5,904 research outputs found
Robust Ground Target Detection by SAR and IR Sensor Fusion Using Adaboost-Based Feature Selection
Long-range ground targets are difficult to detect in a noisy cluttered environment using either synthetic aperture radar (SAR) images or infrared (IR) images. SAR-based detectors can provide a high detection rate with a high false alarm rate to background scatter noise. IR-based approaches can detect hot targets but are affected strongly by the weather conditions. This paper proposes a novel target detection method by decision-level SAR and IR fusion using an Adaboost-based machine learning scheme to achieve a high detection rate and low false alarm rate. The proposed method consists of individual detection, registration, and fusion architecture. This paper presents a single framework of a SAR and IR target detection method using modified Boolean map visual theory (modBMVT) and feature-selection based fusion. Previous methods applied different algorithms to detect SAR and IR targets because of the different physical image characteristics. One method that is optimized for IR target detection produces unsuccessful results in SAR target detection. This study examined the image characteristics and proposed a unified SAR and IR target detection method by inserting a median local average filter (MLAF, pre-filter) and an asymmetric morphological closing filter (AMCF, post-filter) into the BMVT. The original BMVT was optimized to detect small infrared targets. The proposed modBMVT can remove the thermal and scatter noise by the MLAF and detect extended targets by attaching the AMCF after the BMVT. Heterogeneous SAR and IR images were registered automatically using the proposed RANdom SAmple Region Consensus (RANSARC)-based homography optimization after a brute-force correspondence search using the detected target centers and regions. The final targets were detected by feature-selection based sensor fusion using Adaboost. The proposed method showed good SAR and IR target detection performance through feature selection-based decision fusion on a synthetic database generated by OKTAL-SE.1146Ysciescopu
The archaeological contribution of forensic craniofacial reconstruction to a portrait drawing of a Korean historical figure
Craniofacial reconstruction (CFR) is a technique used to rebuild the living facial appearance onto a skull in order to recognise or identify an individual. This technique is primarily employed in forensic investigation, but also utilised in archaeological research to recreate the faces of paleontological and archaeological humans. In this study, the face of a 17th century historical figure from Korea was reconstructed utilising computerized tomography from the mummified remains. A geographic surface comparison programme was employed to evaluate the accuracy of the CFR produced using a three-dimensional computerized modelling system. Analysis of the facial tissue depth discrepancies demonstrated that the CFR may have acceptable resemblance to the living face of the historical individual. Using computerised graphic technology, the CFR outcome, along with the archaeological information about the hair style, ornaments, and dress discovered in the tomb, a portrait-styled in the typical drawing trend from the era was created. The research suggests that current CFR techniques can provide an accurate portrait drawing of historical figures in Korea
Two maternal origins of Chinese domestic light-body type goose
China is particularly rich in goose genetic resources. The systemic study of genetic diversity and origin of Chinese indigenous geese will provide important scientific basis for the conservation, utilization of resources and human history. The 521 bp control region (D-loop) of mitochondrial DNA from 13 lightbody type breeds was sequenced. The results showed that in the D-loop region of the 13 gray goose breeds, the content of T, C, A and G nucleotides was 23.8, 29.0, 32.2 and 15.1%, respectively. The average haplotype diversity (Hd) and nucleotide diversity (Pi) of domestic geese were 0.2153 and 0.00046, respectively. The 13 light-body type breeds had bigger nucleotide variance value among populations than the value within populations and all the breeds did not exist population expansion.Shared haplotype analysis and systemic systematic evolution analysis revealed that Chinese lightbody type domestic goose owned two maternal origins. YL goose breed originated from greylag goose (anser anser), and the other 12 light- body type goose breeds originated from swan goose (anser cygnoides)
Mobile Communication Signatures of Unemployment
The mapping of populations socio-economic well-being is highly constrained by
the logistics of censuses and surveys. Consequently, spatially detailed changes
across scales of days, weeks, or months, or even year to year, are difficult to
assess; thus the speed of which policies can be designed and evaluated is
limited. However, recent studies have shown the value of mobile phone data as
