A cost-efficient and equitable facility location problem for public service

Beijing Zhongke Journal Publising Co. Ltd.

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The mathematical model is easy to understand, effective in application, relatively simple to solve, and outperforms the existing equitable location approaches. This model can also be easily extended for other planning scenarios. Image credit: the authors.

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Credit: Beijing Zhongke Journal Publising Co. Ltd.

This study is led by Dr. Yunfeng Kong from the Faculty of Geographical Science and Engineering at Henan University. Dr. Kong and his team are dedicated to geospatial optimization research, focusing on mathematical models, intelligent algorithms, and applications for vehicle routing, facility location planning, and geographic districting. One of their latest research contributions, the Cost-Efficient and Equitable Facility Location Problem (CEEFLP), provides spatially equitable solutions for public service planning.

Delivering quality services in a cost-efficient and equitable manner is critical to the general public. However, according to Dr. Kong, balancing facility costs, travel efficiency, and spatial equity in location planning remains both theoretically and practically challenging. Existing equitable location models are often highly complex, conflict with travel convenience, and/or are computationally intractable.

Dr. Kong and his graduate students proposed a novel location problem to balance travel efficiency and spatial equity in 2023 and extended the model to include facility cost in 2024. “Theoretically, the CEEFLP is a three-objective optimization problem that minimizes facility cost, travel distance, and spatial inequity. We simplified the problem into a bi-objective optimization by combining travel distance and the spatial inequity indicator. Furthermore, we solved the problem by converting the cost objective into a cost constraint,” said Dr. Kong

The effectiveness of the CEEFLP was tested using four well-known benchmark instances, five author-generated instances and five real-world urban and rural instances. Their experimental results demonstrate that the proposed model effectively balances facility cost, travel cost, and spatial equality in site-selection of facilities. Two key findings emerge from the Pareto-optimal solutions: Increasing the facility cost budget can simultaneously reduce travel costs and improve spatial equality. Once the facility cost budget is determined, all spatial equality indicators can be improved with only a slight increase in mean travel distance. 

The authors claim that the CEEFLP is easy to understand, effective in application, relatively simple to solve, and outperforms the existing equitable location approaches, making it a valuable tool for public service planning applications.

 

 

In the six location planning outcomes, each cross symbol represents the location of a service facility, and the colored polygon surrounding the facility represents its service area. Outcome (e) presents the most cost-efficient and equitable solution. Image credit: the authors.

Credit

Beijing Zhongke Journal Publising Co. Ltd.

See the article:

A cost-efficient and equitable facility location problem for public service: Model, algorithm, and benchmark analysis.

https://doi.org/10.12082/dqxxkx.2025.250035

https://www.sciengine.com/JGIS/doi/10.12082/dqxxkx.2025.250035（If you want to see the English version of the full text, please click on the 科大讯飞翻译(iFLYTEK Translation)  in the article page.）

 

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DOI

10.12082/dqxxkx.2025.250035 

Article Title

A Cost-Efficient and Equitable Facility Location Problem for Public Service Planning

Article Publication Date

25-May-2025

 

Chimpanzees use medicinal leaves to perform first aid

Scientists observed chimpanzees in Uganda apparently cleaning and treating their own and others’ wounds

Frontiers

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Social grooming between two chimpanzees in the Budongo Forest. Photograph by Dr Elodie Freymann.

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Credit: Dr Elodie Freymann

Scientists studying chimpanzees in Budongo Forest, Uganda, have observed that these primates don’t just treat their own injuries, but care for others, too — information which could shed light on how our ancestors first began treating wounds and using medicines. Although chimpanzees elsewhere have been observed helping other community members with medical problems, the persistent presence of this behavior in Budongo could suggest that medical care among chimpanzees is much more widespread than we realized, and not confined to care for close relatives.  

“Our research helps illuminate the evolutionary roots of human medicine and healthcare systems,” said Dr Elodie Freymann of the University of Oxford, first author of the article in Frontiers in Ecology and Evolution. “By documenting how chimpanzees identify and utilize medicinal plants and provide care to others, we gain insight into the cognitive and social foundations of human healthcare behaviors.” 

