Studying the Synthesis of Cupprous Oxide Nanocrystals

From the Washington University Office of Undergraduate Research Digest (WUURD), Vol. 12, 05-01-2017. Published by the Office of Undergraduate Research. Joy Zalis Kiefer, Director of Undergraduate Research and Associate Dean in the College of Arts & Sciences; Lindsey Paunovich, Editor; Helen Human, Programs Manager and Assistant Dean in the College of Arts and Sciences Mentor: Bryce Sadtle

Silent Majority, Violent Majority: The Counter-Revolution in 70s Cinema

«There is one question, Inspector Callahan: Why do they call you ‘Dirty Harry’?» Harry, it is explained, «…Hates everybody: Limeys, Micks, Hebes, Fat Degos, Niggers, Honkies, Chinks…especially Spics». Don Siegel’s Dirty Harry (1971), famously labeled «fascist» by prominent film critic Pauline Kael, nonetheless represented something new and unique—the “Silent Majority’s” entry into liberal New Hollywood, a veritable counter-reformation to the new social movements having sprung up in the late Sixties and early Seventies. Far from the traditional American Right, however, and distinctly un-Fascist (in as much as the term means more than a simple epithet), these films acted to unite traditional European philosophy and revolutionary thought with organic conservative American tendencies, resulting in hybrid films which challenged the new social movements, while working within the medium of liberal New American Cinema. The article will address three themes from the era: violence and race in the city, revenge against “liberated women”, and fear and loathing of homosexuality. In each instance, using primary evidence from films and critical reviews from the Seventies and the present era, in addition to American and European theorists, the article will show how the counter-revolution in Seventies cinema failed to expunge the “revolutionary spirit” of the era. Rather, the Silent Majority’s visions of visual violence and reactionary values became part and parcel of the new liberated culture of the “Me Decade,” forever bounding the conservative celluloid revolt to the new cinematic culture

Beyond Broca’s area: why undergraduate neuroscience education matters

Patients with psychiatric illness often present a unique challenge to medical students: in contrast to some medical conditions, in which patients may seem to be stricken by a disease, patients with certain psychiatric illnesses may seem complicit with the illness. Questions of free will, choice, and the role of the physician can quickly become overwhelming. This may result in students feeling helpless, disinterested, or even resentful. Here we argue that integrating a modern neuroscience perspective into medical education allows students to conceptualize psychiatric patients in a way that promotes empathy and enhances patient care. Specifically, a strong grasp of neuroscience prevents the future physician from falling into dualistic thinking in which the psychosocial aspects of a patient’s presentation are considered beyond the realm of medicine. The value of incorporating neuroscience into a full, biopsychosocial formulation is demonstrated with the case example of a “difficult patient.

The role of surface roughness, albedo, and Bowen ratio on ecosystem energy balance in the Eastern United States

Land cover and land use influence surface climate through differences in biophysical surface properties, including partitioning of sensible and latent heat (e.g., Bowen ratio), surface roughness, and albedo. Clusters of closely spaced eddy covariance towers (e.g., \u3c10 \u3ekm) over a variety of land cover and land use types provide a unique opportunity to study the local effects of land cover and land use on surface temperature. We assess contributions albedo, energy redistribution due to differences in surface roughness and energy redistribution due to differences in the Bowen ratio using two eddy covariance tower clusters and the coupled (land-atmosphere) Variable-Resolution Community Earth System Model. Results suggest that surface roughness is the dominant biophysical factor contributing to differences in surface temperature between forested and deforested lands. Surface temperature of open land is cooler (−4.8 °C to −0.05 °C) than forest at night and warmer (+0.16 °C to +8.2 °C) during the day at northern and southern tower clusters throughout the year, consistent with modeled calculations. At annual timescales, the biophysical contributions of albedo and Bowen ratio have a negligible impact on surface temperature, however the higher albedo of snow-covered open land compared to forest leads to cooler winter surface temperatures over open lands (−0.4 °C to −0.8 °C). In both the models and observation, the difference in mid-day surface temperature calculated from the sum of the individual biophysical factors is greater than the difference in surface temperature calculated from radiative temperature and potential temperature. Differences in measured and modeled air temperature at the blending height, assumptions about independence of biophysical factors, and model biases in surface energy fluxes may contribute to daytime biases

Tree Resin Flow Dynamics during an Experimentally Induced Attack by Ips avulsus, I. calligraphus, and I. grandicollis

The success of tree colonization by bark beetles depends on their ability to overcome host tree defenses, including resin exudation and toxic chemicals, which deter bark beetle colonization. Resin defenses during insect outbreaks are challenging to study in situ, as outbreaks are stochastic events that progress quickly and thus preclude the establishment of baseline observations of non-infested controls. We use synthetic aggregation pheromones to demonstrate that confined Ips bark beetle herbivory can be successfully initiated to provide opportunities for studying interactions between bark beetles and their hosts, including the dynamics of constitutive and induced resin exudation. In Pinus taeda L. plantations between 12 and 19 years old in North and South Carolina, U.S., trees were affixed with pheromone lures, monitored for evidence of bark beetle attacks, and resin samples were collected throughout the growing season. Baiting increased beetle herbivory to an extent sufficient to produce an induced resin response. Attacked trees exuded about three times more resin at some time than control trees. This supports previous work that demonstrated that information on constitutive resin dynamics alone provides an incomplete view of a host tree's resistance to bark beetle attack.Peer reviewe

