Reversible Motion Research Articles

Evaluating the Physical Condition of Students of the Military Academies of the Greek Armed Forces based on Simple Tests. Comparison of the Physical Condition of First Year Students to Third Year Students

The present study provides useful information on the Hellenic Armed personnel and their physical condition. To evaluate this, five tests of the Eurofit bundle were used. These tests were: a) shuttle run (endurance run), b) 30 meters sprint, c) hand grip strength test, d) Vertical jump test, e) sit and reach test. There was a comparison between first-year and third-year students at the school of Regular Non-commissioned officers from the Hellenic Armed Forces. A total of 75 students at the School of Regular Non-Commissioned Officers were evaluated for their physical condition, through the aforementioned Eurofit tests. They were divided in two groups, 33 first-year students and 42 third-year students. All of them were male individuals between the ages of 18 and 21. The working hypothesis was thus related to the possibility of different results in the physical condition of first year students as compared to third-year students. The subjects were tested on the shuttle run endurance test, the 30-meter sprint, the hand grip strength, the vertical reverse motion jump and the sit and reach test (flexibility test). The average values of the tests were at a fairly high level compared to the results of similar studies (endurance: 8.57 - 8.93 stages, sprint: 4.32 - 4.32sec, grip strength: 48.5 - 58.2kp, jump: 30.1 - 34.4cm, flexibility: 18.10 - 18.17cm). Comparison of performance between freshmen and third-year students revealed that there were no statistically significant differences between the two groups, with the exception of the vertical jump (threeyear students’ dominance, 34.4 ± 5.7 vs 30.1 ± 5.5 cm). The correlation analysis showed low to moderate correlation coefficients between the performance of sprint and other tests (r = -0.28 to -0.39) and of course a high correlation of performance on the grip strength between right and left hand (r = 0.87). Studies that are longer in duration and with a larger sample should be conducted to assess the performance of applied training programs in the Schools of the Hellenic Armed Forces. Scientific research must be conducted in that direction. At the same time, basic physical fitness parameters should be analyzed to examine the performance and preparedness of the Hellenic army.

A motion planning method for a car based on environmental feature-adaptive polynomial fitting and intelligent obstacle avoidance strategies

This paper proposes an improved method for car motion planning aimed at addressing the limitations of traditional path planning and obstacle avoidance algorithms in complex environments. The study utilizes Bi-RRT* and polynomial fitting for path planning, incorporating an environment-adaptive polynomial fitting technique based on obstacle density to enhance path precision in areas with high obstacle density. In the local planning phase, intelligent switching of the car’s obstacle avoidance strategies is implemented, allowing the car to use reverse motion or lateral avoidance in high-density regions to prevent stalling. Furthermore, problem decomposition and approximation methods are applied to large-scale quadratic programming (QP) problems in path tracking, improving the efficiency of the MPC algorithm. Experimental results demonstrate that the proposed method significantly enhances the car’s motion performance and stability in complex environments.

A compact structure and high-speed actuator designed by imitating the movement of wave

By imitating the natural phenomenon of waves pushing leaves, a compact novel wave-type piezoelectric actuator is proposed in this paper. Compared to traditional inchworm piezoelectric actuators, it combines the clamping unit and driving unit into an arc-shaped flexible driving foot (AFDF). Clamping and driving functions are realized by alternately controlling two ends of the AFDF using two piezoelectric stacks (PESs). One motion unit instead of two makes control simpler, the structure more compact and a faster movement speed. The static model of the AFDF is developed to characterize the mapping laws between structural dimensions and actuator amplification ratios, and the dynamic model represents the relationship between the control signals and move displacements, thus demonstrating the feasibility of the actuator. Finally, a prototype was fabricated, and a testing system was set up to conduct performance evaluations of its motion capabilities. At the driving frequencies of 370 Hz and 380 Hz, the maximum forward and reverse motion speeds can reach 4.345mm/s and 4.537mm/s, respectively. In the range of 0.1-10N, there is no significant change in motion speed, and it has good stability. Its resolution for forward and reverse motion can reach 106nm and 109nm, respectively.

