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Plumbago auriculata Lam., a typical distylous plant, undergoes heteromorphic self-incompatibility (HetSI). The use of in vitro flowering allows the early identification of a plant's style morphology, and this process can be used to increase the efficiency of the breeding process and expedite research on the flowering mechanisms of P. auriculata. Here, we used seeds of P. auriculata as explants; obtained plantlets; and assessed the effects of temperature, thermoperiod, photoperiod, and light intensity on the in vitro flowering of the plants. The optimum temperature treatment was a diurnal alternation of 35 °C for 12 h and 25 °C for 12 h. Under these conditions, flower bud formation occurred within approximately 33 d, and the flowering percentage was as high as 91%. A photoperiod of 16 h and a light intensity of 200 µmol m−2 s−1 also promoted in vitro flowering. Under these conditions, flower buds formed within approximately 33 d, and the flowering percentage was approximately 90%. However, relatively long photoperiods and high light intensity suppressed flower bud development, reduced flowering, and shortened flower lifespan. The in vitro flowers had a lighter colour and smaller petals than did the in vivo flowers, although their floral structures (including their reproductive structures) were intact. This work demonstrates a stable system for the induction of in vitro flowering in P. auriculata and describes suitable temperature (35 °C/25 °C) and light (16 h photoperiod and 200 µmol m−2 s−1) conditions for rapid in vitro flowering. This system allows the efficient identification of long and short P. auriculata morphs and allows the formulation of a reasonable cultivation plan. The methods described here provide technical support for the development, utilization, and rapid propagation of excellent new P. auriculata varieties.

With the rapid development of single‐cell sequencing technology, the Langendorff perfusion system has emerged as a common approach to decompose cardiac tissue and obtain living cardiomyocytes to study cardiovascular disease with the mechanism of cardiomyocyte biology. However, the traditional Langendorff perfusion system is difficult to master, and further, the viability and purity of cardiomyocytes are frequently unable to meet sequencing requirements due to complicated devices and manipulate processes. Here, we provide an optimized Langendorff perfusion system with a simplified and standardized operating protocol which utilizes gravity as the perfusion pressure, includes a novel method for bubbles removing and standardizes the criteria for termination of digestion. We obtained stable cardiomyocyte with high viability and purity after multiple natural gravity sedimentation. The combination of the optimized Langendorff perfusion system and the multiple natural gravity sedimentation provides a stable system for isolating adult mouse heart, which will provide higher‐quality cardiomyocytes for further experiments.

The Hohenberg–Martin dilemma of conserving versus gapless theories for systems with Bose–Einstein condensate is considered. This dilemma states that, generally, a theory characterizing a system with broken global gauge symmetry, which is necessary for Bose–Einstein condensation, is either conserving, but has a gap in its spectrum, or is gapless, but does not obey conservation laws. In other words, such a system either displays a gapless spectrum, which is necessary for condensate existence, but is not conserving, which implies that it corresponds to an unstable system, or it respects conservation laws, describing a stable system, but the spectrum acquires a gap, which means that the condensate cannot appear. An approach is described, resolving this dilemma, and it is shown to give good quantitative agreement with experimental data. Calculations are accomplished in the Hartree–Fock–Bogolubov approximation.

In the recent literature, some practical systems have been modeled as interval systems. In this investigation, an improved approximation technique is first proposed for model reduction in single-input-single-output continuous interval systems; then, the proposed technique is extended to reduce multi-input-multi-output continuous interval systems. The proposed technique is based on a multipoint Pade approximation. Additionally, the technique generates a stable model for a given stable system. The results show that the Routh table integrated multipoint Pade approximation is a good way to reduce continuous interval systems.

An analytical investigation in a vertical fluid saturated porous layer distant from the axis of rotation is presented when vibration occurs in the presence of a stable temperature gradient. A linear stability analysis is used to determine the convection threshold in terms of the critical Rayleigh number for variation within the porous layer and for the offset distance from the axis of rotation. The results indicate that the presence of vibration in a stable system serves to reduce the Rayleigh numbers (both within the porous layer and due to offset from the axis of rotation), thus destabilizing the system when a stabilizing temperature gradient exists.

