Hypersonic flow analysis

While the zonal grid system of Transonic Navier-Stokes (TNS) provides excellent modeling of complex geometries, improved shock capturing, and a higher Mach number range will be required if flows about hypersonic aircraft are to be modeled accurately. A computational fluid dynamics (CFD) code, the Compressible Navier-Stokes (CNS), is under development to combine the required high Mach number capability with the existing TNS geometry capability. One of several candidate flow solvers for inclusion in the CNS is that of F3D. This upwinding flow solver promises improved shock capturing, and more accurate hypersonic solutions overall, compared to the solver currently used in TNS

The Role Of Neuropilin2a/b And Sema3fa In The Protoglomerular Targeting Of Zebrafish Olfactory Sensory Neurons

During development, zebrafish olfactory sensory neurons (OSNs) project axons from the olfactory epithelium to neuropil structures in the olfactory bulb (OB) known as protoglomeruli. OSNs expressing either OMP or TRPC2 exclusively project axons to two distinct, complementary sets of protoglomeruli. It is not known how differential protoglomerular targeting of these two populations is maintained. The guidance receptors nrp2a and nrp2b, along with their ligand sema3fa, were identified through RNAseq as potential candidates responsible for differential protoglomerular targeting of OMP- and TRPC2-class OSNs. Nrp2a and nrp2b are expressed in TRPC2-class OSNs, while sema3fa is expressed in OMP-class OSNs and OB. To investigate the involvement of these guidance factors in OSN axon guidance, the protoglomerular targeting fidelity of OSNs expressing OMP:RFP or TRPC2:Venus were assessed in nrp2a, nrp2b, and sema3fa mutants. The roles for these three guidance factors were further investigated through genetic interaction studies and live time-lapse imaging experiments. Targeting fidelity of TRPC2-class OSNs is degraded in nrp2a, nrp2b, and sema3fa mutants with increased rates of misprojecting axons observed in OMP-specific protoglomeruli as well as non-protoglomerular regions within the OB. Genetic interaction experiments suggest that nrp2a and nrp2b are partially redundant and that sema3fa is likely one of multiple guidance cues that acts in the same pathway as nrp2a and nrp2b. Live time-lapse imaging experiments comparing nrp2a and sema3fa mutants to their heterozygous siblings show that the dynamic behavior of TRPC2-class OSN growth cones are altered in mutant animals. The results support a model in which sema3fa functions as a repulsive cue to exclude nrp2a- and/or nrp2b-expressing TRPC2-class OSNs from OMP-specific protoglomeruli as well as form the dorsal-medial OB, adding to a growing list of guidance factors involved in protoglomerular targeting of OSNs. I also describe a protocol for the registration of guidance cue expression data in the 36hpf OB and present an unbiased registration template and model of the 72hpf OB and protoglomeruli. This work highlights the complex interaction of guidance factors involved in protoglomerular targeting of OSNs and lays a foundation for the systematic study of olfactory circuit formation

Project RISE: Recognizing Industrial Smoke Emissions

Industrial smoke emissions pose a significant concern to human health. Prior works have shown that using Computer Vision (CV) techniques to identify smoke as visual evidence can influence the attitude of regulators and empower citizens to pursue environmental justice. However, existing datasets are not of sufficient quality nor quantity to train the robust CV models needed to support air quality advocacy. We introduce RISE, the first large-scale video dataset for Recognizing Industrial Smoke Emissions. We adopted a citizen science approach to collaborate with local community members to annotate whether a video clip has smoke emissions. Our dataset contains 12,567 clips from 19 distinct views from cameras that monitored three industrial facilities. These daytime clips span 30 days over two years, including all four seasons. We ran experiments using deep neural networks to establish a strong performance baseline and reveal smoke recognition challenges. Our survey study discussed community feedback, and our data analysis displayed opportunities for integrating citizen scientists and crowd workers into the application of Artificial Intelligence for social good.Comment: Technical repor

StoryChat: Designing a Narrative-Based Viewer Participation Tool for Live Streaming Chatrooms

