173 research outputs found
Revisión de los eventos de afloramiento en Galicia: eventos fuera de temporada en las rías (1967–2009)
Over the last decades several studies have been conducted on upwelling along the Galician coast that have significantly improved the knowledge of this process. These investigations showed that upwelling along this coast is a frequent phenomenon during the spring and summer months, pumping colder Eastern North Atlantic Central Water into the rias. Nevertheless, several upwelling events in autumn and winter have been characterized in the Galician rias, indicating that the upwelling process along the Galician coast is not a phenomenon restricted to spring and summer. In this study the recurrence of these upwelling events has been reviewed from published articles and analyzed from 1967 to 2009 along the western and northern Galician coasts in terms of an upwelling index. The highest mean number of days under favorable upwelling conditions per month was observed during spring and summer on the western (18–26 days) and northern (12–14 days) coasts. During autumn and winter the number of days was lower (11–18 days, western coast; 8–10 days, northern coast) although not negligible, showing the possibility of observing upwelling events during this period. In fact, during these months a significant probability of observing favorable upwelling conditions along both coasts (26%) was found, though the most probable situation corresponded to unfavorable upwelling conditions (44%). The results thus revealed that these events cannot be considered isolated episodes. Upwelling processes in the rias should be observed under favorable conditions, such as prevalence of northerly wind at the adjacent western Galician shelf, independently of the season.Durante las últimas décadas se han llevado a cabo varios estudios relacionados con el fenómeno de afloramiento a lo largo de la costa de Galicia que han mejorado significativamente el conocimiento de este proceso. De los resultados de estos trabajos se ha encontrado que el afloramiento a lo largo de esta costa es un fenómeno frecuente durante los meses de primavera y verano, introduciendo Agua Central del Atlántico Norte en el interior de las rías. Sin embargo, en las rías gallegas se han caracterizado varios eventos de afloramiento durante otoño e invierno que indican que este proceso no es un fenómeno exclusivo de las estaciones de primavera y verano. En este estudio se hace una revisión de estos eventos teniendo en cuenta artículos ya publicados y también se analiza su recurrencia a lo largo de las costas oeste y norte de Galicia a partir de datos de índice de afloramiento de 1967 a 2009. El número medio de días por mes con condiciones favorables de afloramiento más elevado se observó durante los meses de primavera y verano en la costa oeste (18–26 días) y costa norte (12–14 días). Durante otoño e invierno este número de días fue menor (11–18 días, costa oeste; 8–10 días, costa norte) aunque no despreciable, indicando la posibilidad de observar eventos de afloramiento durante este periodo. De hecho, durante estos meses se observó una cierta probabilidad de obtener condiciones favorables de afloramiento a lo largo de ambas costas (26%), aunque la situación más probable correspondió a condiciones desfavorables (44%). Estos resultados revelaron que estos eventos no se pueden considerar como episodios aislados. De esto se deduce que los procesos de afloramiento en las rías deberían ser observados bajo condiciones favorables, tales como vientos predominantes del norte en la plataforma adyacente, independientemente de la estación.publishe
The national inventory of geological heritage: methodological approach and results
A existência de um inventário nacional de património geológico é fundamental para se poderem implementar estratégias de geoconservação. Este trabalho apresenta a metodologia usada no desenvolvimento do mais completo inventário de geossítios, realizado até ao momento em Portugal, assim como os principais resultados obtidos. O inventário vai integrar o Sistema de Informação do Património Natural e o Cadastro Nacional dos Valores Naturais Classificados, ambos geridos pelo Instituto de Conservação da Natureza e da Biodiversidade.The existence of a national inventory of the geological heritage is of paramount importance for the implementation of a geoconservation strategy. This paper presents the methodological approach used to produce the most complete geosites inventory in Portugal, so far, and the obtained results. This inventory will be uploaded into the National Database of Natural Heritage managed by the Portuguese authority for nature conservation.Este trabalho é apoiado pela Fundação para a Ciência e a Tecnologia, através do financiamento plurianual do CGUP e do projecto de investigação “Identificação, caracterização e conservação do património geológico: uma estratégia de geoconservação para Portugal” (PTDC/CTE-GEX/64966/2006).info:eu-repo/semantics/publishedVersio
Why Are Outcomes Different for Registry Patients Enrolled Prospectively and Retrospectively? Insights from the Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF).
