45 research outputs found
3D Active Metric-Semantic SLAM
In this letter, we address the problem of exploration and metric-semantic
mapping of multi-floor GPS-denied indoor environments using Size Weight and
Power (SWaP) constrained aerial robots. Most previous work in exploration
assumes that robot localization is solved. However, neglecting the state
uncertainty of the agent can ultimately lead to cascading errors both in the
resulting map and in the state of the agent itself. Furthermore, actions that
reduce localization errors may be at direct odds with the exploration task. We
propose a framework that balances the efficiency of exploration with actions
that reduce the state uncertainty of the agent. In particular, our algorithmic
approach for active metric-semantic SLAM is built upon sparse information
abstracted from raw problem data, to make it suitable for SWaP-constrained
robots. Furthermore, we integrate this framework within a fully autonomous
aerial robotic system that achieves autonomous exploration in cluttered, 3D
environments. From extensive real-world experiments, we showed that by
including Semantic Loop Closure (SLC), we can reduce the robot pose estimation
errors by over 90% in translation and approximately 75% in yaw, and the
uncertainties in pose estimates and semantic maps by over 70% and 65%,
respectively. Although discussed in the context of indoor multi-floor
exploration, our system can be used for various other applications, such as
infrastructure inspection and precision agriculture where reliable GPS data may
not be available.Comment: Submitted to RA-L for revie
Identification and characterization of psychrotrophic strain of Planococcus maritimus for glucosylated C30 carotenoid production
Cold-adapted bacteria produce various pigments as their adaptive strategy. Here, we studied an aerobic, gram-positive motile coccoid bacterial strain KK21, isolated from the Siachen, Himalayas and characterized the major pigments present in it. The KK21 strain is capable of growth in a broad range of temperature (-4 to 37°C), pH (6.0-13.0) and salinity (0.5-8%). Phylogenetic analysis based on 16S rRNA gene sequence showed that it belongs to the genus Planococcus and closely related to P. maritimus. Total pigment extraction was best found in polar methanol. Alanine among amino acids, NaCl among inorganic salts and evening primrose amongst oils best supported the pigment production at 10°C after 6 days in BHI at neutral pH of 7.0. Maximum pigment production was recorded at 3% of NaCl concentration. In photoprotection activity, radiation exposed plates showed increased colony forming units and more than 3.5 times of total carotenoid production after 15 min exposure compared to the control group. Detailed characterization of orange pigment was done systematically by TLC, HPLC and MALDI-TOF. Chromatographic and MALDI-TOF data have revealed the exclusive presence of glycosylated C30-carotenoid in P. maritimus KK21 with m/z of 655.871
Sensitivity of a real-time PCR method for the detection of transgenes in a mixture of transgenic and non-transgenic seeds of papaya (\u3cem\u3eCarica papaya\u3c/em\u3e L.)
