Floors in ancient Greek luxury villa were laid with recycled glass

Peer-Reviewed Publication

UNIVERSITY OF SOUTHERN DENMARK

 

IMAGE: EXCAVATION AND MOSAIC FLOORS OF VILLA. view more 

CREDIT: UNIVERSITY OF SOUTHERN DENMARK

Although this 1700 years old luxury villa was excavated and examined both in 1856 and in the 1990s, it still has secrets to reveal.

New secrets have now been revealed by an international research team, with Professor and expert in archaeometry, Kaare Lund Rasmussen from University of Southern Denmark leading the so called archaeometric analyses: using chemical analysis to determine which elements an object was made of, how it has been processed, etc.

Others in the team are Thomas Delbey from Cranfield University in England and the classical archaeologists Birte Poulsen and Poul Pedersen from Aarhus University and University of Southern Denmark. The team’s work is published in the journal Heritage Science, including archaeometric analysis of 19, approximately, 1600 years old mosaic tesserae.

One of seven wonders of the world

The tesserae originate from an excavation of a villa from late antiquity, located in Halikarnassos (today Bodrum in Anatolia, Turkey). Halikarnassos was famous for King Mausolus' giant and lavish tomb, which was considered one of the seven wonders of the world.

The villa was laid out around two courtyards and the many rooms were adorned with mosaic floors. In addition to geometric patterns, there were also motifs of various mythological figures and scenes taken from Greek mythology; e.g. Princess Europa being abducted by the god Zeus in the form of a bull and Aphrodite at sea in her seashell.

Motifs from the stories of the much younger Roman author Virgil are also represented.

Inscriptions in the floor have revealed that the owner was named Charidemos and that the villa was built in the mid-fifth century.

CAPTION

selection of the mosaic tesserae, investigated by professor Kaare Lund Rasmussen/ University of Southern Denmark.

CREDIT

Kaare Lund Rasmussen/University of Southern Denmark

A costly luxury

Mosaic flooring was a costly luxury: expensive raw materials like white, green, black, and other colors of marble had to be transported from distant quarries. Other stone materials, ceramics and glasses also had to be imported.

- I received 19 mosaic tesserae for analysis in my lab in Denmark. Of these, seven were of glass in different colors; purple, yellow, red, and deep red. My conclusion is that six of them are probably made of recycled glass, says Kaare Lund Rasmussen.

This conclusion is based on a chemical analysis called inductively coupled plasma mass spectrometry. With it, the research team has determined the concentrations of no less than 27 elements, some of them all the way down to a concentration of billionths of a gram.

Waning of Roman Empire

- We were able to distinguish between base glass from Egypt and base glass from the Middle East and also, we could determine which elements were added by the ancient craftsmen to color the glasses and to make them opaque, which was preferred at the time, he says.

It is of course difficult to extrapolate from only seven glass mosaic tesserae, but the new results fit very well with the picture of Anatolia in late antiquity. As the power of the Roman Empire waned, trade routes were closed or rerouted, which probably led to a shortage of goods in many places - including raw materials for glass production in Anatolia.

This, together with the stories depicted on the floors, allows the classical archaeologists to put together a more detailed picture of what was fashionable in late antiquity and what the possibilities were for the artistic unfolding.

CAPTION

Detail of mosaic floor

CREDIT

Kaare Lund Rasmussen/University of Southern Denmark.

JOURNAL

Heritage Science

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Materials and technology of mosaics from the House of Charidemos at Halikarnassos (Bodrum, Turkey)

Study: Explosive volcanic eruption produced rare mineral on Mars

Researchers publish scenario that explains 2016 discovery by NASA’s Curiosity rover

Peer-Reviewed Publication

RICE UNIVERSITY

 

IMAGE: KIRSTEN SIEBACH IS AN ASSISTANT PROFESSOR IN RICE’S DEPARTMENT OF EARTH, ENVIRONMENTAL AND PLANETARY SCIENCES AND A MISSION SPECIALIST ON NASA’S CURIOSITY MARS ROVER TEAM. view more 

CREDIT: PHOTO BY TOMMY LAVERGNE/RICE UNIVERSITY

HOUSTON – (July 25, 2022) – Planetary scientists from Rice University, NASA’s Johnson Space Center and the California Institute of Technology have an answer to a mystery that’s puzzled the Mars research community since NASA’s Curiosity rover discovered a mineral called tridymite in Gale Crater in 2016.

