Comment

Comment by Dr. Krishna Kumari Challa yesterday

Widespread wildfires across Canada and droughts in the Amazon in 2023 released about the same amount of carbon to the atmosphere as North America's total fossil fuel emissions, underscoring the severe impact of climate change on natural ecosystems.

The Amazon—one of the world's most crucial carbon sinks—is showing signs of long-term strain, with some regions shifting from absorbing carbon to becoming net sources of carbon emissions.

The researchers suggest that the declining capacity of Earth's land ecosystems to absorb carbon dioxide may indicate that these natural carbon sinks are nearing their limits and no longer able to provide the mitigation service they have historically offered by absorbing half of human-induced carbon dioxide emissions.
Consequently, achieving safe global warming limits will require even more ambitious emission reductions than previously anticipated, the scientists say.
The study also highlights that current climate models might be underestimating the rapid pace and impact of extreme events, such as droughts and fires, on the degradation of these crucial carbon reservoirs.

Piyu Ke et al, Low latency carbon budget analysis reveals a large decline of the land carbon sink in 2023, National Science Review (2024). DOI: 10.1093/nsr/nwae367

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Extreme heat weakens land's power to absorb carbon, analysis finds

A new European Space Agency-backed study shows that the extreme heat waves of 2023, which fueled huge wildfires and severe droughts, also undermined the land's capacity to soak up atmospheric carbon. This diminished carbon uptake drove atmospheric carbon dioxide levels to new highs, intensifying concerns about accelerating climate change.

Measurements from Hawaii's Mauna Loa Observatory showed that atmospheric carbon concentrations surged by 86% in 2023 compared to the previous year, marking a record high since tracking began in 1958.

Despite this sharp increase, fossil fuel emissions only rose by about 0.6%, suggesting that other factors, such as weakened carbon absorption by natural ecosystems, may have driven the spike.

An international team of scientists analyzed global vegetation models and satellite data to investigate the underlying causes and deliver an expedited carbon budget report for 2023.

Typically, land absorbs roughly one-third of human-generated carbon dioxide emissions. However, the team's research published in National Science Review reveals that in 2023, this capacity fell to just one-fifth of its usual level, marking the weakest land carbon sink performance in two decades.

Part 1

Comment by Dr. Krishna Kumari Challa yesterday

We are already counting on forests and oceans to mop up our past emissions, most of which came from burning stuff we dug out of the ground. We can't expect them to compensate for future emissions as well. By mid-century, any carbon that still comes out of the ground will have to go back down, to permanent storage. That's Geological Net Zero.
Countries report both emissions and removals, but using all removals in climate targets is a recipe for continued warming. Natural carbon sinks currently clean up around half our annual emissions for free, but this ecosystem service must be kept separate from the fossil emissions driving climate change. Relabeling things will not stop global warming, say the scientists.
They stress that: It is a common assumption that removing carbon from the atmosphere to offset burning of fossil fuels is as effective as not burning fossil fuels in the first place. It is not.
Offsetting continued fossil fuel use with carbon removal will not be effective if the removal is already being counted on as part of the natural carbon cycle and if the carbon is not permanently stored. Unless we can increase transparency in national Greenhouse gas reporting and target setting, offsets will become part of the problem instead of part of the solution.
Land is limited, we rely on it for food, nature, biodiversity, leisure, water storage, and so on. It cannot offset more than a portion of fossil emissions even now, probably less in future, with worsening pressures on the biosphere such as population increase, fires, and drought.

"Giving carbon credits for natural processes that are happening anyway undermines trust in the whole idea of offsetting. We have to urgently protect natural carbon sinks, but there are more scientifically credible and equitable ways of doing this than relying on carbon offset markets."
Is anybody listening?

Myles Allen, Geological Net Zero and the need for disaggregated accounting for carbon sinks, Nature (2024). DOI: 10.1038/s41586-024-08326-8. www.nature.com/articles/s41586-024-08326-8

Part 2

Comment by Dr. Krishna Kumari Challa yesterday

Redefining net zero will not stop global warming, scientists say

This is really absurd. Governments and countries are trying to evade climate goals to stop global warming. 

In a study, led by the University of Oxford's Department of Physics and published 18 November in Nature, an international group of authors who developed the science behind net zero demonstrate that relying on 'natural carbon sinks' like forests and oceans to offset ongoing CO2 emissions from fossil fuel use will not actually stop global warming.

The science of net zero, developed over 15 years ago, does not include these natural carbon sinks in the definition of net human-induced CO₂ emissions.

