460 research outputs found
Analysis of individual differences in neurofeedback training illuminates successful self-regulation of the dopaminergic midbrain
The dopaminergic midbrain is associated with reinforcement learning, motivation and decision-making – functions often disturbed in neuropsychiatric disorders. Previous research has shown that dopaminergic midbrain activity can be endogenously modulated via neurofeedback. However, the robustness of endogenous modulation, a requirement for clinical translation, is unclear. Here, we examine whether the activation of particular brain regions associates with successful regulation transfer when feedback is no longer available. Moreover, to elucidate mechanisms underlying effective self-regulation, we study the relation of successful transfer with learning (temporal difference coding) outside the midbrain during neurofeedback training and with individual reward sensitivity in a monetary incentive delay (MID) task. Fifty-nine participants underwent neurofeedback training either in standard (Study 1 N = 15, Study 2 N = 28) or control feedback group (Study 1, N = 16). We find that successful self-regulation is associated with prefrontal reward sensitivity in the MID task (N = 25), with a decreasing relation between prefrontal activity and midbrain learning signals during neurofeedback training and with increased activity within cognitive control areas during transfer. The association between midbrain self-regulation and prefrontal temporal difference and reward sensitivity suggests that reinforcement learning contributes to successful self-regulation. Our findings provide insights in the control of midbrain activity and may facilitate individually tailoring neurofeedback training
Driving pressure during general anesthesia for open abdominal surgery (DESIGNATION) : study protocol of a randomized clinical trial
Background
Intraoperative driving pressure (Delta P) is associated with development of postoperative pulmonary complications (PPC). When tidal volume (V-T) is kept constant, Delta P may change according to positive end-expiratory pressure (PEEP)-induced changes in lung aeration. Delta P may decrease if PEEP leads to a recruitment of collapsed lung tissue but will increase if PEEP mainly causes pulmonary overdistension. This study tests the hypothesis that individualized high PEEP, when compared to fixed low PEEP, protects against PPC in patients undergoing open abdominal surgery.
Methods
The "Driving prESsure durIng GeNeral AnesThesIa for Open abdomiNal surgery trial" (DESIGNATION) is an international, multicenter, two-group, double-blind randomized clinical superiority trial. A total of 1468 patients will be randomly assigned to one of the two intraoperative ventilation strategies. Investigators screen patients aged >= 18 years and with a body mass index <= 40 kg/m(2), scheduled for open abdominal surgery and at risk for PPC. Patients either receive an intraoperative ventilation strategy with individualized high PEEP with recruitment maneuvers (RM) ("individualized high PEEP") or one in which PEEP of 5 cm H2O without RM is used ("low PEEP"). In the "individualized high PEEP" group, PEEP is set at the level at which Delta P is lowest. In both groups of the trial, V-T is kept at 8 mL/kg predicted body weight. The primary endpoint is the occurrence of PPC, recorded as a collapsed composite of adverse pulmonary events. Discussion DESIGNATION will be the first randomized clinical trial that is adequately powered to compare the effects of individualized high PEEP with RM versus fixed low PEEP without RM on the occurrence of PPC after open abdominal surgery. The results of DESIGNATION will support anesthesiologists in their decisions regarding PEEP settings during open abdominal surgery
Kepler-21b: A 1.6REarth Planet Transiting the Bright Oscillating F Subgiant Star HD 179070
We present Kepler observations of the bright (V=8.3), oscillating star HD
179070. The observations show transit-like events which reveal that the star is
orbited every 2.8 days by a small, 1.6 R_Earth object. Seismic studies of HD
179070 using short cadence Kepler observations show that HD 179070 has a
frequencypower spectrum consistent with solar-like oscillations that are
acoustic p-modes. Asteroseismic analysis provides robust values for the mass
and radius of HD 179070, 1.34{\pm}0.06 M{\circ} and 1.86{\pm}0.04 R{\circ}
respectively, as well as yielding an age of 2.84{\pm}0.34 Gyr for this F5
subgiant. Together with ground-based follow-up observations, analysis of the
Kepler light curves and image data, and blend scenario models, we
