scholarly journals Bumblebee visual allometry results in locally improved resolution and globally improved sensitivity

2018 ◽  
Author(s):  
Gavin J. Taylor ◽  
Pierre Tichit ◽  
Marie D. Schmidt ◽  
Andrew J. Bodey ◽  
Christoph Rau ◽  
...  
Keyword(s):  
Visual Information ◽  
Bombus Terrestris ◽  
3D Structure ◽  
Visual Quality ◽  
X Ray ◽  
Optical Sensitivity ◽  
Eye Size ◽  
Novel Method ◽  
Related Individuals

AbstractThe quality of visual information that is available to an animal is limited by the size of its eyes. Differences in eye size can be observed even between closely related individuals but we understand little about how this affects visual quality. Insects are good models for exploring the effects of size on visual systems because many species exhibit size polymorphism, which modifies both the size and shape of their eyes. Previous work in this area has been limited, however, due to the challenge of determining the 3D structure of eyes. To address this, we have developed a novel method based on x-ray tomography to measure the 3D structure of insect eyes and calculate their visual capabilities. We investigated visual allometry in the bumblebee Bombus terrestris and found that size affects specific aspects of visual quality including binocular overlap, optical sensitivity across the field of view, and visual resolution in the dorsofrontal visual field. This holistic study on eye allometry reveals that differential scaling between different eye areas provides substantial flexibility for larger bumblebees to have improved visual capabilities.

scholarly journals Bumblebee visual allometry results in locally improved resolution and globally improved sensitivity

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Gavin J Taylor ◽  
Pierre Tichit ◽  
Marie D Schmidt ◽  
Andrew J Bodey ◽  
Christoph Rau ◽  
...  
Keyword(s):  
Visual Information ◽  
Bombus Terrestris ◽  
3D Structure ◽  
X Ray ◽  
Optical Sensitivity ◽  
Eye Size ◽  
Visual Systems ◽  
Novel Method ◽  
Related Individuals

The quality of visual information that is available to an animal is limited by the size of its eyes. Differences in eye size can be observed even between closely related individuals, yet we understand little about how this affects vision. Insects are good models for exploring the effects of size on visual systems because many insect species exhibit size polymorphism. Previous work has been limited by difficulties in determining the 3D structure of eyes. We have developed a novel method based on x-ray microtomography to measure the 3D structure of insect eyes and to calculate predictions of their visual capabilities. We used our method to investigate visual allometry in the bumblebee Bombus terrestris and found that size affects specific aspects of vision, including binocular overlap, optical sensitivity, and dorsofrontal visual resolution. This reveals that differential scaling between eye areas provides flexibility that improves the visual capabilities of larger bumblebees.

scholarly journals A Novel Method to Improve the Visual Quality of X-ray CR Images

2011 ◽  
Vol 3 (4) ◽  
pp. 25-31 ◽  
Author(s):  
Huiqin Jiang ◽  
Zhongyong Wang ◽  
Ling Ma ◽  
Yumin Liu ◽  
Ping Li
Keyword(s):  
Visual Quality ◽  
X Ray ◽  
Novel Method

scholarly journals ART-UP: A Novel Method for Generating Scanning-Robust Aesthetic QR Codes

2021 ◽  
Vol 17 (1) ◽  
pp. 1-23
Author(s):  
Mingliang Xu ◽  
Qingfeng Li ◽  
Jianwei Niu ◽  
Hao Su ◽  
Xiting Liu ◽  
...  
Keyword(s):  
State Of The Art ◽  
Visual Quality ◽  
Qr Code ◽  
Quick Response ◽  
Estimation Model ◽  
Qr Codes ◽  
Excellent Performance ◽  
Novel Method ◽  
Coarse To Fine

Quick response (QR) codes are usually scanned in different environments, so they must be robust to variations in illumination, scale, coverage, and camera angles. Aesthetic QR codes improve the visual quality, but subtle changes in their appearance may cause scanning failure. In this article, a new method to generate scanning-robust aesthetic QR codes is proposed, which is based on a module-based scanning probability estimation model that can effectively balance the tradeoff between visual quality and scanning robustness. Our method locally adjusts the luminance of each module by estimating the probability of successful sampling. The approach adopts the hierarchical, coarse-to-fine strategy to enhance the visual quality of aesthetic QR codes, which sequentially generate the following three codes: a binary aesthetic QR code, a grayscale aesthetic QR code, and the final color aesthetic QR code. Our approach also can be used to create QR codes with different visual styles by adjusting some initialization parameters. User surveys and decoding experiments were adopted for evaluating our method compared with state-of-the-art algorithms, which indicates that the proposed approach has excellent performance in terms of both visual quality and scanning robustness.

