Determinants of soil organic matter chemistry in maritime temperate forest ecosystems

While the influence of climate, vegetation, management and abiotic site factors on total carbon budgets and turn-over is intensively assessed, the influences of these ecosystem properties on the chemical complexity of soil organic matter (SOM) remains poorly understood. This study addresses the chemical composition of NaOH-extracted SOM from maritime temperate forest sites in Flanders (Belgium) by pyrolysis-GC/MS. The studied forests were chosen based on dominant tree species (Pinus sylvestris, Fagus sylvatica, Quercus robur and Populus spp.), soil texture and soil-moisture conditions. Differences in extractable-SOM pyrolysis products were correlated to site variables including dominant tree species, management of the woody biomass, site history, soil properties, total carbon stocks and indicators for microbial activity. Despite of a typical high intercorrelation between these site variables, the influence of the dominant tree species is prominent. The extractable-SOM composition is strongly correlated to litter quality and available nutrients. In nutrient-poor forests with low litter quality, the decomposition of relatively recalcitrant compounds (i.e. short and mid-chain alkanes/alkenes and aromatic compounds) appears hampered, causing a relative accumulation of these compounds in the soil. However, if substrate quality is favorable, no accumulations of recalcitrant compounds were observed, not even under high soil-moisture conditions. Former heathland vegetation still had a profound influence on extractable-SOM chemistry of young pine forests after a minimum of 60 year

Weathering processes and mineral neoformation at serpentinite areas from Galicia (Spain)

[Resumen] Se realiza un estudio de muestreos en distintos grados de alteración, desde roca fresca a fracción arcilla de horizontes edáficos. El orden de movilidades geoquímicas es Mg > Si, Ca > Na»Al = Fe, en una primera etapa, y un mayor enriquecimiento en Fe en los estadios más avanzados. El grado de alteración aleanzado se encuentra en una posición intermedia al obtenido para este tipo de rocas en áreas mediterráneas y tropicales y siempre es mucho menor que el observado sobre otros materiales básicos de Galicia. A pesar de que termodinámicamente las soluciones de suelos y arroyos se sitúan en un campo intermedio entre filosilicatos 1/1 Y2/1, estos últimos en medios de peor drenaje, la escasez de Al inhibe la formación de arcillas de tipo caolinita, siendo los productos de neoformación típicos en los medios más evolucionados oxihidrósidos de Fe y precipitados silíceos.[Abstract] In a serpentinite area several samples with different degrees of weathering, ranging from fresh rock to clay fractions of soil horizons, were studied. During weathering, the geochemical mobility of the elements follows the order Mg > Si, Ca > Na» Al = Fe in the initial phases, showing a gre.ater aproach to Fe pole in more advanced stages. The intensity of weathering is intermediate between that obtained for serpentinites in mediterranean and tropical areas, and never reachs the high levels found in other basic rocks of Galicia. The composition of stream waters and soil solutions falls between the stability fields of 1/1 and 2/ llayer silicates, last ones mostly in poorly drained areas. In spite of this fact, the scarcity of Al inhibit the formation of kaolinite; iron oxihidroxides and precipitated silica being the most typical secondary products in the more envolved environments

Preferential degradation of polyphenols from Sphagnum - 4-isopropenylphenol as a proxy for past hydrological conditions in Sphagnum-dominated peat

The net accumulation of remains of Sphagnum spp. is fundamental to the development of many peatlands. The effect of polyphenols from Sphagnum on decomposition processes is frequently cited but has barely been studied. The central area of the Rödmossamyran peatland (Sweden) is an open lawn that consists mostly of Sphagnum spp. with a very low contribution from vascular plants. In order to determine the effects of decay on sphagnum phenols, 53 samples of a 2.7 m deep core from this lawn were analysed with pyrolysis gas chromatography-mass spectrometry (pyrolysis-GC/MS) and compared with more traditional decomposition proxies such as C/N ratio, UV light transmission of alkaline peat extracts, and bulk density. Factor Analysis of 72 quantified pyrolysis products suggested that the variation in 4-isopropenylphenol was largely determined by aerobic decomposition instead of Sphagnum abundance. In order to evaluate the effects of aerobic decay in Sphagnum peat, down-core records from different climatic regions were compared using molecular markers for plant biopolymers and C/N ratio. These included markers for lignin from vascular plants ((di)methoxyphenols), polyphenols from Sphagnum spp. (4-isopropenylphenol), and cellulose (levoglucosan). Our results indicate that polyphenols from Sphagnum are preferentially degraded over polysaccharides; consequently the variability of the marker for sphagnum acid, 4-isopropenylphenol, was found indicative of decomposition instead of reflecting the abundance of Sphagnum remains. The fact that 4-isopropenylphenol is aerobically degraded in combination with its specificity for Sphagnum spp. makes it a consistent indicator of past hydrological conditions in Sphagnum-dominated peat. In contrast, the variability of C/N records in Sphagnum-dominated peat was influenced by both vegetation shifts and decomposition, and the dominant effect differed between the studied peatlands. Our results provide direction for modelling studies that try to predict possible feedback mechanisms between peatlands and future climate change, and indicate that the focus in Sphagnum decay studies should be on carbohydrates rather than on phenolic compounds

Human intestinal microbiota composition is associated with local and systemic inflammation in obesity.

