On the functions of astrocyte-mediated neuronal slow inward currents

Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of astrocytes.These events are significantly slower than the excitatory postsynaptic currents.Parameters of slow inward currents are determined by seve ral factors including the mechanisms of astrocytic activation and glutamate release,as well as the diffusion pathways from the release site towards the extra synaptic recepto rs.Astrocytes are stimulated by neuronal network activity,which in turn excite neurons,forming an astrocyte-neuron feedback loop.Mostly as a consequence of brain edema,astrocytic swelling can also induce slow inward currents under pathological conditions.There is a growing body of evidence on the roles of slow inward currents on a single neuron or local network level.These events often occur in synchro ny on neurons located in the same astrocytic domain.Besides synchronization of neuronal excitability,slow inward currents also set synaptic strength via eliciting timing-dependent synaptic plasticity.In addition,slow inward currents are also subject to non-synaptic plasticity triggered by long-la sting stimulation of the excitatory inputs.Of note,there might be important regionspecific differences in the roles and actions triggering slow inward currents.In greater networks,the pathophysiological roles of slow inward currents can be better understood than physiological ones.Slow inward currents are identified in the pathophysiological background of autism,as slow inward currents drive early hypersynchrony of the neural networks.Slow inward currents are significant contributors to paroxysmal depolarizational shifts/interictal spikes.These events are related to epilepsy,but also found in Alzheimer's disease,Parkinson's disease,and stroke,leading to the decline of cognitive functions.Events with features overlapping with slow inward currents(excitatory,N-methyl-Daspartate-receptor mediated currents with astrocytic contribution) as ischemic currents and spreading depolarization also have a well-known pathophysiological role in worsening consequences of stroke,traumatic brain injury,or epilepsy.One might assume that slow inward currents occurring with low frequency under physiological conditions might contribute to synaptic plasticity and memory formation.However,to state this,more experimental evidence from greater neuronal networks or the level of the individual is needed.In this review,I aimed to summarize findings on slow inward currents and to speculate on the potential functions of it.

Inward particle transport driven by biased endplate in a cylindrical magnetized plasma

The inward particle transport is associated with the formation of peaked density profiles,which contributes to improve the fusion rate and the realization of steady-state discharge.The active control of inward particle transport is considered as one of the most critical issues of magnetic confinement fusion.Recently,it is realized preliminarily by adding a biased endplate in the Peking University Plasma Test(PPT)device.The results reveal that the inward particle flux increases with the bias voltage of the endplate.It is also found that the profile of radial electric field(Er)shear is flattened by the increased bias voltage.Radial velocity fluctuations affect the inward particle more than density fluctuations,and the frequency of the dominant mode driving inward particle flux increases with the biased voltage applied to the endplate.The experimental results in the PPT device provide a method to actively control the inward particle flux using a biased endplate and enrich the understanding of the relationship between E_(r)×B shear and turbulence transport.

ODEs IN BANACH SPACES AND FIXED POINTS OF WEAKLY INWARD MAPS

This paper is an attempt to investigate systematically fixed points of weakly inward maps by using some basic results from differential equations in Banach spaces. By investigating the Poincare operators for such differential equations, we establish a fixed point index theory for two classes of weakly inward maps.

FIXED POINT INDEX THEORY FOR WEAKLY INWARD MAPPINGS

In this paper we define a fixed point index theory for locally Lip., completely continuous and weakly inward mappings defined on closed convex sets in general Banach spaces where no other artificial conditions are imposed. This makes ns to deal with these kinds of mappings more easily. As obvious applications, some results in [3],[5],[7],[9],[10] are deepened and extended.

Fixed Point Curve for Weakly Inward Contractions and Approximate Fixed Point Property

In this paper, we discuss the concept of fixed point curve for linear interpolations of weakly inward contractions and establish necessary condition for a nonex- pansive mapping to have approximate fixed point property.

FIXED POINTS FOR WEAKLY INWARD MAPPINGS IN BANACH SPACES (Ⅱ)

S. Hu and Y. Sun[1] defined the fixed point index for weakly inward mappings, investigated its properties and studied fixed points for such mappings. In this paper, following S. Hu and Y. Sun, we further investigate boundary conditions, under which the fixed point index for i（A, Ω, p） is equal to nonzero, where i（A, Ω, p） is the completely continuous and weakly inward mapping. Correspondingly, we can obtain many new fixed point theorems of the completely continuous and weakly inward mapping, which generalize some famous theorems such as Rothe＇s theorem, Altman＇s theorem, Petryshyn＇s theorem etc. in the case of weakly inward mappings. In addition, our conclusions extend the famous fixed point theorem of cone expansion and compression to the case of weakly inward mappings. Moreover, the main results contain and generalize the corresponding results in the recent work[2].

