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NNadir

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Gender: Male
Current location: New Jersey
Member since: 2002
Number of posts: 27,302

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Reduced neutralization of SARS-CoV-2 B.1.1.7 variant by convalescent and vaccine sera

Before citing this paper, let me start with the "Do not panic button, by excerpting the study's limitations from the end of the paper.

To wit:

Limitations of the study

The correlates of protection from SARS-CoV-2 infection are yet to be established. The in vitro neutralization assays reported here do not convey the contributions to in vivo protection provided by T cells nor the contributions of Fcγ receptor interactions and complement activation. Convalescent plasma and vaccine serum were taken relatively soon after acute illness or following vaccination; it is possible that titers will drop over time to a point where they are no longer high enough to provide protection. It will be interesting to understand the antibody response made by people infected by B.1.1.7, particularly how antibodies adapt to the N501Y change, but also the deletions occurring in the NTD. It will also be instructive to look at how well convalescent or vaccine serum can neutralize the other recently described variants B.1.351 and P.1 and, conversely, how well serum from patients infected with these variants can neutralize B.1.1.7 and the original Wuhan strains.


I have added the bold.

The paper under discussion is this one: Reduced neutralization of SARS-CoV-2 B.1.1.7 variant by convalescent and vaccine sera (Mongkolsapaya, Stuart, Screaton et al., Cell VOLUME 184, ISSUE 8, P2201-2211.E7, APRIL 15, 2021)

This article is open sourced, and anyone can read it, so I'll just excerpt a few things, and show, for convenience, a few graphics.

From the introduction:

Since its first appearance in Wuhan in December 2019, SARS-CoV-2 rapidly spread around the world leading the WHO to declare a pandemic on March 11, 2020. Since then, drastic public health measures, including draconian lockdowns with severe economic cost, have been enacted to contain virus spread. Although initially successful at containing disease, many countries are now experiencing further waves of infection, coinciding with winter in the northern hemisphere, with infections in some countries outpacing those seen during the first wave (Kröger and Schlickeiser, 2021).
Huge strides have been made in the understanding of SARS-CoV-2 over the last year, which are exemplified by the licensing of several vaccines (in the UK those made by Pfizer-BioNtech, Moderna, and Oxford-AstraZeneca), which are being rolled out in massive global vaccination programs, with the aim to reach billions of individuals in 2021. Furthermore, Janssen and Novavax have recently reported results showing good efficacy and also report efficacy against the UK B.1.1.7 strain (https://blogs.sciencemag.org/pipeline/archives/2021/01/29/jj-and-novavax-data). In parallel, a number of potently neutralizing monoclonal antibodies (mAbs) have been developed that are in late-stage trials to be used prophylactically or therapeutically (Baum et al., 2020, Yang et al., 2020).

SARS-CoV-2 is a large positive-stranded RNA virus; the major virion surface glycoprotein is the trimeric spike that attaches the virus to host cells via the ACE2 receptor and, through a series of conformational changes, allows fusion of host and virion membranes releasing the virus RNA into the cell to start the infection cycle (Hoffmann et al., 2020; Ou et al., 2020). Spike is the target of RNA (Polack et al., 2020; Baden et al., 2021), viral vectored (Voysey et al., 2021), and inactivated virus and recombinant protein-based vaccines (Yadav et al., 2020).

Because of the huge number of genome replications that occur in infected populations and error-prone replication, viral mutations do and will continue to occur (Robson et al., 2020). Although the vast majority will be inconsequential or detrimental to viral fitness, a few may give the virus a competitive advantage and be the subject of rapid natural selection relating to transmission advantage, including enhanced replication and immune evasion. This leads to the emergence of dominant new variant viruses. Coronaviruses, as we are seeing with COVID-19, have the potential to alter their proteins with dramatic effect (Denison et al., 2011).

In recent months, a number of mutations in the spike protein have been exemplified by viruses that have grown in alternative hosts such as mink and transmitted back to humans or in immunocompromised chronically infected individuals (Kemp et al., 2020; Oude Munnink et al., 2021; Hayashi et al., 2020). While most of these mutations currently show little evidence of a selective advantage in humans, variants have been identified with multiple mutations in spike, which appear to have distinct selective advantages and have rapidly expanded in prevalence, notably that first identified in Kent in the UK (lineage B.1.1.7) and unrelated variants detected in South Africa (501Y.V2 also known as B.1.351) and Manaus in Brazil (P.1). All of these contain mutations in the ACE2 receptor binding footprint of the receptor binding domain (RBD), one in B.1.1.7, three in 501Y.V2, and three in P.1, with the N501Y mutation being common to all.


