bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of recycled materials and hybrid fibers on the properties of self-compacting concrete
Authors: Dawood Eethar , Al-Heally Maysam
Published: March 2021

Self-compacting concrete (SCC) has many properties comparing to conventional concrete and represents a good choice towards sustainability. The use of different recycled materials contributes to seize the negative impact of huge amount of waste on the ecosystem. In this study, locally available materials have been used as partially cement replacements. Such materials including ceramic waste powder (CWP) and glass powder (GP) in addition to fly ash with total cement replacement of 30%(12%CWP+8%GP+12%Fly ash) have been found to increase the compressive strength by about 7% compared to the control SCC. Normal aggregate was replaced by recycled aggregate with different recycled aggregate which are Recycled Concrete (RC), Crushed red brick (REB) and Crushed ceramic (CER.) The percentages of replacements are: 25%, 50%, 75% and 100%, for each type of aggregate. The results show that the increase of the amount of recycled aggregates decreases the strength properties of SSC and effect on workability of SSC also the result show a reduction in oven dry density. The combination of different type of recycled aggregate shows a reduction in SSC strength. The use of fibers shows better performance of SSC compared to combination aggregate mix without fiber but reduce the workability of SCC. However, the fiber content of 1.0% shows the best result of the mechanical properties, whereas, fiber content up to 1.5% affects negatively on concrete properties. The use of hybrid fiber also increases the strength properties of concrete.
Análisis de una expresión gráfica inédita en la Región de Murcia: Los grabados históricos del Caño del Barracón y de la Torre de Inchola (Alhama de Murcia)
Authors: Rabal Saura Gregorio , Castejón Porcel Gregorio
Published: March 2021

En Inchola, caserío situado en la umbría de la Sierra de Carrascoy, se levantan los restos de una estructura defensiva medieval, llamada Torre de Inchola, y los de una antigua conducción hidráulica conocida como Caño del Barracón. En ambas edificaciones se desarrolla un variado repertorio de signos grabados sobre sus muros, entre los que predominan los que reproducen la forma de herradura. En este trabajo se describe la tipología de los grabados, proponiendo posibles líneas de interpretación histórica y una probable datación de los mismos en el contexto de los inicios de la Edad Moderna en el Reino de Murcia.

In Inchola, a hamlet located in the shaded areas of the Sierra de Carrascoy, we find the remains of a medieval defensive structure, called Torre de Inchola, and those of an old hydraulic conduction known as Caño del Barracón. There is a wide collection of signs engraved on the walls of both constructions. The signs reproducing horseshoe shapes predominate. This paper describes the typology of these engravings, proposing different lines of historical interpretation and a likely dating in the context of the beginnings of the Modern Age in the Kingdom of Murcia
Antropología periférica
Authors: Martínez Francisco
Published: March 2021

Desde Estonia, un país situado en la periferia de Europa (y donde la Antropología tiene una tradición limitada), el artículo analiza lo que significa ser ‘periférico’ dentro de la antropología europea: ¿Hablamos de relevancia, capacitación, tipo de colaboraciones, restricciones disciplinarias, relación de dependencia, mecanismos de in/visibilidad, reputación científica o de financiación? El artículo concluye con una nota positiva, indicando que los márgenes globales del conocimiento también se pueden convertir en centros de producción teórica a su manera, sea como plataforma de experimentación o como hub regional. También indica que hay una forma distinta de reflexividad en las periferias, más vernácula y experimental.

From Estonia, a country located on the periphery of Europe (and where Anthropology has a limited tradition, the article analyzes what it means to be ‘peripheral’ within European anthropology: Are we talking about relevance, training, type of collaborations, disciplinary restrictions, dependency relationship, mechanisms of in/visibility, scientific reputation or funding? The article concludes on a positive note, stating that the global peripheries of knowledge can also become centers of knowledge production in their own way, either as a platform for experimentation or as a regional hub. Also that there is a different form of reflexivity in the peripheries, more vernacular and experimental.
Marcas de ataque atribuidas a un seláceo en una vértebra de mosasaurio del Cretácico Superior de Álava (región Vasco-Cantábrica)
Authors: Corral J. Carmelo , Pereda Suberbiola Xabier , Bardet Nathalie
Published: March 2021

Se describe una vértebra caudal de mosasaurio (Squamata) con estructuras de bioerosión procedente del CretácicoSuperior de la Región Vasco-Cantábrica. El espécimen proviene de niveles margosos de la Formación de Vitoria(Campaniense superior) de Jáuregui, Álava. La morfología de las estructuras observadas en el centro vertebralse asemeja mucho a las características incisiones de un selacio con una dentición de tipo cortante (o con unatendencia hacia ese modelo). La presencia en la misma formación de dientes aislados de tiburones lamniformescomo Squalicorax kaupi (Agassiz, 1843) y Cretolamna appendiculata (Agassiz, 1843) permite suponer que sonmarcas causadas probablemente por uno de estos selacios. Se trata de una de las escasas evidencias de depredacióno actividad carroñera de un tiburón sobre un mosasaurio en el registro fósil europeo.
Corales tabulados del Ordovícico (Caradoc) de la Precordillera Argentina
Authors: Fernández-Martínez Esperanza , Carrera Marcelo G. , Rodríguez Sergio
Published: March 2021

En este estudio se describen por primera vez dos corales tabulados del Ordovícico de la Precordillera Argentina. Se trata de un ejemplar asignado a aff. Paleofavosites sp., procedente de la formación Las Aguaditas y otro clasificado como ?Billingsaria sp., procedente de la Formación Las Plantas, ambos del Caradoc. La escasez del material y detalles problemáticos de su microestructura en el primero de los casos y la mala preservación en el segundo impiden llegar a determinaciones taxonómicas más precisas.
Fragmentary remains of Odontocetes (Cetacea, Mammalia) from the Miocene of the Lower Tagus Basin (Portugal)
Authors: Estevens Mário , Antunes Miguel Antunes
Published: March 2021

