The Mountain Institute

Hybrid metal‐dielectric metasurfaces, exhibiting bound states in the continuum (BICs), support high‐quality factor resonances and electric field confinement due to their ability to restrain radiation loss. However, the dynamic transformation between quasi‐BICs and BICs in hybrid nanostructures by symmetry breaking in a multiplicity of ways remains a significant challenge. Herein, a novel humidity‐modulated strategy is demonstrated, which regulates the dynamic transition from quasi‐BICs to BICs based on the symmetry‐breaking in geometry and permittivity for the hybrid photonic‐plasmonic asymmetric gratings (HPAG), which consists of two alternating dielectric gratings deposited on an aluminum oxide and gold film. The regulatory mechanism involves the humidity‐sensitive polyvinyl alcohol, which undergoes volume expansion and refractive index reduction as the relative humidity (RH) increases. Its Q‐factor of a quasi‐BIC in HPAG reached up to 873, primarily due to the breaking of out‐of‐plane symmetry. The HPAG can be used for humidity sensing with a sensitivity of up to 2.63/RH. Moreover, the humidity‐modulated strategy is proven to be suitable for similar nanostructures (e.g., cylinder dimers, tetrameric cubes, and loop antennae). The results indicate that the humidity‐modulated strategy is a promising approach for regulating optical characteristics and is applied in micro/nanophotonic devices, such as humidity sensors, and active components.

Agriculture is central to sustainable development both from provisioning and pressure perspectives. It is hence imperative to measure its diverse outcomes, for which various global indicator systems have been developed. Yet, these come with trade‐offs, for example, between comparability among countries versus specificity to national context. This poses the question how relevant generic indicators are for national stakeholders and how specific information requirements can be integrated within a globally comparable assessment. Herein, we present the co‐evaluation of an existing system of global agricultural sustainability indicators with national stakeholders from agricultural practice, research and education, public administration, private sector, and NGOs in Austria, representing an expert community. Focusing on the relevance of the indicators and the requirements for complementary metrics, we found that particularly social themes and related indicators were highly specific to the national context, followed by economic and environmental aspects. Co‐interpretation of selected indicator trajectories showed that drivers and interactions were highly complex and may change over time, emphasizing also the importance of complementary contextual information. Yet, availability of data to measure indicators proposed by stakeholders remains a key limitation to the adaptation of the indicator system. We outline two options for improving the relevance of the global indicator system: (a) substituting less relevant indicators or (b) introducing a second tier covering regionally important aspects. To explore which of the two options is most appropriate across geographies and whether unified approaches to such a regionalization are indeed feasible, we propose to include the co‐creation of regionalized indicator frameworks in future iterations across agriculturally diverse countries.

Photodetectors with tunable polarization sensitivity play a significant role in decoding signals in optical communications, extracting polarization‐encrypted information, and the environmental monitoring of polarization variations. Metasurfaces are widely used in polarized photodetectors, while the responses for different polarization incidences follow a determinable and consistent correspondence. In this paper, an electrically tunable polarization photodetector composed of MoTe2 and gold metasurface is proposed for on‐chip polarization‐sensitive near‐infrared (900–1200 nm) detection. Through contact engineering and electro‐tuning, highly‐tunable Schottky barriers are achieved. This enables the modulation of photoelectric conversion via the excitation of surface plasmon polaritons, which in turn allows for continuous adjustment on the degree of linear polarization of a settled metasurface ranging from 0.2 to an ultimate value of 1.0. The results outline a paradigm to achieve a polarization‐dependent electrically tunable response, which is promising for on‐chip information processing in integrated optics.

Climate change among other biogeophysical and socioeconomic stressors affects livelihoods of poor farmers and pastoralists in the Pamir Mountains of Tajikistan. Here, women play an important role in agriculture despite facing challenges related to land ownership, child rearing, spousal migration, water management, lack of training, and exposure to natural hazards. Climate change exacerbates these challenges but is not constant nor well documented in this region. Women manage most of the 1.3 million kitchen gardens and some small dehkan farms scattered across the terrain, many of which are in confined valleys on debris fans that represent some of the only relatively flat land. These fans are highly vulnerable to periodic debris flows and snow avalanches with all 30 fans with farms in the lower Gunt River valley (below 3000 m) populated. While temperatures in the Pamir have increased from May through July since 1950, precipitation is more complex with some increases in June. These patterns affect hazard occurrence and water availability creating challenges for woman farmers and begging the need for granular climate assessments. Given little government support for woman farmers along with the male-dominated agricultural and water management sectors, international donors and NGOs need to increasingly support rural women as agents of climate change adaptation and mitigation by providing science-based solutions and effective training.

