During reproductive life, the human endometrium undergoes around 480 cycles of growth, breakdown and regeneration should pregnancy not be achieved. This outstanding regenerative capacity is the basis ...for women's cycling and its dysfunction may be involved in the etiology of pathological disorders. Therefore, the human endometrial tissue must rely on a remarkable endometrial somatic stem cells (SSC) population. Here we explore the hypothesis that human endometrial side population (SP) cells correspond to somatic stem cells. We isolated, identified and characterized the SP corresponding to the stromal and epithelial compartments using endometrial SP genes signature, immunophenotyping and characteristic telomerase pattern. We analyzed the clonogenic activity of SP cells under hypoxic conditions and the differentiation capacity in vitro to adipogenic and osteogenic lineages. Finally, we demonstrated the functional capability of endometrial SP to develop human endometrium after subcutaneous injection in NOD-SCID mice. Briefly, SP cells of human endometrium from epithelial and stromal compartments display genotypic, phenotypic and functional features of SSC.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Indoor broadband power-line noise is composed of three main terms: impulsive components, narrowband interferences, and background noise. Most impulsive components have a cyclostationary behavior. ...However, while some of them consist of impulses of considerable amplitude, width, and repetition rates of 50/100 Hz (in Europe), others have lower amplitude and shorter width but repetition rates of up to hundreds of kilohertz. Classical studies compute statistics of the impulse characteristics without taking into account these significant differences. This paper presents a detailed analysis of these noise terms with a clear distinction between their constituent terms. A classification of the narrowband interferences according to their power spectral density and their statistical behavior is also given. Finally, the instantaneous power spectral density of the background noise and its probability distribution are investigated. Some of the results presented in this paper are available for download from the web site http://www.plc.uma.es/index_eng.htm.
New tourism trends, such as vacation rentals websites and low-cost tourism, have generated a new environment of interactions between tourism and the citizens. To this, we must add the fortuitous ...increase in demand in some touristic destinations. This has derived in situations of rejection in traditionally tourism-dependent environments. In this study, which is focused on the city of Barcelona, we use work-field data to analyze the elements that lie behind the popular aversion to tourism. Assuming a non-forced analysis that takes the Social Exchange Theory as a framework, we have determined that the negative economic effects derived from the increase in the number of accommodations destined for vacation rentals and in the demand lie behind this rejection. The main impacts that are perceived directly from these factors are: the increase in residential rentals prices and a shift from a traditional market to one oriented to the tourist with higher prices. It has also been determined that the most vulnerable population groups are those who manifest a stronger rejection, tenants of apartments in city centers, and citizens with a low/medium income, who perceive rises in the prices and a change in the market focus to a larger extent.
•This study has identified the 13 most vulnerable countries in terms of tourism competitiveness.•The most vulnerable are Panama, Georgia, Bahrain, Morocco, Montenegro, Albania, Mexico, Dominican ...Republic, Jordan, Tunisia, Cape Verde, Honduras, and Lebanon.•The keys dimensions that condition the competitiveness have been identified.•These dimensions are related to cultural heritage, protection of natural areas, information and communication technologies, among others.
Business activities within the tourism industry are especially suffering from the consequences of the COVID19 pandemic. Those countries whose economy depends largely on tourism will experience a troublesome situation for years to come. Their return to a normal situation will be conditioned by the competitiveness of their tourism sector. The study begins by pinpointing the countries that have been more hardly stricken by the pandemic and in which tourism accounts for a greater share of the GDP. A comparative analysis of the competitiveness of these countries with that of world-leading countries will be carried out so as to conclude which will face the recovery period in a more vulnerable situation. The measurement of tourism competitiveness will be supported by the creation of a synthetic indicator based on the P2 distance method. A group of 13 countries has been identified as the most vulnerable, and it is advisable to act urgently in the following areas: the promotion of cultural elements and the historical and artistic heritage, the protection of natural areas, the availability of information and communication technologies, the international openness of the destination, and the availability of transportation infrastructures and tourist services.
Tourism is a key sector in the sustainable development of rural environments. Its ability to create stable employment and an acceptable level of profits is conditioned by the stability of tourist ...activity throughout the year. This paper compares the level of seasonality of a group of rural destinations to that of coastal and urban destinations. By doing so, we intend to determine whether seasonality-related problems exist in the rural environment or not. The second aim is related to the first one: the proposal of a new, more comprehensive and objective methodology that can measure the intensity of seasonality based on a DP2 synthetic indicator. The DP2 indicator groups information about different representative variables of seasonality. The study takes the main tourist spots in Spain as a reference. The analysis concludes that the annual level of stability of rural tourism is not far from the stability of urban tourism, which is the most stable, as seasonality is much higher in coastal destinations. The methodology that provides the framework to build the DP2 indicator has allowed us to identify which variables explain the differences in the level of seasonality of each destination to a large extent. The results showed that the variables that do so are related to the internalization of the destination and changes in the availability of bed places.
