493 research outputs found
Whither Critical Management and Organization Studies? For a Performative Critique of Capitalist Flows in the Wake of the COVID‐19 Pandemic
No full textZanoni, P (corresponding author), Hasselt Univ, Hasselt, Belgium.
[email protected]
Production and Characterization of Astaxanthin Nanoparticles
No full textThere is increasing interest on behalf of consumers and the food industry for the enrichment of common food with health-promoting bioactive molecules. Clinical studies have demonstrated that tangible health benefits may derive from the intake of bioactive compounds, in the prevention of dietary related pathologies such as diabetes, cancer, obesity and cardiovascular diseases. The beneficial effect is usually given by the presence in food of peculiar molecules such us carotenoids, polyphenols, polyunsaturated fatty acids and bioactive peptides, to cite a few. Unfortunately, these compounds display high susceptibility to environmental conditions such as light, extreme pH and temperature, and to standard food manufacturing processes. They can also account for undesirable flavors, colors or affect final product stability and appearance, thus rendering their presence in the product an issue rather than a useful addition. The addition of nutrients in small quantities into a food system may not significantly affect its proprieties, but the high amounts, often required to meet certain health claims and benefits, might bring to a product with a poorly acceptable sensory profile and a scarce stability. In particular, lipophilic bioactive ingredients display a major challenge. Besides their limited solubility in most of the foods and beverages, they are characterized by high susceptibility to oxidation and by a lower adsorption through the gastrointestinal tract in comparison to more hydrophilic substances, meaning a scanty bioavailability. Hence, there is a pressing need for the production of edible delivery systems or carriers that could efficiently encapsulate, protect and improve the handling of lipophilic molecules. The objective of this thesis was to develop a system suitable for the encapsulation of lipophilic molecules, capable of: a) protecting the ingredient from the surrounding environment (extreme pH, heat, UV light, oxygen); b) preserving its functionality (e.g. antioxidant activity); c) reducing the impact on the organoleptic level; d) improving the bioavailability of the encapsulated molecules. This last point in particular could be achieved by using sub-cellular delivery systems referred to as nanoparticles or nanocarriers, which may potentially enhance the transport across the intestinal wall. To this purpose, astaxanthin was chosen as a model bioactive compound. Astaxanthin is a keto-carotenoid that displays several biological activities, such as high antioxidant capacity, that may contribute to the prevention of degenerative pathologies like diabetes, cancer, cardiovascular diseases and chronic bowel disease. However, like all carotenoids it is characterized by a strong lipophilic character that makes its inclusion in many types of aqueous-based foods and beverages rather a challenge. This aspect is the main cause of its poor absorption through the human intestinal mucosae. Moreover, astaxanthin is labile to common processing conditions such as the presence of light and oxygen, extreme pH and high temperatures. For these reasons a lot of efforts have been put in these past years to find suitable solutions for its protection and manipulation. In order to develop the suitable encapsulate, in chapter 2 an emulsification and solvent-evaporation technique was used as encapsulation approach; whey proteins were selected as the matrix to envelope the core constituted by an astaxanthin-enriched oleoresin derived from Haematococcus pluvialis, a microalgae representing the main natural source of the carotenoid. The process was optimized by varying crucial parameters and the stability of the nanoparticles was tested in different conditions. This analysis highlighted a better performance of the encapsulated molecule in comparison to the starting oleoresin. Good release properties during in-vitro simulated digestion and the increase of the solubility in water were observed. In chapter 3, the study was focused on the research for plant alternative proteins as encapsulating matrices in order to satisfy the increasing interest of the consumers for substitutes of animal-deriving ingredients. This allowed to identify pea protein isolate as a valid candidate for the development of a vegetarian/vegan-allergen free nanocarrier. Finally, Chapter 4 dealt in depth with the antioxidant properties displayed by the astaxanthin nanoparticles through in vitro colorimetric assay and by the development of a cell-based assay. The encapsulates showed higher antioxidant capacity in comparison to the oleoresin. The uptake of the nanoparticles was studied in cell model systems through confocal laser microscopy and flow cytometry that indicated a probable energy-dependent mechanism
La lingua per lo studio e la formazione degli insegnanti: l’esperienza di un laboratorio di formazione
No full textThe present paper proposes some considerations deriving from an educational workshop dedicated to teachers of lower-secondary schools in the province of Forlì-Cesena. A brief description of the theoretical framework is followed by a description of how the workshop was structured, which topics were covered, the reasons behind the choice of topics and the reflections that have arisen, in order to draw some concluding remarks on this experience.Il contributo propone alcune riflessioni nate dall’esperienza di un laboratorio di formazione indirizzato agli insegnanti delle scuole secondarie di primo grado della provincia di Forlì-Cesena. Dopo una breve descrizione del quadro teorico di riferimento, si descrive la struttura del laboratorio, evidenziando gli argomenti trattati, le ragioni che hanno guidato nella scelta degli argomenti e le principali riflessioni che ne sono scaturite, per tracciare un breve bilancio conclusivo di questa esperienza