A holographic tensor metasurface (HTM) is proposed to independently manipulate both the co‐polarized and cross‐polarized holograms while avoiding crosstalk between the two different channels. A complementary metal‐oxide semiconductor (CMOS) chip operating in the millimeter‐wave band is employed to excite the HTM. The CMOS chip consists of a sub‐harmonic mixer and a power amplifier, and a transition based on coaxial and microstrip lines is designed to connect the chip with a planar feed. By integrating the CMOS chip with the proposed HTM, a novel imaging system is established, which converts intermediate frequency (IF) signals into radio frequency (RF) signals for multi‐channel holographic imaging. Different from conventional spatial‐wave illuminated metasurfaces, the proposed surface‐wave illuminated HTM fed by a planar monopole antenna eliminates the misalignment error between the horn feeding and metasurface. The chip‐integrated millimeter‐wave imaging system is experimentally validated. With the advantages of low cost, low profile, and planar integration, the proposed framework may boost the commercialization of metasurface‐based portable holographic imaging systems.

This paper presents a novel consensus Gaussian mixture probability hypothesis density (GM-PHD) filter to enhance state estimation accuracy for time-varying targets using multiple sensors. The consensus GM-PHD, which relies on the modified Bayesian Consensus Filter (BCF) with the logarithmic opinion pool, is employed to fuse local intensities and achieve the consensus intensity after BCF iterations. Rigorous theoretical proofs are given to guarantee the consistency of the BCF iterations. To alleviate the computational burden, a sampling-based method is further proposed which only updates the particle weights during BCF iterations. Subsequently, particles are resampled based on their weights and then the Expectation-Maximum algorithm reconstructs the Gaussian Mixture Model utilized in the GM-PHD filter from the resampled samples. Simulations involving linear and nonlinear target systems demonstrate the superior performance of the proposed approach in multi-target tracking accuracy compared to existing methods.

We use a magnetron sputtering system to grow a tantalum film on a sapphire substrate with a niobium buffer layer at room temperature. The tantalum film is in α-phase, which is preferred for superconducting quantum devices. We fabricate a superconducting heavy fluxonium qubit with this niobium-buffered tantalum film, which demonstrates good performance. Forbidden transitions and sideband transition phenomena between specific energy levels are observed. Due to the specific design parameters, the fluxonium described herein exhibits high anharmonicity while maintaining a long decoherence time in the higher energy states, making it well-suited for use as a qudit and enabling high-dimensional quantum computation. With further optimization of the film deposition process, superconducting qubits other than fluxoniums with higher performance are expected to be obtained using these multilayer films grown at room temperature.

Mercury is a highly toxic trace metal that readily biomagnifies in food webs where it is inaccessible to current bioremediation methods. Animals could potentially be engineered to detoxify mercury within their food webs to clean up impacted ecosystems. We demonstrate that invertebrate (Drosophila melanogaster) and vertebrate (Danio rerio) animal models can express organomercurial lyase (MerB) and mercuric reductase (MerA) from Escherichia coli to demethylate methylmercury and remove it from their biomass as volatile elemental mercury. The engineered animals accumulated less than half as much mercury relative to their wild-type counterparts, and a higher proportion of mercury in their tissue was in the form of less bioavailable inorganic mercury. Furthermore, the engineered animals could tolerate higher exposures to methylmercury compared to controls. These findings demonstrate the potential of using engineered animals for bioremediation and may be applied to reduce the burden of methylmercury in impacted ecosystems by disrupting its biomagnification or to treat contaminated organic waste streams.