"N501Y" refers to the 501st amino acid residue in the spike protein. The "N" refers to the asparagine that was in that position in the original virus first sequenced in Wuhan patients which has been replaced by a tyrosine ("Y" in the mutant "B.1" series. I have read elsewhere that it has been recently discovered that this mutant is slightly more lethal than the original, and also that it is more infectious.

The tests described herein are in vitro, sometimes called, someone niavely as being "test tube." There is very little evidence that this variant has reduced the protective effects of the existent vaccines by a large amount, and the vaccines are still helping us in a very big way.

Still, the need to not panic does not preclude an understanding, as mentioned in the introductory text, that this virus can, and does mutate, and given the situation. Therefore it is a good idea to hold on to supplies you may have, such as masks and sanitizers.



Some pictures from the text:



In the caption, "RBD" refers to the "receptor binding domain," the part of the spike protein that attaches to the ACE2 protein on the surface of cells.

The caption:

Figure 1The B.1.1.7 variant spike protein and effect on ACE binding of the N501Y mutation

(A) The SARS-CoV-2 spike trimer is depicted as a gray surface with mutations highlighted in yellow-green or with symbols. The RBD N501Y and the NTD 144 and 69–70 deletions are highlighted with green stars and red triangles, respectively. On the right, a protomer is highlighted as a colored ribbon within the transparent gray spike surface, illustrating its topology and marking key domains.

(B) The RBD “torso” analogy. The RBD is represented as a gray surface with the ACE2 receptor binding site in dark green. Binding sites for the panel of antibodies (Dejnirattisai et al., 2021) on which this study draws are represented by spheres. The spheres represent the point at which placing spherical antibodies would optimally predict the BLI competition data and are colored according to their neutralization, from red (potent) to blue (non-neutralizing). The position of the B.1.1.7 N501Y mutation in the RBD is highlighted in light green toward the right shoulder.

(C) Proximity of ACE2 to N501Y. The RBD is depicted as in (B) with ACE2 bound (in yellow cartoon format) with glycosylation drawn as sticks.

(D) Left panel: interactions of N501 of WT RBD with residues Y41 and K353. The structure shown is the complex of N501 RBD with ACE2 determined by X-ray crystallography (PDB ID 6M0J, Lan et al., 2020). When the 501 is mutated to a tyrosine with the conformation seen in the N501Y RBD-269 Fab complex (right panel), Y501 makes T-shaped ring stacking interactions with Y41 and more hydrophobic contacts with K353 of ACE2 (note there are minor clashes of the side chain of Y501 to the end of the K353 side chain, which has ample room to adjust to optimize interactions).

(E) BLI plots for WT (left) and N501Y (right) RBDs binding to ACE2. A titration series is shown for each (see STAR Methods). Note the much slower off rate for the mutant.


Some text:

Characterizing the N501Y mutation in the RBD

The RBD may be likened to a classic human torso; in this analogy, the shoulders and neck are involved in interactions with the ACE2 receptor (Figures 1B and 1C) (Dejnirattisai et al., 2021). In this context, residue 501 lies within the footprint of the receptor on the right shoulder and is involved in hydrophobic interactions, especially with the side chains of residues Y41 and K353 of ACE2 with the 501 mutation from N to Y offering the opportunity for enhanced interactions (Figures 1C and 1D).
Effect on ACE2 affinity

It has been reported that mutations at 501 can increase affinity for ACE2 (Starr et al., 2020; Gu et al., 2020), although these data are not for the mutation to Y. In contrast, Zahradník et al., 2021 report direct selection of N501Y when evolving the RBD to enhance affinity. We therefore investigated the effect of this mutation on ACE2 binding by RBD using biolayer interferometry (BLI) (Figure 1E). The results indicate a marked (7-fold) increase in binding affinity due to a slower off rate: WT RBD(501N)-ACE2: KD 75.1 nM (Kon 3.88E4 /Ms, Koff 2.92E-3 /s), RBD(501Y)-ACE2: KD 10.7 nM (Kon 6.38E4 /Ms, Koff 6.85E-4/s). This is in-line with enhanced interactions of the tyrosine side chain with the side chains of residues Y41 and K353 of ACE2 (Figure 1D). In the context of a multivalent interaction at the cell surface, this effect would be amplified. This alone might account for the selection of the N501Y mutation and an increase in transmission.


