The study of the cell cycle focuses on mechanisms that regulate the timing and frequency of DNA duplication and cell division. As a biological concept, the cell cycle is defined as the period between successive divisions of a cell. During this period, the contents of the cell must be accurately replicated. Microscopists had known about cell division for more than one hundred years, but not until the 1950s, through the pioneering work of Alma Howard and Stephen Pelc, did they become aware that DNA replication took place only at a specific phase of the cell cycle and that this phase was clearly separated from mitosis. Howard and Pelc's work in the broad bean, Vicia faba, revealed that the cell goes through many discrete phases before and after cell division. From this understanding, scientists then identified the four characteristic phases of the cell cycle: mitosis (M), gap 1 (G1), DNA synthesis (S), and gap 2 (G2). The study of these phases, the proteins that regulate them, and the complex biochemical interactions that stop or start DNA replication and cell division (cytokinesis) are the primary concerns of cell cycle biologists.
The most significant progress in this research field came with the demonstration that specific protein complexes involving cyclins were critical for regulating the passage of cells through the cell cycle. These early observations came from biological studies of the cells of rapidly dividing fertilized frog eggs as well as mutant yeast cells that could not divide. The observations suggested that regulation of the cell cycle is conserved throughout eukaryotes, which has since proved to be the case. The mechanism of division in bacteria differs from that of eukaryotes, and the control of their cell cycle is also somewhat different, although again it is linked with DNA replication.
Although the cell cycle is a highly integrated process, distinct areas of interest within this field of study have emerged. For instance, many genes and proteins that influence the passage from one phase of the cell cycle to another have been identified. When their expression is altered by mutation or aberrant regulation, they are usually classed as oncogenes. Other proteins act to hold the cell at distinct points in the cycle (checkpoints) and are known as tumor suppressor genes. Apart from those with a clearly regulatory role, many proteins have important functions in other aspects of the cell cycle; one is replication of DNA and organelles, which is a fascinating process that includes its own repair mechanisms and self-editing. Other fields focus primarily on themechanical processes of cell cleavage into two daughter cells at the end of mitosis and on the condensation and decondensation of chromatin.
How does the cell cycle affect our daily lives? Indeed, most cancers are the result of inappropriate cell division, often stemming from aberrations in normal cell cycle regulation. Considerable research is directed to identifying alterations in cell cycle regulatory proteins, both as targets for therapeutic intervention and as biomarkers that may indicate prognoses for tumors. In addition, the field of stem cell biology is closely linked to cell cycle regulation because these pluripotent cells can divide slowly over long periods and yet initiate growth and differentiation when required. Other areas of current research include investigating cell cycle regulation in the growth of organs and in regeneration, where dormant cells can be switched back into a replicative state.
How have scientists studied the cell cycle? Originally, cell cycle studies were the preserve of microscopy, but today many specific techniques in addition to those widely employed in cell and molecular biology are applied. Fluorescence-activated cell sorting has allowed biologists to both identify cells at particular points of the cell cycle and isolate them. It is possible to monitor how cells that have been exposed to different agents can progress through the cycle. Central to the identification and isolation of key genes has been the ability to isolate temperature-sensitive mutant yeast cells that can be blocked at certain stages of the cycle for closer study. The ability to synchronize cultures so that all cells are at the same point in the cell cycle has also been a boon to capturing a glimpse of common mechanisms and isolating key proteins.
Although we now know much about the regulation of the cell cycle, it is clear that we have a long way to go, particularly in understanding the complexity of the interactions between the vast multitude of proteins already identified. Current research has identified a large number of signaling pathways, many comprising several genes, involved in regulating progression through the cycle. Several of these pathways can interact, and knowledge of these interactions will be vital to developing effective strategies for intervention in cancer and other growth abnormalities, such as developmental deformities. In addition, how the cell cycle responds to DNA damage is an area of active research because random aberrations in replication and even environmental toxins can affect vulnerable DNA strands. Ultimately, the success of stem cell-based therapies will depend on a detailed knowledge of how cells can be maintained through many divisions without losing their potential to differentiate or transform into tumor precursors. The study of the cell cycle has vast relevance to the health, well-being, and biology of all organisms, from the growth and development of these organisms, to cancer and aging humans, to the potential for disease and injury repair via stem cell therapies.
Een online cursus via GooglePlus hangouts en Moodle.
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the newest course offering is “CQX 003: Galaxies and Galaxy Clusters”. Just like the previous course offering, CQX003 is an 8-session, 4-week course, which will explore galaxies, galaxy clusters, and brief introduction to cosmology....."
