1,606 research outputs found
Granular lightweight fill composed of sand and tire scrap
A granular geomaterial, known as sand-tire lightweight fill, was proposed by blending sand with disposed tire scrap in proportions. The geomaterial can be used as alternative backfill in many infrastructure works, where less overburdens and lateral loads are expected. The reuse of tire scraps may not only address growing environmental and economic concerns, but also help solve geotechnical problems associated with low soil shear strength. In this study, an experimental testing program was undertaken with the goal of evaluating the compression and shear behavior of the materials. Three tests were implemented, i.e., 1-D compression tests, direct shear tests and consolidated drained triaxial compression tests. A compression strain-load model was proposed to describe its compression behavior. Rebound-reload tests revealed that materials' plastic deformation was associated with the mixing ratios. The tire scrap content was found to influence the stress-strain and volumetric strain behavior of the mixtures. Mixtures underwent shear contraction during shearing processes, which is different from the shear dilation of compact sands. Effects of mixing ratios and stress conditions on shear deformation behaviors were also discussed.An Deng and Jin-Rong Fenghttp://ascelibrary.org/doi/abs/10.1061/41041%28348%291
Suffix Tree of Alignment: An Efficient Index for Similar Data
We consider an index data structure for similar strings. The generalized
suffix tree can be a solution for this. The generalized suffix tree of two
strings and is a compacted trie representing all suffixes in and
. It has leaves and can be constructed in time.
However, if the two strings are similar, the generalized suffix tree is not
efficient because it does not exploit the similarity which is usually
represented as an alignment of and .
In this paper we propose a space/time-efficient suffix tree of alignment
which wisely exploits the similarity in an alignment. Our suffix tree for an
alignment of and has leaves where is the sum of
the lengths of all parts of different from and is the sum of the
lengths of some common parts of and . We did not compromise the pattern
search to reduce the space. Our suffix tree can be searched for a pattern
in time where is the number of occurrences of in and
. We also present an efficient algorithm to construct the suffix tree of
alignment. When the suffix tree is constructed from scratch, the algorithm
requires time where is the sum of the lengths
of other common substrings of and . When the suffix tree of is
already given, it requires time.Comment: 12 page
Urothelial Inverted Papilloma of the Lower Urinary Tract—A Benign Lesion or a Precursor of Malignancy?
ObjectiveWe investigated the clinical characteristics and follow-up results of patients with a lower urinary tract inverted papilloma (IP) in our hospital, with the intention of clarifying whether certain groups require more aggressive surveillance.Materials and MethodsWe conducted a retrospective study of lower urinary tract IP, using the pathology database of Taipei Veterans General Hospital, from September 1992 to February 2008. In total, 67 patients were enrolled. Patients' clinical characteristics, symptoms, tumor locations, and follow-up data were analyzed.ResultsAmong the 67 patients diagnosed with IP, 59 were male and eight were female, with a mean age of 67.9 ± 12.4 years. Gross hematuria and lower-urinary-tract symptoms were the most common symptoms. All of the patients received transurethral resection as initial treatment. Thirty-eight of these patients were monitored for a median of 21 months (range: 3–168 months). Seven patients had synchronous urothelial malignancies, and one had recurrent IP during follow-up. No patient had subsequent urothelial carcinoma or IP recurrence without a synchronous or previous urothelial malignancy during follow-up.ConclusionThere is a low incidence of developing a subsequent malignancy with a simple IP lesion during follow-up. Rigorous surveillance may be unnecessary in IP patients without a synchronous or previous urothelial malignancy
More Model-Independent Analysis of b->s Processes
We study model-independently the implications of non-standard scalar and
pseudoscalar interactions for the decays b ->s gamma, b -> s g, b -> s l^+l^-
(l=e,mu) and B_s -> mu^+ mu^-. We find sizeable renormalization effects from
scalar and pseudoscalar four-quark operators in the radiative decays and at
O(alpha_s) in hadronic b decays. Constraints on the Wilson coefficients of an
extended operator basis are worked out. Further, the ratios R_H = BR(B -> H
mu^+ mu^-)/BR(B -> H e^+ e^-), for H=K^(*), X_s, and their correlations with
B_s -> mu^+ mu^- decay are investigated. We show that the Standard Model
prediction for these ratios defined with the same cut on the dilepton mass for
electron and muon modes, R_H= 1 + O(m^2_mu/m^2_b), has a much smaller
theoretical uncertainty (<1%) than the one for the individual branching
fractions. The present experimental limit R_K < 1.2 puts constraints on scalar
and pseudoscalar couplings, which are similar to the ones from current data on
BR(B_s -> mu^+ mu^-). We find that new physics corrections to R_{K*} and
R_{X_s} can reach 13% and 10%, respectively.Comment: 28 pages, 6 figures; Table 1 updated, two refs added (to appear in
PRD
B_s --> mu+ mu- decay in the R-parity violating minimal supergravity
We study B_s --> mu+ mu- in the context of the R-parity violating minimal
