Interspecific wood trait variation predicts decreased carbon residence time in changing forests

1. Increasing disturbance will result in a significant flux in aboveground carbon (C) from live trees to deadwood, concurrent with compositional shifts. While interspecific decay variation is widely reported, the implications of forest compositional change on ecosystem-level deadwood decay and consequently, the future of a globally significant C pool have not been previously explored. 2. Leveraging a 25-year treefall record for two eastern hardwood forests in central Illinois, USA, we used a chronosequence approach to estimate downed deadwood decay rates for eight common tree taxa. We hypothesized the increasing dominance of Acer spp. in eastern forests, due to disturbance regime changes, is driving a decrease in the mean species-weighted deadwood decay rate, decreasing the total C storage capacity of regional forests. 3. We observed significantly greater interspecific variation in deadwood decay rates than short- term studies, with a thirteen-fold difference in half-lives between Aesculus glabra (T1/2 = 6.4 years) and Quercus spp. (T1/2 = 77.8) logs. The canopy-dominant Acer saccharum (T1/2 = 17.8) decayed significantly faster than other historically dominant eastern taxa, Quercus spp. and Fraxinus spp. (T1/2 = 47.4). At multi-decadal timescales, wood traits, notably taxon initial wood C:N ratio and Mn concentration, outweighed environmental factors in explaining variation in decay rates. A significant interaction between soil pH and wood Mn, which co-regulate microbial lignin degradation, suggests a similar importance of Mn in modulating woody debris decay rates as has been previously described for litter decay. 4. Synthesis. Our decay estimates highlight the importance of long-term studies for accurately assessing decay of recalcitrant species (high C:N ratio), as short-term decay studies are prone to underestimating their decay rates. Our results suggest that current and future forest compositional changes will have direct consequences on the residence time of the deadwood C pool due to interspecific wood trait variation

Integrated geomechanics and geological characterization of the Devonian-Mississippian Woodford Shale

Thesis (M.S.)--University of Oklahoma, 2011.Includes bibliographical references (leaves 91-101).In this thesis, preserved Woodford Shale samples of different mineralogy compositions were obtained from a shallow research well in Oklahoma and prepared for various laboratory mechanical characterizations including the Ultrasonic Pulse Velocity (UPV) measurements, the unconfined compressive test, and the Inclined Direct Shear Testing Device (IDSTD™). In addition, the Woodford Shale fracture propertie, including anisotropic tensile strength and fracture toughness, were investigated through a suite of Brazilian Tensile and Chevron tJotched Semicircular Bend (CNSCB) tests with acoustic emission (AE) recorded during testing. The geomechanics characteristics of the Woodford Shale were modeled with correlation to mineralogy and micro-fabric on its effects on the mechanical properties were also studied with results from thin sections and XRD analysis performed on tested samples. The UPV and Brazilian test results show a clear anisotropic nature of Woodford Shale poroelastic properties and tensile strength. Investigations on the effects of shale mineralogy and morphology on its anisotropic mechanical properties show correlation between the degrees of anisotropy with clay packing density variation. Despite the limited number of tests reported, an increasing trend of Woodford Shale tensile strength with carbonate content could be observed. This proportional increase of tensile strength with carbonate content may suggest the strength-increasing nature of carbonate minerals in the Woodford Shale. CNS CB test results showed that the fracture toughness of the quartz-rich Upper Woodford samples is significantly higher (up to 57%) than the fracture toughness of samples from the more clay-rich Middle and Lower Woodford. This will lead to a lot of variability in hydraulic fracture planning and design. Also, the acoustic emissions prior to the fracture propagation in CNSCB tests could only be observed for the lower clay samples belonging to the Upper Woodford. Furthermore, the integration of these results with the previously defined sequence stratigraphic framework resulted in the definitions of brittle and ductile couplets at the parasequence scale, which might be valuable for well placement and completion designs

Dysregulation of Complement System in Neuropsychiatric Disorders: A Mini Review

Complement system is one of the most important defense mechanisms of the innate immune system. In addition to their roles in immune regulation, complement proteins are also involved in neurodevelopment and adult brain plasticity. Complement dysregulation has been shown in neurodevelopmental disorders including schizophrenia and autism spectrum disorder as well as in mood disorders. A number of clinical as well as genetic studies suggest the role of complement proteins in the cortical thinning and excessive synaptic pruning frequently associated with schizophrenia. The changes in complement proteins are also associated with the pathophysiology of autism spectrum disorder, major depressive disorder and bipolar disorder, but warrant further research. In addition, rodent models suggest a strong case for complement system in anxiety-like behavior. In this article, we review the recent findings on the role of complement system in neuropsychiatric disorders. The possible uses for future complement targeted therapies are also discussed

