Fundamental Functions Research Articles

Biocrusts intensify grassland evapotranspiration through increasing evaporation and reducing transpiration in a semi-arid ecosystem

Biological soil crusts (biocrusts) are living ground covers that result from intimate associations between soil particles and organisms, which can modify soil properties and support fundamental ecosystem functions in drylands. Despite numerous studies concerning effects of biocrusts on soil hydrological processes, their impacts on grassland evapotranspiration have remained unanswered. By using micro-lysimeters, we conducted in-situ monitoring of evapotranspiration of bare soil vs. cyanobacterial-moss mixed biocrusts, gramineous grass vs. gramineous grass with biocrusts, and leguminous grass vs. leguminous grass with biocrusts over two months in a semi-arid ecosystem. Results suggested that compared to the bare soil, the biocrusts significantly increased soil evaporation rate by 20.9 %. Underneath gramineous and leguminous grasses, the biocrusts increased the average evapotranspiration rate by 9.4 % and 13.4 %. The evaporation of biocrusts contributed 8.1–10.6 % to the average evapotranspiration rate and 8.2–12.6 % to the cumulative evapotranspiration amount. Additionally, the biocrusts increased soil moisture by 12.5 % and decreased temperature by 3.4 % at 10 cm depth compared to the bare soil. However, the biocrusts beneath grasses led to a reduction in soil moisture by 10.0 % and 20.0 %, while causing an increase in temperature by 9.9 % and 2.9 %, respectively. Enhanced evaporation of the biocrusts could be mainly attributed to their higher water retention ability in comparison to the bare soil. Meanwhile, beneath grasses, the biocrusts decreased soil water content in deeper layers, potentially limited grass transpiration by reducing water availability for grass roots. Based on these results, we concluded that the biocrusts intensify grassland evapotranspiration through increasing soil evaporation and reducing grass transpiration. Our findings highlight that biocrusts play a crucial role in modulating surface water fluxes, potentially exert remarkable effects on dryland vascular plants development and ecosystem stability.

Concept design, application and optimization of operational parameters for new forced safety injection tank system

Background The engineered safety systems are designed to execute fundamental safety functions encompassing reactivity confinement, reactivity control and decay heat removal. Failure of any one of these functions can result in severe accident conditions. Passive systems have been implemented as a better option for plant safety. This research proposes a modification of existing safety injection tanks to the new forced safety injection tanks (FSITs) that utilize the backpressure from the pressurizer or steam generator to drive coolant into the reactor core under high pressure conditions. Methods FSITs aim to extend the coping-time during accidents like Station Blackout, providing an extended timing window for deployment of FLEX systems. The mathematical design is proposed and implemented into the thermal-hydraulic input of a nuclear power plant to demonstrate the system’s applicability that was demonstrated by leveraging the conventional PRA approach and risk quantification. Results The suggested system useful when used in the accident scenario of Station black out in-coincident with turbine-driven pumps fail to run. As the proposed design is a conceptual design, the optimization of associated operational parameters and set points is necessary. This optimization is performed using the risk analysis and virtual control environment-based Dynamic Probabilistic Risk Assessment framework. The method and findings of this study affirm that the coping-time for Station Blackout can be significantly extended, ensuring a substantial margin for the effective deployment of the FLEX. Conclusions A concept design of a passive forced safety injection system was suggested and demonstrated by integrating the mathematical model into a thermal-hydraulic model of a nuclear power plant. The parameters were optimized and the results demonstrated that the new system was effective in recovering the nuclear power plant from the accidents such as SBO with turbine-driven pumps fail to operate.

Research on the Impact of Economic Development on Financial Derivatives

This paper aims to further investigate the impact of economic growth on the demand for financial derivatives, provide effective support to financial market participants and investors, and promote the stable development of financial markets. Firstly, time series analysis models, including autoregressive, mixed autoregressive, and moving average regression, are established by considering various factors in the financial market. Secondly, the basic characteristics of financial derivatives are thoroughly analyzed, and relevant variables are selected for explanation. Finally, the paper elucidates the fundamental functions of financial derivatives and their role in economic growth. The empirical results show that the correlation coefficient between non-financial institution derivatives and enterprise value is 0.2049, and the impact of enterprise economic growth on derivatives demand is 0.0003. Through time series analysis, the study reveals the impact mechanisms of economic cycles, business fluctuations, and other factors on the financial derivatives market, providing effective support for investors and participants.

