Distant Screen Research Articles

Image of a black hole illuminated by a parabolic screen

A model of an illuminating black hole surface (“parabolic screen”) is proposed. This allows to avoid in a natural way the appearance of edge effects related with photons moving along the screen plane. The temperature distribution along the radius corresponds to the corresponding distribution for a relativistic disk (Novikov-Thorne disk). It is shown that the structure of the formed black hole shadow essentially differs from the case when the source of photons is a distant screen, since in the considered model the photons, subjected to strong gravitational lensing of the black hole, are emitted by the “backward” side of screen, which would not be visible in the absence of the black hole. In the thin screen approximation, shadow images are constructed for the Schwarzschild black hole in the cases when the angle between the symmetry axis of the illuminating screen and the direction to the observer is equal to 5, 30, 30 and 80 angular degrees, similar images for the Kerr black hole are constructed for the cases of 60 and 80 angular degrees.

Epidemiology of the non-head and neck sebaceous carcinoma and implications for distant metastasis screening.

Extraocular sebaceous carcinoma (SC), particularly those outside the head and neck region, is rare and not well-described. This study aimed to explore the epidemiology and identify the prognostic factors of non-head and neck SC, describe the possible relevant factors of distant metastasis, and provide implications for distant metastasis screening. Data from the 17 registries in the Surveillance, Epidemiology, and End Results database were retrospectively collected for patients with SC outside the head and neck from 2000 through 2020. Overall survival (OS) and disease-specific survival (DSS) were the primary endpoints. Survival analysis was conducted through Kaplan-Meier curves, and multivariate analysis was carried out using Cox proportional hazard models. A total of 1,237 patients with SC outside the head and neck were identified. The mean age at diagnosis of the entire patient cohort was 67.7 years (30 to 90+ years), and the mean tumor size was 2.2 cm (0.1-16 cm). Patients with distant disease experienced the lowest OS (mean, 29.5 months) than those with localized disease and regional disease (p < 0.0001). Multivariate analysis revealed that age, tumor size, and stage were independent determinants of OS; age, stage, and primary site were independent determinants of DSS. Tumor grade and lymph node status had less prognostic value for survival. Undifferentiated tumors have a trend toward distant metastasis, especially those at the primary site of the trunk. The prognosis of the non-head and neck SC is excellent, while the survival of distant disease is very poor. Distant metastasis screening can be considered for undifferentiated tumors, especially those located in the trunk region with large tumor sizes.

Improving Fecal Immunochemical Test Collection for Colorectal Cancer Screening During the COVID-19 Pandemic.

Colonoscopy is a first-line method for colorectal cancer (CRC) screening. However, cost-effective noninvasive tests, such as high-sensitivity guaiac-based fecal occult blood test (gFOBT) and fecal immunochemical test (FIT), are also used. The COVID-19 pandemic had a substantial negative impact on CRC screening rates. The James A. Haley Veterans Affairs Hospital (JAHVAH) continued socially distant CRC screening using FITs, but encountered inefficiencies due to high rates of incorrectly collected FIT samples. A quality improvement (QI) project was conducted to increase correctly collected and testable FIT kits upon initial laboratory submission. The ambulatory QI project sought out root causes for incorrectly returned FITs and proposed Plan-Do-Study-Act (PDSA) cycles based on a series of approved action plans. A multidisciplinary team of laboratory, nursing, administrative, and primary care staff worked together to discover 6 major root causes. Our multipronged PDSA cycle attempted to set up redundant patient reminders, centralize the FIT dispersal process, and make the patient-FIT interface more user-friendly. All PDSA solutions were implemented over 4 months. Lack of collection date was the most common reason for incorrectly returned FIT kits and the focus of PDSA improvements. The rate of FITs with missing collection dates dropped from 24% prior to PDSA to 14% in April 2021. The rate of correctly returned FIT kits rose from 38% before the project to 72% afterwards, surpassing the 20% improvement goal. FIT is a useful method for CRC screening that can be particularly helpful when in-person visits are limited, as seen during the COVID-19 pandemic. The increase in demand for FITs during the pandemic revealed process deficiencies and gave JAHVAH an opportunity to improve workflow.

