1,256 research outputs found
Bird migration:Flying high to avoid overheating?
Acts of flight have always baffled humans. Recent tracking studies of birds only add to the awe and mystery. A new study shows that migrating great snipes fly high — over two kilometres high — during the day and lower at night. Why
Incidencia de los ambientes de aprendizaje mediados por TIC para mejorar los proesos de visualización en la resolución de problemas de matemáticas
Los Pruebas Saber de grado 3° y 5° evidencian graves dificultades en matemáticas, debido a la resolución de problemas, un
aspecto que influye, es la poca trascendencia en ciertos procesos, como la visualización, Zimmermann y Cunningham señalan
(2013, citado por Martinovic, Freiman y Karadag p. 213) la visualización en los procesos de aprendizaje de la matemática
contribuye al desarrollo de una comprensión más profunda y significativa tanto de las ideas matemáticas y las relaciones entre
los conceptos matemáticos. Por ello se planteo una estrategia de intervención que potencian los procesos de visualización
mediados por TIC, bajo una metodología cualitativa de tipo interpretativa (Sampiere, Fernandez y Batista 2010) que permitió la
descripción de los aspectos relevantes a medida que se daban las diferentes interacciones en el trabajo de campo, evidenciando
que estas dificultades se ven aminoradas en la medida que los estudiantes interactúan con las situaciones didácticas diseñadas
mediada por tic
Modelling stand biomass fractions in Galician Eucalyptus globulus plantations by use of different LiDAR pulse densities
Aims of study: To evaluate the potential use of canopy height and intensity distributions, determined by airborne
LiDAR, for the estimation of crown, stem and aboveground biomass fractions.
To assess the effects of a reduction in LiDAR pulse densities on model precision.
Area of study: The study area is located in Galicia, NW Spain. The forests are representative of Eucalyptus globulus
stands in NW Spain, characterized by low-intensity silvicultural treatments and by the presence of tall shrub.
Material and methods: Linear, multiplicative power and exponential models were used to establish empirical
relationships between field measurements and LiDAR metrics.
A random selection of LiDAR returns and a comparison of the prediction errors by LiDAR pulse density factor
were performed to study a possible loss of fit in these models.
Main results: Models showed similar goodness-of-fit statistics to those reported in the international literature. R2
ranged from 0.52 to 0.75 for stand crown biomass, from 0.64 to 0.87 for stand stem biomass, and from 0.63 to 0.86
for stand aboveground biomass. The RMSE/MEAN · 100 of the set of fitted models ranged from 17.4% to 28.4%.
Models precision was essentially maintained when 87.5% of the original point cloud was reduced, i.e. a reduction
from 4 pulses m–2 to 0.5 pulses m–2.
Research highlights: Considering the results of this study, the low-density LiDAR data that are released by the
Spanish National Geographic Institute will be an excellent source of information for reducing the cost of forest
inventories
Life Cycle Engineering 4.0: A Proposal to Conceive Manufacturing Systems for Industry 4.0 Centred on the Human Factor (DfHFinI4.0)
Engineering 4.0 environments are characterised by the digitisation, virtualisation, and connectivity of products, processes, and facilities composed of reconfigurable and adaptive socio-technical cyber-physical manufacturing systems (SCMS), in which Operator 4.0 works in real time in VUCA (volatile, uncertain, complex and ambiguous) contexts and markets. This situation gives rise to the interest in developing a framework for the conception of SCMS that allows the integration of the human factor, management, training, and development of the competencies of Operator 4.0 as fundamental aspects of the aforementioned system. The present paper is focused on answering how to conceive the adaptive manufacturing systems of Industry 4.0 through the operation, growth, and development of human talent in VUCA contexts. With this objective, exploratory research is carried, out whose contribution is specified in a framework called Design for the Human Factor in Industry 4.0 (DfHFinI4.0). From among the conceptual frameworks employed therein, the connectivist paradigm, Ashby's law of requisite variety and Vigotsky's activity theory are taken into consideration, in order to enable the affective-cognitive and timeless integration of the human factor within the SCMS. DfHFinI4.0 can be integrated into the life cycle engineering of the enterprise reference architectures, thereby obtaining manufacturing systems for Industry 4.0 focused on the human factor. The suggested framework is illustrated as a case study for the Purdue Enterprise Reference Architecture (PERA) methodology, which transforms it into PERA 4.0
