Biota and geomorphic processes as key environmental factors controlling soil formation at Elephant Point, Maritime Antarctica

We examined the main soil forming factors affecting the soil composition, soil properties and the associated soilforming processes at Elephant Point, a small ice-free environment in the South Shetland Islands, Maritime Antarctica. For this purpose, we collected twenty soil samples from each of ten different sites distributed along a linear transect running from the coast to the front of the Rotch Dome glacier. The samples were obtained from surface layers (0–10 cm) and at depth (40–50 cm), although collection was limited in the moraine area by the permafrost table. We determined pH, electrical conductivity, size particle distribution, total organic carbon, total nitrogen and total concentrations of Al, Fe, Ca and P, for physical and chemical characterization of the samples. We also analysed the samples to determine the bioavailability of nutrients and Fe, Al and P partitioning and finally examined them by isotopic (δ15N) and X-ray diffraction (XRD) analysis. The results of the analyses revealed two clear geochemical environments corresponding to the two most extensive geomorphological units in this peninsula: moraine and marine terraces. Soils from the moraine were characterized by alkaline reaction and high quantity of minerals with a low degree of crystallinity, whereas soils from the marine terraces showed acid reaction, high concentration of organometallic complexes and a high diversity of phosphate minerals (taranakite, minyulite, struvite, hydroxylapatite and leucophosphite), which seem to be generated by phosphatization of faecal matter deposited by seabirds and seals. Consequently, biota activity is the most relevant soil differentiating factor in the marine terraces, which add organic matter and activate geochemical cycles. On the other hand, geomorphic processes strongly affected by physical weathering processes such as glacial abrasion (by grinding process), frost shattering, and wind abrasion are the main soil-forming factors in moraine. These forces break up the parent material, transform it and translocate the products formed.info:eu-repo/semantics/publishedVersio

New Palaeolithic sites from the Depresión de Monforte de Lemos (Lugo, Galicia, Spain)

Este artículo presenta el descubrimiento de nuevos yacimientos paleolíticos en la Depresión de Monforte de Lemos (Noroeste de la Península Ibérica). Esta zona fue rellenada con depósitos cuaternarios que han proporcionado más de 30 yacimientos al aire libre. Como consecuencia del descubrimiento casual de artefactos paleolíticos, se ha desarrollado un proyecto de intervención arqueológica sistemática, que ha demostrado el potencial de esta área. Muchos de los artefactos líticos han sido hallados en superficie, pero además contamos con dos yacimientos que tienen materiales en contexto estratigráfico (O Regueiral y Áspera). En la Depresión de Monforte hemos atestiguado poblamiento humano a lo largo del Pleistoceno medio y superior, con implementos líticos clasificados como Modo 2, Modo 3 y Modo 4. Los yacimientos más importantes son As Lamas, Chao de Fabeiro (ambos con industria lítica de Modo 2, que incluye bifaces y hendedores), O Regueiral (Modo 3) y Valverde (Modo 4). Por consiguiente, la Depresión de Monforte reúne las condiciones apropiadas para el desarrollo de un estudio diacrónico sobre la evolución del comportamiento técnico durante el Paleolítico, y su relación con la evolución del medioambiente a lo largo del PleistocenoThis paper reports the discovery of new Paleolithic sites in the Depresión de Monforte de Lemos (Monforte Basin, NW of the Iberian Peninsula). This zone was filled with Quaternary deposits that have yielded 30 open air sites. Due to the casual discovery of Paleolithic artifacts a systematic archaeological work was carried out, assessing the archaeological potential of this area. Most of these lithic artifacts were found on surface, but also we have located two sites with archaeological materials in stratigraphic context (O Regueiral and Áspera). In the basin of Monforte we have recognized a human settlement along the Middle and Upper Pleistocene, with lithic implements classified as Mode 2, Mode 3 and Mode 4. The most important sites are As Lamas, Chao de Fabeiro (both with Mode 2 lithic industry, that includes handaxes and cleavers), O Regueiral (Mode 3), and Valverde (Mode 4). Thus the Monforte Basin has the adequate conditions to accomplish a diachronic study on the evolution of the strategies of technical behavior during the Paleolithic, and its relation with the evolution of Pleistocene environmentEste trabajo se enmarca en el proyecto de investigación “Ocupaciones humanas durante el Pleistoceno de la Cuenca media del Miño” financiado por el Ministerio de Educación y Ciencia y fondos FEDER de la UE (HUM2007-63662/HIST)S

