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Potential effectiveness of harvest weed seed control (HWSC) systems depends upon seed shatter of the target weed species at crop maturity, enabling its collection and processing at crop harvest. However, seed retention likely is influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter phenology in thirteen economically important broadleaf weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after physiological maturity at multiple sites spread across fourteen states in the southern, northern, and mid-Atlantic U.S. Greater proportions of seeds were retained by weeds in southern latitudes and shatter rate increased at northern latitudes. Amaranthus species seed shatter was low (0 to 2%), whereas shatter varied widely in common ragweed (Ambrosia artemisiifolia L.) (2 to 90%) over the weeks following soybean physiological maturity. Overall, the broadleaf species studied shattered less than ten percent of their seeds by soybean harvest. Our results suggest that some of the broadleaf species with greater seed retention rates in the weeks following soybean physiological maturity may be good candidates for HWSC.
Seed shatter is an important weediness trait on which the efficacy of harvest weed seed control (HWSC) depends. The level of seed shatter in a species is likely influenced by agroecological and environmental factors. In 2016 and 2017, we assessed seed shatter of eight economically important grass weed species in soybean [Glycine max (L.) Merr.] from crop physiological maturity to four weeks after maturity at multiple sites spread across eleven states in the southern, northern, and mid-Atlantic U.S. From soybean maturity to four weeks after maturity, cumulative percent seed shatter was lowest in the southern U.S. regions and increased as the states moved further north. At soybean maturity, the percent of seed shatter ranged from 1 to 70%. That range had shifted to 5 to 100% (mean: 42%) by 25 days after soybean maturity. There were considerable differences in seed shatter onset and rate of progression between sites and years in some species that could impact their susceptibility to HWSC. Our results suggest that many summer annual grass species are likely not ideal candidates for HWSC, although HWSC could substantially reduce their seed output at during certain years.
Identifying early risk factors for the development of social anxiety symptoms has important translational implications. Accurately identifying which children are at the highest risk is of critical importance, especially if we can identify risk early in development. We examined continued risk for social anxiety symptoms at the transition to adolescence in a community sample of children (n = 112) that had been observed for high fearfulness at age 2 and tracked for social anxiety symptoms from preschool through age 6. In our previous studies, we found that a pattern of dysregulated fear (DF), characterized by high fear in low threat contexts, predicted social anxiety symptoms at ages 3, 4, 5, and 6 years across two samples. In the current study, we re-evaluated these children at 11–13 years of age by using parent and child reports of social anxiety symptoms, parental monitoring, and peer relationship quality. The scores for DF uniquely predicted adolescents’ social anxiety symptoms beyond the prediction that was made by more proximal measures of behavioral (e.g., kindergarten social withdrawal) and concurrent environmental risk factors (e.g., parental monitoring, peer relationships). Implications for early detection, prevention, and intervention are discussed.
OBJECTIVES/SPECIFIC AIMS: The overall goal of this project is to enhance the use of GCRA in Latina breast cancer survivors at high risk of hereditary breast and ovarian cancer to reduce disparities in GCRA uptake. The aims of the study are to (1) develop a cultural adaptation of an evidence-based TGC intervention that consists of phone genetic counseling and a booklet, (2) evaluate the impact of TGC Versus Usual Care, and (3) explore the communication patterns in TGC and genetic counseling sessions with an interpreter. METHODS/STUDY POPULATION: We are conducting a 2-phase, mixed methods study. In Phase I we will develop a cultural adaption of an evidence-based intervention (TGC) for high-risk Latina breast cancer survivors using the Learner Verification and Revision Framework (n=15). In Phase II we will use a cluster randomized design with four community sites randomized to Spanish TGC (n=2 sites) or usual care (n=2 sites) (n=60; 15 per site). The primary outcome is genetic counseling uptake. Among women who receive genetic counseling either through TGC (n~30) or with an interpreter (n~15), we will assess counseling quality by reviewing 20 randomly selected audiotaped sessions (10 TGC; 10 interpreters). We will evaluate women’s HBOC knowledge and satisfaction with counseling. Communication processes and outcomes will be assessed using gold standard RIAS quantitative coding system and qualitative discourse analysis. RESULTS/ANTICIPATED RESULTS: We elicited input from transdisciplinary team members to develop an initial adaptation of a TGC print booklet and intervention protocol for use with high-risk Latina breast cancer survivors with limited English proficiency. The booklet contains low-literacy information about HBOC, risk factors, pros and cons of testing, and management strategies. Based on these materials and prior work, we anticipate TGC will consist of one 1 hour or less TGC session by phone. Participants interested in pursuing testing will receive a saliva kit and will participate in a second TGC session (30 min) to discuss test results and management options. DISCUSSION/SIGNIFICANCE OF IMPACT: Given access barriers and the shortage of Spanish-speaking genetic counselors, adapting and translating TGC intervention is a promising strategy that could reduce disparities by broadening the reach and accessibility to genetic counseling while enhancing the quality of the service for Latinas with limited English proficiency.
