790 research outputs found
Trichites of Strombidium (Ciliata Oligotrichita) are extrusomes
No full textThe trichites of Strombidium and related genera have been considered either as a cytoskeletal armature or as extrusomes.
To demonstrate their true nature, a study was undertaken on two marine Strombidium species by ultrastructural and cytochemical
analysis as well as in vivo experiments. Trichites, extending from the cortex into the cell, are rod-shaped, membrane-bounded, and have
a complex structure. The following elements of the trichites, are distinguishable: an electron-transparent lumen, a laminated layer, and
a compact layer. In trichites of one species, thin ‘‘rings’’ surround the lumen. Numerous short, curved tubules with a polysaccharide
wall are present in the cytoplasm surrounding the trichites. At the cortical end, each trichite is enveloped by a ‘‘cap’’ of electron-dense
proteinaceous material. In some cases, the cortical alveoli appear interrupted, forming a ‘‘hole’’ for trichite ejection. Ejection of rodshaped
structures, up to 5 times longer than resting trichites, was obtained by in vivo treatments with dextran and aminoethyldextran.
Negative staining indicated that these structures were transformed trichites. As no other possible extrusive structures were observed in
the cytoplasm of Strombidium, trichites were considered extrusomes
Anatol Stern e Bruno Jasieński
No full textThe Author presents her first Italian translation of Anatol Stern's article (excerpted from his monograph on Polish Avant-garde "Rebelled Poetry. Sketches on Interwar Period Poetry" [1964, 2nd issue 1970]) about an other prominent initiator and ideologist of Polish Futurism, Bruno Jasieński. After the "Thaw", Stern first contributed to Jasieński's rehabilitation, publishing his poetry and the novel "I burn Paris" and writing several essays about his work. The presented article also offers a large choice of translated fragments of Jasieński's poetry, just a few known in Italy, and a Stern's artistic profile with a bibliography of his Italian version work
Emerging Role of the Ubiquitin Proteasome System in the Control of Shoot Apical Meristem Function
No full textThe shoot apical meristem (SAM) is a population of undifferentiated cells at the tip of the shoot axis that establishes early during plant embryogenesis and gives rise to all shoot organs throughout the plant's life. A plethora of different families of transcription factors (TFs) play a key role in establishing the equilibrium between cell differentiation and stem cell maintenance in the SAM. Fine tuning of these regulatory proteins is crucial for a proper and fast SAM response to environmental and hormonal cues, and for development progression. One effective way to rapidly inactivate TFs involves regulated proteolysis by the ubiquitin/26S proteasome system (UPS). However, a possible role of UPS-dependent protein degradation in the regulation of key SAM TFs has not been thoroughly investigated. Here, we summarize recent evidence supporting a role for the UPS in SAM maintenance and function. We integrate this survey with an in silico analysis of publicly-available microarray databases which identified ubiquitin ligases that are expressed in specific areas within the SAM, suggesting that they may regulate or act downstream of meristem-specific factors. [ Giovanna Frugis (Corresponding author)
Functional traits of plants and pollinators explain resource overlap between honeybees and wild pollinators
No full textManaged and wild pollinators often cohabit in both managed and natural ecosystems. The western honeybee, Apis mellifera, is the most widespread managed pollinator species. Due to its density and behaviour, it can potentially influence the foraging activity of wild pollinators, but the strength and direction of this effect are often context-dependent. Here, we observed plant–pollinator interactions in 51 grasslands, and we measured functional traits of both plants and pollinators. Using a multi-model inference approach, we explored the effects of honeybee abundance, temperature, plant functional diversity, and trait similarity between wild pollinators and the honeybee on the resource overlap between wild pollinators and the honeybee. Resource overlap decreased with increasing honeybee abundance only in plant communities with high functional diversity, suggesting a potential diet shift of wild pollinators in areas with a high variability of flower morphologies. Moreover, resource overlap increased with increasing trait similarity between wild pollinators and the honeybee. In particular, central-place foragers of family Apidae with proboscis length similar to the honeybee exhibited the highest resource overlap. Our results underline the importance of promoting functional diversity of plant communities to support wild pollinators in areas with a high density of honeybee hives. Moreover, greater attention should be paid to areas where pollinators possess functional traits similar to the honeybee, as they are expected to be more prone to potential competition with this species. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00442-022-05151-6
