PALEONTOLOGY

New insights into the evolution and paleoecology of mosasaurs: most comprehensive study to date

Iconic extinct marine lizards continue to surprise us

Utrecht University

 

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Sarabosaurus dahli life reconstruction

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Credit: Andrey Atuchin

Mosasaurs are extinct marine lizards, spectacular examples of which were first discovered in 1766 near Maastricht in the Netherlands, fueling the rise of the field of vertebrate palaeontology (the study of fossil remains of animals with backbones). Palaeontologist Michael Polcyn presented the most comprehensive study to date on the early evolution and ecology of these extinct marine reptiles. On 16 December, Polcyn will receive his PhD from Utrecht University for his research into the evolution of the mosasaurs. "Mosasaurs are a textbook example of macroevolution, the emergence of new and distinct groups of animals, above the level of species. Although they have been studied for centuries, new discoveries, novel research approaches, and the application of technology, are still teaching us about their relationships and behaviors, some of which continues to surprise us. For example, through the use of detailed comparative anatomy aided by micro-CT scanning technology, we have gained a much better understanding of what group of lizards mosasaurs likely evolved from.”

Additionally, use of these advanced imaging technologies has allowed him to study the internal structures of the braincases of mosasaurs, and sort out the early evolutionary relationships of some previously problematic fossil taxa. “This study not only addressed the early evolution of the group, but also explored small- and large-scale aspects of their feeding biology,” Polcyn continued. “One spectacular example was a specimen I discovered in Angola, that had the remains of three other mosasaurs in its stomach, one of which was the same taxon as the predator, and documented the first occurrence of cannibalism in mosasaurs."

To the sea

Mosasaurs belong to a group of lizards that took to the sea about 100 million years ago (just like the ancestors of the whales later did). Throughout their 34-million-year history, they evolved into well-adapted marine animals that occupied a wide variety of niches and habitats. Together with a large number of other species, they became extinct 66 million years ago, in the aftermath of the meteorite impact that also wiped out the dinosaurs. "A relatively large number of fossils are known from the second half of the evolutionary history of mosasaurs, allowing a good understanding of the relationships among those species, which have been classified into four major groups," says Polcyn. “Much less is known about their early evolutionary history, and how those major groups are related to one another, their origins, and the origin of mosasaurs as a whole.” To address these gaps, Polcyn has focused on bringing new discoveries to light and restudying historical specimens with advanced imaging technologies, providing significant new anatomical information that is used to infer phylogenetic relationships. Polcyn’s work helps resolve a long-running scientific debate, concluding mosasaurs are not very closely related to snakes, but supporting the idea that their closest relatives are near the monitor lizards.

You are what you eat

Not much was previously known about the feeding habits of mosasaurs either, but a small, yet no less remarkable gap in that knowledge was filled with the discovery, by Polcyn in Angola, of a fossilized mosasaur with three other mosasaurs in its stomach, one being the same species as the predator. "Whether that mosasaur was a scavenger or actively hunted its prey cannot be said with certainty; however, we do have the first documented example of cannibalism in mosasaurs. Additionally, we gained insights into how mosasaurs processed their prey, and relative body size of prey and predator." Also included in his dissertation is a large-scale study of the feeding behaviour of mosasaurs, looking at how mosasaurs divided their foraging areas through the evolutionary history of the group. Polcyn integrated previously published data, along with a new, very large sample that covered a period from 92 to 66 million years ago and included finds from all over the world. The result of that study illuminate patterns of foraging area segregation, and feeding diversity in mosasaurs.

About

Polcyn's entry into palaeontology followed a non-traditional academic path. After serving in the U.S. submarine service and a career in technology and engineering, he devoted himself to research on extinct vertebrates, with a focus on marine reptiles. He is currently a Senior Research Fellow at ISEM at Southern Methodist University in Dallas, Texas.

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Method of Research

Meta-analysis

Subject of Research

Animals

A new species of flying reptiles reshuffles the timeline of pterosaur evolution

Staatliche Naturwissenschaftliche Sammlungen Bayerns

 

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Reconstruction of Melkamter pateko

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Credit: Palaeo-Artist: Pedro Andrade

About 230 million years ago, almost 80 million years before the first bird appeared, their distantly related cousins, the pterosaurs took to the sky, as the first group of active fliers among the vertebrates. Pterosaurs developed active, flapping flight with the help of a wing membrane, which was mainly spanned by the strongly elongated fourth finger of the hand.

