Prepoznavanje građevina pogođenih potresom temeljem korelacijske detekcije promjena obilježja teksture na SAR snimkama

The detection of building damage due to earthquakes is crucial for disaster management and disaster relief activities. Change detection methodologies using satellite images, such as synthetic aperture radar (SAR) data, have being applied in earthquake damage detection. Information contained within SAR data relating to earthquake damage of buildings can be disturbed easily by other factors. This paper presents a multitemporal change detection approach intended to identify and evaluate information pertaining to earthquake damage by fully exploiting the abundant texture features of SAR imagery. The approach is based on two images, which are constructed through principal components of multiple texture features. An independent principal components analysis technique is used to extract multiple texture feature components. Then, correlation analysis is performed to detect the distribution information of earthquake-damaged buildings. The performance of the technique was evaluated in the town of Jiegu (affected by the 2010 Yushu earthquake) and in the Kathmandu Valley (struck by the 2015 Nepal earthquake) for which the overall accuracy of building detection was 87.8% and 84.6%, respectively. Cross-validation results showed the proposed approach is more sensitive than existing methods to the detection of damaged buildings. Overall, the method is an effective damage detection approach that could support post-earthquake management activities in future events.Detekcija oštećenja građevina uzrokovanih potresom od presudne je važnosti za upravljanje rizicima od katastrofa i aktivnostima prilikom elementarnih nepogoda. Metodologije detekcije promjena, koristeći satelitske snimke kao što su podaci radara sa sintetičkim otvorom antene (SAR), korištene su u detekciji oštećenja od potresa. Informacije sadržane unutar SAR podataka, koje se odnose na oštećenja građevina uzrokovana potresom, mogu lako sadržavati šumove zbog drugih faktora. Ovaj rad prikazuje viševremenski pristup detekciji promjena kako bi se identificirale i procijenile informacije koje se odnose na oštećenja od potresa koristeći u potpunosti značajke teksture SAR snimaka. Pristup se temelji na dvije snimke koje su izrađene kroz glavne komponente višestrukih osobina tekstura. Neovisna analiza glavnih komponenti koristi se kako bi se izdvojile komponente višestrukih tekstura. Nakon toga provodi se korelacijska analiza kako bi se detektirale informacije o distribuciji građevina oštećenih potresom. Učinkovitost ove tehnike ispitana je u gradu Jiegu (kojega je 2010. godine pogodio potres Yushu) te u dolini Kathmandu (koju je 2015. godine pogodio potres Nepal), u kojoj je ukupna točnost detektiranja građevina bila 87,8%, odnosno 84,6%. Rezultati međusobne provjere valjanosti pokazali su da je predloženi pristup osjetljiviji od postojećih metoda za detektiranje oštećenih građevina. Općenito govoreći, metoda je učinkovit pristup detektiranja oštećenja koji može u budućnosti pružati potporu u aktivnostima upravljanja nakon potresa

Elevation Extraction from Spaceborne SAR Tomography Using Multi-Baseline COSMO-SkyMed SAR Data

SAR tomography (TomoSAR) extends SAR interferometry (InSAR) to image a complex 3D scene with multiple scatterers within the same SAR cell. The phase calibration method and the super-resolution reconstruction method play a crucial role in 3D TomoSAR imaging from multi-baseline SAR stacks, and they both influence the accuracy of the 3D SAR tomographic imaging results. This paper presents a systematic processing method for 3D SAR tomography imaging. Moreover, with the newly released TanDEM-X 12 m DEM, this study proposes a new phase calibration method based on SAR InSAR and DEM error estimation with the super-resolution reconstruction compressive sensing (CS) method for 3D TomoSAR imaging using COSMO-SkyMed Spaceborne SAR data. The test, fieldwork, and results validation were executed at Zipingpu Dam, Dujiangyan, Sichuan, China. After processing, the 1 m resolution TomoSAR elevation extraction results were obtained. Against the terrestrial Lidar ‘truth’ data, the elevation results were shown to have an accuracy of 0.25 ± 1.04 m and a RMSE of 1.07 m in the dam area. The results and their subsequent validation demonstrate that the X band data using the CS method are not suitable for forest structure reconstruction, but are fit for purpose for the elevation extraction of manufactured facilities including buildings in the urban area