This first systematic account of the scarcely studied Miocene cetaceans from Portugal describes 17 previously unpublished odontocete specimens from the Lower Tagus Basin. In spite of their fragmentary nature, at least a familial assignment was accomplished for most, and some were even tentatively ascribed to known genera: the Physeteridae are represented only by isolated teeth of “Scaldicetus” type; the Platanistidae by a tympanic not definitely assigned to a particular genus; the Eurhinodelphinidae by a lumbar vertebra and an atlas, both only tentatively referred to this family; and the Kentriodontidae comprise the most diversified forms, including rostral and mandibular fragments of a kentriodontine close to Rudicetus, isolated teeth of another kentriodontine (cf. Macrokentriodon sp.), and rostral and mandibular fragments of an undetermined lophocetine. Some additional scrappy remains are listed only as Odontoceti indet. This small sample includes forms known both from the eastern and western North Atlantic, and the Mediterranean,thus reasserting the importance of the geographic position of Portugal as a link between all of these regions. Further systematic research may precise with which of them the Lower Tagus Basin Miocene odontocete fauna has a closer relationship, although, based on this preliminary data, the greater similarity seems at present to be with the western North Atlantic.
Braquiópodos chonetoideos del Carbonífero de México
Authors: Sour Tovar Francisco , Martínez Chacón M. Luisa
Published: March 2021

Se describen cuatro especies de chonétidos procedentes del Carbonífero de México. El anóplido Yagonia collinsoni Carter se ha recolectado en capas de la Formación Vicente Guerrero, del Osageense (Misisípico) de Tamaulipas, en el noreste de México. De la Formación Ixtaltepec, Pensilvánico Inferior-Medio de Oaxaca, en el sureste de México, se describen el anóplido Tornquistia sp. y los rugosochonétidos Neochonetes (N.) granulifer (Owen) y Neochonetes (N.) mixteco n. sp. La presencia del género Yagonia en el Osageense de Tamaulipas representa el registro más antiguo del género y señala relaciones paleogeográficas entre Australia, Suramérica y Norteamérica. El hallazgo de Tornquistia establece con certeza su existencia en Norteamérica. Las especies de Neochonetes (N.) que se describen se relacionan con linajes típicamente norteamericanos; la nueva especie se incluye en el grupo de Neochonetes (N.) carboniferus.
Calcareous marine algae from the Carboniferous (Moscovian-Gzhelian) of the Cantabrian Zone (NW Spain)
Authors: Mamet Bernard , Villa Elisa
Published: March 2021

A taxonomic revision of shallow-water Carboniferous (Pennsylvanian) red and green algae observed in Ponga, Picos de Europa and Pisuerga-Carrión Units in NW Spain is presented. Some microproblematics are included. Thirty-two genera are described; three genera and four species are new: Anatolipora cantabriensis n. sp., Pelayella multiporosa n. gen., n. sp., Kasimophyllum demuesensis n. gen., n. sp. and Penella pongaensis n. gen., n. sp. The microflora is typically Western Paleotethyan and remarkably similar to that observed in the Carnic Alps and Central Urals.
Estudio paleoambiental de nuevos yacimientos de plantas y vertebrados de la “unidad intermedia” del Mioceno Medio de la Cuenca De Madrid
Authors: Fernández Marrón M.ª Teresa , Fonollá Ocete José Fernando , Sesé Benito Carmén , Jiménez Rodrigo Juan Carlos
Published: March 2021

Se dan a conocer los vegetales fósiles (macrorrestos foliares, frutos y palinomorfos) y una asociación de microvertebrados encontrados en yacimientos descubiertos en la “Unidad Intermedia” del Mioceno de Madrid. Los restos paleobotánicos y palinológicos se encuentran en cinco yacimientos, mientras que los de microvertebrados aparecen en otro distinto, cercano a los anteriores y estratigráficamente por encima de éstos. En general la palinoflora identificada es bastante uniforme en todos los yacimientos; no así la macroflora que presenta peculiaridades en alguno de ellos. Los datos paleobotánicos ponen de manifiesto una vegetación muy diversa con géneros y especies característicos de medios montanos, abanicos aluviales, márgenes lacustre-palustres y lagunares. Los resultados del estudio de la macroflora y de los palinomorfos se representan y ubican en un perfil sintético y en un bloque diagrama esquemático. La asociación de vertebrados fósiles está constituida por dos taxones de reptiles (un lacértido y un ánguido), y entre los mamíferos el esciúrido Heteroxerus cf. rubricati, el glírido cf. Armantomys sp., el cricétido Megacricetodon collongensis - crusafonti, un insectívoro y varios restos de lagomorfos no determinables taxonómicamente. Desde un punto de vista bioestratigráfico esta asociación faunística puede situarse dentro del Mioceno Medio en el Aragoniense Superior, entre la zonas F, G1 y G2 de Daams y Freudenthal (1988a) correlacionables con la unidad NM 6 según la biozonación de Mein (1975). El medio ambiente indicado por esta fauna sería de clima relativamente seco y fundamentalmente abierto.
The neogene of the Lower Tagus Basin (Portugal)
Authors: Pais João
Published: March 2021

