435 research outputs found
Use of computational fluid dynamics to compare upper airway pressures and airflow resistance in brachycephalic, mesocephalic, and dolichocephalic dogs
Brachycephalic dog breeds are prone to breathing difficulties because of their upper airway anatomy. Several surgical techniques exist to correct anatomical pathologies and common surgical approaches aim to correct functional abnormalities in the nares and/or the soft palate. However, further research is needed to improve clinical outcomes. This study evaluated air pressure and airflow resistance in the upper airways and trachea in nine sedated, sternally recumbent dogs of different skull types (dolichocephalic, n = 3; mesocephalic, n = 3; brachycephalic, n = 3). CT images were acquired from the nostrils to the caudal border of the lungs and geometrical reconstruction of the upper airway and trachea was performed. Analysis of computational fluid dynamics was performed using inspiratory flow adapted to bodyweight for each dog. Flow (L/min) and pressure (cmH2O) were computed for the entire upper airway and trachea. Resistance (cmH2O/L/min) was calculated using pressure differences between the nose, larynx, and trachea. In this pilot study, statistical comparisons were not performed. Pressure maps, airflow, and resistance were similar in dolichocephalic and mesocephalic breeds. Median pressure difference (3.76 cmH2O) and resistance (0.154 cmH2O/L/min) between the nose and larynx were numerically higher in brachycephalic dogs than in other breeds (0.45 cmH2O and 0.016 cmH2O/L/min, respectively). Median pressure difference (0.205 cmH2O) and resistance (0.009 cmH2O/L/min) between the larynx and trachea was numerically similar in all dogs, except for the English bulldog. The methodology used in this preliminary study to quantify airflow characteristics such as pressure and resistance could improve the understanding of brachycephalic obstruction airway syndrome
The PREVENTION Challenge: How Good Are Humans Predicting Lane Changes?
While driving on highways, every driver tries to be aware of the behavior of
surrounding vehicles, including possible emergency braking, evasive maneuvers
trying to avoid obstacles, unexpected lane changes, or other emergencies that
could lead to an accident. In this paper, human's ability to predict lane
changes in highway scenarios is analyzed through the use of video sequences
extracted from the PREVENTION dataset, a database focused on the development of
research on vehicle intention and trajectory prediction. Thus, users had to
indicate the moment at which they considered that a lane change maneuver was
taking place in a target vehicle, subsequently indicating its direction: left
or right. The results retrieved have been carefully analyzed and compared to
ground truth labels, evaluating statistical models to understand whether humans
can actually predict. The study has revealed that most participants are unable
to anticipate lane-change maneuvers, detecting them after they have started.
These results might serve as a baseline for AI's prediction ability evaluation,
grading if those systems can outperform human skills by analyzing hidden cues
that seem unnoticed, improving the detection time, and even anticipating
maneuvers in some cases.Comment: This work was accepted and presented at IEEE Intelligent Vehicles
Symposium 202
Human-vehicle interaction for autonomous vehicles in crosswalk scenarios: Field experiments with pedestrians and passengers
This paper presents the results of real-world testing of human-vehicle
interactions with an autonomous vehicle equipped with internal and external
Human Machine Interfaces (HMIs) in a crosswalk scenario. The internal and
external HMIs were combined with implicit communication techniques using gentle
and aggressive braking maneuvers in the crosswalk. Results have been collected
in the form of questionnaires and measurable variables such as distance or
speed when the pedestrian decides to cross. The questionnaires show that
pedestrians feel safer when the external HMI or the gentle braking maneuver is
used interchangeably, while the measured variables show that external HMI only
helps in combination with the gentle braking maneuver. The questionnaires also
show that internal HMI only improves passenger confidence in combination with
the aggressive braking maneuver.Comment: 6 pages, 7 figures, 4 tables, conferecence pape
On studying the interaction between different stent models and rabbit tracheal tissue: numerical, endoscopic and histological comparison
Stenting technique is employed worldwide for treating atherosclerotic vessel and tracheal stenosis. Both diseases can be treated by means of metallic stents which present advantages but are affected by the main problem of restenosis of the stented area. In this study we have built a rabbit trachea numerical model and we have analyzed it before and after insertion and opening of two types of commercial stent: a Zilver® FlexTM Stent and a WallStentTM. In experimental parallel work, two types of stent were implanted in 30 New Zealand rabbits divided in two groups of 10 animals corresponding to each stent type and a third group made up of 10 animals without stent. The tracheal wall response was assessed by means of computerized tomography by endoscopy, macroscopic findings and histopathological study 90 days after stent deployment. Three