226 research outputs found
Spatial frequency channels in experimentally strabismic monkeys revealed by oblique masking
AbstractAlthough the spatial vision deficits of human strabismic amblyopes have been well documented, surprisingly little is known about the mechanisms underlying their visual performance. In an effort to reveal the structure underlying the spatial vision deficits associated with strabismic amblyopea, we measured the performance of monkeys (Macaca nemestrina) with experimental strabismus in a contrast detection task with oblique masks. The masks were two adjacent identical oblique sine-wave gratings modulated in space by a Gaussian envelope. The target stimulus was a vertically oriented Gabor patch that appeared superimposed on the center of either the left or the right mask. The animals were trained by operant methods to indicate the location of the target. We measured detection thresholds in each eye independently for a large number of test and mask spatial frequencies. For each test spatial frequency, detection thresholds were elevated in the presence of the mask. The threshold evaluations showed a peak for a particular spatial frequency that was typically similar to the test spatial frequency. This pattern of results is consistent with the idea that the tests are detected by a discrete number of channels tuned to a narrow range of spatial frequencies. The data from the deviated eyes did not appear qualitatively different from those of the fellow eyes, and could be accounted by the same number of channels in both eyes. Quantitative estimates of the channels' characteristics revealed that the channels derived from the deviated eyes' data were similar to those yielded by the fellow eyes, but showed a reduction in their sensitivity to contrast
Reinforced feedback in virtual environment for rehabilitation of upper extremity dysfunction after stroke: preliminary data from a randomized controlled trial.
OBJECTIVES: To study whether the reinforced feedback in virtual environment (RFVE) is more effective than traditional rehabilitation (TR) for the treatment of upper limb motor function after stroke, regardless of stroke etiology (i.e., ischemic, hemorrhagic). DESIGN: Randomized controlled trial. Participants. Forty-four patients affected by stroke. Intervention. The patients were randomized into two groups: RFVE (N = 23) and TR (N = 21), and stratified according to stroke etiology. The RFVE treatment consisted of multidirectional exercises providing augmented feedback provided by virtual reality, while in the TR treatment the same exercises were provided without augmented feedbacks. Outcome Measures. Fugl-Meyer upper extremity scale (F-M UE), Functional Independence Measure scale (FIM), and kinematics parameters (speed, time, and peak). RESULTS: The F-M UE (P = 0.030), FIM (P = 0.021), time (P = 0.008), and peak (P = 0.018), were significantly higher in the RFVE group after treatment, but not speed (P = 0.140). The patients affected by hemorrhagic stroke significantly improved FIM (P = 0.031), time (P = 0.011), and peak (P = 0.020) after treatment, whereas the patients affected by ischemic stroke improved significantly only speed (P = 0.005) when treated by RFVE. CONCLUSION: These results indicated that some poststroke patients may benefit from RFVE program for the recovery of upper limb motor function. This trial is registered with NCT01955291
RACIAL AND ETHNIC DISPARITIES IN THE CRIMINAL JUSTICE SYSTEM IN NEBRASKA
What are racial and ethnic disparities (RED)? RED refers to racial and ethnic differences in contacts and experiences with the criminal and juvenile justice systems.1,2 Measuring the extent to which RED exist in the justice system is a first step toward identifying the ways to improve upon how well the system upholds the principle of equal treatment under the law.3 Prior research shows that RED are prevalent across multiple points of contact with the juvenile justice system in Nebraska.1,3 There is also a large body of evidence demonstrating RED in the adult criminal justice system nationwide.4 The purpose of this brief is to describe what the data show regarding racial disparities in the state of Nebraska and what is yet to be understood.