Mast cells are key actors in inflammatory reactions. Upon activation, they release histamine, heparin and nerve growth factor, among many other mediators that modulate immune response and neuron ...sensitization. One important feature of mast cells is that their population is usually increased in animal models and biopsies from patients with irritable bowel syndrome (IBS). Therefore, mast cells and mast cell mediators are regarded as key components in IBS pathophysiology. IBS is a common functional gastrointestinal disorder affecting the quality of life of up to 20% of the population worldwide. It is characterized by abdominal pain and altered bowel habits, with heterogeneous phenotypes ranging from constipation to diarrhea, with a mixed subtype and even an unclassified form. Nutrient intake is one of the triggering factors of IBS. In this respect, certain components of the daily food, such as fatty acids, amino acids or plant-derived substances like flavonoids, have been described to modulate mast cells' activity. In this review, we will focus on the effect of these molecules, either stimulatory or inhibitory, on mast cell degranulation, looking for a nutraceutical capable of decreasing IBS symptoms.
The active forms of Au and Pt in CeO2-based catalysts for the water–gas shift (WGS) reaction are an issue that remains unclear, although it has been widely studied. On one hand, ionic species might ...be responsible for weakening the Ce–O bonds, thus increasing the oxygen mobility and WGS activity. On the other hand, the close contact of Au or Pt atoms with CeO2 oxygen vacancies at the metal–CeO2 interface might provide the active sites for an efficient reaction. In this work, using in situ X-ray absorption spectroscopy, we demonstrate that both Au and Pt remain unoxidized during the reaction. Remarkable differences involving the dynamics established by both species under WGS atmospheres were recognized. For the prereduced Pt catalyst, the increase of the conversion coincided with a restructuration of the Pt atoms into cuboctahedrical metallic particles without significant variations on the overall particle size. Contrary to the relatively static behavior of Pt0, Au0 nanoparticles exhibited a sequence of particle splitting and agglomeration while maintaining a zero oxidation state despite not being located in a metallic environment during the process. High WGS activity was obtained when Au atoms were surrounded by oxygen. The fact that Au preserves its unoxidized state indicates that the chemical interaction between Au and oxygen must be necessarily electrostatic and that such an electrostatic interaction is fundamental for a top performance in the WGS process.
Clustering is presently one of the main routing techniques employed in randomly deployed wireless sensor networks. This paper describes a novel centralized unequal clustering method for wireless ...sensor networks. The goals of the algorithm are to prolong the network lifetime and increase the reliability of the network while not compromising the data transmission. In the proposed method, the Base Station decides on the cluster heads according to the best scores obtained from a Type-2 Fuzzy system. The input parameters of the fuzzy system are estimated by the base station or gathered from the network with a careful design that reduces the control message exchange. The whole network is controlled by the base station in a rounds-based schedule that alternates rounds when the base station elects cluster heads, with other rounds in which the cluster heads previously elected, gather data from their contributing nodes and forward them to the base station. The setting of the number of rounds in which the Base Station keeps the same set of cluster heads is another contribution of the present paper. The results show significant improvements achieved by the proposal when compared to other current clustering methods.
In the vehicular ad hoc networks (VANETs), due to the high mobility of vehicles, the network parameters change frequently and the information that the sender maintains may outdate when it wants to ...transmit data packet to the receiver, so for improving the routing efficiency and reliability, we propose the probability prediction-based reliable and efficient opportunistic routing (PRO) algorithm for VANETs. The PRO routing algorithm can predict the variation of signal-to-interference-plus-noise ratio (SINR) and packet queue length (PQL) of the receiver. The prediction results are used to determine the utility of each relaying vehicle in the candidate set. The calculation of the vehicle's utility is the weight-based algorithm, and the weights are the variances of SINR and PQL. The relaying priority of each relaying vehicle is determined by the value of its utility. By these innovations, the PRO can achieve better routing performance (such as the packet delivery ratio, the end-to-end delay, and the network throughput) than the SRPE, ExOR (street-centric), and greedy perimeter stateless routing algorithms.
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