293 research outputs found
Learning from students' perception on professors through opinion mining
Students' perception of classes measured through their opinions on teaching
surveys allows to identify deficiencies and problems, both in the environment
and in the learning methodologies. The purpose of this paper is to study,
through sentiment analysis using natural language processing (NLP) and machine
learning (ML) techniques, those opinions in order to identify topics that are
relevant for students, as well as predicting the associated sentiment via
polarity analysis. As a result, it is implemented, trained and tested two
algorithms to predict the associated sentiment as well as the relevant topics
of such opinions. The combination of both approaches then becomes useful to
identify specific properties of the students' opinions associated with each
sentiment label (positive, negative or neutral opinions) and topic.
Furthermore, we explore the possibility that students' perception surveys are
carried out without closed questions, relying on the information that students
can provide through open questions where they express their opinions about
their classes
Sustainable tourism policies in Peru and their link with renewable energy: analysis in the main museums of the Moche route
Tourism activity in Peru has been experiencing significant growth in the last ten years, positioning this economic
sector as the third largest contributor to the National Gross Domestic Product (GDP). Likewise, Peru has a high
ecological and climate diversity, which makes it the possessor of renewable energy potential, specifically solar
and wind power. The rapid growth of tourism is leading to generating prospects for becoming a sustainable
destination. In this sense, it is important to understand and evaluate the Peruvian legislative framework for
sustainable tourism and the current state of the implementation of the scenarios provided by the governmental
entity in terms of sustainability, and its link with tourism activity. Based on what has been described, this study is
aimed at evaluating the four most relevant museums in the northern part of Peru; in addition, it contributes to the
studies that exist at the intersection of tourism and sustainability in the chains of activities related to tourism and
calls for rationality applied to tourism management in this region of Latin America. The results of the literature
review of the Peruvian legal framework reveal a lack of specific laws and regulations on sustainable tourism; on
the contrary, there are policies in force that contribute to promoting the development of sustainable tourism. The
quantified evaluation of the solar and wind potentials of the geographical area under study indicates the minimum renewable energy potential necessary for its transformation and use in the development of sustainable
museums and its contribution to sustainable tourism
Importance of tissue sampling, laboratory methods, and patient characteristics for detection of Pneumocystis in autopsied lungs of non-immunosuppressed individuals
To understand the epidemiological significance of Pneumocystis detection in a lung tissue sample of non-immunosuppressed individuals, we examined sampling procedures, laboratory methodology, and patient characteristics of autopsy series reported in the literature. Number of tissue specimens, DNA-extraction procedures, age and underlying diagnosis highly influence yield and are critical to understand yield differences of Pneumocystis among reports of pulmonary colonization in immunocompetent individuals.publishersversionpublishe
NetKet 3: Machine Learning Toolbox for Many-Body Quantum Systems
We introduce version 3 of NetKet, the machine learning toolbox for many-body quantum physics. NetKet is built around neural-network quantum states and provides efficient algorithms for their evaluation and optimization. This new version is built on top of JAX, a differentiable programming and accelerated linear algebra framework for the Python programming language. The most significant new feature is the possibility to define arbitrary neural network ansätze in pure Python code using the concise notation of machine-learning frameworks, which allows for just-in-time compilation as well as the implicit generation of gradients thanks to automatic differentiation. NetKet 3 also comes with support for GPU and TPU accelerators, advanced support for discrete symmetry groups, chunking to scale up to thousands of degrees of freedom, drivers for quantum dynamics applications, and improved modularity, allowing users to use only parts of the toolbox as a foundation for their own code
Caracterización epidemiológica de los casos humanos de ántrax en Perú, 2015 - 2019
