Validation of Lateral Gap Leakage Objective Function for Use in Multi-Objective Optimization of Gerotor Pumps

Gerotor pumps are a common pump choice used in the automotive, agricultural, and construction fields for their low cost and durability. Recently, demanding applications have called for significant design improvements in gear geometry. To address these design challenges, multi-objective optimization has been applied to gear geometry. The goal of this work is to introduce minimizing of lateral-gap leakage to the multi-objective optimization. An objective function for evaluating lateral-gap leakage based on 1D, pressure driven flow is proposed. This simplified approach is compared to CFD simulation solving of Reynolds equation with two pressure boundaries. Comparison of the simplified relation and the CFD simulation are used to validate the objective function for use in optimization

Use of stable isotopes to assess the intraspecific foraging niche of males and female colour morphs of the damselfly Enallagma hageni

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102631/1/een12075.pd

Spatiotemporal Variability in Biomass and Forage Quality Across a Temperate Landscape with Heterogeneous Phenology Patterns (Poster)

Although spatial and temporal heterogeneity in grassland biomass and forage quality is well-recognized to play an important role in migratory ungulate population dynamics, attempts to directly quantify biomass and forage quality across temperate landscapes throughout the growing season are limited. It is generally recognized that biomass and forage quality are directly related to phenology, but little is known about how seasonal biomass and forage quality differs across land use and biophysical gradients with varying phenology patterns. This study uses field estimates of biomass, chlorophyll concentration, crude protein, and in vitro dry matter digestibility collected from 20, 250m2 grassland plots throughout the summers of 2013 and 2014 to quantify how biomass and forage quality differ across land uses and biophysical gradients in the migratory elk (Cervus elaphus) range in the Upper Yellowstone River Basin. Key findings were that irrigated agriculture had overall greater and longer available biomass and forage quality throughout the growing season compared to private and public grasslands with natural phenology patterns. And that areas that begin growth later in the season had overall greater biomass and forage quality than areas with mid and early phenology characteristics, but availability was shorter. These results suggest that seasonal patterns of biomass and forage quality differ with phenological characteristics across temperate landscapes. This information should be incorporated in our understanding of spatiotemporal patterns of vegetation important for studying migratory ungulate ecology and predicting the effects of climate change and human land use on vegetation dynamics in temperate landscapes

The vertical distribution and biological transport of marine microplastics across the epipelagic and mesopelagic water column.

Plastic waste has been documented in nearly all types of marine environments and has been found in species spanning all levels of marine food webs. Within these marine environments, deep pelagic waters encompass the largest ecosystems on Earth. We lack a comprehensive understanding of the concentrations, cycling, and fate of plastic waste in sub-surface waters, constraining our ability to implement effective, large-scale policy and conservation strategies. We used remotely operated vehicles and engineered purpose-built samplers to collect and examine the distribution of microplastics in the Monterey Bay pelagic ecosystem at water column depths ranging from 5 to 1000 m. Laser Raman spectroscopy was used to identify microplastic particles collected from throughout the deep pelagic water column, with the highest concentrations present at depths between 200 and 600 m. Examination of two abundant particle feeders in this ecosystem, pelagic red crabs (Pleuroncodes planipes) and giant larvaceans (Bathochordaeus stygius), showed that microplastic particles readily flow from the environment into coupled water column and seafloor food webs. Our findings suggest that one of the largest and currently underappreciated reservoirs of marine microplastics may be contained within the water column and animal communities of the deep sea

Progress in Interferometry for LISA at JPL

Recent advances at JPL in experimentation and design for LISA interferometry include the demonstration of Time Delay Interferometry using electronically separated end stations, a new arm-locking design with improved gain and stability, and progress in flight readiness of digital and analog electronics for phase measurements.Comment: 11 pages, 9 figures, LISA 8 Symposium, Stanford University, 201

Author Correction: The vertical distribution and biological transport of marine microplastics across the epipelagic and mesopelagic water column.

An amendment to this paper has been published and can be accessed via a link at the top of the paper

Maternal health conditions during pregnancy and acute leukemia in children with Down syndrome: A Children's Oncology Group study

Children with Down syndrome (DS) have about a 20-fold increased risk of developing leukemia. Early childhood infections may protect against acute lymphoid leukemia (ALL) in children with and without DS. We examined whether maternal infections and health conditions during pregnancy were associated with acute leukemia in children with DS

Vitamin supplement use among children with Down syndrome and risk of leukemia: A Children’s Oncology Group (COG) Study

Vitamin supplements have been proposed for children with Down syndrome (DS) with claims of improving cognitive abilities, or immune or thyroid function. Several studies have shown decreased levels of zinc in this population. Because children with DS have a 50-fold increased risk of developing acute leukemia during the first 5 years of life, we explored the relation between child vitamin and herbal supplement use and the risk for leukemia in a case-control study. During the period 1997–2002, we enrolled 158 children with DS aged 0–18 years that were diagnosed with acute lymphoblastic leukemia (ALL) (n=97) or acute myeloid leukemia (AML) (n=61) at participating COG institutions. We enrolled 173 DS children without leukemia (controls), selected from the cases’ primary care clinic and frequency matched on age. Data were collected via telephone interviews with mothers of the index child regarding use of multivitamins, zinc, vitamin C, iron, and herbal supplements, including age at first use, frequency and duration. Among controls, 57% reported regular multivitamin use (≥ 3 times/week for ≥ 3 months) compared with 48% of ALL cases and 61% of AML cases. We found no evidence of an association between child’s regular multivitamin use and ALL or AML (adjusted odds ratios (ORs)=0.94 [95% confidence interval 0.52, 1.70] and 1.90 [0.73, 4.91], respectively. There was a suggestion of an increased risk for AML associated with regular multivitamin use during the first year of life or for an extended duration (ORs = 2.38 [0.94, 5.76] and 2.59 [1.02, 6.59], respectively). Despite being the largest study of DS-leukemia, our sample size was small, resulting in imprecise effect estimates. Future research should include larger sample sizes as well as a full assessment of diet including vitamin supplementation to adequately examine the relation between nutritional status and childhood leukemia