The Role of Communication Systems in the Fundamental Functions of Indonesian Air Force

The Role of Communication Systems in the Fundamental Functions of Indonesian Air Force

Adenosine signalling to astrocytes coordinates brain metabolism and function

Brain computation performed by billions of nerve cells relies on a sufficient and uninterrupted nutrient and oxygen supply1,2. Astrocytes, the ubiquitous glial neighbours of neurons, govern brain glucose uptake and metabolism3,4, but the exact mechanisms of metabolic coupling between neurons and astrocytes that ensure on-demand support of neuronal energy needs are not fully understood5,6. Here we show, using experimental in vitro and in vivo animal models, that neuronal activity-dependent metabolic activation of astrocytes is mediated by neuromodulator adenosine acting on astrocytic A2B receptors. Stimulation of A2B receptors recruits the canonical cyclic adenosine 3′,5′-monophosphate–protein kinase A signalling pathway, leading to rapid activation of astrocyte glucose metabolism and the release of lactate, which supplements the extracellular pool of readily available energy substrates. Experimental mouse models involving conditional deletion of the gene encoding A2B receptors in astrocytes showed that adenosine-mediated metabolic signalling is essential for maintaining synaptic function, especially under conditions of high energy demand or reduced energy supply. Knockdown of A2B receptor expression in astrocytes led to a major reprogramming of brain energy metabolism, prevented synaptic plasticity in the hippocampus, severely impaired recognition memory and disrupted sleep. These data identify the adenosine A2B receptor as an astrocytic sensor of neuronal activity and show that cAMP signalling in astrocytes tunes brain energy metabolism to support its fundamental functions such as sleep and memory.

Human-following task without a prior map

Purpose The human-following task is a fundamental function in human–robot collaboration. It requires a robot to recognize and locate a target person, plan a path and avoid obstacles. To enhance the applicability of the human-following task in various scenarios, it should not rely on a prior map. This paper aims to introduce a human-following method that meets these requirements. Design/methodology/approach For the identification and localization of the target person (ILTP), this paper proposes an approach that integrates data from a camera, a light detection and ranging (LiDAR) and a ultra-wideband (UWB) anchor. For path planning and obstacle avoidance, a modified timed-elastic-bands (TEB) algorithm is introduced. Findings Compared to the UWB-only method, where only UWB is used to locate the target person, the proposed ILTP method in this paper reduces the localization error by 41.82%. Experimental results demonstrate the effectiveness of the ILTP and the modified TEB method under various challenging conditions. Such as crowded environments, multiple obstacles, the target person being occluded and the target person moving out of the robot’s field of view. The complete experimental videos are available for viewing on https://youtu.be/ZKbrNE1sePM. Originality/value This paper offers a novel solution for human-following tasks. The proposed ILTP method can recognize the target person among multiple individuals, determine whether the target person is lost and publish the target person’s position at a frequency of 20 Hz. The modified TEB algorithm does not rely on a prior map. It can plan paths and avoid obstacles effectively.

From macro to micro: slow-wave sleep and its pivotal health implications

Research on slow-wave sleep (SWS) began almost a century ago, not long after the discovery of electroencephalography. From maintaining homeostasis to memory function, the pivotal role of SWS in health has been established. The elucidation of its mechanisms and functions is directly related to the fundamental question of why people sleep. This comprehensive review first summarizes the basic science of SWS from anatomical and physiological aspects. It describes the fundamental mechanisms and functions of SWS, including hormonal regulation, developmental changes in SWS across the lifespan, and associations between SWS and optimal physical, psychological, and cognitive functions. Next, the relationship between SWS and physical and mental disorders, for which increasing knowledge has accumulated in recent years, is discussed from both research and clinical perspectives. Conditions such as memory impairment, sleep-disordered breathing, neurodevelopmental disorders, and various psychiatric disorders are of concern. The relationship between SWS and the glymphatic system, which is responsible for waste clearance in the brain, has also been explored, highlighting the potential neuroprotective role of SWS. Finally, we discuss the future direction of the field regarding whether interventions in SWS can improve health. We also address the problem of the inconsistent definitions of SWS, slow-wave activity, and slow oscillations. This review emphasizes the importance of discussing SWS from both macro- and microarchitectural perspectives and highlights its potential clinical and research impacts. By reviewing these aspects, we aim to contribute to a deeper understanding of SWS and the future development of this research field.

