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Study points at low uptake of COVID-19 vaccine boosters by immunocompromised people in the US – News-Medical.Net

In a recent study published in JAMA Network Open, researchers performed a retrospective cohort study among immunocompromised patients registered with Kaiser Permanente Southern California (KPSC), an integrated healthcare system in the United States of America (USA) between December 14, 2020, and August 6, 2022.

Study: Analysis of mRNA COVID-19 Vaccine Uptake Among Immunocompromised Individuals in a Large US Health System. Image Credit: chatuphot/Shutterstock

Researchers determined the uptake of messenger ribonucleic acid (mRNA) coronavirus disease 2019 (COVID-19) vaccine in these patients. Additionally, they explored the factors associated with receiving at least four booster doses.

Background

The US Centers for Disease Control and Prevention (CDC) recommends additional doses of the COVID-19 vaccine for immunocompromised individuals. In October 2021, the CDC reduced the interval between the primary two-dose vaccination regimen and the first booster dose by at least five months for better protection of immunocompromised people.

Again, in February 2022, the CDC reduced this gap to at least three months. In May 2022, CDC revised all prior recommendations. They declared that immunocompromised patients could receive a fifth dose (second booster) of an mRNA COVID-19 vaccine.

Rapidly changing CDC guidelines created confusion, and many immunocompromised people could not adhere to them. Nonadherence in this high-risk subpopulation resulted in severe COVID-19 cases with public health implications.

About the study

In the present study, researchers used the KPSC electronic health record (EHR) system to acquire data for all immunocompromised individuals ≥18 years. However, they included only those individuals who had an immunocompromising disease in the year before the study began or those receiving immunosuppressive medications when the study began. They also had to meet either of these two inclusion conditions for up to a year, i.e., December 14, 2021.

The researchers used a pre-validated algorithm to identify immunocompromising conditions and medications, which relied on the International Statistical Classification of Diseases, Tenth Revision (ICD-10) codes.

Further, the team restricted the study analyses to immunocompromised patients who received only mRNA COVID-19 vaccines. They censored a participant at demise or disenrollment from the KPSC system.

Results

The researchers screened 44529 of 3133341 KPSC members ≥18 years with at least one year of KPSC membership in December 2020, for the study. However, the final cohort had only 42,697 individuals, of which 18,789 (44%) were ≥65 years; 20061 (47%) were women, and the remaining 53% were men. The study cohort comprised Asian or Pacific Islanders, Black Americans, Hispanics, and White people, in percentages of 10.1%, 12.1%, 33.5%, and 41.9%.

While 36,606 had received a single dose of an mRNA vaccine (BNT162b2 or mRNA-1273), 1588 had received a combination of these two vaccines. Some included individuals had also received fourth and fifth doses per CDC recommendations.

By the end of the study duration, over 61% of immunocompromised patients had received three or fewer doses of an mRNA vaccine, and 37.5% had received four doses. Intriguingly, only 0.9% of patients had received five as per CDC recommendations. Also, by April 2022, i.e., six months after the CDC recommendation, barely 14% of eligible immunocompromised individuals had received a fourth dose [i.e., their first booster]). Indeed, the uptake of first and second boosters was slower in this high-risk population and failed to meet the CDC recommendations.

Moreover, these results did not vary after accounting for booster dose eligibility. Thus, of 13,054 fourth dose recipients who received it at least four months before the culmination of the study, only 391, i.e., 3%, had received a fifth dose (second booster).

A Cox proportional hazards regression analyses revealed that adults ≥65 years were more likely to receive four doses than 18-44 and 45-64 years-olds. Likewise, compared to Black and Hispanic individuals, this likelihood was higher for White immunocompromised individuals. Individuals receiving high-dose corticosteroids were also less likely to receive the booster dose of an mRNA COVID-19 vaccine.

Conclusions

The current study results highlighted a considerable gap in adherence to CDC recommendations for boosting immunocompromised individuals. In the US, COVID-19 mRNA vaccine uptake is among the highest in California. Yet, by August 2022, despite CDC recommendations, only 0.9% of immunocompromised individuals enrolled with the KPSC had received five doses of an mRNA COVID-19 vaccine. Also, only 41% had received four mRNA monovalent doses, i.e., one booster.