supergravity in the high tan beta regime. We find that the lowest value of the
branching ratio can go well below the present LHCb sensitivity and hence B_s
--> mu+ mu- can even be invisible to the LHC. We also find that the present
upper bound on Br(B_s --> mu+ mu-) puts strong constraint on the minimal
supergravity parameter space. The constraints become more severe if the upper
bound is close to its standard model prediction.Comment: 18 pages, 10 figures; version to be published in European Physical
Journal
Morphology of the archaellar motor and associated cytoplasmic cone in Thermococcus kodakaraensis
Archaeal swimming motility is driven by archaella: rotary motors attached to long extracellular filaments. The structure of these motors, and particularly how they are anchored in the absence of a peptidoglycan cell wall, is unknown. Here, we use electron cryotomography to visualize the archaellar basal body in vivo in Thermococcus kodakaraensis KOD1. Compared to the homologous bacterial type IV pilus (T4P), we observe structural similarities as well as several unique features. While the position of the cytoplasmic ATPase appears conserved, it is not braced by linkages that extend upward through the cell envelope as in the T4P, but rather by cytoplasmic components that attach it to a large conical frustum up to 500 nm in diameter at its base. In addition to anchoring the lophotrichous bundle of archaella, the conical frustum associates with chemosensory arrays and ribosome‐excluding material and may function as a polar organizing center for the coccoid cells
Roles of insulin-like growth factor II in cardiomyoblast apoptosis and in hypertensive rat heart with abdominal aorta ligation
Although IGF-II activating the IGF-II receptor signaling pathway has been found to stimulate cardiomyocyte hypertrophy, the role of IGF-II in cardiac cell apoptosis remains unclear. This study aimed to identify the roles of IGF-II and/or IGF-II receptors (IGF-II/IIR) in cardiomyoblast apoptosis and in hypertensive rat hearts with abdominal aorta ligation. Cultured rat heart-derived H9c2 cardiomyoblasts and excised hearts from Sprague-Dawley rats with 0- to 20-day complete abdominal aorta ligation, a model of ANG II elevation and hypertension, were used. IGF-II/IIR expression, caspase activity, DNA fragmentation, and apoptotic cells were measured by RT-PCR, Western blot, agarose gel electrophoresis, and TUNEL assay following various combinations of ANG II, IGF-II/IIR antibody, CsA (calcineurin inhibitor), SP-600125 (JNK inhibitor), SB-203580 (p38 inhibitor), U-0126 (MEK inhibitor), or Staurosporine (PKC inhibitor) in H9c2 cells. ANG II-induced DNA fragmentation and TUNEL-positive cells were blocked by IGF-II/IIR antibodies and antisense IGF-II, but not by IGF-II sense. IGF-II-induced apoptosis was blocked by IGF-IIR antibody and CsA. The increased gene expressions of IGF-II and -IIR induced by ANG II were reversed by U-0126 and Sp600125, respectively. Caspase 8 activities induced by ANG II were attenuated by U-0126, SP-600125, and CsA. DNA fragmentation induced by ANG II was totally blocked by SP-600125, and CsA and was attenuated by U-0126. In rats with 0- to 20-day complete abdominal aorta ligation, the increases in IGF-II/IIR levels in the left ventricle were accompanied by hypertension as well as increases in caspase 9 activities and TUNEL-positive cardiac myocytes. ANG II-induced apoptosis was reversed by IGF-II/IIR blockade and coexisted with increased transactivation of IGF-II and -IIR, which are mediated by ERK and JNK pathways, respectively, both of which further contributed to cardiomyoblast apoptosis via calcineurin signaling. The increased cardiac IGF-II, IGF-IIR, caspase 9, and cellular apoptosis were also found in hypertensive rats with abdominal aorta ligation
Analysis of Various Polarization Asymmetries In The Inclusive Decay In The Fourth-Generation Standard Model
In this study a systematical analysis of various polarization asymmetries in
inclusive b \rar s \ell^+ \ell^- decay in the standard model (SM) with four
generation of quarks is carried out. We found that the various asymmetries are
sensitive to the new mixing and quark masses for both of the and
channels. Sizeable deviations from the SM values are obtained. Hence, b \rar s
\ell^+ \ell^- decay is a valuable tool for searching physics beyond the SM,
especially in the indirect searches for the fourth-generation of quarks (.Comment: 19 Pages, 10 Figures, 3 Table
A Simple Approach to Fourth Generation Effects in Decay
In a scenario in which fourth generation fermions exist, we study effects of
new physics on the differential decay width, forward-backward asymmetry
and integrated branching ratio for
decay with . Prediction of the new physics on the mentioned
quantities essentially differs from the Standard Model results, in certain
regions of the parameter space, enhancement of new physics on the above
mentioned physical quantities can yield values as large as two times of the SM
predictions, whence present limits of experimental measurements of branching
ratio is spanned, contraints of the new physics can be extracted.
For the fourth generation CKM factor we
use and ranges, take into consideration the
possibility of a complex phase where it may bring sizable contributions,
obtained no significant dependency on the imaginary part of the new CKM factor.
For the above mentioned quantities with a new family, deviations from the SM
are promising, can be used as a probe of new physics.Comment: 9 pages aps forma
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