Rapid computation of the plasma dispersion function: Rational and multi-pole approximation, and improved accuracy

The plasma dispersion function Z(s) is a fundamental complex special integral function widely used in the field of plasma physics. The simplest and most rapid, yet accurate, approach to calculating it is through rational or equivalent multi-pole expansions. In this work, we summarize the numerical coefficients that are practically useful to the community. In addition to the Padé approximation to obtain coefficients, which are accurate for both small and large arguments, we also employ optimization methods to enhance the accuracy of the approximation for the intermediate range. The best coefficients provided here for calculating Z(s) can deliver 12 significant decimal digits. This work serves as a foundational database for the community for further applications.

Semiconductor lasers for photonic neuromorphic computing and photonic spiking neural networks: A perspective

Photonic neuromorphic computing has emerged as a promising avenue toward building a high-speed, low-latency, and energy-efficient non-von-Neumann computing system. Photonic spiking neural network (PSNN) exploits brain-like spatiotemporal processing to realize high-performance neuromorphic computing. Linear weighting and nonlinear spiking activation are two fundamental functions of a SNN. However, the nonlinear computation of PSNN remains a significant challenge. Therefore, this perspective focuses on the nonlinear computation of photonic spiking neurons, including numerical simulation, device fabrication, and experimental demonstration. Different photonic spiking neurons are considered, such as vertical-cavity surface-emitting lasers, distributed feedback (DFB) lasers, Fabry–Pérot (FP) lasers, or semiconductor lasers embedded with saturable absorbers (SAs) (e.g., FP-SA and DFB-SA). PSNN architectures, including fully connected and convolutional structures, are developed, and supervised and unsupervised learning algorithms that take into account optical constraints are introduced to accomplish specific applications. This work covers devices, architectures, learning algorithms, and applications for photonic and optoelectronic neuromorphic computing and provides our perspective on the challenges and prospects of photonic neuromorphic computing based on semiconductor lasers.

Information and Communication Technology Usage in School Management: A Case of Selected Hwange District Schools in Matabeleland North Province, Zimbabwe

Apart from the fundamental function of teaching and learning, schools also ensure the realisation of the institutions' aims and vision. This is possible through use of Information and Communication Technology (ICT) which has been identified as an essential global phenomenon for efficient and effective schools. Hence, the purpose of this study was to examine usage of ICT in school management in Hwange District. A qualitative approach driven by the interpretivism paradigm was adopted. A case study design focusing on selected schools was employed. Thematically analysed data were collected through semi-structured interviews and document analysis. Findings indicated that the selected school heads mainly used ICT platforms such as WhatsApp, emails and printed documents for communication. Parents, through School Development Committee, provided internet connectivity for easy communication while the school heads used their personal smart phones. The study found that school heads faced various hurdles in using ICT in their management duties. These challenges included lack of resources, inadequate knowledge and skills to use ICT tools, work overload, inadequate funds to acquire ICT hardware and software equipment, lack of appropriate ICT infrastructure, limited internet access and sporadic power supplies. Despite the difficulties encountered, the study concluded that there were visible pockets of good practices in the use of ICT by selected school heads. The study recommended that the Ministry of Primary and Secondary Education should capacitate school heads through ICT training. This will result in efficiency and effectiveness of school heads in execution of their management functions.

Metabolic and Immune Systems Are the Primary Tenets of Biological Life

A theory is much broader than a hypothesis or a conjecture if it can provide explanations for a wide range of observations while remaining robust to challenges through experimentation. There is a paucity of such theories in biology. The main motivation behind this research was to propose a broad theory of biological life and to explore whether it can be used as a framework for understanding health and disease conditions. A conceptual and theoretical approach was followed for this purpose. Extensive exploration and analysis of the biomedical literature in a non-systematic but purposeful manner were undertaken. They were then extrapolated using a top-down approach to identify the fundamental systems mediating life processes. Two attributes must exist for the survival of any biological life form, including the ability to grow and the ability to self-protect. These two functions are performed by the metabolic system and immune system, respectively. It is proposed that all other processes and every entity in a life form are involved in conducting these two fundamental functions. It is inferred that both of these functions exhibit the universal characteristics of duality and complementarity, features that cut across disciplines. A given life form may thus be biased toward one of the two processes mediated by the immune system and metabolic system at different stages in its life history. Identifying factors that confer bias might provide a better understanding of biology with direct implications for medicine. It is proposed that life and disease could be the result of the interplay of immune and metabolic systems acting complementarily. Other physiological systems lend support to the balancing act between the immune and metabolic systems in a biological life form.

