117,874 research outputs found
Cocaine-induced liver disease in the European eel, Anguilla anguilla.
No full textCocaine is a potent psychostimulant and highly addicting drug, causing hepatotoxicity in humans, laboratory animals and fish1. Due to the worldwide use of cocaine, it is detected in surface waters2; despite its low concentrations, cocaine induces toxic effects in the European eel3,4. In this study, the effect of cocaine on
the liver of the European eel was evaluated. A stock solution of 0.006 mg/mLcocaine free-base in ethanol was prepared. Male silver eels were exposed for fifty days to 20 ng/ Lof cocaine; untreated control, vehicle control and two post-exposure recovery groups (exposed to cocaine and then deprived of it and only exposed to tap following parameters were evaluated: liver morphology; cytochrome oxidase (COX) activity, as a marker of oxidative
metabolism5; caspase-3 activity, as a marker of apoptosis activation6; GRP78 expression, as a marker of the unfolded protein response7; blood glucose level, as a marker of stress8; serum levels
of alanine aminotransferase (ALT) and C-reactive protein (CRP), markers of liver injury8,9. In the exposed eels, loss of parenchymal cells and lipid content, and necrotic areas were observed. COX and caspase-3 activities, GRP78 expression, blood glucose level, ALT and CRP levels increased. In the post-exposure recovery eels COX
returned to control values, caspase-3 activity was lower whereas GRP78 expression, blood glucose level, ALT and CRP levels were higher than controls. These results show that even low cocaine concentrations
affect the eel liver, suggesting potential impact on the survival of this species.
References
1. Arinç E, Bozcaarmutlu A. J Biochem Mol Toxicol 2003;17:169-76.
2. Rosi Marshall EJ, et al. J Hazard Mater 2015;282:18-25.
3. Capaldo A, et al. Sci Tot Environ 2018;640-641:862-73.
4. Capaldo A, et al. Ecotoxicol Environ Saf 2019;169:112-9.
5. Lionetti L, et al. Cell Mol Life Sci 2004;61:1366-71.
6. Brentnall M, et al. BMC Cell Biol 2013;14:32.
7. Kaufman RJ. Genes & Devel 1999;13:1211-33.
8. Banaee M, et al. Pest Biochem Physiol 2011;99:1-6.
9. Giannini EG, et al. CMAJ 2005;172:367-79
La Catena del Valore
No full textAttività primarie e di supporto; la catena del valore della Sony Corporation; la catena del valore come strumento di analisi interna; collegamenti verticali e sistema del valore; dal sistema alla costellazione del valore
La Curva di Esperienza
No full textLa curva di esperienza; fattori che possono portare alla riduzione dei costi in funzione dell'accumulazione di esperienza; implicazioni per la strategia
Le Strategie Competitive
No full textleadership di costo; differenziazione; focalizzazione; economie di scala; l'internazionalizzazione dell'economia
Alleanze Strategiche
No full textQuesto lavoro propone un modello interpretativo delle alleanze strategiche che utilizza due dimensioni di classificazione, volte ad esplicitare, rispettivamente, le interdipendenze esistenti tra le organizzazioni coinvolte e l¿oggetto delle relazioni. Dopo aver esaminato le singole categorie di alleanze individuabili lungo ciascuna dimensione, esso perviene ad una mappa bidimensionale, mostrandone la capacità di inquadrare i lineamenti fondamentali e i percorsi evolutivi delle diverse fattispecie relazionali da una prospettiva knowledge-based. Dall¿angolo visuale del ricercatore, il modello qui avanzato intende stimolare la riflessione teorica sulle diverse ipotesi di collaborazione interorganizzativa e sull¿evoluzione delle conseguenti relazioni. In ambito aziendale, la mappa attori-oggetto delle relazioni si propone quale utile supporto nei processi organizzativi di sense-making che conducono a rappresentazioni mentali condivise dei connotati di fondo e delle potenzialità, tanto dei singoli accordi quanto dell¿intera rete di alleanze di un¿impresa. Sul piano strategico, inoltre, l¿approccio delineato può essere di ausilio alla costruzione e alla gestione di un portafoglio di alleanze equilibrato, ispirato da una strategia relazionale in grado di contemperare il mero accesso alla conoscenza dei partner con contenuti di apprendimento da interazione e di generazione congiunta di innovazione
It’s how widely you search and from where you get the pieces. How search scope and the origins of knowledge impact the innovative performance of R&D alliances
No full textInnovation is a fundamental source of competitive advantage, and a large literature has struggled to understand the drivers of innovation and how they should be managed to increase innovative performance (Brown and Eisenhardt, 1995). Evolutionary theorists and organizational scholars have taught us that innovation arises from the exploration of new trajectories, which in turn leads to the creation of new knowledge (Nelson and Winter, 1982; March, 1991). The new knowledge, however, typically results from novel combinations of existing pieces of knowledge obtained from multiple different, internal and external, sources (Schumpeter, 1934; Galunic and Rodan, 1998; Fleming, 2001). Based on this stylized picture of the innovation process, we argue that, in order to better understand what drives innovative performance, we need to focus both on how economic actors search for new knowledge (i.e., explore), and on the characteristics of the existing knowledge that is combined to generate innovation. In this paper we make a first step towards using the above framework for empirical research.