The diagnostic yield of preoperative screening for oral cancer in dogs over 15 years, part 2: distant screening.

Determine diagnostic yield of chest, abdomen, and 4-site screening to diagnose metastatic disease and secondary diseases of prognostic significance in dogs with oral cancer. Medical records from 381 dogs with histologically confirmed oral tumors that underwent preoperative screening were retrospectively reviewed. Thoracic metastasis was diagnosed in 4.9% (0.9% odontogenic, 6.5% nonodontogenic) of oral tumors. Oral malignant melanoma and multilobular osteochondrosarcoma were most at risk. Abdominal metastasis was diagnosed in 2% of oral tumors (0% odontogenic, 3.1% nonodontogenic) and cytologically confirmed in 2 cases (0.6% [2/295)] of all abdominal ultrasounds (AUS) 5.5% [2/36] of all AUS that had cytology). Both cases had oral malignant melanoma. Incidental disease was diagnosed in 53.1% and 81.3% of thoracic and abdominal screenings, respectively. Major findings were more common in AUS (7.8%) compared to thoracic screening (1.9%). The prevalence of incidental findings was similar for odontogenic and nonodontogenic tumors. Both metastasis and major findings were diagnosed more commonly with thoracic CT compared to radiographs. Metastasis or a major finding of prognostic significance was diagnosed in at least 1 test in 27.8% of patients that had head CT, lymph node cytology, thoracic screening, and AUS (n = 115). Major incidental findings were more commonly detected with AUS and were diagnosed in 1 in every 12 patients. However, metastatic disease was most commonly detected with thoracic screening. When all 4 screening tests are performed, there is an approximately 1 in 4 chance of diagnosing metastasis or major significant disease regardless of tumor type.

Clinicomics-guided distant metastasis prediction in breast cancer via artificial intelligence

BackgroundBreast cancer has become the most common malignant tumour worldwide. Distant metastasis is one of the leading causes of breast cancer-related death. To verify the performance of clinicomics-guided distant metastasis risk prediction for breast cancer via artificial intelligence and to investigate the accuracy of the created prediction models for metachronous distant metastasis, bone metastasis and visceral metastasis.MethodsWe retrospectively enrolled 6703 breast cancer patients from 2011 to 2016 in our hospital. The figures of magnetic resonance imaging scanning and ultrasound were collected, and the figures features of distant metastasis in breast cancer were detected. Clinicomics-guided nomogram was proven to be with significant better ability on distant metastasis prediction than the nomogram constructed by only clinical or radiographic data.ResultsThree clinicomics-guided prediction nomograms on distant metastasis, bone metastasis and visceral metastasis were created and validated. These models can potentially guide metachronous distant metastasis screening and lead to the implementation of individualized prophylactic therapy for breast cancer patients.ConclusionOur study is the first study to make cliniomics a reality. Such cliniomics strategy possesses the development potential in artificial intelligence medicine.

Knowledge, Attitude, and Practice of Cervical Cancer Screening among Women Infected with HIV in Kasenengwa District of Eastern Province, Zambia

