90 research outputs found
Exploiting Data and Human Knowledge for Predicting Wildlife Poaching
Poaching continues to be a significant threat to the conservation of wildlife
and the associated ecosystem. Estimating and predicting where the poachers have
committed or would commit crimes is essential to more effective allocation of
patrolling resources. The real-world data in this domain is often sparse, noisy
and incomplete, consisting of a small number of positive data (poaching signs),
a large number of negative data with label uncertainty, and an even larger
number of unlabeled data. Fortunately, domain experts such as rangers can
provide complementary information about poaching activity patterns. However,
this kind of human knowledge has rarely been used in previous approaches. In
this paper, we contribute new solutions to the predictive analysis of poaching
patterns by exploiting both very limited data and human knowledge. We propose
an approach to elicit quantitative information from domain experts through a
questionnaire built upon a clustering-based division of the conservation area.
In addition, we propose algorithms that exploit qualitative and quantitative
information provided by the domain experts to augment the dataset and improve
learning. In collaboration with World Wild Fund for Nature, we show that
incorporating human knowledge leads to better predictions in a conservation
area in Northeastern China where the charismatic species is Siberian Tiger. The
results show the importance of exploiting human knowledge when learning from
limited data.Comment: COMPASS 201
Evaluation of Fengyun-3C Soil Moisture Products Using In-Situ Data from the Chinese Automatic Soil Moisture Observation Stations: A Case Study in Henan Province, China
Soil moisture (SM) products derived from passive satellite missions are playing an increasingly important role in agricultural applications, especially crop monitoring and disaster warning. Evaluating the dependability of satellite-derived soil moisture products on a large scale is crucial. In this study, we assessed the level 2 (L2) SM product from the Chinese Fengyun-3C (FY-3C) radiometer against in-situ measurements collected from the Chinese Automatic Soil Moisture Observation Stations (CASMOS) during a one-year period from 1 January 2016 to 31 December 2016 across Henan in China. In contrast, we also investigated the skill of the Advanced Microwave Scanning Radiometer 2 (AMSR2) and Soil Moisture Active/Passive (SMAP) SM products simultaneously. Four statistical parameters were used to evaluate these products’ reliability: mean difference, root-mean-square error (RMSE), unbiased RMSE (ubRMSE), and the correlation coefficient. Our assessment results revealed that the FY-3C L2 SM product generally showed a poor correlation with the in-situ SM data from CASMOS on both temporal and spatial scales. The AMSR2 L3 SM product of JAXA (Japan Aerospace Exploration Agency) algorithm had a similar level of skill as FY-3C in the study area. The SMAP L3 SM product outperformed the FY-3C temporally but showed lower performance in capturing the SM spatial variation. A time-series analysis indicated that the correlations and estimated error varied systematically through the growing periods of the key crops in our study area. FY-3C L2 SM data tended to overestimate soil moisture during May, August, and September when the crops reached maximum vegetation density and tended to underestimate the soil moisture content during the rest of the year. The comparison between the statistical parameters and the ground vegetation water content (VWC) further showed that the FY-3C SM product performed much better under a low VWC condition (0.3 kg/m2), and the performance generally decreased with increased VWC. To improve the accuracy of the FY-3C SM product, an improved algorithm that can better characterize the variations of the ground VWC should be applied in the future
Machine Learning Based Crop Drought Mapping System by UAV Remote Sensing RGB Imagery
Water stress has adverse effects on crop growth and yield, where its monitoring plays a vital role in precision crop management. This paper aims at initially exploiting the potentials of UAV aerial RGB image in crop water stress assessment by developing a simple but effective supervised learning system. Various techniques are seamlessly integrated into the system including vegetation segmentation, feature engineering, Bayesian optimization and Support Vector Machine (SVM) classifier. In particular, wheat pixels are first segmented from soil background by using the classical vegetation index thresholding. Rather than performing pixel-wise classification, pixel squares of appropriate dimension are defined as samples, from which various features for pure vegetation pixels are extracted including spectral and color index (CI) features. SVM with Bayesian optimization is adopted as the classifier. To validate the developed system, a Unmanned Aerial Vehicle (UAV) survey is performed to collect high-resolution atop canopy RGB imageries by using DJI S1000 for the experimental wheat fields of Gucheng town, Heibei Province, China. Two