The feasibility of assembling and maintaining complex and expensive automatic equipment for navigation locks is considered. The hydraulic structures, including the hydraulic component of the locks, represent a stable system designed to function reliably for many decades. From the point of view of the present authors, a prediction of their state may be carried out by professional hydraulic engineers without the use of automatic equipment

The weak-signal detection approaches based on stochastic resonance (SR) are beneficial in detecting weak vibration signals from strong background noise. Therefore, many SR-based methods for mechanical incipient fault diagnosis appear. Among various nonlinear SR models, the underdamped tri-stable SR system, which has better output performance than other ones, has shown its potential superiority in weak-signal detection. The shortcomings for this model include its nonstandard forms of nonlinear potential functions and its inadequate research on parameter-adjusting mechanism for parameter-fixed noisy signals. In order to solve these issues, a standard tri-stable SR system is introduced in this paper and its SR performance is studied. Furthermore, a multi-parameter-adjusting SR (MPASR) model for the standard tri-stable system is proposed and its parameter adjustment rules for different input signals to produce SR are fully studied. At last, we propose a weak-signal detection method based on MPASR of the standard tri-stable system and employ two practical examples to demonstrate its feasibility in incipient fault diagnosis.

In this paper, a finance system with delay is considered. By analyzing the corresponding characteristic equations, the local stability of equilibrium is established. The existence of Hopf bifurcations at the equilibrium is also discussed. Furthermore, formulas for determining the direction of Hopf bifurcation and the stability of the bifurcating periodic solutions are derived by applying the normal form method and center manifold theorem. Finally, numerical simulation results are presented to validate the theoretical analysis. Numerical simulation results show that delay can lead a stable system into a chaotic state.

We investigated the atomic fill site probability distributions across supercell structures of RT12-xTi (R=Nd, Sm, T=Fe, Co). We use a combined molecular dynamics and Boltzmann distribution approach to extrapolate the probability distributions for Ti substitution from lower to higher temperatures with an equilibrium condition to assess how temperature affects the predictability of the structures fill path. It was found that the Nd and Sm based Fe systems have the highest filling probability path at lower temperatures but the cohesive energy change due to Ti substitution in Sm and Nd based crystals indicates that a more stable system could be achieved with a combination Co and Fe in the transition metal site., Comment: 5 pages, 4 figures, 2 tables

Monogeneans are ectoparasites that may cause losses in production and productivity in the aquaculture of Colossoma macropomum. Chemotherapeutics used in aquaculture usually have major adverse effects on fish; hence, the use of essential oils has been considered advantageous, but these are not soluble in water. Thus, the use of nanostructures to enhance water solubility of compounds and improve bioactivity may be very promising. This study investigated the antiparasitic activity of nanoemulsion prepared with Copaifera officinalis oleoresin (50, 100, 150, 200 and 300 mg/L), against monogenean parasites from the gills of C. macropomum. The particle size distribution and zeta potential suggested that a potentially kinetic stable system was generated. The nanoemulsion from C. officinalis oleoresin achieved high efficacy (100%) at low concentrations (200 and 300 mg/L) after 15 min of exposure. This was the first time that a nanoemulsion was generated from C. officinalis oleoresin using a solvent-free, non-heating and low-energy method. Moreover, this was the first time that an antiparasitic against monogeneans on fish gills, based on nanoemulsion of C. officinalis oleoresin, was tested. Made available in DSpace on 2018-06-17T00:32:30Z (GMT). No. of bitstreams: 1 CPAFAP2018EffectsofananoemulsionwithCopaifera.pdf: 580839 bytes, checksum: e8c63f8a0e6d3a734c8cf7a810589003 (MD5) Previous issue date: 2018-06-15

