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Digital Photographs (digital + photograph)
Selected AbstractsChange in supporting tissue following loss of a permanent maxillary incisor in childrenDENTAL TRAUMATOLOGY, Issue 6 2007Helen D. Rodd Abstract,,, Alveolar bone resorption is an inevitable consequence of tooth loss and may be detrimental to long-term dental aesthetics and function. The aim of the present study was to quantify the degree of tissue resorption following the loss of a permanent incisor in a young population. The study group comprised 11 boys and five girls who all required the extraction of a permanent maxillary central incisor due to trauma-related sequelae. Mean age at tooth loss was 10.8 years. Upper alginate impressions were taken at regular intervals following tooth loss and were cast in yellow dental stone. Study models were sectioned longitudinally through the mid-point of both the maxillary incisor socket and the contra-lateral incisor to provide a thin plaster section. Digital photographs were acquired of the edentulous (A1) and dentate (A2) surfaces of this section and image analysis software was employed to quantify the surface area of both A1 and A2. At 3 months postextraction, mean A1 was 15.7% less than mean A2. By 6 months mean A1 had further reduced and was 25.3% less than that of the corresponding dentate alveolus. However, at subsequent time intervals following tooth extraction (>6 months), tissue loss appeared to stabilise with an overall reduction in tissue area remaining at 22%. This reduction in supporting tissue area was found to be highly statistically significant (P = 0.002, anova). Furthermore, girls appeared to have an overall greater degree of tissue loss than boys (P = 0.015). Further research is indicated to explore factors influencing the degree of tissue loss following incisor extraction and the benefit of therapeutic interventions in limiting this resorption. [source] Yield prediction from digital image analysis: A technique with potential for vineyard assessments prior to harvestAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 3 2004GREGORY M. DUNN Abstract Digital photographs were taken of four 1 m × 1 m portions of canopy of Cabernet Sauvignon grapevines, as they were being progressively de-fruited close to harvest. The program EasyAccess version 6.3 was used to select ,fruit' pixels by visually setting red, green and blue threshold values and tolerances for the first image and applying these to all other images. The program was then used to automatically count ,fruit' pixels and the total number of pixels for each image. Even though two hours separated the first and last photographs, the ratio of ,fruit' pixels to total image pixels explained 85% of the variation in yield (kg per linear m of fruiting wire) for all 16 vine × de-fruiting combinations. This improved to between 94 and 99% for individual portions of canopy. Implications from our present digital image analysis for future development of both automated and spatially aware methods to predict vineyard yield are discussed. [source] A Simple Tool for Teaching Flap Design with Digital ImagesDERMATOLOGIC SURGERY, Issue 12 2001Daniel Berg MD Background. Defects created by excision or Mohs micrographic surgery must be analyzed and surgical options including flaps must be considered. Teaching flap design to dermatology trainees is often done at the bedside of the patient with the trainee describing or marking a proposed flap. Open discussion of the options in this way is sometimes unnerving for the patient. Blackboard discussions or drawings are limited in their realism. Objective. To describe a rapid, simple method using commonly available software to allow a trainee to draw and redraw a proposed flap on a digital image of the defect without the time and cost of printing. Methods. We describe a feature in the widely used presentation program Microsoft PowerPoint which can be used to draw on an imported digital image in various colors. Results. A digital photograph taken at the bedside can quickly be loaded into PowerPoint and viewed as a full-screen picture on a computer. Using an electronic pen, multiple lines can be drawn and erased on the picture, allowing surgical planning and teaching away from the bedside. Conclusion. Design and analysis of potential incision lines for a flap can be done quickly using a digital image and commonly available software, allowing a new option for teaching flap design. [source] Validity of non-mydriatic cameras for screening and follow-up in diabetic retinopathyACTA OPHTHALMOLOGICA, Issue 2007J IBANEZ Purpose: To determine the validity of a non-mydriatic camera for screening and grading diabetic retinopathy (DR). To establish the number of photographs and the field width needed for a correct DR follow-up. Methods: A cross-sectional, observational