On Superstring Disk Amplitudes in a Rolling Tachyon Background

We study the tree level scattering or emission of n closed superstrings from a decaying non-BPS brane in Type II superstring theory. We attempt to calculate generic n-point superstring disk amplitudes in the rolling tachyon background. We show that these can be written as infinite power series of Toeplitz determinants, related to expectation values of a periodic function in Circular Unitary Ensembles. Further analytical progress is possible in the special case of bulk-boundary disk amplitudes. These are interpreted as probability amplitudes for emission of a closed string with initial conditions perturbed by the addition of an open string vertex operator. This calculation has been performed previously in bosonic string theory, here we extend the analysis for superstrings. We obtain a result for the average energy of closed superstrings produced in the perturbed background.Comment: 15 pages, LaTeX2e; uses latexsym, amssymb, amsmath, slashed macros; (v2): references added, some typo fixes; (v3): reference adde

Investigation on stability of weld morphology, microstructure of processed zones, and weld quality assessment for hot wire gas tungsten arc welding of electrolytic tough pitch copper

In the present investigation, stability of weld morphology was investigated in case of electrolytic tough pitch copper (12 mm thickness) processed by Hot Wire Gas Tungsten Arc Welding (HW GTAW) using CuNi filler wire with variations of processing conditions, using different combination of hot wire’s parameters such as feed rate and current. The assessment of weld bead geometry was performed using visual examination (during and after welding), and macrographic dimensional measurements of weld bead geometry such as depth of penetration and depth to width ratio. In addition to the stability of weld bead geometries, microstructural variations and weld quality assessments were studied using optical microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and micro-hardness measurements in case of processed sample observed with most uniform weld bead geometry. The results revealed that minimum dimensional variations of weld bead geometry throughout the processed length was obtained with 5.42 mm bead width, 1.2 mm bead height, 1.8 mm penetration, and 0.36 depth to width ratio when hot wire’s parameters were 0.6 m/min wire feed rate and 90 amps hot wire current. The bridging mode of metal transfer helps to receive more stable weld bead geometry with minimum dimensional variations. Ni filler wire of HW GTAW improves the hardness in the Heat affected zone (70 HV0.3) and weld zone (80 HV0.3), which were 33% and 17% higher of base material. The weld zone was consisting of mixed mode of grains such as dendrites just above the fusion line and cellular grains further above dendrites in case of processed sample of minimum dimensional variations of weld bead geometry throughout the processed length

Disk Partition Function and Oscillatory Rolling Tachyons

An exact cubic open string field theory rolling tachyon solution was recently found by Kiermaier et. al. and Schnabl. This oscillatory solution has been argued to be related by a field redefinition to the simple exponential rolling tachyon deformation of boundary conformal theory. In the latter approach, the disk partition function takes a simple form. Out of curiosity, we compute the disk partition function for an oscillatory tachyon profile, and find that the result is nevertheless almost the same.Comment: 17 pages, 2 figures. v4: discussion clarified, appendix added, conclusions unchanged; version to appear in J.Phys.

Phase 1 study of JNJ-64619178, a protein arginine methyltransferase 5 inhibitor, in patients with lower-risk myelodysplastic syndromes

Splicing factor (SF) gene mutations are frequent in myelodysplastic syndromes (MDS), and agents that modulate RNA splicing are hypothesized to provide clinical benefit. JNJ-64619178, a protein arginine methyltransferase 5 (PRMT5) inhibitor, was evaluated in patients with lower-risk (LR) MDS in a multi-part, Phase 1, multicenter study. The objectives were to determine a tolerable dose and to characterize safety, pharmacokinetics, pharmacodynamics, and preliminary clinical activity. JNJ-64619178 was administered on a 14 days on/7 days off schedule or every day on a 21-day cycle to patients with International Prognostic Scoring System (IPSS) Low or Intermediate-1 risk MDS who were red blood cell transfusion-dependent. Twenty-four patients were enrolled; 15 (62.5 %) patients had low IPSS risk score, while 18 (75.0 %) had an SF3B1 mutation. Median duration of treatment was 3.45 months (range: 0.03–6.93). No dose limiting toxicities were observed. The 0.5 mg once daily dose was considered better tolerated and chosen for dose expansion. Twenty-three (95.8 %) patients experienced treatment-emergent adverse events (TEAE). The most common TEAEs were neutropenia (15 [62.5 %]) and thrombocytopenia (14 [58.3 %]). JNJ-64619178 pharmacokinetics was dose-dependent. Target engagement as measured by plasma symmetric di-methylarginine was observed across all dose levels; however, variant allele frequency of clonal mutations in bone marrow or blood did not show sustained reductions from baseline. No patient achieved objective response or hematologic improvement per International Working Group 2006 criteria, or transfusion independence. A tolerable dose of JNJ-64619178 was identified in patients with LR MDS. However, no evidence of clinical benefit was observed.This study was supported by Janssen Research & Development, LLC.Peer reviewe

Review Article- Hepatic resection: An insight

Over a long period of years, surgery of the liver was associated with a high complication rate, and therefore was the domain of a small number of specialists. Thanks to our better understanding of the biological, anatomical, technical and pathological aspects of hepatic resection, most complications can now be avoided. The main thrust of this article is to make valuable information available for younger colleagues, with emphasis on providing a differentiated synopsis of the problems of this formidable surgery with particular reference to practical situations

Processing of Copper by Keyhole-Gas Tungsten Arc Welding for Uniformity of Weld Bead Geometry

Keyhole gas tungsten arc welding (K-GTAW) was applied to characterize the weld bead geometry in case of the 6 mm thick electrolytic tough pitch copper. Various conditions of welding speeds and preheating on the bead geometry were studied for its uniformity. Visual examination, macro bead dimensional analysis, microhardness profile across the transverse section, microstructural analyses were performed to investigate the K-GTAW on electrolytic tough pitch copper. The results revealed that full penetration of 6 mm can be obtained in a single pass using keyhole mode in GTAW. Keyhole length and width were majorly affected by the welding speed and preheating temperature. Significant variations in weld bead geometry were observed even when high heat input conditions were applied without preheating. Uniform weld bead geometry of 5 mm bead width and depth to width ratio of 0.42 was obtained for a length of 80 mm using appropriate preheating of 300°C and heat input condition of 1.37 kJ/mm (resulted from 300 amperes welding current, 120 mm/min welding speed, and 15.3 volts voltage). In the uniform weld bead geometry, the weld and heat affected zones were consisted of coarse grains relative to base material, wherein the micro hardness variations were observed.Peer reviewe

Review Article- Hepatic resection: An insight

Over a long period of years, surgery of the liver was associated with a high complication rate, and therefore was the domain of a small number of specialists. Thanks to our better understanding of the biological, anatomical, technical and pathological aspects of hepatic resection, most complications can now be avoided. The main thrust of this article is to make valuable information available for younger colleagues, with emphasis on providing a differentiated synopsis of the problems of this formidable surgery with particular reference to practical situations