Reduction of noise in gyro outputs

Technique is described to reduce extraneous gyro output signals by using relatively inexpensive shrouds which do not increase power comsumption. Shrouds reduce noise by minimizing mass of gas spinning with rotor, reducing Reynolds number near rotor, and inducing laminar flow

Zooming in on protein–RNA interactions: a multilevel workflow to identify interaction partners

Interactions between proteins and RNA are at the base of numerous cellular regulatory and functional phenomena. The investigation of the biological relevance of non-coding RNAs has led to the identification of numerous novel RNA-binding proteins (RBPs). However, defining the RNA sequences and structures that are selectively recognised by an RBP remains challenging, since these interactions can be transient and highly dynamic, and may be mediated by unstructured regions in the protein, as in the case of many non-canonical RBPs. Numerous experimental and computational methodologies have been developed to predict, identify and verify the binding between a given RBP and potential RNA partners, but navigating across the vast ocean of data can be frustrating and misleading. In this mini-review, we propose a workflow for the identification of the RNA binding partners of putative, newly identified RBPs. The large pool of potential binders selected by in-cell experiments can be enriched by in silico tools such as catRAPID, which is able to predict the RNA sequences more likely to interact with specific RBP regions with high accuracy. The RNA candidates with the highest potential can then be analysed in vitro to determine the binding strength and to precisely identify the binding sites. The results thus obtained can furthermore validate the computational predictions, offering an all-round solution to the issue of finding the most likely RNA binding partners for a newly identified potential RBP

A "Kane's Dynamics" Model for the Active Rack Isolation System

In the late 1980s, microgravity researchers began to voice their concern that umbilical-transmitted energy could significantly degrade the acceleration environment of microgravity space science experiments onboard manned spacecraft. Since umbilicals are necessary for many experiments, control designers began to seek ways to compensate for these "indirect" disturbances. Hampton, et al., used the Kane s method to develop a model of the active rack isolation system (ARIS) that includes (1) actuator control forces, (2) direct disturbance forces, and (3) indirect, actuator-transmitted disturbances. Their model does not, however, include the indirect, umbilical-transmitted disturbances. Since the umbilical stiffnesses are not negligible, these indirect disturbances must be included in the model. Until the umbilicals have been appropriately included, the model will be incomplete. This Technical Memorandum presents a nonlinear model of ARIS with umbilicals included. Model verification was achieved by utilizing two commercial-off-the-shelf software tools. Various forces and moments were applied to the model to yield simulated responses of the system. Plots of the simulation results show how various critical points on an ARIS-outfitted international standard payload rack behave under the application of direct disturbances, indirect disturbances, and control forces. Simulations also show system response to a variety of initial conditions

Development of control systems for space shuttle vehicles, volume 1

Control of winged two-stage space shuttle vehicles was investigated. Control requirements were determined and systems capable of meeting these requirements were synthesized. Control requirements unique to shuttles were identified. It is shown that these requirements can be satisfied by conventional control logics. Linear gain schedule controllers predominate. Actuator saturations require nonlinear compensation in some of the control systems

Effects of on-farm hatching on short term stress indicators, weight gain, and cognitive ability in layer chicks

Layer chicks are usually transported early in life, experiencing immediate post-hatch food and water deprivation and various transport-related stressors with potentially negative long-term consequences for learning, cognition and welfare. In contrast, as chicks are only temporarily exposed to these stressors, the experienced stress could be sub-chronic which may improve cognitive flexibility. The aim of this exploratory study was therefore to investigate the acute and long-term effects of on-farm hatching (OFH) compared to conventional hatching. Dekalb White layer chicks were subjected to either OFH (n = 47) with ad libitum access to feed and water or temporary post-hatch resource deprivation and eight hour transport (RDT; n = 42). Physical and behavioural measures were collected to examine short-term effects of the treatment procedures. To determine longer term effects, treatment differences in learning and cognitive flexibility were assessed in a Y-maze using several paradigms (reversal, attentional-shift, extinction) between 4 and 12 weeks of age (WOA). Compared to OFH chicks, RDT had: greater corticosterone levels after transport (F1,19 =8.15, p = 0.01, RDT (16.24 ± 1.20 ng/mL) vs. OFH (8.13 ± 1.20 ng/mL) and post-recovery (F1,19 =4.93, p = 0.04; RDT (11.69 ± 1.35 ng/mL) vs. OFH (5.31 ± 1.37)), and lower body mass after resource deprivation and transport (F2258 =9.7, p < 0.001, RDT (33.14 ± 0.33 g) vs. OFH (37.62 ± 0.28 g)). Performance of activity behaviours (foraging, drinking, resting, wing-assisted running) after transport exhibited treatment by time interactions. Additionally, a tendency for OFH being heavier than RDT chicks was observed up to 11 WOA. The majority of birds learned the initial association in the Y-maze between a reward and location (77% of n = 19 RDT and n = 29 OFH chicks) or light stimulus (91% of n = 12 RDT and n = 11 OFH chicks). Subsequently, a number of chicks reached the learning criterion in the location reversal (24% of n = 13 RDT and n = 24 OFH chicks) and the light-to-location attentional-shift (47% of n = 11 RDT and n = 10 OFH chicks), and most of these chicks succeeded in the following extinction paradigm (80% of n = 3 RDT and n = 7 OFH chicks). No treatment effects were detected in any phase of cognitive testing. In conclusion, treatment affected behaviour and health parameters suggesting RDT animals were recovering from resource deprivation and transport. Continued treatment differences in body mass throughout rearing demonstrated long term effects as well although no effects on initial learning and cognitive flexibility were identified. Future work is needed to determine what mechanisms are responsible for the observed health and behavioural differences

