Source: http://news.feedzilla.com/en_us/stories/politics/top-stories/294015676?client_source=feed&format=rss
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Sunday, March 24, 2013
Saturday, March 23, 2013
Cooled integrated circuit amplifies with lowest noise so far
Mar. 22, 2013 ? Researchers at Chalmers University of Technology, Sweden, have demonstrated an integrated amplifier with the lowest noise performance so far. The amplifier offers new possibilities for detecting the faintest electromagnetic radiation, for example from distant galaxies.
A fundamental property for the first microwave amplifier in the radio receiver is its noise figure. This is normally given in decibel (dB). A typical noise figure for low-noise amplifiers in mobile communication systems is tenths of a decibel.
Last year, Chalmers reported a world record for a low-noise amplifier in the journal Electron Device Letters. The amplifier exhibited a minimum noise figure of 0.018 dB across a bandwidth of 4-8 GHz. However, since the low-noise amplifier was designed in a hybrid solution, scaling up to larger quantities turned out to be very difficult.
Chalmers has now in collaboration with a company called Low-Noise Factory published an article on an integrated ultra-low-noise amplifier. The scientists have developed a unique indium phosphide-based process for what is known as high electron mobility transistors (HEMT). Transistors and other semiconductor components have been fabricated on a monolithic chip on an indium phosphide wafer. All parts of the design such as semiconductor layers, components, process and circuit design have been optimised for the lowest noise performance.
As a result, an integrated 2.0 x 0.75 mm amplifier with an ultra-low-noise figure of 0.045 dB was demonstrated. The amplifier had a very large bandwidth of 0.5-13 GHz and a high gain exceeding 38 dB across the frequency band. In order to show such extreme performance, the amplifier was cooled to minus 260 degrees of Celsius.
"The combination of high gain, large bandwidth and ultra-low-noise figure makes this circuit very at-tractive for large multipixel arrays containing thousands of antennas," says Jan Grahn, research group leader at Chalmers.
"The integrated ultra-low-noise process enables the fabrication of thousands of amplifiers with identi-cal performance. One potential future application is in the world's largest radio telescope SKA (Square Kilometer Array) that is being planned, an international project where the Onsala Space Observatory at Chalmers is one of the acting members. In huge applications such as the SKA, even a small noise-figure reduction in the first low-noise amplifier in the receiver chain may potentially bring about major savings in the final system design."
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The above story is reprinted from materials provided by Chalmers University of Technology.
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Journal References:
- J. Schleeh, G. Alestig, J. Halonen, A. Malmros, B. Nilsson, P. A. Nilsson, J. P. Starski, N. Wadefalk, H. Zirath, J. Grahn. Ultralow-Power Cryogenic InP HEMT With Minimum Noise Temperature of 1 K at 6 GHz. IEEE Electron Device Letters, 2012; 33 (5): 664 DOI: 10.1109/led.2012.2187422
- Joel Schleeh, Niklas Wadefalk, Per-?ke Nilsson, J. Piotr Starski, Jan Grahn. Cryogenic Broadband Ultra-Low-Noise MMIC LNAs for Radio Astronomy Applications. IEEE Transactions on Microwave Theory and Techniques, 2013; 61 (2): 871 DOI: 10.1109/TMTT.2012.2235856
Note: If no author is given, the source is cited instead.
Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.
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Movie review: Tina Fey makes the grade in - The Salt Lake Tribune
This film image released by Focus Features shows Tina Fey in a scene from "Admission." (AP Photo/Focus Features, David Lee)
Review ? Plenty of wit in collegiate comedy-drama.
Tina Fey didn?t write "Admission," but between her performance and Karen Croner?s script, this smart and sweet comedy-drama is brimming with her dry wit and complex characters.
Fey plays Portia Nathan, a detail-obsessed admissions officer at Princeton University, where only one applicant out of 20 is accepted. Portia is ruthless in cutting through padded applications and helicopter parents to find the best students. She is particularly intent on doing so this year, as her boss (Wallace Shawn) has announced his retirement, and she?s competing with office rival Corinne (Gloria Reuben) for his job.
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?Admission?
Tina Fey shines as a neurotic college-admissions officer in this sweet, smart comedy-drama.
Where ? Theaters everywhere.
When ? Opens Friday, March 22
Rating ? PG-13 for language and some sexual material.
Running time ? 117 minutes.