Are there racial disparities in arrests in Nebraska? Relative to the racial makeup of the state population, there is significant disparity in the racial composition of the arrests in each year from 2014 to 2019.5,6 Inequity for African Americans is the largest contributor to the overall disparity. As shown in Figure 1, from 2014 to 2019, African Americans made up approximately 5% of the state population but accounted for 17.45–20.82% of arrests. American Indians/Alaskan Natives were also overrepresented in arrests (3.23–3.59%) relative to their portion the population (approximately 1%). Whites and Asians/Pacific Islanders are underrepresented in all six years
Vision After Early-Onset Lesions of the Occipital Cortex: I. Neuropsychological and Psychophysical Studies
We analyzed the visual functions of two
patients (MS, FJ) with bilateral lesion of the
primary visual cortex, which occurred at gestational
age 33 wk in MS and at postnatal month 7
in FJ. In both patients basic visual functions—
visual acuity, contrast sensitivity, color, form,
motion perception—are similarly preserved or
modestly impaired. Functions requiring higher
visual processing, particularly figure-ground
segregation based on textural cues, are severely
impaired. In MS, studied longitudinally, the
deficits attenuated between the ages of 4.5 and 8
y, suggesting that the developing visual system
can display a considerable degree of adaptive
plasticity several years after the occurrence of a
lesion. In FJ (age 18:9 to 20:6 y), who is more
impaired, the recovery, if any, was less
Functional changes in the lower extremity after non-immersive virtual reality and physiotherapy following stroke
Objective: To analyse the effect of virtual reality (VR) therapy combined with conventional physiotherapy on balance, gait and motor functional disturbances, and to determine whether there is an influence on motor recovery in the subacute (< 6 months) or chronic (> 6 months) phases after stroke. Methods: A total of 59 stroke inpatients (mean age 60.3 years (standard deviation (SD) 14.8); 14.0 months (SD 25.7) post-stroke) were stratified into 2 groups: subacute (n = 31) and chronic (n = 28). Clinical scales (Fugl-Meyer lower extremity (FM LE); Functional Independence Measure (FIM); Berg Balance Scale (BBS); Functional Ambulation Category (FAC); modified Ashworth scale (MAS); 10-metre walk test (10MWT); and kinematic parameters during specific motor tasks in sitting and standing position (speed; time; jerk; spatial error; length) were applied before and after treatment. The VR treatment lasted for 15 sessions, 5 days/week, 1 h/day. Results: The subacute group underwent significant change in all variables, except MAS and length. The chronic group underwent significant improvement in clinical scales, except MAS and kinematics. Motor impairment improved in the severe = 19 FM LE points, moderate 20-28 FM LE points, mild = 29 FM LE points. Neither time since stroke onset nor affected hemisphere differed significantly between groups. The correlations were investigated between the clinical scales and the kinematic parameters of the whole sample. Moreover, FM LE, BBS, MAS, and speed showed high correlations (R2> 0.70) with independent variables. Conclusion: VR therapy combined with conventional physiotherapy can contribute to functional improvement in the subacute and chronic phases after stroke
Vision After Early-Onset Lesions of the Occipital Cortex: II. Physiological Studies
In one of two patients (MS and FJ) with
bilateral, early-onset lesion of the primary
visual cortex, Kiper et al. (2002) observed
a considerable degree of functional recovery. To
clarify the physiological mechanisms involved
in the recovery, we used fMRI and quantitative
EEG to study both patients. The fMRI
investigations indicated that in both patients,
isolated islands of the primary visual cortex are
functioning, in the right hemisphere in MS and
in the left in FJ. The functional recovery
observed in MS roughly correlated with the
functional maturation of interhemispheric
connections and might reflect the role of corticocortical connectivity in visual perception. The
functionality of interhemispheric connections
was assessed by analyzing the changes in
occipital inter-hemispheric coherence of EEG
signals (ICoh) evoked by moving gratings. In
the patient MS, this ICoh response was present
at 7:11 y and was more mature at 9:2 y. In the
more visually mpaired patient, FJ, a consistent
increase in ICoh to visual stimuli could not be
obtained, possibly because of the later occurrence
of the lesion
Life Science Zurich Learning Center – A New Symbiosis of Research Institutions and Schools
The Life Science Learning Center (LSLC) was officially founded in 2005. It is a branch of the pre-existing Life Science Zurich, an organization created by and belonging to the University of Zurich and the Swiss Federal Institute of Technology Zurich to promote and support life sciences
in several central parts of society. The LSLC's primary goals are to offer educational opportunities for school children as well as continuing education for teachers of the primary and secondary school levels. In particular, the LSLC facilitates various types of interactions between schools
