Improving Navigation Through Cooperation and Path Planning

The ability to reliably estimate own-states is very important for Unmanned Aerial Vehicles (UAVs) in executing their missions. Most current approaches for UAV state estimation rely on fusing inertial information from accelerometers and gyroscopes with absolute position information from a position sensor. Global Positioning System (GPS) is one of the most widely used position sensors. However, GPS signals are not reliable, and can be jammed by adversarial forces. Without the aid of an absolute position reference such as GPS the navigation solution of the system is going to drift with time. The problem of two autonomous vehicles traveling in a two dimensional environment from an initial location to a known goal location without any absolute position reference is considered. The effect of cooperation between the vehicles by considering the measurements such as relative range to help in improving the navigation state estimation and its effect on the observability of the system is discussed. The reduction in the navigation solution drift of the system, with cooperation between the agents, using measured relative information and its effect on the observability of the system while taking different paths is discussed. Simulations and theoretical results show that relative motion between the agents helps reduce the navigation drift of the agents when there is no absolute position reference.Mechanical & Aerospace Engineerin

Differential expression and role of p21cip/waf1 and p27kip1 in TNF-α-induced inhibition of proliferation in human glioma cells

<p>Abstract</p> <p>Background</p> <p>The role of TNF-α in affecting the fate of tumors is controversial, while some studies have reported apoptotic or necrotic effects of TNF-α, others provide evidence that endogenous TNF-α promotes growth and development of tumors. Understanding the mechanism(s) of TNF-α mediated growth arrest will be important in unraveling the contribution of tissue associated macrophages in tumor resistance. The aim of this study was to investigate the role of Cyclin Dependent Kinase Inhibitors (CDKI) – p21^cip/waf1and p27^kip1in TNF-α mediated responses in context with p53 and activation of NF-κB and Akt pathways. The study was done with human glioma cell lines -LN-18 and LN-229 cells, using monolayer cultures and Multicellular Spheroids (MCS) as <it>in vitro </it>models.</p> <p>Results</p> <p>TNF-α induced inhibition of proliferation and enhanced the expression of p21^cip/waf1and p27^kip1in LN-18 cells. p21 was induced on exposure to TNF-α, localized exclusively in the nucleus and functioned as an inhibitor of cell cycle but not as an antiapoptotic protein. In contrast, p27 was constitutively expressed, localized predominantly in the cytoplasm and was not involved in arrest of proliferation. Our data using IκBα mutant LN-18 cells and PI3K/Akt inhibitor-LY294002 revealed that the expression of p21 is regulated by NF-κB. Loss of IκBα function in LN-229 cells (p53 positive) did not influence TNF-α induced accumulation of pp53 (Ser-20 p53) suggesting that p53 was not down stream of NF-κB. Spheroidogenesis enhanced p27 expression and p21 induced by TNF-α was significantly increased in the MCS compared to monolayers.</p> <p>Conclusion</p> <p>This study demarcates the functional roles for CDKIs-p21^cip/waf1and p27^kip1during TNF-α stimulated responses in LN-18 glioma cells. Our findings provide evidence that TNF-α-induced p21 might be regulated by NF-κB or p53 independently. p21 functions as an inhibitor of cell proliferation and does not have a direct role in rendering the cells resistant to TNF-α mediated cytotoxicity.</p

Wells Go Deeper

We believe that everyone deserves access to clean water resources. Unfortunately, worldwide nearly 1.1 billion people do not have access to it. UN SDG 6 is focused on clear water and sanitation, so our group has decided to focus on this for our service. More specifically, farmers across the world have limited access to water sources and therefore cannot consistently provide adequate crop yield. Our solution to this problem is to have a well-digging service to be hired by anyone, but marketed mainly towards farmers. This way, we will be able to give more access to clean water to anyone who may need it. We will also charge to make enough of a profit to fund other sanitation efforts in countries where these services may not be well affordable. Our company will be called Wells Go Deeper, a play on words implying that wells go deeper than the surface, both because they are holes in the ground and because our company is focused on providing access to clean water around the world

Tubercular Osteomyelitis of Femur: Imaging Findings

A 28-year-old male patient presented with chief complaints of pain in his left knee for one month, difficulty walking for three weeks, and on-and-off fever for the past month. He denied any history of weight loss or loss of appetite. There was no significant past medical history. Local examination of the left knee revealed swelling and tenderness over the lateral femoral condyle with restricted range of motion. Blood investigations were normal except for an elevated erythrocyte sedimentation ratio of 36 mm/hr. Initially, an X-ray was performed, showing multiple small lytic areas within the epimetadiaphyseal region of the lateral condyle of the lower end of the femur [Table/Fig-1]. Subsequent Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scans were conducted, revealing a large lytic lesion with irregular margins in the posterolateral cortex of the lower end of the femur [Table/Fig-2], which appeared hyperintense on Proton Density Fat Saturated (PDFS) MRI images and hypointense on T1-weighted images [Table/Fig-3]. Severe surrounding marrow oedema was noted, along with mild reactive joint effusion. The tibia and fibula appeared normal, without synovial thickening or joint involvement. The knee joint ligaments were also normal. Based on the imaging findings, acute osteomyelitis was considered, with a primary bone tumour as a differential diagnosis. The patient underwent excision biopsy and curettage under spinal anaesthesia, revealing a granulomatous infection with positive staining for acid-fast bacilli. The patient was prescribed antitubercular drugs and advised to undergo physiotherapy, knee bending, and static quadriceps exercises. The patient’s condition improved, and he was subsequently discharged

Ultra-Performance Liquid Chromatography–Tandem Mass Spectrometric Method for the Determination of Artemisinin in Rat Serum and its Application in Pharmacokinetics

A rapid and sensitive ultra-performance liquid chromatography–tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to quantify artemisinin in rat serum. The lower limit of quantification (LLOQ) was 4 ng/mL. The calibration curve was linear from 4 ng/mL to 10,000 ng/mL (R = 0.998). The assay was based on the selected reaction monitoring (SRM) transitions at m/z 305.4–151.10 for artemisinin and m/z 335.2–163.10 for arteether (internal standard). The artemisinin and internal standard can be separated from endogenous interferences in rat serum. Inter- and intra-day assay variation was less than 15%. The extraction recoveries ranged from 80.0 to 107.3% at the three concentrations (5000, 2000, and 200 ng/mL). This method was successfully applied to pharmacokinetic studies of artemisinin after intravenous and oral administration to rats

Generation of control signals using second-Nyquist zone technique for superconducting qubit devices

There is growing interest in developing integrated room temperature control electronics for the control and measurement of superconducting devices for quantum computing applications. With the availability of faster DACs, it has become possible to generate microwave signals with amplitude and phase controls directly without requiring any analog mixer. In this report, we use the evaluation kit ZCU111 to generate vector microwave pulses using the second-Nyquist zone technique. We characterize the performance of the signal generation and measure amplitude variation across second Nyquist zone, single-sideband phase noise, and spurious-free dynamic range. We further perform various time-domain measurements to characterize a superconducting transmon qubit and benchmark our results against traditionally used analog mixer setups.Comment: 18 pages, 5 figure