2,324 research outputs found
Book Review: Four Lives in Paris
Book review of: Hugh Ford, Four Lives in Paris (North Point Press, 198
A study of a treatment camp for emotionally disturbed children summer 1949
Thesis (M.S.)--Boston Universit
Automated potentiometric techniques for the on-site monitoring of anion concentrations in water
Students supported: 2 Grad Students, 2 Undergraduate StudentsCharacteristics of several of the new non-glass ion-selective electrodes and of several reference electrodes were studied in detail. The most significant finding of the research was the development of a new high accuracy standard addition technique for the potentiometric determination of nitrate ion in a cell without liquid junction using the fluoride ion-selective electrode as a reference. This method eliminates the liquid junction and dilution and activity coefficient changes cancel. The standard addition technique with the fluoride electrode as a reference is applicable to all monovalent anions for which an electrode is available and enables the determination of anion concentrations to within 1 percent relative accuracy. Low temperature potentiometric titrations of perchlorate and tetrafluoroborate ions were investigated and found to give very high accuracy and reasonably good sensitivity for these ions. Tetraphenylarsonium chloride was used as a titrant for perchlorate and tetrafluoroborate. The application of the nitrate ion-selective electrode to following nitrate ion concentration in microbial cultures was investigated. It was found to be useful for following nitrate ion reduction in situ.Project # B-023-MO Agreement # 14-01-0001-191
A NOVEL TECHNIQUE TO MEASURE DIASTOLIC FUNCTION USING A PROTOTYPE SPECKLE TRACKING ECHOCARDIOGRAPHY SYSTEM: RESULTS FROM THE RADIOFREQUENCY-BASED SPECKLE TRACKING ECHOCARDIOGRAPHY TO EVALUATE DIASTOLIC FUNCTION (RF-SPEED) STUDY
LOCALITY UNCERTAINTY AND THE DIFFERENTIAL PERFORMANCE OF FOUR COMMON NICHE-BASED MODELING TECHNIQUES
We address a poorly understood aspect of ecological niche modeling: its sensitivity to different levels of geographic uncertainty in organism occurrence data. Our primary interest was to assess how accuracy degrades under increasing uncertainty, with performance measured indirectly through model consistency. We used Monte Carlo simulations and a similarity measure to assess model sensitivity across three variables: locality accuracy, niche modeling method, and species. Randomly generated data sets with known levels of locality uncertainty were compared to an original prediction using Fuzzy Kappa. Data sets where locality uncertainty is low were expected to produce similar distribution maps to the original. In contrast, data sets where locality uncertainty is high were expected to produce less similar maps. BIOCLIM, DOMAIN, Maxent and GARP were used to predict the distributions for 1200 simulated datasets (3 species x 4 buffer sizes x 100 randomized data sets). Thus, our experimental design produced a total of 4800 similarity measures, with each of the simulated distributions compared to the prediction of the original data set and corresponding modeling method. A general linear model (GLM) analysis was performed which enables us to simultaneously measure the effect of buffer size, modeling method, and species, as well as interactions among all variables. Our results show that modeling method has the largest effect on similarity scores and uniquely accounts for 40% of the total variance in the model. The second most important factor was buffer size, but it uniquely accounts for only 3% of the variation in the model. The newer and currently more popular methods, GARP and Maxent, were shown to produce more inconsistent predictions than the earlier and simpler methods, BIOCLIM and DOMAIN. Understanding the performance of different niche modeling methods under varying levels of geographic uncertainty is an important step toward more productive applications of historical biodiversity collections
A Comparison of Molecular and Histopathological Changes in Mouse Intestinal Tissue Following Whole-Body Proton- or Gamma-Irradiation
There are many consequences following exposure to the space radiation environment which can adversely affect the health of a crew member. Acute radiation syndrome (ARS) involving nausea and vomiting, damage to radio-sensitive tissue such as the blood forming organs and gastrointestinal tract, and cancer are some of these negative effects. The space radiation environment is ample with protons and contains gamma rays as well. Little knowledge exists to this point, however, regarding the effects of protons on mammalian systems; conversely several studies have been performed observing the effects of gamma rays on different animal models. For the research presented here, we wish to compare our previous work looking at whole-body exposure to protons using a mouse model to our studies of mice experiencing whole-body exposure to gamma rays as part of the radio-adaptive response. Radio-adaptation is a well-documented phenomenon in which cells exposed to a priming low dose of radiation prior to a higher dose display a reduction in endpoints like chromosomal aberrations, cell death, micronucleus formation, and more when compared to their counterparts receiving high dose-irradiation only. Our group has recently completed a radio-adaptive experiment with C57BL/6 mice. For both this study and the preceding proton research, the gastrointestinal tract of each animal was dissected four hours post-irradiation and the isolated small intestinal tissue was fixed in formalin for histopathological examination or snap-frozen in liquid nitrogen for RNA isolation. Histopathologic observation of the tissue