Tectono-stratigraphic basin evolution in the Tehuacán-Mixteca highlands, south western México

The morphological evolution of the basins in the Sierra Madre del Sur (SMS), southern México is poorly understood. This work explains for the first time the geomorphological development of the tectonic, fluvially-interconnected SMS basins named San Juan Raya (SJRb) and Zapotitlán (ZAPb). The evolution of the SJRb and ZAPb are analysed within the context of the transformations of the well-studied Tehuacán basin (TEHb). A new interpretation of a series of tectonic features of the TEHb valley area is also presented. Published geological data and extensive field work provided the basis for our geomorphological and evolutionary interpretation of basin evolution of this part of Mesoamerica during the late Cenozoic. Stratigraphic and sedimentary records suggest that after the late Cretaceous-early Cenozoic orogeny the TEHb and ZAPb were closed basins, and that the TEHb graben system was activated during the Paleogene as a response to the dominant regional NW-SE trending faults. We propose that the ZAPb and SJRb formed sequentially during the Neogene as a result of new E-W, N-S and NE-SW faults. The continuation of the TEHb extension during the Oligocene widened its lowland area and allowed the formation of an extensive lake. No alluvial or fluvial records of this interval are found in the ZAPb and SJRb. No sedimentation rather than formation and subsequent erosion of such sediments is supported by the basin morphology and by the absence of re-worked alluvial deposits at the outlet area where both connect to the TEHb. By middle to late Miocene the TEHb lost its endorheic configuration, ending the lake-type deposition while new faults initiated the opening of the ZAPb. Intensive tectonics, alluvial deposition and the confinement of the Tehuacán lake to the north sector of this basin characterised the Pliocene. During the late Pliocene to the early Pleistocene the formation of the SJRb was initiated. Quaternary faulting related to basin extension along the north watershed of the SJRb and ZAPb is supported by independent data on the biogeography of the cactus Mammillaria pectinifera. We introduce the idea that the departure from the regional NW-SE fault alignment that formed the major Miocene basins to a more local E-W trend that formed Neogene-Quaternary basins was probably a response to the latest post-orogenic relaxation of the crust in the Mixteca terrane

How woody plants adjust above- and below-ground traits in response to sustained drought

This is the final version. Available on open access from Wiley via the DOI in this recordFuture increases in drought severity and frequency are predicted to have substantial impacts on plant function and survival. However, there is considerable uncertainty concerning what drought adjustment is and whether plants can adjust to sustained drought. This review focuses on woody plants and synthesises the evidence for drought adjustment in a selection of key above-ground and below-ground plant traits. We assess whether evaluating the drought adjustment of single traits, or selections of traits that operate on the same plant functional axis (e.g. photosynthetic traits) is sufficient, or whether a multi-trait approach, integrating across multiple axes, is required. We conclude that studies on drought adjustments in woody plants might overestimate the capacity for adjustment to drier environments if spatial studies along gradients are used, without complementary experimental approaches. We provide evidence that drought adjustment is common in above-ground and below-ground traits; however, whether this is adaptive and sufficient to respond to future droughts remains uncertain for most species. To address this uncertainty, we must move towards studying trait integration within and across multiple axes of plant function (e.g. above-ground and below-ground) to gain a holistic view of drought adjustments at the whole-plant scale and how these influence plant survival.Natural Environment Research Council (NERC)MINECOEuropean Union Horizon 202

Seedlings from marginal and core populations of European beech (Fagus sylvatica L.) respond differently to imposed drought and shade

Warming temperatures and altered precipitation patterns threaten plant populations worldwide. European beech (Fagus sylvatica) is a species that expresses both high phenotypic plasticity and local adaptation among populations. Beech seedlings’ susceptibility to prolonged drought may be dictated by their immediate light environment. We tested whether seedlings of four beech provenances, from contrasting edaphoclimatic environments, expressed differences in trait responses to imposed water stress under sun and shade treatments. Populations from the southern range margin were expected to display greater water-stress tolerance and core populations’ faster growth rates in the absence of abiotic limitations. Both high light and water stress induced differences in trait responses among provenances, but traits that failed to respond to our experimental treatments likewise did not segregate at the provenance level. Hence, those traits responding to light, e.g., increasing leaf flavonol index and leaf mass area, also tended to differ among rovenances. Similarly, there was evidence of local adaptation among provenances in traits, like midday leaf water potential, responding to water stress. Exceptionally, there was a three way interaction water- × -light- × -provenance for stomatal conductance which converged among provenances under water stress. Leaf chlorophyll content also varied both with light and water in a provenance-specific manner. We found core provenances’ growth traits to outperform others under favourable onditions, whereas southern and high-elevation populations displayed traits adapted to tolerate high irradiance. Only stomatal conductance produced a complementary interactive response between light- × -water across provenances, whereas other traits responded less to combined water stress and high irradiance than to either treatment alone.Peer reviewe