Tridymite is a high-temperature, low-pressure form of quartz that is extremely rare on Earth, and it wasn’t immediately clear how a concentrated chunk of it ended up in the crater. Gale Crater was chosen as Curiosity’s landing site due to the likelihood that it once held liquid water, and Curiosity found evidence that confirmed Gale Crater was a lake as recently as 1 billion years ago.

“The discovery of tridymite in a mudstone in Gale Crater is one of the most surprising observations that the Curiosity rover has made in 10 years of exploring Mars,” said Rice’s Kirsten Siebach, co-author of a study published online in Earth and Planetary Science Letters. “Tridymite is usually associated with quartz-forming, explosive, evolved volcanic systems on Earth, but we found it in the bottom of an ancient lake on Mars, where most of the volcanoes are very primitive.”

Siebach, an assistant professor in Rice’s Department of Earth, Environmental and Planetary Sciences, is a mission specialist on NASA’s Curiosity team. To suss out the answer to the mystery, she partnered with two postdoctoral researchers in her Rice research group, Valerie Payré and Michael Thorpe, NASA’s Elizabeth Rampe and Caltech’s Paula Antoshechkina. Payré, the study’s lead author, is now at Northern Arizona University and preparing to join the faculty of the University of Iowa in the fall.

Siebach and colleagues began by reevaluating data from every reported find of tridymite on Earth. They also reviewed volcanic materials from models of Mars volcanism and reexamined sedimentary evidence from the Gale Crater lake. They then came up with a new scenario that matched all the evidence: Martian magma sat for longer than usual in a chamber below a volcano, undergoing a process of partial cooling called fractional crystallization that concentrated silicon. In a massive eruption, the volcano spewed ash containing the extra silicon in the form of tridymite into the Gale Crater lake and surrounding rivers. Water helped break down the ash through natural processes of chemical weathering, and water also helped sort the minerals produced by weathering.

The scenario would have concentrated tridymite, producing minerals consistent with the 2016 find. It would also explain other geochemical evidence Curiosity found in the sample, including opaline silicates and reduced concentrations of aluminum oxide.

“It's actually a straightforward evolution of other volcanic rocks we found in the crater,” Siebach said. “We argue that because we only saw this mineral once, and it was highly concentrated in a single layer, the volcano probably erupted at the same time the lake was there. Although the specific sample we analyzed was not exclusively volcanic ash, it was ash that had been weathered and sorted by water.”

If a volcanic eruption like the one in the scenario did occur when Gale Crater contained a lake, it would mean explosive volcanism occurred more than 3 billion years ago, while Mars was transitioning from a wetter and perhaps warmer world to the dry and barren planet it is today.

“There’s ample evidence of basaltic volcanic eruptions on Mars, but this is a more evolved chemistry,” she said. “This work suggests that Mars may have a more complex and intriguing volcanic history than we would have imagined before Curiosity.”

The Curiosity rover is still active, and NASA is preparing to celebrate the 10th anniversary of its landing next month.

The research was funded by NASA (15-MSLPSP15_2-0051, 15-MSLPSP15_0015, 80NSSC22K0732), the National Science Foundation (1947616) and Rice’s Department of Earth, Environmental and Planetary Sciences.

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Peer-reviewed paper:

“Tridymite in a lacustrine mudstone in Gale Crater, Mars: Evidence for an explosive silicic eruption during the Hesperian” | Earth and Planetary Science Letters | DOI: 10.1016/j.epsl.2022.117694

