jimmydasaint

I just gave the article a quick scan, but, as you know, DNA is made of a 'backbone' of sugar and phosphate, with 4 bases facing to the inside of the spiral - A, C, G and T. The XNA changes the sugar from the normal deoxyribose to other sugars, such as arabinose. So far, DNA can be made into XNA using mutated DNA polymerases. Also, mutated reverse transcriptase-like DNA polymerases can change the XNA back into DNA with excellent fidelity of base sequences. If I read the article correctly, XNA was not made into RNA. I have found a picture of XNA which looks pretty similar to the canonical two antiparallel strands of DNA : http://www.google.co.uk/imgres?q=XNA+helical+structure&um=1&hl=en&sa=N&rls=com.microsoft:en-gb:IE-SearchBox&rlz=1I7ADSA_enGB421&biw=1260&bih=560&tbm=isch&tbnid=FKkgDunguEJkBM:&imgrefurl=http://www.vancouversun.com/technology/Scientists%2Bcreate%2Bsynthetic%2Bcapable%2Bevolution/6491155/story.html&docid=KgflSUdzQ9bK6M&imgurl=http://www.vancouversun.com/technology/6388572.bin&w=620&h=400&ei=Kv2TT-bFBYn68QOm2_3NDA&zoom=1&iact=hc&vpx=73&vpy=262&dur=187&hovh=180&hovw=280&tx=165&ty=99&sig=102168260961876594193&page=1&tbnh=96&tbnw=149&start=0&ndsp=23&ved=1t:429,r:7,s:0,i:83

Why not look at the Science News thread. XNA is cutting edge if you understand your nucleotides.

It is exciting and cutting edge research. However, I would be cautious about the possibilities of this research. So far, the XNA's cannot be translated into amino acids. They are not recognised by conventional DNA or RNA polymerases so they do not present an environmental hazard. However, the use of these XNA's does not seem to be to generate new lfe forms but to do the following, because of their molecular tougness: Link to Magazine Article

IMO, dosage, state of immune system, genetic predisposition, interactions with the environment and a host of other factors are involved in transmission of herpesviruses. Looking at the article you cited on very low doses of viruses, down to 0.1 pfu, causing infection in a model system, the authors are circumspect in their findings. Moreover, the results are for gamma herpesvisuses called Epstein Barr Virus and Kaposi sarcoma-causing herperviruses. IIRC, these are commonly transmitted by saliva and not by bottoms on toilet seats. Additonally, the virus was administered by intraperitioneal injection and not swabs. Did you know that? Link to Paper I could not find your references on effectiveness of neutrophil and macrophage in viral infection but the large human population would seem to indicate their role in success, as the first arm of the immune system, and in contributing to the survival of the human species. The second study that you cited did show shedding in sites that could possibly be exposed to toilet seats. However, given the sheer variability of social, environmental and genetic factors, it is very difficult to establish if herpesvirus could be spread this way. Link to Genital Shedding Paper

The OP is a bit problematic IMHO. Although persistence of bacteria and viruses on surfaces such as door handles and banisters etc... has an evidential basis, we still have to consider the important dosage effect of the virus in question and also skin and mucosal immunity as well as the state of the immune system of the person sitting on the seat, amonsgst other factors. The answer would have to be that the chances are high against infection from a toilet seat. Humans have a very powerful non specific arm of the immune system (for example macrophages and neutrophils) which are capable of ingesting foreign materials. Additionally, the specific arm of the immune system, exemplified by the production of antibodies such as IgA and IgM are also associated with mucosal/skin surfaces, IIRC, as a powerful deterrent to the internalisation of viruses.

