660 research outputs found

    Subsidence in Coastal Cities Throughout the World Observed by InSAR

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    We measured subsidence rates in 99 coastal cities around the world between 2015 and 2020 using the PS Interferometric Synthetic Aperture Radar method and Sentinel-1 data. In most cities, part of the land is subsiding faster than sea level is rising. If subsidence continues at present rates, these cities will be challenged by flooding much sooner than projected by sea level rise models. The most rapid subsidence is occurring in South, Southeast, and East Asia. However, rapid subsidence is also happening in North America, Europe, Africa, and Australia. Human activity—primarily groundwater extraction—is likely the main cause of this subsidence. Expanded monitoring and policy interventions are required to reduce subsidence rates and minimize their consequences

    The Weight of New York City: Possible Contributions to Subsidence From Anthropogenic Sources

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    New York City faces accelerating inundation risk from sea level rise, subsidence, and increasing storm intensity from natural and anthropogenic causes. Here we calculate a previously unquantified contribution to subsidence from the cumulative mass and downward pressure exerted by the built environment of the city. We enforce that load distribution in a multiphysics finite element model to calculate expected subsidence. Complex surface geology requires multiple rheological soil models to be applied; clay rich soils and artificial fill are calculated to have the highest post-construction subsidence as compared with more elastic soils. Minimum and maximum calculated building subsidence ranges from 0 to 600 mm depending on soil/rock physical parameters and foundation modes. We compare modeled subsidence and surface geology to observed subsidence rates from satellite data (Interferometric Synthetic Aperture Radar and Global Positioning System). The comparison is complicated because the urban load has accumulated across a much longer period than measured subsidence rates, and there are multiple causes of subsidence. Geodetic measurements show a mean subsidence rate of 1–2 mm/year across the city that is consistent with regional post-glacial deformation, though we find some areas of significantly greater subsidence rates. Some of this deformation is consistent with internal consolidation of artificial fill and other soft sediment that may be exacerbated by recent building loads, though there are many possible causes. New York is emblematic of growing coastal cities all over the world that are observed to be subsiding (Wu et al., 2022, https://doi.org/10.1029/2022GL098477), meaning there is a shared global challenge of mitigation against a growing inundation hazard

    An optimized procedure greatly improves EST vector contamination removal

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    <p>Abstract</p> <p>Background</p> <p>The enormous amount of sequence data available in the public domain database has been a gold mine for researchers exploring various themes in life sciences, and hence the quality of such data is of serious concern to researchers. Removal of vector contamination is one of the most significant operations to obtain accurate sequence data containing only a cDNA insert from the basecalls output by an automatic DNA sequencer. Popular bioinformatics programs to accomplish vector trimming include LUCY, cross_match and SeqClean.</p> <p>Results</p> <p>In a recent study, where the program SeqClean was used to remove vector contamination from our test set of EST data compiled through various library construction systems, however, a significant number of errors remained after preliminary trimming. These errors were later almost completely corrected by simply using a re-linearized form of the cloning vector to compare against the target ESTs. The modified trimming procedure for SeqClean was also compared with the trimming efficiency of the other two popular programs, LUCY2, and cross_match. Using SeqClean with a re-linearized form of the cloning vector significantly surpassed the other two programs in all tested conditions, while the performance of the other two programs was not influenced by the modified procedure. Vector contamination in dbEST was also investigated in this study: 2203 out of the 48212 ESTs sampled from dbEST (2007-04-18 freeze) were found to match sequences in UNIVEC.</p> <p>Conclusion</p> <p>Vector contamination remains a serious concern to the data quality in the public sequence database nowadays. Based on the results presented here, we feel that our modified procedure with SeqClean should be recommended to all researchers for the task of vector removal from EST or genomic sequences.</p

