Corona and radio interference on power lines

Call number: LD2668 .R4 1968 M

Effect of induced hyperthyroidism on pancreas of adult female albino rats

Introduction: A condition known as hyperthyroidism can lead to a wide range of health issues, including osteoporosis, oxidative liver damage, diabetes mellitus, as well as cardiovascular disease.Objective: To examine the detrimental effects of hyperthyroidism on the pancreatic structure of adult female albino rats.Materials and Methods: twenty-one adult virgin female albino rats were assigned to 2 groups; control and induction of hyperthyroidism. Serological analysis to assess thyroid functions, oxidative stress and lipid peroxidation analysis was carried out. Pancreatic samples were processed for light microscopic examination.Results: Hyperthyroidism caused both biochemical and histological changes on pancreas of adult female albino rats. The biochemical changes in the form of significant decreased in the thyroid stimulating hormone serum level, significant reduction in level of serum superoxide dismutase and the malondialdehyde level was significantly increased in the hyperthyroid rats. The histological changes were loss of its general architecture. The pancreatic acini appeared irregular, vacuolated and had dark nuclei. Some islets of Langerhans appeared shrunken and the acini did not have the normal smooth demarcation from the surface.Conclusion: Hyperthyroidism seriously affected the histological structure of the pancreas with subsequent disturbance in the biochemical markers

TS-LoRa: Time-slotted LoRaWAN for the Industrial Internet of Things

Automation and data capture in manufacturing, known as Industry 4.0, requires the deployment of a large number of wireless sensor devices in industrial environments. These devices have to be connected via a reliable, low-latency, low-power and low operating-cost network. Although LoRaWAN provides a low-power and reasonable-cost network technology, its current ALOHA-based MAC protocol limits its scalability and reliability. A common practise in wireless networks is to solve this issue and improve scalability through the use of time-slotted communications. However, any time-slotted approach comes with overheads to compute and disseminate the transmission schedule in addition to ensuring global time synchronisation. Affording these overheads is not straight forward with LoRaWAN restrictions on radio duty-cycle and downlink availability. Therefore, in this work, we propose TS-LoRa, an approach that tackles these overheads by allowing devices to self-organise and determine their slot positions in a frame autonomously. In addition to that, only one dedicated slot in each frame is used to ensure global synchronisation and handle acknowledgements. Our experimental results with 25 nodes show that TS-LoRa can achieve more than 99% packet delivery ratio even for the most distant nodes. Moreover, our simulations with a higher number of nodes revealed that TS-LoRa exhibits a lower energy consumption than the confirmable version of LoRaWAN while not compromising the packet delivery ratio

FREE - Fine-grained scheduling for reliable and energy-efficient data collection in LoRaWAN

LoRaWAN promises to provide wide-area network access to low-cost devices that can operate for up to ten years on a single 1000-mAh battery. This makes LoRaWAN particularly suited for the data collection applications (e.g., monitoring applications), where device lifetime is a key performance metric. However, when supporting a large number of devices, LoRaWAN suffers from a scalability issue due to the high collision probability of its Aloha-based MAC layer. The performance worsens further when using acknowledged transmissions due to the duty-cycle restriction at the gateway. For this, we propose FREE, a fine-grained scheduling scheme for reliable and energy-efficient data collection in LoRaWAN. FREE takes advantage of applications that do not have hard delay requirements on data delivery by supporting the synchronized bulk data transmission. This means data are buffered for transmission in scheduled time slots instead of transmitted straight away. FREE allocates spreading factors, transmission powers, frequency channels, time slots, and schedules slots in frames for LoRaWAN end-devices. As a result, FREE overcomes the scalability problem of LoRaWAN by eliminating collisions and grouping acknowledgments. We evaluate the performance of FREE versus different legacy LoRaWAN configurations. The numerical results show that FREE scales well and achieves almost 100% data delivery and the device lifetime is estimated over ten years independent of traffic type and network size. In comparison to poor scalability, low data delivery and device lifetime of fewer than two years for acknowledged data traffic in the standard LoRaWAN configurations

Consistency of Acetabular Height in Sequential Bilateral Total Hip Arthroplasty

Background: Achieving appropriate leg length after surgery remains a concern for surgeons performing total hip arthroplasty (THA). The focus of surgeons trying to equalize leg length has been primarily on positioning of the femoral implant. This study evaluates the impact of acetabular height on leg length and its impact on femoral component choices during THA. Methods: We reviewed standing pelvic radiographs of 100 patients who underwent staged bilateral THA by a single surgeon from 2016 to 2019. Leg length discrepancies and acetabular heights were determined from preoperative and postoperative radiographs. The difference between the first and second operative hips was compared at each stage of the procedures. Results were analyzed using paired t-tests. Results: There is a significant increase in mean leg length and acetabular height after both the first and second stages of the procedure. Although there was a small change in average acetabular height for each procedure, height increased or decreased by greater than 5 mm in 44 of 200 cases. Comparing left to right hips after the second surgery disclosed no statistically significant differences in acetabular height or leg length. Conclusion: Acetabular height and leg length changes with each stage of the procedure in sequential bilateral THA. In almost 25% of cases, the acetabular height changed by more than 5 mm. This has significant implications and needs to be considered during preoperative planning as well as operative decision-making. To account for these differences, a THA may require intraoperative acetabular assessment and changes in femoral positioning and sizing to achieve the optimal leg length