study was carried out to assess the validity of the non-mydriatic Topcon TRC-NW6S retinograph. Validity proportions were calculated. Kappa analysis was made to determine the agreement with conventional fundoscopy exploration performed by indirect ophthalmoscopy and retinal biomicroscopy. One 45º single-field non-mydriatic digital photograph was taken in 82 eyes for DR screening. For DR grading, several combinations of retinal fields were photographed in 247 eyes, first without pupillary dilatation and later with mydriasis. Results: In DR screening, 88.2% sensitivity and 96.9% specificity were obtained, where 9% of the tests were invalid. In DR grading diagnosis, the kappa analysis showed close agreement (k>0.8) based on at least two 45º photographs with mydriasis. However, when attempting to detect macular edema (ME), the maximum kappa statistic obtained did not go above 0.71, showing 67% maximum sensitivity. The sensitivity for detecting derivable DR was similar to that obtained with indirect ophthalmoscopy (94-98%). Conclusions: The non-mydriatic retinograph is a valid instrument for DR screening only when taking one 45º non-mydriatic photograph per eye. However, given that the sensitivity for proliferative DR (PDR) was worse, when grading DR, we would recommend obtaining nine retinal photographs (mosaic) with mydriasis. Used in this way, the apparatus is extremely useful for detecting derivable DR cases. [source] Measuring egg size using digital photography: testing Hoyt's method using Florida Scrub-Jay eggsJOURNAL OF FIELD ORNITHOLOGY, Issue 1 2007Eli S. Bridge ABSTRACT Egg volumes are most often estimated using a mathematical model that incorporates length and width measurements and a species-specific shape variable. Although adequate in many respects, this technique does not account for intraspecific variation in egg shape. We developed a computer-automated technique that uses calibrated digital photographs to render precise measurements of several egg-size parameters including length, width, volume, and surface area. The system extracts egg outlines from photographs, and divides each egg into latitudinal slices that are subsequently regarded as simple geometric shapes (cylinders or cone frustra) with volumes and surface areas that can be summed to generate size parameters for the entire egg. We tested this technique using 491 eggs from Florida Scrub-Jay (Aphelocoma coerulescens) nests and compared the resulting egg volumes with volumes calculated using the preeminent method of estimating volume from linear measurements. Our method was highly accurate, and differences between the volumes from our method and the alternative method were strongly associated with variation in egg shape. Advantages of our technique include decreased handling of eggs and increased accuracy. Software resources and additional information regarding the technique are available at http://www.archbold-station.org/abs/data/birddata/Bridge-JFO-eggsize.htm. SINOPSIS El volumen de los huevos comunmente es estimado utilizando un modelo matemático en donde se incorpora el ancho y el largo del huevo y la variable de la forma de este. Aunque es un método adecuado en muchos aspectos, esta técnica no toma enconsideracion las variaciones intraespecificas de la forma de los huevos. Desarrollamos una técnica automática con computadora, que usa fotografia digital calibrada para ofrecer medidas de los huevos incluyendo largo, ancho, volumen y área superficial. El sistema extrae parámetros de los huevos de fotografías y divide cada huevo en rebanadas latitudinales, que subsecuentemente son tomadas como formas geométricas (e.g., cilindros o conos) con volumenes y áreas superficiales, que a su vez pueden ser utilizadas para obtener el largo y el ancho. Pusimos a prueba esta técnica con 491 huevos del Azulejón (Aphelocoma coerulescens) y comparamos el volumen de los huevos obtenidos con el computador con volumenes calculados con el método usual de medidas lineales. Nuestro método fue preciso y las diferencias en los volumenes usando nuestro método y las del método clásico estuvieron asociadas a la variación en la forma de los huevos. Entre las ventajas de nuestra técnica encontramos una disminución en la manipulación de los huevos y un aumento en la presición de los datos tomados. Los recursos computacionales que se necesitan e información adicional sobre esta técnica se encuentra disponible en: http://www.archbold-station.org/abs/data/birddata/Bridge-JFO-eggsize.htm. [source] Source Camera Identification for Heavily JPEG Compressed Low Resolution Still Images,JOURNAL OF FORENSIC SCIENCES, Issue 3 2009Erwin J. Alles M.Sc. Abstract:, In this research, we examined whether fixed pattern noise or more specifically Photo Response Non-Uniformity (PRNU) can be used to identify the source camera of heavily JPEG compressed digital