What you might not know about cotton

As a plant molecular researcher, I started my research on Arabidopsis, just as many researchers did. I did my BS thesis on the fine mapping of a gene controling flowering time using an F2 mapping population. On joining PGML in 2003, I started working on the physical and genetic mapping of Gossypium species.

Cotton, as we know it, is famous for its lint fiber that made possible the billion-dollar cotton industry. I don't have to emphasize the importance of cotton fiber in our lives: without it, most of us will literally lose our underpants. However, the benefits cotton has brought us extends much more beyond textile. "Naked" cotton seeds from the ginning process can be further processed to produce cotton oil. This oil is then used in many versatile ways, one of which is to produce potato chips. That's not all, even the remainings after that can be used to feed live stock, and guess what, the cows and hourses loved it.

So, isn't a plant that gave us so much worth understanding more about?

Where does cotton fiber come from

As you might know, the word cotton usually refers to the genus "Gossypium", which composes of over 50 species all over the world. Most of these species doesn't produce spinnable fiber, and therefore are "wild" species. The cotton as we know it in the industry are mainly the four domesticated species: Gossypium barbadense, Gossypium hirsutum, Gossypium herbaceum and Gossypium arboreum. The first two species are tetraploid cotton, and are mainly cultivated in the Americas, and hence the name "New World" cotton species; while the latter two species are diploid cotton, and are mainly cultivated in Asia, hence are called "Old World" cotton species.

The amazingly long cotton fiber in the cultivated species are mainly due to artificial selection, or domestication efforts. As is shown in the figure below, the Gossypium species are categorized into 8 different "genomes" according to their behavior in meiosis. The fiber producing cotton came from the A genome cotton, and the tetraploid New World cotton came from a polyploidization event merging the A genome and the D genome, which happened around 1 million years ago. You might ask about how the two cotton genome species A and D from two different continents can meet with each other to form the tetraploid genome. The answer is still anybody's guess.

Cotton fiber is a single cell expanding from the epidermal cells of the seed coat. It might be the longest single cell in the plant kingdom. Four different stages are involved in the development of cotton fiber: initiation, elongation, secondary cell wall fromation, and maturation. The first two steps are quite self-explainatory, like blowing up a long balloon, the osmotic pressure pushes the cell outwards. The secondary cell wall start to form after that, which is a peocess of accumulating cellulose on the inside of the primary cell wall. The maturation is basically the drying up and dying of the cell, leaving the fine quality fiber behind. Much speculation has been raised as to the relationship between cotton fiber and other trichoms in plants. You can find more about that in one of the reviews i wrote here.

What do we know about the cotton genome so far

Not much, compared to Arabidopsis and rice, and even maize; but we have much more resources compared to other crop species like melon or banana. If you ask me, i think cotton genome research has not get as much attention as it deserves.

Genetic mapping for the whole genome has been done for the AD, A and D genome cotton species. This is mainly contributed by four different resources: the PGML (Plant Genome Mapping Laboratory, UGA), USDA-ARS, Nanjing Acriculture University in China, and a French group under Dr. JM Lacape. Physical mapping of tetraploid cotton is been approached by USDA-ARS in colaboration with Hongbin Zhang's lab in TAMU, and for the diploid D genome cotton, in PGML by Dr. Andrew Paterson and me. You can find information about the D genome physical map here. BAC libraries resources and ESTs databases are also quite abundant, for the A, D and AD genome that is. Sadly, for other genomes, relatively less is known.

Much research about the evolution of genome size has been done using cotton as a model system, for obvious reasons: cotton genomes diverged from each other relatively recently, and huge variation in genome size among different diploid genomes have already been detected. Relating to the research on genome size evolution, the profiling of transposible elements in the cotton genomes has been done by the Wendel lab. More detail can be found in the bookchapter i wrote for Andy's book on the physical composition of the cotton genomes here.

