Thursday, August 27, 2009

Pushing the limits of GPS navigation

In the last few posts I have presented my thoughts on recent developments in mobile maps and related applications market, focusing especially on GPS navigation capabilities of mobile phones. Today just a brief reference to yet another option to consider: ALK CoPilot Live (for iPhone OS) - only US and Canada at the moment. iPhone version follows Windows Mobile and Symbian applications and I only mention it because it’s the first one marketed for under U$35.

There is a good range of options for getting road directions information on mobile phones, from basic and free Google Maps for mobiles, native iPhone and Nokia driving directions applications through to free, almost fully featured demo GPS navigation tool from NAVIGON and a range of inexpensive applications from all top GPS navigation service providers. As I already stated in my earlier post, mobile phones have become fully enabled GPS navigation devices, so not much more to be said on this topic unless we look beyond just “in-car navigation” and into augmented reality capabilities.

To kick start a new series of topics just a quick note about what does “augmented reality” concept mean. In simple words, Augmented Reality (AR) is a term referring to a capability of blending digital, computer-generated visual effects with real-time footage of a surrounding real-world environment. A practical example of implementation of this concept is a “Head-Up Display” in the latest BMW 7 Series Sedan:

[image courtesy of BMW www.bmw.com]
“Head-Up Display presents important information - speed, navigation directions and alerts - directly in the driver's field of vision. The information is projected via the windscreen into the driver's field of vision, thus minimizing distraction. The virtual image appears approximately two metres away, at the end of the bonnet. The driver's attention stays on the road ahead and the eye strain of repeated refocusing is eliminated.”

There are also quite interesting early attempts to create augmented reality applications for mobile phones which I will review it in the next post on this topic.

Google Map Static goes V2

Google has just announced the release of new, upgraded version of static map. Functionality has been extended to allow encoding of polylines, drawing filled polygons, specifying marker locations as address as well as latitude and longitude coordinates, and referencing colours in 24-bit as well as 32-bit formats. V1 has been deprecated so, any applications using the original version will need to be upgraded to the latest version. Full documentation is availabe from Google site.


Static option of Google Map is very handy for those situations where bandwidth is an issue (eg. for users out in the bush on dial-up Internet connection or for mobile phone applications) or where there is no need for interactivity with the map. Although static map is originally intended as just an image service, some interactivity can be scripted to mimic basic functionality of Google Map proper.

For example, I have created a dial-up version of aus-emaps.com home page for users who find initial download of Javascript files and frequent refresh of multiple map tiles of Google Map proper too much to handle on their browsers. I didn’t have a chance yet to convert this application for use on mobile handsets but it will happen in the future. The new functionality options in version 2 extend the range of applications that could be developed on this platform. It definitely warrants a closer look as current Static Google Map is the closest thing to a “dynamic map server” (ie. a web service that would convert user data into an image representation and deliver it back as map tiles) – capability still missing in Google Map stable.

Via: Google Geo Developers Blog: Static Maps API v2: Encoded Paths, Polygons & Geocoding

Monday, August 24, 2009

Dr. Stephan

After a very challenging summer, I've finally turned in my written thesis, so it's official: I have my Ph.D. I'm publishing the abstract below. These findings should all be published in peer-reviewed journals in the next 6 months.


Ataxin-7 Conserved Motifs Determine the Severity of the Neurodegenerative Disorder Spinocerebellar Ataxia Type 7 in Transgenic Mice and Influence Lifespan in Yeast

Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant, progressive neurodegenerative disorder whose characteristic features are cerebellar ataxia, dysarthria, and retinal cone-rod dystrophy culminating in blindness. SCA7 is caused by an abnormally long glutamine-coding CAG repeat in the SCA7 gene, which encodes the protein Ataxin-7.

Ataxin-7 contains several conserved motifs that may influence the toxicity of the glutamine tract. Among these are three conserved regions (conserved block I – III), two caspase-7 cleavage sites, a nuclear export signal and two monopartite nuclear localization signals (NLS). Previous investigations have shown that the caspase-7 cleavage site D266 is required for the full toxicity of the Ataxin-7 protein in cell culture. We generated SCA7 transgenic mice expressing a 92 CAG version of the human SCA7 cDNA, with and without a D266N mutation. Mice carrying the D266N mutation were protected from SCA7-like neurodegeneration, behavioral signs and shortened lifespan.

