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Objective To study the expression of plasma membrane Ca2+-ATPase isoform 2 (PMCA2) and its alternative splicing at sites A (the first intracellular loop) and C (the C-terminal region) in the neonatal rat cochlea. Methods The cochleae from rats postnatal day 3 to postnatal day 4 (P3–P4) were dissected, fixed, embedded, and sectioned. Meanwhile, the cochlear coils from neonatal rats were isolated and fixed. Using immunofluorescence staining, the expression of PMCA2 was respectively examined in the cochlear sections and cochlear coils. In addition, the total RNAs of basilar membrane (BM, including the organ of corti, the same below), spiral ganglion (SG), spiral ligament (SL, including SV, the same below), and the whole cochlea from neonatal rats were respectively extracted and reverse transcribed to cDNAs, then subjected to primers flanking site A or C in the PMCA2 gene using reverse transcription polymerase chain reaction (RT-PCR). Western blot was also applied to detect the expression of PMCA2 isoforms in the cochlear tissues. Results We found that PMCA2 is strongly expressed in outer hair cell (OHC) bundles, SG, and stria vascularis (SV), weakly expressed in Reissner's membrane (RM), and occasionally expressed in inner hair cell (IHC) bundles. Moreover, w/a is the major splice form of PMCA2 present in hair cell bundles, z/b and z/c are the major splice forms of PMCA2 present in SG, and w/a and w/c are the major splice forms of PMCA2 present in SV. In the whole cochlea, variants w, y, and z were detected at site A, and variants a, b, and c were detected at site C. Using Western blot, variant a or b was also detectable in the same cochlear tissues mentioned above. Conclusions PMCA2 and its splice variants at sites A and C are differentially expressed in cochlear tissues of neonatal rat.

The global bifurcations and chaotic motions are investigated analytically for an arch structure with parametric and forced excitation. The critical curves separating the chaotic and non-chaotic regions are drawn, which show that the system in the case of 1:1 resonance is more easily chaotically excited than the case of 1:2 resonance. There exist “uncontrollable regions” or “chaotic bands” for the system as the natural frequency varies. There also exists a “controllable frequency” for the system with linear and cubic parametric excitation. The system can be chaotically excited through infinite subharmonic bifurcations of odd/even orders. Numerical results agree with the analytical ones.

The stability and chaotic motions of a damped satellite partially filled with liquid which is subjected to external disturbance are investigated in this paper. With linearization analysis, the stability of the two non-trivial equilibrium points is studied. The homoclinic and heteroclinic orbits are found by using the undetermined coefficient method, and the convergence of the series expansions of these two types of orbits is proved. It analytically demonstrates that there exist homoclinic orbits of the Si’lnikov type that join the two non-trivial equilibrium points to themselves, and therefore smale horseshoes and the horseshoe chaos occur for this system via the Si’lnikov criterion. In addition, there also exists a heteroclinic orbit connecting the two non-trivial equilibrium points. Numerical simulations are also given, which verify the analytical results. The system can be chaotic through period-doubling bifurcations as the amplitude of the external disturbance varies, and backward period-doubling bifurcations as the angular momentum of the rotor varies.

The chaotic dynamics of the transport equation for the L-mode to H-mode near the plasma in a tokamak is studied in detail with the Melnikov method. The transport equations represent a system with external and parametric excitation. The critical curves separating the chaotic regions and nonchaotic regions are presented for the system with periodically external excitation and linear parametric excitation, or cubic parametric excitation, respectively. The results obtained here show that there exist uncontrollable regions in which chaos always take place via heteroclinic bifurcation for the system with linear or cubic parametric excitation. Especially, there exists a controllable frequency, excited at which chaos does not occur via homoclinic bifurcation no matter how large the excitation amplitude is for the system with cubic parametric excitation. Some complicated dynamical behaviors are obtained for this class of systems.

