202 research outputs found
New Results on Ultrafast Coherent Excitation of Molecular Vibrations in Liquids
Coherent Raman probe scattering experiments are performed to study dynamical processes of polyatomic liquids at 300 K. For single homogeneous transitions the dephasing timeT 2 is readily obtained from time resolved investigations. Spectral studies show an interesting time dependent shift in scattered frequency. After the excitaiton the vibrating molecules are shown to relax freely with their resonance frequency. Multiple, equally spaced transitions exhibit a beating phenomenon which provides the dephasing time and the frequency interval between neighboring vibrational states. Inhomogeneously broadened systems do not allow a ready determination of the dephasing time by the present probing technique. Previous experiments on the subject have to be reconsidered
Role of organic components in sol-gel glasses
Organic groupings play an important role for the preparation of glasses by the sol-gel route. They are responsible for the solubility of precursors, interact during the polycondensation process, the drying and ageing step and during firing. For processing, important parameters e.g. hydrolysis rates and the SiOH formation can be controlled by proper choice of the hydrolysable group. If organics remain in the glass network, remarkable changes of properties (density, hardness, refractive index) occur
Ignite: November 1968
This alternative newspaper was published at the University of North Dakota in November 1968 and feature articles written at University, as well as re-prints from other national publications.
The issue features the following articles: Organized Crime at U.N.D. by Janelle Hongess (the editor of Ignite); The New Folk by Doug Rankin; This Mad White World by Bill Borden (UND English Professor); The Second Time Around by Thomas DeBaggio; Prayer for the Suffering by Charles Kaiser; What Misled Colleagues Can Do by Alfred Hobbs; The Sibyl Speaks; Refusal News by Maris Cakars; Academic Freedom Behind Machine Gun Mounts by Thomas DeBaggio; Censorship: Pluralistic Ignorance by Charles Kaiser; and 14 Lines by Mike Evangelist.https://commons.und.edu/und-books/1013/thumbnail.jp
PD-1+ natural killer cells in human non-small cell lung cancer can be activated by PD-1/PD-L1 blockade
Natural killer (NK) cells are critically involved in anti-tumor immunity by targeting tumor cells. In this study, we show that intratumoral NK cells from NSCLC patients expressed elevated levels of the immune checkpoint receptor PD-1 on their cell surface. In contrast to the expression of activating receptors, PD-1; +; NK cells co-expressed more inhibitory receptors compared to PD-1; -; NK cells. Intratumoral NK cells were less functional compared to peripheral NK cells, and this dysfunction correlated with PD-1 expression. Tumor cells expressing PD-L1 inhibited the functionality of PD-1; +; NK cells in ex vivo models and induced PD-1 clustering at the immunological synapse between NK cells and tumor cells. Notably, treatment with PD-1 blockade was able to reverse PD-L1-mediated inhibition of PD-1; +; NK cells. Our findings highlight the therapeutic potential of PD-1; +; NK cells in immune checkpoint blockade and could guide the development of NK cell-stimulating agents in combination with PD-1 blockade
BACCardI - a tool for the validation of genomic assemblies, assisting genome finishing and intergenome comparison
Bartels D, Kespohl S, Albaum S, et al. BACCardI - a tool for the validation of genomic assemblies, assisting genome finishing and intergenome comparison. Bioinformatics. 2005;21(7):853-859.Summary: We provide the graphical tool BACCardI for the construction of virtual clone maps from standard assembler output files or BLAST based sequence comparisons. This new tool has been applied to numerous genome projects to solve various problems including (a) validation of whole genome shotgun assemblies, (b) support for contig ordering in the finishing phase of a genome project, and (c) intergenome comparison between related strains when only one of the strains has been sequenced and a large insert library is available for the other. The BACCardI software can seamlessly interact with various sequence assembly packages. Motivation: Genomic assemblies generated from sequence information need to be validated by independent methods such as physical maps. The time-consuming task of building physical maps can be circumvented by virtual clone maps derived from read pair information of large insert libraries