Authors: Valerie Payré, Kirsten Siebach, Michael Thorpe, Paula Antoshechkina and Elizabeth Rampe

https://doi.org/10.1016/j.epsl.2022.117694

Image downloads:

https://mars.nasa.gov/resources/7438/looking-up-at-mars-rover-curiosity-in-buckskin-selfie/
CAPTION: NASA's Curiosity Mars rover snapped this low-angle self-portrait at the site where it drilled into a rock July 30, 2015, producing a powder (visible in foreground) that was later confirmed to contain the rare mineral tridymite. (Image courtesy of NASA/JPL-Caltech/MSSS)

https://mars.nasa.gov/resources/7604/buckskin-drill-hole-and-chemin-x-ray-diffraction/
CAPTION: NASA's Curiosity Mars Rover drilled this hole to collect sample material from a rock target called "Buckskin" on July 30, 2015. The diameter of the hole is slightly smaller than a U.S. dime. Rock powder from the drill site was subsequently delivered to a laboratory inside the rover and found to contain the rare mineral tridymite. (Image courtesy of NASA/JPL-Caltech/MSSS)

https://news-network.rice.edu/news/files/2022/07/0725_MARS-ks-lg.jpg
CAPTION: Kirsten Siebach (Photo courtesy of Rice University)

Related stories:

Mars, happy to see you again – Feb. 22, 2021
https://news.rice.edu/news/2021/mars-happy-see-you-again

Rice scientist joins next Mars adventure – Dec. 2, 2020
https://news.rice.edu/news/2020/rice-scientist-joins-next-mars-adventure

Links:

Siebach Lab: kirstensiebach.com/lab

Department of Earth, Environmental and Planetary Sciences: earthscience.rice.edu

Wiess School of Natural Sciences: naturalsciences.rice.edu

This release can be found online at news.rice.edu.

Follow Rice News and Media Relations via Twitter @RiceUNews.

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation’s top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 4,240 undergraduates and 3,972 graduate students, Rice’s undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 1 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger’s Personal Finance.

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JOURNAL

Earth and Planetary Science Letters

DOI

10.1016/j.epsl.2022.117694 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Tridymite in a lacustrine mudstone in Gale Crater, Mars: Evidence for an explosive silicic eruption during the Hesperian

New methodology helps predict soil recovery after wildfires

Peer-Reviewed Publication

AMERICAN SOCIETY FOR MICROBIOLOGY

Washington, D.C. - Soils influence water quality, and they are critical to plant growth. However, it has been difficult to predict how plant growth and water quality would change in the wake of wildfires. Now, a team of Colorado investigators has devised new methodology to enable such predictions. The research is published in Applied and Environmental Microbiology, a journal of the American Society for Microbiology.

“To make practical predictions about recovery, we had to use a modern artificial intelligence tool called statistical learning,” said John Spear, Ph.D., professor, Civil and Environmental Engineering, Colorado School of Mines, Golden, Colo. “When we fed data about the microbes and nutrients into this model, we were able to predict how soil is changed by fire far more accurately.”

Spear emphasized that combining information on the types and quantities of both microbes and nutrients increased accuracy. Another intriguing discovery was that including microbiota that are uncommon in soil—those that constituted less than 1% of the microbiome—was critical to the predictions’ accuracy.

“This apparent contradiction is a fascinating outcome of our study and runs contrary to the common wisdom that if we measure 99% of what’s living in soil, we’ll have a great sense of how that soil will behave,” said first author Alexander S. Honeyman, Ph.D., research associate at the Colorado School of Mines.

The investigators were also able to predict water quality by analyzing the microbiome for species that affect both soil regeneration and downstream waters, said Spear, who added that the methodology may lead to a better understanding of both terrestrial and aquatic ecosystem recovery post-wildfire.

In the study, “We went out to 2 active wildfires in Colorado in 2018 and 2019, and collected soil shortly after the smoldering stopped,” said Spear. “This was as simple as shoveling soil into a bucket. We returned to the same sites for 3 summers [2018, 2019, and 2020], collecting more samples, and followed up as the landscape recovered from the black of burn to the green of new growth.”

Back in the lab, the investigators measured soil carbon, nitrogen and other important molecules. They also took the census of the microbiome—the species present, and the quantities of each in the soils.

“The trick,” said Spear, “was to do this over and over in a thorough fashion for 3 years, generating a dataset of more than 500 soil samples. Then, we wanted to see if the pattern of recovery of soil after fire could be predicted from this unique dataset, using statistical learning.”

The methodology worked, despite the fact that the dataset is quite diverse—representing different severities of wildfire and various soil types and seasons. “That’s good news for our approach, because [the methodology] appears to work on many different conditions of soil,”  said Spear.

