Telescope to Observe Planetary Systems (TOPS): a high throughput 1.2-m visible telescope with a small inner working angle

The Telescope to Observe Planetary Systems (TOPS) is a proposed space mission to image in the visible (0.4-0.9 micron) planetary systems of nearby stars simultaneously in 16 spectral bands (resolution R~20). For the ~10 most favorable stars, it will have the sensitivity to discover 2 R_E rocky planets within habitable zones and characterize their surfaces or atmospheres through spectrophotometry. Many more massive planets and debris discs will be imaged and characterized for the first time. With a 1.2m visible telescope, the proposed mission achieves its power by exploiting the most efficient and robust coronagraphic and wavefront control techniques. The Phase-Induced Amplitude Apodization (PIAA) coronagraph used by TOPS allows planet detection at 2 lambda/d with nearly 100% throughput and preserves the telescope angular resolution. An efficient focal plane wavefront sensing scheme accurately measures wavefront aberrations which are fed back to the telescope active primary mirror. Fine wavefront control is also performed independently in each of 4 spectral channels, resulting in a system that is robust to wavefront chromaticity.Comment: 12 pages, SPIE conference proceeding, May 2006, Orlando, Florid

A Century of Grading Research: Meaning and Value in the Most Common Educational Measure

Grading refers to the symbols assigned to individual pieces of student work or to composite measures of student performance on report cards. This review of over 100 years of research on grading considers five types of studies: (a) early studies of the reliability of grades, (b) quantitative studies of the composition of K-12 report card grades, (c) survey and interview studies of teachers’ perceptions of grades, (d) studies of standards-based grading, and (e) grading in higher education. Early 20th century studies generally condemned teachers’ grades as unreliable. More recent studies of the relationships of grades to tested achievement and survey studies of teachers’ grading practices and beliefs suggest that grades assess a multidimensional construct containing both cognitive and non-cognitive factors reflecting what teachers value in student work. Implications for future research and for grading practices are discussed

Pulmonary toxicity and lung tumorigenic potential of surrogate metal oxides in gas metal arc welding–stainless steel fume: Iron as a primary mediator versus chromium and nickel

In 2017, the International Agency for Research on Cancer classified welding fumes as “car- cinogenic to humans” (Group 1). Both mild steel (MS) welding, where fumes lack carcino- genic chromium and nickel, and stainless steel (SS) increase lung cancer risk in welders; therefore, further research to better understand the toxicity of the individual metals is needed. The objectives were to (1) compare the pulmonary toxicity of chromium (as Cr(III) oxide [Cr2O3] and Cr (VI) calcium chromate [CaCrO4]), nickel [II] oxide (NiO), iron [III] oxide (Fe2O3), and gas metal arc welding-SS (GMAW-SS) fume; and (2) determine if these metal oxides can promote lung tumors. Lung tumor susceptible A/J mice (male, 4–5 weeks old) were exposed by oropharyngeal aspiration to vehicle, GMAW-SS fume (1.7 mg), or a low or high dose of surrogate metal oxides based on the respective weight percent of each metal in the fume: Cr2O3 + CaCrO4 (366 + 5 μg and 731 + 11 μg), NiO (141 and 281 μg), or Fe2O3 (1 and 2 mg). Bronchoalveolar lavage, histopathology, and lung/liver qPCR were done at 1, 7, 28, and 84 days post-aspiration. In a two-stage lung carcinogenesis model, mice were initi- ated with 3-methylcholanthrene (10 μg/g; intraperitoneal; 1x) or corn oil then exposed to metal oxides or vehicle (1 x/week for 5 weeks) by oropharyngeal aspiration. Lung tumors were counted at 30 weeks post-initiation. Results indicate the inflammatory potential of the metal oxides was Fe2O3 \u3e Cr2O3 + CaCrO4 \u3e NiO. Overall, the pneumotoxic effects were negligible for NiO, acute but not persistent for Cr2O3 + CaCrO4, and persistent for the Fe2O3 exposures. Fe2O3, but not Cr2O3 + CaCrO4 or NiO significantly promoted lung tumors. These results provide experimental evidence that Fe2O3 is an important mediator of welding fume toxicity and support epidemiological findings and the IARC classification

