664 research outputs found
Plaqueta decorada de la cueva de El Horno (Ramales de la Victoria, Cantabria) en su contexto local y regional
En la actualidad, uno de los retos más relevantes de la investigación sobre el Paleolítico es el de superar definitivamente el paradigma del yacimiento único, abordando el estudio de las sociedades de cazadores desde una perspectiva regional, tal y como demanda el carácter móvil de las mismas. De hecho, la movilidad debería ser considerada siempre en nuestras estrategias de investigación acerca de los grupos paleolíticos, y no sólo al abordar el estudio de materiales más o menos exóticos. El arte mueble, estudiado desde el punto de vista de las cadenas operativas, aporta datos relevantes para la compresión de las sociedades de cazadores en su territorio. Los resultados del análisis de una plaqueta de arenisca procedente del nivel 2 de El Horno (Ramales de la Victoria, Cantabria), atribuido al Magdaleniense superior-final, constituyen un buen ejemplo de lo comentado. La cara A de la plaqueta presenta el grabado de una cabeza de probable cierva, un tema poco común a finales del Magdaleniense, cuyo estudio tecnológico ha revelado que se trata de la obra de un artista inexperto. La cara B está grabada y pintada, y los estigmas identificados sugieren la utilización de la plaqueta como mortero para machacar algún material, quizá el propio ocre. En ese sentido, el material presentado aporta elementos de juicio a la reflexión actual acerca de la tradicional dicotomía establecida en el arte mobiliar entre los soportes utilitarios y no utilitarios
Differentiation of Trichuris species using a morphometric approach
Trichuris trichiura is a nematode considered as the whipworm present in humans and primates. The systematics of the genus Trichuris is complex. Morphological studies of Trichuris isolated from primates and humans conclude that the species infecting these hosts is the same. Furthermore, numerous molecular studies have been carried out so far to discriminate parasite species from humans and Non-Human Primates using molecular techniques, but these studies were not performed in combination with a parallel morphological study. The hypothesised existence of more species of Trichuris in primates opens the possibility to revise the zoonotic potential and host specificity of T. trichiura and other putative new species of whipworms. In the present work, a study of Trichuris Roederer, 1761 (Nematoda:Trichuridae) parasitizing C. g. kikuyensis, P. ursinus, Macaca sylvanus, Pan troglodytes, and Sus scrofa domestica has been carried out using modern morphometric techniques in order to differentiate populations of Trichuris isolated from four species of captive NHP from different geographical regions, and swine, respectively. The results obtained revealed strong support for geometrical morphometrics as a useful tool to differentiate male Trichuris populations. Therefore, morphometrics in combination with other techniques, such as molecular biology analyses, ought to be applied to further the differentiation of male populations. On the other hand, morphometrics applied to female Trichuris species does not seem to contribute new information as all the measurements combinations of obtained from females always showed similar resultsMinistry of Economy,Industry and Competitiveness(CGL2017-83057)FEDER funds, the Junta de Andalucía (BIO-338)V Plan Propio de Investigación of the University of Sevill
An Overview on the Latest Nature-Inspired and Metaheuristics-Based Image Registration Algorithms
El trabajo corresponde a una publicación con invitación realizada por la revista, en cuya elaboración participaron miembros del equipo de investigación PAIDI de la Universidad de Jaén "Ingeniería Computacional Aplicada", cuyo responsable es el primer autor de la publicación. La investigación corresponde a una línea de investigación desarrollada por el autor desde 2003.The development of automated image registration (IR) methods is a well-known
issue within the computer vision (CV) field and it has been largely addressed from multiple
viewpoints. IR has been applied to a high number of real-world scenarios ranging from remote
sensing to medical imaging, artificial vision, and computer-aided design. In the last two decades,
there has been an outstanding interest in the application of new optimization approaches for dealing
with the main drawbacks present in the early IR methods, e.g., the Iterative Closest Point (ICP)
algorithm. In particular, nature-inspired computation, e.g., evolutionary computation (EC), provides
computational models that have their origin in evolution theories of nature. Moreover, other general
purpose algorithms known as metaheuristics are also considered in this category of methods.
