Sunday, June 02, 2024

 

USTC researchers overcome environmental noise to achieve high-fidelity quantum teleportation




UNIVERSITY OF SCIENCE AND TECHNOLOGY OF CHINA
Overcoming noise in quantum teleportation with multipartite hybrid entanglement 

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STAGES OF NOISY QUANTUM TELEPORTATION.

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CREDIT: ZHAO-DI LIU ET AL.




A research team led by Academician GUO Guangcan from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), in collaboration with the research team at the University of Turku, Finland, successfully overcame environmental noise to achieve high-fidelity quantum teleportation by utilizing multipartite hybrid entanglement. Their findings were published in Science Advances on May 1st.

Quantum teleportation serves as a crucial protocol in quantum communication, enabling the remote transmission of unknown quantum states through the utilization of quantum entanglement. However, due to the fragile nature of quantum entanglement, quantum teleportation is highly susceptible to noise. Achieving high-fidelity quantum teleportation in noisy environments has been a pressing challenge.

Previously, to address the decoherence issue of open quantum systems in a noisy environment, the research team devised a comprehensive method for regulating photon polarization and frequency, leveraging sophisticated optical path design and programmable spatial light modulators. This approach enabled them to create a fully controllable phase decoherence quantum simulator and achieve quantum teleportation that surpasses noise, utilizing nonlocal memory effects.

However, nonlocal memory effects require stringent quantum resources such as environmental entanglement, which are not generally attainable. Building on these results, the current work presents a more versatile quantum teleportation technique that effectively mitigates environmental noise.

Employing the fully controllable phase decoherence quantum simulator, the researchers introduced specific phase modulations into the environment to prepare a dual-photon polarization-frequency hybrid entangled initial state. Subsequently, these photons were distributed to two separate user terminals, where each underwent decoherence evolution.

Ultimately, through classical communication, the researchers executed suitable unitary operations on the retrieved quantum bits to restore the transmitted quantum state, achieving a measured fidelity approaching 90%. The polarization states never violated Bell's inequality, indicating quantum teleportation based on hidden quantum nonlocality. This method offers a new way to overcome environmental noise, distinct from conventional techniques such as dynamic decoupling and decoherence-free subspaces, and enhances the understanding of quantum nonlocality.

 

Does recreational marijuana legalization affect a state’s college enrollment?



WILEY




New research has revealed up to a 9% increase in college freshmen enrollments in US states that have legalized recreational marijuana compared with states without such legalization. The study, which is published in Economic Inquiry, found that the increase was from out-of-state enrollments, with early adopter states and public non-research institutions experiencing the most pronounced increases.

Recreational marijuana legalization did not negatively impact degree completion or graduation rate, and it did not affect college prices, quality, or in‐state enrollment.

The findings suggest that some students perceive recreational marijuana legalization as a positive factor that influences their college choice.

“Future research should focus on how this policy impacts peer dynamics and the selection of academic disciplines, with a special emphasis on differentiating between STEM [Science, Technology, Engineering, and Mathematics] and non-STEM fields,” said the study’s author Ahmed El Fatmaoui, MBA, a graduate student at the University of Oklahoma.

URL upon publication: https://onlinelibrary.wiley.com/doi/10.1111/ecin.13225

 

Additional Information
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The information contained in this release is protected by copyright. Please include journal attribution in all coverage. For more information or to obtain a PDF of any study, please contact: Sara Henning-Stout, newsroom@wiley.com.

About the Journal
Published since 1962, Economic Inquiry is a highly regarded scholarly journal in economics publishing articles of general interest across the profession. Quality research that is accessible to a broad range of economists is the primary focus of the journal.

About Wiley
Wiley is a knowledge company and a global leader in research, publishing, and knowledge solutions. Dedicated to the creation and application of knowledge, Wiley serves the world’s researchers, learners, innovators, and leaders, helping them achieve their goals and solve the world's most important challenges. For more than two centuries, Wiley has been delivering on its timeless mission to unlock human potential. Visit us at Wiley.com. Follow us on FacebookTwitterLinkedIn and Instagram.

Is a train’s risk of derailment affected by its length?


WILEY





Longer freight trains are more likely to derail compared with shorter trains, according to new research published in Risk Analysis. The increased risk held even after accounting for the need for fewer trains if more cars were on each train.

