Deep-tissue confocal imaging of the central projections of ovipositor sensory afferents in the Egyptian cotton leafworm,Spodoptera littoralis

The pre-ovipositon behavior of moths is largely dependent upon the cues that a gravid female perceives while assessing potential oviposition sites. Assessment of such sites is accomplished, at least in part, by mechanosensory and gustatory sensilla located on the ovipositor whose sensory neurons project into the terminal abdominal ganglion (TAG). Using anterograde backfill staining, confocal laser scanning microscopy, and three dimensional reconstruction, we traced and analyzed the central projections of the sensory neurons housed in the sensilla located on the ovipositor papillae and explored the neuropilar composition of the TAG in the Egyptian cotton leafworm, Spodoptera littoralis. The TAG consists of three fused neuromeres (6–8th Ner) associated with the 6–8th abdominal segments. Within the TAG, and specifically in the 8th neuromere, four unstructured neuropilar compartments are present; the dorso-ipsilateral motor neuropil (MN), the medio-ipsilateral mechanosensory neuropil (MchN), the medio-ipsilateral small gustatory neuropil (GN), and the medio-contralateral posterior ovipositor glomerulus (Og). The Og appears quite compact, with a hollow core free of terminal arborizations. The MchN is further subdivided into 4 unstructured glomeruli in the 8th neuromere, whose afferents are subsequently extended into 3 glomeruli in the 7th and 6th neuromeres. Few neurites of the Og are populated with large dense varicosities reminiscent of neurosecretory vesicles. Given that all ovipositor nerves converge into a common ganglionic center, the TAG, we assume that this ganglion may be a center for coordination of oviposition behaviors, including movements of the ovipositor during assessment of oviposition substrates and egg laying in S. littoralis.     

颠倒睡眠状态调制心率变异性信号的功率谱和基本尺度熵分析

心率变异性(HRV)信号能够提供心脏活动状态的重要信息.通过建立颠倒睡眠模型,联合功率谱和基本尺度熵方法分析颠倒睡眠状态下24 h的HRV信号,研究颠倒睡眠对自主神经相互作用以及HRV信号混沌强度的调制.结果表明,颠倒睡眠导致自主神经在昼夜间的活动节律发生颠倒,基本尺度熵在昼夜的变化趋势也随之发生逆转,因此HRV信号的混沌强度与自主神经的相互作用密切相关,进一步研究两者之间的关系发现:HRV信号的混沌强度与交感神经的调制强度正相关,与迷走神经的调制强度负相关.     

Phosphites and Hexafluoroacetone-Hexafluoroacetylacetones: a Comparison

Abstract

Selected acyclic and cyclic phosphites (RO)₂PX (1-5) were reacted with activated ketones (CF₃)₂CO (6) and Z-CF₃C(O)CH=C(OH)CF₃ (7a) / E-CF₃C(O)CH=C(OSiMe₃)CF₃ (7b) in order to study the influence of R and X on the product formation. A new type of insertion, a 1,4 group shift and cyclo-addition reactions yielding five membered rings and bicyclic fused systems were observed. In most cases phosphonates and their λ⁵[sgrave]⁵ P derivatives were obtained. The ketones in question can be considered versatile reactants in phosphorus chemistry.     

UiO-66-NH2 and Zeolite-Templated Carbon Composites for the Degradation and Adsorption of Nerve Agents

Composites of metal-organic frameworks and carbon materials have been suggested to be effective materials for the decomposition of chemical warfare agents. In this study, we synthesized UiO-66-NH₂/zeolite-templated carbon (ZTC) composites for the adsorption and decomposition of the nerve agents sarin and soman. UiO-66-NH₂/ZTC composites with good dispersion were prepared via a solvothermal method. Characterization studies showed that the composites had higher specific surface areas than pristine UiO-66-NH₂, with broad pore size distributions centered at 1–2 nm. Owing to their porous nature, the UiO-66-NH₂/ZTC composites could adsorb more water at 80% relative humidity. Among the UiO-66-NH₂/ZTC composites, U_0.8Z_0.2 showed the best degradation performance. Characterization and gas adsorption studies revealed that beta-ZTC in U_0.8Z_0.2 provided additional adsorption and degradation sites for nerve agents. Among the investigated materials, including the pristine materials, U_0.8Z_0.2 also exhibited the best protection performance against the nerve agents. These results demonstrate that U_0.8Z_0.2 has the optimal composition for exploiting the degradation performance of pristine UiO-66-NH₂ and the adsorption performance of pristine beta-ZTC.     

