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  * MY RESEARCH (part 1)  



Mathematical statistics

Statistical genetics

Social medicine



(Psychiatric genetics)

(Season of birth issues: neurotransmitters, suicide, and personality)

(Season of birth issues: gene-environment interaction)

(Season of birth issues: Born lucky?)

(Other research (NOT season of birth) )

(Doctoral supervision: Postconflict displaced persons in Ethiopia)

(Doctoral supervision: The effect of support and disease awareness education on depression in primary health care)




The history of discovery is full of arrivals
at unexpected destinations,
and arrivals at the right destination
by the wrong boat.
- Arthur Koestler




I am going to take the reader on a tour of several research topics that I have been involved in during the years. At the outset, I want to declare that I do not consider myself to be any remarkable researcher, and I have not made any revolutionary discoveries. The level of my research activity has been fluctuating throughout the years, with my research production appearing at irregular intervals, and with many quiet intervals in between. The fields of research I have devoted myself to have been shifting, and at times I have returned to a previous field, albeit from a different angle. It is as if I have floated around without stress, taking life as it unfolds.

I feel that I have been offered many opportunities in life, I have been "given a break" many times in my life for research projects, but I have not used these opportunities optimally, mainly because I have often found it difficult to "keep my eye on the ball" due to my diverging interests. I have somehow psychologically resisted getting "stuck" with any particular area for long periods.

Such a behaviour can often lead one to become a "Jack of all trades but master of none". Subjectively, I often feel myself neither a Jack of any field nor a master of any field. Seen from this perspective, I have only browsed through mathematical statistics, statistical genetics, social science, biological psychiatry, and epidemiological psychiatry.

However, a quality in me that has been found by others to be positive, has been that I have usually made myself extremely well-read in the area I am doing research on.

Nonetheless, research is something that has been my passion in many ways. It has been a principal source of pleasure for me, it has been my hobby, it has stimulated me to read widely across diverse scientific disciplines, it has given me spiritual nourishment.

I have realized all the more when doing research and reading in different scientific disciplines, that the core activity or essence of doing research requires a similar aptitude in different fields, be it mathematics, genetics, social science or clinical science. Research requires, among others, curiosity, detective-ness, perseverance, and luck. I think of a parallel, not in content but in structure, that is given by different religions. I have found there also that the core essence of spirituality is similar in different religions, although the specific models may be different. In research, one gets a tremendous amount of satisfaction to see ones name published internationally in journals, and being cited by others.


There is one thing that I have learnt the hard way during the course of my research. This is elegantly said by a scientist called Brailsford Robertson: "It is not the talents we possess so much as the use we make of them that counts in the progress of the world". So to be successful, one has to be able to make use of one's talents, not only possess them, and conversely, those who are considered successful in the community, are not necessarily the most talented ones.

Another thing that I have learnt concerns the concept of being original or creative or come up with a new idea. You often read stories about scientists who had put forward theories which were not accepted by the scientific community until many years later, when further developments in research point to the same theory. Actually, there is no dearth of new ideas or new theories. For every new idea that did not get accepted by the community until many years later, there are thousands of new ideas that turn out to be false and useless in time. So the problem a scientist faces is, which of the new ideas floating around are the ones that are "true" or useful?

Also, for an individual scientist, it is not enough to come up with a new idea - it is still more important to show that the idea indeed works and can be useful to push ahead the frontiers of science. So a person who is prolific in ideas is not necessarily more useful or more successful than someone with less ideas, but who has the ability and perseverance to make the ideas workable.



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"The art of scientific investigation" is the best book I know of the process of scientific research, although it was first written many years ago.

Doing research is also a pleasant adventure, like trekking!


Mathematical statistics:

I owe my contributions in mathematical statistics to the generous support and encouragement from Professor Gunnar Kulldorff, Umeå. Already in 1972, he offered me a parttime work (amanuens) at his department, which was a starting point for me to pursue knowledge in the field of mathematical statistics. He was my supervisor for all the research I undertook in that subject.

Gunnar Kulldorff had met a lot of good indian statisticians, since there are a lot of them both in India and in northern America. So Gunnar had a very high opinion about the culture of theoretical and applied statistics among indians. I think that it was one of the factors which made Gunnar very positively inclined towards me.

