Theory of the Injun 5 VLF Poynting flux measurements

VLF Poynting flux measurement technique used on Injun 5 satellit

Learning Redundant Motor Tasks With and Without Overlapping Dimensions: Facilitation and Interference Effects

Prior learning of a motor skill creates motor memories that can facilitate or interfere with learning of new, but related, motor skills. One hypothesis of motor learning posits that for a sensorimotor task with redundant degrees of freedom, the nervous system learns the geometric structure of the task and improves performance by selectively operating within that task space. We tested this hypothesis by examining if transfer of learning between two tasks depends on shared dimensionality between their respective task spaces. Human participants wore a data glove and learned to manipulate a computer cursor by moving their fingers. Separate groups of participants learned two tasks: a prior task that was unique to each group and a criterion task that was common to all groups. We manipulated the mapping between finger motions and cursor positions in the prior task to define task spaces that either shared or did not share the task space dimensions (x-y axes) of the criterion task. We found that if the prior task shared task dimensions with the criterion task, there was an initial facilitation in criterion task performance. However, if the prior task did not share task dimensions with the criterion task, there was prolonged interference in learning the criterion task due to participants finding inefficient task solutions. These results show that the nervous system learns the task space through practice, and that the degree of shared task space dimensionality influences the extent to which prior experience transfers to subsequent learning of related motor skills

Sensory Motor Remapping of Space in Human-Machine Interfaces

Studies of adaptation to patterns of deterministic forces have revealed the ability of the motor control system to form and use predictive representations of the environment. These studies have also pointed out that adaptation to novel dynamics is aimed at preserving the trajectories of a controlled endpoint, either the hand of a subject or a transported object. We review some of these experiments and present more recent studies aimed at understanding how the motor system forms representations of the physical space in which actions take place. An extensive line of investigations in visual information processing has dealt with the issue of how the Euclidean properties of space are recovered from visual signals that do not appear to possess these properties. The same question is addressed here in the context of motor behavior and motor learning by observing how people remap hand gestures and body motions that control the state of an external device. We present some theoretical considerations and experimental evidence about the ability of the nervous system to create novel patterns of coordination that are consistent with the representation of extrapersonal space. We also discuss the perspective of endowing human–machine interfaces with learning algorithms that, combined with human learning, may facilitate the control of powered wheelchairs and other assistive devices

Modern Legislation, Metropolitan Court, Miniscule Results: A Study of Detroit\u27s Landlord-Tenant Court

This article is a description of a study of cases filed and tried in the Detroit, Michigan, Common Pleas Court, Landlord-Tenant Division, during 1970 and 1971. The court is in a large urban center and handles a high volume of cases, in most of which one or both parties appear without an attorney. The impetus for the study was Michigan legislation passed in 1968, which gave tenants additional defenses to summary eviction procedures. The main goal of the study was to observe the effects of the legislation on tenants who were subject to summary proceedings in Detroit. The purpose of the study was not just an analysis of landlord-tenant law or practices per se, but also the more general inquiry into the administration of justice and practical effects of reform legislation

Remembering Forward: Neural Correlates of Memory and Prediction in Human Motor Adaptation

We used functional MR imaging (FMRI), a robotic manipulandum and systems identification techniques to examine neural correlates of predictive compensation for spring-like loads during goal-directed wrist movements in neurologically-intact humans. Although load changed unpredictably from one trial to the next, subjects nevertheless used sensorimotor memories from recent movements to predict and compensate upcoming loads. Prediction enabled subjects to adapt performance so that the task was accomplished with minimum effort. Population analyses of functional images revealed a distributed, bilateral network of cortical and subcortical activity supporting predictive load compensation during visual target capture. Cortical regions – including prefrontal, parietal and hippocampal cortices – exhibited trial-by-trial fluctuations in BOLD signal consistent with the storage and recall of sensorimotor memories or “states” important for spatial working memory. Bilateral activations in associative regions of the striatum demonstrated temporal correlation with the magnitude of kinematic performance error (a signal that could drive reward-optimizing reinforcement learning and the prospective scaling of previously learned motor programs). BOLD signal correlations with load prediction were observed in the cerebellar cortex and red nuclei (consistent with the idea that these structures generate adaptive fusimotor signals facilitating cancelation of expected proprioceptive feedback, as required for conditional feedback adjustments to ongoing motor commands and feedback error learning). Analysis of single subject images revealed that predictive activity was at least as likely to be observed in more than one of these neural systems as in just one. We conclude therefore that motor adaptation is mediated by predictive compensations supported by multiple, distributed, cortical and subcortical structures

