SURGE: Continuous Detection of Bursty Regions Over a Stream of Spatial Objects

With the proliferation of mobile devices and location-based services, continuous generation of massive volume of streaming spatial objects (i.e., geo-tagged data) opens up new opportunities to address real-world problems by analyzing them. In this paper, we present a novel continuous bursty region detection problem that aims to continuously detect a bursty region of a given size in a specified geographical area from a stream of spatial objects. Specifically, a bursty region shows maximum spike in the number of spatial objects in a given time window. The problem is useful in addressing several real-world challenges such as surge pricing problem in online transportation and disease outbreak detection. To solve the problem, we propose an exact solution and two approximate solutions, and the approximation ratio is $\frac{1-\alpha}{4}$ in terms of the burst score, where $\alpha$ is a parameter to control the burst score. We further extend these solutions to support detection of top-$k$ bursty regions. Extensive experiments with real-world data are conducted to demonstrate the efficiency and effectiveness of our solutions

Which is better to preserve pulmonary function: Short-term or prolonged leukocyte depletion during cardiopulmonary bypass?

ObjectivesNeutrophils are crucial in the development of acute lung injuries during cardiopulmonary bypass. However, the efficacy of leukocyte depletion on pulmonary protection remains controversial, possibly owing to different filtration strategies used in the literature. In this study, we investigated whether short-term leukocyte depletion strategy is more efficacious than prolonged leukocyte depletion in preserving pulmonary function.MethodsEighteen adult dogs were randomized equally into 3 groups. Leukocyte-depleting filters were used for 10 minutes in the LD-S group, throughout cardiopulmonary bypass in the LD-T group, and not used in the control group. Neutrophil counts, elastase, and interleukin-8 concentrations in plasma, myeloperoxidase and interleukin-8 concentrations in pulmonary tissue, and pulmonary vascular resistance and oxygen index were determined to evaluate the inflammatory response and damage to pulmonary function.ResultsAlthough the neutrophil count and pulmonary parenchymal myeloperoxidase contents were significantly lower in both LD-S and LD-T groups than that in the control group, lower pulmonary parenchymal interleukin-8 level, lower pulmonary vascular resistance (113 ± 33 dyne · s/cm5), higher oxygen index (366 ± 82.3 mm Hg), and thinner alveolus wall thickness were seen only in the LD-S group, and the pulmonary parenchymal interleukin-8 levels were also lower in the LD-S group after cardiopulmonary bypass. The plasma elastase and interleukin-8 levels were significantly lower in the LD-S group, but they were significantly higher in the LD-T group compared with the control group after cardiopulmonary bypass.ConclusionsShort-term rather than prolonged leukocyte depletion during cardiopulmonary bypass appears to be more efficacious in protecting pulmonary function via attenuation of the extracorporeal circulation–induced inflammatory response

Molecular Characterization, Phylogenetic, Expression, and Protective Immunity Analysis of OmpF, a Promising Candidate Immunogen Against Yersinia ruckeri Infection in Channel Catfish

Outer membrane porins, as the major components of Gram-negative bacterial membrane proteins, have been proven to be involved in interactions with the host immune system and potent protective antigen candidates against bacterial infection in fish. Outer membrane porin F (OmpF) is one of the major porins of Yersinia ruckeri (Y. ruckeri), the causative agent of enteric red mouth disease of salmonid and non-salmonid fish. In the present study, the molecular characterization and phylogenetic analysis of OmpF gene was studied, heterogenous expression, immunogenicity and protective immunity of OmpF were systemically evaluated as a subunit vaccine for channel catfish against Y. ruckeri infection. The results showed that OmpF gene was highly conserved among 15 known Yersinia species based on the analysis of conserved motifs, sequences alignment and phylogenetic tree, and was subjected to negative/purifying selection with global dN/dS ratios value of 0.649 throughout the evolution. Besides, OmpF was also identified to have immunogenicity by western blotting and was verified to be located on the surface of Y. ruckeri using cell surface staining and indirect immunofluorescence assays. Moreover, recombinant OmpF (rtOmpF) as a subunit vaccine was injected with commercial adjuvant ISA763, significantly enhanced the immune response by increasing serum antibody levels, lysozyme activity, complement C3 activity, total protein content, SOD activity, immune-related genes expression in the head kidney and spleen, and survival percent of channel catfish against Y. ruckeri infection. Thus, our present results not only enriched the information of molecular characterization and phylogenetics of OmpF, but also demonstrated that OmpF holds promise to be used as a potential antigen against Y. ruckeri infection in fish