New rapid-curing, stable polyimide polymers with high-temperature strength and thermal stability

Additive-type polymerization reaction forms thermally stable polyimide polymers, thereby eliminating the volatile matter attendant with the condensation reaction. It is based on the utilization of reactive alicyclic rings positioned on the ends of polyimide prepolymers having relatively low molecular weights

Continued development of V. vinifera inflorescence primordia in winter dormant buds

Continued development of inflorescence primordia in winter dormant buds of Vitis vinifera 'Pinot Noir' is reported. In buds sampled from a commercial vineyard in the cool climate wine region of Southern Tasmania, mitotic activity was evident throughout the period from harvest to bud swell the following season. Results showed that in spite of buds entering apparent dormancy, cell division and inflorescence development continued throughout the winter months.

Contingent negative variation (CNV) associated with sensorimotor timing error correction.

INTRODUCTION: Detection and subsequent correction of sensorimotor timing errors are fundamental to adaptive behavior. Using scalp-recorded event-related potentials (ERPs), we sought to find ERP components that are predictive of error correction performance during rhythmic movements. METHOD: Healthy right-handed participants were asked to synchronize their finger taps to a regular tone sequence (every 600ms), while EEG data were continuously recorded. Data from 15 participants were analyzed. Occasional irregularities were built into stimulus presentation timing: 90ms before (advances: negative shift) or after (delays: positive shift) the expected time point. A tapping condition alternated with a listening condition in which identical stimulus sequence was presented but participants did not tap. RESULTS: Behavioral error correction was observed immediately following a shift, with a degree of over-correction with positive shifts. Our stimulus-locked ERP data analysis revealed, 1) increased auditory N1 amplitude for the positive shift condition and decreased auditory N1 modulation for the negative shift condition; and 2) a second enhanced negativity (N2) in the tapping positive condition, compared with the tapping negative condition. In response-locked epochs, we observed a CNV (contingent negative variation)-like negativity with earlier latency in the tapping negative condition compared with the tapping positive condition. This CNV-like negativity peaked at around the onset of subsequent tapping, with the earlier the peak, the better the error correction performance with the negative shifts while the later the peak, the better the error correction performance with the positive shifts. DISCUSSION: This study showed that the CNV-like negativity was associated with the error correction performance during our sensorimotor synchronization study. Auditory N1 and N2 were differentially involved in negative vs. positive error correction. However, we did not find evidence for their involvement in behavioral error correction. Overall, our study provides the basis from which further research on the role of the CNV in perceptual and motor timing can be developed

Are open educational resources the future of e-learning?

Increased interest in more open approaches to learning, in particular Open Educational Resources is reflected in the programmes of international organisations, national initiatives and the actions of individual institutions. However, while some see OER as an indicator of the future of learning, others are much more sceptical and doubt their long-term success. This paper considers the vision of OER as part of future learning solutions in the society driven by technology and knowledge. Supported by an examination of specific national contexts and linked to research from relevant initiatives arguments in favour of using OER are outlined. These include their value in both developing and developed countries, and flexible ways of use in structured courses and in informal, learner-driven environments. This is balanced by highlighting concerns that relate mainly to current issues of certification, quality and intellectual property rights, but also potential problems such as the lack of instructor-learner interaction and the dominance of OER initiatives from English-speaking universities. The paper concludes that OER have an immense potential as long as the elements that contribute to their success are identified and harnessed, and barriers effectively dealt with

The variable polarity plasma arc welding process: Its application to the Space Shuttle external tank

The technical history of the variable polarity plasma arc (VPPA) welding process being introduced as a partial replacement for the gas shielded tungsten arc process in assembly welding of the space shuttle external tank is described. Interim results of the weld strength qualification studies, and plans for further work on the implementation of the VPPA process are included

Parkinson\u27s Disease in Louisiana, 1999-2012: Based on Hospital Primary Discharge Diagnoses, Incidence, and Risk in Relation to Local Agricultural Crops, Pesticides, and Aquifer Recharge

