3,227 research outputs found
Low cloud investigations for project FIRE: Island studies of cloud properties, surface radiation, and boundary layer dynamics. A simulation of the reflectivity over a stratocumulus cloud deck by the Monte Carlo method
The radiation field over a broken stratocumulus cloud deck is simulated by the Monte Carlo method. We conducted four experiments to investigate the main factor for the observed shortwave reflectively over the FIRE flight 2 leg 5, in which reflectivity decreases almost linearly from the cloud center to cloud edge while the cloud top height and the brightness temperature remain almost constant through out the clouds. From our results, the geometry effect, however, did not contribute significantly to what has been observed. We found that the variation of the volume extinction coefficient as a function of its relative position in the cloud affects the reflectivity efficiently. Additional check of the brightness temperature of each experiment also confirms this conclusion. The cloud microphysical data showed some interesting features. We found that the cloud droplet spectrum is nearly log-normal distributed when the clouds were solid. However, whether the shift of cloud droplet spectrum toward the larger end is not certain. The decrease of number density from cloud center to cloud edges seems to have more significant effects on the optical properties
Distinct forms of the ß subunit of GTP-binding regulatory proteins identified by molecular cloning
Two distinct β subunits of guanine nucleotide-binding regulatory proteins have been identified by cDNA cloning and are referred to as β 1 and β 2 subunits. The bovine transducin β subunit (β 1) has been cloned previously. We have now isolated and analyzed cDNA clones that encode the β 2 subunit from bovine adrenal, bovine brain, and a human myeloid leukemia cell line, HL-60. The 340-residue Mr 37,329 β 2 protein is 90% identical with β 1 in predicted amino acid sequence, and it is also organized as a series of repetitive homologous segments. The major mRNA that encodes the bovine β 2 subunit is 1.7 kilobases in length. It is expreβed at lower levels than β 1 subunit mRNA in all tiβues examined. The β 1 and β 2 meβages are expreβed in cloned human cell lines. Hybridization of cDNA probes to bovine DNA showed that β 1 and β 2 are encoded by separate genes. The amino acid sequences for the bovine and human β 2 subunit are identical, as are the amino acid sequences for the bovine and human β 1 subunit. This evolutionary conservation suggests that the two β subunits have different roles in the signal transduction process
Utilizing Win Ratio Approaches and Two-Stage Enrichment Designs for Small-Sized Clinical Trials
Conventional methods for analyzing composite endpoints in clinical trials
often only focus on the time to the first occurrence of all events in the
composite. Therefore, they have inherent limitations because the individual
patients' first event can be the outcome of lesser clinical importance. To
overcome this limitation, the concept of the win ratio (WR), which accounts for
the relative priorities of the components and gives appropriate priority to the
more clinically important event, was examined. For example, because mortality
has a higher priority than hospitalization, it is reasonable to give a higher
priority when obtaining the WR. In this paper, we evaluate three innovative WR
methods (stratified matched, stratified unmatched, and unstratified unmatched)
for two and multiple components under binary and survival composite endpoints.
We compare these methods to traditional ones, including the Cox regression,
O'Brien's rank-sum-type test, and the contingency table for controlling study
Type I error rate. We also incorporate these approaches into two-stage
enrichment designs with the possibility of sample size adaptations to gain
efficiency for rare disease studies
A Microfluidic Platform for Precision Small-volume Sample Processing and Its Use to Size Separate Biological Particles with an Acoustic Microdevice.
A major advantage of microfluidic devices is the ability to manipulate small sample volumes, thus reducing reagent waste and preserving precious sample. However, to achieve robust sample manipulation it is necessary to address device integration with the macroscale environment. To realize repeatable, sensitive particle separation with microfluidic devices, this protocol presents a complete automated and integrated microfluidic platform that enables precise processing of 0.15-1.5 ml samples using microfluidic devices. Important aspects of this system include modular device layout and robust fixtures resulting in reliable and flexible world to chip connections, and fully-automated fluid handling which accomplishes closed-loop sample collection, system cleaning and priming steps to ensure repeatable operation. Different microfluidic devices can be used interchangeably with this architecture. Here we incorporate an acoustofluidic device, detail its characterization, performance optimization, and demonstrate its use for size-separation of biological samples. By using real-time feedback during separation experiments, sample collection is optimized to conserve and concentrate sample. Although requiring the integration of multiple pieces of equipment, advantages of this architecture include the ability to process unknown samples with no additional system optimization, ease of device replacement, and precise, robust sample processing
Sharing and Preserving Computational Analyses for Posterity with encapsulator
Open data and open-source software may be part of the solution to science's
"reproducibility crisis", but they are insufficient to guarantee
reproducibility. Requiring minimal end-user expertise, encapsulator creates a
"time capsule" with reproducible code in a self-contained computational
environment. encapsulator provides end-users with a fully-featured desktop
environment for reproducible research.Comment: 11 pages, 6 figure
Constructing Filler-Gap Dependencies in Chinese Possessor Relative Clauses
PACLIC 19 / Taipei, taiwan / December 1-3, 200
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