Search results for " renewal."
showing 10 items of 66 documents
First survey on zoonotic helminthosis in urban brown rats (Rattus norvegicus) in Spain and associated public health considerations.
2018
Abstract The brown rat, Rattus norvegicus, with a worldwide distribution, is the most commensal species among synanthropic rodents, since its main habitat, in urban as well as in rural areas, is always linked to humans. Therefore, people living in close proximity to rodent populations can be exposed to infection. Whereas bacteria and viruses are the best known rat-associated zoonoses in urban environments, the role of brown rats as reservoirs for helminth parasites and the associated risk for humans are less well known. Specifically, this role has not been analyzed in Spain to date. A total of 100 R. norvegicus trapped in the sewage system (n = 85), and parks (n = 15) of Barcelona was exami…
Hematopoietic Stem Cells Reversibly Switch from Dormancy to Self-Renewal during Homeostasis and Repair
2008
Bone marrow hematopoietic stem cells (HSCs) are crucial to maintain lifelong production of all blood cells. Although HSCs divide infrequently, it is thought that the entire HSC pool turns over every few weeks, suggesting that HSCs regularly enter and exit cell cycle. Here, we combine flow cytometry with label-retaining assays (BrdU and histone H2B-GFP) to identify a population of dormant mouse HSCs (d-HSCs) within the lin(-)Sca1(+)cKit(+)CD150(+)CD48(-)CD34(-) population. Computational modeling suggests that d-HSCs divide about every 145 days, or five times per lifetime. d-HSCs harbor the vast majority of multilineage long-term self-renewal activity. While they form a silent reservoir of th…
Differential expression levels of Sox9 in early neocortical radial glial cells regulate the decision between stem cell maintenance and differentiation
2021
ABSTRACTRadial glial progenitor cells (RGCs) in the dorsal forebrain directly or indirectly produce excitatory projection neurons and macroglia of the neocortex. Recent evidence shows that the pool of RGCs is more heterogeneous than originally thought and that progenitor subpopulations can generate particular neuronal cell types. Using single cell RNA sequencing, we have studied gene expression patterns of two subtypes of RGCs that differ in their neurogenic behavior. One progenitor type rapidly produces postmitotic neurons, whereas the second progenitor remains relatively quiescence before generating neurons. We have identified candidate genes that are differentially expressed between thes…
The resilience of Finnish farms: Exploring the interplay between agency and structure
2020
Resilience implies, in its essence, the capacity of a system to tolerate disturbances while retaining its essential functions. In the context of agriculture, resilience thinking calls for considering the ability of farms to thrive in turbulent times along with the ability of the ecological system – in which the agricultural production is embedded – to retain its function and integrity. Resilience is a relevant conceptual tool to analyse the contradictory management demands that farms are facing within the current neoliberal market regime: being economically viable and environmentally sustainable. In this study, the resilience of farms was operationalised through farmers' perceptions concern…
MUTAMENTI E PERMANENZE DELLA PALERMO ANTICA MUTATIONS AND PERMANENCES IN ANCIENT PALERMO
2017
La Palermo Antica si identifica con il Centro Storico, la cui complessità è il frutto dell’incontro di culture succedutesi nei secoli e che ha dato alla città la sua attuale facies. Questi luoghi sono oggi un microcosmo complesso dove i modelli culturali dei nuovi abitanti si relazionano al preesistente generando nuove espressioni dell’intervento antropico. L’analisi è volta ai nuovi scenari urbani, alle impronte, ai segni e ai mutamenti generati da un processo insediativo che vede coinvolti i nuovi residenti e le loro risorse, in un ambito che ha tutte le potenzialità per restituire Palermo al suo ruolo di capitale nell’ottica dell’integrazione, dell’accoglienza, della riqualificazione e v…
Convergence of Markov Chains
2020
We consider a Markov chain X with invariant distribution π and investigate conditions under which the distribution of X n converges to π as n→∞. Essentially it is necessary and sufficient that the state space of the chain cannot be decomposed into subspaces that the chain does not leave, or that are visited by the chain periodically; e.g., only for odd n or only for even n.
Determination of Evapotranspiration and Crop Coefficient of Cactus Pear (Opuntia ficus-indica Mill.) with an Energy Balance Technique
2013
A micrometeorological approach based on surface renewal technique was adopted to estimate evapotranspiration fluxes and crop coefficient data from an irrigated cactus pear (Opuntia ficus-indica Mill.) orchard under Mediterranean climatic conditions. High-frequency temperature readings were taken above the canopy top in order to get surface renewal sensible heat flux values (HSR). These values were compared against eddy covariance sensible heat fluxes (HEC) for calibration. Latent heat flux (or evapotranspiration, ET) was obtained as the residual of the energy balance equation using HSR. In field measurements of biophysical crop features, physiological characteristic and soil hydraulic compo…
Knowledge creation. The ongoing search for strategic renewal
2014
Purpose– The purpose of this paper is to analyse how changes in a set of structural design variables (i.e. liaison position, networked design, innovation teams and work teams) affect the creation of new knowledge within organizations. The enablers intention, autonomy, fluctuation and creative chaos, redundancy, variety, and trust and commitment, taken from Nonaka's framework, are used as intermediate variables.Design/methodology/approach– A sample of 167 large Spanish companies was used to empirically test a general relational model.Findings– The analysis yielded two main conclusions. First, the relationship between structural variables and enablers, and, second, the relationship of enabler…
Strategic Vision of a Euro-Mediterranean Port City: A Case Study of Palermo
2013
Italian harbours assume a decisive role in order to develop a Euro-Mediterranean web for maritime transportation. The geostrategic position of the Italian peninsula can be seen as a logistic platform at the centre of the maritime trades in the Mediterranean area, giving to its port cities the role of gateway of economic flows. The port poles, meant as hubs, are able to attract investments and create economic growth and territorial development through new operative models of urban usage and management. The management policies have to consider the environmental characteristics and distinctive features, respecting the identity of the places as concrete evidence of history, a source of intellec…
Ville et fortifications : de l'héritage à la production du territoire urbain
2015
A large number of french cities host military historical edifices (citadels, barracks, bastions, defensive walls, etc.). Although their initial defensive functions have been lost over time, these edifices remain deeply rooted in the urban fabric of their host cities. They continue exerting an impact on these cities’ urban morphology and modern-time functions as well as the way in which the concept of city is understood. Cities nowadays face some new challenges,the increasing awareness of urban sprawl and its consequences, coupled with an urge to promote a renewed and sustainable urbanism, invites us to adopt new approaches to study urban fortifications. In addition to their symbolic aspect,…