Self-regulating Properties Research Articles

Novel Smart Microreactors Equipped with Responsive Catalytic Nanoparticles on Microchannels.

Nowadays efficient and reliable control of highly exothermic reactions to effectively prevent overheating or even explosions still remains a challenging task, although newly developed microreactor technology has shown promise. Here, we report a novel smart microreactor system equipped with responsive catalytic nanoparticles on microchannels for self-regulated control over highly exothermic reactions by responding to the reaction-generated heat. On the basis of shrinking/swelling behaviors of polymeric networks in the responsive catalytic nanoparticles, the smart microreactor could respond to the change of reaction temperature to tune the catalysis activity of catalytic particles in a thermo-feedback process. As a breakthrough result, highly exothermic reactions carried out in such a microreactor can be well-controlled in a self-regulation process without any manual assistance, efficiently ensuring the safety of the reaction. Such smart responsive catalytic systems have high potential and are attractive as a new generation of efficient tools that feature a self-regulation property for highly exothermic catalytic reactions.

Numerical analysis of temperature field improvement with nanoparticles designed to achieve critical power dissipation in magnetic hyperthermia

Magnetic nanoparticle (MNP) hyperthermia is a promising emerging therapy for cancer treatment that is minimally invasive and has been successfully used to treat different types of tumors. The power dissipation of MNPs, which is one of the most important factors during a hyperthermia treatment, is determined by the properties of MNPs and characteristics of the magnetic field. This paper proposes a method based on the finite element analysis for determining the value of the power dissipation of particles (PDP) that can maximize the average temperature of the tumor during treatment and at the same time guarantee that the maximum temperature is within the therapeutic range. The application of the critical PDP value can improve the effectiveness of the treatment since it increases the average temperature in the tumor region while limiting the damage to the healthy tissue that surrounds it. After the critical PDP is determined for a specific model, it is shown how the properties of the MNPs can be chosen to achieve the desired PDP value. The transient behavior of the temperature distribution for two different models considering blood vessels is analyzed as a case study, showing that the presence of a blood vessel inside the tumor region can significantly decrease the uniformity of the temperature field and also increase the treatment duration given its cooling effects. To present a solution that does not depend upon a good model of the tumor region, an alternative method that uses MNPs with low Curie temperature is proposed, given the temperature self-regulating properties of such MNPs. The results demonstrate that the uniformity of the temperature field can be significantly increased by combining the optimization procedure proposed in this paper with the use of low-Curie-temperature MNPs.

Ecosystem management as a wicked problem.

Ecosystems are self-regulating systems that provide societies with food, water, timber, and other resources. As demands for resources increase, management decisions are replacing self-regulating properties. Counter to previous technical approaches that applied simple formulas to estimate sustainable yields of single species, current research recognizes the inherent complexity of ecosystems and the inability to foresee all consequences of interventions across different spatial, temporal, and administrative scales. Ecosystem management is thus more realistically seen as a "wicked problem" that has no clear-cut solution. Approaches for addressing such problems include multisector decision-making, institutions that enable management to span across administrative boundaries, adaptive management, markets that incorporate natural capital, and collaborative processes to engage diverse stakeholders and address inequalities. Ecosystem management must avoid two traps: falsely assuming a tame solution and inaction from overwhelming complexity. An incremental approach can help to avoid these traps.

An experimental study of the influence of a thermosyphon filling ratio on a temperature distribution in characteristic points along the vapor channel height

Results of experimental studies of heat transfer in a thermosyphon illustrating the influence of the filling ratio and the heat load on the temperature distribution in the vapor channel, evaporation and condensation zones are presented. The thermosyphon was made of copper and was 161 mm high with side walls 1.5 mm thick, bottom cover 2 mm thick, an internal dimmer of the evaporation part of 54 mm and an internal diameter of the vapor channel of 39.2 mm. Based on the results of experimental studies, temperature dependences were established in the characteristic cross sections of the thermosyphon on the heat flux value supplied to the bottom cover. In addition, a well-appearing thermosyphon self-regulation property has been found – the growth of the heat load in the evaporation zone in the range from 1940 to 7685 W/m 2 does not lead to a decrease in the heat removal intensity from the heat-release region.