photographs of resolution 640 × 480 pixels. We extracted PRNU patterns from both reference and questioned images using a two-dimensional Gaussian filter and compared these patterns by calculating the correlation coefficient between them. Both the closed and open-set problems were addressed, leading the problems in the closed set to high accuracies for 83% for single images and 100% for around 20 simultaneously identified questioned images. The correct source camera was chosen from a set of 38 cameras of four different types. For the open-set problem, decision levels were obtained for several numbers of simultaneously identified questioned images. The corresponding false rejection rates were unsatisfactory for single images but improved for simultaneous identification of multiple images. [source] Treatment of classic Kaposi sarcoma with a nicotine dermal patch: a phase II clinical trialJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 9 2008JJ Goedert Abstract Background, Kaposi sarcoma (KS), a malignancy of dermal endothelial cells that is caused by human herpesvirus 8 (HHV8) infection, is sensitive to perturbations of immunity. Nicotine might be effective against KS because of its immunologic and vascular effects and because smoking is associated with a low risk of KS. Objective and study design, We conducted a masked, randomized phase 2 clinical trial of transdermal nicotine and placebo patches to assess the safety and efficacy of nicotine against classic KS (cKS). Subjects and methods, Three cKS lesions, predominantly nodules, in each of 24 non-smoking patients were randomly assigned to 15 weeks continuous treatment with nicotine patch (escalated to 7 mg), identical masked placebo patch or no patch. Changes in lesion area and elevation from baseline through six follow-up visits, by direct measurement and by two independent readers using digital photographs of the lesions, were compared using non-parametric and regression methods. Changes in longitudinal levels of HHV8 antibodies and DNA in blood cells were similarly assessed. Results, There were no systemic or serious adverse events, and compliance was good. One patient resumed smoking and discontinued patches, and two patients withdrew at week 12 for unrelated indications. Six (29%) of the remaining 21 suspended use of patches to relieve local skin irritation; four of these six completed the trial at reduced dose. Treatment assignment was not associated with significant or consistent changes in cKS lesion area or elevation, HHV8 viral load or antibodies. Conclusion, Transdermal nicotine and placebo patches caused no serious toxicities but had no demonstrable effect on nodular cKS lesions or HHV8 levels. [source] Selective transcutaneous delivery of energy to porcine soft tissues using intense ultrasound (IUS),,LASERS IN SURGERY AND MEDICINE, Issue 2 2008W. Matthew White MD Abstract Objective Various energy delivery systems have been utilized to treat superficial rhytids in the aging face. The Intense Ultrasound System (IUS) is a novel modality capable of transcutaneously delivering controlled thermal energy at various depths while sparing the overlying tissues. The purpose of this feasibility study was to evaluate the response of porcine tissues to various IUS energy source conditions. Further evaluation was performed of the built-in imaging capabilities of the device. Materials and Methods Simulations were performed on ex vivo porcine tissues to estimate the thermal dose distribution in tissues after IUS exposures to determine the unique source settings that would produce thermal injury zones (TIZs) at given depths. Exposures were performed at escalating power settings and different exposure times (in the range of 1,7.6 J) using three IUS handpieces with unique frequencies and focal depths. Ultrasound imaging was performed before and after IUS exposures to detect changes in tissue consistency. Porcine tissues were examined using nitro-blue tetrazolium chloride (NBTC) staining sensitive for thermal lesions, both grossly and histologically. The dimensions and depth of the TIZs were measured from digital photographs and compared. Results IUS can reliably achieve discrete, TIZ at various depths within tissue without surface disruption. Changes in the TIZ dimensions and shape were observed as source settings were varied. As the source energy was increased, the thermal lesions became larger by growing proximally towards the tissue surface. Maximum lesion depth closely approximated the pre-set focal depth of a given handpiece. Ultrasound imaging detected well-demarcated TIZ at depths within the porcine muscle tissue. Conclusion This study demonstrates the response of porcine tissue to various energy dose levels of Intense Ultrasound. Further study, especially on human facial tissue, is necessary in order to understand the utility of