For the study, investigators assessed information on US freight train accidents between 2013–2022 from Federal Railroad Administration databases. The team found that running 100-car trains would lead to an 11% higher risk of derailment compared with running 50-car trains, even when accounting for the fact that only half as many 100-car trains would need to run. For 200-car trains, the risk was 24% higher than for 50-car trains.

“Because the Federal Railroad Administration doesn’t collect data on the length of trains that aren’t in accidents, this research involved some innovative modeling that we explain in detail in the paper, but the increased risk of longer trains is clearly shown,” said corresponding author Robin L. Dillon, PhD, of Georgetown University.

URL upon publication: https://onlinelibrary.wiley.com/doi/10.1111/risa.14312

 

Additional Information
NOTE: 
The information contained in this release is protected by copyright. Please include journal attribution in all coverage. For more information or to obtain a PDF of any study, please contact: Sara Henning-Stout, newsroom@wiley.com.

About the Journal
Risk Analysis provides a focal point for new developments in the field of risk analysis publishing critical empirical research and commentaries dealing with risk issues. A wide range of topics covered include human health and safety risks, microbial risks, engineering, mathematical modeling, risk characterization, risk communication, risk management and decision-making, risk perception, acceptability, and ethics, laws and regulatory policy and ecological risks.

About Wiley
Wiley is a knowledge company and a global leader in research, publishing, and knowledge solutions. Dedicated to the creation and application of knowledge, Wiley serves the world’s researchers, learners, innovators, and leaders, helping them achieve their goals and solve the world's most important challenges. For more than two centuries, Wiley has been delivering on its timeless mission to unlock human potential. Visit us at Wiley.com. Follow us on FacebookTwitterLinkedIn and Instagram.

URBAN STUDIES

To what extent are pharmaceutical and illicit drugs contaminating city rivers?



WILEY




In research published in Environmental Toxicology & Chemistry, investigators sampled water from 19 locations across the Hudson and East Rivers in 2021 and 2022 to identify and quantify the prescribed pharmaceuticals and drugs of abuse that are making their way into New York City’s rivers and to determine the source of these pollutants.

Metoprolol and atenolol (blood pressure medications), benzoylecgonine (the main metabolite of cocaine), methamphetamine (a stimulant), and methadone (an opioid) were the most prevalent drugs, present in more than 60% of water samples.

More drugs and higher concentrations were detected in water contaminated by Enterococci (bacteria that live in the intestinal tract) and after rainfall, indicating an impact from sewer overflow. However, the presence of drugs in clean water and during periods of dry weather indicated that wastewater treatment plant discharge may also contribute to the presence of drugs in rivers.

“This study shows how pharmaceuticals and drugs of abuse enter the New York City aquatic environment, highlighting the necessity of improving the current water management system,” said corresponding author Marta Concheiro-Guisan, PharmD, PhD, of the John Jay College of Criminal Justice.

URL upon publication: https://onlinelibrary.wiley.com/doi/10.1002/etc.5891

 

Additional Information
NOTE: 
The information contained in this release is protected by copyright. Please include journal attribution in all coverage. For more information or to obtain a PDF of any study, please contact: Sara Henning-Stout, newsroom@wiley.com.

About the Journal
Environmental Toxicology & Chemistry (ET&C) publishes papers describing original experimental or theoretical work that significantly advances understanding in the area of environmental toxicology, environmental chemistry, and hazard/risk assessment. ET&C is interdisciplinary in scope and integrates the fields of environmental toxicology; environmental, analytical, and molecular chemistry; ecology; physiology; biochemistry; microbiology; genetics; genomics; environmental engineering; chemical, environmental, and biological modeling; epidemiology; and earth sciences.

About Wiley
Wiley is a knowledge company and a global leader in research, publishing, and knowledge solutions. Dedicated to the creation and application of knowledge, Wiley serves the world’s researchers, learners, innovators, and leaders, helping them achieve their goals and solve the world's most important challenges. For more than two centuries, Wiley has been delivering on its timeless mission to unlock human potential. Visit us at Wiley.com. Follow us on FacebookTwitterLinkedIn and Instagram.

Living with risk: Building the future of resilient cities



HIGHER EDUCATION PRESS
Action model for multiple agencies in general planning framework for resilient management of flood disasters in the context of climate change 

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ACTION MODEL FOR MULTIPLE AGENCIES IN GENERAL PLANNING FRAMEWORK FOR RESILIENT MANAGEMENT OF FLOOD DISASTERS IN THE CONTEXT OF CLIMATE CHANGE.
 