Women living with Human Immunodeficiency Virus (WLHIV) have a higher risk of developing cervical cancer due to their immune-compromised state. Cervical cancer screening leads to early detection and treatment. The aim of the study was to determine the knowledge, attitude, and practices of cervical cancer screening among women infected with HIV in Kasenengwa District, Eastern Province, Zambia. A descriptive cross-sectional study design using a semi-structured questionnaire was used to collect data from 266 WLHIV. Basic descriptive statistics were done using SPSS version 23.0. Almost two-thirds (62.7%) of the 266 WLHIV in the study had adequate knowledge about cervical cancer screening. Almost three-fifths of the respondents (57.1%) had a negative attitude toward cervical cancer screening. The majority (78.2%) had been counselled by healthcare workers on cervical cancer screening with good emotional support from family members (72.9%). About two-thirds (68.4%) of the respondents had been screened for cervical cancer. Most women indicated that they didn’t have access to cervical cancer screening services because they did not know where to go (61.5%) and distant screening sites (56.3%) WLHIV in the study had adequate knowledge, but unfavorable attitude towards cervical cancer screening, while two-thirds had been screened for cervical cancer. Accessibility to screening sites was poor. More education and sensitization are needed in the district to eliminate misconceptions about cervical cancer screening, which may influence uptake. Keywords: Cervical Cancer; Screening; Knowledge; Practice.

'I'm not perfect': Navigating screen time among parents of young children during COVID-19.

BackgroundThe use of screen time for young children has been hotly debated among experts. This study explored the utilization of screen time among mothers with young children during the COVID‐19 pandemic. The objective of this study was to understand maternal motivation for utilizing screen time and how mothers have engaged in screen time since the beginning of the pandemic.MethodThis paper uses a sample of n = 25 mothers who participated in an in‐depth interview about parenting during the COVID‐19 pandemic. The team utilized a thematic analysis approach to qualitatively code the transcripts. All analyses were conducted in Dedoose 8.3, and all transcripts were coded by three independent researchers to enhance rigour.ResultsFive main themes emerged from the interviews: (1) harbouring screen guilt versus letting it go, (2) managing full‐time work and full‐time parenting, (3) prioritizing mental sanity, (4) socially distant supports demand screen time and (5) screens can have positive uses, too.ConclusionDuring the COVID‐19 pandemic, mothers have resorted to screen time use to cope with increased stress and challenges. However, mothers have also found positive uses for screen time, such as connection with extended family members, peer interaction and educational activities. Findings highlight the need to differentiate screen time use by quality and to update formal screen time guidelines considering changing roles of technology.

When ethnographic work turns into distant screen visits: A note on flexible inflexibility during the COVID-19 pandemic.

This colloquium shares experiences from doing ethnographic fieldwork with young children and the challenges that followed due to the COVID-19 pandemic. The project DIGIKIDS Sweden has its focus on very young children (birth to three years) and their engagement with digital media technologies in their homes. The pandemic put the project on hold, but in the families where the fieldwork had already started, the authors decided to change the methods of data collection. Digital screen visits were introduced and, at first, this seemed to be flexible, and they adjusted to the new environment. At the same time, this flexibility also became an inflexible experience due to the use of technology.

Young’s Two-Slit Experiment Without a Laser

The Young’s two-slits experiment is arguably one of the most famous and beautiful experiments in physics. In introductory physics labs the experiment is almost exclusively carried out using a laser, and it is introduced this way in some introductory physics textbooks. In the case of laser illumination, light passes directly through the slits and spreads out by diffraction so that interference fringes can be viewed on a distant screen. Most students, in our experience, are unaware that the experiment can be carried out in any other way. But the laser approach depends on the remarkable light emitted by the laser: it is spatially coherent, meaning that the phase relationship between the light emitted from the slits is constant, and it is extremely bright, meaning that real interference fringes can be seen on the screen. When carried out with classical, incoherent light, a quasi-monochromatic source such a sodium lamp must first be rendered spatially coherent by focusing the light through a pinhole and then using this light to illuminate the two slits. Fringe patterns will certainly be formed, but they need to be observed by either viewing with an eyepiece or allowing them to fall directly on the photosensor of a camera. It is implied in other physics texts that the fringe pattern can be cast onto a screen and viewed, but this is not feasible because the fringes are just not bright enough. Here we report an arrangement where an extended incoherent source can be used and fringes made bright enough to be observed on a screen.

