154 research outputs found

    Digital Disconnection as an Opportunity for the Tourism Business: A Bibliometric Analysis

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    The aim of this study is to carry out a bibliometric review of the existing research on digital disconnection and Digital Free Tourism (DFT) to discover the extent to which this new trend affects technology users and the tourism market. To do this, a systematic literature review and a bibliometric analysis of the research on digital disconnection contained in the Scopus and Web of Science databases were used. This research includes publications from 2012 to December 2021, which included a total of 37 publications about digital disconnection and digital free tourism in scientific journals indexed in the main scientific databases. The analysis concludes that DFT is a growing economic trend in research and that the phenomenon of digital disconnection is beginning to be a peremptory need for more and more users. This work is original and interesting for researchers specialising in technology addictions, as well as academics and professionals in the tourism sector, because the extensive use of smart devices is becoming a type of addiction in many areas and can be a new opportunity for the tourism market. The DFT phenomenon can improve the response to these types of addictions and be a temporary escape and alternative to technological devices. Doi: 10.28991/ESJ-2022-06-05-013 Full Text: PD

    Robustness of Cooperation in the Evolutionary Prisoner's Dilemma on Complex Networks

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    Recent studies on the evolutionary dynamics of the Prisoner's Dilemma game in scale-free networks have demonstrated that the heterogeneity of the network interconnections enhances the evolutionary success of cooperation. In this paper we address the issue of how the characterization of the asymptotic states of the evolutionary dynamics depends on the initial concentration of cooperators. We find that the measure and the connectedness properties of the set of nodes where cooperation reaches fixation is largely independent of initial conditions, in contrast with the behavior of both the set of nodes where defection is fixed, and the fluctuating nodes. We also check for the robustness of these results when varying the degree heterogeneity along a one-parametric family of networks interpolating between the class of Erdos-Renyi graphs and the Barabasi-Albert networks.Comment: 18 pages, 6 figures, revised version accepted for publication in New Journal of Physics (2007

    A population-based controlled experiment assessing the epidemiological impact of digital contact tracing

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    While Digital contact tracing (DCT) has been argued to be a valuable complement to manual tracing in the containment of COVID-19, no empirical evidence of its effectiveness is available to date. Here, we report the results of a 4-week population-based controlled experiment that took place in La Gomera (Canary Islands, Spain) between June and July 2020, where we assessed the epidemiological impact of the Spanish DCT app Radar Covid. After a substantial communication campaign, we estimate that at least 33% of the population adopted the technology and further showed relatively high adherence and compliance as well as a quick turnaround time. The app detects about 6.3 close-contacts per primary simulated infection, a significant percentage being contacts with strangers, although the spontaneous follow-up rate of these notified cases is low. Overall, these results provide experimental evidence of the potential usefulness of DCT during an epidemic outbreak in a real population

    Clonal human fetal ventral mesencephalic dopaminergic neuron precursors for cell therapy research

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    A major challenge for further development of drug screening procedures, cell replacement therapies and developmental studies is the identification of expandable human stem cells able to generate the cell types needed. We have previously reported the generation of an immortalized polyclonal neural stem cell (NSC) line derived from the human fetal ventral mesencephalon (hVM1). This line has been biochemically, genetically, immunocytochemically and electrophysiologically characterized to document its usefulness as a model system for the generation of A9 dopaminergic neurons (DAn). Long-term in vivo transplantation studies in parkinsonian rats showed that the grafts do not mature evenly. We reasoned that diverse clones in the hVM1 line might have different abilities to differentiate. In the present study, we have analyzed 9 hVM1 clones selected on the basis of their TH generation potential and, based on the number of v-myc copies, v-myc down-regulation after in vitro differentiation, in vivo cell cycle exit, TH+ neuron generation and expression of a neuronal mature marker (hNSE), we selected two clones for further in vivo PD cell replacement studies. The conclusion is that homogeneity and clonality of characterized NSCs allow transplantation of cells with controlled properties, which should help in the design of long-term in vivo experimentsThis work was supported by grants from the Spanish Ministry of Economy and Competitiveness (formerly Science and Innovation; PLE2009-0101, SAF2010-17167), Comunidad Autónoma Madrid (S2011-BMD-2336), Instituto Salud Carlos III (RETICS TerCel, RD06/0010/0009) and European Union (Excell, NMP4-SL-2008-214706). This work was also supported by an institutional grant from Foundation Ramón Areces to the Center of Molecular Biology Severo Ocho

