The cyclical shape of the headless molecule means that it has different chemical properties than the linear headless lipid believed to be generated by the protein, Cordes explained. "We didn't find what we thought we were going to find," Cordes added. Binford, an arachnologist who has traveled the world in search of the eight-legged creatures, collected the spiders, isolated their DNA and milked their venom, which was then frozen and shipped to the UA labs for analysis. who, completed her doctorate and a postdoc at the UA.Ĭordes, Bandarian and Daniel Lajoie, a PhD candidate in Cordes's lab, tested venom from three species of brown recluse spiders from North and South America. The research team includes Cordes Vahe Bandarian, an associate professor also in the UA's department of chemistry and biochemistry and Greta Binford, an associate professor of biology at Lewis and Clark College in Portland, Ore. So initially scientists believed that this was all that was happening, then that became established in the literature." "Part of the outcome of the reaction, the release of the head group, is the same. The lipid knocks off its own head by making a ring within itself, prompted by the protein from the spider venom, Cordes explained. "The very first step of this whole process that leads to skin and tissue damage or systemic effects is not what we all thought it was," Cordes said. The research team has discovered that in the test tube, the venom protein causes lipids to bend into a ring structure upon the loss of the head portion, generating a cyclical chemical product that is very different than the linear molecule it was assumed to produce. The protein acts to cleave off the head portion of the lipids, leaving behind, scientists long have assumed, a simple, linear, headless lipid molecule. The protein, once injected into a bite wound, attacks phospholipid molecules that are the major component of cell membranes. "This is not a protein that is usually found in the venom of poisonous animals," said Matthew Cordes, an associate professor in the UA's department of chemistry and biochemistry and member of the UA BIO5 Institute who led the study, published today in the journal PLOS ONE. One of few common spiders whose bites can have a seriously harmful effect on humans, the brown recluse has venom that contains a rare protein that can cause a blackened lesion at the site of a bite, or a much less common, but more dangerous, systemic reaction in humans. The finding has implications for understanding how these spider bites affect humans and for the development of possible treatments for the bites. University of Arizona researchers led a team that has discovered that venom of spiders in the genus Loxosceles, which contains about 100 spider species including the brown recluse, produces a different chemical product in the human body than scientists believed.
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Digital pianos typically use analog sensors for their keyboard action, as opposed to digital sensors of a regular electronic keyboard and synthesizer. Some digital pianos incorporate actual hammers to better simulate a grand piano's touch. Instruments that less accurately simulate the feel of an acoustic piano may be described as semi-weighted, while those that are more accurate may be said to possess hammer action. Instruments with fewer keys, and those with keys that are unweighted (similar to electric organs and synthesizers) or not velocity-sensitive tend to be called electronic or digital keyboards rather than digital pianos. The keys are weighted to simulate the action of an acoustic piano and are velocity-sensitive so that the volume and timbre of a played note depends on how hard the key is pressed. Similar to a traditional acoustic piano, the defining feature of a digital piano is a musical keyboard with 88 keys. Digital pianos are often used in music schools and music studios as a replacement for traditional instruments. Some digital pianos can emulate other sounds besides the piano, the most common ones being pipe organ, electric piano, Hammond organ, and harpsichord. Like other electronic musical instruments, they can be connected to an amplifier or a PA system to produce a sound loud enough for a large venue or, at the other extreme, may be heard through headphones only. In addition, they do not need to be tuned, and their tuning can be modified to match the tuning of another instrument (e.g. While digital pianos may sometimes fall short of acoustic ones in feel and sound, their advantages include being smaller, weighing much less, and costing less than an acoustic piano. Others may be very simple, without a stand. Some digital pianos are designed to also look like an upright or grand piano. They also incorporate weighted keys, which recreate the feel of an acoustic piano. Digital pianos use either synthesized emulation or recorded samples of an acoustic piano, which are played through one of more internal loudspeakers. A digital piano in an upright piano form factorĪ digital piano is a type of electronic keyboard instrument designed to serve primarily as an alternative to the traditional acoustic piano, both in how it feels to play and in the sound it produces. Set the multimeter to Rx1 and touch the probes to the contacts. These wires need to be disconnected before removing the fuse. To test it, access the control panel and find the two wires that connect the fuse to the control panel. If the fuse is broken, the dishwasher may not turn on. If not, the motor start delay should be replaced.Ī dishwasher’s thermal fuse protects the machine from overheating. This should also produce a reading of zero or near zero. Once that happens, touch the probes to the relay terminals. The next step is to turn the start relay upside down so the plunger drops. It should display a reading of zero or near zero. Refer to the wiring diagram in the owner’s manual, set the multimeter to Rx1, and test the coil. Usually located next to the pump in the lower access panel, the motor start relay needs to be removed to be tested. If the results are different from the manual’s, the timer should be replaced.Ī motor start relay supplies power to the motor and signals it to start. The owner’s manual will contain information regarding the expected reading, but many models will be within the range of 2,000 to 3,500 ohms of resistance. With the multimeter set at Rx1000, touch the probes to the contacts. It’s important to refer to the wiring diagram in the owner’s manual to find which contacts to test. The timer is typically located in the control panel, but sometimes it’s found in the lower kickplate. The dishwasher timer sets the start and end times for the wash cycles. Be sure to disconnect the machine from its power source before attempting these steps. If the door-latch assembly and the selector switch are working properly, there are a few additional parts to test to see if they’re the cause of the problem. Photo: You can check the timer, electronic control, motor start relay, and thermal fuse. If the reading displays another result, the door latch assembly will need to be replaced. If it’s at zero or near zero, the switches are fine. Touch the meter’s probes to the switch terminals and check the reading. Remove the switches and check them with a multimeter on Rx1.Double-check to see if the latch activates the switches when it’s inserted.Remove the door panel to find the latch and switches located at the top of the door.Disconnect the machine from its power source.To test the dishwasher latch and switches: Inspecting the latch for visible signs of damage or checking the switches with a multimeter can pinpoint a problem. If the door cannot close properly to activate the switches, the dishwasher won’t be able to start. The door-latch assembly not only keeps the door tightly closed to prevent leaks, but it signals the control panel that it’s time to begin a wash cycle. If the door isn’t closing properly, the door latch or switches may be to blame. If the dishwasher will not turn on, check the door latch. Check the door latch to make sure it’s working properly. You will want to check the owner’s manual for the manufacturer’s instructions regarding a reset for a dishwasher that has power but won’t turn on. Some machines may have a reset button or require a specific procedure to reset. If you notice that the buttons are illuminated or flashing, unplugging the machine for a minute or two and then plugging it back in can help reset the dishwasher. To remedy this, allow the drain cycle to run, let it sit for 60 to 90 seconds, then press the start button once. If the start button has been pushed more than once, the dishwasher may revert to a drain cycle. If the dishwasher won’t start but has power, it could be stuck between cycles. It’s recommended to refer to the owner’s manual for instructions on correctly disabling the child lock or delayed-start features. Or, if a delayed-start feature has been accidentally selected, it can prevent the dishwasher from turning on when the start button is pushed. Some dishwashers have a child-lock feature that prevents an accidental start or changes to the wash cycle. |