722 research outputs found
Insulin-like growth factor I is an independent coregulatory modulator of natural killer (NK) cell activity.
We aimed to investigate the natural killer (NK) cell activity in
hGH-deficient adults and to analyze the effect of insulin-like growth
factor (IGF)-I in uivo and in vitro on NK cell activity. NK cell activity
was measured in a 4-h nonisotopic assay with europium-labeled and
cryopreserved K-562 cells. NK-cell numbers were measured after
incubation with murine monoclonal CD3 and CD16 antibodies by flow
cytometry analysis. In a cross-sectional study, the basal and interferon-
p (IFN-P) stimulated (1000 IU/ml) NK cell activity of 15 hGHdeficient
patients and 15 age- and sex-matched controls was measured.
The percentages and absolute numbers of CD3./16+ NK-cells
were not significantly different in the patient vs. control group. The
basal and IFN-P stimulated NK cell activity however was significantly
decreased in the patient vs. control group at all effecter/target
(E/T) cell ratios from 12.5-100 (e.g. 17 ? 3 vs. 28 ? 3% lysis without
IFN-P, P < 0.05, and 42 t 4 vs. 57 2 4% lysis with IFN-0, P < 0.05;
both at E/T 50). IGF-I levels of patients and controls showed a significant
positive correlation with NK cell activity (r = 0.37; P < 0.05).
In an IGF-I in vitro study (IGF-I in vitro 250-1250 kg/L), the basal and
IFN-P stimulated NK cell activity of 13 hGH-deficient patients and of
18 normal subjects was significantly enhanced by IGF-I in vitro (e.g.
GH-deficient patients: 9 ? 2 us. 10 2 2% lysis without IFN-P, P < 0.05
and 25 + 4 vs. 30 + 4% lysis with IFN-/3, P < 0.005; and normal
subjects: 15 + 3 vs. 23 ? 3% lysis without IFN-/3, P < 0.001 and 35 2
4 us. 44 + 5% lysis with IFN-P, P < 0.001; both at IGF-I 500 pg/L).
In summary, in our cross-sectional study, adult GH-deficient patients
showed a significantly lower basal and IFN-P stimulated NK cell
activity than matched controls, despite equal NK cell numbers. IGF-I
levels of patients and controls showed a weak positive correlation with
NK cell activity. In an in vitro study, IGF-I significantly enhanced
basal and IFN-P stimulated NK cell activity of hGH-deficient patients
and also of normal subjects. The decreased NK cell activity in GHdeficient
patients may be caused at least in part by low serum IGF-I
levels. IGF-I appears to be an independent coregulatory modulator of
NK cell activity. (Endocrinology 137: 5332-5336, 1996
Peculiar Features of the Interaction Potential between Hydrogen and Antihydrogen at Intermediate Separations
We evaluate the interaction potential between a hydrogen and an antihydrogen
using the second-order perturbation theory within the framework of the
four-body system in a separable two-body basis. We find that the H-Hbar
interaction potential possesses the peculiar features of a shallow local
minimum located around interatomic separations of r ~ 6 a.u. and a barrier
rising at r~5 a.u. Additional theoretical and experimental investigations on
the nature of these peculiar features will be of great interest.Comment: 13 pages, 6 figure
Subjective Experiences of the Benefits and Key Elements of a Cognitive Behavioral Intervention Focused on Community Work Outcomes in Persons With Mental Illness
New research suggests that group-based cognitive behavioral therapy (CBT) may help improve employment outcomes in persons with mental illness, yet the effects and potential key elements facilitating change in such interventions are unclear. Using a mixed methods approach, this study examined the perspectives of persons with mental illness after participating in a pilot study of the “CBT for Work Success” intervention. Findings demonstrate that participants valued the intervention and perceived that it assisted them in achieving work goals. Therapeutic effects included improved self-efficacy, work motivation, enhanced sense of self as workers, and increased beliefs that work success is attainable. CBT for Work Success elements perceived to be important in facilitating work goals included cognitive restructuring, behavioral coping strategies, problem solving work barriers, meaningful reflection on oneself as a worker, and important factors associated with the group process. The authors discuss the implications of these findings and future research directions
A Pilot Test of Group Based Cognitive Behavioral Therapy to Augment Vocational Services for Persons With Serious Mental Illness: Feasibility and Competitive Work Outcomes
Persons with serious mental illness (SMI) struggle with work functioning even with the assistance of vocational services. The current study sought to address this problem by examining a cognitive-behavioral therapy to augment vocational services. Fifty-two adults with SMI receiving vocational services participated in a pre-post feasibility trial of the Cognitive Behavior Therapy for Work Success (CBTw) intervention. CBTw is a 12-week manualized intervention that addresses cognitive and behavioral factors that impact work functioning. Competitive work outcomes were assessed in the 12 weeks preceding baseline and after the intervention. The results demonstrate strong session attendance and a low attrition rate. There were also significant improvements in work outcomes. Specifically, among participants unemployed at baseline, 50.0% attained work during follow-up. These findings provide preliminary evidence that CBTw may be a feasible intervention to augment vocational services; further controlled research should examine its benefit to work outcomes in people with SMI
