davidhollander

> Inefficient conversion of dietary ALA to DHA is neither correlated nor causative to anything

It's correlated with being a human, but the significance of very inefficient conversion versus trivial conversion is simply that it prevents us from claiming they are metabolically identical goods.

>Which is it, inefficient or non-existent in humans?

Inefficient. 'ALA->DHA' shorthand was meant to token the previous idea of "efficient endogenous ALA to DHA conversion" and not initialize a new false one.

>no evidence to suggest inadequate DHA

I think you're missing the point by intentionally or unintentionally rephrasing this in terms of avoiding a negative. Let me requote the initial context by jeremymims:

> Just for the record, fish consumption is linked to increased IQ in children because of the presence of Omega-3 Fatty Acids. Did you know though that both Flaxseed and Walnuts are both better, cheaper, and less environmentally damaging sources of Omega 3s than fish?

My primary point is that one cannot rationally assert that the numerous positive IQ benefits scientific literature attributes to consumption of fish and fish oil are somehow equally or better attributable to walnut and flax consumption. The evidence indicates differing methods of action and a need to consider their health benefits independently.

>you didn't read the article you linked

Is this a joke? The article specifically states:

>It is not enough to assume that ALA exerts effects through conversion to EPA and DHA, as the process is highly inefficient in humans.

>with higher levels of ALA, no net rise in the level of circulating DHA occurred [2,3]. For example, feeding 10.7 g/d of ALA from flaxseed oil for 4 weeks failed to increase low DHA levels in breast milk of lactating women [4]. Some estimate that only 5–10% and 2–5% of ALA in healthy adults is converted to EPA and DHA, respectively [5], while others suggest that humans convert less than 5% of ALA to EPA or DHA [6]. The International Society for the Study of Fatty Acids and Lipids (ISSFAL) recently released an official statement on the conversion efficiency of ALA to DHA. They concluded that the conversion of ALA to DHA is on the order of 1% in infants"

Now let's examine the actual context of your quote:

>"While there is discrepancy in ALA conversion rates in rats, these studies imply that dietary ALA could sufficiently supply the brain with DHA in the absence of exogenous DHA intake. It is important to note that the hepatic DHA synthesis rates observed for rats do not extend to humans [44]. The higher rates reflect a more efficient ALA elongation process in mice and rats"

It specifically states that ALA->DHA is only a phenomena that occurs in rats and not humans.

>Studies on rats are far from conclusive... but then why claim it's a human-health fact?

Exactly my point. The human studies clearly state it is not reliably converted, and you are claiming it IS based on a rat study. The whole article I linked is based on the assumption it is NOT, and from the perspective that we should be examining the health benefits of ALA independently from the health benefits of fish oil.

> increased IQ in children because of the presence of Omega-3 Fatty Acids. Did you know though that both Flaxseed and Walnuts are both better

The fatty acid in both Flaxseed and Walnuts you are referring to is alpha Linolic acid (ALA), whereas fish contains Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). Out of these, only DHA is found in the brain. If DHA is not present in the diet, ALA can be converted into it, but only at an extremely low rate of efficiency [1]

The only reliable vegan source of DHA I am aware of is certain types of algae. Additionally, by consuming extremely large quantities of nuts you will typically be overloading your copper to zinc ratio.

[1] http://dx.doi.org/10.1186%2F1476-511X-8-33 "Are all n-3 polyunsaturated fatty acids created equal?"

> The website that started these conversations has listed only ocean fish

http://whichfish.org/detail/catfish_us_farmed.html http://whichfish.org/detail/crayfish_us.html http://whichfish.org/detail/trout_rainbow_trout.html http://whichfish.org/detail/tilapia_organic_or_closed_produc...

> The best option that should be on this list is to not eat any fish at all.

Your logic fails for the following reasons:

- not all fish are from the ocean

- not all species of fish are in fact overfished. There is no Sardine crisis.

- Fish consumption is linked to increased IQ including in babies and children

- Piscetarians have lower rates of heart disease than both vegans and occasional meat eaters

- Promoting abstinence over harm reduction is generally a very silly and inefficient way to do things

SeafoodWatch already has a pretty solid iPhone and Android app that does this[1], but I'm all for more options and having raw JSON available.