Natural sinks play a vital role in moderating the impact of current emissions and draw down atmospheric CO2 concentrations after the date of net zero, stabilizing global temperatures. Yet governments and corporations are increasingly turning to them to offset emissions, rather than reducing fossil fuel use or developing more permanent CO2 disposal options.

Emissions accounting rules encourage this by creating an apparent equivalence between fossil fuel emissions and drawdown of CO₂ by some natural carbon sinks, meaning a country could appear to have 'achieved net zero' while still contributing to ongoing warming.

The authors call on governments and corporations to clarify how much they are counting on natural carbon sinks to meet their climate goals, as well as recognizing the need for "Geological Net Zero."

Geological Net Zero means balancing flows of carbon into and out of the solid Earth, with one ton of CO₂ committed to geological storage for every ton still generated by any continued fossil fuel use. Given the cost and challenges of permanent geological CO₂ storage, achieving Geological Net Zero will require a substantial reduction in fossil fuel use.

The authors stress the importance of protecting and maintaining natural carbon sinks while accepting that doing so cannot compensate for ongoing fossil fuel use. Total historical CO₂ emissions determine how much a country or company has contributed to the global need for ongoing natural carbon sinks.

Part 1

Comment by Dr. Krishna Kumari Challa on Tuesday

On July 27, medical evaluation revealed light vaginal bleeding and dark discharge, with ultrasonography indicating fetal macrosomia.

By August 5, continued symptoms and decreased fetal movements led to the confirmation of fetal demise.

Molecular diagnostics confirmed acute OROV infection, ruling out dengue, Zika, chikungunya, and Mayaro viruses. Minimal invasive tissue sampling of the stillborn infant revealed OROV RNA in multiple fetal tissues, establishing vertical transmission.

Phylogenetic analysis using maximum-likelihood inference positioned the virus within the OROVBR-2019-2024 lineage, consistent with strains from the ongoing outbreak. These findings link the stillbirth directly to the current OROV spread in Brazil, highlighting the virus's potential risks during pregnancy.

The report should sound the alarm for health care providers to consider OROV infection in pregnant women presenting with fever and related symptoms in endemic or emerging regions.

 Carlos Garcia Filho et al, A Case of Vertical Transmission of Oropouche Virus in Brazil, New England Journal of Medicine (2024). DOI: 10.1056/NEJMc2412812

Part 2

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Comment by Dr. Krishna Kumari Challa on Tuesday

Oropouche virus transmission to unborn child confirmed

The first confirmed case of vertical transmission of Oropouche virus (OROV) has been reported by 23 researchers from eight distinct institutions in Brazil.

OROV, a zoonotic arbovirus, was first isolated from the blood of a charcoal worker with a high fever in 1955 on the Caribbean island of Trinidad. Outbreaks have typically occurred south of the Amazon, isolated within Amazonian villages.

In 2024, OROV infections were detected in previously non-endemic areas across all five Brazilian regions. These expansions into previously unaffected regions involve new virus variants emerging from genetic reassortment.

In a letter to the editor titled "A Case of Vertical Transmission of Oropouche Virus in Brazil," published October 30, 2024, in the New England Journal of Medicine, researchers report on a case from Ceará, a state historically free from OROV, finding its first infection case through active laboratory surveillance.

Subsequent investigations identified 171 cases, predominantly in the rural valleys of the Baturité Massif. Agricultural landscapes in this region favor the Culicoides paraensis midge, a small biting fly sometimes referred to as "no-see-ums" due to their tiny size. Culicoides is the primary vector for OROV transmission to humans.

A notable case involved a 40-year-old pregnant woman at 30 weeks gestation who developed fever, chills, muscle aches, and severe headache. Routine prenatal care had previously identified gestational diabetes, managed with metformin, and four routine obstetric ultrasounds.

Part 1

Comment by Dr. Krishna Kumari Challa on Monday

Self-treatment sparks ethics debate

Virologist Beata Halassy treated her own breast cancer by injecting the tumour with viruses she grew in the lab. In 2020, Halassy discovered she had a second recurrence of breast cancer at the site of a previous mastectomy. To avoid another bout of chemotherapy, she self-administered experimental oncolytic virotherapy. Halassy has now been cancer-free for four years. Her decision to treat herself, and subsequently publish a report detailing the process, has sparked discussion about the ethics of self-experimentation and the risk it might encourage others to try unproven treatments. “It took a brave editor to publish the report,” says Halassy.