Existing integration of radar detection and communication (IDAC) systems are in general based on multi‐input multi‐output multi‐stations or single‐base transceiver splitting. However, these methods are challenging to realise IDAC for integrated receive‐transmit half‐duplex (IRTHD) pulse radars, which are detection‐centric and are based on self‐transmission and self‐reception systems. The majority of recent studies in the field of IDAC for IRTHD pulse radars have focused on utilising time‐division approaches to avoid conflicts, thereby also creating competition for radar time resources. In this paper, a pointer scheduling algorithm based on Tabu search (PS‐TS) is proposed for IRTHD pulse radars, which solves the challenge of simultaneous efficient detection and communication. Firstly, the study presents a model for radar device‐to‐device (D2D) opportunistic communication and proposes a framework for pulse interleaving based on pointer scheduling to realise IDAC. Secondly, the PS‐TS algorithm employs a Tabu search strategy to maintain high‐quality solutions to avoid local optima and introduces a tolerance factor to maximise the communication success rate (CSR) with the minimal time expenditure. Simulation results indicate that the PS‐TS algorithm outperforms the genetic algorithm and particle swarm optimisation in terms of robustness, CSR, and computational efficiency, providing real‐time scheduling for IDAC systems.

Gas chromatography‐ion mobility spectrometry (GC–IMS) technology boasts several salient features, including fast detection, portability, simple sample preparation, and nondestructive detection, making it a highly appealing tool in tea research. By harnessing its prowess in detecting and analyzing volatile compounds present in tea, GC–IMS has found numerous applications within the broad realm of tea studies. These applications encompass discerning geographical origins, analyzing aroma profiles, classifying tea grades, distinguishing harvest seasons, monitoring aroma variations during processing, and storage, differentiating tea varieties and categories. In the current study, the development history and performance characteristics of GC–IMS technology are presented. Furthermore, the relevant research studies of the application of GC–IMS in tea field are summarized, highlighting its practical applications and impacts. Additionally, the promotion strategies and improvement methods for enhancing of GC–IMS in the qualitative analysis of volatile compounds are put forward. Looking ahead, the potential avenues for the application of GC–IMS in tea quality control, online monitoring of tea manufacturing, detection of tea adulteration, and tea storage environment management are proposed. The versatility and precision of GC–IMS make it a promising technology that can to some extent change the tea industry's understanding and assurance of product quality.

A novel short-term time series forecasting scheme based on evolutionary interpolation of Chebyshev polynomials is presented in this paper. The uniqueness of the proposed scheme lies in the higher density of Chebyshev nodes at the ends of the interpolation interval. Thus, the structural representation of the algebraic interpolant closer to the present moment of time becomes more accurate compared to the older Chebyshev nodes. The internal smoothing scheme is used to find a balance between the ability of the algebraic interpolant to reflect the local dynamics and to suppress the unwanted effects outside the interpolation interval. Evolutionary optimization algorithms are used to define near-optimal corrections of nodal values of the time series. The proposed nonlinear mapping scheme used on the last elements of an equally spaced time series enables a more accurate extrapolation of the soft algebraic interpolant. To our knowledge, this is the first attempt to employ non-uniform Chebyshev nodes for the prediction of an equally spaced time series. Computational experiments with several standard time series are used to demonstrate the efficacy and the accuracy of the proposed one-step-ahead forecasting scheme.

