1. Asthma is an allergic reaction in the lungs. The muscles in the lungs 21 , blocking the airways from the trachea to the alveoli. The symptoms of asthma often include coughing, 22 in the chest, shortness of breath, and/or wheezing. Often, people who have asthma find it hard to breathe, and they frequently have problems when exercising or trying to keep fit. They may also produce a “wheezing” sound when they breathe. In extreme cases, they will have asthma attacks, also known as asthma 23 , which can be life threatening. Asthma and allergies are related because allergens can trigger asthma attacks. Patients who work in environments where allergens are common may also develop asthma. In the late 20th century, scientists found 24 proof to previous theory to the cause of asthma. They now theorize it is healthier lives and lack of exposure to pathogens. Like allergies, asthma develops 25 time, and patients are not born with the disease.

     The kidneys are located in the posterior part of the abdomen. The right kidney sits just below the liver, while the left kidney is under the diaphragm, next to the spleen. On the vertebral level, they are approximately positioned from T12 to L3. In a normal human adult, the kidneys are about 12 centimeters long and five centimeters thick, and weigh 150 grams. They filter the blood and secrete water and nitrogenous waste (urea, creatinine, and so forth) in the form of urine. The medical field that studies the functions and diseases of the kidneys is called nephrology.

    The kidneys are composed of nephrons. Each nephron consists of a glomerulus, Bowman’s capsule, and renal tubule. There are more than a million nephrons within a healthy adult kidney. The vital function of the nephron is to remove waste from blood plasma. It also helps to maintain a normal fluid balance in the body by reabsorbing water and some electrolytes back into the blood.

    Urine is formed by a process of filtration and reabsorption in the nephron. Blood enters the nephron via the arteriole. As it passes through the glomerulus, water is filtered through the glomerular membrane and collected in the Bowman’s capsule. The filtrate then passes through the proximal tubule, loop of Henle, distal tubule, and collecting tubule. Other substances, such as uric acid and hydrogen ions, are also added to the urine.

    Whether they’re swooping in to deliver packages or spotting victims in disaster zones, swarms of flying robots could have a range of important applications in the future, a new study found. The robots can switch from driving to flying without colliding with each other and could offer benefits beyond the traditional flying-car concepts of sci-fi lore, the study said.

    Robots with similar versatility could fly over impediments on the ground or drive under overhead obstacles. But currently, robots that are good at one mode of transportation are usually bad at others, study lead author Brandon Araki, a roboticist at the Massachusetts Institute of Technology’s Computer Science and Artificial Intelligence Laboratory, and his colleagues said in their new study.

    The researchers previously developed a robot named the “flying monkey” that could run and fly, as well as grasp items. However, the researchers had to program the paths the flying monkey would take; in other words, it could not find safe routes by itself.

    Now, these scientists have developed flying cars that can both fly and drive through a simulated city-like setting that has parking spots, landing pads and no-fly zones. Moreover, these drones can move autonomously without colliding with each other, the researchers said. “Our vehicles can find their own safe paths,” Araki told Live Science.

    The researchers took eight four-rotor “quadcopter” drones and put two small motors with wheels on the bottom of each drone, to make them capable of driving. In simulations, the robots could fly for about 295 feet (90 meters) or drive for 826 feet (252 meters) before their batteries ran out.

    The roboticists developed algorithms that ensured the robots did not collide with one another. In tests in a miniature town made using everyday materials such as pieces of fabric for roads and cardboard boxes for buildings, all drones successfully navigated from a starting point to an ending point on collision-free paths. Adding the driving apparatus to each drone added weight and so slightly reduced battery life, decreasing the maximum distances the drones could fly by about 14 percent, the researchers said. Still, the scientists noted that driving remained more efficient than flying, offsetting the relatively small loss in efficiency in flying due to the added weight.

    “The most important implication of our research is that vehicles that combine flying and driving have the potential to be both much more efficient and much more useful than vehicles that can only drive or only fly,” Araki said.

    The scientists cautioned that fleets of automated flying taxis are likely not coming anytime soon. “Our current system of drones certainly isn’t robust enough to actually carry people right now,” Araki said. Still, these experiments with quadcopters help explore “various ideas related to flying cars,” he said.

    The scientists detailed their findings on June 1 at the Institute of Electrical and Electronics Engineers’ International Conference on Robotics and Automation in Singapore.