Cloning a gene from a genome whose genomic mapping and sequence data is lacking is a tedius and painful process. That is probably the reason why still no genes has been cloned in cotton. But the good news is, given the huge boost in genomic sequences, EST sequences and BAC library information in recent genomic analysis, new doors into cloning cotton genes has been opened. This include using BAC library and physical mapping data in selecting intereting BAC clones; developing new markers from BAC end sequences; developing new markers from already sequenced genomes such as Arabidopsis using syteny and colinearity relationships and even direct gene prediction using already sequenced genomes. I am interested in these new approaches, and is actually trying to clone a gene using all the available resources. Please refer to my project description page for more details.

Where does my research fit in the big picture

The lab i am working in is called the Plant Genome Mapping Laboratory. Just as it seems, mapping is what i will be doing for the most part of my research. This includes both physical mapping and genetic mapping. The D-genome physical map would be the first physical map for a diploid cotton species, if not the first for all cotton species. The important of the D genome chromosomes in contrbuting to cotton fiber genes is well recorded in recent research ariticles. So, this map will be very useful both in understanding the D genome composition, but will shed light in many other research on cotton species as well.

The Li2 gene, if cloned, will be the first fiber related gene to be cloned in cotton species. Apart from the information it provide for understanding the formation of cotton fiber, my approach will confirm the possibility of using markers developed from Arabidopsis syntenic regions in the cloning and mapping of cotton genes. This might foster new research that lead to the characterization of more cotton genes using similar approaches.

Introduction

Many genes and QTLs related to cotton fiber quality have been characterized and mapped in the past decades(Paterson, Saranga et al. 2003; Rong, Pierce et al. 2005; Desai, Chee et al. 2008); however, still no gene has been successfully cloned. Here we report the progress in cloning a gene (Ligon lintless-2, Li2) (Narbuth and Kohel 1990) that is involved in cotton lint fiber development.

Three interconnected approaches have been underway to get to the Li2 gene: firstly, fine mapping/chromosome walking is being done based on the latest mapping results (Rong, Pierce et al. 2005); secondly, syntenic relationship with Arabidopsis (Rong, Bowers et al. 2005) has been used in new marker development through cotton ESTs; thirdly, a physical map of D-genome cotton (unpublished data), with the help of extensive overgo hybridization data on both tetraploid and diploid genome libraries, is being used in the construction of BAC contigs spanning the region.

Fine mapping results confirmed the chromosomal location of the gene in previous mapping efforts, and added two new markers close to the gene. Two BAC contigs from D-genome physical map is found to cover the upstream region of the gene. BACs are being selected for end-sequencing and shotgun sequencing to facilitate future marker development and gene prediction.

The different approaches

Fine mapping

This is the traditional way by which most genes has been cloned, and an indispensable step toward the cloning of any gene of interest. The purpose of this step, is to search for markers that has a confirmed linkage to the gene within a very small window genetic map. The idea is illustrated in the figure below (figure origin: Chi et al.) The gene is first maped to a small region on a reference genetic map, and from the flanking markers on the genetic map, new markers closer to the gene is developed and mapped to close up to the target. This is done recursively until the window is small enough that there are only ~10 genes in the interval. Then all these candidate genes shall be researched to determine if one of them is the targeted one.

As you may have figured, this approach is very time consuming, and not only that, several foreseeable obstacles can be listed right away: 1. in order to have higher resolution on the map, a huge mapping population is needed to complete the job. The closer it get to the gene, the harder it is to find recombinant individuals, and therefore, the larger mapping population is required; 2. in a species where not very much sequence and other supporting information is available, the designing of new markers can be challenging. The first step mapping can be done using existing markers on the reference genetic map (suppose we have one for the species of interest), but later steps requires additional new and closer markers to be continuously implemented. Most popular marker used in plant genetics nowadays are SSR and RFLP markers, both of which requires sequence information in the designing. ESTs and other publicly available sequences have already been thoroughly exploited in the construction of the reference genetic map, and we need new sequence resources or other methods to design new markers; 3. even if we have the marker information we needed and the population we can work on, the mapping and scoring can still be a drag.

To cope with the obstacles mentioned above, we took a slightly different approach. To shrink down the population size needed in further fine mapping approaches, we screened the F2 mapping population for only those individuals with recombination within the region. To do this we selected two markers from each side of the gene, and screen through ~1000 F2 individuals. Given the distance between the flanking markers are ~5 cM, we are expecting to get around 50 to 100 individuals that showed different genotypes in the markers immediately upstream and downstream of the gene. By doing this, we only need to test the new markers on these recombinant individuals in the next rounds, instead of screening hundreds of non-informative individuals.

