Saturday, May 4, 2013

return to blogs

Just feel how mindful I was before! Decide to come back to blog my thinkings.

Sunday, September 26, 2010

20 new things for today

  1. I had lunch with Tony (he serves as the instructor for the junior students).
    1. During the lunch I realized that I should have paid more attention to the brand names of the tools, for he asked several times about the names which I cannot tell.
    2. He also mentioned that it is important to initiate, when I said there are relatively less casual talks on science compared with that abroad. He also encouraged me to initiate a party inviting all the Northeastern people of China in this institute, if I want to get to know people from other areas.
    3. He said he works 13 hrs a day.
    4. He pushed himself to read by listing the books, when he was in college. He doesn't need the list now, for he already got used to reading every day.
  2. We use different lenses, and we differentiate them by their focal length (by saying focal length we simplify the lens set as one piece of lens). Larger focal length--like in our lab we have 105mm, 85mm, and 50mm lenses—means lower optical power, which is associated with larger magnification of distant objects, and a narrower angle of view. Conversely, shorter focal length or higher optical power is associated with a wider angle of view. In our lab we make two lenses connected front to front, and this makes the rears of the lenses facing cortex and CCD, separately. Fine adjustments should be made to make sure the cortex captured sharply on the CCD, which includes adapter applied between lenses or between lens and CCD, finely tuned distance between lenses and cortex, and etc.

Saturday, September 25, 2010

20 new things for today

  1. Agar cools quicker than I anticipated. Drop 3-4 drips of it and screw the ring quickly.
  2. Japan releases Chinese trawler captain, but refuses to apologize. It is said that China's banning on raw material (Rare earth) exportation to Japan, which is crucial for the high-tech industry in Japan, is the real stirring response for the Japan's release.
  3. One of the usages of rare earth elements is to produce phosphor. Got its name from element of phosphorus, but phosphor has a completely different mechanism on lightening—the former is because of chemiluminescence (some oxidization-reduction reaction), whereas the latter is because of phosphorescence (slow decay, >1ms) or fluorescence (quick decay, tens of nanoseconds).
  4. But why materials made of rare earth element emit light? Simply put, it's because of the electronic band structure in the crystals. An incoming particle (such as a UV photon) excites an electron from the valence band (trapped and cannot move under usual state) to either exciton band or conduction band. The excitons are loosely bound electron-hole pairs which wander through the crystal lattice until they are captured as a whole by impurity centers. The latter then rapidly de-excite by emitting scintillation light (fast component). As for the elections excited to the conduction band, the holes associated with them in the conduction band are independent (compared to the loosely bound pairs in exciton band). Those holes and electrons are captured successively by impurity centers exciting certain metastable states not accessible to the excitons. The delayed de-excitation of those metastable impurity states, slowed down by reliance on the low-probability forbidden mechanism, again results in light emission (slow component).
  5. Usage? Lighting, mainly on fluorescent lamps, and on some occasions used on metal halide lamps. Glow-in-the-dark toys. Electroluminescence (used commonly in LCD backlights). White LED (turning the blue light from LED into white). Cathode ray tube (television).

Tuesday, August 24, 2010

Matlab demo we should really make good use of!

I found Matlab demo really impressive.
The voice of the narrator is friendly, and the techs introduced are useful and also enlightening.

You can find the link to the demos easily in help-matlab-demos. Enjoy!

Sunday, June 27, 2010

Mu-ming Poo's Letter to his students in 2002

Mu-ming Poo is head of the Division of Neurobiology, Department of Molecular and Cell Biology at University of California, Berkeley, California, USA. He is also director of the Institute of Neuroscience, Chinese Academy of Sciences, Shanghai, China.

To all lab members:

Over the past several months, it has become clear to me that if there is no drastic change in the lab, Poo lab will soon cease to be a productive, first-rate lab that you chose to join in the first place. Lab progress reports over the past six months have clearly shown the lack of progress in most projects. One year ago, when we first moved to Berkeley, I expressed clearly to everyone my expectation from each one in the lab. The most important thing is what I consider to be sufficient amount of time and effort in the lab work. I mentioned that about 60 hr working time per week is what I consider the minimal time an average successful young scientist in these days has to put into the lab work. There may be a few rare lucky fellows like Florian, who had two Nature papers in his sleeve already, can enjoy life for a while and still get a job offer from Harvard. No one else in the lab has Florian's luxury to play around.

Thus I am imposing strict rules in the lab from now on:

1. Every one works at least 50 hr a week in the lab (e.g., 8+ hr a day, six days a week). This is by far lower than what I am doing every day and throughout most of my career. You may be smarter or do not want to be as successful, but I am not asking you to match my time in the lab.

