299 research outputs found
Scientific Objectives, Measurement Needs, and Challenges Motivating the PARAGON Aerosol Initiative
Aerosols are involved in a complex set of processes that operate across many spatial and temporal scales. Understanding these processes, and ensuring their accurate representation in models of transport, radiation transfer, and climate, requires knowledge of aerosol physical, chemical, and optical properties and the distributions of these properties in space and time. To derive aerosol climate forcing, aerosol optical and microphysical properties and their spatial and temporal distributions, and aerosol interactions with clouds, need to be understood. Such data are also required in conjunction with size-resolved chemical composition in order to evaluate chemical transport models and to distinguish natural and anthropogenic forcing. Other basic parameters needed for modeling the radiative influences of aerosols are surface reflectivity and three-dimensional cloud fields. This large suite of parameters mandates an integrated observing and modeling system of commensurate scope. The Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON) concept, designed to meet this requirement, is motivated by the need to understand climate system sensitivity to changes in atmospheric constituents, to reduce climate model uncertainties, and to analyze diverse collections of data pertaining to aerosols. This paper highlights several challenges resulting from the complexity of the problem. Approaches for dealing with them are offered in the set of companion papers
An Integrated Approach for Characterizing Aerosol Climate Impacts and Environmental Interactions
Aerosols exert myriad influences on the earth's environment and climate, and on human health. The complexity of aerosol-related processes requires that information gathered to improve our understanding of climate change must originate from multiple sources, and that effective strategies for data integration need to be established. While a vast array of observed and modeled data are becoming available, the aerosol research community currently lacks the necessary tools and infrastructure to reap maximum scientific benefit from these data. Spatial and temporal sampling differences among a diverse set of sensors, nonuniform data qualities, aerosol mesoscale variabilities, and difficulties in separating cloud effects are some of the challenges that need to be addressed. Maximizing the long-term benefit from these data also requires maintaining consistently well-understood accuracies as measurement approaches evolve and improve. Achieving a comprehensive understanding of how aerosol physical, chemical, and radiative processes impact the earth system can be achieved only through a multidisciplinary, inter-agency, and international initiative capable of dealing with these issues. A systematic approach, capitalizing on modern measurement and modeling techniques, geospatial statistics methodologies, and high-performance information technologies, can provide the necessary machinery to support this objective. We outline a framework for integrating and interpreting observations and models, and establishing an accurate, consistent, and cohesive long-term record, following a strategy whereby information and tools of progressively greater sophistication are incorporated as problems of increasing complexity are tackled. This concept is named the Progressive Aerosol Retrieval and Assimilation Global Observing Network (PARAGON). To encompass the breadth of the effort required, we present a set of recommendations dealing with data interoperability; measurement and model integration; multisensor synergy; data summarization and mining; model evaluation; calibration and validation; augmentation of surface and in situ measurements; advances in passive and active remote sensing; and design of satellite missions. Without an initiative of this nature, the scientific and policy communities will continue to struggle with understanding the quantitative impact of complex aerosol processes on regional and global climate change and air quality
Physiological and pathological brain activation in the anesthetized rat produces hemodynamic-dependent cortical temperature increases that can confound the BOLD fMRI signal
Anesthetized rodent models are ubiquitous in pre-clinical neuroimaging studies. However, because the associated cerebral morphology and experimental methodology results in a profound negative brain-core temperature differential, cerebral temperature changes during functional activation are likely to be principally driven by local inflow of fresh, core-temperature, blood. This presents a confound to the interpretation of blood-oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) data acquired from such models, since this signal is also critically temperature-dependent. Nevertheless, previous investigation on the subject is surprisingly sparse. Here, we address this issue through use of a novel multi-modal methodology in the urethane anesthetized rat. We reveal that sensory stimulation, hypercapnia and recurrent acute seizures induce significant increases in cortical temperature that are preferentially correlated to changes in total hemoglobin concentration (Hbt), relative to cerebral blood flow and oxidative metabolism. Furthermore, using a phantom-based evaluation of the effect of such temperature changes on the BOLD fMRI signal, we demonstrate a robust inverse relationship between both variables. These findings suggest that temperature increases, due to functional hyperemia, should be accounted for to ensure accurate interpretation of BOLD fMRI signals in pre-clinical neuroimaging studies
An unusual cause for Coffin–Lowry syndrome: Three brothers with a novel microduplication in RPS6KA3
Coffin–Lowry syndrome (CLS) is a rare X‐linked disorder characterized by moderate to severe intellectual disability, hypotonia, craniofacial features, tapering digits, short stature, and skeletal deformities. Using whole exome sequencing and high‐resolution targeted comparative genomic hybridization array analysis, we identified a novel microduplication encompassing exons five through nine of RPS6KA3 in three full brothers. Each brother presented with intellectual disability and clinical and radiographic features consistent with CLS. qRT‐PCR analyses performed on mRNA from the peripheral blood of the three siblings revealed a marked reduction of RPS6KA3 levels suggesting a loss‐of‐function mechanism. PCR analysis of the patients’ cDNA detected a band greater than expected for an exon 4–10 amplicon, suggesting this was likely a direct duplication that lies between exons 4 through 10, which was later confirmed by Sanger sequencing. This microduplication is only the third intragenic duplication of RPS6KA3, and the second and smallest reported to date thought to cause CLS. Our study further supports the clinical utility of methods such as next‐generation sequencing and high‐resolution genomic arrays to detect small intragenic duplications. These methods, coupled with expression studies and cDNA structural analysis have the capacity to confirm the diagnosis of CLS in these rare cases
Feasibility and safety of GliaSite brachytherapy in treatment of CNS tumors following neurosurgical resection
Purpose: To investigate feasibility and safety of GliaSite
brachytherapy for treatment of central nervous system (CNS) tumors
following neurosurgical resection. We report mature results of
long-term follow-up, outcomes and toxicity. Materials and Methods: In
the period from 2004 to 2007, 10 consecutive adult patients with
recurrent, newly diagnosed, and metastatic brain malignancies underwent
GliaSite brachytherapy following maximally safe neurosurgical
resection. While 6/10 (60%) patients were treated for recurrence,
having previously been treated with external beam radiotherapy (EBRT),
4/10 (40%) received radiotherapy (RT) for the first time. A median dose
of 52.0 Gy (range, 45.0 - 60.0 Gy) was prescribed to 0.5 cm - 1.0 cm
from the balloon surface. Radiation Therapy Oncology Group (RTOG)
criteria were used to assess toxicities associated with this technique.