Neurofilaments are intrinsic determinants of axonal caliber

Neurofilaments (NFs) are intrinsic determinants of axonal caliber in large-caliber myelinated nerve fibers. Axonal caliber is influenced by the number of NFs in the axon (axonal NF content) and the spacing between adjacent NFs (interfilament distance). Axonal NF content depends on the level of NF gene expression, the amount of NF protein entering the axon, and the velocity at which NF protein moves within the axon. In this review we discuss possible factors affecting both axonal NF content and interfilament distance; these include the ratio of NF subunits, the level of phosphorylation of these subunits, interactions with target cells, and interactions with ensheathing glial cells.     

Physiological Studies of Retrusive Movements of the Human Tongue

SUMMARY: This study identified that physiologically the superior pharyngeal constrictor muscle at the level of the base of the tongue contributes to retrusive movement of the tongue with constriction of the mid-pharyngeal cavity and possesses unique properties in terms of motor speech control along with the genioglossus muscle. From a kinematic study involving trans-nasal fiberscopy and lateral X-ray fluorography, retrusive movement of the tongue was highly correlated with constrictive movement of the mid-pharyngeal cavity. An electromyographic study revealed that the superior pharyngeal constrictor muscle at the level of the base of the tongue contributes to retrusive movement of the tongue and that the genioglossus muscle contributes to protrusive movement. We also noted that this relationship between the activities of these two muscles were in response to postural changes during vowel productions without changes in the acoustic features. These findings suggest that these two muscles act not only antagonistically to produce retrusive and protrusive movement of the tongue, but also they complement each other to conserve the shape of the vocal tract for speech production. The functional relationship between these two muscles could contribute the consecutive movement of human speech production under various conditions and might be useful when applying rehabilitation approaches for the patients with neurological speech and swallowing disorders.     

Activity inAplysia buccal ganglia characterized by signal processing techniques

Summary Two procedures aimed at a synthetic, quantitative characterization of the integrative activity in a small system of nerve cells are proposed, and applications to the buccal ganglion of the molluskAplysia are described. Both methods are based on cross-correlation evaluation. The first method processes intracellular signals simultaneously recorded from pairs of neurones, and reveals and measures the occurrence of shared synaptic input. The second method processes extracellular multiunit signals recorded by two cuff electrodes placed around one nerve, and evaluates the impulse traffic, subdivided according to direction and speed of propagation. The outcome of both methods may be used to represent the state of the system, and may provide a basis to further studies on its dynamics. Paper presented at the International Workshop ?Fluctuations in Physics and Biology: Stochastic Resonance, Signal Processing and Related Phenomena?, Elba, 5–10 June 1994.     

Inhibitory Effect of Anisodamine on the Neuropathic Hyperalgesia Following Peripheral Nerve Injury(Ⅱ)

A peripheral neuropathy with hyperalgesia and allodynia was produced by loosely tying constrictive ligature around the left sciatic nerve of rats, i.v. injection of anisodamine 20mg/Kg abolished both neuropathic hyperalgesia responses to noxious radiant heat and ectopic discharges generated from the injured region of the nerve. Anisodanime applied either systemically or locally to the damaged area of the nerve not only ceased the spontaneous ectopic discharges recorded from A_β to C fibers but also blocked the afferent ectopic discharge elicited by K~+ channel blocker, noradrenaline, Ca~(2+) or antidromic stimulation of sciatic nerve proximal to the injured nerve area. The experiments indicated that anisodamine probably possessed a calcium channel blocker-like activity and produced selective block of the new channels in the injured area. It is suggested that anisodamine may be a candidate therapeutic agent in relieving hyperalgesia and allodynia following nerve injury.     

Analysis of Vocal-fold Vibrations from High-Speed Laryngeal Images Using a Hilbert Transform-Based Methodology

This paper presents a Hilbert transform-based approach to analyze vocal fold vibrations in human subjects exhibiting normal and abnormal voice productions. This new approach is applied to the analysis of glottal area waveform (GAW) and is capable of providing useful information on the vocal fold vibration. The GAW is extracted from high-speed laryngeal images by delineating the glottal edge for each image frame. An analytic signal is generated through the Hilbert transform of the GAW, which yields a recognizable pattern of the vocal fold vibration in the analytic phase plane. The vibratory pattern is comprehensive and can be correlated with specific voice conditions. Quantitative measures of the glottal perturbation are introduced using the analytic amplitude and instantaneous frequency obtained from the analysis. Examples of clinical voice recordings are used to evaluate and test the effectiveness of this approach in providing qualitative representation and quantitative characteristics of vocal fold vibratory behavior. The results demonstrate the potential of using this new analytical tool incorporated with the high-speed laryngeal imaging modality for clinical voice assessment.