2. By working, I mean real bench work. This does not include surfing on the computer and sending and receiving e-mails for non-scientific matters unrelated to your work (you can do this after work in the lab or at home), and excessive chatting on nonscientific matters. No long lunch break except special occasions. I suggest that everyone puts in at least 6 hr concentrated bench work and 2+ hr reading and other research-related activity each day. Reading papers and books should be done mostly after work. More time can be spent on reading, literature search and writing during working hours when you are ready for writing a paper.

3. I must be informed in person by e-mail (even in my absence from the lab) when you are absent from the lab for a whole day or more. Inform me early your vacation plan. Taking more than 20 working days out of one year is the maximum to me. In fact, none of you are reporting any vacation and sick leave on your time sheet (against the university rule, although I have been signing the sheets), but you know roughly how many days you were not here.

On the whole, I understand and accept the fact that you may not fulfill the above requirements all the time, due to health reasons, occasional personal business. But if you do not like to follow the rules because it is simply a matter of choice of life style, I respect your choice but suggest you start making plans immediately and leave the lab by the end of January 31. I will do my best to help you to locate a lab to transfer or to find a job.

If you do accept the conditions I describe above, I am happy to continue to provide my best support to your work, hopefully more than I have done in the past. I will review the progress of everyone in the lab by the end of June of 2002. I expect everyone to have made sufficient progress in the research so that a good paper is in sight (at least to the level of J. Neuroscience). If you cannot meet this goal at that time, I will have to ask you to prepare to leave my lab by the end of August.

Tuesday, December 22, 2009

[cited] Fractal Brains: Fractal Thoughts

by Dr. David Pincus

Researchers from the University of Cambridge took a big step forward this year in understanding how our brains work. It seems that the brain has a fractal organization. This likely gives us much of what we consider human. And at a deeper level these findings may help to connect us in a very fundamental way to the rest of the natural world.

The research team of Kitzbichler, Smith, Christensen, and Bullmore published their results in an article called "Broadband Criticality of Human Brain Network Synchronization," which is available on-line for free. I've had the article for about six months and had been meaning to post something on it. So at the outset I'd like to thank "Neel" for getting me going to actually re-read the article and post something with an interesting question he posed about neurological complexity and intelligence to the Chaotic Life blog at Psychology Today last month. I'd also like to thank my friend and colleague from NY, Grant Brenner for alerting me to the article when it first came out.

The design, results and context for this study are very sophisticated, and the implications are quite abstract. So I'm going to do my best to be clear. First the context: Many natural systems exhibit fractal organization and behavior. A fractal is a branchlike structure. Think of a tree: (1) Trees have many more small branches than large ones. This characteristic is also sometimes called a "power-law" or "inverse power law" or a "1/f" organization. Each of these terms means that there are exponentially more small branches compared to big ones. (2) Trees are "self-similar," meaning that small branching patterns resemble larger ones. This characteristic is also sometimes called "scale invariance" or "scale free" because no matter the size you are looking at, the general branching shape is the same. (3) The complexity of tree branching patterns can be quantified. Fractals are called "fractals" because they exist in fractional dimensions. A line fits perfectly in one-dimension. A plane (like a piece of paper) fits in two-dimensions. Fractals fit in between a line and a plane (or in the real world between two and three dimensions). More simply, because they are so complex, with huge numbers of tini tiny branches, trees never quite reach three dimensions. If you put them in a box, there will always be some space left over.

You may quickly recognize that many other natural structures besides trees are fractals: Neurons, rivers, the respiratory system, the circulatory system, geological fault lines, snow-flakes, and so on.

Natural systems also produce fractal behavior over time or in dynamics. Earthquakes are a common example. There are many more small earthquakes than large ones (which is nice by the way). Other examples include the size of extinction events in animal species, numbers of academic publications (a few researchers do huge amounts of work and the rest of us do just a little), numbers of hits to web-sites, wait times in stop-and-go traffic, and word usage in literature (i.e., zipf's law).

Why do systems do this? There are many reasons. Essentially, fractal systems have many opportunities for growth, change and re-organization. Yet they also are very robust. They maintain their coherence; they hold together well, even under tough circumstances. They are balanced in this respect, between order and chaos. They are simple, yet also very complex. This balance is often referred to as "criticality," thus the title of the article: "Broadband Criticality." And the term "self-organized" is often added because systems tend to become fractal on their own, simply by putting a lot of system components together and allowing them to exchange information. Think of a party. All you need to do is come up with enough people at the same place and time and they will start to form complex patterns of connection with one another.

