| Big quake aftershocks plague New Zealand city By ROB GRIFFITH 2010-09-08T11:35:10ZCHRISTCHURCH, New Zealand (AP) -- A strong aftershock rocked terrified residents of New Zealand's earthquake-stricken city of Christchurch on Wednesday, as officials doubled their estimate for repairing the damage following nearly 300 temblors in five days.... hosted.ap.org |
Evolution's bone of contention on display The first Australian exhibition of a prehistoric boy is expected to reignite passionate debate about evolution. abc.net.au |
Today's Mystery Bird for you to identify | GrrlScientist Today's Mystery Bird could be dubbed "the blue bird of happiness", except that it is not really blue at allMystery Bird photographed at Heritage Community Park, Blacksburg, Virginia, USA. [I will identify this bird for you in 48 hours]Image: Audrey DeRose-Wilson, 2 October 2010 (look at this bird with binoculars).Nikon D80, 70-300mm, f/5.6, 1/400, iso: 160This neotropical migrant's blue plumage is not based on pigments at all. Instead, it uses another strategy to create blue feathers. Can you tell me about that?Daily Mystery Bird Rules: 1. Please name at least one field mark that supports your identification, keeping in mind that more than one field mark is often necessary to distinguish between species. IDs without any supporting information are not valid and may be deleted by the moderators. 2. Expert and intermediate level birders: do NOT try to be the first to blurt out the mystery bird's ID. Instead, please provide helpful hints, such as descriptions, literary references, puns, personal anecdotes, and other forms of discussion and assistance for beginning birders and for those following on their iPhones without naming the species. Expert and intermediate birders are free to name the bird species 24 or more hours after it was first published.3. Each mystery bird is usually accompanied by a question or two. These questions can be useful for identifying the pictured species, but may instead be used to illustrate an interesting aspect of avian biology, behaviour or evolution, or may be intended to generate conversation on other topics, such as conservation. 4. Each bird species will be demystified 48 hours after publication. If you have bird images, video or mp3 files that you'd like to share with a large and appreciate audience, feel free to email them to me for consideration.GrrlScientistguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
Science's memory man | Mo Costandi The man who revolutionised the way we understand the brain continues to provide insights in the workings of human memory two years after his death, says Mo CostandiIn late August, 1953, a 27-year-old man was admitted to Hartford Hospital in Hartford, Connecticut for an operation that not only dramatically changed his life, but also revolutionised the study of the human brain and led to the emergence of the field we now call cognitive neuropsychology.The patient had been suffering from epileptic seizures for more than 15 years. The seizures occurred so frequently, and were so severe, that he was unable lead a normal life.The cause of his epilepsy was unknown. It may have been the accident that occurred in his childhood. At the age of 9, he was knocked down by a cyclist, banging his head and losing consciousness briefly. But he also had a family history of epilepsy – three cousins on his father's side of the family also suffered from it.Regardless of its cause, his epilepsy had become so debilitating that he was ready to try just about anything to have it treated. He had been prescribed the maximum dosage of the strongest available anti-convulsant, but it wasn't working. So when William Beecher Scoville, a neurosurgeon at the Hartford Hospital, suggested a radical experimental procedure, he agreed.The operation was performed on 1 September 1953, as a last ditch effort to rid him of his debilitating seizures. It involved the surgical removal of two small structures, called the hippocampus and amygdala, from both hemispheres of his brain.Little did either the surgeon or his patient know how profound the effects of the operation would be. Although it stopped his seizures almost entirely, he was left with severe anterograde amnesia, or an inability to form any new memories. He had not become a different person after the operation, so much as lost certain aspects of his sense of self-identity altogether.Soon after the operation, Brenda Milner administered to him a comprehensive battery of memory and intelligence tests. The first paper describing the results, published with Scoville in 1957, introduced the patient to the medical community by his initials, HM, and eventually revolutionised memory research.At the time, investigators knew little about the neural substrates of memory. Decades earlier, in a series of now-famous experiments, Karl Lashley taught rats to find their way through a maze then tried to erase what he called "the memory trace" by lesioning different parts of the cerebral cortex. No matter what part of their cortex had been damaged, his rats could still find their way through the maze, and Lashley concluded that memory was distributed throughout the brain rather than localised in any specific location.Milner's early work with HM showed without a doubt that the hippocampus is essential for memory. Her tests also showed that he could retain small amounts of information for short periods of time. This suggested that memory consisted of at least two distinct components, and led Richard Atkinson and Richard Schiffrin to propose their influential Dual Memory Model, according to which memory consists of separate short-term and long-term stores.Milner, working with her PhD student Suzanne Corkin, further showed that HM retained the ability to learn and remember simple motor skills, revealing yet another distinct form of memory. Corkin – who is now a professor of behavioural neuroscience at MIT – subsequently found that HM could draw a relatively detailed map of his house, and suggested this was because the regions surrounding the hippocampus were left intact.HM died on 2 December 2008, aged 82, and his full name was revealed to be Henry Gustav Molaison. In the 55 years between his operation and his death, Molaison became the best known case study in the history of neuroscience and psychology. His case is to be found in every textbook, and is known to every student of these disciplines.Scoville and Milner's 1957 paper describing his amnesia has been cited over than 1,700 times since its publication. To say that he has contributed more to memory research than any other individual would be no exaggeration. "Sadly, however," Corkin wrote in a 2002 article, "he will remain unaware of his fame and of the impact that his participation in research has had on scientific and medical communities internationally".Furthermore, the hippocampus is now the most intensively studied region of the brain. In thousands of labs around the world, researchers dissect slices of hippocampal tissue from the brains of rats and mice, and impale the neurons with microelectrodes in order to elucidate the cellular mechanisms of memory.Current thinking holds that memory is dependent upon a process called long-term potentiation, whereby the connections between hippocampal neurons are strengthened. This mechanism was first postulated in the late 1940s by Donald Hebb, Milner's PhD supervisor. (Hebb studied for own his PhD under Wilder Penfield, the pioneering neurosurgeon who developed the technique Scoville used to identify the damaged tissue in HM's brain.Even after his death, HM will continue to provide further insights into memory. Immediately after he died, his brain was removed and carefully transported to the Brain Observatory at the University of California, San Diego, where director Jacopo Annese supervised the sectioning of the organ into thousands of hair-thin slices.And this is but the first phase of an on-going project. Now that HM's brain has been sectioned, it will be stained in various ways to reveal the cellular architecture. The data will be put online, and made freely available for memory researchers to use.Molaison will be remembered by non-scientists, too, as the inspiration for the lead character in Christopher Nolan's 2000 film Memento, which remains as one of the few accurate cinematic portrayals of amnesia.Further reading:Scoville, WB & Milner, B (1957). Loss of Recent Memory After Bilateral Hippocampal Lesions. Journal of Neurology, Neurosurgery and Psychiatry 20: 11-21. (Click here for pdf format)NeurosciencePsychologyMo Costandiguardian.co.uk © Guardian News & Media Limited 2010 | Use of this content is subject to our Terms & Conditions | More Feeds guardian.co.uk |
Cuckoos no match for local birds There is a limit to how convincingly the common cuckoo can mimic other birds, according to new research. news.bbc.co.uk |