3,463 research outputs found
The Radio Jet Associated with the Multiple V380 Ori System
The giant Herbig-Haro object 222 extends over 6 in the plane of the
sky, with a bow shock morphology. The identification of its exciting source has
remained uncertain over the years. A non-thermal radio source located at the
core of the shock structure was proposed to be the exciting source. However,
Very Large Array studies showed that the radio source has a clear morphology of
radio galaxy and a lack of flux variations or proper motions, favoring an
extragalactic origin. Recently, an optical-IR study proposed that this giant HH
object is driven by the multiple stellar system V380 Ori, located about 23
to the SE of HH 222. The exciting sources of HH systems are usually detected as
weak free-free emitters at centimeter wavelengths. Here we report the detection
of an elongated radio source associated with the Herbig Be star or with its
close infrared companion in the multiple V380 Ori system. This radio source has
the characteristics of a thermal radio jet and is aligned with the direction of
the giant outflow defined by HH~222 and its suggested counterpart to the SE,
HH~1041. We propose that this radio jet traces the origin of the large scale HH
outflow. Assuming that the jet arises from the Herbig Be star, the radio
luminosity is a few times smaller than the value expected from the
radio-bolometric correlation for radio jets, confirming that this is a more
evolved object than those used to establish the correlation.Comment: 13 pages, 3 figure
Statistical mechanics model of angiogenic tumor growth
We examine a lattice model of tumor growth where survival of tumor cells
depends on the supplied nutrients. When such a supply is random, the extinction
of tumors belongs to the directed percolation universality class. However, when
the supply is correlated with distribution of tumor cells, which as we suggest
might mimick the angiogenic growth, the extinction shows different, and most
likely novel critical behaviour. Such a correlation affects also the morphology
of the growing tumors and drastically raise tumor survival probability.Comment: 4 page
Comparison of the use of sodium carbonate (washing soda crystals) and apomorphine for inducing emesis in dogs
Objective: To describe the use of sodium carbonate and apomorphine in a historical cohort of dogs, compare the occurrence of emesis and report any adverse effects recorded. Methods: This historical, observational study included information from medical records of dogs that received an emetic agent. The occurrence of emesis with apomorphine or sodium carbonate was calculated and the association between emesis and agent was explored, with the odds ratio and 95% confidence interval (CI) reported. A non-inferiority analysis of the occurrence of emesis for sodium carbonate was performed against an equivalence range of ±7% of the estimated occurrence of emesis with apomorphine. Owners were emailed a short survey about their dog's health after their visit to the hospital for induced emesis. Results: Records for 787 dogs seen from January 2007 to December 2013 were included. For apomorphine, 382/392 dogs showed emesis (97%, 95% CI 95–100%). For sodium carbonate, 320/395 dogs showed emesis (81%, 95% CI 77–85%), which fell below the equivalence range for apomorphine (97 ± 7%, 90–100%) and was considered inferior. The odds ratio of emesis with apomorphine to sodium carbonate was 9.0 (95% CI 4.6–17.6). Of 18 responses to the survey, 5 reported abnormalities after emesis (3 with sodium carbonate, 2 with apomorphine). Conclusion: The occurrence of emesis with sodium carbonate was high but inferior to apomorphine. However, the advantages of sodium carbonate, including less expense and ease of accession compared with apomorphine, make it a viable choice in emergency medicine
Time-dependent versus static quantum transport simulations beyond linear response
To explore whether the density-functional theory non-equilibrium Green's
function formalism (DFT-NEGF) provides a rigorous framework for quantum
transport, we carried out time-dependent density functional theory (TDDFT)
calculations of the transient current through two realistic molecular devices,
a carbon chain and a benzenediol molecule inbetween two aluminum electrodes.
