Synchronous Changes Research Articles

The acute effect of bitemporal electroconvulsive therapy on synchronous changes in heart rate variability and heart rate in patients with depression

Objective.The transient autonomic nervous system responses induced by electroconvulsive therapy (ECT) may serve as critical indicators of treatment efficacy and potential side effects; however, their precise characteristics remains unclear. Considering that the intense stimulation of ECT may disrupt the typical antagonistic relationship between the sympathetic and parasympathetic branches, this study aims to conduct a meticulous analysis of the rapid changes in heart rate variability (HRV) and HR during ECT, with a particular focus on their synchronized interplay.Methods.Pulse interval sequences were collected from 50 sessions of bitemporal ECT administered to 27 patients diagnosed with major depressive disorder. The average HR and ultra-short term HRV indices RMSSD and SDNN, as well as the Poincaré indices SD1, SD2 and SD2/SD1, were calculated using a 10 s sliding window with a step size of 1 s. In particular, the synchronous changes between SD1, SD2, SD2/SD1 and HR were analyzed.Results.The synchronous changes of the indices showed different characteristics over time. In particular, SD1, SD2 and HR increased significantly by 41.50 ± 11.45 ms, 33.97 ± 10.98 ms and 9.68 ± 2.00 bpm respectively between 8 and 20 s, whereas they decreased significantly by 19.89 ± 9.07 ms, 17.54 ± 8.54 ms and 3.80 ± 1.33 bpm respectively between 45 and 53 s after ECT stimulus onset. SD1 and SD2 both had highly significant positive correlations with HR in the above phases.Conclusion.The results suggest that bitemporal ECT induces the sympathetic and parasympathetic co-activation during the early ictal period and brief co-inhibition approximately 45 s after stimulus. Our findings may provide new insights comprehending the mechanisms of ECT and its associated cardiovascular risks.

Dual-mode ratiometric optical sensor for rapid visual detection of Hg2+ with poly(adenine)-assisted silver nanoclusters anchoring on tetrahedral DNA framework.

Cytosine-rich and poly(adenine)-tailed tetrahedral DNA framework (TDF) is designed as template (A8-TDF) for anchoring silver nanoclusters (AgNCs) and igniting the dual-color fluorescence of AgNCs. The resultant DNA-AgNCs simultaneously emits red and green fluorescence, and the quantum yield of red fluorescence is as high as 44.8%. The red fluorescence can be selectively quenched by Hg2+ within 2 min due to the redox reaction between Hg2+ and Ag0 as well as the subsequent Ag amalgamation. Meanwhile, the green fluorescence is enhanced. Thus a ratiometric fluorescence sensor is constructed for rapid and visual Hg2+ detectionbased on the synchronous change of two fluorescence signals. In addition, the resultant AgNCs probe also provides ratiometric colorimetric sensing of Hg2+ and simultaneously shows a visible color change from pink to yellow along with increasing content of Hg2+. The detection limits of ratiometric fluorescence and colorimetric modes are 0.24 nM and 1.32 nM, respectively. The method has been applied to the determinationof Hg2+ in water samples, and recoveries ranged between 94.1 and 108.7%. This study not only provides a new guideline to modulate the fluorescence emission of AgNCs by scientifically designing terminal DNA sequence but also provides a facile and efficient single-probe and dual-mode ratiometric sensing platform for the routine determination and field monitoring of Hg2+.

A temperature-sensitive and fluorescent Tr-CD/AuNP-based catalyst for efficient, monitorable, and recyclable catalytic reactions.

