271 research outputs found
WPO-Net: Windowed Pose Optimization Network for Monocular Visual Odometry Estimation.
Visual odometry is the process of estimating incremental localization of the camera in 3-dimensional space for autonomous driving. There have been new learning-based methods which do not require camera calibration and are robust to external noise. In this work, a new method that do not require camera calibration called the "windowed pose optimization network" is proposed to estimate the 6 degrees of freedom pose of a monocular camera. The architecture of the proposed network is based on supervised learning-based methods with feature encoder and pose regressor that takes multiple consecutive two grayscale image stacks at each step for training and enforces the composite pose constraints. The KITTI dataset is used to evaluate the performance of the proposed method. The proposed method yielded rotational error of 3.12 deg/100 m, and the training time is 41.32 ms, while inference time is 7.87 ms. Experiments demonstrate the competitive performance of the proposed method to other state-of-the-art related works which shows the novelty of the proposed technique
Maximum power point tracking implementation by Dspace controller integrated through Z-Source inverter using particle swarm optimization technique for photovoltaic applications
Maximum Power Point Tracking (MPPT) technique is used to extract maximum power from the photovoltaic system. This paper involves working on an enhanced Particle Swarm Optimization (PSO) based MPPT method for the photovoltaic (PV) system integrated through Z-Source inverter. The main benefit of the proposed method is the diminishing of the steady-state oscillation when the maximum power point (MPP) is located. Additionally, during an extreme environmental condition, such as partial shading and large fluctuations of irradiance and temperature, the proposed method has the capability to track the MPP. This algorithm is implemented in dspace 1104 controller. MATLAB simulations are carried out under varying irradiance and temperature conditions to evaluate its effectiveness. Its performance is compared with a conventional method like Perturb and observe (P&O) method
Reproduction in the deep-sea penaeoid shrimp Aristeus alcocki Ramadan, 1938 (Decapoda: Penaeoidea: Aristeidae) from southwestern India
The Arabian red shrimp, Aristeus alcocki Ramadan, 1938, is one of the targets of commercial
trawlers operating since 2000 along the Indian coasts at depths of 200–850 m. We report
for the first time on the reproductive biology, insemination frequency, ovarian maturation,
gonadosomatic index (GSI), size at maturity, and fecundity of A. alcocki investigated macroscopically
and validated histologically using monthly trawl samples from the southwestern
coast of India. Females have an open thelycum with five gonad developmental stages (I to V)
and two stages (I and II) in males. A total of 4,170 specimens were examined and 68.6% of
the females had been inseminated (carapace length (CL) 22.0–53.0 mm), predominantly during
January to May. Females in stage I (immature) measured on average CL 25.5 ± 0.87 mm,
those in stages IV and V (mature) CL 41.5 ± 0.62 mm. Immature males were smaller, mean
CL 20.5 ± 0.5 mm. Size at first sexual maturity for females was estimated as CL 35.07 mm
(total length (TL) 120–170 mm) and the inseminated specimens (CL50is) were mature at CL
31.45 mm using a non-linear method. The smallest mature female was CL 35 mm, whereas
the size at maturity (CL50ms) of males was estimated as CL 19.6 mm (TL 75–96 mm). We also
report synchronous oocyte development and continuous spawning activity with a peak during
January to April. Information on the reproduction of this deep-water shrimp will help fishery
managers estimate the stock sustainability and develop resource management measures
Economical cultivation system of microalgae Spirulina platensis for lipid production
The marine algae Spirulina platensis was cultured in a medium of palm oil mill effluent (POME) and the production of lipid in the biomass was optimized. Among 7 species Spirulina platensis was isolated from the marine sample which have greater lipid potential was collected from Pantai Teluk Cempedak, Kuantan which is located at East Coast region of Pahang state. At 28+2 °C, the maximum lipid content in the biomass harvested at the end of a 15 days batch culture was quantified with the following values of the experimental factors: POME concentration with (10%, 20% and 30%) (v/v) and light intensity (3,000 lux, 4,000 lux, 5,000 lux). Under the optimized conditions with 20% of POME, the maximum dry mass concentration of the was 754.5 mg L−1 with lipid 34.5% production on day 13 of a batch culture, declining to ∼687 mg L−1 on day 15. At 5,000 lux light intensities, the maximum yield obtained was 854.6 mg L−1 with lipid 35.8% production on day 14, it declined to 732.8 mg L−1 on day 15
Analysis of bioactive compounds from Gracilaria foliifera based on lunar phases
Gracilaria foliifera, sustainable renewable resources in the marine environment. Gracilaria, a genus of red algae, notable for its economic importance as an agarophyte. In the present study, experiments were performed to investigate the phytochemical constituents of Gracilaria foliifera. Samples were collected during three different lunar phases namely new moon, full moon and between days. The collected seaweeds were shade dried and extracted by ethyl acetate. The crude metabolites are subjected to phytochemical analysis, antioxidant activity, and qualitative analysis of the compounds by TLC. Further the crude extract was evaluated by GCMS. Among the different lunar phases, the presence of phytochemical compounds, antioxidants activity, is maximum during the full moon days which also showed appreciable amount than the samples collected during new moon phase and transition phase