Two point-source interference: a study of the formation of concentric circular fringes

In this short paper, the hyperbola-based analysis of wave interference recently developed by Thomas is employed to study the pattern of concentric circular fringes captured on a distant screen, when its plane is oriented orthogonal to the line joining two coherent point-sources. Newton’s rings are another instance of concentric circular fringes, generated with an extended source and a plano-convex lens-glass plate combination. The underlying geometry of the latter scenario, as described in the literature, allows for the estimation of two important physical parameters viz. the wavelength of light and the refractive index of a liquid medium. It is demonstrated here that the geometrical arrangement of the former scenario can in principle, be utilized to reach the same ends as well. Additionally, the hallmark distinguishing features of both types of circular fringe patterns are qualitatively and quantitatively elucidated.

Multiple slit interference: a hyperbola based analysis

The textbook description of multiple slit interference employs a standard path difference formula that was originally calculated for the purpose of analyzing Young’s double slit experiment. It was arrived at on the basis of a pair of assumptions that help simplify the geometry of the slit-barrier-screen arrangement and the ensuing formalism needed to estimate the positions of interference fringes on the detection screen. According to the conventional approach, convergent rays of light that emanate from different slits can be treated as effectively parallel in the far field limit. Such a parallel ray approximation-based analysis was shown by Thomas (2019; 2020) to be redundant, paradoxical and limited in accuracy. In this paper, the task of reformulation that began previously with the elementary two-slit experiment is now extended to encompass the N-slit scenario, diffraction at a single-slit and the formation of circular fringes. In order to derive one of the key results (the generalized hyperbola theorem for N-point sources), a novel computational technique called analytical induction is introduced. The procedure involves a synthesis of concepts from Cartesian geometry and discrete mathematics, namely coordinate transformation by Euclidean translation and a method of proof called the principle of mathematical induction, respectively. The final goal attained are two distribution functions that succinctly and precisely describe the variation of intensity of interference fringes on the distant screen, when it is oriented parallel and perpendicular relative to the line joining the sources. A comparison is drawn between the predictions of the conventional and the new analyses by means of numerical-graphical simulation with MATLAB. The theoretical methods and results presented herein may have a significant bearing in areas of applied optics like interferometry and diffraction crystallography. On the pedagogic front, it is suggested that the current geometrical program being visually more intuitive, be incorporated into the standard curriculum of an advanced undergraduate/graduate level course in physical optics, to complement the conventional approach.

Quantum memories and the double-slit experiment: implications for astronomical interferometry

Thomas Young’s slit experiment lies at the heart of classical interference and quantum mechanics. Over the last 50 years, it has been shown that particles (e.g., photons, electrons, large molecules), even individual particles, generate an interference pattern at a distant screen after passage through a double slit, thereby demonstrating wave-particle duality. We revisit this famous experiment by replacing both slits with single-mode fiber inputs to two independent quantum memories that are capable of storing the incident electromagnetic field’s amplitude and phase as a function of time. At a later time, the action is reversed: the quantum memories are read out in synchrony, and the single-mode fiber outputs are allowed to interact, consistent with the original observation. In contrast to any classical memory device, the write and read processes of a quantum memory are non-destructive and hence preserve the photonic quantum states. In principle, with sufficiently long storage times and sufficiently high photonic storage capacity, quantum memories operating at widely separated telescopes can be brought together to achieve optical interferometry over arbitrarily long baselines.

Distant Glowing Screens: Lessons Learned from Adapting to Online Instruction

Distant Glowing Screens: Lessons Learned from Adapting to Online Instruction

Systematic Review of Simulated Airway Management Whilst Wearing Personal Protective Equipment

(Br J Anaesth. 2020;125:e301–e305) Tracheal intubation is required in approximately 2.3% of COVID-19 patients. As COVID-19 is highly transmissible, airway management is high-risk for healthcare workers. The use of full personal protective equipment (PPE) is common among published recommendations for reducing the risk of transmission to healthcare workers during intubation. Other common recommendations include using video laryngoscopy with a distant screen display, avoiding manual bag-mask ventilation and involving senior staff. These recommendations were based on experiences from present and past pandemics rather than controlled studies. This systematic review aimed to evaluate current best practices for airway management while using PPE by reviewing studies using manikin-based simulation.