Decontaminating patients who have been exposed to hazardous chemicals can directly benefit the patients’ health by saving lives and reducing the severity of toxicity. While the importance of decontaminating patients to prevent the spread of contamination has long been recognized, its role in improving patient health outcomes has not been as widely appreciated. Acute chemical toxicity may manifest rapidly—often minutes to hours after exposure. Patient decontamination and emergency medical treatment must be initiated as early as possible to terminate further exposure and treat the effects of the dose already absorbed. In a mass exposure chemical incident, responders and receivers are faced with the challenges of determining the type of care that each patient needs (including medical treatment, decontamination, and behavioral health support), providing that care within the effective window of time, and protecting themselves from harm. The US Department of Health and Human Services and Department of Homeland Security have led the development of national planning guidance for mass patient decontamination in a chemical incident to help local communities meet these multiple, time-sensitive health demands. This report summarizes the science on which the guidance is based and the principles that form the core of the updated approach. (Disaster Med Public Health Preparedness. 2014;0:1–7)
Recent research indicates that cognitive reserve mitigates the clinical expression of neuropsychological impairment in multiple sclerosis (MS). This literature primarily uses premorbid intelligence and lifetime experiences as indicators. However, changes in current recreational activities may also contribute to the maintenance of neural function despite brain atrophy. We examined the moderation effects of current changes in recreational activity on the relationship between brain atrophy and information processing speed in 57 relapsing-remitting MS patients. Current enrichment was assessed using the Recreation and Pastimes subscale from the Sickness Impact Profile. In patients reporting current declines in recreational activities, brain atrophy was negatively associated with cognition, but there was no such association in participants reporting stable participation. The MRI metric-by-recreational activity interaction was significant in separate hierarchical regression analyses conducted using third ventricle width, neocortical volume, T2 lesion volume, and thalamic volume as brain measures. Results suggest that recreational activities protect against brain atrophy's detrimental influence on cognition. (JINS, 2013, 19, 1–6)
Thin films of zirconium oxide (ZrOx) and hafnium oxide (HfOx) were rf sputtered onto fused silica substrates in an oxygen rich argon environment. Pure zirconium and hafnium targets were used, and the oxygen partial pressure was varied to control the oxygen stoichiometry. Measurement of the EPR characteristics of the ZrOx films indicated two peaks corresponding to two orientations of the magnetic field. This anisotropic response suggested the films were polycrystalline with a preferred orientation. This was confirmed by XRD pole figures. The measured g-values for the ZrOx films were less than the free-spin g-value, indicating the defects corresponded to electron traps. It was further shown that the lower the oxygen partial pressure during deposition, the larger the EPR response, strongly suggesting the traps correspond to oxygen vacancies in ZrOx. Hafnium oxide thin films were also characterized by EPR. The EPR measurements indicated the presence of a single resonance peak, suggesting these films were polycrystalline without a preferred orientation or amorphous. XRD measurements confirmed that the HfOx films were amorphous. The g-value for these films was greater than that the free-spin value, indicating the presence of possibly self-trapped oxygen hole centers. These results will be discussed in the context of prior experimental and theoretical work on these systems.
