RADIOLOGICAL EVALUATION OF LEAD APRON INTEGRITY IN FIVE SELECTED HOSPITALS IN ABUJA, NIGERIA

2021 ◽  
Vol 35 (1) ◽  
Author(s):  
Ibrahim Ilupeju
Keyword(s):  
Diagnostic Value ◽  
Ionising Radiation ◽  
Transmission Factor ◽  
Transmission Measurement ◽  
Radiological Evaluation ◽  
Large Area ◽  
Effective Protection ◽  
Lead Apron ◽  
Transmittance Factor ◽  
Over Time

Background: The general consensus is that any exposure to ionising radiation carries a risk. Diagnostic radiology is the largest (87%) contributor to man-made ionising radiation, therefore any economical and socially acceptable means of reducing dose without compromising the diagnostic value of the procedure must be worth implementing. Aim: This study is aimed at evaluating lead apron integrity in five selected Hospitals in Abuja, Nigeria. Methodology: The methodology approach includes the application of a large area beam for transmission measurement with the placement of OSLD before and behind the ten (10) lead aprons to determine the entrance and exit dose as well as the transmission factor. In this study, a lead apron consisting of 0.25mm and 0.35mm thickness were examined. Results: The result shows that the transmittance factor of the entrance and exit dose through the lead equivalent aprons is directly proportional to the age of the apron with NHA1 having the highest transmission factor (0.83) and oldest age (16 years). WGH2 has the lowest transfer factor (0.12) and the least age (1 year). Conclusion: Lead aprons loses their attenuation capability over time and should be replaced after 15 years at most for effective protection against ionizing radiation.

scholarly journals Influence of premature loss of the first permanent molar on the dental arches morphology – radiological evaluation

2017 ◽  
Vol 63 (4) ◽  
pp. 180-183
Author(s):  
Andreea Pop ◽  
◽  
Radu Septimiu Câmpian ◽  
Mariana Păcurar ◽  
Ecaterina Ionescu ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Vertical Plane ◽  
Radiological Evaluation ◽  
Panoramic Radiographs ◽  
Permanent Molar ◽  
Permanent Molars ◽  
First Permanent Molars ◽  
Over Time

Objectives. The purpose of this research was to radiological identify the morphological changes of the dental arcades resulting from the premature loss of the permanent first molars. Material and method. The study was conducted between 2014-2016 on a group of 50 patients aged 12-15 years who presented themselves with the imminence of premature loss of the first permanent molars. 1: 1 panoramic radiographs were performed before the extractions and at 6 and 12 months after the extractions respectively. Results and discussions. The changes in position of the antagonist teeth and those of the second permanent molars, in the two dental arches, both in the sagittal and in the vertical plane were revealed. Conclusions. The premature loss of the first permanent molars, especially after the eruption of the second permanent molars, causes unwanted dental movements and severe dental-maxillary abnormalities over time.

Dynamic change, recruitment and resilience in reef-forming glass sponges

2015 ◽  
Vol 96 (2) ◽  
pp. 429-436 ◽  
Author(s):  
Amanda S. Kahn ◽  
Laura J. Vehring ◽  
Rachel R. Brown ◽  
Sally P. Leys
Keyword(s):  
Dynamic Change ◽  
Small Scale ◽  
Western Canada ◽  
Large Area ◽  
Remotely Operated Vehicle ◽  
Strait Of Georgia ◽  
The Face ◽  
Glass Sponges ◽  
Over Time ◽  
Sponge Reefs

Glass sponge reefs on the continental shelf of western Canada and south-east Alaska are considered stable deep-sea habitats that do not change significantly over time. Research cruises using a remotely operated vehicle equipped with accurate GPS positioning have allowed us to observe the same sponges at two reefs in the Strait of Georgia, British Columbia to document recruitment, growth and response to damage over time. Spermatocysts and putative embryos found in winter suggest annual, asynchronous reproduction. Juvenile sponges (2–10 cm in osculum diameter) in densities up to 1 m−2 were more concentrated near live sponges and sponge skeletons than away (Spearman rank correlations, P < 0.0001 for live cover and for skeletons), suggesting that recruitment occurs in particular regions using sponge skeletons as substrate. Most sponges showed no change in shape or size over 2–3 years, but some had died while others showed growth of 1–9 cm year−1. Deposition rates of reef-cementing sediments were 97 mm year−1 at Galiano Reef and 137 mm year−1 at Fraser Reef, but sediments eroded so that there was no net gain or loss over time. Sponges recovered within 1 year from small-scale damage that mimicked bites by fish or nudibranchs; however sponges did not recover from crushing of a large area (1.5 × 2 m2) even 3 years later. These observations and experiments show that while recruitment and growth of sponge reefs is more dynamic than previously thought, the reefs are not resilient in the face of larger-scale disturbances such as might be inflicted by trawling.