It is possible that vaccine hesitancy among immunocompromised individuals stemmed from some safety concerns. They might have misinterpreted changing CDC guidelines as a lack of vaccine effectiveness specifically for immunocompromised. However, the most likely reason is the confusion among medical practitioners. Amid changing CDC guidelines, they remained confused about how and at what intervals to give fourth and fifth vaccine doses to immunocompromised people.

The advent of Omicron and pandemic fatigue could have also contributed to lower uptake of booster doses in this high-risk population. Given boosters are critical for preventing severe COVID-19 outcomes and the vulnerability of this population, medical practitioners and public health personnel should make targeted efforts to ensure that immunocompromised individuals remain updated with ever-evolving COVID-19 booster dose recommendations.

Journal reference:

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This strange donkey orchid uses UV light to trick bees into thinking it has food – Phys.org

This strange donkey orchid uses UV light to trick bees into thinking it has food
A winter donkey orchid (left) and a prickly bitter-pea. Credit: Cal Wood/iNaturalist; caitlind164/iNaturalist, CC BY

If you’ve ever compared a frozen pizza to the photo on the box, you know the feeling of being duped by appetizing looks.

In our latest study published in Ecology and Evolution, we show that animals—in this case, bees—are also prone to being tricked into making poor decisions, which explains a lot about how gaps in perception are exploited in nature.

When Charles Darwin was testing the theory of evolution 150 years ago, he looked at the interaction between flowering plants and the animals that forage to collect nectar.

This helped establish that flowers have adaptations to promote easier pollinator access, making it beneficial for the animal who gets a food “reward” from them. At the same time, it means the plants get pollinated and can reproduce.

One perplexing problem is some that reproduce by pollination are non-rewarding—the animal doesn’t get nectar from visiting the flower. This is true of certain orchids, yet these flowers are still visited by pollinators and survive well in nature.

<div data-thumb="https://scx1.b-cdn.net/csz/news/tmb/2023/this-strange-donkey-or-2.jpg" data-src="https://scx2.b-cdn.net/gfx/news/2023/this-strange-donkey-or-2.jpg" data-sub-html="Flower shape and colour properties of an orchid (upper row) and a native pea flower (lower row) shown in the field, as individual flowers, and with spectral measurements. Credit: Scaccabarozzi et al., 2023, Author provided”>

This strange donkey orchid uses UV light to trick bees into thinking it has food
Flower shape and colour properties of an orchid (upper row) and a native pea flower (lower row) shown in the field, as individual flowers, and with spectral measurements. Credit: Scaccabarozzi et al., 2023, Author provided

A mistaken identity

With the benefit of modern scientific tools like a spectrophotometer that measures the amount of color, digital ultraviolet (UV) photography and computer modeling of how bees see the world, our international team set out to understand how some orchids have evolved dazzling floral displays.

Our chosen species was the winter donkey orchid (Diuris brumalis), endemic to Western Australia. This non-rewarding, food deceptive plant blooms at the same time as rewarding native pea plants (Daviesia).

As a result, native Trichocolletes bees appear to mistake the orchid for legume plants frequently enough that the orchid gets pollinated.

We quantified the flower color signals from both plants, revealing the main component of the visual information perceived by a bee was in the short wavelength UV region of the spectrum.

This made sense—while our vision sees blue, green and red wavelengths of light as primary colors, bees can see UV reflected light but lack a channel for perceiving primary red.

By using computer models of bee pollinator perception, we observed the orchid mimic species and the native pea plant species did actually look similar in color to bees.

<div data-thumb="https://scx1.b-cdn.net/csz/news/tmb/2023/this-strange-donkey-or-3.jpg" data-src="https://scx2.b-cdn.net/gfx/news/2023/this-strange-donkey-or-3.jpg" data-sub-html="UV photographs of orchid flowers (upper left panel) in natural state and also with applied UV blocking screen. Middle panels show false-colour photographs of flower appearance for a bee, and right hand panel a computer model of how bee vision perceives flower colours. Credit: Scaccabarozzi et al., 2023, Author provided”>

This strange donkey orchid uses UV light to trick bees into thinking it has food
UV photographs of orchid flowers (upper left panel) in natural state and also with applied UV blocking screen. Middle panels show false-colour photographs of flower appearance for a bee, and right hand panel a computer model of how bee vision perceives flower colours. Credit: Scaccabarozzi et al., 2023, Author provided

Putting a UV block on flowers

What was surprising, however, was the non-rewarding orchid flowers—pollinated by deception—actually have more conspicuous advertising for bee vision.