Follow-up was assessed with MRI scans and was available on all enrolled
patients. Results: Median follow-up was 38 months (range, 18 - 57
months). Mean size of GliaSite balloon was 3.4 cm (range, 2.0 - 4.0
cm). Median survival was 14.0 months for the entire cohort after the
treatment. The 17.6 and 16.0 months average survival for newly
diagnosed and recurrent high grade gliomas (HGG), respectively,
translated into a three-month improvement in survival in patients with
newly diagnosed HGG compared to historical controls (P = 0.033). There
were no RTOG grades 3 or 4 acute or late toxicities. Follow-up magnetic
resonance imaging (MRI) imaging did not identify radiation necrosis.
Conclusions: Our data indicate that treatment with GliaSite
brachytherapy is feasible, safe and renders acceptable local control,
acute and long-term toxicities. We are embarking on testing larger
numbers of patients with this treatment modality
What is values work? A review of values work in organisations. Kap. 3
I: H.Askeland, G. Espedal, B. Jelstad Løvaas & S. Sirris (Eds.), Understanding values work : Institutional perspectives in organizations and leadershipThrough a review of the existing empirical studies and emerging literature on values work in organisations, this paper aims to disambiguate the phenomenon of values work. Values work is understood as ongoing value performances situated in everyday practice in organisations. As such, values work is identified as social and institutional processes of constructing agency, actions and practice in organisations. In this chapter, I show how values work is part of both a performative tradition of process studies and an institutional work tradition that strives to change, disrupt and maintain institutions. Further, I outline how future studies can broaden the field of values work.publishedVersio
Standardizing Slimness: How Body Weight Quantified Beauty in the Netherlands, 1870–1940
This chapter investigates the history of one of the most powerful quantitative beauty standards: weight. The chapter argues that weight is neither a natural nor a neutral standard for the beauty ideals of slimness and fatness. It is shown first how, in late nineteenth-century Netherlands, weight had not yet become a standard of beauty but was rather a bodily curiosity, measured at fairgrounds. The chapter then analyses Dutch newspaper advertisements for slimming remedies to show that, by the 1930s, weight was strongly established as a standard of beauty, scales having ceased to be a fairground attraction. The chapter concludes with an exploration of the consequences of this new standard of beauty, which complicated its character by partially separating it from the visual
Китаб Ибрагима Хосеневича из коллекции Национальной библиотеки Республики Беларусь как исторический источник : реферат к дипломной работе / Инна Чеславовна Кевра; БГУ, Исторический факультет, Кафедра источниковедения; науч. рук. Белявский А.М.
The construct of individualism–collectivism (IND-COL) has become the definitive standard in cross-cultural psychology, management, and related fields. It is also among the most controversial, in particular, with regard to the ambiguity of its dimensionality: Some view IND and COL as the opposites of a single continuum, whereas others argue that the two are independent constructs. We explored the issue through seven different tests using original individual-level data from 50 studies and meta-analytic data from 149 empirical publications yielding a total of 295 sample-level observations that were collected using six established instruments for assessing IND and COL as separate constructs. Results indicated that the dimensionality of IND-COL may depend on (a) the specific instrument used to collect the data, (b) the sample characteristics and the cultural region from which the data were collected, and (c) the level of analysis. We also review inconsistencies, deficiencies, and challenges of conceptualizing IND-COL and provide guidelines for developing and selecting instruments for measuring the construct, and for reporting and meta-analyzing results from this line of research
BIDCHIPS: bias decomposition and removal from ChIP-seq data clarifies true binding signal and its functional correlates
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