Evaluation of phosphorus soil test benchmarks

Non-Peer Reviewe

Balancing Thymocyte Adhesion and Motility: A Functional Linkage Between β1 Lntegrins and The Motility Receptor RHAMM

Thymocyte differentiation involves several processes that occur in different anatomic sites within the thymus. Therefore, thymocytes must have the ability to respond to signals received from stromal cells and adopt either adhesive or motile behavior. We will discuss our data indicating human thymocytes use α4β1 integrin, α5β1 integrin and RHAMM to mediate these activities. Immature multinegative (MN; CD3–4–8–19-) thymocytes use α4β1 and α5β1 integrins to mediate weak and strong adhesion. This subset also uses α4β1 integrin to mediate motility. As thymocytes differentiate, they begin to express and use RHAMM to mediate motility in conjunction with α4β1 and α5β1 integrins. Motile thymocytes use β1 integrins to maintain weakly adhesive contacts with substrate to provide traction for locomoting cells, thus weak adhesion is a requirement of motile behavior. Hyaluronan (HA) is also required by thymocytes to mediate motility. HA binding to cell surface RHAMM redistributes intracellular RHAMM to the cell surface where it functions to mediate motility. We propose that the decision to maintain adhesive or motile behavior is based on the balance between low and high avidity binding conformations of β1 integrins on thymocytes and that RHAMM:HA interactions decrease high avidity binding conformations of integrins pushing the balance toward motile behavior

Chemical changes in standing cereal straw residues in chemfallow and its relationship to N, P, and S availability in two cropping systems

Non-Peer ReviewedIn recent years, conventional mechanical fallow has slowly shifted to chem-fallow on the prairies. With the chemical system of weed control, the straw is not mixed with the soil until seeding the following spring; meanwhile the nutrient status of the straw may change during the fallow period. The C:N, C:P, and C:S ratios may be expanding, resulting in a potential for increased immobilization once the straw is worked into the soil. To determine how the nutrient status of the standing straw residue may be changing, four chem-fallow treatments were chosen and the standing cereal residue sampled at six week intervals starting in June of 1993. Two treatments are located in the Brown soil zone (site 1) and two are located in the Black Soil Zone (site 2). At site 1 there is a treatment of wheat-fallow and a treatment of barley-fallow. At site 2 there is a wheat-fallow treatment and a treatment of wheat in rotation with flax, peas, and fallow. Site 1 is pre-tilled prior to seeding while site 2 is direct-seeded. Results for the first three months of the chem-fallow period reveal that water extractable sulfate, phosphate, and total nitrogen decrease over time accompanied by a widening of the C:N, C:S, and C:P ratios. This may suggest a greater immobilization potential per unit weight of straw when worked into the soil

Simulating and quantifying legacy topographic data uncertainty: an initial step to advancing topographic change analyses

Rapid technological advances, sustained funding, and a greater recognition of the value of topographic data have helped develop an increasing archive of topographic data sources. Advances in basic and applied research related to Earth surface changes require researchers to integrate recent high-resolution topography (HRT) data with the legacy datasets. Several technical challenges and data uncertainty issues persist to date when integrating legacy datasets with more recent HRT data. The disparate data sources required to extend the topographic record back in time are often stored in formats that are not readily compatible with more recent HRT data. Legacy data may also contain unknown error or unreported error that make accounting for data uncertainty difficult. There are also cases of known deficiencies in legacy datasets, which can significantly bias results. Finally, scientists are faced with the daunting challenge of definitively deriving the extent to which a landform or landscape has or will continue to change in response natural and/or anthropogenic processes. Here, we examine the question: how do we evaluate and portray data uncertainty from the varied topographic legacy sources and combine this uncertainty with current spatial data collection techniques to detect meaningful topographic changes? We view topographic uncertainty as a stochastic process that takes into consideration spatial and temporal variations from a numerical simulation and physical modeling experiment. The numerical simulation incorporates numerous topographic data sources typically found across a range of legacy data to present high-resolution data, while the physical model focuses on more recent HRT data acquisition techniques. Elevation uncertainties observed from anchor points in the digital terrain models are modeled using “states� in a stochastic estimator. Stochastic estimators trace the temporal evolution of the uncertainties and are natively capable of incorporating sensor measurements observed at various times in history. The geometric relationship between the anchor point and the sensor measurement can be approximated via spatial correlation even when a sensor does not directly observe an anchor point. Findings from a numerical simulation indicate the estimated error coincides with the actual error using certain sensors (Kinematic GNSS, ALS, TLS, and SfM-MVS). Data from 2D imagery and static GNSS did not perform as well at the time the sensor is integrated into estimator largely as a result of the low density of data added from these sources. The estimator provides a history of DEM estimation as well as the uncertainties and cross correlations observed on anchor points. Our work provides preliminary evidence that our approach is valid for integrating legacy data with HRT and warrants further exploration and field validation

