Effect of Head Orientation on the Diagnostic Sensitivity of Posturography in Patients with Compensated Unilateral Lesions

1992 ◽  
Vol 106 (4) ◽  
pp. 355-362 ◽  
Author(s):  
Kamran Barin ◽  
Curtis M. Seitz ◽  
D. Bradley Welling
Keyword(s):  
Postural Sway ◽  
Head Position ◽  
Diagnostic Sensitivity ◽  
Test Sequence ◽  
Order Effects ◽  
Head Orientation ◽  
Additional Information ◽  
Head Extension ◽  
The Difference ◽  
Unilateral Vestibulopathy

Patients with compensated unilateral vestibular lesions often have no detectable abnormality on conventional posturography. The purpose of this study was to determine whether a change in head orientation could improve the diagnostic sensitivity of the test for these patients. Twenty-four patients with known unilateral vestibulopathy and twenty-four normal controls were tested on the EqulTest apparatus in four head positions: head centered, head tilted right, head tilted left, and head extended. The sensory organization test was performed for each head position, using a single trial for each sensory condition. The test sequence was randomized to account for simple order effects. The subject's equilibrium was quantified by a performance index and a composite score of all sensory conditions was calculated for each head position. Patients with unilateral vestibulopathy had more postural sway with the head tilted contralateral to the side of lesion. The difference between the mean composite scores for ipsilateral and contralateral head tilts was statistically significant ( p < 0.05). When individual trials were compared, equilibrium scores were significantly different only for sensory conditions that required vestibular input. Head extension increased postural sway in both patients and controls. Equilibrium scores were significantly different for all sensory conditions in which the support was sway-referenced. We suggest that the results of head extension in patients are similar to those found in normal individuals. However, equilibrium scores for right-left head flits are sensitive to the side of lesion and can provide additional information for patients with unilateral vestibulopathy.

Head Extension Effect in Static Posturography

1995 ◽  
Vol 104 (7) ◽  
pp. 570-573 ◽  
Author(s):  
Marcel E. Norré
Keyword(s):  
Postural Sway ◽  
Normal Subjects ◽  
Standing Position ◽  
Positive Zero ◽  
Vestibular Disorders ◽  
Foam Rubber ◽  
Static Posturography ◽  
Head Extension ◽  
The Difference ◽  
Extension Effect

The effect of head extension on the standing position has been studied by analysis of recordings made by static posturography type III (SPGIII), a set of six tests of posturography for sensory interaction. The head extension effect in posturography was evaluated by comparing the results of testing with head extension on a stable platform and on foam rubber to testing with a normal head position. In normal subjects head extension increased the postural sway, but there was no more effect on foam rubber than on the stable platform. For patients with peripheral vestibular disorders the head extension effect on the measured postural sway was evaluated by the difference from the normal condition. This difference could be positive, zero, or negative on the stable platform as well as on foam rubber. In both patients and normal subjects, foam rubber had no more effect than the stable platform. The several types of results could be seen in each category of peripheral vestibular disorders. Only minor nuances could be observed: positive differences were more pronounced in benign paroxysmal positional vertigo, whereas negative ones were more obvious in unilateral vestibular deficits. These findings, moreover, deny that head extension in SPGIII should be considered a condition revealing vestibular dysfunction, as has been supposed. As head extension has an influence on the neck proprioceptor as well as on the position of the otoliths, its effect is ambiguous, which makes the interpretation rather difficult. A neck proprioceptive as well as an otolithic explanation appears to have some clinical support.

scholarly journals Urinary Microbiome Characteristics in Female Patients with Acute Uncomplicated Cystitis and Recurrent Cystitis

2021 ◽  
Vol 10 (5) ◽  
pp. 1097
Author(s):  
Jeong-Ju Yoo ◽  
Hee Shin ◽  
Ju Song ◽  
Minjung Kim ◽  
Jina Yun ◽  
...  
Keyword(s):  
Urine Culture ◽  
Culture Methods ◽  
Microbiome Composition ◽  
Additional Information ◽  
Transurethral Catheter ◽  
Urinary Microbiome ◽  
Acute Uncomplicated Cystitis ◽  
The Difference ◽  
Uncomplicated Cystitis ◽  
Recurrent Cystitis

