Wired Waters: Bacterial Electric Circuits Facilitate Chemistry in Marine Sediments

Bacteria in ocean sediments appear to string together nanowires to connect complementary but spatially separated chemical processes, according to a new study. The finding is the first example of a natural electrical circuit bridging a macroscopic gap, in this case more than a centimeter across, to mediate a biogeochemical process on either side.

Below the sediment surface there is plenty of hydrogen sulfide and carbon for bacteria to consume via oxidation, or removing electrons, but the electron acceptor is up at the sediment surface, in the form of dissolved oxygen in the overlying water. So the bacteria evidently form a sort of conductive chain, comprising biological nanowires and possibly pyrite grains embedded in the mud, that allows electrons from the oxidation of hydrogen sulfide and carbon within the sediment to contribute to the reduction of oxygen by other microbes at the sediment surface.

"It's such a smart thing for bacteria to make this electric connection," says Lars Peter Nielsen, a biologist at the University of Aarhus in Denmark who led the research, published in the February 25 issue of Nature. (Scientific American is part of Nature Publishing Group.) Bacteria sitting in the top layer of sediment receive electrons that they use to consume oxygen from oxygen-deprived but well-nourished bacteria deep down, which consume hydrogen sulfide and carbon. "It's a very smart division of labor in which there's certainly a strong evolutionary fitness," Nielsen says.

The researchers made the discovery by accident, Nielsen says. He and his colleagues noticed something odd in glass tubes containing seafloor mud from nearby Aarhus harbor and Aarhus Bay that had been left undisturbed for weeks following an experiment. Oxygen from seawater permeated only the upper millimeter or so of sediment, but the researchers noticed something happening much deeper in the mud, more than a centimeter below, as if oxygen were available down there, as well. "We could see that the hydrogen sulfide—that's what makes the mud stink—had disappeared in this part of the sediment, which in this context could only be due to reaction with oxygen," Nielsen says. "But there was no oxygen." The explanation, he says, came to him late one night: What if there were some sort of wire linking the two regions?

As it turned out, other research groups had shown that some bacteria can transfer electrons via conductive pili, tiny hairs extending far beyond a bacterium's body that can act as nanowires. In 2005 microbiologist Gemma Reguera, then at the University of Massachusetts Amherst, demonstrated with her colleagues the existence of such bacterial nanowires in Geobacter sulfurreducens. (Nielsen says that he and his colleagues have not identified the bacterial species that provide conductivity in the seafloor mud.)

Reguera, now at Michigan State University, says the new research finally establishes that the bio-nanowires play a role in nature. "There's a lot of buzz about whether we can measure conductivity in the sediment and relate it to biology and microbes, but there has never been the proof," Reguera says. "This paper actually proved it." She notes that the study's authors took great pains to exclude other possible explanations for the subsurface oxidation, whether from sediment mixing by tiny organisms or from oxidation by nonbiological agents such as nitrates and metallic oxides.

"At the end of the day, the key in this study is really the velocity of the response—how fast the electrons transfer across the sediments," Reguera says. When the researchers switched the electric current off by deoxygenating the water, thereby removing the electron acceptor at the sediment surface, the depth of the hydrogen sulfide layer in the sediment rose in less than an hour, as deeper microbes could no longer consume it. "There is nothing known that could explain it but bacterial nanowires," Reguera says.

source:- scientificamerican.com

Time Management - Urgent v important

Time management refers to a range of skills, tools, and techniques used to manage time when accomplishing specific tasks, projects and goals. This set encompasses a wide scope of activities, and these include planning, allocating, setting goals, delegation, analysis of time spent, monitoring, organizing, scheduling, and prioritizing. Initially time management referred to just business or work activities, but eventually the term broadened to include personal activities as well. A time management system is a designed combination of processes, tools and techniques.

Time management tasks can be split into urgent and important. To help you in sorting them you can use a matrix system.

The definitions:

Urgent

Urgent tasks are deadline based. This is usually independent of yourself and is often driven by others. The sooner the task needs completion the More urgent it is. This has no relation to importance.

Important

The importance of a job drives how much 'time' you want to spend on it. Notice that this is independent of 'urgency' and is what you want to do not what you Actually spend on it. For any task the quality of your output will often relate to the time you spend on it.

Rank:
Once you have ranked your list of jobs for 'urgency' and 'importance' you will be able to put them into a matrix as in the diagram above.

Box 1

These are urgent and important. They must be done now. These are critical activities and also support you goals. In terms of crises they may be a mixture of problems that you could have avoided with better planning or were completely unexpected.

Box 2

These are ‘urgent’ but ‘not important’. They tend to be jobs not related to your goals but generated by others. Because you don’t really want to spend much time on tasks not connected with your goals you may wish to try an delegate these.

Box 3

These items are ‘not urgent’. This means their deadlines are in the future. They are important so you must do them. So plan them well for carrying out in the future.
A lot of jobs will fall in this area make sure you plan properly or you will have problems later.

Box 4

These are neither ‘urgent’ or ‘important’. These can be simple trivial tasks that you ought to avoid doing but you may end up doing just to ‘get them out of the way’.
Be wary as some of these tasks may be trivial now but they may move into a higher ranked category if not seen to.

This system is very black and white but will need some interpretation for real life examples. If someone telephones you for urgent information you are not likely to put them on hold while you put the task into one of the boxes and deal with it appropriately.

