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

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

Neighborhood Characteristics and Elevated Blood Pressure in Older Adults

IMPORTANCE: The local environment remains an understudied contributor to elevated blood pressure among older adults. Untargeted approaches can identify neighborhood conditions interrelated with racial segregation that drive hypertension disparities. OBJECTIVE: To evaluate independent associations of sociodemographic, economic, and housing neighborhood factors with elevated blood pressure. DESIGN, SETTING, AND PARTICIPANTS: In this cohort study, the sample included Health and Retirement Study participants who had between 1 and 3 sets of biennial sphygmomanometer readings from 2006 to 2014 or 2008 to 2016. Statistical analyses were conducted from February 5 to November 30, 2021. EXPOSURES: Fifty-one standardized American Community Survey census tract variables (2005-2009). MAIN OUTCOMES AND MEASURES: Elevated sphygmomanometer readings over the study period (6-year period prevalence): a value of at least 140 mm Hg for systolic blood pressure and/or at least 90 mm Hg for diastolic blood pressure. Participants were divided 50:50 into training and test data sets. Generalized estimating equations were used to summarize multivariable associations between each neighborhood variable and the period prevalence of elevated blood pressure, adjusting for individual-level covariates. Any neighborhood factor associated (Simes-adjusted for multiple comparisons P ≤ .05) with elevated blood pressure in the training data set was rerun in the test data set to gauge model performance. Lastly, in the full cohort, race- and ethnicity-stratified associations were evaluated for each identified neighborhood factor on the likelihood of elevated blood pressure. RESULTS: Of 12 946 participants, 4565 (35%) had elevated sphygmomanometer readings (median [IQR] age, 68 [63-73] years; 2283 [50%] male; 228 [5%] Hispanic or Latino, 502 [11%] non-Hispanic Black, and 3761 [82%] non-Hispanic White). Between 2006 and 2016, a lower likelihood of elevated blood pressure was observed (relative risk for highest vs lowest tertile, 0.91; 95% CI, 0.86-0.96) among participants residing in a neighborhood with recent (post-1999) in-migration of homeowners. This association was precise among participants with non-Hispanic White and other race and ethnicity (relative risk, 0.91; 95% CI, 0.85-0.97) but not non-Hispanic Black participants (relative risk, 0.97; 95% CI, 0.85-1.11; P = .48 for interaction) or Hispanic or Latino participants (relative risk, 0.84; 95% CI, 0.65-1.09; P = .78 for interaction). CONCLUSIONS AND RELEVANCE: In this cohort study of older adults, recent relocation of homeowners to a neighborhood was robustly associated with reduced likelihood of elevated blood pressure among White participants but not their racially and ethnically marginalized counterparts. Our findings indicate that gentrification may influence later-life blood pressure control

Forestry and environmental conditions as determinants of pine marten Martes martes occurrence in Norway

The European pine marten Martes martes is often associated with late seral stage coniferous forest stands. Earlier research has indicated that this species may be negatively influenced by clearcutting practices. However, the effects of current clearcutting methods on pine marten occurrence in conjunction with changing environmental conditions are not well known. In this study, we combined four complete years of nationwide data collected during a long-term camera trap (CT) monitoring program in Norway. We employed a multi-scale occupancy model to investigate the relationship of pine marten occurrence to clearcuts (regenerating stands & LE; 10 years old) and forests & GE; 120 years old. We also examined pine marten detection in relation to habitat features (i.e. dominant microsite characteristics) and to varying snow depths and temperatures. We found no relationship between pine marten occurrence and the proportions of old forest and clearcuts at the landscape scale. At the habitat-patch scale, pine marten occurrence was positively associated with the presence of old forest patches and terrain ruggedness, but not with clearcuts & LE; 100 m from sites. At CT sites near clearcuts, the detection probability was negatively correlated with snow depth. In contrast, pine marten occurrence was positively associated with snow depth at CT sites > 100 m from clearcuts. Furthermore, the detection probability increased with temperature and the presence of boulders at CT sites. Boulders may provide important access points for foraging, and cover for resting and predator avoidance. While previous studies indicate that pine martens prefer older forest and avoid clearcuts, the current level and scale of clearcutting in Norway does not appear to influence its occurrence at the landscape scale

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

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

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