idealized trachea models, one model for each group, were created in order to perform the computational study. The animal model was used to validate the numerical findings and to attempt to find qualitative correlations between numerical and experimental results. Experimental findings such as inflammation, granuloma and abnormal tissue growth, assessed from histomorphometric analyses were compared with derived numerical parameters such as wall shear stress (WSS) and maximum principal stress. The direct comparison of these parameters and the biological response supports the hypothesis that WSS and tensile stresses may lead to a greater tracheal epithelium response within the stented region, with the latter seeming to have the dominant role. This study may be helpful for improving stent design and demonstrates the feasibility offered by in-silico investigated tracheal structural and fluid dynamics
Metavolcanic rocks from schistose domain of Galicia-Tras-os-Montes: petrography, geochemistry and tectonic environment (Galice, NW. Spain)
[Resumen] Se estudia el vulcanismo intercalado en los grupos litoestratigráficos inferiores que integran el Dominio Esquistoso de Galicia Tras-os-Montes (DEGTM) denominados de muro a techo Santabaía, Nogueira y Paraño. El grupo de LalínForcarei que completa la secuencia no será tratado en este trabajo. La edad de estos grupos debe comprender desde el Precámbrico hasta el Devónico Inf. Los tres grupos tiene un cierto carácter vulcanosedimentario, más marcado en el grupo de Santabaía que en los dos grupos superiores. Se encuentran en ellos diferentes niveles volcánicos y vulcanosedimentarios de espesor y continuidad lateral variables, correspondientes a neises microporfídicos de dos micas y ortoneises biotíticos, además de algún nivel de riolitas y tranquitas presentes hacia la parte alta del grupo de Paraño. Geoquímicamente se caracteriza por ser un vulcanismo ácido de naturaleza calcoalcalina en el que predominan los términos riolíticos y iodacíticos de alto contenido en K, posiblemente originado en la zona externa de un margen continental pasivo existente durante el Ordovícico-Silúrico en el NO. de la Península, en el que tendrían lugar diferentes episodios o etapas de aportes volcánicos alternando con etapas más largas de sedimentación detrítica.[Abstract] The Vulcanism interbedded in the lower litostratigraphic groups of the DEGTM
is studied. Those gruoups are known as Santabaia, Nogueira and Paraño from bo~tom to top; The sequence is completed with the Lalín-Forcarei group that is not studied in this paper. The age of the whole sequence is probably, from Precambrian to lower Devonian. The three groups show volcano-sedimentary features which are dominant in the Santabaia group. Several volcanic and volcano-sedimentary levels with different thickness and extension are found; these correspond to two mica microporfidic gneisses and biotitic ortogneisses and seldom ryolites and trachites in the uppermost pan of the Paraño group. Geochemically correspond to acid calcoalcaline vulcanites with ryolites and K rich ryodacites as main types. These rocks are possibily related to an external area of a continental margin which existed during Ordovician-Silurian time in the NW of the Iberian Peninsula. Several volcanic stages would alternate with sedimentation in this geotectonic environment
Neuroprotective effects of EpoL against oxidative stress induced by soluble oligomers of Aβ peptide
Erythropoietin is a glycoproteic hormone that regulates hematopoiesis by acting on its specific receptor (EpoR). The expression of EpoR in the central nervous system (CNS) suggests a role for this hormone in the brain. Recently, we developed a new Epo variant without hematopoietic activity called EpoL, which showed marked neuroprotective effects against oxidative stress in brain ischemia related models. In this study, we have evaluated the neuroprotective effects of EpoL against oxidative stress induced by chronic treatment with Aβ. Our results show that EpoL was neuroprotective against Aβ-induced toxicity by a mechanism that implicates EpoR, reduction in reactive oxygen species, and reduction in astrogliosis. Furthermore, EpoL treatment improved calcium handling and SV2 levels. Interestingly, the neuroprotective effect of EpoL against oxidative stress induced by chronic Aβ treatment was achieved at a concentration 10 times lower than that of Epo. In conclusion, EpoL, a new variant of Epo without hematopoietic activity, is of potential interest for the treatment of diseases related to oxidative stress in the CNS such as Alzheimer disease.Grant Innova-Corfo “13IDL2-18688”; Conicyt Grant “Beca Doctorado Nacional no. 21130386”; Fondecyt Grant “1161078
Adaptation and Testing of the Factorial Structure of the Physical Education Grit Scale for Use in Secondary Education in Spain