To further characterize the role of conserved motifs in SCA7 pathology, we generated SCA7 transgenic mice carrying point mutations in both C-terminal NLSs (KKRK -> KAAK). Previous work has shown that nuclear localization is an important step in the pathology of CAG repeat disorders. We observed that mice lacking C-terminal NLS activity were substantially protected from degeneration of the retina and cerebellum, SCA7-like behavioral signs and shortened lifespan.

Age is the primary risk factor for neurodegenerative disease. Even in the absence of overt disease, the aging brain shows histopathological and molecular changes reminiscent of neurodegeneration. To explore the link between neurodegenerative disease and aging, we have examined the replicative lifespan of Saccharomyces cerevisiae missing the SCA7 ortholog, SGF73. This strain exhibits an unusually long lifespan, which is dependent on the function of the NAD+-dependent deacetylase SIR2. We present evidence that the extended lifespan of the SGF73 null strain is due to the influence of Sgf73 on the activity of Sir2 and the histone deubiquitinase Ubp8. Furthermore, we show that the level of ubiquitinated H2B is elevated in an SCA7 transgenic mouse line, indicating that an alteration in Ubp8 activity may play a role in SCA7 pathology and that aging and neurodegeneration may share a common mechanism.

The Great Media Evolution

Recently I was flicking through some old notes and I came across a list of links to pages on Gopher. Yes, there used to be another Internet protocol before World Wide Web became popular! It prompted a few thoughts on how media and related technologies evolved over the years… The following graph illustrates a few milestones.



1. The first modern newspaper:
In 1605 Johann Carolus publishes the first printed newspaper, Relation, in Strasbourg, now in France but at the time a part of the so-called ’Deutsches Reich’. [wan-press.org]

2. The first radio station broadcasting:
In 1919 The Netherlands was the first country in the world to start radio station broadcasting. [Wikipedia]

3. The first television service:
In 1928 United States of America, as the first country in the world, introduced mechanical television. [Wikipedia]

4. The first commercial color television:
In 1963 commercial transmission of color television begun. [Wikipedia]

5. The first satellite television service (Direct Broadcast Satellite):
The world's first experimental educational and Direct Broadcast Satellite (ATS-6), was launched in 1974. The first Soviet geostationary satellite to carry Direct-To-Home television, called Ekran, was launched in 1976. [Wikipedia]

6. The first mobile phone:
The first commercial cellular network was launched by NET in Tokyo Japan in 1979. [Wikipedia]

7. The beginning of World Wide Web (as we know it):
On August 6, 1991, Tim Berners-Lee posted a short summary of the World Wide Web project on the alt.hypertext newsgroup. This date also marked the debut of the Web as a publicly available service on the Internet. [Wikipedia]


It is interesting to observe how the range of media channels expanded in recent years. The big question (another one!) in my mind is however, “what will be the next big thing”!? It will surely be something very obvious but my imagination doesn’t reach as far into the future and it is a very unsettling feeling… So instead, a quick comment on something more predictable that is happening right now.

One thing that is clearly emerging is convergence of digital media. You can read newspapers online, get the latest TV or radio news streamed live to your browser, download movies to burn on DVD, you can read teletext news on your TV, subscribe to high definition movies on demand, soon also you will be able to browse the Internet on a TV set, and there is a good chance your mobile handset supports all of the above functionality as well.

There are two important conclusions that can be drawn. Firstly, that content portability is of utmost importance for information providers. Separation of data from interaction and delivery mechanisms is the main challenge to ensure efficiency in dissemination and in reaching target audience through various media channels and in various places (home and on the road, etc.). And of course to enable efficient archiving, discovery and retrieval on demand.

TV and radio news can be transcribed and catalogued, transcriptions can be turned into articles or announcements, catalogues can be indexed by search engines and made discoverable. Ultimately, any “digital bit” may be adapted (transformed and/or enhanced) for a particular media channel. It is already happening to a certain extent but because ownership of various media channels is in separate hands, conflicting interests currently hinder adoption of the above process as a widespread practice (making a room for a new player perhaps?).

