CHICAGO – Scientists have come up with a new way to watch bacteria as they swim, which is expected to eventually help trap Escherichia coli bacteria and modify the microbes’ environment without hindering the way they move.
The new approach uses optical traps, microfluidic chambers and fluorescence to get an improved picture of how E. coli get around.
YannChemla, a professor of Physics at the University of Illinois, says that the microfluidic chambers provide a controlled environment in which the bacteria swim, and allow them to introduce specific stimuli – such as chemical attractants – to see if the microbes change direction in response to that stimulus.
Chemla, who jointly led the study with physics professor IdoGolding, further says that optical traps use lasers to confine individual cells without impeding their rotation or the movement of their flagella.
The researcher calls the optical traps “bacterial treadmills”.
According to the researchers, movement of the bacterial cell alters the light from the laser, and, thereby, help track its behaviour.
Fluorescent markers enhance visualization of the bacteria and their flagella under a microscope, say the researchers.
While earlier studies have been unable to follow individual bacterial cells moving in three dimensions for more than about 30 seconds, the new approach allows the researchers to track a single bacterium as it swims for up to an hour, and that is why it may offer a new look at questions that so far have been unanswerable.
“For example, some people have asked whether E. coli has a nose. Does it have a front and back?” Nature magazine quoted Golding as saying.
He and his colleagues have observed that while the bacterium can travel in either direction, most E.coli have “a pronounced preference” for one over the other.
The researchers found that after most tumbles, a bacterium usually continued swimming in the same general direction, but that about one in six tumbles caused it to change direction completely.
They were also able to quantify other features of bacterial swimming, such as changes in velocity and the time spent running and tumbling.
They hope that their novel method will allow scientists to address many more questions about this model organism.
“That’s the typical way biology moves forward. You develop a new measurement capability and then you can use that to go back and look at fundamental questions that people had been looking at but had no way of answering,” Golding said.
A research article describing the new technique has been published in the journal Nature Methods.
She seemed so in charge of her balanced life. So I asked my student, this longtime, top producer, exactly how she managed to juggle so much and so well. Her response was the same I’ve heard repeatedly from achievers over the years, “I learned how to really concentrate.” When the vision is clear, braking down specific goals or tasks becomes easier. The ability to concentrate on single issues at a time becomes do-able and the success process becomes easier to control and duplicate.
The basic theme you hear from pro athletes at the peak of their game is the same you hear from great parents, teachers, students, scientists, realtors, doctors, communicators etc. They share a view that it is never the glitches, setbacks, disappointments that hold a person back, but rather the message the person assigns to those events or to any distractions. Stuff happens. How we choose to view and respond to these happenings determines whether we move away from or toward our personal power.
Many don’t feel they run their life. They feel their life runs them. They use others’ actions and opinions as well as their own experiences as excuses for what they choose to do. It’s like using an out-of-town guest as an excuse to do no work, as if the guest is pointing a gun and saying, “Take care of me every moment or I’ll shoot.” Or, we see external changes over which we have no control, like an interest rate change, and suddenly some find the way they sleep, communicate, project the future, view their colleagues or even their family, changes too. We’ve all been cut off in traffic. The driver who did the cutting, whether intentional or inadvertent, drives off focused on his destination. But how often have we, the ones cut off, invited that long gone, other driver to live, rent-free in our head? Learning to “let go” is not a just some random concept. Letting gois a way of coping with our distractions and disappointments in a healthy, productive way.
Letting go is about focusing elsewhere, by conscious choice. We don’t let go by saying, “I don’t want to think about it.” That’s like highlighting with a yellow marker the very thought we want to avoid. Imagine a teacher directing, “OK class… don’t think of a purple elephant…. large orange ears flapping in the breeze.” What did you see.. even if you tried to “let go” of it? Yet, there is a way to let go and it’s simple. We simply turn our attention to something else and keep placing our mind exactly where we want it to be until the mind gets the message. The mind learns by our repetition that we’re serious and in control of the DIRECTION of our attention. Imagine allowing all distractions and challenges to do only one thing: to serve as a reminder to focus and concentrate on those ideas and things about which we CAN do something, and towards those things that have value for own highest, most exciting, magnificent, “worth-it” goals.
And the great news is – this chosen FOCUS and CONCENTRATION is a way of responding and behaving that can be practiced and learned.
Here are a few simple tools to “get ‘er done:”
1. DO the SESSIONS. One way to establish excellence in focus and concentration is to practice the relaxation and self-hypnosis sessions I teach in seminars.