an enabling methodology for demographic modeling and measurement. In this work,
we investigate whether indicators extracted from mobile phone usage can reveal
information about the socio-economical status of microregions such as districts
(i.e., average spatial resolution < 2.7km). For this we examine anonymized
mobile phone metadata combined with beneficiaries records from unemployment
benefit program. We find that aggregated activity, social, and mobility
patterns strongly correlate with unemployment. Furthermore, we construct a
simple model to produce accurate reconstruction of district level unemployment
from their mobile communication patterns alone. Our results suggest that
reliable and cost-effective economical indicators could be built based on
passively collected and anonymized mobile phone data. With similar data being
collected every day by telecommunication services across the world,
survey-based methods of measuring community socioeconomic status could
potentially be augmented or replaced by such passive sensing methods in the
future
Bioreducible Polymer-delivered siRNA Targeting MMP-9: Suppression of Granulation Tissue Formation after Bare Metallic Stent Placement in a Rat Urethral Model
To evaluate the effectiveness of small interfering RNA (siRNA) targeting matrix metalloproteinase 9 (MMP-9) in suppressing granulation tissue formation caused by bare metallic stent placement in a rat urethral model. All experiments were approved by the committee of animal research. In 20 Sprague-Dawley male rats (weight range, 300-350 g), a self-expanding metallic bare stent was inserted in the urethra with fluoroscopic guidance. One group of 10 rats (group A) was treated with MMP-9 siRNA/bioreducible branched polyethylenimine-disulfide cross-linked-indocyanine green (bioreducible BPEI-SS-ICG), while the other group of 10 rats (group B) received control siRNA/bioreducible BPEI-SS-ICG treatment. All rats were sacrificed at 4 weeks. The therapeutic effectiveness of the MMP-9 siRNA/bioreducible BPEI-SS-ICG complex was assessed by comparing the two results of retrograde urethrography, histologic examination, and quantification of MMP-9 by using zymography and Western blot analysis between the two groups. The Mann-Whitney U test was used to evaluate differences. Stent placement was successful in all rats without a single case of migration at follow-up. Retrograde urethrography performed 4 weeks after stent placement demonstrated significantly larger luminal diameters of the urethra within the stents in group A compared with those in group B (P = .011). Histologic analysis revealed that the mean percentage of granulation tissue area (P < .001), mean number of epithelial layers (P < .001), and mean thickness of submucosal fibrosis (P < .001) were significantly decreased in group A compared with group B. Meanwhile, the mean density of inflammatory cell infiltration did not significantly differ between the two groups (P = .184). Quantitative analysis disclosed MMP-9 levels to be lower in group A relative to group B, indicating positive inhibition of MMP-9 by MMP-9 siRNA/bioreducible BPEI-SS-ICG. MMP-9 siRNA/bioreducible BPEI-SS-ICG is effective for inhibiting granulation tissue formation after bare metallic stent placement in a rat urethral model.X1143Ysciescopu
Cross-domain neurobiology data integration and exploration
<p>Abstract</p> <p>Background</p> <p>Understanding the biomedical implications of data from high throughput experiments requires solutions for effective cross-scale and cross-domain data exploration. However, existing solutions do not provide sufficient support for linking molecular level data to neuroanatomical structures, which is critical for understanding high level neurobiological functions.</p> <p>Results</p> <p>Our work integrates molecular level data with high level biological functions and we present results using anatomical structure as a scaffold. Our solution also allows the sharing of intermediate data exploration results with other web applications, greatly increasing the power of cross-domain data exploration and mining.</p> <p>Conclusions</p> <p>The Flex-based PubAnatomy web application we developed enables highly interactive visual exploration of literature and experimental data for understanding the relationships between molecular level changes, pathways, brain circuits and pathophysiological processes. The prototype of PubAnatomy is freely accessible at:[<url>http://brainarray.mbni.med.umich.edu/Brainarray/prototype/PubAnatomy</url>]</p
Interplay between telecommunications and face-to-face interactions - a study using mobile phone data
In this study we analyze one year of anonymized telecommunications data for
over one million customers from a large European cellphone operator, and we
investigate the relationship between people's calls and their physical
location. We discover that more than 90% of users who have called each other
have also shared the same space (cell tower), even if they live far apart.