The authors utilized a set of 377 antibodies isolated from patients either who had been infected in the first wave. 80 of these have been fully mapped to elucidate the binding sites of the antibodies. In many cases, they found reduced binding.

However, as noted in the first excerpt from the last part of the paper's main text, the reduced binding does not preclude vaccine protection. Notably, the infection can be managed by T-cells as opposed to B-cell antibodies.

The full paper is available for reading for free. It may take some sophistication to understand all that is being said in there, but I think it readable and it's worth mucking around in it. If there are any questions that I may be able to answer, let me know and I'll do my best.

For now, we seem safe, if we've been vaccinated. If we're dumb assed anti-vax Republicans, the Darwin award awaits; this strain is definitely more lethal, although still susceptible to being managed by the vaccines.

Still the situation in India, affording many opportunities to generate new strains suggests that new vaccines may be required at some point. Some that have modified to reflect the new strains have already been prepared and are being tested in patients. We have considerable infrastructure for the manufacture of these, and considerable knowledge capital as well, so we're in relatively good shape. It is important that we do our best to provide other nations with access to these vaccines, since all of humanity shares this risk.

Be safe. Be well.

I learned a new German word today that's relatively new even to Germans, "Dunkelflaute"

I learned it here: Variability in Deeply Decarbonized Electricity Systems (John Bistline, Environmental Science & Technology 2021 55 (9), 5629-5635)

The context:

These resources exhibit variability across different time scales, including subhourly resource fluctuations, larger ramps across multiple hours, sustained periods of high or low output for multiple days (the German term dunkelflaute or “dark doldrums” refers to extended periods with limited sunshine or wind), seasonal effects, and even variability across years and decades (e.g., interannual variation in hydro and wind resources).


While my German is very, very, very, very rusty - it's been years since I did anything significant with that language - I have a feeling that Dunkelflaute worries some people, pisses others off:

Das heißt: In vier Jahren werden nur noch rund 67.000 Megawatt gesicherte Kapazität zur Verfügung stehen, obwohl Deutschland in Spitzenzeiten 81.000 Megawatt verbraucht. Kommt es zu einer „kalten Dunkelflaute“ ohne nennenswerten Wind- und Solarstrom, wäre die deutsche Stromversorgung in diesen Stunden, Tagen oder Wochen auf ausländische Lieferungen zwingend angewiesen.

Die Zeiten, in denen solche Knappheiten am Markt neue Investitionsanreize auslösten, sind vorbei. „Stattdessen sind wir schon heute auf eine Reihe von Reparaturmaßnahmen angewiesen: Netzreserve, Kapazitätsreserve oder netztechnische Betriebsmittel kaschieren mehr schlecht als recht die Defizite der deutschen Energiepolitik und Marktkonditionen“, schimpft Kapferer: „Auf Dauer wird das nicht funktionieren.“


In der „kalten Dunkelflaute“ rächt sich die Energiewende

With my bad German, I translate this as: The Energy Transition Is Taking Revenge in Cold, Dark, Doldrums.

I could be wrong though, maybe it doesn't translate that way. Maybe it translates as "Don't worry; be happy."

Here's another reference to Dunkelflaute, in English from another journal, Mesoscale modeling of a “Dunkelflaute” event (Basu et al., Wind Energy, Volume24, Issue1 January 2021 Pages 5-23)

An excerpt from this open source journal:

Unlike fossil fuel‐based energy sources, some of the renewable energy sources (especially, wind and solar) strongly rely on meteorological conditions. As such sources of energy play a larger role in electricity networks, this presents an increasing challenge in terms of balancing supply and demand. Therefore, it is important to increase our understanding and forecasting capability of certain weather phenomena which can result in adverse renewable energy production from a system operator perspective. Such advanced knowledge and tools will further support the continuing growth of renewables in the foreseeable future.

