Biology Blog Education: Januari 2009

Sabtu, 31 Januari 2009

Genetic drift in Iceland

Iceland has intrigued human population geneticists for some time and Icelanders are one of the most studied human populations because of their relatively small population and relatively large degree of isolation. These two features combine to give genetic drift more power than in most populations. A paper in PLoS Genetics this month spells out exactly how important genetic drift has been. There's a report on the paper here.
In the case of Iceland this means that genetic drift is a very powerful force in shaping variation, specifically, in increasing the rate of extinction of haplotypes and bringing to fixation other haplotypes.

Jumat, 30 Januari 2009

Well, I already posted about this week's New Scientist article with its provocative cover.

There's a post about it on PZ Myers Pharyngula blog.

Pity Roger Highfield, editor of New Scientist, which published an issue in which the cover was the large, bold declaration that "DARWIN WAS WRONG". He has been target by a number of big name scientists who have been hammering him in a small typhoon of outraged private correspondence (I've been part of it) that his cover was a misdirected and entirely inappropriate piece of sensationalism.

The editor seem to have anticipated this issue in the accompanying editorial, but is the cover appropriate or not? Interesting debate.

As we celebrate the 200th anniversary of Darwin's birth, we await a third revolution that will see biology changed and strengthened. None of this should give succour to creationists, whose blinkered universe is doubtless already buzzing with the news that "New Scientist has announced Darwin was wrong". Expect to find excerpts ripped out of context and presented as evidence that biologists are deserting the theory of evolution en masse. They are not.

VIRTUAL BIO LABS! INJECT DNA INTO VIRTUAL FLIES!

Happy Friday! Here's a real treat. Two Virtual labs you can play around with this weekend! :)

But before you do we need to update your internet browser...click the link below so you can download and install the Adobe Shockwave 11 plugin: http://get.adobe.com/shockwave/thankyou/

Ok, now that you are all powered up with Shockwave, get ready for some virtual lab time!

Virtual Lab 1: Transgenic Fly Lab
This lab will familiarize you with the science and techniques used to make transgenic flies. Transgenic organisms, which contain DNA that is inserted experimentally, are used to study many biological processes. In this lab, you will create a transgenic fly to study circadian rhythms. (Click here for more on experimental design.) The fly glows only when a certain gene involved in circadian rhythms is activated. After making the glowing fly, you will use it to explore basic principles of circadian biology and genetics.

Teachers: Click here for more information on how this exercise can be used in your classes.

Basic Steps

1. Make transgenic flies.
o Prepare DNA that will be incorporated into the fly genome.
o Prepare fly embryos.
o Inject fly embryos with DNA.
o Breed flies.
o Select transgenic progeny.
o Examine light output from transgenic adults.

The period gene is a key component of the fly's molecular clock (Bargiello, et al., 1984; Darlington et al. 1998; Wager-Smith, and Kay, 2000; Young 2000). The period (or per) gene's transcription and translation oscillate in a regular pattern that has a period of 24 hours. A mutation in this gene results in a fly with an altered period; the name period was therefore given to this gene (Konopka and Benzer 1971). (Click here for more on the discovery of the period gene.) This predictable pattern is harnessed in the experiments here to provide a window into how clock molecules change. Specifically, part of the period gene is linked to the luciferase gene (per-luc) such that whenever the period gene is "on," light is produced in the cells where period gene transcription is occurring (Brandes et al. 1996). This elegant model allows us to look at changes in genes simply by looking at the glow of these transgenic flies.

2. Use transgenic flies to study circadian rhythms and genetics.
o Measure per-luc gene expression (that is, light emissions) under different light-dark conditions.
o Examine diff

Virtual BIO Lab 2: Virtual Bacterial Identification Introduction
Welcome to the Virtual Bacterial Identification Lab. The purpose of the lab is to familiarize you with the science and techniques used to identify different types of bacteria based on their DNA sequence. Not long ago, DNA sequencing was a time-consuming, tedious process. With readily available commercial equipment and kits, it is now routine. The techniques used in this lab are applicable in a wide variety of settings, including scientific research and forensic labs.

Basic Steps
* Prepare a sample from a patient and isolate whole bacterial DNA.
* Make many copies of the desired piece of DNA.
* Sequence the DNA.
* Analyze the sequence and identify the bacteria.