Gold nanoparticles (AuNPs) have been widely used as efficient and environmentally friendly catalysts due to their high specific surface area and abundant active sites. However, AuNP-based catalytic systems face several challenges, including the instability of AuNPs during the reaction, the difficulty in monitoring the process, which can easily result in insufficient reaction due to short reaction time or waste of resources due to long reaction time, as well as issues of catalyst recovery. This study proposes a novel catalyst integrating various functions, such as high stability, the capacity for real-time monitoring of the catalytic process, and rapid recycling. Temperature-sensitive polymers (HPEI-IBAm) terminated with isobutyramide (IBAm) groups were prepared by reacting isobutyric anhydride with hyperbranched polyethyleneimine (HPEI). Subsequently, temperature-sensitive and reducing fluorescent carbon dots (Tr-CDs) were synthesized using HPEI-IBAm as a carbon source. Tr-CDs can reduce the HAuCl4 precursor in situ, yielding high-performance catalysts, Tr-CDs/AuNPs, with both temperature-sensitive and fluorescence properties. With the help of changes in fluorescence intensity and the real-time synchronous change in the reaction conversion rate, monitoring of the catalytic reaction process is achieved. Moreover, their temperature sensitivity enables the rapid recovery of the catalysts. Using the reduction of p-nitrophenol as a model, we thoroughly investigated the catalytic performance of Tr-CDs/AuNPs. Importantly, the catalytic process exhibited a good linear relationship between the change in fluorescence intensity and the reaction time (R2 = 0.9993) and maintained a synchronous change with the conversion rate, enabling the monitoring of the reaction process. Meanwhile, the catalytic efficiency of this catalyst remained above 90% after five recycling and reuse cycles, indicating no obvious decline in catalytic activity. This catalyst demonstrates good performance, reusability, and real-time reaction monitoring, promising bright application prospects.

Эколого-географическая характеристика озера Пелёнкино (Ростовская область) по материалам ретроспективных и современных исследований

The physical and geographical characteristics and geological structure of Lake Pelenkino are described. During the analysis of the results of the satellite survey, it was found that the area, length and width of the water surface of the reservoir, as well as the length of the lake's shoreline, the elongation index, and the compactness of the lake vary significantly both by year and by season. It has been suggested that the water surface area and the chemical composition of the water are influenced by both the amount of precipitation and wind-driven effects in the Sea of Azov. The chemical composition of water and mud solution is prone to accumulation of an equivalent amount of Mg2+ relative to Ca2+ over time, which may be due, along with the influence of a hydrological factor, to a change in the physical and chemical equilibrium in the water-mud system. According to the description of the well cores, deposits up to a depth of about 15-35 cm are represented by silt (mud), which first turns into steel-gray clay of a semi-liquid consistency, and then to the bottom of the layer into denser clay. The physical and chemical parameters of the mud of Lake Pelenkino allow us to classify them as continental, silt, mineral, medium mineralized, slightly alkaline, slightly sulfide peloids. Lithological control was found for a set of parameters (pH, Eh, CH4, Ssulfide), which manifests itself in their synchronous change during the transition from silts to the bedrock sediments of the reservoir bed – steel-gray clays. The content of gross mercury in the mud and sediments of the lake does not exceed the threshold of the Low range of Exposure (EQL), equal to 0.15 micrograms/g of dry weight. The bottom sediments of the rivers of the Pelenkino Lake basin and its mud themselves are under anthropogenic influence, which primarily forms a low level of perfringence titer values and its virulence. The use of lake mud for therapeutic purposes without prior preparation is not recommended.

Glacial isostatic adjustment driven by asymmetric ice sheet melt during the Last Interglacial causes multiple local sea-level peaks

Global mean sea-level (GMSL) change during the Last Interglacial (LIG, 129−116 ka) gives perspective on how ice sheets respond to warming. Observations of multiple peaks in LIG relative sea level (RSL) records, combined with an assumption that the Laurentide Ice Sheet (LIS) collapsed prior to the LIG, have been used to infer Greenland and Antarctic ice sheet melt histories as well as oscillations in LIG GMSL. However, evidence for an LIS outburst flood at ca. 125 ka and extensive early-LIG Antarctic melt suggests that Laurentide remnants may have persisted longer into the LIG than typically thought even as Antarctic melt accelerated. Here, we explore the effect of concurrent early-Holocene Laurentide persistence and Antarctic collapse on glacial isostatic adjustment and sea level. In our models, we hold GMSL constant at present levels (i.e., GMSL = 0) from 128 ka to 117 ka by balancing excess Laurentide ice with early-LIG Antarctic melt. We find that due to glacial isostatic adjustment, this synchronous but asymmetric ice change causes multiple RSL peaks, separated by ∼4.2 ± 2.5 m of RSL fall near North America and ∼1.3 ± 0.7 m around the Indian Ocean. This spatial pattern resembles observations. These results show that multiple peaks in LIG RSL could have occurred with asymmetric ice changes between the Northern and Southern Hemisphere that sum to little, if any, change in GMSL. Our work highlights the need for LIG modeling studies to consider that dynamic cryospheric changes can occur even with near-constant GMSL.