In the course of their evolution, the flight capabilities of pterosaurs were improved. Whereas most early forms had still rather short wings and a long tail, the derived subgroup of pterodactyloids had slender, elongate wings and a shortened tail. These animals included basically all Cretaceous pterosaurs and the largest flying animals ever, such as Quetzalcoatlus, which reached wingspans of 12 m or more.The transition from the basal forms to the pterodactyloids happened during the Jurassic, and the first representatives of this group appear in the fossil record in the Late Jurassic, some 160 million years ago. However, our knowledge of pterosaur evolution in the Jurassic is based almost exclusively on the fossil record of the Northern Hemisphere, as very few fossils are known from the southern continents.

Alexandra Fernandes and Prof. Oliver Rauhut of the Bavarian State Collection for Paleontology and Geology (SNSB - Bayerische Staatssammlung für Paläontologie and Geologie) have now introduced a new species of pterosaur from the late Early Jurassic (some 178 million years ago) of Chubut province, Argentina. The new species, named Melkamter pateko, shows several characters of the advanced pterodactyloids – but is around 15 million years older than its next-oldest known relative. Apparently, the origin of this group of pterosaurs reaches much further back in time than currently recognized.

The location of Melkamter's find is also remarkable. The new species comes from an inland setting - apparently this pterosaur lived far from the nearest seacoast. Most known Jurassic pterosaurs come from marine environments and obviously lived close to the sea and probably mainly fed on fish and other marine organisms. In contrast, Melkamter probably mainly fed on insects. This occurrence in inland environments and preference for non-aquatic prey supports recent suggestions that pterodactyloids might have originated in such environments.

„It is possible that an early specialization in highly mobile prey such as flying insects contributed to the evolutionary success of the pterodactyloids. This find highlights not only how little we still know about the pterosaurs of the Southern Hemisphere, but also the potential that the southern continents have to improve our understanding of pterosaur evolution”, explains Alexandra Fernandes reseacher at the Bavarian State Collection for Paleontology and Geology and first author of the study. The study was recently published in the scientific journal Royal Society Open Science.

 

Location of Melkamter pateko (right) in the Argentine province of Chubut

Credit

Oliver Rauhut

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Journal

Royal Society Open Science

DOI

10.1098/rsos.241238 

Subject of Research

Animals

Article Title

The oldest monofenestratan pterosaur from the Queso Rallado locality (Cañadón Asfalto Formation, Toarcian) of Chubut Province, Patagonia, Argentina

Article Publication Date

11-Dec-2024

 

Sleepers made from recycled plastic could make railways even more eco-friendly

Railway sleepers produced from selected recycled plastics are just as strong and could save thousands of tons of emissions and, shows study

Frontiers

Railways, the most climate-friendly mode of transport bar long-distance buses, are bound to play an important role in the fight for net zero. The total emissions of railway travel are currently 31 grams of CO2 equivalents (CO2e) per passenger kilometer, half the amount as for the most economical electrical vehicles.

But the carbon emissions of railway traffic can be further reduced, shows a new study in Frontiers in Sustainability by authors in Finland. This is because typical construction materials such as steel and concrete are energetically costly to produce, transport, handle, and maintain. Even on the busiest train lines, these costs amount to 30% of total emissions, and this percentage increases sharply as the traffic volume decreases.

“Here we show that recycled plastics could be used as the material for railway sleepers and that overall emissions would be reduced. A smaller carbon footprint is achieved when currently incinerated waste streams are used as material,” said Dr Heikki Luomala, the study’s first author and a project manager at Tampere University.

“We estimate that the CO2 reduction by repulping the available waste stream in Finland could amount to the heating emissions of 1,200 households, that is 3,610 tCO2e (tons of CO2 equivalents) per year.”

