1,034 research outputs found
EFECTO DE NIVELES CRECIENTES DE VINAZA EN EL RENDIMIENTO AGROINDUSTRIAL DE LA CAÑA DE AZÚCAR EN UN SUELO ULTISOL DEL DEPARTAMENTO DE CAAZAPÁ, PARAGUAY
Con el objetivo de evaluar el efecto de la vinaza en el rendimiento agroindustrial de la caña de azúcar variedad SP 81-3250, se condujo un experimento en el predio de la Facultad de Ciencias Agrarias de la Universidad Nacional de Asunción, Filial Caazapá, ubicado en la localidad 20 de Julio, en un suelo "Rhodic Palodult" del orden Ultisol del distrito de Caazapá. El mismo se ejecutó durante la campaña agrícola 2007/8. El diseño experimental adoptado fue en bloques completos al azar, con cuatro tratamientos y cuatro repeticiones. Cada unidad experimental estuvo conformada por cuatro hileras de seis metros de longitud y separadas entre sí por una distancia de 1,40 m. Los tratamientos estudiados fueron niveles crecientes de vinaza: 0, 50, 100 y 150 m3/ha. Las variables evaluadas en el momento de la cosecha a los 12 meses de cultivo, fueron: rendimiento agrícola, número de cañas por metro lineal, longitud de caña, diámetro de caña, contenido de solidos solubles totales expresados en ºBrix y pureza. Los resultados indican que la aplicación de niveles crecientes de vinaza en el cultivo de la caña de azúcar, ha sido eficaz en el mejoramiento del rendimiento agrícola, induciendo incrementos en la productividad que va del 23 al 42 %. Por otro lado, la vinaza no afectó los parámetros de calidad industrial de la caña de azúcar, expresados en % de brix y pureza
Credence cues of pork are more important than consumers' culinary skills to boost their purchasing intention
The role of consumers' culinary skills on purchasing cues of pork, with emphasis on niche demands (outdoor husbandry and/or certified organic), was assessed in cross-country regions of Spain (Catalonia and Aragon) and Portugal (North). A sample of 974 respondents answered an on-line survey with questions regarding consumer purchasing habits, product involvement and intrinsic and credence attributes. They also chose between two contrasting boneless pork loins and express willingness to pay (WTP) for different product scenarios with different pig farm facilities and for organic pork standards. Two optimal segments were identified based on food-related habits: ‘uninvolved’ and ‘innovative cook lovers’, both similarly balanced across socio-demographics, score for credence attributes or consumer involvement dimensions. Overall mean WTP premium across countries was 11.8% for marbled pork, 20.0% for outdoor pork and 24.3% for organic logo stamp. Credence cues of pork claiming health issues (absence of antibiotics and hormone residues) rather than consumers' culinary skills defined the WTP for niche pork in these regions
¿Afectan los taninos condensados de la dieta a los resultados productivos, la composición de ácidos grasos y el color de la carne de cordero?
This meta-analysis evaluated the effect of condensed tannins (TC) (polyphenols formed from flavan-3-ol monomers) on the growth performance, fatty acid composition and lamb meat colour, based on the results of 41 publications (years 1998-2019) that allowed making up to 67 comparisons between batches of experimental lambs compared with a control lot within the same trial. These lots were divided into two groups, according to the dietary TC content difference between the control and experimental batch (medium level, 16 g/kg DM or high, 25 g/kg DM). The mean difference between each experimental group and its control lot was calculated for average daily gain, average feed intake, feed conversion rate, intramuscular fat, fatty acid profile and chromatic meat colour attributes. No significant differences were observed in the growth performance due to dietary TC inclusion, being much important the effect of other nutrients, such as crude protein and crude fat. A consistent reduction in the ratio of saturated fatty acids/polyunsaturated fatty acids and rumenic acid content in meat was observed. However, dietary inclusion of TC did not improve meat colour attributes compared to control groups
Evolución paleogeográfica, paleoclimática y paleoambiental de la costa meridional de la Península Ibérica durante el Pleistoceno superior. El caso de la Cueva de Nerja (Málaga, Andalucía, España).
