Differential spacecraft charging on the geostationary operational environmental satellites

Subsystems aboard the Geostationary Operational Environmental Satellites 4 and 5 showed instances of anomalous changes in state corresponding to false commands. Evidence linking the anomalous changes to geomagnetic activity, and presumably static discharges generated by spacecraft differential charging induced by substorm particle injection events is presented. The anomalies are shown to be correlated with individual substorms as monitored by stations of the North American Magnetometer Chain. The relative frequency of the anomalies is shown to be a function of geomagnetic activity. Finally a least squares fit to the time delay between substorm initiation and spacecraft anomaly as a function of spacecraft local time is shown to be consistent with injected electron populations with energy in the range 10 keV to 15 keV, in agreement with present understanding of the spacecraft charging mechanism. The spacecraft elements responsible for the differential charging were not satisfactorily identified. That question is currently under investigation

Optimization of a Managed Aquifer Recharge Network

2014 S.C. Water Resources Conference - Informing Strategic Water Planning to Address Natural Resource, Community and Economic Challenge

Magnetospheric multiprobes: Investigations and instrumentation

The multiprobe scientific objectives are to: (1) determine the spatial structure of plasma phenomena such as the aurora, convection reversals, and ion troughs; (2) separate spatial and temporal variations in these phenomena; (3) determine field aligned current densities; (4) perform multiple point analysis of particle beams, wave fields, and plasma clouds that are injected into the ionosphere and magnetosphere by Spacelab active experiment facilities. Trade studies described include: instrument accommodations, power, attitude determination, electric field antennas, storage and ejection, thermal control, tracking communications, command and data management, payload and mission specialist support, functional objectives, and orbital analysis

Repeated unilateral handgrip contractions alter functional connectivity and improve contralateral limb response times

In humans, motor learning is underpinned by changes in sensorimotor network functional connectivity (FC). Unilateral contractions increase FC in the ipsilateral primary motor cortex (M1) and supplementary motor area (SMA); areas involved in motor planning and execution of the contralateral hand. Therefore, unilateral contractions are a promising approach to augment motor performance in the contralateral hand. In a within-participant, randomized, cross-over design, 15 right-handed adults had two magnetic resonance imaging (MRI) sessions, where functional-MRI and MR-Spectroscopic Imaging were acquired before and after repeated right-hand contractions at either 5% or 50% maximum voluntary contraction (MVC). Before and after scanning, response times (RTs) were determined in both hands. Nine minutes of 50% MVC contractions resulted in decreased handgrip force in the contracting hand, and decreased RTs and increased handgrip force in the contralateral hand. This improved motor performance in the contralateral hand was supported by significant neural changes: increased FC between SMA-SMA and increased FC between right M1 and right Orbitofrontal Cortex. At a neurochemical level, the degree of GABA decline in left M1, left and right SMA correlated with subsequent behavioural improvements in the left-hand. These results support the use of repeated handgrip contractions as a potential modality for improving motor performance in the contralateral hand

A quantitative polymerase chain reaction-enzyme immunoassay for accurate measurements of human papillomavirus type 16 DNA levels in cervical scrapings

A quantitative polymerase chain reaction-enzyme immunoassay (Q-PCR-EIA) was developed to measure the amount of human papillomavirus (HPV) 16 DNA per genome equivalent in cervical scrapings. The quantitative approach was based on a combined competitive PCR for both HPV 16, using the general primer GP5+/6+ PCR, and β-globin DNA. The two competitive PCRs involve co-amplification of target sequences and exogenously added DNA constructs carrying a rearranged 30 bp sequence in the probe-binding region. The accuracy of quantification by combining the two competitive PCR assays was validated on mixtures of HPV 16 containing cervical cancer cells of CaSki and SiHa cell lines. Comparison of this fully quantitative PCR assay with two semi-quantitative HPV PCR assays on a series of crude cell suspensions from HPV 16 containing cervical scrapings revealed remarkable differences in the calculated relative HPV load between samples. We found evidence that correction for both intertube variations in PCR efficiency and number of input cells/integrity of DNA significantly influence the outcome of studies on viral DNA load in crude cell suspensions of cervical scrapings. Therefore, accurate measurements on viral DNA load in cervical scrapings require corrections for these phenomena, which can be achieved by application of this fully quantitative approach. © 1999 Cancer Research Campaig

Charting the elements of pedagogic frailty

Background: The concept of pedagogic frailty has been proposed as a unifying concept that may help to integrate institutional efforts to enhance teaching improvement within universities by helping to maintain a simultaneous focus on four key areas that are thought to impede development. Purpose: The variation in internal structure of the four dimensions of pedagogic frailty and the links that have been proposed to connect them are explored here through the analysis of interviews with academics working in a variety of disciplinary areas. Methods: The application of concept map-mediated interviews allows us to view the variable connections within and between these dimensions and the personal ways they are conceptualised by academics working across the heterogeneous university context. Results: The data show that academics conceptualise the discourse of teaching in various ways that have implications for the links that may be developed to integrate the elements within the model. Conclusions: Whilst the form and content of the maps representing dimensions of the pedagogic frailty model exhibit considerable variation, it is suggested that factors such as academic resilience and the explicit use of integrative concepts within disciplines may help to overcome some of the vulnerabilities that accompany pedagogic frailty. The data also raises questions about the links between factors that tend to be under individual control and those that tend towards institutional control

A qualitative study on the effects of psychoactive substance use upon artistic creativity

Background: Psychoactive substance use has often been claimed to help generate and facilitate the artistic creative process. Aims: The present study explored the role of artists’ substance use in their creative processes and their efforts to balance between enhancement and relaxation. Methods: Semi-structured interviews concerning the artistic creative process and the role of psychoactive substance use were recorded with 72 artists and analyzed using content analysis. The participants were classified according to their substance use in three groups (Cannabis Group, Alcohol Group, and Control Group). Results: Results show that both alcohol and cannabis were used to facilitate creativity and the emotional states that are necessary for the artistic creative process. Participants in the Control group reported that listening to music might function as a mind-altering tool. It was also found that for some artists, substance use is not only characteristic to creation, but it is also part of their everyday lives. Conclusion: Artists are aware of the balancing phenomenon during the artistic creative process. Whether psychoactive substance(s) or other environmental stimuli (such as music) are used to reach the required effect appears to depend upon the individual

Different expressions of the same mode: a recent dialogue between archaeological and contemporary drawing practices

In this article we explore what we perceive as pertinent features of shared experience at the excavations of an Iron Age Hillfort at Bodfari, North Wales, referencing artist, archaeologist and examples of seminal art works and archaeological records resulting through inter-disciplinary collaboration. We explore ways along which archaeological and artistic practices of improvisation become entangled and productive through their different modes of mark-making. We contend that marks and memories of artist and archaeologist alike emerge interactively, through the mutually constituting effects of the object of study, the tools of exploration, and the practitioners themselves, when they are enmeshed in the cross-modally bound activities. These include, but are not limited to, remote sensing, surveying, mattocking, trowelling, drawing, photographing, videoing and sound recording. These marks represent the co-signatories: the gesture of the often anonymous practitioners, the voice of the deposits, as well as the imprint of the tools, and their interplay creates a multi-threaded narrative documenting their modes of intra-action, in short our practices. They occupy the conceptual space of paradata, and in the process of saturating the interstices of digital cognitive prosthetics they lend probity to their translations in both art form and archive

MLL2 Is Required in Oocytes for Bulk Histone 3 Lysine 4 Trimethylation and Transcriptional Silencing

Conditional knockout mouse strategies identify the histone methyltranferase MLL2 as a key player in epigenetic reprogramming of female gametes