Currently browsing the Science Category

Recommended posts: Physicists Observe New Property of Matter - The Future of Science - Primary Science Education in China and the USA - 20 Scientists Who Have Helped Shape Our World - Web Science - Weekly Science Podcasts - Ants on Stilts for Science

Unexpected Risks Found In Editing Genes To Prevent Inherited Disorders

Mitochondrial replacement seeks to remove genes known to cause genetic defects from embryos in order to allow for a baby to avoid inheriting the defect.

Mitochondrial Replacement Techniques: Ethical, Social, and Policy Considerations from the USA National Academy of Sciences

Accordingly, the committee recommends that any initial MRT clinical investigations focus on minimizing the future child’s exposure to risk while ascertaining the safety and efficacy of the techniques. The recommended restrictions and conditions for initial clinical investigations include

  • limiting clinical investigations to women who are otherwise at risk of transmitting a serious mtDNA disease, where the mutation’s pathogenicity is undisputed, and the clinical presentation of the disease is predicted to be severe, as characterized by early mortality or substantial impairment of basic function; and
  • transferring only male embryos for gestation to avoid introducing heritable genetic modification during initial clinical investigations.

Following successful initial investigations of MRT in males, the committee recommends that FDA could consider extending MRT research to include the transfer of female embryos if clear evidence of safety and efficacy from male cohorts, using identical MRT procedures, were available, regardless of how long it took to collect this evidence; preclinical research in animals had shown evidence of intergenerational safety and efficacy; and FDA’s decisions were consistent with the outcomes of public and scientific deliberations to establish a shared framework concerning the acceptability of and moral limits on heritable genetic modification.

The research in this area is interesting and our ability to help achieve healthy lives continues to grow. The path to a bright future though is not without risk. It requires careful action to pursue breakthrough improvements while minimizing the risks we take to achieve better lives for us all.

Unexpected Risks Found In Editing Genes To Prevent Inherited Disorders

Earlier this month, a study published in Nature by Shoukhrat Mitalipov, head of the Center for Embryonic Cell and Gene Therapy at the Oregon Health and Science University in Portland, suggested that in roughly 15 percent of cases, the mitochondrial replacement could fail and allow fatal defects to return, or even increase a child’s vulnerability to new ailments.

The findings confirmed the suspicions of many researchers, and the conclusions drawn by Mitalipov and his team were unequivocal: The potential for conflicts between transplanted and original mitochondrial genomes is real, and more sophisticated matching of donor and recipient eggs — pairing mothers whose mitochondria share genetic similarities, for example — is needed to avoid potential tragedies.

“This study shows the potential as well as the risks of gene therapy in the germline,” Mitalipov says. This is especially true of mitochondria, because its genomes are so different than the genomes in the nucleus of cells. Slight variations between mitochondrial genomes, he adds, “turn out to matter a great deal.”

Related: Gene Duplication and EvolutionThe Challenge of Protecting Us from Evolving Bacterial ThreatsOne Species’ Genome Discovered Inside Another’s (2007)Looking Inside Living Cells

20 Most Popular Post on the Curious Cat Science and Engineering Blog in 2016

These were the most popular (by number of page views) posts on our blog in 2016.

photo of John Hunter with snow covered mountain peaks in the background

John Hunter, Olympic National Park (where the mountain peaks are colder and covered in snow)

Continue reading

Engineering Mosquitos to Prevent the Transmission of Diseases

Mosquitos are responsible for huge amount of suffering and death. In 2015 200,000,000 people were infected with malaria and 500,000 died.

It is amazing what knowledge science has provided about the causes of human disease. It is great to have videos like this available that let us learn a bit about it from a short and understandable video.

Using our scientific knowledge to design and implement solutions offers great possibilities. But we also have to worry about the risks of such attempts. Making decisions about what risks to take requires well informed people that are able to understand the opportunities and risks and make intelligent decisions.