The Tertiary Lower Tagus Basin (LTB) occupies a large area in Portugal and constitutes a symmetric basin of the oriental huge Upper Tagus Basin, centered at Madrid (Spain). The LTB was an endorreic basin during the Paleogene.  Marine connection occurred at the Lower Aquitanian; at the Lisbon – Setúbal Peninsula region the sedimentation was in the ocean/continent interface, with several changes in the coast line. Apparently, the first marine transgression came from South, originating a gulf with a N-S coral reef that attained the Lisbon area. Occidental communication to the sea was established after the Burdigalian.The sedimentary and palaeontologic record of the distal sector of the LTB (Lisbon–Setúbal Peninsula) is related to sea level changes. The fossil richness – dinoflagellates, spores, pollen, plant macrorremains, foraminifera, ostracoda, molluscs, echinids, fishes, reptiles, mammals – and O and C isotopes, constitutes a large source of information for environmental and palaeogeographical reconstitutions, as well as for the establishment of correlations between marine and continental deposits. The analysis and the integration of a large amount of lithological and biostratigraphical data joined with isotopic ages (K/Ar and 87Sr/86Sr), allow the establishement of a chronostratigraphic framework for the distal part of the Miocene of the LTB and the definition of 10 depositional sequences, in part agreeing with the Haq’s 3rd order eustatic cycles. Climatic evolution during the Miocene has been also characterized. At continental environments, the faunas and floras point out to an alternation of moist and dry episodes, the dryest one at the Langhian
Moluscos del Tirreniense (Pleistoceno Superior) de la Playa la Araña-Cala del Moral (Málaga)
Authors: Vera-Peláez José Luis , Lozano-Francisco M. Carmen , Ramos Fernández Julián , Cortés Sánchez Miguel
Published: March 2021

Se ha realizado un estudio taxonómico de los moluscos del Tirreniense (Pleistoceno Superior) encontrados en la Playa de la Araña-Cala del Moral (Málaga). Se aporta un listado de 45 especies de invertebrados, de los que 43 son moluscos, un equinodermo (Echinoidea) y un coral (Antozoa). Éste constituye el segundo afloramiento con mayor riqueza específica del Tirreniense andaluz después de Roquetas de Mar (Almería).
Asociaciones de braquiópodos del Oxfordiense medio-Kimmeridgiense inferior en la Zona Prebética (Sureste de España): Relación con las litofacies y el gradiente proximal-distal de la plataforma
Authors: Reolid Matías
Published: March 2021

Las asociaciones de macroinvertebrados bentónicos del Oxfordiense medio (Zona Transversarium)-Kimmeridgiense inferior (Zona Planula p.p.) correspondientes al Prebético, son analizadas prestando especial atención a la composición y rasgos tafonómicos de los braquiópodos. Este análisis ha permitido observar una estrecha relación entre la composición taxonómica de las asociaciones de braquiópodos, el gradiente proximal-distal y el tipo de litofacies. Algunos géneros de braquiópodos se encuentran limitados casi exclusivamente a determinadas litofacies, así Nucleata y Lacunosella se registran preferentemente en el grupo de litofacies grumosas que constituyen la sedimentación más intraclástica y de tamaño de grano más grueso, correspondientes a las áreas más distales de la plataforma (Prebético Interno). Los sectores comparativamente más proximales presentan áreas con predominio del grupo de litofacies espongiolíticas (sector oriental del Prebético Externo) donde los braquiópodos son más abundantes y diversos, siendo mayoritarios Monticlarella y Placothyris, y áreas con predominio de la litofacies de ritmita margoso-calcárea (sector central del Prebético Externo) donde los braquiópodos y otros organismos bentónicos sésiles aparecen en relación con pequeñas bioconstrucciones. Los factores que influyeron en la composición taxonómica y distribución de las asociaciones de macroinvertebrados bentónicos, y concretamente en las asociaciones de braquiópodos, fueron: el tipo de sustrato, la energía del medio, la tasa de sedimentación y la disponibilidad de nutrientes en suspensión.
Arachnostega gastrochaenae Bertling, 1992 en fósiles del Dobrotiviense (Ordovícico Medio) de los Montes de Toledo (SO de España)
Authors: Rodrigues Nuno PC , Gil Cid María Dolores , Arroyo Fernando , Huineman Miguel , Lara Ricardo , Torices Angélica
Published: March 2021

En el Dobrotiviense inferior (Ordovícico Medio) de los Montes de Toledo se encuentran evidencias de bioturbación en moldes internos de moluscos (bivalvos, gasterópodos, rostroconchas y cefalópodos), trilobites y equinodermos. De este modo, podemos identificar la presencia de los organismos que han dejado esas evidencias en el registro fósil, aumentando así el conocimiento sobre las comunidades marinas ordovícicas del SO español. El análisis de los fósiles donde se encuentran estas estructuras nos permite inferir que han sido producidas en un sustrato firme (moldes internos sin evidencias de reelaboración post-diagenética). Por otro lado, tienen un tipo de preservación en relieve negativo y completo. Ambas observaciones sugieren que son estructuras de bioturbación. El estudio icnotaxonómico nos permite llegar a la conclusión de que los ejemplares analizados se pueden identificar como Arachnostega gastrochaenae. El interés de este hallazgo está relacionado con la primera descripción de estructuras de bioturbación en moldes internos de invertebrados del Paleozoico español. La completa descripción de esta icnoespecie posibilita confirmar su presencia en facies siliciclásticas. Además, viene a corroborar la antigüedad de estos icnofósiles. Así, su registro estratigráfico incluye el Ordovícico, Carbonífero?-Pérmico?, Jurásico, Cretácico y Actualidad. Del mismo modo, viene a ampliar el número de grupos de organismos cuyos moldes internos presentan este tipo de estructuras de bioturbación, pues sólo se conocían ejemplos, hasta ahora, en bivalvos, braquiópodos, trilobites y, muy recientemente, equinodermos. Los organismos productores de estas galerías serían probablemente poliquetos vágiles o pequeños crustáceos.
RECENSIÓN. Foundations of Phylogenetic Systematics.
Authors: Poyato Ariza Francisco José
Published: March 2021