While touring schools in the Northeast, Portia gets a call from John Pressman (Paul Rudd), who operates an alternative high school in New Hampshire. John tells Portia he?s got a great "diamond in the rough" student, Jeremiah Balakian (Nat Wolff). Then John drops the bombshell: He believes Jeremiah was the baby boy Portia gave up for adoption 16 years ago, when she attended Dartmouth.
When the news comes, Portia?s life is already in turmoil. Her staid English-professor boyfriend (Michael Sheen) suddenly dumps her for a sultry Virginia Woolf scholar (Sonya Walger). Further complicating things are Portia?s undeniable attraction to John and her issues with her feminist-scholar mom (Lily Tomlin).
Director Paul Weitz takes Croner?s intelligent script ? adapted from Jean Hanff Korelitz?s novel ? and wrings out solid humor from Portia?s comic struggles to balance her professionalism with her newly unearthed maternal instincts. Weitz also has fun depicting the cutthroat competition in academia, where transcripts and essays substitute for a genuine understanding of a student?s inner being. As for Weitz, his r?sum? is a roller coaster of varying quality, from the funny "American Pie" and the smart "In Good Company" to the detestable "Little Fockers" and last year?s overwrought "Being Flynn."
As Fey?s first true star vehicle, "Admission" is a perfect follow-up to her recently concluded run on "30 Rock." Here, she has a nice, easygoing chemistry with Rudd (hard to believe they?ve never done a movie together before) and trades barbs with Tomlin with an unforced agility. But Fey?s at her best riding solo, distilling Portia?s neurotic perfectionism just in the way she keeps her desk.
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Copyright 2013 The Salt Lake Tribune. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.
Source: http://www.sltrib.com/sltrib/entertainment2/56024052-223/admission-fey-portia-tina.html.csp
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Women | Johanna Breede PHOTOKUNST | Berlin
Women are a major driving force of photography. No sooner had French pioneer Louis Daguerre introduced the media to the public in 1839 than it began to be used as a method to portray female beauty. It was American chemist John W. Draper who ushered women into photography with a portrait of his sister Dorothy. And ever since, the suspicion has been that a wooing Orpheus lurks behind the cold technology of the camera - an artist whose intentions are to captivate and seduce women with photographs.?
But women have not only left their mark on photography as models and backdrops. They have contributed stylistically behind the camera itself as well. On the occasion of International Women's Day on 8 March 2013, the exhibition "Women" explores the feminine side of photography. Fifteen photographic approaches document aesthetic and temporal characteristics in images and depictions of femininity.
? stefan moses 'Stra?enbahnschaffnerinnen K?ln, 1963
?
The exhibition begins with the complex light montages from the pre-war work of Heinz Hajek-Halke. The Berlin-based photographer exemplifies the staged embodiment of femininity during the avant-garde movement. Hajek-Halke?s experimental techniques did not simply display women's bodies, the photographer rendered pygmalionesque recreations of light on silver gelatin paper.?
The approach of many photojournalists in the postwar era -Robert Lebeck, Stefan Moses, Hannes Kilian and Max Scheler ? was quite different. Their names stand for a new international image of the German woman. Portraits of American divas such as Eartha Kitt and Elizabeth Taylor document the return of glamor to the Adenauer Republic. But women at work also garnered the attention of this generation of photographers. Among others, Robert Lebeck?s 1964 photograph of Sicilian washerwomen in Cullera exemplifies journalistic art, and ties in with so-called "life photography". The dancing workers in this photo illustrate far more than playful flirtation with the camera ? the photo represents a photographic search for dignity and grace.
? Isa Marcelli, Serie 'Parfums' 2012/agence r?v?lateur
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Wasp spiders' move north explained
22 March 2013
Last updated at 00:54
Temperature tolerance is key to the spread of wasp spiders into northern Europe, according to scientists.
Since the 1930s the distinctive spiders have expanded their range from the Mediterranean coast to Norway.
Researchers in Germany traced the population boom to breeding between the native European spiders and an isolated colony living near the Black Sea.
Molecular Ecology reports the genetic mixing resulted in generations rapidly adapting to living in colder climates.
Wasp spiders (Argiope bruennichi) are commonly named for their bright, striped abdomens and were recently recorded by the Woodland Trust in Usk, south Wales for the first time.
The first official records of this conspicuous species in the UK were made in the 1920s.
Henrik Krehenwinkel from the Max Planck Institute for Evolutionary Biology, Germany, analysed the DNA of spiders caught across their current range, and museum specimens to understand more about their evolutionary history.
Piecing together the genetic puzzle, he found that the spiders diverged after the last ice age: part of the population stayed on the Mediterranean while a colony headed east to Central Asia.