Self-organizing critical systems are also very good at connecting, both internally and also to other surrounding systems. The branches of a tree are connected in a very lovely way. If you shake one branch, you'll see broad shaking across the tree. Fractal structures hang together nicely. Yet they branches may be trimmed without affecting the overall structure. Indeed, if you trim them far enough out (above the growth bud, "post-traumatic growth" or "whatever doesn't kill you makes you stronger") they will often grow even stronger, with more complex connections in the outer branches. Finally, branchlike patterns easily connect to other systems - a literal web of life. A tree with many fractal branches (and also roots) can better connect to the sun (and soil) to gather and exchange life sustaining nutrients.

In the past 10 to 20 years, researchers in psychology have been finding increasing examples of fractal patterns across each of the domains of psychology: Including intentional behaviors, visual search, and speech patterns. In my own lab within the past few years we have found that interpersonal relationships are organized as fractals and most recently that the self-concept is a fractal, with complexity being associated with health in both the psychological and social domains. Furthermore, it appears that fractal complexity (or rigidity) is routinely exchanged among biological, psychological and social processes. Fractal personality structure helps us to grow and connect, as do fractal relationships, and each likely has direct influences on physical health by encouraging integration and flexibility among circulatory, respiratory, and immune systems.

The study by Kitzbichler et al (2008) has added to much prior research suggesting that the brain exhibits fractal behavior. This makes a necessary link between the physical processes of the brain and each of the larger scale fractals we see in broader personality and social relationships. It is clear that biological, psychological and social dynamics are highly interlinked across scales, each impacting the other over time in myriad ways. With fractal organization at each of these scales, one may propose that they in some respects they are all part of the same fractal tree so to speak.

Kitzbichler et al (2008) used two measures of synchronization across brain systems: (1) the "phase-lock interval" and the "lability of global synchronization." The phase-lock interval is the amount of time that different brain regions are doing the same thing together - the amount of time in which they are synchronized. Essentially, this is a time-based measure of brain system coordination. The other measure, "lability of global synchronization" is a space-based measure. This measure tells you how global are the shifts in brain system synchronization, how broad are they, how far reaching.

Leaving out the many wonderful technical details of their analyses, they found that both measures showed clear-cut fractal patterning. This means that the amount of time that different brain regions spend in sync is branchlike - with many short linkage times and fewer long ones. And the spread of these linkages across brain regions was branchlike too, with many small spreads and few large ones.

These results, along with the evidence that has come before them, provide a much truer picture of how the brain is organized and how it works. Such is the core of basic research. The applications of these results may be considered to be virtually unlimited, and will over time impact every branch of applied neuroscience - intelligence, consciousness, empathy, body-mind medicine, psychiatry and psychotherapy.

What I would prefer to speculate upon instead would be the broader implications. Indeed what these robust results within the brain suggest is a possible mechanism for the "Broadband Connectivity" we share with the rest of the natural world. Inasmuch as fractal dynamics in broadband synchronization exist at every scale of measurable reality - from quantum to cosmic, perhaps human consciousness is both simply and profoundly a portal through which such fractal connectivity flows. Perhaps the linkages that so effect our growth and integration at the biopsychosocial scales extend much deeper into the roots of matter, and much farther into the cosmos than modernist science has ever imagined. Science appears to be nearing a period of neo-vitalism, with scientifically grounded ways of exploring the attractive worldview of our root-civilizations - that everything in life is connected and that all of the universe is alive within these connections.

Sure - some connections are more proximal than others. Kitzbichler et al. found that functionally connected brain regions were more likely to find and stay in sync with one another for longer periods of time, yielding fractal complexity measures that were less flexible than the connections among more distant regions. Similarly, one's life-partner will be more likely to drive you crazy than the moon.

Nevertheless, it will be interesting to see if certain systemic states encourage coherence, magnifying the connections among apparently separate systems. For example, the human stress response is a likely candidate for increasing the short-term coherence among biological, psychological and social processes. When you are stressed, your bodily systems band together, your psychological systems become clear and focused, and your social dynamics become coherent as well as you band together and form strict leadership hierarchies. Does human stress have broader impacts? Can their effect be measured even as far as the quantum realm? Conversely, can quantum systems become "stressed" leading them to reach into our macro world? Maybe so, maybe not. One thing is for sure, this blog is already way to long and abstract to fully consider these possibilities. Perhaps another day..?

Monday, December 21, 2009

The Power of the Power of Now

I'm reading a book named the power of now these days. One notion in this book worth sharing is that you should never receive the talking sounds in your head as youself. Rather, any thoughts in your head can be viewed by an upper thought. So in this sense, only those thoughts that you are not so deep in are near to what you really are, or say the true yourself.

What this notion can be used by everyday life should be that we should always keep an eye on the way we think. We should never feel too content on the way we are thinking, for it may be not as good as we thought. Observe the way people are thinking via their talking and thier questions. Feel ease to expose our own thoughts and the way we think also. Learn from this kind of comparison.