scholarly journals Understanding the relationship between visual-angle and eye-angle for reliable determination of the field-of-view in ultra-wide field fundus photography

2021 ◽  
Author(s):  
Xincheng Yao ◽  
Devrim Toslak ◽  
Taeyoon Son ◽  
Jiechao Ma
Keyword(s):  
Visual Angle ◽  
Field Of View ◽  
Fundus Photography ◽  
Wide Field ◽  
Reliable Determination ◽  
The Relationship

The Optical Measurement of Lapse Rate *

1950 ◽  
Vol 31 (2) ◽  
pp. 51-55 ◽  
Author(s):  
Robert G. Fleagle
Keyword(s):  
Optical Measurement ◽  
Vertical Gradient ◽  
Lapse Rate ◽  
Speed Of Light ◽  
Indirect Methods ◽  
Reliable Determination ◽  
Air Density ◽  
Lapse Rates ◽  
The Relationship

The need for reliable determination of the temperature of the air very near the ground and the difficulties inherent in measurement of this quantity by the ordinary indirect methods are pointed out. It is suggested that the dependence of the speed of light on air density provides a convenient method for the determination of the temperature near the ground by direct measurement of the lapse rate, and evidence is given from other papers to show that this is feasible where the vertical gradient of humidity is not great. The relationship between apparent elevation and lapse rates of temperature and vapor pressure is derived, and the relationship is illustrated by the results of computations.

scholarly journals Clinic-based ultra-wide field retinal imaging in a pediatric population

2019 ◽  
Vol 5 (S1) ◽  
Author(s):  
Nikisha Kothari ◽  
Stacy Pineles ◽  
David Sarraf ◽  
Federico Velez ◽  
Gad Heilweil ◽  
...  
Keyword(s):  
Pediatric Population ◽  
Case Series ◽  
Retinal Imaging ◽  
Field Of View ◽  
Fundus Photography ◽  
Arterial Phase ◽  
Wide Field ◽  
Retrospective Case ◽  
Additional Information ◽  
Common Diagnosis

Abstract Background Pediatric retinal disorders, although uncommon, can be challenging to assess in the clinic setting and often requires an exam under anesthesia. The purpose of our study was to evaluate the use of ultra-wide field retinal imaging in children without sedation in an outpatient clinic. Methods We performed a retrospective case series of patients 18 years or younger who received ultra-wide field imaging over a one year period. The age, gender, and clinical course were documented. Color fundus and red-free images were reviewed to assess field of view. Ultra-wide field autofluorescence (UWF-FAF) was evaluated for abnormal autofluorescence patterns and ultra-wide field fluorescein angiography (UWF-FA) was assessed for angiographic phase and field of view. Results A total of 107 eyes of 55 patients with a mean age of 11.1 years (SD 3.7 years, range 3–18 years) were evaluated. Twenty-seven (49%) patients were male. The most common diagnosis was retinopathy of prematurity (7 of 55 patients, 12.7%) followed by trauma (7.4%), Coats disease (7.4%), and rhegmatogenous retinal detachment (7.4%). The number of quadrants visualized anterior to the equator correlated with patient age (r = 0.4, p < 0.01). On UWF-FA, 6 of 14 patients (43%) had images of the arterial phase captured and 14 of 14 patients (100%) had images of the venous phase or later captured. Conclusions We demonstrated that UWF imaging is obtainable in children as young as 3 years old without sedation. UWF fundus photography, UWF-FAF and UWF-FA were useful clinical adjuvants to examination and provide additional information for documenting and monitoring pediatric retinal diseases.

scholarly journals Molecular markers in population genetics and breeding of cultivated plants

2019 ◽  
Author(s):  
Юрий Чесноков ◽  
Yuriy Chesnokov ◽  
Наталья Кочерина ◽  
Natalia Kocherina ◽  
Владимир Косолапов ◽  
...  
Keyword(s):  
Population Genetics ◽  
Cultivated Plants ◽  
Reliable Determination ◽  
Factors Affecting ◽  
Physiological And Biochemical Characteristics ◽  
Cultivated Plant ◽  
Agricultural Plants ◽  
The Relationship ◽  
Physiological And Biochemical