scholarly journals Simulating Ionising Radiation in Gazebo for Robotic Nuclear Inspection Challenges

Robotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 86
Author(s):  
Thomas Wright ◽  
Andrew West ◽  
Mauro Licata ◽  
Nick Hawes ◽  
Barry Lennox
Keyword(s):  
Operating System ◽  
Radiation Transport ◽  
Ionising Radiation ◽  
Robotic Systems ◽  
Radioactive Materials ◽  
Robot Operating System ◽  
Transport Code ◽  
Radiation Sources ◽  
Reduce Risk ◽  
Over Time

The utilisation of robots in hazardous nuclear environments has potential to reduce risk to humans. However, historical use has been largely limited to specific missions rather than broader industry-wide adoption. Testing and verification of robotics in realistic scenarios is key to gaining stakeholder confidence but hindered by limited access to facilities that contain radioactive materials. Simulations offer an alternative to testing with actual radioactive sources, provided they can readily describe the behaviour of robotic systems and ionising radiation within the same environment. This work presents a quick and easy way to generate simulated but realistic deployment scenarios and environments which include ionising radiation, developed to work within the popular robot operating system compatible Gazebo physics simulator. Generated environments can be evolved over time, randomly or user-defined, to simulate the effects of degradation, corrosion or to alter features of certain objects. Interaction of gamma radiation sources within the environment, as well as the response of simulated detectors attached to mobile robots, is verified against the MCNP6 Monte Carlo radiation transport code. The benefits these tools provide are highlighted by inclusion of three real-world nuclear sector environments, providing the robotics community with opportunities to assess the capabilities of robotic systems and autonomous functionalities.

scholarly journals Comparative Analysis Based on the Spike Glycoproteins of SARS-CoV2 Isolated from COVID 19 Patients of Different Countries

2020 ◽  
Author(s):  
Preeti Mangar ◽  
Smriti Pradhan ◽  
Subecha Rai ◽  
Khusboo Lepcha ◽  
Vivek Kumar Ranjan ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Point Mutations ◽  
World Health Organisation ◽  
World Health ◽  
Structural Proteins ◽  
Spike Glycoprotein ◽  
The World ◽  
Transmittance Factor ◽  
Over Time

SARS-CoV2 popularly known as (COVID-19) has presently received worldwide attention. It has been considered a pandemic by the World Health Organisation. Owing to its high transmittance factor the virus has brought about many deaths and spread to all the major countries of the world. Scientists and Researchers worldwide are giving their full efforts to develop a vaccine. In our present study, we have included the comparative analysis of the different spike glycoprotein sequences of the patients suffering from COVID-19 from different countries where this pandemic has occurred. Spike glycoproteins are the structural proteins that bring about the binding of the SARS-CoV-2 viral molecule to the ACE2 receptor of the host following which infection occurs. Through this data, we have shown the different point mutations in the spike glycoproteins that occurred over time in different countries as the disease progressed.

scholarly journals A cost-efficient face learning mechanism: The impact of stability in appearance on the resolution of facial representations

2021 ◽  
Author(s):  
Christel Devue ◽  
Sofie de Sena ◽  
Jade Wright
Keyword(s):  
Large Scale ◽  
Diagnostic Value ◽  
Learning Mechanism ◽  
Coarse Information ◽  
Reliable Representation ◽  
Cost Efficient ◽  
Recognition Errors ◽  
The Cost ◽  
The Impact ◽  
Over Time

The way faces become familiar and what information is represented as familiarity develops has puzzled researchers in the field of human face recognition for decades. In this paper, we propose a cost-efficient mechanism of face learning to describe how facial representations form over time and that explains why recognition errors occur. Encoding of diagnostic facial information would follow a coarse-to-fine trajectory, modulated by the intrinsic stability in individual faces’ appearance. In four experiments, we draw on a robust and ecological method using a proxy of exposure to famous faces in the real world to test hypotheses generated by the model and we manipulate test images to probe the nature of facial representations. We consistently show that stable facial appearances help create more reliable representation in early stages of familiarisation but that their resolution remains relatively low and therefore less discriminative over time. In contrast, variations in appearance hinder recognition at first but encourage refinement of representations with further exposure. Consistent with the cost-efficient face learning mechanism we propose, facial representations built on a foundation of large-scale coarse information. When coarse information loses its diagnostic value through the experience of variations across encounters, facial details and their spatial relationships receive additional representational weights.