    Role of Physical Activity and Fitness in the Characterization and Prognosis of the Metabolically Healthy Obesity Phenotype: a Systematic Review and Meta-Analysis

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    The aims of the present article are to systematically review and meta-analyze the existing evidence on: 1) differences in physical activity (PA), sedentary behavior (SB), cardiorespiratory fitness (CRF) and muscular strength (MST) between metabolically healthy obesity (MHO) and metabolically unhealthy obesity (MUO); and 2) the prognosis of all-cause mortality and cardiovascular disease (CVD) mortality/morbidity in MHO individuals, compared with the best scenario possible, i.e., metabolically healthy normal-weight (MHNW), after adjusting for PA, SB, CRF or MST. Our systematic review identified 67 cross-sectional studies to address aim 1, and 11 longitudinal studies to address aim 2. The major findings and conclusions from the current meta-analysis are: 1) MHO individuals are more active, spend less time in SB, and have a higher level of CRF (yet no differences in MST) than MUO individuals, suggesting that their healthier metabolic profile could be at least partially due to these healthier lifestyle factors and attributes. 2) The meta-analysis of cohort studies which accounted for PA (N = 10 unique cohorts, 100% scored as high-quality) support the notion that MHO individuals have a 24-33% higher risk of all-cause mortality and CVD mortality/morbidity compared to MHNW individuals. This risk was borderline significant/non-significant, independent of the length of the follow-up and lower than that reported in previous meta-analyses in this topic including all type of studies, which could be indicating a modest reduction in the risk estimates as a consequence of accounting for PA. 3) Only one study has examined the role of CRF in the prognosis of MHO individuals. This study suggests that the differences in the risk of all-cause mortality and CVD mortality/morbidity between MHO and MHNW are largely explained by differences in CRF between these two phenotypes

    Wnt5a Regulates Midbrain Dopaminergic Axon Growth and Guidance

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    During development, precise temporal and spatial gradients are responsible for guiding axons to their appropriate targets. Within the developing ventral midbrain (VM) the cues that guide dopaminergic (DA) axons to their forebrain targets remain to be fully elucidated. Wnts are morphogens that have been identified as axon guidance molecules. Several Wnts are expressed in the VM where they regulate the birth of DA neurons. Here, we describe that a precise temporo-spatial expression of Wnt5a accompanies the development of nigrostriatal projections by VM DA neurons. In mice at E11.5, Wnt5a is expressed in the VM where it was found to promote DA neurite and axonal growth in VM primary cultures. By E14.5, when DA axons are approaching their striatal target, Wnt5a causes DA neurite retraction in primary cultures. Co-culture of VM explants with Wnt5a-overexpressing cell aggregates revealed that Wnt5a is capable of repelling DA neurites. Antagonism experiments revealed that the effects of Wnt5a are mediated by the Frizzled receptors and by the small GTPase, Rac1 (a component of the non-canonical Wnt planar cell polarity pathway). Moreover, the effects were specific as they could be blocked by Wnt5a antibody, sFRPs and RYK-Fc. The importance of Wnt5a in DA axon morphogenesis was further verified in Wnt5a−/− mice, where fasciculation of the medial forebrain bundle (MFB) as well as the density of DA neurites in the MFB and striatal terminals were disrupted. Thus, our results identify a novel role of Wnt5a in DA axon growth and guidance

    The Opportunistic Pathogen Propionibacterium acnes: Insights into Typing, Human Disease, Clonal Diversification and CAMP Factor Evolution

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    We previously described a Multilocus Sequence Typing (MLST) scheme based on eight genes that facilitates population genetic and evolutionary analysis of P. acnes. While MLST is a portable method for unambiguous typing of bacteria, it is expensive and labour intensive. Against this background, we now describe a refined version of this scheme based on two housekeeping (aroE; guaA) and two putative virulence (tly; camp2) genes (MLST4) that correctly predicted the phylogroup (IA1, IA2, IB, IC, II, III), clonal complex (CC) and sequence type (ST) (novel or described) status for 91% isolates (n = 372) via cross-referencing of the four gene allelic profiles to the full eight gene versions available in the MLST database (http:// pubmlst.org/pacnes/). Even in the small number of cases where specific STs were not completely resolved, the MLST4 method still correctly determined phylogroup and CC membership. Examination of nucleotide changes within all the MLST loci provides evidence that point mutations generate new alleles approximately 1.5 times as frequently as recombination; although the latter still plays an important role in the bacterium’s evolution. The secreted/cell-associated ‘virulence’ factors tly and camp2 show no clear evidence of episodic or pervasive positive selection and have diversified at a rate similar to housekeeping loci. The co-evolution of these genes with the core genome might also indicate a role in commensal/normal existence constraining their diversity and preventing their loss from the P. acnes population. The possibility that members of the expanded CAMP factor protein family, including camp2, may have been lost from other propionibacteria, but not P. acnes, would further argue for a possible role in niche/host adaption leading to their retention within the genome. These evolutionary insights may prove important for discussions surrounding camp2 as an immunotherapy target for acne, and the effect such treatments may have on commensal lineages

