New insights into the potential for early steps of biological evolution on Mars

Peer-Reviewed Publication

INDIANA UNIVERSITY

 

IMAGE: THIS RAW IMAGE FROM THE CURIOSITY ROVER SHOWS THE HEXAGON-SHAPED MUDCRACKS FILLED WITH SALT. view more 

CREDIT: NASA/JPL-CALTECH/MSSS, LANL.

That the planet Mars had habitable surface environments early in its existence has been firmly established by the scientific community.  These environments provided water, energy sources, elements like carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulfur, as well as critical catalytic transition metals associated with life as we know it. However, whether that potential stimulated further progression towards the independent evolution of life on Mars is unknown.

A team of scientists comprised of Juergen Schieber, a Professor in the Department of Earth and Atmospheric Sciences within the College of Arts and Sciences at Indiana University Bloomington, and colleagues on NASA’s Curiosity Rover mission, uncovered the first tangible evidence for sustained wet-dry cycling on early Mars. The latter condition is considered essential for prebiotic chemical evolution, a stepping-stone towards the emergence of life.

In a new paper, “Sustained wet-dry cycling on early Mars,” published in the scientific journal Nature, Schieber and his co-authors utilized data from the Curiosity Rover that currently explores Gale Crater to examine ancient pattern of mudcracks filled with salt (geometric patterns like pentagons or hexagons) observed in 3.6 billion year old mudstones.  As mud dries out, it shrinks and fractures into T-shaped junctions – like what Curiosity discovered previously at “Old Soaker,” a collection of mud cracks lower down on Mount Sharp. Those junctions are evidence that Old Soaker’s mud formed and dried out once, while the recurring exposures to water that created the new mud cracks caused the T-junctions to soften and become Y-shaped, eventually forming a hexagonal pattern.

Although Professor Schieber’s main research interest is the geology of shales and mudstones on Earth, his interest in the underlying fundamentals prompted him to postulate an abundance of mudstones on Mars, and that got him into a conversation with people that were planning the Mars Science Lab (MSL) Curiosity Rover mission at NASA’s Jet Propulsion Laboratory in Southern California. “Given my expertise about these rocks I was invited to join the MSL science team, and since landing in August 2012, 11 years ago almost to the day, our traverse has been dominated by mudstones,” said Professor Schieber.

Sustained wet-dry cycling on Mars—a consequence of a repeated desiccation, recharge, and flooding, creates cracks in the lake bed and within those cracks high salt concentrations develop that force the crystallization of minerals left after the lake’s evaporation, and cementation of sediment.  Ultimately this process was preserved as the polygonal (hexagon- or pentagon-shaped) patterns observed with the Rover. Due to desiccation, the residual water likely had high concentrations of dissolved salts and, potentially, of organic molecules that can serve as the building blocks of life.

“The theory is, that as these elements and organic molecules are forced closer and closer together with increasing salinity, they may start polymerizing and make longer chains, creating the conditions for spontaneous chemistry that may start the complex chemical evolution that could lead to living organisms,” said Schieber. “It is that mental image that got us excited when we observed these honeycomb-shaped, or polygonal, ridge patterns on the surface of mudstone beds. Here was evidence for wetting and drying that could drive interesting chemistry within the cracks.”

Knowing from earlier studies that likely residuals from the lake’s desiccation should be calcium and magnesium sulfate minerals, the team used the “Chemcam” instrument on the Curiosity Rover to probe the cemented ridges to confirm their chemical composition.

The sedimentary features of the mudstones that Schieber and his co-authors studied can be interpreted to have resulted from multiple wetting and drying cycles resulting in mineral precipitates—minerals left behind when water evaporates—stacked on top of each other over time.  If organic molecules were present in residual brines, this setting may have been conducive to the evolution of more complex organic molecules and pre-biotic chemistry, the study authors report.

Overlays highlight the geometric patterns.