Television‐induced electronegative photoparoxysmal response: an extratemporal seizure mimic?

AbstractVideo‐EEG monitoring is an established gold‐standard procedure for diagnosis and differentiation of epileptic and non‐epileptic seizures. Epilepsy misdiagnosis, to which factors such as EEG artifact misinterpretation contribute to, is common, and can have long‐lasting iatrogenic repercussions to the clinical management of affected patients. Among the many types of responses to photic stimulation, artifacts and physiologic and epileptic responses are possible. All of these can interfere with EEG interpretation when provoked by a source of illumination. Photic‐induced responses are of increasing relevance given the ubiquity of screens and other light‐emitting electronics in our modern world. One of these, the photoparoxysmal response, is a frequent finding in photosensitive patients with genetic generalized epilepsies. Various responses beyond abnormal occurrence of cortical spikes or spike‐and‐wave discharges are known to occur on EEG in response to intermittent photic stimulation (IPS), with different clinical implications. To our knowledge, we report a unique electronegative photoparoxysmal response during video‐EEG monitoring induced by fluctuating illumination caused by a distant television screen. This response mimicked an extratemporal seizure in a young woman with frontal lobe epilepsy, admitted for presurgical evaluation. Novel electronegative responses to electronic devices during video‐EEG monitoring merit consideration by EEG interpreters to help avoid misdiagnosis.

Разработка комплексной программы профилактики и лечения аномалий рефракции у детей школьного возраста

Aim: to develop a complex preventive and therapeutic program for refractive errors in school year children. Patients and Methods: 1,760 pupils of elementary, secondary, and high school of eight schools of Almaty (1,302 pupils of gymnasiums and 458 pupils of general education schools and sport boarding school) were examined. The 1st step was a preventive screening. The 2nd step was a distant interactive screening by teachers. The 3rd step was an eye examination of schoolers with low vision. The efficacy of the detection of visual impairments in schoolers during preventive and distant computer screening was compared. In addition, significant indicators for visual impairment monitoring in schoolers were identified. A "Program for the Prevention of the Development and Progression of Refractive Errors in Schoolchildren" was developed. To evaluate its efficacy, 140 pupils of general education schools with refractive errors and 1,302 pupils of gymnasiums with refractive errors or their high risk underwent eye examinations. In addition, to compare the effect of wearing glasses/contact lenses with full correction on the quality of life, 31 schoolers aged 12–17 with refractive errors were selected. Results: the rate of visual impairments was 28.4% among the pupils of general education schools and 31.3% among the pupils of gymnasiums. The most common refractive error was myopia (46.9% and 65.4%, respectively). As children moved through their school carrier, the proportion of myopia tended to increase. Accommodative dysfunction ranked second 48.5% and 29.7%, respectively). Time spent on distant screening was twice less compared to time spent on preventive screening. Visual acuity, cycloplegic refraction, reserves of relative accommodation, and axial length (measured by ultrasound) were indicators of visual impairments in children during monitoring. Poor general health was reported in 33% of children who wear glasses and 15% of children who wear contact lenses. Keywords: refractive errors, myopia, accommodation, schoolchildren, distant screening, prevention, vision correction with contact lenses. For citation: Botabekova T.K., Aldasheva N.A., Abdullina V.R. et al. Complex program for the prevention of the development and progression of refractive errors in school year children. Russian Journal of Clinical Ophthalmology. 2021;21(3):135–142 (in Russ.). DOI: 10.32364/2311- 7729-2021-21-3-135-142.

