Knowing one's own behavioral state has long been theorized as critical for contextualizing dynamic sensory cues and identifying appropriate future behaviors. Ascending neurons (ANs) in the motor system that project to brain are well positioned provide such signals. However, what ANs encode where they convey these signals remains largely unknown. Here, through large-scale functional imaging behaving animals morphological quantification, we report encoding targeting of hundreds genetically...

We report a reproducible technique of making side-polished fibers by embedding in silicon V grooves and polishing them mechanically. Details techniques are described. The attenuation characteristics polished were measured liquid-drop method; the results excellent agreement with existing theoretical predictions. To facilitate comparisons, we cast expressions for constant terms three generalized parameters: b parameters fiber new parameter Vex external medium. By using these parameters, can...

The use of broad-band sources, polarized and unpolarized, in fiber gyroscopes with linearly birefringent fibers, is studied theoretically. Polarization-mode coupling the modeled using one-mode center. Gyroscope output equations are obtained which useful interpreting an origin noise limiting cases low high birefringence. Interference effects shown to be related mode at particular locations fiber. extent these governed by a depolarization length for numerical estimates given.

Abstract To understand neural circuits that control limbs, one must measure their activity during behavior. Until now this goal has been challenging, because limb premotor and motor have largely inaccessible for large-scale recordings in intact, moving animals—a constraint is true both vertebrate invertebrate models. Here, we introduce a method 2-photon functional imaging from the ventral nerve cord (VNC) of behaving adult Drosophila melanogaster . We use to reveal patterns across...

Deciphering how the brain regulates motor circuits to control complex behaviors is an important, long-standing challenge in neuroscience. In fly, Drosophila melanogaster , this coordinated by a population of ~ 1100 descending neurons (DNs). Activating only few DNs known be sufficient drive like walking and grooming. However, what additional role larger plays during natural remains largely unknown. For example, they may modulate core behavioral commands or comprise parallel pathways that are...

Optical directional couplers with variable separation are introduced and analyzed. Closed form solutions to the coupled-mode equations coupling coefficient presented. A procedure for design of best geometry a variety applications utilizing spacing is also

Abstract The dentate gyrus (DG) is the primary gate of hippocampus and controls information flow from cortex to proper. To maintain normal function, granule cells (GCs), principal neurons in DG, receive fine-tuned inhibition local-circuit GABAergic inhibitory interneurons (INs). Abnormalities circuits DG are associated with several brain disorders, including epilepsy, autism, schizophrenia, Alzheimer disease. Therefore, understanding network mechanisms control GCs functional...

The reduction of the degree polarization broad-band light due to propagation in ordinary single-mode fiber is examined theoretically and experimentally. Previous work extended account for polarization-mode coupling along by developing a model one discrete mode-coupling center extending it qualitatively include multiple centers. existence nonzero long lengths shown be mode at particular positions related coherence associated with site. experimental results generally support developed.

Changes to the structure and function of neural networks are thought underlie evolutionary adaptation animal behaviours. Among many developmental phenomena that generate change programmed cell death (PCD) appears play a key role. We show occurs continuously throughout insect neurogenesis happens soon after neurons born. Mimicking an role for increasing numbers, we artificially block PCD in medial neuroblast lineage Drosophila melanogaster , which results production ‘undead’ with complex...

Simple polarimetric force sensors based on high birefringence fibers are investigated theoretically and experimentally. The sensor consists of a linearly polarized light source, birefringent fiber, an analyzer or polarizing prism two photo detectors. At the input, one polarization modes is excited. output, power in orthogonal mode detected. In theoretical investigation, modeled as concatenation three fiber sections with short middle section stress sensing element. treated anisotropic media...

Diffusion techniques have provided an alternative to thin film technology for the fabrication of LiNbO3 and LiTaO3 light guiding layers. The effects metal dielectric overlays on propagation TE TM modes in diffused optical waveguides with expontential profile are investigated. Also examined strip loaded metal-clad providing 2-D confinement beam.

Abstract The dynamics and connectivity of neural circuits continuously change on timescales ranging from milliseconds to an animal’s lifetime. Therefore, understand biological networks, minimally invasive methods are required repeatedly record them in behaving animals. Here we describe a suite devices that enable long-term optical recordings the adult Drosophila melanogaster ventral nerve cord (VNC). These consist transparent, numbered windows replace thoracic exoskeleton, compliant implants...

A class of optical fiber intensity sensors that do not require the use external structures to impose perturbations on fibers is presented. The topological are formed directly onto cladding. geometry features defined photolithographically and by chemical etching. etched sensing elements have been fabricated tested as strain sensors. Depending amount cladding material removed symmetry structure, measured gauge factor may be larger than 100. responses gauges linear, repeatable, a high cyclic...

A new optical fiber Fabry-Perot (F.P.) temperature sensor is proposed and demonstrated. In particular, it can discern the rise from drop. With this sensor, change direction of be determined as a function time. The basic concept has been verified experimentally. results F.P. measurement compare well with an independent thermocouple measurement. To provide further insight, details experimentally observed interference fringes have also compared to computer simulation. Possible real-time...

The polarization characteristics of fiber couplers made birefringent single-mode fibers are studied. effect anisotropic interfiber coupling, birefringence, angular misalignment fibers, and twisting on the coupler identified. compared with that isolated uncoupled same birefringence length. equivalent lumped element representations for three classes also presented.

Abstract Knowledge of one’s own behavioral state—whether one is walking, grooming, or resting—is critical for contextualizing sensory cues including interpreting visual motion and tracking odor sources. Additionally, awareness posture important to avoid initiating destabilizing physically impossible actions. Ascending neurons (ANs), interneurons in the vertebrate spinal cord insect ventral nerve (VNC) that project brain, may provide such high-fidelity state signals. However, little known...

A study is made of the scattering a plane electromagnetic wave by long and thin metallic wire in which case arbitrary incidence considered. The Wiener‐Hopf technique used to solve integral equation. Explicit rather simple expressions for induced current, far‐field pattern, backscattering cross sections are found; numerical results presented. These reasonable agreement with existing experimental data.

Reconstruction of the anterior skull base is one greatest challenges for reconstructive surgeons. Sometimes, defect so large that a local flap insufficient reconstruction. In this report, we present case malignant meningioma base. The tumor was treated by surgical excision resulting in from to nasal cavity. entire within cranial vault. reconstruction achieved using free composite de-epithelialized anterolateral thigh and vastus lateralis muscle flap. Postoperative monitoring included hand...

Coefficients that characterize the contribution to total waveguide dispersion from guide geometry and material are introduced. These cast in terms of normalized parameters frequency, asymmetry measure, effective index. This allows plotting universal curves for coefficients step thin film exponentially graded slab waveguides applicable all such structures.

Optical-fiber strain gauges with asymmetric etched structures have been analyzed, fabricated, and tested. These sensors are very sensitive a gauge factor as high 170 flat frequency response to at least 2.7 kHz. The depends on the asymmetry of number sections. To understand physical principles involved, researchers used structural analysis programs based finite-element method analyze fibers under tensile stress. results show that lateral bends induced when they stretched axially. relate...