51,238 research outputs found
Climatic variations along an aridity gradient drive significant trait intraspecific variability in Mediterranean plant species
No full textDrought represents one of the main sources of stress for plants in the Mediterranean region, and climate change is further escalating this stress. Plants can employ several response strategies to cope with stress, reflected in the adoption of specific Plant Functional Traits (PFTs). Trait-based approaches commonly meet three issues: they may overlook Intraspecific Variability (ITV), they could focus on large spatial scales, or they could focus on few traits. Here we present evidence that it's possible to observe ITV in morphological and anatomical trait syndromes between three local populations of Phillyrea latifolia, Pistacia lentiscus, and Quercus ilex, distributed along an aridity gradient. Thicker, physiologically expensive leaves and lower heights found in the drier sites mainly conform to drought-resistance strategies, while trait spectra from Cistus salviifolius were found not to vary significantly across sites. Thus, the amount of ITV observable at a local scale varies between species. We conclude that climate can easily drive a significant amount of ITV for several species, reflected in their trait spectra, among plant populations that are geographically close to each other. This highlights the importance of local environmental variability and implies that different populations hailing from nearby sites might respond differently to climate change
Within or Without? Problems of Perspective in Charlotte Smith, Anna Laetitia Barbauld and Dorothy Wordsworth
No full textRomantic Women Poets: Genre and Gender focuses on the part played by women poets in the creation of the literary canon in the Romantic period in Britain. Its thirteen essays enrich our panoramic view of an age that is traditionally dominated by male authors such as Wordsworth, Coleridge, Byron, Shelley, Keats and Scott. Instead the volume concentrates on the poetical theory and practice of such extraordinary and fascinating women as Joanna Baillie, Charlotte Smith, Anna Laetita Barbauld, Dorothy Wordsworth, Helen Maria Williams, Lady Morgan, Ann Radcliffe, Mary Shelley, Letitia Elizabeth Landon, Anna Seward, and Lady Caroline Lamb. Female and male poetics, gender and genres, literary forms and poetic modes are extensively discussed together with the diversity of behaviour and personal responses that the individual women poets offered to their age and provoked in their readers. There have been several important collections of essays in this particular area of study in the last few years, but this volume reflects and complements much of this earlier critical work with specific strengths of its own
Leggenda di famiglia
No full textSi tratta di un'edizione critica e traduzione di un testo teatrale scozzese del primo Ottocento mai tradotto in italiano e di cui non esiste un'edizione critica novecentesca nemmeno in lingua inglese. E' un testo tuttavia di grande importanza scientifica perchè inaugura la corrente del dramma storico che sarà in voga nel romanticismo dopo gli splendori rinascimentali
Prefazione
No full textPresentazione e discussione della prima traduzione italiana del dramma "Bloody Poetry" del drammaturgo contemporaneo inglese Howard Brenton
REGULATION OF THE HEMATOPOIETIC SELF-RENEWAL AND LINEAGE CHOICE: ROLE OF PBX1 AND MICRO-RNAS
No full textHematopoiesis is a highly regulated process (Orkin and Zon, 2008). For a constant supply of short-lived terminally differentiated blood cells, and for rapid response to hematopoietic stresses, HSCs are endowed with the ability to continuously provide more mature progenitors while properly maintaining their pool size, without exhaustion, throughout life. This equilibrium is finely maintained on one hand by precisely balancing self-renewal and differentiation in HSCs, and on the other hand by regulating proliferation and differentiation also of their downstream progenitors, including lineage choice. Thus, understanding mechanisms of regulation of self-renewal versus differentiation of HSCs and downstream progenitors is a central issue in stem cell field, since tiny alteration of these mechanisms may lead to hematopoietic failure and disease.
Pbx1 is a transcription factor that positively regulates post-natal HSC quiescence. Its absence in HSCs causes an excessive proliferation that leads to their exhaustion, indicating a profound self-renewal defect, and premature myeloid differentiation at the expenses of lymphoid differentiation (Ficara et al., 2008). However, the precise molecular mechanisms through which Pbx1 exerts its function in HSCs and its role in progenitor biology are two still unexplored issues. In particular, it is not known whether Pbx1 function is also mediated by micro-RNAs, crucial new players in the regulation of proliferation and differentiation in several tissues, including the hematopoietic system.
Taking advantage of Pbx1 conditional KO mice, in this study, we demonstrate that Pbx1 functions as a brake on cell differentiation not only in HSCs but also in multi-potent and myeloid-restricted progenitors, to maintain progenitor reservoirs and lymphoid potential. In absence of Pbx1, both myeloid and lymphoid progenitors are able to differentiate into mature progeny but with higher efficiency and premature kinetic for the myeloid lineage and a decreased efficiency in the lymphoid (and erythroid) lineage. Pbx1 acts also upstream to lineage restricted progenitors, affecting lineage choice of multipotent progenitors (MPPs) by restraining myeloid differentiation and allowing lymphoid differentiation.
Moreover, we show that in the absence of Pbx1 HSCs display an altered micro-RNA profile, which resembles the normal MPP profile, suggesting a role for miRNAs in maintaining HSC identity.
Pbx1-null HSCs and MPPs show specific lists of DE miRNAs, with substantial overlaps with the normal HSC-to-MPP transition. Combining miRNA data with transcriptional profile data of the same populations (Ficara et al., 2008) allowed searching for miRNA predicted targets whose change in expression inversely correlates with those of mRNAs. This analysis, coupled with extensive bioinformatics studies (promoter analysis, co-targeting and GSEA) allowed selection of very few candidate miRNAs to be further studied for their specific role in maintaining HSC self-renewal, and their possible regulation by Pbx1. In addition to a list of Pbx1-dependent miRNAs in HSCs and MPPs, we also analyzes for the first time miRNAs characteristic of the normal transition from HSCs to the first MPP stage, which represent an important finding for understanding miRNAs physiologically involved at the apex of hematopoietic system. Overall, this analysis set the basis for the discovery of miRNAs involved in the regulation of self-renewal versus differentiation of HSCs
ICU acquired neuropathy and myopathy
No full textPatients admitted to intensive care often develop complications. Among these, acquired difficulties with neuromuscular function are widely recognised as potential causes of clinical worsening and delayed recovery in these individuals. Critical Illness Pofineuropathy and Critical Illness Myopathy are the most commonly recognised disorders which often occur simultaneously in the critically ill patients. Incidence of both Critical Illness Polineuropathy (from 2 to 80%) and Critical Illness Myopathy (from 1 to 7%) vary consistently according to the patients' selection, being diagnosis mainly addressed by clinical signs and electromyography test. Awareness among health care professionals, early recognition and diagnosis, patient's education about outcome and long-term prognosis, streamlining rehabilitation perspectives are considered short- and long-term key aspects which may optimise care in these patients. This short review will provide the main aspects dealing with definitions, epidemiology, risk factors, and clinical management of acquired difficulties with neuromuscular function in the critical care area
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