Bipartite consensus problems of Lurie multi-agent systems over signed graphs: A contraction approach

This paper examines the bipartite consensus problems for the nonlinear multi-agent systems in Lurie dynamics form with cooperative and competitive communication between different agents. Based on the contraction theory, some new conditions for the nonlinear Lurie multi-agent systems reaching bipartite leaderless consensus and bipartite tracking consensus are presented. Compared with the traditional methods, this approach degrades the dimensions of the conditions, eliminates some restrictions of the system matrix, and extends the range of the nonlinear function. Finally, two numerical examples are provided to illustrate the efficiency of our results.

Revisiting the Electron Radius in Light of Length Contraction

In previous work, the electron radius was identified as the “actual electron radius.” However, this is more accurately described as the electron radius at rest. This study reexamines the electron with an emphasis on the electron radius under motion, incorporating the effects of length contraction. The findings suggest that the radius is subject to Lorentz contraction, which has interesting implications for relativistic effects at the subatomic level.

Generalized Kannan-type contraction and fixed point theorems

In this paper,the generalized Kannan-type contraction in cone metric spaces over Banach algebras is introduced.The fixed point theorems satisfying generalized contractive conditions are obtained,without appealing to completeness of X or normality of the cone.The continuity of the mapping is relaxed.Furthermore,we prove that the completeness in cone metric spaces over Banach algebras is necessary if the generalized Kannan-type contraction has a fixed point in X.These results greatly generalize several well-known comparable results in the literature.

Enhancing the activity of FeNi bimetallic electrocatalysts on overall water splitting by Nd_(2)O_(3)-induced FeNi lattice contraction

The development of high-efficiency and cost-effective bifunctional electrocatalysts for overall water splitting remains a formidable challenge.Herein,FeNi-Nd_(2)O_(3) nanoparticles anchored on N-doped carbon nanotubes(FeNi-Nd_(2)O_(3)/NCN) are designed for highly effective overall water splitting via a facile two-step hydrothermal approach.The synthetic FeNi-Nd_(2)O_(3) hetero-trimers(Fe 2p-Ni 2p-Nd 3d orbital coupling)on NCN achieve excellent oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) activities with overpotentials of 270 and 120 mV at 10 mA cm^(-2) in 1 M KOH solution.Moreover,a small voltage of 1.52 V at 10 mA cm^(-2) is achieved when FeNi-Nd_(2)O_(3)/NCN is assessed as bifunctional catalyst for overall water splitting,which is superior to the typically integrated Pt/C and RuO_(2) counterparts(1.54 V at 10 mA cm^(-2)).The related characterizations including X-ray absorption fine structure(XAFS)spectroscopy show that the remarkably improved activity is originated from Nd_(2)O_(3)-induced FeNi bimetallic lattice contraction.Furthermore,density functional theory(DFT) calculations indicate that the lattice contraction reduces binding energies of intermediates by downshifting the position of FeNi bimetallic d-band center relative to the Fermi level to optimize catalytic performance.Therefore,the Nd_(2)O_(3)-induced FeNi bimetallic lattice contraction may provide a new perspective for designing and synthesizing innovative catalytic systems.

Physical Transformations of Agri-Food Products during Their Convective Drying: Characterization of the Contraction and Isotropicity of Okra

The physical transformations in terms of contraction of okra dimensions during convective drying were examined. During drying, the lateral and longitudinal dimensions of okra decrease over time. The lateral dimensions go from their initial value to around 53%, 65% and 66% of this value after 530 min. The length of the two samples used goes from 8.65 and 9.02 cm to 6.79 and 7.52 cm after 14,300 min, i.e. a variation of 78.50% and 83.37%. All the two directions give variations almost linear depending on the water content. These linear contractions result in a volume contraction of the okra. It considerably decreases in volume during the drying process. The volume goes from 831.32 cm3 to 367.57 cm3 in min, a variation of 44.22%. The isotropic index reveals that okra does not behave the same in the lateral and longitudinal directions. It contracts its diameter more than its length.