    Weaning practices in phenylketonuria vary between health professionals in Europe

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    Background: In phenylketonuria (PKU), weaning is considered more challenging when compared to feeding healthy infants. The primary aim of weaning is to gradually replace natural protein from breast milk or standard infant formula with solids containing equivalent phenylalanine (Phe). In addition, a Phe-free second stage L-amino acid supplement is usually recommended from around 6 months to replace Phe-free infant formula. Our aim was to assess different weaning approaches used by health professionals across Europe. Methods: A cross sectional questionnaire (survey monkey (R)) composed of 31 multiple and single choice questions was sent to European colleagues caring for inherited metabolic disorders (IMD). Centres were grouped into geographical regions for analysis. Results: Weaning started at 17-26 weeks in 85% (n=81/95) of centres, > 26 weeks in 12% (n=11/95) and 26 weeks. First solids were mainly low Phe vegetables (59%, n=56/95) and fruit (34%, n=32/95). A Phe exchange system to allocate dietary Phe was used by 52% (n=49/95) of centres predominantly from Northern and Southern Europe and 48% (n=46/95) calculated most Phe containing food sources (all centres in Eastern Europe and the majority from Germany and Austria). Some centres used a combination of both methods. A second stage Phe-free L-amino acid supplement containing a higher protein equivalent was introduced by 41% (n=39/95) of centres at infant age 26-36 weeks (mainly from Germany, Austria, Northern and Eastern Europe) and 37% (n=35/95) at infant age > 1y mainly from Southern Europe. 53% (n=50/95) of centres recommended a second stage Phe-free L-amino acid supplement in a spoonable or semi-solid form. Conclusions: Weaning strategies vary throughout European PKU centres. There is evidence to suggest that different infant weaning strategies may influence longer term adherence to the PKU diet or acceptance of Phe-free L-amino acid supplements; rendering prospective long-term studies important. It is essential to identify an effective weaning strategy that reduces caregiver burden but is associated with acceptable dietary adherence and optimal infant feeding development.Peer reviewe

    Early feeding practices in infants with phenylketonuria across Europe

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    Background: In infants with phenylketonuria (PKU), dietary management is based on lowering and titrating phenylalanine (Phe) intake from breast milk or standard infant formula in combination with a Phe-free infant formula in order to maintain blood Phe levels within target range. Professionals use different methods to feed infants with PKU and our survey aimed to document practices across Europe. Methods: We sent a cross sectional, survey monkey (R) questionnaire to European health professionals working in IMD. It contained 31 open and multiple-choice questions. The results were analysed according to different geographical regions. Results: Ninety-five centres from 21 countries responded. Over 60% of centres commenced diet in infants by age 10 days, with 58% of centres implementing newborn screening by day 3 post birth. At diagnosis, infant hospital admission occurred in 61% of metabolic centres, mainly in Eastern, Western and Southern Europe. Breastfeeding fell sharply following diagnosis with only 30% of women still breast feeding at 6 months. 53% of centres gave pre-measured Phe-free infant formula before each breast feed and 23% alternated breast feeds with Phe-free infant formula. With standard infant formula feeds, measured amounts were followed by Phe-free infant formula to satiety in 37% of centres (n = 35/95), whereas 44% (n = 42/95) advised mixing both formulas together. Weaning commenced between 17 and 26 weeks in 85% centres, >= 26 weeks in 12% and <17 weeks in 3%. Discussion: This is the largest European survey completed on PKU infant feeding practices. It is evident that practices varied widely across Europe, and the practicalities of infant feeding in PKU received little focus in the PKU European Guidelines (2017). There are few reports comparing different feeding techniques with blood Phe control, Phe fluctuations and growth. Controlled prospective studies are necessary to assess how different infant feeding practices may influence longer term feeding development.Peer reviewe
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