New markers came from two different resources: cotton BAC sequences, and Arabidopsis sequences. These will be discussed in detail in the following paragraphs.

The use of large-insert BAC libraries

We are lucky to have a large collection of cotton BAC libraries maintained in our lab. These include the library for the two most widely cultivated AD genome species: G. barbadense and G. hirsutem, and also A genome and D genome species from which the tetraploid genome is derived. Details of all the cotton libraries are described in the following table:

Library Name Genome Species Name Cultivar Genome Size [1C (Mbp)] Insert Size (kb) Library Coverage Number of Clones (Number of Plates) Vector GAD AD Gossypium barbadense Pima S6 ~2500 90 5x 99,840 (260) pBeloBAC11 (HindIII site) GAHin (GA_Aba) A Gossypium arboreum AKA 8401 ~1750 143 9.3x 110,592 (288) pAGIBAC1 (pIndigoBAC536 SwaI) GAMbo A Gossypium arboreum AKA 8401 ~1750 115 6x 110,592 (288) pECBAC1 (BamHI site) GCNH AD Gossypium hirsutum Tamcot GCNH ~2500 110 2.5x 49,536 (129) GKH (GK_Ba) outgroup Gossypioides kirkii ~579 132 8.4x 36,864 (96) pIndigoBAC536 (HindIII site) GKE (GK_Bb) outgroup Gossypioides kirkii ~579 110 41,472 (108) pIndigoBAC536 (EcoRI site) GLH (GL_Bb) F Gossypium longicalyx ~1592 125 4.3x 55,296 (144) pIndigoBAC536 (HindIII site) GLE (GL_Bc) F Gossypium longicalyx ~1592 105 55,296 (144) pIndigoBAC536 (EcoRI site) GLM (GL_Ba) F Gossypium longicalyx ~1592 130 4.5x 55,296 (144) pEZ BAC (MboI site) GR D Gossypium raimondii wild type ~900 100 9.0x 92,160 (240) (HindIII site) GRB (GR_Bb) D Gossypium raimondii ~1255 100 4.4x 55,296 (110) (should be 42,240) pEZ BAC (BstyI site) GRE (GR_Bc) D Gossypium raimondii 110 36,864 (96) pIndigoBAC536 (EcoRI site) MAXXA AD Gossypium hirsutum Acala Maxxa ~2118 137 8.5x 129,024 (336) pCUGIBAC1 (HindIII site)

Through these libraries, we are able to identify BACs that contain the sequence of interest through overgo hybridization experiments. This is a technique that use probes designed from low-copy sequences to hybridize to large DNA libraries, with a purpose of finding BACs in the target library that contains the source sequence. This method is being used in many labs doing genomic research across the nation. Markers that are mapped close to the Li2 gene in the first step, are used in designing overgo probes to select for BACs that contain sequences from the Li2 region.

Markers used:

• NAU3991
• Gr_ea17F11
• A1676
• A1552
• Gate4BC11
• Gate4BC01
• Cotton FRA-8 gene*
  

Library probed:

• MAXXA
  
• GAD
• GR
  

BACs hit by these markers in the AD genome libraries are subject to end sequencing. The analysis of the sequences will help us rule out some of the false positive hits in the overgo experiments. This can be done through comparing to sytenic region sequences in other species such as popular and Arabidosis. The sequences that are confirmed to be from the Li2 region will be used in further marker designing.

The GR physical map

In my other project during my PhD years, I builit a FPC physical map of the D genome G. raimondii, with the help of Gary Pierce. This gave us a chance to look for contigs that contains the Li2 gene directly.

As indicated above, the GR library (for G raimondii) is also used in the overgo experiments. We further examined if the BACs hit by these markers are confined in a small number of contigs, as they are close together in the genetic map. Much to my delight, although the G. raimondii physical map result is still preliminary, we are able to see clear patterns indicating that two contigs could be anchored to the Li2 region. In the following figure, it shows that this relationship is confirmed by multiple probes designed from genetic markers from the region.