For example, the main display outer flower petals were significantly larger on the orchid plants, and also produced a stronger UV color signal.

To understand if such signaling was biologically relevant, we next conducted with the plants. We used a special UV sun-blocking solution to remove the strong UV signals in half of the orchid species, while the other half retained their natural appearance.

At the completion of the field season, several months latter, we could measure which plants were more successfully pollinated by bees, revealing the strong UV signals had a significant role in promoting pollination in the orchids.

A second interesting finding of the field experiments was the distance between the pea flowers and their copycat orchids was a major factor in the success of the orchids’ deception strategy.

If the orchids with strong UV signals were within close proximity—a meter or two—to the rewarding native pea flowers, the deception was less successful and few orchid flowers were pollinated. However, if the deceptive were about eight meters away from the rewarding model species, this produced the highest success rate in pollination.

Why deception works

It turns out a distance of about eight meters is important because of the way bee brains process color. When bees see a pair of colors in , they can evaluate them at the same time. This leads to very precise color matching. A similar process happens in —we also have to see colors at the same time.

However, seeing color stimuli with a time interval in between means the brain has to remember the first color, inspect the second color, and make a mental calculation about whether the two samples are indeed the same.

Neither bee brains, nor our own, are good at successive color comparisons. This is why when we purchase paint for a repair job we take a sample to get a precise match, rather than try and remember what we thought the color should look like.

Deceptive flowers are successful by exploiting this perceptual gap in how brains have to code information when need to fly several meters in search of more food.

By using a “look at me” strategy (essentially, better advertising than other plants) it is possible to survive in nature without actually offering a food reward to the pollinators. To do this, the plants need to be at an optimal distance from the plants they are mimicking. Not too close and not too far, and success is assured.

More information:
Daniela Scaccabarozzi et al, Mimicking orchids lure bees from afar with exaggerated ultraviolet signals, Ecology and Evolution (2023). DOI: 10.1002/ece3.9759

Provided by
The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

Citation:
This strange donkey orchid uses UV light to trick bees into thinking it has food (2023, February 2)
retrieved 2 February 2023
from https://phys.org/news/2023-02-strange-donkey-orchid-uv-bees.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

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The world’s oldest fossils or oily gunk? Research suggests these 3.5 billion-year-old rocks don’t contain signs of life – Phys.org

The world's oldest fossils or oily gunk? Research suggests these 3.5 billion-year-old rocks don't contain signs of life
Credit: Saul Shepstein, Author provided

The Pilbara region of Western Australia is home to one of the most ancient surviving pieces of Earth’s crust, which has been geologically unchanged since its creation some 3.5 billion years ago.

Some of the oldest signs of life have been found here, in the North Pole area west of the town of Marble Bar, in black rocks composed of fine-grained quartz called chert.

Some features in the so-called “Apex chert” have been identified as the fossilized remains of microbes much like the bacteria that still survive today. However, scientists have debated the true origin of these features ever since they were discovered 30 years ago.

In new research published in Science Advances, we show the carbon-rich compounds also found in the chert may have been produced by non-biological processes. This suggests the supposed “fossils” are not remnants of early lifeforms but rather artifacts of chemical and geological processes.

Controversial Pilbara fossils

In 1993, American paleobiologist William Schopf spotted carbon-rich filaments in outcrops of the 3.45 billion year old Apex chert. He interpreted them as the charred remains of fossilized microbes similar to cyanobacteria, which were Earth’s first oxygen-producing organisms and are still abundant today.

The world's oldest fossils or oily gunk? Research suggests these 3.5 billion-year-old rocks don't contain signs of life
Veins of black chert found in the Pilbara open a window onto Earth as it was 3.5 billion years ago. Credit: Birger Rasmussen

The existence of fossilized cyanobacteria in such old rocks would imply that life was already pumping oxygen into the air more than a billion years before Earth’s atmosphere became rich in oxygen.

A key piece of evidence in favor of life was the association of with the ancient fossils. This is because living cells are made up of large , which comprise mainly carbon as well as hydrogen, nitrogen, oxygen and other elements.