When you relax your mind (relaxing your body is great, but relaxing your mind is the key to excellence), many distractions may pull at you. As you keep bringing your mind back to your chosen focus (positive affirmations, imagery), like a puppy gets the message when you gently and consistently repeat, your mind gets the message and learns. Do these training sessions with yourself and just like muscles in the body, your mind gets stronger and more disciplined. Practice directing your mind to those acts and abilities you want, for example reading fast with perfect comprehension, giving clear presentations that are on target, being inspired by rejection or intimidating tactics of others, prospecting with confidence, experiencing memory that accesses with ease the images and details that serve, playing fluid, powerful, golf, being relaxed and confident taking tests, etc. Being “present” or “in the moment” are not just phrases. Like letting go, they are skills which can be learned and perfected for a better way of performing.
2. ASK YOURSELF the MILLION DOLLAR QUESTION. Another way of practicing the development of focus and concentration is to, throughout the day, ask yourself “Is what I am doing the most beneficial thing I could be doing, right NOW?”
Write this question on a 3×5 card and carry it with you for a couple of weeks to ingrain the sense of control you really do have over your time and energy. Don’t wait to be moved by this little reminder. If the answer is “Yes,” continue doing what you’re doing. If the answer is “No,” pay attention and take action that moves you NOW to your best use of your focused attention and resources of time, energy. The beginning of any process of change may be erratic and uncomfortable. It is also totally worthwhile. Look at the people who you think “have it together” and you may not necessarily find the most gifted or brilliant, but you will likely find those who choose to “shift gears” smoothly and be totally present. Copy success. Copy their best attributes.
3. CELEBRATE VICTORIES. Think about it: Confidence in this area of developing focus, like confidence about anything else doesn’t necessarily come from belief or faith, it comes from creating victories which we acknowledge. Start from wherever you are and show yourself what you CAN do. When you do something well, avoid the trap of thinking “It’s no big deal.” Acknowledge successes, little or giant, as of equal value relative to your ability to have success. What’s small to you may be huge to someone else.. and vice versa. Celebration of each success, without judgment of its size, continues to move us forward while creating a new habit. This is using our power and strengthening the habit of concentration.
The practice of self hypnosis will greatly facilitate your ability to focus. One of the definitions of self hypnosis is Heightened Awareness. If you commit yourself to practice a couple of sessions each day, within two to three weeks you will find some very interesting shifts in concentration and consciousness take place. Learn how, do it, celebrate your successes, benefit. Start NOW.
Please take a look at my CDs that can help you focus in your business and personal life and prepare you to have the best year ever. The choice is always there and the choice is always yours.
BOSTON – Bacteria that generate power could be used in microbial fuel cells to convert waste into electricity, according to the latest research.
University of Massachusetts (U-M) researchers isolated bacteria with large numbers of tiny projections called pili which transfer electrons to generate power in fuel cells, more efficiently than counterparts with a smooth surface.
The researchers isolated a strain of Geobacter sulfurreducens which they called KN400 that grew prolifically on the graphite anodes of fuel cells.
The bacteria formed a thick bio-film on the anode surface, which conducted electricity. The researchers found large quantities of pilin, a protein that makes the tiny fibres that conduct electricity through the sticky bio-film.
“The filaments form microscopic projections called pili that act as microbial nanowires,” said DerekLovley, U-M professor. “Using this bacterial strain in a fuel cell to generate electricity would greatly increase the cell’s power output.”
Microbial fuel cells can be used in monitoring devices in environments where it is difficult to replace batteries if they fail but to be successful they need to have an efficient and long-lasting source of power.
Lovley described how KN400 might be used in sensors placed on the ocean floor to monitor migration of turtles.
These findings were reported at the Society for General Microbiology’s meeting at Heriot-Watt University, Edinburgh
ORLANDO – A microbiologist has uncovered an unknown mechanism that helps a deadly food-borne bacterium subvert healthy cells.
Listeria monocytogenes is a bacterium that can cause pregnant women to lose their foetuses and can trigger meningitis fatalities among the elderly or people with compromised immune systems.
The bacterium has been linked to outbreaks traced to food processing plants in the US and Canada. Those cases in eight states were linked to people eating contaminated sliced turkey meat.
Scientists have long known that Listeria spreads from one human cell to another. Bacteria growing in one cell move fast enough to create a finger-like structure that protrudes from the cell and pushes into an adjacent cell. The bacteria then infects the adjacent cell.