Community care 

The scientists studied two communities of chimpanzees in the Budongo Forest — Sonso and Waibira. Like all chimpanzees, members of these communities are vulnerable to injuries, whether caused by fights, accidents, or snares set by humans. About 40% of all individuals in Sonso have been seen with snare injuries. 

The researchers spent four months observing each community, as well as drawing on video evidence from the Great Ape Dictionary database, logbooks containing decades of observational data, and a survey of other scientists who had witnessed chimpanzees treating illness or injury. Any plants chimpanzees were seen using for external care were identified; several turned out to have chemical properties which could improve wound healing and relevant traditional medicine uses. 

During their direct observational periods, the scientists recorded 12 injuries in Sonso, all of which were likely caused by within-group conflicts. In Waibira, five chimpanzees were injured — one female by a snare, and four males in fights. The researchers also identified more cases of care in Sonso than in Waibira. 

“This likely stems from several factors, including possible differences in social hierarchy stability or greater observation opportunities in the more thoroughly habituated Sonso community,” said Freymann. 

The roots of modern medicine? 

The researchers documented 41 cases of care overall: seven cases of care for others — prosocial care — and 34 cases of self-care. These cases often included several different care behaviors, which might be treating different aspects of a wound, or might reflect a chimpanzee’s personal preferences.  

“Chimpanzee wound care encompasses several techniques: direct wound licking, which removes debris and potentially applies antimicrobial compounds in saliva; finger licking followed by wound pressing; leaf-dabbing; and chewing plant materials and applying them directly to wounds,” said Freymann. “All chimpanzees mentioned in our tables showed recovery from wounds, though of course we don’t know what the outcome would have been had they not done anything about their injuries.  

“We also documented hygiene behaviors, including the cleaning of genitals with leaves after mating and wiping the anus with leaves after defecation — practices that may help prevent infections.”  

Who cares? 

Of the seven instances of prosocial care, the researchers found four cases of wound treatment, two cases of snare removal assistance, and one case where a chimpanzee helped another with hygiene. Care wasn’t preferentially given by, or provided to, one sex or age group. On four occasions, care was given to genetically unrelated individuals.  

“These behaviors add to the evidence from other sites that chimpanzees appear to recognize need or suffering in others and take deliberate action to alleviate it, even when there's no direct genetic advantage,” said Freymann. 

The scientists call for more research into the social and ecological contexts in which care takes place, and which individuals give and receive care. One possibility is that the high risk of injury and death which Budongo chimpanzees all face from snares could increase the likelihood that these chimpanzees care for each other’s wounds, but we need more data to explore this.  

“Our study has a few methodological limitations,” cautioned Freymann. “The difference in habituation between the Sonso and Waibira communities creates an observation bias, particularly for rare behaviors like prosocial healthcare. While we documented plants used in healthcare contexts, further pharmacological analyses are needed to confirm their specific medicinal properties and efficacy. Also, the relative rarity of prosocial healthcare makes it challenging to identify patterns regarding when and why such care is provided or withheld. These limitations highlight directions for future research in this emerging field.” 

A young chimpanzee cares for a wound on his knee [VIDEO] | 

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Journal

Frontiers in Ecology and Evolution

DOI

10.3389/fevo.2025.1540922 

Method of Research

Observational study

Subject of Research

Animals

Article Title

Self-Directed and Prosocial Wound Care, Snare Removal, and Hygiene Behaviors Amongst the Budongo Chimpanzees

Article Publication Date

14-May-2025

 

New marine-biodegradable polymer decomposes by 92% in one year, rivals nylon in strength

A strong yet biodegradable alternative to nylon: development of polyester-amide material that decomposes in marine environments while retaining high mechanical strength

National Research Council of Science & Technology

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Research results on Eco-friendly polyesteramide (PEA) materials with excellent mechanical properties and outstanding biodegradability in marine environments

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Credit: Korea Research Institute of Chemical Technology(KRICT)

Nylon-based products such as clothing and fishing nets are notoriously slow to degrade, especially in marine environments, contributing significantly to global ocean pollution. A Korean research team has now developed an innovative material that can be produced using existing manufacturing infrastructure and effectively addresses this problem.