Seasonal dynamics of the absolute and relative mass of organs of male Wistar rats at the age of 3 months

Rationale. It is relevant to develop reference values of the “norm” and their ranges in physiology and pathophysiology when using animals of genetically purebred lines in different periods of ontogenesis and in different seasons of the year. The goal was to study the parameters of absolute and relative weight of the body and organs of sexually mature male Wistar rats at the age of 3 months in different seasons. Materials and methods. The study was conducted on 160 male Wistar rats aged 3 months. During the year, seasonal indicators of absolute and relative weight of the body, brain, spleen, thymus, liver, kidneys, adrenal glands, heart, lungs, and testes were measured. Results. The most constant seasonal changes were found in the absolute mass of all organs, while the values of the relative mass factors showed seasonal variability in only 50% jf cases. Synchronous seasonal changes were noted in the kidneys and adrenal glands. Whereas the thymus and spleen were characterized by the absence of simultaneity. The most pronounced seasonal variability in both mass indicators was found in the heart. Conclusion. Absolute organ mass is one of the most sensitive parameters when studying reference values, however, changes in relative mass factors should be considered. The importance of studying both indicators is explained by the fact that changes in organ mass often precede morphological changes. This study is one of the first in Russia in which reference ranges for the mass of the main organs of a healthy genetically homogeneous Wistar rats population at the age of 3 months were established, and the trend of their seasonal changes was generalized. Further study of the main causes of changes in organ mass in combination with anatomico-pathological data is necessary.

Fetal ECG-based analysis reveals the impact of fetal movements and maternal respiration on maternal-fetal heart rate synchronization

Identifying and understanding prenatal developmental disorders at an early stage are crucial as fetal brain development has long-term effects on an individual’s life. The maturation of the fetal autonomic nervous system (ANS) is believed to influence the coordination and direction of maternal-fetal heartbeat synchronization. Fetal behavioral states (FBSes) include quiet sleep (1F), active sleep (2F), quiet awake (3F), and active awake (4F). In this study, the focus is on fetal movements, leading to the grouping of 1F and 3F into a quiet state, while 2F and 4F are combined to form an active state. Thus, the FBSes discussed in this article consist of fetal quiet and active states. Here, we explore the relationship between FBSes and the coupling of maternal and fetal heartbeats. We also seek to understand how maternal breathing patterns influence this coupling while considering FBSes. The study involved 105 healthy fetuses with gestational ages (GA) from 20 to 40 weeks. Non-invasive electrocardiogram (ECG) signals were recorded for 3 to 10 minutes. The ECG samples were separated into three gestational groups (Early: 16 ≤ GA < 25, Mid: 25 ≤ GA < 32, and Late: 32 ≤ GA < 40 weeks). Maternal respiration rate and coupling strength parameters were calculated for various maternal-fetal heartbeat coupling ratios. The findings of the study indicated that FBSes influenced maternal-fetal HR coupling strength during late gestation but not during early and mid-gestation. The changes in maternal-fetal HR synchronization or communication as gestation progresses occur in both FBSes. Furthermore, we noticed a significantly higher level of maternal-fetal heartbeat synchronization during periods of higher respiratory rates when the fetus was in a quiet state. These results emphasize how FBSes impact the synchronization of maternal-fetal HR and contribute to the understanding of fetal growth and health.

