Date:
August 22, 2017

Source:
American Chemical Society

Summary:
Photosynthesis provides energy for the vast majority of life on Earth. But chlorophyll, the green pigment that plants use to harvest sunlight, is relatively inefficient. To enable humans to capture more of the sun’s energy, scientists have taught bacteria to cover themselves in tiny, highly efficient solar panels to produce useful compounds.

 

Artist’s rendering of bioreactor (left) loaded with bacteria decorated with cadmium sulfide, light-absorbing nanocrystals (middle) to convert light, water and carbon dioxide into useful chemicals (right).
Credit: Kelsey K. Sakimoto

 

 

Photosynthesis provides energy for the vast majority of life on Earth. But chlorophyll, the green pigment that plants use to harvest sunlight, is relatively inefficient. To enable humans to capture more of the sun’s energy than natural photosynthesis can, scientists have taught bacteria to cover themselves in tiny, highly efficient solar panels to produce useful compounds.

The researchers are presenting their work today at the 254th National Meeting & Exposition of the American Chemical Society (ACS).

“Rather than rely on inefficient chlorophyll to harvest sunlight, I’ve taught bacteria how to grow and cover their bodies with tiny semiconductor nanocrystals,” says Kelsey K. Sakimoto, Ph.D., who carried out the research in the lab of Peidong Yang, Ph.D. “These nanocrystals are much more efficient than chlorophyll and can be grown at a fraction of the cost of manufactured solar panels.”

Humans increasingly are looking to find alternatives to fossil fuels as sources of energy and feedstocks for chemical production. Many scientists have worked to create artificial photosynthetic systems to generate renewable energy and simple organic chemicals using sunlight. Progress has been made, but the systems are not efficient enough for commercial production of fuels and feedstocks.

Research in Yang’s lab at the University of California, Berkeley, where Sakimoto earned his Ph.D., focuses on harnessing inorganic semiconductors that can capture sunlight to organisms such as bacteria that can then use the energy to produce useful chemicals from carbon dioxide and water. “The thrust of research in my lab is to essentially ‘supercharge’ nonphotosynthetic bacteria by providing them energy in the form of electrons from inorganic semiconductors, like cadmium sulfide, that are efficient light absorbers,” Yang says. “We are now looking for more benign light absorbers than cadmium sulfide to provide bacteria with energy from light.”

Sakimoto worked with a naturally occurring, nonphotosynthetic bacterium, Moorella thermoacetica, which, as part of its normal respiration, produces acetic acid from carbon dioxide (CO2). Acetic acid is a versatile chemical that can be readily upgraded to a number of fuels, polymers, pharmaceuticals and commodity chemicals through complementary, genetically engineered bacteria.

When Sakimoto fed cadmium and the amino acid cysteine, which contains a sulfur atom, to the bacteria, they synthesized cadmium sulfide (CdS) nanoparticles, which function as solar panels on their surfaces. The hybrid organism, M. thermoacetica-CdS, produces acetic acid from CO2, water and light. “Once covered with these tiny solar panels, the bacteria can synthesize food, fuels and plastics, all using solar energy,” Sakimoto says. “These bacteria outperform natural photosynthesis.”

The bacteria operate at an efficiency of more than 80 percent, and the process is self-replicating and self-regenerating, making this a zero-waste technology. “Synthetic biology and the ability to expand the product scope of CO2 reduction will be crucial to poising this technology as a replacement, or one of many replacements, for the petrochemical industry,” Sakimoto says.

So, do the inorganic-biological hybrids have commercial potential? “I sure hope so!” he says. “Many current systems in artificial photosynthesis require solid electrodes, which is a huge cost. Our algal biofuels are much more attractive, as the whole CO2-to-chemical apparatus is self-contained and only requires a big vat out in the sun.” But he points out that the system still requires some tweaking to tune both the semiconductor and the bacteria. He also suggests that it is possible that the hybrid bacteria he created may have some naturally occurring analog. “A future direction, if this phenomenon exists in nature, would be to bioprospect for these organisms and put them to use,” he says.

A video on the research is available at https://www.youtube.com/watch?v=opl5CnDA_2c&feature=youtu.be

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Source: American Chemical Society. “Cyborg bacteria outperform plants when turning sunlight into useful compounds.” ScienceDaily. ScienceDaily, 22 August 2017. <www.sciencedaily.com/releases/2017/08/170822092234.htm>.

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Researchers discover a new molecule, ‘Singheart,’ that may hold the key to triggering the regeneration and repair of damaged heart cells

Date:
August 21, 2017

Source:
National University Health System

Summary:
New research has discovered a potential means to trigger damaged heart cells to self-heal. The discovery could lead to groundbreaking forms of treatment for heart diseases. For the first time, researchers have identified a long non-coding ribonucleic acid (ncRNA) that regulates genes controlling the ability of heart cells to undergo repair or regeneration. This novel RNA, called ‘Singheart,’ may be targeted for treating heart failure in the future.

 

A mouse heart cell with 2 nuclei (blue) and Singheart RNA labelled by red fluorescent dyes.
Credit: A*STAR’s Genome Institute of Singapore

 

 

New research has discovered a potential means to trigger damaged heart cells to self-heal. The discovery could lead to groundbreaking forms of treatment for heart diseases. For the first time, researchers have identified a long non-coding ribonucleic acid (ncRNA) that regulates genes controlling the ability of heart cells to undergo repair or regeneration. This novel RNA, which researchers have named “Singheart,” may be targeted for treating heart failure in the future. The discovery was made jointly by A*STAR’s Genome Institute of Singapore (GIS) and the National University Health System (NUHS), and is now published in Nature Communications.

Unlike most other cells in the human body, heart cells do not have the ability to self-repair or regenerate effectively, making heart attack and heart failure severe and debilitating. Cardiovascular disease (CVD) is the leading cause of death worldwide, with an estimated 17.7 million people dying from CVD in 2015. CVD also accounted for close to 30% of all deaths in Singapore in 2015.

In this project, the researchers used single cell technology to explore gene expression patterns in healthy and diseased hearts. The team discovered that a unique subpopulation of heart cells in diseased hearts activate gene programmes related to heart cell division, uncovering the gene expression heterogeneity of diseased heart cells for the first time. In addition, they also found the “brakes” that prevent heart cells from dividing and thus self-healing. Targeting these “brakes” could help trigger the repair and regeneration of heart cells.