Both nature-inspired and metaheuristic algorithms have been extensively adopted for tackling
the IR problem, thus becoming a reliable alternative for optimization purposes. In this contribution,
we aim to perform a comprehensive overview of the last decade (2009–2019) regarding the successful
usage of this family of optimization approaches when facing the IR problem. Specifically, twenty-four
methods (around 16 percent) of more than one hundred and fifty different contributions in the
state-of-the-art have been selected. Several enhancements have been accordingly provided based on
the promising outcomes shown by specific algorithmic designs. Finally, our research has shown that
the field of nature-inspired and metaheuristic algorithms has increased its interest in the last decade
to address the IR problem, and it has been highlighted that there is still room for improvemen
Epidemiological survey and risk factors associated with hepatitis E virus in small ruminants in southern Spain
Autochthonous cases of hepatitis E (HE) associated with zoonotic genotypes HEV-3 and HEV-4 have significantly increased in industrialized countries over the last decade. Suidae are generally recognized as the main reservoirs of these genotypes. Susceptibility to HE virus (HEV) infection and zoonotic potential have also been confirmed in other species, including sheep and goat. However, the information about their role in the epidemiology of HEV remains very scarce. The objective of this study was to assess the prevalence, spatial distribution and risk factors associated with HEV exposure in sheep and goats in southern Spain, the country with the highest census of small domestic ruminants in the European Union. Blood samples from 240 sheep and 240 goats were collected between 2015 and 2017. Sera were analysed in parallel using a commercial double-antigen ELISA and real-time PCR. A total of 38 (7.9%; 95%CI: 5.5–10.3) out of 480 sampled animals showed anti-HEV antibodies. By species, the seroprevalences found in sheep and goats were 2.1% (5/240; 95%CI: 0.3–3.9) and 13.8% (33/240; 95%CI: 9.4–18.1) respectively. Anti-HEV antibodies were found on 19 (59.4%; 95%CI: 42.4–76.4) of the 32 sampled farms. The GEE model showed that species (goat) and number of small ruminants in the farm (≤348 animals and ≥538 animals) were risk factors potentially associated with HEV exposure in small ruminants in the study area. HEV RNA was not detected in any of the 480 (0.0%; 95%CI: 0.0–0.8) tested animals. Our results confirm that sheep and goats are naturally, but not equally exposed to HEV and indicate the widespread spatial distribution of HEV among small ruminant populations in southern Spain. Further studies are required to elucidate the role of sheep and goat in the epidemiology of HEV and their potential implications for public health
Short-term exposure of mice to cigarette smoke and/or residual oil fly ash produces proximal airspace enlargements and airway epithelium remodeling
Chronic obstructive pulmonary disease (COPD) is associated with inflammatory cell reactions, tissue destruction and lung remodeling. Many signaling pathways for these phenomena are still to be identified. We developed a mouse model of COPD to evaluate some pathophysiological mechanisms acting during the initial stage of the disease. Forty-seven 6- to 8-week-old female C57/BL6 mice (approximately 22 g) were exposed for 2 months to cigarette smoke and/or residual oil fly ash (ROFA), a concentrate of air pollution. We measured lung mechanics, airspace enlargement, airway wall thickness, epithelial cell profile, elastic and collagen fiber deposition, and by immunohistochemistry transforming growth factor-β1 (TGF-β1), macrophage elastase (MMP12), neutrophils and macrophages. We observed regional airspace enlargements near terminal bronchioles associated with the exposure to smoke or ROFA. There were also increases in airway resistance and thickening of airway walls in animals exposed to smoke. In the epithelium, we noted a decrease in the ciliated cell area of animals exposed to smoke and an increase in the total cell area associated with exposure to both smoke and ROFA. There was also an increase in the expression of TGF-β1 both in the airways and parenchyma of animals exposed to smoke. However, we could not detect inflammatory cell recruitment, increases in MMP12 or elastic and collagen fiber deposition. After 2 months of exposure to cigarette smoke and/or ROFA, mice developed regional airspace enlargements and airway epithelium remodeling, although no inflammation or increases in fiber deposition were detected. Some of these phenomena may have been mediated by TGF-β1