Durante el congreso Fourth Internacional Meeting on Mesozoic Fishes, organizado recientemente en la Universidad Autónoma de Madrid, el editor alemán Friedrich Pfeil presentó sus últimas novedades, entre las que destaca sin duda el libro aquí comentado. Se trata de la primera traducción al inglés de un libro de gran relevancia que, por haber estado publicado hasta ahora exclusivamente en alemán, no ha encontrado aún la repercusión que merece.
Siendo un libro que alcanza elevadas cotas de especialización, no es necesario un gran conocimiento previo para sumergirse en su lectura, ya que el Prof. Wägele realiza una exposición clara y rigurosa, desde lo más general hasta lo más específico, asimilable por cualquier lector interesado en la materia.
Nos encontramos ante un curso completo de Sistemática teórica y práctica en un sólo y relativamente breve, dada la amplitud de lo abarcado, volumen. La inferencia filogenética en la clasificación de los organismos es una herramienta indispensable hoy en día en todos los campos de la Biología, incluyendo por supuesto la Paleobiología. De ahí el indudable interés que este libro puede y debe despertar en nuestra comunidad paleontológica.
Presencia de icnitas de dinosaurios en el Cretácico Superior del margen sur del sinclinal de Tremp (prov. de Lleida, Cataluña, España)
Authors: Llompart Carme
Published: March 2021

Se dan a conocer dos nuevos yacimientos de icnitas de dinosaurios en el Cretácico Superior prepirenaico (facies Garumniense) al sur del pueblo de Moror (Conca de Tremp). Las huellas se conservan en dos niveles diferentes. En el afloramiento estratigráficamente más alto se presentan en calizas margosas. Son huellas que por sus dimensiones y morfología se atribuyen a terópodos; esta es la primera referencia a incitas de terópodos en la Conca de Tremp y en los Pirineos. El afloramiento estratigráficamente más bajo, asimismo en calizas algo margosas muy bioturbadas y afectadas por grietas de desecación, presenta icnitas de mayor tamaño que por sus dimensiones y morfología se atribuyen a ornitópodos, posiblemente hadrosaúridos. Representan la primera cita de icnitas de hadrosaúridos en el Cretácico Superior de la Conca de Tremp.
Lower Devonian stromatoporoids from the northern Obejo-Valsequillo-Puebla de la Reina Domain (Badajoz and Córdoba provinces, Southern Spain)
Authors: May Andreas
Published: March 2021

The stromatoporoid fauna from three locations in the “Peñón Cortado Limestone” (Pragian to Upper Emsian) from the area of Quintana de la Serena (Badajoz Province) and Peñarroya-Pueblonuevo (Córdoba Province) in the Obejo-Valsequillo-Puebla de la Reina Domain (Sierra Morena, Southern Spain) were investigated. The 71 stromatoporoid specimens collected belong to 11 different species.
The “Peñón Cortado” section in the Córdoba Province contains two different stromatoporoid-bearing horizons with very different fauna (bed 14 and bed 19b). In the older bed 14 dominates Plectostroma salairicum (Javorskij, 1930), meanwhile in the younger bed 19b Actinostroma compactum Ripper, 1933 and Pseudotrupetostroma anacontentoae May, 2005b dominate. The fauna of the younger bed 19b of the location “Peñón Cortado” correlate well with the stromatoporoid-bearing beds of the locations “Guadámez II” and “La Chamorra” in the Badajoz Province.
The absence of stromatoporoids with branched skeletons and the scarcity of stromatoporoids of the type which forms thin-layered crusts probably inhibited reef development. A possible explanation for this may be a relatively low water temperature.
Biogeographically, the fauna of the Sierra Morena belong to the Old World Realm and is closely related to Emsian fauna of Australia and Canada. The fauna indicate an Emsian age for the stromatoporoid-bearing beds in the “Peñón Cortado Limestone”. Furthermore, the stromatoporoids from the locations “Guadámez II” and “La Chamorra” suggest an Upper Emsian age much more strongly than a Lower Emsian age.
Presencia de Ciconia maltha (aves, ciconiidae) en el Pleistoceno Inferior-Medio del Valle de Tarija, Bolivia
Authors: Agnolin Federico
Published: March 2021

Un tarsometatarso incompleto de un Ciconiidae fósil es aquí descripto. El material procede de la Formación Tarija (Pleistoceno Inferior-Medio) de Bolivia. El tarsometatarso es asignable a la gran especie extinta Ciconia maltha, hasta ahora reportada en el Pleistoceno Medio-Tardío de Norte y Centroamérica. El material aquí descripto representa el primer registro para Ciconia maltha en Sudamérica y el primero para la familia Ciconiidae en Bolivia.
Nuevo registro de Hippidion principale (Mammalia, Perissodactyla) del Pleistoceno de Mar del Sur, Argentina
Authors: Alberdi María Teresa , Prado José Luis , Favier-Dubois Cristian M
Published: March 2021

Se describen un cráneo y una mandíbula incompleta de Hippidion principale, hallados en la zona costera de Mar del Sur (provincia de Buenos Aires). La sección estratigráfica analizada no cuenta con dataciones radiométricas o estudios paleomagnéticos que permitan calibrar con precisión la edad de los depósitos portadores de Hippidion. En base a correlaciones estratigráficas, los restos de Hippidion se sitúan en el Pleistoceno superior
Pingüinos (Aves, Spheniscidae) en Coquimbo (Mioceno Medio-Plioceno Tardío), Chile y su vinculación con las corrientes oceánicas
Authors: Acosta-Hospitaleche Carolina , Canto Jhoann , Tambussi Claudia P
Published: March 2021