EFFECTS OF THE HOE 694 ON TRANSIENT INWARD CURRENT AND NA^+- CA^(2+) EXCHANGE IN GUINEA PIG CARDIOMYOCYTES

To determine the effects of HOE 694, a new and potent Na＋- H＋ exchanger blocker, on transient inward current (Iti) and Na＋- Ca2＋ exchange during hypoxia- reoxygenation in guinea pig cardiomyocytes. Methods. Cardiomyocytes were isolated from adult guinea pig ventricle. Experiment was performed in an experimental chamber that allowed the cells to be exposed to a sufficiently low O2 pressure. The cells were subjected to hypoxia and reoxygenation. The ionic currents were studied with patch clamp technique. Results. In the absence of HOE 694, hypoxia- reoxygenation induced Iti in 12 of 15 experiments; but in cardiomyocytes pretreated with HOE 694 (10～ 50μ mol/L), the incidence of Iti observed during reoxygenation was reduced to 5 of 11 experiments and 3 of 10 experiments, P Conclusions. Blockade of the Na＋- H＋ exchange by HOE 694 could reduce Ca2＋ overload upon hypoxia- reoxygenation, and inhibition of Na＋- H＋ exchange may also indirectly decrease Na＋- Ca2＋ exchange activity during hypoxia.

How U.S. Antidumping Actions Affect China＇s Inward and Outward FDI

This paper presents an empirical study of how U.S. antidumping （AD） actions against China affect China ＇s inward and outward foreign direct investment （FDI） based on the international division of labor model. Our findings are as follows： （1） The U.S.-China trade deficit has been widened by both downstream firms in China established through vertical FDI and also inward enterprises established through horizontal FDI. The widening deficit in turn exacerbates vitriolic complaints in the U.S. about injury to its industries. This will lead to further U.S. AD actions discouraging FDI in China. （2） U.S. AD cases against China have negatively impacted China＇s metal manufacturing, chemical and, especially, textile industries in terms of exports and inward FDI. From 2004 to 2009, the share of total inward FDI going to China＇s manufacturing sector has dropped drastically by almost 20 percent. This supports predictions made using the international division of labor model. （3） With U.S. AD actions against Chinese products on the rise, Chinese firms chose not to circumvent such barriers through outward FDI in the U.S. but rather through outward FDI in tax havens. Such a pattern of outward FDI is not helpful for China to establish its own successful industrial development model.

State-Based Determinants of Inward FDI Stock in the U.S. Economy

This paper has empirical character and investigates locational determinants of the inward foreign direct investment （FDI） stock among 50 states of the United States. The analysis uses annual data for the period from 1997 to 2007. The study identifies several state-specific determinants of FDI and investigates the changes in their importance during the study period. Our results show that among the major determinants, the real per capita income, real per capita expenditure on education, FDI related employment, plus real research and development expenditure are found to have a significant positive impact on inward FDI. There is also evidence that manufacturing density and unionization exert a small positive impact on inward FDI. In addition, per capita state taxes, the share of scientists and engineers in the workforce, real capital expenditure, and unemployment rate exert a negative impact on FDI.

Quantification and influence factor analysis on total inward leakage of N95 respirators by simulating healthcare professional’s procedures

Respiratory protection is critical to minimize airborne infection risk for healthcare workers.The main factor affecting infection risk in the medical scenario is leakage between the respirator and the healthcare workers’face.However,it is difficult to quantify the effectiveness of respirators due to the numerous influencing factors.The medical activities were simulated by the fitting test,and the inverse of the results were used to get the total inward leakage of respirators.114 subjects were divided according to gender,profession,age,risk area,and BMIs,participated in fitting test of four N95 respirators.The result showed that the value range of total inward leakage for tested N95 respirators was between 0.50%and 2.39%.Flat-folded respirators were more prone to leakage than cup-shaped ones,so it was essential to account for the impact of respirator shape.Similarly,this study found that gender and profession had no significant correlation with total inward leakage.Some medical procedures include bending,and turning head from side to side,or up and down,which had a significant influence on the protective efficacy of the N95 respirator.Facial dimensions and BMI exerted a more pronounced influence on the protective efficacy of the N95 respirator,and they were in the correlations.Healthcare personnels wore a well-fitting N95 respirator properly for excellent protection,reducing occurrence of nosocomial infections and occupational exposures,and optimizing respiratory protection strategies.