In vitro and in vivo effects of lutein against cisplatin-induced ototoxicity

This is peer reviewed version of the following article Experimental and Toxicologic Pathology 68.4 (2016): 197-204, which has been published in final form at http://dx.doi.org/10.1016/j.etp.2016.01.003Introduction: Cisplatin is a commonly prescribed drug that produces ototoxicity as a side effect. Lutein is a carotenoid with antioxidant and anti-inflammatory properties previously tested for eye, heart and skin diseases but not evaluated to date in ear diseases. Aim: To evaluate the protective effects of lutein on HEI-OC1 auditory cell line and in a Wistar rat model of cisplatin ototoxicity. Materials and Methods: In vitro study: Culture HEI-OC1 cells were exposed to lutein (2.5-100 μM) and to 25 μM cisplatin for 24 h. In vivo study: Twenty eight female Wistar rats were randomized into three groups. Group A (n = 8) received intratympanic lutein (0.03 mL) (1 mg/mL) in the right ear and saline solution in the left one to determine the toxicity of lutein. Group B (n = 8) received also intraperitoneal cisplatin (10 mg/kg) to test the efficacy of lutein against cisplatin ototoxicity. Group C (n = 12) received intratympanic lutein (0.03 mL) (1 mg/mL) to quantify lutein in cochlear fluids (30 min, 1 h and 5 days after treatment). Hearing function was evaluated by means of Auditory Steady-State Responses before the procedure and 5 days after (groups A and B). Morphological changes were studied by confocal laser scanning microscopy. Results: In vitro study: Lutein significantly reduced the cisplatin-induced cytotoxicity in the HEI-OC1 cells when they were pre-treated with lutein concentrations of 60 and 80 μM. In vivo study: Intratympanic lutein (1 mg/mL) application showed no ototoxic effects. However it did not achieve protective effect against cisplatin-induced ototoxicity in Wistar rats. Conclusions: Although lutein has shown beneficial effects in other pathologies, the present study only obtained protection against cisplatin ototoxicity in culture cells, but not in the in vivo model. The large molecule size, the low dose administered, and restriction to diffusion in the inner ear could account for this negative result.Research supported by a Spanish FIS Grant EI 11/00742

Late Quaternary evolution of alluvial fans in the Playa, El Fresnal region, northern Chihuahua desert, Mexico: Palaeoclimatic implications

The Playa El Fresnal area is a tilted terrane characteristic of an extensional basin. It is a half graben/tilted-block system with a playa-lake on the basin floor flanked by piedmonts covered by alluvial fans. Structural heterogeneities within normal fault zones influenced the geomorphic expression of the uplifted footwall blocks of associated volcanism, and the downdropped hanging wall. The footwall area is the main sediment source, but the hanging wall-derived sediments are more extensive. The ancient alluvial fans are in the distal part, whereas the hanging-wall sediments are located in the apex area. A geomorphic analysis of the relative topographic position of the alluvial fans, degree of dissection of the original surfaces, general sedimentology (facies description), and stream channel network type, highlights the importance of climatic change in interpreting alluvial-fan surfaces. Three generations of alluvial fans were identified on the footwall and hanging wall slopes. They were formed during the late Quaternary climatic shift, consistent with the main climatic changes recorded in the paleolake stratig-raphy of northern Mexico and the American Southwest. These alluvial fans consist mainly of debris-flow deposits from flash floods, probably triggered by a change from relatively moist to arid conditions. They contrast with the typically lower-flow-regime of thick-bedded, cross-bedded, and lenticular channel facies, and associated floodplain sequences of rivers

Late Quaternary evolution of alluvial fans in the Playa, El Fresnal region, northern Chihuahua desert, Mexico: Palaeoclimatic implications

The Playa El Fresnal area is a tilted terrane characteristic of an extensional basin. It is a half graben/tilted-block system with a playa-lake on the basin floor flanked by piedmonts covered by alluvial fans. Structural heterogeneities within normal fault zones influenced the geomorphic expression of the uplifted footwall blocks of associated volcanism, and the downdropped hanging wall. The footwall area is the main sediment source, but the hanging wall-derived sediments are more extensive. The ancient alluvial fans are in the distal part, whereas the hanging-wall sediments are located in the apex area. A geomorphic analysis of the relative topographic position of the alluvial fans, degree of dissection of the original surfaces, general sedimentology (facies description), and stream channel network type, highlights the importance of climatic change in interpreting alluvial-fan surfaces. Three generations of alluvial fans were identified on the footwall and hanging wall slopes. They were formed during the late Quaternary climatic shift, consistent with the main climatic changes recorded in the paleolake stratig-raphy of northern Mexico and the American Southwest. These alluvial fans consist mainly of debris-flow deposits from flash floods, probably triggered by a change from relatively moist to arid conditions. They contrast with the typically lower-flow-regime of thick-bedded, cross-bedded, and lenticular channel facies, and associated floodplain sequences of rivers

Natural selection on cork oak: allele frequency reveals divergent selection in cork oak populations along a temperature cline