CREDIT

NASA/JPL-CALTECH/MSSS, LANL

JOURNAL

Nature

DOI

10.1038/s41586-023-06220-3 

METHOD OF RESEARCH

Imaging analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Sustained wet–dry cycling on early Mars

ARTICLE PUBLICATION DATE

9-Aug-2023

 

Chemicals from maize roots influence wheat yield

Peer-Reviewed Publication

UNIVERSITY OF BERN

 

IMAGE: WHEAT FIELD AT THE EXPERIMENTAL SITE OF AGROSCOPE IN POSIEUX, CANTON OF FRIBOURG, SWITZERLAND. view more 

CREDIT: IMAGE: VALENTIN GFELLER

Maize roots secrete certain chemicals that affect the quality of soil. In some fields, this effect increases yields of wheat planted subsequent to maize in the same soil by more than 4%. This was proven by researchers from the University of Bern. While the findings from several field experiments show that these effects are highly variable, in the long term they may yet help to make the cultivation of grains more sustainable, without the need for additional fertilizers or pesticides.

Plants produce an abundance of special chemicals. Some of these are released into the soil and influence its quality. This, in turn, affects the next plant to grow in the soil. So far, little research has taken place on the extent to which the excreted chemicals can be used in agriculture to increase productivity. Recently, however, researchers from the Institute of Plant Sciences (IPS) at the University of Bern have conducted field experiments in this area. With their findings published in the scientific journal eLife, the researchers demonstrate that specialized metabolitesfrom the roots of the maize plant can bring about an increase in the yields of subsequently planted wheat under agriculturally realistic conditions.

How maize root chemicals affect wheat

On the basis of earlier studies conducted by researchers at the Institute of Plant Sciences (IPS) at the University of Bern, it was known that so-called benzoxazinoids – natural chemicals which maize plants release through their roots – change the composition of microorganisms in the soil on the roots and therefore influence the growth of the subsequent plants that grow in the soil. The present study investigated whether plant-soil feedbacks of this kind also occur under realistic agricultural conditions. “Such field experiments are essential to test the transferability of basic research into practice and thus assess the potential agronomic benefit,” explains Valentin Gfeller, who worked on the project as a doctoral student at IPS and now works at the Research Institute of Organic Agriculture FiBL. During a two-year field experiment, two lines of maize were initially grown, only one of which released benzoxazinoids into the soil. Three varieties of winter wheat were then grown on the differently conditioned soils. On this basis, it was possible to demonstrate that the excretion of benzoxazinoids improves germination and increases tillering, growth and crop yield.

Fewer pests, same quality

In addition to the increased crop, lower levels of infestation by some pests were also observed. “A yield increase of 4% may not sound spectacular, but it is still significant considering how challenging it has become to enhance wheat yields without additional inputs,” explained Matthias Erb, Professor for Biotic Interactions at the Institute of Plant Sciences, who led the study together with Klaus Schläppi of the University of Basel. “Whether effects of this kind actually make a significant difference for overall agricultural productivity and sustainability remains to be seen, however, as yield also depends on many other factors,” explains Erb. The study demonstrates the potential of using specialized plant compounds to improve crop productivity through variety-specific rotations.

Within the framework of the “One Health” Interfaculty Research Cooperation (IRC) at the University of Bern (see box), it was also possible to investigate the quality of the wheat at the level of individual chemical elements. Together with the Institute of Geography of the University of Bern and Agroscope, the Swiss centre of excellence for agricultural research, it was possible to demonstrate that the increase in harvest due to benzoxazinoids does not have any negative impact on wheat grain quality.

Plant chemicals persist in the soil

To better understand the underlying mechanism, the researchers completed a variety of analyzes of the soil and roots. The benzoxazinoid-producing plants accumulated these chemicals  and their degradation products in the soil close to their roots. Furthermore, in collaboration with the University of Basel, it was confirmed that benzoxazinoids influence the community of bacteria and fungi in and on maize roots. However, soil nutrients were not altered. Benzoxazinoids also proved to be particularly persistent in the soil. The extent to which wheat growth and overall yield are directly or indirectly affected by benzoxazinoids through soil microorganisms will be subject to further investigation.

Soil properties are important

To test the effects of soil properties, together with the University of Basel and Agroscope, the research team conducted another two-year field experiment to investigate how these plant-soil feedbacks from benzoxazinoids act in a more heterogeneous field. The composition of the soil chemistry and microorganisms in the field in question varied considerably. The researchers succeeded in showing that the influence of benzoxazinoids on the growth and resistance of wheat depends on this different composition. “A better understanding of the effects of soil properties  on plant-soil feedbacks is crucial in terms of the future use in sustainable agriculture,” explains Valentin Gfeller.

