Transient Changes in Melt Pool Size in Laser Additive Manufacturing Processes

Mechanical Engineerin

The Reciprocal Nature of Pedagogical and Technical Knowledge and Skill Development between Experts and Novices

This paper outlines the findings of a study focused on the impact an expert teacher’s pedagogical and technical knowledge and skill may have on the pedagogical and technical development of pre-service technology education teachers. Specifically, this inquiry falls within the context of traditional wooden boat building in [province/state], [country]. Understanding the relationship between an expert’s knowledge and skill, and the development of a novice’s knowledge and skill is vitally important for institutions charged with graduating technology education teachers.  Exploring the impact of pre-service teachers’ pedagogical and technical development was considered in relation to an expert teacher’s pedagogical content knowledge, and the nuance between declarative and procedural knowledge within technological activity.  Data were collected from semi-structured interviews and workshop session observations. The sample was purposeful as the participants were recruited from boat building workshops between 2017 and 2019 and the 2017-2018 technology education diploma program cohort from X University. Thematic analysis was used to identify major themes within the data. A descriptive visual framework based on the data analysis was constructed to highlight the complexities of teaching and learning within the multifaceted setting of a technical activity. An analysis of the data indicates that fostering and maintaining reciprocal interpersonal relationships between experts, novices, and peers are critical for the development of pre-service teacher technical and pedagogical knowledge and skill

The 2018 Midterm Election: Nevada and the Nation Post-Election Analysis

Brookings Mountain West, in partnership with CSUN, was pleased to present part two of a two-part analysis on the 2018 Midterm elections. The 2018 Midterms included elections for all 435 members of the House of Representatives, including four seats in Nevada. In the U.S. Senate, 34 seats were up for election, including one seat in Nevada. Across the United States, 36 states elected governors, including the State of Nevada. The Democratic Party sought to flip a minimum of 24 seats to become the majority party in House and 2 seats to become the majority party in the Senate. Two Mountain West states, Nevada and Arizona, presented the best opportunity for the Democratic Party to flip seats in the U.S. Senate. Republicans looked to flip seats in 10 states that Donald Trump won in 2016. Panelists reacted to the policy issues and voting trends that resulted from the 2018 Midterm elections

Sex allocation theory reveals a hidden cost of neonicotinoid exposure in a parasitoid wasp

P.R.W. was funded by the University of Stirling, C.V.B. and S.M.G. were funded by Nuffield Research Placements and N.C., J.G. and D.M.S. were funded by NERC (NE/J024481/1).Sex allocation theory has proved to be one the most successful theories in evolutionary ecology. However, its role in more applied aspects of ecology has been limited. Here we show how sex allocation theory helps uncover an otherwise hidden cost of neonicotinoid exposure in the parasitoid wasp Nasonia vitripennis. Female N. vitripennis allocate the sex of their offspring in line with Local Mate Competition (LMC) theory. Neonicotinoids are an economically important class of insecticides, but their deployment remains controversial, with evidence linking them to the decline of beneficial species. We demonstrate for the first time to our knowledge, that neonicotinoids disrupt the crucial reproductive behaviour of facultative sex allocation at sub-lethal, field-relevant doses in N. vitripennis. The quantitative predictions we can make from LMC theory show that females exposed to neonicotinoids are less able to allocate sex optimally and that this failure imposes a significant fitness cost. Our work highlights that understanding the ecological consequences of neonicotinoid deployment requires not just measures of mortality or even fecundity reduction among non-target species, but also measures that capture broader fitness costs, in this case offspring sex allocation. Our work also highlights new avenues for exploring how females obtain information when allocating sex under LMC.Publisher PDFPeer reviewe

Alternative foraging strategies among brown bears (Ursus arctos) fishing for chum salmon (Oncorhynchus keta) at McNeil River, Alaska

Previous research on the fishing behavior of bears (Ursus spp.) along salmon streams suggests that dominant individuals forage more efficiently than their competitors; specifically, large adult males are the most efficient foragers at a given stream due to their ability to dominate the most productive locations. I tested this hypothesis by observing 26 individual brown bears (U. arctos) fishing for chum salmon (Oncorhynchus keta) at McNeil River, Alaska, over 33 days during the summer of 2010. In contrast with previous findings I did not observe strong relationships between the foraging efficiency of individual bears and the frequency with which they engaged in dominance-related behaviors (e.g., displacing competitors, stealing fish, using more productive locations). While some individuals seemed to employ dominance as a strategy to achieve high catch rates, other individuals achieved high foraging efficiency by employing alternative foraging strategies that did not involve dominance-related behaviors. My observations suggest that bears at McNeil River employ a variety of fishing strategies, of which dominance-related behavior is but one alternative. I suggest that where foraging efficiency is concerned, an individual bear\u27s ability to develop an effective foraging strategy may be more important than its social dominance. My findings open the door to intriguing questions for future research into which physical or cognitive traits lead to the development of successful foraging strategies among brown bears fishing for salmon

Hepatitis C Virus Induces Regulatory T Cells by Naturally Occurring Viral Variants to Suppress T Cell Responses

Regulatory T cell markers are increased in chronically infected individuals with the hepatitis C virus (HCV), but to date, the induction and maintenance of Tregs in HCV infection has not been clearly defined. In this paper, we demonstrate that naturally occurring viral variants suppress T cell responses to cognate NS3358-375 in an antigen-specific manner. Of four archetypal variants, S370P induced regulatory T cell markers in comparison to NS3358-375-stimulated CD4 T cells. Further, the addition of variant-specific CD4 T cells back into a polyclonal culture in a dose-dependent manner inhibited the T cell response. These results suggest that HCV is able to induce antigen-specific regulatory T cells to suppress the antiviral T cell response in an antigen-specific manner, thus contributing to a niche within the host that could be conducive to HCV persistence

Farm Level Comparison of H.R. 2646 and S. 1731

The provisions in the House (H.R. 2646) and Senate (S. 1731) farm bills are analyzed with respect to their impacts on 94 representative crop, livestock, and dairy farms. The analysis incorporates both historical price and production risk for the farms so the “safety net” aspects of the bills can be compared. Representative crop livestock and dairy farms for major production regions across the county are analyzed. Information to describe and simulate these farms comes from a panel of farmers in each local area. The farm panels are reconvened frequently to update their farm’s data. The representative farm data base has been used for policy analysis for more than 15 years. The simulation model used for the analysis was developed by AFPC scientists.Agribusiness, Agricultural and Food Policy,

SImMER: A Pipeline for Reducing and Analyzing Images of Stars

We present the first public version of SImMER, an open-source Python reduction pipeline for astronomical images of point sources. Current capabilities include dark-subtraction, flat-fielding, sky-subtraction, image registration, FWHM measurement, contrast curve calculation, and table and plot generation. SImMER supports observations taken with the ShARCS camera on the Shane 3-m telescope and the PHARO camera on the Hale 5.1-m telescope. The modular nature of SImMER allows users to extend the pipeline to accommodate additional instruments with relative ease. One of the core functions of the pipeline is its image registration module, which is flexible enough to reduce saturated images and images of similar-brightness, resolved stellar binaries. Furthermore, SImMER can compute contrast curves for reduced images and produce publication-ready plots. The code is developed online at \url{https://github.com/arjunsavel/SImMER} and is both pip- and conda-installable. We develop tutorials and documentation alongside the code and host them online. With SImMER, we aim to provide a community resource for accurate and reliable data reduction and analysis.Comment: 12 pages, 5 figures. Accepted to PAS