Histone chaperone activity of Arabidopsis thaliana NRP1 is blocked by cytochrome c
Higher-order plants and mammals use similar mechanisms to repair and tolerate oxidative DNA damage. Most studies on the DNA repair process have focused on yeast and mammals, in which histone chaperone-mediated nucleosome disassembly/reassembly is essential for DNA to be accessible to repair machinery. However, little is known about the specific role and modulation of histone chaperones in the context of DNA damage in plants. Here, the histone chaperone NRP1, which is closely related to human SET/TAF-I, was found to exhibit nucleosome assembly activity in vitro and to accumulate in the chromatin of Arabidopsis thaliana after DNA breaks. In addition, this work establishes that NRP1 binds to cytochrome c, thereby preventing the former from binding to histones. Since NRP1 interacts with cytochrome c at its earmuff domain, that is, its histone-binding domain, cytochrome c thus competes with core histones and hampers the activity of NRP1 as a histone chaperone. Altogether, the results obtained indicate that the underlying molecular mechanisms in nucleosome disassembly/reassembly are highly conserved throughout evolution, as inferred from the similar inhibition of plant NRP1 and human SET/TAF-I by cytochrome c during DNA damage response
Seroreversion of IgG anti-HEV in HIV cirrhotic patients: A long-term multi-sampling longitudinal study
The aim of our study was to evaluate HEV antibody kinetics in HIV/HCV-coinfected patients with cirrhosis. A longitudinal retrospective study was designed. Patients were followed up every 6 months; anti-HEV IgG and IgM antibodies levels and HEV-RNA by qPCR were analysed. The prevalence and incidence of every HEV infection marker were calculated. The kinetics of anti-HEV IgG and IgM during the follow-up were evaluated. Seventy-five patients comprised the study population. The seroprevalence observed was 17.3%. None showed IgM antibodies or HEV-RNA at baseline. None showed detectable HEV viral load during the study period. After a median follow-up of 5.1 years, two of 62 seronegative patients (3.2%) seroconverted to IgG antibody. The incidence for IgM was 2.7%. Of the 13 patients with IgG seropositivity at baseline, five (38.5%) seroreverted. Meanwhile, of the two patients who exhibited IgM positivity during the study, one (50%) showed intermittent positivity. We found that HEV seropositivity is common in HIV/HCV-coinfected cirrhotic patients. A remarkable rate of IgG seroreversions and IgM intermittence was found, limiting the use of antibodies for the diagnosis of HEV infection in this population
Active control of Alfvén eigenmodes in magnetically confined toroidal plasmas
Alfvén waves are electromagnetic perturbations inherent to magnetized plasmas that can be
driven unstable by a free energy associated with gradients in the energetic particles’ distribution
function. The energetic particles with velocities comparable to the Alfvén velocity may excite
Alfvén instabilities via resonant wave–particle energy and momentum exchange. Burning
plasmas with large population of fusion born super-Alfvénic alpha particles in magnetically
confined fusion devices are prone to excite weakly-damped Alfvén eigenmodes (AEs) that, if
allowed to grow unabated, can cause a degradation of fusion performance and loss of energetic
ions through a secular radial transport. In order to control the fast-ion distribution and associated
Alfvénic activity, the fusion community is currently searching for external actuators that can
control AEs and energetic ions in the harsh environment of a fusion reactor. Most promising