Related: Video showing malaria breaking into cellScientists Building a Safer Mosquito (2006)Engineering Mosquitoes to be Flying Vaccinators (2010)

PISA Science Education Results Show Singapore, Japan and Estonia Leading

The most comprehensive comparison of student achievement in math and science around the globe is completed by the Organisation for Economic Co-operation and Development (OECD). The 2015 Program for International Student Assessment (PISA) focuses on science understanding of 15 year olds (the 2012 report focused on math).

2015 results for the science portion (rank – country – mean score)(I am not listing all countries):

  • 1 – Singapore – 556
  • 2 – Japan – 538
  • 3 – Estonia – 534
  • 4 – Taiwan – 532
  • 5 – Finland – 531
  • 6 – Canada – 528
  • 7 – Vietnam – 525
  • 8 – China – 520*
  • 9 – Korea – 516
  • 13 – Germany – 509
  • 13 – UK – 509
  • 23 – USA – 496
  • 26 – Sweden – 493 (this is also the OECD average)
  • 56 – Mexico – 416
  • 61 – Brazil – 401

* I am merging several distinct Chinese locations reported in the official report.

The 2015 PISA include 72 participating countries and economies. From the PISA report:

On average across OECD countries, 25% of boys and 24% of girls reported that they expect to work in a science-related occupation. But boys and girls tend to think of working in different fields of science: girls envisage themselves as health professionals more than boys do; and in almost all countries, boys see themselves as becoming information and communications technologies (ICT) professionals, scientists or engineers more than girls do.

Related: 2009 results of science education student achievement around the globe2012 results for the science portion (math was the focus in 2012)The Economic Consequences of Investing in Science EducationCountry H-index Ranking for Science Publications

Eating Nuts May Reduce the Risk of Heart Disease, Cancer and Other Diseases

A large analysis of current research shows that people who eat at least 20g of nuts a day have a lower risk of heart disease, cancer and other diseases. The analysis of all current studies on nut consumption and disease risk has revealed that 20g a day – equivalent to a handful – can cut people’s risk of coronary heart disease by nearly 30%, their risk of cancer by 15%, and their risk of premature death by 22%.

While this is reassuring news to those of us (like me) that frequently eat nuts I am not sold on their evidence. Heath research is prone to overstating the benefits. Still there is little reason to avoid making nuts part of a healthy diet. That is a big part of the reason I have. They offer benefits and maybe even great ones (as indicated in this research) without much risk.

An average of at least 20g of nut consumption was also associated with a reduced risk of dying from respiratory disease by about a half, and diabetes by nearly 40 percent, although the researchers note that there is less data about these diseases in relation to nut consumption.

The study, led by researchers from Imperial College London and the Norwegian University of Science and Technology, is published in the journal BMC Medicine, Nut consumption and risk of cardiovascular disease, total cancer, all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective studies (open access paper).

The research team analysed 29 published studies from around the world that involved up to 819,000 participants, including more than 12,000 cases of coronary heart disease, 9,000 cases of stroke, 18,000 cases of cardiovascular disease and cancer, and more than 85,000 deaths.

While there was some variation between the populations that were studied, such as between men and women, people living in different regions, or people with different risk factors, the researchers found that nut consumption was associated with a reduction in disease risk across most of them.

Continue reading

Learning About Bacterial Biofilms

Unlike bacterial biofilms can be visible to the naked eye. As with many instances of bacteria they are often harmless to us but when the bacteria are dangerous the biofilm offers them protection (which is why they form such structures).

Unlocking the secrets of bacterial biofilms – to use against them by Karin Sauer

The term “biofilms” suggests a thin, two-dimensional substance, but these communities feature microscopic-scale tower-like structures crisscrossed with water channels, all of which is encased in a protective, self-produced slimy layer. The bacteria within communicate and demonstrate cooperative behavior reminiscent of primitive organs.

According to the National Institutes of Health, more than 65 percent of chronic inflammatory and infectious diseases are due to biofilms. According to recent studies, biofilm-related infections claim as many lives as heart attack or cancer.

