930 resultados para Stone, Crushed.


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The quality and availability of aggregate for pc concrete stone varies across Iowa. Southwest Iowa is one area of the state that is short of quality aggregates. The concrete stone generally available in the area is limestone from the Argentine or Winterset ledges with an overburden of up to 150 feet. This concrete stone is classified as Class 1 durability and is susceptible to 'ID"-cracking. In addition, the general engineering soil classification rates the soils of southwest Iowa as having the poorest subgrade bearing characteristics in the state. 1 The combination of poor soils and low quality aggregate has contributed to premature deterioration of many miles of portland cement concrete pavement. Research project HR-209 was initiated in 1979 to explore alternative construction methods that may produce better pavements for southwest Iowa.

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The safe and responsible development of engineered nanomaterials (ENM), nanotechnology-based materials and products, together with the definition of regulatory measures and implementation of "nano"-legislation in Europe require a widely supported scientific basis and sufficient high quality data upon which to base decisions. At the very core of such a scientific basis is a general agreement on key issues related to risk assessment of ENMs which encompass the key parameters to characterise ENMs, appropriate methods of analysis and best approach to express the effect of ENMs in widely accepted dose response toxicity tests. The following major conclusions were drawn: Due to high batch variability of ENMs characteristics of commercially available and to a lesser degree laboratory made ENMs it is not possible to make general statements regarding the toxicity resulting from exposure to ENMs. 1) Concomitant with using the OECD priority list of ENMs, other criteria for selection of ENMs like relevance for mechanistic (scientific) studies or risk assessment-based studies, widespread availability (and thus high expected volumes of use) or consumer concern (route of consumer exposure depending on application) could be helpful. The OECD priority list is focussing on validity of OECD tests. Therefore source material will be first in scope for testing. However for risk assessment it is much more relevant to have toxicity data from material as present in products/matrices to which men and environment are be exposed. 2) For most, if not all characteristics of ENMs, standardized methods analytical methods, though not necessarily validated, are available. Generally these methods are only able to determine one single characteristic and some of them can be rather expensive. Practically, it is currently not feasible to fully characterise ENMs. Many techniques that are available to measure the same nanomaterial characteristic produce contrasting results (e.g. reported sizes of ENMs). It was recommended that at least two complementary techniques should be employed to determine a metric of ENMs. The first great challenge is to prioritise metrics which are relevant in the assessment of biological dose response relations and to develop analytical methods for characterising ENMs in biological matrices. It was generally agreed that one metric is not sufficient to describe fully ENMs. 3) Characterisation of ENMs in biological matrices starts with sample preparation. It was concluded that there currently is no standard approach/protocol for sample preparation to control agglomeration/aggregation and (re)dispersion. It was recommended harmonization should be initiated and that exchange of protocols should take place. The precise methods used to disperse ENMs should be specifically, yet succinctly described within the experimental section of a publication. 4) ENMs need to be characterised in the matrix as it is presented to the test system (in vitro/ in vivo). 5) Alternative approaches (e.g. biological or in silico systems) for the characterisation of ENMS are simply not possible with the current knowledge. Contributors: Iseult Lynch, Hans Marvin, Kenneth Dawson, Markus Berges, Diane Braguer, Hugh J. Byrne, Alan Casey, Gordon Chambers, Martin Clift, Giuliano Elia1, Teresa F. Fernandes, Lise Fjellsbø, Peter Hatto, Lucienne Juillerat, Christoph Klein, Wolfgang Kreyling, Carmen Nickel1, and Vicki Stone.

