Evaluation of tree-based routing Ethernet

Tree-based Routing (TRE) revisits Tree-based Routing Architecture for Irregular Networks (TRAIN)—a forwarding scheme based on a spanning tree that was extended to use some shortcut links.We propose its adaptation to Ethernet, using a new type of hierarchical Ethernet addresses and a procedure to assign them to bridges. We show that compared to RSTP, TRE offers improved throughput. The impact of transient loops in TRE is lower compared to the application of the classical shortest path routing protocols to Ethernet. Finally, TRE is self-configuring and its forwarding process is simpler and more efficient than in standard Ethernet and shortest path routing proposals.Publicad

Hierarchical Up/Down Routing Architecture for Ethernet backbones and campus networks

We describe a new layer two distributed and scalable routing architecture. It uses an automatic hierarchical node identifier assignment mechanism associated to the rapid spanning tree protocol. Enhanced up/down mechanisms are used to prohibit some turns at nodes to break cycles, instead of blocking links like the spannning tree protocol does. The protocol performance is similar or better than other turn prohibition algorithms recently proposed with lower complexity O(Nd) and better scalability. Simulations show that the fraction of prohibited turns over random networks is less than 0.2. The effect of root bridge election on the performance of the protocol is limited both in the random and regular networks studied. The use of hierarchical, tree-descriptive addresses simplifies the routing, and avoids the need of all nodes having a global knowleddge of the network topology. Routing frames through the hierarchical tree at very high speed is possible by progressive decoding of frame destination address, without routing tables or port address learning. Coexistence with standard bridges is achieved using combined devices: bridges that forward the frames having global destination MAC addresses as standard bridges and frames with local MAC frames with the proposed protocol.Publicad

IAA : Información y actualidad astronómica (4)

Sumario : Investigación : Galaxias huéspedes de cuásares.-- El gigante gaseoso y su gran mancha roja.-- Ventana Abierta: Un futuro incierto.-- Charlas con… John Hutchings.-- Actualidad Científica: La edad de la galaxia.-- Sorpresas en el cinturón de Kuiper.-- Actividades IAA.-- Agenda.N

HURP/HURBA: Zero-configuration hierarchical Up/Down routing and bridging architecture for Ethernet backbones and campus networks

Ethernet switched networks do not scale appropriately due to limitations inherent to the spanning tree protocol. Ethernet architectures based on routing over a virtual topology in which turns are prohibited offer improved performance over spanning tree, although in some cases suffer from excessive computational complexity. Up/Down routing is a turn prohibition algorithm with low computational complexity. In this paper we propose HURBA, a new layer-two architecture that improves Up/Down routing performance due to an optimization based on the use of hierarchical addressing, while preserving the computational complexity of Up/Down. The resulting architecture requires zero-configuration, uses the same frame format as Ethernet, allows upgrades by software update, and is compatible with 802.1D bridges by means of encapsulation. HURP protocol builds automatically a core with the interconnected HURP routing bridges and the standard bridges get connected to the edges in standard spanning trees. Simulations show that the performance of HURP, evaluated over various combinations of network topology and size, is close to the one of shortest path, is consistently better than that of Up/Down, and is equal or better than Turn Prohibition, with the advantage of having a lower complexity.En prens

The microbiome of the uropygial secretion in hoopoes is shaped along the nesting phase