Revealing the slip distribution and seismogenic structure of the magnitude 6.2 Jishishan (Gansu) earthquake in 2023 through multi-source InSAR observations

ABSTRACT On 18 December 2023, Jishishan County in Gansu Province, China, was struck by an earthquake with magnitude 6.2, resulting in considerable loss of life and property. The seismogenic fault and rupture model of the event has sparked significant controversy, leading to diverse opinions among researchers. Some attribute the earthquake to the northern segment of the west-dipping Lajishan fault, whereas others consider an east-dipping blind fault on the Jishishan fault to be the seismogenic fault. This study integrates InSAR observations, aftershock relocation, and active tectonic analysis to determine the structure and rupture characteristics of seismogenic faults. Considering the active fault distribution, a listric fault model has emerged as the most plausible source of this earthquake event. The model of this study suggests a hidden branch of the southern segment of the Lajishan fault, whose reverse movement caused an uplift in the shallow crust. Supported by InSAR-derived coseismic deformation data and relocated aftershocks, this seismogenic model provides valuable insights into the regional tectonic framework. This study emphasizes the complexity of fault systems involved in earthquake genesis and contributes to a deeper understanding of seismic risk in the area.

Cannabigerol Mitigates Haloperidol-Induced Vacuous Chewing Movements in Mice.

Chronic use of typical antipsychotics can lead to varying motor effects depending on the timing of analysis. Acute treatment typically induces hypokinesia, resembling parkinsonism, while repeated use can result in tardive dyskinesia, a hyperkinetic syndrome marked by involuntary orofacial movements, such as vacuous chewing movements in mice. Tardive dyskinesia is particularly concerning due to its potential irreversibility and associated motor discomfort. One prevailing theory suggests that tardive dyskinesia arises from hypersensitivity of D2-type dopaminergic receptors caused by continuous blockade from typical antipsychotics like haloperidol. Additionally, increased inflammation, oxidative stress, and elevated FosB protein expression in the dorsolateral striatum are implicated in its pathophysiology. Current treatments for tardive dyskinesia often lack clear efficacy and may lead to significant side effects. Cannabigerol, a non-psychotomimetic cannabinoid with antioxidant and anti-inflammatory properties, has been investigated for its potential antidyskinetic effects. In this study, mice were treated with cannabigerol at doses of 3 and 10mg/kg to evaluate its ability to prevent, ameliorate, or reverse haloperidol-induced vacuous chewing movements. Cannabigerol successfully reduced vacuous chewing movements without affecting normal motor activity, exacerbating haloperidol-induced hypokinesia, or inducing dyskinetic effects on its own. However, no significant reversal of the haloperidol-induced motor effects was observed under the current protocol. Furthermore, cannabigerol did not alter FosB expression or microglia morphology. These findings underscore the need for further research to explore cannabigerol's therapeutic potential and contribute to our understanding of its possible clinical applications in managing tardive dyskinesia.

The Paradoxical State: The Political Economy of Multidimensional Gender Inequality in Korea

ABSTRACT Why do Korean women, who live in one of the most technologically and economically dynamic countries in the world, lag so far behind men in most important aspects of social life? Conventional answers to this question believe that more government intervention is needed, but Korea has followed state feminist policies since democratisation with limited success. This article draws on insights from the field of feminist political economy and the theory of performativity to propose a revised model of state–society interaction that better explains this puzzle. Historically, the South Korean state has oscillated between creating gender inequality for its economic and political nation-building projects, and then seeking to reduce it for the purposes of social reproduction. However, this reverse movement is ‘sticky’ because many non-state actors’ performances of gender inequality are resistant to state feminism, and others are closely associated with national identity. We conduct a plausibility probe of our model by applying it to three key performances of gender in Korea: traditional culture, conscription, and sex work. Our findings suggest the need for more bottom-up activism and campaigns against actors within and beyond the state who continue to resist gender equality.

Dielectric nonlinearity analysis of BNT–ST–BT relaxor ferroelectric thin films with different film thicknesses

Thickness-dependent dielectric nonlinear properties of 0.78Bi0.5Na0.5TiO3–0.2SrTiO3–0.02BaTiO3 thin films in a thickness range of 0.62–1.62 μm were investigated in this work. It was demonstrated that the dielectric properties decreased with the decrease in thickness due to the substrate clamping inducing the degeneration of intrinsic contribution and the reduced domain wall mobility. A low DC electric field promoted domain switching and reversible domain wall motion. The domain mobility was suppressed by a high DC electric field, which resulted in reduced dielectric permittivity combined with the tunability of intrinsic dielectric response.

