Water quality management decisions in Colorado

Submitted to Office of Water Resources Research, U.S. Department of the Interior.Includes bibliographical references.OWRR project no. A-10-COLO

Institutional requirements for optimal water quality management in arid urban areas

Summarizes Completion reports no. 45-47.AER72-73WRW-GVS-RCW-TLH28.Funded in part by the United States Department of the Interior, Office of Water Resources Research, as authorized by the Water Resources Research Act of 1964, and pursuant to Grant Agreement no. 14-31-0001-3567

Consolidation of irrigation systems, phase II: engineering, economic, legal, and sociological requirements

Submitted to Office of Water Research and Technology, United States Department of the Interior.OWRT project no. B-083-COLO

Making Friends with Yourself: A Mixed Methods Pilot Study of a Mindful Self-Compassion Program for Adolescents

The aims of this mixed-method pilot study were to determine the feasibility, acceptability, and preliminary psychosocial outcomes of “Making Friends with Yourself: A Mindful Self-Compassion Program for Teens” (MFY), an adaptation of the adult Mindful Self-Compassion program. Thirty-four students age 14–17 enrolled in this waitlist controlled crossover study. Participants were randomized to either the waitlist or intervention group and administered online surveys at baseline, after the first cohort participated in the intervention, and after the waitlist crossovers participated in the intervention. Attendance and retention data were collected to determine feasibility, and audiorecordings of the 6-week class were analyzed to determine acceptability of the program. Findings indicated that MFY is a feasible and acceptable program for adolescents. Compared to the waitlist control, the intervention group had significantly greater self-compassion and life satisfaction and significantly lower depression than the waitlist control, with trends for greater mindfulness, greater social connectedness and lower anxiety. When waitlist crossovers results were combined with that of the first intervention group, findings indicated significantly greater mindfulness and self-compassion, and significantly less anxiety, depression, perceived stress and negative affect post-intervention. Additionally, regression results demonstrated that self-compassion and mindfulness predicted decreases in anxiety, depression, perceived stress, and increases in life satisfaction post-intervention. MFY shows promise as a program to increase psychosocial wellbeing in adolescents through increasing mindfulness and self-compassion. Further testing is needed to substantiate the findings

Antireflection coatings from analogy between electron scattering and spin precession

We use the analogy between scattering of a wave from a potential, and the precession of a spin-half particle in a magnetic field, to gain insight into the design of an antireflection coating for electrons in a semiconductor superlattice. It is shown that the classic recipes derived for optics are generally not applicable due to the different dispersion law for electrons. Using the stability conditions we show that a Poisson distribution of impedance steps is a better approximation than is a Gaussian distribution. Examples are given of filters with average transmissivity exceeding 95% over an allowed band

Quantifying bamboo coral growth rate nonlinearity with the radiocarbon bomb spike : a new model for paleoceanographic chronology development

© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 125 (2017): 26-39, doi:10.1016/j.dsr.2017.04.006.Bamboo corals, long-lived cold water gorgonin octocorals, offer unique paleoceanographic archives of the intermediate ocean. These Isididae corals are characterized by alternating gorgonin nodes and high Mg-calcite internodes, which synchronously extend radially. Bamboo coral calcite internodes have been utilized to obtain geochemical proxy data, however, growth rate uncertainty has made it difficult to construct precise chronologies for these corals. Previous studies have relied upon a tie point from records of the anthropogenic Δ14C bomb spike preserved in the gorgonin nodes of live-collected corals to calculate a mean radial extension rate for the outer ~50 years of skeletal growth. Bamboo coral chronologies are typically constructed by applying this mean extension rate to the entire coral record, assuming constant radial extension with coral age. In this study, we aim to test this underlying assumption by analyzing the organic nodes of six California margin bamboo corals at high enough resolution (<0.5 mm) to identify the Δ14C bomb spike, including two tie points at 1957 and 1970, plus coral collection date (2007.5) for four samples. Radial extension rates between tie points ranged from 10 to 204 μm/year, with a decrease in growth rate evident between the 1957-1970 and 1970- 2007.5 periods for all four corals. A negative correlation between growth rate and coral radius (r = -0.7; p = 0.03) was determined for multiple bamboo coral taxa and individuals from the California margin, demonstrating a decline in radial extension rate with specimen age and size. To provide a mechanistic basis for these observations, a simple mathematical model was developed based on the assumption of a constant increase in circular cross sectional area with time to quantify this decline in radial extension rate with coral size between chronological tie points. Applying the area-based model to our Δ14C bomb spike time series from individual corals improves chronology accuracy for all live-collected corals with complete Δ14C bomb spikes. Hence, this study provides paleoceanographers utilizing bamboo corals with a method for reducing age model uncertainty within the anthropogenic bomb spike era (~1957-present). Chronological uncertainty is larger for the earliest portion of coral growth, particularly for skeleton precipitated prior to bomb spike tie points, meaning age estimations for samples living before 1957 remain uncertain. Combining this technique with additional chronological markers could improve age models for an entire bamboo coral. Finally, the relative consistency in growth rate in similarly-aged corals of the same depth and location supports the hypothesis that skeletal growth may be limited by local environmental conditions.This research was made possible by National Science Foundation Award #1420984 to M. LaVigne and a Clare Boothe Luce Fellowship to M. Frenkel