Gunnar had taught us a course on survey sampling, and since he had done research in that area, he suggested in 1973 that I look at the problem of sampling from a population on two occasions, where the statistical information obtained from the first occasion could be utilized to make sampling on the second occasion more efficient. He suggested that I look at the sampling scheme where the units from the population are selected with varying probabilities, a so-called pps sampling. This was the first real opportunity for me to ponder on a scientific problem like a detective, and look at it from different angles to try find a better way than previously known. This is when I discovered the pleasure and beauty of doing research!

In this exploration for extending the theory from sampling on one occasion to two occasions, I came upon an approach and method that was more efficient than suggested in a publication by a JNK Rao, who was a renowned statistician in that field. This constituted my MSc thesis, a part of which I sent for publication to an international journal called Sankhya. I was delighted when the paper was accepted and published in 1974, since this was my first publication in a scientific journal!

A beauty of doing research, which most researchers do not openly talk about, is seeing your name published and spread all over the world. As a researcher you feel a part of an international community. You get a deep satisfaction that maybe you have done some little minute thing that is communicated internationally. So, for example, I remember one day, when on return from an international conference, Gunnar Kulldorff said to me that he had met the above-mentioned JNK Rao, who had asked Gunnar who this indian person was at his dept who published nice research - he had been a reviewer of my published paper!

I also remember one amusing incident. We once had a short visit in Umeå around 1975 by a professor AR Sen from Canada, he was of indian origin. (Gunnar Kulldorff had contacts with many renowned researchers in statistics worldwide). When I met him at the dept and greeted him, he said that he had heard of an indian female statistician in Umeå, and he would very much like to meet her. I pondered for a few seconds, I was surprized since I did not know of any, which I told him. He insisted, and said he had read her paper in Sankhya recently. Then I understood what the problem was. Jayanti as a name in most parts of India is a female name. Actually my name is Jayantilal, which is a purely male name, but I have shortened it for convenience, and my passport and official documents contain Jayantilal.

Then it was time to choose an area of research for my doctoral thesis. A few years previously, Gunnar Kulldorff had spent his sabbatical in the USA, and had got involved with an area called selection and ranking procedures. Briefly, this consists of statistical methods and procedures when selecting the best of a number of competing commodities, for example drugs, grains, vehicles, etc, with regards to a specified criterion of goodness. Gunnar was continuously collecting a bibliography in this area of research, including yet unpublished technical reports from all over the world. So in a way, Gunnar had a "gold-mine" for doing research in this field.

I started thinking in terms of some newer methods and procedures in selection problems, and Gunnar helped me formulate the ideas and formalize them. I employed the so-called likelihood ratio, and realized that there was a bridge between selection and ranking problems and another area of reseach in statistics called statistical inference under order restrictions. My doctoral thesis, called selection and ranking procedures based on likelihood ratios, was defended on 1 June 1979.

In the Swedish academic system, the PhD candidate has to defend his or her thesis "in public". This means that three weeks before the defence date, the thesis should be available to anyone who wants to read it. Usually, a notice is put in the local newspaper about the event. On the defence day, the "opponent" (an external professor who has been decided upon in advance) and the candidate sit in front of the audience (everybody allowed) and discuss the thesis. The opponent usually has questions and queries, some of them quite tricky, and the candidate has to respond to them successfully. When they are finished with each other (takes a couple to three hours), the (three to five) members of the examining committee are asked in turn to put questions to the candidate. After that, the floor is open to the rest of the audience to put questions or give comments. The committee meets behind closed doors after the defence to pass the thesis if the contents and the defence were both successful. For the evening, the candidate has usually planned a nice party for relatives and friends and colleagues, since the relatives have come travelling to witness the event. In most cases the candidate obtains a pass, but in those rare cases where he or she does not, it is terribly painful since the guests have been invited to the evening party in advance.

My doctoral thesis entitled "Selection and ranking procedures based on likelihood ratios", defended on 1 June, 1979.

Unfortunately, a substantial part of my thesis remained unpublished (in journals), because I did not have the preseverance for carrying through the research process upto the very end, which includes the tedious task of revising and re-revising and satisfying the reviewers and editors, for publication - I am somewhat better today in this respect, although not enough.

In those days, when I was younger and less mature, I had an impression that all discoveries and research ideas were completely original, which nobody had thought of before. I have subsequently realized that most discoveries and research ideas are obtained by the person who puts on the last topping ("the last straw that makes something new emerge"), and this person is not the originator of the whole idea, he or she just happened to be lucky enough to be in the right place at the right time.

