New Gene Found That Helps Plants Beat The Heat
NeScienceDaily (Oct. 14, 2008) — Michigan State University plant scientists have discovered another piece of the genetic puzzle that controls how plants respond to high temperatures. That may allow plant breeders to create new varieties of crops that flourish in warmer, drier climatesw Gene Found That Helps Plants Beat The Heat.
The MSU researchers found that the gene bZIP28 helps regulate heat stress response in Arabidopsis thaliana, a member of the mustard family used as a model plant for genetic studies. This is the first time bZIP28 has been shown to play a role heat tolerance. The research is published in the Oct. 6 issue of the Proceedings of the National Academy of Sciences.
"We also found that bZIP28 was responding to signals from the endoplasmic reticulum, which is the first time the ER has been shown to be involved with the response to heat," said Robert Larkin, MSU assistant professor of biochemistry and molecular biology and corresponding author of the paper. "We're finding that heat tolerance is a more complex process than was first thought."
Previous research has shown that the nucleus, the "brain" of the cell, and cytosol, the fluid inside cells, play a role in how plants respond to heat. The endoplasmic reticulum, a membrane in the cell that consists of small tubes and sac-like structures, is mainly responsible for packaging and storing proteins in the cell.
According to Christoph Benning, MSU professor of biochemistry and molecular biology and a member of the research team, the scientists were looking for genes that turn other genes on and off and are tied to cell membranes. These membrane-tethered gene switches are seen in animals but hadn't been studied in great detail in plants.
"The bZIP28 protein is anchored in the endoplasmic reticulum, away from its place of action," Benning explained. "But when the plant is stressed by heat, one end of bZIP28 is cut off and moves into the nucleus of the cell where it can turn on other genes to control the heat response. Understanding how the whole mechanism works will be the subject of more research."
Plants with an inactive bZIP28 gene die as soon as temperatures reach a certain level.
Other scientists on the research team are Federica Brandizzi, MSU associate professor of plant biology and member of the Plant Research Lab, and Hangbo Gao, former MSU post-doctoral research associate.
The work was sponsored by the MSU-DOE Plant Research Lab. Benning's research also is supported by the Michigan Agricultural Experiment Station.
Scientists Trigger Cancer-like Response From Embryonic Stem Cells
ScienceDaily (Oct. 13, 2008) — Scientists from The Forsyth Institute, working with collaborators at Tufts and Tuebingen Universities, have discovered a new control over embryonic stem cells' behavior. The researchers disrupted a natural bioelectrical mechanism within frog embryonic stem cells and trigged a cancer-like response, including increased cell growth, change in cell shape, and invasion of the major body organs. This research shows that electrical signals are a powerful control mechanism that can be used to modulate cell behavior.
The team of Forsyth Institute scientists, led by Michael Levin, Ph.D., Director of the Forsyth Center for Regenerative and Developmental Biology, have identified a new function for a potassium (KCNQ1) channel, mutations of which are known to be involved in human genetic diseases such as Romano-Ward and Jervell-Lange-Nielsen syndromes. The team interrupted the flow of potassium through KCNQ1 in parts of the Xenopus frog embryo. This resulted in a striking alteration of the behavior of one type of embryonic stem cell: the pigment cell lineage of the neural crest. When mutated, these pigment cells over-proliferate, spread out, and become highly invasive of blood vessels, liver, heart, and neural tube, leading to a deeply hyper-pigmented tadpole.
The body's natural biophysical signals, driven by ion transporter proteins and resulting in endogenous voltage gradients and electric fields, have been implicated in embryonic development and regeneration. The data in this study, which will be published in the Proceedings of the National Academy of Sciences on October 13, 2008, have not only elucidated a novel role for the KCNQ1 channel in regulating key cell behaviors, but for the first time have also revealed the molecular identity of a biophysical switch by means of which neoplastic-like properties can be conferred upon a specific embryonic stem cell sub-population. These data reveal that key properties of embryonic stem cells can be controlled through bioelectrical signals, identify transmembrane voltage potential as a novel regulator of neural crest function in embryonic development, and demonstrate that potassium flows can be an important aspect of cellular environment, which is known to regulate both cancer and stem cells.