The piece of DNA used for identifying bacteria is the region that codes for a small subunit of the ribosomal RNA (16S rRNA). We will refer to this piece as 16S rDNA. Different bacterial species have unique 16S rDNA sequences. The identification relies on matching the sequence from your sample against a database of all known 16S rDNA sequences. (Learn more about ribosomal RNA.)

Learning Objectives
* What kind of patient samples are used for the purpose of identifying possible pathogens?
* What does PCR do, how does it work, and why is it useful?
* How do you separate the desired DNA from all others?
* How does an automatic DNA sequencer work?
* Why is it possible to use a DNA sequence to identify bacteria?

Kamis, 29 Januari 2009

CCBER

Next Thursday (2/5) we will visit the Cheadle Center for Biodiversity and Ecological Restoration. You can find information and directions at their website. We will meet there at 11.00 am and you should allow 5 minutes to cycle or 10-15 minutes if you are walking over there - although that is naturally dependent on where you are walking from......

Here's a

map showing the bike route from CCS (click for a larger version).

Holy WIKI Grail Found: OPEN WETWARE!

I am sure everyone else already knows about this. But, I was blown away. This WIKI is huge and tells you everything about protocols, materials, blogs and other resources. Personally, I'm not at the level yet where I can use the techniques contained here, but for those who are, you should already have this in your back pocket.

VISIT: http://openwetware.org/wiki/Main_Page

"OpenWetWare (OWW) is overseen by Stanford University bioengineering professor Drew Endy, until recently at MIT. Harvard Medical School systems biologist Pam Silver, an early convert to OWW, has all of her experiments and protocols on the site. “I think it has made my lab members feel that they are part of a larger community of scientists who share ideas,” she says, “and that their research can move forward more quickly.” Silver maintains that the freeflowing interactions on OWW have contributed to her work in bioenergy and her educational efforts in systems biology. “I always encourage people to be as open as possible,” she says. “No one has to join OpenWetWare, but that's where the cool people are.”" SEE THE FULL HHMI ARTICLE

BIO Documentary (learner.org): -2003- Rediscovering Biology: Molecular to Global Perspectives

Here is a more up to date Biology documentary (2003) also from Oregon Public Broadcasting.

It's available in streaming format only, so you first you need to go to www.learner.org and sign up for free. Then make sure you enable pop ups and click just on the links below.

This documentary also has its own web site with an Online Textbook, Case Studies, expert Interview Transcripts, Image & Animation Archive, and a Glossary!
http://www.learner.org/courses/biology/index.html

Rediscovering Biology: Molecular to Global Perspectives
(2003) "Great advances have been made in the field of biology in recent decades that will continue to have a major impact on our lives. Rediscovering Biology: Molecular to Global Perspectives explains these developments for teachers of high school biology to update their content knowledge and understanding. The multimedia course materials—video, online text, interactive Web activities, and course guide—will help new and veteran biology teachers become familiar with current research methods and tools that will lead to new discoveries in the coming decades. Thirteen half-hour video programs feature interviews with expert scientists involved in groundbreaking research, such as Eric Lander of the MIT Genomics Center and Rita Colwell, director of the National Science Foundation. Detailed animations provide a micro-level view of biological processes and techniques such as mass spectrometry and microarray analysis. Supporting and expanding the video content, the course guide and interactive Web site provide learning activities, additional information, a detailed glossary, annotated animations, and case studies that invite teachers to run their own mini research projects. An extensive online text, downloadable for printing, covers the content participants need to know for the 13 units. Produced by Oregon Public Broadcasting."

Session 1. Genomics
Having determined the complete DNA nucleotide sequence of humans and several other organisms, today’s research has shifted to identifying genes and determining their functions. This session reviews the techniques used in BLAST searches, microarray experiments, and other genomics tools.

Session 2. Proteins and Proteomics
Researchers know it is the proteins made by a cell that determine what that cell does. This session explores the varying complements of proteins and their effects, structures, and interactions within the mechanism of cell function, and introduces the larger picture of proteomics and systems biology.