The Teaching of Lyric Meters and the Reception of Horace in Kyiv-Mohylanian Poetics
No full textIn this article, by analyzing the use of Horace’s poetry in the teaching of metrics provided in the Kyiv Mohylanian poetics, the author shows how Latin poetry was usedas a didactic tool to support the education of devout men and loyal citizens.Siedina particularly dwells on the Sapphic and Alcaic metrical systems, as they were the most widely exemplified in the poetics. Next to the ‘simple’ quotation of Horace’s lyrics, the author individuates other modes of Horatian imitation, all of which entail its Christianization: parodies, following the masterful example of M. K. Sarbiewski, the transformation of Horace’s lyric in a Christian key, and the use of Horatian meters to compose poems on Christian topics (particularly appreciated were paraphrases of the psalms by the Scottish poet G. Buchanan). Such a Christianization of Horace and other classical authors was in line with the Christian interpretation/ imitation of Horace that had begun in Western Europe in the first centuries after Christ and continued in different guises well into the seventeenth and eighteenth centuries. The author observes that many motifs of Horace’s poetry could easily be made to coincide with the ethical and religious tenets of education at the Kyiv Mohyla Academy: for instance, reflections on the brevity of human life, the impossibility of achieving complete happiness, the avoidance of excesses, contentment with little, love of virtue and the like. In conclusion, Siedina asserts that the Christianization and moralization of Horace’s poetry, next to denying the legitimacy of the pagan pantheon, to which a Christian one was opposed, was a way for people to implicitly assert their own worth and distinct cultural identity, which in early-modern Ukraine, as elsewhere, in great part passed through schooling and literature
Eni prekei ... Il santuario di Altino in località Fornace e gli aspetti del culto nel Veneto preromano
No full textThe paper focuses the attention on the features and chronological development of cult in preroman Veneto. In this perspective the Author analyzes the beginning of the most important worship, connecting them to the time of making cities. At the beginning, probably around the half of 7° cent. BC, the most important sanctuaries are the one devoted to Reitia and the one devoted to Alkomnoi, both in Este; a third relevant worship is near the hill, at Montegrotto, connected to the city of Padua. Only in the middle of the 6° century BC other worship evolved, in different places and with different purposes, both in the mountains and in the plain. Between them, the sanctuary of the God Altno- in Altino is one of the most important for the boundary function near the Adriatic sea and the connection with Picenes, Etruscans and Greeks
Scrittura e resistenza: i giorni veri di Giovanna Zangrandi
No full textThis work highlights the exceptional figure of Giovanna Zangrandi, Italian alpinist, writer and partisan. She was a resolute and emancipated woman who, after the armistice of 1943, decided to fight back and confront the Nazi occupation by participating in dangerous missions that were decisive for the survival of her partisan brigade. At the end of the war, she then devoted herself to writing, achieving prestigious literary awards./n
The aim of this essay is to remember Giovanna Zangrandi experience, celebrating her courage and analyzing in particular her work I giorni veri. Diario della Resistenza, the notebooks written by the author during the most critical phases of the war.L’obiettivo di questo lavoro è ricordare l’eccezionale figura di Giovanna Zangrandi, alpinista, scrittrice e partigiana italiana. Donna risoluta ed emancipata, in seguito all’armistizio del 1943 decise di ribellarsi e fronteggiare l’occupazione nazista partecipando a pericolose missioni ad alta quota, decisive per la sopravvivenza della sua brigata partigiana. Al termine della guerra, si dedicò quindi alla scrittura, sua grande passione, riuscendo ad ottenere prestigiosi riconoscimenti letterari. Il risultato che questa ricerca vuole conseguire è valorizzare l’esperienza di Giovanna Zangrandi, celebrandone il coraggio e analizzando in particolare la sua opera I giorni veri. Diario della Resistenza, ovvero i quaderni scritti dall’autrice durante le fasi più critiche della guerra di liberazione
Propulsori di urbanità
No full textIl saggio “Propulsori di urbanità” fa parte del volume ”La stazione della metropolitana propulsore di urbanità diffusa”, di cui Giovanna Bianchi è co-autrice con Alessandra Criconia, che raccoglie gli esiti della ricerca universitaria SURFas (Strategie Urbane Reti Forme dell’abitare sostenibile, Sapienza Università di Roma 2012), coordinata dalle stesse autrici. Il volume si interroga sui caratteri della stazione della metropolitana o della ferrovia urbana quale strumenti-chiave della multimodalità, nella convinzione che la stazione “piccola” possa diventare un propulsore di urbanità diffusa, grazie alla ricchezza e varietà di funzioni sviluppate all’interno e all’esterno, nello spazio di prossimità. Il saggio è organizzato in tre parti.