Dorsal Column Spinal Cord Stimulation Attenuates Brain-Spine Connectivity through Locomotion- and Visuospatial-Specific Area Activation in Progressive Freezing of Gait

Introduction: Freezing of gait (FOG) is a clinical phenomenon with major life impairments and significant reduction in quality of life for affected patients. FOG is a feature of Parkinson’s disease and a hallmark of primary progressive FOG, currently reclassified as Progressive Supranuclear Palsy-progressive gait freezing (PSP-PGF). The pathophysiology of FOG and particularly PGF, which is a rare degenerative disorder with a progressive natural history of gait decline, is poorly understood. Mechanistically, changes in oscillatory activity and synchronization in frontal cortical regions, the basal ganglia, and the midbrain locomotor region have been reported, indicating that dysrhythmic oscillations and coherence could play a causal role in the pathophysiology of FOG. Deep brain stimulation and spinal cord stimulation (SCS) have been tested as therapeutic neuromodulation avenues for FOG with mixed outcomes. Methods: We analyzed gait and balance in 3 patients with PSP-PGF who received percutaneous thoracic SCS and utilized magnetoencephalography (MEG), electroencephalography, and electromyography to evaluate functional connectivity between the brain and spine. Results: Gait and balance did not worsen over a 13-month period. This observation was accompanied by decreased beta-band spectral power in the whole brain and particularly in the basal ganglia. This was accompanied by increased functional connectivity in and between the sensorimotor cortices, basal ganglia, temporal cortex, and cerebellum, and a surge in corticomuscular coherence when SCS was paired with visual cues. Conclusion: Our results suggest synergistic activity between brain and spinal circuits upon SCS for FOG in PGF, which may have implications for future brain-spine interfaces and closed-loop neuromodulation for patients with FOG.

CD39 activities in the treated acupoints contributed to the analgesic mechanism of acupuncture on arthritis rats.

Our previous work had identified that at the acupuncture point (acupoint), acupuncture-induced ATP release was a pivotal event in the initiation of analgesia. We aimed to further elucidate the degradation of ATP by CD39. Acupuncture was administered at Zusanli acupoint on arthritis rats, and pain thresholds of the hindpaws were determined. Pharmacological tools or adeno-associated viruses were administered at the acupoints to interfere with targeting signals. Protein expression was determined with qRT-PCR, WB, or immunofluorescent labeling. Cultured keratinocytes, HaCaT line, were subjected to hypotonic shock to simulate needling stimulation. Extracellular ATP and adenosine levels were quantified using luciferase-luciferin assay and ELISA, respectively. Acupuncture-induced prompt analgesia was impaired by inhibiting CD39 activities to prevent the degradation of ATP to AMP but was mimicked by using CD39 agonists. Acupuncture-induced ATP accumulation exhibited synchronous changes. Similarly, acupuncture analgesia was hindered by suppressing CD73 to prevent the conversion of AMP to adenosine. Furthermore, the acupuncture effect was replicated by agonism at P2Y2Rs but inhibited by antagonism at them. Acupuncture upregulated CD73 and P2Y2Rs but not CD39. Immunofluorescent labeling demonstrated that keratinocytes were a primary site for these proteins. Shallow acupuncture also demonstrated antinociception. In vitro tests showed that hypotonic shock induced HaCaT cells to release ATP and adenosine, which was impaired by suppressing CD39 and CD73, respectively. Finally, agonism at P2Y2Rs promoted ATP release and [Ca2+]i rise. CD39 at the acupoints contributes to the analgesic mechanism of acupuncture. It may facilitate adenosine signaling in conjunction with CD73 or provide an appropriate ATP milieu for P2Y2Rs. Skin tissue may be one of the scenes for these signalings.

Haematogenous seeding in mycosis fungoides and Sézary syndrome: Current evidence and clinical implications.

Cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of diseases characterised by abnormal neoplastic T-cell growth in the skin. Mycosis fungoides (MF), the most common CTCL, manifests as erythematous skin patches and/or plaques, tumours or erythroderma. The disease may involve blood, lymph nodes and rarely viscera. Sézary syndrome (SS) is a unique leukaemia/lymphoma syndrome related to MF, which presents with blood and skin involvement at diagnosis. The pathogenesis of MF/SS is not fully elucidated. The presence of skin lesions at distant sites underpins a hypothesis that MF/SS lesions may develop through haematogenous seeding. Phenotypic similarities between malignant and normal T-cells led to the notion that disease-initiating mutations occur in specific subtypes of mature T-cells, which are responsible for most CTCLs. However, this mature T-cell precursor model is not always consistent with clinical observations and research on MF/SS pathogenesis. Here, we review evidence supporting an alternative model of pathogenesis for MF/SS involving haematogenous seeding as a key process responsible for the initiation and progression of the disease. According to this hypothesis, malignant transformation occurs at an early stage of T-cell development (probably in bone marrow or thymus), yielding circulating neoplastic T-cells which colonise the skin where the microenvironment is most permissive for proliferation and evolution. These mutated precursor cells seed the skin where they find a suitable niche to develop into clinically perceptible disease. Subsequently, malignant T-cells can re-enter the bloodstream, re-seed pre-existing lesions and seed new areas of the skin, causing synchronous and convergent changes in the transcriptomic profile of lesions and tumours, and clinical disease progression - 'consecutive haematogenous seeding' captures this temporal phenomenon. This model radically changes the current understanding of CTCL pathogenesis, transforming it from a primarily cutaneous disease with secondary involvement of blood, to a systemic disease, where the spread of malignant cells through the blood to the skin is not a phenomenon of advanced disease but is an essential component of pathogenesis. This understanding of MF/SS could have several clinical implications, including standardising our approach to assessing blood tumour burden, potential advances in prognosis and monitoring, and investigating combination treatments to improve patient outcomes.

Hysteresis of unfrozen water content of tailing mud with freeze-thaw and its correlation with electrical conductivity

Identifying the correlation between the hysteresis of unfrozen water content and the electrical conductivity (EC) of tailing mud with freeze-thaw is essential for determining the range of frost hazards in tailings ponds by field conductivity measurement and enabling targeted treatment in coastal and seasonally frozen areas. In this study, dynamics of unfrozen water content and temperature of saturated tailing mud samples with 0.0–5.0 % NaCl were evaluated with 5TM sensor while the EC with the frequency domain reflectometry (FDR) sensor. Results show that unfrozen water hysteresis of tailing mud with freeze-thaw occurred below phase-change temperatures, with the cooling section above the warming. The area of hysteresis curve rose upon higher salinity or fewer freeze-thaw cycles. Phase-change temperatures of tailing mud, including freezing and thawing points, depressed with higher salinity but were less affected by freeze-thaw cycles, with the former coinciding with the liquidus line of NaCl solution while the latter located above. The EC curve also exhibits hysteresis with freeze-thaw and the initial salinity determines both the maximum EC value and the slope logEC/T below phase-change temperatures. It was concluded that the unfrozen water content, converted salt concentration and EC of frozen tailing mud show synchronous changes. A modified Michalowski model, with phase-change temperatures and residual unfrozen water content respectively simplified as proportional and exponential functions of initial salinity, was established to characterize the unfrozen water hysteresis of tailing mud with freeze-thaw cycles. A simple EC model with hysteresis was then developed by approximating the EC of frozen tailing mud as a power function of the converted salt concentration, which was applied to the tailing mud with 0.5–5.0 % NaCl in the range of −20 °C up to phase-change temperatures.

Hyperscanning: from inter-brain coupling to causality.

In hyperscanning studies, participants perform a joint task while their brain activation is simultaneously recorded. Evidence of inter-brain coupling is examined, in these studies, as a predictor of behavioral change. While the field of hyperscanning has made significant strides in unraveling the associations between inter-brain coupling and changes in social interactions, drawing causal conclusions between brain and behavior remains challenging. This difficulty arises from factors like the inherently different timescales of behavioral responses and measured cerebral activity, as well as the predominant focus of existing methods on associations rather than causality. Specifically, a question remains as to whether inter-brain coupling between specific brain regions leads to changes in behavioral synchrony, or vice-versa. We propose two novel approaches to addressing this question. The first method involves using dyadic neurofeedback, wherein instances of inter-brain coupling are directly reinforced. Such a system could examine if continuous changes of inter-brain coupling are the result of deliberate mutual attempts to synchronize. The second method employs statistical approaches, including Granger causality and Structural Equation Modeling (SEM). Granger causality assesses the predictive influence of one time series on another, enabling the identification of directional neural interactions that drive behavior. SEM allows for detailed modeling of both direct and indirect effects of inter-brain coupling on behavior. We provide an example of data analysis with the SEM approach, discuss the advantages and limitations of each approach and posit that applying these approaches could provide significant insights into how inter-brain coupling supports crucial processes that occur in social interactions.

