16+ spin-gap isomer in 96Cd Nara Singh, B S; Liu, Z; Wadsworth, R ...
Physical review letters,
2011-Oct-21, Letnik:
107, Številka:
17
Journal Article
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A β-decaying high-spin isomer in (96)Cd, with a half-life T(1/2)=0.29(-0.10)(+0.11) s, has been established in a stopped beam rare isotope spectroscopic investigations at GSI (RISING) experiment. The ...nuclei were produced using the fragmentation of a primary beam of (124)Xe on a (9)Be target. From the half-life and the observed γ decays in the daughter nucleus, (96)Ag, we conclude that the β-decaying state is the long predicted 16(+) "spin-gap" isomer. Shell-model calculations, using the Gross-Frenkel interaction and the πν(p(1/2),g(9/2)) model space, show that the isoscalar component of the neutron-proton interaction is essential to explain the origin of the isomer. Core excitations across the N=Z=50 gaps and the Gamow-Teller strength, B(GT) distributions have been studied via large-scale shell-model calculations using the πν(g,d,s) model space to compare with the experimental B(GT) value obtained from the half-life of the isomer.
Summary
We applied regression techniques to a large cohort of patients to understand why certain patients are prescribed medications to prevent glucocorticoid-induced osteoporosis (GIO). Rates of ...prescriptions to prevent osteoporosis were low. The presence of drugs and disorders associated with osteoporosis and gastrointestinal conditions actually are associated with a decreased likelihood of receiving osteoporosis-preventing medications.
Introduction
To understand why some patients are prescribed medications to prevent GIO while other patients are not, we examined whether there is an association among osteoporosis-inducing medical conditions or medications and prescriptions for osteoporosis prophylaxis in a large cohort of rheumatoid arthritis patients on chronic glucocorticoids.
Methods
Department of Veterans’ Affairs national administrative databases were used to construct a cohort (
n
= 9,605) and provide the data for this study. Multivariate logistic regression was performed to determine medical conditions and medications associated with dispensing of GIO-preventive medications, controlling for sociodemographic variables, comorbidities, glucocorticoid dosage, prior fractures, and rheumatoid arthritis severity. A subanalysis examined predictors of early GIO prevention.
Results
Subjects were more likely to receive GIO prophylaxis if they were older, African American, treated with multiple antirheumatic disease-modifying drugs, or received greater glucocorticoid exposure. The prescription of certain drug classes (loop diuretics and anticonvulsants) and conditions (malignancy, renal insufficiency, alcohol abuse, and hepatic disease) were associated with lower likelihood of GIO prophylaxis, despite putative links between these agents/conditions and osteoporosis. The presence of gastrointestinal disorders dramatically decreased likelihood of GIO prophylaxis. Few characteristics predicted the dispensing of GIO-preventing medications within 7 days of the initial glucocorticoid start date.
Conclusions
Rates of prescriptions to prevent osteoporosis in a cohort of older men with rheumatoid arthritis on chronic glucocorticoids were low. Gastrointestinal disorders and drugs and disorders potentially linked to osteoporosis are associated with diminished odds of being prescribed GIO-preventing medications.
Isobaric charge-exchange reactions induced by beams of 112Sn have been investigated at the GSI facilities using the fragment separator FRS. The high-resolving power of this spectrometer makes it ...possible to obtain the isobaric charge-exchange cross sections with an accuracy of 3% and to separate quasi-elastic and inelastic contributions in the missing-energy spectra, in which the inelastic component is associated to the in-medium excitation of baryonic resonances such as the Δ resonance. We report on the results obtained for the (p,n) and (n,p) channels excited by using different targets that cover a large range in neutron excess.