Traditionally, the diagnostic mainstay of recurrent urinary tract infection has been urinary culture. However, the causative uropathogen of recurrent cystitis has not been well established. Urine DNA next-generation sequencing (NGS) can provide additional information on these infections. Herein, we compared urine NGS results and urine cultures in patients with acute uncomplicated cystitis (AUC) and recurrent cystitis (RC), and evaluated the difference in microbiome patterns in the NGS results. Patients who underwent urine culture and NGS due to AUC or RC were retrospectively reviewed. All urine samples were collected via a transurethral catheter and studied utilizing a type of NGS called 16S ribosomal RNA gene amplification and sequencing. The sensitivity of urine NGS was significantly higher than that of conventional urine culture (69.0% vs. 16.7%, p < 0.05). The detection rate of urine NGS was slightly lower in the RC group than in the AUC group (67.7% vs. 72.7%). Microbiome diversity was significantly higher in the RC group compared to the AUC group (p = 0.007), and the microbiome composition was significantly different between the AUC and RC groups. In the urine NGS results, Pseudomonas, Acinetobacter, and Enterobacteriaceae were found in the AUC group, and Sphingomonas, Staphylococcus, Streptococcus, and Rothia spp. were detected in the RC group. Urine NGS can significantly increase the diagnostic sensitivity compared to traditional urine culture methods, especially in RC patients. AUC and RC patients had significant differences in bacterial diversity and patterns. Therefore, recurrent cystitis might be approached from a different perspective.

Detection of polar stratospheric clouds with ERS-2/GOME data

1995 ◽  
Vol 13 (4) ◽  
pp. 395-405
Author(s):  
R. Meerkoetter
Keyword(s):  
Radiative Transfer ◽  
European Research ◽  
Polar Stratospheric Clouds ◽  
Additional Information ◽  
Tropospheric Aerosol ◽  
Ozone Monitoring ◽  
The Difference ◽  
Stratospheric Clouds

Abstract. Based on radiative transfer calculations, it is studied whether polar stratospheric clouds (PSCs) can be detected by the new Global Ozone Monitoring Experiment (GOME) on board the second European Research Satellite (ERS-2) planned to be launched in 1995. It is proposed to identify PSC-covered areas by use of an indicator, the Normalized Radiance Difference (NRD), which relates the difference of two spectral radiances at 0.515 µm and 0.67 µm to one radiance measured in the centre of the oxygen A-band at 0.76 µm. Simulations are carried out for two solar zenith angles, θ=78.5° and θ=86.2°. They indicate that, in presence of PSCs and with increasing solar zenith angles above θ=80°, the NRD decrease to values clearly below those derived under conditions of a cloud-free stratosphere. Results for θ=86.2° show that the method is successful independent of existing tropospheric clouds, of different tropospheric aerosol loadings, and of surface albedos. Results for θ=78.5° illustrate that PSC detection under conditions of smaller solar zenith angles θ80° needs additional information about tropospheric clouds.

Somatosensory and Auditory Brain Stem Conduction after Head Injury: A Comparison with Clinical Features in Prediction of Outcome

Neurosurgery ◽  
1990 ◽  
Vol 26 (2) ◽  
pp. 278-285 ◽  
Author(s):  
Kenneth Lindsay ◽  
Aydin Pasaoglu ◽  
David Hirst ◽  
Gwen Allardyce ◽  
Ian Kennedy ◽  
...  
Keyword(s):  
Head Injury ◽  
Brain Stem ◽  
Evoked Potential ◽  
Predictive Accuracy ◽  
Normal Subjects ◽  
Prediction Of Outcome ◽  
Prognostic Information ◽  
Additional Information ◽  
Auditory Brain Stem ◽  
The Difference

