Lunar navigation study, summary volume Final report, Jun. 1964 - May 1965

Lunar surface navigation and guidance study to implement lunar surface vehicle exploration mission

Lunar navigation study, sections 1 through 7 Final report, Jun. 1964 - May 1965

Lunar navigation analysis using passive nongyro, inertial navigation, and radio frequency technolog

Computational Essays: An Avenue for Scientific Creativity in Physics

Computation holds great potential for introducing new opportunities for creativity and exploration into the physics curriculum. At the University of Oslo we have begun development of a new class of assignment called computational essays to help facilitate creative, open-ended computational physics projects. Computational essays are a type of essay or narrative that combine text and code to express an idea or make an argument, usually written in computational notebooks. During a pilot implementation of computational essays in an introductory electricity and magnetism course, students reported that computational essays facilitated creative investigation at a variety of levels within their physics course. They also reported finding this creativity as being both challenging and motivating. Based on these reflections, we argue that computational essays are a useful tool for leveraging the creative affordances of programming in physics education.Comment: Accepted to the 2019 Physics Education Research Conference Proceeding

The KELT Follow-Up Network And Transit False-Positive Catalog: Pre-Vetted False Positives For TESS

The Kilodegree Extremely Little Telescope (KELT) project has been conducting a photometric survey of transiting planets orbiting bright stars for over 10 years. The KELT images have a pixel scale of ~23\u27\u27 pixel⁻¹—very similar to that of NASA\u27s Transiting Exoplanet Survey Satellite (TESS)—as well as a large point-spread function, and the KELT reduction pipeline uses a weighted photometric aperture with radius 3\u27. At this angular scale, multiple stars are typically blended in the photometric apertures. In order to identify false positives and confirm transiting exoplanets, we have assembled a follow-up network (KELT-FUN) to conduct imaging with spatial resolution, cadence, and photometric precision higher than the KELT telescopes, as well as spectroscopic observations of the candidate host stars. The KELT-FUN team has followed-up over 1600 planet candidates since 2011, resulting in more than 20 planet discoveries. Excluding ~450 false alarms of non-astrophysical origin (i.e., instrumental noise or systematics), we present an all-sky catalog of the 1128 bright stars (6 \u3c V \u3c 13) that show transit-like features in the KELT light curves, but which were subsequently determined to be astrophysical false positives (FPs) after photometric and/or spectroscopic follow-up observations. The KELT-FUN team continues to pursue KELT and other planet candidates and will eventually follow up certain classes of TESS candidates. The KELT FP catalog will help minimize the duplication of follow-up observations by current and future transit surveys such as TESS

Optogenetic control of Drosophila using a red-shifted channelrhodopsin reveals experience-dependent influences on courtship

Optogenetics allows the manipulation of neural activity in freely moving animals with millisecond precision, but its application in Drosophila melanogaster has been limited. Here we show that a recently described red activatable channelrhodopsin (ReaChR) permits control of complex behavior in freely moving adult flies, at wavelengths that are not thought to interfere with normal visual function. This tool affords the opportunity to control neural activity over a broad dynamic range of stimulation intensities. Using time-resolved activation, we show that the neural control of male courtship song can be separated into (i) probabilistic, persistent and (ii) deterministic, command-like components. The former, but not the latter, neurons are subject to functional modulation by social experience, which supports the idea that they constitute a locus of state-dependent influence. This separation is not evident using thermogenetic tools, a result underscoring the importance of temporally precise control of neuronal activation in the functional dissection of neural circuits in Drosophila

How computation can facilitate sensemaking about physics: A case study

We present a case study featuring a first-year bio-science university student using computation to solve a radioactive decay problem and interpret the results. In a semi-structured cognitive interview, we use this case to examine the process of sensemaking in a computational science context. We observe the student entering the sensemaking process by inspecting and comparing computational outputs. She then makes several attempts to resolve the perceived inconsistency, foregrounding knowledge from different domains. The key to making sense of the model for this student proves to be thinking about how to implement a better model computationally. This demonstrates that integrating computation in physics activities may provide students with opportunities to engage in sensemaking and critical thinking. We finally discuss some implications for instruction.Comment: 4 pages. Updated after peer review to be ready for inclusion in the PERC 2018 proceeding

Intersectional Discrimination and Change in Blood Pressure Control among Older Adults: The Health and Retirement Study

