The Magellan/IMACS Catalog of Optical Supernova Remnant Candidates in M83

We present a new optical imaging survey of supernova remnants in M83, using data obtained with the Magellan I 6.5m telescope and IMACS instrument under conditions of excellent seeing. Using the criterion of strong [S II] emission relative to Halpha, we confirm all but three of the 71 SNR candidates listed in our previous survey, and expand the SNR candidate list to 225 objects, more than tripling the earlier sample. Comparing the optical survey with a new deep X-ray survey of M83 with Chandra, we find 61 of these SNR candidates to have X-ray counterparts. We also identify an additional list of 46 [O III] -selected nebulae for follow-up as potential ejecta-dominated remnants, seven of which have associated X-ray emission that makes them strong candidates. Some of the other [O III]-bright objects could also be normal ISM-dominated supernova remnants with shocks fast enough to doubly ionize oxygen, but with Halpha and [S II] emission faint enough to have been missed. A few of these objects may also be H II regions with abnormally high [O III] emission compared with the majority of M83 H II regions, compact nebulae excited by young Wolf-Rayet stars, or even background AGN. The supernova remnant Halpha luminosity function in M83 is shifted a factor of ~ 4.5x higher than for M33 supernova remnants, indicative of a higher mean ISM density in M83. We describe the search technique used to identify the supernova remnant candidates and provide basic information and finder charts for the objects.Comment: 40 pages, 15 figures, accepted for ApJ

Viewpoint: Design and Engineering Convergence Education in a Korean and Australian Context

Background - In this article, we provide two views on product design engineering education of two design educators from Korea and Australia. We argue that industrial design and engineering design need to be combined in order to support a total design philosophy that aims to improve design education. Therefore, the changing direction of design education for a total design perspective — and Korean and Australian design education — including industry situations are discussed. Product design education in Korea has focused on developing the physical appearance of a product. The concept of engineering design was recently introduced in Korea, and most design schools still belong to art schools. Nowadays, Korean industry is required to develop new businesses in the manufacturing sector, as the industry is facing the situation where ???fast follower??? strategy does not work for sustained growth and ultimately sustained success. This has grabbed the attention of product design engineers who can develop creative designs and materialize the concepts. In contrast, Australia is facing the end of a mining boom as well as a significant decline in automotive manufacturing. This has forced industry to challenge innovation in manufacturing which has generally been made up of SMEs. As such, the role of product design engineering is emphasized. We conclude that product design engineering education with industrial design and mechanical engineering can be primitive to strengthen the competitiveness of the manufacturing industry in both countries. Methods - The views provided in this article were assembled from the existing literature, and based on our current experience of running design engineering convergence education programs in undergraduate and graduate levels. In general, the arguments made in this article are not attracted from theoretical and empirical research. They are rather based on our own perspectives of design engineering education. Thus, the views can be more critically based on holistic analyses of industry situations. Results & Conclusions - In this article, we examine that how a strong and well-defined product design engineering program within a university context can add significant value to the industry. Product design engineering is a hybrid program that combines analytical engineering sciences with creative industrial design capabilities. It provides a platform that can reshape product offerings for companies that seek to diversify or expand into new markets. Product design engineering links seamlessly toward current industry needs by producing creative design engineers at the forefront of innovation and new product development.ope

Sex and Gender Differences in Attention-Deficit / Hyperactive disorder (ADHD): A Literature Review