We develop a model of informal favor exchange within a social network where the cost of providing a favor is stochastic. The community has a norm, which specifies a cost threshold under which one should perform a favor if asked, as well as a punishment—exclusion from the network of the “noncompliers,” that is, of those who do not perform favors despite their cost being below the threshold, and those who refuse to punish nonperformers. We show that there always exists a cost threshold such that all agents participating in the favor exchange system receive strictly positive expected utility, and the system is a stable system. For systems involving stars and regular networks, we provide an ordering of the highest cost threshold supporting their stability. We also identify the conditions under which systems are efficient and show that, among all efficient systems, the one with the complete network provides the highest sum of expected utilities. An efficient system, however, need not be stable.

A microbial fuel cell (MFC) based on a new wild-type strain of Salinivibrio sp. allowed the self-sustained treatment of hypersaline solutions (100 g L-1 , 1.71 m NaCl), reaching a removal of (87±11) % of the initial chemical oxygen demand after five days of operation, being the highest value achieved for hypersaline MFC. The degradation process and the evolution of the open circuit potential of the MFCs were correlated, opening the possibility for online monitoring of the treatment. The use of alginate capsules to trap bacterial cells, increasing cell density and stability, resulted in an eightfold higher power output, together with a more stable system, allowing operation up to five months with no maintenance required. The reported results are of critical importance to efforts to develop a sustainable and cost-effective system that treats hypersaline waste streams and reduces the quantity of polluting compounds released.

We have studied the formation of epitaxial ferromagnetic/ferrimagnetic MnGa(0 0 1)/Mn4N(0 0 1) heterostructures by using spin polarized first principles calculations. In particular, we have analyzed the stability of the surface and interface as function of the N content. Since the Mn4N(0 0 1) has two stable surface terminations with a (1 × 1) periodicity, we have used them as substrates to grow MnGa. The interface formation energy formalism has been applied to describe the stability of all proposed models. Our calculations show that Mn at the interface is energetically favorable. Moreover, stability of the MnGa surface has a direct nitrogen dependence. Specifically, without extra N, the Ga-terminated surface is stable in the whole range of chemical potential for both substrates. Once N is added to the surface, the MnN-terminated surface becomes stable in both substrates for different ranges of chemical potential. Although MnGa and Mn4N are not antiferromagnetic materials, they form a local antiferromagnetic-like arrangement at the interface. This thermodynamically stable system could have potential applications in the construction of new generation spintronic devices.

Fog computing is a distributed computing paradigm at the edge of the network and requires cooperation of users and sharing of resources. When users in fog computing open their resources, their devices are easily intercepted and attacked because they are accessed through wireless network and present an extensive geographical distribution. In this study, a credible third party was introduced to supervise the behavior of users and protect the security of user cooperation. A fog computing security mechanism based on human nervous system is proposed, and the strategy for a stable system evolution is calculated. The MATLAB simulation results show that the proposed mechanism can reduce the number of attack behaviors effectively and stimulate users to cooperate in application tasks positively.

Since a T-type three-level PWM converter has several advantages in terms of harmonics and conduction loss, it has been widely adopted for various low voltage applications. However, a neutral point voltage control is necessarily required for stable system operation, and an offset voltage can effectively provide the required neutral point current under unbalanced load conditions. Nevertheless, all types of unbalanced loads cannot be accommodated, in other words, there is a limitation on how much unbalanced load conditions can be allowed. Therefore, this paper analyzed the maximum allowable unbalanced load conditions in the T-type three-level PWM converter. This result can be properly utilized for an effective design verification considering unbalanced load conditions as well as a comprehensive approach for the stable system operation. The feasibility of the analytical result is verified through simulation and experimental tests.

Pickering emulsion, which is an emulsion stabilized by solid particles, offers a wide range of potential applications because it generally provides a more stable system than surfactant-stabilized emulsion. Among various solid stabilizers, nanocellulose may open up new opportunities for future Pickering emulsions owing to its unique nanosizes, amphiphilicity, and other favorable properties (e.g. chemical stability, biodegradability, biocompatibility, and renewability). In this review, the preparation and properties of nanocellulose-stabilized Pickering emulsions are summarized. We also provide future perspectives on their applications, such as drug delivery, food, and composite materials.

