8,095 research outputs found
Operation Warp Speed: Projects responding to the COVID-19 pandemic
The 2020 COVID-19 pandemic has profound socio-economic consequences. Extraordinary times call for extraordinary measures, so this paper focuses on radical changes to accepted practice in project organizing in response. In particular, we focus on schedule compression to deliver outputs to mitigate the immediate impact of the pandemic on health. In the spirit of engaged scholarship, which is problem-driven rather than theory-driven, we address directly the evidence of what happened in two empirical vignettes and one more substantial case study â the CoronavirusUY app; emergency field hospitals; and vaccine development. We then suggest the implications for project management theory in discussion
A self-validating control system based approach to plant fault detection and diagnosis
An approach is proposed in which fault detection and diagnosis (FDD) tasks are distributed to separate FDD modules associated with each control system located throughout a plant. Intended specifically for those control systems that inherently eliminate steady state error, it is modular, steady state based, requires very little process specific information and therefore should be attractive to control systems implementers who seek economies of scale. The approach is applicable to virtually all types of process plant, whether they are open loop stable or not, have a type or class number of zero or not and so on. Based on qualitative reasoning, the approach is founded on the application of control systems theory to single and cascade control systems with integral action. This results in the derivation of cause-effect knowledge and fault isolation procedures that take into account factors like interactions between control systems, and the availability of non-control-loop-based sensors
Suspended silicon integrated platform for the long-wavelength mid-infrared band
The atmospheric-transmission window and the fingerprint region of many substances overlaps with the long-wave infrared band. This has enabled the emergence of a new path for photonic integrated circuits, which could exploit the potential applications of this wavelength range, including chemical and bio sensing. In this work we review our latest advances in the suspended silicon platform with subwavelength grating lateral cladding at 7.7-”m wavelength. Suspended waveguides only require one lithographic etch step and can be specifically designed to maximize sensitivity when used as sensors. Waveguides with propagation loss of 3.1±0.3 dB/cm are demonstrated, as well as bends with less than 0.1 dB/bend. Suspended waveguides based on shifted Bragg grating lateral cladding are also reported, with propagation loss of 5.1±0.6 dB/cm. These results prepare the ground for the development of a platform capable of covering the entire mid-infrared band.
Keywords: suspended silicon, mid-infrared, long-wave infrared, subwavelength grating, Bragg.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂa Tech
Quantum slow-roll and quantum fast-roll inflationary initial conditions: CMB quadrupole suppression and further effects on the low CMB multipoles
Quantum fast-roll initial conditions for the inflaton which are different
from the classical fast-roll conditions and from the quantum slow-roll
conditions can lead to inflation that last long enough. These quantum fast-roll
initial conditions for the inflaton allow for kinetic energies of the same
order of the potential energies and nonperturbative inflaton modes with nonzero
wavenumbers. Their evolution starts with a transitory epoch where the redshift
due to the expansion succeeds to assemble the quantum excited modes of the
inflaton in a homogeneous (zero mode) condensate, and the large value of the
Hubble parameter succeeds to overdamp the fast-roll of the redshifted inflaton
modes. After this transitory stage the effective classical slow-roll epoch is
reached. Most of the efolds are produced during the slow-roll epoch and we
recover the classical slow-roll results for the scalar and tensor metric
perturbations plus corrections. These corrections are important, both for
scalar and for tensor perturbations, if scales which are horizon-size today
exited the horizon by the end of the transitory stage and as a consequence the
lower CMB multipoles get suppressed (fast-roll) or enhanced (precondensate).
These two types of corrections can compete and combine in a scale dependent
manner. They arise as natural consequences of the quantum nonperturbative
inflaton dynamics, and provide a consistent and contrastable model for the
origin of the suppression of the quadrupole and for other departures of the low
CMB multipoles from the slow-roll inflation-LambdaCMB model which are to be
contrasted to the TE and EE multipoles and to the forthcoming and future CMB
data.Comment: LaTeX, 14 pages, 3 figure
Discovery of a novel quinoxalinhydrazide with a broad-spectrum anticancer activity
Previously, we discovered a novel class of salicylhydrazide compounds with remarkable activity in hormone-dependent and -independent human cancer cells. We then designed and synthesized numerous analogues. Among these analogues, a quinoxalinhydrazide compound, SC144, exhibited desirable physicochemical and drug-like properties and therefore was selected for further preclinical investigation. In the present study, we evaluated the in vitro activity of SC144 in a range of drug-sensitive and -resistant cancer cell lines as well as its in vivo efficacy in MDA-MB-435 and HT29 mice xenograft models. The broad-spectrum cytotoxicity of SC144 is especially highlighted by its potency in ovarian cancer cells resistant to cisplatin, breast-cancer cells resistant to doxorubicin, and colon cancer cells resistant to oxaliplatin. Furthermore, its activity was independent of p53, HER-2, estrogen and androgen receptor expressions. We also examined the effect of SC144 on cell cycle progression and apoptosis in select cell lines. Considering its cytotoxicity profile in a variety of in vitro and in vivo cancer models as well as its effects on cell cycle regulation and apoptosis, SC144 appears to represent a promising agent for further clinical development
Discovery of the broad-lined Type Ic SN 2013cq associated with the very energetic GRB 130427A
Long-duration gamma-ray bursts (GRBs) at z < 1 are in most cases found to be
accompanied by bright, broad-lined Type Ic supernovae (SNe Ic-BL). The
highest-energy GRBs are mostly located at higher redshifts, where the
associated SNe are hard to detect observationally. Here we present early and
late observations of the optical counterpart of the very energetic GRB 130427A.