Which leads me to the second conclusion. The convergence of media and resulting greater choice of access platforms also mean greater competition between different media channels. Mr Murdoch and Fairfax are free to try to implement user pay subscription for online content of their newspapers but unless they have a world monopoly on the news this will not work (apparently, Mr Murdoch is trying to achieve just that, colluding with other big media publishers). However, news is becoming a commodity. For example, Internet gives me the ability to watch English version of French news, listen to the American radio for the latest updates, get news headlines from Google and if the event is important enough, it will be faster on Twitter than in any other media channel.

There is one more transformation happening that is threatening traditional media companies – emergence of “personal newsrooms” (like blogs or cooperatives of high profile journalists). Internet makes it all possible as it is a very cheap media channel, reaching millions (unlike press, TV or radio which are constrained by licensing rules and heavy investment in infrastructure). People follow people with authority and whom they can trust and large corporations cannot easily offer that “personal touch” without heavy investment to create “personal brands” (and the bigger the “brand” the more expensive it is to retain the individual!).

So, although I am unable to predict what will be the next new media channel, if I was running a media company I would go after all existing channels with my content. And the only way to do it is via a mix of direct investment in capabilities and partnerships with existing operators. The dominant “new age” media player may not be the News or Fairfax but just an aggregator of content or an organisation like Australian Broadcasting Corporation that covers many channels (subsidised by taxpayers and free to the public). Some food for thought.

Friday, August 21, 2009

Free player to share YouTube videos

It's a weekend so, let's have some fun! Today I am launching another free widget that will enable anyone to create YouTube video playlists and share them via email, websites, social network sites, or just bookmark for private enjoyment. The player can be embedded in a web page or can be linked to as a stand alone page from any electronic document or from personal favorites/bookmarks folder. YouTube video player (limited functionality alpha release at this stage) is available from aus-emaps.com’s free widgets page.

Since the focus of aus-emaps.com is on Australia, I have compiled a few thematic playlists to demonstrate the functionality of YouTube player. Ironically, YouTube is not the easiest place to find good playlists. Many videos are removed or muted due to copyright infringements, others are just of poor quality, so it takes an effort to put together something decent. Here is a small sample:

What every traveler to Australia should know
Selection of travel videos and facts about Australia
Ten timeless Australian hits
Chaser War on Everything

YouTube Player alpha edition supports the following functionality:


Over the next few months I will be extending player functionality to allow editing and saving play lists directly to YouTube or to private folders. Also, I will add some tools to simplify creation of personal lists and enable submitting them to aus-emaps.com for listing. For now, the simplest way to play a custom playlist is to create one on YouTube, or follow the pattern in this file: http://www.aus-emaps.com/ytp/playlist.xml, and reference location of the list in the URL, as in the examples above.

Visit free widgets page on aus-emaps.com for further instructions on how to embed the player into a website.

Please report any problems, or further development suggestions via feedback on aus-emaps.com site.

Enjoy!

Thursday, August 20, 2009

Tom Tom GPS navigation in iPhone

It’s a sign of times. Mobile phones have become fully enabled GPS navigation devices. After early lead from lesser know GPS navigation companies, like NAVIGON, now major players are rushing to the market to catch up. Tom Tom has just released mobile phone enabled version of its navigation software for iPhone. This application is only available in Europe but the rest of the world will follow soon.

First impressions of Tom Tom’s iPhone navigation tool are quite positive. I’ll just highlight a few comments, after The Inquirer:

“onscreen mapping interface … is pretty much identical to every other TomTom device on the market”

“other makers have flashier interfaces …. but TomTom is sticking to the principle that less is more, plumping for speed and simplicity rather than gorgeous graphics and distracting bells and whistles.”

TomTom for iPhone works equally well in landscape or portrait modes, switching slickly between the two… [however]…as soon as you get a call… it defaults to portrait view.”

TomTom for iPhone stood up particularly well against its standalone siblings with route replanning taking around five seconds on average and the lag between map position and actual location being accurate to about 10 metres.”

