5,861 research outputs found
Characterization of a Second Bovine Rotavirus Serotype
Bovine rotavirus (BRV) V 1005 was characterized by two-way cross-neutralization tests as a second serotype of BRV. Virions and inner shell particles of 65 nm and 55 nm diameter respectively, and empty capsids of 65 nm and 55 nm diameter were separated by density gradient centrifugation. Three polypeptides of molecular weight 60,000, 36,000 and 28,000 (minor protein) could be identified in the outer shell of virions and in the larger empty capsids. Inner shell particles contained three polypeptides of molecular weight 105,000, 83,000 and 43,000. Both sizes of empty capsids showed two polypeptides of molecular weight 75,000 and 55,000 not found in virions. Pulse-labelling of infected cells revealed eight major and three minor intracellular viral polypeptides. Viral polypeptide synthesis started at about 6 hours p.i. and correlated in time with double-stranded RNA synthesis. As soon as viral polypeptide synthesis was detectable, newly synthesized viral polypeptides were incorporated into intracellular viral particles. Radioactive viral polypeptides appeared without a longer lag period in extracellular viruses from 6 hours p.i. onward
THz conductivity of SrCaRuO
We investigate the optical conductivity of SrCaRuO across the
ferromagnetic to paramagnetic transition that occurs at . The thin films
were grown by metalorganic aerosol deposition with onto
NdGaO substrates. We performed THz frequency domain spectroscopy in a
frequency range from 3~cm to 40~cm (100~GHz to 1.4~THz) and at
temperatures ranging from 5~K to 300~K, measuring transmittivity and phase
shift through the films. From this we obtained real and imaginary parts of the
optical conductivity. The end-members, ferromagnetic SrRuO and paramagnetic
CaRuO, show a strongly frequency-dependent metallic response at
temperatures below 20~K. Due to the high quality of these samples we can access
pronounced intrinsic electronic contributions to the optical scattering rate,
which at 1.4~THz exceeds the residual scattering rate by more than a factor of
three. Deviations from a Drude response start at about 0.7~THz for both
end-members in a remarkably similar way. For the intermediate members a higher
residual scattering originating in the compositional disorder leads to a
featureless optical response, instead. The relevance of low-lying interband
transitions is addressed by a calculation of the optical conductivity within
density functional theory in the local density approximation (LDA)
Shaping a superconducting dome: Enhanced Cooper-pairing versus suppressed phase coherence in coupled aluminum nanograins
Deterministic enhancement of the superconducting (SC) critical temperature
is a long-standing goal in material science. One strategy is engineering
a material at the nanometer scale such that quantum confinement strengthens the
electron pairing, thus increasing the superconducting energy gap , as
was observed for individual nanoparticles. A true phase-coherent SC condensate,
however, can exist only on larger scales and requires a finite phase stiffness
. In the case of coupled aluminium (Al) nanograins, can exceed that of
bulk Al by a factor of three, but despite several proposals the relevant
mechanism at play is not yet understood. Here we use optical spectroscopy on
granular Al to disentangle the evolution of the fundamental SC energy scales,
and , as a function of grain coupling. Starting from well-coupled
arrays, grows with progressive grain decoupling, causing the
increasing of . As the grain-coupling is further suppressed,
saturates while decreases, concomitantly with a sharp decline of .
This crossover to a phase-driven SC transition is accompanied by an optical gap
persisting above . These findings identify granular Al as an ideal
playground to test the basic mechanisms that enhance superconductivity by
nano-inhomogeneity.Comment: 6 + 6 pages (manuscript + supplementary material
The FCC\u27s Minority Ownership Policies from Broadcasting to PCS
The Federal Communication Commission\u27s (FCC\u27s) proposed minority preference scheme for broadcast spectrum allocation has been called into question in the wake of the Supreme Court(s recent decision in Adarand Constructors, Inc. v. Pena. The Authors begin by discussing the development of minority preference schemes in the 1970s and 1980s and the changes in the methods through which the FCC has awarded broadcast licenses. In 1993, the FCC was granted the authority to auction spectrum allocation, provided that the FCC ensured the economic opportunity of minority-owned business under such a competitive bidding regulatory regime. However, this grant of authority presented the FCC with a legal concern: ensuring that the a minority preference scheme was not violative of the Equal Protection Clauses of the Fifth and Fourteenth Amendments. To this end, the FCC established entrepreneurs\u27 blocks in which two spectrum blocks were set-aside for applicants meeting certain financial qualifications. These financial-based eligibility restrictions appeared to create a solid legal foundation. However, the Adarand decision has resulted in the FCC postponing the proposed entrepreneurs\u27 block auction indefinitely.