control techniques are based on (i) variable fast-ion sources to modify gradients in the energetic
particles’ distribution, (ii) localized electron cyclotron resonance heating to affect the fast-ion slowing-down distribution, (iii) localized electron cyclotron current drive to modify the
equilibrium magnetic helicity and thus the AE existence criteria and damping mechanisms, and
(iv) externally applied 3D perturbative fields to manipulate the fast-ion distribution and thus the
wave drive. Advanced simulations help to identify the key physics mechanisms underlying the
observed AE mitigation and suppression and thus to develop robust control techniques towards
future burning plasmas.EURATOM 633053Marie-Curie Actions 321455Ministerio de Economía y Competitividad RYC-2011-09152, FIS2015-69362-
Inhibition of the PP2A activity by the histone chaperone ANP32B is long-range allosterically regulated by respiratory cytochrome c
Repair of injured DNA relies on nucleosome dismantling by histone chaperones and de-phosphorylation events carried out by Protein Phosphatase 2A (PP2A). Typical histone chaperones are the Acidic leucine-rich Nuclear Phosphoprotein 32 family (ANP32) members, e.g. ANP32A, which is also a well-known PP2A inhibitor (a.k.a. I1PP2A). Here we report the novel interaction between the endogenous family member B—so-called ANP32B—and endogenous cytochrome c in cells undergoing camptothecin-induced DNA damage. Soon after DNA lesions but prior to caspase cascade activation, the hemeprotein translocates to the nucleus to target the Low Complexity Acidic Region (LCAR) of ANP32B; in a similar way, our group recently reported that the hemeprotein targets the acidic domain of SET/Template Activating Factor-Iß (SET/TAF-Iß), which is another histone chaperone and PP2A inhibitor (a.k.a. I2PP2A). The nucleosome assembly activity of ANP32B is indeed unaffected by cytochrome c binding. Like ANP32A, ANP32B inhibits PP2A activity and is thus herein referred to as I3PP2A. Our data demonstrates that ANP32B-dependent inhibition of PP2A is regulated by respiratory cytochrome c, which induces long-distance allosteric changes in the structured N-terminal domain of ANP32B upon binding to the C-terminal LCAR. In agreement with the reported role of PP2A in the DNA damage response, we propose a model wherein cytochrome c is translocated from the mitochondria into the nucleus upon DNA damage to modulate PP2A activity via its interaction with ANP32B. © 2021 The Author(s
Una propuesta de enseñanza de didáctica general y didáctica especial en la formación inicial de profesores de biología (Córdoba, Argentina)
La profesionalidad docente puede considerarse como uno de los aspectos característicos de las tendencias actuales en el campo de la didáctica y de la educación (Camilloni, 2016). De hecho, una de las preocupaciones de la gestión universitaria en Argentina está centrada más que nunca en transformar la formación de los profesores para la educación secundaria (Rasetto, 2012). De hecho, una de las preocupaciones de la gestión universitaria en Argentina está centrada más que nunca en transformar la formación de los profesores para la educación secundaria, recuperando la centralidad de la enseñanza como eje de la actividad profesional, la articulación teoría-práctica, la investigación educativa, la contextualización en los distintos ámbitos de intervención docente, así como también, los fundamentos éticos y el compromiso social de la tarea educativa (Rasetto, 2012).
En esta ponencia relatamos la génesis y algunas experiencias que emergen del desarrollo de una propuesta de trabajo en las cátedras de Didáctica General (DG) y Didáctica Especial (DE) del quinto y sexto semestre, respectivamente, de la carrera de Profesorado en Ciencias Biológicas en la Universidad Nacional de Córdoba, Argentina. Con ello, nos proponemos no sólo dar sentido a nuestros posicionamientos epistemológicos, ideológicos, teórico-metodológicos -lo que abordaremos a continuación-, sino también, seguidamente, recuperar la reflexión a partir de la experiencia (Larrosa, 2006) como profesores de DG y DE
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