The workings of “message”—a coherent, brand-like biographical chronotope—as it has long-circulated in the specifically American system of fifty-state presidential electoral politics helps to explain the outcome of the 2016 vote. The agōn of positive and negative messaging about the respective candidates, Secretary Clinton and Mr. Trump, seems to have worked, at the regional margins of an otherwise remarkably stable system, to the ultimate disadvantage of the former and the ultimate advantage of the latter.

The contractile apparatus of cardiomyocytes is considered to be a stable system. However, it undergoes strong rearrangements during heart development as cells progress from their non-muscle precursors. Long-term culturing of mature cardiomyocytes is also accompanied by the reorganization of their contractile apparatus with the conversion of typical myofibrils into structures of non-muscle type. Processes of heart development as well as cell adaptation to culture conditions in cardiomyocytes both involve extracellular matrix changes, which appear to be crucial for the maturation of contractile apparatus. The aim of this review is to analyze the role of extracellular matrix in the regulation of contractile system dynamics in cardiomyocytes. Here, the remodeling of actin contractile structures and the expression of actin isoforms in cardiomyocytes during differentiation and adaptation to the culture system are described along with the extracellular matrix alterations. The data supporting the regulation of actin dynamics by extracellular matrix are highlighted and the possible mechanisms of such regulation are discussed.

A common feature of pattern formation in both space and time is the destabilization of a stable equilibrium solution of an ordinary differential equation by adding diffusion or delay, or both. Here we study linear stability of general reactiondiffusion systems with off-diagonal time delays. We show that a delay-stable system cannot be destabilized by diffusion, and that a diffusion stable system is also stable with respect to delay, if the diffusion is sufficiently fast. A system with direct negative feedback which is strongly stable with respect to diffusion can be destabilized by off-diagonal delay.

We describe an ultra-stable, ultra-robust, straightforward and low-cost approach for the colorimetric detection of H2S with nanocrystalline cellulose (NCC) based on the reaction of H2S with lead acetate. The presence of NCC not only mediates the seed growth of a PbS/NCC complex, but also acts as a stabilizer protecting PbS from precipitation. This stable system is so robust that it can be used to quantitatively detect H2S even after two-year storage.

A species exhibits a hydra effect when, counter-intuitively, increased mortality of the species causes an increase in its abundance. Hydra effects have been studied in many continuous time (differential equation) multispecies models, but only rarely have hydra effects been observed in or studied with discrete time (difference equation) multispecies models. In addition most discrete time theory focuses on single-species models. Thus, it is unclear what unifying characteristics determine when hydra effects arise in discrete time models. Here, using discrete time multispecies models (where total abundance is the single variable describing each population), I show that a species exhibits a hydra effect in a stable system only when fixing that species’ density at its equilibrium density destabilizes the system. This general characteristic is referred to as subsystem instability. I apply this result to two-species models and identify specific mechanisms that cause hydra effects in stable communities, e.g., in host–-parasitoid models, host Allee effects and saturating parasitoid functional responses can cause parasitoid hydra effects. I discuss how the general characteristic can be used to identify mechanisms causing hydra effects in communities with three or more species. I also show that the condition for hydra effects at stable equilibria implies the system is reactive (i.e., density perturbations can grow before ultimately declining). This study extends previous work on conditions for hydra effects in single-species models by identifying necessary conditions for stable systems and sufficient conditions for cyclic systems. In total, these results show that hydra effects can arise in many more communities than previously appreciated and that hydra effects were present, but unrecognized, in previously studied discrete time models.