Keith Ireton, microbiology professor at the University of Central Florida (UCF) and his team have discovered a previously unknown second process that gradually overwhelms the second cell’s ability to defend itself from infection.
The plasma membrane, or outer layer, of healthy human cells normally exhibits tension. Such tension might be expected to prevent Listeria from spreading to adjacent uninfected cells.
However, Ireton’s lab found that a Listeria protein called InlC appears to relieve tension at the plasma membrane in infected cells, making it easier for moving bacteria to deform the membrane and then spread into adjacent, healthy cells.
“Our discovery could have relevance for bacterial pathogens that cause Shigellosis or Rocky Mountain spotted fever, as these bacteria resemble Listeria in their ability to move inside the host cell and spread,” Ireton says.
SAN DIEGO – Don’t spank your kids if you want them to be very intelligent. A ground-breaking research has found that children who are spanked have lower IQs.
Corporal punishment is extremely stressful and can become a chronic stressor for young children, says Murray Straus, professor at the University of New Hampshire.
“All parents want smart children. This research shows that avoiding spanking and correcting misbehavior in other ways can help that happen,” says Straus.
“It is time for psychologists to recognize the need to help parents end the use of corporal punishment and incorporate that objective into their teaching and clinical practice,” he says.
Straus found that children in the US who were spanked had lower IQs four years later than those who were not spanked.
Straus and MalliePaschall, senior research scientist at the Pacific Institute for Research and Evaluation, studied nationally representative samples of 806 children aged two to four, and 704 kids ages five to nine. Both groups were retested four years later.
IQs of children aged two to four who were not spanked were five points higher four years later than the IQs of those who were spanked.
The IQs of children aged five to nine years old who were not spanked were 2.8 points higher four years later than the IQs of children the same age who were spanked.
Straus and colleagues in 32 nations used data on corporal punishment experienced by 17,404 university students when they were children.
“How often parents spanked made a difference. The more spanking the slower the development of the child’s mental ability. But even small amounts of spanking made a difference,” Straus says.
His analysis indicates the strongest link between corporal punishment and IQ was for those whose parents continued to use corporal punishment even when they were teenagers, says a New Hampshire release.
Straus said corporal punishment can become a chronic stressor for young children who typically experience punishment three or more times a week. For many it continues for years.
These results were presented Friday at the 14th International Conference on Violence, Abuse and Trauma in San Diego.
They have also been published in the Journal of Aggression Maltreatment & Trauma.
LONDON – Got a messy cleanup problem that requires a molecule-by-molecule fix? Instead of nanotech, how about deploying an array of ready-made, versatile bacteria? Scientists studying a genus of the rock-dwelling bacteria called Shewanella have found out how the organisms can transform minerals by zapping them with tiny electrical currents. The discovery could lead to new types of fuel cells to generate electricity, to better environmental-cleanup techniques, and possibly even to a new generation of organically made materials.
Bacteria live in almost every environment on Earth, from the ocean’s deepest trenches to the Himalayas’ highest peaks. Perhaps the main reason is their supreme adaptability. Animals use oxygen as part of metabolism. But some microbes can thrive in the absence of oxygen, something that has puzzled scientists for nearly half a century. Even when scientists finally discovered that the organisms were using rocks instead of oxygen to purge electrons, they still couldn’t figure out the exact molecular mechanism that made such metabolism possible.
Now, after 5 years of studies in laboratories in the United States and the United Kingdom, a team has discovered the elusive process. It turns out that Shewanella use a class of proteins on their surface that functions like an electrical wire between the bacteria’s interior and exterior. The proteins–called deca-heme c-class cytochromes–bond with the rock molecules and convey electrons out through the cell membrane, the composition of which normally functions as an insulator. The process also chemically alters the rock, releasing elements such as iron and manganese, the team reports online this week in the Proceedings of the National Academy of Sciences.
“As a geochemist, I was surprised to see just how much ‘machinery’ the microbe builds to move electrons,” says co-author SusanBrantley of Pennsylvania State University, University Park. She says that mechanism could be the key to using Shewanella and related bacteria in activities such as electricity production and oil-spill cleanup. Lab experiments have shown that other kinds of bacteria can generate an electrical current. Likewise, bacteria over time will clean up oil spills. The new research, Brantley explains, could lead to cheaper and more efficient ways to do both by tweaking the bacteria’s metabolism.
The fact that Shewanella live underground naturally makes them ideal candidates for environmental-cleanup tasks, says biochemist and lead author DavidRichardson of the University of East Anglia in the United Kingdom. “Understanding their biochemistry could help to develop strategies to stimulate their activities [at the cleanup sites],” he says.
