It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Wednesday, March 12, 2025
Smart humidity sensor transforms human behavior recognition
Aerospace Information Research Institute, Chinese Academy of Sciences
A cutting-edge humidity sensing system has been unveiled, capable of monitoring human behaviors in real-time through the detection of respiratory patterns. This breakthrough technology integrates a highly sensitive humidity sensor with a thermistor and micro-heater, enabling exceptional accuracy in behavior recognition. By using porous nanoforests as the sensing material, the system exhibits remarkable sensitivity, stability, and gas selectivity. With the added power of machine learning algorithms, the system achieves an impressive 96.2% accuracy in identifying human behaviors, positioning it as a game-changer in healthcare, smart homes, and everyday health monitoring.
Human behavior recognition has become increasingly vital across various domains, from healthcare to smart home automation. Traditional methods, such as video analysis and wearable devices, often face privacy concerns, environmental limitations, and the need for multiple sensors. Respiration, a key physiological signal, changes with different physical conditions, making it a promising metric for behavior recognition. However, current humidity sensors fall short in terms of sensitivity and stability, particularly when detecting subtle respiratory shifts, such as rapid or weak breathing. This gap has highlighted the urgent need for advanced sensors capable of accurately tracking and analyzing human behavior in real-time.
In an exciting development, researchers from the Institute of Microelectronics of the Chinese Academy of Sciences have introduced a novel humidity sensing system, detailed (DOI: 10.1038/s41378-024-00863-6) in Microsystems & Nanoengineering on January 22, 2025. This system incorporates a thermistor and micro-heater with porous nanoforests as the sensing material, achieving an impressive 96.2% accuracy in recognizing human behaviors through respiration monitoring. The integration of machine learning further enhances the system's ability to provide real-time analysis, setting the stage for transformative applications in healthcare and smart home technologies.
At the heart of this research is the innovative humidity sensor utilizing porous nanoforests (NFs). The sensor operates within a humidity range of 60–90% relative humidity (RH) and boasts a sensitivity of 0.56 pF/%RH. A micro-heater enhances its sensitivity by 5.8 times, enabling the detection of even the faintest humidity changes in exhaled air. The inclusion of a thermistor allows for precise temperature monitoring, ensuring long-term stability and accuracy. With a rapid response time of just 2.2 seconds, along with excellent gas selectivity, the sensor is ideally suited for monitoring respiratory activity.
Behavior recognition is driven by a convolutional neural network (CNN) that analyzes the sensor's humidity, temperature, and time data. By converting these one-dimensional signals into three-dimensional maps, the system can classify nine common behaviors, such as walking, sleeping, and exercising, with a high degree of accuracy (96.2%). Integrated into a mask, the sensor continuously collects respiratory data, which is wirelessly transmitted to smartphones or computers for analysis. This seamless fusion of hardware and software demonstrates the system's immense potential for practical use in healthcare and daily life.
Dr. Haiyang Mao, the lead researcher of the study, emphasized the significance of this breakthrough: "This innovative humidity sensing system represents a significant leap forward in real-time behavior recognition. By combining advanced sensor technology with machine learning, we've created a reliable and highly accurate tool for monitoring human behaviors, which has profound implications for both healthcare and smart home technologies."
The potential applications of this intelligent humidity sensing system are vast. In healthcare, it could be used to monitor patients with respiratory conditions or those needing to track physical activity levels. In smart homes, it could enhance comfort and safety by automatically adjusting appliances based on occupants' behaviors. Furthermore, the system's ability to detect subtle changes in respiration may also provide valuable insights into emotional states, such as anxiety or stress, opening new pathways for mental health monitoring. With its impressive accuracy and real-time capabilities, this system is set to be a cornerstone of future health electronics and intelligent living.
This work was supported by National Natural Science Foundation of China (Grant Nos. 62474192 and 62201567), Youth Innovation Promotion Association, Chinese Academy of Sciences (Grant Nos. 2022048 and 2022117), State Key Laboratory of Dynamic Test jointly built by Province and Ministry Open Fund (Grant No. 2022-SYSJJ-07).
