Year 2016 face_with_colon_three
Heme proteins can catalyze the formation of carbon–silicon bonds.
Category: evolution – Page 39
Dr. David Cohen comments on 10-year results from a trial of transcatheter vs. surgical aortic valve replacement:
Over the past decade, transcatheter aortic valve replacement (TAVR) has evolved from a niche procedure to treat severe aortic stenosis in high-risk patients to a mainstream procedure that is also performed in intermediate-and low-risk patients. With this evolution in practice, the large number of younger patients with life expectancies 10 years now receiving TAVR has raised concerns about its durability and patients’ long-term outcomes. Now, 10-year results are available from the NOTION trial of TAVR versus surgical aortic valve replacement (SAVR) that was conducted between 2009 and 2013 (NEJM JW Cardiol May 29 2015 and J Am Coll Cardiol 2015; 65:2184).
Two hundred eighty patients aged 70 years (mean age, 79 years; mean predicted risk of surgical mortality, 3%) were randomized to SAVR using any commercially available bioprosthesis or TAVR using the first-generation self-expanding CoreValve device. At 10-year follow-up, there was no significant between-group difference in the composite of death, stroke, or myocardial infarction (66% for both groups) or any of the individual components. Rates of bioprosthetic valve failure and repeat valve intervention were also similar. However, the rate of bioprosthetic valve dysfunction was lower with TAVR, largely reflecting lower rates of patient–prosthesis mismatch. The rate of structural valve deterioration was lower with TAVR as well, driven mainly by lower transvalvular gradients with TAVR that emerged early and persisted throughout follow-up.
Although limited by its modest sample size, the NOTION trial provides the longest available follow-up of any TAVR-versus-SAVR randomized trial to date. Overall, the results provide reassurance that there are no important differences in major clinical outcomes between the two strategies, and the echocardiographic data suggest sustained differences in hemodynamic performance in favor of TAVR. Nonetheless, given the advanced age of the patients at the time of enrollment, we should be cautious in extrapolating these findings to younger patients with severe aortic stenosis or to patients with bicuspid aortic valve disease (who were excluded from NOTION). These findings emphasize the tension between ongoing innovation and the desire for long-term outcomes data for our cardiac devices.
Postbiological_V4.Pdf
Posted in evolution
Cosmologists are wrestling with an interesting question: how much clumpiness does the Universe have? There are competing but not compatible measurements of cosmic clumpiness and that introduces a “tension” between the differing measurements. It involves the amount and distribution of matter in the Universe. However, dark energy and neutrinos are also in the mix. Now, results from a recent large X-ray survey of galaxy clusters may help “ease the tension”
The eROSITA X-ray instrument orbiting beyond Earth performed an extensive sky survey of galaxy clusters to measure matter distribution (clumpiness) in the Universe. Scientists at the Max Planck Institute for Extraterrestrial Physics recently shared their analysis of its cosmologically important data.
“eROSITA has now brought cluster evolution measurement as a tool for precision cosmology to the next level,” said Dr. Esra Bulbul (MPE), the lead scientist for eROSITA’s clusters and cosmology team. “The cosmological parameters that we measure from galaxy clusters are consistent with state-of-the-art cosmic microwave background, showing that the same cosmological model holds from soon after the Big Bang to today.”
University of Melbourne researchers are leading a new push to address the growing harm of antimicrobial resistance (AMR) as more humans and animals become seriously ill or die from infections that medicine once treated easily.
Over-use and misuse of microbe-killing drugs – including antibiotics, antivirals and antifungals – is the main driver accelerating the evolution of resistance to these drugs in bacteria, viruses, fungi and parasites around the world.
The World Health Organisation calls AMR a top global public health threat that was directly responsible for 1.27 million deaths and contributed to 4.95 million deaths in 2019.
Scentists have uncovered a fascinating link between ancient viruses and the development of myelination, the biological process crucial for the advanced functioning of the nervous system in vertebrates, including humans.
Scientists discovered a gene, ‘RetroMyelin,’ from ancient viruses, essential for myelination in vertebrates, suggesting viral sequences in early vertebrate genomes were pivotal for developing complex brains. This breakthrough in Cell unravels how myelination evolved, highlighting its significance in vertebrate diversity.
NB Whilst claims of logical possibility intended to support reality claims (such as Swinburne’s proposal of disembodied existence) become subject to constraints of reality, those not intended to support any reality claim need not be subject to such constraints.
Selected Resources (see also part 1):
Churchland, P — Brain-Wise: Studies in Neurophilosophy (2002)
Swinburne, R — Evolution of the soul (1986)
Swinburne, R — Interview with Science and Religion News (2006)
Valentine, E — Conceptual Issues in Psychology (1992)
Velmans, M — Understanding Consciousness (2000)
An alien invasion capable of triggering catastrophic changes is underway across North America. At least 70 imported earthworm species have colonized the continent, and represent a largely overlooked threat to native ecosystems, according to a new study by researchers at Stanford University, Sorbonne University, and other institutions.
The analysis, recently published in the journal Nature Ecology & Evolution, provides the largest-ever database of such earthworms and warns of the need to better understand and manage the invaders in our midst.
“Earthworms tell the story of the Anthropocene, the age we live in,” said study senior author Elizabeth Hadly, the Paul S. and Billie Achilles Professor in Environmental Biology in the Stanford School of Humanities and Sciences. “It is a story of global homogenization of biodiversity by humans, which often leads to the decline of unique local species and the disruption of native ecosystem processes.”
A 280-million-year-old fossil that has baffled researchers for decades has been shown to be—in part—a forgery, following new examination of the remnants.
The discovery has led the team, headed by Dr. Valentina Rossi of University College Cork, Ireland (UCC) to urge caution in how the fossil is used in future research.
Tridentinosaurus antiquus was discovered in the Italian Alps in 1931 and was thought to be an important specimen for understanding early reptile evolution. Its body outline, appearing dark against the surrounding rock, was initially interpreted as preserved soft tissues. This led to its classification as a member of the reptile group Protorosauria.
Transposable elements are mobile genetic elements that can relocate within the genome and disrupt the normal function of genes, but are at the same time a source of evolutionary diversity. The lab of Tugce Aktas at the Max Planck Institute for Molecular Genetics has identified a novel pathway that keeps the activity of transposons in somatic cells in check after they have been transcribed.
Their findings have now been published in Nature. The work is a collaboration with the labs of Zachary D. Smith at the Yale Stem Cell Center, U.S., and Franz-Josef Müller from the Universitätsklinikum Schleswig-Holstein, Germany.
Over the course of evolution, the genomes of many organisms have become cluttered with ancient genetic remnants from evolution or parts of retroviruses that inserted their genetic code millions of years ago. Nearly half of the human genome consists of these transposable elements, or transposons.