Regulation of the BMP Signaling-Responsive Transcriptional Network in the Drosophila Embryo.

The BMP signaling pathway has a conserved role in dorsal-ventral axis patterning during embryonic development. In Drosophila, graded BMP signaling is transduced by the Mad transcription factor and opposed by the Brinker repressor. In this study, using the Drosophila embryo as a model, we combine RNA-seq with Mad and Brinker ChIP-seq to decipher the BMP-responsive transcriptional network underpinning differentiation of the dorsal ectoderm during dorsal-ventral axis patterning. We identify multiple new BMP target genes, including positive and negative regulators of EGF signaling. Manipulation of EGF signaling levels by loss- and gain-of-function studies reveals that EGF signaling negatively regulates embryonic BMP-responsive transcription. Therefore, the BMP gene network has a self-regulating property in that it establishes a balance between its activity and that of the antagonistic EGF signaling pathway to facilitate correct patterning. In terms of BMP-dependent transcription, we identify key roles for the Zelda and Zerknüllt transcription factors in establishing the resulting expression domain, and find widespread binding of insulator proteins to the Mad and Brinker-bound genomic regions. Analysis of embryos lacking the BEAF-32 insulator protein shows reduced transcription of a peak BMP target gene and a reduction in the number of amnioserosa cells, the fate specified by peak BMP signaling. We incorporate our findings into a model for Mad-dependent activation, and discuss its relevance to BMP signal interpretation in vertebrates.

Measuring Self-Regulation in Second Language Learning

Self-regulation has become a widely discussed subject in education as it facilitates learners’ ability to master their own learning. The purpose of the present study is to examine the psychometric properties of self-regulation in second language learning via Rasch measurement. A total of 528 high-school students from an East Asian country participated in the study, and the Self-Regulating Capacity in English Language Learning (SRClang) Scale was used as a self-report instrument. The results suggest that self-regulation in second language learning as measured by the SRClang Scale does not appear to be unidimensional. Based on item-model fit statistics, several items in the SRClang Scale may need to be revised or removed. Nonetheless, the response categories in the SRClang Scale function well as intended, and the scale can reliably separate items and persons based on their difficulty levels and ability trait levels, respectively. Overall, the SRClang Scale serves as an appropriate measure of self-regulatory capacity in second language learning.

Moral Identity and Moral Emotion Experience: a Cross-cultural Analysis

Despite the importance of individual's moral self-regulation at work, moral emotions as a self-regulation property have received sporadic attentions in the organizational wrongdoing context. Howeve...

Adaptive automatic control system with PI-controller frequency tuning

Application of adaptive control systems, based on selftuning controllers with a test periodic signal is considered in the paper. The main purpose of the study is to develop a new adaptive control algorithm since the technological process maintenance quality directly affects the automatic control system profitability. To implement the control algorithm, digital controllers, based on microprocessors, allowing to realize complex mathematical processing of the input data can be used.The methods for implementing the adaptive control systems with harmonic input signal, using the method of frequency-division of control channels and self-tuning are discussed. The method of quick adaptive tuning of one-loop local automatic control systems using test harmonic signal is given in the paper. The considered control object must have self-regulation properties and medium persistence. To identify the control object, modern error estimate prediction method used.The method is based on analyzing the properties of the system output signal and calculating PI-controller settings, guaranteeing aperiodic transient of the set parameters. When optimizing the PI-controller settings, direct quality indicators of transient of closed-loop control system are estimated.The results of developing the adaptive control algorithm can be applied in one-loop control systems with simple local technological objects, and can also serve as a basis for further research of control systems, which use harmonic signals to obtain more information about the control object

Formation of polypyrrole/metal hybrid interfacial layer with self-regulation functions via ultrasonication

The authors proposed a novel method of formation of polymer/metal hybrid interfacial layer with switchable properties by using ultrasonication. Intensive ultrasonication leads to the formation of a rough metal interface and triggers free-radical polymerization of monomers in the interfacial region of metal surface. Thus, polymer layer exhibits excellent adhesion to the bulk metal. The novel concept was demonstrated for polypyrrole/aluminum systems. Hydrophilic/hydrophobic properties and corrosion resistance also due to doping/dedoping of polypyrrole of the interfacial layers can be adjusted based on particular application. The proposed method can serve as a platform for formation of interfaces with self-regulating properties: self-healing, switchable hydrophylicity.