The time-temperature-transformation (TTT) curve for the δ → α′ isothermal martensitic transformation in a Pu-1.9 at. % Ga alloy exhibits an anomalous double-C curve. Recent work suggests that an ambient temperature conditioning treatment enables the lower-C curve. However, the mechanisms responsible for the double-C are still not fully understood. When the δ → α′ transformation is induced by pressure, an intermediate γ′ phase is observed in some alloys. It has been suggested that transformation at upper-C temperatures may proceed via this intermediate phase, while lower-C transformation progresses directly from δ to α′. To investigate the possibility of thermally induced transformation via the intermediate γ′ phase, in situ x-ray diffraction at the Advanced Photon Source was performed. Using transmission x-ray diffraction, the δ → α′ transformation was observed as a function of time and temperature in samples as thin as 30 μm. The intermediate γ′ phase was not observed at -120°C (upper-C curve) or -155 °C (lower-C curve). Results indicate that the bulk of the α′ phase forms relatively rapidly at -120 and -155 °C.
The gallium-stabilized Pu-2.0 at. % Ga alloy undergoes a partial or incomplete low-temperature martensitic transformation from the metastable δ phase to the gallium-containing, monoclinic α′ phase near -100 °C. This transformation has been shown to occur isothermally and it displays anomalous double-C kinetics in a time-temperature-transformation (TTT) diagram, where two nose temperatures anchoring an upper- and lower-C describe minima in the time for the initiation of transformation. The underlying mechanisms responsible for the double-C behavior are currently unresolved, although recent experiments suggest that a conditioning treatment—wherein, following an anneal at 375 °C, the sample is held at a sub-anneal temperature for a period of time—significantly influences the upper-C of the TTT diagram. As such, elucidating the effects of the conditioning treatment upon the δ⟶α′ transformation can provide valuable insights into the fundamental mechanisms governing the double-C kinetics of the transition. Following a high-temperature anneal, a differential scanning calorimeter (DSC) was used to establish an optimal conditioning curve that depicts the amount of α′ formed during the transformation as a function of conditioning temperature for a specified time. With the optimal conditioning curve as a baseline, the DSC was used to explore the circumstances under which the effects of the conditioning treatment were destroyed, resulting in little or no transformation.
Under ambient conditions, a Pu-2.0 at.% Ga alloy is retained in the metastable δ phase. Upon cooling to approximately -120 °C, the face-centered-cubic δ phase partially transforms to the metastable monoclinic α′ phase via a martensitic transformation. The kinetics of the δ⟶α′ transformation are reported to have double-C curve kinetics in a time-temperature-transformation (TTT) diagram, but the mechanisms responsible for this unusual behavior are not understood. Our work focuses on determining the underlying cause of the two noses. Optical microscopy has been used to investigate the role of “conditioning”—an isothermal hold at sub-anneal temperatures—on the δ⟶α′ transformation and to illuminate any disparities in transformation products. Conditioning was found to affect substantially the amount of transformation that occurs at particular points corresponding to both the upper- and lower-C of the TTT diagram.
This is an exciting time to be involved in plutonium metallurgical research. Over the past few years, there have been significant advances in our understanding of the fundamental materials science of this unusual metal, particularly in the areas of self-irradiation induced aging of Pu, the equilibrium phase diagram, the homogenization of δ-phase alloys, the crystallography and morphology of the α'-phase resulting from the isothermal martensitic phase transformation, and the phonon dispersion curves, among many others. In addition, tremendous progress has been made, both experimentally and theoretically, in our understanding of the condensed matter physics and chemistry of the actinides, particularly in the area of electronic structure. Although these communities have made substantial progress, many challenges still remain. This brief overview will address a number of important challenges that we face in fully comprehending the metallurgy of Pu with a specific focus on aging and phase transformations.
We develop a straightforward procedure to price derivatives by a bivariate tree when the underlying process is a jump-diffusion. Probabilities and jump sizes are derived are derived by matching higher order moments or cumulants. We give comparisons with other published results along with convergence proofs and estimates of the order of convergence. The bivariate tree approach is particularly useful for pricing long-term American options and long-term real options because of its robustness and flexibility. We illustrate the pedagogy in an application involving a long-term investment project.