Dos restos de pingüinos (Spheniscidae) procedentes de la Formación Coquimbo (Mioceno Medio- Plioceno Tardío) expuesta en “La Cantera” (cercanías de la ciudad de Coquimbo), en el sector sur-oriente (IV Región de Chile) son descriptos en este trabajo. Éstos se suman a los escasos vertebrados ya exhumados en el área y constituyen las primeras aves registradas para esta localidad. Corresponden a formas exclusivas de las costas de América del Sur y aparentemente más relacionadas con los pingüinos modernos que a las formas de altas latitudes. Los hábitos de vida y los requerimientos ambientales de los pingüinos vivientes (asociados a corrientes templadas frías) permiten inferir que en el momento de la sedimentación de la Formación Coquimbo, ya habría existido la influencia de la corriente fría de Humboldt. Coincidentemente, se reconoce un prolongado episodio frío hacia los ca. 15-12 Ma, en las aguas de la costa pacífica, momento en el cual se habría depositado la Unidad 2 (una de las 13 unidades previamente reconocidas) de la Formación Coquimbo.
La prensa ante la audiencia mariposa
Authors: Montaña Blasco Mireia
Published: March 2021

El auge de los nuevos medios digitales ha provocado una disminución de la reputación de la prensa escrita en los últimos años. Esta situación ha promovido que se haga, por primera vez, una campaña de comunicación conjunta para reposicionar este medio en el Reino Unido.
Quantum information, qubits y computación quántica
Authors: Cavaller Víctor
Published: March 2021

Buenas expectativas en el ámbito de la Quantum Information empiezan a divisarse después de años de investigación básica, estancamiento tecnológico y promesas empresariales incumplidas. La teoría de la información cuántica surgió hacia finales del siglo pasado al hacerse evidentes los límites físicos de la computación basada en el tradicional sistema binario. Al aumentar la escala de integración, y ante la imposibilidad de fabricar chips infinitamente pequeños por el llamado efecto túnel (que ocurre cuando la señal eléctrica salta de canal), surgió la necesidad de descubrir nuevas formas tecnológicas para la computación.
¿Dinámicas de campo en los inicios de la antropología científica en Chile? Algunas consideraciones y debates situados a inicios del siglo XX.
Authors: Mora Héctor Iván
Published: March 2021

En este artículo se exponen algunos antecedentes claves en lo que podemos denominar proceso de institucionalización de la antropología científica hacia inicios del siglo XX, en específico relativos a la identificación de instancias institucionales, actores y debates que tuvieron lugar en dicha época en torno a lo que se definió como “objeto”: la población indígena o nativa pasada y presente que habitaba el territorio nacional. Lo anterior da cuenta de la emergencia de un campo investigativo sin disciplina, el que no logra su consolidación como tal en la escena universitaria y/o formativa de la época, ni tampoco su continuidad como campo autónomo. Sin un respaldo persistente por parte del Estado, y como es característico en la emergencia de la ciencia en América Latina, la antropología se levanta a partir del esfuerzo de actores concretos que la alimentan desde un imaginario que la sitúa como ciencia moderna, bajo el imperativo moral de registra lo que desaparece ante el progreso.
Del Yo al Nosotras y de lo Personal a lo Político: La Construcción de la Conciencia de Género en Talleres para Mujeres
Authors: López Castillo Bárbara Catalina
Published: March 2021

El estudio realiza un análisis sobre un conjunto de actividades pedagógicas con financiamiento estatal, orientadas a mujeres consideradas vulnerables, que promueven concienciación de género al abordar temáticas como ejercicio de derechos, participación política y social y otras materias vinculadas al empoderamiento femenino. Se trata de los Talleres para Mujeres, ejecutados por la Fundación para la Promoción y Desarrollo de la Mujer y específicamente, del Taller de Desarrollo Personal del sector Pishuinco, en la Comuna de Valdivia entre abril y junio de 2015. Fundada en una metodología etnográfica, esta pesquisa se sirve de la antropología del género, la educación popular y la pedagogía feminista, e incorpora reflexiones que abarcan desde el feminismo de la segunda ola hasta el feminismo post colonial para problematizar la experiencia que describe, destacando las potencialidades de los procesos colectivos de concienciación, y a la vez poniendo en tela de juicio al fenómeno mismo de la construcción de conciencia de género.
Development of Induced Breeding Technique for Freshwater Fish Gobi, Glossogobius giuris (Hamilton, 1822) Using Pituitary Gland (PG) Extract
Authors: Yeasmine Selina , Rahman M. Aminur , Sarower-E-Mahfuj Md. , Sku Sonia , Hossen Md. Nazmul , Rahman M. Anisur , Mollah Md. Fazlul Awal
Published: March 2021

This study aimed to establish induced breeding technique of freshwater fish gobi (Glossogobius giuris), using the pituitary gland (PG) extract. Six experiments were conducted at the Department of Fisheries Biology and Genetics, Faculty of Fisheries, Bangladesh Agricultural University, Mymensingh, Bangladesh. First breeding trial was conducted in June using 40, 45, and 50 mg PG kg-1 body weight of the female fish. None of the fish was ovulated in the 1st trial. Two more breeding trials were conducted in July and August, using 6 mg (T1), 8 mg (T2) and 10 mg (T3) PG kg-1 body weight of female, and 3 mg (T4), 4 mg (T5) and 5 mg (T6) PG kg-1 body weight of male fish. After treatment, the ovulation rates were recorded as 56.33±1.53, 82.67±2.52 and 75.33±1.53% in July and 58.00±2.65, 94.67±1.53 and 78.33±1.53% in August under the treatments T1, T2 and T3, respectively. Hatching rates of eggs were observed as 52.00±4.36, 81.67±3.21 and 72.33±6.03% in July, and 54.67±3.23, 91.67±3.06 and 73.67±5.13% in August under the T1, T2 and T3, respectively. Hatching time was ranged from 35 to 48 h and after the absorption of yolk sac (60-72 h), they were survived well when fed with tubificid worms and mixed zooplankton. The female treated with the dose of 8 mg PG kg-1 body weight in August showed the best performance so far as the ovulation, fertilization and hatching rates were concerned, while the single dose of 4 mg kg-1 body weight of PG was found to be effective for male fish in both months. The findings obtained from the present study reveals that induced breeding of G. giuris, using PG extract is successful for large scale production of quality seed in captive condition, which would further facilitate towards the aquaculture production and biodiversity conservation of this important fish species to a greater extent.
Nitrogen and Sulfur Incorporation into Graphene Oxide by Mechanical Process
Authors: Sánchez-Salas Roque , Muñoz-Sandoval Emilio , Endo Morinobu , Morelos-Gómez Aarón , López-Urías Florentino
Published: March 2021