Les interruption de gestation d'origine infectieuse en élevage bovin laitier a l'Île de la Réunion

A l'ile de la reunion, un suivi de reproduction a été effectué dans 23 élevages bovins laitiers d'octobre 1998 à décembre 2000 pour déterminer les facteurs de risque de l'infertilité, et plus spécifiquement l'implication de 11 agents infectieux dans les interruptions de gestation. Le pourcentage moyen d'avortements cliniques à été de 5,3%. Des diagnostics de gestation séquentiels suite à une intervention de reproduction (dosage de progestérone, de PSPB, échographie et palpation transrectale) ont permis de distinguer : les IA ou saillies réalisées sur fausses chaleurs (11% des interventions), les gestations (G), les non-fécondation ou mortalités embryonnaires précoces (NF/MEP), les interruptions de gestation subcliniques (IGS), les avortements cliniques (A), et les cas où la distinction entre NF/MEP et IGS est impossible (NF/MEP -IGS). Leurs pourcentages calculés à partir de 2036 IA ou saillies réalisées sur "vraies chaleurs" ont été respectivement de 32%, 36%, 10%,1% et 21%. 310 interruptions de gestation ont fait l'objet d'analyses sérologiques pour 11 agents infectieux : BHV-1, BVDV, Chlamydophila abortus, Coxiella burnetii, Leptospira sejroë, Leptospira hebdomadis, Mycoplasma bovis, Neospora caninum, Anaplasma marginale, Babesia bovis et Babesia bigemina. Un agent infectieus au moins a été identifié dans 80% des interruptions de gestation. Pour les interruptions de gestation dont l'étologie infectieuse a été mise en évidence, de 2 à 7 agents pathogènes ont été identifiés dans 70% des cas. De nombreuses associations de germes sont possibles. L'analyse des correspondances multiples a révélé l'importance de l'association entre les trois hémoparasites A. marginale, B. bovis, B. bigemina, et dans un nombre de cas plus limité, des associations entre L. sejroë et BVD, B.bigemina et C.burnetii, et M. bovis et L. sejroë. Les agents infectieux le plus souvent mis en cause ont été par ordre décroissant la néosporose, la BVD, la leptospirose à L. sejroë , puis les hémoparasitoses (essentiellement l'anaplasmose), et enfin la mycoplasmose et la fièvre Q. Des mesures prophylactiques sont proposées

UV RESONANCE RAMAN INVESTIGATION OF EXPLOSIVES’ UV PHOTOCHEMISTRY

Detection of explosives has become an important field of research due to the increased number of terrorist attacks utilizing improvised explosive devices (IEDs). We show that UV resonance Raman (UVRR) spectroscopy is a sensitive and incisive technique for detection of explosives. Deep UV excitation of explosives gives resonance enhancement and greater sensitivity enabling trace detection of explosives and their photochemical products. We demonstrate how we can utilize UVRR to analyze characteristic spectral changes that result from explosives’ photochemistry. In this work, we examined the 229 nm photochemistry of some of the main military explosives, TNT, RDX, and PETN in solution and solid state. We monitored the decrease in intensity of the UVRR bands of the initial explosive and the increase in intensity of the UVRR photoproduct bands during photolysis. Detection of photochemical product UVRR bands can be used to detect the previous presence of explosives even after they have been photolyzed. We determined solution state quantum yields, which gives insight to the susceptibility of the explosive to photolysis upon irradiation. We also determined the initial photoproducts formed by photolysis by using high performance liquid chromatography-high resolution mass spectrometry (HPLC-HRMS) measurements

Cell cycle regulation of p34cdc2 kinase activity in Physarum polycephalum

The regulation of the mitotic histone H1 kinase activity has been analyzed during the naturally synchronous cell cycle of Physarum polycephalum plasmodia. The universal binding property of the p13suc1 Schizosaccharomyces pombe gene product was used to precipitate and assay the cdc2 histone H1 kinase activity. The kinase activity peaks at the beginning of metaphase and its decline, which requires protein synthesis, appears to be an early event during the metaphase process. Microtubular poisons, temperature shifts and DNA synthesis inhibitors were used to perturb cell cycle regulatory pathways and characterize their effects on cdc2 kinase activation. Our results suggest that the full activation of the mitotic kinase requires at least two successive triggering signals involving microtubular components and DNA synthesis

A diferen?a como conte?do curricular: an?lise a partir de um estudo do caso em uma escola de ensino m?dio