Design and experimental study of a practical Osculating Inward Cone Waverider Inlet

A design method based on tip to tail streamline tracing and osculating inward cone methods is discussed for designing the integrated Osculating Inward Cone Waverider Inlet（OICWI）. A practical geometrical constrained experimental model of OICWI is designed based on the validated design method. It has a total contraction ratio of 4.61 and inner contraction ratio is 2.0. Wind-tunnel tests have been conducted for the OICWI model at free stream Mach number（Ma） of 4.0, 3.5 and 3.0 respectively. The experimental results show that the OICWI has high flow capture ratio and compression abilities. It can self-start at Ma= 3.5 and 4.0 and its flow capture ratio is 0.73 at Ma= 4.0, and Angle of Attack（AOA） 0°. The research results show that the OICWI has advantages of inward cone waverider and streamline tracing inlet. Present OICWI is a novel approach for waverider inlet integration studies and it will promote the use of waverider inlet integration configuration in the studies of airbreathing hypersonic vehicles.

A parameterized geometry design method for inward turning inlet compatible waverider

Intensive studies have been carried out on generations of waverider geometry and hypersonic inlet geometry. However, integration efforts of waverider and related air-intake system are restricted majorly around the X43A-like or conical flow field induced configuration, which adopts mainly the two-dimensional air-breathing technology and limits the judicious visions of developing new aerodynamic profiles for hypersonic designers. A novel design approach for integrating the inward turning inlet with the traditional parameterized waverider is proposed. The proposed method is an alternative means to produce a compatible configuration by linking the off-the-shelf results on both traditional waverider techniques and inward turning inlet techniques. A series of geometry generations and optimization solutions is proposed to enhance the lift-to-drag ratio. A quantitative but efficient aerodynamic performance evaluation approach （the hypersonic flow panel method） with lower computational cost is employed to play the role of objective function for opti- mization purpose. The produced geometry compatibility with a computational fluid dynamics （CFD） solver is also verified for detailed flow field investigation. Optimization results and other numerical validations are obtained for the feasibility demonstration of the proposed method.

Effects of La^(3+) on inward K^+ channels at plasma membr in guard cells

The effects of La3+ on inward K+ channels at plasma membrane in vicia guard cells are investigated using the whole-cell patch-clamp recording mode. It is shown that La3+ on both sides of plasma membrane blocks inward K+ currents in a concentration- dependent manner, indicating that La3+ binding sites may exist on both sides of plasma membrane in guard cells in vicia. The dose response is fitted by the Michaelis-Menten relation characterized by an inhibitor constant Ki of 2.56±0.25 μmol·L?1 (outside membrane) and (1.18±0.11)×10?15 mol·L?1 (inside membrane). Intracellular La3+ has much stronger inhibitory effect on inward K+ currents than ex- tracellular La3+ does, suggesting there may exist stronger binding sites inside membrane than outside membrane. Since ion channel activities of guard cells directly affect plant stomatal movement and water status, our results imply that rare earth elements might have potential practical values in regulating plant water status and strengthening plant drought endurance.

Effect of Various Field Shapers on Magnetic Pressure in Electromagnetic Inward Tube Forming

In this paper,the influence of various field shapers and their shapes on the distribution of the magnetic flux densities and applied forces on the work-piece in the electromagnetic inward tube forming are studied numerically using the FEA software MAXWELL.First the model was verified with experimental results and thereafter four kinds of field shapers(conical,cylindrical,concave and convex)were considered.Effects of their geometries,such as air gap between field shaper and tube work-piece,height of the step in single and multiple stepped field shaper on magnetic flux densities and magnetic pressures were studied.The results of this research can be applied to design field shaper,tube compression technology,and improve the efficiency of the coil.It is seen that magnetic force decreases if height of step in convex field shaper increases but effective forming region enlarges.Decreasing air gap has also a positive influence on magnetic field increase.Though the object of this research is limited to field shaper for inward tube forming,the results can also be applied to the field shaper for tube bulging.

Design method with controllable velocity direction at throat for inward-turning inlets

In the design of a hypersonic inward-turning inlet by applying the traditional basic flowfield, a reflected shock-wave is formed in the isolator due to the continuous reflection of the cowlreflected shock wave in the basic flow-field, which interacts with the boundary layer to produce a considerable influence on the performance of the inlet. Here, a basic flow-field design method that can control the velocity direction at the throat section is developed, and numerical simulations are conducted to demonstrate the effectiveness of this method. The method presented in this paper can achieve the absorption of the reflected waves at the shoulder of the basic flow-field by adjusting the variation law of the center radius in the basic flow-field, and a smooth transition between the compression surface and the isolator can also be produced. The Mach number and total pressure recovery coefficient of the inlet designed according to this method are 3.00 and 0.657, respectively, at design point(the incoming flow Mach number Ma1= 6.0). The results show that with this method, the inlet can efficiently weaken both the reflection of the shock wave and the interaction between the boundary layer and the reflected shock waves, which improves the aerodynamic performance of the inlet.