Presentamos los cambios paleogeográficos, paleoclimáticos y paleoambientales acontecidos en la costa mediterránea meridional de la Península Ibérica durante el Pleistoceno superior y comienzos del Holoceno, analizados a partir de la cartografía batimétrica y geomorfológica de la franja costera submarina del este de Málaga, del registro de la temperatura de la superficie del mar de Alborán obtenido en el sondeo MD95-2043 y de los datos radiométricos, paleobiológicos y arqueológicos proporcionados por el registro estratigráfico del yacimiento de la Cueva de Nerja (Nerja, Málaga, España). Este registro sedimentario, con doce etapas de erosión y sedimentación, se emplazó en las salas más exteriores de la cavidad entre los estadios finales del Pleistoceno superior y el Holoceno medio en un lapso cronológico comprendido entre 29600 y 3940 años cal BP. Durante ese tiempo, la posición del mar estuvo situada a diferentes cotas por debajo de su posición actual, lo que condicionó la emersión de una franja costera de diferente amplitud a lo largo del tiempo, en la que las poblaciones humanas que habitaron la Cueva de Nerja desarrollaron sus actividades. Igualmente se observa una notable variación en la temperatura superficial del agua del mar y una serie de cambios en la composición de la vegetación y la fauna de vertebrados e invertebrados explotadas por los habitantes de la Cueva de Nerja. En este contexto cabe señalar la presencia en el registro de la cavidad de diferentes especies marinas de latitudes septentrionales y aguas más frías, actualmente ajenas al Mediterráneo
Post-transcriptional control of a stemness signature by RNA-binding protein MEX3A regulates murine adult neurogenesis
Neural stem cells (NSCs) in the adult murine subependymal zone balance their self-renewal capacity and glial identity with the potential to generate neurons during the lifetime. Adult NSCs exhibit lineage priming via pro-neurogenic fate determinants. However, the protein levels of the neural fate determinants are not sufficient to drive direct differentiation of adult NSCs, which raises the question of how cells along the neurogenic lineage avoid different conflicting fate choices, such as self-renewal and differentiation. Here, we identify RNA-binding protein MEX3A as a post-transcriptional regulator of a set of stemness associated transcripts at critical transitions in the subependymal neurogenic lineage. MEX3A regulates a quiescence-related RNA signature in activated NSCs that is needed for their return to quiescence, playing a role in the long-term maintenance of the NSC pool. Furthermore, it is required for the repression of the same program at the onset of neuronal differentiation. Our data indicate that MEX3A is a pivotal regulator of adult murine neurogenesis acting as a translational remodeller.© 2023. The Author(s)
Stereoselective Synthesis of Highly Substituted Tetrahydropyrans through an Evans Aldol-Prins Strategy
A direct and general method for the synthesis of naturally occurring 2,3,4,5,6-pentasubstituted tetrahydropyrans has been developed, employing β,γ-unsaturated N-acyl oxazolidin-2-ones as key starting materials. The combination of the Evans aldol addition and the Prins cyclization allowed the diastereoselective and efficient generation of the desired oxacycles in two fashions: a one-pot Evans aldol-Prins protocol, in which five new σ bonds and five contiguous stereocenters were straightforwardly generated, and a two-step version, which additionally permitted the isolation of β,γ-unsaturated alcohol precursors bearing an N-acyl oxazolidin-2-one in the α position. From these alcohols were also obtained halogenated pentasubstituted tetrahydropyrans as well as 2,3,4,5-tetrasubstituted tetrahydrofurans, shedding light on the mechanism of the process. Computational studies were consistent with the experimental findings, and this innovative Evans aldol-Prins strategy was performed for the preparation of a battery of more than 30 densely substituted tetrahydropyrans, unprecedentedly fused to a 1,3-oxazinane-2,4-dione ring, both in a racemic fashion and in an enantiomeric fashion. These novel molecules were successfully submitted to several transformations to permit simple access to a variety of differently functionalized tetrahydropyrans. Most of these unique molecules were evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria and the yeast Candida albicans, and some structure-activity relationships were established.Facultad de Ciencias ExactasLaboratorio de Investigación y Desarrollo de Bioactivo
Stereoselective Synthesis of Highly Substituted Tetrahydropyrans through an Evans Aldol-Prins Strategy