A joint research team led by Dr. Hyun-Yeol Jeon and Dr. Hyo-Jeong Kim at the Korea Research Institute of Chemical Technology (KRICT), Senior Researcher Sung-Bae Park, Professor Dong-Yeop Oh at Inha University, and Professor Je-Young Park at Sogang University has developed a high-performance polyester-amide (PEA) polymer that decomposes by over 92% in one year under real marine conditions, while maintaining strength and flexibility comparable to nylon. This material is not only scalable and recyclable but also applicable to a wide range of uses such as textiles, fishing nets, and food packaging.

Unlike conventional biodegradable plastics that suffer from low durability and heat resistance, the PEA polymer combines ester (for biodegradability) and amide (for toughness) linkages in an optimal ratio. This design offers both high degradability and mechanical durability.

Traditionally, the synthesis of polymers with both ester and amide groups required toxic organic solvents. However, the team developed a new two-step melt polymerization process that eliminates the need for solvents and enables industrial-scale production (up to 4 kg) in a 10-liter reactor. Importantly, this method is compatible with existing polyester manufacturing facilities with only minor modifications, enhancing its industrial scalability.

Marine biodegradability tests conducted off the coast of Pohang showed that the new PEA achieved up to 92.1% degradation within one year—significantly outperforming existing biodegradable plastics such as PLA (0.1%), PBS (35.9%), and PBAT (21.1%). Even more complete biodegradation occurs under composting conditions, where microbial populations are higher.

The tensile strength of the PEA reached up to 110 MPa, surpassing that of nylon 6 and PET. In practical experiments, a single PEA fiber strand was able to lift a 10 kg object without breaking. When woven into fabrics, it also withstood ironing at 150°C, confirming its high thermal resistance.

In addition to performance, sustainability was a key focus of the research. The PEA was synthesized using long-chain dicarboxylic acids derived from castor oil (a non-edible crop), and caprolactam derivatives recovered from recycled nylon 6 waste. This upcycling approach reduced CO₂ emissions to just one-third that of conventional nylon 6—lowering emissions from 8–11 kg CO₂eq/kg to 2.3–2.6 kg CO₂eq/kg.

The team is currently evaluating the material for commercialization, with expectations for industrial adoption within two years.

Dr. Sungbae Park stated, “The key achievement is that this material overcomes the limitations of conventional biodegradable plastics while offering nylon-level performance.” KRICT President Young-Kuk Lee added, “This technology marks a pivotal step toward the commercialization of biodegradable engineering plastics and will significantly contribute to solving the global marine plastic pollution crisis.”

This research was published as a cover article in the March 2025 issue of Advanced Materials (IF: 27.4). Dr. Sungbae Park and postdoctoral researcher Hojung Kwak are co-first authors, and Drs. Jeon and Kim (KRICT), Prof. Oh (Inha University), and Prof. Park (Sogang University) are corresponding authors.

  

Evaluation of Ironing behavior and mechanical properties of melt-spun fibers for eco-friendly apparel and industrial applications

Credit

Korea Research Institute of Chemical Technology(KRICT)

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KRICT is a non-profit research institute funded by the Korean government. Since its foundation in 1976, KRICT has played a leading role in advancing national chemical technologies in the fields of chemistry, material science, environmental science, and chemical engineering. Now, KRICT is moving forward to become a globally leading research institute tackling the most challenging issues in the field of Chemistry and Engineering and will continue to fulfill its role in developing chemical technologies that benefit the entire world and contribute to maintaining a healthy planet. More detailed information on KRICT can be found at https://www.krict.re.kr/eng/

The study was conducted with support from KRICT’s basic research fund and the Ministry of Trade, Industry and Energy, and the Ministry of Agriculture, Food and Rural Affairs.