Productivity Gap and Inward FDI Spillovers: Theory and Evidence from China

This paper constructs a two-stage sequential game model to shed light on the spillover effect of inward FDI on the efficiency of domestic firms in host countries.Our model shows that,given an optimal joint-venture policy made by foreign firms,the impact of the spillover effect of inward FDI is contingent upon the productivity gap between the domestic firms and foreign ones.In particular,we demonstrate that the spillover effect of inward FDI varies negatively with the productivity gap between domestic lowproductivity firms and foreign firms but works in the opposite way for high-productivity firms.This suggests that once the productivity gap widens,the entry of foreign firms will increase the efficiency of high-productivity firms but reduce the efficiency of lowproductivity firms.In support of our theoretical model,we provide robust empirical results by using the dataset of annual survey of Chinese industrial enterprises.

Regulating role of acetylcholine and its antagonists in inward rectified K^+ channels from guard cell protoplasts of Vicia faba

The inward rectified potassium current of Vicia faba guard cell protoplasts treated with acetylcholine (ACh) or the antagonists of its receptors were recorded by employing the patch clamp technique. The results show that ACh at lower concentrations increases the inward K+ current, in contrast, ACh at higher concentrations inhibits it. Treated with d-Tubocurarine (d-Tub), an antagonist of the nicotine ACh receptor (nAChR) inhibits the inward K+ current by 30%. Treated with atropine (Atr), an antagonist of the muscarine (Mus) ACh receptor (mAChR) also inhibits it by 36%. However, if guard cell protoplasts are treated with d-Tub and Atr together, the inward K+ current is inhibited by 60%-75%. Tetraethylammonium chloride (TEA), a strong inhibitor of K+ channels has no effect on the inward K+ current regulated by ACh, suggesting that there are inward K+ channels modulated by AChRs on the membrane of the guard cell protoplasts. These data demonstrate an ACh-regulated mechanism for stomatal movement.

How Does Inward FDI Hinder or Promote Outward FDI？ Three Cases of Chinese Automotive Industry

In this paper we investigate the mechanisms underlying dynamic linkages between inward FDI and outward internationalization in the Chinese automotive industry. While several studies have examined the relationship between inward and outward FDI using empirical data, this is among the first to employ a case study approach to investigate how international joint ventures （IJVs） established between foreign and Chinese automakers can shape their internationalization motivation, degree, and speed. We discuss some unique features of Chinese carmakers with and without IJVs to elucidate how firms without IJVs will be more driven to expand internationally while firms with IJVs face constraints in venturing abroad.

Arabidopsis shaker pollen inward K^+ channel SPIK functions in SnRK1 complex-regulated pollen hydration on the stigma

Pollen hydration is a critical step that determines pollen germination on the stigma. KINγ is a plantspecific subunit of the SNF-1-related protein kinase 1 complex （SnRK1 complex）. In pollen of the Arabidopsis kinβγ mutant, the levels of reactive oxygen species were decreased which lead to compromised hydration of the mutant pollen on the stigma. In this study, we analyzed gene expression in kinβγ mutant pollen by RNA-seq and found the expression of inward shaker K^＋ channel SPIK was down-regulated in the kinβγ /pollen. Furthermore, we showed that the pollen hydration of the Arabidopsis spik mutant was defective on the wild-type stigma, althoughthe mutant pollen demonstrated normal hydration in vitro. Additionally, the defective hydration of spik mutant pollen could not be rescued by the wild-type pollen on the stigma, indicating that the spik mutation deprived the capability of pollen absorption on the stigma. Our results suggest that the Arabidopsis SnRK1 complex regulates SPIK expression, which functions in determining pollen hydration on the stigma.

Characteristics of the inward-rectifying potassium current in mouse ventricular myocytes and its relation to early after-depolarization

The properties of the inward-rectifying potassium current (IK1) were studied in the single myocytes isolated from adult mouse ventricles by the whole-cell patch-damp technique for the first time. Most of the properties of IK1 including channel conductances, activation, inactivation, rectification and external K+ sensitivity in mouse ventricular myocyte were similar to those in other species, but the current-voltage (1-V) curve of mouse ventricular myocyte showed no negative slope, i.e the slope in the range of membrane potential 50 mV positive to the reversal potential (VRev) was virtually flat and remained at a low current level ((59±39) pA). Under the superfusion of Tyrode's solution with 3mmol/L K+ and 3mmol/L Cs+, IK1 in the above region nearly decreased to zero, and then the early after-depolarization (EAD) occurred. The results suggest that this distinctive characteristic of IK1 in mouse ventricular myocyte may relate to the high susceptibility to EA0 in mouse myocardium. The inhibition of IK1 seems to be a prerequisite for the occurrence of EAD in this experiment.