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CREDIT: URBAN PLANNING FORUM




The disasters frequently happened these years made the term “resilience” gained increasing attention. Since the end of the 20th century, the way of responding to disaster risks has evolved from disaster prevention to reduction, and now to resilience governance, shifting from the pursuit of “zero risk” to living with risk.

Professor Guofang Zhai currently serves as the Director of the Center for Urban Safety and Development at Nanjing University was interviewed. His main research interests and practice include territorial spatial planning, urban public safety planning, and particularly focuses on the development and evaluation of resilient city construction both in China and abroad.

He highlighted the primary task is to enhance infrastructure resilience. Facing the issue of spatial imbalance of urban resilience, it is essential to give full play to the role of territorial spatial planning, with whole-process, multi-factor, multisystem research on urban resilience as an important reference for planning and design, and take disaster scenario simulation as a crucial technical approach. It is necessary to implement both engineering and non-engineering measures, to increase public awareness of risks and to encourage individual participation into the building of resilient cities. Planners and designers should also have a deeper understanding of the possible disasters and be prepared for emergency responses to disasters that exceed standard defense levels. 

The work entitled “Living With Risk: Building the Future of Resilient Cities” was published on the journal of Landscape Architecture Frontiers (February 15, 2024).

 

Emotional context in decision-making: Challenging Lewin's motivational conflicts theory



THE HEBREW UNIVERSITY OF JERUSALEM




A new study reviewed and challenged Kurt Lewin’s long-standing motivational conflicts theory with new findings that suggest the difficulty of resolving conflicts depends on the emotional context. The study found that avoidance-avoidance conflicts are more challenging in positive and neutral contexts, while no significant difference was found in negative contexts. The results of this study expand our understanding of decision-making conflicts.

A recent series of experiments conducted by PhD student Maya Enisman and Dr. Tali Kleiman from the Psychology department at the Hebrew University of Jerusalem, challenges the longstanding theory of motivational conflict resolution introduced by Kurt Lewin. According to Lewin, conflicts between two undesirable outcomes (avoidance-avoidance conflicts) are typically harder to resolve than those between two desirable ones (approach-approach conflicts).

Lewin posited that avoidance-avoidance conflicts, where individuals must choose between two undesirable outcomes, are typically more challenging to resolve compared to approach-approach conflicts, which involve choosing between two desirable options. In avoidance-avoidance conflicts, the intensity of negative feelings associated with both choices and the difficulty in decision-making often lead to heightened psychological distress. Unlike approach-approach conflicts, where decision-making may involve selecting the option with the most benefits, avoidance-avoidance conflicts require navigating between two undesirable outcomes or finding a compromise to minimize negative consequences.

Maya Enisman and Dr. Tali Kleiman’s  new study, which includes five experiments, argues that the difficulty of resolving these conflicts is not solely the result of the type of conflict, but rather depends on the compatibility between the conflicts and the emotional context in which they occur. The findings suggest that avoidance-avoidance conflicts are notably more challenging in positive affective contexts, but show no significant difference in resolution difficulty from approach-approach conflicts in negative contexts.

The study also introduces a neutral condition to provide a baseline for these effects, contrasting with previous research which did not account for the impact of the affective context. These insights test the boundaries of the accepted wisdom that has prevailed since Lewin’s theory was first proposed in 1931.

The researchers also pointed out the social influence of these conflicts, noting how avoidance-avoidance dilemmas are often depicted in idioms like “between a rock and a hard place,” reflecting the deep-seated nature of such conflicts in human experience. In contrast, approach-approach conflicts are less likely to be expressed in similarly vivid terms, suggesting a social representation that aligns with Lewin’s original findings.

“This study revisits a foundational theory in Social Psychology and opens new pathways for understanding decision-making conflicts under various contextual influences.” stated PhD student Maya Enisman, lead researcher of the study.

Scent detection dogs discern odour molecules better than previously thought


UNIVERSITY OF HELSINKI
scent dog Kössi 

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SCENT DOG KÖSSI

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CREDIT: EGIL BJÖRKMAN




According to a recent study, dogs trained to detect scent may be able to identify significantly lower concentrations of odour molecules than has previously been documented.

A study carried out by the University of Helsinki's DogRisk research group, the University of Eastern Finland and Wise Nose – Scent Discrimination Association in Finland investigated the threshold for scent detection in dogs. 

The study revealed that dogs can learn to identify concentrations of eucalyptus hydrolate that are clearly below the detection threshold of sophisticated analytical instruments used today. The concentrations were also far below previously reported levels. Dogs’ extraordinary sense of smell can be exploited, for example, in search and rescue operations and in medical detection.