Improving lignocellulose thermal stability by chemical modification with boric acid for incorporating into polyamide

The preparation of bio-composites based on engineering plastic is always restricted by the low thermal stability of lignocellulose. In this study, the thermal stability of lignocellulose was improved by boric acid modification. Then, the borated lignocellulose was characterized to analyze the mechanism of involved in the improvement of thermal stability. Furthermore, the untreated and borated lignocellulose was combined with polyamide 6 to produce bio-composites. The effects of lignocellulose content and boric acid modification on the color, thermal stability and mechanical properties of the resulting composites were compared and analyzed. Boric acid protected lignocellulose from thermal degradation, increasing the lightness of the resulting composites. However, boric acid appeared to have a negative effect on the mechanical strength of the resulting composites. In summary, this study demonstrated that bio-composites based on engineering plastic could be prepared by improving the thermal stability of lignocellulose using a boric acid treatment

Gene expression analysis of induced pluripotent stem cells from aneuploid chromosomal syndromes

BACKGROUND: Human aneuploidy is the leading cause of early pregnancy loss, mental retardation, and multiple congenital anomalies. Due to the high mortality associated with aneuploidy, the pathophysiological mechanisms of aneuploidy syndrome remain largely unknown. Previous studies focused mostly on whether dosage compensation occurs, and the next generation transcriptomics sequencing technology RNA-seq is expected to eventually uncover the mechanisms of gene expression regulation and the related pathological phenotypes in human aneuploidy. RESULTS: Using next generation transcriptomics sequencing technology RNA-seq, we profiled the transcriptomes of four human aneuploid induced pluripotent stem cell (iPSC) lines generated from monosomy × (Turner syndrome), trisomy 8 (Warkany syndrome 2), trisomy 13 (Patau syndrome), and partial trisomy 11:22 (Emanuel syndrome) as well as two umbilical cord matrix iPSC lines as euploid controls to examine how phenotypic abnormalities develop with aberrant karyotype. A total of 466 M (50-bp) reads were obtained from the six iPSC lines, and over 13,000 mRNAs were identified by gene annotation. Global analysis of gene expression profiles and functional analysis of differentially expressed (DE) genes were implemented. Over 5000 DE genes are determined between aneuploidy and euploid iPSCs respectively while 9 KEGG pathways are overlapped enriched in four aneuploidy samples. CONCLUSIONS: Our results demonstrate that the extra or missing chromosome has extensive effects on the whole transcriptome. Functional analysis of differentially expressed genes reveals that the genes most affected in aneuploid individuals are related to central nervous system development and tumorigenesis

A Novel Role for Minimal Introns: Routing mRNAs to the Cytosol

BACKGROUND: Introns and their splicing are tightly coupled with the subsequent mRNA maturation steps, especially nucleocytoplasmic export. A remarkable fraction of vertebrate introns have a minimal size of about 100 bp, while majority of introns expand to several kilobases even megabases in length. PRINCIPAL FINDINGS: We carried out analyses on the evolution and function of minimal introns (50-150 bp) in human and mouse genomes. We found that minimal introns are conserved in terms of both length and sequence. They are preferentially located toward 3' end of mRNA and non-randomly distributed among chromosomes. Both the evolutionary conservation and non-random distribution are indicative of biological relevance. We showed that genes with minimal introns have higher abundance, larger size, and tend to be universally expressed as compared to genes with only large introns and intron-less genes. Genes with minimal introns replicate earlier and preferentially reside in the vicinities of open chromatin, suggesting their unique nuclear position and potential relevance to the regulation of gene expression and transcript export. CONCLUSIONS: Based on these observations, we proposed a nuclear-export routing model, where minimal introns play a regulatory role in selectively exporting the highly abundant and large housekeeping genes that reside at the surface of chromatin territories, and thus preventing entanglement with other genes located at the interior locations

