Archive for the ‘life’ Category

Herbal medicine and its dangers

December 18, 2016

I recently heard a talk by Thomas Efferth of the Institute for Pharmacology of the University of Mainz on herbal medicine. There is a common point of view that substances derived from plants are harmless and good while the chemical drugs of standard medicine are evil. The speaker emphasized that plants have good reasons for not being good to those who eat them. They do not have immune systems of the type we do and they cannot run away and so it is natural that they use poisons to defend themselves. Herbal medicines are effective in some cases but they need to be subject to controls as much as do substances obtained by artificial chemical means. In the talk a number of examples of the dangers of ‘natural’ medicines were presented and I will write about some of them here.

The first example is that of Aristolochia. This a large genus of plants, some of which are poisonous. One of these, Aristolochia clematitis, has been extensively used in herbal medicine. It was used extensively in the west in ancient times and is used in traditional Chinese medicine until today. In the talk the story was told of an incident which happened in Belgium. There was a product sold as a means of losing weight which contained a Chinese plant. It sold so well that the manufacturer’s supplies of the plant were running out. When more was ordered a fateful mistake took place. There are two plants which have the same name in China. The one is that which was originally contained in the weight-loss product. The other is the poisonous Aristolochia fangchi and it was the one which was delivered. This led to more than 100 cases of kidney failure in the people using the product. Another way in which plants can be dangerous is as weeds in crop fields. In the Balkans contamination of grain with Aristolochia clematitis led to a kidney disease called Balkan nephropathy, with 35000 recorded cases. The substance, aristolochic acid, which is responsible for the kidney toxicity is also known to be a strong carcinogen. Interestingly, this substance is not poisonous for everyone and its bad effects depend a lot on the variability in liver enzymes among individuals.

A class of substances used by many plants to protect themselves against insects are the pyrrolizidine alkaloids. These substances are hepatotoxic and carcinogenic. They may move through the food chain being found, for instance, in honey. It has been noted that there may be risks associated to the amount of these substances contained in medicinal herbs used both in the West and in China. It was mentioned in the talk that drinking too much of certain types of herbal tea may be damaging to health. The problem is usually not the plants that are the main components of the teas but other plants which may be harvested with them in small quantities. There is at least one exception to this, namely coltsfoot (Tussilago farfara). In one case the death of an infant due to liver disease is believed to be due to the mother drinking this type of tea during pregnancy. After that the sale of coltsfoot was banned in Germany.

There were some remarks in the talk on heavy metals which I found quite suprising. One concerned ayurvedic medicine which has an aura of being gentle and harmless. In fact in many of these substances certain heavy metals are added delibrately (lead, mercury and arsenic). According to Wikipedia more than 80 cases of lead poisoning due to ayurvedic ‘medicines’ have been recorded. Another remark was that there can be significant concentrations of heavy metals in tobacco smoke. The negative health effects of smoking are sufficiently well known but this aspect was new to me.

Another theme in the talk was interactions between herbal medicines and normal drugs. Apparently it is often the case that patients who use herbal remedies are afraid to mention this to their doctors since they think this may spoil the relationship to their practitioner. Then it can happen that a doctor is suprised by the fact that a drug he prescribes is not working as expected. Little does he know that the patient is secretly taking a ‘natural’ drug in parallel. An example is St. John’s wort which is sometimes taken as a remedy for depression. It may work and it has no direct negative effects but it can be problematic because it reduces the effects of other drugs taken at the same time, e.g. the contraceptive pill. It changes the activity of liver enzymes and causes them to eliminate other drugs from the body faster than would normally happen, thus causing an effective reduction of the dose.

We are surrounded by poisonous plants. I was always sceptical of the positive effects of ‘natural’, plant-derived medicines. Now I have realised how seriously the dangers of these substances should be taken.

Honesty is the best policy

December 10, 2016

Yesterday I did the following thought experiment. I imagined a situation where someone asked me two questions, saying that I should answer spontaneously without thinking too long. The first question was ‘Are you happy with your life?’ and the second ‘Are you happy with the society around you?’ My answer to the first question was ‘yes’ and to the second ‘no’. I then started thinking about the cause of the discrepancy between these two answers. I came to the conclusion that it has a lot to do with the concept of ‘honesty’. I believe in and live according to the phrase in the title of this post, ‘honesty is the best policy’ while I feel that in the society around me lies have a huge influence. It is also worth remarking that lies are not the only kind of dishonesty.