Abstract Evoked potential conduction times in brain stem auditory (BCT) and central somatosensory pathways (CCT) were recorded from 23 normal subjects and 101 patients with severe head injury. Abnormalities in the CCT and the BCT findings correlated with the clinical indices of brain damage (coma score, motor response, pupil response, and spontaneous and reflex eye movements) in the head-injured patients and each correlated with outcome at 6 months from the injury. The CCT in the “best” hemisphere produced the strongest correlation with outcome (P&lt;0.001). The correlation of the CCT with outcome was stronger in the 47 patients examined 2 to 3 days after the injury (P&lt;0.001) compared to the 34 patients examined within 24 hours after the injury (P&lt;0.02). No such difference was noted for the BCT. Serial studies within the first 2 weeks of injury did not show a consistent pattern and repetition of the investigation over this period did not provide any additional information. We used an INDEP-SELECT discriminant analysis program to determine whether information from the evoked potential data could improve prediction of outcome based on clinical data alone. With the addition of the CCT, the predictive accuracy (expressed as the correct classification probability) increased only slightly from 77 to 80%, and the difference was not significant. We conclude that central somatosensory and auditory brain stem conduction times provide useful prognostic information in paralyzed or sedated patients, but when neurological examination is feasible the benefits of evoked potential analysis do not justify the effort involved in data collection.

Neural network processing of radar scanning data array

2021 ◽  
Author(s):  
V.E. Dmitriyev ◽  
D.V. Popov ◽  
V.A. Shakhnov
Keyword(s):  
Spatial Perception ◽  
Digital Processing ◽  
Radar Data ◽  
Information Value ◽  
Data Array ◽  
Additional Information ◽  
Distribution Of Values ◽  
The Difference ◽  
Radar Data Processing ◽  
Made In

This article deals with the digital processing of a matrix radar image. The information received from the radar scanner needs to be transformed to enable visual perception. The article describes the main methods of digital processing of matrix data, presents the images transformed by them. The aim of the article was the development of a radar data processing algorithm that identifies the contours and edges of examined objects. The authors propose an algorithm for isolating the geometric structure of the scanned area. The difference between the processing method and the known analogues is based on the nature of the change in the values of the array being processed and consists in the double operation of extracting the gradient of the distribution of values. The software implementation of the algorithm is made in C++ using methods from an open library of computer vision. The efficiency of the algorithm was estimated based on comparison with the algorithms for determining edges based on linear filtering and neural networks. The results of the work can be used to create software for mobile short-range radar devices. Imaging from object boundaries and their edges provides spatial perception of the image by the operator, and free areas are available for rendering additional information. This solution allows you to combine scanning devices and thereby increase the information value of the result.

Linguistic cues facilitate children’s understanding of belief-reporting sentences

2021 ◽  
pp. 014272372110486
Author(s):  
Xiaowen Zhang ◽  
Peng Zhou
Keyword(s):  
Gold Medal ◽  
Judgment Task ◽  
False Belief ◽  
Value Judgment ◽  
Additional Information ◽  
Linguistic Cues ◽  
Truth Value ◽  
The Difference ◽  
Underlying Mechanisms ◽  
Mental Verbs

It has been well-documented that although children around 4 years start to attribute false beliefs to others in classic false-belief tasks, they are still less able to evaluate the truth-value of propositional belief-reporting sentences, especially when belief conflicts with reality. This article investigates whether linguistic cues, verb factivity in particular, can facilitate children’s understanding of belief-reporting sentences. Two experiments were implemented, one testing children’s knowledge of verb factivity using a gold medal task, and one investigating children’s interpretation of belief-reporting sentences using a truth-value-judgment task. Both experiments took advantage of the contrast between neutral non-factive mental verbs and strong negatively biased mental verbs. What sets the two apart is that the complement clause following a strong negatively biased mental verb is definitely false, whereas the one following a neutral non-factive mental verb remains indeterminate in the absence of additional information. The findings were that, first, 4-year-old children were able to tell the difference between the two types of mental verbs in factivity, and second, children’s performance was significantly improved when a strong negatively biased mental verb than when a neutral non-factive mental verb was used as the main verb of the belief-reporting sentences. The findings suggest that the use of strong negatively biased mental verbs facilitates children’s understanding of belief-reporting sentences. Implications of the findings are discussed in relation to the underlying mechanisms connecting verb factivity and false-belief understanding.

scholarly journals Value-at-risk modeling and forecasting with range-based volatility models: empirical evidence