The challenges faced by students during Physical Education classes embrace both physical and academic aspects. Therefore, each individual possesses a series of internal psychological mechanisms, such as Grit, which allow them to adapt and overcome the vicissitudes. However, there are no scales that assess Grit in Span. Thus, the aim of the present study is to test the factor structure of the Physical Education Grit Scale in Span of Physical Education classes. For this purpose, 857 secondary school students took part in the present study. In order to test the factor structure, a confirmatory factor analysis, an exploratory factor analysis, an analysis of the reliability of the questionnaire and an analysis of temporal stability were carried out. The results showed that the factor structure consisted of two factors and four sub-factors (¿2/df = 2.17 (p = 0.001); CFI = 0.96; TLI = 0.96; IFI = 0.96; RMSEA = 0.051; SRMR = 0.037). In addition, the reliability and temporal stability analyses showed acceptable indices. Based on these results, evidence of reliability and validity of the Physical Education Grit Scale in Span of Physical Education is provided
Habitat use by Gadiculus argenteus (Pisces, Gadidae) in the Galician and Cantabrian Sea waters (NE Atlantic)
Forage fish species play a crucial role in most ecosystems, transferring energy from plankton to larger fishes. Therefore, understanding the factors driving the dynamics of forage fish populations is essential in marine ecosystems. Gadiculus argenteus is an important forage fish species in the Galicia and Cantabrian Sea ecosystem. In this study, the influence of several biotic and abiotic factors on the distribution of this species was examined using generalized additive models in a 2-step approach. G. argenteus habitat preference was not affected by changes in annual abundance during the study period (1998-2019). From the variables selected in the final models, depth and geographic location (latitude and longitude) were the most important factors to describe the presence of G. argenteus. Peak abundance was found on the upper slope and although the species was found throughout the study area, its higher abundance values were located in Galician waters. The species seemed to avoid coarse sand bottoms, with mean chlorophyll a concentration showing a positive effect on the presence and abundance of G. argenteus. Interestingly, the observed aggregations of G. argenteus showed a remarkable similarity to the commercial trawling footprint in the area, suggesting a strong link between the distribution of this forage species and the distribution of its predators, most of which are important commercial species. Further work should focus on a better understanding of this relationship to provide important information on the study of the structure and functioning of the marine ecosystem of the northern Spanish continental shelf.Versión del editor2,48
Antibody response in patients admitted to the hospital with suspected SARS-CoV-2 infection: results from a multicenter study across Spain
Aim: To evaluate the serological response against SARS-CoV-2 in a multicenter study representative of the Spanish COVID pandemic.
Methods: IgG and IgM + IgA responses were measured on 1466 samples from 1236 Spanish COVID-19 patients admitted to the hospital, two commercial ELISA kits (Vircell SL, Spain) based on the detection of antibodies against the viral spike protein and nucleoprotein, were used.
Results: Approximately half of the patients presented antibodies (56.8% were IgM + IgA positive and 43.0% were IgG positive) as soon as 2 days after the first positive PCR result. Serological test positivity increased with time from the PCR test, and 10 days after the first PCR result, 91.5% and 88.0% of the patients presented IgM + IgA and IgG antibodies, respectively.
Conclusion: The high values of sensitivity attained in the present study from a relatively early period of time after hospitalization support the use of the evaluated serological assays as supplementary diagnostic tests for the clinical management of COVID-19
Propuesta de evaluación del programa de: Juegos para estimular las inteligencias múltiples de Celso Antunes (2006)
La inteligencia no siempre es sinónimo de sacar la máxima nota en un examen en la vida escolar del alumnado. Es mucho más. A lo largo de los años, diversas investigaciones han puesto de manifiesto la existencia de diversas teorías que comprenden diferentes definiciones de inteligencia, siendo entre las más destacadas la Teoría de las Inteligencias Múltiples de Howard Gardner o la Inteligencia Emocional. Los estudios recientes sobre el cerebro humano han revelado que poseemos diversas formas de inteligencia que, si se estimulan mediante medios eficaces, en las distintas fases de la vida, pue den aumentar nuestras capacidades. Y si encima, conseguimos este desarrollo cognitivo mediante una forma lúdica, mucho mejor. Esto nos hace plantear la propuesta de la evaluación de un programa para el desarrollo de las inteligencias múltiples a través de diferentes formas de juego adaptado al contexto del aula.Intelligence does not always mean a high draw on a test in school life of students. It is much more. Over the years, several studies have revealed the existence of several theories that comprise different definitions of intelligence among the most prominent being the Theory of Multiple Intelligences by Howard Gardner or Emotional Intelligence. Recent studies on the human brain have shown that we have various forms of intelligence which, if stimulated by effective means, at different stages of life, can increase our capabilities. Top and on, get this cognitive development through a playful way, much better. This leads us to raise the proposed assessment of to program for the development of multiple intelligences through different game play adapted to the classroom context.peerReviewe
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