It is cool but seems to be a model system in use. Although the ease with which an embryo can be split by a wave means that coral can respond quickly to reef damage quickly. Interesting. Link

Again, another excellent answer. I would consider that most mutations are neutral. However, I did not read the last paragraph of one of your responses and just wanted to point out that there is a large number of human mutations that do affect fitness and decrease the opportunity for successful reproduction, in the current environment. For example, there are a number mentioned in wiki: Wiki List of Genetic Disorders That is all I meant by 'balance'. Of course you have to be candid about the contribution that those affected could make to the gene pool and define evolutionary fitness. I don't know how relevant this article is, but it suggests that the skin colour of the Europeans may have evolved to increase the 'fitness' to make vitamin D in light-deprived areas. Link and Link to Paper

I accept the point that the market does dictate wages paid to players in team sports and that male team sports generate far more income than female teams. I accept also that males are physically stronger than females and that this physical disparity means that women have very little chance of winning a man's sport generally. Males also prefer watching male sports presumably. They like watching other men get hot and sweaty. Fine. Would you then agree that women are equal in educational and employment opportunities? I would argue that women are badly under-represented in academic occupations, in government and in becoming CEO's of well-known companies - but that is a separate issue altogether, and deserves a separate post.

You gave an excellent answer to the previous few posts. However, IMO, many mutations are either neutral or downright deleterious. I believe there should be caution and some balance when human mutations are mentioned Halucigenia.

What about Huntington's Disease, Motor Neuron Disease, Alzheimer's Disease and Polydactyly?

How equal do I want it? Equal prize money for starters. I was making the point initially that there is no equality between genders in sport despite our proclamations about equality for women generally in society. Nevertheless when it comes to prize money, women get paid far less for winning golf, and, to my knowledge, tennis tournaments, in the past (which are now awarding equal money). What is the underlying silent script? It seems to say that women's sports are less worthy, and that, to my mind, is unfair.

Well, I have some poetic and some interesting answers. However, is it possible that we are talking about psycopathy as a lack of empathy towards an individual and we can then classify this as being evil. I take that it is not easy to distinguish evil people from those that have empathy, by conversation or by a questionnaire of some sort, otherwise it would be easy to disengage socially from these people. I have a professionally qualified friend who quite openly wishes to take a baseball bat to his managers and has said that he has, in his head, rehearsed a routine where he can 'bash these people to death'. He also has problems with explosive anger. Are these signs of psycopathy or evil. He is also a committed Christian, which implies to me that the environment can control or ameliorate the natural feelings to get even and to kill others that wrong you. Any thoughts? Dylan Thomas

Just a thought here. By evil, I mean are there people who are born with a complete lack of empathy towards other individuals and therefore are completely selfish and self-serving? If so, the concern is that can we blame these people for their subsequent actions or do we contextualise their evil with their particular genomic profile? In short if you are born with the genetic profile of a murderer and then go on to murder people. can you claim that your genetic predisposition can provide suitable extenuating circumstances?

This is a nasty virus, spread by mosquitoes as Tony McC mentioned. However, I have realised that there are two versions of Dengue. One is milder but not fatal, whilst the other, Dengue Haemorrhagic Fever, is more dangerous as the name suggests. Dengue Fever Dengue Fever Dengue Haemorrhagic Fever The only treatment I could find was for people to keep hydrated during Dengue Fever but for medical intervention to transfuse blood during blood loss in Dengue Haemorrhagic Fever.

Interesting point. The authors mentioned this genetic and phenotypic heterogeneity in mammals: Article Additionally, another hypothesis is made. The phenotype, in general, that was stabilised in evolutionary terms, would result in a signalling process involving cyclic AMP. The species that produced progesterone in spontaneous decidualisation of the endometrium also would show an up-regulation of cAMP, with or without the presence of an embryo, but in species that were non-menstruating, there would only be a cAMP up-regulation in the presence of an embryo. The jury is still out I think...

Read you loud and clear JC! I am not trying to patronise you. However, back to the main point which is decidualisation should be re-stated. Most primates have spontaneous decidualisation in the absence of an embryo. Mice only have a thickened endometrium when they need it. The authors looked at the degree of invasion of the maternal tissue by the embryo and mammals that menstruate also showed haemochorial invasion of the endometrium. This led to a new hypothesis, which can also include the previous hypothesis about primate sexual behaviour and removal of pathogens. Agreed. I don't think your mind is at all feeble, nor did I suggest it. However, I would have read the original article in order to understand the viewpoint of the researchers. It is, after all, just a hypothesis.