If I am honest what is the reason? One important influence is my upbringing. I grew up in a family which was very attached to telling the truth. Here the influence of my mother was particularly strong. What influenced me was not so much what she said on the subject as the example of how she behaved. My mother’s attachment to honesty had a lot to do with her attachment to religion. I did not inherit her religion, becoming an atheist in my teens. I also did not inherit her moral convictions but I did inherit certain patterns of moral behaviour. One thing that stops me telling lies is simply that I find it very unpleasant due to childhood conditioning. Since truth plays a central role in mathematics it is perhaps natural that mathematicians should tend to be truthful, also in everyday life. It might also conversely be the case that among people who go into academia those with a specially strong attachment to truth might tend to go in the direction of mathematics.

Probably the main motivation for lying is the hope to gain some advantage by doing so. This may be short-sighted if despite a short-term profit the net long-term payment is negative. The idea that this is often the case is one motivation for me not to lie. Another is the fact that lies require management in order to profit from them. It is necessary to remember the lies you told so as not to betray yourself and it is also necessary to remember the corresponding true version. A lot of profitable lies require a lot of management and this is stress which I like to avoid. More thoughts in similar directions can be found on this web page

What types of dishonesty in society bother me? One is political correctness. It means sanctions againt telling the truth, or just speaking plainly rather than in euphemisms, in many situations. There are some cases where there may be good reasons for measures like this but I think that in the majority of cases there are no good reasons. They are based on arbitrary conventions or at best on misguided ideas of well-meaning people. I prefer to speak openly but I often avoid doing so and simply keep quiet in order to avoid problems. I would prefer if this was not so often necessary. A related topic is that of reference letters. When I write references for people applying for academic jobs I generally feel free to tell the truth. For jobs outside academia things are very different. There telling the truth might easily lead to disaster since open criticism is often effectively forbidden. Instead it is necessary to write in code and even then the information which might be helpful for the employer, or for the applicant, might not get through. In other situations it is necessary to be careful when criticising people but it is wrong not to criticise. Constructive criticism can be good. I am happy when I receive constructive criticism although it may be unpleasant at the moment it arrives. I believe that it is also important to make statements in certain situations like ‘in my opinion person X is better than person Y at doing task Z’. This is not a comparison of the value of the two people in general but just in the context of a particular ability.

One other theme I want to mention is marriage, because my marriage is one of the things in my life which contributes most to my happiness. When I use the word ‘marriage’ here I mean it to denote a long-term romantic relationship, not only one which is recognised legally by a piece of paper. I have been married in the latter sense for eight years but the underlying relationship goes back sixteen years. I would not dare to write here about individual marriages (apart from my own) but I will say something about averages. It seems that with time marriages in our society become less and less stable and last for shorter times. I believe in marriage in the old-fashioned sense of ’till death do us part’ and I think it is very unfortunate for many people that they have replaced this by a sequence of shorter-term relationships accompanied by difficult separations. The relation of this topic to that of honesty is as follows. I think that separations often result from the fact that the people involved are pursuing short term gains at the expense of the partner. Then the short-term gains turn into long-term losses. In a talk I heard recently the speaker voiced the opinion that the kind of degradation of marriage (or of love) I have been talking about is due to the fact that many people going into relationships have not had the experience of good marriages in their childhood. I had the advantage of growing up in surroundings where this type of relationship was widespread and I had very direct experience of how it was in the case of my own parents.

A visit to Iceland

September 4, 2016

I just returned from 10 days as a tourist in Iceland. It was not my first time there. Years ago I went on a cruise which included two stops in Iceland, one in Reykjavik and one in Akureyri. In each case there was a short bus tour to see some typical sights – a waterfall, a geysir and a volcanic region with bubbling mud and hot springs. This time I had a chance to see a lot more. I enjoyed the cruise a lot but I had the impression that the majority of the people on the ship were very bored. The main antidote to the boredom offered was lots of food. One day I got up from the dinner table and went on deck. There had been no indication that there might be something interesting to see. When I opened the door I was confronted with a beautifully conical volcano covered with ice, Snaefellsjökull. (I will come back to the interesting issue of Icelandic pronuciation later.) This was one of my strongest impressions from the whole cruise. The volcano is at the end of a long peninsula to the north of Reykjavik. This time I learned that this volcano is the esoteric centre of Iceland and that it was the starting point of Jules Verne’s Journey to the Centre of the Earth. This was not really a point on the programme of the tour this time but it was clearly visible with binoculars from the hotel in Rekjavik where we spent the last two nights. I had one view of it which was monochrome due to the light conditions but where the sharp edges of the crater stood our clearly.