The research was motivated by Honeyman’s decade of experience as a volunteer firefighter, and having lost his home to a Colorado wildfire in 2010. This experience raised important questions for him. Would soil recover nutrients that had been lost in a fire? The investigators also wanted to know whether water quality would be renewed. "We asked ourselves how we could describe recovery in a way that’s actually useful to land managers,” said Spear, noting that, “our forest service coauthors, who are land managers, really liked this work.”

As climate change contributes to more frequent fires, it is critical that we understand how to manage the recovery of burned soil, particularly in the western U.S., said Spear.

Spear noted that the methodology could likely also be applied to agriculture to boost food production “even while using less water and less fertilizer, thus saving money.”
 

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The American Society for Microbiology is the largest single life science society, composed of more than 30,000 scientists and health professionals. ASM's mission is to promote and advance the microbial sciences.

ASM advances the microbial sciences through conferences, publications, certifications, educational opportunities and advocacy efforts. It enhances laboratory capacity around the globe through training and resources. It provides a network for scientists in academia, industry and clinical settings. Additionally, ASM promotes a deeper understanding of the microbial sciences to diverse audiences.

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JOURNAL

Applied and Environmental Microbiology

DOI

10.1128/aem.00343-22 

ARTICLE TITLE

Statistical Learning and Uncommon Soil Microbiota Explain Biogeochemical Responses after Wildfire

Particle phase chemistry enables soot to better seed clouds 

New study challenges current understanding of the formation mechanism

New study challenges current understanding of the formation mechanism of atmospheric secondary organic aerosol – Particle chemistry appears to have a strong influence on the climate impact of soot and organic aerosols from wildfires or anthropogenic combustion.

Peer-Reviewed Publication

MAX PLANCK INSTITUTE FOR CHEMISTRY

 

IMAGE: THE FIGURE SHOWS THAT HIGHLY OXYGENATED ORGANIC MOLECULES WITH HIGH UNSATURATION (HU-HOMS) ARE FORMED BY THE MULTIGENERATIONAL PHOTO-OXIDATION OF LARGE POLYCYCLIC AROMATIC HYDROCARBONS (PAHS) ON SOOT. view more 

CREDIT: HTTPS://DOI.ORG/10.1016/J.CHEMPR.2022.06.011

Highly oxygenated organic molecules are a key component of atmospheric secondary organic aerosol. However, the origin and formation mechanism of highly oxygenated organic molecules with high unsaturation (HU-HOMs), remain unknown. But now an international team of researchers has found that photooxidation of large polycyclic aromatic hydrocarbons (PAHs) on soot by singlet oxygen and superoxide anion radicals can be an important source of the unexplained HU-HOMs widely observed in the atmosphere. The team was led by Yafang Cheng from the Max Planck Institute for Chemistry and Chuncheng Chen from the Institute of Chemistry, Chinese Academy of Sciences. Their results are based on molecular-level investigations of the photochemical aging of soot by O2. The PAH-derived HU-HOMs exhibit lactone and anhydride functional groups and can substantially increase the hydrophilicity of soot.

The increase in the hydrophilicity of soot after photochemical aging is expected to further influence the fate and effects of soot aerosols in the atmosphere: e.g., becoming better cloud condensation nuclei, more easily being involved in aqueous phase chemistry and aging, altering its wet deposition process etc.

Deciphering the molecular formulae

The researchers characterized the evolution of molecular composition during the photoaging of soot by applying laser desorption ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry (LDI FT-ICR MS), an ultrahigh-resolution mass spectrometry technique allowing confident assignment of the molecular formulae. In situ attenuated total internal reflection IR (ATR-IR) was used to investigate the evolution of functional groups during soot oxidation. They find that highly oxygenated organic molecules with high unsaturation (HU-HOMs) are formed through a multigenerational photochemical oxidation pathway, where ketones, aldehydes, and acids are produced by the photooxidation of large polycyclic aromatic hydrocarbons on soot in the initial stage, followed by the formation and accumulation of lactones and anhydrides on further oxidation.

“In this heterogeneous photochemical oxidation, O2 molecules are the initial oxidant, which is further photosensitized to form reactive oxygen species such as singlet oxygen and superoxide anion radicals,” said Meng Li, postdoc in Yafang Cheng’s group and the first author of the study. “Considering the abundance of O2 in the troposphere, this oxidation pathway should be a very important aging process for PAHs and soot particles, especially in clean and remote regions”, added Meng Li.