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Peripheral nerve regeneration following injury occurs spontaneously, but many of the processes require metabolic energy. The mechanism of energy supply to axons has not previously been determined. In the central nervous system, monocarboxylate transporter 1 (MCT1), expressed in oligodendroglia, is critical for supplying lactate or other energy metabolites to axons. In the current study, MCT1 is shown to localize within the peripheral nervous system to perineurial cells, dorsal root ganglion neurons, and Schwann cells by MCT1 immunofluorescence in wild-type mice and tdTomato fluorescence in MCT1 BAC reporter mice. To investigate whether MCT1 is necessary for peripheral nerve regeneration, sciatic nerves of MCT1 heterozygous null mice are crushed and peripheral nerve regeneration was quantified electrophysiologically and anatomically. Compound muscle action potential (CMAP) recovery is delayed from a median of 21days in wild-type mice to greater than 38days in MCT1 heterozygote null mice. In fact, half of the MCT1 heterozygote null mice have no recovery of CMAP at 42days, while all of the wild-type mice recovered. In addition, muscle fibers remain 40% more atrophic and neuromuscular junctions 40% more denervated at 42days post-crush in the MCT1 heterozygote null mice than wild-type mice. The delay in nerve regeneration is not only in motor axons, as the number of regenerated axons in the sural sensory nerve of MCT1 heterozygote null mice at 4weeks and tibial mixed sensory and motor nerve at 3weeks is also significantly reduced compared to wild-type mice. This delay in regeneration may be partly due to failed Schwann cell function, as there is reduced early phagocytosis of myelin debris and remyelination of axon segments. These data for the first time demonstrate that MCT1 is critical for regeneration of both sensory and motor axons in mice following sciatic nerve crush.

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We investigate the population genetic structure of the Maghrebian bat, Myotis punicus, between the mainland and islands to assess the island colonization pattern and current gene flow between nearby islands and within the mainland. Location North Africa and the Mediterranean islands of Corsica and Sardinia. Methods We sequenced part of the control region (HVII) of 79 bats across 11 colonies. The phylogeographical pattern was assessed by analysing molecular diversity indices, examining differentiation among populations and estimating divergence time. In addition, we genotyped 182 bats across 10 colonies at seven microsatellite loci. We used analysis of molecular variance and a Bayesian approach to infer nuclear population structure. Finally, we estimated sex-specific dispersal between Corsica and Sardinia. Results Mitochondrial analyses indicated that colonies between Corsica, Sardinia and North Africa are highly differentiated. Within islands there was no difference between colonies, while at the continental level Moroccan and Tunisian populations were highly differentiated. Analyses with seven microsatellite loci showed a similar pattern. The sole difference was the lack of nuclear differentiation between populations in North Africa, suggesting a male-biased dispersal over the continental area. The divergence time of Sardinian and Corsican populations was estimated to date back to the early and mid-Pleistocene. Main conclusions Island colonization by the Maghrebian bats seems to have occurred in a stepping-stone manner and certainly pre-dated human colonization. Currently, open water seems to prevent exchange of bats between the two islands, despite their ability to fly and the narrowness of the strait of Bonifacio. Corsican and Sardinian populations are thus currently isolated from any continental gene pool and must therefore be considered as different evolutionarily significant units (ESU).

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Enfrontar-se a un volum de la col·lecció Bouquins, editada per Robert Laffont, és gairebé un sinònim de qualitat i d¿un alt nivell científic. Per fer front al repte d¿un volum dedicat a la Prehistòria l¿editor ha triat un dels professionals francesos de més prestigi, el professor Denis Vialou, que, rodejat d¿altres investigadors, ha sabut treure un producte útil i d¿un abast universal.

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El objetivo de este trabajo es analizar el carácter de la industria lítica, y más concretamente del análisis de materias primas, como uno de los marcadores espaciales y culturales en el seno de los territorios de explotación de las comunidades prehistóricas de cazadores-recolectores. Proponemos una aproximación basada en la arqueopetrología como elemento que, junto con la contextualización geográfica y los análisis tecnológicos, ayuda a la definición de las pautas paleoculturales de aprovisionamiento directo e intercambios de dichos grupos en relación con la explotación de los recursos abióticos.

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En este artículo presentamos un estudio de síntesis de los pulidores de arenisca del Paleolítico Superior y del Epipaleolítico/ Mesolítico de Europa. El trabajo surgió a partir del hallazgo de cuatro ejemplares, los más meridionales de Europa y los únicos de la Península Ibérica, en el transcurso de las recientes excavaciones de los niveles epipaleolíticos del XQ milenio B.P., del abrigo del Filador(Margalef de Montsant, Priorat, Tarragona).

