Identifying Policy-relevant Indicators for Assessing Landscape Vegetation Patterns to Inform Planning and Management on Multiple-use Public Lands.

Understanding the structure and composition of landscapes can empower agencies to effectively manage public lands for multiple uses while sustaining land health. Many landscape metrics exist, but they are not often used in public land decision-making. Our objectives were to (1) develop and (2) apply a process for identifying a core set of indicators that public land managers can use to understand landscape-level resource patterns on and around public lands. We first developed a process for identifying indicators that are grounded in policy, feasible to quantify using existing data and resources, and useful for managers. We surveyed landscape monitoring efforts by other agencies, gathered science and agency input on monitoring goals, and quantified the prevalence of potential indicators in agency land health standards to identify five landscape indicators: amount, distribution, patch size, structural connectivity, and diversity of vegetation types. We then conducted pilot applications in four bureau of land management (BLM) field offices in Arizona, California, and Colorado to refine procedures for quantifying the indicators and assess the utility of the indicators for managers. Results highlighted the dominance of upland and the limited extent of riparian/wetland vegetation communities, moderate connectivity of priority vegetation patches, and lower diversity of native vegetation types on BLM compared to non-BLM lands. Agency staff can use the indicators to inform the development of quantitative resource management objectives in land use plans, evaluate progress in meeting those objectives, quantify potential impacts of proposed actions, and as a foundation for an all-lands approach to landscape-level management across public lands.

Infrared properties of high-purity silicon.

High-purity silicon is a readily available material of utility in realizing a variety of long-wavelength optical and guided wave components. The transmittance of uncompensated for silicon is measured in the far- and mid-infrared regimes at room and cryogenic temperatures. The experimental and analysis techniques used to extract the refractive index from 100-1000cm-1 (100-10 µm) are presented, and the results are compared to the literature. An average refractive index below 300cm-1, n^(300K)=3.417+i8.9×10-5, which transitions in cooling to n^(10K)=3.389+i4.9×10-6, is observed.

Far-infrared properties of cyclic olefin copolymer.

Cyclic olefin copolymer (COC) is an amorphous thermoplastic with desirable dielectric and mechanical characteristics for optical applications. In particular, its low refractive index, overall mechanical strength, and absence of strong absorption features make it a promising substrate material for far-infrared applications, which include frequency-selective surfaces, scattering filters, and windows. The dielectric properties of selected COC formulations are surveyed from $ \approx 10 - 700\,\, {{\rm cm}^{ - 1}} $≈10-700cm-1 ($ 1000 - 14\,\, \unicode{x00B5} {\rm m} $1000-14µm), and representative usage as a thin film membrane structure in optical filters is presented.

Dielectric properties of conductively loaded polyimides in the far infrared.

The dielectric properties of selected conductively-loaded polyimide samples are characterized in the microwave through far-infrared wavebands. These materials, belonging to the Vespel family, are more readily formed by direct machining than their ceramic-loaded epoxy counterparts and present an interesting solution for realizing absorptive optical control structures. Measurements spanning a spectral range from 1 to 600 cm-1 (0.03-18 THz) were performed and used in parametrization of the media's dielectric function at frequencies below ≈3 THz.

Deep reactive ion etched anti-reflection coatings for sub-millimeter silicon optics.

Refractive optical elements are widely used in millimeter and sub-millimeter (sub-mm) astronomical telescopes. High-resistivity silicon is an excellent material for dielectric lenses given its low loss tangent, high thermal conductivity, and high index of refraction. The high index of refraction of silicon causes a large Fresnel reflectance at the vacuum-silicon interface (up to 30%), which can be reduced with an anti-reflection (AR) coating. In this work, we report techniques for efficiently AR coating silicon at sub-mm wavelengths using deep reactive ion etching (DRIE) and bonding the coated silicon to another silicon optic. Silicon wafers of 100 mm diameter (1 mm thick) were coated and bonded using the silicon direct bonding technique at high temperature (1100°C). No glue is used in this process. Optical tests using a Fourier transform spectrometer show sub-percent reflections for a single-layer DRIE AR coating designed for use at 320 µm on a single wafer. Cryogenic (10 K) measurements of a bonded pair of AR-coated wafers also reached sub-percent reflections. A prototype two-layer DRIE AR coating to reduce reflections and increase bandwidth is presented, and plans for extending this approach are discussed.