A talk John Resig gave at EmpireJS 2012 on the new Khan Academy Computer Science platform. John Resig is the inventor of jQuery and has written several Javascript books. He is now in charge of Computer Science at Khan Academy.
Whether you are looking for a master’s degree program, computer science classes, a K-12 curriculum, or GED study program, this list gives you50 Top Sources Of Free eLearning Courses -
In the fall of 2011 Peter Norvig taught a class with Sebastian Thrun on artificial intelligence at Stanford attended by 175 students in situ -- and over 100,000 via an interactive webcast. He shares what he learned about teaching to a global classroom.
Lectures are in Playlists and are alphabetically sorted with thumbnail pictures. No fee, no registration required - learn at your own pace. Certificates can be arranged with presenting universities.
Start: October 2012 (6 weeks long) Workload: 3-5 hours/week Medicine Health and Society & Medical Ethics
This course will explore the process of evaluating investigational vaccines in clinical trials including informed consent, recruitment, enrollment, safety evaluation, and quality data collection.
Vaccines are evaluated through a series of clearly defined controlled studies to assess these investigational products for safety, immunogenicity and efficacy before they are approved for licensure. All clinical vaccine trials are bound by international ethical guidelines and, in the case of US trials, Food and Drug Administration (FDA) regulations.
Good Clinical Practice is defined by the International Conferences on Harmonization (ICH) as: “A standard for the design, conduct, performance, monitoring, auditing, recording, analysis, and reporting of clinical trials that provides assurance that the data and reported results are credible and accurate, and that the rights, integrity and confidentiality of trial subjects are protected.”
That’s a tall order, so how is it done? Individuals who enroll as subjects in these trials play an essential role in the development and evaluation of new and improved candidate vaccines. They are average citizens who volunteer to roll up their sleeves and, in the process, make a tremendous difference in society. So why do they volunteer and what safeguards do we put in place to protect their rights, safety and well-being while in the trial? What are the responsibilities of the investigators, sponsors and ethics committees who conduct and oversee these trials?
Along with our colleagues, we will introduce you to how GCP is applied in clinical vaccine trials to ensure proper and ethical scientific conduct. The course will use examples from real vaccine trials to demonstrate the application of the FDA Code of Federal Regulations and ICH GCP Guidelines to explore methods and best practices involved in implementing phase I and II vaccine clinical trials. This short course offering through Coursera is based on our work at the Center for Immunization Research and an in-depth graduate course taught at the Johns Hopkins Bloomberg School of Public Health.
Start: 26 November 2012 (12 weeks long) Workload: 5-6 hours/week Humanities and Social Sciences
Reasoning is important. This course will teach you how to do it well. You will learn how to understand and assess arguments by other people and how to construct good arguments of your own about whatever matters to you.
This course will teach you how to do it well. You will learn some simple but vital rules to follow in thinking about any topic at all and some common and tempting mistakes to avoid in reasoning. We will discuss how to identify, analyze, and evaluate arguments by other people (including politicians, used car salesmen, and teachers) and how to construct arguments of your own in order to help you decide what to believe or what to do. These skills will be useful in dealing with whatever matters most to you.
This is a survey of modern world history, from a global perspective, beginning with the economic and political revolutions of the late 18th century and ending with contemporary conditions.
This course can be essential to students in many fields. A global perspective is indispensable. It is impossible to provide adequate answers to a lot of the big questions about modern history – questions about economic conditions, remarkable beliefs, novel institutions, or terrible wars – without tracing interactions that span regions across the world.
This is a ‘big picture’ course that also uses a ‘zoom lens,’ to bring some places and lives into close-up focus. No formal previous training is required, though you may find yourself reaching for an encyclopedia to recall unfamiliar places and peoples. No matter what background knowledge you bring, this course will force you to reach further. You have to tackle culture, politics, warfare, anthropology, plenty of economics – and that’s just a start. Welcome to the modern world!
Machine Learning is a foundational discipline that forms the basis of much modern data analysis. It combines theory from areas as diverse as Statistics, Mathematics, Engineering, and Information Technology with many practical and relevant real life applications. The focus of the current summer school is big data analytics, distributed inference, scalable algorithms, and applications to the digital economy. The event is targeted at research students, IT professionals, and academics from all over the world.
This school is suitable for all levels, both for researchers without previous knowledge in Machine Learning, and those wishing to broaden their expertise in this area. That said, some background will prove useful. For a research student, the summer school provides a unique, high-quality, and intensive period of study. It is ideally suited for students currently pursuing, or intending to pursue, research in Machine Learning or related fields. Limited scholarships are available for students to cover accommodation, registration costs, and partial travel expenses.