"In regenerative medicine, a key goal is to control the number, position, and type of cells," said the paper's first author, Junji Morokuma, Ph.D. "This research is especially exciting because it shows the importance of electrical signals for changing cell behavior, identifies a new role in developmental and cell biology for the KCNQ1 ion channel, and strengthens the link between stem cells and tumor cells. Added Doug Blackiston, Ph.D., paper co-author, "In the future, this work may lead to a greater understanding of the causes of cancer and ways to potentially halt its metastasis, as well as suggesting new techniques by which stem cells may be controlled in biomedical applications."
Michael Levin, Ph.D., is a Senior Member of the Staff in The Forsyth Institute and the Director of the Forsyth Center for Regenerative and Developmental Biology. Through experimental approaches and mathematical modeling, Dr. Levin and his group examine the processes governing large-scale pattern formation and biological information storage during animal embryogenesis. The lab investigates mechanisms of signaling between cells and tissues that allow a living system to reliably generate and maintain a complex morphology. The Levin team studies these processes in the context of embryonic development and regeneration, with a particular focus on the biophysics of cell behavior.
This work was supported by grants from The National Institutes of Health, The American Heart Association, The National Highway Traffic Safety Administration and the March of Dimes
i got this article from Mrs.S.M
when you are working in the field of biotechnology you need to deal with several systems such as fementor,distillation tower,incubator,autoclave ,and so on.
in this regard i towering figure which always warn you is the amount of energy fed to system and the energy coming out of your system as well. and here you may take care of the beneficiary of the energy.
In this post the i want to go though this hypothesis that says: the input heat to a system has always a certain amount of losses .And meanwhile i will generally describe how the heat loss amount from a system can be calculated.
So consider a distillation tower .how to determine the heat losses from a distillation tower?
A distillation tower (Distillation column) is a collection of equipment which provides us a high concentration of liquid from a low concentration liquid by heating the liquid mixture .in the other word, Distillation is the procedure of separating a certain liquids from a liquid mixture base of differences in their tendency to vaporize (Volatility).in the distillation process we have not any chemical reaction and actually the separation of liquids will be done physically.
In a typical distillation tower we have:
A tank: it is containing the mixture which is going to be separated (in our case containing Ethanol and water
Fractionating column: comprising platforms, known as trays, which refluxing distillate inside the column, and runs back down into the liquid below.
Boiler: the boiler is producing steam this steam provides the necessary heat to boil the liquid . In this case the steam coming from boiler comes through a hose, and divides to two paths:
One line of the Steam heats the ethanol coming from tank
another line of steam heats the reflux liquid mixture draining from fractionating column. The role of this steam is like a motor for distillation tower
A temperature menu: that shows the temperature of different parts of distillation tower
.
Control panel: to switch the tower On and shut it down and also adjust the effective elements.
Valves, Pumps, hoses, pipes, Pressure and temperature gauges.
In this system the low concentration ethanol comes from the tank and get warm by
steam which is produced by boiler .but we should note that the steam has no direct contact with ethanol and only by heat conduction through the glass the heat transfer will be done.
The liquid ethanol will evaporate and starts to go up the column .we have 10 trays in
the column. Vapour goes up and condensed ethanol (liquid) steps down (drop down). Here we have exchange between liquid phases and vapour phase. Ethanol concentration in the vapour is higher in the higher trays.
On the top of the column there is a condenser that condenses the ethanol that is now pure.
There are five places which you should take the samples:
Distillate D
Feed F
Waste W
Steam From Boiler
Cooling Water
In order to calculate the heat loss, you should use the Heat Balance formula:
IN=OUT
And it means that the heat entered to the system should be equal to the heat coming out of the system.
Now we should start to calculate the Energy flow for each five samples.
after defining the energy flow for each sample you should put them in the main energy balance equation then you can obtain the energy which you have lost from your system