The TDDFT simulations for the steady state current exactly reproduce the
results of fully self-consistent DFT-NEGF calculations even beyond linear
response. In contrast, sizable differences are found with respect to an
equilibrium, non-self-consistent treatment which are related here to
differences in the Kohn-Sham and fully interacting susceptibility of the device
region. Moreover, earlier analytical conjectures on the equivalence of static
and time-dependent approaches in the low bias regime are confirmed with high
numerical precision.Comment: 4 pages, 4 figure
Time-dependent density functional theory based Ehrenfest dynamics
Time-dependent density functional theory based Ehrenfest dynamics with atom-centered basis functions is developed in present work. The equation of motion for electrons is formulated in terms of first-order reduced density matrix and an additional term arises due to the time-dependence of basis functions through their dependence on nuclear coordinates. This time-dependence of basis functions together with the imaginary part of density matrix leads to an additional term for nuclear force. The effects of the two additional terms are examined by studying the dynamics of H 2 and C 2H 4, and it is concluded that the inclusion of these two terms is essential for correct electronic and nuclear dynamics. © 2011 American Institute of Physics.published_or_final_versio
Prescribing of Antipsychotic Medication in a Medicaid Population: Use of Polytherapy and Off-Label Dosages
OBJECTIVES: To describe the use of atypical antipsychotic medications in a Medicaid-enrolled population composed primarily of elderly and disabled patients. Our analyses focused upon the frequency of use of polytherapy with multiple antipsychotic medications and the prescribing of off-label dosages.
METHODS: We conducted a cross-sectional retrospective analysis of oral antipsychotic medication use, as prescribed for this population in 2003. The unit of analysis was the patient. We determined the prevalence of use of each type of antipsychotic medication according to gender and age group and determined the extent of use of combination therapies with multiple oral antipsychotic medications. Using the dosage ranges described in the product labeling, we identified the percentage of patients prescribed in-range dosages, overall and for each atypical antipsychotic medication studied. Those identified as receiving out-of-range (off-label) dosages were further stratified by gender and age group. The statistical significance of differences between these proportions was assessed using the chi-square test.
RESULTS: Of the 8,616 patients meeting our inclusion criteria, 7,748 (90%) received monotherapy with an oral antipsychotic medication and 868 patients (10%) received polytherapy with multiple oral antipsychotic medications. Approximately 2 of 3 patients receiving atypical antipsychotic medications were prescribed a dosage that was within the range recommended in the product labeling. Dosages lower than recommended in the product labeling were prescribed for 27% of patients receiving atypical antipsychotics, while 6% of patients received an above-range dosage. The frequency of patients receiving in-range dosages varied substantially among medications. Younger patients and male patients were more frequently prescribed above-range dosages while older patients and female patients were more frequently prescribed below-range dosages of these medications (P less than 0.001 for both findings).
CONCLUSION: In this subpopulation of Medicaid enrollees who were prescribed antipsychotic medications, we found a 10% incidence of use of antipsychotic polytherapy and a 33% incidence of prescribing of dosages outside the range listed in the product labeling. These findings suggest that physicians commonly prescribe antipsychotic medications in a manner that differs from the recommendations described in the prescribing information. The off-label use of atypical antipsychotic medications raises important questions regarding the purpose and applicability of the product labeling and the role and ability of the pharmacist to provide information regarding the risks and benefits of therapy as commonly prescribed
Randomised controlled study of treatment for mild and moderate sleep apnoea
Health Services Research Fund & Health Care and Promotion Fund: Research Dissemination Reports (Series 6)published_or_final_versio
SN2007ax : An Extremely Faint Type Ia Supernova
We present multi-band photometric and optical spectroscopic observations of
SN2007ax, the faintest and reddest Type Ia supernova (SNIa) yet observed. With
M_B = -15.9 and (B-V)max = 1.2, this SN is over half a magnitude fainter at
maximum light than any other SNIa. Similar to subluminous SN2005ke, SN2007ax
also appears to show excess in UV emission at late time. Traditionally,
Delta-m_15(B) has been used to parameterize the decline rate for SNeIa.
However, the B-band transition from fast to slow decline occurs sooner than 15
days for faint SNeIa. Therefore we suggest that a more physically motivated
parameter, the time of intersection of the two slopes, be used instead. Only by
explaining the faintest (and the brightest) supernovae, we can thoroughly
understand the physics of thermonuclear explosions. We suggest that future
surveys should carefully design their cadence, depth, pointings and follow-up
to find an unbiased sample of extremely faint members of this subclass of faint
SNeIa.Comment: Accepted for publication in ApJ
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