“There has always been a suspicion that the heart holds the key to its own healing, regenerative and repair capability. But that ability seems to become blocked as soon as the heart is past its developmental stage. Our findings point to this potential block that when lifted, may allow the heart to heal itself,” explained A/Prof Roger Foo, the study’s lead author, who is Principal Investigator at both GIS and NUHS’ Cardiovascular Research Institute (CVRI) and Senior Consultant at the National University Heart Centre, Singapore (NUHCS).

“In contrast to a skin wound where the scab falls off and new skin grows over, the heart lacks such a capability to self-heal, and suffers a permanent scar instead. If the heart can be motivated to heal like the skin, consequences of a heart attack would be banished forever,” added A/Prof Foo.

The study was driven by first author and former Senior Research Fellow at the GIS, Dr Kelvin See, who is currently a Postdoctoral Researcher and Mack Technology Fellow at University of Pennsylvania.

“This new research is a significant step towards unlocking the heart’s full regenerative potential, and may eventually translate to more effective treatment for heart diseases. Heart disease is the top disease burden in Singapore and strong funding remains urgently needed to enable similar groundbreaking discoveries,” said Prof Mark Richards, Director of CVRI.

Executive Director of GIS, Prof Ng Huck Hui added, “This cross-institutional research effort serves as a strong foundation for future heart studies. More importantly, uncovering barriers that stand in the way of heart cells’ self-healing process brings us another step closer to finding a cure for one of the world’s biggest killers.”

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Materials provided by National University Health SystemNote: Content may be edited for style and length.


Journal Reference:

  1. Kelvin See, Wilson L. W. Tan, Eng How Lim, Zenia Tiang, Li Ting Lee, Peter Y. Q. Li, Tuan D. A. Luu, Matthew Ackers-Johnson, Roger S. Foo. Single cardiomyocyte nuclear transcriptomes reveal a lincRNA-regulated de-differentiation and cell cycle stress-response in vivoNature Communications, 2017; 8 (1) DOI: 10.1038/s41467-017-00319-8

 

Source: National University Health System. “Repairing damaged hearts with self-healing heart cells: Researchers discover a new molecule, ‘Singheart,’ that may hold the key to triggering the regeneration and repair of damaged heart cells.” ScienceDaily. ScienceDaily, 21 August 2017. <www.sciencedaily.com/releases/2017/08/170821094253.htm>.

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Scientists sequence a whole genome on a Welsh mountainside to identify a plant species within hours

Date:
August 21, 2017

Source:
Royal Botanic Gardens Kew

Summary:
A new article reveals the opportunities for portable, real-time DNA sequencing in plant identification and naming. Using a handheld DNA sequencing device they conducted the first genomic plant sequencing in the field at a fraction of the speed of traditional methods, offering exciting possibilities to conservationists and scientists the world over.

 

The field identification of two different white flowers Arabidopsis thaliana and Arabidopsis lyrata ssp. petraea was achieved by sequencing random parts of the plants’ genomes and comparing their new data to a database of reference genome sequences.
Credit: Alex Papadopolous

 

 

In a paper published today in Scientific Reports(Nature Publishing Group), researchers at the Royal Botanic Gardens, Kew, detail for the first time the opportunities for plant sciences that are now available with portable, real-time DNA sequencing.

Kew scientist and co-author of the paper Joe Parker says; “This research proves that we can now rapidly read the DNA sequence of an organism to identify it with minimum equipment. Rapidly reading DNA anywhere, at will, should become a routine step in many research fields. Despite hundreds of years of taxonomic research, it is still not always easy to work out which species a plant belongs to just by looking at it. Few people could correctly identify all the species in their own gardens.”

Over the last forty years, DNA sequencing has revolutionised the scientific world but has remained laboratory-bound. Using current methods, a complete experiment to identify a species, from fieldwork to result, could easily take a scientist months to complete. Species identification is, by nature, a largely a field-based area of pursuit, thereby limiting the pace of discovery and decision making that can depend upon it. Using new technology to identify species quickly and on-site is critical for scientific research, the conservation of biodiversity and in the fight against species crime.

In this new study, Kew scientists used the portable DNA sequencer, the MinION from Oxford Nanopore Technologies, to analyse plant species in Snowdonia National Park. This was the first time genomic sequencing of plants has been performed in the field.

This technology, commercially launched in 2015, has since been used in Antarctica, in remote regions affected by disease, and on the International Space Station.

One of the successes illustrated in the paper is the field identification of two innocuous white flowers, Arabidopsis thaliana and Arabidopsis lyrata ssp. petraea. This was achieved by sequencing random parts of the plants’ genomes, avoiding the tricky and time consuming process of targeting specific pieces of DNA which is the more traditional approach for identifying species with DNA.

The researchers compared their new data to a freely available database of reference genome sequences to make their identification. Crucially, replicating their experiment in Kew’s Jodrell Laboratory with other DNA sequencing methods allowed them to devise sophisticated statistics to understand the useful properties of this new kind of data for the first time.

Alexander Papadopulos, Kew scientist and co-author on the paper, says; “Accurate species identification is essential for evolutionary and ecological research, in the fight against wildlife crime and for monitoring rare and threatened species. Identifying species correctly based on what they look like can be really tricky and needs expertise to be done well. This is especially true for plants when they aren’t in flower or when they have been processed into a product. Our experiments show that by sequencing random pieces of the genome in the field it’s possible to get very accurate species identification within a few hours of collecting a specimen. More traditional methods need a lot of lab equipment and have often only provided enough information to identify a sample to the genus level.”

There are other useful properties of their data too. This field sequenced data can be used to assemble a whole genome sequence, act as a reference database for the species and help understand evolutionary relationships. Currently, the team is exploring the feasibility of rapidly generating a reference sequence database from the incredibly diverse collection of plants help in Kew’s living collection and herbarium as well as applications for monitoring plant health.

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Materials provided by Royal Botanic Gardens KewNote: Content may be edited for style and length.


Journal Reference:

  1. Joe Parker, Andrew J. Helmstetter, Dion Devey, Tim Wilkinson, Alexander S. T. Papadopulos. Field-based species identification of closely-related plants using real-time nanopore sequencingScientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-08461-5

 

Source: Royal Botanic Gardens Kew. “Into the wild for plant genetics: Scientists sequence a whole genome on a Welsh mountainside to identify a plant species within hours.” ScienceDaily. ScienceDaily, 21 August 2017. <www.sciencedaily.com/releases/2017/08/170821085646.htm>.

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Date:
August 17, 2017

Source:
University of Hawaii at Manoa

Summary:
Oceanographers report completing the largest single-site microbiome gene catalog constructed to date. With this new information, the team discovered nutrient limitation is a central driver in the evolution of ocean microbe genomes.