The classical double slit experiment–a study of the distribution of interference fringes formed on distant screens of varied shapes

The double slit experiment was the first demonstrative proof of the wave nature of light. It was expounded by the English physician-physicist Thomas Young in 1801 and it soon helped lay to rest the then raging Newton–Huygens debate on whether light consisted of a fast-moving stream of particles or a train of progressive waves in the ether medium. In the experiment, light is made to pass through two very narrow slits spaced closely apart. A screen placed on the other side captures a pattern of alternating bright and dark bands called fringes which are formed as a result of the phenomenon of interference. In prior work by the same author, it was shown that the conventional analysis of Young’s experiment that is used in many introductory physics textbooks, suffers from a number of limitations in regards to its ability to accurately predict the positions of these fringes on the distant screen. This was owing to the adoption of some needless and paradoxical assumptions to help simplify the geometry of the slit barrier-screen arrangement. In the new analysis however, all such approximations were discarded and a hyperbola theorem was forwarded which was then suitably applied to determine the exact fringe positions on screens of varied shapes (linear, semi-circular, semi-elliptical). This paper further builds on that work by laying down the mathematical framework necessary for counting fringes and then comparing their distributions on differently shaped screens, using MATLAB software package for numerical–graphical simulation. In addition, a pair of equivalent laws of proportionality are predicted that govern the distribution of fringes independent of the shape of the detection screen employed.

Результаты первого клинического опыта дистантного скрининга зрения у школьников г. Хабаровска

Результаты первого клинического опыта дистантного скрининга зрения у школьников г. Хабаровска

Automation of the kidney function prediction and classification through ultrasound-based kidney imaging using deep learning

Prediction of kidney function and chronic kidney disease (CKD) through kidney ultrasound imaging has long been considered desirable in clinical practice because of its safety, convenience, and affordability. However, this highly desirable approach is beyond the capability of human vision. We developed a deep learning approach for automatically determining the estimated glomerular filtration rate (eGFR) and CKD status. We exploited the transfer learning technique, integrating the powerful ResNet model pretrained on an ImageNet dataset in our neural network architecture, to predict kidney function based on 4,505 kidney ultrasound images labeled using eGFRs derived from serum creatinine concentrations. To further extract the information from ultrasound images, we leveraged kidney length annotations to remove the peripheral region of the kidneys and applied various data augmentation schemes to produce additional data with variations. Bootstrap aggregation was also applied to avoid overfitting and improve the model’s generalization. Moreover, the kidney function features obtained by our deep neural network were used to identify the CKD status defined by an eGFR of <60 ml/min/1.73 m2. A Pearson correlation coefficient of 0.741 indicated the strong relationship between artificial intelligence (AI)- and creatinine-based GFR estimations. Overall CKD status classification accuracy of our model was 85.6% —higher than that of experienced nephrologists (60.3%–80.1%). Our model is the first fundamental step toward realizing the potential of transforming kidney ultrasound imaging into an effective, real-time, distant screening tool. AI-GFR estimation offers the possibility of noninvasive assessment of kidney function, a key goal of AI-powered functional automation in clinical practice.

Off‐Axis Holography with Uniform Illumination via 3D Printed Diffractive Optical Elements

AbstractDiffractive optical elements (DOEs) provide a compact and energy‐efficient solution to project arbitrary grayscale images onto a distant screen. Unfortunately, they invariably suffer from the zero order spot, which is caused mainly by undiffracted light that travels along the optical axis of an illuminating laser beam. To produce projected images without the bright spot, one can either shift the intended projection off‐axis or block the zero order. However, images projected by these methods are occluded by the dark fringes of the diffraction pattern (“shadowing” effect) or increase the complexity of the optical setup. Here, a new type of DOE is introduced with blazed facets to shift the laser power into the off‐axis direction. By adding blazed facets onto each phase element of a computer‐generated hologram, far‐field projections that are free of both the zero order spot and shadowing effects are produced while maintaining a diffraction efficiency as high as 86%. The blazed facets are fabricated by 3D direct laser writing, which enables continuous phase modulation within a single pixel. This concept of sub‐pixel level modification of diffractive optical elements can be extended to other applications requiring precise wavefront shaping or detection, such as 3D displays, mixed‐reality technology, and optical analog computing.