Runoff Quality Responses to Cattle-Gazing Strategy and Grassed Buffer Zone Length

Grazed pastures represent a source of potential nonpoint pollution. In comparison to other nonpoint sources (e.g., row-cropped lands), relatively little information exists regarding possible magnitudes of pollution from grazed pasture; how that pollution is affected by weather, soil, management and other variables; and how the pollution can be minimized. The objective of this study was to assess how the quality of runoff from simulated grazed pasture is influenced by grazing duration (4-12 weeks), grazing strategy (no grazing, conventional grazing and rotational grazing), and by the use of grassed buffer strips (ranging in length from O to 18.3 m) installed down-slope of simulated pasture. The study was conducted at the University of Kentucky Maine Chance Agricultural Experiment Station north of Lexington. Plots (2.4 m wide by 6.1 to 30.5 m long) were constructed and established in Kentucky 31 tall fescue (Festuca arundinacea Schreb.) to represent pasture. Grazing was simulated by application of beef cattle manure to the plots. Runoff was generated by applying simulated rainfall. Runoff samples were collected and analyzed according to standard methods for nitrogen (N), phosphorus (P), total suspended solids (TSS), and fecal coliform (FC). Runoff concentrations and transport of N and P from the plots used to simulate conventional and rotational grazing were low and, in many cases, not different from those measured for ungrazed plots. Runoff FC concentrations were greater for the simulated grazed plots than for the control plots, but there was no difference in concentrations between the simulated conventional and rotational grazing treatments. The buffer strips were very effective in removing TKN, P04-P, TSS and FC in incoming runoff from manured plots. Concentrations of all these parameters were indistinguishable from background levels after crossing a buffer length of 6.1 m. This finding is attributed largely to very high infiltration in the plots used to assess the buffer strips

Physiological Assessment and Behavioral Interaction of Wild and Hatchery Juvenile Salmonids : The Relationship of Fish Size and Growth to Smoltification in Spring Chinook Salmon.

Experiments were performed to determine the relative influence of size and growth rate on downstream migratory disposition and physiology in yearling spring chinook salmon (Oncorhynchus tshawtscha) smolts. A group of juvenile chinook salmon was size graded into small and large categories with half the fish in each group reared at an elevated temperature, resulting in four distinct treatment groups: Large Warm (LW), Large Cool (LC), Small Warm (SW), and Small Cool (SC). Fish from warm-water treatment groups displayed significantly higher growth rates than cool-water groups. Fish were tagged and released into a natural creek where downstream movement was monitored. For each of the two releases, fish that migrated past a weir within the first 5 days postrelease had significantly higher spring growth rates than fish that did not migrate within that period. Significant differences in length for the same fish were only found in the second release. Also for the second release, fish from the warm water treatment groups were recovered in higher proportions than fish from cool water groups. The results indicate that increased growth rate in the spring has a positive relation to downstream migratory disposition. Furthermore, there is a relation between smolt size and migration; however, this relation is weaker than that found between growth rate and migration

Correction to “Evidence for asymmetric nonvolcanic rifting and slow incipient oceanic accretion from seismic reflection data on the Newfoundland margin”

Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 111 (2006): B12403, doi:10.1029/2006JB004769

Microbiota‐Dependent Metabolite Trimethylamine N‐Oxide and Coronary Artery Calcium in the Coronary Artery Risk Development in Young Adults Study (CARDIA)

BACKGROUND: Clinical studies implicate trimethylamine N-oxide (TMAO; a gut microbiota-dependent nutrient metabolite) in cardiovascular disease risk. There is a lack of population-based data on the role of TMAO in advancing early atherosclerotic disease. We tested the prospective associations between TMAO and coronary artery calcium (CAC) and carotid intima-media thickness (cIMT). METHODS AND RESULTS: Data were from the Coronary Artery Risk Development in Young Adults Study (CARDIA), a biracial cohort of US adults recruited in 1985-1986 (n=5115). We randomly sampled 817 participants (aged 33-55 years) who attended examinations in 2000-2001, 2005-2006, and 2010-2011, at which CAC was measured by computed tomography and cIMT (2005-2006) by ultrasound. TMAO was quantified using liquid chromotography mass spectrometry on plasma collected in 2000-2001. Outcomes were incident CAC, defined as Agatston units=0 in 2000-2001 and >0 over 10-year follow-up, CAC progression (any increase over 10-year follow-up), and continuous cIMT. Over the study period, 25% (n=184) of those free of CAC in 2000-2001 (n=746) developed detectable CAC. In 2000-2001, median (interquartile range) TMAO was 2.6 (1.8-4.2) μmol/L. In multivariable-adjusted models, TMAO was not associated with 10-year CAC incidence (rate ratio=1.03; 95% CI: 0.71-1.52) or CAC progression (0.97; 0.68-1.38) in Poisson regression, or cIMT (beta coefficient: -0.009; -0.03 to 0.01) in linear regression, comparing the fourth to the first quartiles of TMAO. CONCLUSIONS: In this population-based study, TMAO was not associated with measures of atherosclerosis: CAC incidence, CAC progression, or cIMT. These data indicate that TMAO may not contribute significantly to advancing early atherosclerotic disease risk among healthy early-middle-aged adults