Development and Characterization of Astaxanthin-Containing Whey Protein-Based Nanoparticles
No full textAstaxanthin (ASX) is a carotenoid of great interest due to its potential health benefits. However, its use in the food, feed, and pharmaceutical fields is limited due to low bioavailability, poor stability during thermochemical treatments, susceptibility to oxidation, and poor organoleptic characteristics. The aim of this work was to develop a method to stabilize astaxanthin extracted from the microalgae Haematococcus pluvialis (H.p.) and to improve its nutritional and functional properties through nanoencapsulation. Nanoparticles (NPs) were produced by emulsification-solvent evaporation technique starting from H.p. oleoresin using whey proteins concentrate (WPC) as stabilizer. The efficiency of encapsulation was 96%. The particle size (Z-average) was in the range of 80-130 nm and the superficial charge (measured as zeta-potential) was negative (-20 to -30 mV). The stability of the NPs upon resuspension in water was assayed through a panel of stress tests, i.e., extreme pH, UV radiation, Fe3+ exposition, and heating at 65 °C, that always showed a superior performance of encapsulated ASX in comparison to oleoresin, even if NPs tended to precipitate at pH 3.5-5.5. Simulated gastroenteric digestion was conducted to study the release of ASX in physiological conditions, and showed a maximum bioaccessibility of 76%, with 75% ASX converted into the more bioavailable free form. The collected data suggest that NPs might have possible future applications as supplements for human and animal diets
Post-Diversity, Precarious Work for All: Unmaking borders to govern labour in the Amazon warehouse
No full textThis paper investigates the (un)making of borders as a form of labour governmentality in one of Amazon's warehouses in Poland. Guided by a critical theory of borders as a form of labour governmentality under global capitalism, we identify organizational practices through which socio-demographic categories traditionally deployed as principles of organizing work (e.g., gender, age, ability) are unmade: the management of deskilled labour through an algorithmic system, the non-selective hiring of workers, the enforcement of social norms of interpersonal respect and a universal system of casualized employment. Together, these practices constitute workers as undifferentiated, interchangeable and equal labour, let them compete with each other under harshly exploitative conditions, and continuously dispose of the least productive among them, keeping all in structural uncertainty. The study contributes to the critical diversity literature by showing a 'post-diversity' governmentality that rests on equality, competition and precarization of labour as a whole, rather than segregation and marginalization through an 'ideal worker' norm. This labour governmentality operates by eliciting consent from historically subordinated workers and eliminating the advantage of historically relatively privileged ones. Unmaking borders within labour inside the organization, this governmentality at the same time crucially rests on borders outside it.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: We would like to acknowledge the funding Patrizia Zanoni received from the Flemish
Research Fund (FWO), grant no. G085119N and Miłosz Miszczyński from the National Science Centre, Poland, grant no. 2019/35/B/HS4/04136.
We would like to thank our respondents, the guest editors of the special issue, the anonymous reviewers, the members of the Chair Organization Studies of the Utrecht School of Governance, the members of SEIN - Identity, Diversity & Inequality Research at Hasselt University, the participants in EGOS Sub-theme ‘Diversity and intersectionality: Struggles for recognition and redistribution in organizations and (self-)entrepreneurship’ in 2021 in Amsterdam (online) and the EGOS sub-theme ‘Re-organizing imperfections at work: negotiating power and control in employment relations’ in 2022 in Vienna for their generous feedback on previous versions of the paper. Last but not least, we thank ERA-NET CHANSE for allowing us to further build on this line of research through the Humans in Digital Logistics (HuLog) project, grant no. 101004509 (2022-2025)
Design and characterization of nanomaterials for monitoring their biological reactivity
No full textDurante il mio dottorato, ho supportato la valutazione del rischio di nanomateriali focalizzandomi sulla caratterizzazione e controllo di proprietà e comportamenti che influenzano l'esposizione e che determinano meccanismi potenzialmente pericolosi per uomo e ambiente. Attraverso sei diverse nanoparticelle divise qui in cinque casi studio, ho impostato i progetti sperimentali per misurare le proprietà intrinseche (composizione, dimensione e morfologia), le dipendenti dal sistema (aggregazione e dissoluzione nei mezzi) e le proprietà correlate alla reattività delle nanoparticelle. Tutti i nanomateriali di riferimento e commerciali sono stati selezionati come rappresentativi di un'ampia classe di componenti al fine di massimizzare l'impatto complessivo della ricerca. In una prospettiva "read-across", tali nanoparticelle sono state selezionate come rappresentative di tre diverse classi di raggruppamento: solubili (Ag, CuO e ZnO), passive (SiO2) e attive (CeO2 e TiO2).