[1] http://www.montereybayaquarium.org/cr/SeafoodWatch/web/sfw_i...

This is the same business idea as gooey.com, a dot com bust http://www.jamesaltucher.com/2011/02/my-name-is-james-a-and-...

However, they required that you download a separate piece of software. This AJAX and feels more spontaneous, easy to get started, probably resulting in a much higher growth rate.

>A bunch of discussions about why Google+ is better then Facebook etc...

Deflection, a common strategy by those who have not taken a walk with Mark Zuckerberg. By changing the topic, they avoid the social discomfort that comes with acknowledging they were not woodsworthy.

Exploring space with humans for the possibility of positive technological side effects does not seem a reliable, long term way to increase the number of people in space at any given time, if that is your primary goal. It seems like a way to temporarily boost the number by around 3.

If the goal is to increase the number of humans in space for the sake of increasing the number of humans in space, one would probably need to do research into a colonial business model sustainable enough to get investors and governments on board.

>you're just straight-up wrong about file transfers and polling. The select(), epoll(), et. al. syscalls are exactly what you want for large network file transfers.

I think there's some confusion on your end. My assertion was not that you shouldn't use polling for file transfers, but that you also needs to use at least one additional fork\ thread to do the polling in a second event loop to isolate disk-dependent connections, because polling does not work on the disk part of a file transfer, only the network part.

> standard C syscalls can easily indicate when the main thread would block while trying to read or write

Only on the socket end. Not the regular-file end. This has been the case for a long time on linux with O_NONBLOCK and regular files (aka not pipes\sockets\processes). Which OS\kernel version are you using?

I understand the desire for action, but we need to invent another task besides exploration to engage in. I.e. resource exploitation. Purely observational exploration of outer space is a task for which we are extremely maladapted (vacuum, long distances, etc.) that robots will probably always be better at.

>Almost certainly because space exploration is underfunded.

Or because there is currently no benefit in conducting exploration using humans instead of robots.

I'd contend the opposite, polling is better for dynamic content.

Let's say you have 1000 requests for a landing page, and the landing page has a data request that scrapes the entire database to find the popular-maximum-geo-similarity-reccomendation-zone-geo-user-thing list for the entire site, but only updates once every 10 seconds.

Ideally, you want to only send at most 1 request to your database every 10 seconds, without having to open a new connection. If you are doing a polling server and have all 1000 clients waiting for the data, you can trigger a callback to all of them when the database reports back without having to recopy data, use shared memory, do more ipc, or context switches. And for the 1000 clients to pause to wait for that single combined data callback, no extra blocking reads\connections to anything were necessary.

If by static content you are referring to file transfers, polling does not actually work on regular files in Linux. I believe they will always return ready to read even if reading would block. So usually a thread or forked process is actually required when handling files unless you dont mind disk seeks pausing the entire event loop on your server.

Only downside with LuaAPR is you're back to writing Apache style servers, with an OS thread for every connection instead of using non-blocking sockets where possible (Didn't find any support for nonblocking sockets or a select\poll variant in the linked docs)

For my Lua server [1] I currently use the nixio library from the LuCI project and polling instead[2]

Although the downside of both nixio and Lua/APR library is the use of compiled C bindings to manually interact with the virtual machine.

The exciting development with LuaJIT is the high performance FFI that allows you to make system calls and create structs directly from in Lua[3], so I am currently considering switching from nixio to ljsyscall when I do a new version [4]

[1]https://github.com/davidhollander/ox

[2]http://neopallium.github.com/nixio/

[3]http://luajit.org/ext_ffi_tutorial.html

[4]https://github.com/justincormack/ljsyscall

During the interview http://askobama.twitter.com/ at 42m20s, they claim that 10% of the questions are on Education, whereas twitsprout shows only 2% were on Education.

Comments from last time this was submitted:

http://news.ycombinator.com/item?id=1814355

> Even with the iteration count, SHA512 is not exactly meant to be slow.

Increasing iteration count is synonymous with intending something to be slow. BCrypt itself uses a default of 2^10 iterations in most bindings. PBKDF2 + and an NIST studied hashing algo like SHA512 is a perfectly valid method.