Evidence that non-syndromic familial tall stature has an oligogenic origin including ciliary genes
Human growth is a complex trait. A considerable number of gene defects have been shown to cause short stature, but there are only few examples of genetic causes of non-syndromic tall stature. Besides rare variants with large effects and common risk alleles with small effect size, oligogenic effects may contribute to this phenotype. Exome sequencing was carried out in a tall male (height 3.5 SDS) and his parents. Filtered damaging variants with high CADD scores were validated by Sanger sequencing in the trio and three other affected and one unaffected family members. Network analysis was carried out to assess links between the candidate genes, and the transcriptome of murine growth plate was analyzed by microarray as well as RNA Seq. Heterozygous gene variants in CEP104, CROCC, NEK1, TOM1L2, and TSTD2 predicted as damaging were found to be shared between the four tall family members. Three of the five genes (CEP104, CROCC, and NEK1) belong to the ciliary gene family. All genes are expressed in mouse growth plate. Pathway and network analyses indicated close functional connections. Together, these data expand the spectrum of genes with a role in linear growth and tall stature phenotypes.Genetics of disease, diagnosis and treatmen
Characterization of AKT independent effects of the synthetic AKT inhibitors SH-5 and SH-6 using an integrated approach combining transcriptomic profiling and signaling pathway perturbations
<p>Abstract</p> <p>Background</p> <p>Signal transduction processes mediated by phosphatidyl inositol phosphates affect a broad range of cellular processes such as cell cycle progression, migration and cell survival. The protein kinase AKT is one of the major effectors in this signaling network. Chronic AKT activation contributes to oncogenic transformation and tumor development. Therefore, analogs of phosphatidyl inositol phosphates (PIAs) were designed as new small drugs to block AKT activity for cancer treatment. Here we characterize the biological effects of the PIAs SH-5 and SH-6 in colorectal cancer cell lines.</p> <p>Methods</p> <p>Serum-starved or serum-supplemented human colorectal cancer cell lines SW480, HT29 and HCT116 were exposed to SH-5 and SH-6. AKT activation was determined by western blotting. Cell viability was assessed using a colorimetric XTT-based assay, apoptosis and cell cycle changes were monitored by FACS analysis. The dynamics of cell morphology alterations was evaluated by confocal and time-lapse microscopy. Transcriptional changes due to inhibitor treatment were analyzed using Affymetrix HG-U133A microarrays and RT-PCR.</p> <p>Results</p> <p>While the PIAs clearly reduce AKT phosphorylation in serum starved cells, we did not observe a significant reduction under serum supplemented conditions, giving us the opportunity to analyze AKT independent effects of these compounds. Both inhibitors induce broadly the same morphological alterations, in particular changes in cell shape and formation of intracellular vesicles. Moreover, we observed the induction of binucleated cells specifically in the SW480 cell line. Gene expression analysis revealed transcriptional alterations, which are mostly cell line specific. In accordance to the phenotype we found a gene group associated with mitosis and spindle organization down regulated in SW480 cells, but not in the other cell lines. A bioinformatics analysis using the Connectivity Map linked the gene expression pattern of the inhibitor treated SW480 cells to PKC signaling. Using confocal laser scanning microscopy and time lapse recording we identified a specific defect in the last step of the cytokinesis as responsible for the binucleation.</p> <p>Conclusions</p> <p>The PIAs SH-5 and SH-6 impinge on additional cellular targets apart from AKT in colorectal cancer cells. The effects are mostly cell line specific and have an influence at the outcome of the treatment. In view of potential clinical trials it will be necessary to take these diverse effects into consideration to optimize patient treatment.</p
Angelman Syndrome Protein UBE3A Interacts with Primary Microcephaly Protein ASPM, Localizes to Centrosomes and Regulates Chromosome Segregation
