Thin film optical filter fabrication and characterization

Thin film coatings have a large number of applications. For example, one can eliminate unwanted reflection on a photographic lens or unwanted wavelengths of light in optics experimentation. The fabrication and characterization of films whose refractive indices can be arbitrarily modulated (‘Rugate Filters’) is an ongoing exploration in materials science1,2. Therefore, calibrating a process which can manufacture such films is a relevant pursuit in forwarding such explorations. Reactive magnetron sputter deposition is a commonly used technique for the productions of thin films3,4. This technique steadily flows reactive gas (RG) into a vacuum chamber in which an electric field has been established. The RG is then ionized by the electric field which causes it to bombard a solid target placed inside the chamber. Many of the atoms which are displaced by the ionized gas further travel towards an adjacent substrate (Figure 1). Ideally, this occurs in such a way as to deposit the newly formed molecule on the surface a glass slide. In our case the RG, N2, and O2 were intended to deposit Si3N4 and SiO2 whose indices of refraction are respectively high and low (Figure 4). Reproducibility of this contrast is essential in the fabrication of the desired optical devices. In order to determine that these intended reactions occurred in a reproducible way, the thickness and refractive index of the films where calculated from the Transmission Spectra of the films

Age truncation and portfolio effects in Puget Sound Pacific herring

Forage fish undergo dramatic changes in abundance through time. Long-term fluctuations, which have historically been attributed to changes in recruitment, may also be due to changes in adult mortality. Pacific herring, a lightly exploited forage fish in Puget Sound, WA, have exhibited shifts in age structure and decreases in spawning biomass during the past 30 years. Here, we investigate changes in adult mortality as a potential explanation for these shifts. Using a hierarchical, age-structured population model, we indicate that adult natural mortality for Puget Sound Pacific herring has increased since 1973. We find that natural mortality has increased for every age class of adult (age 3+), especially age 4 fish, whose estimated mortality has doubled over the survey time period (from M=0.84 to M=1.76). We demonstrate that long-term shifts in mortality explain changes in age structure, and may explain biomass declines and failure to reach management thresholds for some spawning sites in Puget Sound. Temporal shifts in natural adult mortality could have negative implications for herring and herring predators. For predators, these implications include a reduction in the stability of the herring resource

Prion protein gene sequence and chronic wasting disease susceptibility in white-tailed deer (Odocoileus virginianus)

The sequence of the prion protein gene (PRNP) affects susceptibility to spongiform encephalopathies, or prion diseases in many species. In white-tailed deer, both coding and non-coding single nucleotide polymorphisms have been identified in this gene that correlate to chronic wasting disease (CWD) susceptibility. Previous studies examined individual nucleotide or amino acid mutations; here we examine all nucleotide polymorphisms and their combined effects on CWD. A 626 bp region of PRNP was examined from 703 free-ranging white-tailed deer. Deer were sampled between 2002 and 2010 by hunter harvest or government culling in Illinois and Wisconsin. Fourteen variable nucleotide positions were identified (4 new and 10 previously reported). We identified 68 diplotypes comprised of 24 predicted haplotypes, with the most common diplotype occurring in 123 individuals. Diplotypes that were found exclusively among positive or negative animals were rare, each occurring in less than 1% of the deer studied. Only one haplotype (C, odds ratio 0.240) and 2 diplotypes (AC and BC, odds ratios of 0.161 and 0.108 respectively) has significant associations with CWD resistance. Each contains mutations (one synonymous nucleotide 555C/T and one nonsynonymous nucleotide 286G/A) at positions reported to be significantly associated with reduced CWD susceptibility. Results suggest that deer populations with higher frequencies of haplotype C or diplotypes AC and BC might have a reduced risk for CWD infection – while populations with lower frequencies may have higher risk for infection. Understanding the genetic basis of CWD has improved our ability to assess herd susceptibility and direct management efforts within CWD infected areas.https://digitalcommons.snc.edu/faculty_staff_works/1029/thumbnail.jp

Does a Computer Science Graduation Requirement Contribute to Increased Enrollment in Advanced Computer Science Coursework?

