753 research outputs found
Modeling and motion analysis of autonomous paragliders
This report describes a preliminary study on modeling and control of parafoil and payload systems with the twofold objective of developing tools for automatic testing and classification of parafoils and of devising autonomous paragliders able to accomplish long-range delivery or monitoring tasks. Three different models of decreasing complexity are derived and their accuracy compared by simulation
Tubo-Ovarian Abscess Formation in Users of Intrauterine Devices Remote From Insertion: A Report of Three Cases
Background: The association between tubo-ovarian abscess formation and the presence of an intrauterine
device (IUD) is well recognized. It has been suggested that the risk of upper-genital-tract
infection is highest during the immediate period following the insertion of an IUD, returning to
baseline by 5 months postinsertion. We present 3 cases of women who, 10–21 years after insertion of
their IUDs, developed tubo-ovarian abscesses that were not causally related to sexually transmitted
diseases (STDs) or actinomycetes
Development of the Daily Living Questionnaire (DLQ): A Factor Analysis Study
Background: Performance of daily activities and participation in life events involves higher-level cognitive abilities. The purpose of this study was to develop a self-report scale for detecting everyday difficulties in activities/participation tied with higher-level cognitive deficiency and to examine its reliability and validity.
Method: The Daily Living Questionnaire’s (DLQ) content and face validity were established. Internal consistency following an exploratory factor analysis, as well as construct validity, were initiated with a convenience sample of 194 healthy adults, aged 18 to 85 years, and 34 adults diagnosed with Multiple Sclerosis (MS).
Results: The four factors received in Part A, activities and participation, explained 56.77% of the DLQ’s total variance, while the cumulative percentage of variance comprised of the three factors of Part B, cognitive symptoms or impairments, was 57.47%. High levels of internal consistency were demonstrated for both parts (.94 and .97, respectively). Construct validity was confirmed. While no significant gender differences were found, significant differences were found both between age groups and between participants with MS and controls.
Implications: Initial results suggest that the DLQ is a valid tool for detecting difficulties in daily activities/participation related to cognitive impairments among adults
Analyzing and Quantifying the Gain-of-Function Enhancement of IP3 Receptor Gating by Familial Alzheimer's Disease-Causing Mutants in Presenilins
Familial Alzheimer’s disease (FAD)-causing mutant presenilins (PS) interact with inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) Ca2+ release channels resulting in enhanced IP3R channel gating in an amyloid beta (Aβ) production-independent manner. This gain-of-function enhancement of IP3R activity is considered to be the main reason behind the upregulation of intracellular Ca2+ signaling in the presence of optimal and suboptimal stimuli and spontaneous Ca2+ signals observed in cells expressing mutant PS. In this paper, we employed computational modeling of single IP3R channel activity records obtained under optimal Ca2+ and multiple IP3 concentrations to gain deeper insights into the enhancement of IP3R function. We found that in addition to the high occupancy of the high-activity (H) mode and the low occupancy of the low-activity (L) mode, IP3R in FAD-causing mutant PS-expressing cells exhibits significantly longer mean life-time for the H mode and shorter life-time for the L mode, leading to shorter mean close-time and hence high open probability of the channel in comparison to IP3R in cells expressing wild-type PS. The model is then used to extrapolate the behavior of the channel to a wide range of IP3 and Ca2+ concentrations and quantify the sensitivity of IP3R to its two ligands. We show that the gain-of-function enhancement is sensitive to both IP3 and Ca2+ and that very small amount of IP3 is required to stimulate IP3R channels in the presence of FAD-causing mutant PS to the same level of activity as channels in control cells stimulated by significantly higher IP3 concentrations. We further demonstrate with simulations that the relatively longer time spent by IP3R in the H mode leads to the observed higher frequency of local Ca2+ signals, which can account for the more frequent global Ca2+ signals observed, while the enhanced activity of the channel at extremely low ligand concentrations will lead to spontaneous Ca2+ signals in cells expressing FAD-causing mutant PS.published_or_final_versio
Augmented Reality and Functional Skills Acquisition Among Individuals With Special Needs: A Meta-Analysis of Group Design Studies
Forensically Relevant False Memories in the DRM Paradigm
