113,098 research outputs found
Discomfort, Pressure Distribution and Safety in Operator's Seat-A Critical Review
No full textRosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is an Invited Paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 5 (2003): H. Dhingra, V. Tewari, and S. Singh. Discomfort, Pressure Distribution and Safety in Operator's Seat-A Critical Review. Vol. V. July 2003
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Reduced cyclooxygenase 2 levels after hypoxia exposure result in the loss of immunoprivilege of allogeneic mesenchymal stem cells
No full textAllogenic mesenchymal stem cells (MSCs) from young and healthy donors have demonstrated the potential to treat multiple degenerative disorders. However, recent pre-clinical and clinical studies
report that immunogenicity and poor survival of transplanted MSCs impairs the efficacy of cells for regenerative applications. According to these studies, initially immunoprivileged under in vitro conditions, MSCs are targeted by the host immune system after transplantation in the ischemic tissues.
We performed in vitro and in vivo (rat myocardial infarction [MI] model) studies using bone-marrow derived MSCs to elucidate the mechanisms responsible for the switch of MSCs from immunoprivileged to immunogenic state, under ischemic conditions. MSCs were cultured under normal or hypoxic conditions (0.4%O2, 24hr), and the levels of immunosuppressive molecules cyclooxygenase-2 (COX2, rate limiting enzyme for PGE2 synthesis) and prostaglandin E2 (PGE2) were assessed using western blot and ELISA, respectively. Our results show that the levels of COX2 and PGE2 decreased in MSCs following exposure to hypoxia. Activation of immune response was evaluated using flow cytometry analysis after
co-culturing leukocytes with MSCs lacking, or over-expressing COX2. We also found that proteasome-mediated degradation of COX2 in hypoxic MSCs is responsible for PGE2 decrease and loss of immunoprivilege of MSCs. Finally, when COX2 over-expressing MSCs were transplanted in rat MI model we found that maintaining COX2 levels improved their survival in vivo. While investigating the
mechanisms involved in COX2 degradation, we found that interaction of COX2 with COP9 signalosome subunit 5 (CSN5) under normoxia prevents its degradation by the proteasome. On the other hand,
hypoxia mediated decrease in the levels of CSN5 and, its reduced binding to COX2, makes COX2 protein susceptible to proteasome-mediated degradation. This subsequently causes PGE2 downregulation and loss of immunoprivilege of MSCs. Our results provide novel mechanistic evidence that PGE2 is downregulated in hypoxic MSCs causing post-transplantation rejection of allogeneic MSCs. This suggests that new strategies that target CSN5-COX2 signaling may improve survival and utility of transplanted allogeneic MSCs in the ischemic heart
Self-assembled strained nanostructures for light emission grown using molecular beam epitaxy
No full textIII-V nanostructures are widely researched for applications in dislocation-resistant light emitters for photonic integrated circuits, quantum computing and single photon emitters. The 0D nanostructures include quantum dots (QDs), dot in a well (DWELLs), sub-monolayer QDs and droplet epitaxy QDs, while 1D elongated structures include quantum dashes and nanowires (NWs). The optical properties of nanostructures can be controlled through size, composition, strain and band-offsets during epitaxial growth and can be tailored precisely to emit light with photon energies suited to the application, spanning 0.2-2.0 eV. This thesis explores two novel QD based light emitters in the visible and near-infrared wavelength regime. In the first part of the thesis, we demonstrate the growth and characterization of tensile strained Ge QDs and Ge NWs phase segregated in the III-V matrix via Volmer-Weber growth mode emitting at 1200 nm. The second part of the thesis demonstrates the dislocation tolerance of compressively strained InP QDs grown on lattice-matched GaAs and lattice-mismatched Si substrate via Stranski-Krastanov growth mode emitting at 713 nm.
The first part of the thesis explores the growth of tensile strained Ge QDs and NWs phase segregated in the III-V matrix. Epitaxial growth of phase segregated Ge nanostructures embedded within III-V compound semiconductors is a promising way to achieve a high biaxial tensile strain along with precise control of nanostructure density, size and morphology. Here we demonstrate growth of phase-segregated Ge quantum dots (QDs) and compare them to our previously reported Ge nanowires (NWs); both are strained to an In0.52Al0.48As matrix with a high biaxial tensile strain of 3.6%. Despite the similar growth conditions, there exist pronounced differences in the lateral size and planar density of Ge QDs and Ge NWs, with Ge QDs showing significantly larger size, lower density and structural anisotropy along the in-plane [1-10] direction. In addition to the difference in morphology, Ge QDs are shown to be more prone to plastic relaxation by formation of dislocations and stacking faults, which we attribute to their larger in-plane size. Finally, tensile Ge QDs are shown to exhibit strong room-temperature photoluminescence at 1176 nm, which is blueshifted from the case of Ge NWs.