One attraction of Iceland for me was the bird life. It seems that the country has claimed exclusive rights on the puffin. The numerous tourist shops in Reykjavik are called ‘puffin shops’ due to the number of representations of that bird they sell. I also saw puffin offered as one of the constituents of a special menu also including whale and horse meat. We spent one night in Vik and I discovered two stranded fulmars on a grass area not far from the hotel. These birds can only take off from an elevated starting point like a cliff or from water. If one lands on a flat area some distance from the sea then it is doomed unless it gets help. I rescued two of them by carrying them (ten minutes walk including crossing a road with significant traffic) to the sea. Since there had not been a big storm I suppose they had come down during their first flight after leaving the nest. (There were fulmars nesting on inland cliffs on the other side of the hotel from the sea.) Fortunately I still knew how to catch them and pick them up without hurting them or being the victim of their defence mechanism of spitting foul-smelling oil when feeling threatened. I enjoyed seeing a few glaucous gulls in the harbour in Reykjavik on the last day. Probably the last time I saw any was on the cruise I already mentioned. It was also nice to see and hear many whimbrels. The first one already welcomed me at the airport when I arrived.

I felt at home in the natural surroundings in Iceland and after a few days I thought of one explanation. There are very few trees in Iceland and this is just as it is in Orkney where I grew up. The first time I was on the mainland of Scotland when I was four years old I said ‘I don’t like this place – you can’t see anything for trees’. There are many areas in Iceland where there is only sand, rocks, water and ice. I had the impression of seeing what the Earth is really like, without the veil of green which we usually see. I also got an impression of what it is really like to live next to a volcano. I was in a museum close to (and devoted to) Eyafjallajökull, the infamous producer of ash with the complicated name. I learned that one US journalist just called it E15, due to the number of letters. There was a film showing in the museum explaining what people living near the volcano experienced at the time of the last eruption. Coming back to the name, the pronunciation of Icelandic does seems to be a difficult question but also an interesting one. I would like to spend some time understanding it better. There are nice videos on the pronuciation of Eyafjallajökull here and here. The final double l is the really tricky point. There are points of similarity between the Icelandic language and the dialect I grew up with. This is due to the influence of an extinct language called Norn which was spoken on Orkney and Shetland in past centuries and which is related to (Old) Icelandic. For instance the oystercatcher is called tjaldur in Icelandic and chaldro in our dialect.

I also had some culinary experiences. At breakfast in the hotels there was always a bottle of cod liver oil on the table. I remember this liquid from my childhood as a threat used on young children. ‘If you do not behave yourself I will give you a spoonfull of cod liver oil.’ Due to persistent encouragement from Eva I tried a little and found it not as bad as I expected. Our guide also gave us some pieces of Greenland shark to try. He gave  us a warning about the taste and some of the alcholic drink called the black death to wash it down with. It tastes of nothing at first but chewing leads to a strong taste reminiscent of urine. In fact the flesh of the shark is poisonous due to its content of trimethylamine N-oxide. In Iceland it is treated by first burying it for several weeks and then drying it to get rid of the poison. The result is considered a delicacy. The Greenland shark is interesting because of the fact that it was recently discovered that it can live to be four hundred years old, only becoming sexually mature when it is 150. I want to read more about it.

As a final comment on Iceland: the weather was much better than we expected!

An eternal pedestrian

June 13, 2016

I am presently visiting Japan. My host is Atsushi Mochizuki who leads the Theoretical Biology Laboratory at RIKEN in Wako near Tokyo. RIKEN is a research organisation which was founded in 1917 using the Kaiser-Wilhelm-Gesellschaft as a model. Thus it is a kind of Japanese analogue of the Max Planck Society which is the direct descendant of the Kaiser-Wilhelm-Gesellschaft. I had only been in Japan once before and looking at my records I see that that was in August 2005. At that time I attended a conference in Sendai, a place which I had never heard of before I went there. Since then it has become sadly famous in connection with the damage it suffered from the tsunami which also caused the Fukushima nuclear disaster. At least I had even then previously heard of Tohoku University which is located in the city.