“This new HU-HOM formation pathway could be a characteristic evolution pathway of primary organic aerosols from various combustions, due to the widespread existence of PAHs there, thus contributing to a more comprehensive understanding of the chemical evolution of organic aerosols”, said Yafang Cheng who leads the Minerva Independent Research Group at the MPIC.

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JOURNAL

Chem

DOI

10.1016/j.chempr.2022.06.011 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Highly Oxygenated Organic Molecules with High Unsaturation Formed upon Photochemical Aging of Soot

Revealing how different parts of mixed convective-stratiform clouds distinctly respond to cloud seeding

Peer-Reviewed Publication

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

 

IMAGE: FIGURE (A) AND (B) SHOW MACRO- AND MICRO-PHYSICAL CHARACTERISTICS OF MIXED CONVECTIVE-STRATIFORM CLOUDS BEFORE AND AFTER CLOUD SEEDING, RESPECTIVELY. THE HIGHER CLOUD TOP IS THE CONVECTIVE REGION, AND THE LOWER CLOUD TOP IS THE STRATIFORM REGION. view more 

CREDIT: DEJUN LI

Cloud seeding is a method of placing condensation nuclei into clouds that induce rain or snowfall. Seeding is a complex process, and its effectiveness depends on the target cloud type. To better understand the mechanisms behind seeding, in a recent study, scientists showed how a connected mixture of both convective and stratiform clouds responds to cloud seeding.

 

Using data from Ka-band cloud profiling radar (KPR) measurements onboard aircraft, along with the remote sensing observations from SNPP and Himawari-8 satellites, members of the Hubei Weather Modification innovation team (HBWM), under the guidance of Prof. Chuanfeng ZHAO from Beijing Normal University (Currently at Peking University), published their findings in Advances in Atmospheric Sciences.

 

“A mixed convective-stratiform cloud is one type of precipitating cloud with complex structure, composed of both cumulus clouds and stratiform clouds.” said the study’s first author, Dejun LI, Chief Expert on Weather Modification in Hubei Province.

 

LI elaborated that the successful launch of NPP in 2011, Himawari-8 in 2014, and the new high-resolution instrument components of KPR developed by satellite scientists at the University of Wyoming in 2014, all make observing the fine structure of cloud properties possible. This study measures the properties of mixed convective-stratiform clouds using KPR onboard aircraft in China for the first time.

 

Based on the KPR measurements before and after seeding, along with multi-source data including satellite observations, researchers now have the ability to analyze the characteristics of icing seeding tracks within the stratiform region and cloud seeding mechanisms in the convective region. This wealth of data gives important clues that help determine the differences in the cloud’s macro- and micro-physical properties.

 

“Few researchers have carried out studies regarding the characteristics and mechanisms of cloud responses to seeding at different parts of clouds.” said Dr. LI. “This is mainly due to the scarcity of observation instruments for cloud macro- and micro- physical properties, the insufficiency of confidence from single source of cloud observations, and so on.”

 

According to corresponding author Prof. ZHAO, the distinct seeding responses of stratiform and convective regions within a stratocumulus cloud are quite different. In the convective region, the cloud top is higher, which is associated with more released heat and stronger convection due to water-ice conversion. This results in both a greater number of and larger precipitation particles.

 

Within the stratiform region, the radar echo becomes weaker near cloud tops, indicating that liquid droplets are converting to ice crystals faster than in the convective region, causing icing seeding tracks to occur.

 

“Now that we have discovered how these mechanisms between the convective and stratiform regions respond to cloud seeding, future studies should further investigate application into mesoscale weather model simulations.” adds Prof. ZHAO.

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JOURNAL

Advances in Atmospheric Sciences

DOI

10.1007/s00376-022-2003-8 

ARTICLE TITLE

Macro- and Micro-physical Characteristics of Different Parts of Mixed Convective-stratiform Clouds and Differences in Their Responses to Seeding

ARTICLE PUBLICATION DATE

23-Jul-2022

Not just fun and games: Federal Hall exhibition explores the Bill of Rights

Business Announcement

NYU TANDON SCHOOL OF ENGINEERING

BROOKLYN, New York, Monday, July 25, 2022 – Visitors to the Federal Hall National Memorial in New York City will encounter an interactive art project comprising games designed to bring elements of the Bill of Rights to life in an exhibition of immersive digital games. The project, “Shall Make, Shall Be: The Bill of Rights at Play,” which opened July 4, 2022 and runs through August 31 at the Federal Hall’s Grand Rotunda. 