Microsystems & Nanoengineeringis an online-only, open access international journal devoted to publishing original research results and reviews on all aspects of Micro and Nano Electro Mechanical Systems from fundamental to applied research. The journal is published by Springer Nature in partnership with the Aerospace Information Research Institute, Chinese Academy of Sciences, supported by the State Key Laboratory of Transducer Technology.
As major changes continue for our planet’s climate, scientists are concerned about how plants will grow and adapt.
Researchers in the MSU-DOE Plant Research Laboratory, or PRL, Sharkey lab are studying changes in plant metabolism that occur when plants are grown in high light, high CO2 (HLHC) conditions.
They found that under these conditions, plants photosynthesize more, which can lead to larger plants, and potentially larger crop yields. However, there are tradeoffs; scientists also found that plants lose carbon under these conditions, which they need to make food. This study was published in Scientific Reports.
Environmental conditions are predicted to continue changing in two major ways. First, atmospheric carbon dioxide is projected to continue increasing. Second, a phenomenon known as global brightening is changing light levels as more solar radiation makes its way to the ground than in previous decades.
Scientists predict these conditions will impact plant metabolism, or the internal mechanisms in plants that allow them to live and grow.
“Our work demonstrates that it’s very important to study photosynthesis and the carbon metabolism in plants,” said Yuan Xu, postdoctoral researcher in the Sharkey lab and first author on the study. “Especially when we think about conditions for the future based on predictions. If you want to do bioengineering in the future, to make a plant that can better adapt to these future conditions, you need to focus on these areas.”
This study revealed two major findings: under these future conditions, plants increase their rate of photosynthesis, but their rate of respiration in the light remains consistent with current conditions.
Increasing the rate of photosynthesis means the plant can make more sucrose and starch, the food it needs to survive.
“Most carbon fixed in photosynthesis becomes either starch [to use later] – like putting money in your bank account – or sucrose (table sugar) to use now – like buying an ice cream cone,” said Thomas D. Sharkey, University Distinguished Professor in the PRL. “The most surprising observation was that extra carbon at high light and high carbon dioxide went much more to starch (76% increase) rather than sucrose (41% increase). This may help plants become more resilient because they will have extra carbon for growth or defense.” Sharkey is also in the Department of Biochemistry & Molecular Biology and the Plant Resilience Institute.
Increased rates of photosynthesis may also lead to larger plants, as the plant is making more food for itself. This can potentially lead to larger yields of the crops we eat.
But a remaining issue is that plants also lose some carbon during photosynthesis – carbon which the plant could be using to make food. During a process known as respiration in light, or RL, CO2 is released by the plant.
This study found that RL remains constant in current and future conditions. What this means is the rate at which CO2 is released by the plant through the RL pathway is the same, despite the increase in photosynthesis.
Innovative methods
The researchers used a unique technique to measure RL. Typically, RL is measured using gas exchange methods such as the Laisk or Kok methods. However, these methods only work in low light conditions.
“That’s why this study is unique,” Xu explained. “We used a new approach to measure the RL in the high light condition that cannot be measured using the old method.”
Xu used a method known as isotopically nonstationary metabolic flux analysis, or INST-MFA, to look at gas exchange in HLHC conditions. This method is tried and true in bacteria and fungi studies but has only been used in a handful of plant studies over the past decade.
The Sharkey lab will continue to use innovative research methods to study respiration in the light. Understanding this process will allow a better understanding of carbon dioxide uptake and release in the future.
“We know from this study that many things are changed [under future conditions] including photosynthesis, photorespiration and respiration in the light,” Xu said. “This gave a hint for future work.”
Proposed working model of OfWRKY17-OfC3H49 responding to ambient temperature regulates flowering by inhibiting OfSOC1B expression in Osmanthus fragrans.
As global temperatures rise, the ability to understand how plants respond to heat has never been more critical. A recent study has uncovered a molecular mechanism by which elevated temperatures inhibit flowering in Osmanthus fragrans, a beloved ornamental plant. The research highlights how the OfC3H49 gene, activated by heat, suppresses flowering by inhibiting vital flowering-related genes. This discovery not only enriches our understanding of how temperature controls flowering but also paves the way for developing climate-resilient plant varieties and improving ornamental plant cultivation strategies.
