1,132 research outputs found
Independence in critical reading: An instructional strategy
Why can\u27t students read critically
Safe Positively Invariant Sets for Spacecraft Obstacle Avoidance
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140643/1/1.g000115.pd
Lung cancer screening
Randomised controlled trials, including the National Lung Screening Trial (NLST) and the NELSON trial, have shown reduced mortality with lung cancer screening with low-dose CT compared with chest radiography or no screening. Although research has provided clarity on key issues of lung cancer screening, uncertainty remains about aspects that might be critical to optimise clinical effectiveness and cost-effectiveness. This Review brings together current evidence on lung cancer screening, including an overview of clinical trials, considerations regarding the identification of individuals who benefit from lung cancer screening, management of screen-detected findings, smoking cessation interventions, cost-effectiveness, the role of artificial intelligence and biomarkers, and current challenges, solutions, and opportunities surrounding the implementation of lung cancer screening programmes from an international perspective. Further research into risk models for patient selection, personalised screening intervals, novel biomarkers, integrated cardiovascular disease and chronic obstructive pulmonary disease assessments, smoking cessation interventions, and artificial intelligence for lung nodule detection and risk stratification are key opportunities to increase the efficiency of lung cancer screening and ensure equity of access.</p
An Optical Study of BG Geminorum: An Ellipsoidal Binary with an Unseen Primar Star
We describe optical photometric and spectroscopic observations of the bright
variable BG Geminorum. Optical photometry shows a pronounced ellipsoidal
variation of the K0 I secondary, with amplitudes of ~0.5 mag at VRI and a
period of 91.645 days. A deep primary eclipse is visible for wavelengths <
4400A; a shallower secondary eclipse is present at longer wavelengths. Eclipse
timings and the radial velocity curve of the K0 secondary star indicate an
interacting binary where a lobe-filling secondary, M_2 ~ 0.5 Msun, transfers
material into a extended disk around a massive primary, M_1 ~ 4.5 Msun. The
primary star is either an early B-type star or a black hole. If it did contain
a black hole, BG Gem would be the longest period black hole binary known by a
factor of 10, as well as the only eclipsing black hole binary system.Comment: 27 pages, includes 8 figures and 5 tables, accepted to A
Radiative transition rates and collision strengths for Si II
Aims. This work reports radiative transition rates and electron impact
excitation collision strengths for levels of the 3s23p, 3s3p2, 3s24s, and 3s23d
configurations of Siii. Methods. The radiative data were computed using the
Thomas-Fermi-Dirac-Amaldi central potential, but with the modifications
introduced by Bautista (2008) that account for the effects of electron-electron
interactions. We also introduce new schemes for the optimization of the
variational parameters of the potential. Additional calculations were carried
out with the Relativistic Hartree-Fock and the multiconfiguration Dirac-Fock
methods. Collision strengths in LS-coupling were calculated in the close
coupling approximation with the R-matrix method. Then, fine structure collision
strengths were obtained by means of the intermediate-coupling frame
transformation (ICFT) method which accounts for spin-orbit coupling effects.
Results. We present extensive comparisons between the results of different
approximations and with the most recent calculations and experiment available
in the literature. From these comparisons we derive a recommended set of gf-
values and radiative transition rates with their corresponding estimated
uncertainties. We also study the effects of different approximations in the
representation of the target ion on the electron-impact collision strengths.