Information on the use of molecular and traditional genetic markers in population genetics and breeding of agricultural plants is presented. An assessment of the level of diversity in populations is given using different types of markers, both at the level of alleles and at the level of individual nucleotides, including the measurement of differentiation within different marker systems. The relationship between molecular divergence, phenotypic divergence and co-origin described. The factors affecting the reliable determination of quantitative trait loci highlighted. Special attention is paid to the mapping of Mendelian genes. Special attention paid to the physiological and biochemical characteristics and their role in the manifestation and identification of economically valuable properties of cultivated plant species. Information is provided on the main hardware and software commonly used to conduct statistical calculations and establish a disequilibrium of marker/trait linking in populations. The purpose of the main computer programs, the most widely used for genetic mapping and establishing a marker / trait association, is briefly discussed.

scholarly journals Estimation of the Reconstruction Parameters for Atom Probe Tomography

2008 ◽  
Vol 14 (4) ◽  
pp. 296-305 ◽  
Author(s):  
Baptiste Gault ◽  
Frederic de Geuser ◽  
Leigh T. Stephenson ◽  
Michael P. Moody ◽  
Barrington C. Muddle ◽  
...  
Keyword(s):  
Tomographic Reconstruction ◽  
Three Dimensional ◽  
Atom Probe ◽  
Field Of View ◽  
Wide Field ◽  
Detection Systems ◽  
Wide Field Of View ◽  
Systematic Determination ◽  
Consistent Method

The application of wide field-of-view detection systems to atom probe experiments emphasizes the importance of careful parameter selection in the tomographic reconstruction of the analyzed volume, as the sensitivity to errors rises steeply with increases in analysis dimensions. In this article, a self-consistent method is presented for the systematic determination of the main reconstruction parameters. In the proposed approach, the compression factor and the field factor are determined using geometrical projections from the desorption images. A three-dimensional Fourier transform is then applied to a series of reconstructions, and after comparing to the known material crystallography, the efficiency of the detector is estimated. The final results demonstrate a significant improvement in the accuracy of the reconstructed volumes.

scholarly journals Widefield imaging of retinal and choroidal tumors

2019 ◽  
Vol 5 (S1) ◽  
Author(s):  
Natalia F. Callaway ◽  
Prithvi Mruthyunjaya
Keyword(s):  
Fundus Autofluorescence ◽  
Imaging Modalities ◽  
Fundus Photography ◽  
Wide Field ◽  
Indocyanine Angiography ◽  
Relationship Of ◽  
The Relationship ◽  
Field Imaging ◽  
Wide Field Imaging ◽  
Sd Oct

Abstract Background Wide-field imaging plays an increasingly important role in ocular oncology clinics. The purpose of this review is to describe the commonly used wide-field imaging devices and review conditions seen in ocular oncology clinic that underwent wide-field imaging as part of the multimodal evaluation. Summary of review Wide-field or wide-angle imaging is defined as greater than 50° field of view. Modern devices can reach far beyond this reporting fields of view up to 267°, when utilizing montage features, with increasingly impressive resolution. Wide-field imaging modalities include fundus photography, fluorescein angiography (FA), fundus autofluorescence (FAF), indocyanine angiography (ICG), spectral domain optical coherence tomography (SD-OCT), and recently wide-field OCT Angiography (OCTA). These imaging modalities are increasingly prevalent in practice. The wide-field systems include laser, optical, and lens based systems that are contact or non-contact lens systems each with its own benefits and drawbacks. The purpose of this review is to discuss commonly used wide-field imaging modalities for retinal and choroidal tumors and demonstrate the use of various widefield imaging modalities in select ocular oncology cases. Conclusions Clinical examination remains the gold standard for the evaluation of choroidal and retinal tumors. Wide-field imaging plays an important role in ocular oncology for initial documentation, surgical planning, determining the relationship of the tumor to adjacent ocular structures, following tumor size after treatment, and monitoring for recurrence.

STM studies of crystal growth

1991 ◽  
Vol 49 ◽  
pp. 374-375
Author(s):  
M. G. Lagally
Keyword(s):  
Crystal Growth ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Sputter Deposition ◽  
Field Of View ◽  
Scanning Tunneling ◽  
Wide Field ◽  
Tunneling Microscopy ◽  
Wide Field Of View ◽  
The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

A panel of mono- and dinucleotide microsatellite markers is required for reliable determination of the MSI status in colorectal cancer

2001 ◽  
Vol 120 (5) ◽  
pp. A599-A599
Author(s):  
C ARNOLD ◽  
A GOEL ◽  
J CARETHERS ◽  
L WASSERMAN ◽  
C COMPTON ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Microsatellite Markers ◽  
Reliable Determination

Thromboplastin Related Differences in the Determination of International Normalised Ratio: A Cause for Concern?

