Genetics & Molecular Biology
In 1935 one of the founders of modern genetics, J. B. S. Haldane, studied men in London with the blood disease hemophilia and estimated that there would be a one in 50,000 incidence of mutations causing hemophilia in the gene affected – the equivalent of a mutation rate of perhaps one in 25 million nucleotides across the genome.
Others have measured rates at a few further specific genes or compared DNA from humans and chimpanzees to produce general estimates of the mutation rate expressed more directly in nucleotides of DNA.
16 scientists report today the first direct measurement of the…
jgerke |
For the past few days I've been fiddling with a set of data that measure the effects of single nucleotide changes on an organism's phenotype across a variety of environments and genetic backgrounds. Any good statistics manual will tell you the best way to analyze the type of data I have is through logistic regression with a generalized linear model. So, I tried that. Here are the results:
> logistic - glm(y~full_model, family=binomial(link="logit"))> summary(logistical)Null deviance: 20650253 on 860 degrees of freedomResidual deviance: 118972…
L. syn. A. barbadensis Mill. is a perennial, herbaceous and succulent species which belongs to the family Liliaceae. It is a short-stemmed plant bearing fleshy, mucilaginous leaves. The margin of the leaves becomes spiny with maturity. The plant is a native to the Mediterranean region chiefly to the warm dry areas of South and tropical Africa and is widely adopted in other tropical countries. The leaves contain the purgative aloin and its use in folk medicine as embalming for skin and other disorders goes back over thousands of years (Gjerstad and Riner 1968). Tizard et al. (1994)…
I've been mean to computational/network/systems biologists recently (twice). Real soon here I'm going to get into some positive aspects of these fields, but before that, I have to slam systems biology one more time.
Guess which blurb was written within the last 5 years, and which one was written more than 30 years ago:
#1:
XXX is a newly emerging field that promises to be of considerable importance in the coming years. Its focus is the integrated functioning of the intact system, rather than the chemical and physical properties of the isolated molecular components that comprise the system.…
The so-called SHOX gene (short stature homeobox gene) is responsible for the normal growth of bones and is often mutated in short-stature patients. Short stature is considered when final height of an individual is no more than 160 cm (men) or 150 cm (women).
Researchers in Heidelberg have now discovered that sequences of genetic material on the X and Y chromosome that regulate this gene are also crucial for growth in children.
These gene regulators determine how frequently a gene is copied, thus how effective it is. In many cases, the mutation of one regulatory sequence of the homeobox…
UC Santa Barbara scientists have revealed what they call a potential new drug delivery system - a biological mechanism for delivery of nanoparticles into tissue.
They developed a peptide, a small piece of protein that can carry "cargo" for delivery into the cell, whose cargo could be a nanoparticle, or even a cell.
Riding on the peptide, the cargo gets out of the blood vessel and penetrates the tissue.
The drug is located at one end of the peptide. At the other is the "C terminal," which has the "motif" –– an amino acid sequence including arginine or lysine, that causes the tissue penetration…
This research paper attempts to investigate the influence of N, P &K on chlorophyll, carbohydrate, proteins and sapogenin contents of Asparagus racemosus (Willd.). The treatment consisted different concentrations of Nitrogen (N 20, N 40, N 80 and N 160 mg.kg–1), Phosphorus (P 20, P 40, P 80 and P 160 mg.kg–1) and Potassium (K 40, K 80 and K 160 mg.kg–1) in the form of Urea (46%, H2NCONH2), Superphosphate (16%, P2O5) and Muriate of potash (60% K2O) respectively. A significant increase in the chlorophyll content was recorded with all the applications of N, P&K. Root protein and…
Craig Venter says that in a few months, his team will have created the first genuine artificial life form. As you may recall, Venter's team did the first whole genome transplant a few years back, which involved taking the genome of one species of bacteria and putting it into the genome-free cell of another closely related species. The new hybrid species was able to reboot with the new genome. According to The Times:
Artificial life will be created within four months, a controversial scientist has predicted. Craig Venter, who led a private project to sequence the human genome, told The Times…
Seriously, if you have to ask, then you should probably just keep your mouth shut. Because nothing good is going to come of asking.
The question? Whether or not 18-year-old South African runner Caster Semenya, who won the 800-meter race at the World Athletics Championship in Berlin, is a chick or a dude.
Imagine crossing the finish line to thunderous applause, accolades, etc. Job well done after pouring so much effort into this race. And then, some insensitive prick says, wait, are you actually a girl?
NPR reports:
"Suspicions fueled by Semenya's appearance and athletic performance…
I'm not the only one who hates computational biologists:
Zhang et al. (11), Braunewell and Bornholdt (12), Ge et al. (13), and Okabe and Sasai (14) have presented stochastic models of the yeast cell cycle based on a deterministic Boolean model from Li et al. (15). The main concern of all of these authors was the robustness of cell cycle progression in the presence of intrinsic and extrinsic sources of noise. None of them compared their models to observed statistics of cell cycle properties in wild-type or mutant cells.
In sciencese, that's a major dig against computational biologists. You…