5,450 research outputs found
Evaluation of Pit-trap Transects With Varied Trap Spacing in a Northern Michigan Forest
The study compared effects of four distances between traps (range 0.5-4.0 m) on arthropod captures. Twelve traps were aligned in each of four transects, and 20 samples. trap were obtained during summer and fall in a northern Michigan deciduous forest. Catches proved to be unaffected by trap spacing. Rather, they reflected local within-site differences in abundance of dominant species
Observations of attenuation at 20.6, 31.65 and 90.0 GHz: Preliminary results from Wallops Island, VA
Ground based radiometric observations of atmospheric attenuation at 20.6, 31.65, and 90.0 GHz were made at Wallops Island, Virginia during April and May 1989. Early results from the analysis of the data set are compared with previous observations from California and Colorado. The relative attenuation ratios observed at each frequency during clear, cloudy, and rainy conditions are shown. Plans for complete analysis of the data are described
Optical particle counter measurement of marine aerosol hygroscopic growth
International audienceA technique is developed for the determination of the hygroscopic growth factor of dry particles with diameter between 0.3 and 0.6 ?m and is applied to measurements made during the second Dynamics and Chemistry of Marine Stratocumulus experiment (DYCOMS-II). Two optical particle counters are utilized, one measures the aerosol size spectrum at ambient relative humidity and the other simultaneously dries the aerosol prior to light scattering detection. Growth factors are based on measurements made in the region of the Mie scattering curve where scattered light intensity increases monotonically with dry and wet particle diameter, i.e. D<0.9 ?m. Factors influencing the accuracy of the measurement are evaluated, including particle drying, refractive index and shape. Growth factors at 90±3% ambient relative humidity in marine airmasses 400 km west of San Diego, California range between 1.5 and 1.8. This suggests that a significant fraction of the particle mass, between 40 and 70%, is either non-hygroscopic or weakly hygroscopic
Exploring the Benefits of Remanufacture during Product Prototyping:A Cost and Time Based Analysis
The emerging oral pathogen, Filifactor alocis, modulates antimicrobial responses of primed human neutrophils.
Almost 50% of the adult population older than 30 years of age suffers from some form of periodontitis, a chronic inflammatory disease of the periodontal tissue caused by microbial subversion of the host immune response. Neutrophils are the most abundant leukocyte present in the oral mucosa. In periodontitis, periodontal pathogens have developed strategies to evade neutrophil antimicrobial responses and promote bacterial growth. Among these oral pathogens is Filifactor alocis which can modulate neutrophils’ antimicrobial responses by preventing phagosome maturation. During inflammation, neutrophils that reach the gingival tissue are primed by cytokines and chemokines. However, the response of primed human neutrophils to F. alocis is currently unknown. To address this gap in knowledge, human neutrophils were primed with TNF-α, an established priming agent, and the kinetics of phagocytosis and intracellular ROS production in response to serum opsonized F. alocis were tested. Our results showed a significant increase in phagocytosis of F. alocisby TNF-α-primed neutrophils compared to unprimed cells. However, the significant increase in bacteria uptake was not accompanied by increased ROS production. F. alocis significantly downregulated the respiratory burst response in human neutrophils independently of priming with TNF-α. Interestingly, priming of neutrophils with IL-8 did not result in a significant increase in phagocytosis of F. alocis, but IL-8-primed neutrophils did have a similar ROS phenotype to TNF-α-primed neutrophils. This suggests dome ability of F. alcois to modulate the phagocytic ability of IL-8-primed neutrophils. Future studies will aim to characterize F. alocis’ virulence factors that modulate neutrophil responses
DIMENSIONS OF KNOWLEDGE IN PROTOTYPING:A REVIEW AND CHARACTERISATION OF PROTOTYPING METHODS AND THEIR CONTRIBUTIONS TO DESIGN KNOWLEDGE
Spatial and temporal distribution of supercooled cloud liquid water during wintertime storms over the northern Colorado Rockies, The
August 1984.Includes bibliographical references (page 58).Sponsored by National Science Foundation ATM-78-19260.Sponsored by National Science Foundation ATM-81-09890
Effects of Pax3 mutation and Neural Crest genetic ablation on congenital heart function and embryonic lethality
poster abstractCongenital heart defects (CHDs) occur in approximately one percent of births every year (American Heart Association, 2008). This makes it the most frequently occurring congenital defect in humans. My research is aimed at using two mutant cardiac neural crest (CNC) mouse models to study the mechanisms underlying congenital heart failure in utero with particular interests in understanding the processes of outflow tract (OFT) septation and myocardial homeostasis. The first mouse model is a Pax3 systemic knockout, which is lethal by mouse gestational day14, and has an insufficient number of migratory CNC cells. The second mouse model is a Wnt1Cre-mediated neural crest-ablated model, which is surprisingly viable and survives to birth, despite having no migratory CNC cells.
My data indicates that both mouse models have similar heart structural anomalies including failure of the OFT to divide and interventricular septation defects. However, in utero heart function is significantly perturbed in Pax3 mutants when compared to that of the ablated mutant model. Via comparison of these two mutant mouse models, I have been able to assess the tissuespecific contribution of the CNC cell lineage during in utero heart morphogenesis, as well as to identify the beta-adrenergic pathway as the underlying mechanistic pathway that is important for the observed differences in myocardial function and subsequent congenital heart failure and lethality in the Pax3 mutants. By doing so, I am now able to demonstrate pharmacological rescue of the Pax3 mutants to birth, via bypassing or stimulation of the aforementioned pathway.
By understanding the causes of congenital heart failure and subsequent lethality in the Pax3 genetic model, and successfully achieving pharmacological rescue to birth, I believe the results of my project will allow me to translate my findings into better treatment strategies for newborn patients with similar CHDs
Evaluation of the aerosol indirect effect in marine stratocumulus clouds: Droplet number, size, liquid water path, and radiative impact
Introduction to HOBIT, a b-Jet Identification Tagger at the CDF Experiment Optimized for Light Higgs Boson Searches
We present the development and validation of the Higgs Optimized b
Identification Tagger (HOBIT), a multivariate b-jet identification algorithm
optimized for Higgs boson searches at the CDF experiment at the Fermilab
Tevatron. At collider experiments, b taggers allow one to distinguish particle
jets containing B hadrons from other jets; these algorithms have been used for
many years with great success at CDF. HOBIT has been designed specifically for
use in searches for light Higgs bosons decaying via H ! b\bar{b}. This fact
combined with the extent to which HOBIT synthesizes and extends the best ideas
of previous taggers makes HOBIT unique among CDF b-tagging algorithms.
Employing feed-forward neural network architectures, HOBIT provides an output
value ranging from approximately -1 ("light-jet like") to 1 ("b-jet like");
this continuous output value has been tuned to provide maximum sensitivity in
light Higgs boson search analyses. When tuned to the equivalent light jet
rejection rate, HOBIT tags 54% of b jets in simulated 120 GeV/c2 Higgs boson
events compared to 39% for SecVtx, the most commonly used b tagger at CDF. We
present features of the tagger as well as its characterization in the form of
b-jet finding efficiencies and false (light-jet) tag rates.Comment: 40 pages, 16 figue
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