In doing so, we start from the assumption that firms and their innovative activities are embedded in complex interpersonal and interorganizational networks that influence innovative performance at the firm, dyad, and network levels (Kreiner and Schultz, 1993; Liebeskind et al., 1996; Capaldo, 2007). Specifically, we focus on dyadic interfirm R&D alliances (R&D alliances hereinafter), which have been shown to be a tremendous source of innovation in previous literature (Shan, Walker and Kogut, 1994; Baum, Calabrese and Silverman, 2000). However, while the drivers of innovation performance at the firm level have been examined extensively (e.g. Stuart, 2000; Sampson, 2007), little is known about the factors that influence innovative performance at the dyad level.
In an attempt to fill this gap, we focus on two relevant such factors, namely the scope of the search performed by the allied firms and the geographical and organizational origins of the knowledge resources that the participating organizations contribute to the alliance and integrate across their boundaries for the benefit of the relationship. We develop testable hypotheses about the (both separate and joint) impact of these factors on the innovative performance of R&D alliances, and we test them on a sample of 1912 R&D alliances established by ten multinationals operating in the Electric and Electronic Equipment (EEE) industry
The Dark Side of Photocatalysis: One Thousand Ways to Close the Cycle
No full textPhotocatalytic strategies have recently revolutionized the field of organic synthesis. However, while the progress has been impressive in terms of reported methodologies, less attention has been devoted to mechanistic aspects. In this regard, key to the development of efficient strategies is the recovery of the exhausted photocatalyst formed upon quenching of the excited state. This review summarizes the different ways available to turn over the photocatalyst and classifies them according to the species responsible for this step, being a reaction intermediate, a co-catalyst, a reaction partner or an electrode. Finally, an analysis of the common aspects of the described alternatives is offered, also showcasing how the tuning of the photocatalyst turn-over step can completely divert the reaction outcome
Decatungstate as Direct Hydrogen Atom Transfer Photocatalyst for SOMOphilic Alkynylation
No full textA versatile approach for the alkynylation of a variety of aliphatic hydrogen donors, including alkanes, is reported. We used tetrabutylammonium decatungstate as photocatalyst to generate organoradicals from C–H/Si–H bonds via hydrogen atom transfer. The latter intermediates underwent SOMOphilic alkynylation by methanesulfonyl alkynes to afford internal alkynes upon loss of a sulfonyl radical. The effect of different radicofugal groups on the reaction outcome was evaluated and rationalized via a combined experimental and computational approach
Alleanze strategiche e reti per la crescita e la competizione
No full textIl capitolo è organizzato come segue. Dopo aver introdotto le due fondamentali direttrici lungo le quali ci muoveremo e aver chiarito alcuni aspetti preliminari – concernenti la sovrapponibilità dei diversi obiettivi della collaborazione, la natura processuale e co-evolutiva delle alleanze e i rischi di fallimento connaturati ad esse – procederemo all’esposizione dei più noti criteri di classificazione degli accordi interimpresa. Esamineremo poi in dettaglio le differenti spiegazioni delle scelte di collaborazione – e, dunque, le ragioni, i vantaggi e i rischi di tali scelte – secondo le principali prospettive teoriche emerse in letteratura, soffermandoci in particolare sulla spiegazione offerta dalla recente visione knowledge-based della collaborazione.
Il seguito del capitolo sarà dedicato all’analisi di alcune rilevanti specificità delle relazioni di collaborazione finalizzate allo sviluppo di innovazione tecnologica e all’approfondimento delle principali problematiche concernenti le reti di imprese. A tale ultimo proposito, ci soffermeremo sul concetto di impresa centrale e sulle capacità relazionali che la stessa è chiamata a sviluppare per svolgere con successo il ruolo di centro strategico in una rete di partner. Infine, tireremo le fila dell’analisi svolta approfondendo le relazioni esistenti tra collaborazione interimpresa, successo e sostenibilità del vantaggio competitivo, in un’ottica squisitamente resource-based, per poi mostrare come l’analisi dei processi di collaborazione tra imprese possa mettere in discussione alcuni fondamentali argomenti della stessa resource-based view, e proporre i connotati fondamentali di una “visione relazionale” del vantaggio competitivo
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