OBJECTIVE: Intestinal microbiota have been suggested to contribute to development of obesity, but the mechanism remains elusive. We relationship between microbiota composition, intestinal permeability, inflammation in non-obese and obese subjects. DESIGN AND METHODS: Fecal microbiota composition of 28 subjects (BMI 18.6-60.3kg/m2 ) was analyzed phylogenetic profiling microarray. Fecal calprotectin and plasma C- protein levels were determined to evaluate intestinal and systemic Furthermore, HbA1c , and plasma levels of transaminases and lipids were Gastroduodenal, small intestinal, and colonic permeability were assessed multi-saccharide test. RESULTS: Based on microbiota composition, the population segregated into two clusters with predominantly obese (15/19) exclusively non-obese (9/9) subjects. Whereas intestinal permeability differ between clusters, the obese cluster showed reduced bacterial decreased Bacteroidetes/Firmicutes ratio, and an increased abundance of pro-inflammatory Proteobacteria. Interestingly, fecal calprotectin was detectable in subjects within the obese microbiota cluster (n=8/19, Plasma C-reactive protein was also increased in these subjects correlated with the Bacteroidetes/Firmicutes ratio (rs =-0.41, p=0.03). CONCLUSIONS: Intestinal microbiota alterations in obese subjects are with local and systemic inflammation, suggesting that the obesity- microbiota composition has a pro-inflammatory effect

Monitoramento da multidisciplinaridade no processo de transferência de tecnologia em uma universidade: proposta de análise de cluster

ABSTRACTThis paper discusses the management of the technology transfer process conducted by a Technology Transfer Office (TTO) of a federal public university. Patent co-authorship and multidisciplinarity were used as concepts to evaluate and monitor the quality of academic and practical contribution and their potential for commercial application, using descriptive statistics and cluster analysis. Considering only multidisciplinary patents, binary cluster analysis was conducted, using Jaccard similarity measurement and single linkage method to determine proximity among academic units. Apart from the analysis of the number of patents, the approach enabled discussions and questions regarding the differences between patent generation patterns, resultant from the specific organizational culture and structures. The discussions are relevant to improve the identification of opportunities in technology transfer processes by the TTO

Motivational factors mediate the association of general self-efficacy and performance outcomes in acutely hospitalised older patients

Objectives: To study (i) the association of general self-efficacy (GSE) on the course of subjective (i.e. basic and instrumental activities of daily living (ADLs and IADLs) and objective physical performance outcomes (short physical performance battery (SPPB)) among older persons from discharge up to 3 months post-discharge and (ii) the extent to whether motivational factors such as depressive symptoms, apathy and fatigue mediate this association.Methods: Prospective multi-centre cohort of acutely hospitalised patients aged ≥70 (Hospital-ADL study). Structural equation modelling was used to analyse the structural relationships.Results: The analytic sample included 236 acutely hospitalised patients. GSE had a significant total effect on the course of subjective and objective performance outcomes (ADLs: β = -0.21, P &lt; 0.001, IADLs: β = -0.24, P &lt; 0.001 and SPPB: β = 0.17, P &lt; 0.001). However, when motivational factors as mediator were included into the same model, motivational factors (IADLs: β = 0.51, P &lt; 0.001; SPPB: β = 0.49, P &lt; 0.001) but not GSE remained significantly associated with IADLs (β = -0.06, P = 0.16) and SPPB (β = 0.002, P = 0.97). Motivational factors partially mediated the relationship between GSE and ADLs (β = -0.09, P = 0.04). The percentage of mediation was 55, 74 and 99% for ADLs, IADLs and SPPB, respectively.Conclusions: Motivational factors and GSE are both associated with subjective and objective performance outcomes. However, the relationship between GSE and subjective and objective performance outcomes was highly mediated by motivational factors. Taken together, this suggests that GSE is important to being physically active but not sufficient to becoming more physical active in acutely hospitalised older patients; motivation is important to improving both subjective and objective performance.</p