 

A rosette sampler captures water at specified depths at Station ALOHA.
Credit: Tara Clemente, UH M?noa

 

 

Microbes dominate the planet, especially the ocean, and help support the entire marine food web. In a recent report published in Nature Microbiology, University of Hawai’i at M?noa (UHM) oceanography professor Ed DeLong and his team report the largest single-site microbiome gene catalog constructed to date. With this new information, the team discovered nutrient limitation is a central driver in the evolution of ocean microbe genomes.

As a group, marine microbes are extremely diverse and versatile with respect to their metabolic capabilities. All of this variability is encoded in their genes. Some marine microorganisms have genetic instructions that allow them to use the energy derived from sunlight to turn carbon dioxide into organic matter. Others use organic matter as a carbon and energy source and produce carbon dioxide as a respiration end-product. Other, more exotic pathways have also been discovered.

“But how do we characterize all these diverse traits and functions in virtually invisible organisms, whose numbers approach a million cells per teaspoon of seawater?” asked DeLong, senior author on the paper. “This newly constructed, comprehensive gene catalog of microbes inhabiting the ocean waters north of the Hawaiian Islands addresses this challenge.”

Water samples were collected over two years, and modern genome sequencing technologies were used to decode the genes and genomes of the most abundant microbial species in the upper 3,000 feet of water at the Hawai’i Ocean Time-series (HOT) Program open ocean field site, Station ALOHA.

Just below the depth of sunlit layer, the team observed a sharp transition in the microbial communities present. They reported that the fundamental building blocks of microbes, their genomes and proteins, changed drastically between depths of about 250-650 feet.

“In surface waters, microbial genomes are much smaller, and their proteins contain less nitrogen — a logical adaptation in this nitrogen-starved environment,” said Daniel Mende, post-doctoral researcher at the UHM School of Ocean and Earth Science and Technology (SOEST) and lead author on the paper. “In deeper waters, between 400-650 feet, microbial genomes become much larger, and their proteins contain more nitrogen, in tandem with increasing nitrogen availability with depth.”

“These results suggest that the availability of nutrients in the environment may actually shape how microbial genomes and proteins evolve in the wild,” said DeLong. “Another surprising finding of the study is that the microbial ‘genomic transition zone’ observed occurs over a very narrow depth range, just beneath the sunlit layer. Below about 650 feet deep, the fundamental properties of microbial genomes and proteins are relatively constant, all the way down to the seafloor.”

In collaboration with a computer science group led by professor Bonnie Hurwitz at the University of Arizona, the new database is available to scientists worldwide who are seeking to describe the nature and function of microbes in the global oceans.

“These new data will provide an important tool for understanding the nature and function of the ocean’s microbiome today, as well as help predict its trajectory into the future,” said DeLong.


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Materials provided by University of Hawaii at ManoaNote: Content may be edited for style and length.


Journal Reference:

  1. Daniel R. Mende, Jessica A. Bryant, Frank O. Aylward, John M. Eppley, Torben Nielsen, David M. Karl, Edward F. DeLong. Environmental drivers of a microbial genomic transition zone in the ocean’s interiorNature Microbiology, 2017; DOI: 10.1038/s41564-017-0008-3

 

Source: University of Hawaii at Manoa. “New gene catalog of ocean microbiome reveals surprises.” ScienceDaily. ScienceDaily, 17 August 2017. <www.sciencedaily.com/releases/2017/08/170817162014.htm>.

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Date:
August 16, 2017

Source:
New York University

Summary:
How do we detect the meaning of music? We may gain some insights by looking at an unlikely source — sign language — a newly released linguistic analysis concludes.

 

What can sign language teach us about music?
Credit: © whiteshadow18 / Fotolia

 

 

How do we detect the meaning of music? We may gain some insights by looking at an unlikely source, sign language, a newly released linguistic analysis concludes.

“Musicians and music lovers intuitively know that music can convey information about an extra-musical reality,” explains author Philippe Schlenker, a senior researcher at Institut Jean-Nicod within France’s National Center for Scientific Research (CNRS) and a Global Distinguished Professor at New York University. “Music does so by way of abstract musical animations that are reminiscent of iconic, or pictorial-like, components of meaning that are common in sign language, but rare in spoken language.”

The analysis, “Outline of Music Semantics,” appears in the journal Music Perception; it is available, with sound examples, here: http://ling.auf.net/lingbuzz/002942. A longer piece that discusses the connection with iconic semantics is forthcoming in the Review of Philosophy & Psychology (“Prolegomena to Music Semantics”).

Schlenker acknowledges that spoken language also deploys iconic meanings–for example, saying that a lecture was ‘loooong’ gives a very different impression from just saying that it was ‘long.’ However, these meanings are relatively marginal in the spoken word; by contrast, he observes, they are pervasive in sign languages, which have the same general grammatical and logical rules as do spoken languages, but also far richer iconic rules.

Drawing inspiration from sign language iconicity, Schlenker proposes that the diverse inferences drawn on musical sources are combined by way of abstract iconic rules. Here, music can mimic a reality, creating a “fictional source” for what is perceived to be real. As an example, he points to composer Camille Saint Saëns’s “The Carnival of the Animals” (1886), which aims to capture the physical movement of tortoises.

“When Saint Saëns wanted to evoke tortoises in ‘The Carnival of Animals,’ he not only used a radically slowed-down version of a high-energy dance, the Can-Can,” Schlenker notes. “He also introduced a dissonance to suggest that the hapless animals were tripping, an effect obtained due to the sheer instability of the jarring chord.”

In his work, Schlenker broadly considers how we understand music–and, in doing so, how we derive meaning through the fictional sources that it creates.

“We draw all sorts of inferences about fictional sources of the music when we are listening,” he explains. “Lower pitch is, for instance, associated with larger sound sources, a standard biological code in nature. So, a double bass will more easily evoke an elephant than a flute would. Or, if the music slows down or becomes softer, we naturally infer that a piece’s fictional source is losing energy, just as we would in our daily, real-world experiences. Similarly, a higher pitch may signify greater energy–a physical code–or greater arousal, which is a biological code.”

Fictional sources may be animate or inanimate, Schlenker adds, and their behavior may be indicative of emotions, which play a prominent role in musical meaning.

“More generally, it is no accident that one often signals the end of a classical piece by simultaneously playing more slowly, more softly, and with a musical movement toward more consonant chords,” he says. “These are natural ways to indicate that the fictional source is gradually losing energy and reaching greater repose.”

In his research, Schlenker worked with composer Arthur Bonetto to create minimal modifications of well-known music snippets to understand the source of the meaning effects they produce. This analytical method of ‘minimal pairs,’ borrowed from linguistics and experimental psychology, Schlenker posits, could be applied to larger musical excerpts in the future.