For years, researchers have known that temperature influences flowering in plants, but the precise molecular pathways remain elusive, especially in ornamental species like Osmanthus fragrans. While some plants bloom earlier with warmer temperatures, others experience delayed flowering. This variation in response is particularly concerning in the face of climate change. Understanding the genetic networks behind these responses is essential, as it could help improve plant resilience. Given these challenges, in-depth research into temperature-sensitive genes is crucial for advancing agricultural practices.
Published (DOI: 10.1093/hr/uhae273) in Horticulture Research on January 1, 2025, this study conducted by researchers from Zhejiang Agriculture and Forestry University focuses on Osmanthus fragrans, a plant known for its varying flowering patterns under different temperatures. Using transcriptomic analysis, the team identified the OfC3H49 gene, which plays a central role in delaying flowering by suppressing the expression of key flowering genes. Their findings reveal a novel molecular module—OfWRKY17-OfC3H49—that orchestrates this temperature-induced flowering inhibition.
This research uncovers a critical mechanism behind the delayed flowering of Osmanthus fragrans when exposed to high temperatures. The team identified OfC3H49, a gene that is upregulated under heat stress and acts as a transcriptional repressor. By binding to the promoter of the OfSOC1B gene, a key regulator of flowering, OfC3H49 suppresses its expression, delaying the transition from vegetative to reproductive growth. The study further revealed that the WRKY transcription factor OfWRKY17 plays a pivotal role in activating OfC3H49 under heat stress. Overexpression of both genes in transgenic Arabidopsis plants resulted in delayed flowering, confirming their regulatory roles. These findings enhance our understanding of the complex genetic interactions that govern temperature-responsive flowering in plants, offering new avenues for enhancing plant resilience to heat stress in the future.
Dr. Bin Dong, a leading researcher in plant molecular biology, stated, “This discovery not only enriches our understanding of temperature-regulated flowering in ornamental plants but also offers essential insights for developing heat-tolerant varieties. As climate change accelerates, this knowledge is crucial for ensuring stable production of both crops and ornamental plants in a warming world.”
The insights from this study could have far-reaching implications for plant breeding, especially in developing crops and ornamental plants that can withstand rising temperatures. By targeting the regulatory pathways involving OfC3H49 and OfWRKY17, breeders may be able to create varieties of Osmanthus and other species better adapted to a changing climate. This research lays the foundation for breeding strategies that promote plant resilience, helping to secure food production and preserve the aesthetic value of ornamental plants in the face of global temperature shifts.
This work was supported by the National Natural Science Foundation of China (Grant Nos. 31902057 and 32072615), Zhejiang Provincial Natural Science Foundation of China (Grant No. LQ19C160012), and the key research and development program of Zhejiang Province (Grant No. 2021C02071).
Horticulture Research is an open access journal of Nanjing Agricultural University and ranked number one in the Horticulture category of the Journal Citation Reports ™ from Clarivate, 2023. The journal is committed to publishing original research articles, reviews, perspectives, comments, correspondence articles and letters to the editor related to all major horticultural plants and disciplines, including biotechnology, breeding, cellular and molecular biology, evolution, genetics, inter-species interactions, physiology, and the origination and domestication of crops.
A recent study by Chinese scientists has revealed the intricate molecular machinery driving energy exchange within chloroplasts, shedding light on a key event in the evolution of plant life. Led by FAN Minrui from the Center for Excellence in Molecular Plant Sciences of the Chinese Academy of Sciences, the research elucidates the structure and function of the ATP/ADP translocator—a crucial member of the nucleotide transporter (NTT) family of proteins—which facilitates the transfer of energy across chloroplast membranes.
Their findings were published online in Nature in an article entitled “Structure and mechanism of the plastid/parasite ATP/ADP translocator” on March 13.
The findings not only deepen our understanding of chloroplast endosymbiosis—the process by which ancient bacteria became integrated into plant cells as chloroplasts—but also offer potential avenues for improving crop yields and developing new drugs to combat intracellular pathogens.
Chloroplasts are essential for energy production in plants—playing a similar role as mitochondria (the powerhouses of animal cells) do in animals. However, mitochondria use the ATP/ADP translocator AAC to export ATP (the “energy currency” of cells) to the cytoplasm and import ADP for ATP synthesis. In contrast, chloroplasts employ an NTT protein to import ATP from the cytoplasm to fuel photosynthesis, starch synthesis, and fatty acid synthesis, while exporting ADP and inorganic phosphate (Pi). Notably, the chloroplast NTT protein is highly specific for ATP/ADP, unlike some related proteins in diatoms that can transport a broader range of nucleotides.