Session 3. Evolution and Phylogenetics
The ability to compare DNA sequences from different organisms is refining our perspective on evolution. This session illustrates how molecular techniques are now combined with fossil evidence to explore relationships in organisms from whales to anthrax.

Session 4. Microbial Diversity
Microbial diversity far surpasses all other diversity on the planet. This session examines recent studies of microbes including extremophiles, the comparisons of Bacteria and Archaea, and the formation and life cycle of biofilms.

Session 5. Emerging Infectious Diseases
New diseases arise and old diseases, such as malaria and influenza, are returning with renewed vigor. This session studies the complex causes and far-reaching impacts of emerging infectious diseases around the globe.

Session 6. HIV and AIDS
Studying individuals with natural resistance to HIV has led to insights into the infection process and may produce new treatments or a vaccine. This session explores recent developments in the study of HIV and AIDS, the future global impact of the current infection levels, and the ethical issues surrounding current research and treatments.

Session 7. Genetics of Development
Organisms as different as flies, fish, and humans share a set of genes, known as a genetic toolkit, which guides development. This session presents new perspectives on the remarkable similarity in these molecules and processes and the ethical questions involved in this research.

Session 8. Cell Biology and Cancer
Cancers result when genes required for normal cell function are mutated and the resulting cells undergo other changes ultimately leading to uncontrolled division. This session reveals new information on normal cell function, proto-oncogenes and tumor suppressor genes and their role in the cell cycle, and current research in drug design for specific cancers.

Session 9. Human Evolution
Homo sapiens is now the only living representative of what was once a multi-branched bush of hominid species. This session examines mitochondrial Eve and other fossil clues that increasingly point to Africa as the point of origin of our species. How did humans replace their hominid cousins, including Neanderthal, leaving the chimpanzee as our closest living relative?

Session 10. Neurobiology
Neurons’ electrical activity results in the release of neurotransmitters that account for everything from survival to addiction to learning and memory. This session explains how neurons communicate to achieve all these functions.

Session 11. Biology of Sex and Gender
Several genes help determine what makes a human embryo develop female or male sexual anatomies. This session examines recent findings which have challenged previous beliefs about the roles of anatomy, environment, and genetics in the determination of gender, and the evolution of sexual determination.

Session 12. Biodiversity
With current extinction rates exceeding those of previous mass extinctions, many biodiversity studies focus on efforts to count the Earth’s species before they are lost. This session explores current field experiments studying complex ecosystems and how environmental and biodiversity changes might affect their functions.

Session 13. Genetically Modified Organisms
While genetic modification of organisms has occurred for millennia, we now have the tools to insert specific genes from one organism into cells of unrelated species. This session illustrates the processes used and how such genetically transformed organisms are increasingly common in agriculture, industry, and medicine, and introduces the ethical considerations of GMO research.

BIO Documentary (learner.org): -1999- An Introduction to Microbiology

The documentary below is available in streaming format only. First you need to go to www.learner.org and sign up for free. Then make sure you enable pop ups and click just on the links below.

Unseen Life on Earth: An Introduction to Microbiology
(1999) "Peer into the microbial world with this comprehensive microbiology series. This series helps students understand microbial functions and how microorganisms affect everything from medicine to environmental issues to global politics. Dynamic visuals — such as animations and scanning electron micrographs — and case studies including DNA testing and dramatic battles against dangerous viruses illustrate the work and effects of microorganisms. Students gain an enhanced appreciation of the field of microbiology as they meet scientists carrying on their investigations in the lab and in the field. Unseen Life on Earth is designed for general microbiology courses for majors and allied health students. It is also useful as a resource for life science courses in college and high school." (Produced by Oregon Public Broadcasting in association with Baker & Simon Associates and the American Society for Microbiology)

VOD1. The Microbial Universe
The world of microorganisms is a dynamic one, and all other life forms depend on microbial metabolic activity. Recent genetic research has uncovered only about one percent of the microbes that remain to be discovered.

VOD2. The Unity of Living Systems
All cellular organisms — prokaryotic and eukaryotic — share basic chemical similarities. Out of these similarities, however, emerge diverse patterns of cell assembly. Students encounter the tools to understand various cell types and their relationship to noncell entities such as viruses.