Propulsion efficiency of bodies appended with multiple flapping fins: When more is less

Underwater animals propel themselves by flapping their pectoral and caudal fins in a narrow range of frequencies, given by Strouhal number St, to produce transitional vortex jets (St is generally expressed non-dimensionally as the product of flapping frequency and stroke (arc) length divided by forward speed). The organized nature of the selection of St and of the vortex jet is thought to maximize hydrodynamic efficiency, although the exact mechanism is not known. Our recent Stuart-Landau equation models, which have self-regulation properties, indicate that the fin and its jet vortices couple. Temporal maps of forces in single isolated fins show a bimodal behavior in certain ranges of the transitional Reynolds number; this behavior bears resemblance to neural bifurcation properties that owe their origin to the self-regulation mechanism. In view of our theoretical and biorobotic evidence of self-regulation in single flapping fins, we explore if this property is altered in a fin-appended body, the goal being to understand how the narrow selection of St, self-regulation, and maximization of hydrodynamic efficiency are related. Swimming vehicles of 1-m scale have been built where a rigid cylindrical body is appended with six flapping fins, three at each end. The fins are rigid, have a rounded leading edge and a laminar section (NACA 0012), and are hinged at one end. The planform is an abstracted version of the penguin wing; it has low aspect ratio and a chord Reynolds number that varies in the transitional range from 10 000 to 60 000. The fin geometry, Reynolds number range, and the nonflexible nature of the main body are in common with those in penguins, and the length and displacement volume are similar to those of sharks. The maximum hydrodynamic efficiency of the fin-appended body (0.40) is lower than that of the single fin (0.57), but is close to that of a fish using several fins. The propulsion density (kW/m3 of displacement volume) of the fin-appended cylinder is similar to that of a cruising shark. If we allow comparison of electrical versus thermal measurements, the total efficiency of the fin-appended body is similar to that of the damselfly and dragonfly, which are also based on vortex propulsion. The fin force fluctuations are modeled by a van der Pol oscillator. Measured phase maps of force fluctuation versus its time derivative correlate with the Strouhal numbers. Until stabilization, the maximum hydrodynamic efficiency of the fin-appended body increases with fin Reynolds number in a staircase pattern whose boundaries correlate with similar transitional sub-regimes in single fins, including the bimodal sub-regimes, thereby relating efficiency with the self-regulating jet vortex oscillators. At low Reynolds numbers, the peak of hydrodynamic efficiency remains flat over a wide range of St, becoming steeper at higher Reynolds numbers with the maximum occurring at lower values of St. The modeling shows that for self-regulation, future biorobotic design should focus on the reduction of structural damping and on a fin-body assembly that has reciprocal energetic interaction with the shed vortex.

ELECTROPHYSIOLOGICAL CORRELATES OF FUNCTIONAL COMPREHENSION SYSTEMS SELF-CONTROL

We have studied the electrophysiological mechanisms of providing optimal manifestation of non-specific characteristics and self-regulation properties of the functional comprehension systems and measuring the length of a sound signal and spatio-temporal parameters reflecting the processes occurring in the action result acceptors. It has been established that various self-regulation properties of the same functional system differed greatly in the links with EEG-rhythms, the peculiarities of the dynamic connection between various parts of the brain and the necessary nonspecific activation of CNS connected with the activating influences of the dominating motivation. It has been shown that with the similar character of dependence of the same self-regulation properties of different functional systems on EEG-rhythms and changes in their spatio-temporal synchronization, they were provided by different levels of the CNS generalized activation.