Graphene oxide (GO) is one of the carbon nanomaterials used most in novel applications due to its easy synthesis, easy exfoliation, doping potential performance, and good compatibility in composites. Mechanochemical method is used for GO reduction and doping during ball milling (BM) process. Urea and thiourea molecules are employed as nitrogen (N) and sulfur‐nitrogen (S,N) dopant agents, respectively. The elemental composition of BM‐GO‐urea exhibits 7.7 at% of N, whereas BM‐GO‐thiourea displays 6 at% of S with 5.6 at% of N. Using density functional calculations, urea, and thiourea molecules are covalently joined to the carboxyl functional groups. It is shown that nitrogen doping favors a HOMO energy decrement when the molecules are directly attached to graphene sheets in the absence of carboxyl groups, making it energetically less expensive to share electrons in undoped nanomaterials. In contrast, the urea and thiourea molecules joined to graphene sheets via carboxyl groups with deep HOMO energies and low nitrogen‐doping variations. The results demonstrate the viability of the BM technique for GO reduction and N/S dope‐functionalize. Furthermore, the mechanochemical methodology described is employed in graphite with urea and thiourea molecules to contrast results.
Dual Mode Rotary Triboelectric Nanogenerator for Collecting Kinetic Energy from Bicycle Brake
Authors: Zhou Han , Liu Guoxu , Gao Yikui , Wang Zheng , Qin Yuhan , Wang Yiqian , Lin Yuan , Xie Yuanyuan , Chen Yuanfen , Zhang Chi
Published: March 2021

Regenerative braking system is a promising technology for electrical vehicles, in which the excess kinetic energy can be effectively collected and utilized. As a new energy technology based on contact electrification, triboelectric nanogenerator (TENG) is suitable for harvesting dissipated kinetic energy in braking systems. Herein, a dual mode rotary TENG (DMR‐TENG) is reported, which is installed on the bicycle disc brake for collecting kinetic energy in riding mode and braking mode. First, the electric generation mechanism of DMR‐TENG is analyzed and then the characteristics in different structural and kinematic parameters by simulation and experiment are investigated. Furthermore, a linkage mechanism is designed for two modes switching by controlling the distance between two triboelectric layers of the DMR‐TENG. The results illustrate that the DMR‐TENG can simultaneously illuminate 156 serial LEDs as a warning signal while riding and braking. In addition, it can charge a 300 μF capacitor and act as a power source to drive a speedometer, which can measure the bicycle speed in real time. Herein, a considerable prospect in vehicle kinetic energy collecting is demonstrated and may have potential application in intelligent transportation.
Sowing ratio determines forage yields and economic benefits of oat and common vetch intercropping
Authors: Wang Shang , Chen Gong , Yang Yadong , Zeng Zhaohai , Hu Yuegao , Zang Huadong
Published: March 2021

Mixtures of annual legumes with cereal grasses in forage production are considered to have great advantages and are extensively used in the agro–pastoral region of China. However, the effect of sowing ratio on forage yields and economic benefits of oat (Avena sativa L.) and common vetch (Vicia sativa L.) intercropping remains largely unknown. A 2 yr field experiment was conducted with seven sowing ratios (sowing ratio of oat as 0, 25, 33, 50, 67, 75, and 100%) for oat and common vetch intercropping in northeastern China. Intercropping showed significant advantages in forage yield, land equivalent ratio (LER), and net income in the 2 yr. Oat was the dominant partner in the mixtures, strongly outcompeting common vetch. A sowing ratio of oat at 50% produced the highest forage yields of 10.8–11.1 t ha‐1 in spring seeding and 4.9–7.7 t ha‐1 in summer seeding, which were 28.7–66.4% and 12.6–166.9% higher than those in monocultures, respectively, if we considered two years together. In any case, oat forage yield just slightly decreased with a decreasing share in the intercrops, whereas common vetch forage yields strongly decreased. The highest LERs were detected in a sowing ratio of oat at 50%, which was 11–57% higher than other sowing ratios. Similarly, the highest annual net incomes of US$1,336 and $1,088 ha‐1 were also obtained in a sowing ratio of oat at 50% in the 2 yr. In conclusion, oat and common vetch intercropping have greater forage yields and economic benefits compared with the corresponding monocultures in the agro–pastoral region of China, and a sowing ratio of oat at 50% is recommended.
Magnetization Transfer to Enhance NOE Cross‐Peaks among Labile Protons: Applications to Imino–Imino Sequential Walks in SARS‐CoV‐2‐Derived RNAs
Authors: Novakovic Mihajlo , Kupče Ēriks , Scherf Tali , Oxenfarth Andreas , Schnieders Robbin , Grün J. Tassilo , Wirmer‐Bartoschek Julia , Richter Christian , Schwalbe Harald , Frydman Lucio
Published: March 2021

2D NOESY plays a central role in structural NMR spectroscopy. We have recently discussed methods that rely on solvent‐driven exchanges to enhance NOE correlations between exchangeable and non‐exchangeable protons in nucleic acids. Such methods, however, fail when trying to establish connectivities within pools of labile protons. This study introduces an alternative that also enhances NOEs between such labile sites, based on encoding a priori selected peaks by selective saturations. The resulting selective magnetization transfer (SMT) experiment proves particularly useful for enhancing the imino–imino cross‐peaks in RNAs, which is a first step in the NMR resolution of these structures. The origins of these enhancements are discussed, and their potential is demonstrated on RNA fragments derived from the genome of SARS‐CoV‐2, recorded with better sensitivity and an order of magnitude faster than conventional 2D counterparts.
Asymmetric Cobalt‐Catalyzed Regioselective Hydrosilylation/Cyclization of 1,6‐Enynes
Authors: You Yang'en , Ge Shaozhong
Published: March 2021