A new approach was proposed to analyze the stability of the linear continuous stationary dynamic systems. It is based on the decomposition of a square H2 norm of the transfer function of the dynamic system into parts corresponding either to particular eigenvalues of the system matrix, or to pairwise combinations of these eigenvalues. The spectral decompositions of a square H2 norm of the transfer function with multiple poles were obtained using the residues of the transfer function and their derivatives. Exact analytical expressions for calculation of the quadratic forms of the corresponding expansions were derived for an arbitrary location of the eigenvalues in the left half-plane. The obtained decompositions allow one to characterize the contribution of individual eigen-components or their pairwise combinations into the asymptotic variation of the system energy. We propose the energy criterion for estimation of the system stability margins that uses an evaluation of energy accumulated in a group of weakly stable system modes. This approach is illustrated by calculating the energy of a band-pass filter.

Meksika ile Amerika Birleşik Develeri (ABD) arasında 1950’lerin ortalarından 1980’lerin ortalarına kadar istikrarlı bir göç sistemi oluşmuş, hakim göç modelleri bu sistem ile onun sosyal ve ekonomik şartlarla şekillenen çıktılarını çok iyi kuramsallaştırmıştı. Bu göçler, genellikle erkek işçilerin, sınırın kuzey ve güneyindeki işgücü piyasalarındaki arz ve talep dengesindeki değişimlere, iki ülkedeki ücret yapılarına, Meksika’da gerçekleşen yapısal ekonomik değişimlere ve krizlere bir tepki olarak şekillenen döngüsel hareketleri olarak gelişmişti. Bu gelişmede göçmen ağlarının neoklasik ekonomisinin, bölünmüş işgücü piyasası kuramının, işçi göçünün yeni ekonomisinin, sosyal sermaye teorisinin, dünya sistemleri teorisinin, devlet davranışını açıklayan kuramsal modellerin işaret ettiği süreçlerin ve göçmen ağlarının genişlemesinin etkisi olmuştu. Ancak 1986’dan sonra, bu göç sistemi radikal bir biçimde değişti. Hareketlilik erkek işçilerin sınırlı sayıdaki eyalete ve şehre yönelen döngüsel göçü olmaktan çıktı ve net göç hızı keskin bir biçimde yükseldi. Göç, ülke geneline yönelen ve ailelerin gelip yerleştiği bir nitelik aldı. Bu dönüşüm, hakim kuramların iddia ettiği gibi sosyal, ekonomik veya siyasi faktörlerdeki değişimlerin sonucu olarak değil, Meksika–ABD sınırının askerileşmesini de beraberinde getiren kamuoyundaki dinamik süreçlerin sonucunda ortaya çıktı. Bu makalede önceki çalışmalara dayanarak bu dinamik süreci sonuçlarıyla birlikte tarif ediyorum. Bunu yaparken de bürokratların, siyasetçilerin ve uzmanların, aslında olmayan göç krizlerinin toplumsal inşası ve siyasi üretimi süreçlerinde etkili olan ve kendi menfaatleri doğrultusunda attıkları adımlara daha fazla kuramsal dikkat gösterilmesi gerekliliğini vurguluyorum.ABSTRACT IN ENGLISHA Missing Element in Migration TheoriesFrom the mid-1950s through the mid-1980s, migration between Mexico and the United States constituted a stable system whose contours were shaped by social and economic conditions well-theorized by prevailing models of migration. It evolved as a mostly circular movement of male workers going to a handful of US states in response to changing conditions of labour supply and demand north and south of the border, relative wages prevailing in each nation, market failures and structural economic changes in Mexico, and the expansion of migrant networks following processes specified by neoclassical economics, segmented labour market theory, the new economics of labour migration, social capital theory, world systems theory, and theoretical models of state behaviour. After 1986, however, the migration system was radically transformed, with the net rate of migration increasing sharply as movement shifted from a circular flow of male workers going a limited set of destinations to a nationwide population of settled families. This transformation stemmed from a dynamic process that occurred in the public arena to bring about an unprecedented militarization of the Mexico-US border, and not because of shifts in social, economic, or political factors specified in prevailing theories. In this paper I draw on earlier work to describe that dynamic process and demonstrate its consequences, underscoring the need for greater theoretical attention to the self-interested actions of politicians, pundits, and bureaucrats who benefit from the social construction and political manufacture of immigration crises when none really exist