The 15 dogs that participated in the study had different training backgrounds. Some dogs had experience of nose work, which is a hobby and competitive dog sport, while some had been trained to identify diseases, mould or pests.

In the study, the dogs were to differentiate samples containing low concentrations of eucalyptus hydrolate from samples containing only water. The focus was on determining the lowest concentration that the dogs could detect for certain. The study included three different tests where the concentrations of the hydrolate were diluted gradually until the dogs could no longer identify the scent.  This determined the threshold for their scent detection ability. 

“The dogs’ scent detection threshold initially varied from 1:10⁴–1:10²³ but narrowed down to 1:10¹⁷–1:10²¹ after a training period. In other words, the dogs needed 1 to 10 molecules per millilitre of water to detect the right sample. For perspective, a single yeast cell contains 42 million molecules,” describes the principal investigator of the study, Anna Hielm-Björkman from the University of Helsinki. 

In addition, the researchers found that there was great variation between the eucalyptus hydrolate products commonly used in nose work. They analysed ten commercial products and detected, for instance, different concentrations of eucalyptol and lower alcohols.

“This explains why many dogs used to commercial eucalyptus hydrolates showed unexpectedly poor results in the study. Their sense of smell is so precise that they did not identify the eucalyptus hydrolate used in the study to be same substance that they were familiar with. This demonstrates the importance of using standardised nose work products in both training and sports competitions,” concludes Visiting Researcher Soile Turunen from the University of Eastern Finland. 

 

Nuclear waste to be scanned before final disposal


The final disposal operations of spent nuclear fuel are being prepared to start next year in Finland as the first place in the world.



UNIVERSITY OF HELSINKI

Cross-section image of a fuel rod 

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THE CROSS-SECTION IMAGE OF A FUEL ROD ASSEMBLY SHOWS INDIVIDUAL RODS, LIKE A HANDFUL OF PENCILS SEEN FROM ABOVE.

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CREDIT: RIINA VIRTA




At Olkiluoto in Eurajoki, preparations are underway to start the disposal of spent nuclear fuel in the Finnish bedrock next year – as the first place in the world.

After use, nuclear fuel becomes strongly radiating and dangerous waste. It contains a large amount of uranium and plutonium, which are building blocks for nuclear weapons. All these materials must be intact when the fuel rods are stored in their final deposit. This is why they must be meticulously and dependably measured before depositing them.

“This way, we can be sure of what is being deposited in the bedrock, and that all nuclear materials will remain in peaceful use,” says visiting researcher Riina Virta at the University of Helsinki.

All the important information must be gathered before the final disposal. The measurements must also be stored in a way that will be accessible and understandable to human beings for thousands, even hundreds and thousands of years.

For her doctoral thesis, Riina Virta has studied measuring methods for nuclear waste at the University of Helsinki in cooperation with the Helsinki Institute of Physics (HIP). Virta also works as an inspector in the nuclear materials safeguards section of the Radiation and Nuclear Safety Authority.

Gamma camera sees inside assembly

In her thesis work, Riina Virta developed a PGET device, i.e. an imaging method called passive gamma emission tomography, which measures the gamma radiation emitted by spent nuclear fuel. Nuclear fuel consists of rods, a few metres long and containing uranium, which are gathered into an assembly to act as a fuel element. The PGET instrument can produce an exact cross-section image of the fuel assembly.

The cross-section image allows us to check that the assembly still retains all the rods. The challenging thing with this method is that the fuel dampens the radiation very efficiently.

“In practice, the radiation from the middle of the assembly just barely reaches the detector, i.e. the ‘camera’. We wanted to fix this problem in our research.”

The image quality was improved e.g. by developing the collection of data and using that data more wisely. The method was also developed so that the instrument can be used, not just in water, but in air, as well. This makes it adaptable to the Finnish plants taking care of the final disposal. The research also developed software tools to make the operative application of the method easier.

The performance of the method was proven with the help of an extensive library of field measurements carried out in Finnish nuclear power plants.

“This means the method has been studied in detail and found to work well, and now we are just waiting for the operations of final disposal to start in Olkiluoto,” says Virta.

M.Sc.(Tech.) Riina Virta will defend her doctoral dissertation “Gamma tomography of spent nuclear fuel for geological repository safeguards” on 4 June 2024 at 12 noon at the Faculty of Science at the University of Helsinki. The public examination will be held at Physicum E204, Gustaf Hällströmin katu 2. More details on the dissertation.