Este trabalho visa trazer considera??es acerca do tratamento da quest?o da diferen?a no curr?culo da escola. Para isso foram aplicados question?rios aos professores e discentes e realizada a an?lise do Projeto Pol?tico Pedag?gico da Escola Estadual Brasiliano Braz na cidade de S?o Francisco-MG. A fundamenta??o te?rica deste estudo consistiu em leituras no campo do curr?culo como Lopes (2014); Macedo (2014) e Silva (2014); cultura e a sua rela??o com a educa??o (CANDAU, 2011; VEIGA-NETO, 2003) e identidade e diferen?a (BHABHA, 2014; HALL, 2006; SILVA, 2014). Foram analisados, tamb?m, documentos oficiais instituintes de pol?ticas nacionais voltadas para educa??o b?sica como a Lei de Diretrizes e Bases da Educa??o Nacional (LDBEN - Lei n? 9.394/96). Como resultado da an?lise qualitativa dos dados da pesquisa emp?rica constatou-se que o curr?culo ? um espa?o de fronteira cultural em que sujeitos diferentes interagem. Ao se questionar sobre como o trabalho pedag?gico da escola aborda a quest?o da diferen?a, os resultados evidenciam que a diferen?a ? entendida a partir de marcadores identit?rios espec?ficos e que grande parte dos estudantes presenciou algum tipo de discrimina??o ou preconceito relacionado ?s diferen?as ?tnico-raciais. Quando houve questionamento em rela??o ? necessidade e expectativa quanto ? abordagem da diferen?a no contexto escolar, a sexualidade foi a que obteve maior n?mero de cita??es. Em rela??o aos professores o tema viol?ncia ? preponderante, revelando ser esta uma preocupa??o no ambiente escolar. Quanto ao termo diferen?a este se apresenta predominantemente associado ? cultura e ? necessidade de tratamentos igualit?rios das identidades pessoais.Disserta??o (Mestrado Profissional) ? Programa de P?s-Gradua??o em Educa??o, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017.This work aimed to bring considerations about the treatment of the difference question in school curriculum. For this, questionnaires were applied to teachers and students and it was performed the analysis of the State School Brasiliano Braz Pedagogico Political Project in S?o Francisco city-MG. The theoretical basis of this study was readings in the Curriculum field such as Lopes (2014); Macedo (2014) e Silva (2014); culture and its relation to education (CANDAU, 2011; VEIGA-NETO, 2003) and identity and difference (BHABHA, 2014; HALL, 2006; SILVA, 2014). It was also analysed official documents of national policies focused on basic education, such as the Law on Guidelines and Bases of National Education (LDBEN - Law No. 9.394 / 96). As this qualitative data analysis result of empirical research was found that the curriculum is a cultural frontier space in which different subjects interact between themselves. When questioning how the school pedagogical work addresses the question of difference, the results show that the difference is understood from specific identity markers and that most of the students witnessed some kind of discrimination or prejudice related to ethno-racial differences. When there was questioning about the necessity and expectation addressed to the approach of difference in school context, sexuality was the one that obtained the highest number of citations. In relation to teachers, the concern about violence is preponderant, revealing that this is a concern in the school environment. As for the term difference, this is predominantly associated with culture and the need for equal treatment of personal identities

Three years of morphologic changes at a bowl blowout, Cape Cod, USA

© 2017 Elsevier. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/ This author accepted manuscript is made available following 24 month embargo from date of publication (July 2017) in accordance with the publisher’s archiving policyThis study presents measurements of blowout topography obtained with annual terrestrial laser surveys carried out over a three-year period at a single, large bowl blowout located in the Provincelands Dunes section of Cape Cod National Seashore, in Massachusetts. The study blowout was selected because its axis is aligned with northwest winds that dominate the region, and because it was seemingly interacting with a smaller saucer blowout that had recently formed on the southern rim of the primary feature. Assuming that blowouts enlarge both horizontally and vertically in response to the wind regime, the objectives of the study were to determine both the amount of horizontal growth that the blowout experiences annually and the spatial patterns of vertical change that occur within the blowout. Changes to the blowout lobe surrounding the feature were also determined for areas with sparse enough vegetation cover to allow laser returns from the sand surface. The results show that the blowout consistently expanded outward during the three years, with the greatest expansion occurring at its southeast corner, opposite the prevailing winds. The most significant occurrence was the removal, in the first year, of the ridge that separated the two blowouts, resulting in a major horizontal shift of the southern rim of the new combined blowout. This displacement then continued at a lesser rate in subsequent years. The rim also shifted horizontally along the northwest to northeast sections of the blowout. Significant vertical loss occurred along the main axis of the blowout with the greatest loss concentrated along the southeast rim. On the lobe, there were large areas of deposition immediately downwind of the high erosion zones inside the blowout. However, there were also small erosion areas on the lobe, extending downwind from eroding sections of the rim. This study shows that: 1. blowouts can experience significant areal and volumetric changes in short periods of time; 2. significant changes may occur relatively suddenly when adjacent blowouts combine into a single feature; and 3. the sediment transport paths are highly controlled by the topography. The joining of two blowouts not only creates a new larger feature, but it also releases large amounts of sediment that are then distributed across the landscape downwind, creating a potential for major changes to a landscape over the longer term