191 research outputs found

    Respuesta de zamia incognita l. al cultivo in vitro, una alternativa para su conservación

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    Título en ingles: In vitro culture response on Zamia incognita,  an alternative for preservation Resumen: Las Zamiaceas son plantas relictuales consideradas fósiles vivientes. En Colombia, el 65% de esta familia se encuentra en alguna categoría de amenaza, por la destrucción del hábitat e intensa recolección. Teniendo en cuenta que entre las ventajas de la propagación in vitro está la conservación ex situ de germoplasma, el presente trabajo tuvo como objetivo evaluar el potencial de regeneración de plantas de Z. incognita a partir de explantes foliares y embriones cigoticos. Se evaluó el efecto de diferentes combinaciones de Auxinas (2,4-D y ANA) y citoquininas (KIN, BAP y TDZ) sobre la formación de callo  y la regeneración de brotes (directa o indirecta), utilizando como medio basal MS (MB1) y medio basal B5 modificado (MB2). La formación de callo se presentó sobre un amplio rango de concentraciones de 2,4-D con KIN y 2,4-D con BAP, independientemente del medio basal, pero no en los explantes tratados con ANA más KIN o TDZ.  Para los explantes foliares no hubo respuesta  a la formación de embriones somáticos y/o brotes con las combinaciones y concentraciones hormonales evaluadas, no obstante los callos inducidos en MB2 con 2,4-D (0,22 mg/l) y BAP (0, 1, 2, 3 mg/l) fueron diferentes, su aspecto nodular, color crema y  apariencia proembriogénica coincidió con una gran cantidad de células meristemáticas potenciales para el proceso de regeneración. A partir de embriones cigoticos inmaduros se logró la formación de embriones somáticos en el medio MB2 exento de reguladores o conteniendo 2,4-D solo (0,22 mg/l) y en combinación con BAP (1 mg/l), sin lograr el proceso de conversión a plántulas. Palabras clave: micropropagación; hojas jóvenes; reguladores de crecimiento; embriones cigóticos; medio basal. Abstract: Zamiaceas are relict plants considered living fossils. In Colombia, 65% of this family is under some threat category due to their habitat destruction and their intense collection. Given that the advantages of in vitro propagation is ex situ conservation of germoplasm, this study aimed to evaluate the regeneration potential of  Z incognita plants  from leaf explants and zygotic embryos. The effect of different combinations of auxin (2.4-D and NAA) and cytokinins (KIN, BAP and TDZ) was evaluated on the formation of callus and shoot regeneration (direct or indirect), using MS (MB1) basal medium and B5 (MB2) basal modified medium.  The callus formation was presented over a wide concentration range of 2.4-D with KIN and 2.4-D with BAP, regardless of the basal medium, but not in explants treated with ANA more TDZ or KIN. For leaf explants there was no response to the formation of somatic embryos or shoots with hormonal combinations and concentrations evaluated; however, MB2 calluses induced with 2.4-D (0.22 mg / l) and BAP (0. 1 , 2. 3 mg / l) were different, their nodular aspect, cream color and pro-embryogenic appearance coincided with a lot of potential meristematic cells for the regeneration process. From immature zygotic embryos, somatic embryo formation in the MB2 medium was achieved without growth regulators or containing 2.4-D alone (0.22 mg /l) or 2.4-D in combination with BAP (1 mg/l) without achieving the conversion process to seedlings. Key words: microprogation; young leaves; plant growth regulators; zygotic embryos; basal medium

    Respuesta de zamia incognita l. al cultivo in vitro, una alternativa para su conservación