Nature | 
Reference: https://www.mdpi.com/2076-393X/12/9/958

Comment by Dr. Krishna Kumari Challa on Monday

For instance, participants who wore makeup daily in the first and third trimesters had 14% and 17% higher plasma and breast-milk PFAS concentrations, respectively, compared to people who did not wear makeup every day. In addition, the researchers found that people using colored-permanent dye one to two days postpartum had higher PFAS levels (16% to 18% increases compared to never using them) in human milk concentrations.

The researchers noted that the study examined only four types of PFAS among thousands that are used in industry and commerce. Thus, the study likely underestimated the extent of exposure to all PFAS from these products during pregnancy.

Amber M Hall et al, Personal care product use and per- and polyfluoroalkyl substances in pregnant and lactating people in the Maternal-Infant Research on Environmental Chemicals study, Environment International (2024). DOI: 10.1016/j.envint.2024.109094

Part 2

Comment by Dr. Krishna Kumari Challa on Monday

Using personal care products during and after pregnancy can increase exposure to toxic chemicals

For people who are pregnant or nursing, more use of personal care products is associated with higher detectable levels of synthetic chemicals known to have adverse health effects, a new study by researchers has found.

The study,   published in Environment International, found that using personal care products like nail polish, makeup and hair dye while pregnant or lactating is associated with significantly higher levels of per- and polyfluoroalkyl substances, known as PFAS, in blood plasma and breast milk.

While PFAS are ubiquitous in the environment, this study indicates that personal care products are a modifiable source of PFAS. People who are concerned about their level of exposure to these chemicals during pregnancy or while breastfeeding may benefit from cutting back on personal care products during those times.

PFAS are synthetic chemicals that have been used in consumer products and industrial settings since the 1950s due to their ability to resist oil, water and heat. The study notes that PFAS have been associated with a range of adverse health effects, including liver disease, cardiometabolic and cardiovascular issues, and various cancers.

While several studies have detected these chemicals in personal care products directly, few have evaluated whether using these products impacts internal PFAS concentrations.

This is important, she added, because exposure to PFAS during pregnancy could contribute to adverse birth outcomes such as decreased birth weight, preterm birth, some neurodevelopmental disorders and diminished vaccine response in children.

The analyzed data from the Maternal-Infant Research on Environmental Chemicals Study, which enrolled 2,001 pregnant people from 10 cities across Canada between 2008 and 2011. The researchers evaluated the contribution of the use of personal care products on PFAS concentrations in prenatal plasma (6 to 13 weeks gestation) and human milk (2 to 10 weeks postpartum). Participants reported frequency of use across eight product categories during the first and third pregnancy trimesters, one to two days postpartum, and 2 to 10 weeks postpartum.

In first-trimester pregnant people, the researchers found that higher use of nail care products, fragrances, makeup, hair dyes and hair sprays or gels was associated with higher plasma PFAS concentrations. Similar results were observed for third-trimester personal care product use and breast-milk PFAS concentrations at 2 to 10 weeks postpartum.

Part1

Comment by Dr. Krishna Kumari Challa on Monday

While the researchers cannot pinpoint the exact reasons for why the adults learn faster, they have a few theories.

"The results demonstrate that the older the participants are, the more skillful they become during the early stages of training. This suggests that they get more out of the task introduction. We suspect that cognitive development and an increased ability to process information play a role—meaning adults may have more experience receiving instructions and translating them into action.

"The difference may also be because the fully developed nervous system of an adult provides better structural conditions for learning. In other words, after many years of schooling, adults may be more experienced learners and thereby more efficient at learning new things.
The picture changes when it comes to retention.

"When the researchers looked at what happens from the end of training until the participants return the next day, the dynamic reverses. While the youngest participants actually improve overnight, adults lose some of their ability to perform. This means the youngest ones are better at consolidating and reinforcing their memory after they've practiced,
According to the researchers, this suggests that sleep benefits children's learning and memory more. But other factors could also be at play. For example, older children and adults typically sleep less and have more "competing" activities throughout the day. Memory-consolidation processes in the nervous system continue for hours after the training ends.
When a math class ends, the brain keeps working on what was taught, and in doing so, reinforces memory. Sleep is known to aid consolidation. But engaging in other activities in the hours after—especially those that involve learning—can interfere with memory processes and the consolidation of what was just learned.
While the overall learning outcome doesn't vary drastically across age groups, the study does show that the learning process differs significantly depending on age, with underlying mechanisms influenced by the maturity of one's central nervous system.

Mikkel Malling Beck et al, Distinct mechanisms for online and offline motor skill learning across human development, Developmental Science (2024). DOI: 10.1111/desc.13536

Part 2

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