    極端水文事件土砂量對陳有蘭溪河川型態演變影響分析

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    The total sediment yield from the 1999 Chichi earthquake to Typhoon Morakot in 2009 in the Chenyoulan River watershed is around 158.1×106 m3. The excess sediment yield has resulted in serious sediment deposition, widening river width and river meandering in the Chenyoulan River. By comparison of DEMs from 2004 and 2010, sediment deposits are obvious at the convergences of the tributaries and the in main river. Especially apparent are the deposited depth of 2.9 m at the convergence of the Junkeng River and the main river and the deposited depth of 2.6 m at the convergence of the Shibachong River and the main river. The serious sediment deposition has also resulted in river meandering and serious scouring upstream from the convergence of the Shibachong River and the main river, and widening river width and scouring in the main channel downstream from the convergence of the Shibachong River and the main river.陳有蘭溪集水區由1999 年集集地震至2009 年莫拉克颱風約產生158.1×106 m3 土砂量,巨量土砂產出在主河段造成河段淤積、拓寬及擺盪;以2004 年及2010 年DEM 比較結果,支流匯入溪處是主要土砂堆積處,又以郡坑溪匯入處之淤積2.9 m 及十八重溪匯入處之淤積2.6m 為最;受土砂淤積影響,在十八重溪上游匯入處上游河段以河道擺盪及河岸淘刷為主,在十八重溪匯入處下游河段則以河道拓寬及主深槽刷深為主

    MiniZero: Comparative Analysis of AlphaZero and MuZero on Go, Othello, and Atari Games

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    This paper presents MiniZero, a zero-knowledge learning framework that supports four state-of-the-art algorithms, including AlphaZero, MuZero, Gumbel AlphaZero, and Gumbel MuZero. While these algorithms have demonstrated super-human performance in many games, it remains unclear which among them is most suitable or efficient for specific tasks. Through MiniZero, we systematically evaluate the performance of each algorithm in two board games, 9x9 Go and 8x8 Othello, as well as 57 Atari games. For two board games, using more simulations generally results in higher performance. However, the choice of AlphaZero and MuZero may differ based on game properties. For Atari games, both MuZero and Gumbel MuZero are worth considering. Since each game has unique characteristics, different algorithms and simulations yield varying results. In addition, we introduce an approach, called progressive simulation, which progressively increases the simulation budget during training to allocate computation more efficiently. Our empirical results demonstrate that progressive simulation achieves significantly superior performance in two board games. By making our framework and trained models publicly available, this paper contributes a benchmark for future research on zero-knowledge learning algorithms, assisting researchers in algorithm selection and comparison against these zero-knowledge learning baselines. Our code and data are available at https://rlg.iis.sinica.edu.tw/papers/minizero.Comment: Submitted to IEEE Transactions on Games, under revie

    巨額土砂匯入對和社溪河相演變之影響

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    Macro-sediment impulses induced by particular typhoons and rainstorms are the main reason for serious sediment disasters in the Heshe River. For example, the sediment input during Typhoon Morakot in 2009 which accounted for 95.8% of the annual sediment discharge is the most serious of these disasters. Since Typhoon Morakot, the sediment input has decreased, as there have been less serious typhoons and rainstorms, thus, transforming the river morphology from a braided river into meandering river. In addition, river bends and topographical notches restrain sediment from moving downstream and store it in these locations. These factors have indirectly increased the erosion density of the river banks by 2.5 to 10.5 times.特定之颱風及豪雨事件為和社溪集水區內巨額土砂進入河道造成相關土砂災害之主 要因素;尤以2009 年莫拉克颱風其間之輸砂量,佔該年總輸砂量之95.8%最為嚴重。然而,莫拉克颱風過後並無發生規模較大之颱風及豪雨事件,因此進入和社溪之土砂漸減,使得因土砂堆積造成之辮狀河川逐漸走向蜿蜒。此外,河川轉折點跟隘口處都會抑止土砂往下游運移並使土砂集中於此處,間接造成河岸淘刷密度增加2.5 至10.5 倍

    Concurrent image-guided intensity modulated radiotherapy and chemotherapy following neoadjuvant chemotherapy for locally advanced nasopharyngeal carcinoma