Background: Retrospective and prospective observational studies are designed to reflect real-world evidence on clinical practice, but can yield conflicting results. The GARFIELD-AF Registry includes both methods of enrolment and allows analysis of differences in patient characteristics and outcomes that may result. Methods and Results: Patients with atrial fibrillation (AF) and ≥1 risk factor for stroke at diagnosis of AF were recruited either retrospectively (n = 5069) or prospectively (n = 5501) from 19 countries and then followed prospectively. The retrospectively enrolled cohort comprised patients with established AF (for a least 6, and up to 24 months before enrolment), who were identified retrospectively (and baseline and partial follow-up data were collected from the emedical records) and then followed prospectively between 0-18 months (such that the total time of follow-up was 24 months; data collection Dec-2009 and Oct-2010). In the prospectively enrolled cohort, patients with newly diagnosed AF (≤6 weeks after diagnosis) were recruited between Mar-2010 and Oct-2011 and were followed for 24 months after enrolment. Differences between the cohorts were observed in clinical characteristics, including type of AF, stroke prevention strategies, and event rates. More patients in the retrospectively identified cohort received vitamin K antagonists (62.1% vs. 53.2%) and fewer received non-vitamin K oral anticoagulants (1.8% vs . 4.2%). All-cause mortality rates per 100 person-years during the prospective follow-up (starting the first study visit up to 1 year) were significantly lower in the retrospective than prospectively identified cohort (3.04 [95% CI 2.51 to 3.67] vs . 4.05 [95% CI 3.53 to 4.63]; p = 0.016). Conclusions: Interpretations of data from registries that aim to evaluate the characteristics and outcomes of patients with AF must take account of differences in registry design and the impact of recall bias and survivorship bias that is incurred with retrospective enrolment. Clinical Trial Registration: - URL: http://www.clinicaltrials.gov . Unique identifier for GARFIELD-AF (NCT01090362)
3D Point Cloud Analysis via Transformer-Based Graph Learning for Multiple Sclerosis Screening in OCT Images
Presented at: 28th International Conference on Knowledge-Based and Intelligent Information & Engineering Systems (KES 2024)[Abstract]: Multiple Sclerosis (MS), the leading cause of non-traumatic neurological impairment in young adults, manifests morphological changes in the retina observable in Optical Coherence Tomography (OCT) images. These changes in the Retinal Nerve Fibre Layer (RNFL) and the Ganglion Cell Layer - Bruch’s Membrane (GCL-BM) serve as potential computational biomarkers for MS. In this work, we propose a transformer-based graph learning approach for analyzing 3D point clouds generated from RNFL and GCL-BM contours, marking a first in the application of geometric deep learning (GDL) to MS diagnosis via OCT scans. Our proposal, tailored for efficiency, synergizes the global contextual strengths of transformers with the detailed, structure-aware capabilities of graph neural networks. Such integration allows for the nuanced analysis of complex retinal structures, significantly boosting the precision of MS detection by uncovering patterns not discernible to the human eye. Additionally, we conducted a comprehensive study on the optimal downsampling size of input 3D point clouds, ensuring efficient data processing without compromising diagnostic accuracy. Our optimal configuration achieved a test F1-Score of 0.88, using only 4.0% of total 3D points, showcasing the effectiveness of our method despite the higher computational demands compared to less complex, albeit less precise, configurations. These promising results are the first in the study of 3D analysis and transformer-based geometric deep learning for MS screening based on OCT images, which are revolutionizing neurophtalmological research.Funded by Instituto de Salud Carlos III (ISCIII), Government of Spain, [projects PI17/01726 and PI20/00437]; Inflammatory Disease Network (RICORS) [project RD21/0002/0050]; Ministerio de Ciencia e Innovacion, Government of Spain [ projects PID2019-108435RB-I00, TED2021-131201B-I00, and PDC2022-133132-I00]; Consellería de Educacion, Universidade, e Formación Profesional, Xunta de Galicia, Grupos de Referencia Competitiva, [grant number ED431C 2020/24]. Also supported by the ISCIII under the grant [FORT23/00010] as part of the Programa FORTALECE of Ministerio de Ciencia e Innovacion.Xunta de Galicia; ED431C 2020/2
Edible bio-based nanostructures: delivery, absorption and potential toxicity
The development of bio-based nanostructures as nanocarriers of bioactive compounds to specific body sites has been presented as a hot topic in food, pharmaceutical and nanotechnology fields. Food and pharmaceutical industries seek to explore the huge potential of these nanostructures, once they can be entirely composed of biocompatible and non-toxic materials. At the same time, they allow the incorporation of lipophilic and hydrophilic bioactive compounds protecting them against degradation, maintaining its active and functional performance. Nevertheless, the physicochemical properties of such structures (e.g., size and charge) could change significantly their behavior in the gastrointestinal (GI) tract. The main challenges in the development of these nanostructures are the proper characterization and understanding of the processes occurring at their surface, when in contact with living systems. This is crucial to understand their delivery and absorption behavior as well as to recognize potential toxicological effects. This review will provide an insight into the recent innovations and challenges in the field of delivery via GI tract using bio-based nanostructures. Also, an overview of the approaches followed to ensure an effective deliver (e.g., avoiding physiological barriers) and to enhance stability and absorptive intestinal uptake of bioactive compounds will be provided. Information about nanostructures potential toxicity and a concise description of the in vitro and in vivo toxicity studies will also be given.Joana T. Martins, Oscar L. Ramos, Ana C. Pinheiro, Ana I. Bourbon, Helder D. Silva and Miguel A. Cerqueira (SFRH/BPD/89992/2012, SFRH/BPD/80766/2011, SFRH/BPD/101181/2014, SFRH/BD/73178/2010, SFRH/BD/81288/2011, and SFRH/BPD/72753/2010, respectively) are the recipients of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, POPH-QREN and FSE, Portugal). The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes," REF.NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. We also thank to the European Commission: BIOCAPS (316265, FP7/REGPOT-2012-2013.1) and Xunta de Galicia: Agrupamento INBIOMED (2012/273) and Grupo con potencial de crecimiento. The support of EU Cost Action FA1001 is gratefully acknowledged
