scholarly journals Hyperspectral Pansharpening in the Reflective Domain with a Second Panchromatic Channel in the SWIR II Spectral Domain

2021 ◽  
Vol 14 (1) ◽  
pp. 113
Author(s):  
Yohann Constans ◽  
Sophie Fabre ◽  
Michael Seymour ◽  
Vincent Crombez ◽  
Yannick Deville ◽  
...  
Keyword(s):  
Performance Assessment ◽  
Supervised Classification ◽  
Significant Contribution ◽  
Spectral Domain ◽  
Extended Version ◽  
Mixed Pixel ◽  
Assessment Protocol ◽  
Fusion Methods ◽  
The Mean ◽  
Spectral Ranges

Hyperspectral pansharpening methods in the reflective domain are limited by the large difference between the visible panchromatic (PAN) and hyperspectral (HS) spectral ranges, which notably leads to poor representation of the SWIR (1.0–2.5 μm) spectral domain. A novel instrument concept is proposed in this study, by introducing a second PAN channel in the SWIR II (2.0–2.5 μm) spectral domain. Two extended fusion methods are proposed to process both PAN channels, namely, Gain-2P and CONDOR-2P: the first one is an extended version of the Brovey transform, whereas the second one adds mixed pixel preprocessing steps to Gain-2P. By following an exhaustive performance-assessment protocol including global, refined, and local numerical analyses supplemented by supervised classification, we evaluated the updated methods on peri-urban and urban datasets. The results confirm the significant contribution of the second PAN channel (up to 45% of improvement for both datasets with the mean normalised gap in the reflective domain and 60% in the SWIR domain only) and reveal a clear advantage for CONDOR-2P (as compared with Gain-2P) regarding the peri-urban dataset.

scholarly journals Functional Monitoring after Trabeculectomy or XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography and Visual Field Indices—A Retrospective Comparative Cohort Study

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 273
Author(s):  
Marc Schargus ◽  
Catharina Busch ◽  
Matus Rehak ◽  
Jie Meng ◽  
Manuela Schmidt ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Cohort Study ◽  
Visual Field ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Treatment Groups ◽  
Rnfl Thickness ◽  
Comparative Cohort Study ◽  
The Mean ◽  
All Treatment

The aim of this study was to compare the efficacy of trabeculectomy (TE), single XEN microstent implantation (solo XEN) or combined XEN implantation and cataract surgery (combined XEN) in primary open-angle glaucoma cases, naïve to prior surgical treatment, using a monocentric retrospective comparative cohort study. Intraocular pressure (IOP) and the number of IOP-lowering drugs (Meds) were monitored during the first 24 months after surgery. Further disease progression was monitored using peripapillary retinal nerve fiber layer (RNFL) thickness examinations using spectral domain optical coherence tomography (OCT) as well as visual acuity (VA) and visual field (VF) tests. In the TE group (52 eyes), the mean IOP decreased from 24.9 ± 5.9 to 13.9 ± 4.2 mmHg (p < 0.001) and Meds decreased from 3.2 ± 1.2 to 0.5 ± 1.1 (p < 0.001). In the solo XEN (38 eyes) and the combined XEN groups, the mean IOP decreased from 24.1 ± 4.7 to 15.7 ± 3.0 mmHg (p < 0.001) and 25.4 ± 5.6 to 14.7 ± 3.2 mmHg (p < 0.001), while Meds decreased from 3.3 ± 0.8 to 0.8 ± 1.2 (p < 0.001) and 2.7 ± 1.2 to 0.4 ± 1.0 (p < 0.001), respectively. The VF and VA indices showed no sign of further deterioration, the RNFL thickness further decreased in all treatment groups after surgery. TE and XEN led to comparable reductions in IOP and Meds. Although the VA and VF indices remained unaltered, the RNFL thickness continuously decreased in all treatment groups during the 24-month follow-up.

scholarly journals Geographic mapping of choroidal thickness in myopic eyes using 1050-nm spectral domain optical coherence tomography

2015 ◽  
Vol 08 (04) ◽  
pp. 1550012 ◽  
Author(s):  
Qinqin Zhang ◽  
Maureen Neitz ◽  
Jay Neitz ◽  
Ruikang K. Wang
Keyword(s):  
Optical Coherence Tomography ◽  
High Myopia ◽  
Choroidal Thickness ◽  
Retinal Pigment ◽  
Reduction Rate ◽  
Radial Distance ◽  
Spectral Domain ◽  
Temporal Region ◽  
Optical Coherence ◽  
The Mean