Live streaming platforms and existing viewer participation tools enable users to interact and engage with an online community, but the anonymity and scale of chat usually result in the spread of negative comments. However, only a few existing moderation tools investigate the influence of proactive moderation on viewers' engagement and prosocial behavior. To address this, we developed StoryChat, a narrative-based viewer participation tool that utilizes a dynamic graphical plot to reflect chatroom negativity. We crafted the narrative through a viewer-centered (N=65) iterative design process and evaluated the tool with 48 experienced viewers in a deployment study. We discovered that StoryChat encouraged viewers to contribute prosocial comments, increased viewer engagement, and fostered viewers' sense of community. Viewers reported a closer connection between streamers and other viewers because of the narrative design, suggesting that narrative-based viewer engagement tools have the potential to encourage community engagement and prosocial behaviors

Biomimetic/Optical Sensors for Detecting Bacterial Species

Biomimetic/optical sensors have been proposed as means of real-time detection of bacteria in liquid samples through real-time detection of compounds secreted by the bacteria. Bacterial species of interest would be identified through detection of signaling compounds unique to those species. The best-characterized examples of quorum-signaling compounds are acyl-homoserine lactones and peptides. Each compound, secreted by each bacterium of an affected species, serves as a signal to other bacteria of the same species to engage in a collective behavior when the population density of that species reaches a threshold level analogous to a quorum. A sensor according to the proposal would include a specially formulated biomimetic film, made of a molecularly imprinted polymer (MIP), that would respond optically to the signaling compound of interest. The MIP film would be integrated directly onto an opticalwaveguide- based ring resonator for optical readout. Optically, the sensor would resemble the one described in Chemical Sensors Based on Optical Ring Resonators (NPO-40601), NASA Tech Briefs, Vol. 29, No. 10 (October 2005), page 32. MIPs have been used before as molecular- recognition compounds, though not in the manner of the present proposal. Molecular imprinting is an approach to making molecularly selective cavities in a polymer matrix. These cavities function much as enzyme receptor sites: the chemical functionality and shape of a cavity in the polymer matrix cause the cavity to bind to specific molecules. An MIP matrix is made by polymerizing monomers in the presence of the compound of interest (template molecule). The polymer forms around the template. After the polymer solidifies, the template molecules are removed from the polymer matrix by decomplexing them from their binding sites and then dissolving them, leaving cavities that are matched to the template molecules in size, shape, and chemical functionality. The cavities thus become molecular-recognition sites that bind only to molecules matched to the sites; other molecules are excluded. In a sensor according to the proposal, the MIP would feature molecular recognition sites that would bind the specific signaling molecules selectively according to their size, shape, and chemical functionality (see figure). As the film took up the signaling molecules in the molecular recognition sites, the index of refraction and thickness of the film would change, causing a wavelength shift of the peak of the resonance spectrum. It has been estimated that by measuring this wavelength shift, it should be possible to detect as little as 10 picomoles of a peptide signaling compound

Laparoscopic versus open liver resection: a meta‐analysis of long‐term outcome

AbstractBackgroundLaparoscopic liver resection is growing in popularity, but the long‐term outcome of patients undergoing laparoscopic liver resection for malignancy has not been established. This paper is a meta‐analysis and compares the long‐term survival of patients undergoing laparoscopic (LHep) versus open (OHep) liver resection for the treatment of malignant liver tumours.MethodsA PubMed database search identified comparative human studies analysing LHep versus OHep for malignant tumours. Clinical and survival parameters were extracted. The search was last conducted on 18 March 2012.ResultsIn total, 1002 patients in 15 studies were included (446 LHep and 556 OHep). A meta‐analysis of overall survival showed no difference [1‐year: odds ratio (OR) 0.71, 95% confidence interval (CI) 0.42 to 1.20, P = 0.202; 3‐years: OR 0.76, 95% CI 0.56 to 1.03, P = 0.076; 5‐years: OR 0.8, 95% CI 0.59 to 1.10, P = 0.173]. Subset analyses of hepatocellular carcinoma (HCC) and colorectal metastases (CRM) were performed. There was no difference in the 1‐, 3‐, and 5‐year survival for HCC or in the 1‐year survival for CRM, however, a survival advantage was found for CRM at 3 years (LHep 80% versus OHep 67.4%, P = 0.036).ConclusionsLaparoscopic surgery should be considered an acceptable alternative for the treatment of malignant liver tumours