3,507 research outputs found
Apparatus and method of capturing an orbiting spacecraft
Apparatus and a method of capturing an orbiting spacecraft by attaching a grapple fixture are discussed. A probe is inserted into an opening, such as a rocket nozzle, in the spacecraft until a stop on the prove mechanism contacts the spacecraft. A lever is actuated releasing a spring loaded rod which moves axially along the probe removing a covering sleeve to expose spring loaded toffle fingers which pivot open engaging the side of the opening. The probe is shortened and tensioned by turning a screw thread, pressing the fingers inside of the opening to compress the spacecraft between the toggle fingers and the stop. A grapple fixture attached to the probe, which is thus secured to the spacecraft, is engaged by appropriate retrieval means such as a remote manipulator arm
Songbird organotypic culture as an in vitro model for interrogating sparse sequencing networks
Sparse sequences of neuronal activity are fundamental features of neural circuit computation; however, the underlying homeostatic mechanisms remain poorly understood. To approach these questions, we have developed a method for cellular-resolution imaging in organotypic cultures of the adult zebra finch brain, including portions of the intact song circuit. These in vitro networks can survive for weeks, and display mature neuron morphologies. Neurons within the organotypic slices exhibit a diversity of spontaneous and pharmacologically induced activity that can be easily monitored using the genetically encoded calcium indicator GCaMP6. In this study, we primarily focus on the classic song sequence generator HVC and the surrounding areas. We describe proof of concept experiments including physiological, optical, and pharmacological manipulation of these exposed networks. This method may allow the cellular rules underlying sparse, stereotyped neural sequencing to be examined with new degrees of experimental control
The Many State Doctrines of Forum Non Conveniens
Forum non conveniens is not as ancient or monolithic as U.S. courts often assume. The doctrine, which permits judges to decline to hear cases they believe would more appropriately be heard in another sovereign’s courts, was only adopted by the U.S. Supreme Court for use in nonadmiralty cases in 1947; the doctrine’s “deep roots in the common law” are thought instead to have grown in the states.
This Article tests that account by surveying the forum non conveniens doctrines of all fifty states and the District of Columbia. What we found should change how judges, practitioners, and scholars view the doctrine. First, forum non conveniens in the states does not have a “long history”—it is a twentieth-century phenomenon. Second, before the 1950s, no states permitted dismissal of claims brought against local defendants. Third, state experience with forum non conveniens has been and continues to be highly variable. Most states adopted a forum non conveniens doctrine only after the Supreme Court did; many initially rejected it, and half a dozen still prohibit its use in cases involving in-state plaintiffs or in-state causes of action. Idaho has yet to adopt the doctrine.
In addition to these doctrinal lessons, the states’ experience with forum non conveniens provides a useful case study for examining what we term “procedural federalism,” meaning the interactions between state and federal institutions that affect procedural development. Procedural federalism reminds us that the procedure we have is not necessarily the “best” procedure we could conceive while simultaneously drawing our attention to pockets of divergence that may offer promising reforms. More broadly, it suggests a different approach to history than the one currently ascendant in federal courts and commentary. The iterative nature of procedural federalism makes clear that doctrines like forum non conveniens do not have perfect pasts, needing only to be rediscovered to be understood properly. Rather, procedural history is useful because it can help us understand how we ended up with the doctrines we have today, in order to better evaluate where we should go next
Techniques for the Regeneration of Wideband Speech from Narrowband Speech
This paper addresses the problem of reconstructing wideband speech signals from observed narrowband speech signals. The goal of this work is to improve the perceived quality of speech signals which have been transmitted through narrowband channels or degraded during acquisition. We describe a system, based on linear predictive coding, for estimating wideband speech from narrowband. This system employs both previously identified and novel techniques. Experimental results are provided in order to illustrate the system’s ability to improve speech quality. Both objective and subjective criteria are used to evaluate the quality of the processed speech signals
Seasonal variation and impact of waste-water lagoons as larval habitat on the population dynamics of Culicoides sonorensis (Diptera:Ceratpogonidae) at two dairy farms in northern California.
The Sacramento (northern Central) Valley of California (CA) has a hot Mediterranean climate and a diverse ecological landscape that is impacted extensively by human activities, which include the intensive farming of crops and livestock. Waste-water ponds, marshes, and irrigated fields associated with these agricultural activities provide abundant larval habitats for C. sonorensis midges, in addition to those sites that exist in the natural environment. Within this region, C. sonorensis is an important vector of bluetongue (BTV) and related viruses that adversely affect the international trade and movement of livestock, the economics of livestock production, and animal welfare. To characterize the seasonal dynamics of immature and adult C. sonorensis populations, abundance was monitored intensively on two dairy farms in the Sacramento Valley from August 2012- to July 2013. Adults were sampled every two weeks for 52 weeks by trapping (CDC style traps without light and baited with dry-ice) along N-S and E-W transects on each farm. One farm had large operational waste-water lagoons, whereas the lagoon on the other farm was drained and remained dry during the study. Spring emergence and seasonal abundance of adult C. sonorensis on both farms coincided with rising vernal temperature. Paradoxically, the abundance of midges on the farm without a functioning waste-water lagoon was increased as compared to abundance on the farm with a waste-water lagoon system, indicating that this infrastructure may not serve as the sole, or even the primary larval habitat. Adult midges disappeared from both farms from late November until May; however, low numbers of parous female midges were detected in traps set during daylight in the inter-seasonal winter period. This latter finding is especially critical as it provides a potential mechanism for the "overwintering" of BTV in temperate regions such as northern CA. Precise documentation of temporal changes in the annual abundance and dispersal of Culicoides midges is essential for the creation of models to predict BTV infection of livestock and to develop sound abatement strategies
The Sky's the Limit: Re-lightable Outdoor Scenes via a Sky-pixel Constrained Illumination Prior and Outside-In Visibility
Inverse rendering of outdoor scenes from unconstrained image collections is a
challenging task, particularly illumination/albedo ambiguities and occlusion of
the illumination environment (shadowing) caused by geometry. However, there are
many cues in an image that can aid in the disentanglement of geometry, albedo
and shadows. We exploit the fact that any sky pixel provides a direct
measurement of distant lighting in the corresponding direction and, via a
neural illumination prior, a statistical cue as to the remaining illumination
environment. We also introduce a novel `outside-in' method for computing
differentiable sky visibility based on a neural directional distance function.
This is efficient and can be trained in parallel with the neural scene
representation, allowing gradients from appearance loss to flow from shadows to
influence estimation of illumination and geometry. Our method estimates
high-quality albedo, geometry, illumination and sky visibility, achieving
state-of-the-art results on the NeRF-OSR relighting benchmark. Our code and
models can be found https://github.com/JADGardner/neusk
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