scholarly journals Protein microcrystallography using synchrotron radiation

IUCrJ ◽  
2017 ◽  
Vol 4 (5) ◽  
pp. 529-539 ◽  
Author(s):  
Masaki Yamamoto ◽  
Kunio Hirata ◽  
Keitaro Yamashita ◽  
Kazuya Hasegawa ◽  
Go Ueno ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Data Collection ◽  
Diffraction Data ◽  
Structure Determination ◽  
Structural Features ◽  
X Ray ◽  
Data Collection Strategy ◽  
Technological Developments ◽  
Novel Method

The progress in X-ray microbeam applications using synchrotron radiation is beneficial to structure determination from macromolecular microcrystals such as smallin mesocrystals. However, the high intensity of microbeams causes severe radiation damage, which worsens both the statistical quality of diffraction data and their resolution, and in the worst cases results in the failure of structure determination. Even in the event of successful structure determination, site-specific damage can lead to the misinterpretation of structural features. In order to overcome this issue, technological developments in sample handling and delivery, data-collection strategy and data processing have been made. For a few crystals with dimensions of the order of 10 µm, an elegant two-step scanning strategy works well. For smaller samples, the development of a novel method to analyze multiple isomorphous microcrystals was motivated by the success of serial femtosecond crystallography with X-ray free-electron lasers. This method overcame the radiation-dose limit in diffraction data collection by using a sufficient number of crystals. Here, important technologies and the future prospects for microcrystallography are discussed.

ASSESSING THE QUALITY OF THE HOMOLOGY-MODELED 3D STRUCTURES FROM ELECTROSTATIC STANDPOINT: TEST ON BACTERIAL NUCLEOSIDE MONOPHOSPHATE KINASE FAMILIES

2007 ◽  
Vol 05 (03) ◽  
pp. 693-715 ◽  
Author(s):  
PETRAS KUNDROTAS ◽  
PAULINA GEORGIEVA ◽  
ALEXANDRA SHOSHEVA ◽  
PETYA CHRISTOVA ◽  
EMIL ALEXOV
Keyword(s):  
3D Structure ◽  
Three Dimensional ◽  
3D Models ◽  
Structural Defects ◽  
Large Protein ◽  
Homologous Proteins ◽  
X Ray ◽  
3D Structures ◽  
Large Sets

In this study, we address the issue of performing meaningful pKa calculations using homology modeled three-dimensional (3D) structures and analyze the possibility of using the calculated pKa values to detect structural defects in the models. For this purpose, the 3D structure of each member of five large protein families of a bacterial nucleoside monophosphate kinases (NMPK) have been modeled by means of homology-based approach. Further, we performed pKa calculations for the each model and for the template X-ray structures. Each bacterial NMPK family used in the study comprised on average 100 members providing a pool of sequences and 3D models large enough for reliable statistical analysis. It was shown that pKa values of titratable groups, which are highly conserved within a family, tend to be conserved among the models too. We demonstrated that homology modeled structures with sequence identity larger than 35% and gap percentile smaller than 10% can be used for meaningful pKa calculations. In addition, it was found that some highly conserved titratable groups either exhibit large pKa fluctuations among the models or have pKa values shifted by several pH units with respect to the pKa calculated for the X-ray structure. We demonstrated that such case usually indicates structural errors associated with the model. Thus, we argue that pKa calculations can be used for assessing the quality of the 3D models by monitoring fluctuations of the pKa values for highly conserved titratable residues within large sets of homologous proteins.

scholarly journals Measuring Visual Quality of Street Space Based on Deep Learning and Street View Picture : Pilot in The Lilong Area in Shanghai

2019 ◽  
Author(s):  
Qinglai Zhang ◽  
◽  
Jiatian Bu ◽  
Yifan Yi ◽  
◽  
...  
Keyword(s):  
Visual Information ◽  
Visual Quality ◽  
Semantic Segmentation ◽  
Visual Appearance ◽  
Average Value ◽  
Street View ◽  
Street Space ◽  
Potential Factors ◽  
Street Scene

