4,886 research outputs found
Air Taxi Skyport Location Problem for Airport Access
Witnessing the rapid progress and accelerated commercialization made in
recent years for the introduction of air taxi services in near future across
metropolitan cities, our research focuses on one of the most important
consideration for such services, i.e., infrastructure planning (also known as
skyports). We consider design of skyport locations for air taxis accessing
airports, where we present the skyport location problem as a modified
single-allocation p-hub median location problem integrating choice-constrained
user mode choice behavior into the decision process. Our approach focuses on
two alternative objectives i.e., maximizing air taxi ridership and maximizing
air taxi revenue. The proposed models in the study incorporate trade-offs
between trip length and trip cost based on mode choice behavior of travelers to
determine optimal choices of skyports in an urban city. We examine the
sensitivity of skyport locations based on two objectives, three air taxi
pricing strategies, and varying transfer times at skyports. A case study of New
York City is conducted considering a network of 149 taxi zones and 3 airports
with over 20 million for-hire-vehicles trip data to the airports to discuss
insights around the choice of skyport locations in the city, and demand
allocation to different skyports under various parameter settings. Results
suggest that a minimum of 9 skyports located between Manhattan, Queens and
Brooklyn can adequately accommodate the airport access travel needs and are
sufficiently stable against transfer time increases. Findings from this study
can help air taxi providers strategize infrastructure design options and
investment decisions based on skyport location choices.Comment: 25 page
Studies on the inheritance of leaf blast resistance in rice
Studies on the inheritance of leaf blast resistance in seven differential varieties of rice tested against two Indian isolates of the international races IA-11 add ID-1 of Pyricularia oryzae Cav. under standardized experimental conditions revealed the presence of three dominant genes, one each in Zenith. Tetep and Ginga conferring resistance to IA-11 and two, one each in Zenith and Tetep, to the race ID-1. The genes of Zenith were independent of those of Tetep. C.l. 5309 possessed inhibitory genes inhibiting the resistance of Zenith but not of Telep. Mode of segregation of resistance o Norin 20 to the race IA-11 was found to be anamolous. Studies on the crosses among susecptible varieties showed the existence of dominant genes conferring susceptibility, two each in P.I. 180061 and Yakeiko. This is a new feature of the present studies and its utility in evolving homozygous recessive resistant varieties have been pointed out
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Recovery of rough surface in ducting medium from grazing angle scattered wave
A method is developed for rough surface reconstruction using fields scattered at grazing angles in a medium with a linearly varying refractive index and Neumann boundary condition. This regime represents a ducting medium, bounded by a perfectly conducting surface with a TM incident field or an acoustically hard surface. This significantly extends the iterated marching method, based upon the parabolic integral equation for forward-scattered field components [Chen and Spivack, J. Opt. Soc. Am. A 35, 504–513 (2018)]. The approach, which uses a fixed frequency, is able to accurately recover multiscale surfaces and is found to be robust with respect to measurement noise and localized perturbations.</jats:p
Multiphysics Simulations of Thermal Shock Testing of Nanofibrous High Power Targets
Increase of primary beam power for neutrino beam-lines leads to a reduced
lifespan for production targets. New concepts for robust targets are emerging
from the field of High Power Targetry (HPT); one idea being investigated by the
HPT R&D Group at Fermilab is an electrospun nanofiber target. As part of their
evaluation, samples with different densities were sent to the HiRadMat facility
at CERN for thermal shock tests. The samples with the higher density,
irradiated under a high intensity beam pulse, exhibit major damage at the
impact site whereas those with the lower density show no apparent damage. The
exact cause of this failure was unclear at the time. In this paper, we present
the results of multiphysics simulations of the thermal shock experienced by the
nanofiber targets that suggest the failure originates from the reduced
permeability of the high density sample to air flow. The air present in the
porous target expands due to heating from the beam, but is unable to flow
freely in the high density sample, resulting in a larger back pressure that
blows apart the nanofiber mat. We close with a discussion on how to further
validate this hypothesis.Comment: IPAC'24 - 15th International Particle Accelerator Conferenc
Dynamic patterns of expertise: The case of orthopedic medical diagnosis
The aim of this study was to analyze dynamic patterns for scanning femoroacetabular impingement (FAI) radiographs in orthopedics, in order to better understand the nature of expertise in radiography. Seven orthopedics residents with at least two years of expertise and seven board-certified orthopedists participated in the study. The participants were asked to diagnose 15 anteroposterior (AP) pelvis radiographs of 15 surgical patients, diagnosed with FAI syndrome. Eye tracking data were recorded using the SMI desk-mounted tracker and were analyzed using advanced measures and methodologies, mainly recurrence quantification analysis. The expert orthopedists presented a less predictable pattern of scanning the radiographs although there was no difference between experts and non-experts in the deterministic nature of their scan path. In addition, the experts presented a higher percentage of correct areas of focus and more quickly made their first comparison between symmetric regions of the pelvis. We contribute to the understanding of experts' process of diagnosis by showing that experts are qualitatively different from residents in their scanning patterns. The dynamic pattern of scanning that characterizes the experts was found to have a more complex and less predictable signature, meaning that experts' scanning is simultaneously both structured (i.e. deterministic) and unpredictable