In this paper, we focus on one such weather phenomenon called “Dunkelflaute” as it is rapidly becoming a major concern for the renewable energy community.6 The word Dunkelflaute was coined by combining two German words “Dunkelheit” (darkness) and “Windflaute” (little wind) to describe heavy overcast skies and weak wind conditions. These meteorological events can last from a few hours to a few consecutive days. It is needless to say that under the influence of such a meteorological condition, little or no wind and solar energy can be produced.

On the 30th April 2018, an unexpected Dunkelflaute event occurred over the southern part of the North Sea and caused a large imbalance in renewable power generation and overall consumption. Given the acuteness of the situation, TenneT—the main transmission system operator for Germany and the Netherlands—had to issue an emergency alert in the Netherlands.7, 8 The crisis could not be avoided by simple load management or by making use of reserve power; instead, a substantial amount of electricity had to be imported from neighboring countries at high market price.

This Dunkelflaute event was not an isolated episode. As a matter of fact, over the past few years, several Dunkelflaute events occurred in Belgium,9-12 Germany,6, 13-15 and other neighboring countries. Some of them caused significant impacts on the power grids and electricity markets. There is no reason to believe that the occurrences of Dunkelflaute will subside in the future. Instead, with the ever increasing penetration of renewables in the power grid, the (negative) impacts of Dunkelflaute events will likely become more and more detrimental.
.

Germany by the way, is famous for phasing out nuclear energy, which will be complete by the end of next year. They have announced the intention to phase out coal "by 2038." At the current rate, of 2.4 ppm per year of carbon dioxide accumulations , as determined from the weekly Mauna Loa CO2 data from last week using a 12 month running average of weekly data, "by 2038," the carbon dioxide concentrations on this planet will be 444 ppm, up from 420.01 ppm recorded in the week beginning April 25, 2021.

In 2011, when the Energiewende plan was first published, including a nuclear phase out, the rate of increase in the dangerous fossil fuel waste carbon dioxide in the planetary atmosphere, again as a 12 month running average of weekly data, was 2.03 ppm/year, as recorded on May 8, 2011.

(The figures rely on the average difference between the weekly reading and the reading of the same week 10 years earlier.)

In the year 2000, for the week beginning May 7, 2000, the figure was 1.50 ppm/year. The concentration of the dangerous fossil fuel waste carbon dioxide in the planetary atmosphere as measured at Mauna Loa for the week beginning May 7, 2000 was 371.70 ppm.

Don't worry, be happy.

Air pollution from coal kills people by the way. Air pollution deaths worldwide easily outstrip, on a daily basis, Covid-19 deaths.

So called "nuclear waste," hasn't killed anybody in recent times, but lots of people pull their hair out claiming it could, some day, somewhere. In modern times could is a much scarier word than is, as in "nuclear waste could kill someone someday" as opposed to "coal air pollution is killing people every day.

Am I crazy for thinking Germany, once the country of Planck, Sommerfeld, Hilbert, Born, Heisenberg and others of similar powers, has things ass backwards?

I guess I am.

Dunkelflaute. Dark doldrums.

For a last comment, I'll excerpt a few remarks from another paper using the word "Dunkelflaute" from the Oxford Institute for Energy Studies, leaving aside what should be, but perhaps isn't, obvious, that no country that burns dangerous natural gas is "decarbonized."

The role of natural gas, renewables and energy efficiency in decarbonisation in Germany: The need to complement renewables by decarbonized gas to meet the Paris target

Focusing only on renewables in power and not addressing thermal power will not automatically lead to reaching the decarbonisation target and will jeopardise reliability of supply for Germany and its neighbours. In the end, the resulting upcoming shortfall of dispatchable power may even throw into question the nuclear phaseout as fixed by law. With the closing of dispatchable capacity (nuclear – by law, conventional – due to market drivers) Germany will face an increasing gap between available dispatchable power and peak load, according to the NEP 2030. This gap cannot be filled with whatever extra capacity there is in wind and PV. Turning to neighbours for reliable power is not an option, as these countries are facing similar problems, as well as other country-specific problems.


The reason that so called "renewable energy," was phased out in the 19th and early 20th century was that most people, even more so than today, lived short, miserable lives of dire poverty.

Even today, poverty is best defined by a lack of access to energy.