Two types of plastic tested

Luomala and colleagues studied the feasibility and GHG emission savings resulting from gradually phasing out the wooden and concrete railway sleepers in Finland and replacing them with recycled plastic. The lifespan of a sleeper is between 10 to 60 years and decreases with increasing traffic intensity, due to mechanical damage.

An important source of plastic waste is the packaging sector, which uses up approximately 40% of the total plastic production. Within this industry, so-called liquid packaging board (LPB) – a mix of polyethylene, polypropylene, ethylene vinyl alcohol, and polyethylene terephthalate – is the fastest growing product. Another important source of plastic waste is electronic and electrical equipment, accounting for approximately 6% of total plastic usage. Its main plastic component is acrylonitrile butadiene styrene (ABS).

In the past, plastic waste was often exported from Finland to the Far East, but in recent years the ‘ALL-IN for Plastics Recycling’ (PLASTin) initiative was launched to make Finland a leader in plastic recycling.

Luomala et al. produced specimens of railway sleepers (0.15m thick, 0.25m wide, and 2.6m long) made from LPB and ABS and subjected these to a battery of mechanical tests. Their intent was to test if the prototypes confirmed to international standards for the plastic and railway industries.

Implementation in the real world is on track

Specimens made from both types of plastic passed the strength and bending tests. But only recycled ABS was able to withstand the maximum tested temperature of 55°C without significant softening during hot summers.

“Recycled ABS is much more suitable as railway sleeper material than recycled LPB: the strength and stiffness properties of ABS are approximately three times higher and closer to that of wooden sleepers,” said Luomala.

Plastic railway sleepers offer several advantages, for example easy formability, low cost, light weight, and resistance to environmental conditions. The use of recycled plastic also allows greater design flexibility for sleeper shape.

The Finnish Transport Infrastructure Agency has already shown interest in the study’s findings.

“When it comes to the implementation of recycled ABS for use as railway sleepers, further tests should first be conducted at full scale. Their long-term behavior, for example in terms like UV resistance, should also be tested,” warned Luomala.

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Journal

Frontiers in Sustainability

DOI

10.3389/frsus.2024.1460159 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Reducing the carbon footprint of railway sleepers using recycled plastics

Article Publication Date

12-Dec-2024

  

A new, more economical and sustainable material is designed that uses sunlight to decontaminate the air

University of Córdoba

 

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Image of the research team that carried out the work

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Credit: University of Córdoba

Nitrogen oxides (NOx) are a group of gases formed by nitric oxide and nitrogen dioxide. They are produced, above all, by the burning of fossil fuels. Due to their harmful effects on human health and the environment, in recent years they have been in the scientific community's crosshairs. A research team at the Chemical Institute for Energy and the Environment (IQUEMA), attached to the University of Cordoba, has developed a photocatalytic material capable of effectively reducing these gases, achieving results similar to others developed to date, but through a more economical and sustainable process.

Photocatalysis, or how light can decontaminate cities

There are chemical reactions that can be favored or accelerated in the presence of light. In the case of nitrogen oxides, light energy, in the presence of a material that functions as a catalyst, makes it possible to oxidize the nitrogen oxides in the atmosphere and convert them into nitrates and nitrites.

The first author of this research paper, Laura Marín, explained that, unlike other photocatalytic reactions, which only operate under ultraviolet light, this new material boasts the advantage of working effectively with visible light, which is much more abundant and makes up most of the solar spectrum, allowing greater use to be made of the sun's energy. 

To do this, the research team has synthesized a new compound by combining two different types of materials: carbon nitride (which allows the reaction to be activated in the presence of visible light) and lamellar double hydroxides, which have the capacity to catalyze the reaction, in addition to featuring economical and easily scalable production. 

Professor Ivana Pavlovic, one of the researchers who participated in the study, explained that the new process is capable of converting 65% of nitrogen oxides under visible light irradiation, a percentage very similar to that achieved by other photocatalysts, but with the advantage that this new system uses minerals such as magnesium and aluminum, which are "cheaper, abundant in nature, and benign, compared to other photocatalysts used to date, which contain cadmium, lead or graphene," the researcher pointed out.