2017 ◽  
Vol 28 (75) ◽  
pp. 361-376 ◽  
Author(s):  
Leandro dos Santos Maciel ◽  
Rosangela Ballini
Keyword(s):  
At Risk ◽  
Value At Risk ◽  
Garch Models ◽  
Time Interval ◽  
Risk Modeling ◽  
Additional Information ◽  
Volatility Models ◽  
Modeling And Forecasting ◽  
The Difference ◽  
Market Indexes

ABSTRACT This article considers range-based volatility modeling for identifying and forecasting conditional volatility models based on returns. It suggests the inclusion of range measuring, defined as the difference between the maximum and minimum price of an asset within a time interval, as an exogenous variable in generalized autoregressive conditional heteroscedasticity (GARCH) models. The motivation is evaluating whether range provides additional information to the volatility process (intraday variability) and improves forecasting, when compared to GARCH-type approaches and the conditional autoregressive range (CARR) model. The empirical analysis uses data from the main stock market indexes for the U.S. and Brazilian economies, i.e. S&P 500 and IBOVESPA, respectively, within the period from January 2004 to December 2014. Performance is compared in terms of accuracy, by means of value-at-risk (VaR) modeling and forecasting. The out-of-sample results indicate that range-based volatility models provide more accurate VaR forecasts than GARCH models.

scholarly journals Employing multiple synchronous outcome samples per subject to improve study efficiency

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Roger P. A’Hern
Keyword(s):  
Primary Outcome ◽  
Sampling Error ◽  
Optimum Number ◽  
Intra Class Correlation ◽  
Additional Information ◽  
True Value ◽  
The Difference ◽  
Highly Correlated ◽  
The Cost ◽  
Multiple Samples

Abstract Background Accuracy can be improved by taking multiple synchronous samples from each subject in a study to estimate the endpoint of interest if sample values are not highly correlated. If feasible, it is useful to assess the value of this cluster approach when planning studies. Multiple assessments may be the only method to increase power to an acceptable level if the number of subjects is limited. Methods The main aim is to estimate the difference in outcome between groups of subjects by taking one or more synchronous primary outcome samples or measurements. A summary statistic from multiple samples per subject will typically have a lower sampling error. The number of subjects can be balanced against the number of synchronous samples to minimize the sampling error, subject to design constraints. This approach can include estimating the optimum number of samples given the cost per subject and the cost per sample. Results The accuracy improvement achieved by taking multiple samples depends on the intra-class correlation (ICC). The lower the ICC, the greater the benefit that can accrue. If the ICC is high, then a second sample will provide little additional information about the subject’s true value. If the ICC is very low, adding a sample can be equivalent to adding an extra subject. Benefits of multiple samples include the ability to reduce the number of subjects in a study and increase both the power and the available alpha. If, for example, the ICC is 35%, adding a second measurement can be equivalent to adding 48% more subjects to a single measurement study. Conclusion A study’s design can sometimes be improved by taking multiple synchronous samples. It is useful to evaluate this strategy as an extension of a single sample design. An Excel workbook is provided to allow researchers to explore the most appropriate number of samples to take in a given setting.

scholarly journals Preliminary results using PET/MR in glioblastoma patients treated with regorafenib: an 18F-FET and DWI-ADC comparison

2021 ◽  
Author(s):  
Alessandro Spimpolo ◽  
Giuseppe Lombardi ◽  
Sara Berti ◽  
Cristina Campi ◽  
Maria Giulia Anglani ◽  
...  
Keyword(s):  
Early Response ◽  
Recurrent Glioblastoma ◽  
Response To Treatment ◽  
Fet Pet ◽  
Additional Information ◽  
Rano Criteria ◽  
Percentage Difference ◽  
Before And After ◽  
The Difference ◽  
Cancer Network