Genesio system, which is a three-dimensional system with only one quadratic nonlinear term, is considered. It has two equilibrium points for some parameters. The Hopf bifurcation is discussed, and the existence of the homoclinic orbit for this system has been proven by using the undetermined coefficient method. As a result, the Si’lnikov criterion guarantees that the Genesio system has Smale horseshoe chaos.

Using a combination of analytical and numerical methods, the paper studies the stability and bifurcations for a model of a nonlinear coupled pitch-roll ship. The model represents a two-degree-of-freedom system with quadratic coupling subjected to a modulated sinusoidal excitation. Three types of critical points for the bifurcation response equations near the combination resonance in the presence of internal resonance are considered. These points are characterized by a double zero and two negative eigenvalues, a double zero and a pair of purely imaginary eigenvalues, and two pairs of purely imaginary eigenvalues, respectively. For each case, the stability regions for the initial equilibrium solution and the critical bifurcation curves are obtained. The amplitude response curves with respect to detuning/damping parameters for critical bifurcation parameters are obtained for the first two types, and detailed analyses of the eigenvalues of the linearized system for each parametric region are given. For the third type, with the aid of normal form theory, the explicit expressions of the critical bifurcation curves leading to incipient and secondary bifurcations are obtained. Bifurcations leading to 2D, 3D tori and their stability conditions are also investigated. Some new dynamical behaviors are presented for this system.

Stability and bifurcation behaviors for a model of a flexible beam undergoing a large linear motion with a combination parametric resonance are studied by means of a combination of analytical and numerical methods. Three types of critical points for the bifurcation equations near the combination resonance in the presence of internal resonance are considered, which are characterized by a double zero and two negative eigenvalues, a double zero and a pair of purely imaginary eigenvalues, and two pairs of purely imaginary eigenvalues in nonresonant case, respectively. The stability regions of the initial equilibrium solution and the critical bifurcation curves are obtained in terms of the system parameters. Especially, for the third case, the explicit expressions of the critical bifurcation curves leading to incipient and secondary bifurcations are obtained with the aid of normal form theory. Bifurcations leading to Hopf bifurcations and 2-D tori and their stability conditions are also investigated. Some new dynamical behaviors are presented for this system. A time integration scheme is used to find the numerical solutions for these bifurcation cases, and numerical results agree with the analytic ones.

The stability and bifurcations of a hinged-hinged pipe conveying pulsating fluid with combination parametric and internal resonances are studied with both analytical and numerical methods. The system has geometric cubic nonlinearity. Three types of critical points for the bifurcation response equations are considered. These points are characterized by a double zero and two negative eigenvalues, double zero and a pair of purely imaginary eigenvalues, and two pairs of purely imaginary eigenvalues, respectively. With the aid of normal form theory, the expressions for the critical bifurcation lines leading to incipient and secondary bifurcations are obtained. Possible bifurcations leading to 2-D tori are also investigated. Numerical simulations confirm the analytical results.

Bifurcations and chaotic motions of a class of mechanical system subjected to a superharmonic parametric excitation or a nonlinear periodic parametric excitation are studied, respectively, in this paper. Chaos arising from the transverse intersections of the stable and unstable manifolds of the homoclinic and heteroclincic orbits is analyzed by Melnikov's method. The critical curves separating the chaotic and nonchaotic regions are plotted. Chaotic dynamics are compared for these systems with a periodic parametric excitation or a superharmonic parametric excitation, or a nonlinear periodic parametric excitation. Especially, some new dynamical phenomena are presented for the system with a nonlinear periodic parametric excitation.