Exploring MicroRNA and Exosome Involvement in Malignant Pleural Mesothelioma Drug Response
Simple Summary Malignant pleural mesothelioma (MPM) is a deadly thoracic malignancy with limited treatment options. Chemotherapy remains the most widely used first-line treatment for unresectable MPM but is hampered by drug resistance issues. Small molecule inhibitors and microRNA mimics have shown promising potential for the treatment of MPM in preclinical studies, but are yet to be successfully implemented in the clinical setting. Our study aims to provide an understanding of the molecular mechanism(s) that mediate drug response in MPM. The inhibitor of apoptosis family member, survivin, has been reported to be over-expressed in MPM and is associated with drug resistance. Therefore, we particularly focused on determining the cellular mechanism(s) that contribute to MPM cell response to a survivin small molecule inhibitor, YM155. Our study provides key information to facilitate a prediction of the potential utility of small molecule inhibitors and microRNA mimics as treatment options for MPM. Malignant pleural mesothelioma (MPM) is a deadly thoracic malignancy and existing treatment options are limited. Chemotherapy remains the most widely used first-line treatment regimen for patients with unresectable MPM, but is hampered by drug resistance issues. The current study demonstrated a modest enhancement of MPM cell sensitivity to chemotherapy drug treatment following microRNA (miRNA) transfection in MPM cell lines, albeit not for all tested miRNAs. This effect was more pronounced for FAK (PND-1186) small molecule inhibitor treatment; consistent with previously published data. We previously established that MPM response to survivin (YM155) small molecule inhibitor treatment is unrelated to basal survivin expression. Here, we showed that MPM response to YM155 treatment is enhanced following miRNA transfection of YM155-resistant MPM cells. We determined that YM155-resistant MPM cells secrete a higher level of exosomes in comparison to YM155-sensitive MPM cells. Despit
Racism and anti-racism in Europe: a critical analysis of concepts and frameworks
The targets and expressions of racism vary across Europe. This article discusses the relevance of different descriptions and analyses of racism despite the different terms used in different countries such as ‘ethnic minority’, ‘foreigner’ or ‘black’ and different interpretations of which differences matter. It shows the significance of a cross-national European perspective on racism. There are important convergences across European countries in the discourses and practices of racism, particularly the distinction between ‘useful’ and ‘abusive’ migrants. A cross-European perspective can be an important inspiration for anti-racist struggles
Efficient presentation of both cytosolic and endogenous transmembrane protein antigens on MHC class II is dependent on cytoplasmic proteolysis
Peptides from extracellular proteins presented on MHC class II are mostly generated and loaded in endolysosomal compartments, but the major pathways responsible for loading peptides from APC-endogenous sources on MHC class II are as yet unclear. In this study, we show that MHC class II molecules present peptides from proteins such as OVA or conalbumin introduced into the cytoplasm by hyperosmotic pinosome lysis, with efficiencies comparable to their presentation via extracellular fluid-phase endocytosis. This cytosolic presentation pathway is sensitive to proteasomal inhibitors, whereas the presentation of exogenous Ags taken up by endocytosis is not. Inhibitors of nonproteasomal cytosolic proteases can also inhibit MHC class II-restricted presentation of cytosolically delivered protein, without inhibiting MHC class I-restricted presentation from the same protein. Cytosolic processing of a soluble fusion protein containing the peptide epitope I-Eα 52-68 yields an epitope that is similar to the one generated during constitutive presentation of I-Eα as an endogenous transmembrane protein, but is subtly different from the one generated in the exogenous pathway. Constitutive MHC class II-mediated presentation of the endogenous transmembrane protein I-Eα is also specifically inhibited over time by inhibitors of cytosolic proteolysis. Thus, Ag processing in the cytoplasm appears to be essential for the efficient presentation of endogenous proteins, even transmembrane ones, on MHC class II, and the proteolytic pathways involved may differ from those used for MHC class I-mediated presentation
Nuclear matrix elements calculation for decay of Sn using nonclosure approach in nuclear shell model
In this study, we calculate the nuclear matrix elements (NMEs) for the light
neutrino-exchange mechanism of neutrinoless double beta ) decay
of Sn within the framework of the interacting nuclear shell model using
the effective shell model Hamiltonian GCN5082. A novel method based on a
nonclosure approach is employed, wherein for the intermediate nucleus
Sb, effects of energy of 100 states for each = to
and to (=1) are explicitly included in
the NMEs calculation. Other common effects such as the finite size of nucleons,
higher-order effects of nucleon currents, and short-range correlations (SRC) of
nucleons are also taken into account. The extracted optimal closure energy is
2.9 MeV for a total NME of Sn decay, which is
independent of different forms of SRC parametrizations. A comparison of NMEs
and half-lives with some of the recent calculations is presented. Further, to
gain a comprehensive understanding of the role of nuclear structure on the
decay, the dependence of NMEs on spin-parity of the
intermediate states, coupled spin-parity of neutrons and protons, and the
number of intermediate states, is explored. It is observed that the inclusion
of the effects of excitation energies of the intermediate nucleus yields more
reliable NMEs. The present findings provide valuable insights for experimental
investigations of decay of Sn in India and elsewhere.Comment: 12 pages, 6 figures, submitted in the journal Physical Review C.
arXiv admin note: text overlap with arXiv:2308.0821
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