Concerns about a very old PhD advisor?

I’m thinking about taking a 70-year old math professor as my PhD advisor, in a US school. I like his teaching and research. If I don’t choose him, I would probably have to switch fields, which I can do with some pain, since I have not specialized deeply yet. My main concerns are:

• As he is far more likely than a young supervisor to pass away suddenly due to his age, how should I best plan for this scenario? What will happen to me if it happens?



• He is also far more likely to retire than a young supervisor – could his retirement (in the unspecified future) cause problems for my future career in academia, with respect to references and networking?

Related: How should I take a potential PhD supervisor's age into account, when planning to follow PhD with habilitation?

Answer

One minor counterpoint to @adipro's answer: rather than age of the professor, consider where they stand in their professional career. Age aside, you want to make sure that they're still highly active in the research community. I made the mistake of being what turned out to be my advisor's last graduate student; not a good position to be in. To present the case more generally: While all the positive points listed by @adipro were are true of someone close to retirement, they may simply might not care as much about things you care about. Specifically:

• They have no pressure to publish, and consequently, your need to publish doesn't scratch any itch of theirs


• Since they're close to retiring, they won't want to enter extensive collaborations, as they will likely be gone before the work is done. (This is referring to long, multi-year projects, not smaller stuff.)


• Their interest in grant-writing will be far less than yours, for the same reason as the preceding point; multi-year research efforts will likely complete after they're gone.

When researching potential advisors, talk to their graduate students about the number of grants they've applied for in the past two years, the number of new students they've taken on, the number of new collaborations they've started, and the like. You want to make sure they're not winding things down, as that means they'll be less interested in things you care about, such as creating new relationships, writing more papers, and finding new grants.

genetics - Is it possible to genetically modify a plant at home?

Would I be able to genetically modify a plant at home? What equipment will be necessary? I think it might be a fun change from the 'norm' of regular hybridisation, to try some inter-family gene insertion, instead of staying within a genus. Are some plants easier to modify than others?

Answer

Well, that depends on your home. ;) I think it is not an easy process.

There are two main methods that are used to genetically modify plants:

Using the bacterium, Agrobacterium tumifaciens, as a vector for the DNA. Agrobacterium has the ability to infect plants and insert DNA into a plant's genome. It causes crown gall tumours in natural infections. This method has mainly been used to modify broad leaved plants, such as sugar beet and oilseed rape, but is now also being applied to monocot species, such as maize and rice

Particle bombardment or biolistics where the DNA to be inserted is coated on minute gold particles and fired into plants cells. This approach is used for monocot plants such as maize and rice

Here I found simple step by step article, but lil bit old. may be there are new methods for this process. How To Genetically Modify a Seed, Step By Step

evolution - What is needed for a G-matrix?

I have been doing a lot of reading on quantitative genetics and the G- (and B-) matrix lately. I get the principle behind performing the analysis now but I am still not sure how to do it. I'd like to be able to try it out with some dummy/old data in R to see how it is done.

Let's pretend I have measured 5 traits of Drosophila (Wing length, lifespan, eye pigmentation, bristle number, and fitness). Could I construct a G-matrix for the population from this data and also get a B-matrix to measure the selection on the traits?

Aims of the post:

1) What information (trait measurements, fitness scores etc.) is needed to construct G- and B- matrices?

2) I would like to find print or online material that would guide me in actually implementing this method. It seems like there is an awful lot of papers saying that G-matrices are great, but no one actually says how to do them in real life...

Answer

To construct the G-matrix you need additive genetic variances and covariances for all traits, so you normally need results from breeding experiments (e.g. phenotypic midparent-offspring data), that you can do parent-offspring regressions on. Don't know any good online sources but see Balding et al. 2007 p. 534ff for some info. I've seen methods that claim that the G-matrix can be estimated directly from phenotypic data from unrelated individuals (e.g. Zintzaras 2011) or from genomic info e.g. SNPs (Vattikuti et al. 2013), but are not familiar with these and do not know how reliable they are.

A clear background on using mixed models to estimate the G-matrix, including examples/tutorials, can be found in Wilson et al (2009).

Or did you have something else/something more specific in mind?

human biology - Presence of MHC on red blood cells

Do red blood cells have no MHC? (I have often heard that they do not.)

If so why are they not destroyed by immune cells?