We report an enantioselective cobalt‐catalyzed hydrosilylation/cyclization reaction of 1,6‐enynes with secondary and tertiary hydrosilanes employing a catalyst generated in situ from the combination of Co(acac)2 and (R,Sp)‐Josiphos. A wide range of oxygen‐, nitrogen‐, and carbon‐tethered 1,6‐enynes reacted with Ph2SiH2, (EtO)3SiH, or (RO)2MeSiH to afford the corresponding chiral organosilane products in high yields and up to >99 % ee. This cobalt‐catalyzed hydrosilylation/cyclization also occurred with prochiral secondary hydrosilane PhMeSiH2 to yield chiral alkylsilanes containing both carbon‐ and silicon‐stereogenic centers with excellent enantioselectivity, albeit with modest diastereoselectivity. The chiral organosilane products from this cobalt‐catalyzed asymmetric hydrosilylation/cyclization could be converted to a variety of chiral five‐membered heterocyclic compounds by stereospecific conversion of their C−Si and Si−H bonds without loss of enantiopurity.
Structural and Molecular Dynamics Analysis of Plant Serotonin N‐Acetyltransferase Reveal an Acid/Base‐Assisted Catalysis in Melatonin Biosynthesis
Authors: Liao Lijing , Zhou Yuanze , Xu Youdong , Zhang Yuhao , Liu Xikai , Liu Biao , Chen Xinxin , Guo Yan , Zeng Zhixiong , Zhao Yucheng
Published: March 2021

Serotonin N‐acetyltransferase (SNAT) is the key rate‐limiting enzyme in melatonin biosynthesis. It mediates melatonin biosynthesis in plants by using serotonin and 5‐methoxytryptamine (5‐MT), but little is known of its underlying mechanisms. Herein, we present a detailed reaction mechanism of a SNAT from Oryza sativa through combined structural and molecular dynamics (MD) analysis. We report the crystal structures of plant SNAT in the apo and binary/ternary complex forms with acetyl‐CoA (AcCoA), serotonin, and 5‐MT. OsSNAT exhibits a unique enzymatically active dimeric fold not found in the known structures of arylalkylamine N‐acetyltransferase (AANAT) family. The key residues W188, D189, D226, N220, and Y233 located around the active pocket are important in catalysis, confirmed by site‐directed mutagenesis. Combined with MD simulations, we hypothesize a novel plausible catalytic mechanism in which D226 and Y233 function as catalytic base and acid during the acetyl‐transfer reaction.
pH Feedback Lifecycles Programmed by Enzymatic Logic Gates Using Common Foods as Fuels
Authors: Fan Xinlong , Walther Andreas
Published: March 2021

Artificial temporal signaling systems, which mimic living out‐of‐equilibrium conditions, have made large progress. However, systems programmed by enzymatic reaction networks in multicomponent and unknown environments, and using biocompatible components remain a challenge. Herein, we demonstrate an approach to program temporal pH signals by enzymatic logic gates. They are realized by an enzymatic disaccharide‐to‐monosaccharide‐to‐sugar acid reaction cascade catalyzed by two metabolic chains: invertase‐glucose oxidase and β‐galactosidase‐glucose oxidase, respectively. Lifetimes of the transient pH signal can be programmed from less than 15 min to more than 1 day. We study enzymatic kinetics of the reaction cascades and reveal the underlying regulatory mechanisms. Operating with all‐food grade chemicals and coupling to self‐regulating hydrogel, our system is quite robust to work in a complicated medium with unknown components and in a biocompatible fashion.
High‐Throughput Quality Control Assay for the Solid‐Phase Synthesis of DNA‐Encoded Libraries of Macrocycles**
Authors: Roy Animesh , Koesema Eric , Kodadek Thomas
Published: March 2021

There is considerable interest in the development of libraries of scaffold‐diverse macrocycles as a source of ligands for difficult targets, such as protein–protein interaction surfaces. A classic problem in the synthesis of high‐quality macrocyclic libraries is that some linear precursors will cyclize efficiently while some will not, depending on their conformational preferences. We report here a powerful quality control method that can be employed to readily distinguish between scaffolds that do and do not cyclize efficiently during solid‐phase synthesis of thioether macrocycles without the need for tedious liquid chromatography/mass spectrometry analysis. We demonstrate that this assay can be employed to identify linear impurities in a DNA‐encoded library of macrocycles. We also use the method to establish a useful quality control protocol for re‐synthesis of putative macrocyclic screening hits.
Residual Chlorine Induced Cationic Active Species on a Porous Copper Electrocatalyst for Highly Stable Electrochemical CO2 Reduction to C2+
Authors: Li Minhan , Ma Yuanyuan , Chen Jun , Lawrence Robert , Luo Wei , Sacchi Marco , Jiang Wan , Yang Jianping
Published: March 2021

Electrochemical carbon dioxide (CO2) reduction reaction (CO2RR) is an attractive approach to deal with the emission of CO2 and to produce valuable fuels and chemicals in a carbon‐neutral way. Many efforts have been devoted to boost the activity and selectivity of high‐value multicarbon products (C2+) on Cu‐based electrocatalysts. However, Cu‐based CO2RR electrocatalysts suffer from poor catalytic stability mainly due to the structural degradation and loss of active species under CO2RR condition. To date, most reported Cu‐based electrocatalysts present stabilities over dozens of hours, which limits the advance of Cu‐based electrocatalysts for CO2RR. Herein, a porous chlorine‐doped Cu electrocatalyst exhibits high C2+ Faradaic efficiency (FE) of 53.8 % at −1.00 V versus reversible hydrogen electrode (VRHE). Importantly, the catalyst exhibited an outstanding catalytic stability in long‐term electrocatalysis over 240 h. Experimental results show that the chlorine‐induced stable cationic Cu0/Cu+ species and the well‐preserved structure with abundant active sites are critical to the high FE of C2+ in the long‐term run of electrochemical CO2 reduction.
Correlations in rheological behavior between large amplitude oscillatory shear and steady shear flow of silica‐filled star‐shaped styrene‐butadiene rubber compounds: Experiment and simulation
Authors: Pole Sandeep S. , Isayev Avraam I.
Published: March 2021