Symbiotic bacteria diversity and metabolome analyses of Nostoc sphaeroides grown under different organic carbon sources

Organic carbon source plays a fundamental function in the metabolism and production of photosynthetic microorganisms. Herein, this study explored the effects of carbon source additions (glucose, sucrose and sodium acetate) on growth and biochemical components of the economic cyanobacterium Nostoc sphaeroides. The effects of sucrose and sodium acetate on its metabolomics changes, as well as the diversity and community composition of symbiotic bacteria, were analyzed. Results showed that sucrose noticeably enhanced the relative growth rate of N. sphaeroides. The content of phycocyanin was significantly greater under sodium acetate than under other carbon sources. Some metabolites associated with amino acid biosynthesis was significantly enriched under sodium acetate, implying its critical role in phycocyanin synthesis. Sodium acetate had a significant impact on the diversity and community composition of symbiotic bacteria. Additionally, partial symbiotic bacteria were shown to be involved in the amino acid metabolism of N. sphaeroides. These findings provided valuable insights into the mechanisms of N. sphaeroides on its metabolic responses to carbon source changes and the synergy of its symbiotic bacteria, contributing to the establishment of effective carbon source supply strategies for artificial cultivation and resource restoration.

Biomechanical design optimization and experimental verification of Bezier curve based two-sectional cervical pillow with variable-density cellular structure

The fundamental function of an optimal cervical pillow is to provide sufficient support to maintain normal spinal alignment and minimize biological stress on the contact surface throughout sleep. The recent advancements in cervical pillows have mainly focused on the subjective and objective evaluations of support comfort, as well as the relationship between pillow height and cervical vertebrae posture. However, only a few studies have addressed shape design guidelines and mechanical performances of the pillows themselves. In this study, a two-sectional contour cervical pillow comprising an arc and a Bezier curve is designed to support the head and neck. The design of the arc-shaped neck section incorporates the Cobb’s angle and Borden value from healthy individuals to reflect the consistency of normal cervical anatomical features. The Bezier curve-based head section takes the head length and neck depth into account as significant individual differences. Static analysis and lattice optimization are performed in ANSYS Workbench to develop a variable-density cellular structure, aimed at improving air permeability and reducing the risk of pressure ulcers associated with the cervical pillow. The rapid prototyping technique fused deposition modeling (FDM) and thermoplastic material polylactic acid (PLA) are employed for fabricating different cellular structures. The results demonstrate that the neck section experiences less stress and greater deformation in comparison to the head section, indicating good comfort and support provided by the designed cervical pillow. Additionally, the compressive, bending, and cushion properties of the 3D-printed cervical pillow with variable-density cellular structure are experimentally validated, further confirming its effectiveness.

Systemic Means of Persuasion and Argument Evaluation

The paper discusses the role of systemic means of persuasion in argument evaluation. The core class of systemic means of persuasion is regress stoppers, whose fundamental function is to halt the infinite regress of justification by making claims, premises, or overall position expressed in a persuasive message more acceptable to a recipient. The paper explores how systemic means of persuasion contribute to the structure of arguments in the Toulmin model and serve as cues for heuristic processing of persuasive messages. It also presents the results of the stylometric analysis and statistical data on the usage of systemic means of persuasion in three corpora which suggest that systemic means of persuasion constitute strategies independent of the strategy based on explicit argumentation marked by inference indicators.

Electronic Devices Based on Heterostructures of 2D Materials and Self-Assembled Monolayers.

2D materials (2DMs), known for their atomically ultrathin structure, exhibit remarkable electrical and optical properties. Similarly, molecular self-assembled monolayers (SAMs) with comparable atomic thickness show an abundance of designable structures and properties. The strategy of constructing electronic devices through unique heterostructures formed by van der Waals assembly between 2DMs and molecular SAMs not only enables device miniaturization, but also allows for convenient adjustment of their structures and functions. In this review, the fundamental structures and fabrication methods of three different types of electronic devices dominated by 2DM-SAM heterojunctions with varying architectures are timely elaborated. Based on these heterojunctions, their fundamental functionalities and characteristics, as well as the regulation of their performance by external stimuli, are further discussed.