The Reverse Lunge: A Descriptive Electromyographic Study

Limited studies exist examining the reverse lunge. The purpose of this study was to describe the activation of the rectus femoris (RF), biceps femoris (BF), gluteus medius (GMed), and gluteus maximus (GMax) of both limbs during a bodyweight reverse lunge movement. A secondary purpose was to describe the phases of the stationary (non-moving) and lead (moving) limbs during the reverse lunge. Surface electromyography (EMG) was used to record the activity of the target muscles in 20 healthy adults (10 male, 10 female; aged 22–25). Root mean squared values for mean maximum and average percent activation normalized to maximum voluntary isometric contraction (MVIC) activation were calculated. Descriptive terminology was created to describe the phases of the lunge for both limbs. The mean maximum percentage of muscle activation for the RF and BF was greater in the lead limb, while GMed and GMax activations were greater in the stationary limb. Only the lead limb RF and stationary limb GMed reached a strengthening stimulus in mean maximum percentage measurements. Clinically, it may be important to consider when each muscle is maximally active and at what percentage of its MVIC to properly prescribe the reverse lunge in a safe manner.

Development of a reversible motion wire-electrochemical spark cutting (RM-WECSC) setup for profile cutting with high cutting rate in a microcut width of Al2O3 ceramic epoxy nanocomposite

Development of a reversible motion wire-electrochemical spark cutting (RM-WECSC) setup for profile cutting with high cutting rate in a microcut width of Al2O3 ceramic epoxy nanocomposite

Topological transformation of synthetic ferromagnetic skyrmions: thermal assisted switching of helicity by spin-orbit torque

This study demonstrates the controllable switching of skyrmion helicity using spin-orbit torque, enhanced by thermal effects. Electric current pulses applied to a [Pt/Co]3/Ru/[Co/Pt]3 multilayer stripe drive skyrmions in a direction opposite to the current flow. Continuous pulsing results in an unexpected reversal of skyrmion motion. Micromagnetic simulations reveal that skyrmions in the upper and lower ferromagnetic layers exhibit distinct helicities, forming a hybrid synthetic skyrmion. The helicity switch of this hybrid structure accounts for the motion reversal. This study introduces innovative helicity control methods, advancing spintronic device applications, including data storage and quantum computing based on skyrmion helicity.

Studies of stationary features in jets: BL Lacertae

Context. High-resolution very long baseline interferometry observations have revealed a quasi-stationary component (QSC) in the relativistic jets of many blazars, which represents a standing recollimation shock. VLBA monitoring of the BL Lacertae jet at 15 GHz shows the QSC at a projected distance of about 0.26 mas from the radio core. Aims. We study the trajectory and kinematics of the QSC in BL Lacertae on sub-parsec scales using 15 GHz VLBA data of 164 observations over 20 years from the MOJAVE program and 2 cm VLBA Survey. Methods. To reconstruct the QSC’s intrinsic trajectory, we used moving average and trajectory refinement procedures to smooth out the effects of core displacement and account for QSC positioning errors. Results. We identified 22 QSC reversal patterns with a frequency of ∼1.5 per year. Most reversals have an acute angle < 90° and a few have a loop-shaped or arc-shaped trajectory. Where observed, combinations of reversals show reversible and quasi-oscillatory motion. We propose a model in which a relativistic transverse wave passes through the QSC, generating a short-lived reverse motion, similar to the transverse motion of a seagull on a wave. According to the model, relativistic waves are generated upstream and the reverse motion of the QSC is governed by the amplitude, velocity, and tilt of the wave as it passes through. The apparent superluminal speeds of the QSC (∼2 c) are then due to the relativistic speed of the jet’s transverse wave (< 0.3 c in the host galaxy rest frame) combined with the relativistic motion towards the observer. The measured superluminal speeds of the QSC indirectly indicate the presence of relativistic transverse waves, and the size of the QSC scattering on the sky is proportional to the maximum amplitude of the wave. We find that most of the transverse waves are twisted in space. In the active state of the jet, the directions of the twisting waves are random, similar to the behaviour of the wave in a high-pressure hose, while in the jet stable state, the wave makes quasi-oscillations with regular twisting. Conclusions. The study of QSC dynamics in BL Lac-type blazars is important for evaluating the physical characteristics of relativistic transverse jet waves. The latter have important implications for jet physics and open up possibilities for modelling the physical conditions and location in the jet necessary for the excitation of relativistic transverse waves.