Forensic interviews and eyewitness testimony clearly rely on memory. Because in 85% of criminal prosecutions there is no medical nor trace evidence, the burden is on what witnesses report hearing/seeing; thus memory is the evidence! However, cognitive frailties, including forgetting and retrieval failures, combined with misinformation threaten the accuracy and credibility of witnesses’ recollections. Overall, these factors foment illusory memories with serious consequences when forensic events are at issue. This observation tracks with false memory findings in a simple laboratory task, the Deese-Roediger-McDermott (DRM) Paradigm. Herein participants study word lists each containing thematically-related items converging upon a critical, non-presented, word. Consider Chair as the missing item for this list: table, sit, legs, couch etc. Subsequently, participants remember many presented words and with high frequency “recollect” the critical lure (e.g., Chair) as well. We examined “forensic” DRM materials exemplified by the list containing words related to Guilty, the non-presented word. Control and emotionally tinged, lists provided baselines for correct and incorrect recognition memory. True memory averaged 63%, yet critical item false memory was higher at 67%, a common outcome. Correct memory for forensic lists (62%) was comparable to control (66%) and emotional (57%) lists. All list types produced substantial levels of false memory, with control/emotional at 72% and forensic “only” at 58% revealing that legal material is not immune to the false memory effect. We also report a recall experiment and then discuss forensic implications of DRM experiments, arguments bolstered because our results are grounded on stimuli relevant to criminal justice
Exoanal ultrasound of the anal sphincter: normal anatomy and sphincter defects
To describe the sonographic appearance of normal anal sphincter anatomy and sphincter defects evaluated with a conventional 5 MHz convex transducer placed on the perineum. Design Prospective, single-blind study. Setting Department of Obstetrics and Gynecology, University of Michigan Medical Center, USA. Population Twenty-five women with symptoms of faecal incontinence, 11 asymptomatic nulliparous women, and 32 asymptomatic parous women. Methods A convex scanner was placed on the perineum with the woman in lithotomy position. Images were taken at three levels of the sphincter canal. Pictures were evaluated by two examiners who were blinded to the case history of the women and to the results of each other for the presence or absence of sphincter defects. Main outcome measures Description of anal sphincter appearance on endoanal ultrasound. Reproducibilty of the evaluation of sphincter defects. Results The internal anal sphincter is visible as a hypoechoic circle; the external anal sphincter shows a hyperechoic pattern. Proximally the sling of the puborectalis muscle is visible. Sphincter defects were detected in 20 women. In all five women who subsequently underwent surgery, the presence and location of the defect was confirmed at the time of surgery. Examiners were in agreement 100% of the time on the presence or absence of internal defects. They disagreed in one patient on the presence of an external defect. Conclusion Exoanal ultrasound provides information on normal anatomy and on defects of the anal sphincter.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75125/1/j.1471-0528.1997.tb12056.x.pd
Adaptive thrust vector control during on-orbit servicing
On-orbit servicing missions often include a final propulsive phase where a spacecraft pushes the other one towards a different orbit. Specifically this is the case of the debris grasping mission where the chaser, after capturing the target by means of robotic arms, has to perform a de-orbit operation. The large thrust involved needs a perfect alignment with respect to the center of mass or the system composed by chaser and target, in order to avoid attitude changes. Such accurate alignment is quite difficult to achieve especially when the characteristics of the target are not perfectly known. A procedure is proposed in this paper, allowing a complete estimation of the center of mass position and of the moments of inertia of the system, starting from the data obtained by the gyros mounted on board of the spacecraft. The output is used to design a maneuver for correcting the target and chaser relative position by moving the robotic arms. Numerical simulations show the proficiency and the applicability of the estimation algorithm and of re-alignment maneuver to a selected mission scenario
A Comparison of Different Pelvic Reconstruction Surgeries Using Mesh for Pelvic Organ Prolapse Patients
This study was carried out in order to compare the effects in different surgeries using mesh in pelvic organ prolapse patients whose leading points were C. Thirty-nine patients were categorized into 3 groups: group A pelvic reconstruction with hysterectomy; group B hysterectomy prior to pelvic reconstruction; and group C pelvic reconstruction with uterus preserved. At first visit, POP-Q stage was determined, and age, BMI, admission days, operation time, post-operative stage and complications were observed and results were analyzed and compared. All patients who were operated upon converted to stage one month following the operation, and no further change was observed except in one patient. Group admission days were not significantly different, but tended to be lower in group C. Group average operation times between 'group A and B' and 'group A and C' were statistically different. No significant difference was observed in post-operative complications between the groups, but 3 members of group A developed erosion, whereas no erosion occurred in groups B and C. Pelvic reconstruction using mesh is a highly efficient method of treating pelvic organ prolapse. Improvements in stage and post-operative complications were not significantly different in the groups. However, uteropexy showed a shorter operation time, fewer admission days, and less erosion due to mesh than conventional pelvic reconstruction with hysterectomy
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