Development and application of molecular markers in fisheries, aquaculture, and industry of representative temperate and tropical sea cucumbers: a review

Sea cucumber has emerged as a crucial economic species in aquaculture in China because of its remarkable nutritional and medicinal value. However, wild sea cucumber populations have experienced a decline due to overfishing and environmental factors, underscoring the urgent need for genetic resource conservation and biotechnology innovation within the sea cucumber aquaculture and breeding industry. The development of the sea cucumber industry is still impeded by challenges and difficulties. Nevertheless, significant progress has been made through the utilization of molecular markers, which have effectively addressed a number of fisheries and aquaculture issues. In recent years, diverse types of molecular markers including mitochondrial DNA, microsatellites, and SNP markers have been developed and extensively applied in various aspects of sea cucumber research. These markers play vital roles in genetic sex identification, germplasm resource evaluation, population structure assessment, as well as marker-assisted breeding in marine ranching and sea cucumber aquaculture and breeding industry. This review provides an overview of the fundamental principles, functions, and characteristics associated with various markers employed across various sea cucumber species while also discussing their applications within different aspects of the sea cucumber fisheries, aquaculture, and breeding industry.

Multi-scale entropy assessment of magnetoencephalography signals in schizophrenia

Schizophrenia is a severe disruption in cognition and emotion, affecting fundamental human functions. In this study, we applied Multi-Scale Entropy analysis to resting-state Magnetoencephalography data from 54 schizophrenia patients and 98 healthy controls. This method quantifies the temporal complexity of the signal across different time scales using the concept of sample entropy. Results show significantly higher sample entropy in schizophrenia patients, primarily in central, parietal, and occipital lobes, peaking at time scales equivalent to frequencies between 15 and 24 Hz. To disentangle the contributions of the amplitude and phase components, we applied the same analysis to a phase-shuffled surrogate signal. The analysis revealed that most differences originate from the amplitude component in the δ, α, and β power bands. While the phase component had a smaller magnitude, closer examination reveals clear spatial patterns and significant differences across specific brain regions. We assessed the potential of multi-scale entropy as a schizophrenia biomarker by comparing its classification performance to conventional spectral analysis and a cognitive task (the n-back paradigm). The discriminative power of multi-scale entropy and spectral features was similar, with a slight advantage for multi-scale entropy features. The results of the n-back test were slightly below those obtained from multi-scale entropy and spectral features.

All‐Photonic Synapses for Biomimetic Ocular System

AbstractThe human visual system to process real‐time light signals and safeguard against excessive light exposure serves as a model for artificial vision systems. Despite the wide use of optoelectronic synaptic devices in such simulations, their complex circuitry and high energy consumption have impeded further development. Herein, a biomimetic ocular system utilizing organic all‐photonic synapses is constructed to realize sensation, memory, processing, and protective light reflex abilities. The synaptic performances are facially regulated by simple molecular engineering to afford a record PPF value of 430%. Impressively, a large area (400 cm2) synaptic device with a high uniformity (96%) exhibited four fundamental functions of an ocular system for the first time, which significantly simplified the circuit system and reduced energy consumption. This work provides a facial strategy to construct all‐photonic synapses, holding great potential in prosthetics and neurorobotics.

Prevention and treatment of microstomia.

The mouth, located in the lower third of the face, is a uniquely visible structure. It serves as a vital organ both aesthetically and functionally, playing a key role in speech, expression, and fundamental oral functions. Consequently, any alterations or defects in its shape, due to various causes, can lead to aesthetic and functional deficiencies. These issues may also result in challenges with social interactions and a decrease in confidence. In cases of microstomia, various surgical approaches are proposed based on the location, extent, shape, and cause of the defect, leading to numerous case reports. Plastic surgeons are proficient in oral reconstruction; however, cases of microstomia are relatively rare, which reduces their familiarity and interest in these cases. Additionally, preferences for oral size and shape vary according to factors such as geographical region and ethnicity, further complicating the functional definition of microstomia. Therefore, both subjective patient and physician judgments play crucial roles in the diagnosis and treatment of microstomia, as these may vary depending on individual and societal aspects. This review aims to classify the various causes and definitions of microstomia, as well as its non-surgical and surgical treatment options, with the goal of the treatment of this condition.

The mechanism of human color vision and potential implanted devices for artificial color vision.

Vision plays a major role in perceiving external stimuli and information in our daily lives. The neural mechanism of color vision is complicated, involving the co-ordinated functions of a variety of cells, such as retinal cells and lateral geniculate nucleus cells, as well as multiple levels of the visual cortex. In this work, we reviewed the history of experimental and theoretical studies on this issue, from the fundamental functions of the individual cells of the visual system to the coding in the transmission of neural signals and sophisticated brain processes at different levels. We discuss various hypotheses, models, and theories related to the color vision mechanism and present some suggestions for developing novel implanted devices that may help restore color vision in visually impaired people or introduce artificial color vision to those who need it.