Built environment indicates of street space quality have been carried out in a profound influence on the image of city，human behavior and public health. A street that is considered as a fundamental element in urban studies. Of the 5 elements of the image of a city, i.e. landmarks, paths, nodes, districts and edges, suggested that the paths are the most dominant elements, the research of which would provide a basis for the clustering and organization of the meanings and associations of the other four elements and the city as a whole. Additionally, taking a quantitative measurement of the visual appearance of street space has proven to be challenging because visual information is inherently ambiguous and semantically impoverished. Recent developed image semantic segmentation techniques and Street View Picture dataset make it possible to eliminate the previous restrictions, Furthermore, bringing forward a research paradigm shift. Lilong, which typically represent for historical street space in Shanghai, are selected for empirical study .This paper attempts to measure subjective qualities of the Lilong environment comprehensively and objectively. By employing Street View Picture, pictorial information is the proxy for street physical appearance, which utilizes the image semantic segmentation techniques (The model used in this study is Deep lab V3 which can achieve a 85.7% pixelwise accuracy when classifying 150 categories of objects) to parse an street scene into scene elements, such as buildings, roads, pavement, trees, cars, pedestrians, and bicycles. Then, the elements corresponding to each street point in the two directions of spatial coordinate are summarized and the average value is calculated. The potential factors were calculated based on 3-dimensional composition calculation of greenery, openness, enclosure and motorization may serve as indicators for inferring. The outcomes were used to evaluate the street types, functionality, quality, time, status, and human activities of a street. The result indicates that visual quality of Lilongs are barely satisfactory, while some regeneration projects in the historical protection block is better. A lot of Lilongs are in shortage of visual green, relative more continuous but with low vertical diversity. In the most recent 6 years, less than 2.74 million square meters Lilongs are not regenerated which are mainly slow building renovation. A series of quantitative analyses demonstrates the ability and great potential of auto-calculation method useful for auditing street environments.

scholarly journals Selection in a 3D microtomographic image the region with the highest quality

2019 ◽  
pp. 160-168 ◽  
Author(s):  
A S Kornilov ◽  
I V Safonov ◽  
A V Goncharova ◽  
I V Yakimchuk
Keyword(s):  
Flow Simulation ◽  
Visual Quality ◽  
Quality Measures ◽  
Ct Images ◽  
Ct Image ◽  
Micro Ct ◽  
X Ray ◽  
Image Slice ◽  
Selection Of

We present an algorithm for processing of X-ray microtomographic (micro-CT) images that allows automatic selection of a sub-volume having the best visual quality for further mathematical simulation, for example, flow simulation. Frequently, an investigated sample occupies only a part of a volumetric image or the sample can be into a holder; a part of the image can be cropped. For each 2D slice across the Z-axis of an image, the proposed method locates a region corresponding to the sample. We explored applications of several existing blind quality measures for an estimation of the visual quality of a micro-CT image slice. Some of these metrics can be applied to ranking the image regions according to their quality. Our method searches for a cubic area located inside regions belonging to the sample and providing the maximal sum of the quality measures of slices crossing the cube across the Z-axis. The proposed technique was tested on synthetic and real micro-CT images of rocks.

X-ray fluorescence determination of zinc sulfate in acidic zinc plating electrolyte

2020 ◽  
Vol 86 (10) ◽  
pp. 18-22
Author(s):  
K. N. Vdovin ◽  
K. G. Pivovarova ◽  
N. A. Feoktistov ◽  
T. B. Ponamareva
Keyword(s):  
Zinc Sulfate ◽  
Zinc Coating ◽  
Electrolyte Composition ◽  
Complexometric Titration ◽  
X Ray ◽  
Fluorescence Determination ◽  
Zinc Plating ◽  
Zinc Determination