Many proteins associated with the phenotype microcephaly have been localized to the centrosome or linked to it functionally. All the seven autosomal recessive primary microcephaly (MCPH) proteins localize at the centrosome. Microcephalic osteodysplastic primordial dwarfism type II protein PCNT and Seckel syndrome (also characterized by severe microcephaly) protein ATR are also centrosomal proteins. All of the above findings show the importance of centrosomal proteins as the key players in neurogenesis and brain development. However, the exact mechanism as to how the loss-of-function of these proteins leads to microcephaly remains to be elucidated. To gain insight into the function of the most commonly mutated MCPH gene ASPM, we used the yeast two-hybrid technique to screen a human fetal brain cDNA library with an ASPM bait. The analysis identified Angelman syndrome gene product UBE3A as an ASPM interactor. Like ASPM, UBE3A also localizes to the centrosome. The identification of UBE3A as an ASPM interactor is not surprising as more than 80% of Angelman syndrome patients have microcephaly. However, unlike in MCPH, microcephaly is postnatal in Angelman syndrome patients. Our results show that UBE3A is a cell cycle regulated protein and its level peaks in mitosis. The shRNA knockdown of UBE3A in HEK293 cells led to many mitotic abnormalities including chromosome missegregation, abnormal cytokinesis and apoptosis. Thus our study links Angelman syndrome protein UBE3A to ASPM, centrosome and mitosis for the first time. We suggest that a defective chromosome segregation mechanism is responsible for the development of microcephaly in Angelman syndrome
Nonuniform sampling and maximum entropy reconstruction in multidimensional NMR
NMR spectroscopy is one of the most powerful and versatile analytic tools available to chemists. The discrete Fourier transform (DFT) played a seminal role in the development of modern NMR, including the multidimensional methods that are essential for characterizing complex biomolecules. However, it suffers from well-known limitations: chiefly the difficulty in obtaining high-resolution spectral estimates from short data records. Because the time required to perform an experiment is proportional to the number of data samples, this problem imposes a sampling burden for multidimensional NMR experiments. At high magnetic field, where spectral dispersion is greatest, the problem becomes particularly acute. Consequently multidimensional NMR experiments that rely on the DFT must either sacrifice resolution in order to be completed in reasonable time or use inordinate amounts of time to achieve the potential resolution afforded by high-field magnets.Maximum entropy (MaxEnt) reconstruction is a non-Fourier method of spectrum analysis that can provide high-resolution spectral estimates from short data records. It can also be used with nonuniformly sampled data sets. Since resolution is substantially determined by the largest evolution time sampled, nonuniform sampling enables high resolution while avoiding the need to uniformly sample at large numbers of evolution times. The Nyquist sampling theorem does not apply to nonuniformly sampled data, and artifacts that occur with the use of nonuniform sampling can be viewed as frequency-aliased signals. Strategies for suppressing nonuniform sampling artifacts include the careful design of the sampling scheme and special methods for computing the spectrum. Researchers now routinely report that they can complete an N-dimensional NMR experiment 3 times faster (a 3D experiment in one ninth of the time). As a result, high-resolution three- and four-dimensional experiments that were prohibitively time consuming are now practical. Conversely, tailored sampling in the indirect dimensions has led to improved sensitivity.Further advances in nonuniform sampling strategies could enable further reductions in sampling requirements for high resolution NMR spectra, and the combination of these strategies with robust non-Fourier methods of spectrum analysis (such as MaxEnt) represent a profound change in the way researchers conduct multidimensional experiments. The potential benefits will enable more advanced applications of multidimensional NMR spectroscopy to study biological macromolecules, metabolomics, natural products, dynamic systems, and other areas where resolution, sensitivity, or experiment time are limiting. Just as the development of multidimensional NMR methods presaged multidimensional methods in other areas of spectroscopy, we anticipate that nonuniform sampling approaches will find applications in other forms of spectroscopy
Mutational mechanisms shaping the coding and noncoding genome of germinal center derived B-cell lymphomas
B cells have the unique property to somatically alter their immunoglobulin (IG) genes by V(D)J recombination, somatic hypermutation (SHM) and class-switch recombination (CSR). Aberrant targeting of these mechanisms is implicated in lymphomagenesis, but the mutational processes are poorly understood. By performing whole genome and transcriptome sequencing of 181 germinal center derived B-cell lymphomas (gcBCL) we identified distinct mutational signatures linked to SHM and CSR. We show that not only SHM, but presumably also CSR causes off-target mutations in non-IG genes. Kataegis clusters with high mutational density mainly affected early replicating regions and were enriched for SHM- and CSR-mediated off-target mutations. Moreover, they often co-occurred in loci physically interacting in the nucleus, suggesting that mutation hotspots promote increased mutation targeting of spatially co-localized loci (termed hypermutation by proxy). Only around 1% of somatic small variants were in protein coding sequences, but in about half of the driver genes, a contribution of B-cell specific mutational processes to their mutations was found. The B-cell-specific mutational processes contribute to both lymphoma initiation and intratumoral heterogeneity. Overall, we demonstrate that mutational processes involved in the development of gcBCL are more complex than previously appreciated, and that B cell-specific mutational processes contribute via diverse mechanisms to lymphomagenesis
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