Robust Chromium Precursors for Catalysis: Isolation and Structure of a Single-Component Ethylene Tetramerization Precatalyst

We have introduced a new class of stable organometallic Cr reagents (compounds 1–4) that are readily prepared, yet reactive enough to serve as precursors. They were used for ethylene tetramerization catalysis following stoichiometric activation by in situ protonation. This study highlights the importance of balancing stability with reactivity in generating an organometallic precursor that is useful in catalysis. Moreover, precursor 4 allowed for the isolation and crystallographic characterization of a room-temperature stable cationic species, (PNP)CrR_2+ (R = o-C_6H_4(CH_2)_2OMe, PNP = ^iPrN(PPh_2)_2). This complex (5) may be used as a single component precatalyst, without any alkylaluminum reagents. This result provides an unprecedented level of insight into the kind of structures that must be produced from more complicated activation processes

Interaction of Tropical Cyclones with a Dipole Vortex

The purpose of this chapter is to discuss certain disturbances around the pole of a Venus–type planet that result as a response to barotropic instability processes in a zonal flow. We discuss a linear instability of normal modes in a zonal flow through the barotropic vorticity equations (BVEs). By using a simple idealization of a zonal flow, the instability is employed on measurements of the upper atmosphere of Venus. In 1998, the tropical cyclone Mitch gave way to the observational study of a dipole vortex. This dipole vortex might have helped to intensify the cyclone and moved it towards the SW. In order to examine this process of interaction, the nonlinear BVE was integrated in time applied to the 800–200 hPa average layer in the previous moment when it moved towards the SW. The 2‐day integrations carried out with the model showed that the geometric structure of the solution can be calculated to a good approximation. The solution HLC moves very fast westwards as observed. On October 27, the HLA headed north‐eastward and then became quasi‐stationary. It was also observed that HLA and HLC as a coupled system rotates in the clockwise direction

Calendario pluviométrico en el margen oriental del área agrícola argentina

En el margen oriental del área agrícola Argentina se combinan un régimen de precipitaciones abundantes, con frecuentes episodios de tormentas intensas, con suelos pesados de tipo vertisol, lo cual dificulta considerablemente el desarrollo de las labores agrícolas. En dicho ambiente reviste gran importancia contar con calendarios pluviométricos que permitan planificar las tareas agropecuarias. Con esta finalidad, se analizaron los datos diarios de precipitación de cuatro localidades de la Provincia de Entre Ríos, cuyos registros son representativos de lo expuesto, a fin de evaluar la existencia de fechas con probabilidad significativa de que no ocurran precipitaciones y fechas con alta probabilidad de ocurrencia de precipitaciones y alta intensidad de las mismas. Los resultados obtenidos se cotejaron con las fechas de siembra y cosecha de los cultivos más comunes en la zona a fin de determinar las implicancias de los resultados alcanzados. El análisis de los datos demostró que efectivamente hay días del año definidos como días secos, con probabilidad diaria de precipitación menor al 10 % y con cantidad media diaria de precipitación menor a 1 mm, concentrados mayormente en los meses que van de mayo a septiembre; y días de tormenta con probabilidad diaria de precipitación mayor al 20 % y con cantidad media diaria de precipitación mayor a 25 mm, distribuidos a lo largo de todo el año, pero con singularidades en otoño y primavera.The eastern margin of the argentinian agricultural area combines a regime of plentiful precipitations, with frequent heavy storms, with heavy vertisolic soils, which considerably hampers fieldwork. In this environment is very important to develop pluviometric calendars which may allow to plan the agricultural activities. With this aim, data from 4 localizations in Entre Ríos Province, Argentina, were analyzed to assess the existence of dates with significant probability of precipitation or no precipitation. The results obtained were compared with the dates of planting, bloom and harvest of more common crops in the zone to determinate the implications of the reached results. This analysis showed the effective existence of dry days, with a precipitation probability less than 10% and a daily mean under 1 mm, concentrated mainly in the months from May to September, as well as stormy days, with a precipitation probability higher than 20% and a daily mean over 25 mm, distributed all over the year, but with some preference for spring and autumn.Fil: Perez, Silvia P.. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Recursos Naturales y Ambiente. Cátedra de Climatología y Fenologias Agrícolas; ArgentinaFil: Sierra, Eduardo Mario. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Recursos Naturales y Ambiente. Cátedra de Climatología y Fenologias Agrícolas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario; ArgentinaFil: Peschiera, José M.. Universidad de Buenos Aires. Facultad de Agronomia. Departamento de Recursos Naturales y Ambiente. Cátedra de Climatología y Fenologias Agrícolas; Argentin

