June 12th, 2015
A second group has found protein preserved in dinosaur fossils. I wouldn’t call this solid yet, but it is encouraging. This hit the news in September 2009
Fibres and cellular structures preserved in 75-million–year-old dinosaur specimens
Abstract
Exceptionally preserved organic remains are known throughout the vertebrate fossil record, and recently, evidence has emerged that such soft tissue might contain original components. We examined samples from eight Cretaceous dinosaur bones using nano-analytical techniques; the bones are not exceptionally preserved and show no external indication of soft tissue. In one sample, we observe structures consistent with endogenous collagen fibre remains displaying ~67 nm banding, indicating the possible preservation of the original quaternary structure. Using ToF-SIMS, we identify amino-acid fragments typical of collagen fibrils. Furthermore, we observe structures consistent with putative erythrocyte remains that exhibit mass spectra similar to emu whole blood. Using advanced material characterization approaches, we find that these putative biological structures can be well preserved over geological timescales, and their preservation is more common than previously thought. The preservation of protein over geological timescales offers the opportunity to investigate relationships, physiology and behaviour of long extinct animals.
Nature Communications 6, Article number: 7352, 09 June 2015
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May 20th, 2015
RepSox, a TGF-β1 inhibitor, promotes stem cell growth and enhances neurogenesis and muscle regeneration in old mice. Neurogenesis occurs primarily in the dentate gyrus of the hippocampus, and this is where the authors find it. No functional tests are shown.
The compound, 2-(3-(6-Methylpyridin-2-yl)-1H-pyrazol-4-yl)-1,5-naphthyridine or RepSox (PubChem) has been mentioned in half a dozen studies as a drug that promotes stem cell proliferation. Compound sells for research use at $50 / gram.
<p>Systemic attenuation of the TGF-β pathway by a single drug simultaneously rejuvenates hippocampal neurogenesis and myogenesis in the same old mammal. Hanadie Yousef, Michael J. Conboy, Adam Morgenthaler, Christina Schlesinger, Lukasz Bugaj, Preeti Paliwal, Christopher Greer, Irina M. Conboy, David Schaffer
Oncotarget. May 06, 2015. (pdf)
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April 27th, 2015
Bad batteries–vaccum has 13 sub C NiCD cells. Tested voltage on the individual cells and replaced 6 bad cells.
The vaccum still wouldn’t charge–checking the charging circuit board showed a crack in a trace near the edge where the indicator LED is located. A bit of solder fixed it, and now it is charging.
FYI, the main IC on the circuit board is a ABOV MC96P0202, a 8-bit OTP CPU.
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April 26th, 2015
Recently Gao et. al. published “An Estimate of the Average Number of Recessive Lethal Mutations Carried by Humans”. They studied a Hutterite group in South Dakota, highly inbred (63 founders 13 generations ago). From serious genetic diseases common in this population, they determine the number of deleterious variants present in the founders. They find that 0.29 recessive lethal alleles per haploid genome. Since some lethals manifest before birth, they double the estimate to 0.58.
This gives an expected 1.8% increased chance of a genetic disease from two first cousins.
Gao, Z., Waggoner, D., Stephens, M., Ober, C. & Przeworski, M. Genetics 199, 1243–1254 (2015).
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February 1st, 2015
I was sent a link to a blog post, “This Mama Isn’t Scared of the Shmeasle Measles” by Megan Heimer.
I’ll run through the post in a minute, it contains a whole lot of nonsense. First, some links to reliable info:
CDC measles info
CDC Manual for Surveillance of VPD: Chapter 7: Measles
Measles week posts by an immunologist
Now, on to the post…
Read the rest of this entry »
Posted in pseudoscience, Science | No Comments »