1994 ◽  
Vol 72 (03) ◽  
pp. 426-429 ◽  
Author(s):  
S Kitchen ◽  
I D Walker ◽  
T A L Woods ◽  
F E Preston
Keyword(s):  
Patient Management ◽  
External Quality Assessment ◽  
Oral Anticoagulant Therapy ◽  
Warfarin Dosage ◽  
External Quality ◽  
External Quality Assessment Scheme ◽  
International Normalised Ratio ◽  
The Uk ◽  
The Relationship

SummaryWhen the International Normalised Ratio (INR) is used for control of oral anticoagulant therapy the same result should be obtained irrespective of the laboratory reagent used. However, in the UK National External Quality Assessment Scheme (NEQAS) for Blood Coagulation INRs determined using different reagents have been significantly different.For 18 NEQAS samples Manchester Reagent (MR) was associated with significantly lower INRs than those obtained using Diagen Activated (DA, p = 0.0004) or Instrumentation Laboratory PT-Fib HS (IL, p = 0.0001). Mean INRs for this group were 3.15, 3.61, and 3.65 for MR, DA, and IL respectively. For 61 fresh samples from warfarin-ised patients with INRs of greater than 3.0 the relationship between thromboplastins in respect of INR was similar to that observed for NEQAS data. Thus INRs obtained with MR were significantly lower than with DA or IL (p <0.0001). Mean INRs for this group were 4.01, 4.40, and 4.59 for MR, DA, and IL respectively.We conclude that the differences between INRs measured with the thromboplastins studied here are sufficiently great to influence patient management through warfarin dosage schedules, particularly in the upper therapeutic range of INR. There is clearly a need to address the issues responsible for the observed discrepancies.

Modern determinants of endometrium hyperplastic processes pathogenesis

2016 ◽  
pp. 137-142
Author(s):  
V.O. Benyuk ◽  
◽  
V.M. Goncharenko ◽  
T.R. Nykoniuk ◽  
◽  
...  
Keyword(s):  
Conservative Therapy ◽  
Solid Phase ◽  
Research Direction ◽  
Immunohistochemical Method ◽  
Results Of Treatment ◽  
Treatment And Prevention ◽  
Receptor Phenotype ◽  
The Relationship ◽  
Endometrial Proliferation

The objective: to еxplore the relationship between the activity of endometrial proliferation and the state of the local immune response in the uterus in the conditions berprestasi process. Patients and methods. Examined 228 women of reproductive and perimenopausal age with endometrial pathology using ultrasound and then performing hysteroresectoscopy. Determination of the concentrations of the cytokines IL-1, IL-2, IL-6 and TNF was performed by solid phase ELISA. Results. Found a trend that confirms the loss of sensitivity to hormones at the stage of malignancy of the endometrium and can be used as diagnostic determinants in determining the nature of intrauterine pathology and criterion of the effectiveness of conservative therapy. Conclusion. Improving etiopatogenetice approach to the therapy of hyperplastic proce.sses of endometrium with determination of receptor phenotype of the endometrium is a research direction in modern gynecology, which will help to improve the results of treatment and prevention of intrauterine pathology. Key words: endometrial hyperplasia,the receptors for progesterone and estrogen, immunohistochemical method.

Calculating the aerodynamics of vertical axis wind turbines

2012 ◽  
Vol 34 (3) ◽  
pp. 169-184 ◽  
Author(s):  
Hoang Thi Bich Ngoc
Keyword(s):  
Wind Turbine ◽  
Incidence Angle ◽  
Vertical Axis ◽  
Rotor Blades ◽  
Vertical Axis Wind Turbine ◽  
Horizontal Axis Wind Turbine ◽  
Velocity Triangle ◽  
Relationship Of ◽  
The Relationship

Vertical axis wind turbine technology has been applied last years, very long after horizontal axis wind turbine technology. Aerodynamic problems of vertical axis wind machines are discussible. An important problem is the determination of the incidence law in the interaction between wind and rotor blades. The focus of the work is to establish equations of the incidence depending on the blade azimuth, and to solve them. From these results, aerodynamic torques and power can be calculated. The incidence angle is a parameter of velocity triangle, and both the factors depend not only on the blade azimuth but also on the ratio of rotational speed and horizontal speed. The built computational program allows theoretically selecting the relationship of geometric parameters of wind turbine in accordance with requirements on power, wind speed and installation conditions.

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