“Where the App really shines is in the way it integrates with other bits of the iPhone's system and software… [in other mobile navigation applications] calls can cause the mapping system to fall over …[but]… TomTom seems to beaver away happily in the background … and it picks up where it left off as soon as you drop the line.”

As with other applications for iPhone, initial map download is a hefty 1.4GB. TomTom also sells a dashboard mount for the iPhone, enabling using the phone in the car the same way as traditional portable GPS navigation devices. Unfortunately, there is no free version of Tom Tom's software but relatively low price, in comparison to traditional devices, makes up at least partially for that omission.

Wednesday, August 19, 2009

FiveFingers in the Alpine Lakes Wilderness

I recently bought a pair of Vibram FiveFingers Sprint (pictured). They're minimal, lightweight shoes with "toes". They're designed to mimic barefoot walking as closely as possible, while protecting the feet from punctures and abrasion. The soles are thin, flexible and offer no padding whatsoever.

I've always been a barefoot walker, because I enjoy it and our feet evolved to be nude (or close to it). Besides feeling amazing, walking barefoot may allow the body to express better biomechanics. My feet have become tougher over time, but I still can't handle a rough trail barefoot.

When I first put the FiveFingers on, my initial thought was "these don't feel as much like being barefoot as I wish they did". Simply having something between your skin and the ground makes your feet much less sensitive. But I got used to them quickly, eventually using them for my parkour training.

I had a few converstions with my parkour instructor Rafe Kelley, during which I realized I had to re-teach myself how to walk and run correctly. Rafe is well-versed in natural human movement due to his background in MovNat, gymnastics, martial arts, strength training, parkour and anthropology. Modern shoes allow us to walk and run in a way that our bodies did not evolve to tolerate. The padding in shoes allows us to take large steps, in which we overshoot our center of gravity and contact the ground in a jarring manner. It also allows us to strike with our heels when we run, which is not comfortable when you're barefoot.

I took the FiveFingers on a 13-mile hike in the Alpine Lakes wilderness with a few friends last weekend. The Pacific Northwest has to be one of the most beautiful places in the world. I was expecting to use the shoes for a few miles and then swap them for my lightweight hiking shoes (Inov8 Flyroc trail runners). The beginning of the trail was really rocky and I thought I was going to have to take them off in the first few hundred yards. Surprisingly, my feet adapted, and although the trail stayed rocky, it became fairly comfortable by the time we had walked a mile.

I found myself thinking about Rafe's advice, and taking smaller steps that strike closer to my center of gravity. Although my strides were shorter, I had no trouble keeping up, and in fact going up the hills was remarkably easy. We gained 3,000 feet of elevation but I never got winded. I had to pay close attention to foot placement, which kept me from looking around much but was actually kind of fun.

After a few miles, I switched to my hiking shoes, with the idea that I should switch before my feet really started to hurt, rather than after. I immediately noticed that going up hills was harder, especially on my calves. My feet felt more cumbersome as well.

Here's me foraging for mushrooms on the trail. This is Laetiporus sulphureus, also known as "chicken of the woods". It's widely eaten in this area. However, my mushroom guide All That the Rain Primises, and More, had this to say about it:

"If you eat and enjoy this moushroom, always cook it thoroughly and do not serve it to lawyers, landlords, employers, policemen, pit bull owners, or others whose good will you cherish!"

I didn't take my chances. If you're going to pick wild mushrooms, make sure you know what you're doing and carry a regional identification guide. "I recognize them from China/Russia/Europe" kills several people a year in the Pacific Northwest. If you're experienced, this area is a mushroom bonanza. I can't set foot outside without stepping on a king bolete (porcini, cep) in the fall.

I ended up switching back to the FiveFingers for the majority of the hike, about 9 miles of it. The soles of my feet were a bit sore by the end (due to stepping on sharp rocks for miles), but my joints and muscles felt remarkably good! I had no joint pain or muscle tightness. I also felt pretty energetic. This was a big surprise, since I haven't done much hiking this year. The next day, my calves were sore, but that was it.