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Journal Reference:

  1. Philippe Schlenker. Outline of Music SemanticsMusic Perception: An Interdisciplinary Journal, 2017; 35 (1): 3 DOI: 10.1525/mp.2017.35.1.3

 

Source: New York University. “What does music mean? Sign language may offer an answer.” ScienceDaily. ScienceDaily, 16 August 2017. <www.sciencedaily.com/releases/2017/08/170816084905.htm>.

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Date:
August 15, 2017

Source:
NASA/Jet Propulsion Laboratory

Summary:
Mere weeks away from its dramatic, mission-ending plunge into Saturn, NASA’s Cassini spacecraft has a hectic schedule, orbiting the planet every week in its Grand Finale. On a few orbits, Saturn’s largest moon, Titan, has been near enough to tweak Cassini’s orbit, causing the spacecraft to approach Saturn a bit closer or a bit farther away. A couple of those distant passes even pushed Cassini into the inner fringes of Saturn’s rings.

 

These two views of Saturn’s moon Titan exemplify how NASA’s Cassini spacecraft has revealed the surface of this fascinating world.
Credit: NASA/JPL-Caltech/Space Science Institute

 

 

Mere weeks away from its dramatic, mission-ending plunge into Saturn, NASA’s Cassini spacecraft has a hectic schedule, orbiting the planet every week in its Grand Finale. On a few orbits, Saturn’s largest moon, Titan, has been near enough to tweak Cassini’s orbit, causing the spacecraft to approach Saturn a bit closer or a bit farther away. A couple of those distant passes even pushed Cassini into the inner fringes of Saturn’s rings.

Titan will be waiting once again when the road runs out in September. A last, distant encounter with the moon on Sept. 11 will usher Cassini to its fate, with the spacecraft sending back precious science data until it loses contact with Earth.

But this gravitational pushing and shoving isn’t a new behavior for Titan. It’s been doing that all along, by design.

The True Engine of the Mission

Repeated flybys of Titan were envisioned, from the mission’s beginning, as a way to explore the mysterious planet-size moon and to fling Cassini toward its adventures in the Saturn system. Scientists had been eager for a return to Titan since NASA’s Voyager 1 spacecraft flew past in 1980 and was unable to see through the dense, golden haze that shrouds its surface.

Titan is just a bit larger than the planet Mercury. Given its size, the moon has significant gravity, which is used for bending Cassini’s course as it orbits Saturn. A single close flyby of Titan could provide more of a change in velocity than the entire 90-minute engine burn the spacecraft needed to slow down and be captured by Saturn’s gravity upon its arrival in 2004.

The mission’s tour designers — engineers tasked with plotting the spacecraft’s course, years in advance — used Titan as their linchpin. Frequent passes by the moon provided the equivalent of huge amounts of rocket propellant. Using Titan, Cassini’s orbit could be stretched out, farther from Saturn — for example, to send the spacecraft toward the distant moon Iapetus. With this technique, engineers used Titan flybys to change the orientation of Cassini’s orbit many times during the mission; for example, lifting the spacecraft out of the plane of the rings to view them from high above, along with high northern and southern latitudes on Saturn and its moons.

What We’ve Learned

Over the course of its 13-year mission at Saturn, Cassini has made 127 close flybys of Titan, with many more-distant observations. Cassini also dropped off the European Space Agency’s Huygens probe, which descended through Titan’s atmosphere to land on the surface in January 2005.

Successes for Cassini during its mission include the revelation that, as researchers had theorized, there were indeed bodies of open liquid hydrocarbons on Titan’s surface. Surprisingly, it turned out Titan’s lakes and seas are confined to the poles, with almost all of the liquid being at northern latitudes in the present epoch. Cassini found that most of Titan has no lakes, with vast stretches of linear dunes closer to the equator similar to those in places like Namibia on Earth. The spacecraft observed giant hydrocarbon clouds hovering over Titan’s poles and bright, feathery ones that drifted across the landscape, dropping methane rain that darkened the surface. There were also indications of an ocean of water beneath the moon’s icy surface.

Early on, Cassini’s picture of Titan was spotty, but every encounter built upon the previous one. Over the course of the entire mission, Cassini’s radar investigation imaged approximately 67 percent of Titan’s surface, using the spacecraft’s large, saucer-shaped antenna to bounce signals off the moon’s surface. Views from Cassini’s imaging cameras, infrared spectrometer, and radar slowly and methodically added details, building up a more complete, high-resolution picture of Titan.

“Now that we’ve completed Cassini’s investigation of Titan, we have enough detail to really see what Titan is like as a world, globally,” said Steve Wall, deputy lead of Cassini’s radar team at NASA’s Jet Propulsion Laboratory in Pasadena, California.

Scientists now have enough data to understand the distribution of Titan’s surface features (like mountains, dunes and seas) and the behavior of its atmosphere over time, and they have been able to begin piecing together how surface liquids might migrate from pole to pole.

Among the things that remain uncertain is exactly how the methane in Titan’s atmosphere is being replenished, since it’s broken down over time by sunlight. Scientists see some evidence of volcanism, with methane-laden water as the “lava,” but a definitive detection remains elusive.

Cassini’s long-term observations could still provide clues. Researchers have been watching for summer rain clouds to appear at the north pole, as their models predicted. Cassini observed rain clouds at the south pole in southern summer in 2004. But so far, clouds at high northern latitudes have been sparse.

“The atmosphere seems to have more inertia than most models have assumed. Basically, it takes longer than we thought for the weather to change with the seasons,” said Elizabeth Turtle, a Cassini imaging team associate at Johns Hopkins Applied Physics Laboratory, Laurel, Maryland.

The sluggish arrival of northern summer clouds may match better with models that predict a global reservoir of methane, Turtle said. “There isn’t a global reservoir at the surface, so if one exists in the subsurface that would be a major revelation about Titan.” This points to the value of Cassini’s long-term monitoring of Titan’s atmosphere, she said, as the monitoring provides data that can be used to test models and ideas.

Results from the Last Close Pass

Cassini made its last close flyby of Titan on April 22. That flyby gave the spacecraft the push it needed to leap over Saturn’s rings and begin its final series of orbits, which pass between the rings and the planet.

During that flyby, Cassini’s radar was in the driver’s seat — its observation requirements determining how the spacecraft would be oriented as it passed low over the surface one last time at an altitude of 608 miles (979 kilometers). One of the priorities was to have one last look for the mysterious features the team dubbed “magic islands,” which had appeared and then vanished in separate observations taken years apart. On the final pass there were no magic islands to be seen. The radar team is still working to understand what the features might have been, with leading candidates being bubbles or waves.