It is possible to provide reliable and clean and safe energy for those who have it as well as those who still lack it except for scraps of "renewable biomass." This is only true, however, if we stop lying to ourselves. Our water is already dependent on the weather, and is in fact, severely threatened by climate change. Is it really a good idea to make the electricity for the computers we run to say how great so called "renewable energy" is dependent on the weather as well? The electricity to run oxygen generators? Surgical lamps? Our much loved television sets? Refrigerators? Freezers.

Dunkelflaute.

The wikipedia entry for the word:

Dunkelflaute is a term used in the energy sector for a period of time in which little to no energy can be generated with the use of wind and solar power. The term is German in origin and a blend word of the german ‘Dunkelheit’ (darkness) and ‘Flaute’ (little wind). The periods called Dunkelflaute are a big issue in energy infrastructure in which a significant amount of electricity is generated by wind and solar power. To ensure power during such periods alternative energy sources must be present in a sufficient capacity. When that happens countries use either fossil fuels (e.g. oil, methane gas, coal) or hydroelectricity, nuclear power and, less often, energy storage to prevent a power outage.[1][2][3][4][5]

The first use of the term in an academic paper is in 2014.[6]


Dunkelflaute, some ideology is Dunkelflaute.

I just have one thing to say in a time of rising crisis.

I am extremely grateful the Joe Biden is at the helm.

The myriad ways sewage surveillance is helping fight COVID around the world

This is a news item from Nature, which I hope is open sourced:

The myriad ways sewage surveillance is helping fight COVID around the world

Wastewater tracking was used before the pandemic to monitor for polio and illicit drug use, but interest in the field and its applications has now ballooned.


One of my earliest memories as a child was being amazed by toilet bowls, not only how they worked without requiring electricity (that I could see) but also where the "stuff" went.

It appears that fascination never really went away; I find myself thinking about this sewage all the time, not only in the very practical (and sometimes expensive) issue of maintaining my home septic system, but also in connection with broad environmental issues, and equally important, human development goals; about two billion human beings on this planet lack access to improved sanitation, something I find unacceptable in the extreme. Understanding sewage - in many ways one of the worst waste problems in the world - only dangerous fossil fuel waste and biomass combustion waste is responsible for more unnecessary deaths - is extremely important to address the rising fresh water crisis, the collapse of ecosystems in the oceans, and, more subtly, addressing an issue that is going to hit future generations very, very, very hard as a result of our inattention, phosphorous flows.

The extremely advanced development of what has become late in life, my absolute favorite analytical chemistry technique, mass spectrometry, has allowed us to understand things about sewage we never could access previously, in particular the environmental fate of many different kinds of products, not only "personal care products" like soap and cosmetics and pharmaceutical metabolites and unmetabolized excreted pharmaceuticals, collectively abbreviated "PPCP" in the literature, but also the fate of things like paints, flame retardants, fire fighting foams, fabric protection agents...the list goes on and on.

And now the study of sewage is providing insight, using qPCR, the spread of Covid.

Some excerpts from the news item cited at the outset of this brief post:

From the subarctic community of Yellowknife, Canada, to the subtropical city of Brisbane, Australia, scientists in more than 50 nations are now monitoring the spread of SARS-CoV-2 in sewage. The number of sewage-surveillance programmes tracking COVID-19 has exploded during the past year from a dozen or so research projects to more than 200, following the discovery that whole virus particles and viral fragments are shed in faeces.

The information garnered is helping scientists to track down cases, predict surges, identify where to target testing, and estimate overall numbers of infected people in cities or regions. Although sewage surveillance has been used for several decades to identify polio outbreaks and target immunization programmes, and, more recently, to detect illicit drug use, the pandemic has brought new focus and investment in it as a means of tracking public health.

“There was always an interest in wastewater epidemiology, but now it’s taken flight,” says Ana Maria de Roda Husman, an infectious-diseases researcher at the Netherlands National Institute for Public Health and the Environment in Bilthoven.

Since early 2020, SARS-CoV-2 sewage projects have taken off around the world as wastewater experts pivoted to concentrate on the crisis. But the scale and focus of surveillance programmes varies, depending on how severely countries or communities have been hit by the pandemic.