Introduction. The epidemiology of anthrax in Peru is poorly understood. Its high epidemic and epizootic potential could threaten public health, especially in its endemic regions. Objective. To characterize cases of human anthrax in Peru from 2015 to 2019. Methods. A retrospective cross-sectional study was carried out; based on data from the National Epidemiological Surveillance System and investigations of anthrax outbreaks from 2015 to 2019 in Peru. Results. 71 cases of human anthrax were registered, 34 % (n = 24) confirmed and 66 % (n = 47) probable. The most affected were males (55 %) and the age group from 30 to 59 years (45 %) , distributed mainly on the north coast of the country. The self-limited cutaneous form was the most frequent clinical presentation. 94% (n = 67) of the cases had contact with infected cattle. Conclusions. The cases of human anthrax in Peru appear as focalized outbreaks in areas with a history of zoonotic transmission. This report aims to contribute to the epidemiological knowledge of this disease and serve as input in the implementation of prevention and control measures.Introducción. La epidemiología del ántrax en Perú es poco conocida. Su alto potencial epidémico y epizoótico podría amenazar la salud pública, especialmente desde sus regiones endémicas. Objetivo. Caracterizar los casos de ántrax humano en Perú del 2015 al 2019. Métodos. Se realizó un estudio transversal retrospectivo, a partir de los datos del Sistema Nacional de Vigilancia Epidemiológica e investigaciones de brotes en Perú del 2015 al 2019. Resultados. 71 casos de ántrax humano fueron registrados, 34 % (n = 24) confirmados y 66 % (n = 47) probables. Los más afectados fueron varones (55 %) y el grupo etario de 30 a 59 años (45 %). Los casos estuvieron distribuidos principalmente en la costa norte del país. La forma cutánea autolimitada en miembros superiores fue la presentación clínica más frecuente. El 94 % (n = 67) de los casos tuvieron contacto con ganado vacuno infectado. Conclusión. Los casos de ántrax humano en Perú fueron en su mayoría de la forma cutánea, que se presentaron por brotes focalizados en áreas con antecedentes de trasmisión zoonótica. Este reporte pretende aportar al conocimiento epidemiológico de esta enfermedad y servir como insumo en la implementación de medidas de prevención y control
Estimation of Admission D-dimer Cut-off Value to Predict Venous Thrombotic Events in Hospitalized COVID-19 Patients: Analysis of the SEMI-COVID-19 Registry
Background: Venous thrombotic events (VTE) are frequent in COVID-19, and elevated plasma D-dimer (pDd) and dyspnea are common in both entities. Objective: To determine the admission pDd cut-off value associated with in-hospital VTE in patients with COVID-19. Methods: Multicenter, retrospective study analyzing the at-admission pDd cut-off value to predict VTE and anticoagulation intensity along hospitalization due to COVID-19. Results: Among 9386 patients, 2.2% had VTE: 1.6% pulmonary embolism (PE), 0.4% deep vein thrombosis (DVT), and 0.2% both. Those with VTE had a higher prevalence of tachypnea (42.9% vs. 31.1%; p = 0.0005), basal O2 saturation <93% (45.4% vs. 33.1%; p = 0.0003), higher at admission pDd (median [IQR]: 1.4 [0.6–5.5] vs. 0.6 [0.4–1.2] µg/ml; p < 0.0001) and platelet count (median [IQR]: 208 [158–289] vs. 189 [148–245] platelets × 109/L; p = 0.0013). A pDd cut-off of 1.1 µg/ml showed specificity 72%, sensitivity 49%, positive predictive value (PPV) 4%, and negative predictive value (NPV) 99% for in-hospital VTE. A cut-off value of 4.7 µg/ml showed specificity of 95%, sensitivity of 27%, PPV of 9%, and NPV of 98%. Overall mortality was proportional to pDd value, with the lowest incidence for each pDd category depending on anticoagulation intensity: 26.3% for those with pDd >1.0 µg/ml treated with prophylactic dose (p < 0.0001), 28.8% for pDd for patients with pDd >2.0 µg/ml treated with intermediate dose (p = 0.0001), and 31.3% for those with pDd >3.0 µg/ml and full anticoagulation (p = 0.0183). Conclusions: In hospitalized patients with COVID-19, a pDd value greater than 3.0 µg/ml can be considered to screen VTE and to consider full-dose anticoagulation. © 2021, Society of General Internal Medicine
Agrocombustibles: ¿Otro negocio es posible?
Hoy en día, los agrocombustibles (principalmente biodiesel y bioetanol) son objeto de políticas públicas e incentivos, y se ha acelerado su producción a gran escala, con la intención de reducir las emisiones de gases de efecto invernadero, y por tanto contribuir a la mitigación del cambio climático. Las y los autores de este libro integran el Grup de Bionegocis, un espacio multidisciplinario impulsado desde la Campaña “No te Comas el Mundo”, que investiga en Cataluña desde el año 2007 sobre la temática de los agrocombustibles. El principal objetivo de esta publicación se ubica en profundizar algunos aspectos con el objetivo de brindar herramientas de reflexión y de acción. Pretende responder a preguntas tales como: ¿Qué son los agrocombustibles? ¿Es positivo su rendimiento energético? ¿Cuál es la huella hídrica de estos carburantes? ¿Son realmente una respuesta ante el calentamiento global? ¿De dónde proviene la materia prima? ¿Mejoran las condiciones de vida en los países del Sur? ¿Cuáles son los intereses corporativos en este rubro? ¿Generarán los agrocombustibles una mayor Deuda ecológica? ¿Es la segunda generación una respuesta adecuada? ¿Qué perspectivas tenemos ante la Soberanía alimentaria y la Soberanía energética?Peer reviewe
Redefining vascular repair: revealing cellular responses on PEUU—gelatin electrospun vascular grafts for endothelialization and immune responses on in vitro models