Epidemiología y características del ictus isquémico en el adulto joven en Aragón

Introducción Alrededor de 15 millones de personas sufren un ictus cada año, de los que un 10-15% ocurre en menores de 50 años (ictus en el adulto joven). La prevalencia de los distintos factores de riesgo vascular y las estrategias sanitarias para el manejo del ictus varían a nivel mundial, siendo interesante conocer la epidemiología y las características específicas de cada región. El objetivo de este estudio fue determinar la prevalencia de los diferentes factores de riesgo vascular, la etiología y las características de los ictus isquémicos en el adulto joven en la comunidad autónoma de Aragón. Métodos Estudio multicéntrico, de corte transversal, realizado por los Servicios de Neurología de todos los hospitales del Servicio Aragonés de Salud (SALUD). Se identificó a todos los pacientes entre 18 y 50 años que ingresaron en cualquiera de estos hospitales con el diagnóstico de ictus isquémico o AIT entre enero del 2005 y diciembre del 2015. Se recogieron variables demográficas, factores de riesgo vascular y tipo de ictus isquémico entre otras. Resultados En el periodo de estudio, 786 pacientes entre 18 y 50 años ingresaron con el diagnóstico de ictus isquémico o AIT en algún hospital del SALUD, con una tasa anual promedio de 12, 3 por 100.000 habitantes. La mediana de su edad fue de 45 años (RIQ: 40-48 años). El factor de riesgo vascular más prevalente fue el tabaquismo, 404 (51, 4%). La mayoría fue de causa indeterminada (36, 2%), seguida por «otras causas» (26, 5%). La mediana de puntuación en la escala NIHSS fue de 3, 5 (RIQ: 2, 07, 0). En total, 211 (26, 8%) de los ingresos fueron por AIT. De los pacientes que ingresaron con el diagnóstico de ictus isquémico, 59 (10, 3%) se fibrinolizaron. Conclusiones El ictus isquémico en el adulto joven no es infrecuente en Aragón y en un importante número de casos es de etiología indeterminada, por lo que es necesario implementar medidas que nos permitan mejorar su estudio, disminuir su incidencia y prevenir su recurrencia. Introduction: Stroke affects around 15 million people per year, with 10%-15% occurring in individuals under 50 years old (stroke in young adults). The prevalence of different vascular risk factors and healthcare strategies for stroke management vary worldwide, making the epidemiology and specific characteristics of stroke in each region an important area of research. This study aimed to determine the prevalence of different vascular risk factors and the aetiology and characteristics of ischaemic stroke in young adults in the autonomous community of Aragon, Spain. Methods: A cross-sectional, multi-centre study was conducted by the neurology departments of all hospitals in the Aragonese Health Service. We identified all patients aged between 18 and 50 years who were admitted to any of these hospitals with a diagnosis of ischaemic stroke or TIA between January 2005 and December 2015. Data were collected on demographic variables, vascular risk factors, and type of stroke, among other variables. Results: During the study period, 786 patients between 18 and 50 years old were admitted with a diagnosis of ischaemic stroke or TIA to any hospital of Aragon, at a mean annual rate of 12.3 per 100 000 population. The median age was 45 years (IQR: 40-48 years). The most prevalent vascular risk factor was tobacco use, in 404 patients (51.4%). The majority of strokes were of undetermined cause (36.2%), followed by other causes (26.5%). The median NIHSS score was 3.5 (IQR: 2.0-7.0). In total, 211 patients (26.8%) presented TIA. Fifty-nine per cent of the patients admitted with a diagnosis of ischaemic stroke (10.3%) were treated with fibrinolysis. Conclusions: Ischaemic stroke in young adults is not uncommon in Aragon, and is of undetermined aetiology in a considerable number of cases; it is therefore necessary to implement measures to improve study of the condition, to reduce its incidence, and to prevent its recurrence

Assessment of plasma chitotriosidase activity, CCL18/PARC concentration and NP-C suspicion index in the diagnosis of Niemann-Pick disease type C: A prospective observational study