Professor of Inorganic Chemistry and IQUEMA Director Luis Sánchez explained that, in this way, the work represents an important step towards the large-scale development of a system that makes it possible to decontaminate the air under real-world conditions, thus reducing one of the most common pollutant gases in cities, and one whose long-term effects can cause serious health problems.
 

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Journal

Advanced Sustainable Systems

DOI

10.1002/adsu.202400496 

Article Title

The Efficient Coupling between MgAlTi Layered Double Hydroxides and Graphitic Carbon Nitride Boosts Vis Light-Assisted Photocatalytic NOx Removal

Deep-sea hydrothermal vent bacteria hold key to understanding nitrous oxide reduction

Peer-Reviewed Publication

Hokkaido University

 

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Nitrosophilus labii HRV44T is a thermophilic chemolithoautotroph isolated from a deep-sea hydrothermal vent in the Okinawa Trough, Japan. It grows using hydrogen as an electron donor and N2O as an electron acceptor. (Photo by Muneyuki Fukushi, Hokkaido University)

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Credit: Muneyuki Fukushi

Scientists unearth a clue to the molecular mechanisms involved in N2O reduction by deep-sea hydrothermal vent bacteria.

Nitrous oxide (N2O) is the third most potent greenhouse gas after carbon dioxide and methane. It can also be oxidized by physical processes to form ozone-depleting substances. Atmospheric concentrations of N2O have increased since the preindustrial era, making N2O reduction a global challenge.

The only known biological sink of N2O in the biosphere is microbial denitrification. Denitrification is a series of reduction reactions starting with nitrate and ending with the reduction of N2O to nitrogen gas, with no greenhouse effect. This reaction is unique to microorganisms possessing N2O reductase (N2OR; NosZ), highlighting the importance of identifying the molecular mechanisms mediating high N2O reduction activity. 

Researchers at Hokkaido University, in collaboration with colleagues at the Institute of Physical and Chemical Research (RIKEN) and the University of Washington, investigated the molecular mechanisms underlying N2O reduction of a microbial species, Nitrosophilus labii HRV44T, which had been discovered by Hokkaido University researchers in 2020, from a deep-sea hydrothermal vent. The team recently published their results in the journal iScience.

The research team developed a method that enabled them to analyze time-series gene expression at a genome-wide level, called the transcriptome, using RNA extracted from very few cells.

“Time series transcriptomic analysis of HRV44T in response to N2O was more challenging than expected,” said corresponding author Sayaka Mino, Assistant Professor at the Faculty of Fisheries Sciences, Hokkaido University. “We have performed transcriptomic analysis using methods often used in microbial studies, but we failed to capture the gene expression dynamics over short time scales because we could not get enough RNA from just a few cells. The method demonstrated in the current study requires only 1 ng of messenger RNA (mRNA), making it useful for analysis at low cell densities, from which RNA extraction is difficult.”

The time series transcriptomic profiling of HRV44T demonstrated that N2O is not a critical inducer of denitrification gene expression, including nos genes, which are expressed under anaerobic conditions even in the absence of nitrogen oxides as electron acceptors.

“We hypothesize that this feature may contribute to efficient energy metabolisms in deep-sea hydrothermal environments where alternative electron acceptors are occasionally depleted”, said Robert M. Morris, Associate Professor at the University of Washington.

Jiro Tsuchiya, the first author and a JSPS research fellow DC2 at Hokkaido University, and colleagues conducted a statistical analysis of time series data. “Our findings suggest that the denitrification gene nosZ is negatively regulated by transcriptional regulators that typically function as transcriptional activators in response to environmental changes. Although we still need to investigate this result, our study extends the understanding of the regulatory mechanisms controlling gene expression in N2O-reducers and may help increase their ability to respire N2O”, said Tsuchiya.

Deep-sea hydrothermal environments have steep chemical and physical gradients, making them hotspots for bioresources. This study demonstrates the potential for microorganisms in these environments to contribute to N2O mitigations that may help combat climate change. Search for microbial resources with high greenhouse gas reduction efficiency, optimization of their abilities, and elucidation of molecular mechanisms specific to these microorganisms will contribute to developing technologies for environmental remediation by microorganisms.