Study of seasonal variation of accident-derived atmospheric radiocesium in Koriyama City, Fukushima Prefecture, Japan during 2011-2014.

This study measured the atmospheric concentration and deposition flux of radiocesium in Koriyama City, Fukushima Prefecture, Japan, from November 2011 to October 2014. The results show synchronous seasonal change in atmospheric concentration and deposition flux of radiocesium, which is high during winter to early spring and low during summer to autumn. These seasonal variations are similar to those observed in Fukushima City but differ from those in Namie Town, Fukushima Prefecture, comprising a larger contaminated forest area. The evaluation of the relationship between atmospheric 137Cs concentration or 137Cs specific activity in atmospheric particulate matter (PM) and deposition density of 137Cs in PM source area suggest that stronger winds blowing from areas with relatively large 137Cs deposition (west of Koriyama City) toward the study site affect the site's atmospheric 137Cs concentrations.

Improved chronostratigraphy and fine-tuned timing for Late Triassic palaeoenvironmental changes in SW Britain using coupled magnetic polarity and carbon isotope stratigraphy

Understanding the synchronicity of global climatic, environmental, and biotic events around the Norian-Rhaetian boundary (NRB) is problematic because of major international differences in biochronology. We instead use magnetostratigraphic and global carbon isotopic changes to produce more precise global correlation. This work focusses on the base and top of the Rhaetian, with principal age control from a new late Norian to latest Rhaetian magnetostratigraphy from Lavernock (southern Wales) which can be directly correlated to the proposed NRB sections at Pignola Abriola (Italy) and Steinbergkogel (Austria). A disconformity exists in the Lavernock section in its late Norian part (Branscombe Mudstone Formation), but the NRB interval is largely complete. The magnetostratigraphy and a composite δ13Corg stratigraphy from three British sections, demonstrate synchronous changes in both terrestrial and marine records. This analysis indicates the older proposed definition of the NRB from Steinbergkogel is in the upper few metres of the Branscombe Mudstone Formation, while the younger NRB definition from Pignola Abriola is in the upper parts of the Blue Anchor Formation. The latest Rhaetian magnetostratigraphy from Lavernock records reverse magnetochrons UT26r and UT28r which closely pre-date and post-date the widely recognised Marshi and Spelae carbon isotope excursions, respectively. Magnetochrons UT28r and UT27r were previously recognised at St Audrie's Bay (SW England), with relationships to the Newark Supergroup which tightly constrain the first phase of CAMP eruptions to overlap the Spelae excursion. The carbon isotope excursions present in the Blue Anchor Formation lacustrine successions, demonstrate the likely atmospheric, and global spread of these perturbations.

Impact of age-related hearing loss on decompensation of left DLPFC during speech perception in noise: a combined EEG-fNIRS study.

Understanding speech-in-noise is a significant challenge for individuals with age-related hearing loss (ARHL). Evidence suggests that increased activity in the frontal cortex compensates for impaired speech perception in healthy aging older adults. However, whether older adults with ARHL still show preserved compensatory function and the specific neural regulatory mechanisms underlying such compensation remains largely unclear. Here, by utilizing a synchronized EEG-fNIRS test, we investigated the neural oscillatory characteristics of the theta band and synchronous hemodynamic changes in the frontal cortex during a speech recognition task in noise. The study included healthy older adults (n = 26, aged 65.4 ± 2.8), those with mild hearing loss (n = 26, aged 66.3 ± 3.8), and those with moderate to severe hearing loss (n = 26, aged 67.5 ± 3.7). Results showed that, relative to healthy older adults, older adults with ARHL exhibited lower activation and weakened theta band neural oscillations in the left dorsolateral prefrontal cortex (DLPFC) under noisy conditions, and this decreased activity correlated with high-frequency hearing loss. Meanwhile, we found that the connectivity of the frontoparietal network was significantly reduced, which might depress the top-down articulatory prediction function affecting speech recognition performance in ARHL older adults. The results suggested that healthy aging older adults might exhibit compensatory attentional resource recruitment through a top-down auditory-motor integration mechanism. In comparison, older adults with ARHL reflected decompensation of the left DLPFC involving the frontoparietal integration network during speech recognition tasks in noise.

