82,922 research outputs found
Assessing Understanding in School-aged Children
Previous studies have shown that adult subjects can recognize and, under certain conditions, recall material they have learned, but not understood (Wilson & Probst, 1990). Under conditions where the material must be understood to be applied, however, comprehenders and non-comprehenders are not equally successful (Wilson, 1991). Since children\u27s cognitive processes differ from adults\u27, this experiment attempted to replicate Wilson and Probst using 63 fifth-grade students to see if previous findings applied to children
Cortical Axon Trajectories and Growth Cone Morphologies in Fetuses of Acallosal Mouse Strains
Hereditary absence of the corpus callosum (CC) provides an ideal experiment of nature for exploring mechanisms of axon guidance. In this study the prenatal development of CC axons in the acallosal mouse strains BALB/cWah 1 and 129/ ReJ or J was compared with normal hybrid mice by using the lipophilic dyes DiI and DiA. A few I /LnJ mice were also examined. The time of emergence and growth rate of CC axons from four cortical regions (frontal, parietal, temporal, occipital) were normal in acallosal strains. Their CC axons arrived at midplane on schedule but then often looped back to form the longitudinal Probst bundle. The frequency of formation of the Probst bundle was highest for axons from frontal cortex, which arrived at midplane first, and lowest for occipital axons, which arrived last. Once a few CC axons found a path to the other side via the hippocampal commissure, those that arrived later then crossed relatively normally. Some axons from the Probst bundle also managed to traverse midline in this manner. When no CC axons crossed, almost all of them entered the Probst bundle and eventually left it within a few hours to proceed in the ipsilateral white matter, never turning back toward midplane. Growth cones approaching midplane ipsilaterally and those that had crossed midline and entered contralateral white matter, as well as CC axons in the Probst bundle, expressed a normal range of size and complexity. These results demonstrate that the problem with callosal agenesis resides not in the cells of origin or the axons or growth cones themselves but in the substrates of axon guidance at the midsagittal plane
Megan Probst, soprano
This senior recital from September 8, 2001 features Megan Probst (soprano) assisted by Alexis Ignatiou (piano)
Validity of lactic acid in an interval stress test (Probst test) to determine a soccer player´s anaerobic threshold
P. 3-17El objetivo fue
comprobar la validez de un protocolo de esfuerzo incremental, progresivo, máximo y
discontinuo (Test de Probst) para valorar el umbral anaeróbico (UAn), interválico y
específico en futbolistas profesionales mediante un recorrido que simula el esfuerzo
desarrollado en este deporte. Para ello se determinó el UAn de 23 jugadores de la
Liga de Fútbol Profesional (1ª División Española) que realizaron el Test de Probst, y
48h después un Test Lactacidémico en el propio campo de fútbol y sobre el mismo
recorrido. Los resultados muestran elevadas y significativas correlaciones (r=0.79 y
p<0.001) entre las frecuencias cardiacas y velocidades en el UAn obtenidas en ambos
tests. En el Test de Probst el UAn se identificó tanto de forma manual como
matemática, siendo la primera la que mayor relación presentó con el Test
Lactacidémico, sobre todo cuando se analiza la velocidad en el UAn. En conclusión, el
Test de Probst es un test de campo válido para determinar el UAn interválico (UAnI)
de jugadores de fútbol, como indicador del grado de resistencia específica propia del
futbolista, y que permite establecer grupos de trabajo y determinar el porcentaje de
mejora de la misma en periodos sensibles como la pretemporada o valorar su nivel de
condición física a lo largo de la temporadaS
Heavy metals partioning in three French forest soils by sequential extraction procedure
To know the concentration of heavy metal associated to chemical compounds is important to evaluate the environmental risks on soils, particularly regarding ion bioavailability. The relative mobility and strength of binding of heavy metals to the soil components can be studied using a sequential extraction procedure which provides a meaningful comparison between different soil profiles. The heavy metals partitioning bas been identified in three different french forest soils : one cambic podzol, one calcaric cambisol and one mollic andosol, using a new sequential extraction method. Results show that metal fractionation is metal and site specific. The water leaching phase does not contain any metals. The proportion of heavy metal leached in the exchangeable and the acid — soplhuabslee is significant for Cd. The residual
phase is important for Cr, Pb, and to a lesser extend for Ni. The organic matter fraction is dominant for Zn and Cu. Thus, the considered heavy metals are mainly bounded to iron oxides, to the organic matter and to the mineral residue. The order of heavy metals availability in the three soils would be : Zn>Cd>Cu>Pb>NiL&egatd;C r.i sotopes in some extracts of the extraction procedure corroborate the anthropogenic inputs for two soils. These both infomations allow to trace the origin, the mobility and the distribution of Pb in the soil
Significance of floods in metal dynamics and export in a small agricultural catchment
High-resolution monitoring of water discharge and water sampling were performed between early October 2006 and late September 2007 in the Montoussé River, a permanent stream draining an experimental agricultural catchment in Gascogne region (SW France). Dissolved and particulate concentrations of major elements and trace metals (i.e. Al, Fe, Mn, As, Cd, Cr, Cu, Ni, Pb, Sc and Zn) were examined. Our results showed that contamination levels were deficient to moderate, as a result of sustainable agricultural practices. Regarding dynamics, metal partitioning between particulate and dissolved phases was altered during flood conditions: the particulate phase was diluted by coarser and less contaminated particles from river bottom and banks, whereas the liquid phase was rapidly enriched owing to desorption mechanisms. Soluble/reactive elements were washed-off from soils at the beginning of the rain episode. The contribution of the flood event of May 2007 (by far the most significant episode over the study period) to the annual metal export was considerable for particulate forms (72–82%) and moderate for dissolved elements (0–20%). The hydrological functioning of the Montoussé stream poses dual threat on ecosystems, the consequences of which differ from both temporal and spatial scales: (i) desorption processes at the beginning of floods induce locally a rapid enrichment (up to 3.4-fold the pre-flood signatures on average for the event of May 2007) of waters in bioavailable metals, and (ii) labile metals – enriched by anthropogenic sources – associated to particles (mainly via carbonates and Fe/Mn oxides), were predominantly transferred during floods into downstream-connected rivers
Oral History Interview: Jim Probst
This document is a transcript of a statement given by Jim Probst at a public hearing conducted by the West Virginia Department of Energy on June 28, 1988, in Lincoln County. The purpose of the hearing was to give residents a chance to voice their opinions concerning an application by two coal companies to strip-mine at Six Mile Creek in Lincoln County. Jim Probst argues against the permit. He mentions individuals such as Delbert Burchett, Sandra Perry, Keith Burchett, Congressman Wise, Doris Wilson, & Rita Geramello.https://mds.marshall.edu/oral_history/1352/thumbnail.jp
Dissolved organic matter contribution to rain water, throughfall and soil solution chemistry
A method is proposed to determine the acidbase
properties of natural water samples containing
relatively high amounts of dissolved organic
matter. The electroneutrality principle as well
as titration data are used to estimate the organic
anion concentration in open field precipitation,
throughfall and soil solutions, and to develop
empirical models based on pH and dissolved
organic carbon content. The organic acids dissolved
in throughfall have a similar acidic site
density but are weaker than those dissolved in
soil solution, stream and lake waters. This
method is usefull to determine the contribution
of organic anions to the charge balance and to
the buffering capacity of dissolved organic rich
waters with low acid neutralizing capacity. It can
be used also to determine the respective contribution
of natural organics and anthropogenic
minerals to the total acidity of throughfall and
rain waters
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