Flow induced dissolution of femtoliter surface droplet arrays

The dissolution of liquid nanodroplets is a crucial step in many applied processes, such as separation and dispersion in food industry, crystal formation of pharmaceutical products, concentrating and analysis in medical diagnosis, and drug delivery in aerosols. In this work, using both experiments and numerical simulations, we \textit{quantitatively} study the dissolution dynamics of femtoliter surface droplets in a highly ordered array under a uniform flow. Our results show that the dissolution of femoliter droplets strongly depends on their spatial positions relative to the flow direction, drop-to-drop spacing in the array, and the imposed flow rate. In some particular case, the droplet at the edge of the array can dissolve about 30% faster than the ones located near the centre. The dissolution rate of the droplet increases by 60% as the inter-droplet spacing is increased from 2.5 $\mu$m to 20 $\mu$m. Moreover, the droplets close to the front of flow commence to shrink earlier than those droplets in the center of the array. The average dissolution rate is faster for faster flow. As a result, the dissolution time $T_{i}$ decreases with the Reynolds number Re of the flow as $T_{i}\propto Re^{-3/4}$. The experimental results are in good agreement with numerical simulations where the advection-diffusion equation for the concentration field is solved and the concentration gradient on the surface of the drop is computed. The findings suggest potential approaches to manipulate nanodroplet sizes in droplet arrays simply by dissolution controlled by an external flow. The obtained droplets with varying curvatures may serve as templates for generating multifocal microlens in one array

Manuel Varela Rodríguez (Malpica, 1954 – Caión, 2019)

2 pages.-- This work is licensed under a Creative Commons Attribution 4.0 International LicensePeer reviewe

Mieropaleontologieal study of an holoeene eoastal peat in the Ría de Ares (A Coruña, España)

[Resumen] El análisis de polen, diatomeas y foraminíferos de un sedimento litoral en la Ría de Ares (A Coruña, España) ha permitido interpretaciones paleoambientales comparables. Se trata de un sedimento turboso con macrorrestos vegetales. El análisis micropaleontológico de este nivel y las dataciones absolutas sitúan la formación del mismo en el período Subboreal. La lectura paleoecológica obtenida a través del estudio micropaleontológico nos permite reconstituir dos paleoambientes fundamentalmente: un medio continental vegetado y un ambiente con condiciones salobres, consecuencia del aumento del nivel del mar.[Abstract] Pollen, diatoms and foraminifera from a raised marine sediment of the Ría de Ares (A Coruña, Spain) area produced comparable paleoenvironntental interpretations. It is an organic formation with peat associated with numerous vegetal rests. The micropaleontological analysis of this level and the absolute dating, place its formation in the Subboreal periodo The paleoecological reading obtained from a micropaleontological study allows us to reconstitute two basic paleoenvironments: a vegetal continental environment and an environment with salty conditions, as a consequence of the sea level increas

Postglacial evolution of the Lake of Villaseca (NW Iberian Peninsula) inferred from diatom analysis

[Abstract] The lake of Villaseca is located in the foothills of the southern Cantabrian Mountains, nearby Villaseca de Laciana (León,NWIberian Peninsula). This lake has a glacier origin and has been formed due to the obstruction of a lateral moraine of the glacier tongue that will be canalized through the Valley of Brañas de Roble. Once discovered during the Late Glacial (over 23,000 years), the linle basin beganto work as a catchment area. A 893 cm length record has been srudied. Ir shows the postglacial evolution of the lake. Most part of this record (beteween 260-893 cm) is represented by a detritic varved sedimentation, where the absence of diatoms is clear, although the pollen record is continous all through the sequence. In this period, the paleolimnological reconstruction can't be done, because the grains of pollen in the sediment proceed from an alloctonous source and they only reflect the landscape in the surroundings of the lake. With the begining of the Late Glacial the lake of Villaseca began to present an autoctonous diatom flora and the basin changed to mesotrophic and slightly alkaline conditions. The most important data proceed from the study of the diatoms succession, which points out and environment dominated by tychoplanktonic Fragilaria assemblages, only interrupted by a period ofperiphytic, acidophilous and oligotrophic assemblages. During this episode the pollen record points out a stepic vegetation, represented by Artemisia and Poaceae. During the Postglacial, the basin becomes completely filled and the number of acidophilous taxa increase. This is a typical final step of the filling process ofa lake before transforming into a bog as the presence of Sphagnum establishes

JWST CEERS & JADES Active Galaxies at z = 4-7 Violate the Local M∙−M⋆M_\bullet-M_\star Relation at >3σ>3\sigma: Implications for Low-Mass Black Holes and Seeding Models