On the controllability and energy sensitivity of heat-integrated desiccant adsorption dryers

This work studies the controllability of heat-integrated zeolite adsorption dryers. Mean product moisture content, temperature and vitamin C concentration (representative of product quality) are considered as controlled variables. Set-point tracking and disturbance rejection controllability metrics are considered in addition to energy performance sensitivity. In adsorption dryers, the adsorption system introduces extra degrees of freedom of which some input–output pairs are promising. For corresponding inputs, adsorption dryers are shown to have higher steady-state gains than equivalent conventional dryers due to correlation between dehumidification, adsorption heat and the controlled variables. They also show improved resilience to ambient air disturbances due to adsorbent subsystem-induced self-regulation properties. The encouraging mechanisms of the self-regulation are adsorption heat, kinetic and equilibrium properties of the adsorbent. Due to the high correlation between product moisture content and temperature, improved controllability is observed when vitamin C concentration is used as an output variable instead of product temperature. It is thus proposed that on the availability of reliable soft sensors or state estimators, instead of product temperature, vitamin C or some other temperature-dependent quality measure should be controlled in addition to product moisture in decentralised drying system control. Under perfect rejection of unfavourable disturbances like ambient temperature drop and humidity rise, the energy performance of adsorption dryers is not significantly degraded, whereas, it is for conventional systems.

SELF-REGULATION VEGETATIVE CORRELATES OF COMPREHENSION FUNCTIONAL SYSTEMS

Self-regulation was regarded as a system reflecting in its properties the processes occurring in the action results ac ceptor and prone to the regulatory influences of the vegetative nervous system. The aim of the research: revealing of an interrelationship of the vegetative nervous system activation with the self-regulation properties of the information comprehension systems. We have investigated 122 volunteers (88 women and 34 men), aged 18-26 years, having no complaints of their health. The methods used: cardiointervalography and the techniques of evaluation of the sound signal length and spatio-temporal parameters comprehension. The results of the research have demonstrated that the minimal activation and parasympathetics provide the sensitivity to feedback, the medium activation provides high accuracy, style and flexibility of self-regulation. The maximal tension of regulatory systems stipulated the ability to learn and the general plasticity. It has been established that each feature of self-regulation and the processes in the action results acceptor were provided by their intrinsic level of the CNS vegetative activation, they were subject to unequal influences of the dominating motivation, and possessed a similar optimal level of power supply in different functional comprehension systems.

Integral and axial xenon oscillations superposition and vver-1000 core energy-release stability

The effects arising from the interaction between the xenon oscillations of the power and the axial distribution of the energy release in the core as well as the role of these effects in the stability of energy release in VVER≠1000 are examined. It is shown that the reactor poses self-regulation properties. The superposition of the integral and axial xenon oscillations combined with the operation of the automatic power regulator prevents the appearance of diverging xenon oscillations and suppresses low-amplitude oscillations without operator intervention.

Negative feedback in the bone morphogenetic protein 4 (BMP4) synexpression group governs its dynamic signaling range and canalizes development

What makes embryogenesis a robust and canalized process is an important question in developmental biology. A bone morphogenetic protein (BMP) morphogen gradient plays a key role in embryonic development, and we are beginning to understand how the self-regulating properties of its signaling circuitry ensure robust embryonic patterning. An unexplored question is why the BMP signaling circuit is organized as a modular synexpression group, with a prevalence of feedback inhibitors. Here, we provide evidence from direct experimentation and mathematical modeling that the synexpressed feedback inhibitors BAMBI, SMAD6, and SMAD7 (i) expand the dynamic BMP signaling range essential for proper embryonic patterning and (ii) reduce interindividual phenotypic and molecular variability in Xenopus embryos. Thereby, negative feedback linearizes signaling responses and confers robust patterning, thus promoting canalized development. The presence of negative feedback inhibitors in other growth factor synexpression groups suggests that these properties may constitute a general principle.