using standard H&E staining methods to screen for morphologic changes showed an increase in apoptotic lesions for even the lowest doses of 0.1 Gy of protons and 0.05 Gy of gamma rays, and the percentage of apoptotic cells increased with increasing dose. A smaller percentage of crypts showed 3 or more apoptotic lesions in animals that received 6 Gy of gamma-irradiation compared to mice receiving only 2 Gy of protons. Tissue of the gastrointestinal tract was also homogenized and RNA was isolated for cDNA synthesis and real-time PCR analysis. Inspecting apoptotic lesions of the duodenum of the small intestine as an endpoint of damage did not reveal a radio-adaptive response in C57BL/6 mice at the four hour time point. Results of gene expression changes showed consistent up or down regulation of a number of genes for all of the exposure doses that may play a role in proton-induced apoptosis. Preliminary results of gene expression alterations as a result of gamma-irradiation revealed a wealth of genes involved in oxidative stress and antioxidant defense processes being up- or down-regulated only at the highest exposure dose of 6 Gy and the combined dose of 5 cGy with 6 Gy. Those animals undergoing only 5 cGy of gamma-irradiation showed very little modification of gene expression. Taken together these results lead us to conclude that protons cause more severe morphologic damage to the duodenum of the small intestine at a dose of 2 Gy than a higher dose of 6 Gy of gamma rays to the same organ. Both protons and gamma rays lead to significant variation in gene expression at high doses in the small intestine and these changes may provide insight into the mechanism of injury seen in the gastrointestinal tract following radiation exposure. Astronauts experiencing prolonged exposure to protons in the low Earth orbit and in deep space, and experiencing acute exposure to protons from solar particle events, may face biological consequences that will impact a mission s success. We will continue this work by studying, quantifying, and comparing damage due to protons and gamma rays in the small intestine as well as other organs in a time-dependent manner
Dendritic Cell Responses to Early Murine Cytomegalovirus Infection: Subset Functional Specialization and Differential Regulation by Interferon α/β
Differentiation of dendritic cells (DCs) into particular subsets may act to shape innate and adaptive immune responses, but little is known about how this occurs during infections. Plasmacytoid dendritic cells (PDCs) are major producers of interferon (IFN)-α/β in response to many viruses. Here, the functions of these and other splenic DC subsets are further analyzed after in vivo infection with murine cytomegalovirus (MCMV). Viral challenge induced PDC maturation, their production of high levels of innate cytokines, and their ability to activate natural killer (NK) cells. The conditions also licensed PDCs to efficiently activate CD8 T cells in vitro. Non-plasmacytoid DCs induced T lymphocyte activation in vitro. As MCMV preferentially infected CD8α+ DCs, however, restricted access to antigens may limit plasmacytoid and CD11b+ DC contribution to CD8 T cell activation. IFN-α/β regulated multiple DC responses, limiting viral replication in all DC and IL-12 production especially in the CD11b+ subset but promoting PDC accumulation and CD8α+ DC maturation. Thus, during defense against a viral infection, PDCs appear specialized for initiation of innate, and as a result of their production of IFN-α/β, regulate other DCs for induction of adaptive immunity. Therefore, they may orchestrate the DC subsets to shape endogenous immune responses to viruses
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State of the Forest Carbon Markets 2012
Over the last three years, projects that address the relationships between carbon and forests have moved from the sidelines of international climate action to center field. Forestry’s recent advancements are the product of decades of ongoing collaboration among market and environmental experts seeking to strike an ideal balance between forestry projects’ market risks and shared benefits. Market dynamics in 2011 demonstrated that these efforts have never been more pivotal, or complex, as forest carbon projects mature – and find themselves positioned squarely in the midst of some of today’s most challenging policy debates. This year, a record number of forest project developers and secondary market suppliers from around the world shared data about their projects and transactions. This third annual State of the Forest Carbon Markets tracks, reports, and analyzes trends in these responses. This information is primarily based on data collected from respondents to Ecosystem Marketplace’s 2011 forest carbon project developer’s survey, combined with data from the 2012 State of the Voluntary Carbon Markets report. The data and analysis that follow cover forest carbon activity in compliance carbon markets – including the Kyoto Protocol’s Clean Development Mechanism (CDM), the New Zealand Emissions Trading Scheme (NZ ETS), the New South Wales Greenhouse Gas Reduction Scheme (NSW GGAS) and British Columbia’s (BC) Carbon Neutral Government directive – as well as voluntary carbon markets including voluntary Over-the-Counter (OTC) market and country-specific voluntary programs worldwide. In total, we captured responses from 140 project developers or project proponents in the primary forest carbon market and 35 suppliers in the secondary market. Respondents represented 215 individual forest carbon projects, half of which transacted credits in 2011 – totaling 451 projects analyzed in all survey years
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