Month: April 2019

How to replace procmail with fdm

 

 

 

Procmail is still widely used although it is no longer maintained. Its former maintainer on OpenBSD, Philip Gunther, has said that it should be removed from the ports list because of security vulnerability, although it is still there. A suggested alternative is fdm, which both fetches the mail from a POP3 server and filters it, thus replacing both fetchmail and procmail.

I’d been using procmail with fetchmail for a long time but I thought perhaps I should switch to fdm. The main difficulty was that the documentation I found was less complete than what is available for procmail and it took me a fair amount of time to configure it to use my spam filter, which is qsf.

Here is my fdm.conf for anyone who is thinking of making the same switch.  Qsf writes “SPAM” in the subject line of suspect emails so that’s what I filter on.

My fdm.conf

# fdm.conf – see the fdm manual for explanations of the code.

# Set the maximum size of mail:
set maximum-size 128M

# connection settings for my ISP’s mail server:
account “<my POP3 account>”
pop3 server “<my POP3 server>”
user “<my email address>”
pass “<my password>”

# filtering rules (adapted from my .procmailrc):
match “^(To|Cc):.*lyx-users@lists.lyx.org” action mbox “%h/Mail/lyx-users”
match “^(To|cc|Cc|Sender): .*misc@openbsd.org” action mbox “%h/Mail/openbsd”

# forward some mail to a different account (see “My forward file” below):
match “^From:.*Facebook” action pipe “%h/.forward”

# Spam filter rules:
action “spamfilter” rewrite “/home/ac/bin/qsf -s”
match all action “spamfilter” continue
match “^Subject:.*SPAM” action mbox “%h/Mail/spam”

# Set spoolfile for incoming mail:
action “inbox” mbox “/var/mail/ac”
match all action “inbox”

My .forward file

smtp <user@example.com>

Our murderous ancestors?

As David Reich explains in his recent book, genetic studies provide  evidence for the westward spread into central Europe of the Yamnaya
people from the stepes of Central Asia about five thousand years ago. This event is credited with the introduction of Indo-European languages. But exactly how the Yamnaya spread is uncertain. New Scientist has an interesting article on this by Colin Barras, with a rather sensationalist reference to the Yamnaya as ‘the most murderous people’.

Drawing largely on work by the archaeologist Kristian Kristiansen, Barras suggests that the arrival of the Yamnaya was a violent affair. The existing populations were already shrinking by this time, possibly as a result of epidemics of plague. The Yamnaya were probably physically stronger than the indigenous people and were more warlike. There is also a suggestion that they were mostly male.

This scenario reminds me of a poem by Robert Graves, who was influenced by the theory that an earlier matriarchal society had been replaced by a patriarchal one.

Swordsman of the narrow lips
Narrow hips and murderous mind
Fenced with chariots and ships,
By your joculators hailed
The mailed wonder of mankind,
Far to westward you have sailed.

As Barras remarks, these ideas are quite new and are based on evidence from only a few sites. But at present it seems likely that “the steppes migrants were largely male and violent”. This idea is supported bu a finding that mitochondrial DNA, which is maternally inherited, changedrelatively little at this time, while the paternally-inhrited Y-chomosome   changed a great deal.

New Scientist on free will

The current issue of New Scientist  gives pride of place to place to an article by Tom Stafford with the title: ‘It’s not an illusion, you have free will. It’s just not what you think’.

Libet’s research

Stafford refers to the famous experiments carried out by Benjamin Libet in the 1980s (see Freedom Evolves by Danel Dennett and The Illusion of Conscious Will by Daniel M. Wegner). Libet seemed to show that brain activity precedes conscious choice by an appreciable interval and many have take this to mean that free will is an illusion. But Stafford disagrees.

These results aren’t the great challenge to free will that they might seem at first. Their apparent force relies on misguided intuitions about what it means to have free will…. The misconception arises because we have difficulty comprehending causation in complex systems.

In a complex chaotic system, Stafford says, you cannot predict the outcome because there are innumerable possibilities, and human beings are so complex that they will always be unpredictable.

To illustrate this Stafford has created an interactive essay which you can tweet; a bot will then allow you to explore “your own unique path through the story, following the areas that most interest you”. This will convince you that “we are free to make real meaningful choices”.

Yes, our thoughts are caused by our brains, our environment and our history, but this causal mix is unique to each individual at each moment. That explains why human behaviour is so difficult to predict.

 

Continue reading “New Scientist on free will”

An instructive (personal) acupuncture case

 

An alternative to sham?

 

For reasons I discussed in another post, research on whether acupuncture  “works” is bedevilled by the difficullty of finding a control procedure that doesn’t actually do anything. A different approach to the testing of treatments is to use patients as their own controls. This is not often done but it remains a possibility. The idea is to study individuals with long-term symptoms and compare what happens when they are receiving treatment to when they are not. In a paper titled “Patients as their own controls in studies of therapeutic efficacy: Can we trust the results of non-randomized trials?”, Noel S. Weiss and Susan R. Heckbert (Journal of General Internal Medicine July 1988, Volume 3, Issue 4, pp 381–383) endorsed it.

This approach has the potential to provide a valid measure of efficacy if the condition being treated is chronic, if the effect of the therapy given prior to the first evaluation of patient status does not linger into the second period of the study, and if the means by which the evaluation of patient status is performed at the two points in time are comparable.

Case report

I want to describe a case of this kind. The patient is myself so I can’t claim any kind of objectivity, but I think the long period of observation makes it interesting. Anyway, for what it’s worth, here it is. Continue reading “An instructive (personal) acupuncture case”

Book review: Replay, by Ken Grimwood

It would be a disservice to readers to classify this as genre fiction (science fiction, fantasy or whatever). It is good enough to stand up in its own right as fiction pure and simple, and fiction of very high quality at that. It is also a metaphysical novel, but one that avoids any direct allusion to metaphysics. It’s a book I find I can reread at intervals: a good test indeed. Read more

Book review: The Gathering Storm, by Winston S. Churchill

This is the first volume of Churchill’s six-volume memoir of the Second World War. It is in two parts. Book I describes events in the years preceding the outbreak of war and Book II deals with the start of the war. I initially published the reviews of each part separately but here they are combined as one review.  Read more