Nel corso del lavoro ho affrontato tutti i casi di studio seguendo una caratterizzazione graduale a complessità crescente. In primo luogo, ho raccolto informazioni sulle proprietà intrinseche (dimensioni, forma, funzionalizzazione superficiale), che delineano la natura delle nanoparticelle, quindi ho disperso le nanoparticelle in mezzi (eco) tossici rilevanti, misurando le proprietà dipendenti dal sistema derivate dalle interazioni nanoparticelle / mezzo e infine, concentrandomi sull’esposizione umana, ho valutato la traslocazione delle nanoparticelle attraverso la cute umana e la mucosa orale con l’utilizzo del test ex-vivo in vitro di Franz.
La caratterizzazione fisico-chimica delle nanoparticelle nei mezzi umani e ambientali pertinenti (distribuzione dimensionale, dissoluzione statica, potenziale zeta, cinetica della sedimentazione) può supportare la valutazione dell'esposizione, mentre i risultati in-vitro possono essere trasferiti alla valutazione del rischio delle nanoparticelle. Tramite i modelli in-silico dedicati, i dati in-vitro potrebbero essere ulteriormente implementati consentendo l'estrapolazione delle correlazioni esposizione-dose-risposta utilizzabili per implementare la valutazione del rischio. Pertanto, i risultati ottenuti a supporto dell'esposizione e della valutazione dei pericoli potrebbero essere applicati nella prima fase del processo CSA.During my PhD research activity, I supported the risk assessment of nanomaterials focusing on the characterization and control of their properties that drive potentially hazardous mechanisms affecting external and internal exposure. Particularly, I considered the exposure to both human and environmental targets. Throughout six different nanoparticles here organized into five case studies, I set up the experimental designs for measuring NMs intrinsic (composition, dimension and morphology), system-dependent (aggregation and dissolution in media) and fate related properties. Both reference and commercial nanomaterials were selected as representative of a wide class of components maximizing the overall impact of the research. In a “read-across” perspective, such nanoparticles were selected as representative of three different grouping classes: soluble (Ag, CuO and ZnO), passive (SiO2) and active (CeO2 and TiO2).
I faced the case studies following a step by step characterization at increasing complexity. Firstly, I collected information on the intrinsic properties (size, shape, superficial functionalization), that outline the nanoparticles nature, then I dispersed the nanoparticles in relevant (eco)tox media, measuring the system-dependent properties derived from the nanoparticles/medium interaction and finally, moving toward the human exposure routes, I evaluated the in-vitro ex-vivo translocation through dermal or oral mucosa membranes with Franz cell tests.
The nanoparticles physiochemical characterization in relevant human and environmental media (size distribution, static dissolution, zeta potential, sedimentation kinetic) may support the exposure assessment, while the in-vitro results may be transferred to the nanoparticles hazard evaluation. By means of the dedicated in-silico models the in-vitro data could be further implemented enabling the extrapolation of exposure-dose-response correlations usable to implement the risk assessment. Thus, the obtained results in support to exposure and hazard assessment could be applied in the first step of the CSA process
ESD Robustness of AlGaN/GaN HEMT Devices
No full textWe have investigated the robustness of GaN-HEMT devices submitted to ESD events in different configurations. A good scaling of the failure current with the device width has been observed for both drain and gate TLP stresses. We have identified two failure mechanisms, related to the gate-source diode degradation and drain to gate filaments formation. Filaments formation was identified by means of emission microscopy, both while applying DC bias and during the TLP measurement itself. We have also found that the traditional TLP leakage measurement can not be used as a valid failure criterion. On the contrary, the gate-source diode measurement can provide interesting information on the device life-state
«Due fontane che di diverso effetto hanno liquore»: l’intertestualità in traduzione. Il caso ‘Zanoni’ di E. G. Bulwer-Lytton (1842)
No full textThis article deals with the all-but-forgotten literary reception of a Victorian author, Edward Bulwer-Lytton, who became famous in the nineteenth century in Italy thanks to the translations by Francesco Cusani, a famous historian of that period. Then, the author will be compared to the translator, according to the most recent studies in translational stylistics and intertextuality, focusing on the novel Zanoni (1842), translated by Cusani in 1848.L’articolo illustra la fortuna letteraria avuta dall’autore vittoriano oggi poco frequentato, Edward Bulwer-Lytton, che divenne celebre nell’Italia dell’Ottocento grazie alle traduzioni dello storico, Francesco Cusani. Si procederà, dunque, ad un confronto tra autore e traduttore, secondo i più recenti studi in stilistica traduttiva e intertestualità, focalizzando l’attenzione sulla produzione del romanzo Zanoni (1842), tradotto dal Cusani nel 1848
La prima ricezione inglese dell’"Aminta": uno sguardo d’insieme
No full textThe essay deals with the first English destiny of the Aminta by Torquato Tasso, examining its focal moments and the cultural context in which its reception took place. In addition, the article aims to show the reasons why Tasso’s pastoral wasn’t take as a theatrical model by Elizabethan dramatists, despite of the great appreciation that it received on the island and the high regard that the British had of its author
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