La prima parte riflette sull’ipotesi della ricerca – che la stazione della metropolitana o della ferrovia urbana possa essere un propulsore urbano diffuso – a partire da tre temi di sfondo: la mobilità sostenibile declinata in termini di accessibilità a condizioni di urbanità e, dunque, quale nuovo standard qualitativo e prestazionale; una concezione rinnovata di densificazione multiscalare nello spazio ma anche nel tempo; la stazione non come nodo della rete del ferro ma come luogo urbano (microcentralità di quartiere) e, dunque, come spazio pubblico.
La seconda parte offre una lettura mirata della pianificazione (PRG 2008) e della programmazione (PGTU 2015, Carte dei valori dei Municipi 2014) per i quartieri interessati dai casi di studio della ricerca (Roma, quattro stazioni della linea della metropolitana B1 e quattro stazioni urbane della linea ferroviaria FL3), alla cui luce verificare l’ipotesi di ricerca.
La terza parte, infine, avanza considerazioni sintetiche sul metodo operativo proposto dalla ricerca e sulla sua utilità nel progetto della stazione/spazio pubblico.The essay "Propulsori di urbanità" is part of the volume "La stazione della metropolitana propulsore di urbanità diffusa", of which Giovanna Bianchi is co-author with Alessandra Criconia, which collects the results of university research SURFas (Urban Strategies Networks Forms of living sustainable, Sapienza University of Rome 2012), coordinated by the authors themselves. The volume questions the characteristics of the subway station and urban railway, as key tools of multimodality, this in the belief that the "small" station can become a driving force of widespread urbanity, thanks to the richness and variety of functions developed inside and outside, in the proximity space. The essay is organized in three parts.
The first part reflects on the hypothesis of research - that the subway or urban railway station can be a widespread urban driving force - starting from three background themes: sustainable mobility declined in terms of accessibility to urban conditions and, therefore, as a new quality and performance standard; a renewed concept of multiscale densification in space but also over time; the station not as a node of the rail network but as an urban place (neighborhood microcentrality) and, therefore, as a public space.
The second part offers a focus on planning (PRG 2008, PGTU 2015, Maps of the values of the Municipalities 2014) for the neighborhoods affected by the research study cases (Rome, four stations of the B1 subway line and four urban stations of the FL3 railway line), in order to verify the research hypothesis.
Finally, the third part presents synthetic considerations on the operating method proposed by the research and on its usefulness in the design of the station as a public space
Immaginario distopico nella narrativa breve di Giovanna Rivero
No full textThis study aims to investigate contemporary Spanish-American science-fiction short stories, focusing on the emblematic case of the Bolivian author Giovanna Rivero. She is part of a national context that is very prolific in this literary genre, which has been stimulating new studies, symposiums and specialized journals. Her themes, style and language will be investigated through the study of the short stories “Regreso” and “Pasó como un espíritu”, in order to explore the dystopian universe created by the author. Combining Andean cultural heritage and dystopic projection, she manages to outline the current political and sociological context in Bolivia.Lo studio che viene proposto vuole essere una riflessione sulla distopia nella narrativa breve ispanica di fantascienza contemporanea, in particolare trattando il caso emblematico della scrittrice boliviana Giovanna Rivero. L’autrice si inserisce in un contesto nazionale molto attivo per quanto riguarda il genere, che ha visto ultimamente la nascita di studi, attività congressuali e riviste specializzate nel settore. Attraverso l’analisi dei due racconti Regreso e Pasó como un espíritu, si indagheranno quelle modalità tematiche, linguistiche e stilistiche che danno vita a un universo distopico che l’autrice utilizza al servizio di un’analisi critica, politica e sociologica dell’attualità nel paese andino
Unrepresented and “Circumlocuted” People: Public Institutions and Citizens in Dickens’ Little Dorrit
No full textCharles Dickens’ novels often present a peculiar vision of the mid-nineteenth-century Victorian government and, more generally, of public administration. In Little Dorrit, the author presents his personal critique of a corrupt, nepotistic and detached bureaucracy that works to maintain itself, stifling citizens’ economic initiative in the process and likewise hindering the development of society. In the same novel, however, the author presents the Marshalsea prison as an unexpected example of ‘domestic’ administration, an official institution that simultaneously punishes and protects, and where, contrary to the other public institutions, the protagonists have really been part of
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