Category detail:

Box 1

Highly important and urgent tasks should be pretty rare. Particularly, if you have generally planned well. However, jobs in this box need immediate attention, for example, safety issues must be resolved, family crisis, product quality has been compromised, senior management want data for an urgent meeting etc.

Hopefully, you wont see too many of these sorts of issues.

So what does it mean if you are constantly dealing with crises and fire fighting?
If this is the case there is often poor planning at the route of it. This may be your own poor planning in which case you need to deal with it appropriately.
If you are a manager and are constantly dragged into dealing with crises materialising from others you will need to deal with their training.

How many parents spend a lot of needless time sorting out problems of their children?
Quite a few I would guess. Try to examine the route causes and deal with them.

The above techniques will help to keep jobs in box 3 where planning should be carried out more thoroughly.
Confusion over importance can push some tasks from box 2 to 1 by mistake.

In terms of your diary do them straight away.

Box 2

These are the tasks with near deadlines but not relevant to your own goals. Much of your daily activity will come under this heading.
There will be plenty of jobs in this category that are trivial in themselves but would have serious consequences if not done, for example, paying Bills.
Try to spend as little time as possible on this category of task.

People will still spend more time than is necessary on these jobs for a variety of reasons.
If you particularly like a task you will keep with it for too long.
You believe the job is ‘important’ when in fact it isn’t (just urgent) although it may well be important to others it is not to you.
If the quality of the task output is too high (unnecessarily) then you will tend to take up too much time.

The key with items that should only command a small amount of your time is to make sure you understand what is required and do not exceed that requirement.

You will need to put these tasks into your diary for completion ahead of the deadline and plan to give them as little time as possible.

Box 3

These tasks are relevant to your goals so are ‘important’ but ‘not urgent’ in that their deadlines are not immediate.
There are two key sorts of tasks that may appear here to be wary of.
The first are tasks that if left undone can easily end up in Box 1 as a crisis. By ‘done’ we mean that you thoroughly assess these and plan their completion Rigorously so that you are not surprised later with unforeseen events.

Anything can end up in Box 1 if you leave it long enough. One character of a good manager is to ask ‘why?’
If you find too many items ending up in Box 1 ask ‘why?’ and learn from the experience so that it will not happen again.

If you have any room in your diary after putting in the Box 1 and 2 tasks fill some space with Box 3 tasks.

Box 4

These are the rest of the tasks that are ‘not urgent’ and ‘not important’. If you leave these jobs to simmer for say 4 weeks they will either jump to becoming ‘urgent’ into Box 2 or you may find that they are irrelevant and you can bin them. Some items that would be in this area you may be able to automate at a time When you do not need to be there. For example, computers can be backed up, checked for viruses and adware whilst you are sleeping.

If you are inundated with jobs one option is to work longer hours. This is the least attractive option if this carries on for any length of time as it can be physically and mentally draining. The long term option is to improve your Time Management skills.

Many items in Box 4 are done just for fun as they are neither ‘important’ or ‘urgent’.
Job needs:
When you use this system assessing whether a job is ‘important’ or not is possibly easier at home than at work.
In your work environment you will be subject to job descriptions and as such will be obliged to complete tasks that are not necessarily part of your goals.
However, losing your job or position is not a good way to reach your goals so many jobs are ‘important’ in an indirect manner.
Job order:
In theory, you would tackle the jobs in the order Box 1, then 2, then 3 and finally Box 4. It is quite likely that if you did this you would never get into Box 3 on many occasions. Thus some of the Box 3 jobs ought to be done anyway despite the natural order. If you have any gaps in your activities then is the time to start Box 4.

These can be fitted in to your diary once you have accounted for Boxes 1, 2 and 3.
Remember that you may need to pencil some time for potential emergencies and some ‘quiet time’.

Once you have identified a Box for your task think if you need to do it, if not, try and delegate it.

In general, you shouldn’t have much in Boxes 1 and 4 and most of your work in Boxes 2 and 3.
The split should be about 10% Box 1, 10% Box 4 and 40% for Boxes 2 and 3.

If in an audit you find the percentages regular exceed these look at the underlying causes and try to do something about them.

I Love Kung Fu Panda

My favourite quotations from Kung Fu Panda. Just have a look.

There is no charge for awesomeness or attractiveness.

Sorry doesn’t make the noodles.

Why must something be wrong for me to want to see my old friend.

Nothing is impossible.

One often meets his destiny on the road he takes to avid it.

Your mind is like this water, my friend, when it is agitated, it becomes difficult to see, but if you allow it to settle, the answer becomes clear.

There are no accidents.

There is no such thing as level zero.

You are too concerned about what was and what will be.

Yesterday is history, tomorrow is a mystery, but today is a gift. That is why it is called the "present."

There is just news. There is no good or bad.

Look at this tree, Shifu: I cannot make it blossom when it suits me nor make it bear fruit before its time.

No matter what you do, that seed will grow to be a peach tree. You may wish for an apple or an orange, but you will get a peach.

(Shifu) But a peach cannot defeat Tai Lung (Oogway) Maybe it can, if you are willing to guide, to nurture it, to believe in it.

No, you just need to believe. Promise me, Shifu, promise me you will believe.

The secret ingredient is nothing. You heard me. Nothing! There is no secret ingredient.

To make something special you just have to believe it's special.