Purpose: To provide a geographical map of choroidal thickness (CT) around the macular region among subjects with low, moderate and high myopia. Methods: 20 myopic subjects (n = 40 eyes) without other identified pathologies participated in this study: 20 eyes of ≤ 3 diopters (D) (low myopic), 10 eyes between -3 and -6D (moderate myopic), and 10 eyes of ≥ 6D (high myopic). The mean age of subjects was 30.2 years (± 7.6 years; range, 24 to 46 years). A 1050 nm spectral-domain optical coherence tomography (SD-OCT) system, operating at 120 kHz imaging rate, was used in this study to simultaneously capture 3D anatomical images of the choroid and measure intraocular length (IOL) in the subject. The 3D OCT images of the choroid were segmented into superior, inferior, nasal and temporal quadrants, from which the CT was measured, representing radial distance between the outer retinal pigment epithelium (RPE) layer and inner scleral border. Measurements were made within concentric regions centered at fovea centralis, extended to 5 mm away from fovea at 1 mm intervals in the nasal and temporal directions. The measured IOL was the distance from the anterior cornea surface to the RPE in alignment along the optical axis of the eye. Statistical analysis was performed to evaluate CT at each geographic region and observe the relationship between CT and the degree of myopia. Results: For low myopic eyes, the IOL was measured at 24.619 ± 0.016 mm. The CT (273.85 ± 49.01 μm) was greatest under fovea as is in the case of healthy eyes. Peripheral to the fovea, the mean CT decreased rapidly along the nasal direction, reaching a minimum of 180.65 ± 58.25μm at 5 mm away from the fovea. There was less of a change in thickness from the fovea in the temporal direction reaching a minimum of 234.25 ± 42.27 μm. In contrast to the low myopic eyes, for moderate and high myopic eyes, CTs were thickest in temporal region (where CT = 194.94 ± 27.28 and 163 ± 34.89 μm, respectively). Like the low myopic eyes, moderate and high myopic eyes had thinnest CTs in the nasal region (where CT = 100.84 ± 16.75 and 86.64 ± 42.6μm, respectively). High myopic eyes had the longest mean IOL (25.983 ± 0.021mm), while the IOL of moderate myopia was 25.413 ± 0.022 mm (**p < 0.001). The CT reduction rate was calculated at 31.28 μm/D (diopter) from low to moderate myopia, whilst it is 13.49 μm/D from moderate to high myopia. The similar tendency was found for the IOL reduction rate in our study: 0.265 mm/D from low to moderate myopia, and 0.137 mm/D from moderate to high myopia. Conclusion: The CT decreases and the IOL increases gradually with the increase of myopic condition. The current results support the theory that choroidal abnormality may play an important role in the pathogenesis of myopic degeneration.

On the origin of dehydroepiandrosterone sulphate in the blood of fetal sheep

1985 ◽  
Vol 104 (2) ◽  
pp. 279-283 ◽  
Author(s):  
G. C. Liggins ◽  
J.-C. Schellenberg ◽  
F. Amato ◽  
B. Godfrey ◽  
R. F. Seamark
Keyword(s):  
Significant Contribution ◽  
Late Pregnancy ◽  
Dehydroepiandrosterone Sulphate ◽  
Fetal Sheep ◽  
Intact Group ◽  
The Mean ◽  
Ovine Fetal

ABSTRACT Total sulphoconjugated and unconjugated dehydroepiandrosterone (DHA) and total oestrone were measured in plasma of intact sheep fetuses, fetuses hypophysectomized at 104–112 days and fetuses bilaterally adrenalectomized at 98–101 days. At 120–127 days, the mean concentrations of total DHA and oestrone in intact fetuses (n = 13) were 29·7 ± 4·2 (s.e.m.) nmol/l and 14·3 ± 2·8 nmol/l respectively. At term, the values for total DHA and oestrone in hypophysectomized fetuses (n = 13) of 18·0 ± 1·9 nmol/l and 9·1 ±2·0 nmol/l were significantly (P <0·05) lower than the intact group whereas in the adrenalectomized fetuses (n = 8) total DHA (80·8±13·0 nmol/l) was higher (P < 0·05) and total oestrone values were similar to the intact animals. Intrafetal infusion of cortisol at term (1 mg/h for 84 h) raised levels of total oestrone in intact (n = 6; 12·3 ± 2·9 vs 31·6± 8·5 nmol/l) and adrenalectomized (n = 4; 14·2 ± 2·6 vs 190·6 ± 53·0 nmol/l) fetuses and of total DHA in hypophysectomized fetuses (n = 7; 16·0±1·9 vs 31·6 ± 8·5 nmol/l) while infusion of ACTH(1–24) (5 μg/h) was without significant effect in any group. It is concluded that the ovine fetal adrenal in late pregnancy makes no significant contribution either to the high circulating concentrations of DHA sulphate or to the substrates for placental oestrogen synthesis. J. Endocr. (1985) 104, 279–283