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Journal

Advanced Materials

DOI

10.1002/adma.202417266 

Article Title

Development of Marine-Degradable Poly(Ester Amide)s with Strong, Up-Scalable, and Up-Cyclable Performance

BLACK CARBON CONTRAILS

Onion-like nanoparticles found in aircraft exhaust

Revealed by high-resolution transmission electron microscopy

National Institute for Environmental Studies

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(a) Turbostratic (soot) particles (diameter 67 nm). (b) Onion-like particles (diameter 17 nm). (c) Amorphous particles (diameter 26 nm). (d) Trace amorphous particles (diameter 17 nm). The four particle types were divided into single and agglomerated particles, and their fractions are shown.

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Credit: NIES/ZHAW/TMU

1. Background and purpose of the study

Aircraft emit nanoparticles (<50 nm Note 1 in diameter) into the atmosphere, from the ground to the upper troposphere. Studies in Europe, the U.S., and Japan have reported high concentrations of particles in and around airports Ref 1, and there is worldwide concern regarding the effects on human health. The atmospheric heating effects by contrails generated from aircraft exhaust particles are also known, and research is being conducted to assess their potential impacts on climate. Particle number emissions from turbofan jet engines, which are commonly used in civil aviation, are generally dominated by volatile particles (sulfate or organics) rather than non-volatile particles (mostly soot). However, the emission and formation mechanisms of the volatile particles are not well understood. Our research team investigated the physicochemical properties of aircraft exhaust nanoparticles (volatile and non-volatile) to obtain information on the emission and formation mechanisms of volatile particles.

 

2. Methods

We measured the morphology and internal (microphysical) structure of exhaust particles at the engine exit and 15 m downstream of commercial turbofan jet engines at a test facility in Zurich Airport, Switzerland. The morphology and internal structure of the particles were observed by high-resolution transmission electron microscopy (HRTEM) using bulk particulate samples collected on thin films.

 

3. Results and discussion

Four types of aircraft engine exhaust particles with different internal structures were observed (Fig. 1). Type (a) represented turbostratic particles with scattering-layered graphene-like structures Note 2 and were considered typical for soot (non-volatile particles). Type (b) consisted of onion-like particles with partial graphite-like structures, which are well-ordered graphene-like spherical multilayers. Type (c) particles were amorphous (non-crystalline), and type (d) were trace amorphous particles (images are thin and non-crystalline). Before this study, onion-like particles were not identified in the combustion exhaust or atmosphere. Although graphitic soot with the turbostratic structure emitted from aircraft has been studied for many years, three other types of particles were identified for the first time in this study.

 

The number fraction of turbostratic (soot) particles was high at the engine exit and lower than 1% at 15 m downstream (Fig. 1). Fifteen meters downstream, the remaining fraction was dominated by onion-like, amorphous, and trace amorphous particles. These three types of particles were mostly single (non-agglomerated, Note 3) spherical particles with diameters of 10–20 nm. Further analysis suggested that these three types of particles are volatile particles formed via nucleation and condensation downstream of the engine and mainly consist of organic compounds originating from the lubrication oil.

 

4. Outlook

These unique internal structures may affect the physicochemical properties of the particles, including volatility, surface reactivity, and solubility, and potentially affect the interaction of the particles with the human respiratory tract. Our research team found that aircraft emit onion-like, amorphous, and trace amorphous particles in addition to soot particles. However, there are many questions regarding the physicochemical characteristics, origin, and formation mechanism of onion-like particles, and whether they are similar in nature to soot or volatile organic particles, such as oil mist. The onion-like particles may have different dynamics in the atmosphere and in the body compared with other particles; therefore, further research is needed to understand their climate and health implications.

 

In the field of nanomaterials, onion-like particles are synthesized by applying high energy to soot, among other methods. The formation mechanism of onion-like particles from aircraft engines is scientifically interesting and has potential implications in materials and other fields.

