Archive for the ‘Biology’ Category
2009
“Dr. Dean Ransom, AgriLife Research wildlife ecologist in Vernon, has conducted a study of the roadrunner’s ecology and habitat for the past four years. Using radio telemetry and studying more than 50 nests, he and his staff have researched home range, habitat use, nesting ecology and dispersal of young since 2006. The roadrunner is fairly common across the southwestern U.S., but very little is known about the bird, Ransom said. As their name suggests, roadrunners spend most of their time walking and running along the ground, but are capable of flight when pressured. ‘It’s not graceful, but it works,’ he said.
Roadrunner behavior is somewhat unique, Ransom said. They are monogamous and likely mate for life. Also, the male helps in all facets of nesting and feeding the young, including incubating the eggs at night. Nesting activity begins in early April, he said. The nest typically is located in a tree or shrub, about 3-5 feet high, and usually in dense brush not far from an edge, such as a fence line or ranch road.Such nest placement allows ease of movement to and from the nest, quick escape from predators and open areas to hunt and forage for lizards and snakes that bask in the bare dirt, Ransom said.
Most nests are well hidden and difficult to find, he said. They are generally in the crook of a large single-trunk tree, using the main branch of the trunk for stability. The nest is a flat-platformed shallow bowl with the outer rim lined with fairly large twigs and resembles a large mockingbird nest. Roadrunners lay about four eggs on average per nest, but the clutch size can range as high as 10, Ransom said. In the larger clutches, many of the young don’t survive and older nestlings have been documented eating their younger siblings…”
source: eurekalert.org
“Artificial photosynthesis has yet to be cracked, but electrical engineers in the US think that synthetic leaves could be used to generate electricity in a different way – by sweating. Natural leaves constantly lose water through evaporation in a process called transpiration, which draws water from the roots to the very top of even the tallest trees. The new synthetic leaves also lose water through evaporation to create that mechanical water pump effect, and use it to generate power…
Michel Maharbiz at the University of California, Berkeley, working with colleagues at the University of Michigan and MIT, built their leaves from glass wafers shot through with a branching network of tiny water-filled channels arranged like the veins of a leaf. The smaller channels extend to the edge of the plate and have open ends that allow water to evaporate, drawing fluid along the leaf’s central stem at a rate of 1.5 centimetres per second.The researchers added metal plates to the walls of the central stem and connected them to a circuit. The charged plates and the water within the stem create a sandwich of two conducting layers separated by an insulating layer – in effect, a capacitor.The leaf is transformed into a source of power by periodically interrupting the water flowing into the leaf with air bubbles. Thanks to the different electrical properties of air and water, every time a bubble passes between the plates the capacitance of the device changes and a small electric current is generated, which passes to an external circuit where it’s used to pump up the voltage on a storage capacitor. ‘We use the mechanical energy in the liquid flow to change the capacitance and add energy to the capacitor,’ says Maharbiz…”
source: newscienties.com
“Neurons can protect themselves against infection with HIV, new research has demonstrated. They owe their hardiness to a protein called FEZ-1, made uniquely by neurons, and which appears to lock out the virus. The finding raises the possibility of new treatments to thwart HIV by using gene therapy or drugs to activate production of the same protein in cells other than neurons – especially the white blood cells most vulnerable to infection.
Mojgan Naghavi of University College Dublin, Ireland, along with her colleagues Juliane Haedicke and Craig Brown, established the protective effects of FEZ-1 by blocking production of the protein in human neurons. When they did this, the neurons became vulnerable to infection. Likewise, they successfully blocked the usual infections in other types of brain cells, such as microglia, by engineering them to manufacture FEZ-1…”
source: newscientist.com