ELXED POINT THEOREM OF COMPOSITION g-CONTRACTION MAPPING AND ITS APPLICATIONS

Any composition sequential mapping, periodic composition mapping of a complete non-empty metric space M into M with geometric mean contraction ratio less than 1 ( simplifying as 'g-contraction mapping' ) has a unique fixed point in M . Applications of the theorem to the proof of existence and uniqueness of the solutions of a set of non-linear differential equations and a coupled integral equations of symmetric bending of shallow shell of revolution are given.

Mechanochemical model for myosinⅡdimer that can explain the spontaneous oscillatory contraction of muscle

The spontaneous oscillatory contraction（SPOC） of myofibrils is the essential property inherent to the contractile system of muscle. Muscle contraction results from cyclic interactions between actin filament and myosin II which is a dimeric motor protein with two heads. Taking the two heads of myosin II as an indivisible element and considering the effects of cooperative behavior between the two heads on rate constants in the mechanochemical cycle, the present work proposes the tenstate mechanochemical cycle model for myosin II dimer. The simulations of this model show that the proportion of myosin II in different states periodically changes with time, which results in the sustained oscillations of contractive tension, and serves as the primary factor for SPOC. The good fit of this model to experimental results suggests that the cooperative interaction between the two heads of myosin II dimer may be one of the underlying mechanisms for muscle contraction.

DIRECTED HYPERGRAPH THEORY AND DECOMPOSITION CONTRACTION METHOD

A new branch of hypergraph theory-directed hyperaph theory and a kind of new methods-dicomposition contraction(DCP, PDCP and GDC) methods are presented for solving hypernetwork problems.lts computing time is lower than that of ECP method in several order of magnitude.

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.

Myofiber Permeability and Force Production of Rat Muscles Following Eccentric Contractions: The Repeated Bout Effect Depends on the Interval

Past eccentric contraction (ECC)-induced muscle injury reduces the severity of symptoms of subsequent muscle injury;this phenomenon is known as a repeated bout effect (RBE). It has been reported that increases in the duration of the interval between the first and second bouts are linked to weakening of the RBE. However, the histology following the attenuation of the RBE remains unclear. We examined the sustained effects of the second bout with regard to myofiber permeability and muscle force. Sixty-four male rats were randomly assigned to eight groups that varied in the number of exercise sessions and the duration of the interval between the first and second bouts: the non-ECC (Control);the single-injury (Post 1st bout);groups that were allowed to recover for 1, 2, and 4 weeks after a single injury (Pre 2nd bout_1w, Pre 2nd bout_2w, and Pre 2nd bout_4w);and groups that were subjected to second injuries 1, 2, and 4 weeks after the first (Post 2nd bout_1w, Post 2nd bout_2w, and Post 2nd bout_4w). The tibialis anterior was electrically stimulated in each ECC group. Twenty-four hours before muscle sampling, Evans blue dye (EBD) (a marker of myofiber damage) was administered. The maximal isometric contraction tension was measured immediately before sampling. The number of EBD-positive (+) fibers was determined via histological analysis. An RBE was revealed by functional examination at the 1- and 2-week and histological examination at the 1-, 2-, and 4-week time points (P < 0.05). In terms of myofiber permeability, prolongation of the interval before the second bout weakened this effect (P < 0.05). Experiments with 1-, 2-, and 4-week intervals indicated that prolongation of the interval before the second bout weakened the RBE with regard to myofiber permeability.

On Almost Type α-F-Z-Weak Contraction in Metric Spaces

In this article, we introduce a new type of contraction named almost type α-F-Z-weak contraction, which comes from a combination of F-contraction, Z-contraction, and almost contraction, and then we provide sufficient conditions for the existence and uniqueness of fixed point of such contractions in complete metric spaces and give some related fixed point results. In addition, some related fixed point results can derive from our main results.

A Graphlike Manifold Whose Contraction is

For a graphlike manifold whose contraction is a generalized cuneate figure,we deribve a formula in this paper to compute the number of homeomorphism classes of it by using twist operations and the combinatorial theory.

