the validity of cultured erythrocytes in sea turtles suggesting that this approach could provide an understanding of the impact of environmental contaminants on an endangered species in a minimally invasive manner
Partial cloning, tissue distribution and effects of epigallocatechin gallate on hepatic 3-hydroxy-3-methylglutaryl-CoA reductase mRNA transcripts in goldfish (Carassius auratus).
No full textEpigallocatechin gallate (EGCG), the major active component of the green tea, has recently been found to inhibit 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCoAR) activity in vitro and to modulate lipogenesis in vivo. In this studywe have evaluated the effects of short-term in vivo exposure to EGCG (6 μg g−1BWor 9 μg g−1BW) on hepatic HMGCoAR gene expression of goldfish (Carassius auratus). We initially characterized a partial sequence of goldfish HMGCoAR suggesting that the obtained fragment shares high similarity (N92%) with other fish HMGCoAR sequences. Further, the HMGCoAR transcript was detected in all goldfish tissues (except muscle) but primarily in liver, brain and gonads; on the contrary, low expression levels were found in intestine, heart, gill, and kidney. Both EGCG doses significantly decreased hepatic HMGCoAR mRNA levels 180 min postinjection. HMGCoAR was also significantly down-regulated at 90 min after injection in fish treated with the highest dose of EGCG. Our results demonstrate that hepatic HMGCoAR gene expression is acutely responsive to short-term EGCG exposure in goldfish. This finding suggests a potential role of EGCG in transcriptional regulation of the rate-limiting enzyme in cholesterol synthesis
Effects of tributyltin on retinoid X receptor gene expression and global DNA methylation during intracapsular development of the gastropod Tritia mutabilis (Linnaeus, 1758)
No full textThe tributyltin (TBT)-mediated induction of imposex in marine snails is considered a common mechanism of endocrine disruption through the retinoid X receptor (RXR)-dependent pathway. However, there is evidence that regulation of RXR also relates to metabolic processes, differentiation, apoptosis, and embryonic development, playing a key role in molluscan neuronal differentiation and organogenesis. In this regard, very little is known about the gastropod Tritia mutabilis especially in relation to the effects of TBT exposure during intracapsular embryonic development. In this study, we have investigated the RXR expression fold changes of T. mutabilis encapsulated embryos exposed to different concentrations (10−10 to 10−12 M) of TBT up to 10 days of treatment. We demonstrate that RXR is sequentially expressed during development and that exposure to the lowest and highest TBT doses induces time-dependent changes in RXR gene transcription. We also show that TBT treatment is associated with global DNA demethylation and reduced DNA-methyltransferase I (DNMT1) expression and activity levels. Overall, our data indicate that RXR has important functions during the early stages of T. mutabilis embryo development and is involved in mediating the potential epigenetic alterations induced by TBT exposure
Changes in expression of microRNA potentially targeting key regulators of lipid metabolism in primary gilthead sea bream hepatocytes exposed to phthalates or flame retardants
No full textMetabolism disrupting chemicals (MDCs) belong to the group of endocrine-disrupting chemicals (EDCs) and are known to affect endocrine and metabolic functions of liver. There is growing evidence that MDCs may also act modulating the expression levels of micro ribonucleic acids (miRNAs) and thus affecting post-transcriptional expression of hundreds of target genes. Herein, we used a gilthead sea bream in vitro hepatocyte model for analyzing the effects of an exposure to phthalates (i.e. DiDP) or flame retardants (i.e.TMCP) on the expression levels of three miRNAs (i.e. MiR133, MiR29 and MiR199a) selected on the basis of their regulatory roles in signaling pathways related to lipid metabolism. Following computational identification of genes that are regulated by the selected miRNAs, we identified six miRNA targets to be tested in differential gene expression analysis. To determine whether lipid metabolism was altered we have also measured the intracellular total cholesterol and triglyceride levels. The results of our study show that DiDP/TMCP exposure leads to a general decrease in the expression profiles of each miRNA leading to a corresponding upregulation of almost all their putative targets. In addition, these findings were also associated to a corresponding increased hepatocellular lipid content. The present study thus contributes to support the importance of these small molecules in regulating MDC-induced expression of genes associated with hepatic lipid metabolism and highlights the need for more toxicological studies examining miRNAs transcriptional regulatory networks controlling metabolic alterations in fish
Fat body involvement in the plasma vitellogenin changes during recovery phase in Rana esculenta
No full textThe role of fat body in the reproductive physiology of Rana esculenta was investigated during recovery phase. Changes in the ovarian weight, plasma vitellogenin (VTG) and estradiol-17-beta-levels were analyzed in intact frogs, in those without fat bodies (FBD) and in males and females injected with estradiol-17-beta. The ovarian weight decreased by day 28 in intact females but not in FBD animals. At the same time plasma VTG titers sharply decreased on day 21 in intact animals, but no significant changes were found in FBD females. Male frogs never synthetize VTG; they do so, however, after injection of estradiol-17-beta, FBD males showed higher VTG titers than intact males. The results obtained in vitro showed a sharp decrease of vitellogenin added in the medium of cultured fat body. Thus, the in vivo and in vitro results allow us to suggest that fat bodies metabolize plasma vitellogenin, at least during recovery phase; therefore ovarian growth may depend on an interplay among hepatic vitellogenin synthesis, fat body metabolic activity and ovarian uptake
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