JWST is revolutionizing our understanding of the high-z Universe by expanding the black hole horizon, looking farther and to smaller masses, and revealing the stellar light of their hosts. New detections of high-z systems offer unprecedented insights into the formation of the first black holes and their early co-evolution with galaxies. By examining JWST galaxies at z=4-7 that host H$\alpha$-detected black holes, we investigate (i) the high-z $M_\bullet-M_\star$ relation and (ii) the black hole mass distribution, especially in its low-mass range ($M_\bullet\lesssim10^{6.5} M_\odot$). With a detailed statistical analysis, our findings conclusively reveal a high-z $M_\bullet-M_\star$ relation that deviates at $>3\sigma$ confidence level from the local relation: $\log(M_\bullet/M_\odot) = -2.38^{+0.82}_{-0.83}+1.06^{+0.09}_{-0.09}\log(M_\star/M_\odot)$. Black holes are overmassive by $\sim10-100\times$ compared to their local counterparts in similar galactic hosts. This fact is not due to a selection effect in surveys. Moreover, our analysis predicts the possibility of detecting in high-z JWST surveys $5-18\times$ more black holes with $M_\bullet\lesssim10^{6.5} M_\odot$, and $10-30\times$ more with $M_\bullet \lesssim 10^{8.5} M_\odot$, compared to local relation's predictions. The lighter black holes preferentially occupy galaxies with a stellar mass of $\sim 10^{7.5}-10^8 M_\odot$. We have yet to detect these sources because (i) they may be inactive (duty cycles 1%-10%), (ii) the host overshines the AGN, or (iii) the AGN is obscured and not immediately recognizable by line diagnostics. A search of low-mass black holes in existing JWST surveys will further test the $M_\bullet-M_\star$ relation. Current JWST fields represent a treasure trove of black hole systems at z=4-7; their detection will provide crucial insights into their early evolution and co-evolution with their galactic hosts.Comment: Submitted for publication in The Astrophysical Journal Letters. 13 pages, 5 figure

Proxecto de Aprendizaxe-Servizo: proposta de restauración dos hábitats acuáticos do humidal de Cospeito

Banco de experiencias de Aprendizaxe Servizo. Convocatoria 2019/202

Tiny hand gesture recognition without localization via a deep convolutional network

Visual hand-gesture recognition is being increasingly desired for human-computer interaction interfaces. In many applications, hands only occupy about 10% of the image, whereas the most of it contains background, human face, and human body. Spatial localization of the hands in such scenarios could be a challenging task and ground truth bounding boxes need to be provided for training, which is usually not accessible. However, the location of the hand is not a requirement when the criteria is just the recognition of a gesture to command a consumer electronics device, such as mobiles phones and TVs. In this paper, a deep convolutional neural network is proposed to directly classify hand gestures in images without any segmentation or detection stage that could discard the irrelevant not-hand areas. The designed hand-gesture recognition network can classify seven sorts of hand gestures in a user-independent manner and on real time, achieving an accuracy of 97.1% in the dataset with simple backgrounds and 85.3% in the dataset with complex backgrounds

Proposta de restauración dos hábitats acuáticos do humidal de Cospeito

Banco de experiencias de Aprendizaxe Servizo. Convocatoria 2020/202

Subcutaneous tocilizumab in rheumatoid arthritis: findings from the common-framework phase 4 study programme TOZURA conducted in 22 countries

Objectives The aim of this pooled analysis of the TOZURA study programme was to evaluate the efficacy and safety of subcutaneous tocilizumab (TCZ-SC) as monotherapy or in combination with conventional synthetic DMARDs (csDMARDs) in patients with moderate to severe RA who had an inadequate response to csDMARD or anti-TNF agent therapy or who were MTX naïve. Methods TOZURA is a multinational, open-label, single-arm, common-framework, phase 4 study programme (11 protocols, 22 countries). Patients received TCZ-SC 162 mg each week for ⩾24 weeks, administered at the investigator’s discretion, as monotherapy or in combination with a csDMARD. Efficacy, safety and immunogenicity were evaluated; propensity score–based matching was used for between-group comparisons. Results Of 1804 patients, 353 (19.6%) received monotherapy and 1451 (80.4%) received combination therapy. The 28-joint DAS using ESR (DAS28-ESR) in both groups decreased significantly from baseline to week 24 (mean change: monotherapy −3.40, combination therapy −3.46), with no significant difference between groups (P = 0.46). The proportion of patients who achieved DAS28-ESR or Clinical Disease Activity Index remission or ACR 20/50/70/90 responses was similar between groups. Overall, 13.9% of patients withdrew—6.2% for safety reasons and 1.6% for insufficient therapeutic response; 5.8% of patients experienced one or more serious adverse events [14.6/100 patient-years (PY)]; six deaths occurred (0.64/100 PY). Conclusion In a common framework of 11 studies in 22 countries, this phase 4 study programme confirmed TCZ-SC’s known efficacy and safety profile with comparable effects as monotherapy and in combination with csDMARDs