Information about the publication:

Gfeller V, Waelchli J, Pfister S, Deslandes-Hérold G, Mascher F, Glauser G, Aeby Y, Mestrot A, Robert CAM, Schlaeppi K, Erb M. 2023. Plant secondary metabolite-dependent plant-soil feedbacks can improve crop yield in the field. eLife. 12: e84988 https://doi.org/10.7554/eLife.84988

Other related publications:

Gfeller V, Cadot S, Waelchli J, Gulliver S, Terrettaz C, Thönen L, Mateo P, Robert CAM, Mascher F, Steinger T, Bigalke M, Erb M, Schlaeppi K. 2023. Soil chemical and microbial gradients determine accumulation of root-exuded secondary metabolites and plant-soil feedbacks in the field. J Sustain Agric Environ. https://doi.org/10.1002/sae2.12063

Hu, L. et al. 2018. Root exudate metabolites drive plant-soil feedbacks on growth and defense by shaping the rhizosphere microbiota. Nature communications. 9: 2738. https://doi.org/10.1038/s41467-018-05122-7

The Interfaculty Research Cooperation “One Health” The Interfaculty Research Cooperation (IRC) "One Health" examines how environmental chemicals influence the health of the soil, plants, animals and humans. In close collaboration, 9 research groups from the Natural Sciences, Vetsuisse and Medical faculties are examining and quantifying the effect of pesticides, heavy metals and plant defense metabolites on microbial communities at the interfaces between soils, plants, animals and humans. The interdisciplinary approach contributes to a better understanding of how environmental changes affect the health of food chains. The IRC "One Health" combines the strategic topic focuses of "sustainability" and "health and medicine" at the University of Bern and promotes interdisciplinary research on a highly topical subject in life sciences and biology. More about the IRC "One Health" More about the Institute of Plant Sciences

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JOURNAL

eLife

DOI

10.7554/eLife.84988 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Plant secondary metabolite-dependent plant-soil feedbacks can improve crop yield in the field

 

Researchers reveal mechanism triggering Arctic daily warming

Peer-Reviewed Publication

UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA

 

IMAGE: ATMOSPHERIC CONDITIONS ASSOCIATED WITH THE CP ENSO view more 

CREDIT: IMAGE FROM PROF. REN’S TEAM

Prof. REN Baohua and his team from the School of Earth and Space Sciences, the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), uncovered the connection between Arctic daily warming and the equator region as well as Atlantic storms. The series of studies have been published in npj Climate and Atmospheric Science, Environmental Research Letters, and Advances in Atmospheric Sciences.

As one of the coldest places where the average winter temperature is -30℃, the Arctic temperature has reached the melting point several times, for instance, in late December 2015 and 2022. Those Artic daily warming events have drawn growing interest. 

Currently, most researchers focus on the long-term growth of the Arctic temperature but pay little attention to Arctic daily warming events. In the series of studies, the research team investigated the influence of the North Atlantic Oscillation (NAO), the El Niño-Southern Oscillation (ENSO), and the Central Pacific El Niño-Southern Oscillation (CP ENSO) on the Arctic daily warming occurrence.

The researchers investigated the impact of the NAO on the Arctic winter daily warming events induced by Atlantic storms, known as the Atlantic pattern-Arctic Rapid Tropospheric Daily Warming (Atlantic-RTDW) event.

They discovered that the relationship between the NAO and the Atlantic-RTDW-event frequency has weakened since the mid-1980s, which was attributed to a stronger Atlantic Storm Track (AST) activity intensity. During this period, the strong AST induced an enhanced NAO-related cyclone via transient eddy-mean flow interactions, resulting in the disappearance of southerly and northerly wind anomalies over the NA.

Furthermore, the researchers found that ENSO has urged a stronger Rossby wave due to its heightened intensity since the late 1970s, allowing El Niño to deepen the Aleutian Low, thus decreasing (increasing) Arctic daily warming events. This model offered a potential link between the equator and the Arctic which can assist in the prediction of extreme Arctic daily warming events. With global warming, this potential relation may be strengthened.

Nevertheless, after the mid-1980s, the planetary wave associated with CP ENSO could not propagate upwards into the stratosphere, cutting the teleconnection between CP ENSO and Iceland Low. As a result, CP ENSO’s influence on the occurrence frequency of A-RTDW events was weakened.

