643 research outputs found

    Assessing the reactive surface area of soils and the association of soil organic carbon with natural oxide nanoparticles using ferrihydrite as proxy

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    Assessment of the surface reactivity of natural metal-(hydr)oxide nanoparticles is necessary for predicting ion adsorption phenomena in soils using surface complexation modeling. Here, we describe how the equilibrium concentrations of PO4, obtained with 0.5 M NaHCO3 extractions at different solution-to-soil ratios, can be interpreted with a state-of-the-art ion adsorption model for ferrihydrite to assess the reactive surface area (RSA) of agricultural top soils. Simultaneously, the method reveals the fraction of reversibly adsorbed soil PO4 (R-PO4). The applied ion-probing methodology shows that ferrihydrite is a better proxy than goethite for consistently assessing RSA and R-PO4. The R-PO4 pool agrees well with ammonium oxalate (AO)-extractable phosphorus, but only if measured as orthophosphate. The RSA varied between ∼2 and 20 m2/g soil. The corresponding specific surface area (SSA) of the natural metal-(hydr)oxide fraction is ∼350–1400 m2/g, illustrating that this property is highly variable and cannot be represented by a single value based on the AO-extractable oxide content. The soil organic carbon (SOC) content of our top soils increases linearly not only with the increase in RSA but remarkably also with the increase in mean particle size (1.5–5 nm). To explain these observations, we present a structural model for organo-mineral associations based on the coordination of SOC particles to metal-(hydr)oxide cores.Universidad de Costa Rica/[]/UCR/Costa RicaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro de Investigaciones Agronómicas (CIA

    Nonuniform high-gamma (60-500 Hz) power changes dissociate cognitive task and anatomy in human cortex

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    High-gamma-band (\u3e60 Hz) power changes in cortical electrophysiology are a reliable indicator of focal, event-related cortical activity. Despite discoveries of oscillatory subthreshold and synchronous suprathreshold activity at the cellular level, there is an increasingly popular view that high-gamma-band amplitude changes recorded from cellular ensembles are the result of asynchronous firing activity that yields wideband and uniform power increases. Others have demonstrated independence of power changes in the low- and high-gamma bands, but to date, no studies have shown evidence of any such independence above 60 Hz. Based on nonuniformities in time-frequency analyses of electrocorticographic (ECoG) signals, we hypothesized that induced high-gamma-band (60-500 Hz) power changes are more heterogeneous than currently understood. Using single-word repetition tasks in six human subjects, we showed that functional responsiveness of different ECoG high-gamma sub-bands can discriminate cognitive task (e.g., hearing, reading, speaking) and cortical locations. Power changes in these sub-bands of the high-gamma range are consistently present within single trials and have statistically different time courses within the trial structure. Moreover, when consolidated across all subjects within three task-relevant anatomic regions (sensorimotor, Broca\u27s area, and superior temporal gyrus), these behavior- and location-dependent power changes evidenced nonuniform trends across the population. Together, the independence and nonuniformity of power changes across a broad range of frequencies suggest that a new approach to evaluating high-gamma-band cortical activity is necessary. These findings show that in addition to time and location, frequency is another fundamental dimension of high-gamma dynamics

    Considerations of Efficiency and Distributive Justice in Multidimensional Poverty Measurement

