New excavations at the HWK EE site: Archaeology, paleoenvironment and site formation processes during late Oldowan times at Olduvai Gorge, Tanzania

This paper reports the results of renewed fieldwork at the HWK EEsite(Olduvai Gorge, Tanzania). HWK EEis positioned across the boundary between Lower andMiddle Bed II, a crucialinterval for studyingthe emergence of the Acheulean at Olduvai Gorge. Our excavations at HWK EEhave produced one of the largest collections of fossils and artefacts from any Oldowan site, distributed across several archaeological units and a large excavation surface in four separate trenches thatcan be stratigraphically correlated. Here we present the main stratigraphic and archaeological units and discuss site formation processes.Results show a great density of fossils and stone tools vertically through two stratigraphic intervals (Lemuta and Lower Augitic Sandstone)and laterally across an area of around 300 m2, and highlight the confluence of biotic and abiotic agents in the formation of the assemblage. The large size and diversityof the assemblage, as well as its good preservation, qualify HWK EEas a reference sitefor the study of the late Oldowan at Olduvai Gorge and elsewhere in Africa. In addition, thedescriptionof the stratigraphic and archaeological sequenceof HWK EE presented in this paper constitutesthe foundation for further studies on hominin behaviour and palaeoecologyin Lower and Middle Bed II

BODYWAY: ESTEREOTIPOS DE BELLEZA EN LA ESCUELA; INCIDENCIA DE LOS MEDIOS Y REPERCUSIÓN EN LOS CONTEXTOS

Desde los planteamientos de la investigación como estrategia pedagógica (IEP) de Mejía y Manjarrés (2012) se enmarcan múltiples análisis para efecto de la organización de nuevos proyectos curriculares de ciencias en general y de la enseñanza de la química en particular; a partir de lo cual se pretenden aportar al fortalecimiento y flexibilidad de la enseñanza de las ciencias desde una perspectiva investigativa en el marco de la educación en ciencias para la sustentabilidad, que permita la relación de elementos que caracterizan la dimensión y complejidad química en los distintos ambientes de formación, mediante la inclusión de aspectos de relevancia, en pro de generar y desarrollar procesos más consecuentes relacionados con el contexto social, y cultural de los estudiantes. Partiendo de lo anterior en el espacio del CLUB DE CIENCIAS DECONSTRUYENDO CONOCIMIENTO AMBIENTAL, se plantea como forma de mejorar los procesos de enseñanza, la relacion de los aspectos teoricos con las problematicas de la vida diaria, esto mediante la autoreflexion por parte de quienes participan en las situaciones sociales de enseñanza, con el fin de mejorar la racionalidad sus propias practicas educativas y su comprension sobre las mismas, ademas de una construccion social desde las diversas situaciones en las instituciones en que estas practicas se realizan. A partir de lo anterior se procedió a diseñar una propuesta metodológica de para realizar una investigación que permite evidenciar la incidencia que tienen los medios de comunicación masivos en los estereotipos de belleza que poseen las personas, y a su vez como se ven permeados mediante los procesos formativos y la edad de los individuos

Oxidation mechanism of formic acid on the bismuth adatom-modified Pt(111) surface

In order to improve catalytic processes, elucidation of reaction mechanisms is essential. Here, supported by a combination of experimental and computational results, the oxidation mechanism of formic acid on Pt(111) electrodes modified by the incorporation of bismuth adatoms is revealed. In the proposed model, formic acid is first physisorbed on bismuth and then deprotonated and chemisorbed in formate form, also on bismuth, from which configuration the C-H bond is cleaved, on a neighbor Pt site, yielding CO2. It was found computationally that the activation energy for the C-H bond cleavage step is negligible, which was also verified experimentally.This work has been financially supported by the MINECO (Spain) (project CTQ2013-44083-P) and Generalitat Valenciana (project PROMETEOII/2014/013).Perales Rondón, JV.; Ferre Vilaplana, A.; Feliu, J.; Herrero, E. (2014). Oxidation mechanism of formic acid on the bismuth adatom-modified Pt(111) surface. Journal of the American Chemical Society. 136(38):13110-13113. https://doi.org/10.1021/ja505943hS13110131131363