Answer

They do not, at least not normally or noticeably. MHC I occurs on all nucleated cells, and red blood cells do not have nuclei. If they did indeed have MHC on them, blood transfusions would be as successful and as tricky as organ donation. There are reports of MHC detection on red blood cells, but the amount is orders of magnitude smaller than elsewhere, only present for certain MHC alleles, and often transient.

evolution - Why Is Most Life Symmetrical Externally But Not Internally?

Mammals, reptiles, arachnids, insects, etc are all as far as I am aware symmetrical in appearance.

Take a human for instance, make a line from the top of our head right down the middle. However, internally it is not the same. Our organs excluding the kidneys, lungs, reproductive organs, etc are not symmetrically placed in our body.

• Why do we not have an even number of each organ so it can be placed symmetrically?


• If we have a single organ why is it not placed in the middle like the brain or bladder is for instance?


• Is there some evolutionary advantage that led to this setup?

Answer

First, I think it worthwhile considering 'Why would internal symmetry be beneficial?' Developmental simplicity jumps to mind immediately. You can also consider relationship to external organs; the stomach and esophagus are lined up with the mouth which is symmetrical about the sagittal plane. Or maybe even balance; the lungs are large organs and if put to one side would likely cause locomotive issues. (Perhaps this is even an interesting topic for another question.)

That said, I feel, at it's core the evolutionary advantage which led to the lack of ubiquitous internal symmetry is space. Simply put, there is only so much room inside an organism and every little counts. Thus, if there isn't a need for a particular organ to be mirrored about a plane then there is a benefit in putting elsewhere: utilization of space.

I think a fantastic example of this is the human digestive tract. The key factor in the shape of the intestines is utilization of space, which directly affects the point at which is connects to the stomach, itself contributing to the asymmetrical shape of the stomach. One could envision other configurations, sure, and nature has. However, this configuration works quite well and the extraordinary use of limited space seems to outweigh all benefits of symmetry.

To directly respond to your questions above:

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  Question: Why do we not have an even number of each organ so it can be placed symmetrically? Response: Each organ addresses (or addressed) a need of the organism. Addressing that need with multiple organs working in concert has benefits and consequences, as does addressing the need with a single organ alone. These benefits and consequences are balanced throughout the evolution of an organism.

  
  


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  Question: If we have a single organ why is it not placed in the middle like the brain or bladder is for instance? Response: I feel space. Again, there are benefits to symmetry but there are many other factors at play. Some of which, it seems, are more important than symmetry at times.

  
  


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  Question: Is there some evolutionary advantage that led to this setup? Response: I hope this has been addressed - I don't claim to have 'answered' anything, this is a question for discussion.

  
  

Other fuel for discussion:

In thinking through this question I found myself able to rationalize why internal symmetry isn't necessary. However, I'd be interested in seeing opinions on why, then, external symmetry is so prevalent.

conference - Does a low acceptance rate imply quality?

I am presenting a paper in a conference with a 20% acceptance rate. However the conference is just 3 years old and does not figure in the tiered rating system for conferences in my field Computer Science (that some universities use) . Recently I found out that another reputed international conference (that figures in the conference rankings) has almost double the acceptance rate. Did I make the right choice. How should I evaluate conferences in the future??

thesis - Strategies to overcome "academic-apathy" in the final stages of the PhD?

Background - I am doing my PhD in atmospheric physics/photobiology.

Here is a scenario:

• The experiments are complete - the results are far better than expected


• Successfully got the computer program to work properly and have developed another


• Papers are published



• Much of the thesis is drafted

The light at the end of the tunnel is most definitely no longer an oncoming train.

But, at this stage, you just don't feel like working on the thesis, you do other things like cleaning, reading, watching movies - procrastination gets worse, and worse despite the submission deadline coming closer.

The procrastination resulting in more apathy towards the project, despite being fully aware of how much work has been put into the project, how much has been achieved and how little, comparatively, needs to be done.

What strategies are there to overcome this academic-apathy, particularly in this late stage of the thesis?

Answer

My suggestion would be to set minor distinct goals for each day but not overdo them, make them manageable. Mix boring chores with more fun ones so that the fun ones become a reward. This may seem a bit vague or even wooly. The problem I think you are experiencing is that while working on a PhD you get accustomed to stress and like many (myself included) a certain stress is needed to get something, and really the best, out of oneself. This phenomena, in my case, has only gotten worse, and I simply have a hard time getting anything done unless there is some pressure that gets stress levels up. But, with certain tasks it is possible to get stuff done by breaking it down into smaller pieces because if there is no overview or goals are too nebulous then it is not easy to focus on what to do in detail.