this modality in treating the aging face and potentially, other cosmetic applications. Lesers Surg. Med. 40:67,75, 2008. © 2008 Wiley-Liss, Inc. [source] Modelling the distribution of palsas in Finnish Lapland with logistic regression and GISPERMAFROST AND PERIGLACIAL PROCESSES, Issue 1 2002Miska Luoto Abstract The location of palsas (peat mounds with a perennially frozen core) was mapped in an area of 3370 km2 in Finnish Lapland by interpreting aerial digital photographs. Using environmental variables derived from digital land cover data and an elevation model, the distribution of palsas was modelled using geographic information system (GIS) techniques and multiple logistic regression. The relative roles of eight environmental variables potentially affecting the distribution of the palsas were studied in a spatial grid system with 3370 grid squares of 1.0 km2, of which 172 were found to contain palsas. The altitudes of the palsas varied from 180 m to 390 m. In the logistic regression model the probability of the presence of a palsa in a 1.0 km2 square increased with 1) the area of mire, 2) the proportion of flat topography, 3) water cover and 4) elevation of the lowest point in the 1.0 km2 analysis square. The palsa distribution model was validated by fitting it to an independent test area of 300 squares bordering on the main study area: the overall classification rate was 97.67%. The application of GIS data and techniques with logistic regression modelling has potential for wide use in studies on distribution patterns in periglacial processes and landforms. Copyright © 2002 John Wiley & Sons, Ltd. [source] Digit ratios (2D:4D) determined by computer-assisted analysis are more reliable than those using physical measurements, photocopies, and printed scansAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 3 2009Heather C. Allaway Prenatal androgens influence the second to fourth digit ratio (2D:4D) of hands with men having lower ratios than women. Numerous methods are used to assess 2D:4D including, physical measurements with calipers, and measurements made from photocopies, scanned images, digital photographs, radiographs, and scaled tubes. Although each method appears relatively reliable, agreement upon a gold standard is necessary to better explore the putative effects of prenatal androgens. Our objective was to assess the level of intra and interobserver reliability when evaluating 2D:4D using four techniques: (1) physical measurements, (2) photocopies, (3) printed scanned images, and (4) computer-assisted image analysis. Physical measurements, photocopies, and printed scanned images were measured with Vernier calipers. Scanned images were also measured with computer-based calipers. Measurements were made in 30 men and 30 women at two different time points, by three experienced observers. Intraclass correlation coefficients were used to assess the level of reliability. Intraobserver reliability was best for computer-assisted (0.957), followed by photocopies (0.939), physical measurements (0.925), and printed scans (0.842; P = 0.015). Interobserver reliability was also greatest for computer-assisted (0.892), followed by photocopies (0.858), physical measurements (0.795), and printed scans (0.761; P = 0.001). Mean 2D:4D from physical measurements were higher than all other techniques (P < 0.0001). Digit ratios determined from computer-assisted, physical measurements, and printed scans were more reliable in men than women (P = 0.009, P = 0.017, and P = 0.012, respectively). In summary, 2D:4D determined from computer-assisted analysis yielded the most accurate and consistent measurements among observers. Investigations of 2D:4D should use computer-assisted measurements over alternate methods whenever possible. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. [source] Enhanced mixing of Newtonian fluids in a stirred vessel using impeller speed modulationTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2009Wei M. Yek Abstract This paper reports on an experimental study of mixing intensification using speed modulation of a six-blade Rushton turbine in a stirred vessel. Mixing times were measured using a non-intrusive technique based on direct visualisation of an acid-base reaction in a Newtonian fluid. The impeller speed modulation was achieved by using two waveforms: a square wave and a sine wave. The amplitude was fixed between a maximum Reynolds number of Remax,=,60 and minimum Reynolds numbers of Remin,=,40 or 30. The wave periods were varied (10, 20, or 40,s) in order to compare the effects of unsteady stirring on mixing performance. It was observed that a square wave protocol with the shortest wave period and the larger amplitude resulted in the shortest time to destroy the observed isolated mixing regions (IMRs), which are known to exist in stirred vessels operating at