The exhibition, commemorating the 230th anniversary of the Bill of Rights through an interactive collection of works, comprises ten commissioned games, each addressing one of the first ten amendments to the U.S. Constitution. It was designed to involve visitors in ways to consider the underpinnings of what it means to be an American by re-framing the documents that serve as the foundation of U.S. political experience with familiar games — puzzles, arcade games, and popular video game genres, among others. 

R. Luke DuBois, Associate Professor and Co-Director of the Integrated Design & Media program at the NYU Tandon School of Engineering, who conceived the project, said the works draw on the document’s effects, interpretations, and legal meanings in U.S. culture.

“The exhibition consists of critical games, using the mechanisms of play to interrogate, critique, and inform our understanding of civil liberties in the 21st Century,” he said. 

The ten artists, game designers, and collectives selected through an open call to produce the games include: arts.codes (Melissa F. Clarke and Margaret Schedel); Peter Bradley; Danielle Isadora Butler; Arnab Chakravarty, Moaw!, and Ian McNeely; Cherisse Datu and Latoya Peterson; Ryan Kuo; Andy Malone; Shawn Pierre, Vi Trinh; and Lexa Walsh. 

The exhibition was organized by DuBois with Laine Nooney, Assistant Professor of Media, Culture, and Communication at the NYU’s Steinhardt School of Culture, Education, & Human Development; and John Sharp, Professor of Games and Learning at Parsons School of Design, with support from the Frank-Ratchye STUDIO for Creative Inquiry and Professor of Electronic Art at Carnegie Mellon University.

“Shall Make, Shall Be: The Bill of Rights at Play” is co-presented at Federal Hall with the National Parks of New York Harbor Conservancy.

 

 

 

About the New York University Tandon School of Engineering

The NYU Tandon School of Engineering dates to 1854, the founding date for both the New York University School of Civil Engineering and Architecture and the Brooklyn Collegiate and Polytechnic Institute. A January 2014 merger created a comprehensive school of education and research in engineering and applied sciences as part of a global university, with close connections to engineering programs at NYU Abu Dhabi and NYU Shanghai. NYU Tandon is rooted in a vibrant tradition of entrepreneurship, intellectual curiosity, and innovative solutions to humanity’s most pressing global challenges. Research at Tandon focuses on vital intersections between communications/IT, cybersecurity, and data science/AI/robotics systems and tools and critical areas of society that they influence, including emerging media, health, sustainability, and urban living. We believe diversity is integral to excellence, and are creating a vibrant, inclusive, and equitable environment for all of our students, faculty and staff. For more information, visit engineering.nyu.edu.

 

 

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When the invasive fish are native

UB study warns about the ecological impact of native species in waters that do not correspond to them

Peer-Reviewed Publication

UNIVERSITY OF BARCELONA

 

IMAGE: THE TRANSLOCATED SPECIES CAN BE AS MUCH OF A PROBLEM FOR BOTH NATIVE FISH AND EXOTIC FISH, ACCORDING TO THE STUDY. view more 

CREDIT: ADOLFO DE SOSTOA (UNIVERSITY OF BARCELONA - IRBIO)

Exotic fish are a threat to river ecosystems, but what happens when invasive species are native to a territory and have been introduced into waters that are not their original territory? A new study carried out by the UB and published in the journal Science of The Total Environment, has analysed the impact the native fish receive from these species, called translocated species, compared to the effects of exotic invasive species, i.e, those that are not native to any basin in the territory.

The conclusions of the study show that the quality of the habitat is the most important factor for the wellbeing of native fish, but the study also points out that translocated species can become as problematic as the exotic ones.

According to the researchers, these results can have implications in the management of rivers, specially in the context of climate change, since species translocation is a common effect of inter-regional water transfers carried out by some countries to mitigate the consequences of global warming.