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    Título en ingles: In vitro culture response on Zamia incognita,  an alternative for preservation Resumen: Las Zamiaceas son plantas relictuales consideradas fósiles vivientes. En Colombia, el 65% de esta familia se encuentra en alguna categoría de amenaza, por la destrucción del hábitat e intensa recolección. Teniendo en cuenta que entre las ventajas de la propagación in vitro está la conservación ex situ de germoplasma, el presente trabajo tuvo como objetivo evaluar el potencial de regeneración de plantas de Z. incognita a partir de explantes foliares y embriones cigoticos. Se evaluó el efecto de diferentes combinaciones de Auxinas (2,4-D y ANA) y citoquininas (KIN, BAP y TDZ) sobre la formación de callo  y la regeneración de brotes (directa o indirecta), utilizando como medio basal MS (MB1) y medio basal B5 modificado (MB2). La formación de callo se presentó sobre un amplio rango de concentraciones de 2,4-D con KIN y 2,4-D con BAP, independientemente del medio basal, pero no en los explantes tratados con ANA más KIN o TDZ.  Para los explantes foliares no hubo respuesta  a la formación de embriones somáticos y/o brotes con las combinaciones y concentraciones hormonales evaluadas, no obstante los callos inducidos en MB2 con 2,4-D (0,22 mg/l) y BAP (0, 1, 2, 3 mg/l) fueron diferentes, su aspecto nodular, color crema y  apariencia proembriogénica coincidió con una gran cantidad de células meristemáticas potenciales para el proceso de regeneración. A partir de embriones cigoticos inmaduros se logró la formación de embriones somáticos en el medio MB2 exento de reguladores o conteniendo 2,4-D solo (0,22 mg/l) y en combinación con BAP (1 mg/l), sin lograr el proceso de conversión a plántulas. Palabras clave: micropropagación; hojas jóvenes; reguladores de crecimiento; embriones cigóticos; medio basal. Abstract: Zamiaceas are relict plants considered living fossils. In Colombia, 65% of this family is under some threat category due to their habitat destruction and their intense collection. Given that the advantages of in vitro propagation is ex situ conservation of germoplasm, this study aimed to evaluate the regeneration potential of  Z incognita plants  from leaf explants and zygotic embryos. The effect of different combinations of auxin (2.4-D and NAA) and cytokinins (KIN, BAP and TDZ) was evaluated on the formation of callus and shoot regeneration (direct or indirect), using MS (MB1) basal medium and B5 (MB2) basal modified medium.  The callus formation was presented over a wide concentration range of 2.4-D with KIN and 2.4-D with BAP, regardless of the basal medium, but not in explants treated with ANA more TDZ or KIN. For leaf explants there was no response to the formation of somatic embryos or shoots with hormonal combinations and concentrations evaluated; however, MB2 calluses induced with 2.4-D (0.22 mg / l) and BAP (0. 1 , 2. 3 mg / l) were different, their nodular aspect, cream color and pro-embryogenic appearance coincided with a lot of potential meristematic cells for the regeneration process. From immature zygotic embryos, somatic embryo formation in the MB2 medium was achieved without growth regulators or containing 2.4-D alone (0.22 mg /l) or 2.4-D in combination with BAP (1 mg/l) without achieving the conversion process to seedlings. Key words: microprogation; young leaves; plant growth regulators; zygotic embryos; basal medium

    Bibliometric analysis in paediatric dental journals listed in journal citation reports. Current trends

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    Aim The aim of this study was to analyse articles published in paediatric dental journals included in Journal Citation Reports (JCR), to determine current trends in paediatric publishing. Methods Articles included in paediatric dentistry journals in 2020 JCR were selected, published during the period 2008– 2020. After applying inclusion criteria, author-based parameters (article title, first author’s name, institution, sex and number of authors, number of affiliations, first/last author’s origin and geographic origin), and article-based parameters (article type, main topic, research design) were registered for each article. Results A total of 3,027 articles were analysed. The percentage of female authors showed an increasing positive tendency over the decade and the top producing country was the USA (16.5%). Dental surgery was the most recurrent topic (23.4%). Regarding the origin of the first author’s affiliation, 51% proceeded from the paediatric dentistry departments belonging to public institutions, with a decreasing trend in non-academic/ private affiliations. Positive and negative correlations exist between citation count and other variables. Conclusions International Journal of Paediatric Dentistry, Journal of Clinical Pediatric Dentistry, European Journal of Paediatric Dentistry and Pediatric Dentistry were the four main journals in terms of production volume, USA being the most productive country. The most recurrent topic was dental surgery, and the most common design was observational studies. Study design, geographic origin of the articles, article type and main subject of the article might predict citation.Odontologí