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    Ab den 1980er Jahren entwickelte Amartya Sen eine neue Wohlfahrtstheorie: den Capability Approach (Sen, 1979; 1985; 1992; 1999; 2009). Dabei ersetzen Capabilities und Functionings, d.h. das, was Personen tatsächlich in der Lage sind zu tun und zu sein, den traditionellen Einkommensansatz. Armut ist im Capability Approach das Unvermögen, ein bestimmtes Minimum an zentralen Capabilities zu erreichen, die benötigt werden, um das Leben nach den eigenen Vorstellungen zu gestalten. Der Capability Approach hat so viele interessante Eigenschaften, besonders in Bezug auf die Armutsmessung, dass er zunehmend Einfluss in der Wohlfahrtsökonomie gewinnt. Diese Entwicklung wird durch empirische Untersuchungen gefördert, die zeigen, dass dieser multidimensionale Ansatz zur Armutsmessung deutlich andere Ergebnisse generiert als der traditionelle Einkommensansatz (vgl. Klasen, 2000, Alkire und Santos, 2010, Figari, 2012). Der derzeitige multidimensionale Ansatz hat jedoch eine methodische Schwäche: Ungleichheit zwischen Armutsdimensionen wird entweder als Korrelationssensitivität definiert – womit Effizienz aber nicht Verteilungsgerechtigkeit berücksichtigt wird – oder als die Verteilung multipler Mangelerscheinungen in einer Gesellschaft – womit Verteilungsgerechtigkeit aber nicht Effizienz berücksichtigt wird. Die ersten beiden Kapitel dieser Dissertation widmen sich der Behebung dieser methodischen Schwäche. Dazu wird Ungleichheit zwischen Dimensionen zunächst als „korrelationssensitive Verteilung multipler Mangelerscheinungen in einer Gesellschaft“ definiert. Die ersten beiden Kapitel operationalisieren diese erweiterte Definition für den Fall ordinaler und kardinaler Armutsindices. Im Einzelnen wird ein neues Axiom für den ordinalen sowie den kardinalen Fall eingeführt, das das Ausmaß, mit dem ein Ungleichheitsfördernder Tausch Armut sinken (oder steigen) lässt, von der Beziehung zwischen den Armutsdimensionen abhängig macht. Diese Neuerung wird benutzt um eine neue Klasse ordinaler bzw. kardinaler Armutsindices herzuleiten. Diese zwei Klassen sind die ersten additiven Armutsindices die in der Lage sind, sowohl Ungleichheit als auch Korrelationssensitivität zu erfassen. Das dritte Kapitel nutzt das deutsche sozio-ökonomische Panel um zwei ordinale Armutsindices für Deutschland vorzuschlagen, die auf der zuvor entwickelten Methode basieren: den „Deutschen Korrelationssensitiven Armutsindex“ und den „Subjektiven Korrelationssensitiven Armutsindex“. Die beiden Indices werden mit dem offiziellen deutschen Armutsmaß, der Armutsgefährdungsquote, über Dimensionen, Regionen und über die Zeit hinweg verglichen. Die Resultate zeigen vor allem eines: die signifikanten Unterschiede in der Beurteilung von Armut und Armutstrends die durch die verschiedenen Indices versursacht werden und den hohen Mehrwert den die Operationalisierung des Capability Approachs darstellt

    Raman spectroscopy for guidance of vulvar cancer surgery:A pilot study

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    For vulvar squamous cell carcinoma (VSCC), the mainstay of treatment is surgical removal with tumour-free margins. Surgeons still operate without objective tools that provide margin-status. This study assesses Raman spectroscopy potentiality for distinguishing ex-vivo VSCC from healthy tissue in 11 patients. Grid-based Raman maps were obtained from processed spectra. Water content and C-H band ratio (2,910-2,966 cm(-1) / 2810-2890 cm(-1)) were calculated per spectrum and used as linear discriminant parameters. Healthy tissue was differentiated from VSCC with 0.90 discriminative power, 0.79 sensitivity and 0.86 specificity.This is an important step towards the development of objective tools for VSCC surgical guidance

    Temporal variability in trace metal solubility in a paddy soil not reflected in uptake by rice (Oryza sativa L.)

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    Alternating flooding and drainage conditions have a strong influence on redox chemistry and the solubility of trace metals in paddy soils. However, current knowledge of how the effects of water management on trace metal solubility are linked to trace metal uptake by rice plants over time is still limited. Here, a field-contaminated paddy soil was subjected to two flooding and drainage cycles in a pot experiment with two rice plant cultivars, exhibiting either high or low Cd accumulation characteristics. Flooding led to a strong vertical gradient in the redox potential (Eh). The pH and Mn, Fe, and dissolved organic carbon concentrations increased with decreasing Eh and vice versa. During flooding, trace metal solubility decreased markedly, probably due to sulfide mineral precipitation. Despite its low solubility, the Cd content in rice grains exceeded the food quality standards for both cultivars. Trace metal contents in different rice plant tissues (roots, stem, and leaves) increased at a constant rate during the first flooding and drainage cycle but decreased after reaching a maximum during the second cycle. As such, the high temporal variability in trace metal solubility was not reflected in trace metal uptake by rice plants over time. This might be due to the presence of aerobic conditions and a consequent higher trace metal solubility near the root surface, even during flooding. Trace metal solubility in the rhizosphere should be considered when linking water management to trace metal uptake by rice over time