To evaluate clinical value of electrocochleography in diagnosing the Meniere's disease.Patients were saperated as having definite, probable and possible Meniere's disease according to the 1995 AAOHNS guidelines. Then set the probable and possible Meniere's disease as a suspected group. We used four different stimulus (clicks, 1000 Hz tone burst, 2000 Hz and 4000 Hz tone burst) to record electrocochleo-graphy. Those patients in each group received electrocochleography examination, and summating potential (SP)/action potential (AP) ratios were calculated. A prolonged action potential latency shift (AP shift) evoked by rarefaction and condensation clicks was also measured.The click SP/AP positive rate in definite Meniere's disease group was 41.2%, tone burst at 1,000 Hz. 2,000 Hz,4,000 Hz were respectively 80.4%, 72.5%, 37.3%, AP shift positive rate was 45.1%. Using McNemar test, the positive rate of tone burst 1000 Hz (chi2 = 15.04, P0.01) and that of tone burst 2,000 Hz (chi2 = 8.65, P0.01) were statistically significant different when compared with that of click SP/AP, besides the tone burst at 1,000 Hz yielded has the highest sensitivity. The click SP/AP positive rate in suspected group and definite group were respectively 12% and 45.1% (chi2 = 6.610, P0.05) and AP shift positive rate of them were respectively 8.0% and 41.2% (chi2 = 10.460, P0.01). By chis-quare test, the positive rates of click SP/AP and AP shift between these two groups were statistically significant different.Electrocochleography is a reliable test in the diagnosis of Meniere's disease. Compared with clicks, tone burst significantly has a higher sensitivity, especially at 1000Hz and 2000Hz frequencies. A prolonged action potential latency shift evoked by rarefaction and condensation clicks is also a useful addition to diagnosis Meniere' disease.

Na(+)-K(+)-2Cl(-) co-transporter isoform 1 (NKCC1) mRNA and protein decrease with increasing age in the cochlear lateral wall of C57BL/6J (C57) mice. The down-regulation of NKCC1 may influence the K(+) transport efficiency and the homeostasis of ion transport cells, and cause the irreversible damage of cochlear cells in old C57 mice. Our results indicate that NKCC1 may play an important role in the pathogenesis of age-related hearing loss (AHL).The aim of the present study was to investigate the relationship between the functional expression of NKCC1 transporter and the etiology of AHL.C57 mice were used and randomly divided into four groups according to age (4 weeks, 14 weeks, 26 weeks, and 52 weeks). Immunofluorescence technique, quantitative real-time PCR, and western blot were applied to detect the expression of NKCC1 in the cochlear lateral wall of C57 mice at the various ages.In all four groups, the expression of NKCC1 was observed in the stria vascularis and type II fibrocytes of the spiral ligament. Also, the expression of NKCC1 appeared to decrease with age at both the transcriptional level and the protein level.

The kiwifruit (Actinidia chinensis) is an economically and nutritionally important fruit crop with remarkably high vitamin C content. Here we report the draft genome sequence of a heterozygous kiwifruit, assembled from ~140-fold next-generation sequencing data. The assembled genome has a total length of 616.1 Mb and contains 39,040 genes. Comparative genomic analysis reveals that the kiwifruit has undergone an ancient hexaploidization event (γ) shared by core eudicots and two more recent whole-genome duplication events. Both recent duplication events occurred after the divergence of kiwifruit from tomato and potato and have contributed to the neofunctionalization of genes involved in regulating important kiwifruit characteristics, such as fruit vitamin C, flavonoid and carotenoid metabolism. As the first sequenced species in the Ericales, the kiwifruit genome sequence provides a valuable resource not only for biological discovery and crop improvement but also for evolutionary and comparative genomics analysis, particularly in the asterid lineage., The kiwifruit is an economically and nutritionally important fruit crop with high vitamin C content. Here, the authors report the draft genome sequence of a heterozygous kiwifruit and through comparative genomic analysis provide valuable insight into kiwifruit evolution.