The findings provided a new perspective on the weather and climate changes in the Arctic. Those studies can help strengthen the prediction of Arctic daily warming events.

 

Jane FAN Qiong 

Tel: +86-551-63607280 

E-mail:englishnews@ustc.edu.cn

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JOURNAL

npj Climate and Atmospheric Science

DOI

10.1038/s41612-023-00399-y 

ARTICLE TITLE

Change of the CP ENSO’s role in the occurrence frequency of Arctic daily warming events triggered by Atlantic storms

 

Arctic monitoring program plays vital role in global pollution reduction efforts

Peer-Reviewed Publication

CHINESE SOCIETY FOR ENVIRONMENTAL SCIENCES

 

IMAGE: GRAPHICAL ABSTRACT. view more 

CREDIT: ENVIRONMENTAL SCIENCE AND ECOTECHNOLOGY

Historically, the Arctic was considered a pristine region, but scientific research spanning the last three decades has revealed the harsh reality of long-range transported pollutants reaching the Arctic from different corners of the world. In response to this alarming discovery, AMAP was created with the mission to monitor pollution and its effects on the Arctic environment and human health.

In a new article published on 26 July 2023, in the journal Environmental Science and Ecotechnology, researchers from Arctic Knowledge Ltd, presents the initiation and implementation of a systematic scientific and political cooperation in the Arctic related to environmental pollution and climate change, with a special focus on the role of the Arctic Monitoring and Assessment Programme (AMAP). AMAP's pioneering approach, with equal participation of indigenous peoples' organizations alongside Arctic states, seamlessly blending scientific and local knowledge in assessments, has been crucial in understanding the risks posed by persistent organic pollutants (POPs), mercury, radioactivity, and oil pollution, among others. The far-reaching impacts of AMAP's scientific results are evident as its data played a key role in establishing international agreements like the UN Stockholm Convention on POPs and the UN Minamata treaty, resulting in reduced pollution levels not only in the Arctic but also globally. Additionally, AMAP's work has inspired initiatives beyond the Arctic, with ICIMOD establishing HIMAP based on AMAP's model in the Hindu Kush Himalaya (HKM) region. Furthermore, the proposal for the Antarctic Monitoring and Assessment Programme (AnMAP) seeks advice from AMAP, extending the program's influence beyond its original scope. Despite challenges in data sharing and accessing geographical areas for observations, AMAP remains steadfast in its commitment to enhance Arctic monitoring and research data accessibility for international networks and agreements. Given the rapid changes in the Arctic, AMAP's role in fostering continued collaboration and providing science-based policy advice has become more critical than ever. In this regard, AMAP stands as a powerful example of the potential of international cooperation in addressing global challenges and promoting peace and prosperity through science.

Highlights

• AMAP has monitored and assessed Arctic pollution since 1991.
• The main source of Arctic pollution is long-range transport from lower latitudes.
• AMAP data have been fundamental in developing international chemical regulations.
• Food advice has reduced contaminant exposure in local communities.
• Other monitoring and assessment frameworks have been developed after AMAP's model.

In conclusion, AMAP's systematic scientific and political cooperation has been instrumental in recognizing, understanding, and mitigating environmental pollution and climate change in the Arctic. Its efforts have not only led to significant reductions in pollutants in the Arctic but have also influenced global agreements and inspired similar initiatives in other regions.

###

References

DOI

10.1016/j.ese.2023.100302

Funding information

The authors wish to acknowledge the scientists and local communities involved in the AMAP monitoring and assessments as well as the reviewers of the scientific assessments. This long-term work would not have been possible without the dedicated contributions from the AMAP Working Group and the Secretariat. The AMAP work benefitted from financial support by the Arctic countries, the Nordic Council of Ministers, the Nordic Environment Finance Corporation (NEFCO) and the Global Environment Facility Programme (GEF).

About Environmental Science and Ecotechnology

Environmental Science and Ecotechnology (ISSN 2666-4984) is an international, peer-reviewed, and open-access journal published by Elsevier. The journal publishes significant views and research across the full spectrum of ecology and environmental sciences, such as climate change, sustainability, biodiversity conservation, environment & health, green catalysis/processing for pollution control, and AI-driven environmental engineering. The latest impact factor of ESE is 12.6, according to the Journal Citation ReportTM 2022.