scholarly journals A Study on the Use of Radiation-Protective Apron among Interventionists in Radiology

2018 ◽  
Vol 8 ◽  
pp. 34 ◽  
Author(s):  
Roshan Samuel Livingstone ◽  
Anna Varghese ◽  
Shyamkumar N. Keshava
Keyword(s):  
Back Pain ◽  
Ionizing Radiation ◽  
Shoulder Pain ◽  
Large Fraction ◽  
Light Weight ◽  
Physical Strain ◽  
Effective Protection ◽  
Lead Apron ◽  
Knowledge And Practice ◽  
Harmful Effects

Objective: Radiation-protective aprons are commonly used by interventionists to protect against the harmful effects of ionizing radiation. Choice of appropriate aprons with respect to lead equivalence and weight is necessary for effective protection and reduced physical strain. This study evaluates the knowledge and practice of using radiation-protective aprons by interventionists. Materials and Methods: Ninety-one interventional radiologists who attended an annual interventional conference were provided with a questionnaire which included age, years of experience, area of expertise, type and weight of apron used, and physical strain caused due to the use of apron. Results: About 14.3% of the interventionists practiced in an angiographic suite for less than an hour a day, 45% for 2–4 h, 21% for 4–6 h, 10% for 6–10 h, and the rest above 10 h/day. About 68% of the interventionists wore 0.5 mm lead-equivalent (Pbeq) aprons; 15.4% with 0.25 mm Pbeq; about 5.5% with 0.35 mm Pbeq aprons, and the remaining were not aware of the lead equivalence. About 47% reported that they had body aches due to wearing single-sided aprons. Interventionists working more than 10 h/day wearing single-sided lead apron predominantly complained of shoulder pain and back pain. Conclusion: A large fraction of interventionists reported that they had physical strain. It is suggestive for interventionists to wear correct fit and light-weight aprons with appropriate lead equivalence.

scholarly journals Diagnostic accuracy of glabellar tap sign for Parkinson’s disease

2021 ◽  
Author(s):  
Simo Nuuttila ◽  
Mikael Eklund ◽  
Juho Joutsa ◽  
Elina Jaakkola ◽  
Elina Mäkinen ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Diagnostic Value ◽  
Clinical Test ◽  
Diagnostic Validity ◽  
Healthy Controls ◽  
Validity And Reliability ◽  
Dopaminergic Activity ◽  
Over Time

AbstractGlabellar tap or reflex (GR) is an old bedside clinical test used in the diagnostics of Parkinson’s disease (PD), but its diagnostic value is unclear. This study examines the diagnostic validity and reliability of GR in PD in relation to brain dopaminergic activity. GR was performed on 161 patients with PD, 47 patients with essential tremor (ET) and 40 healthy controls immediately prior to dopamine transporter (DAT) [123I]FP-CIT SPECT scanning. The binding ratios were investigated with consideration of the GR result (normal/abnormal). In addition, the consistency of the GR was investigated with 89 patients after a mean follow-up of 2.2 years. PD and ET patients had higher GR scores than healthy controls (p < 0.001), but there was no difference in GR between PD and ET patients (p = 0.09). There were no differences in the ratio of abnormal to normal GRs between the PD and ET groups (73% vs. 64% abnormal, respectively, p = 0.13) or in DAT binding between PD patients with abnormal and normal GRs (p > 0.36). Over follow-up, the GR changed from abnormal to normal in 20% of PD patients despite the presence of clinically typical disease. The sensitivity and specificity of GR for differentiating PD from ET were 78.3% and 36.2%, respectively. Although GR has been used by clinicians in the diagnostics of PD, it does not separate PD from ET. It also shows considerable inconsistency over time, and abnormal GR has no relationship with dopamine loss. Its usefulness should be tested for other clinical diagnostic purposes.

scholarly journals Comparison of Transmission Measurement Methods of Elastic Waves in Phononic Band Gap Materials