Background: The American Medical Women\u27s Association (AMWA) Sex and Gender Health Collaborative identified the need for a concise factsheet for clinicians outlining sex and gender differences in Attention Deficit Hyperactive Disorder (ADHD) as ADHD is underdiagnosed, undertreated, and frequently misdiagnosed in women due to lack of recognition of gender-specific presentation. AMWA\u27s goal is to improve access and exposure to sex and gender differences in healthcare as few medical schools educate students on these differences. The poster summarizes the reviewed literature on the prevalence, diagnosis, referral for, prevention, clinical presentation, and treatment of ADHD with a goal to reduce sex and gender related disparities in the diagnosis and treatment of ADHD. The literature reviewed typically used gender and sex interchangeably. Methods: A Pubmed and Google Scholar search was performed using the search terms “ADHD,” “women,” “sex specific symptoms,” “gender specific symptoms,” “sex specific presentation,” “gender specific presentation.” A total of 25 peer reviewed sources were selected for review. Results: ADHD in girls and women can be misdiagnosed due to comorbidities such as anxiety and depression, with girls more likely to be treated with antidepressants before receiving necessary ADHD treatment compared to boys. Girls may also be misdiagnosed with dysthymia or bipolar disorder. In childhood, girls with ADHD may be perceived as compliant and daydreamers, and cultural misrepresentation and stigma may prevent self-identification. Low self-esteem and impaired peer relationships are common. Prevalence ratios of diagnosed females to males vary from 1:1.8 to 1:16 in children and estimated 1:1.6 in adults. Gender bias contributes to the referral gap between males and females, with teachers more likely to refer boys than girls with equivalent symptom profiles. Diagnosis is based on DSM-5 criteria, but girls\u27 coping mechanisms may mask symptoms. Somatic complaints, poor relationships with peers, anxiety, and poor self-esteem may be initial clues to the impact of ADHD symptoms on women. Discussion: Women with ADHD are frequently underdiagnosed, undertreated, and misdiagnosed due to a lack of recognition of gender-specific symptoms. A thorough understanding of these symptoms, as well as the impact of comorbid conditions and masking, is necessary for accurate diagnosis. Differences in referral and diagnostic rates between males and females are influenced by cultural perception and externalizing vs internalizing factors. Girls and women with ADHD are more likely to exhibit inattention, emotional reactivity, decreased self-esteem, and risky behavior, and satisfactory academic performance does not rule out the possibility of ADHD. Somatic symptoms, peer relationship struggles, and poor self-esteem may be the first indicators of underlying ADHD in some women

On The Nature of ultra-faint Dwarf Galaxy Candidates II: The case of Cetus II

We obtained deep Gemini GMOS-S $g,r$ photometry of the ultra-faint dwarf galaxy candidate Cetus II with the aim of providing stronger constraints on its size, luminosity and stellar population. Cetus II is an important object in the size-luminosity plane as it occupies the transition zone between dwarf galaxies and star clusters. All known objects smaller than Cetus II ($r_h \sim 20$ pc) are reported to be star clusters, while most larger objects are likely dwarf galaxies. We found a prominent excess of main-sequence stars in the colour-magnitude diagram of Cetus II, best described by a single stellar population with an age of 11.2 Gyr, metallicity of [Fe/H] = $-1.28$ dex, an [$\alpha$/Fe] = 0.0 dex at a heliocentric distance of 26.3$\pm$1.2 kpc. As well as being spatially located within the Sagittarius dwarf tidal stream, these properties are well matched to the Sagittarius galaxy's Population B stars. Interestingly, like our recent findings on the ultra-faint dwarf galaxy candidate Tucana V, the stellar field in the direction of Cetus II shows no evidence of a concentrated overdensity despite tracing the main sequence for over six magnitudes. These results strongly support the picture that Cetus II is not an ultra-faint stellar system in the Milky Way halo, but made up of stars from the Sagittarius tidal stream.Comment: 12 pages, 12 figures, Accepted for publication in Ap

Impossibility Theorems for Feature Attribution

Despite a sea of interpretability methods that can produce plausible explanations, the field has also empirically seen many failure cases of such methods. In light of these results, it remains unclear for practitioners how to use these methods and choose between them in a principled way. In this paper, we show that for moderately rich model classes (easily satisfied by neural networks), any feature attribution method that is complete and linear -- for example, Integrated Gradients and SHAP -- can provably fail to improve on random guessing for inferring model behaviour. Our results apply to common end-tasks such as characterizing local model behaviour, identifying spurious features, and algorithmic recourse. One takeaway from our work is the importance of concretely defining end-tasks: once such an end-task is defined, a simple and direct approach of repeated model evaluations can outperform many other complex feature attribution methods.Comment: 36 pages, 4 figures. Significantly expanded experiment

Wind tunnel testing of a novel wingsuit design

A wingsuit is a special suit that is worn to allow the user to fly after jumping off of a high cliff. The wingsuit creates an airfoil shape by adding wings of material between the arms and the sides as well as a tail consisting of material between the legs. The wingsuit allows for the creation of lift and thus human flying. A new and novel wingsuit design is proposed based on the design of a delta wing aircraft. This new wingsuit has material leading from the side of the head and connecting to the top of the arms, extending the area of the forward wing. Using a mannequin in a wind tunnel, the aerodynamic performance of the new wingsuit will be measured and compared to that of the current wingsuit design. The results show that the redesigned wingsuit had a lower lift-to-drag ratio in most testing scenarios. The decrease in lift-to-drag ratio was due to the combination of an increased lift and a higher increased drag