Yesterday, sitting by the river in Wako, I was feeling quite meditative. I was in an area where motor vehicles are not permitted. There were not many people around but most of those who were there were on bikes. I started thinking of how this is typical of what I have experienced in many places I have been. On a walk along the Rhine in Mainz or in the surrounding countryside most of the people you see are on bikes. Copenhagen is completely dominated by bikes. In the US cars dominate. For instance when I was in Miami for a conference and was staying at the Biltmore Hotel I had to walk quite a distance to get dinner for an affordable price. In general the only people I met walking on the streets there were other conference participants. When I visited the University of California at Santa Barbara bikes were not the thing on the campus but it was typical to see students with skateboards. Summing up, I have frequently had the experience that as a pedestrian I was an exception. It seems that for normal people just putting one foot in front of the other is not the thing to do. They need some device such as a car, a bike or a skateboard to accompany them. I, on the other hand, am an eternal pedestrian. I like to walk places whenever I can. I walk twenty minutes to work each day and twenty minutes back. I find that a good way of framing the day. When I lived in Berlin there was a long period when I had a one-way travelling time of 90 minutes by train. I am glad to have that behind me. I did not consciously plan being so near to work in Mainz but I am glad it happened. Of course being a pedestrian has its limits – I could not have come to Japan on foot.

My pedestrian nature is not limited to the literal interpretation of the term. I am also an intellectual pedestrian. An example of this is described in my post on low throughput biology. Interestingly this post has got a lot of hits, more than twice as many as any other post on my blog. This is related to the theme of simple and complex models in biology. Through the talks I have given recently in Copenhagen, Berlin and here in Japan and resulting discussions with different people I have become of conscious of how this is a recurring theme in those parts of mathematical biology which I find interesting. The pedestrian may not get as far as others but he often sees more in the places he does reach. He may also get to places that others do not. Travelling fast along the road may cause you to overlook a valuable shortcut. Or you may go a long way in the wrong direction and need a lot of time to come back. Within mathematics one aspect of being a pedestrian is calculating things by hand as far as possible and using computers as a last resort. This reminds me of a story about the physicist John Wheeler who had a picture of a computer on the wall in his office which he called ‘the big computer’. When he wanted to solve a difficult problem he would think about how he would programme it on the computer and when he had done that thoroughly he had understood the problem so well that he no longer needed the computer. Thus the fact that the computer did not exist except on paper was not a disadvantage.

This is the direction I want to (continue to) go. The challenges along the road are to achieve something essential and to make clear to others, who may be sceptical, that I have done so.

Flying to Copenhagen without a carpet

May 11, 2016

This semester I have a sabbatical and I am profiting from it by travelling more than I usually do. At the moment I am visiting the group of Carsten Wiuf and Elisenda Feliu at the University of Copenhagen for two weeks. The visit here also gives me the opportunity to discuss with people at the Niels Bohr Institute. Note that the authors of the paper I quoted in the post on NF\kappaB were at the NBI when they wrote it and in particular Mogens Jensen is still there now. I gave a talk on some of my work on the Calvin cycle at NBI today. Afterwards I talked to Mogens and one of his collaborators and found out that he is still very active in modelling this system.

I was thinking about my previous visits to Copenhagen and, in particular, that the first one was on a flying carpet. The background to this is that when I was seven years old I wrote a story in school with the title ‘The Magic Carpet’. I do not have the text any more but I know it appeared in the School Magazine that year. In my own version there was also a picture which I will say more about later. But first something about the story, of which I was the hero. I bought the carpet in Peshawar and used it to visit places in the world I was interested in. For some reason I no longer know I had a great wish at that time to visit Copenhagen. Perhaps it was due to coming into contact with stories of Hans Christian Andersen. In any case it is clear that having the chance this was one of the first places I visited using the magic carpet. The picture which I drew showed something closer to home. There I can be seen sitting on the carpet, wearing the blue jersey which was my favourite at that time, while the carpet bent upwards so as to just pass over the tip of the spire of St. Magnus Cathedral in Kirkwall. In the story it was also related that one of the effects of my journey was a newspaper article reporting a case of ‘mass hallucination’. I think my teachers were impressed at my using this phrase at my age. They might have been less impressed if they had known my source for this, which was a Bugs Bunny cartoon.

During my next visit to Copenhagen in 2008 (here I am not counting changing planes there on the way to Stockholm, which I did a few times) I was at a conference at the Niels Bohr Institute in my old research field of mathematical relativity and I gave a talk in that area. Little did I think I would return there years later and talk about something completely different. I remember that there was a photo in the main lecture room where many of the founders of quantum mechanics are sitting in the first row. From my own point of view I am happy that another person who can be seen there is Max Delbrück, a shining example of a switch from physics to biology. My next visit to Copenhagen was for the conference which I wrote about in a previous post. It was at the University. Since that a lot has happened with chemical reaction network theory and with my understanding of it. The lecture course I gave means that some of the points I mentioned in my post at that time are things I have since come to understand in some depth. I look forward to working on projects in that area with people here in the coming days.