Most interesting to the radar team was a set of observations that was both the first and last of its kind, in which the instrument was used to sound the depths of several of the small lakes that dot Titan’s north polar region. Going forward, the researchers will be working to tease out information from these data about the lakes’ composition, in terms of methane versus ethane.

As Cassini zoomed past on its last close brush with Titan, headed toward its Grand Finale, the radar imaged a long swath of the surface that included terrain seen on the very first Titan flyby in 2004. “It’s pretty remarkable that we ended up close to where we started,” said Wall. “The difference is how richly our understanding has grown, and how the questions we’re asking about Titan have evolved.”

The Cassini-Huygens mission is a cooperative project of NASA, ESA (European Space Agency) and the Italian Space Agency. NASA’s Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington. JPL designed, developed and assembled the Cassini orbiter.


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Source: NASA/Jet Propulsion Laboratory. “Cassini says goodbye to a true Titan.” ScienceDaily. ScienceDaily, 15 August 2017. <www.sciencedaily.com/releases/2017/08/170815150205.htm>.

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World’s oceans possess vast, untapped potential for sustainable aquaculture, say marine scientists

Date:
August 14, 2017

Source:
University of California – Santa Barbara

Summary:
Covering 70 percent of Earth’s surface, the world’s oceans are vast and deep. So vast, in fact, that nearly every coastal country has the potential to meet its own domestic seafood needs through aquaculture. In fact, each country could do so using a tiny fraction of its ocean territory.

 

Net pen aquaculture in deep coastal waters.
Credit: NOAA

 

 

Covering 70 percent of Earth’s surface, the world’s oceans are vast and deep. So vast, in fact, that nearly every coastal country has the potential to meet its own domestic seafood needs through aquaculture. In fact, each country could do so using a tiny fraction of its ocean territory.

So finds a study led by scientists from UC Santa Barbara and including researchers from the Nature Conservancy, UCLA and the National Oceanic and Atmospheric Administration. Their research, published in the journal Nature Ecology and Evolution, demonstrates the oceans’ potential to support aquaculture. Also known as fish farming, the practice is the fastest-growing food sector, and it’s poised to address increasing issues of food insecurity around the globe.

“There is a lot of space that is suitable for aquaculture, and that is not what’s going to limit its development,” said lead author Rebecca Gentry, who recently completed her Ph.D. at UCSB’s Bren School of Environmental Science & Management. “It’s going to be other things such as governance and economics.”

According to the study, among the first global assessments of the potential for marine aquaculture, the world’s oceans are rife with aquaculture “hot spots” that provide enough space to produce 15 billion metric tons of finfish annually. That is more than 100 times the current global seafood consumption.

More realistically, the researchers note, if aquaculture were developed in only the most productive areas, the oceans could theoretically produce the same amount of seafood that the world’s wild-caught fisheries currently produce globally, but in less than 1 percent of the total ocean surface — a combined area the size of Lake Michigan.

“There are only a couple of countries that are producing the vast majority of what’s being produced right now in the oceans,” Gentry said. “We show that aquaculture could actually be spread a lot more across the world, and every coastal country has this opportunity.”

The United States, for example, has enormous untapped potential and could produce enough farmed seafood to meet national demand using only 0.01 percent of its exclusive economic zone, Gentry noted. Given that the U.S. imports more than 90 percent of its seafood, aquaculture presents a powerful opportunity to increase domestic supply and reduce the nation’s seafood trade deficit, which now totals over $13 billion.

“Marine aquaculture provides a means and an opportunity to support both human livelihoods and economic growth, in addition to providing food security,” said co-author Ben Halpern, executive director of the UCSB-affiliated National Center for Ecological Analysis and Synthesis (NCEAS). “It’s not a question of if aquaculture will be part of future food production but, instead, where and when. Our results help guide that trajectory.”

To determine aquaculture’s global potential, the researchers identified areas where ocean conditions are suitable enough to support farms. They used synthesized data on oceanographic parameters like ocean depth and temperature and the biological needs of 180 species of finfish and bivalve mollusks, such as oysters and mussels.

The research team ruled out places that would come into conflict with other human uses, such as high shipping zones and marine protected areas, and excluded ocean depths that exceed 200 meters, following current industry practice to keep their assessment economically realistic. Their analysis did not consider all possible political or social constraints that may limit production.

“There’s so much area available that there’s a lot of flexibility to think about how to do this in the best way for conservation, economic development and other uses,” said Gentry.

Co-author Halley Froehlich noted that aquaculture could also help make up for the limitations of wild-caught fisheries. In the past two decades, the wild-caught industry has hit a production wall, stagnating at about 90 million metric tons, with little evidence that things will pick up.

“Aquaculture is expected to increase by 39 percent in the next decade,” said Froehlich, a postdoctoral researcher at NCEAS. “Not only is this growth rate fast, but the amount of biomass aquaculture produces has already surpassed wild seafood catches and beef production.”

Froehlich emphasized that it will be crucial for science, conservation, policy and industry to work together to proactively ensure fish farms are not just well placed but also well managed, such as balancing nutrient inputs and outputs to avoid pollution and monitoring for diseases. This study is a step in that collaborative direction.

“Like any food system, aquaculture can be done poorly; we’ve seen it,” she said, referring to the boom and bust of shrimp farming in the 1990s, a fallout of poor management. “This is really an opportunity to shape the future of food for the betterment of people and the environment.”


Story Source:

Materials provided by University of California – Santa Barbara. Original written by Jenny Seifert. Note: Content may be edited for style and length.


Journal Reference:

  1. Rebecca R. Gentry, Halley E. Froehlich, Dietmar Grimm, Peter Kareiva, Michael Parke, Michael Rust, Steven D. Gaines, Benjamin S. Halpern. Mapping the global potential for marine aquacultureNature Ecology & Evolution, 2017; DOI: 10.1038/s41559-017-0257-9

 

Source: University of California – Santa Barbara. “Tiny fraction of oceans could meet world’s fish demand: World’s oceans possess vast, untapped potential for sustainable aquaculture, say marine scientists.” ScienceDaily. ScienceDaily, 14 August 2017. <www.sciencedaily.com/releases/2017/08/170814125340.htm>.

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Jules Mitchel Receives Red Jacket Award and Time For a Vacation

 

To our loyal readers, friends and colleagues: We are taking time off from the last half of August and the first half of September. See you in September. We started ON TARGET in 1994, first sending the newsletter out by fax. Our weekly newsletter is now being shared with over 6,000 readers each week.

