964 research outputs found
Graduate Degrees of U.S. Army Officers and How They Relate to School Selection and Promotion
This study is concerned with the educational level of United States Army Officers and the influence educational level has on an officerJs selection to attend Army Service Schools. Because I am an Army officer pursuing a graduate degree, I wanted to determine what value such effort might have in my career progression.Distributive Education/Marketin
Deriving asteroid mineralogies from reflectance spectra: Implications for the MUSES-C target asteroid
In an effort to both bolster the spectral database on ordinary chondrites and constrain our ability to deconvolve modal, mineral chemistry and bulk chemical composition information from ordinary chondrites, we have initiated a spectral study of samples with known bulk compositions from the Smithsonian Institution\u27s Analyzed Meteorite Powder collection. In this paper, we focus on deriving a better formula for determining asteroid mineralogies from reflectance spectra. The MUSES-C mission to asteroid 25143 1998 SF36 will allow any derived mineralogies to be tested with a returned sample
Trends in Drug Utilization, Glycemic Control, and Rates of Severe Hypoglycemia, 2006-2013.
ObjectiveTo examine temporal trends in utilization of glucose-lowering medications, glycemic control, and rate of severe hypoglycemia among patients with type 2 diabetes (T2DM).Research design and methodsUsing claims data from 1.66 million privately insured and Medicare Advantage patients with T2DM from 2006 to 2013, we estimated the annual 1) age- and sex-standardized proportion of patients who filled each class of agents; 2) age-, sex-, race-, and region-standardized proportion with hemoglobin A1c (HbA1c) <6%, 6 to <7%, 7 to <8%, 8 to <9%, ≥9%; and 3) age- and sex-standardized rate of severe hypoglycemia among those using medications. Proportions were calculated overall and stratified by age-group (18-44, 45-64, 65-74, and ≥75 years) and number of chronic comorbidities (zero, one, and two or more).ResultsFrom 2006 to 2013, use increased for metformin (from 47.6 to 53.5%), dipeptidyl peptidase 4 inhibitors (0.5 to 14.9%), and insulin (17.1 to 23.0%) but declined for sulfonylureas (38.8 to 30.8%) and thiazolidinediones (28.5 to 5.6%; all P < 0.001). The proportion of patients with HbA1c <7% declined (from 56.4 to 54.2%; P < 0.001) and with HbA1c ≥9% increased (9.9 to 12.2%; P < 0.001). Glycemic control varied by age and was poor among 23.3% of the youngest and 6.3% of the oldest patients in 2013. The overall rate of severe hypoglycemia remained the same (1.3 per 100 person-years; P = 0.72), declined modestly among the oldest patients (from 2.9 to 2.3; P < 0.001), and remained high among those with two or more comorbidities (3.2 to 3.5; P = 0.36).ConclusionsDuring the recent 8-year period, the use of glucose-lowering drugs has changed dramatically among patients with T2DM. Overall glycemic control has not improved and remains poor among nearly a quarter of the youngest patients. The overall rate of severe hypoglycemia remains largely unchanged
Influence of rare regions on magnetic quantum phase transitions
The effects of quenched disorder on the critical properties of itinerant
quantum magnets are considered. Particular attention is paid to locally ordered
rare regions that are formed in the presence of quenched disorder even when the
bulk system is still in the nonmagnetic phase. It is shown that these local
moments or instantons destroy the previously found critical fixed point in the
case of antiferromagnets. In the case of itinerant ferromagnets, the critical
behavior is unaffected by the rare regions due to an effective long-range
interaction between the order parameter fluctuations.Comment: 4 pp., REVTe
Enclosed Versus Open Nursing Stations in Adult Acute Care Psychiatric Settings: Does the Design Affect the Therapeutic Milieu?
Specific efforts by hospital accreditation organizations encourage renovation of nursing stations, so nurses can better see, attend, and care for their patients. The purpose of this study was to examine the effect of nursing station design on the therapeutic milieu in an adult acute care psychiatric unit. A repeated cross-sectional, pretest-posttest design was used. Data were collected from a convenience sample of 81 patients and 25 nursing staff members who completed the Ward Atmosphere Scale. Pretest data were collected when the unit had an enclosed nursing station, and posttest data were collected after renovations to the unit created an open nursing station. No statistically significant differences were found in patient or staff perceptions of the therapeutic milieu. No increase in aggression toward staff was found, given patients' ease of access to the nursing station. More research is needed about the impact of unit design in acute care psychiatric settings
Dynamics at a smeared phase transition
We investigate the effects of rare regions on the dynamics of Ising magnets
with planar defects, i.e., disorder perfectly correlated in two dimensions. In
these systems, the magnetic phase transition is smeared because static
long-range order can develop on isolated rare regions. We first study an
infinite-range model by numerically solving local dynamic mean-field equations.