conservatively show at the >99.7% confidence level (3{\sigma}) that the transit
event is caused by a 1.64{\pm}0.04 R_Earth exoplanet in a 2.785755{\pm}0.000032
day orbit. The exoplanet is only 0.04 AU away from the star and our
spectroscopic observations provide an upper limit to its mass of ~10 M_Earth
(2-{\sigma}). HD 179070 is the brightest exoplanet host star yet discovered by
Kepler.Comment: Accepted to Ap
The effect of antipsychotic medication on sexual function and serum prolactin levels in community-treated schizophrenic patients: results from the Schizophrenia Trial of Aripiprazole (STAR) study (NCT00237913)
<p>Abstract</p> <p>Background</p> <p>The aim of this paper is to evaluate the effect of antipsychotics for the treatment of schizophrenia in a community based study on sexual function and prolactin levels comparing the use of aripiprazole and standard of care (SOC), which was a limited choice of three widely used and available antipsychotics (olanzapine, quetiapine or risperidone) (The Schizophrenia Trial of Aripiprazole [STAR] study [NCT00237913]).</p> <p>Method</p> <p>This open-label, 26-week, multi-centre, randomised study compared aripiprazole to SOC (olanzapine, quetiapine or risperidone) in patients with schizophrenia (DSM-IV-TR criteria). The primary effectiveness variable was the mean total score of the Investigator Assessment Questionnaire (IAQ) at Week 26. The outcome research variables included the Arizona Sexual Experience scale (ASEX). This along with the data collected on serum prolactin levels at week 4, 8, 12, 18 and 26 will be the focus of this paper.</p> <p>Results</p> <p>A total of 555 patients were randomised to receive aripiprazole (n = 284) or SOC (n = 271). Both treatment groups experienced improvements in sexual function from baseline ASEX assessments. However at 8 weeks the aripiprazole treatment group reported significantly greater improvement compared with the SOC group (p = 0.007; OC). Although baseline mean serum prolactin levels were similar in the two treatment groups (43.4 mg/dL in the aripiprazole group and 42.3 mg/dL in the SOC group, p = NS) at Week 26 OC, mean decreases in serum prolactin were 34.2 mg/dL in the aripiprazole group, compared with 13.3 mg/dL in the SOC group (p < 0.001).</p> <p>Conclusion</p> <p>The study findings suggest that aripiprazole has the potential to reduce sexual dysfunction, which in turn might improve patient compliance.</p
Predicting Outcomes in Men With Metastatic Nonseminomatous Germ Cell Tumors (NSGCT): Results From the IGCCCG Update Consortium
Purpose: The classification of the International Germ Cell Cancer Collaborative Group (IGCCCG) plays a pivotal role in the management of metastatic germ cell tumors but relies on data of patients treated between 1975 and 1990. Materials and methods: Data on 9,728 men with metastatic nonseminomatous germ cell tumors treated with cisplatin- and etoposide-based first-line chemotherapy between 1990 and 2013 were collected from 30 institutions or collaborative groups in Europe, North America, and Australia. Clinical trial and registry data were included. Primary end points were progression-free survival (PFS) and overall survival (OS). The survival estimates were updated for the current era. Additionally, a novel prognostic model for PFS was developed in 3,543 patients with complete information on potentially relevant variables. The results were validated in an independent data set. Results: Compared with the original IGCCCG publication, 5-year PFS remained similar in patients with good prognosis with 89% (87%-91%) versus 90% (95% CI, 89 to 91), but the 5-year OS increased from 92% (90%-94%) to 96% (95%-96%). In patients with intermediate prognosis, PFS remained similar with 75% (71%-79%) versus 78% (76%-80%) and the OS increased from 80% (76%-84%) to 89% (88%-91%). In patients with poor prognosis, the PFS increased from 41% (95% CI, 35 to 47) to 54% (95% CI, 52 to 56) and the OS from 48% (95% CI, 42 to 54) to 67% (95% CI, 65 to 69). A more granular prognostic model was developed and independently validated. This model identified a new cutoff of lactate dehydrogenase at a 2.5 upper limit of normal and increasing age and presence of lung metastases as additional adverse prognostic factors. An online calculator is provided (https://www.eortc.org/IGCCCG-Update). Conclusion: The IGCCCG Update model improves individual prognostication in metastatic nonseminomatous germ cell tumors. Increasing age and lung metastases add granularity to the original IGCCCG classification as adverse prognostic factors
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
- …