The effects of flexibility on the formation and evolution of wake vortices behind a heaving plate

The kinematics of vortical structures behind heaving plates with different flexibility has been investigated using particle image velocimetry. The rectangular plates with different thicknesses undergo a trapezoidal velocity profile (acceleration–steady–deceleration). The Reynolds number Rec based on the chord length and the steady velocity is 5330. The formation and evolution processes of the wake vortices are investigated, with the focus on the comparison between the rigid wing and flexible wings. Wake vortices for the rigid wing initiated near the plate edges, while for flexible wings vortices initiated near the quarter-chord from the edges and slid toward the edges as the plates deform and move forward. During the first half cycle (moving forward), both the vortex trajectories and circulation indicate a global two-stage growth of the starting vortices for all the plates, corresponding to the acceleration and steady motion stages, respectively. The flexible plates have larger wake width and attain higher peak circulation initially; however, the circulation for the rigid plate achieves higher peak value during the steady stage. During the second half cycle (moving backward), the vortex trajectories present a two-stage process; however, the circulation is a single growth and decay process. Besides, detailed study reveals that during the acceleration, the circulation grows rapidly and there is a small decay at the end of the acceleration, thus forming the local peak for the first stage. The vortex trajectories for the flexible plates show greater range transversely, as well as the motion reversal in the streamwise direction.

Rapid estimation of source parameters for the 2022 Mw 6.6 Menyuan earthquake with combined high-rate GNSS and strong motion data in Northeastern Tibet

To investigate the reliability of high-rate GNSS in the rapid estimation of source parameters for the 2022 Menyuan Mw 6.6 earthquake, we collected high-rate GNSS and strong motion data within a 200 km radius of the epicenter. We performed high-precision calculations to obtain three-dimensional dynamic displacement waveforms for all stations and analyzed the reliability of source parameter estimation and coseismic deformation acquisition. The three-dimensional dynamic displacement waveforms show that the amplitude of displacement fluctuations at each station decreases with increasing distance from the epicenter. The station closest to the epicenter, C007, recorded a maximum east–west amplitude of 15 cm, a north–south amplitude of 10.8 cm, and a vertical amplitude of only 2.2 cm. The inverted epicenter location using displacement waveforms is (101.263°E, 37.802°N), with an origin time of 17:45:25.9 (UTC) and a magnitude of Mw 6.65. These results are generally consistent with those obtained from seismological methods using the seismic data. By combining high-rate GNSS and strong-motion data for magnitude estimation, an initial value of Mw 6.0 can be obtained 15 s after the earthquake, with stable convergence to Mw 6.6 within 40 s. The quality of magnitude estimation convergence is positively correlated with the number of stations. Based on the displacement waveforms 100 s before and after the earthquake, the coseismic deformation of this event can be quickly obtained. The results show opposite motion trends on the south and north sides of the seismogenic fault, with no significant vertical movement. Our results indicate that using near-field high-rate GNSS and strong motion data can rapidly and effectively estimate the source parameters and coseismic deformation of the strong earthquake, which can provide valuable reference for post-earthquake emergency response and rapid disaster assessment.

Reversible Sliding Motion by Hole-Injection in Ammonium-Linked Ferrocene, Electronically Decoupled from Noble Metal Substrate by Crown-Ether Template Layer.

Artificial molecular machines, especially when based on wheel-and-axle complexes, can generate mechanical motions in response to external stimuli. Ferrocene (Fc) is a key component, but it decomposes at 300 K on metal surfaces. Here, a novel method is presented to construct and control the molecular complex composed of ammonium-linked ferrocene (Fc-amm) and tetrabrominated crown ether (BrCR) on a Cu(111) surface. Fc-amm molecules are periodically arranged on a BrCR monolayer film and imaged using scanning tunneling microscopy and spectroscopy. A lateral motion of the Fc groups by ≈0.1nm is observed for pairs of "edge-on" Fc-amm molecules upon hole injection. This sliding motion is reversible and controlled by the applied voltage. Theoretical analysis indicates that the motion is caused by increased Coulomb repulsion of the hole-doped Fc-amm+ ions and accompanied by a weakening of CH-π interactions. These findings open new avenues for developing nanomolecular devices using on-surface bottom-up processes.