The number of ways sewage surveillance is being used is dizzying. In the United Arab Emirates, researchers have been testing sewage from commercial aircraft to see whether incoming flights were carrying infected passengers1. Scientists in Hong Kong are monitoring sewage in apartment buildings to find undetected infections, and, in Yellowknife, health officials are testing wastewater to discover which viral variants have made it to their city, just 400 kilometres from the Arctic Circle.

Early-warning system
One common application of such surveillance programmes is as an early-warning system. People who are infected start shedding virus fragments a few days before they show symptoms, and de Roda Husman uses this to predict hospitalization numbers a few days ahead of time.

Other groups are using wastewater to find and suppress outbreaks on a much smaller scale...

...Challenges for developing countries

However, more than 70% of sewage-surveillance programmes are in high-income countries2, which have poured resources into wastewater epidemiology. Many researchers in the developing world are struggling.

“Testing in India is incredibly challenging as sewage systems are fragmented,” says Sudipti Arora, an environmental scientist at the Dr. B. Lal Institute of Biotechnology in Jaipur, India. Only about one-third of all towns have sewer networks, she says. “Consequently, slums and rural areas remain largely untested...”

...Many scientists working in the field say that a rare positive outcome of the pandemic might be that it will normalize the use of wastewater to monitor public health — whether for future pandemics or to track other health indicators, such as hormones that indicate stress or levels of caffeine consumption.

“Wastewater epidemiology was under the radar,” says Karthikeyan. “Now, it’s come to the forefront.”

Katherine Jones, Lady Ranelagh, an incomparable intellectual who fell through the cracks of history

This book review, from Nature is probably open sourced:

An incomparable intellectual who fell through the cracks of history

Katherine Jones, Lady Ranelagh, worked at the heart of seventeenth-century scientific debates — in the shadow of her brother, Robert Boyle.


Excerpts:

The foundation of the Royal Society of London in 1660 established an institutional focus for experimental science. The society did not admit female fellows until 1945. A glance at its history gives the impression that seventeenth-century natural philosophy was an entirely male enterprise. Fortunately, feminist scholarship over the past few decades has unearthed women such as philosopher Anne Conway and writers Dorothy Moore and Mary Evelyn, who were active in the intellectual ferment of the time.

Now, Michelle DiMeo has produced a portrait of another influential female thinker who has been hiding in plain sight — as a footnote in the story of her more famous brother, chemist and Royal Society co-founder Robert Boyle. DiMeo reveals Katherine Jones, Lady Ranelagh, as central to political, religious, philosophical and medical discussions, yet destined to be forgotten, because she obeyed the convention that women should not put their thoughts into print. DiMeo, a librarian at the Science History Institute in Philadelphia, Pennsylvania, has used her archival skills to trawl the papers of Ranelagh’s mostly male contemporaries to uncover her role as a public intellectual...

...Married off to Arthur Jones (later Viscount Ranelagh), Katherine had four children by the time she was 25. In 1642, she fled an uprising of Catholic rebels and settled in London with her children. She lived apart from her husband — a boor and gambler – but kept her title.

In London, she became one of the most active members of the circle of correspondents cultivated by the polymath Samuel Hartlib. The group shared, copied and discussed letters and manuscripts; Ranelagh hosted meetings in her home. Members admired her contributions on politics, religion and natural philosophy, dubbing her “the Incomparable” and citing her frequently. The interests of the circle evolved, converging on new, ‘useful’ knowledge revealed through experimental science, especially chemistry. One letter mentions Ranelagh as an early user of optical instruments such as a telescope.

Ranelagh introduced her teenage brother Robert to the circle after he returned from a tour of Europe in 1644; she became his spiritual and intellectual mentor. As he focused on chemistry, she equipped a laboratory at his Dorset home. He thanked her: “the delights I taste in it, make me fancy my laboratory a kind of Elysium” (spelling modernized). In 1668, he moved permanently into Ranelagh’s home in London’s fashionable Pall Mall...

TVA, Eyeing Coal Phaseout by 2035, Will Rely on Nuclear

TVA, Eyeing Coal Phaseout by 2035, Will Rely on Nuclear

The Tennessee Valley Authority (TVA) expects to phase out its coal generation by 2035, but achieving net-zero carbon emissions without raising power prices or adversely affecting reliability will require substantial investments in energy storage and carbon capture and sequestration (CCS). TVA also will need to extend the lifetime of its nuclear power, and adopt the use of small modular reactors (SMRs), said Jeffrey Lyash, its president and CEO.