Why is bcrypt better than simply recursively hashing SHA512 ~2^11 times to produce an equivalent work factor?

Assume wall time is held constant at 1 second per password using both methods: is there an entropy loss or weakness associated with recursive hashing that bcrypt avoids?

>InnoDB with clustered indexes is pretty hard to beat for many scenarios. I hate that Oracle owns it, but damn it works well.

After Oracle stopped distributing the source on their website, an open-source project started continuing its development here: http://www.haildb.com/

Tokyo is my standard database for personal projects and goes great with Lua. Both are lightweight and fast, Cabinet has an excellent binding, and Tyrant has embedding.

Why would it switch to Twisted if it has always had its own lightweight event loop that's always benchmarked significantly faster? Same goes for fapws3 and gevent.

>I don't have any evidence to prove otherwise, but I have a feeling that the raw data is tampered with before release...

Evidence is the currency by which one fulfills burden of proof.

>Why would they up and release data all of a sudden?

You just read an article listing several reasons. All government data is by default public unless related to national security and explicitly upgraded to a higher secrecy level. You could already request to view any of the information being released, but it's cheaper to start moving all public information to one location than to have every agency inconsistently implement its own information handling processes.

It's extremely unlikely the government is coordinating all of its workers to tamper with public disability claims, military recruitment trends, environmental reports, geological surveys, public housing inventories, etc. before posting it on the site.

>(you yield control every time you make a blocking I/O call)

You're referring to is coroutine vs. continuation passing (callback). This is unrelated to whether you also are also forking into a small number of processes for each core. You can do both. Node simply doesn't yet. Nginx with workers is an example of an asynchronous server that does.

In regards to your link and the coroutine yielding approach: Being able to write psuedoblocking and monkeypatching code is not necessarily a good thing! It encourages you to keep making subrequests sequentially in serial, rather than in parallel as comes natural with using callbacks. It also discourages one from using custom continuation logic such as quorums. Examples of when the yielding approach fails:

- You want to both send and read independently on the same connection without creating multiple coroutines\greenthreads\userthreads per connection.

- You want to continue once 2 of 3 data services have calledback that information was successfully stored

I've written a fast single-core asynchronous server here in Lua without using user space thread yielding that you may be interested in: https://github.com/davidhollander/ox

> Node.js’s concurrency mechanisms are simply an approximation of Erlang’s.

Lulz? Here's a much simpler explanation: it's a polling server. It's not an intentional approximation of this or that (Erlang), this is just how event loops using select\poll\epoll\kqueue have always worked. Unless you want to do a bunch of extra work and throw in per-core preforking\threading and scrap the libev dependency Node built upon.

Buddhism for computer scientists:

The default state machine

    thought: if good, go to grasping. if bad, go to repressing. if neutral, ignore.
    grasping: increment mood, repeat until fail. go to fail //always fail
    repressing: repeat until fail. go to fail. //always fail
    fail: decrement mood, goto thought.

The enlightened state machine

    thought: go to observe
    observe: go to thought

http://www.urbandharma.org/pdf/mindfulness_in_plain_english....

>How about hn peeps meet in channel HackerNews?

I'm taking a coding break and will be on for the next hour. HNers are free to add me on BNET using the email in my profile.

If anyone is looking for an open source python version that doesn't require silverlight:

http://brainworkshop.sourceforge.net/

>The GPL has ultimately done more harm than good for open source.

This claim seems to defy the simplest explanation given the historical success of linux, so I think you need to be a bit more rigorous in substantiating your argument.

I'll agree that strictly enforcing 'giving back' is an unnecessary imposition and cost for adopters when a) there are many similar substitutable goods b) open source has momentum: evidence exists that giving back can be positive and in the adopters' interest.

However, neither of those were the case in the era when the GPL was born. The GPL should at least be given credit for helping bootstrap the present state of open source.

>most likely for being Internet Drama with little interest for the wider world.

At least it was better than TechCrunch.

Interesting how this disappeared from HN's front page without being dead-ed.

I seem to recall the 'Programming, Motherfucker' link meeting a similar mysteriously early demise, despite its 800+ upvotes.