All the clones in these two contigs will be end-sequenced for marker development. One of the most promising clone: GR109E22 will be shotgun sequenced. These will be the materials for further approaches toward cloning the gene.

The use of Arabidopsis sequences

In a recent comparative genetics analysis, the sytenic relationship between the cotton genomes and the Arabidopsis genome was established (Rong et al. 2005). This raised the possibility of using the already-sequenced Arabidopsis genome in developing markers for the Gossypium genomes. We designed, through the sytenic relationship with Arabidopsis, new markers for cotton genomic regions of interest, including the Li2 gene region. (Rong et al. unpublished data)

For the Li2 gene region, through blast search, we found it to be sytenic to the Arabidopsis beta5 group (Arabidposis has gone through two rounds of whole genome duplication after diverging from cotton, namely alpha duplication (the recent one) and beta duplication (the more ancient one). Therefore, the beta5 group of Arabidopsis contains 4 paralogous Arabidopsis genomic regions details can be found in Bowers et al. 2003). Cotton ESTs that correspond to regions in the beta5 group are then used for new marker design. Among the new markers desgined through this approach, two are mapped closely to the Li2 gene.

This proves that syntenic relationship across species can be used in designing new markers in gene cloning of a relatively less studied genome.

Perspectives

As more genome sequences will be available (draft cotton D genome, draft poplar genome, draft papaya genome, etc), more resources can be used in the gene cloning process. The process of gene cloning could be dramatically changing due to the availability of these data. The once tedius process that requires a small lab 10 years to acomplish, might be accomplishable within the time frame of a PhD student. However, there still a lot to be done, and novel approaches need to be developed. Exactly how we will be using these data requires intensive collabortation among bioinformatists and traditional wet-lab scientists, by and large, this might requires a changing in the training of new students and new scientists in the years to come.

Reference:

Desai, A., P. W. Chee, et al. (2008). "Correspondence of trichome mutations in diploid and tetraploid cottons." J Hered 99(2): 182-6.

Narbuth, E. V. and R. J. Kohel (1990). "Inheritance and Linkage Analysis of a New Fiber Mutant in Cotton." The Journal of Heredity 81(2): 131-133.

Paterson, A. H., Y. Saranga, et al. (2003). "QTL analysis of genotype x environment interactions affecting cotton fiber quality." Theor Appl Genet 106(3): 384-96.

Rong, J., J. E. Bowers, et al. (2005). "Comparative genomics of Gossypium and Arabidopsis: unraveling the consequences of both ancient and recent polyploidy." Genome Res 15(9): 1198-210.

Rong, J., G. J. Pierce, et al. (2005). "Genetic mapping and comparative analysis of seven mutants related to seed fiber development in cotton." Theor Appl Genet 111(6): 1137-46.

How long does it take to be successful?

Once in a genetics class at UGA, Dr Rich Meagher said to us, that during his entire research career, he has come to know that the time it takes from a complete rookie to an expert in any given subject in science, is two years. I remembered that vividly because it shocked me for a while. Two years? That short? It took me 4 years to get a bachlors degree in General Biology, and another 5 to 6 to become a PhD, and by the time i graduate, i am still not sure, if i can tell others that i am an "expert" in this field. But 2 years? How can you do that?

It didn't take me long to get a feeling of what Dr Meagher really meant that day. The more i know, the more i feel that the basics of all science and all research are complimentary, and are more common than i used to think. All are based on simple logic and reasonings. If we mastered the way of thinking, the art of argument, it doesn't take long at all to get hold of the gists of any subject.

Apart from the underlying rules of thinking, the infrastructure of any science subject is built elegantly similar. It is like building all the skyscrapers: even though they are all different in the exterior and interior design, they all share the basic steel scaffold to keep them in place. If we know how the scaffolds of the science subjects are related to each other, then jumping from one subject to another would not be that hard at all.

