Teachers as researchers: Reflecting on the challenges of research–practice partnerships between school and university in Chile

Teachers have tended to be underestimated as experts of their own practice and relegated to a technical role. In this context, action research appears as a form to legitimate teachers as active agents and producers of educational knowledge. This article aims to examine how a collaborative research–practice partnership between schools and universities in Chile fosters teachers’ role as researchers. It adopts a qualitative methodology based on thematic analysis of data collected from questionnaires and focus groups. In particular, it reports perceptions of inservice teacher researchers who conducted research projects between 2016 and 2017 as a part of a researcher–practitioner partnership strategy implemented by a university in Chile. The findings suggest that the partnerships were highly valued among teachers because the partnerships allowed them to develop pedagogical reflection towards the improvement of their practices and required particular awareness and recognition of roles and the relationships between practical and theoretical knowledge. Finally, possibilities for strengthening teachers’ role as researchers and collaborative research are presented at the end of the article

Lead optimisation of dehydroemetine for repositioned use in malaria

Drug repositioning offers an effective alternative to de novo drug design to tackle the urgent need for novel anti-malarial treatments. The anti-amoebic compound, emetine dihydrochloride, has been identified as a potent in-vitro inhibitor of the multi-drug resistant strain K1 of Plasmodium falciparum (IC50: 47 nM ± 2.1 nM). Dehydroemetine, a synthetic analogue of emetine dihydrochloride has been reported to have less cardiotoxic effects than emetine. The structures of two diastereomers of dehydroemetine were modelled on the published emetine binding site on cryo-EM structure 3J7A (Pf 80S ribosome in complex with emetine) and it was found that (-)-R,S-dehydroemetine mimicked the bound pose of emetine more closely than (-)-S,S-dehydroisoemetine. (-)-R,S-dehydroemetine (IC50 71.03 ± 6.1 nM) was also found to be highly potent against the multi-drug resistant K1 strain of P. falciparum in comparison with (-)-S,S-dehydroisoemetine (IC50 2.07 ± 0.26 μM), which loses its potency due to the change of configuration at C-1′. In addition to its effect on the asexual erythrocytic stages of P. falciparum, the compounds exhibited gametocidal properties with no cross-resistance against any of the multi-drug resistant strains tested. Drug interaction studies showed (-)-R,S-dehydroemetine to have synergistic antimalarial activity with atovaquone and proguanil. Emetine dihydrochloride, and (-)-R,S-dehydroemetine failed to show any inhibition of the hERG potassium channel and displayed activity on the mitochondrial membrane potential indicating a possible multi-modal mechanism of action. [Abstract copyright: Copyright © 2020 Panwar et al.

Exploring wind direction and SO2 concentration by circular-linear density estimation

The study of environmental problems usually requires the description of variables with different nature and the assessment of relations between them. In this work, an algorithm for flexible estimation of the joint density for a circular-linear variable is proposed. The method is applied for exploring the relation between wind direction and SO2 concentration in a monitoring station close to a power plant located in Galicia (NW-Spain), in order to compare the effectiveness of precautionary measures for pollutants reduction in two different years.Comment: 17 pages, 7 figures, 2 table

Neuroendocrine abnormalities in Parkinson's disease

Neuroendocrine abnormalities are common in Parkinson's disease (PD) and include disruption of melatonin secretion, disturbances of glucose, insulin resistance and bone metabolism, and body weight changes. They have been associated with multiple non-motor symptoms in PD and have important clinical consequences, including therapeutics. Some of the underlying mechanisms have been implicated in the pathogenesis of PD and represent promising targets for the development of disease biomarkers and neuroprotective therapies. In this systems-based review, we describe clinically relevant neuroendocrine abnormalities in Parkinson's disease to highlight their role in overall phenotype. We discuss pathophysiological mechanisms, clinical implications, and pharmacological and non-pharmacological interventions based on the current evidence. We also review recent advances in the field, focusing on the potential targets for development of neuroprotective drugs in Parkinson's disease and suggest future areas for research

Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions

Background Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity because of the combined effects of surface chemistry and roughness. The physical and chemical complexity of the plant cuticle limits the development of models that explain its internal structure and interactions with surface-applied agrochemicals. In this article we introduce a thermodynamic method for estimating the solubilities of model plant surface constituents and relating them to the effects of agrochemicals. Results Following the van Krevelen and Hoftyzer method, we calculated the solubility parameters of three model plant species and eight compounds that differ in hydrophobicity and polarity. In addition, intact tissues were examined by scanning electron microscopy and the surface free energy, polarity, solubility parameter and work of adhesion of each were calculated from contact angle measurements of three liquids with different polarities. By comparing the affinities between plant surface constituents and agrochemicals derived from (a) theoretical calculations and (b) contact angle measurements we were able to distinguish the physical effect of surface roughness from the effect of the chemical nature of the epicuticular waxes. A solubility parameter model for plant surfaces is proposed on the basis of an increasing gradient from the cuticular surface towards the underlying cell wall. Conclusions The procedure enabled us to predict the interactions among agrochemicals, plant surfaces, and cuticular and cell wall components, and promises to be a useful tool for improving our understanding of biological surface interactions

Prospect Farm and the Middle and Later Stone Age Occupation of Mt. Eburru (Central Rift, Kenya) in an East African Context