Trip to the US

October 5, 2015

Last week I visited a few places in the US. My first stop was Morgantown, West Virginia where my host was Casian Pantea. There I had a lot of discussions with Casian and Carsten Conradi on chemical reaction network theory. This synergized well with the work I have recently been doing preparing a lecture course on that subject which I will be giving in the next semester. I gave a talk on MAPK and got some feedback on that. It rained a lot and there was not much opportunity to do anything except work. One day on the way to dinner while it was relatively dry I saw a Cardinal and I fortunately did have my binoculars with me. On Wednesday afternoon I travelled to New Brunswick and spent most of Thursday talking to Eduardo Sontag at Rutgers. It was a great pleasure to talk to an excellent mathematician who also knows a lot about immunology. He and I have a lot of common interests which is in part due to the fact that I was inspired by several of his papers during the time I was getting into mathematical biology. I also had the opportunity to meet Evgeni Nikolaev who told me a variety of interesting things. They concerned bifurcation theory in general, its applications to the kinds of biological models I am interested in and his successes in applying mathematical models to understanding concrete problems in biomedical research such as the processes taking place in tuberculosis. My personal dream is to see a real coming together of mathematics and immunology and that I have the chance to make a contribution to that process.

On Friday I flew to Chicago in order to attend an AMS sectional meeting. I had been in Chicago once before but that is many years ago now. I do remember being impressed by how much Lake Michigan looks like the sea, I suppose due to the structure of the waves. This impression was even stronger this time since there were strong winds whipping up the waves. Loyola University, the site of the meeting, is right beside the lake and it felt like home for me due to the combination of wind, waves and gulls. The majority of those were Ring-Billed Gulls which made it clear which side of the Atlantic I was on. There were also some Herring Gulls and although they might have been split from those on the other side of the Atlantic by the taxonomists I did not notice any difference. It was the first time I had been at an AMS sectional meeting and my impression was that the parallel sessions were very parallel, in other words in no danger of meeting. Most of the people in our session were people I knew from the conferences I attended in Charlotte and in Copenhagen although I did make a couple of new acquaintances, improving my coverage of the reaction network community.

In a previous post I mentioned Gheorghe Craciun’s ideas about giving the deficiency of a reaction network a geometric interpretation, following a talk of his in Copenhagen. Although I asked him questions about this on that occasion I did not completely understand the idea. Correspondingly my discussion of the point here in my blog was quite incomplete. Now I talked to him again and I believe I have finally got the point. Consider first a network with a single linkage class. The complexes of the network define points in the species space whose coordinates are the stoichiometric coefficients. The reactions define oriented segments joining the educt complex to the product complex of each reaction. The stoichiometric subspace is the vector space spanned by the differences of the complexes. It can also be considered as a translate of the affine subspace spanned by the complexes themselves. This makes it clear that its dimension s is at most n-1, where n is the number of complexes. The number s is the rank of the stoichiometric matrix. The deficiency is n-1-s. At the same time s\le m. If there are several linkage classes then the whole space has dimension at most n-l, where l is the number of linkage classes. The deficiency is n-l-s. If the spaces corresponding to the individual linkage classes have the maximal dimension allowed by the number of complexes in that class and these spaces are linearly independent then the deficiency is zero. Thus we see that the deficiency is the extent to which the complexes fail to be in general position. If the species and the number of complexes have been fixed then deficiency zero is seen to be a generic condition. On the other hand fixing the species and adding more complexes will destroy the deficiency zero condition since then we are in the case n-l>m so that the possibility of general position is excluded. The advantage of having this geometric picture is that it can often be used to read off the deficiency directly from the network. It might also be used to aid in constructing networks with a desired deficiency.

Rereading ‘To the Lighthouse’

August 23, 2015

There are some statements I started to believe at a certain distant time in my life and which I have continued to accept without further examination ever since. One of these is ‘the English-language author who I admire most is Virginia Woolf’. Another is obtained by replacing ‘English-language author’ by ‘author in any language’ and ‘Virginia Woolf’ by ‘Marcel Proust’. At one point in her diary Virginia Woolf writes that she has just finished reading the latest volume of ‘A la Recherche du Temps Perdu’ which had recently been published. Then she writes (I am quoting from memory here) that she despairs of ever being able to write as well as Proust. Perhaps she was being too modest at that point. Until very recently it was a long time since I had read anything by Woolf. I was now stimulated to do so again by the fact that Eva and I were planning a trip to southern England, including a visit to St. Ives. For me that town is closely associated with Woolf and it is because of the connection to her that I was motivated to visit St. Ives when I spent some time in Cornwall several years ago. (Here I rapidly pass over the fact, without further comment, that the author with the widest popular success whose books have an association with St. Ives is Rosamunde Pilcher.) The other aspect of my first trip to Cornwall which is most distinct in my memory is missing the last bus in Land’s End and having to walk all the way back to Penzance where I was staying. We visited Land’s End again this time but since I did not want miss the bus again I did not have time to visit the ‘Shaun the Sheep Experience’ which is running there at the moment. As a consolation, during a later visit to Shaun’s birthplace, Bristol, I saw parts of the artistic event ‘Shaun in the City’ and had my photograph taken with some of the sculptures of Shaun.