VOD3. Metabolism
The metabolic pathways that produce energy create important environmental transformations. Although living organisms have diverse ways of meeting their energy needs, there is an amazing similarity between all life forms as they carry out metabolism directed to the construction and use of necessary biological molecules.

VOD4. Reading the Code of Life
DNA is central to cell activity, replicating with great fidelity and carrying the information for all proteins. Organisms also regulate the products made from genes in an effort to conserve energy and adapt to new environments.

VOD5. Genetic Transfer
Microbial populations achieve genetic diversity through horizontal gene transfer. Bacteria may transfer genes from one to another by conjugation, transformation, or transduction. Scientists often exploit these processes through recombinant DNA.

VOD6. Microbial Evolution
Recent genetic techniques have led to new theories of evolution and the relationships between organisms. Students examine this "evolution revolution," using molecular sequences to trace the phylogenetic relationships of microbial life. Both the big picture of microbial evolution and the methods necessary for determining molecular phylogenies are examined.

VOD7. Microbial Diversity
What is the relationship between the bacteria, archaea, and eukaryote branches of the tree of life, with their startling variety of organisms? Students see comparisons of organisms in their natural habitats and examine ways of studying these organisms in those habitats and in the laboratory.

VOD8. Microbial Ecology
Humans and all life forms depend on microorganisms as the essential processors of oxygen, mineral nutrients for plant growth, and waste materials. Here we investigate some of the important environments dominated by microbes and how their presence is essential for human life.

VOD9. Microbial Control
In certain situations, microbial control is a necessity. For instance, our food system requires sanitary conditions and hospitals require sterilization techniques. Here we see the options available for various levels of microbial control.

VOD10. Microbial Interactions
There are many symbiotic relationships among microbes and between microbes and higher organisms. Microorganisms have developed mechanisms to defeat animals' defenses against disease. Examples of beneficial and harmful symbiotic relationships are examined here.

VOD11. Human Defenses
Both nonspecific and specific defense strategies can defeat the invasion of microbial pathogens. Students learn about the coordinated defense system of humans through visual analogy, animation, and examples of specific diseases.

VOD12. Microbes and Human Diseases
How microbes come into contact with humans, and the many factors leading to disease outbreaks around the globe, are examined here. Students learn about current efforts to track infectious diseases and the considerations necessary to control disease worldwide.

Microscopy University

Here's a great site that will teach you all about Microscopy. It goes over basic concepts, has flash tutorials, and great galleries of videos and images.

WIKI: Microscopy is the technical field of using microscopes to view samples or objects. There are three well-known branches of microscopy, optical, electron and scanning probe microscopy.

http://www.microscopyu.com/
http://www.microscopyu.com/articles/livecellimaging/

Here are some great videos from the site showing Live Cells!

Live-Cell Imaging: Cell Motility
Explore cell motility in differential interference contrast (DIC) microscopy.
Swept Field Confocal Digital Video Gallery
Live-cell imaging using high speed confocal microscopy and fluorescent proteins.
Confocal Microscopy Digital Video Gallery
Single and dual-color fluorescence imaging in laser scanning confocal microscopy.

Chemical Crystals
Time-lapse videos of chemicals as they change from solid to the liquid state.
Pond Life
Observe the activities of a wide variety of microscopic organisms captured in a typical North Florida pond. Included are nematodes, protozoans, annelids, crustaceans, dipterans, coelenterates, gastrotrichs, rotifers, and tardigrades.

NON-BIO SPECIFIC: Top 10 Universities With Free Courses Online

Thank Johnathan Cline for letting us know about this on DIYBIO@googlegroups.com. Below is a great list put together by Jimmy Ruska. Jimmy has a blog dedicated to listing free learning resources. You can link to his sites here: http://education.jimmyr.com/online_education.php
http://www.jimmyr.com/blog/0_Free_Education.php

I usually do the work for you and give you direct links or embed the videos right in the blog, but I haven't explored all these sites yet, so your just gonna have to dig for yourself this time! :)

#1 UC Berkeley
Ranked as the #1 public school in the United States, Berkeley offers podcasts and webcasts of amazing professors lecturing. Each course has an RSS feed so you can track each new lecture. For printable assignments and notes you can check the professors homepage, which is usually given in the first lecture or google his name. Even though the notes, homework and tests are not directly printed in the berkeley website, as they are in MIT and other courseware sites, it's not a problem to find them. I personally tried to use it for John Wawrzynek's machine structures class and the nutrition courses.