Comparative Analysis of the Exposure and Surgical Freedom of the Endoscopic Extended Minipterional Craniotomy and the Transorbital Endoscopic Approach to the Anterior and Middle Cranial Fossae

2018 ◽  
Vol 17 (2) ◽  
pp. 174-181 ◽  
Author(s):  
Raywat Noiphithak ◽  
Juan C Yanez-Siller ◽  
Juan M Revuelta Barbero ◽  
Raymond I Cho ◽  
Bradley A Otto ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Standard Deviation ◽  
Minimally Invasive ◽  
Vertical Axis ◽  
Endoscopic Approach ◽  
Extended Version ◽  
Specific Approach ◽  
Significant Difference ◽  
Surgical Application ◽  
The Mean

AbstractBACKGROUNDNumerous minimally invasive approaches to the skull base have been successively developed. Knowledge of the surgical nuances of a specific approach may facilitate approach selection. This study sought to compare the nuances of an extended version of the minipterional craniotomy (EMPT) with those of the transorbital endoscopic approach (TOEA) to the anterior and middle cranial fossae (ACF and MCF, respectively).OBJECTIVETo quantitatively analyze and compare the area of exposure and surgical freedom between EMPT and TOEA to the ACF and MCF.METHODSEMPT and TOEA were carried out in 5 latex-injected cadaveric heads, bilaterally (10 sides). For each approach, the area of exposure, surgical freedom, and angle of attack were obtained with neuronavigation and statistically compared.RESULTSNo significant difference was found between the mean area of exposure of EMPT and TOEA at the ACF and MCF (P = .709 and .317, respectively). The mean exposure area at the ACF was of 13.4 ± 2.6 cm2 (mean ± standard deviation) and 13.0 ± 1.9 cm2 for EMPT and TOEA, respectively. Except for the crista galli, EMPT afforded a larger area of surgical freedom at all targets. EMPT also achieved significantly greater attack angles in vertical axis except to the crista galli. The horizontal attack angles to all targets were similar between approaches.CONCLUSIONEMPT and TOEA offer a comparable area of exposure at the ACF and MCF in the cadaver; however, the instrument maneuverability afforded by EMPT is superior. Further studies are necessary to better define their precise surgical application.

scholarly journals Evaluation of the relationship between spatial abilities and anatomy learning

2020 ◽  
Vol 14 (2) ◽  
pp. 139-144
Author(s):  
Mustafa Aydın ◽  
Mehmet Tuğrul Yılmaz ◽  
Muzaffer Şeker
Keyword(s):  
Mental Rotation ◽  
Spatial Ability ◽  
Significant Contribution ◽  
Spatial Abilities ◽  
School Students ◽  
Mental Rotation Test ◽  
Practical Applications ◽  
Significant Difference ◽  
The Mean ◽  
The Relationship

Objectives: The aim of this study was to examine the relationship between the spatial abilities of medical school students and their learning in anatomy. Methods: The spatial abilities of the 120 students (74 females, 46 males) were examined using Mental Rotation Test (MRT). The relationship between the mental rotation scores and the mean scores of their practical and theoretical anatomy examinations was determined in terms of gender. Results: The study revealed that mental rotation skills of female participants were lower than males; however, there was no significant difference in their exam (theoretical and practical anatomy examinations) scores in terms of gender. The spatial ability of the students had a low level significant effect on their anatomy scores, regarding practical applications. Conclusion: The results of the study revealed a significant relationship between students’ spatial ability and their success in practical anatomy examinations. This suggests that improving spatial ability skills may have a significant contribution to practical anatomy learning and may be considered as a part of anatomy education.

scholarly journals Benzo[<i>a</i>]pyrene in urban environments of eastern Moscow: pollution levels and critical loads