levels of soil moisture were designed after seedling establishment for wheat plots by using intelligent irrigation and rain shelter, where field measurements were to obtain ground soil water ratio for each wheat plot. Comparative experiments by three-fold cross-validation demonstrate that pixel-wise classification, with a high computation load, can only achieve an accuracy of 82.8% with poor F1 score of 71.7%; however, the developed system can achieve an accuracy of 89.9% with F1 score of 87.7% by using only spectral intensities, and the accuracy can be further improved to 92.8% with F1 score of 91.5% by fusing both spectral intensities and CI features. Future work is focused on incorporating more spectral information and advanced feature extraction algorithms to further improve the performance
Clinical application of Kirschner wires combined with 5-Ethibond fixation for patella fractures
BackgroundPatella fractures that require surgery are conventionally treated using Kirschner wires (K-wires) and stainless steel wires. In recent years, the nonabsorbable polyester has been reported to have excellent outcomes clinically. Therefore, the goal of our study was to evaluate the effects of Kirschner wires combined with 5-Ethibond on treating patellar fractures.MethodsFrom July 2018 to January 2022, 22 patella fracture patients were treated with Kirschner wires combined with 5-Ethibond. Radiographs of the knees were used to evaluate fracture healing and hardware complications. The clinical results were evaluated through the functional score, knee joint range of motion (ROM), and Bostman patella fracture functional score.ResultsThe average age of patients was 57.4 ± 11.9 (range 33–74) years. The mean follow-up time was 15.2 ± 7.6 (range 4–36) months. The mean operation time was 56.8 ± 8.7 (range 45–80) min. The entire patients had bony union at an average of 10.5 ± 1.9 (range 8–14) weeks. At the final follow-up, the mean range of postoperative ROM was 123.4° ± 14.6° (range 95°–140°), and the functional score was 28.7 ± 1.2 (range 26–30) points. No patient exhibited internal fixation failure, and no symptomatic implants or skin complications were recorded.ConclusionsThe fixation approach using K-wires combined with 5-Ethibond has a lower complication rate and delivers superior clinical results. This research reveals that such technology is a safe and prospective substitute for conventional metal fixation approaches
Whole-genome sequencing of cultivated and wild peppers provides insights into Capsicum domestication and specialization
As an economic crop, pepper satisfies people's spicy taste and has medicinal uses worldwide. To gain a better understanding of Capsicum evolution, domestication, and specialization, we present here the genome sequence of the cultivated pepper Zunla-1 (C. annuum L.) and its wild progenitor Chiltepin (C. annuum var. glabriusculum). We estimate that the pepper genome expanded similar to 0.3 Mya (with respect to the genome of other Solanaceae) by a rapid amplification of retrotransposons elements, resulting in a genome comprised of similar to 81% repetitive sequences. Approximately 79% of 3.48-Gb scaffolds containing 34,476 protein-coding genes were anchored to chromosomes by a high-density genetic map. Comparison of cultivated and wild pepper genomes with 20 resequencing accessions revealed molecular footprints of artificial selection, providing us with a list of candidate domestication genes. We also found that dosage compensation effect of tandem duplication genes probably contributed to the pungent diversification in pepper. The Capsicum reference genome provides crucial information for the study of not only the evolution of the pepper genome but also, the Solanaceae family, and it will facilitate the establishment of more effective pepper breeding programs
The effect of curing conditions on the expansion efficiency of MgO expansion agent
In order to further promote the research and application of MgO expansion agent in concrete field, this paper carried out the effect of different humidity and temperature conditions on the expansion properties of mortar and mortar specimens mixed with MgO expansion agent. In addition, the mechanism of the factors affecting the sensitivity of the MgO expansion agent is revealed by combining microscopic technology. The results show that the higher the curing temperature and the greater the curing humidity, the greater the expansion efficiency of the MgO expansion agent. The temperature of 20~40°C has no obvious effect on the efficiency of the MgO expansion agent, but the expansion value of the specimen doubles as the temperature rises to 40~80°C. Besides, the higher the curing humidity, the better the expansion efficiency of the MgO expansion agent, but the MgO expansion agent is more sensitive to the low humidity environment, and the specimen shrinks in the lower humidity environment (RH=60%)
Validation and Calibration of QAA Algorithm for CDOM Absorption Retrieval in the Changjiang (Yangtze) Estuarine and Coastal Waters