Importance There is a need for additional treatment options for people with type 2 diabetes treated with insulin. Given the limited data on the use of automated insulin delivery (AID) systems in type 2 diabetes, studies evaluating their safety and efficacy are important. Objective To evaluate the association of AID with hemoglobin A 1c (HbA 1c ) levels in a diverse cohort of adults with type 2 diabetes. Design, Setting, and Participants This single-arm prospective trial was conducted at 21 clinical centers in the United States among individuals aged 18 to 75 years with type 2 diabetes who had been using insulin for at least 3 months prior to screening. Participants with AID system use were excluded. The study started with a 14-day standard therapy phase, followed by 13 weeks of treatment with the investigational device. The first participant was enrolled April 11, 2023, and the last participant follow-up visit was February 29, 2024. Intervention Participants used the Omnipod 5 AID System for 13 weeks following the 14-day standard therapy phase. Main Outcomes and Measures Primary outcome was change in HbA 1c level at 13 weeks, tested sequentially for noninferiority (0.3% margin) and superiority, compared with baseline. Results Among 305 participants (mean [SD] age, 57 [11] years; 175 [57%] female; 72 [24%] Black, 66 [22%] Hispanic or Latino, and 153 [50%] White), 289 (95%) completed the trial. At baseline, 223 (73%) were using multiple daily injections, 63 (21%) were using basal insulin without bolus, 17 (6%) were using an insulin pump, 188 (62%) were using continuous glucose monitoring, 168 (55%) were using glucagon-like peptide-1 receptor agonists (GLP-1RAs), and 134 (44%) were using sodium-glucose transport protein 2 inhibitors (SGLT-2is). Following AID use, HbA 1c levels decreased from a mean (SD) of 8.2% (1.3) at baseline to 7.4% (0.9) at 13 weeks (mean difference, −0.8 [95% CI, −1.0 to −0.7] percentage points; P < .001 for noninferiority and superiority). Improvement was seen across various subgroups (age, sex, race and ethnicity, insurance), and notably with or without use of GLP-1RAs or SGLT-2is and regardless of pretrial mealtime insulin regimen. Time in target glucose range (70-180 mg/dL) increased from a mean (SD) of 45% (25) to 66% (17) (mean difference, 20 [95% CI, 18 to 22] percentage points; P < .001). Percentage of time in hypoglycemic ranges of less than 54 mg/dL and less than 70 mg/dL was noninferior compared with standard therapy. There was 1 episode of severe hypoglycemia and none of diabetic ketoacidosis or hyperosmolar hyperglycemic syndrome. Conclusions and Relevance In this nonrandomized clinical trial, HbA 1c levels were lower in a diverse cohort of adults with type 2 diabetes following AID initiation, suggesting that AID may be a beneficial and safe option for people with type 2 diabetes using insulin. Trial Registration ClinicalTrials.gov Identifier: NCT05815342

Water is a valuable resource for rice production, which is an integral component of food security in East Africa (EA). Rice farming is expanding in the region, with up to 90% produced on smallholder farms using traditional flooding and rain-fed methods, vulnerable to climate change and variability. Despite EA's enormous agricultural and crop potential, the region largely depends on rice imports (> 500,000 tons annually) from Asia due to rising gaps between production and consumption. Sustainable water management practices, including alternate wetting and drying (AWD), system of rice intensification (SRI), and drip irrigation are critical for paddy and upland rice production although practiced at micro-research levels with limited adoption of such technologies by smallholder farmers. Herein, we synthesize key information on smallholder irrigation agriculture development and implications for food security in changing climates in the four EA countries (Uganda, Kenya, Tanzania and Ethiopia), based on scientific literature and reports. Several studies indicate water scarcity is a major threat to rice production, while poverty and food insecurity are linked to low agricultural productivity. Although rice production has increased since 2000 because of the slight expansion of irrigation, yields are still low due to insufficient irrigation development, climate change, and variability and poor agronomic practices. Nonetheless, climate-smart water management technologies such as AWD, SRI, and drip irrigation are less used by paddy and upland rice smallholder farmers for several reasons including limited awareness, funding, and technical knowledge. Therefore, commitments of government sectors, NGOs, farmer-based organizations, and private sectors with clear policies are needed to enhance technology transfer, action research, farmer training, and innovation development. These actions are vital to promote knowledge generation and the adoption of technologies to improve water management for increased rice yields, livelihoods, and food security in changing climates.

As modern systems widely deploy protective measures for control data in memory, such as Control-Flow Integrity (CFI), attackers’ ability to manipulate control data is greatly restricted. Consequently, attackers are turning to opportunities to manipulate non-control data in memory (known as Data-Oriented Attacks, or DOAs), which have been proven to pose significant security threats to memory. However, existing techniques to mitigate DOAs often introduce significant overhead due to the indiscriminate protection of a large range of data objects. To address this challenge, this paper adopts a Cyberspace Mimic Defense (CMD) strategy, a generic framework for addressing endogenous security vulnerabilities, to prevent attackers from executing DOAs using known or unknown security flaws. Specifically, we introduce a formalized expression algorithm that assesses whether DOA attackers can construct inputs to exploit vulnerability points. Building on this, we devise a key-area CMD strategy that modifies the coded pathway from input to the vulnerability point, thereby effectively thwarting the activation of the vulnerability. Finally, our experiments on real-world applications and simulation demonstrate that the key-area CMD strategy can effectively prevent DOAs by selectively diversifying parts of the program code.