When I go on a holiday trip somewhere I often like to take a book with me which has some special connection to the place I am going. Often I have little time to actually read the book during the holiday but that does not matter. For Cornwall and, in particular, St. Ives the natural choice was ‘To the Lighthouse’. That novel is set in the Isle of Skye but it is well known that the real-life setting which inspired it (and the lighthouse of the title) was in St. Ives. This lighthouse, Godrevy Lighthouse, cost a little over seven thousand pounds to build, being finished in 1859. In 1892, on one of two visits there, the ten year old Virginia signed the visitors book. The book was sold for over ten thousand pounds in 2011. So in a sense the little girl’s signature ended up being worth more money than the lighthouse she was visiting. Of course, due to inflation, this is not a fair comparison. Looking on my bookshelves at home I was surprised to find that I do not own a copy of ‘To the Lighthouse’. On those shelves I find ‘The Voyage Out’, ‘Jacob’s Room’, ‘Moments of Being’ and ‘Between the Acts’ but neither ‘To the Lighthouse’ nor ‘The Waves’. Perhaps I never owned them and only borrowed them from libraries. I have a fairly clear memory of having borrowed ‘To the Lighthouse’ from the Kirkwall public library. I do not remember why I did so. Perhaps it was just that at that time I was omnivorously consuming almost everything I found in the literature section in that library. Or perhaps it had to do with the fact that lighthouses always had a special attraction for me. An alternative explanation for the fact I do not own the book myself could be that I parted with it when I left behind the majority of the books I owned when I moved from Aberdeen to Munich after finishing my PhD. This was due the practical constraint that I only took as many belongings with me as I could carry: two large suitcases and one large rucksack. I crossed the English Channel on a ferry and I remember how hard it was to carry that luggage up the gangway due to the fact that the tide was high.

I find reading ‘To the Lighthouse’ now a very positive experience. Just a few paragraphs put me in a frame of mind I like. I have the feeling that I am a very different person than what I was the first time I read it but after more than thirty years that is hardly surprising. I also feel that I am reading it in a different way from what I did then. I find it difficult to give an objective account of what it is that I like about the book. Perhaps it is the voice of the author. I feel that if I could have had the chance to talk to her I would certainly have enjoyed it even if she was perhaps not always the easiest of people to deal with. Curiously I have the impression that although I would have found it extremely interesting to meet Proust I am not sure I would have found it pleasant. So why do I think that I may be appreciating aspects of the book now which I did not last time? A concrete example is the passage where Mrs Ramsay is thinking about two things at the same time, the story she is reading to her son and the couple who are late coming home. The possibility of this is explained wonderfully by comparing it to ‘the bass … which now and then ran up unexpectedly into the melody’. I feel, although of course I cannot prove it, that I would not have paid much attention to that passage during my first reading. The differences may also be connected to the fact that I am now married. Often when I am reading a book it is as if my wife was reading it with me, over my shoulder, and this causes me to pay more attention to things which would interest her. A contrasting example is the story about Hume getting stuck in a bog. I am sure I paid attention to that during my first reading and it now conjured up a picture of how I was then, perhaps eighteen years old and still keen on philosophy. After a little thought following the encounter with the story it occurred to me that I knew more of the story about Hume, that he was allegedly forced to say that he believed in God in order to persuade an old woman to pull him out. This extended version is also something I knew in that phase of my life, perhaps through my membership in the Aberdeen University philosophy society. On the other hand this story does come up (at least) two more times in the book and it is a little different from what I remember. What the woman forced him to do was to say the Lord’s Prayer.

I came back from England yesterday and although I did not have much time for reading the book while there I am on page 236 due to the head start I had by reading it before I went on the trip. The day we went to St. Ives started out rainy but the weather cleared up during the morning so that about one o’ clock I was able to see Godrevy lighthouse and look at it through through my binoculars. They also allowed me to enjoy good views of passing gannets and kittiwakes but I think I would have been disappointed if I had made that trip without seeing the lighthouse.