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JOURNAL

Environmental Science and Ecotechnology

DOI

10.1016/j.ese.2023.100302 

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

The role of the Arctic Monitoring and Assessment Programme (AMAP) in reducing pollution of the Arctic and around the globe

Even treated wastewater affects our rivers

New study by Goethe University Frankfurt shows: Effluents from wastewater treatment plants change the invertebrate communities in Hesse’s waters

Peer-Reviewed Publication

GOETHE UNIVERSITY FRANKFURT

 

IMAGE: TREATED WASTEWATER IS DISCHARGED INTO A NEARBY STREAM. IN THIS WAY, NUMEROUS TRACE SUBSTANCES ENTER OUR WATERS. view more 

CREDIT: JONAS JOURDAN

Effluents from wastewater treatment plants have a dual effect: Some species disappear, while others benefit. Especially certain insect orders, such as stonefly and caddisfly larvae, are decimated. Certain worms and crustaceans, by contrast, can increase in number. A team from Goethe University Frankfurt led by Daniel Enns and Dr. Jonas Jourdan has corroborated this in a comprehensive study, which has now been published in the journal Water Research. They examined 170 wastewater treatment plants in Hesse in relation to species composition.

Wastewater treatment plants are an indispensable part of our modern infrastructure; they have made a significant contribution to improving the quality of our surface waters. However, their ability to completely remove what are known as micropollutants from wastewater is mostly limited. These substances include, for example, active ingredients from pharmaceuticals and personal care products, pesticides and other synthetic substances enter waterbodies via the treated wastewater, placing an additional burden on rivers and streams. This exacerbates the challenges faced by already vulnerable insect communities and aquatic fauna. Previous studies – which have primarily focused on single wastewater treatment plants – have already shown that invertebrate communities downstream of such effluents are generally dominated by pollution-tolerant taxa.

Until now, however, it was unclear how ubiquitous these changes are. That is why a team of biologists from Goethe University Frankfurt has now studied extensively how wastewater from 170 wastewater treatment plants in Hesse has an impact on the species composition of invertebrates. This has prompted a change in the common conception that human-induced stressors reduce the number of species in a habitat and thus their diversity: Rather, the findings indicate that a shift in species composition can be observed. The researchers were able to identify significant shifts in the composition of the species community between sites located upstream and downstream of wastewater treatment plants. Some species were particularly affected by effluents from wastewater treatment plants – such as stonefly and caddisfly larvae, which disappear entirely in some places. Other taxa, such as certain worms and crustaceans, by contrast, benefit and are found in greater numbers. This change can be observed especially in streams and smaller rivers. Overall, wastewater treatment plants alter conditions downstream to the advantage of pollution-tolerant taxa and to the disadvantage of sensitive ones.

How can we reduce water pollution?

Modern treatment techniques such as ozonation or activated charcoal filtering can make water treatment in wastewater treatment plants more efficient, allowing a wider range of pollutants, including many trace substances, to be removed from the wastewater before it is released into the environment. Merging smaller wastewater treatment plants can also contribute to reducing the burden on the environment. Whatever measures are taken, it is important to make sure that upstream sections are not already degraded and are in a good chemical and structural condition.

 

Publication: Enns D, Cunze S, Baker NJ, Oehlmann J, Jourdan J (2023) Flushing away the future: The effects of wastewater treatment plants on aquatic invertebrates. Water Research, 120388. doi.org/10.1016/j.watres.2023.120388

 

Picture download: https://www.uni-frankfurt.de/141365425

 

Caption:

Images 1+2: Treated wastewater is discharged into a nearby stream. In this way, numerous trace substances enter our waters. (Photos: Jourdan)

Image 3: The photograph shows a typical wastewater treatment plant. The wastewater passes through various treatment stages to remove pollutants before the treated water is discharged into the environment. (Photo: Jourdan)

 

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JOURNAL

Water Research

DOI

10.1016/j.watres.2023.120388 

CORRECTION: Outdoor air pollution may increase non-lung cancer risk in older adults

HARVARD T.H. CHAN SCHOOL OF PUBLIC HEALTH

 NEWS RELEASE 11-AUG-2023

*This press release was amended on August 9, 2023. Due to a mistake in interpretation of data, the previous version of the release stated the study found that NO2 exposure is associated with a decreased risk of breast cancer. The authors have confirmed that the results showed that NO2 exposure is associated with an increased risk of breast cancer.