All in all, I really like the FiveFingers. I can wear them in places that require shoes, yet remain nearly barefoot. One potential drawback is the price-to-durability ratio. They cost me $80 and I don't expect them to last a year [Update 2013-- they are surprisingly durable]. That being said, I'm putting a beating on them. Parkour training destroys shoes. The rubber seems to be excellent quality (which you'd expect from Vibram), but it's thin and it has cuts in it for flexibility and grip, which will lower its lifespan. The upper is simply a piece of stretchy fabric that tears easily. I'm willing to deal with the durability issues because the advantages outweigh them [update- several FiveFingers wearers have commented that they actually last a surprisingly long time. See comments].

Sunday, August 16, 2009

Trends and opportunities in mobiles market

It is becoming more and more obvious that mobile devices are gaining rapidly in popularity and what is happening in this space resembles very much earlier developments in personal computers and related technology.

The whole “consumer computer age” started in early seventies of last century. The market was initially dominated by hardware suppliers (Atari, IBM, Apple) but soon operating system vendors took control (notably Microsoft). By analogy, for many years when making a call was the primary use of the handset, mobile telephony was dominated by hardware vendors. But now a fierce battle is being fought for the dominant position in the mobile operating system market to run more complex applications.

As in the past, when IBM handed the victory to Microsoft, now it appears that Nokia, market leader in mobile handsets, is helping Symbian to gain equivalent position in the mobile operating system market.


[Other category includes: PalmOS, Binary Runtime Environment for Wireless (BREW) and Android]

The Internet, as we know it, started in 1991 (according to Wikipedia, on August 6, 1991 to be exact; by the way, happy 18th birthday WWW!). This development allowed linking individual computers and its users, which in turn opened up a new communication channel and liberated users from a narrow set of computer functions defined by a dominant supplier. The result is another shift in control, from operating system provider to external service providers such as Google. The battle for dominance is still continuing. The mobile market is not at this stage yet although it can be expected that the timeframe to reach this point will be much shorter than was the case with personal computers.

It all leads me to a conclusion that there may be still some big opportunities in the mobile sector. For example, there is a place in the market for Dell-like mobile handset supplier, capable of building cheaply custom devices (ie. there is an opportunity to commoditise mobile phone hardware market, but the success will depend on access to a very capable and popular operating system; can Australian Kogan Technologies be a candidate?). And there are opportunities in the service provision space with “killer-applications” for mobile Internet, like search engine of mobile friendly Internet content or a “converter” of ordinary content for mobile use. Then there is that next really big thing… more than just the ability to make a call, or browse the Internet or to get road directions form a personal navigation tool. But I don’t know yet what it will be. Do you!? It’s a million dollar question!

Saturday, August 15, 2009

Ischemic Heart Attacks: Disease of Civilization

Or, more precisely, disease of industrial civilization.

The scientific literature contains examples of cultures that don't suffer from the chronic non-communicable diseases that are so common in modern societies. Much of what I've read indicates that heart attacks are practically unique to cultures that have adopted industrial foodways and a modern lifestyle, being infrequent or entirely absent in those that have not.


I recently came across an incredible paper from 1964 in the American Journal of Cardiology, titled "Geographic Pathology of Myocardial Infarction", by lead author Dr. Kyu Taik Lee (Am. J. Cardiol. 13:30. 1964). This was published during a period of intense research into the cardiovascular health of non-industrial cultures, including Dr. George V. Mann's famous
study of the Masai.

The first thing Lee and his colleagues did was collect autopsy statistics from San Francisco and Los Angeles hospitals. They analyzed the data by race, including categories for Caucasian-Americans (white), Japanese-Americans, Chinese-Americans, and Filipino-Americans. All races had a similar incidence of autopsy-proven myocardial infarction (MI = heart attack), including both silent (healed) and fatal MI. For comparison, they included a table with autopsy data from hospitals in Tokyo, South Japan and North Japan. I'm including the data from Tokyo in the graph because it's also an urban environment, but the finding was the same in all three regions. Here's what they found, by age group:
The Japanese had a very low rate of MI compared to both Caucasian-Americans and Japanese-Americans. The rate of MI in Caucasian-Americans and Japanese-Americans did not differ significantly. Thus, location but not race determined the susceptibility to MI.