Strain HRV44T rapidly respires N2O, forming bubbles at the gas-liquid interface. (Photo by Jiro Tsuchiya, Hokkaido University)

Credit

Jiro Tsuchiya

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Journal

iScience

DOI

10.1016/j.isci.2024.111074 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Time course transcriptomic profiling suggests Crp/Fnr transcriptional regulation of nosZ gene in a N2O-reducing thermophile

Porous crystals detect nitric oxide

Ultrasensitive detection of NO using a conductive 2D metal–organic framework

Wiley

Detection of nitric oxide (NO) is important for monitoring air quality because the NO released in the combustion of fossil fuels contributes to acid rain and smog. In medicine, NO is an important messenger molecule and serves as a biomarker for asthma. In the journal Angewandte Chemie, a research team now reports a material that can detect NO reversibly, with low power, and with high sensitivity and selectivity: a copper-containing, electrically conducting, two-dimensional metal–organic framework.

Metal–organic frameworks (MOFs) are latticelike structures consisting of metal “nodes” connected by organic bridges (ligands). An emerging class of MOFs are electrically conducting structures consisting of layers. These 2D-cMOFs have demonstrated great potential as chemiresistive sensors that react to the presence of specific molecules with a change to their electrical resistance, which may allow for particularly sensitive and low-power detection of toxic gases. Problems with such systems have included cross-reactivity with a variety of gases and limited reusability due to irreversible binding of the analytes.

Katherine A. Mirica, Christopher H. Hendon, and their team at Dartmouth College (Hanover, NH, USA), the University of Oregon (Eugene, OR/USA), and Ulsan National Institute of Science and Technology (South Korea), have now developed a reusable 2D-cMOF for the highly selective detection of NO. They chose to use a 2D-cMOF based on copper and hexaiminobenzene, Cu3(HIB)2. Thanks to their different synthetic strategy (the linker was added as an undissolved powder to a solution of Cu2+ ions and potassium acetate), the team produced a material with significantly higher crystallinity (rod-shaped crystallites about 500 nm in length) than has previously been attained.

The crystallites consist of stacked layers of a weblike structure of six-membered rings linked together by copper ions bound to their nitrogen atoms. Spectrometric analyses and computations revealed that the binding sites for NO were Cu-bis(iminobenzosemiquinone) units of the copper-2D-cMOFs. An analogous compound made with nickel instead of copper demonstrated no significant absorption of NO. Evidently, copper ions with a single positive charge, which are present in small amounts in the structure besides those with a twofold positive charge, play an important role in binding NO. Computational studies suggest that the adsorbed NO significantly distorts the structure, destabilizing the bound state, which is the primary cause for the desirable reversibility of the NO adsorption.

This new sensor material detects NO at room temperature and low voltage (0.1 V) with high sensitivity (detection limit about 1.8 ppb) and could be reused for at least seven cycles without regeneration. Quantitative measurements of NO were also successful in the presence of moisture, and showed high enhancement of sensor signal towards NO in comparison to other gases, such as nitrogen dioxide, hydrogen sulfide, sulfur dioxide, ammonia, and carbon monoxide and dioxide.

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About the Author

Dr. Katherine A. Mirica is an Associate Professor of Chemistry at Dartmouth College. Her main research direction focuses on the development of multifunctional porous materials capable for sensing, filtration, and detoxification of hazardous chemicals.

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Journal

Angewandte Chemie International Edition

DOI

10.1002/anie.202419869 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Reversible and Ultrasensitive Detection of Nitric Oxide Using a Conductive Two-Dimensional Metal–Organic Framework

DEI

Diversity and inclusion accelerate the pace of innovation in robotics

Max Planck Institute for Intelligent Systems

 

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The authors of the study (from left to right): Alex Fratzl, Daniela Macari, Ksenia Keplinger, Christoph Keplinger (MPI-IS, W. Scheible)

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Credit: MPI-IS, W. Scheible

Stuttgart – The field of robotics is highly interdisciplinary, encompassing disciplines such as mechanical and electrical engineering, materials science, computer science, neuroscience and biology. The robotics community in itself is a champion of academic diversity. If this academic diversity is paired with workforce diversity – incorporating members of different ethnicities, genders, socioeconomic statuses, ages, life experiences, parental statuses or disabilities – and inclusive leadership, it drives even more disruptive innovation and creativity in the sciences. Hence, promoting diversity and inclusion within research teams is not merely a moral imperative; it is a catalyst for facilitating cutting-edge research and accelerating progress in the field of robotics.