Influence of Vibrotactile Feedback on Controlling Tilt Motion After Spaceflight

We hypothesize that adaptive changes in how inertial cues from the vestibular system are integrated with other sensory information leads to perceptual disturbances and impaired manual control following transitions between gravity environments. The primary goals of this ongoing post-flight investigation are to quantify decrements in manual control of tilt motion following short-duration spaceflight and to evaluate vibrotactile feedback of tilt as a sensorimotor countermeasure. METHODS. Data is currently being collected on 9 astronaut subjects during 3 preflight sessions and during the first 8 days after Shuttle landings. Variable radius centrifugation (216 deg/s, 30% based on the gain or the amount of tilt disturbance successfully nulled. Manual control performance tended to return to baseline levels within 1-2 days following landing. Root-mean-square position error and tilt velocity were significantly reduced with vibrotactile feedback. CONCLUSIONS. These preliminary results are consistent with our hypothesis that adaptive changes in vestibular processing corresponds to reduced manual control performance following G-transitions. A simple vibrotactile prosthesis improves the ability to null out tilt motion within a limited range of motion disturbances

Quantum teleportation and entanglement swapping with linear optics logic gates

We report on the usage of a linear optics phase gate for distinguishing all four Bell states simultaneously in a quantum teleportation and entanglement swapping protocol. This is demonstrated by full state tomography of the one and two qubit output states of the two protocols, yielding average state fidelities of about 0.83 and 0.77, respectively. In addition, the performance of the teleportation channel is characterised by quantum process tomography. The non classical properties of the entanglement swapping output states are further confirmed by the violation of a CHSH-type Bell inequality of 2.14 on average.Comment: 11 pages, 3 figure

Design and Performance of the Advanced-Light-Source Double-crystal Monochromator

A new “Cowan type” double-crystal monochromator, based on the boomerang design used at National Synchrotron Light Source (NSLS) beamline X-24A, has been developed for beamline 9.3.1 at the Advanced Light Source (ALS), a windowless ultrahigh vacuum beamline covering the 1-6 keV photon-energy range. Beamline 9.3.1 is designed to simultaneously achieve the goals of high energy resolution, high flux, and high brightness at the sample. The mechanical design of the monochromator has been simplified, and recent developments in technology have been included. Measured mechanical precision of the monochromator shows significant improvement over existing designs. In tests with x-rays at NSLS beamline X-23Ʌ2, maximum deviations in the intensity of monochromatic light were just 7% during scans of several hundred eV in the vicinity of the Cr K edge (6 keV) with the monochromator operating without intensity feedback. Such precision is essential because of the high brightness of the ALS radiation and the overall length of beamline 9.3.1 (26 m)

Zonation of Central U. S. Earthquake Sources

A variety of analyses are utilized in developing potential earthquake ground shaking at a specific location. Geological procedures for estimating causes of earthquakes are fundamental to the prediction of ground motions. Evaluations of geologic factors compliment mathematical assessments of seismological data. Earthquake potential in the Central United States is predicted using the concept of seismic source zones due to the difficulty of determining active faults. Resolution of these geographic source zones is dependent upon knowledge of historic seismicity, pertinent geologic features, and causative tectonics. Regardless of the method used to delineate source zones, these zones must be geologically and seismologically unique. Statistical testing of historic earthquake catalogues is required for reduction of the data base. The resolution of zones is an iterative process of bounding the zones and determining recurrence rates. Earthquake potential and risk assessment should be understood by the owner and the designer of a facility