The neural control of locomotion involves a constant interplay between the actions of a central pattern generator (CPG) and sensory input elicited by bodily movement. With respect to the CPG, recent ...analysis of fictive locomotion has shown that durations of flexion and extension tend to covary along specific lines in plots of phase duration versus cycle duration. The slopes of these lines evidently depend on internal states that vary among preparations, but, within a preparation, remain rather steady from one sequence to the next. These relationships can be reproduced in a simple oscillator model having two pairs of preset parameters, suggesting that steady internal drives to flexor and extensor half-centers determine how phase durations covary. Regarding the role of sensory inputs, previous experiments have revealed state-dependent rules that govern phase-switching independently of the CPG rhythm. In addition, sensory input is known to modulate motoneuronal activation through stretch reflexes. To explore how sensory input combines with the locomotor CPG, we used a neuromechanical model with muscle actuators, proprioceptive feedback, sensory phase-switching rules, and a CPG. Interestingly, sequences of stable locomotion were always associated with phase durations that conformed to an extensor-dominated phase-duration characteristic (where extension durations vary more than flexion durations). This is the characteristic seen in normal animals, but not necessarily in fictive locomotion, where movement and associated sensory input are absent. This suggests that to produce the biomechanical events required for stability, an extensor-dominated phase-duration characteristic is required. In the model, when the preset CPG phase durations were well matched to coincide the biomechanical requirements, CPG-mediated phase switching produced stable cycles. When CPG phase durations were too short, phases switched prematurely and the model soon fell. When CPG phase durations were too long, sensory rules fired and overrode the CPG, maintaining stability. We posit that under normal circumstances, descending input from higher centers continually adjusts the operating point of the CPG on the preset phase-duration characteristic according to anticipated biomechanical requirements. When the predictions are good, CPG-generated phase durations closely match those required by the kinetics and kinematics, and little or no sensory adjustment occurs. We propose the term "neuromechanical tuning" to describe this process of matching the CPG to the biomechanical requirements.
Functional electrical stimulation (FES) holds great potential for restoring motor functions after brain and spinal cord injury. Currently, most FES systems are under simple finite state control, ...using external sensors which tend to be bulky, uncomfortable and prone to failure. Sensory nerve signals offer an interesting alternative, with the possibility of continuous feedback control. To test feasibility, we recorded from ensembles of sensory neurons with microelectrode arrays implanted in the dorsal root ganglion (DRG) of walking cats. Limb position and velocity variables were estimated accurately (average R2 values >0.5) over a range of walking speeds (0.1-0.5 m s(-1)) using a linear combination of firing rates from 10 or more neurons. We tested the feasibility of sensory control of intraspinal FES by recording from DRG neurons during hindlimb movements evoked by intraspinal microstimulation of the lumbar spinal cord in an anesthetized cat. Although electrical stimulation generated artifacts, this problem was overcome by detecting and eliminating events that occurred synchronously across the array of microelectrodes. The sensory responses to limb movement could then be measured and decoded to generate an accurate estimate of the limb state. Multichannel afferent recordings may thus provide FES systems with the feedback needed for adaptive control and perturbation compensation, though long-term stability remains a challenge.
Functional electrical stimulation (FES) is used to improve motor function after injury to the central nervous system. Some FES systems use artificial sensors to switch between finite control states. ...To optimize FES control of the complex behavior of the musculo-skeletal system in activities of daily life, it is highly desirable to implement feedback control. In theory, sensory neural signals could provide the required control signals. Recent studies have demonstrated the feasibility of deriving limb-state estimates from the firing rates of primary afferent neurons recorded in dorsal root ganglia (DRG). These studies used multiple linear regression (MLR) methods to generate estimates of limb position and velocity based on a weighted sum of firing rates in an ensemble of simultaneously recorded DRG neurons. The aim of this study was to test whether the use of a neuro-fuzzy (NF) algorithm (the generalized dynamic fuzzy neural networks (GD-FNN)) could improve the performance, robustness and ability to generalize from training to test sets compared to the MLR technique. NF and MLR decoding methods were applied to ensemble DRG recordings obtained during passive and active limb movements in anesthetized and freely moving cats. The GD-FNN model provided more accurate estimates of limb state and generalized better to novel movement patterns. Future efforts will focus on implementing these neural recording and decoding methods in real time to provide closed-loop control of FES using the information extracted from sensory neurons.
We plan a semi-exclusive measurement of the 12C(p,dp) reaction to search for η'-mesic nuclei, aiming at investigating in-medium properties of the η′-meson. We employ a 2.5 GeV proton beam impinging ...on a carbon target to produce η′-mesic 11C nuclei via the 12C(p,d)η′⊗11C reaction. Using coincidence measurements of the forward going deuterons, important for missing-mass spectroscopy, and decay protons emitted from the η′-mesic nuclei. for event selection will provide a high experimental sensitivity to observe η'-mesic nuclei. We will perform the measurements by combining the WASA detector system with the fragment separator FRS at GSI and also with the Super-FRS at FAIR in the future. The plan of the experiments and the present status are reported.
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