Using the regional productivity of the Reichspost, the postal service of the German Empire, I investigate whether a public monopolist operates with uniform regional productivity. Using data envelopment analysis efficiency scores, we derive the relative productivity of the post, telegraph, and telephone sectors from 1891 to 1908. Results show a fairly stable system with substantial raw productivity differences between postal districts, and that the expansion of the service offset technological productivity increases for the mail service.

In this paper, the challenging problem of determining the unknown parameters of an identifiable LTI state-space representation of a stable system is addressed by resorting to a specific H∞-norm-based optimization algorithm. More specifically, by assuming the availability of a reliable fully-parameterized representation of the system to identify, the algorithm developed herein consists in restructuring this initial black-box representation of the system dynamics via the optimization of a dedicated maximum eigenvalue-based criterion. This study shows that this H∞-norm-based approach can be seen as a good solution for the identification of gray-box LTI state-space representations and, by extension, as an interesting alternative or a reliable initialization step for the standard output-error techniques.

Consider a discrete-time linear time-invariant descriptor system $Ex(k+1)=Ax(k)$ for $k \in \mathbb Z_{+}$. In this paper, we tackle for the first time the problem of stabilizing such systems by computing a nearby regular index one stable system $\hat E x(k+1)= \hat A x(k)$ with $\text{rank}(\hat E)=r$. We reformulate this highly nonconvex problem into an equivalent optimization problem with a relatively simple feasible set onto which it is easy to project. This allows us to employ a block coordinate descent method to obtain a nearby regular index one stable system. We illustrate the effectiveness of the algorithm on several examples., Comment: 10 pages, 3 tables, 1 figure

Single-parameter single-electron pumps (SEPs) based on a quantum dot have been suggested as promising devices to realize the new definition of the unit of current, the ampere, where quantized current produced from the SEP device is only defined by the elementary charge e and applied external radiofrequency (rf), f, i.e., I = ef. The conventional method to eliminate offset signals in the precision current measurement of pump current has been to measure the current difference between the pump-on and pump-off states. To date, the rf-on and rf-off method has been used to pump between its on and off states. However, this method inevitably induces alternating rf-heating effects and varying temperatures of the device environment, possibly leading to a thermal drift of the offset current. In the current work, we developed a new gate-switching technique that can alternate the pump on and off states while maintaining a constant rf-on state, resulting in a more stable system temperature. Using the gate-switching technique, we achieved a temperature-stabilized environment and performed a precision current measurement with sub-parts per million uncertainty.

Ultra-performance liquid chromatography (UPLC) and Single Standard for Determination of Multi-Components (SSDMC) are becoming increasingly important for quality control of medicinal herbs; this approach was developed for Ganoderma lucidum. Special attention was necessary for the appropriate selection of markers, for determining the reproducibility of the relative retention times (RRT), and for the accuracy of conversion factors (F). Finally, ten components were determined, with ganoderic acid A serving as single standard. Stable system parameters were established, and with successful resolution of those issues, this analytical method could be used more broadly.

Mathematical modelling is the theoretically established tool for developing solar heating systems, e.g. with using transfer functions. If we know the transfer functions of the system, the outlet temperature can be predicted as a function of the input variables (solar irradiance, inlet temperature, environment temperatures), dynamic analysis can be carried out, and stable system control can be effectively designed based on the well-tried methods of control engineering. For these purposes, new, validated transfer functions for solar heating systems are worked out in this study based on a mathematical model, which can be found in the literature and has been applied successfully in the field. The transfer functions are used for dynamic analysis and control design of solar heating systems. The dynamic analysis is presented and the efficiency of the proposed stable control is demonstrated with respect to a real solar heating system.