 

5. Annotations

Note 1. nm: Nanometer. One nanometer is one-millionth of a millimeter (mm). Particle diameter (size) of 50 nm is about 1/1000th the size of cedar pollen (about 30 μm in diameter). One micrometer is 1/1000th of a millimeter.

 

Note 2. Graphene: A thin sheet of material with a crystalline structure of carbon atoms linked together in a hexagonal shape.

 

Note 3. Agglomeration: Adhesion and coalescence of particles to form large aggregates. Soot particles produced by incomplete combustion often form large agglomerates that are shaped like grape bunches.

 

Ref 1．Fushimi, A.; Saitoh, K.; Fujitani, Y.; Takegawa, N. Identification of jet lubrication oil as a major component of aircraft exhaust nanoparticles. Atmos. Chem. Phys. 2019, 19, 6389−6399.

https://doi.org/10.5194/acp-19-6389-2019 (Connect to an external site)

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Journal

ACS ES&T Air

DOI

10.1021/acsestair.4c00309 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Unique Microphysical Structures of Ultrafine Particles Emitted from Turbofan Jet Engines

Echidna microbiome changes while mums nurse puggle

University of Adelaide

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Microbial communities in echidna pseudo-pouches undergo dramatic changes while the animal is lactating, says the University of Adelaide's Isabella Rose Wilson.

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Credit: Ken Hurley

Research from the University of Adelaide shows microbial communities in echidna pseudo-pouches undergo dramatic changes while the animal is lactating, which could help in creating an environment for their young, known as puggles, to thrive.

Echidnas are monotremes, which are the only mammals that lay eggs. The early developmental stage at which they hatch from their egg means that the puggles lack a functioning immune system.

“We know the reproductive microbiome is important to infant health, including for humans, but little is known about how it functions in egg-laying monotremes,” says the University of Adelaide’s Isabella Wilson, whose study was published in FEMS Microbiology Ecology.

“Instead of picking up vaginal microbiota during delivery like other mammals, echidnas are shielded by the eggshell and don’t come into direct contact with the cloaca.”

The first few weeks of life are critical for puggles, as they hatch at an early developmental stage. They continue to grow in the pseudo-pouch, which is created from the contraction of abdominal muscles and disappears when a female is not nursing.

“We investigated changes in the echidna pseudo-pouch microbiota during different stages of the reproductive cycle and found that during lactation pseudo-pouch microbial communities show significant differences in composition compared with samples taken outside of breeding season or during courtship and mating,” Wilson says.

“This suggests that the echidna pseudo-pouch environment changes during lactation to accommodate young that lack a functional adaptive immune system.”

The way puggles suckle may contribute to the shift in microbes.

“Another unique aspect of echidna biology is that they lack nipples. Instead of suckling like other species, the puggle rubs its beak against a part of the pseudo-pouch called the milk patch, causing milk to come out of the skin, sort of like a sweat or oil gland,” says Wilson.

“We think that compounds within the milk and from the skin probably contribute to the changes we see in the pseudo-pouch microbiota during lactation.”

Echidnas are commonly held in zoos in Australia and around the world. Previous work from the same research group showed big differences in the gut microbiome between echidnas in zoos and in the wild.

“We were surprised to find no major difference in the pseudo-pouch between zoo-managed and wild animals, which suggests to us that the milk, rather than external environmental factors like captivity, is what primarily shapes the bacterial landscape of the pseudo-pouch,” Wilson says.

“For conservation in the wild, and in breeding programs, we need to learn more about the bacteria found in echidna pseudo-pouches and better understand how these affect echidna health.”

 

An echidna puggle.

Credit

Peggy Rismiller and Michael McKelvey

The University of Adelaide and the University of South Australia are joining forces to become Australia’s new major university – Adelaide University. Building on the strengths, legacies and resources of two leading universities, Adelaide University will deliver globally relevant research at scale, innovative, industry-informed teaching and an outstanding student experience. Adelaide University will open its doors in January 2026. Find out more on the Adelaide University website.

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DOI

10.1093/femsec/fiaf036