Looking for Design in Materials Design

Despite great advances in computation, materials design is still science fiction. The construction of structure-property relations on the quantum scale will turn computational empiricism into true design.Comment: 3 pages, 1 figur

Characterization of Pump-Induced Acoustics in Space Launch System Main Propulsion System Liquid Hydrogen Feedline Using Airflow Test Data

High intensity acoustic edgetones located upstream of the RS-25 Low Pressure Fuel Turbo Pump (LPFTP) were previously observed during Space Launch System (STS) airflow testing of a model Main Propulsion System (MPS) liquid hydrogen (LH2) feedline mated to a modified LPFTP. MPS hardware has been adapted to mitigate the problematic edgetones as part of the Space Launch System (SLS) program. A follow-on airflow test campaign has subjected the adapted hardware to tests mimicking STS-era airflow conditions, and this manuscript describes acoustic environment identification and characterization born from the latest test results. Fluid dynamics responsible for driving discrete excitations were well reproduced using legacy hardware. The modified design was found insensitive to high intensity edgetone-like discretes over the bandwidth of interest to SLS MPS unsteady environments. Rather, the natural acoustics of the test article were observed to respond in a narrowband-random/mixed discrete manner to broadband noise thought generated by the flow field. The intensity of these responses were several orders of magnitude reduced from those driven by edgetones

Neoplastic cells are a rare component in human glioblastoma microvasculature

Microvascular proliferation is a key biological and diagnostic hallmark of human glioblastoma, one of the most aggressive forms of human cancer. It has recently been suggested that stem-like glioblastoma cells have the capacity to differentiate into functional endothelial cells, and that a significant proportion of the vascular lining in tumors has a neoplastic origin. In principle, this finding could significantly impact the efficacy and development of antiangiogenic therapies targeting the vasculature. While the potential of stem-like cancer cells to form endothelium in culture seems clear, in our clinical experience using a variety of molecular markers, neoplastic cells do not contribute significantly to the endothelial-lined vasculature of primary human glioblastoma. We sought to confirm this impression by analyzing vessels in glioblastoma previously examined using chromogenic in situ hybridization (CISH) for EGFR and immunohistochemistry for mutant IDH1. Vessels containing cells expressing these definitive neoplastic markers were identified in a small fraction of tumors, but only 10% of vessel profiles examined contained such cells and when identified these cells comprised less than 10% of the vascular cellularity in the cross section. Interestingly, these rare intravascular cells showing EGFR amplification by CISH or mutant IDH1 protein by immunohistochemistry were located in the middle or outer portions of vessel walls, but not amongst the morphologic boundaries of the endothelial lining. To more directly address the capacity of glioblastoma cells to contribute to the vascular endothelium, we performed double labeling (Immunofluorescence/FISH) for the endothelial marker CD34 and EGFR gene locus. Although rare CD34 positive neoplastic cells unassociated with vessels were identified (<1%), this analysis did not identify EGFR amplified cells within vascular linings, and further supports our observations that incorporation of glioblastoma cells into the tumor vessels is at best extremely rare, and therefore of questionable clinical or therapeutic significance

Teacher Training Workshop for Educators of Students Who Are Blind or Low Vision

The Independent Laboratory Access for the Blind (ILAB) project has developed a suite of speech accessible tools for students who are blind or low vision to use in secondary and postsecondary science laboratory classes. The following are illustrations of experiments designed to be used by educators to introduce them to the ILAB tools, and to demonstrate how these tools can be incorporated into standard laboratory experiments. Information about the Lawrence Hall of Science’s SAVI/SELPH curriculum is also discussed

Relationships between Swiss needle cast and ectomycorrhizal fungus diversity

Swiss needle cast (SNC) is a disease specific to Douglas-fir (Pseudotsuga menziesii) caused by the ascomycete Phaeocryptopus gaeumannii. Here we examine characteristics of the EM fungus community that are potentially useful in predictive models that would monitor forest health. We found that mean EM density (number of colonized root tips/soil core) varied nearly 10-fold among sites of varying levels of SNC, while mean EM fungus species richness (number of species/soil core) varied by about 2.5 times. Strong relationships were found between EM and SNC parameters: EM species richness was positively correlated with both Douglas-fir needle retention (R² = 0.93) and EM density (R² = 0.65); EM density also was significantly correlated with Douglas-fir needle retention (R² = 0.70). These simple characteristics of the EM fungus community could be used to monitor forest health and generate predictive models of site suitability for Douglas-fir. Based on previous findings that normally common EM types were reduced in frequency on sites with severe SNC, we also hypothesized that some EM fungi would be stress tolerant-dominant species. Instead, we found that various fungi were able to form EM with the stressed trees, but none were consistently dominant across samples in the severely diseased areas.This is the publisher’s final pdf. The article is copyrighted by the Mycological Society of America and published by Allen Press Inc. It can be found at: http://www.mycologia.org/.Keywords: Phaeocryptopus gaeumannii, Climate change, Anthropogenic disturbance, Ecosystem healt

Characterizing Retinal Ganglion Cell Responses to Electrical Stimulation Using Generalized Linear Models

The ability to preferentially stimulate different retinal pathways is an important area of research for improving visual prosthetics. Recent work has shown that different classes of retinal ganglion cells (RGCs) have distinct linear electrical input filters for low-amplitude white noise stimulation. The aim of this study is to provide a statistical framework for characterizing how RGCs respond to white-noise electrical stimulation. We used a nested family of Generalized Linear Models (GLMs) to partition neural responses into different components-progressively adding covariates to the GLM which captured non-stationarity in neural activity, a linear dependence on the stimulus, and any remaining non-linear interactions. We found that each of these components resulted in increased model performance, but that even the non-linear model left a substantial fraction of neural variability unexplained. The broad goal of this paper is to provide a much-needed theoretical framework to objectively quantify stimulus paradigms in terms of the types of neural responses that they elicit (linear vs. non-linear vs. stimulus-independent variability). In turn, this aids the prosthetic community in the search for optimal stimulus parameters that avoid indiscriminate retinal activation and adaptation caused by excessively large stimulus pulses, and avoid low fidelity responses (low signal-to-noise ratio) caused by excessively weak stimulus pulses