low Reynolds number. However, the sine wave protocol led to a slow diffusive mechanism in which IMR structures reached an asymptotic volume and remained visible even after several hours. The results are presented and discussed using digital photographs taken at different time intervals during experimentation. Ce papier présente une étude experimentale concernant l'intensification du mélange en modulant la vitesse d'une turbine de type Rushton a six palettes dans une cuve agitée. Les temps de mélanges sont mesurés avec une technique non-intrusive basée sur la visualisation directe d'une réaction acide-base au sein d'un fluide Newtonien. La modulation de la vitesse de la turbine a été realisée en utilisant deux formes d'ondes: une onde carrée et une onde sinusoidale. L'amplitude de chaque onde a été fixée entre un nombre de Reynolds maximal de Remax,=,60 et un nombre de Reynolds minimal de Remin,=,40 ou 30. Les périodes des ondes étaient variées (10, 20 ou 40,s) dans le but de comparer les effets du mélange non-stationnaire sur les performances du systeme. Il a été observé que le protocole suivant l'onde carrée avec la periode la plus courte et l'amplitude la plus large produisait le temps le plus court necessaire pour la destruction des zones de mélanges isolées (IMRs), dont l'éxistense est connue dans les cuves a mélange opérant aux nombres de Reynolds bas. Toutefois, le protocol suivant une onde sinusoidale a conduit a un mechanisme de diffusion lent dans lequel les IMRs atteignies un volume symptotique et sont restées visibles après plusieurs heures. Les résultats sont présentés and discutés en utilisant des photographes digitales prises à des intervales de temps differents durant les éxperiences. [source] Retinal fractals and acute lacunar strokeANNALS OF NEUROLOGY, Issue 1 2010Ning Cheung MBBS This study aimed to determine whether retinal fractal dimension, a quantitative measure of microvascular branching complexity and density, is associated with lacunar stroke. A total of 392 patients presenting with acute ischemic stroke had retinal fractal dimension measured from digital photographs, and lacunar infarct ascertained from brain imaging. After adjusting for age, gender, and vascular risk factors, higher retinal fractal dimension (highest vs lowest quartile and per standard deviation increase) was independently and positively associated with lacunar stroke (odds ratio [OR], 4.27; 95% confidence interval [CI], 1.49,12.17 and OR, 1.85; 95% CI, 1.20,2.84, respectively). Increased retinal microvascular complexity and density is associated with lacunar stroke. ANN NEUROL 2010;68:107,111 [source] 10 A Rapid, Simple and Inexpensive Method for Construction of Peripheral Vascular Ultrasound PhantomsACADEMIC EMERGENCY MEDICINE, Issue 2008Hal Minnigan Background and Introduction:, Emergency department bedside ultrasound has grown to include ultrasound guidance of vascular access, most recently, peripheral IV access has been described with ultrasound guidance. Simulation of procedures that are crucial to clinical practice is an efficient and reliable way to train and assess competency prior to performance on an actual patient. Ultrasound phantoms that simulate patient anatomy allow the development of hand-eye coordination, orientation and manipulation of the instruments in a controlled setting. In an effort to obviate the cost of commercial products I have developed a very simple and rapid method for building vascular ultrasound phantoms for teaching ultrasound guided peripheral IV placement. Materials and Methods:, Using easily obtainable and inexpensive materials, a simple method is described which allows construction of the phantom in less than 1 hour. This method requires no special tools or construction skills. The total cost for 1 phantom is about $30.00. Most of the components can be reused when the phantom needs to be repoured , the cost to repour a phantom is less than 2. Results:, These phantoms are realistic in terms of visualization of deep upper extremity veins, and include fluid filled vessels which are gravity fed by colored saline. The system is versatile and can be customized to fit the needs of the individual user. Attendees will be provided with a CD comprising a complete materials list with sources of supply, a PowerPoint presentation to guide construction with each step detailed using digital photographs, and videos of use of the phantom. [source] Nucleolar size in choroidal and ciliary body melanomas and corresponding hepatic metastasesACTA OPHTHALMOLOGICA, Issue 4 2010Rana'a T. Al-Jamal Abstract. Purpose:, This study aimed to investigate the relationship between hepatic metastasis and the mean diameter of the 10 largest nucleoli (MLN) in uveal melanoma. Methods:, A cross-sectional histopathological analysis of 37 metastases (13 surgical or needle biopsies, 24 autopsies) and