Microbial symbiont acquisition by hosts may determine the effectiveness of the mutualistic relationships. A mix of vertical and horizontal transmission may be advantageous for hosts by allowing plastic changes of microbial communities depending on environmental conditions. Plasticity is well known for gut microbiota but is poorly understood for other symbionts of wild animals. We here explore the importance of environmental conditions experienced by nestling hoopoes (Upupa epops) during the late nesting phase determining microbiota in their uropygial gland. In cross-fostering experiments of 8 days old nestlings, “sibling-sibling” and “mother-offspring” comparisons were used to explore whether the bacterial community naturally established in the uropygial gland of nestlings could change depending on experimental environmental conditions (i.e., new nest environment). We found that the final microbiome of nestlings was mainly explained by nest of origin. Moreover, cross-fostered nestlings were more similar to their siblings and mothers than to their stepsiblings and stepmothers. We also detected a significant effect of nest of rearing, suggesting that nestling hoopoes acquire most bacterial symbionts during the first days of life but that the microbiome is dynamic and can be modified along the nestling period depending on environmental conditions. Estimated effects of nest of rearing, but also most of those of nest of origin are associated to environmental characteristics of nests, which are extended phenotypes of parents. Thus, natural selection may favor the acquisition of appropriated microbial symbionts for particular environmental conditions found in nests.Support by funding was provided by Spanish Ministerio de Economía y Competitividad, European funds (FEDER) (CGL2013-48193-C3-1-P, CGL2013-48193-C3-2-P), and Junta de Andalucía (P09-RNM-4557). AM-G had a predoctoral grant from the Junta de Andalucía (P09-RNM-4557).Peer reviewe

Non-conservation of folding rates in the thioredoxin family reveals degradation of ancestral unassisted-folding

Evolution involves not only adaptation, but also the degradation of superfluous features. Many examples of degradation at the morphological level are known (vestigial organs, for instance). However, the impact of degradation on molecular evolution has been rarely addressed. Thioredoxins serve as general oxidoreductases in all cells. Here, we report extensive mutational analyses on the folding of modern and resurrected ancestral bacterial thioredoxins. Contrary to claims from recent literature, in vitro folding rates in the thioredoxin family are not evolutionarily conserved, but span at least a ∼100-fold range. Furthermore, modern thioredoxin folding is often substantially slower than ancestral thioredoxin folding. Unassisted folding, as probed in vitro, thus emerges as an ancestral vestigial feature that underwent degradation, plausibly upon the evolutionary emergence of efficient cellular folding assistance. More generally, our results provide evidence that degradation of ancestral features shapes, not only morphological evolution, but also the evolution of individual proteins.This research was supported by FEDER Funds, grant BIO2015-66426-R from the Spanish Ministry of Economy and Competitiveness ( J.M.S.-R.), grant RGP0041/2017 from the Human Frontier Science Program ( J.M.S.-R. and E.A.G.) and National Institutes of Health 1R01AR069137 (E.A.G.), Department of Defence MURI W911NF-16-1-0372 (E.A.G.)

Mapa de series, geoseries y geopermaseries de vegetación de España (Memoria del mapa de vegetación potencial de España). Parte II

Peer Reviewe

Inhaled Methoxyflurane Provides Greater Analgesia and Faster Onset of Action Versus Standard Analgesia in Patients With Trauma Pain: InMEDIATE: A Randomized Controlled Trial in Emergency Departments

Study objective: The objective of the InMEDIATE study was to evaluate the change in intensity of traumatic pain over the first 20 min in adult patients treated with methoxyflurane versus standard analgesic treatment in Spain. This the first randomized, active-controlled, multicenter trial of methoxyflurane in the emergency setting in Europe. Methods: This was a randomized, controlled study that enrolled adult patients with acute moderate to severe (score >= 4 on the 11-point Numeric Rating Scale) trauma-associated pain in 14 Spanish emergency departments. Patients were randomized 1:1 to methoxyflurane (up to 2x3 mL) or standard analgesic treatment. Coprimary endpoints were the change from baseline in Numeric Rating Scale pain intensity score during the first 20 minutes of treatment and time to first pain relief. Results: Three hundred five patients were randomized (methoxyflurane 156; standard analgesic treatment 149). Most patients in the standard analgesic treatment group (70%) received intravenous first-step analgesics and 9.4% of patients were treated with opioids. Mean decrease from baseline in Numeric Rating Scale pain intensity score was greater for methoxyflurane than standard analgesic treatment at all points, with a significant treatment difference overall up to 20 minutes (repeated-measures model 2.47 versus 1.39; treatment difference 1.00; 95% confidence interval 0.84 to 1.32). Median time to first pain relief was significantly shorter for methoxyflurane than standard analgesic treatment (3 versus 10 minutes). Methoxyflurane achieved better patient and clinician ratings for pain control and comfort of treatment than standard analgesic treatment and exceeded patient and clinician expectations of treatment in, respectively, 77% and 72% of cases compared with 38% and 19% for standard analgesic treatment. Conclusion: These results support consideration of methoxyflurane as a nonnarcotic, easy-to-administer, rapid-acting, first-line alternative to currently available analgesic treatments for trauma pain