 

For more than a dozen years, PharmaVOICE magazine has been recognizing the most inspirational, motivational, and transformative individuals throughout the life-sciences industry in its annual July/August PharmaVOICE 100 issue. These individuals illustrate what it means to think bigger, do more, and lead with passion and integrity. This year’s distinguished honorees were nominated by thousands of PharmaVOICE readers and were selected for inclusion based on substantive accounts describing how they have inspired or motivated their colleagues, peers, and even competitors; their positive impact on patients, their organizations, and the industry at large; their innovative and game-changing strategies and thinking; their mentorship and guidance to the next generation of leaders; as well as their willingness to give their time and resources to their communities and philanthropic causes. The PharmaVOICE 100 is the premier awards program whose honorees represent a broad cross section of the global life-sciences industry, including the pharmaceutical, biopharmaceutical, biotechnology, contract research, clinical trial, research and development, patient education, advertising, digital, marketing, technology, academia, as well as multiple other sectors. This diverse group of individuals is also unique in that they represent a wide variety of functional areas – ranging from the clinic to the C-suite.

 

Please join the Celebration on September 14 in New York City, where PharmaVoice will be recognizing this year’s honorees as well as PharmaVOICE 100 honorees throughout the years. This is the one event designed to encourage collaboration and networking among a diverse and executive leadership audience. For more details about the third annual PharmaVOICE 100 Celebration, please go to: http://www.pharmavoice.com/pv100-celebration.

 

One of the criteria for being named a Red Jacket is having been recognized previously as a PharmaVOICE 100 honoree, but it’s much more than that. These individuals, who cross a multitude of industry sectors, have raised the bar in terms of what it means to be an inspired leader for their teams, their companies, their communities, and for the industry at large.

 

For more information about Target Health contact Warren Pearlson (212-681-2100 ext. 165). For additional information about software tools for paperless clinical trials, please also feel free to contact Dr. Jules T. Mitchel. The Target Health software tools are designed to partner with both CROs and Sponsors. Please visit the Target Health Website.

 

Joyce Hays, Founder and Editor in Chief of On Target

Jules Mitchel, Editor

 

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D N A

DNA is a double helix formed by base pairs attached to a sugar-phosphate backbone.

 

People have known for many years that living things inherit traits from their 1) ___. That common-sense observation led to agriculture, centuries ago, the purposeful breeding and cultivation of animals and plants for desirable characteristics. Firming up the details took quite some time, though. Researchers did not understand exactly how traits were passed to the next 2) ___ until the middle of the 20th century. Now it is clear that genes are what carry our traits through generations and that genes are made of deoxyribonucleic acid (DNA). But genes themselves don’t do the actual work. Rather, they serve as instruction books for making functional molecules such as RNA 3) ___ ___ and proteins, which perform the chemical reactions in our bodies. Occasionally, there is a kind of typographical error in a 4) ___ DNA sequence. This mistake – which can be a change, gap or duplication – is called a mutation. A mutation can cause a gene to encode a protein that works incorrectly or that doesn’t work at all. Sometimes, the error means that no protein is made. Not all DNA changes are harmful. Some mutations have no effect, and others produce new versions of proteins that may give a survival advantage to the organisms that have them. Over time, 5) ___ supply the raw material from which new life forms evolve.

 

Our modern understanding of DNA’s role in heredity has led to a variety of practical applications, including forensic analysis, paternity testing, and genetic screening. Thanks to these wide-ranging uses, today many people have at least a basic awareness of DNA. All living things are made of cells. The 6) ___ in the human body have 23 pairs of chromosomes, which are made of DNA, and which reveal a lot about each individual.

DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA). The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or 7) ___, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences. DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double 8) ___ is somewhat like a ladder, with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.

 

An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell. It may be surprising, then, to realize that less than a century ago, even the best-educated members of the scientific community did not know that DNA was the hereditary material! The work of Gregor Mendel showed that traits (such as flower colors in pea plants) were not inherited directly, but rather, were specified by genes passed on from parents to 9) ___. The work of additional scientists around the turn of the 20th century, including Theodor Boveri, Walter Sutton, and Thomas Hunt Morgan, established that Mendel’s heritable factors were most likely carried on chromosomes. Scientists first thought that proteins, which are found in chromosomes along with DNA, would turn out to be the sought-after genetic material. Proteins were known to have diverse amino acid sequences, while DNA was thought to be simply a repetitive polymer, due in part to an incorrect (but popular) model of its structure and composition. Today, we know that DNA is not actually repetitive and can carry large amounts of information, and that DNA itself is the actual 10) ___ material

 

Punnett Square animation, explaining basic genetic inheritance

 

Test your DNA

 

The 23andMe PGS test uses qualitative genotyping to detect clinically relevant variants in the genomic DNA of adults from saliva collected using an FDA-cleared collection device

Sources: https://ghr.nlm.nih.gov/primer/basics/dna; KhanAcademy.com; Wikipedia

 

ANSWERS: 1) parents; 2) generation; 3) ribonucleic acid; 4) gene’s; 5) mutations; 6) cells; 7) sequence; 8) helix; 9) offspring; 10) genetic

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Gregor Mendel (1822-1884)

This photo is from a book published in 1913 by R.C. Punnett, of Punnett Square fame, on Mendelism. Private Collection, Jules T. Mitchel. ©Target Health Inc.

 

 

Gregor Johann Mendel was a scientist, Augustinian friar and abbot of St. Thomas’ Abbey in Brno, Margraviate of Moravia. He was born in a German-speaking family in the Silesian part of the Austrian Empire (today’s Czech Republic) and gained posthumous recognition as the founder of the modern science of genetics. Though farmers had known for millennia that crossbreeding of animals and plants could favor certain desirable traits, Mendel’s pea plant experiments conducted between 1856 and 1863 established many of the rules of heredity, now referred to as the laws of Mendelian inheritance.

 

Mendel worked with seven characteristics of pea plants: plant height, pod shape and color, seed shape and color, and flower position and color. Taking seed color as an example, Mendel showed that when a true-breeding yellow pea and a true-breeding green pea were cross-bred their offspring always produced yellow seeds. However, in the next generation, the green peas reappeared at a ratio of 1 green to 3 yellow. To explain this phenomenon, Mendel coined the terms “recessive“ and “dominant“ in reference to certain traits. (In the preceding example, the green trait, which seems to have vanished in the first filial generation, is recessive and the yellow is dominant.) He published his work in 1866, demonstrating the actions of invisible “factors“ – now called genes – in predictably determining the traits of an organism. The profound significance of Mendel’s work was not recognized until the turn of the 20th century (more than three decades later) with the rediscovery of his laws. Erich von Tschermak, Hugo de Vries, Carl Correns, and William Jasper Spillman independently verified several of Mendel’s experimental findings, ushering in the modern age of genetics.

