5,500 research outputs found
Single-machine scheduling with a time-dependent learning effect
Author name used in this publication: J.-B. WangAuthor name used in this publication: C. T. NgAuthor name used in this publication: T. C. E. Cheng2007-2008 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
Bicriterion scheduling with equal processing times on a batch processing machine
Author name used in this publication: C. T. NgAuthor name used in this publication: T. C. E. Cheng2008-2009 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
The Influence of Accumulated Precipitation on Debris Flow Hazard
Debris flow warning system in Taiwan uses effective accumulated precipitation as the warning criteria. Little research has studied the affected area associated with different levels of accumulated precipitation. The Taipei DF024 potential debris flow torrent is used as an example to study the relation between an affected area and accumulated precipitation. Three different amount of accumulated precipitation 300, 500 (official warning criteria) and 700 mm in 24 hours are chosen for comparison. Average rainfall intensity per hour is calculated from accumulated rainfall through the Monobe formula. Total water flow rate is estimated using the Rational formula and a discharge hydrograph. Maximum debris flow volume is determined by the equilibrium concentration formula. All sources of debris are distributed on landslide areas and river bed from field investigation. DEBRIS-2D is used to simulate debris flows. The results show that the hazard area is proportional to precipitation, and the thickness of maximum debris flow accumulation is between 3 and 3.5 m for all three cases. The relation between accumulated precipitation and hazard area can provide officials with additional information related to resident evacuation.土石流預警在台灣是以有效累積雨量為基準,但在不同累積雨量下的土石流災害範圍,卻少有學者討論。針對這個問題,本文以北市DF024 為例,用其警戒雨量500 毫米做為基準,再選300 和700 毫米的累積雨量做影響範圍的比較。透過物部公式 (Monobe formula) 將累積雨量轉換為降雨強度,並搭配合理化公式和流量歷線去估算集水區產生的總水量,再以土石流平衡濃度公式推估土石流體積量。並經過現場調查,將料源分佈於崩坍地與河床崩積層,最後採用DEBRIS-2D 去模擬土石流影響範圍。在北市DF024 的案例中發現,土石流影響範圍會隨著累積雨量的增加而擴大,但最大土石堆積深度皆在3~3.5 公尺之間。透過此方法得到的土石流影響範圍不只可以連結與累積雨量的關係,並且可提供相關單位一個修正警戒雨量或疏散
範圍決策的參考
Flavor SU(3) symmetry and QCD factorization in and decays
Using flavor SU(3) symmetry, we perform a model-independent analysis of
charmless decays. All the relevant
topological diagrams, including the presumably subleading diagrams, such as the
QCD- and EW-penguin exchange diagrams and flavor-singlet weak annihilation
ones, are introduced. Indeed, the QCD-penguin exchange diagram turns out to be
important in understanding the data for penguin-dominated decay modes. In this
work we make efforts to bridge the (model-independent but less quantitative)
topological diagram or flavor SU(3) approach and the (quantitative but somewhat
model-dependent) QCD factorization (QCDF) approach in these decays, by
explicitly showing how to translate each flavor SU(3) amplitude into the
corresponding terms in the QCDF framework. After estimating each flavor SU(3)
amplitude numerically using QCDF, we discuss various physical consequences,
including SU(3) breaking effects and some useful SU(3) relations among decay
amplitudes of and .Comment: 47 pages, 3 figures, 28 table
Growth suppressive effect of pegylated arginase in malignant pleural mesothelioma xenografts
BACKGROUND: Malignant pleural mesothelioma (MPM) is a difficult-to-treat global disease. Pegylated arginase (BCT-100) has recently shown anti-tumor effects in hepatocellular carcinoma, acute myeloid leukemia and melanoma. This study aims to investigate the effects of PEG-BCT-100 in MPM. METHODS: A panel of 5 mesothelioma cell lines (H28, 211H, H226, H2052 and H2452) was used to study the in vitro effects of BCT-100 by crystal violet staining. The in vivo effects of BCT-100 were studied using 211H and H226 nude mice xenografts. Protein expression (argininosuccinate synthetase, ornithine transcarbamylase, cleaved PARP, cleaved caspase 3, cyclins (A2, D3, E1 and H), CDK4 and Ki67) and arginine concentration were evaluated by Western blot and ELISA respectively. Cellular localization of BCT-100 was detected by immunohistochemistry and immunoflorescence. TUNEL assay was used to identify cellular apoptotic events. RESULTS: Argininosuccinate synthetase was expressed in H28, H226, and H2452 cells as well as 211H and H266 xenografts. Ornithine transcarbamylase was undetectable in all cell lines and xenograft models. BCT-100 reduced in vitro cell viability (IC50 values at 13-24 mU/ml, 72 h) across different cell lines and suppressed tumor growth in both 211H and H226 xenograft models. BCT-100 (60 mg/kg) significantly suppressed tumor growth (p < 0.01) with prolonged median survival (p < 0.01) in both xenograft models. Combining BCT-100 with pemetrexed or cisplatin conferred no additional benefits over single agents. Serum and intratumoral arginine levels were effectively decreased by BCT-100, associated