While these eastern populations adapted to live in climates as diverse as the tropical south of Japan and cold south-eastern Siberia, the spiders in the Mediterranean remained limited to warm areas.
But, according to the research, rising temperatures across the continent in the last century allowed the Mediterranean spiders to join up and breed with a previously isolated Black Sea population.
"This possibly restored genetic variation within a few generations and allowed for rapid adaptation," said Mr Krehenwinkel.
He theorised that the novel combination of genes resulted in new physical characteristics that helped spiders to survive in different environments.
Out in the coldTo test the whether these more northerly spiders adapted a different temperature tolerance than Mediterranean populations, the PhD student analysed how they reacted when moved into one another's habitats.
Southern spiders could not survive the freezing temperatures in the north, and their counterparts suffered from heat stress in the south.
Mr Krehenwinkel explained that the eastern population had adapted to cooler temperatures and this was passed on to European spiders in the population boom.
The result was the rapid adaptation of hardier offspring that could settle further north than their predecessors.
The spiders found in northern Europe have smaller bodies and are not seen in the coldest months of the year.
Scientists attribute both traits to seasonal changes which do not affect southern species. Spiders found in northern Europe "overwinter", meaning their young are buried during the coldest months; emerging in spring.
The spiders then have limited warm months in which they can mature, which restricts how large they can grow before they reproduce in the autumn and the cycle begins again.
Mr Krehenwinkel described the hatchlings as "highly dispersive", commenting that they can cover huge distances via a method known as "ballooning": riding the breeze on a special parachute made of gossamer silk threads.
"By aerial dispersal, little spiders can cover distances of several hundred kilometres," he told BBC Nature.
"Members of different genetic lineages can thus quickly track warming climate, which increases the likelihood of contact."
Join BBC Nature on Facebook and Twitter @BBCNature.
Source: http://www.bbc.co.uk/nature/21877948
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New Jersey Eradicates Asian Long-Horned Beetles After 11-Year Fight
[unable to retrieve full-text content]After 11 years, during which 20,000 trees were removed, the state has eradicated the Asian long-horned beetle.
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Friday, March 22, 2013
How you can Choose The Finest Automated Internet Business ...
There are lots of different ways in order to begin producing cash on-line but you?re likely to discover which many folks need in order to attempt and find an automatic means in order to be able to do that. Should you ever searched with regard to programs in order to demonstrate exactly how to make cash on the internet ?m particular you?re conscious that there are the great selection of various plans accessible, however presently there are not that numerous accessible that maintain that they are able to speed up this particular process. Something you need to be familiar with is the fact that a few of these applications aren?t anything more than frauds that will not ever perform, but a number of could be in a position in order to begin making a person a few money. With regards to actually choosing a program in order to help you speed up the actual cash producing procedure a person are likely to observe that there are lots of issues we?re likely to go over in this post which you should adhere to.
The first thing you have to realize is the fact that any kind of kind of successful internet business may possess a couple of various components for them, and these <>ought in order to show up in the automated technique. Three from the items are certainly needed with regards to creating money online is the excellent marketing product, the means to marketplace this thing and additionally traffic. A good automated application should have every one of these but many significantly this will need an established technique of driving traffic, if your software is lacking in these 3 things, move onto another program.
Constructing an e-mail list is actually something which most successful Online marketers do, of class, in the event that you find a great automated software program that can assist you with this you will be nicely in front of the actual game. Whilst an email checklist is suggested, some Web Marketers haven?t stressed creating a checklist and also have nonetheless realized success, and that?s the reason why this is not definitely required. When the application is actually unclear about itemizing building you are in a position in order to be at liberty to make contact with them as well as uncover in the event that this can be component of their program and just how it works.
There is another variable in order to discover out prior to a person purchase the software and that is to discover in the event that you need to buy the site or even when the plan is merely going to be aiding a person market various on the internet hyperlinks. Whilst there?s nothing wrong along with each one of these methods you are likely to find that having your very own web site is actually generally more suitable with regards to Internet Marketing. One of the primary factors with this particular is primarily simply because if the online program closes for what ever cause all of the promotion you did for that online plan happens to be useless. Nevertheless with regard to these types of who have your personal site where you send people, whatever you might demand to perform is alternative the present online system with an option One and carry on to create cash.
If a program does not provide the money back again make sure you may want in order to spread this particular as this may be among the ripoffs that people were discussing previously. If you stick to the ideas you might completely have the ability to look for a profitable, automated internet business system.
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