Scientists think there are several reasons for this decrease in susceptibility. First, the slimy layer encasing biofilms can make it hard for disinfectants or antimicrobials to even physically reach the bacteria. Also, bacteria living in biofilms experience high stress levels while growing rather slowly, which can render most antibiotics ineffective since they only work on actively growing cells. My favorite theory is that living in a biofilm changes bacteria and their behavior; something about their mix of active genes and proteins just makes them more resilient. Whatever the contributing factors, bacteria growing in a biofilm can be up to 1,000-fold more resistant to antibiotics than the same bacteria grown planktonically.

The use of biofilms predates our use of anti-biotics but the adaptation of forming biofilm communities serves as a protection against antibiotics and so it isn’t a surprise that with more use of antibiotics more surviving bacteria will be those using biofilm strategies.

Controlling biofilms in the future will likely require a combination of strategies, addressing both attachment and escape, with and without the use of antibiotics and communication blockers, and likely in a manner more or less tailored toward the different bacterial lifestyles.

Thankfully for us, we have many researchers exploring options to help us figure out how we can protect ourselves when we need to. We are going to need many different strategies to protect us going forward. Our success will depended on thousands of scientists working on these issues.

Related: Scientists Target Bacteria Where They Live (2009)Using Nanocomposites to Improve Dental Filling Performance (2012)Fighting Superbugs with Superhero Bugs (2015)The Search for Antibiotic Solutions Continues: Killing Sleeper Bacteria Cells (2013)

How Eratosthenes Estimated the Circumference of the Earth Over 2,000 Years Ago

In this video Carl Sagan explains how Greek astronomer Eratosthenes, in 200 BC, was able to deduce and calculate the earth was a sphere about 40,000 km in circumference.

It is wonderful to see how a bit of thought and curiosity have lead mankind to learn so much.

Related: How do Plants Grow Into the Sunlight?Why is it Colder at Higher Elevations?Great Webcast Explaining the Digestive SystemBiology: How Wounds to Our Skin Heal

Promoting Open Science

As I have written many times in the past we need to take back science from the closed-science journals. Historically journals were useful (before the internet). With the advent of the internet (and its spread) instead of maintaining the mission they started with the journals sought to maximize their profit and their own pay and jobs at the expense of sharing scientific knowledge with the world.

Elsevier — my part in its downfall by Timothy Gowers provides another good look at what can be done to promote science, math and engineering by addressing the damage to that goal being done by closed science publishers.

Recently he announced the launch of Discrete Analysis, a new journal that publishes to arXiv.

Disrupting the subscription journals’ business model for the necessary large-scale transformation to open access from the Max Planck Digital Library provides some good ideas for how to promote science in spite of the closed science journals fighting that goal.

There needs to be a shared understanding that the money currently locked in the journal subscription system must be withdrawn and re-purposed for open access publishing services. The current library acquisition budgets are the ultimate reservoir for enabling the transformation without financial or other risks.

Related: The Architecture of Access to Scientific KnowledgeWhy Copyright Extension is a Very Bad IdeaPublishers Continue to Fight Open Access to Science (2007)Harvard Steps Up Defense Against Abusive Journal Publishers (2012)

Dinosaur Bird Wing and Feather in Amber

Rare Dinosaur-Era Bird Wings Found Trapped in Amber

Two tiny wings entombed in amber reveal that plumage (the layering, patterning, coloring, and arrangement of feathers) seen in birds today already existed in at least some of their predecessors nearly a hundred million years ago.

Skin, muscle, claws, and feather shafts are visible, along with the remains of rows of feathers similar in arrangement and microstructure to modern birds.

photo of dinosaur wing in amber with feathers visible

The nearly 100 million year old wing shows a structure that is very similar to modern birds.

The piece in this photo, and others samples, were bought at an amber market in Myitkyina, the capital of Kachin state in northern Myanmar. The region is politically unstable and most of the amber is sold to Chinese consumers for jewelry and decorative carvings.

Read the related posts for more on the wonderful discoveries saved in amber of hundreds of millions of years. We get to read about these amazing discoveries so often it is easy to lose appreciation for how amazing each one is. This photo shows a wind that was used by a dinosaur almost 100 million years ago.