Arrival in Bretzenheim

May 1, 2015

Since I moved to Mainz two years ago my wife has remained in Berlin and we have been searching for a suitable place to live in Mainz or its surroundings. The original plan was to buy a piece of land on which we could build a house. This turned out to be much more difficult than we expected. The only land within our financial horizons was in small villages with almost no infrastructure or had other major disadvantages from our point of view. Eventually, after wasting a lot of time and effort, we stopped searching in the surroundings and looked for something in Mainz itself. Of course this was not easy but eventually we decided to buy a house (still to be built) within a small housing scheme in the district of Mainz called Bretzenheim. There is very little land available in Mainz and the scheme where we will be living is an example of the way in which the few remaining open spaces are being filled up, driven by the high property prices. The house was finished in March and I moved in on a provisional basis on 1st April, giving up my appartment, exactly two years after starting my job in Mainz. (Goodbye Jackdaws! The first birds I saw in what will be our garden were a Carrion Crow, which I am not taking as a bad omen, and a Black Redstart.) Our belongings left Berlin on 16th April and arrived in Mainz on 17th. Eva came to Mainz definitively on the 16th. So now there can be no doubt that a new era has begun for us.

The new house is conveniently situated. From there I can walk to the mathematics institute in 20 minutes and to the main train station in half an hour. It is near the end of a tram line coming from the station. Very close to where the houses have been built a Merovingian grave was found. When the garden centre a little further up the hill was being built the grave of a Merovingian warrior was found who had been buried with his horse. It is just as well for us that the archeologists did not dig too deep or we might have had to wait a long time before we could move in. Whenever you dig a hole in Mainz you are in danger of encountering a distant past and potential problems with the archeology department of the city. To show what can happen I will give an example. In the district of Gonsenheim there is a small stream, the Gonsbach. At some time when progress was fashionable the winding stream was straightened. Later an EU directive came into force which said that streams like this which had been straightened had to be made winding again, for ecological reasons, within a certain number of years. By now the deadline has been reached, or almost reached for the Gonsbach, and the city has started measures to attempt to comply with the directive. They started to dig and found … a Roman settlement. The work had to be stopped, for archeological reasons. So now, as far as I know, the archeological and ecological regulations and the city officials representing them are in deadlock.

Since I am British it is a curiosity for me that one suggested origin of the name Bretzenheim is that it is named after the Britons. It has been suggested that it could be identified with a certain vicus Brittaniae where the Roman Emperor Severus Alexander was murdered in the year 235. The evidence for this seems limited and an alternative hypothesis says that it was named after a locally important man called Bretzo. I cannot imagine what the Britons would have been doing there. Another theory is that the emperor was murdered in Britain and not in Mainz.

Hello Mainz

April 18, 2013

This post is in some sense dual to the earlier one ‘goodbye to Berlin‘. To start with I can confirm that there is no shortage of Carrion Crows (and no Hooded Crows) in Mainz. When I arrived here and was waiting for my landlord to come and let me into my flat I saw some small and intensely green spots of colour in a row of trees in front of me. I knew the source of these – they were what I could see of Ring-Necked Parakeets. I have known for a long time that these birds live wild in England but it was only relatively recently, in the course of my activity looking for jobs, that I realised they were so common in parts of Germany. While in Heidelberg for an interview I observed a big number of them making a lot of noise in a small wood opposite the main railway station. I also saw some of them when I came to Mainz for the interview which eventually led to my present job. In my old institute in Golm I often used to see Red Kites out of my office window. It occurred to me that these might be replaced by Black Kites in Mainz. During my first weekend here I was walking across the campus of the university when I saw a large and unfamiliar bird of prey approaching me. When it came closer I realised that it was a Black Kite. I enjoyed the encounter. Since that I have also seen one from my office window. The Red Kite is a beautiful bird but for some reason I feel closer to its dark relative. It gives me a feeling of the south since the first place I saw these birds many years ago was in the Camargue.

Eva and I have been using Skype to maintain contact. I feel that this big change in our life has not been without benefits for our communication with each other and when I was home last weekend it was a richer experience than many weekends in the last few years. I appreciate the warm welcome I have had from my colleagues here in Mainz and my first days here, while sometimes a bit hectic, have been rewarding. Breaking the routine of years opens up new possibilities. I assured myself that I will not completely have to do without interesting biological talks here by going to a lecture by Alexander Steinkasserer on CD83. This taught me some more about dendritic cells for which this surface molecule is an important marker.