In 2002, Schopf’s interpretation was challenged by English paleobiologist Martin Brasier and his team. They showed the “fossils” displayed a variety of shapes and sizes uncharacteristic of cyanobacteria, and indeed, inconsistent with microbial life. What’s more, they also showed the -bearing black cherts were not horizontal beds deposited on the seafloor, but angled veins cutting across the underlying layers of rock.

The fossil-bearing cherts appeared to have formed at high temperatures during . Brasier argued this environment was hostile to life and the “fossils” were, in fact, formed from graphite impurities in the rock. They also speculated that the carbon associated with the “fossils” may not even be biological in origin.

A lively debate ensued, and it has continued ever since.

<div data-thumb="https://scx1.b-cdn.net/csz/news/tmb/2023/the-worlds-oldest-foss-2.jpg" data-src="https://scx2.b-cdn.net/gfx/news/2023/the-worlds-oldest-foss-2.jpg" data-sub-html="Tiny structures like these, found in ancient black chert, have been interpreted as fossilised bacteria. Credit: Brasier et al.“>

The world's oldest fossils or oily gunk? Research suggests these 3.5 billion-year-old rocks don't contain signs of life
Tiny structures like these, found in ancient black chert, have been interpreted as fossilised bacteria. Credit: Brasier et al.

Microbes or hot fluids?

To try to determine where the carbon-rich deposits in the black chert veins came from, we took a very close look at them with a high-magnification electron microscope.

We found it did not come from fossilized bacteria. The oil-like substance occurs as residues in fractures and as petrified droplets, which have previously been mistaken for ancient fossils.

The textures in the black chert veins indicate they were formed when hot fluids rich in silica and carbon moved through cracks in lava flows below vents in the seafloor similar to modern “black smoker” vents. Upon approaching the seafloor, the hot fluids infiltrated layers of volcanic sediment, replacing it with black chert.

If the carbon came from such a hot fluid, this supports findings that the carbon-rich filaments in the Apex chert are not fossils. However, it also raises a new question.

Typically, organic compounds such as oil and gas, which are referred to as “fossil fuels” because they form from the dead remains of algae, bacteria and plants, are generated when these remains are buried and heated to temperatures above 65℃. Chemical reactions release organic compounds, which may accumulate to form oil and gas fields.

However, the sediments from the North Pole area are very thin (less than 50m thick), poor in organic molecules, and sandwiched between kilometers of lava flows. So, how did the organic compounds form in such surroundings?

The world's oldest fossils or oily gunk? Research suggests these 3.5 billion-year-old rocks don't contain signs of life
Black chert veins may have formed when water came into contact with lava at seafloor vents. Credit: NOAA

Seafloor vents on early Earth

A possible alternative pathway is suggested from experimental evidence and research on Martian meteorites. In the absence of traditional biological sources, some of the organic molecules in the chert veins could have formed by non-biological processes.

For instance, when hot water circulates through lava or other igneous rock, water and carbon dioxide can react with mineral surfaces to form organic compounds. Similar reactions have been proposed to explain the presence of organic molecules in Martian meteorites and in some igneous rocks on Earth.

The carbon in black cherts from the Pilbara outback may therefore represent relics of organic compounds that were produced by reactions between water and rock. Indeed, on the early Earth seafloor vents may have created more organic compounds than biological processes did, making it difficult to distinguish between authentic carbon-bearing fossils and oily artifacts.

While more work is underway, early results suggest life was only just surviving 3.5 billion years ago, struggling to gain a foothold in an inhospitable environment. The world then was wracked by regular volcanic eruptions that covered Earth’s surface in lava, and bathed in harsh solar radiation streaming through an atmosphere with no protective ozone layer.

Looking further back in time, the black cherts offer a glimpse of a lifeless planet. Reactions between water and rock at seafloor vents produced a cocktail of organic compounds, perhaps supplying the raw materials for the assembly of the first living cells.

More information:
Birger Rasmussen et al, Organic carbon generation in 3.5-billion-year-old basalt-hosted seafloor hydrothermal vent systems, Science Advances (2023). DOI: 10.1126/sciadv.add7925

Provided by
The Conversation

This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

Citation:
The world’s oldest fossils or oily gunk? Research suggests these 3.5 billion-year-old rocks don’t contain signs of life (2023, February 2)
retrieved 2 February 2023
from https://phys.org/news/2023-02-world-oldest-fossils-oily-gunk.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no
part may be reproduced without the written permission. The content is provided for information purposes only.

