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"Barnard, H"
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Topoclimate effects on growing season length and montane conifer growth in complex terrain
Spatial variability in the topoclimate-driven linkage between forest phenology and tree growth in complex terrain is poorly understood, limiting our understanding of how ecosystems function as a whole. To characterize the influence of topoclimate on phenology and growth, we determined the start, end, and length of the growing season (GSstart, GSend, and GSL, respectively) using the correlation between transpiration and evaporative demand, measured with sapflow. We then compared these metrics with stem relative basal area increment (relative BAI) at seven sites among elevation and aspects in a Colorado montane forest. As elevation increased, we found shorter GSL (−50 d km−1) due to later GSstart (40 d km−1) and earlier GSend (−10 d km−1). North-facing sites had a 21 d shorter GSL than south-facing sites at similar elevations (i.e. equal to 200 m elevation difference on a given aspect). Growing season length was positively correlated with relative BAI, explaining 83% of the variance. This study shows that topography exerts strong environmental controls on GSL and thus forest growth. Given the climate-related dependencies of these controls, the results presented here have important implications for ecosystem responses to changes in climate and highlight the need for improved phenology representation in complex terrain.
Journal Article
Canola water use indicators as affected by sustained deficit irrigation and plant density in central Free State, South Africa
In South Africa canola (Brassica napus L.) is cultivated in rotation with wheat under winter rainfall in the Western Cape Province, primarily for seed to make oil. Expansion of the crop to the other 8 provinces is proposed to reduce shortages of locally produced plant oils. At the same time, canola can serve as a rotational crop for wheat in these summer rainfall provinces. In central Free State, information on evapotranspiration and various water use indicators for canola as influenced by sustained deficit irrigation and plant density is lacking. An experiment with a line source sprinkler irrigation system was therefore conducted, comprising of full irrigation as a control with 4 sustained deficit irrigation levels (mean reduction in irrigation depth per event of 67%, 52%, 34% and 19%) and 5 plant densities (25, 50, 75, 100 and 125 plants*[m.sup.2]). Mean seasonal maximum evapotranspiration amounted to 429 mm across plant densities. Plant density did not significantly influence seasonal evapotranspiration. Reducing the irrigation depth per event by more than 20% decreased seasonal evapotranspiration by a mean 3.5 mm per percentage increase in irrigation depth. A maximum biomass water productivity of 22 kg*[ha.sup.-1]-[mm.sup.-1] was measured with full irrigation and a plant density of 75 plants*[m.sup.-2]. Seed water productivity amounted to a high of 11 kg*[ha.sup.1]*[mm.sup.-1] with full irrigation and a plant density of 25 plants*[m.sup.-1]. A percentage reduction in irrigation depth and increase in plant density above 25 plants*[m.sup.-1] will reduce seed water productivity by 0.071 and 0.033 kg*[ha.sup.-1]-[mm.sup.-1], respectively. Sustained deficit irrigation increased water use efficiency by a mean 0.5% per percentage reduction in irrigation depth per event. KEYWORDS biomass yield crop factor evapotranspiration seed yield semi-arid
Journal Article
Animation
With an introduction by John Lasseter-- and very little else in the way of words-- this second book in The Artist Series lavishly showcases the most brilliant animation created by such luminaries as Ub Iwerks, Norm Ferguson, Ben Sharpsteen, Hamilton Luske, Dick Huemer, Grim Natwick, Art Babbitt, Fred Moore, Bill Tytla, Frank Thomas, Ollie Johnston, Milt Kahl, Marc Davis, John Lounsbery, Ward Kimball, Eric Larson, Les Clark, Wolfgang Reitherman, John Sibley, Bill Justice, Clyde Geronimi, Ted Berman, Glen Keane, Andreas Deja, Eric Goldberg, Mark Henn and Tony Bancroft. The artwork-- much of which has never before been published-- offers the opportunity to marvel at the those magical lines of pencil that brought life to so many unforgettable Disney characters. Animation represents a rare opportunity to enjoy a glimpse into the truly spectacular trove of treasures from the Walt Disney Animation Research Library.
Book
Influence of trenches and soil water detection instruments on EM38-MK2 sensor readings
Electromagnetic induction (EMI) sensors, such as the EM38-MK2, measure soil apparent electrical conductivity (ECa). The ECa values are then calibrated with soil water content, often determined by metalcontaining instruments. Such instruments and soil trenches may interfere with ECa measurements. This study established whether multi-sensor capacitance probes (small copper rings), neutron water meter access tubes (galvanized steel) and soil trenches interfere with ECa measurements by EM38-MK2 sensors. The EM38-MK2 sensor was moved towards and away from the potential interfering obstruction in a horizontal or vertical mode without re-zeroing the device. The soil trenches had no significant influence on the measurement of ECa. On the other hand, both the capacitance probes and the access tubes influenced the EC a measurement of the EM38-MK2 sensor when it was operated closer than 1 m from the two devices. Measurements of ECa were either less stable (only in the vertical mode) or lower. However, the magnitude of reduction in ECa was so small that it would likely not have any practical influence. Nevertheless, in field surveys with the EM38-MK2 sensor, a distance of at least 1 m should be kept from either the capacitance probes or galvanized-steel access tubes to avoid interferences. When encountering such devices during field surveys, it should be safe to continue measurements without additional re-zeroing of the sensor.