But all these "mastering-one-subject-in-two-years-time" theory do base on a very important prerequisite, and that is we need to be well educated in "thinkology", we need to train our brain to be great thinkers. This can be achieved by mastering one of the many sciences out there, which is what we usually do. By doing that we get to know how one sample building is built from scratch. We get to know the infrastructures, the decoractions, and how it stand tall among all others. However, there might be other ways of doing this, and this lead me to the following thinkings.

My understanding of how teaching should be

The way we are teaching our students is by subjects: maths, English, Chinese, Physics, Chemistry...from grammar school, to middle school, all the way up until some of them graduate with a PhD. No one, or seldom has anyone disputed this division. But just think about how we learn, we can see a major flaw in this system that is applied worldwide in this modern world.

First thing we need to distinguish is between what is a science subject, and what is an ability. For one thing, they could both be learned, but the way we learn it, and how it will affect our way of life, is way more different.

Walking is an ability, talking is an ability, writing is an ability. More sophistically, imagination is ability, logical thinking is an ability, to be able to understand art pieces and enjoy music is ability.

On the other hand, is being able to solve math problems ability? How about designing biological research, writing novels and poems (not just simply writing)? I would call those science subjects. A science subject is an integration of multiple abilities with fine coordination.

Abilities can be learned, trained, refined; science subjects can only be learned through the learning, training and refining of the abilities that made it up. Metaphorically speaking, abilities are base pairs of DNA, and a science subject is a gene; abilities are words, characters, science subjects are beautifully written sentences.

Successful scholars are often those ones who are well trained in most aspects of the basic abilities, and therefore, they seemed to have an advantage in managing every subject they are exposed to, and that’s why we sometimes call them geniuses. You may be thinking about the great thinkers like Aristotle when you are reading just now, and say “at those times, sciences were simple, and don’t need subjective trainings as intense as today’s sciences”, but think more recent scholars: Hua Luogeng, a pretigous mathematician is also a poet and wonderful lecturer; Allan Heeger, won the Nobel Prize for chemistry in 2000, was a physist. Similarly, for many prominent scientists, their research covers a broad range of subjects, and they usually excels in all of them, while some other scientists fought their way through a tiny branch of a subject and still didn’t get any breakthroughs. Ever wonder why? To become a scientist who makes a difference, it is mostly important to lay a solid foundation of basic abilities, than getting trained in a specific science subject.

“Aren’t we done with the basic trainings of listening, reading, writing, imagining, and basic thinking in pre-school educations?” This is a common misconception that needs to be corrected. We usually put ability trainings in the curriculums in pre-school education, and starting from elementary school, we begin to study “math”, “language”, “history”, etc. This seemed intuitive, but is this really the best divisions in class subjects? Students are not getting enough training in imagination, logical thinking, and integration of information through these subjects. They are too much confined by the details of the class, trying to figure out what 23x56 is, or when did Napoleon conquered Europe, and they gradually stopped asking why, and “how come”, and most importantly: “what if”. Good teachers will try to integrate these thinking skills into their teachings, but we have to face the fact that most teachers are still teaching things “students only need to know”.

So my argument here, is that it will make a big difference if we could add courses like “imagination”, “logical thinking” into the curriculum from elementary school to middle school education. Instead of asking the teachers to modify their teaching style to stimulate more active thinking in class, we bring in a whole new set of trainings to guide the students, telling them how to think and react upon different facts. This is what we should do.

Teaching phylosophy statement

< xml="true" ns="urn:schemas-microsoft-com:office:office" prefix="o" namespace="">I believe in passion. Sometimes we do things just because we have to, it was either our duty or responsibility; but there are also times we do things because we have a desire to do it. It would really be great when we are required to do something we really want to do, and for me, this job is teaching.

Biology is among the most fast developing science subjects in recent decades. Its influence has spread out from research labs to nearly every aspects of life: food, environment, industry, forensics and even politics. So it has never been more important in history that we have a good system of biology education, for the need of both providing competent researchers and passing the biological science to everyone.

The uniqueness of biological science requires us to teach differently. Compared to established sciences like physics and chemistry, biology is still like a newborn child, and the emphasis of teaching of biology should be on innovative thinking, dare to question, and dare to explore. On more practical terms, concern more about if the students captured the way of thinking, and less about if the student memorized certain phenomenon, which could be proven wrong centuries later. I integrated these thoughts in my teaching by introducing and discussing the underlying thinking of each experiment with them. And on my test and quizzes, I avoided simply memorization questions and put more points on “why” we do that.