2017 ◽  
Vol 17 (3) ◽  
pp. 2217-2227 ◽  
Author(s):  
Nikolay S. Kasimov ◽  
Natalia E. Kosheleva ◽  
Elena M. Nikiforova ◽  
Dmitry V. Vlasov
Keyword(s):  
Land Use ◽  
Critical Loads ◽  
Significant Contribution ◽  
Urban Environments ◽  
Anthropogenic Sources ◽  
Average Intensity ◽  
Pollution Levels ◽  
Local Background ◽  
Polycyclic Aromatic ◽  
The Mean

Abstract. Polycyclic aromatic hydrocarbons (PAHs), particularly benzo[a]pyrene (BaP), are toxic compounds emitted from various anthropogenic sources. Understanding the BaP concentrations, dynamics and decomposition in soil is required to assess the critical loads of BaP in urban environments. This study is the first attempt to evaluate all major input and output components of benzo[a]pyrene (BaP) balance and to calculate the permissible load on the urban environment in different land-use zones in the Eastern district of Moscow. BaP contamination of the snow cover in the Eastern district of Moscow was related to daily BaP fallout from the atmosphere. In 2010, the mean content of the pollutant in the snow dust was 1942 ng g−1, whereas the average intensity of its fallout was 7.13 ng m−2 per day. Across the territory, BaP winter fallout intensities varied from 0.3 to 1100 ng m−2 per day. The average BaP content in the surface (0–10 cm) soil horizons was 409 ng g−1, which is 83 times higher than the local background value and 20 times higher than the maximum permissible concentration (MPC) accepted in Russia. The variations in soil and snow BaP concentrations among different land-use zones were examined. A significant contribution of BaP from the atmosphere to urban soils was identified. Based on the measurements of BaP atmospheric fallout and BaP reserves in the soils, the critical loads of BaP for the land-use zones in the Eastern district were calculated for different values of degradation intensity and different exposure times. It was established that at an annual degradation intensity of 1–10 %, ecologically safe BaP levels in the soils of all land-use zones, excluding the agricultural zone, will only be reached after many decades or centuries.

scholarly journals EVALUATION OF THE RESULTS OF THE USE OF VEPTR IN PATIENTS WITH SCOLIOSIS

2016 ◽  
Vol 15 (3) ◽  
pp. 181-185
Author(s):  
JOÃO PAULO SILVA ARAÚJO ◽  
MARCOS ANDRÉ COSTA FERREIRA ◽  
ANDRÉ FLAVIO FREIRE PEREIRA ◽  
TULIO ALBUQUERQUE DE MOURA RANGEL ◽  
RODRIGO CASTRO DE MEDEIROS ◽  
...  
Keyword(s):  
Spinal Fusion ◽  
Spinal Instrumentation ◽  
Objective Evaluation ◽  
Complication Rates ◽  
Mean Values ◽  
Fusion Methods ◽  
The Mean ◽  
Getulio Vargas ◽  
Initial Correction

ABSTRACT Objective: Evaluation of the results of the use of VEPTR (Vertical Expandable Prosthetic Titanium Rib - Synthes Spine Co.(r), West Chester, Pennsylvania, USA) as an option in spinal instrumentation without fusion in younger children with scoliosis, considering the complications inherent to spinal fusion in this age group. Methods: Sixteen (16) patients with scoliosis, regardless of etiology, with a mean age of 5.2 (3-8) years, were followed up by Spine Surgery Group at Hospital Getúlio Vargas, Recite-PE, and were submitted to surgical correction of the deformity using VEPTR, from April/2009 to July/2014. The survey was conducted through medical register review, and photographic and radiographic records, with the measurement of pre- and postoperative curves by the Cobb method. Results: The mean values of Cobb angle in the preoperative period, in the immediate postoperative period and after the last distraction were, respectively, 84.1° (112°-60°), 55.4° (92°-16°) and 64.4° (100°-16°), with an average initial correction of 28.7° (34.1%) and final correction of 19.7° (23.4%). The mean follow-up was 23.1 (0-61) months with an average distraction of 3.1 (0-8). The complication rate in this study was 62.5%. Conclusion: The VEPTR presented considerable correction rates of scoliosis curves in patients whose age contraindicate the spinal fusion methods. It is necessary to improve the technique and the implant itself in order to reduce complication rates, which can be considered relatively high, in addition to the conduction of more studies with longer follow-up to determine the actual efficacy of the implant and the maintenance of long-term correction.