Despite its moderate redshift z = 0.3399+/-0.0002, GRB 130427A is at the high
end of the GRB energy distribution, with an isotropic-equivalent energy release
of Eiso ~ 9.6x10^53 erg, more than an order of magnitude more energetic than
other GRBs with spectroscopically confirmed SNe. In our dense photometric
monitoring, we detect excess flux in the host-subtracted r-band light curve,
consistent with what expected from an emerging SN, ~0.2 mag fainter than the
prototypical SN 1998bw. A spectrum obtained around the time of the SN peak
(16.7 days after the GRB) reveals broad undulations typical of SNe Ic-BL,
confirming the presence of a SN, designated SN 2013cq. The spectral shape and
early peak time are similar to those of the high expansion velocity SN 2010bh
associated with GRB 100316D. Our findings demonstrate that high-energy
long-duration GRBs, commonly detected at high redshift, can also be associated
with SNe Ic-BL, pointing to a common progenitor mechanism.Comment: 12 pages, 4 figures, 1 table, accepted for publication in Ap
The Binding Properties of Glycosylated and Non-Glycosylated Tim-3 Molecules on CD4+CD25+ T Cells
PBI mixed matrix hollow fiber membrane: Influence of ZIF-8 filler over H2/CO2 separation performance at high temperature and pressure
High performance and commercially attractive mixed-matrix membranes were developed for H2/CO2 separation via a scalable hollow fiber spinning process. Thin (~300 nm) and defect-free selective layers were successfully created with a uniform distribution of the nanosized (~60 nm) zeolitic-imidazole framework (ZIF-8) filler within the polymer (polybenzimidazole, PBI) matrix. These membranes were able to operate at high temperature (150 °C) and pressure (up to 30 bar) process conditions required in treatment of pre-combustion and syngas process gas streams. Compared with neat PBI hollow fibers, filler incorporation into the polymer matrix leads to a strong increase in H2 permeance from 65 GPU to 107 GPU at 150 °C and 7 bar, while the ideal H2/CO2 selectivity remained constant at 18. For mixed gas permeation, there is competition between H2 and CO2 transport inside ZIF-8 structure. Adsorption of CO2 in the nanocavities of the filler suppresses the transport of the faster permeating H2 and consequently decreases the H2 permeance with total feed pressure down to values equal to the pure PBI hollow fibers for the end pressure of 30 bar. Therefore, the improvement of fiber performance for gas separation with filler addition is compromised at high operating feed pressures, which emphasizes the importance of membrane evaluation under relevant process conditions.The authors acknowledge the financial support of the European Research Council under the European Unionâs Seventh Framework Programme (FP/2007-2013), under grant agreement no. 608490, M4CO2 project. The Laboratorio de MicroscopĂas Avanzadas (LMA) at INA, University of Zaragoza is also acknowledged
Combined Fruit and Vegetable Intake Is Correlated with Improved Inflammatory and Oxidant Status from a Cross-Sectional Study in a Community Setting
Previous studies have examined the relationship between specific nutrient and food intakes with limited markers of either inflammation or oxidant status. The objective of this study was to determine if an increase in combined self-reported fruit and vegetable (F&V) intake in a community setting was associated with improved multiple markers of inflammatory and oxidant status. A community group (N = 1000, age 18â85 years, 61% female) gave two fasted blood samples separated by 12 weeks. Blood inflammatory biomarkers included total leukocytes (WBC), plasma C-reactive protein (CRP), interleukin-6 (IL-6), IL-10, tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1, and granulocyte colony stimulating factor. Measured oxidant status markers were ferric reducing ability of plasma (FRAP), oxygen radical absorbance capacity (ORAC) and plasma F2-isoprostanes. The relation of markers across categories of F&V intake was examined. In analyses controlling for other important dietary and lifestyle factors, IL-6 and TNF-α were significantly lower across categories of increasing F&V intakes (p < 0.008). FRAP and ORAC were significantly higher (p < 0.0001 and p = 0.047 respectively) while F2-isoprostanes was significantly lower (p < 0.0001) across F&V categories. In a community study, several markers of both inflammation and oxidant status were associated in a putatively salutary direction by higher intake of combined F&V, supporting current guidelines suggesting increased F&V consumption for the prevention of chronic diseases
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