PGAweb: A Web Server for Bacterial Pan-Genome Analysis

An astronomical increase in microbial genome data in recent years has led to strong demand for bioinformatic tools for pan-genome analysis within and across species. Here, we present PGAweb, a user-friendly, web-based tool for bacterial pan-genome analysis, which is composed of two main pan-genome analysis modules, PGAP and PGAP-X. PGAweb provides key interactive and customizable functions that include orthologous clustering, pan-genome profiling, sequence variation and evolution analysis, and functional classification. PGAweb presents features of genomic structural dynamics and sequence diversity with different visualization methods that are helpful for intuitively understanding the dynamics and evolution of bacterial genomes. PGAweb has an intuitive interface with one-click setting of parameters and is freely available at http://PGAweb.vlcc.cn/

Reinforcement of continuous fibers for extruded wood-flour/HDPE composites: Effects of fiber type and amount

Continuous-fiber reinforced WPCs were prepared using an extruder with a special die. The effects of the amount (1–7 bundles) and type of fiber (aramid rovings and yarns and carbon and glass yarns) on the mechanical properties of WPCs were studied. The addition of continuous fibers increased the tensile, flexural and impact strength of the composites by up to 47.3%, 83.1% and 713.4%, respectively. The damping ratio analysis revealed that the interfacial bonding of glass-yarn reinforced WPCs was the best among the tested samples. Adding continuous fibers to WPCs at a low volume fraction can promote their use as load-bearing engineered materials

Conversion of lignocellulose into biochar and furfural through boron complexation and esterification reactions

The aim of this work was to study the conversion of lignocellulose into biochar and furfural through boron complexation and esterification reaction. Boric acid was used to modify lignocellulose to obtain a high biochar yield boron-lignocellulosic material through complexation and esterification reactions. Furthermore, clean furfural was obtained as the gas products of boron-lignocellulosic materials pyrolysis. The structures of the boron-lignocellulosic materials were characterized, and their compound principle was revealed. Boric acid treatments increased the initial thermal degradation temperature of lignocellulose and promoted the formation of biochar and furfural. The biochar yield rate increased by 135.7% from 18.6 to 42.9% at 600 ℃ after 5% boric acid solution treatment. Compared with pure lignocellulose, cleaner and higher quantities of furfural were obtained from boron-lignocellulose pyrolysis. Finally, the possible chemical decomposition pathways of boron-lignocellulosic materials were identified. This study provides a new perspective on the thermochemical conversion of lignocellulose to furfural and biochar

Pan-Genomic Study of Mycobacterium tuberculosis Reflecting the Primary/Secondary Genes, Generality/Individuality, and the Interconversion Through Copy Number Variations

Tuberculosis (TB) has surpassed HIV as the leading infectious disease killer worldwide since 2014. The main pathogen, Mycobacterium tuberculosis (Mtb), contains ~4,000 genes that account for ~90% of the genome. However, it is still unclear which of these genes are primary/secondary, which are responsible for generality/individuality, and which interconvert during evolution. Here we utilized a pan-genomic analysis of 36 Mtb genomes to address these questions. We identified 3,679 Mtb core (i.e., primary) genes, determining their phenotypic generality (e.g., virulence, slow growth, dormancy). We also observed 1,122 dispensable and 964 strain-specific secondary genes, reflecting partially shared and lineage-/strain-specific individualities. Among which, five L2 lineage-specific genes might be related to the increased virulence of the L2 lineage. Notably, we discovered 28 Mtb “Super Core Genes” (SCGs: more than a copy in at least 90% strains), which might be of increased importance, and reflected the “super phenotype generality.” Most SCGs encode PE/PPE, virulence factors, antigens, and transposases, and have been verified as playing crucial roles in Mtb pathogenicity. Further investigation of the 28 SCGs demonstrated the interconversion among SCGs, single-copy core, dispensable, and strain-specific genes through copy number variations (CNVs) during evolution; different mutations on different copies highlight the delicate adaptive-evolution regulation amongst Mtb lineages. This reflects that the importance of genes varied through CNVs, which might be driven by selective pressure from environment/host-adaptation. In addition, compared with Mycobacterium bovis (Mbo), Mtb possesses 48 specific single core genes that partially reflect the differences between Mtb and Mbo individuality