Next, the investigators collected autopsy data from hospitals in New Orleans, again divided by race. This time they exained Caucasian-Americans and African-Americans. Both groups had a very high rate of MI, as expected, although the African-Americans had a lower rate than Caucasian-Americans. They also collected data from autopsies in Nigeria and Uganda for comparison. Here are the data for men:
And for women: Again, location but not race largely determined the incidence of MI. MI was extremely rare in the African autopsies. Here's what they had to say:
There was only 1 case of healed myocardial infarction among over 4,000 adult autopsies in the Uganda series, and only 2 cases of healed myocardial infarction among over 500 adult autopsies in the Nigerian series. In the New Orleans Negro series the occurrence rate was far greater in every sex and age group than in either one of the Negro series in East and West Africa.
Over 4,500 autopsies and not a single fatal MI. If this isn't worth studying, what is? These data should be part of first-year training in medicine and health programs.

To satisfy the skeptics, Lee and colleagues imported hundreds of hearts from consecutive autopsies in Albany (USA), Africa, Korea and Japan. They had an American pathologist analyze them side-by side to eliminate any diagnostic bias. Here's what they found:
In the African Negro series no infarct was found in any age group [out of 244 hearts, 39 over 60 years old]. In the Korean series there were only 2 cases of myocardial infarction [out of 106 hearts] and they were both women... In the Japanese series there were 8 cases of myocardial infarction in 259 hearts. All were men...
In the American sample, nearly 40% of the hearts of men and women over 60 showed signs of MI. The findings of the American pathologist confirmed the international autopsy data, showing that diagnostic bias did not contribute to the results significantly. They also took measurements of the thickness of the coronary artery wall, an index of atherosclerosis. They found that the Americans had the most atherosclerosis, but all cultures had some degree of it and there was overlap in the amount of atherosclerosis between samples. This led the investigators to state:
Myocardial infarction and coronary thrombosis are almost nonexistent in Uganda and Nigeria, and the amount of coronary arteriosclerosis is significantly less in Africans than in whites. However, in the two groups there was some overlapping in the degree of arteriosclerosis. No Africans had infarcts, but some had the same or a greater degree of coronary arteriosclerosis as a few whites who had myocardial infarctions. One explanation for this may be that some difference in clotting or clot-lysis mechanisms is present in the two groups. In a previous study, we showed that the incidence of thromboembolic phenomena in the pulmonary circulation [blood clots in the lungs] was low in East Africans as compared with Americans.
Now, the authors' conclusions:
These data strongly suggest that among the Orientals the environmental factor is playing a major role in the etiology of myocardial infarction and coronary thrombosis. If the genetic factor is an important one, those Orientals who moved to this country many years ago or who were born in this country should still maintain their low occurrence rate of myocardial infarction at least to some extent, and one would not expect to see similar occurrence rates of myocardial infarction in Orientals and whites as old as 50 to 59 years... As with the Orientals, this suggests that for Negroes in the United States environmental factors are more important than genetic factors in the etiology of myocardial infarction.
Africans in Africa and Japanese in Japan = low incidence of MI. Africans, Japanese and Caucasians in the US = high and similar incidence of MI. Genes only influence a person's susceptibility to MI when they live in an environment that promotes MI. Otherwise, genes are basically irrelevant.

What do the traditional diets and lifestyles of Japan and Africa have in common? Not much. Even within Nigeria, the diet varies from heavily starch-based (root vegetables, soaked/fermented non-gluten grains, beans, plantains) to mostly reliant on high-fat dairy and meat, though the former is much more common and I'm not sure how much the latter is represented in the data. In fact, I believe it's the wrong question to ask. A better question is "what do we eat/do in the US that traditional Japanese, Koreans, Chinese, Polynesians, Melanesians and Africans don't"? For starters, none of them rely on industrially processed foods. Their food is generally prepared at home using wholesome ingredients and traditional methods.