Nebenwirkungsraten von Opioiden unter äquianalgetischen Dosen im Rahmen intravenöser patientenkontrollierter Analgesie - eine systematische Übersicht und Netzwerkmetaanalyse

Nebenwirkungen während einer Opioidtherapie gehören zur klinischen Praxis und beeinträchtigen nicht nur die Qualität der Schmerztherapie sondern auch die Genesung des Patienten. Eine individuelle, auf das jeweilige Nebenwirkungsprofil und die Bedürfnisse des Patienten abgestimmte Opioidwahl kann die Schmerztherapie optimieren und den Heilungsprozess fördern. Ziel dieser Arbeit war, den Einfluss der Opioidwahl unter äquianalgetischen Bedingungen im Rahmen der intravenösen patientenkontrollierten Analgesie auf das Auftreten der häufigsten Nebenwirkungen zu untersuchen. Hierfür wurden die elektronischen Datenbanken Medline, Embase, Cochrane Library und Web of Science auf randomisierte, kontrollierte Studien durchsucht. Nach Entwicklung und Durchführung einer strukturierten Literaturrecherche wurden insgesamt 168 Studien durch zwei unabhängige Untersucher gelesen und bewertet. Mit der Erstellung einer systematischen Übersichtsarbeit und Netzwerk-Metaanalyse wurden Daten zu 17 unterschiedlichen Opioiden und ihren Nebenwirkungsprofilen verglichen und zusammengefasst. 63 Studien erfüllten die Einschlusskriterien, aus denen Daten zu 5063 Patienten im Alter von 18 bis 90 Jahren extrahiert werden konnten. Primärer Endpunkt dieser Arbeit waren alle opioidinduzierten Nebenwirkungen unter äquianalgetischer Dosierung. Die Nebenwirkungen Übelkeit und Erbrechen, Juckreiz, Sedierung und Atemdepression wurden am häufigsten berichtet. Sekundäre Endpunkte waren die Zufriedenheit der Patienten, die PCA Pumpeneinstellungen sowie der absolute Opioidkonsum. Mit einem relativen Risiko von 1,37 [1,05; 1,80] weist Buprenorphin eine signifikant höhere Rate für Übelkeit und Erbrechen auf, wohingegen Fentanyl mit einem Risiko von 0,82 [0,67; 1,00] weniger Übelkeit und Erbrechen hervorzurufen scheint. Bei den relativen Risiken für Juckreiz scheinen vor allem Nalbuphin mit 0,07 [0,01; 0,60] und Pethidin/Meperidin mit 0,47 [0,25; 0,87] einen kleinen Vorteil zu zeigen. In der mit Scores bewerteten Sedierung weisen Oxymorphon mit -1,40[-2,41; -0,39], Fentanyl mit -1,57 [-2,91; -0,23] und Pethidin/Meperidin mit -1,70[-2,77; -0,62] die statistisch signifikant niedrigsten Raten auf. Aus den in dieser Arbeit extrahierten Daten lassen sich keine Vorteile einer Substanz für die Inzidenz von Atemdepression herleiten. Bei den visuellen Analogskalen für Zufriedenheit erreichen Pethidin/Meperidin mit 0,59 [0,18; 1,00], Fentanyl mit 0,96 [0,39; 1,52], Remifentanil mit 1,80 [1,12; 2,48], Alfentanil mit 1,95 [1,06; 2,85] und Oxycodon mit 2,00 [1,18; 2,82] Mittelwertabweichung, die statistisch signifikant größten Zufriedenheitswerte. Die aus den eingeschlossenen Studien evaluierten analgetischen Potenzen zeigten mehrheitlich Abweichungen über zehn Prozent zu den aktuell gängigen Literaturwerten. Nach Durchschau aller Ergebnisse scheinen vor allem die Opioide Fentanyl und Pethidin/Meperidin unter äquianalgetischen Dosierungen die verträglichsten Nebenwirkungsprofile aufzuweisen. Beide Substanzen können nach Ausschluss individueller Kontraindikationen für die intravenöse postoperative Schmerztherapie empfohlen werden. Die Tendenzen der Nebenwirkungsprofile dieser Arbeit sollten bei der individuellen Schmerztherapie und der Suche nach einer optimalen Substanz für den Patienten berücksichtigt werden

Elucidating the crystal-chemistry of Jbel Rhassoul stevensite (Morocco) by advanced analytical techniques

The composition of Rhassoul clay is controversial regarding the nature of the puremineral clay fraction which is claimed to be stevensite rather than saponite. In this study, the raw and mineral fractions were characterized using various techniques including Fourier transform infrared spectroscopy and magic angle spinning nuclear magnetic resonance (MAS NMR). The isolated fine clay mineral fraction contained a larger amount of Al (>1 wt.%) than that reported for other stevensite occurrences. The 27Al MAS NMR technique confirmed that the mineral is stevensite in which the Al is equally split between the tetrahedral and octahedral coordination sites. The 29Si NMR spectrum showed a single unresolved resonance indicating little or no short-range ordering of silicon. The chemical composition of the stevensite from Jbel Rhassoul was determined to be ((Na0.25K0.20 (Mg5.04Al0.37Fe0.20&0.21)5.61(Si7.76Al0.24)8O20(OH)4). This formula differs from previous compositions described from this locality and shows it to be an Al-bearing lacustrine clay mineral