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En este artículo pretendemos dar a conocer los últimos resultados obtenidos a partir del estudio en profundidad de la industria lítica y de la fauna del yacimiento tarraconense de la Mallada (Perelló); ello nos ayudará a situarlo cronológicamente en los inicios el Magdaleniense Superior Mediterráneo.

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We report the case of a 69-year-old woman, with a BMI of 42.9, suffering from bilateral struvite calculi and who raised end stage renal failure. Urease-synthesizing bacteria, leading to the hydrolysis of urea into ammonium and to an alkaline urine (pH > 7.2), are required for struvite stone formation in humans. Struvite component constitutes the majority of staghom calculi. Patients with struvite stones could lose renal function because of obstructive or pyelonephritic episodes and surgical interventions on the kidney. Therapeutic success needs a follow up by a specialized uro-nephrologist team as soon as possible.

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These studies show that either central pharmacological blockade or genetic ablation of alpha(1B)-adrenoceptors markedly attenuates the behavioral activation caused by modafinil, implicating these receptors in the drug's action.

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Pieces of Iowa’s Past, published by the Iowa State Capitol Tour Guides weekly during the legislative session, features historical facts about Iowa, the Capitol, and the early workings of state government. All historical publications are reproduced here with the actual spelling, punctuation, and grammar retained. January 18, 2012 THIS WEEK: Report by Annie Wittenmyer, State Sanitary Agent BACKGROUND: The 10th General Assembly convened on January 11, 1864, and adjourned on March 29—a 79-day session. There were 138 members in the legislature. The members included 42 Republicans in the Senate and 87 Republicans in the House of Representatives. Democrats numbered four in the Senate and five in the House. Jacob Butler was the Speaker of the House, and Enoch W. Eastman was the Lt. Governor presiding in the Senate. William Stone was Iowa’s governor. Stone was inaugurated on January 14, 1864. He was 36 years old. Governor Stone, a friend of President Abraham Lincoln, rode Lincoln’s funeral train to Springfield, Illinois

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Pieces of Iowa’s Past, published by the Iowa State Capitol Tour Guides weekly during the legislative session, features historical facts about Iowa, the Capitol, and the early workings of state government. All historical publications are reproduced here with the actual spelling, punctuation, and grammar retained. January 25, 2012 THIS WEEK: HOUSE RESOLUTIONS PRESENTED ON JANUARY 8, 1866 BACKGROUND: Background: The 11th General Assembly convened January 8, 1866, and adjourned April 3, 1866—an 86-day session. There were 146 members in the legislature, 48 senators and 98 representatives. Iowa’s Governor was William Milo Stone, and the 1860 census showed Iowa’s population at 482,699. Robert Finkbine represented House district 26. It was Finkbine’ s second term. He was 37 and listed his occupation as “builder.” Robert Finkbine went on to become the Superintendent of Construction for the present day Capitol. House district 26 represented Johnson County in 1866. In 1878, Marion County became the constituency for House district 26. The representative in House district 26 in 1878 was William Milo Stone, previous governor and resident of Knoxville

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Pieces of Iowa’s Past, published by the Iowa State Capitol Tour Guides weekly during the legislative session, features historical facts about Iowa, the Capitol, and the early workings of state government. All historical publications are reproduced here with the actual spelling, punctuation, and grammar retained THIS WEEK: Iowa State Capitol Structural Sandstone Origination From The Iowa Capitol Commissioners Reports Report of Capitol Architect A.H. Piquenard, submitted December 16, 1875 BACKGROUND: The Ste. Genevieve sandstone is the buff color stone on the exterior of the Capitol. The Carroll County sandstone was the light color or contrast stone on the Capitol exterior. The Carroll County stone did not wear well and was removed from the building during the exterior renovations in the 1980s and 1990s. Both sandstones are from Missouri.