Infrared dielectric properties of low-stress silicon oxide.

Silicon oxide thin films play an important role in the realization of optical coatings and high-performance electrical circuits. Estimates of the dielectric function in the far- and mid-infrared regime are derived from the observed transmittance spectrum for a commonly employed low-stress silicon oxide formulation. The experimental, modeling, and numerical methods used to extract the dielectric function are presented.

De-escalation of High-flow Respiratory Support for Children Admitted with Bronchiolitis: A Quality Improvement Initiative.

Bronchiolitis is the most common cause for hospitalization in the first year of life, with hypoxemia and acute respiratory failure as major determinants leading to hospitalization. In addition, the lack of existing guidelines for weaning and discontinuing supplemental oxygen, including high-flow nasal cannula, may contribute to prolonged hospitalization and increased resource utilization. Methods: This single-center quality improvement initiative assessed the effect of implementing a standardized care process for weaning and discontinuing high-flow oxygen for patients hospitalized with bronchiolitis. Patients aged 1-24 months with bronchiolitis admitted to the general wards or ICU step-down unit from February 1, 2018, and January 31, 2020 were included in the study. Primary outcomes included length of stay and time on supplemental oxygen, with time on high-flow oxygen and length of time in ICU step-down unit as secondary outcomes. Balancing measures included transfer rate to Pediatric Intensive Care Unit, intubation rate, 7- and 30-day readmission rates, and 7- and 30-day ED visits after discharge. Results: Following the standardized care process implementation, the mean length of stay decreased from 60.7 hours to 46.7 hours (P < 0.01). In addition, the mean time on any supplemental oxygen decreased by 47% (P < 0.01), the mean time on high-flow oxygen decreased by 45% (P < 0.01), and the mean time in the ICU step-down unit decreased by 27% (P =< 0.01). Balancing measures remained unchanged with no statistically significant differences. Conclusion: Implementing a standardized care process for weaning and discontinuing high-flow oxygen may reduce the length of stay and resource utilization for patients hospitalized with bronchiolitis.

Carbon storage of headwater riparian zones in an agricultural landscape.

BACKGROUND: In agricultural regions, streamside forests have been reduced in age and extent, or removed entirely to maximize arable cropland. Restoring and reforesting such riparian zones to mature forest, particularly along headwater streams (which constitute 90% of stream network length) would both increase carbon storage and improve water quality. Age and management-related cover/condition classes of headwater stream networks can be used to rapidly inventory carbon storage and sequestration potential if carbon storage capacity of conditions classes and their relative distribution on the landscape are known. RESULTS: Based on the distribution of riparian zone cover/condition classes in sampled headwater reaches, current and potential carbon storage was extrapolated to the remainder of the North Carolina Coastal Plain stream network. Carbon stored in headwater riparian reaches is only about 40% of its potential capacity, based on 242 MgC/ha stored in sampled mature riparian forest (forest > 50 y old). The carbon deficit along 57,700 km headwater Coastal Plain streams is equivalent to about 25TgC in 30-m-wide riparian buffer zones and 50 TgC in 60-m-wide buffer zones. CONCLUSIONS: Estimating carbon storage in recognizable age-and cover-related condition classes provides a rapid way to better inventory current carbon storage, estimate storage capacity, and calculate the potential for additional storage. In light of the particular importance of buffer zones in headwater reaches in agricultural landscapes in ameliorating nutrient and sediment input to streams, encouraging the restoration of riparian zones to mature forest along headwater reaches worldwide has the potential to not only improve water quality, but also simultaneously reduce atmospheric CO2.