There are a number of lifestyle factors that probably play a role here.  They probably get more exercise than Americans, even if it's only walking in Tokyo or domestic tasks for women in parts of Africa. Traditional Africans surely get more sunlight and thus more vitamin D. I can't imagine life is less stressful in Tokyo than in San Francisco or Los Angeles.  Cigarettes are probably much less prevalent in parts of Africa than in the modern US.

I really like this study, and I think these graphs should be disseminated as much as possible. I've prepared high-resolution versions in JPEG, Powerpoint and PDF formats. E-mail me (click on my profile for the link) if you would like a copy. Let me know which format(s) you want.

Wednesday, August 12, 2009

Map Basics: Map reading guide

In one of my recent posts I tried to explain basic concepts behind map projections, coordinate systems and geodetic datum and outline characteristics of the ones used in Australia. Today just as short note about another handy resource that explains the concept of a topographic map and provides comprehensive instructions on how to use such maps with a magnetic compass or GPS navigation tools.



The booklet has been published by Geoscience Australia and is an excellent introduction for anyone interested in maps, orienteering or GPS navigation. National Mapping Agency within Geoscience Australia produces topographic maps that cover entire country at different scales. They are available for online use from aus-emaps.com:

Tuesday, August 11, 2009

Cheap acquisition of FriendFeed by Facebook

News has just started to circulate that Facebook acquired FriendFeed, an online service allowing users to aggregat content from most popular social sites (including Facebook). No price was mentioned but according to Wall Street Journal the deal involved U$15 million cash and U$32.5 million in Facebook stock. This would make it a very cheap acquisition!

Just a few months ago DST bought a stake in Facebook for equivalent of U$100 per unique visitor. Now Facebook is acquiring a company for equivalent of U$50 per unique visitor. Plus Facebook gets a big bonus – a bunch of ex-Google engineers who were behind FriendFeed concept.

Admittedly, FriendFeed has just under 1 million uniques and the growth of the service stalled recently so, the price paid is quite a scoop for its owners. However, Facebook can’t complain either, paying just half the value per unique visitor in comparison to what others are prepared to pay for its own traffic. It is all really about acquiring FriendFeed technology and brain power but on like for like basis, the deal was rather cheap for Facebook.

This is one more proof that hight traffic websites are able to sell at higher multiples than smaller sties. A good reason to pursue growth for a sake of exponential increase in value of the entity. It also highlights an interesting “business model” – if you are large and prominent enough you can acquire and aggregate smaller ventures and fund the activity by selling equity at much higher multiple than the value of original acquisitions. A licence to print money … until you start paying too much and can’t find anybody to pay for the excesses - a fine line that many crossed in the past and brought down even very large corporations...

Monday, August 3, 2009

The Diet-Heart Hypothesis: Oxidized LDL, Part I

In my reading about lipoprotein particles (LDL, HDL, etc.) and how they associate with cardiac risk, I've come across three LDL-related markers that associate with risk: LDL cholesterol, LDL particle number, and LDL size/density. Is this a coincidence, or is there a reason for it?

The first marker, LDL cholesterol, is probably nothing more than a crude approximation of particle number. But LDL particle number and size/density are related to something else, that probably actually causes atherosclerosis rather than simply being associated with it: oxidized LDL (oxLDL).

oxLDL is formed when the lipids in LDL particles react with oxygen and break down. This happens specifically to the unsaturated fats in LDL, because saturated fats, by their chemical nature, are very resistant to oxidative damage. Polyunsaturated fats are much more susceptible to oxidative damage than saturated or monounsaturated fats. Linoleic acid (the omega-6 fatty acid found abundantly in industrial seed oils) is the main polyunsaturated fatty acid in LDL.

LDL is packaged with antioxidants in the liver, primarily vitamin E and coenzyme Q10 (CoQ10), to prevent its oxidation. However, the more time it spends in the blood, the more likely it is to exhaust its antioxidant store and become oxidized. Also, the smaller the LDL particle, the more likely it is to become trapped in the vessel wall and become oxidized there.