A long-standing question has been the origin of the NTT protein in chloroplasts. The endosymbiotic theory posits that chloroplasts evolved from cyanobacteria. However, free-living cyanobacteria lack NTT proteins. One hypothesis suggests that an ancestral eukaryotic cell engulfed both a cyanobacterium and a Chlamydia-like bacterium. The cyanobacterium may have acquired an NTT protein from Chlamydia through horizontal gene transfer (gene exchange between organisms), since Chlamydia uses a similar protein to steal ATP from host cells. This protein was then retained during chloroplast evolution. The “energy parasitism” exhibited by Chlamydia and the unique function of this NTT protein have intrigued scientists for years.
To verify this hypothesis, the research group determined the three-dimensional structures of NTT proteins from both Arabidopsis chloroplasts and Chlamydia pneumoniae at near-atomic resolution (2.72–2.90 Ã…). They found that the NTT proteins consist of 12 transmembrane helices, adopting a fold typical of major facilitator superfamily (MFS) transporters. The structures revealed that both proteins share a similar overall architecture despite significant species-specific differences. This supports the hypothesis that the chloroplast NTT protein originated from a Chlamydia-like ancestor.
The study also identified the ATP (or ADP and Pi) binding site within the NTT protein. The binding of ATP involves extensive interactions between its three moieties (adenine, ribose, and phosphate) and the NTT protein. The adenine portion of ATP is sandwiched between aromatic and hydrophobic amino acid residues, with its negatively charged phosphate groups interacting with surrounding positively charged amino acid residues.
The binding site for ADP is similar to that of ATP, but with some conformational differences: The phosphate groups of ATP adopt an extended conformation, whereas the phosphate groups of ADP are folded, resulting in slight variations in the surrounding interacting residues.
Interestingly, the binding position for Pi corresponds exactly to the position of ATP’s γ-phosphate group. To validate these structural findings, the researchers conducted ATP/ADP exchange experiments based on chemiluminescence as well as ATP-32P uptake experiments using radioactive isotopes.
The researchers also analyzed the thermal stability of the NTT protein and found that Pi significantly enhanced ADP binding, suggesting a cooperative effect between the two. This finding aligns with the co-transport properties of ADP and Pi in the NTT protein.
Additionally, the study revealed that when an evolutionarily conserved asparagine residue (N282 in Arabidopsis AtNTT1) in the NTT protein mutates to alanine, the transport activity towards other nucleotides (such as GTP, CTP, and UTP) significantly increases. This suggests that this residue may play a crucial role in the specific recognition of ATP by the NTT protein.
By comparing the structures of the NTT protein in different conformations, along with conducting mutational and functional experiments, the study reveals that the N-terminal and C-terminal domains of the NTT protein are relatively rigid. These domains move relative to each other, and by altering their interactions, the protein facilitates the binding, transmembrane transport, and release of ATP or ADP plus Pi.
This transport mechanism aligns with the “rocker-switch” alternating pathway model of the MFS. In this model, the conformational changes between the N-terminal and C-terminal domains allow the protein to alternately open and close its transport pathway, ensuring the efficient binding and release of the substrate and facilitating its translocation across the membrane. This mechanism is critical to the NTT protein’s ability to carry out its role in ATP/ADP exchange and the co-transport of Pi.
This study not only unveils the molecular mechanism of substrate recognition and transmembrane transport by the chloroplast and Chlamydia ATP/ADP translocator NTT protein but also deepens our understanding of the transmembrane energy transfer mechanism in chloroplast endosymbiosis. It also provides valuable insights on engineering NTT proteins to improve crop yields and designing NTT protein inhibitors to treat diseases caused by obligate intracellular pathogens.
This research was funded by the Center for Excellence in Molecular Plant Sciences of the Chinese Academy of Sciences, the Strategic Priority Research Program of the Chinese Academy of Sciences, the Shanghai Branch of the Chinese Academy of Sciences, and the Science and Technology Innovation Action Plan of Shanghai.
NTT-mediated ATP/ADP translocation across membrane