Tissue-engineered vascular grafts (TEVGs) poised for regenerative applications are central to effective vascular repair, with their efficacy being significantly influenced by scaffold architecture and the strategic distribution of bioactive molecules either embedded within the scaffold or elicited from responsive tissues. Despite substantial advancements over recent decades, a thorough understanding of the critical cellular dynamics for clinical success remains to be fully elucidated. Graft failure, often ascribed to thrombogenesis, intimal hyperplasia, or calcification, is predominantly linked to improperly modulated inflammatory reactions. The orchestrated behavior of repopulating cells is crucial for both initial endothelialization and the subsequent differentiation of vascular wall stem cells into functional phenotypes. This necessitates the TEVG to provide an optimal milieu wherein immune cells can promote early angiogenesis and cell recruitment, all while averting persistent inflammation. In this study, we present an innovative TEVG designed to enhance cellular responses by integrating a physicochemical gradient through a multilayered structure utilizing synthetic (poly (ester urethane urea), PEUU) and natural polymers (Gelatin B), thereby modulating inflammatory reactions. The luminal surface is functionalized with a four-arm polyethylene glycol (P4A) to mitigate thrombogenesis, while the incorporation of adhesive peptides (RGD/SV) fosters the adhesion and maturation of functional endothelial cells. The resultant multilayered TEVG, with a diameter of 3.0 cm and a length of 11 cm, exhibits differential porosity along its layers and mechanical properties commensurate with those of native porcine carotid arteries. Analyses indicate high biocompatibility and low thrombogenicity while enabling luminal endothelialization and functional phenotypic behavior, thus limiting inflammation in in-vitro models. The vascular wall demonstrated low immunogenicity with an initial acute inflammatory phase, transitioning towards a pro-regenerative M2 macrophage-predominant phase. These findings underscore the potential of the designed TEVG in inducing favorable immunomodulatory and pro-regenerative environments, thus holding promise for future clinical applications in vascular tissue engineering
Sixty-four new records for the flora of Peru from rapid biological inventories in the Peruvian Amazon
Durante el período 2000 – 2016, se llevaron a cabo 15 inventarios biológicos en áreas remotas en el pie de monte andino y el llano amazónico del Perú. En estos inventarios, 27 botánicos colectaron un total de 9397 especímenes de plantas vasculares fértiles. Hasta finales del 2017, más de la mitad de estos especímenes se han identificado a nivel de especie, de los cuales 64 especies y 2 géneros (Dicorynia y Monopteryx) representan nuevos registros para la flora del Perú. Si esta tasa de novedades se mantiene, el número de registros nuevos en el material de los inventarios podría aumentar, lo cual nos indica que aún queda mucho por descubrir en la flora andino-amazónica del Perú.Between 2000 and 2016 we carried out 15 rapid biological inventories in remote areas of the Andean foothills and Amazon basin in Peru. During these inventories, 27 botanists collected 9397 fertile vascular plant specimens. By the end of 2017, more than half of these specimens had been identified to species. Of the 2303 species identified to date, 64 species and 2 genera (Dicorynia and Monopteryx) are new records for the flora of Peru. If this rate of discovery proves typical, the number of new records for Peru in the rapid inventory material could increase, which indicates that there is still much to discover in the Peruvian flora
The chemical compound 'Heatin' stimulates hypocotyl elongation and interferes with the Arabidopsis NIT1-subfamily of nitrilases
Temperature passively affects biological processes involved in plant growth. Therefore, it is challenging to study the dedicated temperature signalling pathways that orchestrate thermomorphogenesis, a suite of elongation growth-based adaptations that enhance leaf-cooling capacity. We screened a chemical library for compounds that restored hypocotyl elongation in the pif4-2-deficient mutant background at warm temperature conditions in Arabidopsis thaliana to identify modulators of thermomorphogenesis. The small aromatic compound 'Heatin', containing 1-iminomethyl-2-naphthol as a pharmacophore, was selected as an enhancer of elongation growth. We show that ARABIDOPSIS ALDEHYDE OXIDASES redundantly contribute to Heatin-mediated hypocotyl elongation. Following a chemical proteomics approach, the members of the NITRILASE1-subfamily of auxin biosynthesis enzymes were identified among the molecular targets of Heatin. Our data reveal that nitrilases are involved in promotion of hypocotyl elongation in response to high temperature and Heatin-mediated hypocotyl elongation requires the NITRILASE1-subfamily members, NIT1 and NIT2. Heatin inhibits NIT1-subfamily enzymatic activity in vitro and the application of Heatin accordingly results in the accumulation of NIT1-subfamily substrate indole-3-acetonitrile in vivo. However, levels of the NIT1-subfamily product, bioactive auxin (indole-3-acetic acid), were also significantly increased. It is likely that the stimulation of hypocotyl elongation by Heatin might be independent of its observed interaction with NITRILASE1-subfamily members. However, nitrilases may contribute to the Heatin response by stimulating indole-3-acetic acid biosynthesis in an indirect way. Heatin and its functional analogues present novel chemical entities for studying auxin biology
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