Visit: Berkeley Webcasts
Visit: Berkeley RSS Feeds
Visit: UC Berkeley on Google Video

#2 MIT Open Courseware
The Massachusetts Institute of Technology is ranked 7th nationally in the United States. Many of the courses do not have video lectures. Instead, they have notes in PDF format along with tests and homework.

Visit: MIT OpenCourseware Course Listings
Visit: MIT OpenCourseware Online Textbooks
Visit: MIT Courses With Video Lectures
Visit: MITWorld Public Videos
Visit: MIT Pocast: ZigZag

#3 Carnegie Mellon's Open Learning Initiative
Carnegie Mellon is a private research university ranked equal with Berkeley. Though registration is not required they have a registered user mode that allows you to keep track of your scores and progress. Currently 11 courses are offered. The courses are basically ebooks in a frame-based easy to use navigation system with an occasional powerful interactive Java Applet for practice and testing.

Visit: Carnegie Mellon OLI

#4 Utah State OpenCourseWare
Utah State has a very familiar structure as MIT OCW with large available course listing.

Visit: Utah State Course Listings

#5 Tufts OpenCourseWare
Tufts University in Massachusetts has a very familiar structure as MIT OCW with large available course listing.

Visit: Tufts Course Listings

#6 Openlearn
European site called Open University's OpenLearn supported by The William and Flora Hewlett Foundation. Contains many online course and a different style content management system. I was unable to find anything interactive or any streaming media, though it does have forums for each course. Appears to function mostly as a large educational ebook library.

Visit: OpenLearn

#7 JHSPH OCW
Johns Hopkins University Bloomberg School of Public Health offers health based lecture notes and assigments. You'll find the JHSPH OCW website uses the same familiar navigation structure as MIT OCW. The notes are formatted much more cleanly but I haven't seen exams, and their search bar seems to be broken.

Visit: JHSPH OCW Course Listings
Visit: Johns Hopkins University Podcasts

#8 Connexions
CNX.org is an open-content library of course materials developed by Rice University. It has a huge database of content which is very useful for people who know what they're looking for. It does have ebook style higher level courses courses you can choose from.

Visit: Connexions
Visit: Connexions Course List

#9 Sophia
Initiative is led by Foothill College which contains 8 free courses.

Visit: Sofia

#10 University of Washington Computer Science & Engineering
Contains posted lectures and classnotes. Some of the courses even contain video lectures.
http://www.cs.washington.edu/education/course-webs.html

Notre Dame OpenCourseware
http://ocw.nd.edu/

Wikiversity
From the creators of wikipedia, Wikiversity describes itself as being a community seeking to create and use learning materials and activities. Wikibooks is also incredibly powerful already containing everything from a detailed guide to learning French to Organic Chemistry and Nanotechnology.

Visit: Wikiversity
Visit: Wikibooks

Archive.org Education
Contains 1354 educational resources at the time of posting.

Visit: Archive.org Education

Honorable Mention: Peoi.org

Visit: Peoi.org

More University Video Sites
http://globetrotter.berkeley.edu/conversations/
http://graduateschool.paristech.org/?langue=EN
http://www.researchchannel.org/prog/
http://mitworld.mit.edu/
http://www.princeton.edu/WebMedia/lectures/
http://ci.columbia.edu/ci/
http://www.law.duke.edu/webcast/index.html
http://www.hno.harvard.edu/multimedia/video_mm.html
http://www.law.georgetown.edu/sci/sls.html#Presentations
http://athome.harvard.edu/archive/archive.asp
http://www.ksg.harvard.edu/multimedia/videoarchive.html
http://www.law.harvard.edu/news/webcasts/
http://webcast.oii.ox.ac.uk/?view=Default
http://www.princeton.edu/WebMedia/lectures/
http://www.gsb.stanford.edu/news/audiovideo.html
http://shc.stanford.edu/events/archive.htm
http://www.oid.ucla.edu/Webcast/
http://www.yale.edu/yale300/democracy/mediatranscripts.htm
http://yaleglobal.yale.edu/video.jsp

Rabu, 28 Januari 2009

Blast from the past

Don't forget there are all sorts of interesting posts here from last year. You can browse them using the labels but I'll also try to point out a few of my favorites as we go along. Here are some that are relevant to topics we have been discussing lately

Pedigree collapse and bicycles as dating technology (surely you are intrigued by that title?)
Microbial Genes in the Human Genome
Gene flow
Woof

CHEMGUY Returns to teach us ENTHUSIASTIC Organic Chemistry!