Related: Marine Plankton From 100 Million Years Ago Found in Amber 2008)Learning About Life over 200 Million Years Ago From Samples Trapped In Amber (2012)The evolution of birds from small predatory dinosaursDino-Era Feathers Found Encased in Amber (2008)Amber Pieces Containing Remains from Dinosaurs and Birds Show Feather Evolution (2011)Ancient Whale Uncovered in Egyptian Desert

An Eukaryote that Completely Lacks Mitochondria

If you don’t have any idea what the title means that is ok. I probably wouldn’t have until the last 15 years when I found how interesting biology is thanks to the internet and wonderful resources online making biology interesting. I hope you find learning about biology as interesting as I do.

Look, Ma! No Mitochondria

Mitochondria have their own DNA, and scientists believe they were once free-living bacteria that got engulfed by primitive, ancient cells that were evolving to become the complex life forms we know and love today.

What they learned is that instead of relying on mitochondria to assemble iron-sulfur clusters, these cells use a different kind of machinery. And it looks like they acquired it from bacteria.

The researchers say this is the first example of any eukaryote that completely lacks mitochondria.

However, the results do not negate the idea that the acquisition of a mitochondrion was an important and perhaps defining event in the evolution of eukaryotic cells, he adds.

That’s because it seems clear that this organism’s ancestors had mitochondria that were then lost after the cells acquired their non-mitochondrial system for making iron-sulfur clusters.

Biology is amazing and mitochondria are one of the many amazing details. I wish so much that my education could have given biology a tiny fraction of the interest I have found it in after school.

Related: Human Gene Origins: 37% Bacterial, 35% Animal, 28% EukaryoticOne Species’ Genome Discovered Inside Another’sParasite Evolved from Cnidarians (Jellyfish etc.)Plants, Unikonts, Excavates and SARs

Mountain Lion Roams from South Dakota all the way to 30 Miles from Manhattan

book cover with image of a mountain lion

A Cougar’s Thousand-Mile Quest to Find a Mate

In the late summer of 2009, a young male cougar set off from the Black Hills of South Dakota to look for a mate. And kept going—east across the Great Plains to the Upper Peninsula of Michigan and on to New England, through backyards and parking lots, across highways and railroad tracks, driven by the most powerful force on earth.

Over time he showed up in the Twin Cities of Minnesota and in Wisconsin. He disappeared for a couple months, then shows up almost two years later, 30 miles from Manhattan, in Greenwich, Connecticut. In all he probably traveled 2,000 to 5,000 miles, enough to cross the country twice. He forded all the major rivers of the East, navigated highways and an international boundary. It was one of the most spectacular journeys by an animal ever recorded.

image of map showing the cougar's path across usa

In Heart of a Lion: A Lone Cat’s Walk Across America William Stolzenburg provides an exciting tale of the cat’s journey.

Related: Backyard Wildlife: Mountain Lion (2012)Mountain Lions Returning to the Midwest USA for the First Time in a Century (2012)Big Cats in America (2004)USA Designates Large Areas of New Mexico and Arizona as Critical Habitat for Jaguars (2014)

  • Recent Comments:

    • Alex: This is certainly the future. It is hart warming to see developing countries benefiting from such...
    • Donnie S. Willson: Underground tunnel is a good idea for traffic managment.i really appreciate it.
    • Richard Hopp: Awesome blog post, love the biodiversity. Really excited after watching this video, since I...
    • Robbie Miller: How fantastic, not only a great subject to study, but to be able to travel the world too....
    • Jaspal Singh: Japan has an edge when it comes to humanoid robots. No doubt in few more year, you will find...
    • Marcus Williams: This is actually a marvelous piece of engineering. Kudos for sharing!
    • M Zeeshan Haider: You are so interesting! I don’t believe I’ve truly read through anything like...
    • Jaspal Singh: I fully agree to the post idea. The farming is a natural process and should be free from any...
  • Recent Trackbacks:

  • Links