The two major causes of Parkinson\u27s disease (PD) are genetic susceptibility and exposure to agricultural pesticides. Access to 23,224 individuals\u27 hospital primary discharge diagnoses of PD allowed the mapping of cases against known crop distributions and pesticides. Our main objective was to map PD risks (cases per 10,000 people) against crops and their pesticides. The ZIP Code address locations, and the 2000 and 2010 census data, were used to map the risks of PD throughout Louisiana and in relation to United States Department of Agriculture (USDA)-recorded crops. The introduction of glyphosate-resistant crops appears to have initiated the PD disappearance from northeastern parishes on the west bank of the Mississippi river. Rice and sugar cane are seemingly unassociated with PD, as is the Mississippi itself, except for Jefferson and St. Charles Parishes, which are essentially urban or industrial. The present major PD-affected areas are associated with commercial forests, woodlands, and pastures, and thus with certain arbor-pastoral pesticides, 2,4-D, chlorpyrifos, and paraquat. Human populations at maximum risk are those living in areas of moderate and high aquifer-recharge potential. The levels of estimated pesticide exposure in these recharge areas we were able to access were of variable use, but significant amounts of 2,4-D were being used

New insights into the outflows from R Aquarii

R Aquarii is a symbiotic binary surrounded by a large and complex nebula with a prominent curved jet. It is one of the closest known symbiotic systems, and therefore offers a unique opportunity to study the central regions of these systems and the formation and evolution of astrophysical jets. We studied the evolution of the central jet and outer nebula of R Aqr taking advantage of a long term monitoring campaign of optical imaging, as well as of high-resolution integral field spectroscopy. Narrow-band images acquired over a period of more than 21 years are compared in order to study the expansion and evolution of all components of the R Aqr nebula. The magnification method is used to derive the kinematic ages of the features that appear to expand radially. Integral field spectroscopy of the OIII 5007A emission is used to study the velocity structure of the central regions of the jet. New extended features, further out than the previously known hourglass nebula, are detected. The kinematic distance to R Aqr is calculated to be 178 pc using the expansion of the large hourglass nebula. This nebula of R Aqr is found to be roughly 650 years old, while the inner regions have ages ranging from 125 to 290 years. The outer nebula is found to be well described by a ballistic expansion, while for most components of the jet strong deviations from such behaviour are found. We find that the Northern jet is mostly red-shifted while its Southern part is blue-shifted, apparently at odds with findings from previous studies but almost certainly a consequence of the complex nature of the jet and variations in ionisation and illumination between observations.Comment: 13 pages, 8 figures, accepted for publication in A&

Right to Serve, Right to Lead: Lives and Legacies of the USCT

This is a catalog for an exhibit that follows the evolution of African-American participation in the Civil War, from slaves, to contrabands, to soldiers of the United States Colored Troops (USCT), as well as the lives of black veterans beyond the war, and their ultimate military and social legacy. Using a variety of period items, it creates a narrative that stretches from the Antebellum Period to the current day. In doing so, the exhibit shows how black sacrifice on the battlefield redefined the war\u27s purpose throughout the divided nation, how Jim Crowe suppressed the memory of black participation after Reconstruction, and how the illustrious African-American military tradition left by the USCT endures to this day in their modern heirs

Social and structural conditions for the avoidance of advance care planning in neuro-oncology: a qualitative study

BACKGROUND: Primary brain tumours newly affect >260 000 people each year worldwide. In the UK, every year >10 000 people are diagnosed with a brain tumour while >5000 die annually from the disease. Prognoses are poor, cognitive deterioration common and patients have prolonged palliative needs. Advance care planning (ACP) may enable early discussion of future care decisions. Although a core commitment in the UK healthcare strategy, and the shared responsibility of clinical teams, ACP appears uncommon in practice. Evidence around ACP practice in neuro-oncology is limited. OBJECTIVES: We aimed to elicit key social and structural conditions contributing to the avoidance of ACP in neuro-oncology. DESIGN: A cross-sectional qualitative study design was used. SETTING: One tertiary care hospital in the UK. PARTICIPANTS: Fifteen healthcare professionals working in neuro-oncology participated in this study, including neuro-oncologists, neurosurgeons, clinical nurse specialists, allied healthcare professionals and a neurologist. METHOD: Semi-structured interviews were conducted with participants to explore their assumptions and experiences of ACP. Data were analysed thematically using the well-established framework method. RESULTS: Participants recognised the importance of ACP but few had ever completed formal ACP documentation. We identified eight key factors, which we suggest comprise three main conditions for avoidance: (1) difficulties being a highly emotive, time-intensive practice requiring the right 'window of opportunity' and (2) presence and availability of others; (3) ambiguities in ACP definition, purpose and practice. Combined, these created a 'culture of shared avoidance'. CONCLUSION: In busy clinical environments, 'shared responsibility' is interpreted as 'others' responsibility' laying the basis for a culture of avoidance. To address this, we suggest a 'generalists and specialists' model of ACP, wherein healthcare professionals undertake particular responsibilities. Healthcare professionals are already adopting this model informally, but without formalised structure it is likely to fail given a tendency for people to assume a generalist role