Located within the Nakuru-Naivasha basin on the northern slope of Mt. Eburru, the open-air site of Prospect Farm (Central Rift, Kenya) is one of the few East African sites that have yielded a stratigraphic sequence containing archaeological levels dating from the late Middle Pleistocene to the Holocene. Excavations at the site by Barbara Whitehead Anthony and Glynn Isaac in 1963–1964 exposed Pastoral Neolithic (Stone Bowl culture) and Later Stone Age (LSA; Kenya Capsian) levels overlying four Middle Stone Age (MSA) levels attributed to the Prospect Industry, a local expression of the Kenya Stillbay. This paper integrates the information currently available for the site and discusses its relevance in a wider East African context. Furthermore, it presents the results of a density survey completed in 2014, mapping the spatial distribution of artifacts along the northern slope of Mt. Eburru and providing data on the landscape setting of the site. The survey identified marked differences in the distribution of diagnostic MSA vs. LSA artifacts: whereas MSA finds cluster at two particular mid-altitude locations (2,102–2,108 m and 2,138–2,140 m a.s.l.) corresponding to the position of Anthony’s Localities I and II, LSA finds tend to show a much broader spatial distribution including both higher and lower altitudes

Ego-Splitting and the Transcendental Subject. Kant’s Original Insight and Husserl’s Reappraisal

In this paper, I contend that there are at least two essential traits that commonly define being an I: self-identity and self-consciousness. I argue that they bear quite an odd relation to each other in the sense that self-consciousness seems to jeopardize self-identity. My main concern is to elucidate this issue within the range of the transcendental philosophies of Immanuel Kant and Edmund Husserl. In the first section, I shall briefly consider Kant’s own rendition of the problem of the Egosplitting. My reading of the Kantian texts reveals that Kant himself was aware of this phenomenon but eventually deems it an unexplainable fact. The second part of the paper tackles the same problematic from the standpoint of Husserlian phenomenology. What Husserl’s extensive analyses on this topic bring to light is that the phenomenon of the Ego-splitting constitutes the bedrock not only of his thought but also of every philosophy that works within the framework of transcendental thinking

Structural basis of a redox-dependent conformational switch that regulates the stress kinase p38α

Many functional aspects of the protein kinase p38α have been illustrated by more than three hundred structures determined in the presence of reducing agents. These structures correspond to free forms and complexes with activators, substrates, and inhibitors. Here we report the conformation of an oxidized state with an intramolecular disulfide bond between Cys119 and Cys162 that is conserved in vertebrates. The structure of the oxidized state does not affect the conformation of the catalytic site, but alters the docking groove by partially unwinding and displacing the short αD helix due to the movement of Cys119 towards Cys162. The transition between oxidized and reduced conformations provides a mechanism for fine-tuning p38α activity as a function of redox conditions, beyond its activation loop phosphorylation. Moreover, the conformational equilibrium between these redox forms reveals an unexplored cleft for p38α inhibitor design that we describe in detail.© 2023. The Author(s)

Diferencia en las variables asociadas a la potencia entre jugadores universitarios de fútbol soccer y fútbol rápido

The aim of this study was to compare the power values of university indoor soccer and field soccer players. For the purpose of the study, 10 soccer players (22 ± 2.89years) FUTSOCC group, and 10 fast soccer players (21.1 ± 1.6 years) FUTRAP group, were recruited. The protocol was based on the execution of the exercise of half squat increasing the weight in each series. The following variables were assessed: 1RM, percentage of 1RM with better average power, average power obtained and the time it took to reach the peak power. A level of significance of p≤0.05 was established. The results showed that the FUTSOCC group had higher 1RM, while the FUTRAP group reached higher 1RM percentages at their best average power value and their peak power expression times were lower. In the mean power values there were no significant differences. The results make us conclude that field soccer players have higher levels of maximum strength, but, indoor soccer players are faster in the execution of the movement.En el presente estudio, se pretendió comparar los valores de potencia de jugadores de fútbol rápido y fútbol soccer de categoría universitaria. Se reclutó a 10 jugadores de fútbol soccer (22 ± 2.89 años) grupo FUTSOCC y 10 jugadores de fútbol rápido (21.1 ± 1.6 años) grupo FUTRAP. Se ejecutó el ejercicio de media sentadilla cargada incrementando el peso en cada serie, se evaluaron las siguientes variables: 1RM, porcentaje de RM con mejor potencia media, potencia media obtenida y el tiempo que tardaban en alcanzar la potencia pico. Se estableció un nivel de significación de p≤0.05. Los resultados mostraron que el grupo FUTSOCC tuvo mayor 1RM, mientras que el grupo FUTRAP obtuvo su mejor valor de potencia media con porcentajes de 1RM mayores al igual que sus tiempos de expresión de potencia pico fueron menores en comparación con el FUTSOCC. En los valores de potencia media no hubo diferencias significativas. Los resultados nos hacen concluir que los jugadores de fútbol soccer tienen niveles más elevados de fuerza máxima, pero, los jugadores de fútbol rápido aplican su fuerza en menor tiempo lo que lleva a ser más veloces en la ejecución del movimiento

Quarkonium dissociation by anisotropy

We compute the screening length for quarkonium mesons moving through an anisotropic, strongly coupled N=4 super Yang-Mills plasma by means of its gravity dual. We present the results for arbitrary velocities and orientations of the mesons, as well as for arbitrary values of the anisotropy. The anisotropic screening length can be larger or smaller than the isotropic one, and this depends on whether the comparison is made at equal temperatures or at equal entropy densities. For generic motion we find that: (i) mesons dissociate above a certain critical value of the anisotropy, even at zero temperature; (ii) there is a limiting velocity for mesons in the plasma, even at zero temperature; (iii) in the ultra-relativistic limit the screening length scales as $(1-v^2)^\epsilon$ with \epsilon =1/2, in contrast with the isotropic result \epsilon =1/4.Comment: 39 pages, 26 figures; v2: minor changes, added reference