This guy did such a great job saving us from Moles that I thought I'd bring him back for a Full Organic Biology Course! Ok Chemguy, do your thing! And yes Chemguy I will order myself some "stickies and ballies!"

Back to Basics! Reviewing Units of Measure

Is all this talk of Kilojoules Per Mole leaving you perplexed? It's time to make sure we know all the units of measure. Here is a silly but informative youtube video to make sure your basic foundation is sound. Then check out the sections below for an overview of each type of measurement.

Ok. Now that that's out of the way. Onwards to Mole Land!

MOLES: THE AMOUNT OF SUBSTANCE
In five minutes you will not be confused about Moles ever again! Thank goodness! Thank you "Chemguy" for making the Mole Madness end!

WIKI: The amount of substance, n, of a sample or system is a physical quantity which is proportional to the number of elementary entities present.^[1] "Elementary entities" may be atoms, molecules, ions, electrons, or particles, the choice of which is dependent upon context and must be stated. Amount of substance is sometimes referred to as chemical amount or, incorrectly, as number of moles.^[2] Amount of substance is a quantity that measures the size of an ensemble of entities. It appears in thermodynamic relations such as the ideal gas law, and in stoichiometric relations between reacting molecules as in the law of multiple proportions. The SI unit for amount of substance is the mole (symbol: mol), which is defined as the amount of substance that has an equal number of elementary entities as there are atoms in 12 g of carbon-12.^[3] That number is equivalent to the Avogadro constant, N_A, which has a value^[4] of 6.02214179(30)×10²³ mol⁻¹. The only other unit of amount of substance in current use is the pound mole (symbol: lb-mol.), which is sometimes used in chemical engineering in the United States.^[5]^[6]

1 lb-mol. ≡ 453.592 37 mol (this relation is exact, from the definition of the international avoirdupois pound).

The Avogadro constant (symbols: L, N_A), also called Avogadro's number, is the number of "elementary entities" (usually atoms or molecules) in one mole, that is (from the definition of the mole), the number of atoms in exactly 12 grams of carbon-12.^[1]^[2] The 2006 CODATA6.02214179(30)×10²³ entities per mole.^[3] recommended value is

LENGTH

The image above is a micrograph of a (nanowire curled into a loop in front of a strand of human hair. The nanowires can be as slender as 50 nanometers in width, about one-thousandth the width of a hair. Credit: Limin Tong/Harvard University

WIKI: A nanometer, symbol nm, is a unit of length in the metric system, equal to one billionth of a metre (i.e., 10^-9 m or one millionth of a millimetre). It is one of the more often used units for very small lengths, and equals ten Ångström, an internationally recognized non-SI unit of length. It is often associated with the field of nanotechnology. It is also the most common unit used to describe the manufacturing technology used in the semiconductor industry. It is the most common unit to describe the wavelength of light, with visible light falling in the region of 400–700 nm. The data in compact discs is stored as indentations (known as pits) that are approximately 100. Formerly, millimicron (symbol mµ) was used for the nanometre. The symbol µµ has also been used ^[1]^[2]^[3].

FORCE
The newton (symbol: N) is the SI derived unit of force, named after Isaac Newton in recognition of his work on classical mechanics.The newton is the unit of force derived in the SI system; it is equal to the amount of force required to give a mass of one kilogram an acceleration of one meter per second squared. Algebraically:

${\rm 1~N = 1~\frac{kg\cdot m}{s^2}}.$ ^[1]

Examples:

1 N is the force of Earth's gravity on an object with a mass of about 102 g (¹⁄_9.8 kg) (such as a small apple).
On Earth's surface, a mass of 1 kg exerts a force of approximately 9.80665 N [down] (or 1 kgf). The approximation of 1 kg corresponding to 10 N is sometimes used as a rule of thumb in everyday life and in engineering.
The decanewton (daN) = 10 N is increasingly used when specifying load bearing capacity of items such as ropes and anti-vibration mounts because it is approximately equivalent to the more familiar non-SI unit of force, the kgf.
The force of Earth's gravity on a human being with a mass of 70 kg is approximately 687 N.
The dot product of force and distance is mechanical work. Thus, in SI units, a force of 1 N exerted over a distance of 1 m is 1 N·m of work. The Work-Energy Theorem states that the work done on a body is equal to the change in energy of the body. 1 N·m = 1 J (joule), the SI unit of energy.
It is common to see forces expressed in kilonewtons or kN, where 1 kN = 1 000 N.

ENERGY
WIKI: The joule is the derived unit of energy in the International System of Units. It is defined as:

$\, 1\, \mathrm{J}=1\, \mathrm{kg} \cdot \frac{\mathrm{m}^{2}}{\mathrm{s}^{2}}$

One joule is the amount of energy required to perform the following actions:

The work done by a force of one newton traveling through a distance of one meter;
The work required to move an electric charge of one coulomb through an electrical potential difference of one volt; or one coulomb volt, with the symbol C·V;
The work done to produce power of one watt continuously for one second; or one watt second (compare kilowatt hour), with the symbol W·s. Thus a kilowatt hour is 3,600,000 joules or 3.6 megajoules;
The kinetic energy of a 2 kg mass moving at a velocity of 1 m/s. The energy is linear in the mass but quadratic in the velocity, being given by E = ½mv²;

1 joule is exactly 10⁷ ergs.

1 joule is approximately equal to:

6.2415 ×10¹⁸ eV (electronvolts)
0.2390 cal (calorie) (small calories, lower case c)
2.3901 ×10⁻⁴ kilocalorie, Calories (food energy, upper case C)
9.4782 ×10⁻⁴ BTU (British thermal unit)
0.7376 ft·lbf (foot-pound force)
23.7 ft·pdl (foot poundals)
2.7778 ×10⁻⁷ kilowatt hour
2.7778 ×10⁻⁴ watt hour
9.8692 ×10⁻³ litre-atmosphere

Units defined in terms of the joule include:

1 thermochemical calorie = 4.184 J
1 International Table calorie = 4.1868 J
1 watt hour = 3600 J
1 kilowatt hour = 3.6 ×10⁶ J (or 3.6 MJ)
1 ton TNT exploding = 4.184 GJ

Useful to remember: 1 joule = 1 newton meter = 1 watt second

Practical examples. One joule in everyday life is approximately:

the energy required to lift a small apple one meter straight up.
the energy released when that same apple falls one meter to the ground.
the energy released as heat by a quiet person, every hundredth of a second.
the energy required to heat one gram of dry, cool air by 1 degree Celsius.
one hundredth of the energy a person can receive by drinking a drop of beer.
the kinetic energy of an adult human moving a distance of about a handspan every second.

PRESSURE
WIKI: The pascal (symbol: Pa) is the SI derived unit of pressure, stress, Young's modulus and tensile strength. It is a measure of perpendicular force per unit area i.e. equivalent to one newton per square meter or one joule per cubic metre. In everyday life, the pascal is perhaps best known from meteorological barometric pressure reports, where it occurs in the form of hectopascals (1 hPa = 100 Pa).^[1]. In other contexts, the kilopascal is more commonly used, for example on bicycle tire labels.^[2] One hectopascal corresponds to about 0.1% and one kilopascal to about 1% of atmospheric pressure (near sea level): one hectopascal is thus equivalent to a millibar; one atmosphere is equal to 1013.25 hPa. The pascal (Pa) or kilopascal (kPa) as a unit of pressure measurement is widely used throughout the world and largely replaces the pounds per square inch (psi) unit except in some countries still using the Imperial measurement system. Vehicle owners' guides now specify tire inflation in kilopascals.

1 pascal (Pa) ≡ 1 N/m² ≡ 1 J/m³ ≡ 1 kg/(m·s²)

And here's an online converter you can play around with: http://www.imperialtometric.com/conversion_en.htm

Selasa, 27 Januari 2009

Hear it direct from the source! Tommy Cech talks how he discovered the real role of RNA!