Spatial and temporal variation of fish assemblage associated with aquatic macrophyte patches in the littoral zone of the Ayapel Swamp Complex, Colombia

ABSTRACT: Aim: The purpose of the present study was to examine spatial and temporal variation in fish assemblage structure associated with aquatic macrophytes in the littoral zone of the ASC. Methods: Specimens were caught between January 2008 and February 2009, over four limnimetric moments, using both cast net and seine net. Data on the temperature, electrical conductivity, pH and dissolved oxygen was recorded for the characterization of the water mass in the sites. Results: A total of 34,151 specimens from 44 species were collected. The most abundant species were Eigenmannia virescens, Astyanax caucanus, Astyanax fasciatus, Roeboides dayi and Cyphocharax magdalenae, which together accounted for more than 75% of the sample. Temporal and spatial comparisons showed variation in the environmental conditions and highlighted the existence of heterogeneous abiotic conditions (p0.05) regarding the fish assemblage structure. The multivariate analysis showed no significant relationship between existing environmental conditions and the fish assemblage (p=0.04). The analysis also showed the absence of a relationship between the fish assemblage and environmental variables with respect to the flood pulse and sampling sites (p>0.05). Conclusion: The uniformity of the fish communities that inhabit aquatic macrophyte patches in the littoral region of the ASC may be related to the availability of suitable habitat in structural terms, that probably supports a more abundant and varied wildlife

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Altered immune parameters correlate with infection-related hospitalizations in children with Down syndrome

Q4Q2Artículo original594-599In addition to previously studied immunological variables, the relative expression of IFNGR2, IFNAR1,CD18, and CD275 (all encoded in chromosome 21) on circulating leucocytes and multifunctional T cells(evaluated by an intracellular cytokine/proliferation assay) were compared between children with Downsyndrome (DS) and healthy controls (HC). As previously reported, numbers of lymphocytes, CD4+T cells,Treg cells, B cells, and levels of serum IgM were decreased, and levels of IgG and IgA were increased inchildren with DS. Moreover, the relative expression of CD18 on T and B cells (previously and not previ-ously reported, respectively) were elevated in DS children (p60.01). Age and numbers of B and Treg cellsmoderately correlated with retrospectively identified infection related hospitalizations (rho: 0.300–0.460, p60.003). Age and the numbers of Treg cells also correlated with prospectively identified infec-tion related hospitalizations. Future studies are necessary to clarify the role of these parameters in theimmunity of DS patient

New excavations at the HWK EE site: Archaeology, paleoenvironment and site formation processes during late Oldowan times at Olduvai Gorge, Tanzania

This paper reports the results of renewed fieldwork at the HWK EEsite(Olduvai Gorge, Tanzania). HWK EEis positioned across the boundary between Lower andMiddle Bed II, a crucialinterval for studyingthe emergence of the Acheulean at Olduvai Gorge. Our excavations at HWK EEhave produced one of the largest collections of fossils and artefacts from any Oldowan site, distributed across several archaeological units and a large excavation surface in four separate trenches thatcan be stratigraphically correlated. Here we present the main stratigraphic and archaeological units and discuss site formation processes.Results show a great density of fossils and stone tools vertically through two stratigraphic intervals (Lemuta and Lower Augitic Sandstone)and laterally across an area of around 300 m2, and highlight the confluence of biotic and abiotic agents in the formation of the assemblage. The large size and diversityof the assemblage, as well as its good preservation, qualify HWK EEas a reference sitefor the study of the late Oldowan at Olduvai Gorge and elsewhere in Africa. In addition, thedescriptionof the stratigraphic and archaeological sequenceof HWK EE presented in this paper constitutesthe foundation for further studies on hominin behaviour and palaeoecologyin Lower and Middle Bed II