2,758 research outputs found

    Apparatus and method of capturing an orbiting spacecraft

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    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

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    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

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    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

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    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.

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    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

    Security of infantile attachment as assessed in the strange situation: its study and biological intrepretation

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    We study the Ainsworth \u27Strange Situation\u27 procedure to assess attachment between infant and parent, and intrepret individual variation in terms of modern human behavioral ecology ( sociobiology
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