2009-08-30

[影片] 火蟻打造救生艇逃生

之前幾年紅火蟻的新聞在台灣也是炒得很熱,以下影片就可以看出紅火蟻的生命力真是決定於他們團隊合作的精神,在經過一場大洪水之後,火蟻能集體緊緊相依打造一艘救生艇,漂流在水上,等待機會著陸再重新建立自己的王國。

請參考以下影片。

2009-08-18

[報導] IBM研發DNA微晶片技術


之前IBM研發28奈米製程技術,已經非常不容易了,在大部份的微晶片技術在45奈米左右,最小可以到22奈米,但現在IBM與加州理工學院(California Institution of Technology)合作,開發另一項DNA微晶片技術,將奈米微晶片的精細提升到6奈米的境界。



Nature Nanotechnology

Published online: 16 August 2009 | doi:10.1038/nnano.2009.220

Placement and orientation of individual DNA shapes on lithographically patterned surfaces

Ryan J. Kershner1,4, Luisa D. Bozano1, Christine M. Micheel1,4, Albert M. Hung1,4, Ann R. Fornof1,4, Jennifer N. Cha1,4, Charles T. Rettner1, Marco Bersani1,4, Jane Frommer1, Paul W. K. Rothemund2 & Gregory M. Wallraff1

Artificial DNA nanostructures1, 2 show promise for the organization of functional materials3, 4 to create nanoelectronic5 or nano-optical devices. DNA origami, in which a long single strand of DNA is folded into a shape using shorter 'staple strands'6, can display 6-nm-resolution patterns of binding sites, in principle allowing complex arrangements of carbon nanotubes, silicon nanowires, or quantum dots. However, DNA origami are synthesized in solution and uncontrolled deposition results in random arrangements; this makes it difficult to measure the properties of attached nanodevices or to integrate them with conventionally fabricated microcircuitry. Here we describe the use of electron-beam lithography and dry oxidative etching to create DNA origami-shaped binding sites on technologically useful materials, such as SiO2 and diamond-like carbon. In buffer with approx100 mM MgCl2, DNA origami bind with high selectivity and good orientation: 70–95% of sites have individual origami aligned with an angular dispersion (plusminus1 s.d.) as low as plusminus10° (on diamond-like carbon) or plusminus20° (on SiO2).

2009-08-13

[轉載] 科學家證明鳥怕紅色是天生的喔!

科學家證明鳥怕紅色是天生的喔!(原文連結)

之前就有 paper 說在人類,程度接近的隊伍,穿紅的比較容易贏球。Hill, R. and Barton, R. Nature, 435, 293 (2005)

這篇則是用實驗證明,在鳥類(一種雀鳥),這種害怕是與生俱來的。我很喜歡他們的實驗設計。

作者試著繁殖,紅頭或黑頭的雀鳥 (雀鳥在成年之前都是灰頭的,成年之後頭才會有紅色或黑色),有些組爸媽的顏色跟小朋友不一樣,有些組是一樣的,有些比較大隻、有些比較小隻,在成長過程讓小朋友們知道他們打架打贏的情況是跟頭的顏色沒關係 (就還是跟體型比較有關係)。所以啦,他們的成長過程並沒有恐嚇他們紅色比較容易贏,他們知道打不打得贏跟頭的顏色沒關係,也沒有爸媽一定是什麼顏色的影響。

但接著,在所有的比賽中,紅頭小鳥還是贏了 81.5%,包括有些是被染紅的。(就明明是黑頭小鳥,頭被染成紅色,打架就比較容易贏了。

而且小鳥看到 紅頭的對手就會開始緊張... (他們去測荷爾蒙)。

所以這種對紅色的害怕是天性喔!(突然想到人類的文明始於用火,火對大部分的動物是有嚇阻性的)



Is red an innate or learned signal of aggression and intimidation?
Sarah R. Pryke

Department of Brain, Behaviour and Evolution, Macquarie University, Australia


Red coloration has been associated with dominance and aggression in a number of animals. However, it is unclear whether the increased aggression of red individuals or the avoidance of red opponents is an intrinsic or learnt response. By experimentally controlling for genetic and environmental effects, I tested for innate competitive differences and red-enhanced contest success in sexually immature (uncoloured) red and black head colour morphs of the Gouldian finch, Erythrura gouldiae. Despite juveniles being reared by foster parents of the same and different colour morphs, there were no differences in competitive abilities between uncoloured red and black males. However, when I experimentally added a red head mask to uncoloured males, red (but not black and novel blue coloration) was associated with winning contests, irrespective of an individual's underlying genetics or postindependence social experience. In addition, uncoloured opponents expressed higher stress responses (corticosterone) and avoided conflicts with red-painted competitors. The association between red coloration and aggression may be an innate response to aid facultative fight or submissive decisions, and adds to growing evidence suggesting that red coloration may be a general signal of intimidation.

轉載自:[Hot Fudge]
http://gohotfudge.blogspot.com/2009/08/birds-born-to-fear-red.html

參考資料:
Hill, R. and Barton, R. Nature, 435, 293 (2005) | Article | PubMed | ISI | ChemPort |
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