Our most accurate set of collision strengths were integrated over a Maxwellian
distribution of electron energies and the resulting effective collision
strengths are given for a wide range of temperatures. Our results present
significant differences from recent calculations with the B-spline
non-orthogonal R-matrix method. We discuss the sources of the differences.Comment: 6 figures, 5 tables within text, 2 electronic table
State Assessment of Demographic Data and Youth Development to Advance 4-H Programs
4-H youth development programs throughout the United States can be planned and delivered more effectively in their states by assessing demographic data and following research-based theories and models of positive youth development. A review of the research literature determined current youth development theories and models to effectively guide statewide 4-H program implementation. A state assessment was conducted for demographic areas of youth population age, race, socioeconomic status, health factors, child poverty (includes parent-guardian job status at the onset of COVID), and household structure. The Ohio 4-H Youth Development program utilized the demographic data to establish goals of becoming more diverse and inclusive. In addition, demographic data points help for targeted recruitment of youth to include families from diverse socioeconomic backgrounds, household structures, and those with health risks. Finally, implications and conclusions are presented to serve as an illustration for other states to advance their state 4-H programs and practices
Neutrons from multiplicity-selected La-La and Nb-Nb collisions at 400A MeV and La-La collisions at 250A MeV
Triple-differential cross sections for neutrons from high-multiplicity La-La
collisions at 250 and 400 MeV per nucleon and Nb-Nb collisions at 400 MeV per
nucleon were measured at several polar angles as a function of the azimuthal
angle with respect to the reaction plane of the collision. The reaction plane
was determined by a transverse-velocity method with the capability of
identifying charged-particles with Z=1, Z=2, and Z > 2. The flow of neutrons
was extracted from the slope at mid-rapidity of the curve of the average
in-plane momentum vs the center-of-mass rapidity. The squeeze-out of the
participant neutrons was observed in a direction normal to the reaction plane
in the normalized momentum coordinates in the center-of-mass system.
Experimental results of the neutron squeeze-out were compared with BUU
calculations. The polar-angle dependence of the maximum azimuthal anisotropy
ratio was found to be insensitive to the mass of the colliding
nuclei and the beam energy. Comparison of the observed polar-angle dependence
of the maximum azimuthal anisotropy ratio with BUU calculations for
free neutrons revealed that is insensitive also to the
incompressibility modulus in the nuclear equation of state.Comment: ReVTeX, 16 pages, 17 figures. To be published in Physical Review
Therapeutically engineered induced neural stem cells are tumour-homing and inhibit progression of glioblastoma
Transdifferentiation (TD) is a recent advancement in somatic cell reprogramming. The direct conversion of TD eliminates the pluripotent intermediate state to create cells that are ideal for personalized cell therapy. Here we provide evidence that TD-derived induced neural stem cells (iNSCs) are an efficacious therapeutic strategy for brain cancer. We find that iNSCs genetically engineered with optical reporters and tumouricidal gene products retain the capacity to differentiate and induced apoptosis in co-cultured human glioblastoma cells. Time-lapse imaging shows that iNSCs are tumouritropic, homing rapidly to co-cultured glioblastoma cells and migrating extensively to distant tumour foci in the murine brain. Multimodality imaging reveals that iNSC delivery of the anticancer molecule TRAIL decreases the growth of established solid and diffuse patient-derived orthotopic glioblastoma xenografts 230- and 20-fold, respectively, while significantly prolonging the median mouse survival. These findings establish a strategy for creating autologous cell-based therapies to treat patients with aggressive forms of brain cancer
X-Ray/Ultraviolet Observing Campaign of the Markarian 279 Active Galactic Nucleus Outflow: a close look at the absorbing/emitting gas with Chandra-LETGS
We present a Chandra-LETGS observation of the Seyfert 1 galaxy Mrk 279. This
observation was carried out simultaneously with HST-STIS and FUSE, in the
context of a multiwavelength study of this source. The Chandra pointings were
spread over ten days for a total exposure time of ~360 ks. The spectrum of
Mrk279 shows evidence of broad emission features, especially at the wavelength
of the OVII triplet. We quantitatively explore the possibility that this
emission is produced in the broad line region (BLR). We modeled the broad UV
emission lines seen in the FUSE and HST-STIS spectra following the ``locally
optimally emitting cloud" approach. We find that the X-ray lines luminosity
derived from the best fit BLR model can match the X-ray features, suggesting
that the gas producing the UV lines is sufficient to account also for the X-ray
emission. The spectrum is absorbed by ionized gas whose total column density is
~5x10^{20} cm^{-2}. The absorption spectrum can be modeled by two distinct gas
components (log xi ~ 0.47 and 2.49, respectively) both showing a significant
outflow velocity. However, the data allow also the presence of intermediate
ionization components. The distribution of the column densities of such extra
components as a function of the ionization parameter is not consistent with a
continuous, power law-like, absorber, suggesting a complex structure for the
gas outflow for Mrk 279 (abridged).Comment: 16 pages, 12 figures. To appear in A&
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