Background
Genetically engineered (GE) ringspot virus-resistant papaya cultivars âRainbowâ and âSunUpâ have been grown in Hawaiâi for over 10 years. In Hawaiâi, the introduction of GE papayas into regions where non-GE cultivars are grown and where feral non-GE papayas exist have been accompanied with concerns associated with transgene flow. Of particular concern is the possibility of transgenic seeds being found in non-GE papaya fruits via cross-pollination. Development of high-throughput methods to reliably detect the adventitious presence of such transgenic material would benefit both the scientific and regulatory communities. Results
We assessed the accuracy of using conventional qualitative polymerase chain reaction (PCR) as well as real-time PCR-based assays to quantify the presence of transgenic DNA from bulk samples of non-GE papaya seeds. In this study, an optimized method of extracting high quality DNA from dry seeds of papaya was standardized. A reliable, sensitive real-time PCR method for detecting and quantifying viral coat protein (cp) transgenes in bulk seed samples utilizing the endogenous papain gene is presented. Quantification range was from 0.01 to 100 ng/ÎŒl of GE-papaya DNA template with a detection limit as low as 0.01% (10 pg). To test this system, we simulated transgene flow using known quantities of GE and non-GE DNA and determined that 0.038% (38 pg) GE papaya DNA could be detected using real-time PCR. We also validated this system by extracting DNA from known ratios of GE seeds to non-GE seeds of papaya followed by real-time PCR detection and observed a reliable detection limit of 0.4%. Conclusions
This method for the quick and sensitive detection of transgenes in bulked papaya seed lots using conventional as well as real-time PCR-based methods will benefit numerous stakeholders. In particular, this method could be utilized to screen selected fruits from maternal non-GE papaya trees in Hawaiâi for the presence of transgenic seed at typical regulatory threshold levels. Incorporation of subtle differences in primers and probes for variations in cp worldwide should allow this method to be utilized elsewhere when and if deregulation of transgenic papaya occurs
Physically active men show better semen parameters than their sedentary counterparts
CITATION: Lalinde-Acevedo, P. C., et al. 2017. Physically active men show better semen parameters than their sedentary counterparts. International Journal of Fertility and Sterility, 11(3):156-165, doi:10.22074/ijfs.2017.4881.The original publication is available at http://ijfs.irBackground:
The quality of semen depends upon several factors such as environment, life style, physical activity, age, and occupation. The aim of this study was to analyze and compare the conventional and functional semen parameters in men practicing vigorous physical activity to those of sedentary men.
Materials and Methods:
In this descriptive cross-sectional study, semen samples of 17 physically active men and 15 sedentary men were collected for analysis. Semen analysis was performed according to the World Health Organization (WHO) guidelines, while functional parameters were evaluated by flow cytometry.
Results:
Results showed that several semen parameters (semen volume, viability, progressive motility, total motility, normal morphology, and moribund cells) were superior in the physically active group in comparison with the sedentary group. Semen parameters such as viability, progressive motility and total motility, as well as the percentage of moribund spermatozoa were significantly different between both groups. However, sperm DNA damage, lipid peroxidation and mitochondrial potential were not significantly different among the groups.
Conclusion:
Nevertheless, the physical activity shows better semen parameters than sedentary group. Taken together, our results demonstrate that regular physical activity has beneficial impact in sperm fertility parameters and such a life style can enhance the fertility status of men.http://ijfs.ir/journal/article/abstract/4881Publisher's versio
Decimetre-scaled spectrophotometric properties of the nucleus of comet 67P/Churyumov-Gerasimenko from OSIRIS observations
We present the results of the photometric and spectrophotometric properties of the 67P/Churyumov-Gerasimenko nucleus derived with the Optical, Spectroscopic and Infrared Remote Imaging System instrument during the closest fly-by over the comet, which took place on 2015 February 14 at a distance of ~6 km from the surface. Several images covering the 0°-33° phase angle range were acquired, and the spatial resolution achieved was 11 cm pixel-1. The flown-by region is located on the big lobe of the comet, near the borders of the Ash, Apis and Imhotep regions. Our analysis shows that this region features local heterogeneities at the decimetre scale. We observed difference of reflectance up to 40 per cent between bright spots and sombre regions, and spectral slope variations up to 50 per cent. The spectral reddening effect observed globally on the comet surface by Fornasier et al. (2015) is also observed locally on this region, but with a less steep behaviour. We note that numerous metre-sized boulders, which exhibit a smaller opposition effect, also appear spectrally redder than their surroundings. In this region, we found no evidence linking observed bright spots to exposed water-ice-rich material.We fitted our data set using the Hapke 2008 photometric model. The region overflown is globally as dark as the whole nucleus (geometric albedo of 6.8 per cent) and it has a high porosity value in the uppermost layers (86 per cent). These results of the photometric analysis at a decimetre scale indicate that the photometric properties of the flown-by region are similar to those previously found for the whole nucleus