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    <p>Abstract</p> <p>Background</p> <p>To evaluate the experience of induction chemotherapy followed by concurrent chemoradiationwith helical tomotherapy (HT) for nasopharyngeal carcinoma (NPC).</p> <p>Methods</p> <p>Between August 2006 and December 2009, 28 patients with pathological proven nonmetastatic NPC were enrolled. All patients were staged as IIB-IVB. Patients were first treated with 2 to 3 cycles of induction chemotherapy with EP-HDFL (Epirubicin, Cisplatin, 5-FU, and Leucovorin). After induction chemotherapy, weekly based PFL was administered concurrent with HT. Radiation consisted of 70 Gy to the planning target volumes of the primary tumor plus any positive nodal disease using 2 Gy per fraction.</p> <p>Results</p> <p>After completion of induction chemotherapy, the response rates for primary and nodal disease were 96.4% and 80.8%, respectively. With a median follow-up after 33 months (Range, 13-53 months), there have been 2 primary and 1 nodal relapse after completion of radiotherapy. The estimated 3-year progression-free rates for local, regional, locoregional and distant metastasis survival rate were 92.4%, 95.7%, 88.4%, and 78.0%, respectively. The estimated 3-year overall survival was 83.5%. Acute grade 3, 4 toxicities for xerostomia and dermatitis were only 3.6% and 10.7%, respectively.</p> <p>Conclusion</p> <p>HT for locoregionally advanced NPC is feasible and effective in regard to locoregional control with high compliance, even after neoadjuvant chemotherapy. None of out-field or marginal failure noted in the current study confirms the potential benefits of treating NPC patients by image-guided radiation modality. A long-term follow-up study is needed to confirm these preliminary findings.</p

    Hedgehog overexpression leads to the formation of prostate cancer stem cells with metastatic property irrespective of androgen receptor expression in the mouse model

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    <p>Abstract</p> <p>Background</p> <p>Hedgehog signalling has been implicated in prostate tumorigenesis in human subjects and mouse models, but its effects on transforming normal basal/stem cells toward malignant cancer stem cells remain poorly understood.</p> <p>Methods</p> <p>We produced pCX-shh-IG mice that overexpress Hedgehog protein persistently in adult prostates, allowing for elucidation of the mechanism during prostate cancer initiation and progression. Various markers were used to characterize and confirm the transformation of normal prostate basal/stem cells into malignant cancer stem cells under the influence of Hedgehog overexpression.</p> <p>Results</p> <p>The pCX-shh-IG mice developed prostatic intraepithelial neoplasia (PIN) that led to invasive and metastatic prostate cancers within 90 days. The prostate cancer was initiated through activation of P63<sup>+ </sup>basal/stem cells along with simultaneous activation of Hedgehog signalling members, suggesting that P63<sup>+</sup>/Patch1<sup>+ </sup>and P63<sup>+</sup>/Smo<sup>+ </sup>cells may serve as cancer-initiating cells and progress into malignant prostate cancer stem cells (PCSCs). In the hyperplastic lesions and tumors, the progeny of PCSCs differentiated into cells of basal-intermediate and intermediate-luminal characteristics, whereas rare ChgA<sup>+ </sup>neuroendocrine differentiation was seen. Furthermore, in the metastatic loci within lymph nodes, kidneys, and lungs, the P63<sup>+ </sup>PCSCs formed prostate-like glandular structures, characteristic of the primitive structures during early prostate development. Besides, androgen receptor (AR) expression was detected heterogeneously during tumor progression. The existence of P63<sup>+</sup>/AR<sup>-</sup>, CK14<sup>+</sup>/AR<sup>- </sup>and CD44<sup>+</sup>/AR<sup>- </sup>progeny indicates direct procurement of AR<sup>- </sup>malignant cancer trait.</p> <p>Conclusions</p> <p>These data support a cancer stem cell scenario in which Hedgehog signalling plays important roles in transforming normal prostate basal/stem cells into PCSCs and in the progression of PCSCs into metastatic tumor cells.</p
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