Change in EEG-EMG synchronization reflecting abnormal functional corticomuscular coupling following stroke: A pilot study

Stroke is a common clinical cardiovascular and cerebrovascular disease, which can cause severe motor dysfunction. Therefore, it is an important topic to investigate the abnormality mechanism of the cerebral cortex and the corresponding muscles after stroke. In this study, we investigated the functional corticomuscular coupling (FCMC) at specific frequencies by analyzing differences between stroke patients and healthy controls in hand movements. The transfer spectral entropy (TSE) method was used to analyze simultaneous electroencephalography (EEG) and electromyography (EMG) in the right-hand steady state force task. The results illustrated that healthy subjects had the highest TSE values at the beta band in the EMG→EEG and EEG→EMG directions, and the TSE value in the EEG→EMG direction was higher than that in the EMG→EEG direction. In contrast, for stroke patients, beta band coupling was weakened, and there was a notably higher enhancement of alpha and gamma bands in the EMG→EEG direction relative to the EEG→EMG direction. Further analysis found significant correlations between TSE area values at beta2 and gamma2 bands and clinical rating scales. This study demonstrates the frequency specificity properties of FCMC estimated by TSE can assess the rehabilitation status of stroke patients and contribute to our comprehension of the potential mechanism of motor control systems.

Cardiovascular and vasomotor pulsations in the brain and periphery during awake and NREM sleep in a multimodal fMRI study.

The cerebrospinal fluid dynamics in the human brain are driven by physiological pulsations, including cardiovascular pulses and very low-frequency (< 0.1 Hz) vasomotor waves. Ultrafast functional magnetic resonance imaging (fMRI) facilitates the simultaneous measurement of these signals from venous and arterial compartments independently with both classical venous blood oxygenation level dependent (BOLD) and faster arterial spin-phase contrast. In this study, we compared the interaction of these two pulsations in awake and sleep using fMRI and peripheral fingertip photoplethysmography in both arterial and venous signals in 10 healthy subjects (5 female). Sleep increased the power of brain cardiovascular pulsations, decreased peripheral pulsation, and desynchronized them. However, vasomotor waves increase power and synchronicity in both brain and peripheral signals during sleep. Peculiarly, lag between brain and peripheral vasomotor signals reversed in sleep within the default mode network. Finally, sleep synchronized cerebral arterial vasomotor waves with venous BOLD waves within distinct parasagittal brain tissue. These changes in power and pulsation synchrony may reflect systemic sleep-related changes in vascular control between the periphery and brain vasculature, while the increased synchrony of arterial and venous compartments may reflect increased convection of regional neurofluids in parasagittal areas in sleep.

Industrially induced warming triggered synchronous intensity changes in the East Asian summer and winter monsoons

Anomalies in the East Asian monsoon system significantly disrupt the densely populated East Asian region, underscoring the importance of understanding such changes and improving current predictive abilities. On the basis of instrumental records, previous studies have shown that the East Asian winter monsoon (EAWM) and summer monsoon (EASM) interact with each other. However, owing to the lack of long-term high-resolution EAWM records, it remains unclear how and whether human activity has affected the phase relationship between the EASM and EAWM since the Industrial Revolution. In this study, we present a precisely dated high-resolution EAWM record for the last 300 years from a crater lake in northeastern China. Our results indicate that the EAWM intensity was relatively weak and fluctuated significantly between 1700 and 1850 CE. After 1850 CE, the EAWM strengthened rapidly and exceeded its intensity observed at the end of the Little Ice Age. In addition, a comparison of our reconstructed EAWM record with the published EASM record clearly shows in-phase variations during the Current Warm Period. We concluded that the climatic effects of industrially induced warming enhance the EAWM by slowing the Atlantic meridional overturning circulation and increasing the meridional temperature gradient, while also strengthening the EASM by increasing hemispheric meridional gradients and affecting other large-scale processes. Under the sustained intensification of human activity, the EASM and EAWM are likely to continue exhibiting synchronous variations in the future.