with cytosolic accumulation of BCT-100 within tumor cells. Apoptosis (PARP cleavage in 211H xenografts; Bcl-2 downregulation, and cleavage of PARP and caspase 3 in H226 xenografts; positive TUNEL staining in both) and G1 arrest (downregulation of cyclin A2, D3, E1 and CDK4 in 211H xenografts; suppression of cyclin A2, E1, H and CDK4 in H226 xenografts) were evident with BCT-100 treatment. Furthermore, proliferative factor Ki67 was downregulated in BCT-100 treatments arms. CONCLUSIONS: BCT-100 suppressed tumor growth with prolonged median survival partially mediated by intratumoral arginine depletion resulting in apoptosis and G1 arrest in mesothelioma xenograft models. The findings provide scientific evidence to support further clinical development of BCT-100 in treatment of MPM.published_or_final_versio
Aspects of four-jet production in polarized proton-proton collisions
We examine the intrinsic spin-dependence of the dominant subprocess contribution to four-jet production in polarized proton-proton
collisions using helicity amplitude techniques. We find that the partonic
level, longitudinal spin-spin asymmetry, , is intrinsically large
in the kinematic regions probed in experiments detecting four isolated jets.
Such events may provide another qualitative or semi-quantitative test of the
spin-structure of QCD in planned polarized collisions at RHIC.Comment: 9 pages, LaTeX, 2 uuencoded postscript files attache
A consistent treatment for pion form factors in space-like and time-like regions
We write down some relevant matrix elements for the scattering and decay
processes of the pion by considering a quark-meson vertex function. The pion
charge and transition form factors , , and
are extracted from these matrix elements using a relativistic
quark model on the light-front. We found that, the form factors and
in the space-like region agree well with experiment.
Furthermore, the branching ratios of all observed decay modes of the neutral
pion, that are related to the form factors and
in the time-like region, are all consistent with the data as
well. Additionally, in the time-like region, which deals with the
nonvalence contribution, is also discussed.Comment: 24 pages, 6 figures, to appear in Phys. Rev.
Flavor of quiver-like realizations of effective supersymmetry
We present a class of supersymmetric models which address the flavor puzzle
and have an inverted hierarchy of sfermions. Their construction involves
quiver-like models with link fields in generic representations. The magnitude
of Standard-Model parameters is obtained naturally and a relatively heavy Higgs
boson is allowed without fine tuning. Collider signatures of such models are
possibly within the reach of LHC in the near future.Comment: LaTeX, 17 pages, 3 figures. V2: reference adde
Atomic structures of TDP-43 LCD segments and insights into reversible or pathogenic aggregation.
The normally soluble TAR DNA-binding protein 43 (TDP-43) is found aggregated both in reversible stress granules and in irreversible pathogenic amyloid. In TDP-43, the low-complexity domain (LCD) is believed to be involved in both types of aggregation. To uncover the structural origins of these two modes of β-sheet-rich aggregation, we have determined ten structures of segments of the LCD of human TDP-43. Six of these segments form steric zippers characteristic of the spines of pathogenic amyloid fibrils; four others form LARKS, the labile amyloid-like interactions characteristic of protein hydrogels and proteins found in membraneless organelles, including stress granules. Supporting a hypothetical pathway from reversible to irreversible amyloid aggregation, we found that familial ALS variants of TDP-43 convert LARKS to irreversible aggregates. Our structures suggest how TDP-43 adopts both reversible and irreversible β-sheet aggregates and the role of mutation in the possible transition of reversible to irreversible pathogenic aggregation
Wilson Lines and a Canonical Basis of SU(4) Heterotic Standard Models
The spontaneous breaking of SU(4) heterotic standard models by Z_3 x Z_3
Wilson lines to the MSSM with three right-handed neutrino supermultiplets and
gauge group SU(3)_C x SU(2)_L x U(1) x U(1) is explored. The two-dimensional
subspace of the Spin(10) Lie algebra that commutes with su(3)_C + su(2)_L is
analyzed. It is shown that there is a unique basis for which the initial soft
supersymmetry breaking parameters are uncorrelated and for which the U(1) x
U(1) field strengths have no kinetic mixing at any scale. If the Wilson lines
"turn on" at different scales, there is an intermediate regime with either a
left-right or a Pati-Salam type model. We compute their spectra directly from
string theory, and adjust the associated mass parameter so that all gauge
parameters exactly unify. A detailed analysis of the running gauge couplings
and soft gaugino masses is presented.Comment: 59 pages, 9 figure
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