90 research outputs found
Pseudovivipary, a new form of asexual reproduction in the seagrass Posidonia oceanica
Short communicationThe seagrass Posidonia oceanica is able to reproduce by asexual formation of plantlets directly in the inflorescence. Pseudoviviparous plantlets were observed during May 2004 in 26% of the inflorescences in a P. oceanica meadow off the island of Formentera (Balearic Islands, Western Mediterranean Sea). We do not know how frequently pseudovivipary occurs in Posidonia oceanica, nor the mechanisms triggering it, but this strategy can contribute significantly to short-distance dispersal and meadow maintenance, which is especially relevant in a species whose meadows can persist for thousands of years and whose colonization of new space occurs very slowly.This work was supported by the Fisheries Department (Direcció General de Pesca) of the Balearic Government.Peer reviewe
Comportamiento mecánico en función de la temperatura de aleaciones wolframio-vanadio.
En esta investigación se evalúa el comportamiento mecánico del wolframio puro y de dos de sus aleaciones con contenidos de 2% y 4% de vanadio, fabricadas mediante prensado isostático en caliente (HIP). La caracterización mecánica se ha realizado mediante ensayos de flexión en tres puntos en atmósfera oxidante a distintas temperaturas comprendidas entre temperatura ambiente y 1000 ºC. Adicionalmente, se han realizado ensayos en inmersión en nitrógeno líquido para los de -197 ºC. Estos últimos valores pueden servir para una determinación más precisa de la temperatura la transición dúctil-frágil en éstos materiales, y de su posible comportamiento plástico o frágil a temperatura ambiente. Mediante estos ensayos ha sido posible obtener la tenacidad de fractura, la resistencia mecánica, el límite elástico y el módulo de elasticidad en función de la temperatura. Así mismo, se ha determinado la densidad y la dureza Vickers para dos cargas distintas, lo que permitido determinar la influencia de este parámetro en la medida realizada. Adicionalmente, se han examinado mediante microscopia electrónica de barrido las superficies de fractura. De esta forma ha sido posible determinar el modo de rotura y analizar la relación de las propiedades mecánicas macroscópicas con los micromecanismos de fallo involucrados
Interpretable global-local dynamics for the prediction of eye fixations in autonomous driving scenarios
Human eye movements while driving reveal that visual attention largely depends on the context in which it occurs. Furthermore, an autonomous vehicle which performs this function would be more reliable if its outputs were understandable. Capsule Networks have been presented as a great opportunity to explore new horizons in the Computer Vision field, due to their capability to structure and relate latent information. In this article, we present a hierarchical approach for the prediction of eye fixations in autonomous driving scenarios. Context-driven visual attention can be modeled by considering different conditions which, in turn, are represented as combinations of several spatio-temporal features. With the aim of learning these conditions, we have built an encoder-decoder network which merges visual features' information using a global-local definition of capsules. Two types of capsules are distinguished: representational capsules for features and discriminative capsules for conditions. The latter and the use of eye fixations recorded with wearable eye tracking glasses allow the model to learn both to predict contextual conditions and to estimate visual attention, by means of a multi-task loss function. Experiments show how our approach is able to express either frame-level (global) or pixel-wise (local) relationships between features and contextual conditions, allowing for interpretability while maintaining or improving the performance of black-box related systems in the literature. Indeed, our proposal offers an improvement of 29% in terms of information gain with respect to the best performance reported in the literature.The authors would like to thank the authors from DR(eye)VE Project [49] for the support provided during this work, as well as the Multimedia Processing Group from the Universidad Carlos III de Madrid for their entire personal and academic implication
Impact of goal directed therapy in head and neck oncological surgery with microsurgical reconstruction: free flap viability and complications