The remainder of the Article is a discussion of the Adarand decision and its effect on the proposed blocks. In particular, the Authors discuss whether the FCC-proposed scheme will survive the strict scrutiny standard imposed by Adarand
The FCC\u27s Minority Ownership Policies from Broadcasting to PCS
The Federal Communication Commission\u27s (FCC\u27s) proposed minority preference scheme for broadcast spectrum allocation has been called into question in the wake of the Supreme Court(s recent decision in Adarand Constructors, Inc. v. Pena. The Authors begin by discussing the development of minority preference schemes in the 1970s and 1980s and the changes in the methods through which the FCC has awarded broadcast licenses. In 1993, the FCC was granted the authority to auction spectrum allocation, provided that the FCC ensured the economic opportunity of minority-owned business under such a competitive bidding regulatory regime. However, this grant of authority presented the FCC with a legal concern: ensuring that the a minority preference scheme was not violative of the Equal Protection Clauses of the Fifth and Fourteenth Amendments. To this end, the FCC established entrepreneurs\u27 blocks in which two spectrum blocks were set-aside for applicants meeting certain financial qualifications. These financial-based eligibility restrictions appeared to create a solid legal foundation. However, the Adarand decision has resulted in the FCC postponing the proposed entrepreneurs\u27 block auction indefinitely.
The remainder of the Article is a discussion of the Adarand decision and its effect on the proposed blocks. In particular, the Authors discuss whether the FCC-proposed scheme will survive the strict scrutiny standard imposed by Adarand
Exact -cosmological model coming from the request of the existence of a Noether symmetry
We present an -cosmological model with an exact analytic solution,
coming from the request of the existence of a Noether symmetry, which is able
to describe a dust-dominated decelerated phase before the current accelerated
phase of the universe.Comment: 4 pages, 2 figures, Contribution to the proceedings of Spanish
Relativity Meeting 2008, Salamanca, Sapin, 15-19 September 200
Modeling and Simulation of the Effects of Cyclic Loading on Articular Cartilage Lesion Formation
We present a model of articular cartilage lesion formation to simulate the
effects of cyclic loading. This model extends and modifies the
reaction-diffusion-delay model by Graham et al. 2012 for the spread of a lesion
formed though a single traumatic event. Our model represents "implicitly" the
effects of loading, meaning through a cyclic sink term in the equations for
live cells.
Our model forms the basis for in silico studies of cartilage damage relevant
to questions in osteoarthritis, for example, that may not be easily answered
through in vivo or in vitro studies.
Computational results are presented that indicate the impact of differing
levels of EPO on articular cartilage lesion abatement
Prevalence of stereotypy in individuals with developmental disabilities: a systematic review
Although many researchers have examined the prevalence of stereotypy in individuals with developmental disabilities, the results of previous studies have not been aggregated and analyzed methodically. Thus, we conducted a systematic review of studies reporting the prevalence of stereotypy in individuals with developmental disabilities. Our results indicated that the average prevalence of stereotypy across studies was 61 % and that individuals with autism spectrum disorders had the highest reported prevalence (i.e., 88 %) across specific diagnoses. Children and adults generally had similar overall prevalence measures, but the specific forms varied with age and diagnosis. Studies using the Repetitive Behavior Scale-Revised and the Autism Diagnostic Schedule-Revised generally reported higher estimates of prevalence of specific forms of stereotypy when compared to the Behavior Problem Inventory. However, the latter seemed more sensitive than the Aberrant Behavior Checklist for overall prevalence. Studies with a low risk of bias found a lower prevalence of stereotypy than those with a high risk of bias. Our systematic review underlines the importance of continuing research efforts to improve the assessment and treatment of stereotypy in individuals with developmental disabilities
High-performance silver window electrodes for top-illuminated organic photovoltaics using an organo-molybdenum oxide bronze interlayer
We report an organo-molybdenumn oxide bronze that enables the fabrication of high-performance silver window electrodes for top-illuminated solution processed organic photovoltaics without complicating the process of device fabrication. This hybrid material combines the function of wide-band-gap interlayer for efficient hole extraction with the role of metal electrode seed layer, enabling the fabrication of highly transparent, low-sheet-resistance silver window electrodes. Additionally it is also processed from ethanol, which ensures orthogonality with a large range of solution processed organic semiconductors. The key organic component is the low cost small molecule 3-mercaptopropionic acid, which (i) promotes metal film formation and imparts robustness at low metal thickness, (ii) reduces the contact resistance at the Ag/molybdenumn oxide bronze interface, (iii) and greatly improves the film forming properties. Silver electrodes with a thickness of 8 nm deposited by simple vacuum evaporation onto this hybrid interlayer have a sheet resistance as low as 9.7 Ohms per square and mean transparency ∼80% over the wavelength range 400–900 nm without the aid of an antireflecting layer, which makes them well-matched to the needs of organic photovoltaics and applicable to perovskite photovoltaics. The application of this hybrid material is demonstrated in two types of top-illuminated organic photovoltaic devices
- …