The large amplitude oscillatory shear (LAOS) and steady shear behavior of star‐shaped SSBR/silica 60 phr (21 vol%) compounds with various filler surface areas was measured and simulated. An SBR gum and SBR compounds containing four different silicas with surface areas of 55, 135, 160, and 195 m2/g were utilized. Rheological behavior indicated clear correlation with surface area. LAOS tests showed an increase in dynamic moduli, shear stress, and higher order harmonic contributions with surface area. Elastic and viscous Lissajous figures showed significant distortion at intermediate and higher strain amplitudes. Additionally, ratios of third and fifth order stress harmonics to the first stress harmonic (I3/1 and I5/1, respectively) showed a ''bump'' at intermediate strain amplitudes for the three highest surface area compounds. With regards to steady shear, all materials showed strong shear thinning behavior, and an increase in shear viscosity with surface area. The Cox‐Merz rule was shown to be valid for the SBR gum but not for the filled compounds. However, the complex viscosity as a function of shear rate amplitude at various frequencies at high strain amplitudes and the steady shear viscosity as a function of shear rate coincided. This correlation, referred to as the Philippoff approach, has important ramifications for the rubber industry, providing quick data for predicting processing behavior. The Simhambhatla‐Leonov model was successfully employed to simulate rheological behavior for the SBR gum and the lowest surface area silica compound, but the model yielded mixed results for the higher surface area silica compounds.
Sustained Remission in Patients With Rheumatoid Arthritis Receiving Triple Therapy Compared to Biologic Therapy: A Swedish Nationwide Register Study
Authors: Källmark Hanna , Einarsson Jon T. , Nilsson Jan‐Åke , Olofsson Tor , Saxne Tore , Geborek Pierre , C. Kapetanovic Meliha
Published: March 2021

Objective

To compare the real‐life effectiveness of biologic therapy (a biologic disease‐modifying antirheumatic drug plus methotrexate [MTX]) versus triple therapy (MTX plus sulfasalazine plus hydroxychloroquine/chloroquine) for sustained remission of rheumatoid arthritis (RA).

Methods

RA patients who were registered in the nationwide Swedish Rheumatology Quality Register between 2000 and 2012 and were receiving biologic or triple therapy as a first treatment strategy after MTX monotherapy were included. Sustained remission was defined as a Disease Activity Score in 28 joints (DAS28) of <2.6 for ≥6 months (short‐term sustained remission) or for ≥24 months (long‐term sustained remission). Treatment groups were compared during treatment, at 1 year, and at 2 years for 1) all patients starting therapy and 2) patients continuing to receive therapy, using propensity score–adjusted regression analyses. In addition, survival analyses were used to compare treatment groups at any time during follow‐up irrespective of therapy retention.

Results

A total of 1,502 patients were included (1,155 receiving biologic therapy and 347 receiving triple therapy). For patients starting therapy, the adjusted odds ratios (ORs) of achieving short‐term and long‐term remission, respectively, at 1 year after start of biologic therapy versus triple therapy were 1.79 (95% confidence interval [95% CI] 1.18–2.71) and 1.86 (95% CI 1.00–3.48). At 2 years, the ORs were 1.92 (95% CI 1.21–3.06) and 1.62 (95% CI 0.94–2.79), respectively. For patients continuing to receive therapy, corresponding results at 1 year were 1.12 (95% CI 0.72–1.75) and 1.1 (95% CI 0.59–2.16); at 2 years, 0.85 (95% CI 0.49–1.47) and 0.76 (95% CI 0.41–1.39). Hazard ratios for short‐term and long‐term sustained remission at any time during follow‐up were 1.15 (95% CI 0.91–1.46) and 1.09 (95% CI 0.77–1.54), respectively.

Conclusion

Among patients starting biologic or triple therapy, biologic therapy was more effective for remaining on therapy and achieving sustained remission. However, similar probabilities were found for achieving sustained remission among patients remaining on therapy and at any time during follow‐up irrespective of therapy retention. Although the likelihood of reaching sustained remission is higher with biologic therapy, for certain RA patients triple therapy may still be an alternative to biologic therapy without hampering future chances of obtaining sustained remission.
Auf stürmischer See an Bord gehen
Authors: Abel Robert
Published: March 2021

Ein Experte für Enterprise Feedback Management des amerikanischen SAP‐Tochterunternehmens Qualtrics gibt Tipps für den gelungenen Einstieg unter schwierigen Bedingungen.
Leucht‐ und lautstark
Authors: Kaufmann Susanne
Published: March 2021

Für den Hafen von Kenia hat der belgische Maschinen‐ und Anlagenbauer Meyland drei mobile Wiegetrichter gebaut, die zum Wiegen von Schüttgütern eingesetzt werden. Das Besondere an diesen Wiegetrichtern ist ihre enorme Größe: Sie sind jeweils 13 Meter hoch
Sprung in eine neue ära
Authors: Kraftschik Florian , Claus Jan‐Marten , Dietrich Peter
Published: March 2021

Das Innovationstempo in der Stahlindustrie zieht kräftig an. Auch die Salzgitter Flachstahl GmbH setzt in der Produktion auf modernste Anlagentechnik. Jetzt hält das Industrial Internet of Things (IIoT) Einzug in die Kontibeize 2.