As an example of my previous lack of insight in this, I wrote to a professor Gupta in USA in 1977 when I was in the beginning stages of my doctoral thesis. Gupta had done substantial research in the area of selection and ranking procedures, had a lot of PhD students working in the area, and was the person with whom Gunnar had spent his sabbatical some years previously to learn about the field. Gupta and his associates used the expression "subset selection approach due to Gupta". I realized in my reading that actually, the subset selection approach was proposed by somebody else shortly before Gupta, but the specific procedure that Gupta's group was working on was due to Gupta. So I wrote directly to Gupta and politely asked him if not the "approach due to Gupta" was actually due to this other person. He did not reply, since Gunnar was shortly going to visit him. To Gunnar he took up this matter rather quickly, and said he had got annoyed with the letter, and wondered if I was some politically radical student who wanted to question and create trouble.

Left: Celebrating the defence with a party in the evening, dancing with Ingrid, the wife of Lars-Erik Björkman who made it possible for me to emigrate to Sweden in 1969 (see the page My Education). Right: Enjoying a picnic the following day.

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Professor Gunnar Kulldorff, my tutor in mathematical statistics 1973-1979.

My first ever publication (above) in an international scientific journal (Sankhya, 1974).

A page from a publication based on my thesis, 1980.

My "opponent" prof Sture Holm reviewing my thesis, which I am defending.

My "opponent" waiting for an answer after a tricky question!

My supervisor prof Gunnar Kulldorff inviting the audience to ask questions.



Statistical genetics:

In 1981, the national research councils in Sweden felt that Sweden had too few epidemiologists (persons who study disease risk factors in the society as a whole), and so it was important to send some scholars abroad for a year to train themselves in epidemiology, and thereby increase the competence in this field in Sweden. I got an opportunity train in genetic epidemiology for the year 1983 in the USA, at the University of Hawaii in Honolulu.

Frankly, this year is an example of what I mentioned in the prologue, that I did not take an optimal advantage of the opportunity afforded to me. However, I did read a lot and make some contribution. Moreover, this start in genetics and biology has been useful for me in my subsequent research as a whole.

Genetic epidemiology concerns employing, for example, data on family members, regarding some gene marker and some disease. I wrote a theoretical paper on the subject called linkage analysis, which is used to detect if a disease is linked to a given gene marker. The method of linkage analysis had been known for many years, but the statistical foundations underlying the method ("the lod score method") were not fully elucidated, to which I made my contribution in 1984.

In the course of this research, I met Professor Jurg Ott, now professor at Columbia, and collaborated with him and we published a paper "Tests of gene order from three-locus linkage data" in 1987.

In Sweden I subsequently collaborated with clinical geneticists for further work in the area of linkage analysis during the 1980's and with my colleagues in Psychiatry in Umeå later, as discussed below.



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Crossing-over between two homologous chromosomes is a key phenomenon in linkage analysis

Linkage analysis and genetic mapping analysis use information about the disease status and the gene marker status in each family member in the pedigree (family tree).

With Jurg Ott at a genetics meeting in New Orleans 1993.



Social medicine:

When I was a teacher at the department of social medicine in Umeå 1984-1986, I got interested in the role of social support and social network in promoting the health of the individual. I read very widely about the literature on social networks and the population studies supporting this. The theory was that social support constitutes a buffer between stress and its negative effect on the individual's health, so that it reduces the effect of stress and thus is of benefit. The literature on how the individual copes with the stressful environment (coping strategies) is also related to this. I published some papers in Swedish journals (in Swedish), partly in this area, and partly on the health consequences of migration. I also got interested in the the terms holism and reductionism and wrote a theoretical paper in Swedish. I subsequently extended these thoughts to psychiatry and published a paper in an international journal, entitled "Holism, reductionism, and models in psychiatry".

In Umeå, I also took part in writing discussion articles to the local newspapers, since we had a lot of controversy on the pros and cons of the studies investigating the role of genes in personality, behaviour, and mental disease.

"Do we really inherit alcoholism and criminality?" was the title of my discussion article in the local newspaper.

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To Part 2 (Psychiatry)

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I spent a large part of my time teaching medical statistics to medical students and to clinical researchers in the medical faculty.