4,171 research outputs found
Net Worth Accumulation by Different Quintiles of Older Adults Approaching Retirement Age and 10 Years Later
The shift in responsibility for income security from the government to individuals makes the accumulation of net worth a vital issue. We investigated the rate of net worth accumulation for people aged 51 to 61 in 1991 (N=7,544) and 61 to 71 in 2001 (N=5,711) using the RAND Health and Retirement Study. We found that the rate of net worth accumulation by the fifth (top) quintile was extremely high in 1991, and the distribution of net worth became more skewed in favor of the wealthy in 2001. Older adults in the first and second quintiles are unable to face the challenge of the shift in responsibility for income security from the government to individuals
The nature of solar brightness variations
The solar brightness varies on timescales from minutes to decades.
Determining the sources of such variations, often referred to as solar noise,
is of importance for multiple reasons: a) it is the background that limits the
detection of solar oscillations, b) variability in solar brightness is one of
the drivers of the Earth's climate system, c) it is a prototype of stellar
variability which is an important limiting factor for the detection of
extra-solar planets. Here we show that recent progress in simulations and
observations of the Sun makes it finally possible to pinpoint the source of the
solar noise. We utilise high-cadence observations from the Solar Dynamic
Observatory and the SATIRE model to calculate the magnetically-driven
variations of solar brightness. The brightness variations caused by the
constantly evolving cellular granulation pattern on the solar surface are
computed with the MURAM code. We find that surface magnetic field and
granulation can together precisely explain solar noise on timescales from
minutes to decades, i.e. ranging over more than six orders of magnitude in the
period. This accounts for all timescales that have so far been resolved or
covered by irradiance measurements. We demonstrate that no other sources of
variability are required to explain the data. Recent measurements of Sun-like
stars by CoRoT and Kepler uncovered brightness variations similar to that of
the Sun but with much wider variety of patterns. Our finding that solar
brightness variations can be replicated in detail with just two well-known
sources will greatly simplify future modelling of existing CoRoT and Kepler as
well as anticipated TESS and PLATO data.Comment: This is the submitted version of the paper published in Nature
Astronom
Ellipsometric measurements of the refractive indices of linear alkylbenzene and EJ-301 scintillators from 210 to 1000 nm
We report on ellipsometric measurements of the refractive indices of LAB-PPO,
Nd-doped LAB-PPO and EJ-301 scintillators to the nearest +/-0.005, in the
wavelength range 210-1000 nm.Comment: 7 pages, 4 figure
Intersite coupling effects in a Kondo lattice
The La dilution of the Kondo lattice CeCoIn_5 is studied. The scaling laws
found for the magnetic susceptibility and the specific heat reveal two
well-separated energy scales, corresponding to the single impurity Kondo
temperature T_K and an intersite spin-liquid temperature T^*. The Ce-dilute
alloy has the expected Fermi liquid ground state, while the specific heat and
resistivity in the dense Kondo regime exhibit non-Fermi-liquid behavior, which
scales with T^*. These observations indicate that the screening of the magnetic
moments in the lattice involves antiferromagnetic intersite correlations with a
larger energy scale in comparison with the Kondo impurity case.Comment: 4 pages, 4 figure
Electrochemical polymerisation of phenol in aqueous solution on a Ta/PbO2 anode
This paper deals with the treatment of aqueous phenol solutions using an electrochemical technique. Phenol can be partly eliminated from aqueous solution by electrochemically initiated polymerisation. Galvanostatic electrolyses of phenol solutions at concentration up to 0.1 mol dm−3 were carried out on a Ta/PbO2 anode. The polymers formed are insoluble in acidic medium but soluble in alkaline. These polymers were filtered and then dissolved in aqueous solution of sodium hydroxide (1 mol dm−3). The polymers formed were quantified by total organic carbon (TOC) measurement. It was found that the conversion of phenol into polymers increases as a function of initial concentration, anodic current density, temperature, and solution pH. The percentage of phenol polymerised can reach 15%
Incidence and antibiogram of Vibrio parahaemolyticus in processed and frozen bivalve mollusks in Kuala Terengganu, Malaysia
This study aimed to investigate the prevalence and antibiogram of Vibrio parahaemolyticus in processed bivalve molluscs in Kuala Terengganu. A total of 80 seafood samples, namely mussels (n=20), carpet clams (n=20), cockles (n=20) and scallops (n=20), were subjected to PCR and conventional plating method for the detection of V. parahaemolyticus. V. parahaemolyticus was found in green mussels (55%), carpet clam (80%), cockles (40%) and scallops (55%). Fifty-five V. parahaemolyticus isolates were subjected to 9 types antibiotic sensitivity test using discs diffusion method. All isolates were susceptible to Tetracycline and Gentamycin. Isolates showed high resistance towards Vancomycin (52.73%), Penicillin (45.45%) and Amplicillin (32.73%). Resistance towards Amikacin, Ciprofloxacin and Norfloxacin were found to be 1.82%. It can be concluded that local bivalve molluscs were contaminated with V. parahaemolyticus and isolates showed resistance towards certain antibiotics. Therefore, consumption of raw or semi-cooked bivalve molluscs is not advisable
Liquid-to-liquid phase transition in pancake vortex systems
We study the thermodynamics of a model of pancake vortices in layered
superconductors. The model is based on the effective pair potential for the
pancake vortices derived from the London approximation of a version of the
Lawrence-Doniach model which is valid for extreme type-II superconductors.