Oxidized LDL Correlates Tightly with Cardiac Risk

oxLDL has turned out to be a very sensitive marker of cardiac risk, surpassing traditional markers like LDL, HDL, and triglycerides in most studies to date. Since the discovery of sensitive assays that detect oxidized LDL drawn directly from patient blood, a number of studies have been published supporting its ability to detect atherosclerosis (plaque buildup in the arteries), heart attack risk and even the metabolic syndrome.

Holovet and colleagues published a study comparing the ability of oxLDL and a traditional risk factor assessment to detect coronary artery disease. The traditional method is called the Global Risk Factor Assessment Score (GRAS), and includes age, total cholesterol, HDL, blood pressure, diabetes and smoking status. It's similar to the commonly used Framingham risk score (which, interestingly enough, doesn't include LDL).

GRAS was able to correctly differentiate a healthy person from a person with coronary artery disease 49% of the time, while oxLDL was correct 82% of the time. Thus, oxLDL by itself was far more accurate than a whole battery of traditional cholesterol and cardiac markers. Coronary patients had more than twice the level of circulating oxLDL than the healthy comparison group.

In a large prospective study by Meisinger and colleagues, participants with high oxLDL had a 4.25 higher risk of heart attack than patients with lower oxLDL. oxLDL blew away all other blood lipid markers by nearly a factor of two. From the abstract:
Plasma oxLDL was the strongest predictor of CHD events compared with a conventional lipoprotein profile and other traditional risk factors for CHD.
Oxidized LDL Makes Sense

 Regular, non-oxidized LDL has few properties that would make it a suspect in atherosclerosis. It's just a little particle carrying cholesterol and fats from the liver to other organs. As soon as it oxidizes, however, it becomes pro-inflammatory, immunogenic, damaging to the vessel wall, and most importantly, capable of transforming immune cells called macrophages into foam cells, a major constituent of arterial plaque.

Researchers have been interested in the plaque-generating properties of oxLDL for over three decades, and quite a bit of data have accumulated. They've identified cellular receptors that allow macrophages to ingest oxLDL (CD36 and SR-A). These receptors are specific for oxLDL and do not recognize normal LDL to a significant degree. Mice whose macrophages lack either of these two receptors have the same amount of circulating LDL as normal mice, yet have 60 to 70 percent less atherosclerosis when fed a plaque-forming diet (1, 2). Shorter-term studies have not always been consistent however, suggesting that there are alternative mechanisms. I'll expand on this more later.

Another line of evidence comes from the ability of LDL-borne antioxidants to prevent atherosclerosis in animal models. The powerful synthetic antioxidant probucol greatly reduces atherosclerosis in a number of animal models. It also reduces the extremely high cholesterol rodents and herbivorous animals get when they eat a high-cholesterol "atherogenic diet", but several studies have concluded that the majority of probucol's effect is due to its antioxidant ability rather than its ability to reduce cholesterol (ref).

Vitamin E and CoQ10 are two other LDL-borne antioxidants that can reduce atherosclerosis in animal models, particularly in combination with one another. Vitamin E alone is not as effective, and in some studies totally ineffective, which is one possible explanation for the equivocal results of vitamin E cardiovascular trials in humans. The most effective combination of antioxidants is probably the one provided by a nutrient-dense diet.

In Summary

Multiple lines of evidence suggest that oxidized LDL plays a dominant role in atherosclerosis. Not only is it associated with cardiovascular risk, there's also a large body of evidence suggesting it actually directly contributes to it. 


Google Flash Map goes 3D

Google engineers have just added "perspective" to Flash version of Google Map. Maybe it is not entirely 3D capability, as terrain height is not depicted, but the new functionality enables users to "flip" the map and view it in other than North-South orientation. Google keeps map navigation tools consistent across all platforms (ie. Javascript, Flash, Google Earth and Earth browser plug-in versions) so, if you used one, you will also be familiar with the others, although there are obvious differences in the core functionality of each version.






Another interesting feature of Flash map is smooth, continuous zoom. The map is still constructed from small image tiles so it is not as smooth as can be achieved with real vector data but the effect is reasonably good, especially for areas which have been visited previously and individual tile images are cached on user end. Try holding down the zoom plus (+) or minus (-) buttons to test the new smooth continuous zoom for yourself.