Über die Beurteilung des Gütegrades von Mischungen bei beliebigen Verteilungsgesetzen für die Korngewichte der einzelnen Mischungskomponenten
Two granular materials (P) and (Q) are mixed. The distribution functions of particle weight are supposed to be known for both components (P) und (Q). To judge the efficiency of the mixing process a statistical theory is developed to calculate the variations of the mixture's composition when samples are taken at random from the container. It is important to distinguish the notions of "volume frequency", "weight frequency", and "particle frequency" of the different components within the mixture. Single particles are supposed to obey statistical laws. The results which are stictly valid only for samples with equal numbers of particles are shown to be approximately valid for samples of equal weight (or volume), too. - The theory is generalised for mixtures consisting of three or more components
Urohidrosis as an overlooked cooling mechanism in long-legged birds
Behavioural thermoregulation could buffer the impacts of climate warming on vertebrates.
Specifically, the wetting of body surfaces and the resulting evaporation of body fluids serves as a
cooling mechanism in a number of vertebrates coping with heat. Storks (Ciconiidae) frequently excrete
onto their legs to prevent overheating, a phenomenon known as urohidrosis. Despite the increasingly
recognised role of bare and highly vascularised body parts in heat exchange, the ecological and
evolutionary determinants of urohidrosis have been largely ignored. We combine urohidrosis data
from a scientifically curated media repository with microclimate and ecological data to investigate
the determinants of urohidrosis in all extant stork species. Our phylogenetic generalised linear mixed
models show that high temperature, humidity and solar radiation, and low wind speed, promote
the use of urohidrosis across species. Moreover, species that typically forage in open landscapes
exhibit a more pronounced use of urohidrosis than those mainly foraging in waterbodies. Substantial
interspecific variation in temperature thresholds for urohidrosis prevalence points to different species
vulnerabilities to high temperatures. This integrated approach that uses online data sources and
methods to model microclimates should provide insight into animal thermoregulation and improve
our capacity to make accurate predictions of climate change’s impact on biodiversityinfo:eu-repo/semantics/publishedVersio
Study of the Genetic Variants in BRCA1/2 and Non-BRCA Genes in a Population-Based Cohort of 2155 Breast/Ovary Cancer Patients, Including 443 Triple-Negative Breast Cancer Patients, in Argentina
Gene/s sequencing in hereditary breast/ovary cancer (HBOC) in routine diagnosis is challenged by the analysis of panels. We aim to report a retrospective analysis of BRCA1/2 and non-BRCA gene sequencing in patients with breast/ovary cancer (BOC), including triple-negative breast cancer (TNBC), in our population. In total 2155 BOC patients (1900 analyzed in BRCA1/2 and 255 by multigenic panels) gave 372 (17.2.6%) and 107 (24.1%) likely pathogenic/pathogenic variants (LPVs/PVs), including BRCA and non-BRCA genes, for the total and TNBC patients, respectively. When BOC was present in the same proband, a 51.3% rate was found for LPVs/PVs in BRCA1/2. Most of the LPVs/PVs in the panels were in BRCA1/2; non-BRCA gene LPVs/PVs were in CDH1, CHEK2, CDKN2A, MUTYH, NBN, RAD51D, and TP53. TNBC is associated with BRCA1/2 at a higher rate than the rest of the breast cancer types. The more prevalent PVs in BRCA1/2 genes (mostly in BRCA1) do not rule out the importance to panels of genes, although they are certainly far from shedding light on the gap of the 85% predicted linkage association of BOC with BRCA1/2 and are still not elucidated.Fil: Solano, Angela Rosario. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Mele, Pablo Gustavo. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana. Cátedra de Química Biologica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Jalil, Fernanda S.. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; ArgentinaFil: Liria, Natalia C.. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; ArgentinaFil: Podesta, Ernesto Jorge. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquímica Humana. Cátedra de Química Biologica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Gutiérrez, Leandro G.. Centro de Educaciones Médicas e Investigación Clínica "Norberto Quirno"; Argentin
