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 Wolbachia pipientis is a rather peculiar bacterium.  It's an intracellular organism, and is found in a wide variety of tax, including nematodes, crustacea, and arachnids.  About 20% of insect species are thought to have Wolbachia.  Wolbachia has evolved a number of mechanisms to ensure transmission, which is generally maternal.  There are a number of consequences of infection with these intracellular bacteria observed in different species - including reproductive isolation between infected and uninfected strains of the mosquito Culex pipiens.  I also recall seeing a old paper (though I've long-since lost the citation) which claimes a growth advantage of infected Drosophila larvae in crowded culture, though I think this must have predated the identification of Wolbachia.

So some laboratory Drosophila strains are infected with Wolbachia, while some are not.  This can lead to artefacts in many experiments.  For example, in my own lab, we had some perplexing results concerning the effects of particular transgene on viability of some combinations - the involvement of Wolbachia became clear firstly when we noticed the effects depended on which which strain was paternal and which maternal in the cross, and finally the observation that  this effect vanished after treating the transgenic stocks with antibiotic.  These kind of artefacts are particularly important to consider when working with complex characteristics such as lifespan (as we do in my lab).

An interesting question is why these bacteria persist in insect populations - is there a positive selection?  In this brief paper published in Science, Hedges et al show that Wolbachia infection does influence one important factor in Drosophila: resistance to viral infection.

Viral infections aren't something I think the average Drosophila researcher worries about - we're more likely to worry about infestation with mites, or bacterial infection on the culture medium!  Much of the research on Drosophila immune systems concerns bacterial or fungal infection.  Nonetheles, there are viruses out there that do infect Drosophila, and some with quite odd characteristics, such as sigma virus, which I believe makes flies die on exposure to high levels of carbon dioxide (a problem since nowadays we use carbon dioxide instead of ether to anaesthetise our flies!).  In this paper, Hedges et al look at outcomes of infection with three viruses - Drosophila C virus (DCV), cricket paralysis virus (CrPV) and Flock House virus (FHV). The first two are natural pathogens: all three are lethal to Drosophila when inoculated by injection.

This is a brief paper, with a single figure (there is further supplementary material at the Science website).  Essentially, what they show is that Wolbachia-infected flies survive for longer following injection with DCV than do uninfected flies.  This experiment was done with two Drosophila strains: Oregon RC (a standard laboratory wild type strain - figure 1A) and w¹¹¹⁸(a standard white eyed mutant strain - figure 1B), and interestingly the experiment used "cured" flies as the non-Wolbachia-infected control flies.  this point is important, as it means that genetically, the two strains are the same.  The same effect can be seen with CrPV (figure 1C), and even more markedly with FHV (figure 1D) infections.  [Click on figure for larger version -may require subscription]

So, does this research suggest a positive selection for Wolbachia infection?  Quite possibly.  I don't know very much about natural viral infection in Drosophila, but I suppose that the injection oute of infection used experimentally might be rather more severe than a naturally acquired infection, and while the Wolbachia infected flies do still die in this experiment, perhaps Wolbachia infection leads to significantly greater survival of natural viral infection.

The Register reports latest developments in the Australian Government's ambitions to censor all internet traffic.  Originating as some misguided initiative to "protect the children" (whatever happened to parental responsibility?), it now appears that Australian internet users are likely to face a situation where they must choose from one of two censored streams.  Opting out of the "child-friendly" stream (which blocks a wide range of supposedly harmful content), merely subjects the user to an adult filter that blocks material deemed by the government to be inappropriate for adults.

Is this patronising and paternalistic system the future of the internet?  Or has it the potential to lead to unreasonable censorship?

On whether the proposed system is practical, the UK internet filtering company Censornet is quoted as follows:

However, the firm foresees two issues with any solution. Most filters tackle just the HTTP protocol. But HTTP accounts for an average of 25 per cent of a user's bandwidth, with the rest taken up by other traffic, including email, peer-to-peer and instant messaging. 

Here in the UK, we are subjected to some level of internet filtering.  Wikipedia has an interesting overview of the status of several countries' internet filering policies:

United Kingdom is in ONI's watchlist and is not on RSF's internet enemy list. British Telecommunications ISP passes internet traffic through a service called Cleanfeed which uses data provided by the Internet Watch Foundation to identify pages believed to contain indecent photographs of children. When such a page is found, the system creates a 'URL not found page' error rather than deliver the actual page or a warning page. Other ISPs use different systems such as WebMinder.

But who decides which URLs end up on the filter lists?  Are the public entitled to know?   Where the filter lists are maintained by government agencies, how can we be sure the blocked sites are appropriate?

The Register reports that the anti ID card campaigners No2ID have succeeded in their long standing aim to obtain samples of Home Secretary Jacqui Smith's fingerprints.

Hot on the heels of announcing plans for draconian new communications monitoring Smith is taking forward the batty ID card agenda (first victims: overseas people, second victims: airport workers).  Now it seems a glass bearing her dabs has been "borrowed" and those precious prints preserved, presumably for some nefarious purpose.

On the other hand, there doesn't seem to be much mention of this triumph on the No2ID website... and it's not clear from the Register what the dactylograms in question will be used for.

Apparently Gordon Brown's the next target,,,

Back on 11th October, the Open Rights Group (together with a number of other concerned organisations) held a protest in Parliament Square to publicise the growing surveillance we are all subjected to.  A large mosaic constructed from images of CCTV installations was assembled.  The image (below) has been released under a Creative Commons licence.  A bigger version is available. 

From the ORG "The Big Picture" wiki:

A new yellow speed camera at the end of your road. A fingerprinting system installed at your child's school, or your medical records uploaded to central government computers from your local GP practice. If you're lucky, your daily experience of the database state will, so far, be limited to developments such as this.

But what's the big picture? Put together, these creeping changes constitute a wholesale shift towards a society predicated not on freedom, but on fear. A society of total surveillance. Everyone watched. No­ one trusted.