Influence of different kinematics on shaping ability and accumulated hard tissue debris: an ex vivo study.

To determine the shaping ability, the amount of accumulated hard tissue debris (AHTD) and untouched area is generated by different kinematics through micro-CT. Thirty-two mesial roots of mandibular molars with Vertucci type IV were pre-scanned through micro-CT evaluation and randomized to one of the four experimental groups according to the kinematics tested: Continuous Rotation (CR), Reciprocation (REC), Optimum Torque Reverse (OTR) and Jeni motion. The root canal preparation was performed with HyFlex EDM (Coltène/Whaledent AG) up to OneFile. After each file used, irrigation was performed with 2mL 5.25% NaOCl for 1min. The final rinse was performed with 1ml of 5.25% NaOCl followed by a 1ml of 17% EDTA and, 1ml of distilled water. Then, the samples were scanned and the images, before and after preparation, were superimposed and analyzed to determine the AHTD, untouched areas, canal transportation, centering ability, and shaping time. Data were statistically analyzed using Kruskal-Wallis test and Dunn post hoc with p < 0.05. No significant differences were detected among the tested kinematics in terms of untouched areas, AHTD, canal transportation and shaping time (p > 0.05). Significantly more untouched areas were detected in the coronal third compared to the middle (p = 0.0301) and apical ones (p = 0.0399) under continuous rotation. Moreover, a significantly higher centering ratio in the middle third compared to the apical was observed for Jeni motion (p = 0.0207). The tested kinematics showed similar untouched areas, AHTD, shaping ability and shaping time. All motions determined an appropriate mechanical preparation; yet, none of them was able to prepare all canal walls and keep the root canals completely free from hard tissue debris.

Surprising gender biases in GPT

We present eight experiments exploring gender biases in GPT. Initially, GPT was asked to generate demographics of a potential writer of fourty phrases ostensibly written by elementary school students, twenty containing feminine stereotypes and twenty with masculine stereotypes. Results show a strong bias, with stereotypically masculine sentences attributed to a female more often than vice versa. For example, the sentence “I love playing fotbal! Im practicing with my cosin Michael” was constantly assigned by GPT-3.5 Turbo to a female writer. This phenomenon likely reflects that while initiatives to integrate women in traditionally masculine roles have gained momentum, the reverse movement remains relatively underdeveloped. Subsequent experiments investigate the same issue in high-stakes moral dilemmas. GPT-4 finds it more appropriate to abuse a man to prevent a nuclear apocalypse than to abuse a woman. This bias extends to other forms of violence central to the gender parity debate (abuse), but not to those less central (torture). Moreover, this bias increases in cases of mixed-sex violence for the greater good: GPT-4 agrees with a woman using violence against a man to prevent a nuclear apocalypse but disagrees with a man using violence against a woman for the same purpose. Finally, these biases are implicit, as they do not emerge when GPT-4 is directly asked to rank moral violations. These results highlight the necessity of carefully managing inclusivity efforts to prevent unintended discrimination.

Supramolecular Spring-Like Fe(II) Spin-Crossover Complexes Experiencing Giant and Anisotropic Thermal Expansion Across Two Distinct Temperature Regimes.

Dynamic molecules with tunable chemical and physical properties in response to external stimuli hold great potential for applications in various fields such as information storage, smart molecular machines, and biomimetics. Among them, supramolecular springs and spin-crossover (SCO) complexes can both undergo visible macroscopic changes under heat or light stimulation. In this study, we synthesized a unique trinuclear Fe(II)-SCO complex, [(R-L)FeII{Au(CN)2}2] (R 1), using a chiral chelating ligand decorated with rotatable benzyl rings. The [FeAu2] trinuclear molecules form a 21-helical supramolecular chain via elastic Au Au contacts. Interestingly, the synergy between the multiple dynamic factors (SCO event, rotation of the rings, and flexibility in Au Au distance) endows the complex with multiple switchings in both magnetism and structure, as well as the most intriguing characteristic of giant and anisotropic "breathing" feature in thermal expansion within two distinct temperature regimes. Specifically, complex R 1 undergoes two hysteretic magnetic transitions: a non-spin transition between 360 and 380 K and an unsymmetric SCO transition in the region of 160-280 K, associated with a symmetry-breaking event between the non-polar and polar space groups (P212121↔P21). Both transitions are triggered/accompanied by the rotation (inward vs. outward) of the benzyl rings. Correspondingly, reversible spring-like motions of the helical chains with the helical pitches varying from 11.345140 K to 12.509280 K then back to 11.630380 K Å are observed in the two distinct temperature regimes. This work demonstrates a significant success in incorporating both SCO and spring-like motion in one system, paving the way for designing multifunctional dynamic materials for future devices.