Start: September 2012 (8 weeks long) Workload: 5-7 hours/week (8-10 if completing additional programming exercises) Information, Technology, and Design Computer Science: Artificial Intelligence, Robotics, Vision
This course will use social network analysis, both its theory and computational tools, to make sense of the social and information networks that have been fueled and rendered accessible by the internet.
Everything is connected: people, information, events and places, all the more so with the advent of online social media. A practical way of making sense of the tangle of connections is to analyze them as networks. In this course you will learn about the structure and evolution of networks, drawing on knowledge from disciplines as diverse as sociology, mathematics, computer science, economics, and physics. Online interactive demonstrations and hands-on analysis of real-world data sets will focus on a range of tasks: from identifying important nodes in the network, to detecting communities, to tracing information diffusion and opinion formation.
Ninety-five percent of the present mass-energy density of the Universe is dark. Twenty-five percent is in the form of dark matter holding together galaxies and other large scale structures, and 70% is in the form of dark energy driving an accelerated expansion of the universe. Dark matter and dark energy cannot be explained within the standard model of particle physics. In the first lecture I will review the evidence for dark matter and the observations that point to an explanation in the form of cold dark matter. I will then describe the expected properties of a hypothetical Weakly-Interacting Massive Particle, or WIMP, and review experimental and observational approaches to test the hypothesis. Finally, I will discuss how the LHC might shed light on the problem. In the second lecture I will review the theoretical foundations and observational evidence that the dominant component of the present mass density of the Universe has a negative pressure, which leads to an accelerated expansion of the Universe. I will then describe various approaches to understand the phenomenon. Finally, I will describe an observational program to understand the nature of dark energy. The third lecture will describe the issues and models associated with primordial inflation, the purported rapid expansion of the universe in the first fraction of a second after the bang. Models of inflation also involve beyond the standard model physics. The lecture will describe how present observations can shed light on events that occurred in the first second of the life of the universe.
Free video course on Foundations of Modern Physics by Leonard Susskind of Stanford. This Stanford Continuing Studies course is a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics.
This Stanford Continuing Studies course is a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics. The topics covered in this course focus on classical mechanics, quantum mechanics, the general and special theories of relativity, electromagnatism, cosmology, black holes and statistical mechanics. While these courses build upon one another, each section of the course also stands on its own, and both individually and collectively they will allow the students to attain the "theoretical minnimum" for thinking intelligently about physics. Quantum theory governs the universe at its most basic level. In the first half of the 20th century physics was turned on its head by the radical discoveriies of Max Planck, Albert Einstein, Niels Bohr, Werner Heisenberg, and Erwin Schroedinger. An entire new logical and mathematical foundation - quantum mechanics - eventually replaced classical physics. This course explores the quantum world, including the particle theory of light, the Heisenberg Uncertainty Principle, and the Schroedinger Equation. The course is taught by Leonard Susskind, the Felix Bloch Professor of Physics at Stanford University.
Here is a comprehensive listing of all lectures from Dr. Susskind:
Sensing the excitement from online education tools like edX, Google has just unveiled a (very beta) version of its own course building software. If you’ve ever wanted to run your own online courses, this might be worth your time.
Stanford Mini Med School begins with a journey inside human biology. Starting with a close look at DNA, stem cells and microbes, this quarter moves out from the building blocks of the human body to take a more global view of human health, pandemics and the delivery of health care.
The Abdus Salam International Centre for Theoretical Physics - There are 9934 recorded hours of Physics and Mathematics Lectures available.
Lectures given within the ICTP Postgraduate Diploma Programme are being automatically recorded (see Academic Years: 2007/2008, 2008/2009, 2009/2010, current: 2010/2011), using the EyA technology developed by the ICTP Science Dissemination Unit. The access to this digital material is made here available to the public.
This project aims to enhance ICTP's mandate of transferring knowledge to scientists from developing countries. It is our hope that these public recordings will be useful for students as well as lecturers beginning their teaching careers in science.
Start: 25 June 2012 (4 - 5 weeks long) Workload: 2 hours/week Medicine, Health and Society & Medical Ethics
This course will discuss issues regarding vaccines and vaccine safety: the history, science, benefits, and risks of vaccines, together with the controversies surrounding vaccines and answers to common questions that parents have about vaccines.