The kiwifruit bacterial canker has been recognized as the main kiwifruit pathogen in Sichuan and acquired strong resistance to chemicals during its long evolution under chemical evolutionary pressure. Base on biochemical testing, pathogenic testing and phylogenetic analyses, the results shown that Pseudomonas syringae pv. actinidiae is the causal agents of the “Hongyang” kiwifruit bacterial canker disease. Besides this bacterial pathogen, 14 endophytic fungi of kiwifruit leaves were also isolated and identified, including Penicillium sp. Colletotrichum sp. Phomopsis sp. Alternaria sp. and Nigrospora sp. 8 endophytic fungi were obtained from branches, such as Alternaria sp. Nigrospora sp. Phomopsis sp.and Sordaria sp. and one of the endophytic fungi Nigrospora sp. (No.J2) from branch showed good antagonistic activities to Pseudomonas syringae pv. actinidiae in vitro with the inhibition zone of 14 mm, therefore it has the potential of being used as a biological control agent against kiwifruit bacterial canker.

Although Ca(V)1.3 channels are known to be essential for neuronal excitation and signal transduction in the auditory system, their expression patterns in the cochlea are still not fully understood, particularly in the regions where non-sensory cells are located. We performed immunohistochemistry, western blotting and reverse transcription-polymerase chain reaction (RT-PCR) to identify the expression and distribution of Ca(V)1.3 channels in the rat cochlea. Immunohistochemistry revealed that Ca(V)1.3 channels were localized in the outer hair cells (OHCs), inner hair cells (IHCs), limbus laminae spiralis, spiral ganglion cell, spiral ligament (SL), and stria vascularis (STV). The results of RT-PCR and western blotting demonstrated Ca(V)1.3 channels had a tissue-specific expression pattern. Ca(V)1.3 mRNA and protein were intensively expressed in the basilar membrane and spiral ganglion while moderate level of Ca(V)1.3 channels was observed in SL and STV. Our study preliminarily revealed the expression patterns of Ca(V)1.3 channels in the rat cochlea, providing a theoretical basis for further research on the role of Ca(V)1.3 channels in the periphery auditory system.

This study examined the expression pattern of programmed cell death 5 (PDCD5) in cochlear hair cells and spiral ganglion neurons (SGNs) and its association with age-related hearing loss in mice. Sixty C57BL/6J (C57) mice at different ages were divided into four groups (3, 6, 9 or 12 months). PDCD5 expression was detected by using immunohistochemistry, real-time PCR and Western blot. Morphological change of the cochleae was also evaluated by using immunoassay. The results showed that the expression of PDCD5 had a gradual increase with ageing in both protein and RNA levels in C57 mice, as well as gradually increased apoptosis of cochlear hair cells and SGNs. In addition, we also found that caspase-3 activity was enhanced and its expression was enhanced with ageing. It is implied that overexpression of PDCD5 causes the increase in caspase-3 activity and the subsequent increase of apoptosis in cochlear hair cells and SGNs, and thereby plays a role in the pathogenesis of presbycusis. Thus, PDCD5 may be a new target site for the treatment and prevention of age-related hearing loss.

Research in mammalian hair cell regeneration is hampered by a lack of in vivo model of adult mouse inner ear injury. In the present study we investigated the effects of a combination of a single dose of aminoglycoside followed by a loop diuretic in adult mice. The auditory brainstem response threshold shift, extent and defining characteristics of the cochlear lesion were assessed and verified at different time points post-treatment. Our data indicated that this drug combination caused the rapid and extensive death of outer hair cells (OHCs). OHC death presented throughout the cochlea that commenced in the basal turn by 24 h and progressed apically. In contrast, inner hair cell (IHC) loss was delayed and mild. Terminal deoxynucleotidyl transferase dUTP nick end labelling-positive nuclei demonstrated that the majority of OHCs died via an apoptotic pathway. Auditory threshold shifts of up to 90 dB SPL indicated a profound hearing loss. In addition, the endocochlear potential (EP) in the drug-treated animals displayed a significant decline at 12 h post-treatment followed by recovery by 48 h post-treatment. Despite this recovery, there was a significant and progressive decrease in strial vascularis thickness, which was predominantly due to atrophy of marginal cells. The present study reproduced an adult mouse model of aminoglycoside-induced hearing loss. The mechanism underlying the recovered EP in the model with extensive hair cell death is discussed.