Introduction The ‘Fengtangli’ plum (Prunus salicina Lindl.) is favoured by consumers for its characteristic flavor. The purpose of this study was to explore the characteristics of volatile flavor compounds in ‘Fengtangli’ plum. Methods The flavor compounds of both ‘Fengtangli’ and ‘Siyueli’ plums were analyzed using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOF MS). Results The results revealed the presence of 495 volatile flavor compounds in ‘Fengtangli’ plum and 466 in ‘Siyueli’ plum. The relative concentrations of hydrocarbons, alcohols, ketones, and esters in ‘Fengtangli’ plum were significantly elevated compared to those detected in ‘Siyueli’ plum. Moreover, the sensorial attributes of sweetness, citrus, herbal, floral, and fruity notes were more prominent in ‘Fengtangli’ plum relative to those of ‘Siyueli’ plum. Through the integration of differential metabolite analysis and relative odor activity assessment, it is hypothesized that furan-2-pentyl; (E)-2-octenal; and 1-octen-3-one may represent the characteristic of volatile flavor compounds in ‘Fengtangli’ plum. Discussion The research results may provide a theoretical reference for the development and application of ‘Fengtangli’ plum and the study of the synthesis mechanism of characteristic flavor compounds.

Efforts to restore Peru's megadiverse Andean Forests are rapidly growing. While ecological determinants for restoration success are well known, knowledge on the socio‐economic and governance conditions that allow for the success of ecological restoration using native species is scarce. Using a multi‐stakeholder approach, this paper analyses the motivations, preferences, success factors and governance models for effective ecological restoration of Andean Forests, through 75 semi‐structured interviews with local community members, NGOs and government actors in 11 restoration sites in Peru. We find that across sites and stakeholder groups, the primary motivations for Andean Forest restoration were tied to restoring and improving hydrological resources. Stakeholders valued Andean Forests mostly for their provisioning ecosystem services—with water provision valued by all stakeholders and firewood provision predominantly by communities—followed by regulating services (water retention and climate regulation). Restoration success—the degree of perceived achievement of project objectives—was high at all sites and scored between 2.4 and 3 out of 3. Enabling factors for the restoration success were mostly social and institutional. There was no ‘silver bullet’ to successful restoration; rather, enabling factors included high resource dependence of communities, support from NGOs, participatory management and governance, and the creation of communal conservation agreements. Communities emphasized primarily social and institutional limiting factors, while government stakeholders emphasized technical challenges. We further identified three typologies of how projects engage and compensate communities: a ‘payment model’, a ‘capacity model’ and a ‘mixed model’ which differ in their rentability, longevity and socio‐economic benefits provided. All stakeholder groups favoured active forest restoration and community members identified desirable native plant species with local use and hydrological value. Interviewees also highlighted that restoration needs to go beyond forests, and combine native tree planting, agroforestry, restoration of mountain grasslands and peatlands to holistically improve water resources and long‐term economic benefits at a landscape scale. Synthesis and applications. Andean Forest restoration projects need to consider hydrological ecosystem services in all key restoration stages. Communities need to be involved through participatory processes and receive long‐lasting benefits—both ecosystem services and livelihood incentives—to guarantee long‐term project success. Read the free Plain Language Summary for this article on the Journal blog.