An Architecture for Multi-User Software Development Environments
We present an architecture for multi-user software development environments, covering general, process-centered and rule-based MUSDEs. Our architecture is founded on componentization, with particular concern for the capability to replace the synchronization component - to allow experimentation with novel concurrency control mechanisms - with minimal effects on other components while still supporting integration. The architecture has been implemented in the MARVEL SD
Flashlights: More than A Dozen High-Significance Microlensing Events of Extremely Magnified Stars in Galaxies at Redshifts z=0.7-1.5
Once only accessible in nearby galaxies, we can now study individual stars
across much of the observable universe aided by galaxy-cluster gravitational
lenses. When a star, compact object, or multiple such objects in the foreground
galaxy-cluster lens become aligned, they can magnify a background individual
star, and the timescale of a magnification peak can limit its size to tens of
AU. The number and frequency of microlensing events therefore opens a window
into the population of stars and compact objects, as well as high-redshift
stars. To assemble the first statistical sample of stars in order to constrain
the initial mass function (IMF) of massive stars at redshift z=0.7-1.5, the
abundance of primordial black holes in galaxy-cluster dark matter, and the IMF
of the stars making up the intracluster light, we are carrying out a 192-orbit
program with the Hubble Space Telescope called "Flashlights," which is now
two-thirds complete owing to scheduling challenges. We use the ultrawide F200LP
and F350LP long-pass WFC3 UVIS filters and conduct two 16-orbit visits
separated by one year. Having an identical roll angle during both visits, while
difficult to schedule, yields extremely clean subtraction. Here we report the
discovery of more than a dozen bright microlensing events, including multiple
examples in the famous "Dragon Arc" discovered in the 1980s, as well as the
"Spocks" and "Warhol" arcs that have hosted already known supergiants. The
ultradeep observer-frame ultraviolet-through-optical imaging is sensitive to
hot stars, which will complement deep James Webb Space Telescope infrared
imaging. We are also acquiring Large Binocular Telescope LUCI and Keck-I
MOSFIRE near-infrared spectra of the highly magnified arcs to constrain their
recent star-formation histories
The missing link: Bordetella petrii is endowed with both the metabolic versatility of environmental bacteria and virulence traits of pathogenic Bordetellae
Gross R, Guzman CA, Sebaihia M, et al. The missing link: Bordetella petrii is endowed with both the metabolic versatility of environmental bacteria and virulence traits of pathogenic Bordetellae. BMC Genomics. 2008;9(1): 449.Background: Bordetella petrii is the only environmental species hitherto found among the otherwise host-restricted and pathogenic members of the genus Bordetella. Phylogenetically, it connects the pathogenic Bordetellae and environmental bacteria of the genera Achromobacter and Alcaligenes, which are opportunistic pathogens. B. petrii strains have been isolated from very different environmental niches, including river sediment, polluted soil, marine sponges and a grass root. Recently, clinical isolates associated with bone degenerative disease or cystic fibrosis have also been described. Results: In this manuscript we present the results of the analysis of the completely annotated genome sequence of the B. petrii strain DSMZ12804. B. petrii has a mosaic genome of 5,287,950 bp harboring numerous mobile genetic elements, including seven large genomic islands. Four of them are highly related to the clc element of Pseudomonas knackmussii B13, which encodes genes involved in the degradation of aromatics. Though being an environmental isolate, the sequenced B. petrii strain also encodes proteins related to virulence factors of the pathogenic Bordetellae, including the filamentous hemagglutinin, which is a major colonization factor of B. pertussis, and the master virulence regulator BvgAS. However, it lacks all known toxins of the pathogenic Bordetellae. Conclusion: The genomic analysis suggests that B. petrii represents an evolutionary link between free-living environmental bacteria and the host-restricted obligate pathogenic Bordetellae. Its remarkable metabolic versatility may enable B. petrii to thrive in very different ecological niches
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