Development and use of “ICP-MS TuneSim”: a software app that allows students to simulate tuning an inductively coupled plasma mass spectrometer

A new app, freely available for Windows computers, has been developed to simulate tuning of an inductively coupled plasma mass spectrometer, on the basis of optimization data collected using a sector-field instrument. The app allows students to adjust parameters, including the torch position, gas flows, radio-frequency power, and guard-electrode state, while observing the signal for three “measured” variables in real time. The app has been used with a group of second-year undergraduate students to supplement theoretical material taught in an Atomic Spectrometry lecture course. The exercise familiarized students with key components of the instrument and demonstrated how multiple factors may need to be balanced when performing optimization

Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica

The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems

Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica

The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems

Raccoon (\u3cem\u3eProcyon lotor\u3c/em\u3e) Diets Shed Light on Baylisascaris procyonis Roundworm Prevalence

The raccoon, Procyon lotor, is the definitive host for raccoon roundworm (Baylisascaris procyonis), which causes a dangerous neurological disease known as larva migrans encephalopathy in intermediate hosts. As omnivores, raccoons rely on a variety of food items. Parasitized animals may exhibit altered eating habits and diets, and may undergo genetic variations as a result of parasite abundance. In this study, we analyzed the diets of necropsied raccoons from nine townships of Clark and Greene Counties, Ohio, by examining their stomach contents. We measured the mass of plant material found in raccoon stomachs and recorded the prevalence of B. procyonis. Mean mass of plant material varied among the nine townships surveyed (0.88g – 6.40g), indicating a correlation between raccoon diet and regional landscape. The townships with the least amount of agriculture had the greatest difference between all raccoons and B. procyonis infected raccoons (r²= 0.40). These results suggest that the complexity of raccoon diet exceeds that which can be explained by agricultural landscape alone. These findings help us better understand the relationship between B. procyonis and raccoon diet, therefore helping us to understand the ecological impacts of parasites on animal behavior

Design and characterization of hybrid III–V concentrator photovoltaic–thermoelectric receivers under primary and secondary optical elements

Lattice-matched monolithic triple-junction Concentrator Photovoltaic (CPV) cells (InGa(0.495)P/GaIn(0.012)As/Ge) were electrically and thermally interfaced to two Thermoelectric (TE) Peltier module designs. An electrical and thermal model of the hybrid receivers was modelled in COMSOL Multiphysics software v5.3 to improve CPV cell cooling whilst increasing photon energy conversion efficiency. The receivers were measured for current-voltage characteristics with the CPV cell only (with sylguard encapsulant), under single secondary optical element (SOE) at x2.5 optical concentration, and under Fresnel lens primary optical element (POE) concentration between x313 and x480. Measurements were taken in solar simulators at Cardiff and Jaén Universities, and on-sun with dual-axis tracking at Jaén University. The hybrid receivers were electrically, thermally and theoretically investigated. The electrical performance data for the cells under variable irradiance and cell temperature conditions were measured using the integrated thermoelectric module as both a temperature sensor and as a solid-state heat pump. The performance of six SOE-CPV-TE hybrid devices were evaluated within two 3-receiver strings under primary optical concentration with measured acceptance angles of 1.00o and 0.89o, similar to commercially sourced CPV modules. A six-parameter one-diode equivalent electrical model was developed for the multi-junction CPV cells with SOE and POE. This was applied to extract six model parameters with the experimental I-V curves of type A receiver at 1, 3 and 500 concentration ratios. Standard test conditions (1000W/m2, 25oC and AM1.5G spectrum) were assumed based on trust-region-reflective least squares algorithm in MATLAB. The model fitted the experimental I-V curves satisfactorily with a mean error of 4.44%, and the optical intensity gain coefficient of SOE and POE is as high as 0.91, in comparison with 0.50-0.86 for crossed compound parabolic concentrators (CCPC). The determined values of diode reverse saturation current, combined series resistance and shunt resistance were similar to those of monocrystalline PV cell/modules in our previous publications. The model may be applicable to performance prediction of multi-junction CPV cells in the future

2\u27-O-Methyl at 20-mer Guide Strand 3\u27 Termini May Negatively Affect Target Silencing Activity of Fully Chemically Modified siRNA

Small interfering RNAs (siRNAs) have the potential to treat a broad range of diseases. siRNAs need to be extensively chemically modified to improve their bioavailability, safety, and stability in vivo. However, chemical modifications variably impact target silencing for different siRNA sequences, making the activity of chemically modified siRNA difficult to predict. Here, we systematically evaluated the impact of 3\u27 terminal modifications (2\u27-O-methyl versus 2\u27-fluoro) on guide strands of different length and showed that 3\u27 terminal 2\u27-O-methyl modification negatively impacts activity for \u3e60% of siRNA sequences tested but only in the context of 20- and not 19- or 21-nt-long guide strands. These results indicate that sequence, modification pattern, and structure may cooperatively affect target silencing. Interestingly, the introduction of an extra 2\u27-fluoro modification in the seed region at guide strand position 5, but not 7, may partially compensate for the negative impact of 3\u27 terminal 2\u27-O-methyl modification. Molecular modeling analysis suggests that 2\u27-O-methyl modification may impair guide strand interactions within the PAZ domain of argonaute-2, which may affect target recognition and cleavage, specifically when guide strands are 20-nt long. Our findings emphasize the complex nature of modified RNA-protein interactions and contribute to design principles for chemically modified siRNAs