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‘Angel Wings’ for Satellites Could Help Mitigate Space Junk – CNET

As futuristic as this sounds, real estate in space is booming. Major corporations and science research organizations are actively vying to send satellites into orbit for extraordinary reasons — developing free internet connection; enhancing GPS systems; monitoring climate change; even analyzing Albert Einstein’s trippy general relativity equations

But while humanity continues to advance technologically, experts are growing increasingly worried about a major issue: We’ve found a new area of the universe to pollute. As of 2021, NASA said, more than 27,000 pieces of orbital debris, or “space junk,” resided in our planet’s gravitational tides — and since then, SpaceX alone has sent hundreds more satellites up there

Typically, when they’re done with their equipment, scientists kind of just wait until stuff in Earth’s orbit starts deorbiting and eventually burns up in our atmosphere. This natural process, however, can take a very (very) long time. 

Thus, hoping to pave a cleaner future for our space-y dreams, the European Space Agency announced the strengthening promise of its innovative, prototype aluminum-coated sail. This device can ride up to orbit with a satellite and help it deorbit whenever.

The concept is called the Drag Augmentation Deorbiting System, or ADEO, braking sail — and in late December, the smallest of its kind completed its final successful demo mission since the program’s seminal one in 2018.

A silver space sail is seen with a gleaming star in the background.A silver space sail is seen with a gleaming star in the background.

An artist’s impression of ESA’s prototype braking sail concept.


ESA

How does it work?

Basically, ESA folded up the 3.5-square meter (38-foot) sail until it could fit in what essentially looks like a 10 centimeter (4 inch) jack-in-the-box package. Scientists then attached the component to a privately built spacecraft called the ION satellite carrier. ION was launched via a Falcon 9 rocket on June 30, 2021.

Then, in December 2022, the sail was deployed to showcase a silvery polyamide membrane secured to four carbon reinforced arms positioned in an X-shape. That increased what’s known as the satellite carrier’s atmospheric surface drag, which refers to a force generated by atoms near the top of the atmosphere that travel opposite to the relative motion of something in low Earth orbit. You can think of drag as friction, but with air.

With such a bolstered drag effect, the spacecraft started lowering its orbital altitude at an accelerated pace, expediting the satellite’s ultimate demise: burning up in Earth’s atmosphere.

“The ADEO-N sail will ensure that the satellite will re-enter in around one year and three months, while otherwise it would have reentered in four to five years,” Tiziana Cardone, an ESA structural engineer who oversaw the project, said in a statement.

Earth is seen in the distance from the ION satellite's perspective. Covering most of the screen is part of the breaking space sail.Earth is seen in the distance from the ION satellite's perspective. Covering most of the screen is part of the breaking space sail.

A camera view from the ION satellite after it unfurled the sail.


HTS

For a wonderful mental picture of all this, ESA thinks of the silver sail as the satellite’s “angel wings,” softly helping it float toward its death. The official name of ADEO’s latest mission was, aptly, “Show Me Your Wings.”

Going forward, the agency says this sail can also be scaled up or down depending on what kind of satellite it’s connected to. 

“The largest variation can be as big as 100 square meters and take up to 45 [minutes] to deploy,” the agency said in a press release. “The smallest sail is just 3.5 square meters and deploy in just 0.8 seconds!”

Passive drag systems like this one aren’t exactly a new concept. According to NASA, such devices represent the most “common deorbit device” for satellites orbiting in low Earth orbit, and present an advantage because they’re quite easy to deal with and can be stored super compactly. 

But what’s striking about ESA’s recent achievement with ADEO is that it seems to be working extremely well, keeping in line with widespread efforts to mitigate the huge issue of space junk. Last year, for instance, the Federal Communications Commission adopted a new “five-year rule” for deorbiting satellites, down from the previous 25 years, and ESA itself has a major initiative to address space pollution.

“We want to establish a zero debris policy, which means if you bring a spacecraft into orbit you have to remove it,” Josef Aschbacher, ESA’s director general, said in a statement last year.

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