Journal Article
Public Utilities and Public Health
Barnard describes the overarching goal of the water industry as people before profit, and his reference to improved social justice by way of legal protection against injuries caused by drinking polluted water still plays out today. In the end, this article is a good reminder that the water industry is about more than “pushing water through pipes,” that we have always struggled against pollution and to protect public health, and that it is our past success in these efforts that breeds in consumers “a faith that is the greatest asset of the water department.”
Journal Article
Validation of Ocean Color Remote Sensing Reflectance Using Autonomous Floats
The use of autonomous proling oats for observational estimates of radiometric quantities in the ocean is explored, and the use of this platform for validation of satellite-based estimates of remote sensing reectance in the ocean is examined. This effort includes comparing quantities estimated from oat and satellite data at nominal wavelengths of 412, 443, 488, and 555 nm, and examining sources and magnitudes of uncertainty in the oat estimates. This study had 65 occurrences of coincident high-quality observations from oats and MODIS Aqua and 15 occurrences of coincident high-quality observations oats and Visible Infrared Imaging Radi-ometer Suite (VIIRS). The oat estimates of remote sensing reectance are similar to the satellite estimates, with disagreement of a few percent in most wavelengths. The variability of the oatsatellite comparisons is similar to the variability of in situsatellite comparisons using a validation dataset from the Marine Optical Buoy (MOBY). This, combined with the agreement of oat-based and satellite-based quantities, suggests that oats are likely a good platform for validation of satellite-based estimates of remote sensing reectance.
Journal Article
The Schistosoma mansoni Cytochrome P450 (CYP3050A1) Is Essential for Worm Survival and Egg Development
Schistosomiasis affects millions of people in developing countries and is responsible for more than 200,000 deaths annually. Because of toxicity and limited spectrum of activity of alternatives, there is effectively only one drug, praziquantel, available for its treatment. Recent data suggest that drug resistance could soon be a problem. There is therefore the need to identify new drug targets and develop drugs for the treatment of schistosomiasis. Analysis of the Schistosoma mansoni genome sequence for proteins involved in detoxification processes found that it encodes a single cytochrome P450 (CYP450) gene. Here we report that the 1452 bp open reading frame has a characteristic heme-binding region in its catalytic domain with a conserved heme ligating cysteine, a hydrophobic leader sequence present as the membrane interacting region, and overall structural conservation. The highest sequence identity to human CYP450s is 22%. Double stranded RNA (dsRNA) silencing of S. mansoni (Sm)CYP450 in schistosomula results in worm death. Treating larval or adult worms with antifungal azole CYP450 inhibitors results in worm death at low micromolar concentrations. In addition, combinations of SmCYP450-specific dsRNA and miconazole show additive schistosomicidal effects supporting the hypothesis that SmCYP450 is the target of miconazole. Treatment of developing S. mansoni eggs with miconazole results in a dose dependent arrest in embryonic development. Our results indicate that SmCYP450 is essential for worm survival and egg development and validates it as a novel drug target. Preliminary structure-activity relationship suggests that the 1-(2,4-dichlorophenyl)-2-(1H-imidazol-1-yl)ethan-1-ol moiety of miconazole is necessary for activity and that miconazole activity and selectivity could be improved by rational drug design.
Journal Article
The Development and Validation of a Profiling Glider Deep ISFET-Based pH Sensor for High Resolution Observations of Coastal and Ocean Acidification
Coastal and ocean acidification can alter ocean biogeochemistry, with ecological consequences that may result in economic and cultural losses. Yet few time series and high resolution spatial and temporal measurements exist to track the existence and movement of water low in pH and/or carbonate saturation. Past acidification monitoring efforts have either low spatial resolution (mooring) or high cost and low temporal and spatial resolution (research cruises). We developed the first integrated glider platform and sensor system for sampling pH throughout the water column of the coastal ocean. A deep ISFET (Ion Sensitive Field Effect Transistor)-based pH sensor system was modified and integrated into a Slocum glider, tank tested in natural seawater to determine sensor conditioning time under different scenarios, and validated in situ during deployments in the U.S. Northeast Shelf (NES). Comparative results between glider pH and pH measured spectrophotometrically from discrete seawater samples indicate that the glider pH sensor is capable of accuracy of 0.011 pH units or better for several weeks throughout the water column in the coastal ocean, with a precision of 0.005 pH units or better. Furthermore, simultaneous measurements from multiple sensors on the same glider enabled salinity-based estimates of total alkalinity (AT) and aragonite saturation state (ΩArag). During the Spring 2018 Mid-Atlantic deployment, glider pH and derived AT/ ΩArag data along the cross-shelf transect revealed higher pH and ΩArag associated with the depth of chlorophyll and oxygen maxima and a warmer, saltier water mass. Lowest pH and ΩArag occurred in bottom waters of the middle shelf and slope, and nearshore following a period of heavy precipitation. Biofouling was revealed to be the primary limitation of this sensor during a summer deployment, whereby offsets in pH and AT increased dramatically. Advances in anti-fouling coatings and the ability to routinely clean and swap out sensors can address this challenge. The data presented here demonstrate the ability for gliders to routinely provide high resolution water column data on regional scales that can be applied to acidification monitoring efforts in other coastal regions.
Journal Article