    Cordage, basketry and containers at the Pleistocene-Holocene boundary in southwest Europe. Evidence from Coves de Santa Maira (Valencian region, Spain)

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    In this study we present evidence of braided plant fibres and basketry imprints on clay recovered from Coves de Santa Maira, a Palaeolithic-Mesolithic cave site located in the Mediterranean region of Spain. The anatomical features of these organic fibre remains were identified in the archaeological material and compared with modern Stipa tenacissima (esparto grass). Based on direct dating, the fragments of esparto cord from our site are the oldest worked plant fibres in Europe. Sixty fragments of fired clay are described. The clay impressions have allowed us to discuss the making of baskets and containers. According to their attributes and their functional interpretation, we have grouped them into five types within two broad categories, hearth plates and baskets or containers. The clay pieces identified as fragments of containers with basketry impressions are less common than those of hearth plate remains and they are concentrated in the Epipalaeolithic occupation material (13.2-10.2 ka cal bp). The clay impressions from Santa Maira indicate that some fibres were treated or flattened, a preparation process that is known from historical and ethnological sources

    Informe preliminar sobre la prospección de la Vall del Barxell -Polop (Alcoi-Alcant)

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    Dins del projecte d'estudi del procés de neolitització a les comarques centromeridionals del País Valencià. es presenten els resultats preliminars obringuts en la prospecció sistemàtica deI la capçalera del riu Serpis, la Vall de Barxell-Polop (Alcoi-Alacant).Within the survey project of neolithization in the central and southern regions of the Valencian Country, we present herein the preliminary results achieved so far in the systematic prospecting at the source of the Serpis River, located in the Barxell-Polop Valley, within the municipal boundary of Alcoi, in the Alicante area.Dentro del proyecto de estudio del proceso de Neolitización en las comarcas centromeridionales del País Valenciano. se presentan los resultados preliminares obtenidos en la prospección sistemática de la cabecera del río Serpis, valle del Barxell-Polop (Alcoi. Alacant)

    Funerary practices or food delicatessen? Human remains with anthropic marks from the Western Mediterranean Mesolithic

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    The identification of unarticulated human remains with anthropic marks in archaeological contexts normally involves solving two issues: a general one associated with the analysis and description of the anthropic manipulation marks, and another with regard to the interpretation of their purpose. In this paper we present new evidence of anthropophagic behaviour amongst hunter-gatherer groups of the Mediterranean Mesolithic. A total of 30 human remains with anthropic manipulation marks have been found in the Mesolithic layers of Coves de Santa Maira (Castell de Castells, Alicante, Spain), dating from ca. 10.2-9 cal ky BP. We describe the different marks identified on both human and faunal remains at the site (lithic, tooth, percussion and fire marks on bone cortex). As well as describing these marks, and considering that both human and faunal remains at the site present similar depositional and taphonomic features, this paper also contextualizes them within the archaeological context and subsistence patterns described for Mesolithic groups in the region. We cannot entirely rule out the possibility that these practices may be the result of periodic food stress suffered by the human populations. These anthropophagic events at the site coincide with a cultural change at the regional Epipalaeolithic-Mesolithic transition

    Persistence of anticancer activity in berry extracts after simulated gastrointestinal digestion and colonic fermentation

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    Fruit and vegetable consumption is associated at the population level with a protective effect against colorectal cancer. Phenolic compounds, especially abundant in berries, are of interest due to their putative anticancer activity. After consumption, however, phenolic compounds are subject to digestive conditions within the gastrointestinal tract that alter their structures and potentially their function. However, the majority of phenolic compounds are not efficiently absorbed in the small intestine and a substantial portion pass into the colon. We characterized berry extracts (raspberries, strawberries, blackcurrants) produced by in vitro-simulated upper intestinal tract digestion and subsequent fecal fermentation. These extracts and selected individual colonic metabolites were then evaluated for their putative anticancer activities using in vitro models of colorectal cancer, representing the key stages of initiation, promotion and invasion. Over a physiologically-relevant dose range (0–50 µg/ml gallic acid equivalents), the digested and fermented extracts demonstrated significant anti-genotoxic, anti-mutagenic and anti-invasive activity on colonocytes. This work indicates that phenolic compounds from berries undergo considerable structural modifications during their passage through the gastrointestinal tract but their breakdown products and metabolites retain biological activity and can modulate cellular processes associated with colon cancer