"What our data suggest is that invasions by translocated native species should be taken at least as seriously as those by exotic species in the systems we studied, i.e. the typical medium-sized Mediterranean streams and rivers", notes Alberto Maceda, researcher at the Biodiversity Research Institute (IRBio) of the University of Barcelona and first author of the article. The study included the participation of Adolfo de Sostoa, researcher at IRBio, and experts Ralph Mac Nally and Jian D.L. Yen, from the University of Melbourne (Australia).

A pioneering study on the effects of translocated species

The researchers studied the characteristics of different fish species in fifteen sites of the basins of the north-eastern Iberian Peninsula, but they focused especially on cyprinid species (Cyprinidae), one with the highest species richness in the world and the most common in Europe.

Specifically, researchers analysed indicators of great ecological relevance, such as the native species diversity, abundance and size distribution of native fish when exposed to invasion by exotic or translocated native species. "Before our study, there were studies that highlighted the problem of mixing populations of Mediterranean and Atlantic trout, and some examples of competition between native and translocated native species, but ours is the first study that has analysed the problem from a broader point of view and has combined different indicators", says Alberto Maceda, lecturer at the Faculty of Biology of the UB.

Negative effects on native fish

The results, in line with previous studies, indicate that habitat quality is essential for the conservation of native species. That is, environmental features, such as temperature, water depth or velocity, pH or nutrient levels, are the variables that best explain the variability in characteristics such as abundance or weight of the analysed native species. However, the main novelty of the study is that, after considerng these environmental variables, the results suggest that the translocated species had potentially greater impacts on native fish than the exotic species, despite the fact that the latter contained some widely recognised exotic species, such as carps (Cyprinus carpio) or bleaks (Alburnus alburnus).

As stated by the authors in the paper, the presence of translocated fish was associated with a lower abundance and richness of native fish and smaller native individuals, while the presence of exotic fish was associated with a higher abundance and richness of native fish and generally larger individuals.

There are still many unanswered questions about translocated species

Given the results, the researchers stress the need to study the ecological impact of translocated native species in greater detail. "It is no good assuming that the impacts of exotic species are worse because they come from outside our borders, as we do not yet have enough information to make such assertions. In fact, we have a great lack of knowledge about the diseases, hybridisation problems, trophic competition, etc. that translocated species can bring", highlights the researcher.

Legislative and river management challenge

The conclusions of this study present a considerable challenge for the current legislation and river management, such as, for example, finding oneself in the situation of having to protect and eradicate the same species depending on the hydrological basin in which it is found. Alberto Maceda notes that “Species are usually declared problem species in a political territory, but we can find that a species is native and has invasive populations in the same political area. To make things worse, we may even find that a species is in decline in its native basin, but it is expanding in basins where it has been previously introduced”.

In this context, the researcher points to habitat conservation as the aspect that managers should focus on the most in order to conserve native fish. "In general terms, we think that action should be taken regarding the habitat conservation, because the benefits have multiple dimensions that, on the rebound, can even make native species better competitors against exotic species", he says.

Despite this general recommendation, Alberto Maceda adds that sometimes an intervention against introduced species can also be a solution, especially if they are translocated natives, because they may have similar habitat requirements to natives. "Rivers with poorly conserved habitats also experience the most biological invasions, and it is often difficult to distinguish between the effects of exotic species and habitat. However, in some cases the main detrimental effect is that of translocated native or exotic species, and therefore acting on them, if a complete eradication is feasible, will certainly be beneficial to the river", he concludes.

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JOURNAL

Science of The Total Environment

DOI

10.1016/j.scitotenv.2022.155953 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

“Patterns of species richness, abundance and individual-size distributions in native stream-fish assemblages invaded by exotic and translocated fishes

 SOLITARY IS TORTURE

Rates of solitary confinement of incarcerated people with mental illness three times higher than those without mental illness

Peer-Reviewed Publication

AMERICAN SOCIETY OF CRIMINOLOGY

Harsh prison conditions, including solitary confinement, affect the mental health of incarcerated people. But few studies have considered how the criminalization of mental health status contributes to harsh treatment in the criminal justice system. A new study examined inequities in the incidence and duration of solitary confinement by mental health status. The study found high rates of punitive isolation among those with serious mental illness, with a three times higher rate of solitary confinement for them than for similar incarcerated people without mental health problems.