Another very important part of my teaching philosophy is the relationship with students. I’ve always feel it essential to have a close relationship with my students. Though it might not be agreed by all, being a friend to students, fostering an interactive environment in class is very helpful, especially for smaller classes. During my days as instructor for a lab course, I remembered all my students by their first names by the end of the fourth class, and I like them to call me by first name. I also encourage them talk to me about their difficulties in understanding the materials both in class and out of class. Exchanges of ideas between students are greatly encouraged in my class. This not only helped them express and organize their thoughts, but also helped to connect the class together. By doing so, we changed a lecturing process into more of a peer learning process. The students got more expressive with more feed backs for me, and I can guide them through more easily without the pressure of having to be an authority.

As the development of information technologies, guiding students in finding information outside the class is gaining importance in most of the subjects nowadays. Not only did we used the world wide web for communication and class material distribution, I also introduced my students to general ways to look for additional information from online resources from wikipedia.org to online journal databases. The students will be with me for only one semester or two, but once they mastered the ways to explore on their own, they are ready to teach themselves in future.

Numerous examples of good teaching practice had already be set up by former great instructors, I am always on the look out for new techniques and new thinking that can be integrated to my classes. I appreciate diversity of learning styles, and diversity in class organization can satisfy different students’ needs. Teaching is also a mutual process, and so is learning. Being in one class room, teachers can learn a lot from the students and the students get to be the teacher a lot of the times. The good part, is enjoying it.

Courses that I taught

1103L Concepts in Biology Labs, in Biological Science Division in University of Georgia

Introductory biology lab course in the biological science division in UGA have is composed of four courses: 1103L and 1104L for non-majors, and 1107L and 1108L for majors. Among these, 1103L and 1107L focus more on the molecular biology part, while 1104L and 1108L focus more on ecology.

The course I have taught: 1103L, is a course for non-science major students. I taught three classes of 20 students each week. We meet once a week for two hours in the lab. The curriculum covers basic biological lab operations and concepts from microscope usage to population genetics.

The syllabus of the course is online.

Evaluation averages of one of the classes i taught.

My students

My students are a big part of my joy in life.

I have taugh nearly 100 students now since i started my work as a lab TA. I liked teaching my students a lot, and they like me, too. I got good evaluations from my students in both semesters as a TA, and here are some of their comments on the annomymous online evaluation of the course.

It is hard having a timed quiz because there are so many analytical questions. Also, the quiz material was not always specified the week before so I think a study guide or vocab list would be helpful to guide students as to what to expect. Phil always answered every question, he was so helpful and patient.

Phil did a great job as our lab instructor. I think the lab itself just wasn't that interesting. There wasn't a lot of motivation in it, because our main grades come from the quizzes that tested us on information learned in the last lab's lecture--- not so much the lab itself.

Great TA! He knows his stuff but has a difficult time conveying those thoughts to questioning students. The pre-lab lectures where sometimes long and tedious.

great!

Phill was very helpful and did everything he could to help us understand the topics

Very helpful and very understanding.

Phill was always willing to help his students. I didn't like being quizzed on material from the lab we hadn't done yet..

He did a GREAT job in explaining the labs and teaching the material.

The best lab teacher I have had. I really enjoyed having him as my instructor.

A+

Phill is awesome!!! He was my favorite teacher this semester.

What an excellent TA! Though lab was completely pointless- I learned nothing but got an A in the class, I really liked Phil!

He used terms that made the labs seem duable and some what simple. Definately learned alot in this class

Phill (Lifeng Lin) has been an awesome teacher and he has really made my biology lab enjoyable. He is easy to talk to and always teaches on-level, pertinent information. Phill is funny, but at the same time takes his class seriously. He is by far the best lab teacher I could have asked for. PHILL RULES!!

Good teacher. Only complaint is that the material in the lab does not go along with what is in the class. It would be more helpful if the material was covered at the same time.