Thick-skinned Contractional Salt Structures in the Kuqa Depression,the Northern Tarim Basin:Constraints from Physical Experiments

Thick-skinned contractional salt structures are widely developed in the western Kuqa depression, northern Tarim basin. To understand the mechanisms that govern the development of these structures, physical experiments are conducted and the results show that they are largely governed by the activities of basement faults and the forming of paleo-uplifts and basement slopes. The model materials in this study are dry sand, vaseline and plasticene （or hard foam）, simulating the suprasalt, salt, and subsalt layers respectively. The experiments show that, due to the activities of basement faults and the forming of the paleo-uplifts, salt bodies usually accumulate and thicken significantly on the middle top of the paleo-uplifts which are constrained by the pre-exiting boundary faults. The development of large-scale thrust faults and salt nappes is favored by the basement slops with larger dips. The experiments also conclude that differential structural deformation could occur between the subsalt and suprasalt layers because of the presence of salt layers. Their geometries and the locations of structural highs are different, despite of the great similarities in the uplifted areas. The pierced salt diapir is not observed in the experiments, which indicates that the contractional shortening does not effectively accelerate the development of the salt diapir.

Effect of areca on contraction of colonic muscle strips in rats

AIM: To investigate the effects of areca on the contractile activity of isolated colonic muscle strips in rats and mechanism involved. METHODS: Each strip (LMPC, longitudinal muscle of proximal colon; CMPC, circular muscle of proximal colon; LMDC, longitudinal muscle of distal colon; CMDC, circular muscle of distal colon.) was suspended in a tissue chamber containing 5 mL Krebs solution (37 degrees C), bubbled continuously with 950 mL.L(-1) O(2) and 50 mL.L(-1) CO(2). The mean contractile amplitude (A), the resting tension (T), and the contractile frequency (F) were simultaneously recorded on recorders. RESULTS: Areca dose dependently increased the mean contractile amplitude, the resting tension of proximal and distal colonic smooth muscle strips in rats (P【0.05). It also partly increased the contractile frequency of colonic smooth muscle strips in rats (P【0.05). The effects were partly inhibited by atropine (the resting tension of LMPC decreased from 0.44 +/- 0.12 to 0.17 +/- 0.03; the resting tension of LMDC decreased from 0.71 +/- 0.14 to 0.03 +/- 0.01; the mean contractile amplitude of LMPC increased from -45.8 +/- 7.2 to -30.5 +/- 2.9; the motility index of CMDC decreased from 86.6 +/- 17.3 to 32.8 +/- 9.3; P【0.05 vs areca), but the effects were not inhibited by hexamethonium (P】0.05). CONCLUSION: Areca stimulated the motility of isolated colonic smooth muscle strips in rats. The stimulation of areca might be relevant with M receptor partly.

Metformin attenuates motility,contraction,and fibrogenic response of hepatic stellate cells in vivo and in vitro by activating AMP-activated protein kinase

AIM To investigate the effect of metformin on activated hepatic stellate cells(HSCs) and the possible signaling pathways involved. METHODS A fibrotic mouse model was generated by intraperitoneal injection of carbon tetrachloride(CCl_4) and subsequent treatment with or without metformin. The level of fibrosis was detected by hematoxylin-eosin staining, Sirius Red staining, and immunohistochemistry. The HSC cell line LX-2 was used for in vitro studies. The effect of metformin on cell proliferation(CCK8 assay),motility(scratch test and Transwell assay), contraction(collagen gel contraction assay), extracellular matrix(ECM) secretion(Western blot), and angiogenesis(ELISA and tube formation assay) was investigated. We also analyzed the possible signaling pathways involved by Western blot analysis.RESULTS Mice developed marked liver fibrosis after intraperitoneal injection with CCl_4 for 6 wk. Metformin decreased the activation of HSCs, reduced the deposition of ECM, and inhibited angiogenesis in CCl_4-treated mice. Platelet-derived growth factor(PDGF) promoted the fibrogenic response of HSCs in vitro, while metformin inhibited the activation, proliferation, migration, and contraction of HSCs, and reduced the secretion of ECM. Metformin decreased the expression of vascular endothelial growth factor(VEGF) in HSCs through inhibition of hypoxia inducible factor(HIF)-1α in both PDGF-BB treatment and hypoxic conditions, and it down-regulated VEGF secretion by HSCs and inhibited HSC-based angiogenesis in hypoxic conditions in vitro. The inhibitory effects of metformin on activated HSCs were mediated by inhibiting the Akt/mammalian target of rapamycin(m TOR) and extracellular signal-regulated kinase(ERK) pathways via the activation of adenosine monophosphate-activated protein kinase(AMPK).CONCLUSION Metformin attenuates the fibrogenic response of HSCs in vivo and in vitro, and may therefore be useful for the treatment of chronic liver diseases.