    Experimental evaluation of the usage of ad hoc networks as stubs for multiservice networks

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    This paper describes an experimental evaluation of a multiservice ad hoc network, aimed to be interconnected with an infrastructure, operator-managed network. This network supports the efficient delivery of services, unicast and multicast, legacy and multimedia, to users connected in the ad hoc network. It contains the following functionalities: routing and delivery of unicast and multicast services; distributed QoS mechanisms to support service differentiation and resource control responsive to node mobility; security, charging, and rewarding mechanisms to ensure the correct behaviour of the users in the ad hoc network. This paper experimentally evaluates the performance of multiple mechanisms, and the influence and performance penalty introduced in the network, with the incremental inclusion of new functionalities. The performance results obtained in the different real scenarios may question the real usage of ad-hoc networks for more than a minimal number of hops with such a large number of functionalities deployed

    New insights into the neolithisation process in southwest Europe according to spatial density analysis from calibrated radiocarbon dates

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    The agricultural way of life spreads throughout Europe via two main routes: the Danube corridor and the Mediterranean basin. Current archaeological literature describes the arrival to the Western Mediterranean as a rapid process which involves both demic and cultural models, and in this regard, the dispersal movement has been investigated using mathematical models, where the key factors are time and space. In this work, we have created a compilation of all available radiocarbon dates for the whole of Iberia, in order to draw a chronological series of maps to illustrate temporal and spatial patterns in the neolithisation process. The maps were prepared by calculating the calibrated 14C date probability density curves, as a proxy to show the spatial dynamics of the last hunter-gatherers and first farmers. Several scholars have pointed out problems linked with the variability of samples, such as the overrepresentation of some sites, the degree of regional research, the nature of the dated samples and above all the archaeological context, but we are confident that the selected dates, after applying some filters and statistical protocols, constitute a good way to approach settlement spatial patterns in Iberia at the time of the neolithisation process

    Evaluation and optimization of PCR primers for selective and quantitative detection of marine ANME subclusters involved in sulfate-dependent anaerobic methane oxidation

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    Since the discovery that anaerobic methanotrophic archaea (ANME) are involved in the anaerobic oxidation of methane coupled to sulfate reduction in marine sediments, different primers and probes specifically targeting the 16S rRNA gene of these archaea have been developed. Microbial investigation of the different ANME subtypes (ANME-1; ANME-2a, b, and c; and ANME-3) was mainly done in sediments where specific subtypes of ANME were highly enriched and methanogenic cell numbers were low. In different sediments with higher archaeal diversity and abundance, it is important that primers and probes targeting different ANME subtypes are very specific and do not detect other ANME subtypes or methanogens that are also present. In this study, primers and probes that were regularly used in AOM studies were tested in silico on coverage and specificity. Most of the previously developed primers and probes were not specific for the ANME subtypes, thereby not reflecting the actual ANME population in complex samples. Selected primers that showed good coverage and high specificity for the subclades ANME-1, ANME-2a/b, and ANME-2c were thoroughly validated using quantitative polymerase chain reaction (qPCR). From these qPCR tests, only certain combinations seemed suitable for selective amplification. After optimization of these primer sets, we obtained valid primer combinations for the selective detection and quantification of ANME-1, ANME-2a/b, and ANME-2c in samples where different ANME subtypes and possibly methanogens could be present. As a result of this work, we propose a standard workflow to facilitate selection of suitable primers for qPCR experiments on novel environmental samples.This research is supported by the Dutch Technology Foundation STW (project 10711), which is part of the Netherlands Organization for Scientific Research (NWO), and which is partly funded by the Ministry of Economic Affairs. Research of AJMS is supported by ERC grant (project 323009). Research of PHATand AJMS is supported by the SIAM Gravitation grant (project 024.002.002) of the Netherlands Ministry of Education, Culture and Science and the Netherlands Science Foundation (NWO).info:eu-repo/semantics/publishedVersio
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