The thing is JC, other animals thicken the lining of the womb and don't shed it like humans. The researchers had a hypothesis which is that the thickened layer provides a 'protection' for the mother when an embryo does implant itself and starts to command nutrients, for itself, from the mother. http://php.med.unsw.edu.au/embryology/images/9/96/Week2_001.mov

I think that the article was looking at the point of menstruation from a meta-cognitive evolutionary standpoint. I take your point that the periodic shedding of the endometrium also protects against potential pathogens, or even against potential damage to the endometrium over the duration of a lunar month. As a consequence, the new 'proto' embryo has a brand new lining in which to implant. However, the researchers were looking at spontaneous decidualisation in animals that generally that do not shed their respective endometria. Why would mice build up a thickened layer when there is no mechanism for shedding it? The researchers proposed a hypothetical mechanism for why this happens in a general evolutionary framework and they came up with the hypothesis that the thickening of the endometrium is a defence mechanism against the greedy embryo. I hope this makes sense.

Thanks for the information. What a shame that we cannot use these more commonly. The following site comes to the same conclusions: HowStuffWorks

I think that's Buffy you're thinking about mate. And no wonder. http://www.google.co.uk/imgres?q=buffy+the+vampire&um=1&hl=en&sa=N&rls=com.microsoft:en-gb:IE-SearchBox&rlz=1I7ADSA_enGB421&biw=1280&bih=571&tbm=isch&tbnid=x17OsnZyX-khdM:&imgrefurl=http://dana.web.unc.edu/2011/05/21/buffy-the-vampire-slayer-or-how-i-became-a-card-carrying-member-of-the-cult-of-joss-whedon/&docid=rvqFz4Bf5W5PBM&imgurl=http://dana.web.unc.edu/files/2011/05/Buffy_the_Vampire_Slayer_Sarah_Michelle_Gellar_01.jpg&w=358&h=512&ei=0Z89T-TfH4nE8gP85P26CA&zoom=1&iact=hc&vpx=326&vpy=158&dur=78&hovh=269&hovw=188&tx=108&ty=159&sig=102168260961876594193&page=1&tbnh=159&tbnw=116&start=0&ndsp=12&ved=0CEoQrQMwAQ

I remember reading a book as an eight year-old boy in Scotland which praised the honesty of the man that eventually led America and whose morals prevailed during a vicious Civil War. I was impressed. As a middle-aged man, I came across the idea that everything I thought I knew about this man could have been a myth. I present below 2 accounts about Lincoln; one which is unashamedly sycophantic, and the other is more cynical. Perhaps the truth lies somewhere in the middle. Any comments? Link Sycophantic Link

I agree, the systemic doses have to be quite high. I have to add a correction, the research is from Indonesia, and a quick scan of the methodology leaves me to think that their methodology is questionable. Nevertheless, the journal seems to be peer-reviewed.

Having said that, they can tick off 2 boxes out of three for me - lack of serious noise or gas pollution. The efficency issue is one of mechanical design surely? Something extra to support these engines: Link to Article

I am a bit baffled why the Stirling Engine is not more commonly used when we, as a global community, need to turn out engines which are quiet and clean with a lack of heavy pollutants? What are the restrictions stopping the use of this beautiful engine? Link http://upload.wikimedia.org/wikipedia/commons/c/cc/Alpha_Stirling.gif

I am not trying to simplify how to prevent heart disease, bearing in mind that genetics, diet and behaviour play such an important role in heart disease. However, what if taking high levels of garlic could prevent the risk of atheroma, aneurysm and thrombosis, all so common in the West due to over-nutrition? It appears as if the active agent is S-methyl cysteine found in both garlic and turmeric. So, for the people in Britain who love a good curry, the news is great. Keep eating your curry and you could prevent heart disease... This is an interesting article from the land of curry experts - India: Abstract Link