Using the hypernetted-chain (HNC) approximation, we find that there is a
temperature below which multiple solutions to the HNC equations exist. By
explicitly evaluating the free energy for each solution we find that the system
undergoes a first-order transition between two vortex liquid phases. The
low-temperature phase has larger correlations along the field direction than
the high-temperature phase. We discuss the possible relation of this phase
transition to the liquid-to-liquid phase transition recently observed in
Y-Ba-Cu-O superconductors in high magnetic fields in the presence of disorder.Comment: 7 pages, 6 figure
B meson wave function from the decay
We show that the leading-power meson wave function can be extracted
reliably from the photon energy spectrum of the decay up to
and uncertainty, being the quark mass
and the strong coupling constant. The corrections from
heavy-quark expansion can be absorbed into a redefined leading-power meson
wave function. The two-parton corrections cancel exactly, and the
three-parton meson wave functions turn out to contribute at .
The constructive long-distance contribution through the
transition, being a vector meson, almost cancels the destructive
radiative correction. Using models of the leading-power meson
wave function available in the literature, we obtain the photon energy spectrum
in the perturbative QCD framework, which is then compared with those from other
approaches.Comment: 11 pages, 5 figures with minor correction
Shoulder recovery for head and neck cancer patients after unilateral neck dissection: a pilot exploratory study
An established side-effect of neck dissection (ND) for head and neck (HNC) tumour management includes shoulder dysfunction (SD), which can impact quality of life (QOL). Shoulder strength and range of movement (ROM) are key parameters to be monitored in SD. However, such evaluations are not routinely conducted in the clinical setting. The aim of this study was to evaluate objectively the impact of ND on shoulder functions.
Methods: This is a pilot exploratory study in a tertiary cancer centre. Five participants with unilateral ND and advanced HNC, completed the study. Outcome measures consisted of self-reported QOL questionnaires, C2–T1 dermatomes and shoulder ROM and strength testing. Data was collected at baseline, 1.5-months after surgery and 6-months after diagnosis (after adjuvant treatment completion).
Results: Most outcome measures on the surgically affected side were negatively impacted post-operatively, with varied recovery seen at follow-up. Sensory loss was noted at C3–4 dermatome levels. Shoulder ROM and strength was reduced on the surficial side for all participants, with some recovery after six months except for two participants.
Conclusion: Results of SD after ND are diverse and unique to each patient. Findings from this pilot study indicate that regular rehabilitation/exercise may facilitate recovery of shoulder function post HNC surgery. However, customised rehabilitation may yield better outcomes. Future studies with a larger sample are indicated to validate the findings of this study
Reentrant Melting of Soliton Lattice Phase in Bilayer Quantum Hall System
At large parallel magnetic field , the ground state of bilayer
quantum Hall system forms uniform soliton lattice phase. The soliton lattice
will melt due to the proliferation of unbound dislocations at certain finite
temperature leading to the Kosterlitz-Thouless (KT) melting. We calculate the
KT phase boundary by numerically solving the newly developed set of Bethe
ansatz equations, which fully take into account the thermal fluctuations of
soliton walls. We predict that within certain ranges of , the
soliton lattice will melt at . Interestingly enough, as temperature
decreases, it melts at certain temperature lower than exhibiting
the reentrant behaviour of the soliton liquid phase.Comment: 11 pages, 2 figure
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