Moreover, we find that close to 70% of users who call each other frequently (at
least once per month on average) have shared the same space at the same time -
an instance that we call co-location. Co-locations appear indicative of
coordination calls, which occur just before face-to-face meetings. Their number
is highly predictable based on the amount of calls between two users and the
distance between their home locations - suggesting a new way to quantify the
interplay between telecommunications and face-to-face interactions
Evaluating the feasibility of using candidate DNA barcodes in discriminating species of the large Asteraceae family
<p>Abstract</p> <p>Background</p> <p>Five DNA regions, namely, <it>rbcL</it>, <it>matK</it>, ITS, ITS2, and <it>psbA-trnH</it>, have been recommended as primary DNA barcodes for plants. Studies evaluating these regions for species identification in the large plant taxon, which includes a large number of closely related species, have rarely been reported.</p> <p>Results</p> <p>The feasibility of using the five proposed DNA regions was tested for discriminating plant species within Asteraceae, the largest family of flowering plants. Among these markers, ITS2 was the most useful in terms of universality, sequence variation, and identification capability in the Asteraceae family. The species discriminating power of ITS2 was also explored in a large pool of 3,490 Asteraceae sequences that represent 2,315 species belonging to 494 different genera. The result shows that ITS2 correctly identified 76.4% and 97.4% of plant samples at the species and genus levels, respectively. In addition, ITS2 displayed a variable ability to discriminate related species within different genera.</p> <p>Conclusions</p> <p>ITS2 is the best DNA barcode for the Asteraceae family. This approach significantly broadens the application of DNA barcoding to resolve classification problems in the family Asteraceae at the genera and species levels.</p
Understanding Urban Demand for Wild Meat in Vietnam: Implications for Conservation Actions
Vietnam is a significant consumer of wildlife, particularly wild meat, in urban restaurant settings. To meet this demand, poaching of wildlife is widespread, threatening regional and international biodiversity. Previous interventions to tackle illegal and potentially unsustainable consumption of wild meat in Vietnam have generally focused on limiting supply. While critical, they have been impeded by a lack of resources, the presence of increasingly organised criminal networks and corruption. Attention is, therefore, turning to the consumer, but a paucity of research investigating consumer demand for wild meat will impede the creation of effective consumer-centred interventions. Here we used a mixed-methods research approach comprising a hypothetical choice modelling survey and qualitative interviews to explore the drivers of wild meat consumption and consumer preferences among residents of Ho Chi Minh City, Vietnam. Our findings indicate that demand for wild meat is heterogeneous and highly context specific. Wild-sourced, rare, and expensive wild meat-types are eaten by those situated towards the top of the societal hierarchy to convey wealth and status and are commonly consumed in lucrative business contexts. Cheaper, legal and farmed substitutes for wild-sourced meats are also consumed, but typically in more casual consumption or social drinking settings. We explore the implications of our results for current conservation interventions in Vietnam that attempt to tackle illegal and potentially unsustainable trade in and consumption of wild meat and detail how our research informs future consumer-centric conservation actions
Interpreting 16S metagenomic data without clustering to achieve sub-OTU resolution
The standard approach to analyzing 16S tag sequence data, which relies on
clustering reads by sequence similarity into Operational Taxonomic Units
(OTUs), underexploits the accuracy of modern sequencing technology. We present
a clustering-free approach to multi-sample Illumina datasets that can identify
independent bacterial subpopulations regardless of the similarity of their 16S
tag sequences. Using published data from a longitudinal time-series study of
human tongue microbiota, we are able to resolve within standard 97% similarity
OTUs up to 20 distinct subpopulations, all ecologically distinct but with 16S
tags differing by as little as 1 nucleotide (99.2% similarity). A comparative
analysis of oral communities of two cohabiting individuals reveals that most
such subpopulations are shared between the two communities at 100% sequence
identity, and that dynamical similarity between subpopulations in one host is
strongly predictive of dynamical similarity between the same subpopulations in
the other host. Our method can also be applied to samples collected in
cross-sectional studies and can be used with the 454 sequencing platform. We
discuss how the sub-OTU resolution of our approach can provide new insight into
factors shaping community assembly.Comment: Updated to match the published version. 12 pages, 5 figures +
supplement. Significantly revised for clarity, references added, results not
change
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