Noise-driven oscillations in microbial population dynamics

Microbial populations in the natural environment are likely to experience growth conditions very different from those of a typical laboratory xperiment. In particular, removal rates of biomass and substrate are unlikely to be balanced under realistic environmental conditions. Here, we consider a single population growing on a substrate under conditions where the removal rates of substrate and biomass are not necessarily equal. For a large population, with deterministic growth dynamics, our model predicts that this system can show transient (damped) oscillations. For a small population, demographic noise causes these oscillations to be sustained indefinitely. These oscillations arise when the dynamics of changes in biomass are faster than the dynamics of the substrate, for example, due to a high microbial death rate and/or low substrate flow rates. We show that the same mechanism can produce sustained stochastic oscillations in a two-species, nutrient-cycling microbial ecosystem. Our results suggest that oscillatory population dynamics may be a common feature of small microbial populations in the natural environment, even in the absence of complex interspecies interactions.Comment: 25 pages, 11 figure

Perceptions and experiences of interventions to prevent postnatal depression: a systematic review and qualitative evidence synthesis

Background More women experience depressive symptoms antenatally than postnatally. Supporting women through the antenatal period is recognised as important in mitigating negative outcomes and in preventing postnatal depression (PND). A systematic review was conducted which aimed to provide a detailed service user and service provider perspective on the uptake, acceptability, and perception of harms of antenatal interventions and postnatal interventions for preventing PND. Methods A comprehensive literature search was conducted in 12 major bibliographic databases in November 2012 and updated in December 2014. Studies were included if they contained qualitative evidence on the perspectives and attitudes of pregnant women and postnatal women who had taken part in, or healthcare professionals (HCPs) involved in delivering, preventive interventions for PND. Results Twenty-two studies were included. Support and empowerment through education were identified as particularly helpful to women as intervention components, across all intervention types. Implications for accessing the service, understanding the remit of the service and women's preferences for group and individual care also emerged. Limitations The majority of the included studies were of moderate or low quality, which may result in a lack of rich data consistently across all studies, limiting to some degree interpretations that can be made. Conclusion The synthesis demonstrated important considerations for devising new interventions or adapting existing interventions. Specifically, it is important that individual or group interventions are carefully tailored to women's needs or preferences and women are aware of the remit of the HCPs role to ensure they feel able to access the support required

Disentangling the role of photosynthesis and stomatal conductance on rising forest water-use efficiency

Multiple lines of evidence suggest that plant water-use efficiency (WUE) -the ratio of carbon assimilation to water loss- has increased in recent decades. Although rising atmospheric CO2 has been proposed as the principal cause, the underlying physiological mechanisms are still being debated, and implications for the global water cycle remain uncertain. Here, we addressed this gap using 30-y tree ring records of carbon and oxygen isotope measurements and basal area increment from 12 species in 8 North American mature temperate forests. Our goal was to separate the contributions of enhanced photosynthesis and reduced stomatal conductance to WUE trends and to assess consistency between multiple commonly used methods for estimating WUE. Our results show that tree ring-derived estimates of increases in WUE are consistent with estimates from atmospheric measurements and predictions based on an optimal balancing of carbon gains and water costs, but are lower than those based on ecosystemscale flux observations. Although both physiological mechanisms contributed to rising WUE, enhanced photosynthesis was widespread, while reductions in stomatal conductance were modest and restricted to species that experienced moisture limitations. This finding challenges the hypothesis that rising WUE in forests is primarily the result of widespread, CO2-induced reductions in stomatal conductance

Forest Drought Response Index (ForDRI): A New Combined Model to Monitor Forest Drought in the Eastern United States

Monitoring drought impacts in forest ecosystems is a complex process because forest ecosystems are composed of different species with heterogeneous structural compositions. Even though forest drought status is a key control on the carbon cycle, very few indices exist to monitor and predict forest drought stress. The Forest Drought Indicator (ForDRI) is a new monitoring tool developed by the National Drought Mitigation Center (NDMC) to identify forest drought stress. ForDRI integrates 12 types of data, including satellite, climate, evaporative demand, ground water, and soil moisture, into a single hybrid index to estimate tree stress. The model uses Principal Component Analysis (PCA) to determine the contribution of each input variable based on its covariance in the historical records (2003–2017). A 15-year time series of 780 ForDRI maps at a weekly interval were produced. The ForDRI values at a 12.5km spatial resolution were compared with normalized weekly Bowen ratio data, a biophysically based indicator of stress, from nine AmeriFlux sites. There were strong and significant correlations between Bowen ratio data and ForDRI at sites that had experienced intense drought. In addition, tree ring annual increment data at eight sites in four eastern U.S. national parks were compared with ForDRI values at the corresponding sites. The correlation between ForDRI and tree ring increments at the selected eight sites during the summer season ranged between 0.46 and 0.75. Generally, the correlation between the ForDRI and normalized Bowen ratio or tree ring increment are reasonably good and indicate the usefulness of the ForDRI model for estimating drought stress and providing decision support on forest drought management