Large dimension Configuration Interaction calculations of positron binding to the group II atoms
The Configuration Interaction (CI) method is applied to the calculation of
the structures of a number of positron binding systems, including e+Be, e+Mg,
e+Ca and e+Sr. These calculations were carried out in orbital spaces containing
about 200 electron and 200 positron orbitals up to l = 12. Despite the very
large dimensions, the binding energy and annihilation rate converge slowly with
l, and the final values do contain an appreciable correction obtained by
extrapolating the calculation to the l to infinity limit. The binding energies
were 0.00317 hartree for e+Be, 0.0170 hartree for e+Mg, 0.0189 hartree for
e+Ca, and 0.0131 hartree for e+Sr.Comment: 13 pages, no figs, revtex format, Submitted to PhysRev
Variational calculations for the hydrogen-antihydrogen system with a mass-scaled Born-Oppenheimer potential
The problem of proton-antiproton motion in the --
system is investigated by means of the variational method. We introduce a
modified nuclear interaction through mass-scaling of the Born-Oppenheimer
potential. This improved treatment of the interaction includes the nondivergent
part of the otherwise divergent adiabatic correction and shows the correct
threshold behavior.
Using this potential we calculate the vibrational energy levels with angular
momentum 0 and 1 and the corresponding nuclear wave functions, as well as the
S-wave scattering length. We obtain a full set of all bound states together
with a large number of discretized continuum states that might be utilized in
variational four-body calculations. The results of our calculations gives an
indication of resonance states in the hydrogen-antihydrogen system
Foveated image processing for faster object detection and recognition in embedded systems using deep convolutional neural networks
Object detection and recognition algorithms using deep convolutional neural networks (CNNs) tend to be computationally intensive to implement. This presents a particular challenge for embedded systems, such as mobile robots, where the computational resources tend to be far less than for workstations. As an alternative to standard, uniformly sampled images, we propose the use of foveated image sampling here to reduce the size of images, which are faster to process in a CNN due to the reduced number of convolution operations. We evaluate object detection and recognition on the Microsoft COCO database, using foveated image sampling at different image sizes, ranging from 416×416 to 96×96 pixels, on an embedded GPU – an NVIDIA Jetson TX2 with 256 CUDA cores. The results show that it is possible to achieve a 4× speed-up in frame rates, from 3.59 FPS to 15.24 FPS, using 416×416 and 128×128 pixel images respectively. For foveated sampling, this image size reduction led to just a small decrease in recall performance in the foveal region, to 92.0% of the baseline performance with full-sized images, compared to a significant decrease to 50.1% of baseline recall performance in uniformly sampled images, demonstrating the advantage of foveated sampling
Face or building superiority in peripheral vision reversed by task requirements
Peripheral vision has been the topic of few studies compared with central vision.
Nevertheless, given that visual information covers all the visual field and that
relevant information can originate from highly eccentric positions, the
understanding of peripheral vision abilities for object perception seems
essential. The poorer resolution of peripheral vision would first suggest that
objects requiring large-scale feature integration such as buildings would be
better processed than objects requiring finer analysis such as faces.
Nevertheless, task requirements also determine the information (coarse or fine)
necessary for a given object to be processed. We therefore investigated how task
and eccentricity modulate object processing in peripheral vision. Three
experiments were carried out requiring finer or coarser information processing
of faces and buildings presented in central and peripheral vision. Our results
showed that buildings were better judged as identical or familiar in periphery
whilst faces were better categorised. We conclude that this superiority for a
given stimulus in peripheral vision results (a) from the available information,
which depends on the decrease of resolution with eccentricity, and (b) from the
useful information, which depends on both the task and the semantic
category
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