Mechanisms mediating CCK-8S-induced contraction of proximal colon in guinea pigs

AIM:To investigate the effects of sulfated cholecystokinin octapeptide (CCK-8S) on the contractile activity of guinea-pig proximal colon.METHODS:Proximal colonic smooth muscle (PCSM) strips were obtained from adult female guinea pigs and contractile response of PCSM strips was recorded using a polyphysiograph.PCSM cells were isolated by enzymatic digestion.Resting potential (RP),action potential (AP),large conductance potassium channel currents (IBKCa) and L-type calcium currents (ICa-L) were recorded by patch-clamp techniques.RESULTS:(1) CCK-8S (10-7 mol/L) enhanced the mean contractile amplitude of colonic circular muscle and longitudinal muscle (LM) strips by 56.53% ± 11.92%(P=0.038) and 65.93% ± 12.98% (P=0.019),respectively,as well as the mean frequency of LM by 31.69% ± 13.58% (P=0.023),which were significantly attenuated by pretreating strips with devazepide,nifedipine,iberiotoxin,thapsigargin (TG) and BAPTA-AM (BA) respectively;(2) CCK-8S (10-7 mol/L) increased the AP amplitude by 38.6% ± 3.2% (P=0.015),decreased AP duration by 36.9% ± 8.7% (P=0.026),and depolarized the RP from-61.3 ± 2.7 mV to-29.8 ± 5.9 mV (P=0.032);and (3) Compared with the normal control group,CCK-8S (10-7 mol/L) enhanced the peak current of IBKCa by 18.7% ± 2.1% (from 916 ± 183 pA to 1088 ± 226 pA;at +60 mV;P=0.029),which was inhibited by respective pretreatment with iberiotoxin and devazepide.Additionally,CCK-8S (10-7 mol/L) intensif ied the peak current of ICa-L by 40% (from 60 ± 8 pA to 84 ± 11 pA;at +10 mV;P=0.012),compared to the normal control group,which was apparently suppressed by respective pretreatment with nifedipine,devazepide,TG and BA.In the respective presence of heparin and staurosporine,CCK-8S did not signif icantly enhance IBKCa and ICa-L.CONCLUSION:The results suggest that CCK-8S promotes guinea-pig proximal colon contraction by CCK1 receptors,following activation of the inositol triphosphate-protein kinase C signal transduction pathway.

Rapid bilateral anterior capsule contraction following high myopic cataract surgeries:a case report

We describe a rapid anterior capsule contraction following phacoemulsifiction and intraocular lens(IOL) implantation in an old woman with high myopia. The patient with high myopia complicated with cataract received phacoemulcification and IOL implantation bilaterally .The best-corrected visual acuity (BCVA) improved from 0.1 to 0.4 in the right eye and 0.5 in the left eye 1 week after surgeries.5 weeks after surgery of the right eye and 4 weeks after surgery of the left eye, the patient complained blurred vision in the right eye. BCVA of the right eye was 0.06 and that of the left was 0.1. Slit-lamp examination revealed anterior capsule contraction in both eyes and a fully closed capsulorhexis opening in the right eye. The IOLs were centered but almost completely enclosed, with numerous linear fibrous folds radiating from the hick central fibrosis. We surgically excised the central part of the anterior capsule of the eyes with microscissors, resulting again in BCVA of 0.4 and 0.5 in the right and left eyes respectively. Anterior capsule contraction might appear much earlier than three months after phacoemulsification and IOL implantation surgery in case of high myopia complicated with cataract. Patients with high myopia receive cataract and IOL surgery should be monitored carefully for the rapid development of anterior capsule contraction.