Improving the Practice of Classifier Performance Assessment

2000 ◽  
Vol 12 (2) ◽  
pp. 305-311 ◽  
Author(s):  
N. M. Adams ◽  
D. J. Hand
Keyword(s):  
Performance Assessment ◽  
Supervised Classification ◽  
Classification Rules ◽  
Assessment Criterion ◽  
Classifier Performance

In this note we use examples from the literature to illustrate some poor practices in assessing the performance of supervised classification rules, and we suggest guidelines for better methodology. We also describe a new assessment criterion that is suitable for the needs of many practical problems.

Spectral analogues of the law of the wall, the defect law and the log law

2014 ◽  
Vol 757 ◽  
pp. 498-513 ◽  
Author(s):  
Carlo Zúñiga Zamalloa ◽  
Henry Chi-Hin Ng ◽  
Pinaki Chakraborty ◽  
Gustavo Gioia
Keyword(s):  
Turbulent Energy ◽  
Wall Turbulence ◽  
Spectral Domain ◽  
Energy Spectra ◽  
Scaling Relations ◽  
Mean Velocity ◽  
Law Of The Wall ◽  
The Mean ◽  
Log Law ◽  
The Law

AbstractUnlike the classical scaling relations for the mean-velocity profiles of wall-bounded uniform turbulent flows (the law of the wall, the defect law and the log law), which are predicated solely on dimensional analysis and similarity assumptions, scaling relations for the turbulent-energy spectra have been informed by specific models of wall turbulence, notably the attached-eddy hypothesis. In this paper, we use dimensional analysis and similarity assumptions to derive three scaling relations for the turbulent-energy spectra, namely the spectral analogues of the law of the wall, the defect law and the log law. By design, each spectral analogue applies in the same spatial domain as the attendant scaling relation for the mean-velocity profiles: the spectral analogue of the law of the wall in the inner layer, the spectral analogue of the defect law in the outer layer and the spectral analogue of the log law in the overlap layer. In addition, as we are able to show without invoking any model of wall turbulence, each spectral analogue applies in a specific spectral domain (the spectral analogue of the law of the wall in the high-wavenumber spectral domain, where viscosity is active, the spectral analogue of the defect law in the low-wavenumber spectral domain, where viscosity is negligible, and the spectral analogue of the log law in a transitional intermediate-wavenumber spectral domain, which may become sizable only at ultra-high$\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}\mathit{Re}_{\tau }$), with the implication that there exist model-independent one-to-one links between the spatial domains and the spectral domains. We test the spectral analogues using experimental and computational data on pipe flow and channel flow.

scholarly journals Diurnal Choroidal Thickness Changes in Normal Eyes of Turkish People Measured by Spectral Domain Optical Coherence Tomography

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ozen Ayrancı Osmanbasoglu ◽  
Zeynep Alkin ◽  
Abdullah Ozkaya ◽  
Yavuz Ozpınar ◽  
Ahmet Taylan Yazici ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diurnal Variation ◽  
Choroidal Thickness ◽  
Working Hours ◽  
Mean Amplitude ◽  
Diurnal Change ◽  
Spectral Domain ◽  
Enhanced Depth Imaging ◽  
Optical Coherence ◽  
The Mean

Purpose. To analyse the diurnal variation of central choroidal thickness (CCT) in healthy emetropic patients during working hours.Methods. Fifty healthy young emmetrpic volunteers were included in this study. CCT was measured at 9 AM and 4 PM with spectral domain optical coherence tomography (Spectralis, Heidelberg Engineering) with enhanced depth imaging. Diurnal variation of CCT, the correlation between rigth and left eyes and the demographic factors affecting this variation were assessed.Findings. The mean CCT at 9 AM and 4 PM was 308.7 ± 64.5 μm and 308.7 ± 62 μm, respectively, with a mean diurnal amplitude of −0.03 ± 14.7 μm, ranging between −55 μm and 47 μm, the difference was statistically insignificant (P: 0.9). There were positive correlations between right and left eyes among CCT measurements at 9 AM, 4 PM and the mean amplitude of diurnal change (r: 0.65,P<0.01;r: 0.60,P<0.01;r: 0.45,P: 0.00, resp.). There was a statistically significant negative correlation between the magnitude of diurnal change and age (r: −0.27,P: 0.01).Conclusion. Although the mean CCT in the all group does not show significant variation during working hours, the pattern of diurnal variation may vary from person to person according to age, and there is a great harmony between the two eyes.

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