Distribution, migration and transformation of chromophoric dissolved organic matter (CDOM) in coastal waters are closely related to marine biogeochemical cycle. Ocean color remote sensing retrieval of CDOM absorption coefficient (ag(λ)) can be used as an indicator to trace the distribution and variation characteristics of the Changjiang diluted water, and further to help understand estuarine and coastal biogeochemical processes in large spatial and temporal scales. The quasi-analytical algorithm (QAA) has been widely applied to remote sensing inversions of optical and biogeochemical parameters in water bodies such as oceanic and coastal waters, however, whether the algorithm can be applicable to highly turbid waters (i.e., Changjiang estuarine and coastal waters) is still unknown. In this study, large amounts of in situ data accumulated in the Changjiang estuarine and coastal waters from 9 cruise campaigns during 2011 and 2015 are used to verify and calibrate the QAA. Furthermore, the QAA is remodified for CDOM retrieval by employing a CDOM algorithm (QAA_CDOM). Consequently, based on the QAA and the QAA_CDOM, we developed a new version of algorithm, named QAA_cj, which is more suitable for highly turbid waters, e.g., Changjiang estuarine and coastal waters, to decompose ag from adg (CDOM and non-pigmented particles absorption coefficient). By comparison of matchups between Geostationary Ocean Color Imager (GOCI) retrievals and in situ data, it reveals that the accuracy of retrievals from calibrated QAA is significantly improved. The root mean square error (RMSE), mean absolute relative error (MARE) and bias of total absorption coefficients (a(λ)) are lower than 1.17, 0.52 and 0.66 m−1, and ag(λ) at 443 nm are lower than 0.07, 0.42 and 0.018 m−1. These results indicate that the calibrated algorithm has a better applicability and prospect for highly turbid coastal waters with extremely complicated optical properties. Thus, reliable CDOM products from the improved QAA_cj can advance our understanding of the land-ocean interaction process by earth observations in monitoring spatial-temporal distribution of the river plume into sea
A systematic review of suture-button versus syndesmotic screw in the treatment of distal tibiofibular syndesmosis injury
Abstract Background Now, using a suture-button device to treat distal tibiofibular syndesmotic injuries is overwhelming due to its advantages over screw fixation. Current systematic review was conducted to make a comparison between suture-button fixation and traditionally screw fixation in the treatment of syndesmotic injuries. The outcomes included functional outcomes, implant removal, implant failure, malreduction, post-operative complications (except implant failure and malreduction), and cost-effectiveness aspects. Method A literature search in the electronic databases of Medline, Embase, the Cochrane Library, Web of Science was conducted to identify studies until March 2017. The references of the included articles were also checked for potentially relevant studies. Only English articles were included. We followed the Preferred Reporting Items for Systematics reviews and Meta-Analysis (PRISMA) guidelines in this review. Results Finally, 10 studies were identified, encompassing a total of 390 patients. The mean American Orthopaedic Foot and Ankle Society ankle score (AOFAS) score of 150 patients treated with the suture-button device was 91.06 points, with an average follow-up of 17.58Â months, and the mean AOFAS score of 150 patients treated with syndesmotic screws was 87.78 points, with an average follow-up of 17.73Â months. Implant removal was reported in 5 of 134 (3.7%) patients treated with the suture-button device, and in 54 of 134 (40.2%) patients treated with the syndesmotic screw. No patient in the suture-button fixation group had implant failure, however the rate of implant failure in the screw fixation group was 30.9%. Malreduction was reported in 1 of 93 (1.0%) patients treated with the suture-button device, and in 12 of 95 (12.6%) patients treated with the syndesmotic screw. The rate of post-operative complications in the suture-button fixation group was 12.0% and 16.4% in the screw fixation group. There was only one publication demonstrated about cost-effectiveness aspects, it showed that patients treated with the suture-button device spent on average $1482 less and had a higher quality of life by 0.058 quality-adjusted life-year compared with patients who received fixation with 2 syndesmotic screws in supination-external rotation type 4 injuries. Conclusion Based on our research, though the suture-button fixation group had similar functional outcome (measured on the AOFAS score) and post-operative complication rate compared with the syndesmotic screw fixation group, the suture-button device could lead to better objective range of motion (ROM) measurements and earlier return to work. Besides, the suture-button fixation group had lower rate of implant removal, implant failure, and malreduction. However, high-quality randomized controlled trials with more uniformity in outcome reporting are desirable to determine the long-term effects and cost-effectiveness of the suture-button device
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