Current drainage to a high voltage probe in a dilute plasma

Electron drainage current from dilute plasma through holes in high voltage dielectric probe

Handling uncertainties in background shapes: the discrete profiling method

A common problem in data analysis is that the functional form, as well as the parameter values, of the underlying model which should describe a dataset is not known a priori. In these cases some extra uncertainty must be assigned to the extracted parameters of interest due to lack of exact knowledge of the functional form of the model. A method for assigning an appropriate error is presented. The method is based on considering the choice of functional form as a discrete nuisance parameter which is profiled in an analogous way to continuous nuisance parameters. The bias and coverage of this method are shown to be good when applied to a realistic example.Comment: Accepted by J.Ins

Improving an SSVEP-Based Brain Computer Interface Speller

A brain-computer interface (BCI) is a novel technology that creates direct assistive communication between the brain and a computer. While numerous electroencephalogram (EEG) based BCI-speller applications have been used for communication by adults with physical disabilities; few BCI studies have included children, and none using BCI spellers. A pilot study of a developmentally-appropriate EEG-based speller-storybook interface that relied on steady-state visual evoked potentials (SSVEPs) by two pediatric users with quadriplegic cerebral palsy showed limited speller reliability (E. Floreani, personal communication, September 30, 2021). In the pilot study, the alphabet was parsed between three boxes, each flashing at a different rate (6Hz, 7.5Hz, 10Hz). The users attended to the box containing the required letter, and the BCI interpreted the resulting fluctuations in the EEG to make the selection. The present study sought to improve BCI speller-storybook reliability by improving stimulus timing and by adding auditory feedback. Speller performance was directly correlated with stimuli reliability but there was no significant difference in the average selection time or accuracy for the auditory-visual versus visual conditions. Nevertheless , auditory feedback may still yield an important addition for impaired participants. The results also suggest the speller is more reliable since participants could complete all the trials. Future work will involve testing the auditory-visual feedback condition for impaired participants. An updated speller-storybook interface with improved reliability still may provide a new educational tool to acquire literacy skills for pediatric users with complex communication disorders

A study to develop neutron activation for measuring bone calcium content

Neutron activation analysis for measuring calcium in monkey bone

Promoting sex and gender inclusivity in the classroom: A re-evaluation of discipline norms.

Creating curricula that are inclusive of sex and gender diverse students starts with redefining the classroom environment and how course materials are discussed. Such inclusive environments help increase diversity and representation in STEM. However, traditional approaches to teaching and the use of gendered language can reinforce unsupported notions regarding sex and gender. These notions persist throughout STEM and only serve to alienate our sex and gender diverse students and impact their safety. Thus, we have been exploring how best to approach the topics of sex and gender. Our context is in Biology, as our courses can explore the complexity of biological sex, why it is different from gender, and thus why transgender and non-binary individuals are part of natural variation instead of outliers. However, gendered language and misconceptions can appear in any discipline, in the terminology, metaphors, and examples given in class. In addition, all disciplines must consider how best to foster inclusivity among their students. In this presentation, we invite participants to share experiences and concerns regarding inclusivity in their classes, discuss case studies, and brainstorm with each other on how best to incorporate sex and gender awareness in their disciplines. Participants will come away with an appreciation for why sex and gender inclusivity is important, a framework for applying sex and gender inclusivity to their own curricula, a desire to learn more, and resources to help them on their journey

Uncovering predictability in the evolution of the WTI oil futures curve

Accurately forecasting the price of oil, the world's most actively traded commodity, is of great importance to both academics and practitioners. We contribute by proposing a functional time series based method to model and forecast oil futures. Our approach boasts a number of theoretical and practical advantages including effectively exploiting underlying process dynamics missed by classical discrete approaches. We evaluate the finite-sample performance against established benchmarks using a model confidence set test. A realistic out-of-sample exercise provides strong support for the adoption of our approach with it residing in the superior set of models in all considered instances.Comment: 28 pages, 4 figures, to appear in European Financial Managemen

Geometrical Properties of Two-Dimensional Interacting Self-Avoiding Walks at the Theta-Point

We perform a Monte Carlo simulation of two-dimensional N-step interacting self-avoiding walks at the theta point, with lengths up to N=3200. We compute the critical exponents, verifying the Coulomb-gas predictions, the theta-point temperature T_theta = 1.4986(11), and several invariant size ratios. Then, we focus on the geometrical features of the walks, computing the instantaneous shape ratios, the average asphericity, and the end-to-end distribution function. For the latter quantity, we verify in detail the theoretical predictions for its small- and large-distance behavior.Comment: 23 pages, 4 figure

Bioinformatics characterization of BcsA-like orphan proteins suggest they form a novel family of pseudomonad cyclic-β-glucan synthases

Bacteria produce a variety of polysaccharides with functional roles in cell surface coating, surface and host interactions, and biofilms. We have identified an ‘Orphan’ bacterial cellulose synthase catalytic subunit (BcsA)-like protein found in four model pseudomonads, P. aeruginosa PA01, P. fluorescens SBW25, P. putida KT2440 and P. syringae pv. tomato DC3000. Pairwise alignments indicated that the Orphan and BcsA proteins shared less than 41% sequence identity suggesting they may not have the same structural folds or function. We identified 112 Orphans among soil and plant-associated pseudomonads as well as in phytopathogenic and human opportunistic pathogenic strains. The wide distribution of these highly conserved proteins suggest they form a novel family of synthases producing a different polysaccharide. In silico analysis, including sequence comparisons, secondary structure and topology predictions, and protein structural modelling, revealed a two-domain transmembrane ovoid-like structure for the Orphan protein with a periplasmic glycosyl hydrolase family GH17 domain linked via a transmembrane region to a cytoplasmic glycosyltransferase family GT2 domain. We suggest the GT2 domain synthesises β-(1,3)-glucan that is transferred to the GH17 domain where it is cleaved and cyclised to produce cyclic-β-(1,3)-glucan (CβG). Our structural models are consistent with enzymatic characterisation and recent molecular simulations of the PaPA01 and PpKT2440 GH17 domains. It also provides a functional explanation linking PaPAK and PaPA14 Orphan (also known as NdvB) transposon mutants with CβG production and biofilm-associated antibiotic resistance. Importantly, cyclic glucans are also involved in osmoregulation, plant infection and induced systemic suppression, and our findings suggest this novel family of CβG synthases may provide similar range of adaptive responses for pseudomonads.<br/

No Radio Bursts Detected from FIRST J141918.9+394036 in Green Bank Telescope Observations

Precise localization of the first-known repeating fast radio burst source, FRB 121102 (Spitler et al. 2016; Chatterjee et al. 2017), led to its association with a star-forming region inside a low-metallicity dwarf host galaxy (Tendulkar et al. 2017). This host environment is similar to that typically associated with long gamma-ray bursts (GRB) and superluminous supernovae, potentially linking these astrophysical phenomena (Metzger et al. 2017). In addition, the bursting source is found to be spatially coincident with a compact (< 0.7 pc; Marcote et al. 2017), persistent radio source (Chatterjee et al. 2017). Ofek (2017) identified similar radio sources in the Very Large Array FIRST survey (Becker et al. 1995). One of these sources, FIRST J141918.9+394036 (hereafter FIRST J1419+3940), was identified as a radio transient decaying in brightness by a factor of ~50 over several decades (Law et al. 2018). Very-long-baseline radio interferometric observations support the theory that FIRST J1419+3940 is the afterglow of a long GRB, based on the inferred physical size of the emission region (1.6 ± 0.3 pc; Marcote et al. 2019)