Sayre’s law states, in a formulation quoted by Charles Philip Issawi: “In any dispute the intensity of feeling is inversely proportional to the value of the issues at stake.”
(via wikipedia)
Category: Link
Using Firebug to Evaluate XPath Queries in Firebug
Start the Firebug console and use the ‘$x’ function. It takes one argument, the xpath query in single quotes.
(via browsermob)
Publishing MATLAB Code
This link explains how you can annotate MATLAB code with markup to help communicate your ideas and result to others.
For some tasks I already know that it will beat the LaTeX or copy and paste into Word lifecycle.
Instead of Saying "I Don’t Have Time," Say "It’s Not a Priority"
Instead of Saying “I Don’t Have Time,” Say “It’s Not a Priority”
A Flowchart Cheatsheet
(via extreme presentation via lifehacker)
What is Endocrinology
A lot of papers on endometriosis that talk about measurements are talking about hormones. Reading about the study of those chemicals and mechanisms lead me to read Wikipedia’s article on the topic. These were the main high level points from the introductory paragraph:
- “is a branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions called hormones”
- and it’s mechanisms: “the coordination of metabolism, respiration, excretion, movement, reproduction, and sensory perception depend on chemical cues, substances synthesized and secreted by specialized cells.”
- “is concerned with the study of the biosynthesis, storage, chemistry, and physiological function of hormones and with the cells of the endocrine glands and tissues that secrete them.”
- “The endocrine system consists of several glands, all and in different parts of the body, that secrete hormones directly into the blood rather than into a duct system. Hormones have many different functions and modes of action; one hormone may have several effects on different target organs, and, conversely, one target organ may be affected by more than one hormone.”
- “In the original 1902 definition by Bayliss and Starling, they specified that, to be classified as a hormone, a chemical must be produced by an organ, be released (in small amounts) into the blood, and be transported by the blood to a distant organ to exert its specific function. This definition holds for most “classical” hormones, but there are also paracrine mechanisms (chemical communication between cells within a tissue or organ), autocrine signals (a chemical that acts on the same cell), and intracrine signals (a chemical that acts within the same cell)”
NexJ Scheme
NexJ Scheme is an open source project providing an efficient and powerful interpreter for the programming language Scheme that executes in a Java virtual machine.
Today I was sort of shocked to learn that there is another implementation besides SISC and Kawa that runs on Java!
There wasn’t even an announcement for NexJ on comp.lang.scheme and NexJ has been around for two years :(! Rather it was mentioned on scheme-reports this week.
Tarsnap: Online backups for the truly paranoid
Tarsnap is a secure online backup service for BSD, Linux, OS X, Solaris, Cygwin, and can probably be compiled on many other UNIX-like operating systems. The Tarsnap client code provides a flexible and powerful command-line interface which can be used directly or via shell scripts.
The design of Tarsnap was guided by the following four principles:
Security: Backups should be secure against attackers ranging from “script kiddies” up to major world governments, even if they can compromise the systems on which the backups are being stored. Backups are supposed to be a tool for mitigating damage — not a potential vulnerability to worry about!
Flexibility: Backups should be flexible and convenient. When you decide you want to create an archive, you should be able to store in it whatever files you want; if you decide that you want to delete an archive, you should be able to do it whenever you want, without impacting other archives; and there should be no arbitrary limits on how many archives you have stored, how often you can create new archives, or how long you can keep them for.
Efficiency: Backups should be efficient, using a minimal amount of storage and bandwidth. If you archive the same file twice, it should still only be uploaded and stored once; likewise, if you move, rename, copy, or make small changes to a file (e.g., adding a small amount of new data to the end of a log file or mail spool) you should never need to re-upload the entire file.
Utility: Backups should be provided as a utility, with linear (i.e., per-GB) pricing. Forcing people to figure out ahead of time how much data they want to back up so that they can sign up for the right “plan” is dumb, and having some customers subsidize other customers is inherently unfair.
— tarsnap website
Looks like an interesting service.
How one class brought SICP back at MIT
Zombie-like, 6.001 rises from the dead to threaten students again. Unlike a zombie, though, it’s moving quite a bit faster than it did the first time. Like the original, don’t walk into the class expecting that it will teach you Scheme; instead, it attempts to teach thought patterns for computer science, and the structure and interpretation of computer programs. Three projects will be assigned and graded. Prereq: some programming experience; high confusion threshold.
(via MIT via keegan via planethaskell)
How to Take a Calculus Test
Show what you know.
Don’t invent new math.
Don’t contradict yourself.
Do the easy questions first.
If you don’t know how to do a problem, start by writing down relevant things that you know are true in general.
Break difficult problems into manageable pieces.
Know what a function is, and know what things are functions.
If you aren’t taking a derivative, it’s probably wrong. (see the explanation below)
If you’re doing obscene amounts of computation, it’s probably wrong.
Don’t care about the final answer.
(via Jeremy)