sEMG Feature Analysis on Forearm Muscle Fatigue During Isometric Contractions

In order to detect and assess the muscle fatigue state with the surface electromyography(sEMG) characteristic parameters,this paper carried out a series of isometric contraction experiments to induce the fatigue on the forearm muscles from four subjects,and recorded the sEMG signals of the flexor carpi ulnaris.sEMG's median frequency(MDF) and mean frequency(MF) were extracted by short term Fourier transform(STFT),and the root mean square(RMS) of wavelet coefficients in the frequency band of 5—45 Hz was obtained by continuous wavelet transform(CWT).The results demonstrate that both MDF and MF show downward trends within 1 min; however,RMS shows an upward trend within the same time.The three parameters are closely correlated with absolute values of mean correlation coefficients greater than 0.8.It is suggested that the three parameters above can be used as reliable indicators to evaluate the level of muscle fatigue during isometric contractions.

Microcrystallization and lattice contraction of NiFe LDHs for enhancing water electrocatalytic oxidation

The lattice-oxygen-mediated mechanism is considered as a reasonable mechanism for the electrochemical catalytic oxygen evolution reaction(OER)of NiFe layered double hydroxides(LDHs).A NiFe LDH with distinct lattice contraction and microcrystallization was synthesized via a simple one-step method using sodium gluconate.The lattice contraction is attributed to the interaction of carbon in sodium gluconate and iron in NiFe LDH.The NiFe LDH with optimized microcrystallization and lattice contraction shows a low overpotential of 217 mV at a current density of 10 mA cm^(−2) and excellent durability of 20 h at a high current density of 100 mA cm^(−2).The results revealed that a contractive metal–oxygen bond could boost the intrinsic activity of active sites and the microcrystallization promotes an increase in the number of active sites in terms of unit area.The chemical environment of oxygen elemental characterization and resistance at different chronopotentiometry times confirm that the lattice oxygen element is indeed involved in the process of OER,supporting the lattice-oxygen-mediated mechanism of NiFe LDH.Density functional theory calculations reveal that contractive metal–oxygen bonds induced a reduction of the adsorption energy barrier of intermediate products,thus improving the intrinsic catalytic activity.The special characteristics of microcrystallization and lattice contraction of NiFe LDH provide a strategy to improve both the number and the intrinsic activity of active sites in a versatile manner.

Effects of anti-hypertensive drugs on esophageal body contraction

AIM:To clarify the effects of anti-hypertensive drugs on esophageal contraction and determine their possi-ble relationship with gastro-esophageal reflux disease.METHODS:Thirteen healthy male volunteers were enrolled. Esophageal body peristaltic contractions and lower esophageal sphincter (LES) pressure were measured using high resolution manometry. All subjects were randomly examined on four separate occasions following administrations of nifedipine,losartan,and atenolol,as well as without any drug administration.RESULTS:Peristaltic contractions by the esophageal body were separated into three segments by two troughs. The peak peristaltic pressures in the mid and lower segments of the esophageal body under atenolol administration were signifi cantly higher than those without medication in a supine position. On the other hand,peristaltic pressures under nifedipine administration were lower than those observed without drug ad-ministration. Losartan did not change esophageal body peristalsis. Atenolol elevated LES pressure and slowed peristaltic wave transition,while the effects of nifedip-ine were the opposite. CONCLUSION:Among the anti-hypertensive drugs tested,atenolol enhanced esophageal motor activity,which was in contrast to nifedipine.