Then we use extremal statistics and scaling arguments to discuss the dynamics
beyond mean-field theory. In the tail region of the smeared transition the
dynamics is even slower than in a conventional Griffiths phase: the spin
autocorrelation function decays like a stretched exponential at intermediate
times before approaching the exponentially small equilibrium value following a
power law at late times.Comment: 10 pages, 8eps figures included, final version as publishe
On the critical behavior of disordered quantum magnets: The relevance of rare regions
The effects of quenched disorder on the critical properties of itinerant
quantum antiferromagnets and ferromagnets are considered. Particular attention
is paid to locally ordered spatial regions that are formed in the presence of
quenched disorder even when the bulk system is still in the paramagnetic phase.
These rare regions or local moments are reflected in the existence of spatially
inhomogeneous saddle points of the Landau-Ginzburg-Wilson functional. We derive
an effective theory that takes into account small fluctuations around all of
these saddle points. The resulting free energy functional contains a new term
in addition to those obtained within the conventional perturbative approach,
and it comprises what would be considered non-perturbative effects within the
latter. A renormalization group analysis shows that in the case of
antiferromagnets, the previously found critical fixed point is unstable with
respect to this new term, and that no stable critical fixed point exists at
one-loop order. This is contrasted with the case of itinerant ferromagnets,
where we find that the previously found critical behavior is unaffected by the
rare regions due to an effective long-ranged interaction between the order
parameter fluctuations.Comment: 16 pp., REVTeX, epsf, 2 figs, final version as publishe
Noncovalent magnetic control and reversible recovery of graphene oxide using iron oxide and magnetic surfactants
The unique charging properties of
graphene oxide (GO) are exploited
in the preparation of a range of noncovalent magnetic GO materials,
using microparticles, nanoparticles, and magnetic surfactants. Adsorption
and desorption are controlled by modification of pH within a narrow
window of <2 pH units. The benefit conferred by using charge-based
adsorption is that the process is reversible, and the GO can be captured
and separated from the magnetic nanomaterial, such that both components
can be recycled. Iron oxide (Fe<sub>2</sub>O<sub>3</sub>) microparticles
form a loosely flocculated gel network with GO, which is demonstrated
to undergo magnetic compressional dewatering in the presence of an
external magnetic field. For composites formed from GO and Fe<sub>2</sub>O<sub>3</sub> nanoparticles, it is found that low Fe<sub>2</sub>O<sub>3</sub>:GO mass ratios (<5:1) favor flocculation of GO,
whereas higher ratios (>5:1) cause overcharging of the surfaces
resulting
in restabilization. The effectiveness of the GO adsorption and magnetic
capture process is demonstrated by separating traditionally difficult-to-recover
gold nanoparticles (<i>d</i> ≈ 10 nm) from water.
The fully recyclable nature of the assembly and capture process, combined
with the vast adsorption capacity of GO, presents obvious and appealing
advantages for applications in decontamination and water treatment
Smeared phase transition in a three-dimensional Ising model with planar defects: Monte-Carlo simulations
We present results of large-scale Monte Carlo simulations for a
three-dimensional Ising model with short range interactions and planar defects,
i.e., disorder perfectly correlated in two dimensions. We show that the phase
transition in this system is smeared, i.e., there is no single critical
temperature, but different parts of the system order at different temperatures.
This is caused by effects similar to but stronger than Griffiths phenomena. In
an infinite-size sample there is an exponentially small but finite probability
to find an arbitrary large region devoid of impurities. Such a rare region can
develop true long-range order while the bulk system is still in the disordered
phase. We compute the thermodynamic magnetization and its finite-size effects,
the local magnetization, and the probability distribution of the ordering
temperatures for different samples. Our Monte-Carlo results are in good
agreement with a recent theory based on extremal statistics.Comment: 9 pages, 6 eps figures, final version as publishe
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