g******c
发帖数: 18 | 1 Hi biologists,
It's time to learn Math of Image Compression before a discussion about
picture quality, resolution or background noise can be initiated in this
scientific community.
http://www.ams.org/samplings/feature-column/fcarc-image-compression | F****8
发帖数: 289 | 2 您是韩老师吗？
这是你上月的帖子。
Single stranded DNA is much more difficult compared to double-stranded
plasmid DNA in terms of transformation.
Try these single stranded DNA transformation tricks.
1) transformation done at a low pH of ~6. Low pH significantly reduces the
nuclease activity of cutting single stranded DNA.
2) increase Mg++ to 1 mM. Mg is a conformation stabilizer of DNA and RNA.
3) No EDTA in the transformation system because it deprives Mg++ from the
buffer.
Han is a seasoned scientist with expertise on nucleic acid research. He
knows all of these tricks and may not disclose all of them.
Good luck to all. | g******c
发帖数: 18 | 3 NO.
【在 F****8 的大作中提到】
: 您是韩老师吗？
: 这是你上月的帖子。
: Single stranded DNA is much more difficult compared to double-stranded
: plasmid DNA in terms of transformation.
: Try these single stranded DNA transformation tricks.
: 1) transformation done at a low pH of ~6. Low pH significantly reduces the
: nuclease activity of cutting single stranded DNA.
: 2) increase Mg++ to 1 mM. Mg is a conformation stabilizer of DNA and RNA.
: 3) No EDTA in the transformation system because it deprives Mg++ from the
: buffer.
| F****8
发帖数: 289 | 4 OK，你不是韩老师。
那这应该就是韩老师所说的三个关键的实验技巧，是吗？
【在 g******c 的大作中提到】
: NO.
| m****a
发帖数: 270 | 5 Have you repeated the Ngago experiment using your own fucking suggestions?
【在 g******c 的大作中提到】
: NO.
| c********6
发帖数: 693 | 6 You cannot get the 50 cents
【在 g******c 的大作中提到】
: Hi biologists,
: It's time to learn Math of Image Compression before a discussion about
: picture quality, resolution or background noise can be initiated in this
: scientific community.
: http://www.ams.org/samplings/feature-column/fcarc-image-compression
| g******c
发帖数: 18 | 7 To be honest, the so-called evidence of data manipulation or fabrication in
Han's Paper
is so weak.
So far, two major pieces of evidence have been presented.
The first one is the shape and migration of DNA bands seem not to be similar
to those shown on protein SDS-PAGE. For these IDs, I will suggested a book
of DNA electrophoresis where you can read about some fundamental concepts or
knowledge. The following book are helpful to understand the DNA
electrophoresis data. (DNA Electrophoresis, Edited by Svetlana Makovets,
Institute of Cell Biology,
University of Edinburgh, Edinburgh, UK. Published by Humann Press). The
visualization and capture process normally add non-linear effects on to the
band quantitation. One shall pays attention to these details when he/she
tries to interpret data of electrophoresis.
The second is the background noise issue on Han's picture, the compression
process will filter out the high frequency details of a picture, which
causes a "PS"-like consequence. However, a throughout noise evaluation of
the whole picture will tell the truth. If the noise level is consistent on
the whole picture, it's very unlikely the picture has been manipulated.
The "three tricks" of ssDNA transfection is not a new idea. It has been
hanging around for nearly 20 years. There are some literatures about it.
The injection or transfection efficiency of ssDNA seems to be the key.
Please make sure this step was done properly during a troubleshooting.
It's so sad to see that many young generation scientists are lack of
basic scientific or math knowledge. It's even more sad to see that they are
listening to someone who scrutinizes a scientific paper on an unscientific
or
nonscientific way.
To be fair, to those who are questioning Dr. Han's paper, please write up a
scientific comments and submit to the journal. If your comments meet the
journal's scientific merit, your chance of publishing it will be very high.
Good luck to all.
【在 g******c 的大作中提到】
: Hi biologists,
: It's time to learn Math of Image Compression before a discussion about
: picture quality, resolution or background noise can be initiated in this
: scientific community.
: http://www.ams.org/samplings/feature-column/fcarc-image-compression
|
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