Radio and optical signals are two different carriers with their own distinctive features, and their efficient conversion is pivotal to achieve better performance and wider applications in information transmission. Unlike the conventional radio‐over‐fiber system based on fiber and circuit technologies, herein a laser‐to‐microwave wireless transmission scheme is proposed by dual‐band time‐domain optoelectronic metasurface. By integrating the high‐speed positive‐intrinsic‐negative diodes and meticulously designed photoelectric circuit into the metasurface, the amplitude and phase of the reflected microwaves at different frequency bands can be modulated quickly by laser intensities. Therefore, the on–off keying (OOK) laser can be modulated directly onto the phase shift keying (PSK) and amplitude shift keying (ASK) microwaves on one platform, achieving seamless laser‐to‐microwave transmissions. As a demonstration, a metasurface‐based hybrid wireless communication system is constructed, in which the data can be transmitted through OOK laser signal and received through ASK and PSK microwave signals. Based on the basic signal modulation format, 2.5 Mbps communication rate can be achieved over the hybrid link. This work will be of great benefit to design novel spatial photoelectric devices and wireless communication systems.

Increasing the bath temperature of the hot electron bolometer (HEB) while ensuring sensitivity could expand the application field and reduce the system complexity and cost. This study proposed and prepared a suspended NbN/Nb5N6 HEB with doubled bath temperature and undegraded sensitivity compared to NbN HEB. Under the bath temperature of 9 K, the optical noise equivalent power of the system was still of the order of pW/Hz1/2. Moreover, the influence of thermal relaxation on the device sensitivity was simulated. The results would provide a pathway for improving the bath temperature and detector sensitivity through fine adjustments of the thermal boundaries.

Visible light communication offers distinctive advantages such as low cost, rich spectrum, high communication speed, and environmental protection. Hybrid communication technologies integrate the advantages of radio frequency (RF) communication and visible light communication, playing an essential role in multi‐domain communication systems. However, the access of optical communication to the RF communication network in free space and cross‐media transmission of optical communication remain challenges. To achieve efficient hybrid wireless communications, optical and microwave signal conversion in full space and cross‐domain signal transmission is heavily requisite. Here, dual‐channel optical‐to‐microwave links based on a space‐polarization‐division multiplexed optoelectronic metasurface are proposed and realized, which are realized by double‐sided metasurface based on varactors and two rapid photoelectric conversion circuits integrated into each surface respectively. The dual‐channel optical‐to‐microwave links can achieve direct conversions of light to microwave signals at different polarizations on two surfaces of the metasurface independently and simultaneously. To demonstrate the capability of the conversion links, a dual‐channel hybrid transmission system is constructed and successfully operated. The dual‐channel optical‐to‐microwave conversion links can provide interfaces for visible light communications and RF communications, as well as for multi‐domain communication network interconnection.

Industrial control protocols play a pivotal role in facilitating communication within industrial control systems, and their security is directly intertwined with the overall communication security of the system. Traditional methods that rely on static test cases for fuzzing fail to effectively consider the changing environment to dynamically adjust the strategy for generating test cases. They also struggle to jointly extract the structural and temporal characteristics of industrial control protocols. Consequently, they suffer from the issue of ineffective test cases, resulting in limited ability to discover protocol vulnerabilities. We propose a novel approach called MARLFuzz, which is a multi-agent reinforcement learning-based fuzzing method designed for industrial control protocols. MARLFuzz incorporates a cooperative relationship-based multi-agent reinforcement learning mechanism that guides a fuzzing multi-agent array. This approach aims to achieve efficient and scalable fuzzing of the target protocol under examination. The proposed method begins with message sampling and data preprocessing. Subsequently, a reinforcement learning-based fuzzing test multi-agent array is constructed, along with its corresponding action set. A policy network based on recurrent neural networks is employed to learn temporal and spatial features of messages, while a value network, also based on recurrent neural networks, assists in central training of the multi-agent array. Finally, the decentralized fuzzing is carried out by the array of fuzzing agents. Experimental results conducted on Modbus-TCP and EtherCAT protocols demonstrate that our approach exhibits high effectiveness in generating test cases and efficiently triggering exceptions. It showcases the ability to customize the framework for different target protocols and exhibits strong scalability. The experiments indicate that the test cases of MARLFuzz achieved increases of 10.39% in effective identification rate, 38.68% in the number of anomaly triggers, and 61.87% in anomaly trigger efficiency compared to the best methods in the control group. Furthermore, there was a reduction of 37.96% in the average interval between anomaly triggers.