More information

 

Riina Virta

riina.virta@stuk.fi

+358 50 4713 550

Final information of disposed spent nuclear fuel with Finnish methods

 

Traditional characteristics of Meiyu-Baiu disappeared due to global warming



SCIENCE CHINA PRESS

Traditional Meiyu shaped the unique Orient. 

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FIGURE 1. CONCEPTUAL FRAMEWORK OF HOW THE TRADITIONAL MEIYU HAS SHAPED THE UNIQUE ORIENT FOR MORE THAN A THOUSAND YEARS. THE MOST IMPORTANT SOCIOECONOMIC ASPECTS IN THE YANGTZE RIVER BASIN ARE AGROECOSYSTEM, CULTURE, AND ARCHITECTURE. THE ARROWS INDICATE THE CONNECTIONS BETWEEN THE DIFFERENT ASPECTS, AND THE ROUNDED ARROWS INDICATE INCREASES IN PARAMETERS.

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CREDIT: ©SCIENCE CHINA PRESS




During early summer, a unique and far-reaching meteorological phenomenon occurs in China’s Yangtze River Basin and the main islands of Japan, known as Meiyu in China and Baiu in Japan. Traditional Meiyu-Baiu with significantly misty features has a long course in Asian history and has shaped the unique Orient civilization over thousands of years (Figure 1).

Although the traditional Meiyu-Baiu is closely linked to moldy damage, its continuous and gentle rain moistens the paddy rice at the jointing and booting stage. Meanwhile, the warm and moist conditions also promote the growth of organisms and algae in lakes and rivers, which provide an abundance of food to fisheries. Hence, the Meiyu region is often called “the land of fish and rice” (Figure 1). In addition, rain like thin smoke and fog has shaped the behavioral traits of local inhabitants to be more sensitive, implicit, and elegant. The beauty of the traditional Meiyu became a frequently used literary image. Numerous oriental poems, ink-and-wash paintings, and historical documents have consistently expressed feelings about “misty rains” (Figure 2), which can date back to at least the Jin Dynasty (265–420 AD).

However, in recent decades, both the Meiyu and Baiu have seldom exhibited their traditional misty features. But owing to the lack of quantitative metrics applicable to misty rains, there is still no consensus on whether the traditional Meiyu-Baiu has been declining significantly. Although there have been studies on the detection and attribution of extreme Meiyu events (rainstorms or heatwaves), traditional Meiyu is not an extreme event, and the existing conclusion cannot be directly transferred to its changes. There is no robust understanding of whether and to what extent the changes in the traditional Meiyu-Baiu can be attributed to global warming.

Professors Huijun Wang and Zhicong Yin et al constructed a three-dimensional deviation degree of misty rain (D2MR) for the first time, and found that the D2MR showed a significant upward trend both in Meiyu and Baiu region (Figure 3). This indicates that Meiyu-Baiu in East Asia has gradually lost its traditional characteristics of misty rain, especially in the Meiyu region.

82.5% (75.2-87.2%) and 81.1% (42.6-96.1%) of the D2MR trend in the Meiyu and Baiu regions, respectively, can be attributed to human activities, in which greenhouse gas forcing is the main factor, while the influence of aerosols is relatively insignificant. In a warmer future, the Meiyu-Baiu will continue to further away from its traditional characteristics and enter the "new normal".

The authors, from the Center for Climate System Prediction Research (CCSP), further state that: (1) Human activity is much more active than in ancient times. Whether the suspension of the traditional misty rain is enough to promote and how it will promote the change of human social civilization in East Asia is still worthy of further discussion. (2) The ecosystem, energy system, and transportation network in East Asia may suffer huge losses due to the inability to adapt to the rapid transformation of Meiyu-Baiu to its extreme state, which requires the integration of more disciplines and government departments to tackle and respond.


Distinctively euphemistic poetry and ink-and-wash painting inspired by Meiyu. 

Figure 2. Ancient Chinese poetry with Meiyu as cultural image or theme, and Misty Rain in Suzhou Western Hill (西山雨观图 in Chinese) drawn by Zhou Shen in ~1487 AD of the Ming Dynasty, now is collected by The Palace Museum


Changes of Meiyu-Baiu features.

See the article:

Traditional Meiyu-Baiu has been suspended by global warming

https://doi.org/10.1093/nsr/nwae166