Biomechanical analysis of teeth movement during the repair of mandibular defects using transport disk distraction osteogenesis

IntroductionTeeth movement or rotation is one of the complications of mandibular defect repair using transport disk distraction osteogenesis (TDDO). However, the mechanical reasons are not clearly understood. Material and methodsTo evaluate the biomechanical factors associated with teeth movements during mandibular defect repair with TDDO, a finite element model created from computed tomographic images of the human mandible was adopted to evaluate teeth displacement and the Von Mises stress distribution on the periodontal ligament resulting from the transport disk for teeth subjected to TDDO loading. ResultsUnder a displacement of 0.5 mm to the fixed arm of the transport disk, the teeth on the disk moved away from the distraction. The stress on the periodontal ligament was highest (60 KPa) around the distal neck. Upon the application of 150 g of resistance, the entire tooth moved in the same direction and the isoline gradient was almost parallel to the long axis of the tooth. Although the stress was distributed similarly; it decreased to 0.117 KPa geometrically. DiscussionWhen mandibular defects are repaired with TDDO, the transport disk and anti-distraction forces contribute to the reversal movement or rotation of the teeth, which may become immobility when antagonistic forces are applied in the same direction.

Contrasting Precipitation Variations over the Himalayas–Southeastern Tibetan Plateau in Winter: Insights from the Perspectives of Anthropogenic Warming and Arctic Sea Ice Variations

Abstract Climate warming has caused widespread glacier retreat across the Tibetan Plateau (TP), with notable impacts observed in both the western Himalayas and southeastern TP. Remarkably, over the past two decades, the rate of glacier mass loss has remained stable or even declined in the western Himalayas, whereas a contrasting trend of acceleration has been evident in the southeastern TP. Among various factors considered, the contrasting winter precipitation pattern across the Himalayas–southeastern TP stands out as an important contributor to the observed differences in glacier mass balances. However, the underlying mechanisms behind this phenomenon remain unclear. Here, we provide evidence of a noticeable shift in the climate regime due to anthropogenic warming, altering atmospheric circulation patterns. This, in turn, has led to a significant change in the dominant winter precipitation pattern, favoring the observed contrasting glacier mass balances trend in winter. Additionally, the Barents–Kara Sea ice has emerged as a plausible driver of the interannual variability of the contrasting precipitation pattern, acting by exerting force on the atmosphere and stimulating the Rossby wave propagation. Consequently, it led to the opposite vertical motion and alterations in the moisture budget between the western Himalayas and southeastern TP. Thus, it is crucial to consider the unprecedented anthropogenic warming and Arctic Sea ice variations as potential drivers shaping both past and future glacier behaviors within this domain.

Acclimation Strategies for the Black Sea Diatom Algae Ditylum brightwellii to High Intensity of Light

In cells of a culture of the large diatom Ditylum brightwellii (T. West) Grunow acclimated to weak light (17 μmol photons/(m2 × s)), numerous chloroplasts were evenly distributed throughout the cell cytoplasm. After 10 min of exposure of algae to extremely high illumination (1100 μmol photons/(m2 × s)), their aggregates gradually formed in the center of the cell, which continued until the end of the two-hour exposure period. At light intensities of 510–935 µmol/(photons/(m2 × s) during short-term photoacclimation, chloroplast aggregation was noted for 20–60 min, after which their reverse movement and uniform distribution in the cytoplasm were revealed by the end of the second hour. Under conditions of a longer culture stay at a light intensity of 1100 μmol photons/(m2 × s), the algae retained their viability for only six hours. Long-term photoacclimation of this species, which ended by the end of the second day, was detected when the light weakened by about 2 times. It was expressed as an increase in cell volume and C/Chl a ratio, increased aggregation of chloroplasts in the center of the cell, and a decrease in a number of fluorescent parameters reflecting the efficiency of photosystem II and culture viability.