    A randomized, placebo-controlled double-blinded comparative clinical study of five over-the-counter non-pharmacological topical analgesics for myofascial pain: single session findings

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    <p>Abstract</p> <p>Objectives</p> <p>To investigate the effects of topical agents for the treatment of Myofascial Pain Syndrome (MPS) and Myofascial Trigger Point (MTRP).</p> <p>Methods</p> <p>Subjects with an identifiable trigger point in the trapezius muscle, age 18-80 were recruited for a single-session randomized, placebo-blinded clinical study. Baseline measurements of trapezius muscle pressure pain threshold (PPT: by pressure algometer) along with right and left cervical lateral flexion (rangiometer) were obtained by a blinded examiner. An assessor blinded to the outcomes assessments applied one of 6 topical formulations which had been placed in identical plastic containers. Five of these topicals were proposed active formulations; the control group was given a non-active formulation (PLA). Five minutes after the application of the formula the outcome measures were re-tested. Data were analyzed with a 5-way ANOVA and Holms-adjusted t-tests with an alpha level of 0.05.</p> <p>Results</p> <p>120 subjects were entered into the study (63 females; ages 16-82); 20 subjects randomly allocated into each group. The pre- and post-treatment results for pressure threshold did show significant intra-group increases for the Ben-Gay Ultra Strength Muscle Pain Ointment (BG), the Professional Therapy MuscleCare Roll-on (PTMC roll-on) and Motion Medicine Cream (MM) with an increased threshold of 0.5 kg/cm<sup>2 </sup>(+/-0.15), 0.72 kg/cm<sup><b>2 </b></sup>(+/-0.17) and 0.47 Kg/cm<sup><b>2 </b></sup>(+/-0.19) respectively. With respect to the inter-group comparisons, PTMC roll-on showed significant increases in pressure threshold compared with Placebo (PLA) (p = 0.002) and Icy Hot Extra Strength Cream (IH) (p = 0.006). In addition, BG demonstrated significant increases in pressure threshold compared with PLA (p = 0.0003).</p> <p>Conclusions</p> <p>With regards to pressure threshold, PTMC roll-on, BG and MM showed significant increases in pain threshold tolerance after a short-term application on a trigger points located in the trapezius muscle. PTMC roll-on and BG were both shown to be superior vs placebo while PTMC was also shown to be superior to IH in patients with trigger points located in the trapezius muscle on a single application.</p> <p>CMCC Research Ethics Board Approval # 1012X01, 2011</p

    Erythrocytosis in the general population:clinical characteristics and association with clonal hematopoiesis

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    Erythrocytosis is a common reason for referral to hematology services and is usually secondary in origin. The aim of this study was to assess clinical characteristics and clonal hematopoiesis (CH) in individuals with erythrocytosis in the population-based Lifelines cohort (n 5 147 167). Erythrocytosis was defined using strict (World Health Organization [WHO] 2008/British Committee for Standards in Hematology) and wide (WHO 2016) criteria. Individuals with erythrocytosis (strict criteria) and concurrent leukocytosis and/or thrombocytosis were 1:2 matched with individuals with isolated erythrocytosis and analyzed for somatic mutations indicative of CH ($5% variant allele frequency). One hundred eighty five males (0.3%) and 223 females (0.3%) met the strict criteria, whereas 4868 males (7.6%) and 309 females (0.4%) met the wide criteria. Erythrocytosis, only when defined using strict criteria, was associated with cardiovascular morbidity (odds ratio [OR], 1.8; 95% confidence interval [CI], 1.2-2.6), cardiovascular mortality (hazard ratio [HR], 2.2; 95% CI, 1.0-4.6), and all-cause mortality (HR, 1.7; 95% CI, 1.2-2.6), independent of conventional risk factors. Mutations were detected in 51 of 133 (38%) evaluable individuals, with comparable frequencies between individuals with and without concurrent cytosis. The JAK2 V617F mutation was observed in 7 of 133 (5.3%) individuals, all having concurrent cytosis. The prevalence of mutations in BCOR/BCORL1 (16%) was high, suggesting aberrant epigenetic regulation. Erythrocytosis with CH was associated with cardiovascular morbidity (OR, 9.1; 95% CI, 1.2-68.4) in a multivariable model. Our data indicate that only when defined using strict criteria erythrocytosis is associated with cardiovascular morbidity (especially in the presence of CH), cardiovascular mortality, and all-cause mortality
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