Reviews

Charles Williams: The Third Inkling. Grevel Lindop. Reviewed by Scott McLaren. The Chapel of the Thorn: A Dramatic Poem. Charles Williams. Edited and Introduced by Sørina Higgins. Reviewed by Scott McLaren. Women and C.S. Lewis: What His Life and Literature Reveal For Today’s Culture. Carolyn Curtis and Mary Pomroy Key, eds. Reviewed by Rebekah Choat. Tolkien Among the Moderns. Edited by Ralph C. Wood. Reviewed by Andrew C. Stout. Tolkien. Raymond Edwards. Reviewed by Cait Coker. Children into Swans: Fairy Tales and the Pagan Imagination. Jan Beveridge. Reviewed by Brian Roberts. Trilby/The Crumb Fairy. Charles Nodier. Translated and adapted by Ruth Berman. Reviewed by Kelly Orazi. The Prince of the Aquamarines. Louise Cavalier Levesque. Trans. and with an afterword by Ruth Berman. Reviewed by Kelly Orazi. The Lessons of Nature in Mythology. Rachel S. McCoppin. Reviewed by Kristine Larsen. Hither Shore: Jahrbuch der Deutschen Tolkien Gesellschaft. Special issue: Nature and Landscape in Tolkien. Ed. Thomas Fornet-Ponse et al. Reviewed by Janet Brennan Croft. Seven: An Anglo-American Literary Review. Ed. Marjorie Lamp Mead. Reviewed by Janet Brennan Croft. Tolkien Studies: An Annual Scholarly Review. Ed. Michael D.C. Drout, Verlyn Flieger, and David Bratman. Reviewed by Janet Brennan Croft. The Skill of a Seeker: Rowling, Religion and Gen 9/11. Marilyn R. Pukkila. Reviewed by Emily Moniz Mirova. Light: C.S. Lewis\u27s First and Final Short Story. Charlie W. Starr. Reviewed by Melody Green. The Story of Kullervo. J.R.R. Tolkien. Edited and introduced by Verlyn Flieger. Reviewed by Mike Foster. The Victorian Approach to Modernism in the Fiction of Dorothy L. Sayers. Aoife Leahy. Reviewed by Joe R. Christopher. Reading Joss Whedon. Rhonda V. Wilcox, Tanya R. Cochran, Cynthea Masson, and David Lavery, eds. Reviewed by by Janet Brennan Croft

Two Stellar Components in the Halo of the Milky Way

The halo of the Milky Way provides unique elemental abundance and kinematic information on the first objects to form in the Universe, which can be used to tightly constrain models of galaxy formation and evolution. Although the halo was once considered a single component, evidence for its dichotomy has slowly emerged in recent years from inspection of small samples of halo objects. Here we show that the halo is indeed clearly divisible into two broadly overlapping structural components -- an inner and an outer halo -- that exhibit different spatial density profiles, stellar orbits and stellar metallicities (abundances of elements heavier than helium). The inner halo has a modest net prograde rotation, whereas the outer halo exhibits a net retrograde rotation and a peak metallicity one-third that of the inner halo. These properties indicate that the individual halo components probably formed in fundamentally different ways, through successive dissipational (inner) and dissipationless (outer) mergers and tidal disruption of proto-Galactic clumps.Comment: Two stand-alone files in manuscript, concatenated together. The first is for the main paper, the second for supplementary information. The version is consistent with the version published in Natur

Isometry of medial collateral ligament reconstruction

The purpose of this study was to determine the femoral and tibial fixation sites that would result in the most isometric MCL reconstruction technique. Seven cadaveric knees were used in this study. A navigation system was utilized to determine graft isometry continuously from 0º to 90º. Five points on the medial side of the femur and four on the tibia were tested. A graft positioned in the center of the MCL femoral attachment (FC) and attached in the center of the superficial MCL attachment on the tibia led to the best isometry (2.7 ± 1.1 mm). Movement of the origin superiorly only 4 mm (FS) led to graft excursion of greater than 10 mm (P < 0.01). MCL reconstruction performed with the origin of the MCL within the femoral footprint and the insertion in tibial footprint of the superficial MCL results in the least graft excursion when the knee is cycled between 0º and 90º. Although the MCL often heals without surgical intervention, surgical reconstruction is occasionally in Grade III MCL and combined ligamentous injuries to the knee. This study demonstrates the optimal position of the MCL reconstruction to reproduce the kinematics of the native knee