De novo origins of multicellularity in response to predation

The transition from unicellular to multicellular life was one of a few major events in the history of life that created new opportunities for more complex biological systems to evolve. Predation is hypothesized as one selective pressure that may have driven the evolution of multicellularity. Here we show that de novo origins of simple multicellularity can evolve in response to predation. We subjected outcrossed populations of the unicellular green alga Chlamydomonas reinhardtii to selection by the filter-feeding predator Paramecium tetraurelia. Two of five experimental populations evolved multicellular structures not observed in unselected control populations within ~750 asexual generations. Considerable variation exists in the evolved multicellular life cycles, with both cell number and propagule size varying among isolates. Survival assays show that evolved multicellular traits provide effective protection against predation. These results support the hypothesis that selection imposed by predators may have played a role in some origins of multicellularity

Cosmic 21-cm Fluctuations as a Probe of Fundamental Physics

Fluctuations in high-redshift cosmic 21-cm radiation provide a new window for observing unconventional effects of high-energy physics in the primordial spectrum of density perturbations. In scenarios for which the initial state prior to inflation is modified at short distances, or for which deviations from scale invariance arise during the course of inflation, the cosmic 21-cm power spectrum can in principle provide more precise measurements of exotic effects on fundamentally different scales than corresponding observations of cosmic microwave background anisotropies.Comment: 8 pages, 2 figure

Benchmark Parameters for CMB Polarization Experiments

The recently detected polarization of the cosmic microwave background (CMB) holds the potential for revealing the physics of inflation and gravitationally mapping the large-scale structure of the universe, if so called B-mode signals below 10^{-7}, or tenths of a uK, can be reliably detected. We provide a language for describing systematic effects which distort the observed CMB temperature and polarization fields and so contaminate the B-modes. We identify 7 types of effects, described by 11 distortion fields, and show their association with known instrumental systematics such as common mode and differential gain fluctuations, line cross-coupling, pointing errors, and differential polarized beam effects. Because of aliasing from the small-scale structure in the CMB, even uncorrelated fluctuations in these effects can affect the large-scale B modes relevant to gravitational waves. Many of these problems are greatly reduced by having an instrumental beam that resolves the primary anisotropies (FWHM << 10'). To reach the ultimate goal of an inflationary energy scale of 3 \times 10^{15} GeV, polarization distortion fluctuations must be controlled at the 10^{-2}-10^{-3} level and temperature leakage to the 10^{-4}-10^{-3} level depending on effect. For example pointing errors must be controlled to 1.5'' rms for arcminute scale beams or a percent of the Gaussian beam width for larger beams; low spatial frequency differential gain fluctuations or line cross-coupling must be eliminated at the level of 10^{-4} rms.Comment: 11 pages, 5 figures, submitted to PR

An evaluation of the spread and scale of PatientToc™ from primary care to community pharmacy practice for the collection of patient-reported outcomes: A study protocol

Background Medication non-adherence is a problem of critical importance, affecting approximately 50% of all persons taking at least one regularly scheduled prescription medication and costing the United States more than $100 billion annually. Traditional data sources for identifying and resolving medication non-adherence in community pharmacies include prescription fill histories. However, medication possession does not necessarily mean patients are taking their medications as prescribed. Patient-reported outcomes (PROs), measuring adherence challenges pertaining to both remembering and intention to take medication, offer a rich data source for pharmacists and prescribers to use to resolve medication non-adherence. PatientToc™ is a PROs collection software developed to facilitate collection of PROs data from low-literacy and non-English speaking patients in Los Angeles. Objectives This study will evaluate the spread and scale of PatientToc™ from primary care to community pharmacies for the collection and use of PROs data pertaining to medication adherence. Methods The following implementation and evaluation steps will be conducted: 1) a pre-implementation developmental formative evaluation to determine community pharmacy workflow and current practices for identifying and resolving medication non-adherence, potential barriers and facilitators to PatientToc™ implementation, and to create a draft implementation toolkit, 2) two plan-do-study-act cycles to refine an implementation toolkit for spreading and scaling implementation of PatientToc™ in community pharmacies, and 3) a comprehensive, theory-driven evaluation of the quality of care, implementation, and patient health outcomes of spreading and scaling PatientToc™ to community pharmacies. Expected impact This research will inform long-term collection and use of PROs data pertaining to medication adherence in community pharmacies