 

Key points:

• A cohort study of millions of Medicare beneficiaries found that chronic exposures to PM2.5 and NO2 over a 10-year period increased the risk of developing colorectal and prostate cancers.
• Even in areas with low pollution levels, researchers found substantial associations between exposures to these pollutants and the risk of developing colorectal and prostate cancers, in addition to breast and endometrial cancers.

Boston, MA—Chronic exposure to fine particulate air pollutants (PM2.5) and nitrogen dioxide (NO2) may increase non-lung cancer risk in older adults, according to a study led by Harvard T.H. Chan School of Public Health. In a cohort study of millions of Medicare beneficiaries, the researchers found that exposures to PM2.5 and NO2 over a 10-year period increased the risk of developing colorectal and prostate cancers. The researchers also found that even low levels of air pollution exposure may make people particularly susceptible to developing these cancers, in addition to breast and endometrial cancers.

“Our findings uncover the biological plausibility of air pollution as a crucial risk factor in the development of specific cancers, bringing us one step closer to understanding the impact of air pollution on human health,” said Yaguang Wei, research fellow in the Department of Environmental Health. “To ensure equitable access to clean air for all populations, we must fully define the effects of air pollution and then work towards reducing it.”

The study was published online August 1, 2023, in Environmental Epidemiology.

While air pollution has been established as a risk factor for lung cancer, and a link to breast cancer risk has been emerging, few studies have looked at its effects on prostate, colorectal, and endometrial cancer risk.

Researchers analyzed data from national Medicare beneficiaries aged 65 or older, collected from 2000 to 2016. All subjects were cancer-free for at least the initial 10 years of the study period. The researchers created separate cohorts for each type of cancer—breast, colorectal, endometrial, and prostate—with between 2.2 million and 6.5 million subjects in each cohort. Separate analyses looked at cancer risk under the impacts of air pollutants for various subgroups by factors including age, sex (for colorectal cancer only), race/ethnicity, average BMI, and socioeconomic status.

Drawing from a variety of air pollution data sources, the researchers developed a predictive map of PM2.5 and NO2 concentrations across the contiguous U.S. This was then linked to beneficiaries’ residential ZIP codes to enable the researchers to estimate individual exposures over a 10-year period.

Findings from the nationwide analysis showed that chronic PM2.5 and NO2 exposures increased the risk of developing colorectal and prostate cancers but were not associated with endometrial cancer risk. For breast cancer, NO2 exposure was associated with an increased risk, while the association for PM2.5 was inconclusive. The researchers suggested that the mixed associations may be due to variations in the chemical composition of PM2.5, which is a complex mixture of solid and liquid particles.

When the analysis was restricted to regions where air pollution levels were significantly below national standards and the composition of PM2.5 remained fairly stable, their effect on breast cancer risk was more pronounced. Stronger associations between exposures to both pollutants and endometrial cancer risk were also found at lower pollution levels.

In their analysis of risk by subgroups, the researchers found evidence suggesting that communities with higher average BMI may face disproportionately higher risk of all four cancers from NO2 exposure, and that Black Americans and those enrolled in Medicaid may be more susceptible to cancer risks (prostate and breast, respectively) from PM2.5 exposure.

The researchers noted that even communities with seemingly clean air were not immune to cancer risk. They found substantial associations between exposure to the two pollutants and the risks of all four cancers even at pollution levels below newly updated World Health Organization guidelines (which are lower than current U.S. standards).

“The key message here is that U.S. air pollution standards are inadequate in protecting public health,” said senior author Joel Schwartz, professor of environmental epidemiology. “The Environmental Protection Agency recently proposed stricter standards for PM2.5, but their proposal doesn’t go far enough in regulating this pollutant. Current NO2 standards are also woefully inadequate. Unless all of these standards become much, much stricter, air pollution will continue to result in thousands of unnecessary cases of multiple cancers each year.”

Other Harvard Chan School authors include Edgar Castro, Cristina Su Liu, Xinye Qiu, James Healy, and Bryan Vu.