Non-invasive Electrophysiology I

Non-invasive Electrophysiology I

Morphogenesis versus structuration: on combining structure and action1

The fundamental problem of linking human agency and social structure stalks through the history of sociological theory. Basically it concerns how to develop an adequate theoretical account which deals simultaneously with men constituting society and the social formation of human agents. For any theorist, except the holist, social structure is ultimately a human product, but for any theorist, except advocates of psychologism, this product in turn shapes individuals and influences their interaction. However successive theoretical developments have tilted either towards structure or towards action, a slippage which has gathered in momentum over time. Initially this meant that one element became dominant and the other subordinate: human agency had become pale and ghostly in mid-century functionalism, whilst structure betook an evanescent fragility in the re-flowering of phenomenology. Eventually certain schools of thought repressed the second element almost completely. On the one hand structuralist Marxism and normative functionalism virtually snuffed-out agency-the acting subject became increasingly lifeless whilst the structural or cultural components enjoyed a life of their own, self-propelling or self-maintaining. On the other hand interpretative sociology busily banished the structural to the realm of objectification and facticity-human agency became sovereign whilst social structure was reduced to supine plasticity because of its constructed nature. Although proponents of these divergent views were extremely vociferous, they were also extensively criticized and precisely on the grounds that both structure and action were indispensable in sociological explanation.2 Moreover serious efforts to re-address the problem and to re-unite structure and action had already begun from inside 'the two Sociologies',3 when they were characterized in this manichean way. These attempts emerged after the early sixties from 'general' functionalists,4 'humanistic' marxists5 and from interactionists confronting the existence of strongly patterned conduct.6 Furthermore they were joined in the same decade by a bold attempt

Compensating Inhomogeneities of Neuromorphic VLSI Devices Via Short-Term Synaptic Plasticity

Recent developments in neuromorphic hardware engineering make mixed-signal VLSI neural network models promising candidates for neuroscientific research tools and massively parallel computing devices, especially for tasks which exhaust the computing power of software simulations. Still, like all analog hardware systems, neuromorphic models suffer from a constricted configurability and production-related fluctuations of device characteristics. Since also future systems, involving ever-smaller structures, will inevitably exhibit such inhomogeneities on the unit level, self-regulation properties become a crucial requirement for their successful operation. By applying a cortically inspired self-adjusting network architecture, we show that the activity of generic spiking neural networks emulated on a neuromorphic hardware system can be kept within a biologically realistic firing regime and gain a remarkable robustness against transistor-level variations. As a first approach of this kind in engineering practice, the short-term synaptic depression and facilitation mechanisms implemented within an analog VLSI model of I&F neurons are functionally utilized for the purpose of network level stabilization. We present experimental data acquired both from the hardware model and from comparative software simulations which prove the applicability of the employed paradigm to neuromorphic VLSI devices.

Two kinds of gravitational ejector refrigerator stimulation

Temperatures and levels of refrigerant in the heat exchangers of a gravitational ejector refrigerant make a combined system of numerous mutual couplings. It has some significant properties of self-regulation. There are three kinds of reaction on the self-regulation system of the refrigerator: thermal-type when it is stimulated by changing the temperature of exchangers surrounding, ejector-type stimulated by changing the ejector’s geometry or refrigerant kind, volume-type stimulated by changing the amount of refrigerant. The predicting of a specific reaction of a system balance is difficult but it may be obtained by a mathematical model and calculating experiments.

Cis-Acting Gene Regulatory Activities in the Terminal Regions ofSleeping BeautyDNA Transposon-Based Vectors

Sleeping Beauty (SB) DNA transposon-based vectors belong to a growing family of nonviral integrating vectors that represent attractive alternatives to conventional virus-based integrating gene vehicles. Because of concerns related to mutagenesis and/or activation of cellular genes by integrating vectors, much attention has been paid to integration site preferences and the ability of vectors to influence expression of neighboring genes. Here, we test the hypothesis that terminal repeats of transposons carry cis-acting regulatory sequences. In transient gene expression studies, we demonstrate that the inverted repeats of SB direct gene expression in HeLa cells to levels that are 3-fold higher than in promoter-deficient controls. Inverted repeats pointing toward the transposon center consistently facilitate the highest levels of activity in a number of cell lines. We show that transposon sequences flanking the inverted repeats of SB are required for positive effects on gene expression and, moreover, that these regions contain both stimulatory and inhibitory cis-acting elements. In the context of an integrated SB vector the regulatory activities of the transposon termini are sufficient to drive expression of selectable marker genes carried by the transposon, indicating that opposing transcriptional activities originating from the transposon termini may influence expression of its genetic cargo. Finally, detection of regulatory properties of the terminal repeats of the active Tc3 element from Caenorhabditis elegans leads to the suggestion that transcriptional activities of the inverted repeats are conserved among Tc1/mariner transposons in nature. Our data suggest that SB-based gene vectors may carry ancient properties of self-regulation with potential relevance for SB-directed therapeutic gene transfer.