Background: Niemann-Pick disease type C (NP-C) is a rare, autosomal recessive neurodegenerative disease caused by mutations in either the NPC1 or NPC2 genes. The diagnosis of NP-C remains challenging due to the non-specific, heterogeneous nature of signs/symptoms. This study assessed the utility of plasma chitotriosidase (ChT) and Chemokine (C-C motif) ligand 18 (CCL18)/pulmonary and activation-regulated chemokine (PARC) in conjunction with the NP-C suspicion index (NP-C SI) for guiding confirmatory laboratory testing in patients with suspected NP-C. Methods: In a prospective observational cohort study, incorporating a retrospective determination of NP-C SI scores, two different diagnostic approaches were applied in two separate groups of unrelated patients from 51 Spanish medical centers (n = 118 in both groups). From Jan 2010 to Apr 2012 (Period 1), patients with =2 clinical signs/symptoms of NP-C were considered ''suspected NP-C'' cases, and NPC1/NPC2 sequencing, plasma chitotriosidase (ChT), CCL18/PARC and sphingomyelinase levels were assessed. Based on findings in Period 1, plasma ChT and CCL18/PARC, and NP-C SI prediction scores were determined in a second group of patients between May 2012 and Apr 2014 (Period 2), and NPC1 and NPC2 were sequenced only in those with elevated ChT and/or elevated CCL18/PARC and/or NP-C SI =70. Filipin staining and 7-ketocholesterol (7-KC) measurements were performed in all patients with NP-C gene mutations, where possible. Results: In total across Periods 1 and 2, 10/236 (4%) patients had a confirmed diagnosis o NP-C based on gene sequencing (5/118 4.2%] in each Period): all of these patients had two causal NPC1 mutations. Single mutant NPC1 alleles were detected in 8/236 (3%) patients, overall. Positive filipin staining results comprised three classical and five variant biochemical phenotypes. No NPC2 mutations were detected. All patients with NPC1 mutations had high ChT activity, high CCL18/PARC concentrations and/or NP-C SI scores =70. Plasma 7-KC was higher than control cut-off values in all patients with two NPC1 mutations, and in the majority of patients with single mutations. Family studies identified three further NP-C patients. Conclusion: This approach may be very useful for laboratories that do not have mass spectrometry facilities and therefore, they cannot use other NP-C biomarkers for diagnosis

The global biogeography of tree leaf form and habit

Understanding what controls global leaf type variation in trees is crucial for comprehending their role in terrestrial ecosystems, including carbon, water and nutrient dynamics. Yet our understanding of the factors influencing forest leaf types remains incomplete, leaving us uncertain about the global proportions of needle-leaved, broadleaved, evergreen and deciduous trees. To address these gaps, we conducted a global, ground-sourced assessment of forest leaf-type variation by integrating forest inventory data with comprehensive leaf form (broadleaf vs needle-leaf) and habit (evergreen vs deciduous) records. We found that global variation in leaf habit is primarily driven by isothermality and soil characteristics, while leaf form is predominantly driven by temperature. Given these relationships, we estimate that 38% of global tree individuals are needle-leaved evergreen, 29% are broadleaved evergreen, 27% are broadleaved deciduous and 5% are needle-leaved deciduous. The aboveground biomass distribution among these tree types is approximately 21% (126.4 Gt), 54% (335.7 Gt), 22% (136.2 Gt) and 3% (18.7 Gt), respectively. We further project that, depending on future emissions pathways, 17–34% of forested areas will experience climate conditions by the end of the century that currently support a different forest type, highlighting the intensification of climatic stress on existing forests. By quantifying the distribution of tree leaf types and their corresponding biomass, and identifying regions where climate change will exert greatest pressure on current leaf types, our results can help improve predictions of future terrestrial ecosystem functioning and carbon cycling

Integrated global assessment of the natural forest carbon potential

Forests are a substantial terrestrial carbon sink, but anthropogenic changes in land use and climate have considerably reduced the scale of this system 1. Remote-sensing estimates to quantify carbon losses from global forests 2–5 are characterized by considerable uncertainty and we lack a comprehensive ground-sourced evaluation to benchmark these estimates. Here we combine several ground-sourced 6 and satellite-derived approaches 2,7,8 to evaluate the scale of the global forest carbon potential outside agricultural and urban lands. Despite regional variation, the predictions demonstrated remarkable consistency at a global scale, with only a 12% difference between the ground-sourced and satellite-derived estimates. At present, global forest carbon storage is markedly under the natural potential, with a total deficit of 226 Gt (model range = 151–363 Gt) in areas with low human footprint. Most (61%, 139 Gt C) of this potential is in areas with existing forests, in which ecosystem protection can allow forests to recover to maturity. The remaining 39% (87 Gt C) of potential lies in regions in which forests have been removed or fragmented. Although forests cannot be a substitute for emissions reductions, our results support the idea 2,3,9 that the conservation, restoration and sustainable management of diverse forests offer valuable contributions to meeting global climate and biodiversity targets