During a fireside chat with Sen. Joe Manchin (D-W.Va) on April 28 hosted by the nonprofit international think tank the Atlantic Council—an event focused on the future of low carbon generation in the Appalachian region—Lyash noted the self-funded U.S. corporate agency has already retired 60% of its coal generation. “Our coal units will continue to retire over the next 15 years because they’ve reached the end of life,” he said.

However, TVA’s 2035 coal phaseout is still an “aspirational target” that will depend on environmental impact studies, and ultimately, a board-approved recommendation by the company, spokesperson Jim Hopson told POWER. While TVA does not intend to invest in its coal plants to extend their lifetimes and it “knows the path that it generally wants to take,” environmental impact statements “sometimes can take years to fully prepare and to complete all the necessary studies, so it is unlikely that the board will receive a recommendation for all the plants simultaneously.” he explained. “It’s possible, but more than likely, coal will be phased [out] over a period of a few years.”

The declaration is still a noteworthy development for TVA, which federal legislation created in 1933. As the nation’s largest public power supplier today, the entity has a footprint that serves 10 million people, including in most of Tennessee, northern Alabama, northeastern Mississippi, and southwestern Kentucky and portions of northern Georgia, western North Carolina, and southwestern Virginia...

...Coal Carried TVA for Decades

Last week, Lyash highlighted the TVA’s original mission to spur economic development in the Tennessee Valley and Appalachia, but he noted the entity is also committed to environmental stewardship. Both aspects have driven a significant change in its power generating portfolio (Figure 1), he said.



1. TVA’s changing power portfolio. Source: TVA
While TVA began its coal-fired construction program in the 1940s, the majority of its coal units were placed in service between 1951 and 1973. Just 10 years ago, TVA produced 74,583 GWh—or about 52% of its total generation—from 53 active units at 11 coal plants. Increasingly stringent regulatory requirements over the past decade, along with environmental agreements with several states and environmental groups, forced the company to retire 18 coal units by 2017...


The fantasy that "coal is dead" is very prominent in the United States because of the popularity of replacing it with "transitional" natural gas. In reality, on the planet as a whole, irrespective of the fantasies of the US bourgeoisie in the provinces, coal has been the fastest growing source of energy on the planet as a whole in the 21st century.

The US "coal is dead" fantasy is driven by the willingness to destroy the ground water and much of the surface water of the entire continent by fracking, leaving permanent holes that will be oozing "God knows what" pollutants into the environment of all future generations.

No matter what one hears, natural gas is not clean; it is not sustainable, nor is it transitional. The use, in terms of energy, not the hollow lie of peak capacity, which may be available for a few minutes a day, of dangerous natural gas is rising far faster than is so called "renewable energy," the latter of which would collapse in a New York minute without access to dangerous natural gas.

Unlike all other coal phase outs in the US, by replacing coal with reliable 24/7 nuclear energy - which has the highest capacity utilization of any form of energy on the planet - the TVA is being sensible, not that humanity is being sensible.

Many people think so called "renewable energy" is driving coal phase outs. One hears this garbage thinking all the time. This belief is a form of ignorance, inattention, delusion, etc. Those steel posts in all those wind turbines we're constructing in our effort to convert all remaining wilderness into industrial parks are made using coke, which is coal heated to high temperatures using heat provided by the combustion of coal. Pretty much every wind turbine now operating will be landfill in about 20 to 25 years.

Modern nuclear plants are designed to operate for 60 to 80 years.

I trust you're safe and well.

Eleanor Rigby.



TVA, Kairos Partner to Deploy Molten Salt Nuclear Reactor Demonstration

This looks like Per Peterson's design:

In a notable, dedicated effort by a major U.S. utility to boost the development of an advanced reactor technology, the Tennessee Valley Authority (TVA) and Kairos Power, developer of a novel fluoride salt-cooled, high-temperature nuclear reactor, on May 6 said they will team to demonstrate Kairos’ Hermes test reactor at the East Tennessee Technology Park (ETTP) in Oak Ridge, Tennessee.