Abstract Introduction: The use of regorafenib in recurrent glioblastoma patients has been recently approved by the Italian Medicines Agency (AIFA) and added to the National Comprehensive Cancer Network (NCCN) 2020 guidelines as a preferred regimen. Given its complex effects at the molecular level, the most appropriate imaging tools to assess early response to treatment is still a matter of debate. DWI and 18F–FET PET are promising methodologies providing additional information to the currently used RANO criteria. The aim of this study was to evaluate the variations in DWI/ADC- and 18F-FET PET-derived parameters in patients who underwent PET/MR at both baseline and soon after starting regorafenib. Method: We retrospectively selected 16 consecutive GBM patients who underwent 18F–FET PET/MR before and after two cycles of regorafenib. Patients were sorted into stable (SD) or progressive disease (PD) categories in accordance with RANO criteria. We were also able to analyze 4 SD patients who underwent a third PET/MR after another 4 cycles of regorafenib. 18F–FET uptake greater than 1.6 times the mean background activity was used to define an area to be superimposed on an ADC map at baseline and soon after treatment. A number of metrics were then derived and compared. Result: The average increases in FET and ADC pathological volumes were higher in PD than in SD patients, although in neither case did the difference reach significance. However, when the percentage difference in FET volumes was plotted against the corresponding percentage difference in ADC, a correlation was observed (R = 0.54). Patients with a twofold increase in FET after regorafenib showed a significantly higher increase in ADC pathological volume than the remaining subjects (p = 0.0023). Conclusion: In recurrent glioblastoma patients treated with regorafenib, 18F-FET and ADC metrics, being obtained from completely different measures, could serve as semi-quantitative independent biomarkers of response to treatment. These promising parameters should be tested in a larger cohort of glioblastoma patients treated with regorafenib.

scholarly journals A reply from a ‘pracademic’: It is not all mischief, and there is scope to educate budding authors

2019 ◽  
Vol 45 ◽  
Author(s):  
Mark H.R. Bussin
Keyword(s):  
Private Sector ◽  
Basic Research ◽  
Early Career ◽  
Audit Committees ◽  
Research Issues ◽  
Publish Or Perish ◽  
Additional Information ◽  
Starting Point ◽  
The Difference ◽  
Time To Learn

Problemification: Some academics joined the profession from private sector late in their career. They are sometimes referred to fondly as practical academics or ‘pracademics’ because they still work in private sector and also act as a visiting professor in academia. I sit on eight boards and chair nearly half of them, and serve on audit committees and HR Remuneration committees. I am an example of a ‘pracademic’, and my induction into academia was one sentence – publish or perish. In the private sector, induction can take up to a week. I had one minute.Implications: The implication is that I had to find out what a peer-reviewed journal was and trip into the fact that some peer-reviewed journals are scams and others A rated. Telling the difference in my initial years took its toll. I continually had to ask colleagues – is this journal real? Eventually I realised the DHET list was a good starting point and I started submitting articles. I got more rejections than acceptances at first, with very little explanation. So I learnt nothing and did not know what to do to improve. I had to waste another thousand reviewer hours of time to learn what the requirement was.Research writing is guided by a personal philosophy, and it is about what types of research issues one is inclined towards. For instance, some people are naturally inclined towards basic research and others towards applied research. Others are more oriented towards theory building and testing types for the purpose of creating knowledge for the sake of knowledge. Some others are pragmatic types or realist types and believe real-world problems do not come neatly packaged and are somewhat untidily in presentation calling for discretion or judgement on what to prioritise for research and how to carry out the research. Some are scientist practitioners (evidence informed researchers) and others are practitioner-scientist (practice-led science).Perhaps this kind of orientation to research is what early career researchers need initially; then, they can worry about reproducibility of research findings down the line after grounding themselves into the research space they perceive to belong to and where they feel invested.Purpose: The purpose of this opinion article is to share my journey and sow some doubt in reply to the opinion piece circulated by Efendic and Van Zyl. Whilst I do agree with everything that is said in their article, I believe that there is additional information that needs to be considered. Context is important. Not all academics that submit articles have been in academia for many years. We need to do more to support budding authors.Recommendations: We need to be much more helpful to budding authors than just publishing a page or two called author submission guidelines. These are mostly cosmetic style guides. If we want a higher quality submission and plenty of them – then I believe we need to educate our budding authors of the requirements. Perhaps we need a detailed guide, similar in content and depth as the article of Efendic and Van Zyl (2019). We could consider a podcast setting out the technical guidelines and statistical requirements. Running courses on article publishing by the reviewers is important because that is from the horse’s mouth. Trust me; it is not just a case of sticking to the style guide. You need to really understand some of the under currents of article publishing, for example, quoting as many authors from that particular journal’s list of articles as possible.

Sign in / Sign up

Export Citation Format

Share Document