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1133
Author(s):  
Maximilian Wormser ◽  
Daniel A. Kiefer ◽  
Stefan J. Rupitsch ◽  
Carolin Körner
Keyword(s):  
Wave Attenuation ◽  
Three Dimensional ◽  
Laser Doppler Vibrometer ◽  
Piezoelectric Transducers ◽  
Cellular Structures ◽  
Transmission Factor ◽  
Transmission Measurement ◽  
Quadratic Mean ◽  
Transmitted Waves ◽  
Phononic Band Gaps

Periodic cellular structures can exhibit metamaterial properties, such as phononic band gaps. In order to detect these frequency bands of strong wave attenuation experimentally, several devices for wave excitation and measurement can be applied. In this work, piezoelectric transducers are utilized to excite two additively manufactured three-dimensional cellular structures. For the measurement of the transmission factor, we compare two methods. First, the transmitted waves are measured with the same kind of piezoelectric transducer. Second, a laser Doppler vibrometer is employed to scan the mechanical vibrations of the sample on both the emitting and receiving surfaces. The additional comparison of two different methods of spatial averaging of the vibrometer data, that is, the quadratic mean and arithmetic mean, provides insight into the way the piezoelectric transducers convert the transmitted signal. Experimental results are supported by numerical simulations of the dispersion relation and a simplified transmission simulation.

Forget the Numbers: The Case of a Madagascar Famine

2000 ◽  
Vol 27 ◽  
pp. 143-157 ◽  
Author(s):  
Jeffrey C. Kaufmann
Keyword(s):  
Prickly Pear ◽  
Large Area ◽  
Predominant Species ◽  
Prickly Pear Cactus ◽  
North And South ◽  
Pear Cactus ◽  
Over Time ◽  
Provincial Center

“Famines gather history around them,” we are told, even more so, it seems, with high numbers of dead. These numbers are treated sometimes like monuments for famines, increasing over time according to utilitarian concerns. Sources for a famine on Madagascar show that though high numbers may be useful in drawing attention to a calamity, people closer to the event may not locate this history or situate their memory via numbers. Emphasizing numbers in lieu of other ways of remembering and also forgetting a calamity appear not to be very good guides to this history.The killing famine that struck southern Madagascar in 1930–31 attracted substantial written comment among the French. Everyone seemed to have an opinion about this famine, which followed the surprising and dramatic killing of the predominant species of prickly pear cactus by cochineal insects in the late 1920s. A large area, a seventh of the island (approximately a sixth of France), with a population at the time of around a half million people and perhaps two million head of cattle, was effected by the biological war on cactus. “Cactus pastoralists” were suddenly without a very resourceful plant. It had provided thick fences of protection to these herders and their cattle; its fruit and water a mainstay for people; its singed cladodes a critical source of water and sustenance for cattle.The “furnace of contamination”—the rapidly reproducing cochineal choking to death their cactus hosts—started in 1925 at the southwest provincial center of Toliara and spread to the east, north, and south at a rate of 100 kilometers per year.

scholarly journals Stability under humidity, UV-light and bending of AZO films deposited by ALD on Kapton

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. C. Marques ◽  
J. Faria ◽  
P. Perdigão ◽  
B. M. M. Faustino ◽  
Riina Ritasalo ◽  
...  
Keyword(s):  
Electrical Resistance ◽  
Uv Light ◽  
External Environment ◽  
Atomic Layer ◽  
Curvature Radius ◽  
Large Area ◽  
Layer Deposition ◽  
Resistance Stability ◽  
Over Time

AbstractAluminium doped zinc oxide (AZO) films were grown by Atomic Layer Deposition (ALD) on yellow Kapton and transparent Kapton (type CS) substrates for large area flexible transparent thermoelectric applications, which performance relies on the thermoelectric properties of the transparent AZO films. Therefore, their adhesion to Kapton, environmental and bending stability were accessed. Plasma treatment on Kapton substrates improved films adhesion, reduced cracks formation, and enhanced electrical resistance stability over time, of importance for long term thermoelectric applications in external environment. While exposure to UV light intensity caused the films electrical resistance to vary, and therefore their maximum power density outputs (0.3–0.4 mW/cm3) for a constant temperature difference (∼10 °C), humidity exposure and consecutive bending up to a curvature radius above the critical one (∼18 mm) not. Testing whether the films can benefit from encapsulation revealed that this can provide extra bending stability and prevent contacts deterioration in the long term.

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