TOPS: a small space telescope using phase induced-amplitude apodization (PIAA) to image rocky and giant exo-planets

The Telescope to Observe Planetary Systems (TOPS) is a proposed space mission to image planetary systems of nearby stars simultaneously in a few wide spectral bands covering the visible light (0.4-0.9 μm). It achieves its power by combining a high accuracy wavefront control system with a highly efficient Phase-Induced Amplitude Apodization (PIAA) coronagraph which provides strong suppression very close to the star (within 2 λ/D). The PIAA coronagraphic technique opens the possibility of imaging Earthlike planets in visible light with a smaller telescope than previously supposed. If sized at 1.2-m, TOPS would image and characterize many Jupiter-sized planets, and discover 2 RE rocky planets within habitable zones of the ≈10 most favorable stars. With a larger 2-m aperture, TOPS would have the sensitivity to reveal Earth-like planets in the habitable zone around ≈20 stars, and to characterize any found with low resolution spectroscopy. Unless the occurrence of Earth-like planets is very low (η⊕ <~ 0.2), a useful fraction of the TPF-C scientific program would be possible with aperture much smaller than the baselined 8 by 3.5m for TPF, with its more conventional coronagraph. An ongoing laboratory experiment has successfully demonstrated high contrast coronagraphic imaging within 2 λ/d with the PIAA coronagraph / focal plane wavefront sensing scheme envisioned for TOPS

Eclipse-Ballooning 2017: The U of MN – Twin Cities Experience

The stratospheric ballooning team at the U of MN – Twin Cities started working on eclipse-ballooning in the fall of 2013, even before the Montana Space Grant announced their plan to organize a national Eclipse Ballooning Project. Our team promptly signed up to assist their effort, and have been heavily involved ever since. This presentation will discuss our eclipse-ballooning efforts and progress over the past 4 years. Our experiences include experimenting with a GoPro-based video-telemetry system (which ultimately was not as successful as Montana’s Raspberry-Pi-based system), adopting (then helping test, modify, and teach other teams to learn to use) the Montana telemetry system, practicing with up-range and down-range ground station placement, developing and testing passive anti-rotation devices and active camera-pointing devices to improve video quality, landing two eclipse-telemetry systems in Minnesota lakes one week before the eclipse (ouch!), flying five balloon stacks during the eclipse from near Grand Island, NE, and organizing/hosting AHAC 2017. We will also discuss ways in which we have already begun to use the telemetry equipment for non-eclipse balloon missions. The eclipse project has greatly expanded our HAB network and ballooning capabilities in multiple different directions, and will continue to strongly influence our stratospheric ballooning program for years to come

Good and ‘bad’ deaths during the COVID-19 pandemic: insights from a rapid qualitative study

Dealing with excess death in the context of the COVID-19 pandemic has thrown the question of a good or bad death' into sharp relief as countries across the globe have grappled with multiple peaks of cases and mortality; and communities mourn those lost. In the UK, these challenges have included the fact that mortality has adversely affected minority communities. Corpse disposal and social distancing guidelines do not allow a process of mourning in which families and communities can be involved in the dying process. This study aimed to examine the main concerns of faith and non-faith communities across the UK in relation to death in the context of the COVID-19 pandemic. The research team used rapid ethnographic methods to examine the adaptations to the dying process prior to hospital admission, during admission, during the disposal and release of the body, during funerals and mourning. The study revealed that communities were experiencing collective loss, were making necessary adaptations to rituals that surrounded death, dying and mourning and would benefit from clear and compassionate communication and consultation with authorities

'A good death' during the Covid-19 pandemic in the UK: a report on key findings and recommendations