Drawing from literature, a comprehensive citation analysis, and expert interviews, a team of roboticists and behavioral scientists from the Max Planck Institute for Intelligent Systems in Stuttgart and colleagues derive seven main benefits of workforce diversity and inclusive leadership for robotics research. On December 11, 2024, the team published a viewpoint article in Science Robotics which outlines these benefits and additionally serves as a leadership guide to fellow roboticists who wish to accelerate the pace of innovation within their own teams.

“In this article, we highlight existing scientific literature, analyze citation metrics of robotics papers over the past 25 years, reflect on our personal experiences and observations from working in a diverse and inclusive environment, and share insights from interviews with ten established research leaders in robotics”, says Daniela Macari, who is a doctoral researcher in the Robotic Materials Department at MPI-IS and first author of the article.

The authors identified seven main benefits of diverse and inclusive teams:

1. Analyses of publications across various fields show that diverse teams publish a higher number of papers and have more citations per paper. The now published analysis of robotics papers over 25 years reveals that publications with at least 25% women authors receive significantly more citations and are more likely to rank among the most cited.
2. Diverse teams are better equipped to tackle complex and multifaceted issues from multiple angles, using a broader pool of methods and considering a wider array of potential solutions.
3. Having a diverse team composition sparks unconventional ideas, ultimately driving disruptive innovation and breakthroughs in robotics.
4. Scientific discoveries made by diverse teams are more likely to address the needs of a wider segment of society, resulting in technologies with greater societal relevance.
5. Research teams that reflect the diversity of robotic technology users are better at identifying and mitigating biases in technology and are more likely to consider ethical implications from multiple perspectives.
6. Promoting diversity and inclusive leadership enhances employee satisfaction and helps attract and retain talented researchers, thus keeping academic organizations at the forefront of innovation.
7. Ensuring diverse representation in robotics research not only addresses historical imbalances and systemic inequities but also promotes fairness and equal opportunity for all—regardless of their background and based on their individual potential to advance robotic technology for the benefit of humanity.

If robotics teams around the world embrace a diverse and inclusive environment and foster a sense of belonging and psychological safety, they may achieve higher levels of motivation and commitment to their work, resulting in increased productivity, more disruptive innovation, and maybe even most importantly – less bias in technology.

“Moreover, fostering such an environment, embracing diversity and inclusion within their teams, offers leaders the opportunity to grow into more effective and impactful leaders”, says Dr. Ksenia Keplinger, leader of the research group Organizational Leadership and Diversity at MPI-IS.

“Leading diverse and inclusive research teams challenges us to understand different perspectives and backgrounds, to customize our mentorship style to different group members, and to even adapt our research agendas to embrace new research thrusts aligned with team members’ skills and interests. While this requires constant effort and commitment, it yields long-term benefits in productivity and disruptive innovation for our teams”, adds Prof. Christoph Keplinger, Director of the Robotic Materials Department at MPI-IS.

The leadership guide the authors propose includes measures such as broadening recruitment pools, fostering a culture of inclusion, ensuring wide accessibility to resources, providing role models, and strengthening mentorship and allyship, among others.

  

Team diversity paired with inclusive leadership facilitates cutting-edge research and drives broad applicability.

Credit

MPI-IS

Reference:

Daniela Macari*, Alex Fratzl, Ksenia Keplinger*, Christoph Keplinger*: Accelerating the pace of innovation in robotics by fostering diversity and inclusive leadership. Science Robotics [Vol 9, Issue 97], 11 December 2024, DOI: 10.1126/scirobotics.adt1958

*Corresponding authors

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Journal

Science Robotics

DOI

10.1126/scirobotics.adt1958 

Method of Research

Literature review

Subject of Research

Not applicable

Article Title

Accelerating the pace of innovation in robotics by fostering diversity and inclusive leadership

Article Publication Date

11-Dec-2024