Acquisition of uropygial gland microbiome by hoopoe nestlings

Mutualistic symbioses between animals and bacteria depend on acquisition of appropriate symbionts while avoiding exploitation by non-beneficial microbes. The mode of acquisition of symbionts would determine, not only the probability of encountering but also evolutionary outcomes of mutualistic counterparts. The microbiome inhabiting the uropygial gland of the European hoopoe (Upupa epops) includes a variety of bacterial strains, some of them providing antimicrobial benefits. Here, the mode of acquisition and stability of this microbiome is analyzed by means of Automated rRNA Intergenic Spacer Analysis and two different experiments. The first experiment impeded mothers’ access to their glands, thus avoiding direct transmission of microorganisms from female to offspring secretions. The second experiment explored the stability of the microbiomes by inoculating glands with secretions from alien nests. The first experiment provoked a reduction in similarity of microbiomes of mother and nestlings. Interestingly, some bacterial strains were more often detected when females had not access to their glands, suggesting antagonistic effects among bacteria from different sources. The second experiment caused an increase in richness of the microbiome of receivers in terms of prevalence of Operational Taxonomic Units (OTUs) that reduced differences in microbiomes of donors and receivers. That occurred because OTUs that were present in donors but not in receivers incorporated to the microbiome of the latter, which provoked that cross-inoculated nestlings got similar final microbiomes that included the most prevalent OTUs. The results are therefore consistent with a central role of vertical transmission in bacterial acquisition by nestling hoopoes and support the idea that the typical composition of the hoopoe gland microbiome is reached by the incorporation of some bacteria during the nestling period. This scenario suggests the existence of a coevolved core microbiome composed by a mix of specialized vertically transmitted strains and facultative symbionts able to coexist with them. The implications of this mixed mode of transmission for the evolution of the mutualism are discussedMinisterio de Ciencia e Innovación (España)Junta de Andalucí

Perceived economic self‑sufficiency: a countryand generation‑comparative approach

We thank Michael Camasso and Radha Jagannathan as well as Asimina Christoforou, Gerbert Kraaykamp, Fay Makantasi, Tiziana Nazio, Kyriakos Pierrakakis, Jacqueline O’Reilly and Jan van Deth for their contribution to the CUPESSE project (Seventh Framework Programme; Grant Agreement No. 61325). CUPESSE received additional funding from the Mannheim Centre for European Social Research (MZES) and the Field of Focus 4 “Self-Regulation and Regulation: Individuals and Organisations” at Heidelberg University. We further acknowledge helpful comments on this article by two anonymous reviewers. Julian Rossello provided valuable research assistance.Electronic supplementary material The online version of this article (https ://doi.org/10.1057/ s4130 4-018-0186-3) contains supplementary material, which is available to authorized users.Existing datasets provided by statistical agencies (e.g. Eurostat) show that the economic and financial crisis that unfolded in 2008 significantly impacted the lives and livelihoods of young people across Europe. Taking these official statistics as a starting point, the collaborative research project “Cultural Pathways to Economic Self-Sufficiency and Entrepreneurship in Europe” (CUPESSE) generated new survey data on the economic and social situation of young Europeans (18–35 years). The CUPESSE dataset allows for country-comparative assessments of young people’s perceptions about their socio-economic situation. Furthermore, the dataset includes a variety of indicators examining the socio-economic situation of both young adults and their parents. In this data article, we introduce the CUPESSE dataset to political and social scientists in an attempt to spark a debate on the measurements, patterns and mechanisms of intergenerational transmission of economic self-sufficiency as well as its political implications.CUPESSE project (Seventh Framework Programme; Grant Agreement No. 61325