Lifeng was an awesome teacher! He kept us interested in the subjects. I don't think anyone in my lab was a Biology major, so he made it fun for us to learn about something that we didn't necessarily need to learn. And he made us laugh alot; something key to having fun in a class.

Very awesome TA! Helped out a lot and made lab fun! Enjoyed it!

Technologies

I am a "post-80" guy, so i am very into computers and new technology. Apart from Powerpoints and Excel, i would use new softwares whenever i can.

A demostration of a protein/RNA structure that i made during BCMB6010 can be seen here. (You might need to download install MDLchime plugin for your browser (firefox might not be compatible at the moment).) I never used that in my teaching, but it would be really cool if it has a chance to be used.

Random thoughts

top down vs bottom up

top down: teach the most common sense phenomimon first, explain in layman term the things that we are trying to understand, and why is it intereting to understand them. Then break down to the most superficial and easy to understand explainations, into stuff everyone can understand. Then bring out the need to understand more detail in order to dissect the problem, and then introduce the terms and phrases and details of the process. So the student would understand the big picture first, and may still be able to recall the very top layer of the knowledge, the rationale and layman term explaination ofthe phenominon years later, even if they forgot about the details that entails.

bottom up: start with the details, explain all the scientific terms and words that are gonna be used in the lecture, and make sure they understand it. Then try to piece together those terms into concepts and theories that would explain a common phenominon at the very end.

top down is definately better for non science majors, while i am not sure if bottom up approach is really better for anything.

its more about "what you can produce" than "what you know"

it seemed to me that the earlier years of schooling are very much focused on "what you know". we were tested on memorizing facts and formulas. This gradually changes when we started college, and by the time of graduate school level, the success mostly depend on "what you can produce".

from a pure practical point of view, everything we learn and memorize serves the final purpose of "what we can produce", but how to balance out this in teaching? The problem with the Chinese education system lies in that it stresses too much on what students know, and although we got such a strong system of basic knowledge, innovations are very rare; on the other hand, the western system is more balanced,

ÖÐÎÄ (Chinese)

Raised in Beijing, China. Mandarin Chinese with no accent.

English

Over 15 years of English study, with 5 years living in the US, I am almost as comfortable with English as I am with Chinese. I am most proud of my listening skills and an almost flawless American accent. I am confident in any kind of oral translation assignments, as long as it is between English and Chinese.

Standard Tests and Scores

TOEFL score: 667/677 (perfect score in listening section) Taken in spring 2002, Shanghai

GRE score: 2310/2400 (V.760/800, Q.800/800, A750/800) Taken in spring 2003, Shanghai

SPEAK test score: 60/60 Taken in spring 2004, University of Georgia,US

Sample Translation Works

Works provided here are real assignments from Beijing Institute of Century Simultaneous Interpreting

English to Chinese

Chinese to English

Services

I do written translations for EN-CN and vise versa. I normally charge 5 cents per word (or per character for CN-EN translations) of the source article.

I will be glad to provide interpretation services if it fits in my schedule. This is something i love to do, so I don't care much of the payments.

I would greatly appreciate any opportinities to work for any radio and broadcasting services. Please contact me for voice samples if you are interested.

I started to get interested in FL Studio the first time I got my hands on it in 2004. It allowed me to actually materialize some of the melodies that had been hovering in my mind.

The music that i created are mostly background-like, to reflect certain mood. I haven't tried to compose any songs yet. Once i have time, i think i will try that.

here is a couple of demos for you to have a glance at what i do with it.:

Ramsey inspiration

i composed this piece right when i came back from the university sports center.

Interrupted Calmness

This was done in a late night. I tried to depict the feeling of unsettled mind struggling for peaceful rest.

I have been playing with web page designing for years now. I designed my homepage at UGA with a little help of themes from the internet. I am now able to design and build a dynamic webpage using html and javascript.

Starting 2007, i've decided to dig deeper into webhosting and how it works. I learned the "LAMP" set basically through online tutorials. Now i am able to set up a webserver on both linux and windows independently.

I further learned popular content management systems (CMS) like Wordpress and Drupal. You can find a sample of sites that i have created for fun.

Sample sites:

Personal home page

Drupal site for PGML

jqeury examples: here and here