Dealing with death and bereavement in the context of the Covid-19 Pandemic will present significant challenges for at least the next three months. The current situation does not allow for families andbcommunities to be involved in the process of death in ways in which they would normally hope or expect to be. In addition, mortality rates will disproportionately affect vulnerable households. The government has identified the following communities as being at increased risk: single parent households; multi-generational Black and Minority Ethnic groups; men without degrees in lone households and/or in precarious work; small family business owners in their 50s; and elderlyhouseholds. Our study focused on these groups. This report presents a summary of findings and key recommendations by a team of anthropologists from the London School of Economics who conducted a public survey and 58 cross-community interviews between 3 and 9 April 2020. It explores ways to prepare these communities and households for impending deaths with communications and policy support. More information on the research methodology, data protection and ethical procedures is available in Appendix 1. A summary of relevant existing research can be found in Appendix 2. A list of key contacts across communities for consultation is available on request. Research was focused on “what a good death looks like” for people across all faiths and for vulnerable groups. It examined how communities were already adapting how they dealt with processes of dying, burials, funerals and bereavement during the pandemic, and responding to new government regulations. It specifically focused on five transitions in the process of death, and what consultation processes, policies and communications strategies could be mobilised to support communities through these phases

Children as Research Collaborators: Issues and Reflections from a Mobility Study in Sub-Saharan Africa

This paper reflects on issues raised by work with children in an ongoing child mobility study in three sub-Saharan African countries: Ghana, Malawi and South Africa. There are now 70 school pupils of varying ages involved in the project, but the paper is particularly concerned with the participation of those children 14 years and under. We examine the significant ethical issues associated with working with younger child researchers, and linked questions concerning the spaces open to them in African contexts where local cultural constructions of childhood and associated economic imperatives (which commonly drive family and household endeavour) help shape the attitudes of adults to children’s rights and responsibilities and inter-generational power relations

The Contribution of Dental Amalgam to Urinary Mercury Excretion in Children

BACKGROUND: Urinary mercury concentrations are widely used as a measure of mercury exposure from dental amalgam fillings. No studies have evaluated the relationship of these measures in a longitudinal context in children. OBJECTIVE: We evaluated urinary mercury in children 8–18 years of age in relation to number of amalgam surfaces and time since placement over a 7-year course of amalgam treatment. METHODS: Five hundred seven children, 8–10 years of age at baseline, participated in a clinical trial to evaluate the neurobehavioral effects of dental amalgam in children. Subjects were randomized to either dental amalgam or resin composite treatments. Urinary mercury and creatinine concentrations were measured at baseline and annually on all participants. RESULTS: Treatment groups were comparable in baseline urinary mercury concentration (~ 1.5 μg/L). Mean urinary mercury concentrations in the amalgam group increased to a peak of ~ 3.2 μg/L at year 2 and then declined to baseline levels by year 7 of follow-up. There was a strong, positive association between urinary mercury and both number of amalgam surfaces and time since placement. Girls had significantly higher mean urinary mercury concentrations than boys throughout the course of amalgam treatment. There were no differences by race in urinary mercury concentration associated with amalgam exposure. CONCLUSIONS: Urinary mercury concentrations are highly correlated with both number of amalgam fillings and time since placement in children. Girls excrete significantly higher concentrations of mercury in the urine than boys with comparable treatment, suggesting possible sex-related differences in mercury handling and susceptibility to mercury toxicity.info:eu-repo/semantics/publishedVersio

Felony Murder and Capital Punishment: an Examination of the Deterrence Question

A proper test of the deterrent effect of the death penalty must consider capital homicides. However, the criterion variable in most investigations has been total homicides—most of which bear no legal or theoretical relationship to capital punishment. To address this fundamental data problem, this investigation used Federal Bureau of Investigation data for 1976–1987 to examine the relationship between capital punishment and felony murder, the most common type of capital homicide. We conducted time series analyses of monthly felony murder rates, the frequency of executions, and the amount and type of television coverage of executions over the period. The analyses revealed occasional departures (for vehicle theft and narcotics killings) from the null hypotheses. However, on balance, and in line with the vast majority of capital punishment studies, this investigation found no consistent evidence that executions and the television coverage they receive are associated significantly with rates for total, index, or different types of felony murder