Prior research has shown that students pursuing Exploring Computer Science (ECS) as their first elective course were more likely to pursue another computer science course in high school, as compared to students who took a traditional course as the first course. This study investigated whether the results are consistent when students are pursuing ECS to fulfill the Chicago Public Schools\u27 graduation requirement. ECS is designed to foster deep engagement through equitable inquiry around computer science concepts. It is hypothesized that students who are fulfilling a graduation requirement will pursue additional computer science coursework at rates similar to students who were pursuing ECS as an elective course

First Field Release of a Genetically Engineered, Self-Limiting Agricultural Pest Insect:Evaluating Its Potential for Future Crop Protection

Alternative, biologically-based approaches for pest management are sorely needed and one approach is to use genetically engineered insects. Herein we describe a series of integrated field, laboratory and modeling studies with the diamondback moth, Plutella xylostella, a serious global pest of crucifers. A “self-limiting” strain of Plutella xylostella (OX4319L), genetically engineered to allow the production of male-only cohorts of moths for field releases, was developed as a novel approach to protect crucifer crops. Wild-type females that mate with these self-limiting males will not produce viable female progeny. Our previous greenhouse studies demonstrated that releases of OX4319L males lead to suppression of the target pest population and dilution of insecticide-resistance genes. We report results of the first open-field release of a non-irradiated, genetically engineered self-limiting strain of an agricultural pest insect. In a series of mark-release-recapture field studies with co-releases of adult OX4319L males and wild-type counterparts, the dispersal, persistence and field survival of each strain were measured in a 2.83 ha cabbage field. In most cases, no differences were detected in these parameters. Overall, 97.8% of the wild-type males and 95.4% of the OX4319L males recaptured dispersed <35 m from the release point. The predicted persistence did not differ between strains regardless of release rate. With 95% confidence, 75% of OX4319L males released at a rate of 1,500 could be expected to live between 3.5 and 5.4 days and 95% of these males could be expected to be detected within 25.8–34.9 m from the release point. Moth strain had no effect on field survival but release rate did. Collectively, these results suggest similar field behavior of OX4319L males compared to its wild-type counterpart. Laboratory studies revealed no differences in mating competitiveness or intrinsic growth rates between the strains and small differences in longevity. Using results from these studies, mathematical models were developed that indicate release of OX4319L males should offer efficacious pest management of P. xylostella. Further field studies are recommended to demonstrate the potential for this self-limiting P. xylostella to provide pest suppression and resistance management benefits, as was previously demonstrated in greenhouse studies

Predicting in-Hospital Mortality After an in-Hospital Cardiac Arrest: A Multivariate Analysis

Aim of the study: Most survivors of an in-hospital cardiac arrest do not leave the hospital alive, and there is a need for a more patient-centered, holistic approach to the assessment of prognosis after an arrest. We sought to identify pre-, peri-, and post-arrest variables associated with in-hospital mortality amongst survivors of an in-hospital cardiac arrest. Methods: This was a retrospective cohort study of patients ≥18 years of age who were resuscitated from an in-hospital arrest at our University Medical Center from January 1, 2013 to September 31, 2016. In-hospital mortality was chosen as a primary outcome and unfavorable discharge disposition (discharge disposition other than home or skilled nursing facility) as a secondary outcome. Results: 925 patients comprised the in-hospital arrest cohort with 305 patients failing to survive the arrest and a further 349 patients surviving the initial arrest but dying prior to hospital discharge, resulting in an overall survival of 29%. 620 patients with a ROSC of greater than 20 min following the in-hospital arrest were included in the final analysis. In a stepwise multivariable regression analysis, recurrent cardiac arrest, increasing age, time to ROSC, higher serum creatinine levels, and a history of cancer were predictors of in-hospital mortality. A history of hypertension was found to exert a protective effect on outcomes. In the regression model including serum lactate, increasing lactate levels were associated with lower odds of survival. Conclusion: Amongst survivors of in-hospital cardiac arrest, recurrent cardiac arrest was the strongest predictor of poor outcomes with age, time to ROSC, pre-existing malignancy, and serum creatinine levels linked with increased odds of in-hospital mortality