ABSTRACT
Hydrocephalus is widely known as "hydrocephaly" or "water in the brain," a building up of abnormal cerebrospinal fluid in the brain ventricles. Due to this abnormality, the size of the head becomes larger and increases the pressure in the skull. This pressure compresses the brain and causes damage to the brain. Identification by imaging techniques on the hydrocephalus is mandatory to treat the disease. Various methods and equipment have been used to image the hydrocephalus. Among them, computerized tomography (CT) scan and nuclear magnetic resonance (NMR) are the most considered methods and gives accurate result of imaging. Apart from imaging, cerebrospinal fluid-based biomarkers are also used to identify the condition of hydrocephalus. This review is discussed on "hydrocephalus" and its imaging captured by CT scan and NMR to support the biomarker analysis.
ABSTRACT
The navigation accuracy of the inertial navigation system (INS) can be greatly improved when the inertial measurement unit (IMU) is effectively calibrated and compensated, such as gyro drifts and accelerometer biases. To reduce the requirement for turntable precision in the classical calibration method, a continuous dynamic self-calibration method based on a three-axis rotating frame for the hybrid inertial navigation system is presented. First, by selecting a suitable IMU frame, the error models of accelerometers and gyros are established. Then, by taking the navigation errors during rolling as the observations, the overall twenty-one error parameters of hybrid inertial navigation system (HINS) are identified based on the calculation of the intermediate parameter. The actual experiment verifies that the method can identify all error parameters of HINS and this method has equivalent accuracy to the classical calibration on a high-precision turntable. In addition, this method is rapid, simple and feasible.
ABSTRACT
The star sensor is a precise attitude measurement device for a spacecraft. Star tracking is the main and key working mode for a star sensor. However, during star tracking, false stars become an inevitable interference for star sensor applications, which may result in declined measurement accuracy. A false star detection and isolation algorithm in star tracking based on improved chi-square tests is proposed in this paper. Two estimations are established based on a Kalman filter and a priori information, respectively. The false star detection is operated through adopting the global state chi-square test in a Kalman filter. The false star isolation is achieved using a local state chi-square test. Semi-physical experiments under different trajectories with various false stars are designed for verification. Experiment results show that various false stars can be detected and isolated from navigation stars during star tracking, and the attitude measurement accuracy is hardly influenced by false stars. The proposed algorithm is proved to have an excellent performance in terms of speed, stability, and robustness.
ABSTRACT
Rheumatoid arthritis (RA) is characterized by inflammatory cell infiltration, fibroblast-like synoviocytes (FLS) invasive proliferation, and joint destruction. Cyclic GMP-AMP synthase (cGAS) is a cytosolic DNA sensor that induces immune activation. In this study, we examined whether cGAS plays a role in RA FLS. In this study, cGAS was overexpressed in RA-FLS compared with OA FLS. TNFα stimulation induced cGAS expression in RA FLS. Overexpression of cGAS promoted the proliferation and knockdown of cGAS inhibited the proliferation of RA FLS. cGAS overexpression enhanced the production of proinflammatory cytokines and matrix metalloproteinases (MMPs) as well as AKT and ERK phosphorylation in TNFα-stimulated FLS. In contrast, cGAS silencing inhibited production of proinflammatory cytokines and matrix metalloproteinases (MMPs) as well as AKT and ERK phosphorylation in TNFα-stimulated FLS. These results suggest that cGAS activates the AKT and ERK pathways to promote the inflammatory response of RA FLS, and the development of strategies targeting cGAS may have therapeutic potential for human RA.
Subject(s)
Arthritis, Rheumatoid/pathology , Inflammation/etiology , Nucleotidyltransferases/physiology , Osteoarthritis/pathology , Synovial Membrane/cytology , Cell Proliferation , Cells, Cultured , Humans , MAP Kinase Signaling System/physiology , Proto-Oncogene Proteins c-akt/physiology , Tumor Necrosis Factor-alpha/pharmacologyABSTRACT
Ceriops is a viviparous mangrove with widespread species Ceriops decandra and C. tagal, and an endemic species C. australis. Genetic diversity of the three species was screened in 30 populations collected from 23 locations in the Indo West Pacific (IWP) using Inter-simple sequence repeats (ISSR) and sequences of partial nuclear gene (G3pdh) and chloroplast DNA (trnV-trnM). At the species level, the total gene diversity (Ht) revealed by ISSRs was 0.270, 0.118, and 0.089 in C. decandra, C. tagal, and C. australis, respectively. A total of six haplotypes of G3pdh and five haplotypes of trnV-trnM were recognized among the three species. Only C. decandra was detected containing more than one haplotype from each sequence data set (four G3pdh haplotypes and three trnV-trnM haplotypes). At the population level, genetic diversity of Ceriops was relatively low inferred from ISSRs (He = 0.028, 0.023, and 0.053 in C. decandra, C. tagal, and C. australis, respectively). No haplotype diversity within population was detected from any of the three species. Cluster analysis based on ISSRs identified three major geographical groups in correspond to the East Indian Ocean (EIO), South China Sea (SCS), and North Australia (NA) in both C. decandra and C. tagal. The cladogram from DNA sequences also detected the same three geographical groups in C. decandra. Analysis of molecular variance (AMOVA) revealed that most of the total variation was accounted for by differentiation between the three major geographical regions of both C. decandra and C. tagal. The significant genetic structure may result from the geological events in these regions during the recent Pleistocene glaciations. This study also provided insights into the phylogenetics of Ceriops.
Subject(s)
Genetic Variation/genetics , Rhizophoraceae/genetics , Base Sequence , Genetic Markers , Genetics, Population , Genome, Plant , Minisatellite Repeats/genetics , Oceans and Seas , Pacific Ocean , Phylogeny , Polymorphism, Genetic , Rhizophoraceae/classification , Species SpecificityABSTRACT
Primulina tabacum Hance, is a critically endangered perennial endemic to limestone area in South China. Genetic variability within and among four extant populations of this species was assessed using AFLP markers. We expected a low genetic diversity level of this narrowly distributed species, but our results revealed that a high level of genetic diversity remains, both at population level (55.5% of markers polymorphic, H (E) = 0.220, I (S) = 0.321), and at species level (P = 85.6% of markers polymorphic, H (E) = 0.339, I (S) = 0.495), probably resulting from its refugial history and/or breeding system. High levels of genetic differentiation among populations was apparent based on Nei's genetic diversity analysis (G (st)=0.350). The restricted gene flow between populations is a potential reason for the high genetic differentiation. The population genetic diversity of P. tabacum revealed here has clear implications for conservation and management. To maintain present levels of genetic diversity, in situ conservation of all populations is necessary.