Background: Surgical outcomes in free flap reconstruction of head and neck defects in cancer patients have improved steadily in recent years; however, correct anaesthesia management is also important. The aim of this study has been to show whether goal directed therapy can improve flap viability and morbidity and mortality in surgical patients. Methods: we performed an observational case control study to analyse the impact of introducing a semi invasive device (Flo Trac®) during anaesthesia management to optimize fluid management. Patients were divided into two groups: one received goal directed therapy (GDT group) and the other conventional fluid management (CFM group). Our objective was to compare surgical outcomes, complications, fluid management, and length of stay between groups. Results: We recruited 140 patients. There were no differences between groups in terms of demographic data. Statistically significant differences were observed in colloid infusion (GDT 53.1% vs. CFM 74.1%, p = 0.023) and also in intraoperative and postoperative infusion of crystalloids (CFM 5.72 (4.2, 6.98) vs. GDT 3.04 (2.29, 4.11), p < 0.001), which reached statistical significance. Vasopressor infusion in the operating room (CFM 25.5% vs. GDT 74.5%, p < 0.001) and during the first postoperative 24h (CFM 40.6% vs. GDT 75%, p > 0.001) also differed. Differences were also found in length of stay in the intensive care unit (hours: CFM 58.5 (40, 110) vs. GDT 40.5 (36, 64.5), p = 0.005) and in the hospital (days: CFM 15.5 (12, 26) vs. GDT 12 (10, 19), p = 0.009). We found differences in free flap necrosis rate (CMF 37.1% vs. GDT 13.6%, p = 0.003). One-year survival did not differ between groups (CFM 95.6% vs. GDT 86.8%, p = 0.08). Conclusions: Goal directed therapy in oncological head and neck surgery improves outcomes in free flap reconstruction and also reduces length of stay in the hospital and intensive care unit, with their corresponding costs. It also appears to reduce morbidity, although these differences were not significant. Our results have shown that optimizing intraoperative fluid therapy improves postoperative morbidity and mortalit
Análisis de la infraestructura de movilidad eléctrica en la ciudad de Zaragoza: patrones espaciales de las estaciones de carga para vehículos eléctricos
En el camino a la sostenibilidad de la movilidad urbana, el creciente interés por la movilidad eléctrica, y el consiguiente incremento del parque de vehículos, hace necesaria la existencia de estaciones de carga para vehículos eléctricos, o electrolineras. En la ciudad de Zaragoza su número ha aumentado en los últimos años, sin embargo, queda evaluar si la actual dotación de estaciones, sus características y distribución por la ciudad son apropiadas. Mediante el presente Trabajo fin de grado, se pretende realizar un análisis sistemático del proceso de implantación urbana de este tipo de infraestructura en la ciudad. Esto supone el estudio de la dinámica espaciotemporal experimentada, la caracterización de las estaciones y el análisis de los factores de localización. El trabajo termina con la valoración de si la actual dotación de las infraestructuras estudiadas satisface las expectativas y necesidades de una ciudad compacta de tamaño intermedio y con la proposición de mejoras de la red existente.<br /
An almost dark galaxy with the mass of the Small Magellanic Cloud
Almost Dark Galaxies are objects that have eluded detection by traditional
surveys such as the Sloan Digital Sky Survey (SDSS). The low surface brightness
of these galaxies ((0) mag/arcsec^2), and hence their low surface
stellar mass density (a few solar masses per pc^2 or less), suggests that the
energy density released by baryonic feedback mechanisms is inefficient in
modifying the distribution of the dark matter halos they inhabit. For this
reason, almost dark galaxies are particularly promising for probing the
microphysical nature of dark matter. In this paper, we present the
serendipitous discovery of Nube, an almost dark galaxy with e~ 26.7
mag/arcsec^2. The galaxy was identified using deep optical imaging from the IAC
Stripe82 Legacy Project. Follow-up observations with the 100m Green Bank
Telescope strongly suggest that the galaxy is at a distance of 107 Mpc.
Ultra-deep multi-band observations with the 10.4m Gran Telescopio Canarias
favour an age of ~10 Gyr and a metallicity of [Fe/H]. With a stellar
mass of ~4x10^8 Msun and a half-mass radius of Re=6.9 kpc (corresponding to an
effective surface density of ~0.9 Msun/pc^2), Nube is the most massive and
extended object of its kind discovered so far. The galaxy is ten times fainter
and has an effective radius three times larger than typical ultra-diffuse
galaxies with similar stellar masses. Galaxies with comparable effective
surface brightness within the Local Group have very low mass (~10^5 Msun) and
compact structures (effective radius Re<1 kpc). Current cosmological
simulations within the cold dark matter scenario, including baryonic feedback,
do not reproduce the structural properties of Nube. However, its highly
extended and flattened structure is consistent with a scenario where the dark
matter particles are ultra-light axions with a mass of
m=() eV.}Comment: Accepted for publication in A&A. Main figures are 8, 9 and 1
Neoadjuvant eribulin in HER2-negative early-stage breast cancer (SOLTI-1007-NeoEribulin): a multicenter, two-cohort, non-randomized phase II trial