Who is Thomas Cech? Thomas Cech and Sidney Altman won the Nobel Prize in chemistry in 1989! These guys discovered that RNA in living cells is not only a molecule of heredity but also can function as a biocatalyst! They showed that RNA had an actual active role in the synthesis of proteins. This discovery, came as a complete shock to scientists at the time and really ticked off all the editors at the text book companies. :)

In the video below Dr. Thomas Cech dicusses RNA, its characteristics, and its ability to act as an enzyme. Enjoy!

If you'd like to see more of Dr. Cech you can watch his 1995 lecture here. Warning, this material is the latest and greatest from 1995 so take it with a historical grain of salt!

1995: The Double Life of RNA - Lecture (1 hour total)

hahahaha Campbell's primordial soup?

More TOM! I was going to stop here, but what the heck here's some more Tom Cech!

This lecture is called "RNA - Catalysts, Chemical and Biochemical" once again 1995. Remember parts of this might no longer be true! Check out that 95' era sweater with the white turtle neck! hahaha I was guilty of that!

In this last video Tom gives a great reasoning for why nature placed DNA in a double helix rather than in a single strand like RNA.

From Shore to Sea Lecture Series

The Santa Barbara Maritime Museum in conjunction with the Channel Islands Marine Sanctuary and the Channel Islands National Park Service, hosts the From Shore to Sea Lecture Series, FREE to the public based on scientific and historical topics and issues related to our own Channel Islands. Tuesdays at 7pm at the Santa Barbara Maritime Museum, 113 Harbor Way, Santa Barbara.

Jan. 13 Film Presentation: Air: The Search for One Clean Breath
Barbara Page, Ventura County Air Pollution Control District

Feb. 10 Pelagic & Water Column Fishes of the Santa Barbara Channel
Milton Love, Marine Science Institute, University of California Santa Barbara

Mar. 10 Evaluating Food Web Dynamics as Indicators of Ecosystem Health across the Northern Channel Islands
Anne Salomon, Marine Science Institute, University of California Santa Barbara

Apr. 14 Prisoners Wetland Restoration Project
Paula Power, Channel Islands National Park

May 12 SPLASH - Update on Blue and Humpback Whale Pacific NE Populations
John Calambokidis, Cascadia Research Collective

June 9 CINMS Maritime Heritage Program and Shipwreck Reconnaissance
Robert Schwemmer, Channel Islands National Marine Sanctuary & Kelly Minas, Channel Islands National Park

More TED Inspiration: Going from Digital to DNA

Oh Goody! Yay for the future! Here are some videos from Craig Venter.

In 2001, Craig Venter made headlines for sequencing the human genome. In 2003, he started mapping the ocean's biodiversity. Now he's working to create the first synthetic lifeforms -- microorganisms that can produce alternative fuels. And he's very, very close.

After a 30 Hour intense India BIO cram session...

You need a reward. You need some Big Picture TED talk inspiration! Here's Juan Enriquez. He talks about Decoding the future with genomics. Juan is the founding director of the Harvard Business School Life Sciences Project and has published widely on topics from the technical (global nucleotide data flow) to the sociological (gene research and national competitiveness), and was a member of Celera Genomics founder Craig Venter's marine-based team to collect genetic data from the world's oceans. He is chair and CEO of Biotechonomy, a research and investment firm helping to fund new genomics firms. The Untied States of America, his latest book, looks at the forces threatening America's future as a unified country.

LEARN FROM INDIA!

Ok, these videos are a little hard to understand and it's not the best quality, but they go over a great wealth of information in a very thorough textbook style way. The introductions of each movie are a little too long so you might want to fast forward. But, thank you Prof. S. Dasgupta at the Dept of Chemistry at IIT in Kharagpur!! Guy and Girls, I know this is going to be hard to get through, (it's around 30 hours) but march through it. Pretend its the greatest secret ever been told. It is! We are peering through the rabbit hole fellas. Keep reminding yourself of that. Before we can work with nature, we need to really get to know nature, hang out her, and become best buddies. Now psyche yourself up, forgive prof. Dasgupta's hard to understand English accent, and watch all these movies!

Lecture - 1 Amino Acids I