In the second part of the thesis, we demonstrate epitaxial InP QDs on GaAs on Si virtual substrates with room-temperature photoluminescence (PL) intensity nearly identical to those grown on GaAs substrates. The similarity in PL characteristics is remarkable considering that the active region on the GaAs/Si virtual substrate has a threading dislocation density (TDD) of ~3×10^7 cm-2, as compared to the bulk GaAs substrate with TDD 50× improvement in the luminescence intensity of InP QDs annealed at ~700⁰C for 100 minutes without observable structural degradation or blue-shift in the PL spectrum.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-05-01The student, Pankul Dhingra, accepted the attached license on 2019-04-25 at 12:06.The student, Pankul Dhingra, submitted this Thesis for approval on 2019-04-25 at 12:16.This Thesis was approved for publication on 2019-04-25 at 14:10.DSpace SAF Submission Ingestion Package generated from Vireo submission #13914 on 2019-08-22 at 16:23:56Made available in DSpace on 2019-08-23T20:48:26Z (GMT). No. of bitstreams: 2
DHINGRA-THESIS-2019.pdf: 2735717 bytes, checksum: 55584f4a818d3f00a92b3ad38753e24d (MD5)
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Previous issue date: 2019-04-25Embargo set by: Seth Robbins for item 112387
Lift date: 2021-08-23T20:48:32Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 112387 on 2021-08-24T09:15:38Z
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
EXPERIMENTAL OCULAR CIn.AMYDIAL STUDmS IN LAMBS
No full textAbstract Dhingra P. N., V. M. Mahajan: Experimental Ocular Chlamydial Studies in Lambs. Acta vet. Bmo, 60, 1991: 345-349. Two locally isolated strains of Chlamydia psittaci from sheep and cattle and a Bour strain of Chlamydia trachomatis were instilled onto conjunctiva of 6 lambs. Clinical and laboratory investigations were carried out till 52 day post inoculation. Bour strain did not infect the conjunctiva of lambs. However, both the strains of C. psittaci produced follicles on the lower and upper conjunctiva of lambs during the period varying from 1-4 weeks post infection. Pannus or keratitis was neither observed with human nor animal strains. Laboratory studies which included reisolation, fluorescent staining, cytology and serology were negative throughout with Bour strain while positive at one time or the other with 2 C. psittaci strains during the period of study
Fuel Consumption Monitoring for Travel Demand Modeling
No full textThe purpose of this research is to investigate the impact of fuel consumption patterns on travel demand estimation. This paper evaluates and calibrates travel demand estimation by CUBE software and its relation to fuel consumption, with the use of data provided by Sharif University, for the city of Shiraz, Iran in 1999. This research proves the presence strong correlations between vehicle fuel use and the trip's generation process by exogenous and endogenous variables. The effect of energy consumption patterns on generation and distribution stage of travel demand modeling based on inverse ability has been considered in the present model
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Design, defect reduction, and dislocation tolerance of red lasers on Si (001)
No full textSubmission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-05-01The student, Pankul Dhingra, accepted the attached license on 2022-04-21 at 16:34.The student, Pankul Dhingra, submitted this Dissertation for approval on 2022-04-21 at 16:45.This Dissertation was approved for publication on 2022-04-22 at 12:44.DSpace SAF Submission Ingestion Package generated from Vireo submission #17894 on 2022-11-11 at 12:58:04Monolithic integration of III-V optoelectronic devices with silicon nitride photonics technology could open a wide range of on-chip applications spanning a wide wavelength range of 400 – 4000 nm. The wavelength palette of III-V lasers on Si spans 400 nm – 11 μm with the development of nitride, arsenide and antimonide quantum well (QW) and quantum dot (QD) lasers, leaving a crucial gap in the development of red lasers on Si with 630 – 750 nm emission using phosphide active region. In this dissertation, we demonstrate the development of InGaP QW and InP QD lasers on GaAs and Si (001) substrates, integrated on silicon nitride photonic integrated circuits using molecular beam epitaxy. It is found that InP QDs on Si (001) show a photoluminescence intensity similar to counterparts grown on GaAs (001), despite a threading dislocation density (TDD) of 3.3×107 cm-2. In contrast, InGaP QWs on Si (001), with the same TDD, show 9× degradation in PL intensity compared to QWs on GaAs. We demonstrate post-growth annealing as an essential step towards demonstration of MBE-grown phosphide lasers, with InGaP single quantum well (SQW) and InP multiple quantum dot (MQD) lasers on GaAs operating with a threshold current density (Jth) of 170 A/cm2 and 230 A/cm2 on GaAs (001), the lowest continuous wave (CW) Jth by any growth technique. We also demonstrate strategies to reduce the TDD of epitaxial GaAs/Si from > 4×108 cm-2 to 6×106 cm-2 by using dislocation filtering techniques. Utilizing low-TDD GaAs/Si templates and low-Jth active region design, we show the first CW- room temperature (RT) InGaP SQW and InP MQD lasers on GaAs/Si (001) with Jth of 550 A/cm2 and 690 A/cm2, respectively, the lowest reported to the best of our knowledge. The higher dislocation tolerance of phosphide lasers, compared to arsenide lasers, can be attributed to the low carrier diffusivity in phosphides. The dissertation also presents preliminary results on the integration of visible optoelectronic devices on photonic integrated circuits utilizing silicon nitride waveguides on Si substrates
The Indian Sociologist: Vol. V, No. 10
No full textArticles (in 'The Indian Sociologist': Vol. V, No. 10) : "Terror In England."/"Necessity For An Oriental Union."/"The Trial Before Pilate."/"An Irishman In The british Army On The Martyrdom Of Dhingra."/"An Impartial Englishmans Opinion.
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