Diseño de pruebas para la evaluación de competencias transversales

En 2005, un grupo de profesores de la Universidad Politécnica de Madrid (UPM) constituyó el Grupo de Innovación Educativa DMAE-DIA que fue reconocido como tal por la UPM en 2006 y en 2009. A posteriori, se han incorporado al grupo profesores de la Universidad Complutense de Madrid y de la Universidad Rey Juan Carlos Las líneas de actuación prioritarias del grupo son la evaluación de competencias genéricas y las metodologías de aprendizaje activo. Desde entonces estamos realizando evaluaciones sobre la adquisición por parte de estudiantes de ingeniería de algunas competencias genéricas. En este trabajo mostraremos las dos estrategias que estamos utilizando para evaluar la adquisición de competencias transversales: test psicométricos y pruebas (genéricas y específicas) con contenidos

Comparison of upwelling indices off Baja California derived from three different wind data sources

This report is not copyrighted. The definitive version was published in California Cooperative Oceanic Fisheries Investigations Reports 48 (2007): 204-214.We compared the NOAA Southwest Fisheries Science Center’s Environmental Research Division (formerly Pacific Fisheries Environmental Laboratory: PFEL) coastal upwelling indices along the northern Baja California coast with those derived from winds measured by coastal meteorological stations and estimated by the QuikSCAT satellite. With the exception of the PFEL series at 33°N, the three data sets compare reasonably well, having similar typical year patterns, correlations >0.6, and significant coherences for periods three to five days or longer. By contrast, the seasonal variations, the timing and magnitude of maximum upwelling, and the variability of the PFEL indices at 33°N are significantly different compared to all the other time series, including QuikSCAT at that location. The performance of the QuikSCAT winds close to shore was evaluated using the coastal meteorological station data. Although large root-meansquare (RMS) errors in direction were found for the QuikSCAT winds, both datasets have properties similar to the variance ellipses, and show reasonable coherences for frequencies in the weather band and lower, particularly south of 33°N.This project was partially funded by the U.S. National Science Foundation through grants to J. P. and M. L

Gestión de calidad y desempeño laboral del personal asistencial en una red de salud de Lima provincia, 2023

La presente investigación tuvo como objetivo determinar la relación de la gestión de calidad y el desempeño laboral del personal asistencial de una red de salud de Lima provincia, 2023. Se aplicó un tipo de metodología de investigación básica, diseño no experimental, con corte transversal descriptivo, la muestra estuvo conformada por 109 profesionales asistenciales de una red de salud de Lima provincia. Para la recolección de datos se utilizó el cuestionario. Los resultados determinaron que el nivel de gestión de calidad es medio con un 62.4% y alto con un 37.6%, mientras que el desempeño laboral es medio con un 15.6% y alto con un 84.4%. Se concluyó que no existe una correlación significativa con un Sig. 0.577 siendo p>0.05, entre las variables de gestión de calidad y desempeño laboral del personal asistencial en una red de salud de Lima provincia, 2023

Renormalization of tensor-network states

We have discussed the tensor-network representation of classical statistical or interacting quantum lattice models, and given a comprehensive introduction to the numerical methods we recently proposed for studying the tensor-network states/models in two dimensions. A second renormalization scheme is introduced to take into account the environment contribution in the calculation of the partition function of classical tensor network models or the expectation values of quantum tensor network states. It improves significantly the accuracy of the coarse grained tensor renormalization group method. In the study of the quantum tensor-network states, we point out that the renormalization effect of the environment can be efficiently and accurately described by the bond vector. This, combined with the imaginary time evolution of the wavefunction, provides an accurate projection method to determine the tensor-network wavfunction. It reduces significantly the truncation error and enable a tensor-network state with a large bond dimension, which is difficult to be accessed by other methods, to be accurately determined.Comment: 18 pages 23 figures, minor changes, references adde