Los proyectos de Ingeniería electrónica en el marco de los resultados de aprendizaje EUR-ACE
El sello EUR-ACE® es un certificado que una
agencia autorizada (en España ANECA) otorga a un título de
grado o máster en ingeniería que cumple unos determinados
estándares de calidad. Se trata de una marca de calidad
internacionalmente reconocida que facilita la movilidad y el
reconocimiento de los titulados. Uno de los resultados de
aprendizaje más importantes e incluido como requisito específico
del sello es el relativo a Proyectos de Ingeniería. Este artículo
presenta este resultado de aprendizaje en el ámbito de las
titulaciones de grado y muestra cómo puede incluirse en el caso
concreto de varias asignaturas relacionadas con la Ingeniería
Electrónica
Evolución de los MOOC en el ámbito investigador mediante técnicas de análisis de contenido
Los Massive Open Online Courses (MOOCs)
constituyen un nuevo modelo de docencia que ha ido ganando
popularidad en los últimos años. Su carácter masivo implica un
modelo de enseñanza colaborativa que genera conexiones no sólo
entre el profesor y el alumno, sino también entre los propios
alumnos, que intervienen en foros y participan en procesos de
evaluación por pares. El ámbito de la investigación en educación
no es ajeno a este auge, y el campo de los MOOC también es un
tema emergente, que ofrece además múltiples retos
investigadores en cuanto a su modelo de desarrollo, su impacto
en los modelos tradicionales de educación superior o su gestión
dado su carácter masivo. Aunque en los últimos años son varias
las revistas que han lanzado varios números monográficos sobre
el tema de los MOOCs, no existe un estudio bibliográfico hasta la
fecha que ilustre sus principales retos investigadores. Este
artículo propone la realización de un estudio bibliográfico basado
en técnicas de análisis de contenido que muestre no sólo los
principales ámbitos de interés sino también su evolución en el
tiempo
Endocannabinoid System and Psychiatry: In Search of a Neurobiological Basis for Detrimental and Potential Therapeutic Effects
Public concern on mental health has noticeably increased given the high prevalence of neuropsychiatric disorders. Cognition and emotionality are the most affected functions in neuropsychiatric disorders, i.e., anxiety disorders, depression, and schizophrenia. In this review, most relevant literature on the role of the endocannabinoid (eCB) system in neuropsychiatric disorders will be presented. Evidence from clinical and animal studies is provided for the participation of CB1 and CB2 receptors (CB1R and CB2R) in the above mentioned neuropsychiatric disorders. CBRs are crucial in some of the emotional and cognitive impairments reported, although more research is required to understand the specific role of the eCB system in neuropsychiatric disorders. Cannabidiol (CBD), the main non-psychotropic component of the Cannabis sativa plant, has shown therapeutic potential in several neuropsychiatric disorders. Although further studies are needed, recent studies indicate that CBD therapeutic effects may partially depend on facilitation of eCB-mediated neurotransmission. Last but not least, this review includes recent findings on the role of the eCB system in eating disorders. A deregulation of the eCB system has been proposed to be in the bases of several neuropsychiatric disorders, including eating disorders. Cannabis consumption has been related to the appearance of psychotic symptoms and schizophrenia. In contrast, the pharmacological manipulation of this eCB system has been proposed as a potential strategy for the treatment of anxiety disorders, depression, and anorexia nervosa. In conclusion, the eCB system plays a critical role in psychiatry; however, detrimental consequences of manipulating this endogenous system cannot be underestimated over the potential and promising perspectives of its therapeutic manipulation
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