BACKGROUND: Associations between multiple forms of discrimination and blood pressure control in older populations remain unestablished. METHODS: Participants were 14582 non-institutionalized individuals (59% women) in the Health and Retirement Study aged at least 51 years (76% Non-Hispanic White, 15% Non-Hispanic Black, 9% Hispanic/Latino). Primary exposures included the mean frequency of discrimination in everyday life, intersectional discrimination (defined as marginalization ascribed to more than one reason), and the sum of discrimination over the lifespan. We assessed whether discrimination was associated with change in measured hypertension status (N=14582) and concurrent medication use among reported hypertensives (N=9086) over four years (2008-2014). RESULTS: There was no association between the frequency of everyday discrimination and change in measured hypertension. Lifetime discrimination was associated with higher odds of hypertension four years later among men (OR: 1.21, 95% CI: 1.08, 1.36) but not women (OR: 0.98, 95% CI: 0.86, 1.13). Only among men, everyday discrimination due at least two reasons was associated with a 1.44 (95% CI: 1.03, 2.01)-fold odds of hypertension than reporting no everyday discrimination; reporting intersectional discrimination was not associated with developing hypertension among women (OR: 0.91, 95% CI: 0.70, 1.20). All three discriminatory measures were inversely related to time-averaged antihypertensive medication use, without apparent gender differences (e.g., OR for everyday discrimination-antihypertensive use associations: 0.85, 95% CI: 0.77, 0.94)). CONCLUSIONS: Gender differences in marginalization may more acutely elevate hypertensive risk among older men than similarly aged women. Experiences of discrimination appear to decrease the likelihood of antihypertensive medication use among older adults overall

Smartphone app reveals that lynx avoid human recreationists on local scale, but not home range scale

Outdoor recreation is increasing and affects habitat use and selection by wildlife. These effects are challenging to study, especially for elusive species with large spatial requirements, as it is hard to obtain reliable proxies of recreational intensity over extensive areas. Commonly used proxies, such as the density of, or distance to, hiking paths, ignore outdoor recreation occurring on other linear feature types. Here we utilized crowdsourced data from the Strava training app to obtain a large-scale proxy for pedestrian outdoor recreation intensity in southeast Norway. We used the proxy and GPS-tracking data from collared Eurasian lynx (Lynx lynx) to investigate how recreation affects habitat selection at the home range scale and local scale by lynx during summer. We fitted resource selection functions at the two scales using conditional logistic regression. Our analysis revealed that lynx avoided areas of recreational activity at the local scale, but not at home range scale. Nonetheless, lynx frequently used areas associated with recreation, and to a greater degree at night than during the day. Our results suggest that local-scale avoidance of recreation and temporal adjustments of habitat use by lynx mitigate the need for a home range-scale response towards recreation. Scale-dependent responses and temporal adjustments in habitat use may facilitate coexistence between humans and large carnivores

Selectivity of eurasian lynx Lynx lynx and recreational hunters for age, sex and body condition in roe deer Capreolus capreolus

tional hunters for age, sex and condition in roe deerCapreolus capreolus.-Wildl. Biol. 13: 467-474. Data on the age, sex and condition of roe deer Capreolus capreolus killed by Eurasian lynx Lynx lynx and human hunters were collected in two study areas in the counties of Nord-Trøndelag and Hedmark in central and southeastern Norway, respectively. Data on the age and sex structure of the standing population were also collected. No differences in the age or sex structure of roe deer killed by lynx were found between the two study areas or between years with differing snow depths which was ex-pected to affect age-class vulnerability. The profile of 151 lynx-killed roe deer (24 % adult males, 44 % adult females, 11 % male fawns and 21% female fawns) was not statistically different from that of the standing population. In contrast, hunters killed a significantly larger proportion of adult animals, especially males (44 % adult males, 28 % adult females, 15 % male fawns and 13 % female fawns). The detailed age structure of lynx killed and hunter killed animals was not different within the adult age class. The body condition of roe deer declined during late winter (more so for males than for females), however, there was no difference in the con-dition of roe deer killed by lynx or hunters during early winter (the hunt-ing season ends on 24 December). The overall picture is typical of a stalk-ing predator that has few options to select individuals based on condition, age or sex in a prey species with no sexual dimorphism and which is relatively small in relation to the size of the predator (lynx are 50-70% the size of an adult roe deer). Human hunters, on the other hand, are clearly harvesting a non-random section of the population. The result is that hunting does not replicate natural predation, although lynx preda-tion is likely to have a higher per capita impact on roe deer growth rates

Altitude, latitude and climate zone as determinants of mountain hare (Lepus timidus) coat colour change

Local adaptation to annually changing environments has evolved in numerous species. Seasonal coat colour change is an adaptation that has evolved in multiple mammal and bird species occupying areas that experience seasonal snow cover. It has a critical impact on fitness as predation risk may increase when an individual is mismatched against its habitat's background colour. In this paper, we investigate the correlation between landscape covariates and moult timing in a native winter-adapted herbivore, the mountain hare (Lepus timidus), throughout Norway. Data was collected between 2011 and 2019 at 678 camera trap locations deployed across an environmental gradient. Based on this data, we created a Bayesian multinomial logistic regression model that quantified the correlations between landscape covariates and coat colour phenology and analysed among season and year moult timing variation. Our results demonstrate that mountain hare moult timing is strongly correlated with altitude and latitude with hares that live at higher latitudes and altitudes keeping their winter white coats for longer than their conspecifics that inhabit lower latitudes and altitudes. Moult timing was also weakly correlated with climate zone with hares that live in coastal climates keeping their winter white coats for longer than hares that live in continental climates. We found evidence of some among year moult timing variation in spring, but not in autumn. We conclude that mountain hare moult timing has adapted to local environmental conditions throughout Norway