The findings provide, “finally, the hard-core biochemical information that explains how these kinds of metabolic reactions can take place,” says geochemist EricRoden of the University of Wisconsin, Madison. It is “the full explanation that people in many disciplines have been waiting for,” he says.
Neurogenesis (birth of neurons) is the process by which neurons are generated. Most active during pre-natal development, neurogenesis is responsible for populating the growing brain.
New neurons are continually born throughout adulthood in predominantly two regions of the brain:
Many of the newborn cells die shortly after they are born, but a number of them become functionally integrated into the surrounding brain tissue.
Adult neurogenesis is a recent example of a long-held scientific theory being overturned, with the first evidence of mammalian neurogenesis presented in 1992. Early neuroanatomists, including Santiago Ramon y Cajal, considered the nervous system fixed and incapable of regeneration. For many years afterward, only a handful of biologists (including JosephAltman, ShirleyBayer, and MichaelKaplan) considered adult neurogenesis a possibility.
In 1983, with the characterization of neurogenesis in birds and the use of confocal microscopy, the possibility of mammalian neurogenesis became more apparent, but it was not until the early 1990s that hippocampal neurogenesis was demonstrated in non-human primates and humans. More recently, neurogenesis in the cerebellum of adult rabbits has also been characterized. Further, some authors (particularly ElizabethGould) have suggested that adult neurogenesis may also occur in regions within the brain not generally associated with neurogenesis including the neocortex. However, others have questioned the scientific evidence of these findings arguing that the new cells may be of glial origin.
The functional relevance of adult neurogenesis is uncertain but there is some evidence that hippocampal adult neurogenesis is important for learning and memory. Multiple mechanisms for the relationship between increased neurogenesis and improved cognition have been suggested, including computational theories to demonstrate that new neurons increase memory capacity reduce interference between memories or add information about time to memories.
Experiments aimed at ablating neurogenesis have proven inconclusive, but several studies have proposed neurogenic-dependence in some types of learning. and others seeing no effect. Studies have demonstrated that the act of learning itself is associated with increased neuronal survival. However, the overall findings that adult neurogenesis is important for any kind of learning are equivocal.
Adult-born neurons appear to have a role in the regulation of stress. Studies have linked neurogenesis to the beneficial actions of specific antidepressants, suggesting a connection between decreased hippocampal neurogenesis and depression. In a subsequent paper, scientists demonstrated that the behavioral benefits of antidepressant administration in mice is reversed when neurogenesis is prevented with x-irradiation techniques. In fact, new-born neurons are more excitable than older neurons due to a differential expression of GABA receptors. A plausible model, therefore, is that these neurons augment the role of the hippocampus in the negative feedback mechanism of the HPA-axis (physiological stress) and perhaps in inhibiting the amygdala (the region of brain responsible for fearful responses to stimuli).[vague] This is consistent with numerous findings linking stress-relieving activities (learning, exposure to a new yet benign environment, and exercise) to increased levels of neurogenesis, as well as the observation that animals exposed to physiological stress (cortisol) or psychological stress (e.g. isolation) show markedly decreased levels of new-born neurons.
Some studies have hypothesized that learning and memory are linked to depression, and that neurogenesis may promote neuroplasticity. One study proposes that mood may be regulated, at a base level, by plasticity, and thus not chemistry. Accordingly, the effects of antidepressant treatment would only be secondary to change in plasticity.
Effect of sleep reduction and stress levels on neurogenesis
One study has linked lack of sleep to a reduction in rodent hippocampal neurogenesis. The proposed mechanism for the observed decrease was increased levels of glucocorticoids. It was shown that two weeks of sleep deprivation acted as a neurogenesis-inhibitor, which was reversed after return of normal sleep and even shifted to a temporary increase in normal cell proliferation.
Neurogenesis and Parkinson’s disease
Parkinson’s disease is a neurodegenerative disorder characterized by a progressive loss of dopaminergic neurons in the nigrostriatal projection. Transplantation of fetal dopaminergic precursor cells has paved the way for the possibility of a cell replacement therapy that could ameliorate clinical symptoms in affected patients. Recent years have provided evidence for the existence of neural stem cells with the potential to produce new neurons, particularly of a dopaminergic phenotype, in the adult mammalian brain. Experimental depletion of dopamine in rodents decreases precursor cell proliferation in both the subependymal zone and the subgranular zone. Proliferation is restored completely by a selective agonist of D2-like (D2L) receptors.] Neural stem cells have been identified in the neurogenic brain regions, where neurogenesis is constitutively ongoing, but also in the non-neurogenic zones, such as the midbrain and the striatum, where neurogenesis is not thought to occur under normal physiological conditions.