Burden and Characteristics of the Comorbidity Tuberculosis-Diabetes in Europe: TBnet Prevalence Survey and Case-Control Study
Background: The growing burden of diabetes mellitus (DM) is posing a threat to global tuberculosis (TB) control. DM triples the risk of developing TB, modifies the presenting features of pulmonary TB, and worsens TB treatment outcomes. We aimed to analyze the prevalence of DM among TB patients and to describe the characteristics and clinical presentation of TB-DM patients in Europe. Methods: We performed a cross-sectional survey on the prevalence of DM among consecutively diagnosed adult TB patients in 11 European TB referral centers located in France, Germany, Greece, Italy, Russia, Slovakia, Spain, and the United Kingdom over the period 2007-2015. We also selected DM-TB cases and TB only controls with a 1:3 ratio to perform a case-control analysis, including patients selected from the countries mentioned above plus Norway and Ukraine. Results: Among 3143 TB enrolled patients, DM prevalence overall was 10.7% and ranged from 4.4% in Greece to 28.5% in the United Kingdom. Patients' median ages ranged from 36 to 49 years, and all centers had >60% males; the proportion of foreign-born patients varied widely across sites. In the case-control study, DM was independently associated with older age and, among older patients, with being foreign-born. Among patients with pulmonary involvement, cavities on chest imaging were more frequently observed among those with DM. Conclusions: Diabetes mellitus represents a challenge for TB control in Europe, especially in foreign-born and in elderly patients. Specific screening strategies should be evaluated
Characterization of a winter upwelling event in the Northern Galician Rias
II International Symposium in Marine Sciences = II Simposio internacional de Ciencias del Mar, Vigo, 27-30 abril 2009N
Unusual circulation patterns of the rias baixas induced by minho freshwater intrusion (NW of the Iberian Peninsula)
The Minho River, situated 30 km south of the Rias Baixas, is the most important freshwater source flowing into the Western Galician coast (NW of the Iberian Peninsula). The buoyancy generated by the Minho estuarine plume can reverse the normal circulation pattern inside the Rias Baixas affecting the exchange between the Rias and the ocean, changing the input of nutrients. Nevertheless, this inversion of the circulation patterns is not a well-monitored phenomenon. The only published results based on in situ data related to the presence of the Minho River plume inside the Rias de Vigo and Pontevedra correspond to an event measured on spring 1998. In this case unexpectedly higher inflow surface current velocities were found at the Ria de Pontevedra, located further away from Minho River. Thus, the main aim of this study is to research the main factors inducing this unusual pattern on the circulation of the Rias de Vigo and Pontevedra. A numerical model implementation of MOHID previously developed, calibrated, and validated for this coastal area was used. Several scenarios were performed in order to explain the individual effect of the Minho River, rivers discharging into each Rias, and estuarine morphology changes. According to the model results, the Minho River discharge is a key factor in the establishment of the negative circulation, while small rivers inside the Rias slightly attenuate this circulation. The negative circulation was stronger in Ria de Pontevedra independently of the distance of this coastal system from the Minho River mouth, showing that morphologic estuarine features are the main factor justifying the different local circulation patterns
Morphological and anatomical features of the flowers and fruits during the development of Chamissoa altissima (Jacq.) Kunth (Amaranthaceae)
Enhancement of Cell Membrane Invaginations, Vesiculation and Uptake of Macromolecules by Protonation of the Cell Surface
The different pathways of endocytosis share an initial step involving local inward curvature of the cell’s lipid bilayer. It has been shown that to generate membrane curvature, proteins or lipids enforce transversal asymmetry of the plasma membrane. Thus it emerges as a general phenomenon that transversal membrane asymmetry is the common required element for the formation of membrane curvature. The present study demonstrates that elevating proton concentration at the cell surface stimulates the formation of membrane invaginations and vesiculation accompanied by efficient uptake of macromolecules (Dextran-FITC, 70 kD), relative to the constitutive one. The insensitivity of proton induced uptake to inhibiting treatments and agents of the known endocytic pathways suggests the entry of macromolecules to proceeds via a yet undefined route. This is in line with the fact that neither ATP depletion, nor the lowering of temperature, abolishes the uptake process. In addition, fusion mechanism such as associated with low pH uptake of toxins and viral proteins can be disregarded by employing the polysaccharide dextran as the uptake molecule. The proton induced uptake increases linearly in the extracellular pH range of 6.5 to 4.5, and possesses a steep increase at the range of 4> pH>3, reaching a plateau at pH≤3. The kinetics of the uptake implies that the induced vesicles release their content to the cytosol and undergo rapid recycling to the plasma membrane. We suggest that protonation of the cell’s surface induces local charge asymmetries across the cell membrane bilayer, inducing inward curvature of the cell membrane and consequent vesiculation and uptake
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