Funding for the study came from the National Institutes of Health grants R01ES032418 and P30ES000002.

“Additive effects of ten-year exposures to PM2.5 and NO2 and primary cancer incidence in American older adults,” Yaguang Wei, Mahdieh Danesh Yazdi, Tszshan Ma, Edgar Castro, Cristina Su Liu, Xinye Qiu, James Healy, Bryan N. Vu, Cuicui Wang, Liuhua Shi, Joel Schwartz, Environmental Epidemiology, online August 1, 2023, doi: 10.1097/EE9.0000000000000265

Visit the Harvard Chan School website for the latest news, press releases, and multimedia offerings.

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Harvard T.H. Chan School of Public Health brings together dedicated experts from many disciplines to educate new generations of global health leaders and produce powerful ideas that improve the lives and health of people everywhere. As a community of leading scientists, educators, and students, we work together to take innovative ideas from the laboratory to people’s lives—not only making scientific breakthroughs, but also working to change individual behaviors, public policies, and health care practices. Each year, more than 400 faculty members at Harvard Chan School teach 1,000-plus full-time students from around the world and train thousands more through online and executive education courses. Founded in 1913 as the Harvard-MIT School of Health Officers, the School is recognized as America’s oldest professional training program in public health.

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JOURNAL

Environmental Epidemiology

DOI

10.1097/EE9.0000000000000265 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Additive effects of ten-year exposures to PM2.5 and NO2 and primary cancer incidence in American older adults

Behind the rind: new genomic insights into watermelon evolution, quality, and resilience

Peer-Reviewed Publication

BOYCE THOMPSON INSTITUTE

Watermelon is a globally significant agricultural product, both in terms of the total amount produced and the total economic value generated.

Scientists at the Boyce Thompson Institute have constructed a comprehensive "super-pangenome" for watermelon and its wild relatives, uncovering beneficial genes lost during domestication that could improve disease resistance and fruit quality of this vital fruit crop.

"We aimed to delve deeper into the genetic variations that make watermelons so diverse and unique," stated Professor Zhangjun Fei, the study's lead author. "Our findings not only provide insights into the evolutionary journey of watermelons but also present significant implications for breeding and disease resistance."

The watermelon super-pangenome was built using reference genome sequences and genome resequencing data from 547 watermelon accessions spanning four species - cultivated watermelon (Citrullus lanatus) and its wild relatives C. mucosospermus, C. amarus, and C. colocynthis.

Analyses of the super-pangenome revealed that many disease-resistance genes present in wild species were lost during domestication, as early farmers selected for fruit quality traits like sweetness, flesh color, and rind thickness. "These beneficial genes could be reintroduced into modern cultivars to breed more resilient watermelon varieties," noted Fei.

A key discovery of the research, recently published in the Plant Biotechnology Journal, was the identification of a tandem duplication of the sugar transporter gene ClTST2 that enhances sugar accumulation and fruit sweetness in cultivated watermelon. This genetic variant was rare in wild watermelons but was selected during domestication.

"The super-pangenome provides a valuable genetic toolkit for breeders and researchers to improve cultivated watermelon," said Fei. "By understanding the genetic makeup and evolutionary patterns of watermelons, we can develop varieties with enhanced yield, increased disease resistance, and improved adaptability."

This research was supported by grants from the USDA National Institute of Food and Agriculture Specialty Crop Research Initiative (2015-51181-24285 and 2020-51181-32139) and the US National Science Foundation (IOS-1855585).

About Boyce Thompson Institute
Founded in 1924, Boyce Thompson Institute (BTI) is a premier plant biology and life sciences research institution located in Ithaca, New York. BTI scientists conduct investigations into fundamental research with the goals of increasing food security, improving environmental sustainability, and making basic discoveries that will enhance human health. Throughout this work, BTI is committed to inspiring and educating students and to providing advanced training for the next generation of scientists. BTI is an independent nonprofit research institute that is affiliated with Cornell University. For more information, please visit BTIscience.org.

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JOURNAL

Plant Biotechnology Journal

DOI

10.1111/pbi.14120 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Cells

ARTICLE TITLE

A Citrullus genus super-pangenome reveals extensive variations in wild and cultivated watermelons and sheds light on watermelon evolution and domestication