corresponding primary choroidal and ciliary body melanomas was conducted, using statistical tests appropriate for paired data. The largest nucleoli were measured from digital photographs of silver-stained sections along a 5-mm-wide linear field. Confounders considered were presence of epithelioid cells and microvascular density (MVD), counted as the number of discrete elements labelled by monoclonal antibody QBEND/10 to the CD34 epitope. Results:, Hepatic metastases had more frequent epithelioid cells (p = 0.0047) and a higher MVD (median difference, 7.5 counts/0.313 mm2 more; p = 0.044) than their corresponding primary tumours. Hepatic metastases, especially in autopsy specimens rather than surgical biopsies, tended to have a smaller MLN (median 3.6 ,m) than the corresponding primary tumour (median difference, 0.55 ,m; p = 0.066). The MLN in hepatic metastases was not associated with presence of epithelioid cells and MVD. Overall survival after diagnosis of metastasis was comparable whether hepatic metastases had a large or small MLN (p = 0.95), whereas a high MVD tended to be associated with shorter survival (p = 0.096) among the 13 patients with known survival. Conclusions:, The results suggest that MLN is not a useful marker for assessing prognosis after diagnosis of hepatic metastasis from uveal melanoma. [source] What do patients with glaucoma do when they search and look at everyday scenes?ACTA OPHTHALMOLOGICA, Issue 2009ND SMITH Purpose To test the hypothesis that patients with bilateral glaucoma exhibit different eye movements compared to normally-sighted subjects when viewing computer displayed photographs, or searching for features or items within them. Methods Thirteen glaucoma patients and 17 age-matched subjects with normal vision viewed 28 randomised digital photographs of various everyday scenes displayed on a computer screen for 3 seconds each. Subjects were instructed to view the images as they would when looking at a slideshow. The subjects then viewed another set of images, but were timed to find a feature or item in the scene. Eye movements were simultaneously recorded using an Eyetracking system. Results In the passive viewing experiment, there was a significant reduction in the average number of saccades for glaucoma patients compared to controls (p<0.0001). In addition, average fixation duration was longer and the average area scanned was more restricted in patients compared to controls. In the search task glaucoma patients took, on average, longer to find the objects (p<0.0001) compared to controls. For this task, saccades were still reduced in number. In some cases, individual scanning patterns appeared related to the type and nature of the binocular visual field defect. Conclusion Eye movement behaviour in patients with glaucomatous defects in both eyes differ from normal-sighted subjects when viewing images and photographs. These patients with glaucoma find it more difficult to locate items within scenes compared to normally sighted subjects. Acknowledgements: This work is generously supported by an unrestricted grant from the Special Trustees of Moorfields Eye Hospital. [source] The prevalence of age-related maculopathy (ARM) in an urban Norwegian population: the Oslo Macular StudyACTA OPHTHALMOLOGICA, Issue 5 2006Ólafur M. Björnsson Abstract. Purpose:, To examine the prevalence of early and late age-related maculopathy (ARM) in citizens aged 51 years and older in the city of Oslo and its surroundings. Methods: , We selected a random sample of 800 subjects, using a cross-sectional study design. A total of 459 of the 770 eligible subjects agreed to participate, giving an attendance rate of 59.6%. Stereoscopic colour digital photographs were obtained and graded at a certified reading centre using the International Classification Grading System for ARM. Results:, Early ARM in either eye was found in 43.1% (95% CI 38.5,47.7) of subjects aged 51 years and older. This was due to a much higher prevalence of pigmentary changes, predominantly hyperpigmentation in all age groups, than previously reported; 37.5% of people aged 51,60 years of age had pigmentary changes ,,63 µm, increasing to 66.0% in the oldest age group. In people aged 71 years and older, geographic atrophy (GA) was found in either eye in 3.6% (95% CI 0.4,6.8) and exudative macular degeneration (AMD) was found in either eye in 2.9% (95% CI 0.0,5.7) of subjects. Conclusion:, To our knowledge, this is the first published study to rely solely on digital photography for grading purposes in a population-based study. Early ARM was found to have a higher prevalence than previously reported in other populations. Exudative AMD and GA had similar prevalences to those described in the literature, although the prevalence of GA tended to be higher than previously reported in some surveys. [source] | ||||||||||||||||