This is the first week of lectures here and yesterday brought the first concrete example of the new direction in my academic interests influencing my teaching, with the start of my seminar on ‘ordinary differential equations in biology and chemistry’. The first talk was on Lotka-Volterra equations. The subjects to be treated by other students in later lectures include ones a lot further from classical topics.

Goodbye to Berlin

February 1, 2013

For this post I could not resist the temptation to borrow the title of Christopher Isherwood’s novel although what I am writing about here has very little to do with his book. The connection of the title to the content is that I will soon be leaving Berlin after living here more than fifteen years. I have accepted a professorship at the University of Mainz and I will move there in April. The first time I came to Berlin I landed at Tegel airport and I interpreted the Hooded Crow I saw beside the runway as a good omen. This requires some explanation. In those days the Hooded Crow (Corvus corone cornix) was a subspecies of the Carrion Crow. In the meantime it has been promoted to the rank of a species but that will not concern me here – I am not sure whether I feel I should congratulate it on receiving this honour. It differs from the nominate form (according to the old classification) by having a grey body while Corvus corone corone (Carrion Crow in the narrower sense) is all black. These two forms have the classical property of subspecies that they are allopatric. In other words they occur in more or less disjoint regions. On the boundary between the regions there is little interbreeding. The Orkney Islands where I grew up belong to the land of the Hooded Crow. Most of Great Britain and in fact most of Western Europe belong to the domain of the Carrion Crow. Even Aberdeen, where I studied and did my PhD, belongs to the land of the Carrion Crow. This helps to explain why I associate the Hooded Crow with ‘home’ and the Carrion Crow with ‘foreign parts’. It also has to do with the fact that there was a Hooded Crow which nested regularly in a garden near where I grew up in Orkney. I would climb the tree from time to time to keep an eye on the development of the brood and ring the chicks at the right moment. For these reasons the bird in Tegel seemed to tell me I was coming home. Now I am daring to venture once again (and probably for most of the rest of my life) into the land of the Carrion Crow.

When leaving a place it is natural to think about the good things which you experienced there. What were the best things about Berlin for me? The best thing of all is that Berlin was where I met my wife Eva. Eichwalde, where she lived at that time and where we both live now, has a very special feeling for me which will never go away. (Just for the record, we do not really live in Eichwalde but that is where the nearest train station is, with the result that the platform of the station there has something of the gates of Paradise for me.) Of course I cannot fail to mention the Max Planck Institute for Gravitational Physics which has provided me with a scientific home during all that time. I am grateful to the successive leaders of the mathematical group there, Jürgen Ehlers and Gerhard Huisken, for the working and social environment which they created and maintained. Another important thing about Berlin I will miss is the contact with its excellent research in biology and medicine. I have spent many valuable hours attending the Berlin Life Science Colloquium and I feel very attached to the Paul Ehrlich lecture hall where it usually takes place. The wooden seats are hard but the interest of the lectures was generally more than enough to make me forget that. I will also miss the stimulating atmosphere of the group of Bernold Fiedler at the Free University, which has been a source of a lot of intellectual input and a lot of pleasure.

This is perhaps the moment to say why I am leaving Berlin. Ever since I was a student I have felt a strong allegiance to mathematics. As a child I was concerned with metaphysical questions and later I got interested in physics as the most fundamental part of science. During my undergraduate study I realised that mathematics, and not physics, was the right intellectual environment for me. A key experience for me was that through my study plan I ended up doing two courses on Fourier series, a subject which was new to me, at the same time. One was in physics and one in mathematics. The contrast was like night and day. This may have had something to do with the abilities of the individual lecturers concerned but it was mainly due to essential differences between mathematics and physics. By the end of my studies I had specialized in mathematics and my commitment to that subject has remained constant ever since.

For a long time my strongest connection to mathematics concerned intrinsic aspects of the subject. The significance of applications for me was as a good source of mathematical problems. This has changed over the years and I have become increasingly fascinated by the interplay between mathematics and its applications. At the same time the focus of my interest has moved from mathematics related to fundamental physics to mathematics related to biology and medicine. This change has led to a discrepancy between the research I want to do and the research area of the institute where I work. A Max Planck Institute is by its very nature focussed on a certain restricted spectrum of subjects and this is not compatible with a major change of research direction of somebody working there. This is the reason that I started applying for jobs which fitted the directions of work where my new interests lie. The move to Mainz is the successful endpoint of this process. Moving from a Max Planck Institute to a university will naturally involve spending more time on teaching and less time on research. This does not dismay me. The most important thing is that I will be doing something I believe in. Teaching elementary mathematics and analysis, apart from establishing the basis needed for doing research, is something whose intrinsic value I am convinced of.