As part of their agreement, TVA will provide engineering, operations, and licensing support to help California-based Kairos Power deploy its “low-power” demonstration reactor. According to Kairos, Hermes is a 50-MWth test reactor that will integrate the Kairos Power Fluoride Salt-Cooled High-Temperature Reactor (KP-FHR) as part of a cost- and risk-reduction–focused development pathway that ultimately envisions commercial deployment of a 140-MWe “KP-X” plant.

“Kairos Power’s singular objective for deploying the Hermes Reactor is to demonstrate the capability to deliver an advanced reactor at the costs necessary to make nuclear power the most affordable source of dispatchable electricity in the United States,” it said on Thursday.

The KP-FHR concept, which bagged a $303 million federal award under the Department of Energy’s (DOE’s) Advanced Reactor Demonstration Program (ARDP) risk reduction pathway last December, essentially uses molten fluoride salt as a low-pressure coolant (rather than water, which is used in conventional nuclear reactors). The design also uses fully ceramic tri-structural ISOtropic (TRISO) particle fuel in pebble form, and a high-temperature superheated steam cycle to “convert heat from fission into electricity and to complement renewable energy sources,” the company says...


Molten Salt Nuclear Reactor Demonstration

I'm not a TRISO kind of guy, but any reactor capable of high temperatures is fine with me.

We will need high temperature nuclear reactors if we're even going to have a poor shot at addressing climate change. Without nuclear reactors we have no chance of addressing climate change.

Data from Qatar: Pfizer COVID vaccine protects against worrying coronavirus variants

This is a news item from Nature. I don't have much time today, as my wife and I will be visiting my son to celebrate mother's day, so I won't access or excerpt anything other than the news item, which should be open sourced.

Link to the news item: Pfizer COVID vaccine protects against worrying coronavirus variants (Ewen Callaway Nature May 6, 2021) Data from Qatar provide strongest evidence yet that COVID-19 vaccines can stop strains thought to pose a threat to immunization efforts.

Excerpt:

Qatar’s second wave of COVID-19 was a double whammy. In January, after months of relatively few cases and deaths, the Gulf nation saw a surge driven by the fast-spreading B.1.1.7 variant, which was first identified in the United Kingdom. Weeks later, the B.1.351 strain, which is linked to reinfections and dampened vaccine effectiveness, took hold.

Amid this storm, researchers in Qatar have found some of the strongest evidence yet that current vaccines can quell variants such as B.1.351. Clinical trials in South Africa — where B.1.351 was first identified — had suggested that vaccines would take a hit against such variants. But this study offers a fuller picture of what countries battling such variants can expect.

People in Qatar who received two doses of the Pfizer–BioNTech vaccine were 75% less likely to develop a case of COVID-19 caused by B.1.351 than were unvaccinated people, and had near-total protection from severe disease caused by that strain.

The findings — published on 5 May in The New England Journal of Medicine1 — suggest that current RNA vaccines are a potent weapon against the most worrisome immune-evading variants...



Weaker protection
Researchers in South Africa identified B.1.351 in late 2020, and it’s now the predominant strain there. Laboratory studies show that the variant harbours mutations that blunt the effects of virus-blocking antibodies, and trials suggest that some COVID-19 vaccines are significantly less effective against the strain than against others.

Early lab research suggested that RNA vaccines, including the Pfizer–BioNTech jab, would be weakened by B.1.351, but probably not fully compromised. In April, the companies announced that a small trial in South Africa had found the vaccine to be fully effective against B.1.351, but the study of 800 people recorded a total of just 6 infections caused by B.1.351 in the placebo group, so efficacy might have been much lower.

First evidence that COVID vaccines protect people against new variants

Abu-Raddad’s team analysed tens of thousands of COVID-19 cases that occurred between the start of Qatar’s vaccination campaign in late December and the end of March. Genome sequencing showed that B.1.1.7 and B.1.351 were the predominant coronavirus lineages during this period and, from mid-February, each accounted for about half of the country’s cases...


Qatar, where more than one-third of the population has received at least one dose of the vaccine, might provide an early glimpse at how the worst coronavirus variants can be controlled. Abu-Raddad says there is evidence that the Pfizer–BioNTech vaccine might also be highly effective at blocking transmission of B.1.351. And after cases of the variant peaked in mid-April, he says, “things have been going extremely well, the numbers are going down very, very rapidly”.


Good news...

Mr. Bojangles.

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