VLF electric and magnetic fields observed in the auroral zone with the Javelin 8.46 sounding rocket

VLF electric and magnetic fields observed in auroral zone with Javelin 8.46 sounding rocke

ORION: A Small, Full Capability, General Purpose, Low Earth Orbit Satellite Bus

A low cost general purpose satellite bus has been designed to support a wide variety of small scientific and commercial payloads. The design provides a number of launch options, including the new NASA extended Get- Away-Special * (GAS) canister and several small expendable launch vehicles. The satellite is 48 cm. (19 in,) in diameter, 89 cm. (35 in.) high and weighs approximately 123 kg. (270 Ibs.). The satellite bus provides telemetry, attitude control, orbital boost/station keeping, electrical power, microprocessor and data storage for up to 23 kg. (50 Ibs.) of user payload. The satellite. has a hydrazine propulsion system, with up to 123 m/s (2600 ft/s) delta-V capability. On-board propulsion reduces launcher orbital insertion accuracy requirements and allows the satellite to independently achieve 1480 km. (300 nm. } circular or 4070 km, (2200 nm.) elliptic orbits from an initial orbit of 250 km. (135 nm.)

Thin vs. Thick Description: A Critical Analysis of Representations of PWA in the CSD Literature

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Crisis Management and The Impact of Pandemics on Religious Tourism

The spread of the novel coronavirus (COVID-19) has caused a worldwide shockwave of fear and much misinformation leaving chaos in its wake. Holy shrines and other religious sites have a special place in the hearts and minds of many people. For example, the mosques in Makkah and Medina, Saudi Arabia typically accommodate over one hundred thousand Muslims daily. Due to the spread of COVID-19, both mosques were forced to shut their doors to pilgrims for health and safety reasons. This situation has saddened millions of Muslims all over the globe. The same situation applies to Qom City in Iran, Bethlehem on the West Bank, and the Vatican City. Precautionary actions have caused religious shrines to remain closed until further notice. The methodology used in this study is descriptive and multi-disciplinary. In this paper, the issue of COVID-19 is addressed from the perspective of medical science, chemistry, management science, economics, and religious sociology. This paper sheds light on the history of the virus, its effect on the global economy and crisis-management measures involving sacred places. The paper investigates how faith can expedite the recovery strategies of religious tourism, and consequently the tourism sector will follow suit. The paper elaborates on the potential impact of the pandemic on the future of religious tourism and how the psychological impact of closing Holy Shrines to pilgrims can be a strong driving force for a speedy recovery once the pandemic trickles off

Inhibition of RNA polymerase II transcription in human cells by synthetic DNA-binding ligands

Sequence-specific DNA-binding small molecules that can permeate human cells potentially could regulate transcription of specific genes. Multiple cellular DNA-binding transcription factors are required by HIV type 1 for RNA synthesis. Two pyrrole-imidazole polyamides were designed to bind DNA sequences immediately adjacent to binding sites for the transcription factors Ets-l, lymphoid-enhancer binding factor 1, and TATA-box binding protein. These synthetic ligands specifically inhibit DNA-binding of each transcription factor and HIV type 1 transcription in cell-free assays. When used in combination, the polyamides inhibit virus replication by >99% in isolated human peripheral blood lymphocytes, with no detectable cell toxicity, The ability of small molecules to target predetermined DNA sequences located within RNA polymerase II promoters suggests a general approach for regulation of gene expression, as well as a mechanism for the inhibition of viral replication