Hydraulic impact of pressure transients from water conveyance tunnel on the complex hydrogeological system: A case study HPP Pirot, Serbia

Hydraulic tunnels, integral components of hydropower plant (HPP) systems, traversing diverse rock masses, pose challenges for long-term operation. The study’s main goal was to investigate how hydraulic transients originating from the headrace tunnel transfer through the concrete lining and manifest in surrounding aquifer systems. In this experimental study at the water pressure tunnel of HPP Pirot (Serbia), a novel monitoring approach was employed. The internal piezometers with highly sensitive probes are distributed strategically along the tunnel in different geological environments. This approach involved monitoring of water pressure in the surrounding rock masses and observing the impact of hydraulic transients generated by HPP operation. A comprehensive analysis of monitoring data, incorporating ordinal and partial correlations and considering geological features, provides a profound understanding of groundwater dynamics, pressure transient phenomena, and hydrogeological characterization during HPP operation. The study highlights the complex and spatially diverse hydrogeological environment, emphasizing the varying reactivity of pore pressure during HPP operation, particularly concerning Water Mass Oscillations (WMO). Reactive piezometers near the surge tank demonstrate significant pressure variations, while those located further away display synchronous pressure changes with reduced amplitudes. Schematic hydrogeological models have been created based on the hydraulic impacts of HPPs in different geological environments along the tunnel route. The water pressure response enabled aquifer characterization of (1) a thin-layered, low-fissured aquifer closely related to the reservoir, with low influence on WMO transients; (2) a low-fissured, compartment aquifer or non-aquifer with minimal to no influence on WMO transients; (3) a well-structured karst aquifer system influenced by WMO transients; (4) a fault-controlled zone of deep hypogene karst aquifer discharge highly influenced by WMO transients; and (5) an aquifer with a dominant development of the karst conduit system highly influenced by WMO transients. The study highlights the significance of monitoring water pressure within the rock mass as a fundamental element in analyzing the interaction between water pressure tunnels and the hydrogeological environment. Applying the presented instrumentation and methodology facilitates effective monitoring in research areas where pressure tunnels are constructed.

River algal blooms can be estimated by remote sensing reflectance

Abstract River eutrophication is difficult to diagnose and estimate quantitatively because of its complex degradation mechanism in large river systems. Conventional monitoring and modeling methods are limited to accurately revealing the evolution process and trends of river aquatic organisms. In the present study, based on HJ-1A/1B CCD sensor, combined with genetic algorithm (GA) and regression tree (GART), a remote sensing inversion prediction model was established; the model can estimate algal blooms in the Han River affected by China’s Middle Route of the South-to-North Water Diversion Project (SNWTP). During the outbreak of algal blooms, the near-infrared band reflectance evidently increased between 2009 and 2015, with increasing algal density. The algal density in the downstream of the Han River has a nearly synchronous positive change with the reflectance in the B4 (near-infrared) band and a nearly synchronous reverse change with the B1 (blue) band. B1 and B4 screened by GA reduced redundancy by 14%, leading to a good prediction performance (R 2 = 0.88). According to GART and partial dependence analysis, the B4 band is a crucial characterization factor of algal blooms in the Han River. When the remote sensing band was in the range of B1 ⩾ 0.085 and B4 ⩽ 0.101, the algal density was lower than 0.15 × 107 cells l−1, indicating no algal bloom in the downstream of the Han River. When B4 was &gt;0.103 and B1 ⩽ 0.076, algal density was higher than 1 × 107 cells l−1 and algal blooms were very likely to occur. These findings could provide a scientific reference for diagnosing and predicting large-scale water ecological degradation in similar watersheds.