Zinc sulfate is the main component in the composition of the acidic zinc plating electrolyte. Deviation in the electrolyte composition from the optimum content leads to destabilization of the electrolysis process and deteriorate the quality of the resulting zinc coating. The proper quality of a zinc coating obtained by galvanic deposition can be ensured only with timely monitoring and adjustment of the electrolyte composition. A technique of X-ray fluorescence determination of zinc (in terms of zinc sulfate) in an acidic zinc plating electrolyte is proposed. The study was carried out using an ARL Quant’X energy dispersive spectrometer (Thermo Fisher Scientific, USA) with a semiconductor silicon-lithium detector. The features of the spectrometer design are presented. The optimal parameters of excitation and detection of zinc radiation were specified when the electrolyte sample was diluted 1:1000. The ZnKα1 line was used as an analytical line. The plotted calibration graph is linear, the correlation coefficient being 0.999234. The results of zinc determination according to the developed method were compared with the data of the reference method of complexometric titration to prove the reliability of the procedure. The results are characterized by good convergence and accuracy. The proposed method of X-ray fluorescence zinc determination in a zinc plating electrolyte equals complexometric titration in the limiting capabilities and even exceeds the latter in terms of the simplicity of sample preparation and rapidity. The developed method of X-ray fluorescence determination of zinc is implemented in analysis of the electrolyte used in the continuous galvanizing unit at «METSERVIS LLC».

Counterfeit Parts Recognition and Detection for Failure Analysts

2010 ◽  
Author(s):  
Katherine V. Whittington
Keyword(s):  
Thermal Cycle ◽  
Visual Inspection ◽  
Acoustic Microscopy ◽  
Scanning Acoustic Microscopy ◽  
3D Measurement ◽  
X Ray ◽  
Wide Range ◽  
Electronic Parts ◽  
Testing Awareness

Abstract The electronics supply chain is being increasingly infiltrated by non-authentic, counterfeit electronic parts, whose use poses a great risk to the integrity and quality of critical hardware. There is a wide range of counterfeit parts such as leads and body molds. The failure analyst has many tools that can be used to investigate counterfeit parts. The key is to follow an investigative path that makes sense for each scenario. External visual inspection is called for whenever the source of supply is questionable. Other methods include use of solvents, 3D measurement, X-ray fluorescence, C-mode scanning acoustic microscopy, thermal cycle testing, burn-in technique, and electrical testing. Awareness, vigilance, and effective investigations are the best defense against the threat of counterfeit parts.

OSTEOPOROSIS AND RISK FACTORS IN THE PATIENTS ON CHRONIC HEMODIALYSIS

2015 ◽  
pp. 50-58
Author(s):  
Thi Dung Nguyen ◽  
Tam Vo
Keyword(s):  
Quality Of Life ◽  
Risk Factors ◽  
Bone Density ◽  
Region Of Interest ◽  
Cross Sectional Study ◽  
Chronic Hemodialysis ◽  
Cross Sectional ◽  
X Ray ◽  
Density Reduction

Background: The patients on hemodialysis have a significantly decreased quality of life. One of many problems which reduce the quality of life and increase the mortality in these patients is osteoporosis and osteoporosis associated fractures. Objectives: To assess the bone density of those on hemodialysis by dual energy X ray absorptiometry and to examine the risk factors of bone density reduction in these patients. Patients and Method: This is a cross-sectional study, including 93 patients on chronic hemodialysis at the department of Hemodialysis at Cho Ray Hospital. Results: Mean bone densities at the region of interest (ROI) neck, trochanter, Ward triangle, intertrochanter and total neck are 0.603 ± 0.105; 0.583 ± 0.121; 0.811 ± 0.166; 0.489 ± 0.146; 0.723 ± 0.138 g/cm2 respectively. The prevalences of osteoporosis at those ROI are 39.8%, 15.1%; 28%; 38.7%; and 26.9% respectively. The prevalences of osteopenia at those ROI are 54.8%; 46.3%; 60.2%; 45.2% and 62.7% respectively. The prevalence of osteopososis in at least one ROI is 52.7% and the prevalence of osteopenia in at least one ROI is 47.3%. There are relations between the bone density at the neck and the gender of the patient and the albuminemia. Bone density at the trochanter is influenced by gender, albuminemia, calcemia and phosphoremia. Bone density at the intertrochanter is affected by the gender. Bone density at the Ward triangle is influenced by age and albuminemia. Total neck bone density is influenced by gender, albuminemia and phosphoremia. Conclusion: Osteoporosis in patients on chronic hemodialysis is an issue that requires our attention. There are many interventionable risk factors of bone density decrease in these patients. Key words: Osteoporosis, DEXA, chronic renal failure, chronic hemodialysis

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