 

Mendel was the son of Anton and Rosine (Schwirtlich) Mendel, and had one older sister, Veronika, and one younger, Theresia. They lived and worked on a farm which had been owned by the Mendel family for at least 130 years. During his childhood, Mendel worked as a gardener and studied beekeeping. Later, as a young man, he attended gymnasium in Opava (called Troppau in German). He had to take four months off during his gymnasium studies due to illness. From 1840 to 1843, he studied practical and theoretical philosophy and physics at the Philosophical Institute of the University of Olomouc, taking another year off because of illness. He also struggled financially to pay for his studies, and Theresia gave him her dowry. Later he helped support her three sons, two of whom became doctors. He became a friar in part because it enabled him to obtain an education without having to pay for it himself. As the son of a struggling farmer, the monastic life, in his words, spared him the “perpetual anxiety about a means of livelihood.“

 

When Mendel entered the Faculty of Philosophy, the Department of Natural History and Agriculture was headed by Johann Karl Nestler who conducted extensive research of hereditary traits of plants and animals, especially sheep. Upon recommendation of his physics teacher Friedrich Franz, Mendel entered the Augustinian St Thomas’s Abbey in Brno (called Brunn in German) and began his training as a priest. Born Johann Mendel, he took the name Gregor upon entering religious life. Mendel worked as a substitute high school teacher. In 1850, he failed the oral part, the last of three parts, of his exams to become a certified high school teacher. In 1851, he was sent to the University of Vienna to study under the sponsorship of Abbot C. F. Napp so that he could get more formal education. At Vienna, his professor of physics was Christian Doppler. Mendel returned to his abbey in 1853 as a teacher, principally of physics. In 1856, he took the exam to become a certified teacher and again failed the oral part. In 1867, he replaced Napp as abbot of the monastery. After he was elevated as abbot in 1868, his scientific work largely ended, as Mendel became overburdened with administrative responsibilities, especially a dispute with the civil government over its attempt to impose special taxes on religious institutions. Mendel died on 6 January 1884, at the age of 61, in Brno, Moravia, Austria-Hungary (now Czech Republic), from chronic nephritis. Czech composer Leo? Jan?cek played the organ at his funeral. After his death, the succeeding abbot burned all papers in Mendel’s collection, to mark an end to the disputes over taxation.

 

Gregor Mendel, who is known as the “father of modern genetics“, was inspired by both his professors at the Palacky University, Olomouc (Friedrich Franz and Johann Karl Nestler), and his colleagues at the monastery (such as Franz Diebl) to study variation in plants. In 1854, Napp authorized Mendel to carry out a study in the monastery’s 2 hectares (4.9 acres) experimental garden, which was originally planted by Napp in 1830. Unlike Nestler, who studied hereditary traits in sheep, Mendel focused on plants. Mendel carried out his experiments with the common edible pea in his small garden plot in the monastery. These experiments were begun in 1856 and completed some eight years later. In 1865, he described his experiments in two lectures at a regional scientific conference. In the first lecture he described his observations and experimental results. In the second, which was given one month later, he explained them. After initial experiments with pea plants, Mendel settled on studying seven traits that seemed to be inherited independent of other traits: seed shape, flower color, seed coat tint, pod shape, unripe pod color, flower location, and plant height. He first focused on seed shape, which was either angular or round. Between 1856 and 1863 Mendel cultivated and tested some 28,000 plants, the majority of which were pea plants (Pisum sativum). This study showed that, when true-breeding different varieties were crossed to each other (e.g., tall plants fertilized by short plants), one in four pea plants had purebred recessive traits, two out of four were hybrids, and one out of four were purebred dominant. His experiments led him to make two generalizations, the Law of Segregation and the Law of Independent Assortment, which later came to be known as Mendel’s Laws of Inheritance.

 

A specific illustration: Crossing tall and short plants clarifies some of Mendel’s key observations and deductions.

 

At the time, gardeners could obtain true-breeding pea varieties from commercial seed houses. For example, one variety was guaranteed to give only tall pea plants (2 meters or so); another, only short plants (about 1/3 of a meter in height). If a gardener crossed one tall plant to itself or to another tall plant, collected the resultant seeds some three months later, planted them, and observed the height of the progeny, he would observe that all would be tall. Likewise, only short plants would result from a cross between true-breeding short peas. However, when Mendel crossed tall plants to short plants, collected the seeds, and planted them, all the offspring were just as tall, on average, as their tall parents. This led Mendel to the conclusion that the tall characteristic was dominant, and the short recessive. Mendel then crossed these second-generation tall plants to each other. The actual results from this cross were: 787 plants among the next generation (“grandchildren“ of the original cross of true-breeding cross of tall and short plants) were tall, and 277 were short. Thus, the short characteristic – which disappeared from sight in the first filial generation – resurfaced in the second, suggesting that two factors (now known as genes) determined plant height. In other words, although the factor which caused short stature ceased to exert its influence in the first filial generation, it was still present. Note also that the ratio between tall and short plants was 787/277, or 2.84 to 1 (approximately 3 to 1), again suggesting that plant height is determined by two factors. Mendel obtained similar results for six other pea traits, suggesting that a general rule is at work here: That most given characteristics of pea plants are determined by a pair of factors (genes in contemporary biology) of which one is dominant and the other is recessive.

 

Mendel presented his paper, “Versuche uber Pflanzenhybriden“ (“Experiments on Plant Hybridization“), at two meetings of the Natural History Society of Brno in Moravia on 8 February and 8 March 1865. It generated a few favorable reports in local newspapers, but was ignored by the scientific community. When Mendel’s paper was published in 1866 in Verhandlungen des naturforschenden Vereins Brunn, it was seen as essentially about hybridization rather than inheritance, had little impact, and was only cited about three times over the next thirty-five years. His paper was criticized at the time, but is now considered a seminal work. Notably, Charles Darwin was unaware of Mendel’s paper, and it is envisaged that if he had, genetics as we know it now might have taken hold much earlier. Mendel’s scientific biography thus provides one more example of the failure of obscure, highly-original, innovators to receive the attention they deserve.