A direct and general method for the synthesis of naturally occurring 2,3,4,5,6-pentasubstituted tetrahydropyrans has been developed, employing β,γ-unsaturated N-acyl oxazolidin-2-ones as key starting materials. The combination of the Evans aldol addition and the Prins cyclization allowed the diastereoselective and efficient generation of the desired oxacycles in two fashions: a one-pot Evans aldol–Prins protocol, in which five new σ bonds and five contiguous stereocenters were straightforwardly generated, and a two-step version, which additionally permitted the isolation of β,γ-unsaturated alcohol precursors bearing an N-acyl oxazolidin-2-one in the α position. From these alcohols were also obtained halogenated pentasubstituted tetrahydropyrans as well as 2,3,4,5-tetrasubstituted tetrahydrofurans, shedding light on the mechanism of the process. Computational studies were consistent with the experimental findings, and this innovative Evans aldol–Prins strategy was performed for the preparation of a battery of more than 30 densely substituted tetrahydropyrans, unprecedentedly fused to a 1,3-oxazinane-2,4-dione ring, both in a racemic fashion and in an enantiomeric fashion. These novel molecules were successfully submitted to several transformations to permit simple access to a variety of differently functionalized tetrahydropyrans. Most of these unique molecules were evaluated for their antimicrobial activity against Gram-positive and Gram-negative bacteria and the yeast Candida albicans, and some structure–activity relationships were established
Occurrence of whale barnacles in Nerja Cave (Málaga, southern Spain): Indirect evidence of whale consumption by humans in the Upper Magdalenian
A total of 167 plates of two whale barnacle species (Tubicinella majorLamarck, 1802 and Cetopirus complanatusMörch, 1853) have been found in the Upper Magdalenian layers of Nerja Cave, Mina Chamber (Maro, Málaga, southern Spain). This is the first occurrence of these species in a prehistoric site. Both species are specific to the southern right whale Eubalena australis, today endemic in the Southern Hemisphere. Because of Antarctic sea-ice expansion during the Last Glacial Period, these whales could have migrated to the Northern Hemisphere, and reached southern Spain. Whale barnacles indicate that maritime-oriented forager human groups found stranded whales on the coast and, because of the size and weight of the large bones, transported only certain pieces (skin, blubber and meat) to the caves where they were consumed
Long-term affected flat oyster (Ostrea edulis) haemocytes show differential gene expression profiles from naïve oysters in response to Bonamia ostreae
Palaeolithic – Epipalaeolithic Seapeople of the Southern Iberian coast (Spain): an overview
The significance of coastal areas to human survival and expansion on the planet is undeniable. Their ecological diversity and their use as communication routes are some of their most distinctive qualities. However, the evidence of exploitation of these resources has had an uneven preservation, which is limited to certain regions and more recent events, mainly sites with deposits from the Upper Pleistocene and Holocene. This paper analyses the data available on the use of marine resources between MIS 6 and MIS 1 (c. 150 – 9 ka BP) in Southern Iberia, one of the first regions in Europe where marine faunal remains were discovered, in archaeological deposits from Middle and Upper Palaeolithic. Therefore their presence here has not been a criterion of separation between Neanderthals and Modern humans, but it may be relevant to analyze changes in the use of small preys or assess the economic diversification in regions where this came at an early date. One of the aims of this study was to evaluate the diachronic trends of the different palaeobiological marine remains recovered from coastal and inland archaeological sites. This preliminary extract indicates that the analysis of marine resource exploitation cannot be classed as a mere listing of palaeobiological remains. This information may be relevant in the initial stages, but it is insufficient in the evaluation of techno-economic and sociocultural transformations that can be linked to the use of marine resources. The distribution of palaeobiological marine remains differs over time and also according to the location of the sites with respect to the changing coastline throughout the period analysed. The known sites that preserve evidence of the use of marine resources as a food source are located mainly on the present coastline, or in a range of less than 10 km. Invertebrate remains have been identified in most, whereas fish, bird and mammal bones only in certain sites. Molluscs used as ornaments or pendants and containers are more widely distributed than other species used for food. Because these data must be contextualized, bone and stone tools linked to the exploitation of the marine environment have been added to the palaeobiological information, drawing inferences based on the analogy between both ethnologically and archaeologically documented tools. Symbolic expressions have also been studied, given the significant number of painted and engraved marine fauna depictions, specifically pisciforms and mammals, found in southern Iberia. Lastly, available molecular data has also been evaluated, from the results of isotope analysis on human remains. This combination of palaeobiological, techno-economic, graphic-symbolic and molecular data, allows a first assessment of the use of marine resources in the region
- …