The mechanisms of the response in the murine cochlear lateral wall following sensorineural hearing loss (SNHL) are poorly understood. We focused on comparing the endocochlear potential (EP) with morphological changes in the lateral wall and expression of four important potassium (K(+)) transporters in a mouse model of SNHL induced by co-administration of aminoglycoside and loop diuretic. The expression of the α1 and α2 isoforms of Na,K-ATPase, Na-K-2Cl-Cotransporter-1 (NKCC1) and potassium channel KCNQ1 was assessed. The EP showed a significant decline at 12h post-treatment followed by complete recovery by 2 days post-treatment. The EP was maintained at near normal levels in animals deafened for periods up to 112 days. Despite this recovery, there was a significant and progressive decrease in the thickness of the stria vascularis, which was predominantly due to atrophy of marginal cells. Both protein and mRNA expression of α1 and α2 isoforms of Na,K-ATPase and NKCC1 in the lateral wall were dramatically reduced following a long-term deafening. KCNQ1 expression remained unchanged. These observations provide insight into the detailed mechanisms of EP modulation following SNHL and may have crucial implications in the future treatment of aminoglycoside-induced hearing loss.

A lot of chaotic motions in nonlinear dynamical systems take place arising from the homoclinic/heteroclinic intersections. However, it is difficult to solve the homoclinic or heteroclinic orbits in most nonlinear dynamical systems. One method for solving the homoclinic/heteroclinic orbits of nonlinear dynamical systems, named undetermined coefficient method, is presented in this paper. With this method, the series expansion of the heteroclinic orbit for a new nonlinear system are obtained. It analytically demonstrates that there exists one heteroclinic orbit of the Si’lnikov type that connects the two equilibrium points, therefore Smale horseshoe chaos may occur for this system via the Sil’nikov criterion.

L-type voltage-gated calcium channel subunit alpha1D-/- mice (homozygous mutant, knockout), alpha1D+/- (heterozygous) and alpha1D+/+ (wild-type) have played role in L-type voltage-gated calcium channel alpha1D subunit in auditory function of inner ear as well as sinoatrial node function of the mice.Hearing threshold and endocochlear potential (EP) were measured in the alpha1D knockout mice, heterozygous mice and wild-type mice by auditory brainstem response(ABR), EP recordings and Electrocardiograph (ECG) respectively. To assessment of the vestibular function of the mice, the ability of Balancing was performed by a swim test and a horizontal cylinder test.The auditory function of alD+/+ mice were normal, the mean value for ABR thresholds in response to click sound stimulus was (34.8 +/- 5.7) dB SPL,EP was (105.3 +/- 3.1) mV. The mean value for ABR thresholds in response to click sound stimulus was elevated in alpha1D+/- mice was (54.4 +/- 12.4) dB SPL, relative to that observed in alpha1D+/+ mice significantly increased (P0.05); EP of alpha1D+/- mice was about (75.8 +/- 9.9) mV. alpha1D-/- mice were completely deaf, the ABR wave form was not observed for even 100 dB SPL sound stimuli used and EP was still remain in (48.6 +/- 19.3) mV. alpha1D knockout mice were deaf and demonstrated no vestibular defect. alpha1D+/- and alpha1D-/- mice show significant sinus bradycardia with significant prolongation of the RR interval (146 +/- 1.4 and 244 +/- 2.9, respectively) comparing to the alpha1D+/+ wild-type mice (117 +/- 0.4) in the same littermates. In addition, the homozygous alpha1D-/- show a significant prolongation of the PR interval (53 +/- 0.5) compared to that of the a1D+/+ wild-type mice (38 +/- 0.3).L-type voltage-gated calcium channel alpha1D subunit plays a critical role in calcium homeostasis in the inner ear. Mice lacking of alpha1D calcium channel gene would lead to influence auditory function and sinoatrial node dysfunction subsequently.