 

Mendel began his studies on heredity using mice. He was at St. Thomas’s Abbey but his bishop did not like one of his friars studying animals, so Mendel switched to plants. Mendel also bred bees in a bee house that was built for him, using bee hives that he designed. He also studied astronomy and meteorology, founding the ‘Austrian Meteorological Society’ in 1865. The majority of his published works were related to meteorology. Mendel also experimented with hawkweed (Hieracium) and honeybees. He published a report on his work with hawkweed, a group of plants of great interest to scientists at the time because of their diversity. However, the results of Mendel’s inheritance study in hawkweeds was unlike his results for peas; the first generation was very variable and many of their offspring were identical to the maternal parent. In his correspondence with Carl Nageli, he discussed his results but was unable to explain them. It was not appreciated until the end of the nineteen century that many hawkweed species were apomictic, producing most of their seeds through an asexual process. None of his results on bees survived, except for a passing mention in the reports of Moravian Apiculture Society. All that is known definitely is that he used Cyprian and Carniolan bees, which were particularly aggressive to the annoyance of other monks and visitors of the monastery, such that he was asked to get rid of them. Mendel, on the other hand, was fond of his bees, and referred to them as “my dearest little animals“.

 

During Mendel’s own lifetime, most biologists held the idea that all characteristics were passed to the next generation through blending inheritance, in which the traits from each parent are averaged. Instances of this phenomenon are now explained by the action of multiple genes with quantitative effects. Charles Darwin tried unsuccessfully to explain inheritance through a theory of pangenesis. It was not until the early twentieth century that the importance of Mendel’s ideas was realized. By 1900, research aimed at finding a successful theory of discontinuous inheritance rather than blending inheritance, led to independent duplication of his work by Hugo de Vries and Carl Correns, and the rediscovery of Mendel’s writings and laws. Both acknowledged Mendel’s priority, and it is thought probable that de Vries did not understand the results he had found until after reading Mendel. Though Erich von Tschermak was originally also credited with rediscovery, this is no longer accepted because he did not understand Mendel’s laws. Though de Vries later lost interest in Mendelism, other biologists started to establish modern genetics as a science. All three of these researchers, each from a different country, published their rediscovery of Mendel’s work within a two-month span in the Spring of 1900. Mendel’s results were quickly replicated, and genetic linkage quickly worked out. Biologists flocked to the theory; even though it was not yet applicable to many phenomena, it sought to give a genotypic understanding of heredity which they felt was lacking in previous studies of heredity which focused on phenotypic approaches. Most prominent of these previous approaches was the biometric school of Karl Pearson and W. F. R. Weldon, which was based heavily on statistical studies of phenotype variation. The strongest opposition to this school came from William Bateson, who perhaps did the most in the early days of publicizing the benefits of Mendel’s theory (the word “genetics“, and much of the discipline’s other terminology, originated with Bateson). This debate between the biometricians and the Mendelians was extremely vigorous in the first two decades of the twentieth century, with the biometricians claiming statistical and mathematical rigor, whereas the Mendelians claimed a better understanding of biology. (Modern genetics shows that Mendelian heredity is in fact an inherently biological process, though not all genes of Mendel’s experiments are yet understood.) In the end, the two approaches were combined, especially by work conducted by R. A. Fisher as early as 1918. The combination, in the 1930s and 1940s, of Mendelian genetics with Darwin’s theory of natural selection resulted in the modern synthesis of evolutionary biology.

 

In 1936, R.A. Fisher, a prominent statistician and population geneticist, reconstructed Mendel’s experiments, analyzed results from the F2 (second filial) generation and found the ratio of dominant to recessive phenotypes (e.g. green versus yellow peas; round versus wrinkled peas) to be implausibly and consistently too close to the expected ratio of 3 to 1. Fisher asserted that “the data of most, if not all, of the experiments have been falsified so as to agree closely with Mendel’s expectations,“ Mendel’s alleged observations, according to Fisher, were “abominable“, “shocking“, and “cooked“. Other scholars agree with Fisher that Mendel’s various observations come uncomfortably close to Mendel’s expectations. Dr. Edwards, for instance, remarks: “One can applaud the lucky gambler; but when he is lucky again tomorrow, and the next day, and the following day, one is entitled to become a little suspicious“. Three other lines of evidence likewise lend support to the assertion that Mendel’s results are indeed too good to be true. Fisher’s analysis gave rise to the Mendelian Paradox, a paradox that remains unsolved to this very day. Thus, on the one hand, Mendel’s reported data are, statistically speaking, too good to be true; on the other, “everything we know about Mendel suggests that he was unlikely to engage in either deliberate fraud or in unconscious adjustment of his observations.“ A number of writers have attempted to resolve this paradox. One attempted explanation invokes confirmation bias. Fisher accused Mendel’s experiments as “biased strongly in the direction of agreement with expectation to give the theory the benefit of doubt“. This might arise if he detected an approximate 3 to 1 ratio early in his experiments with a small sample size, and, in cases where the ratio appeared to deviate slightly from this, continued collecting more data until the results conformed more nearly to an exact ratio.

 

In his 2004, J.W. Porteous concluded that Mendel’s observations were indeed implausible. However, reproduction of the experiments has demonstrated that there is no real bias towards Mendel’s data. Another attempt to resolve the Mendelian Paradox notes that a conflict may sometimes arise between the moral imperative of a bias-free recounting of one’s factual observations and the even more important imperative of advancing scientific knowledge. Mendel might have felt compelled “to simplify his data in order to meet real, or feared, editorial objections.“ Such an action could be justified on moral grounds (and hence provide a resolution to the Mendelian Paradox), since the alternative – refusing to comply – might have retarded the growth of scientific knowledge. Similarly, like so many other obscure innovators of science, Mendel, a little known innovator of working class background, had to “break through the cognitive paradigms and social prejudices of his audience. If such a breakthrough “could be best achieved by deliberately omitting some observations from his report and adjusting others to make them more palatable to his audience, such actions could be justified on moral grounds.“

 

Daniel L. Hartl and Daniel J. Fairbanks reject outright Fisher’s statistical argument, suggesting that Fisher incorrectly interpreted Mendel’s experiments. They find it likely that Mendel scored more than 10 progeny, and that the results matched the expectation. They conclude: “Fisher’s allegation of deliberate falsification can finally be put to rest, because on closer analysis it has proved to be unsupported by convincing evidence.“ In 2008 Hartl and Fairbanks (with Allan Franklin and AWF Edwards) wrote a comprehensive book in which they concluded that there were no reasons to assert Mendel fabricated his results, nor that Fisher deliberately tried to diminish Mendel’s legacy. Reassessment of Fisher’s statistical analysis, according to these authors, also disprove the notion of confirmation bias in Mendel’s results.

 

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