Breast cancer; Predictive markers; Translational researchCáncer de mama; Maradores predictivos; Investigación traslacionalCàncer de mama; Marcadors predictius; Recerca translacionalEribulin prolongs overall survival in patients with pre-treated advanced breast cancer. However, no biomarker exists to prospectively select patients who will benefit the most from this drug. SOLTI-1007-NeoEribulin is a phase II, open-label, two-cohort, exploratory pharmacogenomic study in patients with clinical stage I–II HER2-negative breast cancer receiving neoadjuvant eribulin monotherapy treatment. Primary objective was to explore the association of baseline tumor gene expression with pathological complete response in the breast (pCRB) at surgery. Key secondary objectives were pCRB rates in all patients and according to HR status, gene expression changes during treatment and safety. One-hundred one hormonal receptor-positive (HR + ) and seventy-three triple-negative breast cancer (TNBC) patients were recruited. The pCRB rates were 6.4% in all patients, 4.9% in HR + disease and 8.2% in TNBC. The TNBC cohort was interrupted due to a progression disease rate of 30.1%. The pCRB rates differed according to intrinsic subtypes: 28.6% in HER2-enriched, 11.1% in Normal-like, 7.9% in Luminal B, 5.9% in Basal-like and 0% in Luminal A (HER2-enriched vs. others odds ratio = 7.05, 95% CI 1.80–42.14; p-value = 0.032). Intrinsic subtype changes at surgery occurred in 33.3% of cases, mostly (49.0%) Luminal B converting to Luminal A or Basal-like converting to Normal-like. Baseline tumor-infiltrating lymphocytes (TILs) were significantly associated with pCR. Eribulin showed a good safety profile with a low response and pCRB rates. Patients with HER2-negative disease with a HER2-enriched profile may benefit the most from eribulin. In addition, significant biological activity of eribulin is observed in Luminal B and Basal-like subtypes
Identification of Poor-outcome Biliopancreatic Carcinoma Patients With Two-marker Signature Based on ATF6a and p-p38 "STARD Compliant"
Biliopancreatic cancer is one of the most aggressive solid neoplasms, and incidence is rising worldwide. It is known that ATF6¿ is one of the transmembrane proteins that acts crucially in endoplasmic reticulum stress response, and knockdown induces apoptosis of pancreatic cells. Apart from this, p-p38 has been previously correlated with better outcome in pancreatic cancer. Interestingly, ATF6¿ knockdown pancreatic cells showed increased p-p38. The aim of this study was to evaluate the expression of these 2 proteins, p-p38 and ATF6¿, and their correlation with the outcome of biliopancreatic adenocarcinoma patients. Samples from patients with biliopancreatic adenocarcinoma that underwent pancreaticoduodenectomy from 2007 to 2013 were used to construct a tissue microarray to evaluate p-p38 and ATF6¿ proteins by immunohistochemistry. We observed that both markers showed a tendency to impact in the time to recurrence; then a combination of these 2 proteins was analyzed. Combination of ATF6¿(high) and p-p38(low) was strongly associated with a higher risk of recurrence (hazard ratio 2.918, P = 0.013). This 2-protein model remained significant after multivariate adjustment.We proposed a 2-protein signature based on ATF6¿(high) and p-p38(low) as a potential biomarker of risk of recurrence in resected biliopancreatic adenocarcinoma patients
The temporal mutational and immune tumour microenvironment remodelling of HER2-negative primary breast cancers
Càncer de mama; Genòmica del càncer; Biomarcadors tumoralsCáncer de mama; Genómica del cáncer; Biomarcadores tumoralesBreast cancer; Cancer genomics; Tumour biomarkersThe biology of breast cancer response to neoadjuvant therapy is underrepresented in the literature and provides a window-of-opportunity to explore the genomic and microenvironment modulation of tumours exposed to therapy. Here, we characterised the mutational, gene expression, pathway enrichment and tumour-infiltrating lymphocytes (TILs) dynamics across different timepoints of 35 HER2-negative primary breast cancer patients receiving neoadjuvant eribulin therapy (SOLTI-1007 NEOERIBULIN-NCT01669252). Whole-exome data (N = 88 samples) generated mutational profiles and candidate neoantigens and were analysed along with RNA-Nanostring 545-gene expression (N = 96 samples) and stromal TILs (N = 105 samples). Tumour mutation burden varied across patients at baseline but not across the sampling timepoints for each patient. Mutational signatures were not always conserved across tumours. There was a trend towards higher odds of response and less hazard to relapse when the percentage of subclonal mutations was low, suggesting that more homogenous tumours might have better responses to neoadjuvant therapy. Few driver mutations (5.1%) generated putative neoantigens. Mutation and neoantigen load were positively correlated (R2 = 0.94, p = <0.001); neoantigen load was weakly correlated with stromal TILs (R2 = 0.16, p = 0.02). An enrichment in pathways linked to immune infiltration and reduced programmed cell death expression were seen after 12 weeks of eribulin in good responders. VEGF was downregulated over time in the good responder group and FABP5, an inductor of epithelial mesenchymal transition (EMT), was upregulated in cases that recurred (p < 0.05). Mutational heterogeneity, subclonal architecture and the improvement of immune microenvironment along with remodelling of hypoxia and EMT may influence the response to neoadjuvant treatment.This work was supported by Cancer Research UK. L.D.M.A. was partly funded by Spanish Association against cancer
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