and the higher educational and research institutions (University of Zurich and Federal Institutes of Technology): it offers practicals for pupils in a special laboratory, tours of professional research laboratories, pedagogical training for future biology teachers, and specialized modules
of continuing education for teachers. It also contributes to diverse initiatives promoting life sciences in the general public. It is led by a small team of dedicated people based on the Irchel Campus of the University of Zurich
Virtual reality and physiotherapy in post-stroke functional re-education of the lower extremity: A controlled clinical trial on a new approach
Numerous Virtual Reality (VR) systems address post-stroke functional recovery of the lower extremity (LE), most of them with low early applicability due to the gait autonomy they require. The aim of the present study was to evaluate the feasibility of a specific VR treatment and its clinical effect on LE functionality, gait, balance, and trunk control post-stroke. A controlled, prospective, clinical trial was carried out with 20 stroke patients, who were divided into two groups: the first group (VR + CP; n = 10) received combined therapy of 1 h VR and 1 h of conventional physiotherapy (CP) and the second group (CP; n = 10) received 2 h of CP (5 days/week, for 3 weeks). The following pre-post-intervention measuring scales were used: Functional Ambulatory Scale (FAC), Functional Independence Measure (FIM), Fugl-Meyer Assessment (FM), Berg Balance Scale (BBS), and Trunk Control Test (TCT). Only VR + CP showed a significant improvement in FAC. In FIM, CP presented a tendency to significance, whereas VR + CP showed significance. Both groups improved significantly in FM (especially in amplitude/pain in VR + CP and in sensitivity in CP) and in BBS. In TCT, there was a non-significant improvement in both groups. The results indicate that the intervention with VR is a feasible treatment in the post-stroke functional re-education of the LE, with the potential to be an optimal complement of CP
Eltrombopag for the treatment of immune thrombocytopenia: The aegean region of Turkey experience
Objective: Immune thrombocytopenia (ITP) is an immune-mediated disease characterized by transient or persistent decrease of the platelet count to less than 100x109/L. Although it is included in a benign disease group, bleeding complications may be mortal. With a better understanding of the pathophysiology of the disease, thrombopoietin receptor agonists, which came into use in recent years, seem to be an effective option in the treatment of resistant cases. This study aimed to retrospectively assess the efficacy, long-term safety, and tolerability of eltrombopag in Turkish patients with chronic ITP in the Aegean region of Turkey. Materials and Methods: Retrospective data of 40 patients with refractory ITP who were treated with eltrombopag in the Aegean region were examined and evaluated. Results: The total rate of response was 87%, and the median duration of response defined as the number of the platelets being over 50x109/L was 19.5 (interquartile range: 5-60) days. In one patient, venous sinus thrombosis was observed with no other additional risk factors due to or related to thrombosis. Another patient with complete response and irregular follow-up for 12 months was lost due to sudden death as the result of probable acute myocardial infarction. Conclusion: Although the responses to eltrombopag were satisfactory, patients need to be monitored closely for overshooting platelet counts as well as thromboembolic events. © 2015 Turkish Society of Hematology. All rights reserved
Virtual reality rehabilitation system for neuropathic pain and motor dysfunction in spinal cord injury patients
Spinal cord injury (SCI) causes both lower limb motor dysfunction and associated neuropathic pain. Although these two conditions share related cortical mechanisms, different interventions are currently used to treat each condition. With intensive training using entertaining virtual reality (VR) scenarios, it may be possible to reshape cortical networks thereby reducing neuropathic pain and improving motor function. We have created the first VR training system combining action observation and execution addressing lower limb function in incomplete SCI (iSCI) patients. A particular feature of the system is the use of size-adjustable shoes with integrated motion sensors. A pilot single-case clinical study is currently being conducted on six iSCI patients. Two patients tested to date were highly motivated to perform and reported improved physical well-being. They improved in playing skill and in controlling the virtual lower limbs. There were post-intervention indications of neuropathic pain decrease, muscle strength increase, faster walking speed and improved performance on items relevant for ambulation. In addition functional MRI before and after treatment revealed a decreased activation pattern. We interpret this result as an improvement of neuronal synergies for this task. These results suggest that our VR system may be beneficial for both reducing neuropathic pain and improving motor function in iSCI patients
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