A detailed understanding of the factors governing adult neural stem cells in vivo may ultimately lead to elegant cell therapies for neurodegenerative disorders such as Parkinson’s disease by mobilizing autologous endogenous neural stem cells to replace degenerated neurons.
Neurogenesis and Exercise
Scientists have shown that physical activity in the form of voluntary exercise results in an increase in the number of newborn neurons in the hippocampus of aging mice. The same study demonstrates an enhancement in learning of the “runner” (physically active) mice . While the association between exercise-mediated neurogenesis and enhancement of learning remains unclear, this study clearly demonstrates the benefits of physical activity and could have strong implications in the fields of aging and/or Alzheimer’s disease.
Regulation of Neurogenesis
Many factors may affect the rate of hippocampal neurogenesis. Exercise and an enriched environment have been shown to promote the survival of neurons and successful integration newborn cells into the existing hippocampus. Another factor is central nervous system injury since neurogenesis occurs after cerebral ischemia, epileptic seizures, and bacterial meningitis. On the other hand, conditions such as chronic stress and aging can result in a decreased neuronal proliferation.
Adult neural stem cells
Neural stem cells (NSCs) are the self-renewing, multipotent cells that generate the main phenotypes of the nervous system. In 1992, Reynolds and Weiss were the first to isolate neural progenitor and stem cells from the striatal tissue, including the subventricular zone — one of the neurogenic areas — of adult mice brain tissue. Since then, neural progenitor and stem cells have been isolated from various areas of the adult brain, including non-neurogenic areas, such as the spinal cord, and from various species including human.
Epidermal growth factor (EGF) and fibroblast growth factor (FGF) are mitogens that promote neural progenitor and stem cell growth in vitro, though other factors synthesized by the neural progenitor and stem cell populations are also required for optimal growth. It is hypothesized that neurogenesis in the adult brain originates from NSCs. The origin and identity of NSCs in the adult brain remain to be defined.
Neural stem cells are routinely studied in vitro using a method referred to as the Neurosphere Assay (or Neurosphere culture system), first developed by Reynolds and Weiss. While the Neurosphere Assay has been the method of choice for isolation, expansion and even the enumeration of neural stem and progenitor cells, several recent publications have highlighted some of the limitations of the neurosphere culture system as a method for determining neural stem cell frequencies.[vague] In collaboration with Reynolds, STEMCELL Technologies has developed a collagen-based assay, called the Neural Colony-Forming Cell (NCFC) Assay, for the quantification of neural stem cells. Importantly, this assay allows discrimination between neural stem and progenitor cells.
WINSTON-SALEM – Training and experience can affect how a person’s brain is organised, says a US study that compared 20 music conductors and 20 people with no music training.
All the participants were between the ages of 28 and 40. The conductors had an average of more than 10 years experience as a band or orchestra director in middle or high school.
The researchers used functional magnetic resonance imaging (fMRI) to monitor the participants’ brain activity while they performed a difficult hearing task that involved listening for two tones. They had to keep their eyes opened while doing the task.
Experience and brain functioning
Initially, both the conductors and non-musicians showed reduced activity in the brain’s visual processing area and increased activity in the auditory part of the brain. But as the task became harder, only the non-musicians tuned out more of their visual sense. This suggests that the conductors’ music training and experience altered the way their brains work, the researchers said.
“Because the task was equally difficult for everybody, the difference observed between conductors and non-musicians must be related to a change in how they deal with irrelevant sensory information and not just their ability to do the task,” lead author W. David Hairston, a postdoctoral fellow in radiology at the Advanced Neuroscience Imaging Research Laboratory at Wake Forest University Baptist Medical Centre in Winston-Salem, N.C., said in a prepared statement.
“In general, based on the non-musicians, we suggest that the brain actively increases how much information from other senses gets filtered out or ignored when you have to concentrate really hard on one sense,” Hairston said.
He noted that conductors routinely must differentiate between subtle differences in sounds and often have to do this while reading scores and watching/communicating with their musicians. This leads to an ability to focus on a difficult auditory task without having to increase suppression of visual information.
The study results “show how the brain filters information from different senses is very flexible and adaptive and changes with the demands of the task at hand. Additionally, how this operates can change with highly specialized training and experience,” Hairston said.
The study was presented at the Society for Neuroscience annual meeting in San Diego.