A recent study of population divergence at neutral markers and adaptive traits in cork oak has observed an association between genetic distances at locus QpZAG46 and genetic distances for leaf size and growth. In that study it was proposed that certain loci could be linked to genes encoding for adaptive traits in cork oak and, thus, could be used in adaptation studies. In order to investigate this hypothesis, here we (1) looked for associations between molecular markers and a set of adaptive traits in cork oak, and (2) explored the effects of the climate on among-population patterns in adaptive traits and molecular markers. For this purpose, we chose 9-year-old plants originating from thirteen populations spanning a broad range of climatic conditions. Plants established in a common garden site were genotyped at six nuclear microsatellites and phenotypically characterized for six functional traits potentially related to plant performance. Our results supported the proposed linkage between locus QpZAG46 and genes encoding for leaf size and growth. Temperature caused adaptive population divergence in leaf size and growth, which was expressed as differences in the frequencies of the alleles at locus QpZAG46

Beyond species loss: The extinction of ecological interactions in a changing world

© 2014 The Authors. The effects of the present biodiversity crisis have been largely focused on the loss of species. However, a missed component of biodiversity loss that often accompanies or even precedes species disappearance is the extinction of ecological interactions. Here, we propose a novel model that (i) relates the diversity of both species and interactions along a gradient of environmental deterioration and (ii) explores how the rate of loss of ecological functions, and consequently of ecosystem services, can be accelerated or restrained depending on how the rate of species loss covaries with the rate of interactions loss. We find that the loss of species and interactions are decoupled, such that ecological interactions are often lost at a higher rate. This implies that the loss of ecological interactions may occur well before species disappearance, affecting species functionality and ecosystems services at a faster rate than species extinctions. We provide a number of empirical case studies illustrating these points. Our approach emphasizes the importance of focusing on species interactions as the major biodiversity component from which the 'health' of ecosystems depends.Peer Reviewe

Ectomycorrhizal fungal diversity and community structure associated with cork oak in different landscapes

Cork oak (Quercus suber L.) forests play an important ecological and economic role. Ectomycorrhizal fungi (ECMF) are key components for the sustainability and functioning of these ecosystems. The community structure and composition of ECMF associated with Q. suber in different landscapes of distinct Mediterranean bioclimate regions have not previously been compared. In this work, soil samples from cork oak forests residing in different bioclimates (arid, semi-arid, sub-humid, and humid) were collected and surveyed for ectomycorrhizal (ECM) root tips. A global analysis performed on 3565 ECM root tips revealed that the ECMF community is highly enriched in Russula, Tomentella, and Cenoccocum, which correspond to the ECMF genera that mainly contribute to community differences. The ECMF communities from the rainiest and the driest cork oak forests were distinct, with soils from the rainiest climates being more heterogeneous than those from the driest climates. The analyses of several abiotic factors on the ECMF communities revealed that bioclimate, precipitation, soil texture, and forest management strongly influenced ECMF structure. Shifts in ECMF with different hyphal exploration types were also detected among forests, with precipitation, forest system, and soil texture being the main drivers controlling their composition. Understanding the effects of environmental factors on the structuring of ECM communities could be the first step for promoting the sustainability of this threatened ecosystem.This work was supported by Fundacao Ciencia e Tecnologia (FCT/MCTES/PIDDAC, Portugal), under the project (PEst-OE/BIA/UI4046/2014; UID/MULTI/04046/2013) and PhD grant to F.R. (SFRH/BD/86519/2012)

Análisis del rendimiento académico en los estudios de informática de la Universidad Politécnica de Valencia aplicando técnicas de minería de datos

En este trabajo presentamos un análisis del rendimiento académico de los alumnos de nuevo ingreso en la titulación de Ingeniería Técnica en Informática de Sistemas de la Universidad Politécnica de Valencia (UPV) a lo largo de tres cursos, aunque también se ha trabajado con las titulaciones de Ingeniería Técnica en Informática de Gestión y de Ingeniería Informática. Este análisis relaciona el rendimiento con las características socioeconómicas y académicas de los alumnos, que se obtienen en el momento de su matrícula, y que se recogen en la base de datos de la universidad. Hemos definido un indicador del rendimiento para cada alumno, teniendo en cuenta las calificaciones obtenidas y las convocatorias utilizadas. Para el estudio utilizamos técnicas de minería de datos, que pretenden determinar qué nivel de condicionamiento existe entre dicho rendimiento y características como el nivel de conocimientos de entrada del alumno, su contexto geográfico y sociocultural, etc… Esto proporciona una herramienta importante para la acción tutorial, que puede apoyarse en las predicciones de los modelos que se obtienen para encauzar sus recomendaciones y encuadrar las expectativas y el esfuerzo necesario para cada alumno, lógicamente dentro de la cautela habitual a la hora de tratar modelos inferidos a partir de datos.Universidad Politécnica de Valencia, a través del programa PACE