This course will discuss issues regarding vaccines and vaccine safety. Specifically, 1) the history of vaccines, focusing on different strategies used during the past two centuries to make them, 2) the science of vaccines, focusing on methods of attenuation of various viruses and bacteria, 3) the benefits of vaccines, focusing on the impact of vaccines on health both in the United States and abroad, 4) the risks of vaccines, both real and perceived, 5) the controversies surrounding vaccines, specifically that vaccines cause autism, multiple sclerosis, neurodevelopmental delays, diabetes or other chronic problems, and 6) answers to common questions that parents have about vaccines, such as the fear that too many vaccines given too soon weaken, overwhelm, or perturb the immune system or that vaccines contain harmful additives or manufacturing residuals.
How do we design these complex VLSI chips? Answer: CAD software tools. Learn how to build these tools in this class.
A modern VLSI chip is a remarkably complex beast: billions of transistors, millions of logic gates deployed for computation and control, big blocks of memory, embedded blocks of pre-designed functions designed by third parties (called “intellectual property” or IP blocks). How do people manage to design these complicated chips? Answer: a sequence of computer aided design (CAD) tools takes an abstract description of the chip, and refines it step-wise to a final design. This class focuses on the major design tools used in the creation of an Application Specific Integrated Circuit (ASIC) or System on Chip (SoC) design. Our focus is on the key representations that make it possible to synthesize, and to verify, these designs, as they move from logic to layout.
Our goal is for students to understand how the tools themselves work, at the level of their fundamental algorithms and data structures. You should be taking this course if (1) you are interested in building VLSI design tools; (2) you are interested in designing VLSI chips, and you want to know why the tools do what they do; (3) you just like cool algorithms, that work on big cool problems that involve bits, and gates, and geometry, and graphs, and matrices, and time, and...
Start: TBA (6 weeks long) Workload: 5-7 hours/week Health and Society & Medical Ethics
Learn about how social factors that promote mental health can influence the onset and course of mental illness, and how mental illnesses are diagnosed and treated.
Mental health and mental illness used to be something that people didn’t talk about, but now it seems every time we open a newspaper we are hearing about the importance of mental health, or the consequences of mental illness. At this point in our history we understand mental illness and mental health to be largely influenced by biological factors, specifically, workings of the brain. At the same time, we have always known that social factors play a very strong role in promoting mental health and can make big differences in who gets mentally ill, who gets treated for mental illness, and how people can achieve good quality of life after a mental health diagnosis.
This course is an opportunity to explore how social practices and ideas contribute to the ways in which society, families and individuals are affected by mental health and mental illness. We will look at issues like why some people think mental illness is a myth, how people think about mental health and illness in different cultures, who gets mentally ill and why, how families are affected by mental illness and what interventions are available to treat mental illness and promote mental health.
Start: 3 September 2012 (6 weeks long) Workload: 4-6 hours/week Statistics, Data Analysis, and Scientific Computing
Statistics One is designed to be a friendly introduction to very simple, very basic, fundamental concepts in statistics.
Statistics One is designed to be a friendly introduction to very simple, very basic, fundamental concepts in statistics. This course is, quite literally, for everyone. If you think you can't learn statistics, this course is for you. If you had a statistics course before but feel like you need a refresher, this course is for you. Statistics One also provides an introduction to the R programming language. All the examples and assignments will involve writing code in R and interpreting R output. R software is free! It is also an open source programming language. What this means is you can download R, take this course, and start programming in R after just a few lectures. Statistics may seem like a foreign language, and in many ways it is. The ultimate goal of Statistics One is to get people all over the world to speak this language. So consider this your first course in a new and exciting universal language!
This course teaches the engineering fundamentals for long-lived software using the highly-productive Agile development method for Software as a Service (SaaS) using Ruby on Rails.
This course teaches fundamental processes of software engineering using the highly-productive Agile development method for Software as a Service (SaaS) using Ruby on Rails. This is not a "web programming" course: the emphasis is on learning the processes, tools and concepts, using SaaS as the vehicle. We chose SaaS and Rails because we believe the best tools for teaching these concepts are those in the Rails ecosystem. We will spend the first 2 weeks laying some foundations in terms of the Ruby language and important SaaS architectural concepts, then move into Agile development using Rails.
Agile developers continuously refine and refactor a working but incomplete prototype until the customer is happy with result, with the customer offering continuous feedback. Agile emphasizes user stories to validate customer requirements; test-driven development to reduce mistakes; biweekly iterations of new software releases; and velocity to measure progress. We will introduce all these elements of the Agile development cycle, and go through one iteration by adding features to a simple app and deploying it on the cloud using tools like Github, Cucumber, RSpec, SimpleCov, Pivotal Tracker, and Heroku.
This course is based on the first five weeks of a University of California at Berkeley course for senior computer science majors. We plan to offer the second five weeks of the course in late October/ early November.
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This is very interesting for me. I mean how can something so small to the naked eye, play such an important role in one's life?