The study, by researchers at Boston University, Columbia University, and Harvard University, appears in Criminology, a publication of the American Society of Criminology.

“With people in prison confined to their cells for up to 23 hours a day, often denied visitors and phone calls, solitary confinement is an important test case for studying harsh treatment in prisons,” says Jessica T. Simes, assistant professor of sociology at Boston University, who led the study. “Routinely used as punishment for prison infractions, this type of confinement may be subject to the same forces that criminalize people with mental health problems in community settings.”

Researchers analyzed a large administrative dataset that showed all prison admissions and discharges from 2007 to 2016 in Pennsylvania, whose prison population is demographically similar to the national prison population. The study analyzed data for more than 90,000 individuals.

All those entering Pennsylvania prisons for the first time receive a four-day mental health screening at intake. More than half of the men and 18 percent of the women in the study had no prior history of mental illness. More than half of the women and 21 percent of the men had active diagnoses requiring treatment for mental illness. About 11 percent of the women were diagnosed with serious mental illness or intellectual disability; 2 percent of the men were diagnosed with serious mental illness. Similar to the national average, on an average day, 4 percent of the total Pennsylvania prison population was in solitary confinement.

Researchers looked at a classification that indicates the mental health history and treatment needs of people in prison at their first admission. With data on prison misconduct charges and admissions to solitary confinement that result from a charge, they then modelled solitary confinement through the three stages of receiving a ticket written for a charge of misconduct, being sent to solitary confinement, and being sentenced for a given duration, estimating disparities by mental health status at each stage of the disciplinary process, to determine which stage of prison discipline contributes most to overall disparity.

The study found that people with serious mental illness experienced frequent and lengthy periods of solitary confinement, controlling for crime and misconduct histories. The average person in prison with serious mental illness spent three times longer in solitary confinement than a similar person in prison with no history of mental illness.

In addition, disproportionate solitary confinement resulted mostly from the large number of misconduct tickets written by prison staff to mentally ill people in prison, with most tickets for nonviolent misconduct categories of threats and defiance. This highlights the importance of correctional officers at the first stage of the prison disciplinary process, and it suggests that disparities could be reduced by changing the use of discretion through officer training, policy change, or greater oversight.

The study also found that 64 percent of female prisoners had an ongoing mental health diagnosis, putting them at high risk of punitive isolation in prison.

 “Our results are consistent with a process of cumulative disadvantage operating in prisons in which the stigma of mental illness affects decisions at each stage of the prison discipline process,” explains Bruce Western, professor of sociology and director of the Justice Lab at Columbia University, who coauthored the study. “The mental health disparities we found, combined with evidence that isolation in incarceration exacerbates mental illness, underline the extreme potential for institutional harm associated with solitary confinement, and show how U.S. prisons heap the harshest forms of punishment on the most vulnerable.”

Among the study’s limitations, the authors note that administrative records provide limited portraits of prison conditions and may underestimate incidences of solitary confinement. In addition, the study observed only the mental health category assigned at intake and did not account for changes in mental health status over time. And it assessed incidents of disciplinary confinement, not administrative segregation (the former is used for punishment while the latter is used to separate the vulnerable and control conflicts among people in prison).

            “Although we focused on prisons and the disciplinary process leading to solitary confinement, our findings are relevant to the institutional production of social inequality more generally,” suggests Angela Lee, researcher at Harvard University, who coauthored the study. “Institutionalized power relations—whether in prisons, large corporations, classrooms, the military, or border control facilities—facilitate the effects of stigma and accumulated disparity.”

The study was supported by Arnold Ventures, the Robert Wood Johnson Foundation, the National Science Foundation, the Project on Race, Class, and Cumulative Adversity at Harvard University funded by the Ford Foundation and the Hutchins Family Foundation, the Justice and Poverty Project funded by the Ford Foundation, and the Institute for Social and Economic Research and Policy at Columbia University.

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Summarized from Criminology, Mental Health Disparities in Solitary Confinement by Simes, JT (Boston University), Western, B (Columbia University), and Lee, A (Harvard University). Copyright 2022 The American Society of Criminology. All rights reserved.

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JOURNAL

Criminology