Retention time of chlorophacinone in black‐tailed prairie dogs informs secondary hazards from a prairie dog rodenticide bait          下载免费PDF全文

Gary W Witmer  Nathan P Snow  Rachael S Moulton 《Pest management science》2016,72(4):725-730

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Linking Northeast Pacific recruitment synchrony to environmental variability     

Megan M. Stachura  Timothy E. Essington  Nathan J. Mantua  Anne B. Hollowed  Melissa A. Haltuch  Paul D. Spencer  Trevor A. Branch  Miriam J. Doyle 《Fisheries Oceanography》2014,23(5):389-408

We investigated the hypothesis that synchronous recruitment is due to a shared susceptibility to environmental processes using stock–recruitment residuals for 52 marine fish stocks within three Northeast Pacific large marine ecosystems: the Eastern Bering Sea and Aleutian Islands, Gulf of Alaska, and California Current. There was moderate coherence in exceptionally strong and weak year‐classes and correlations across stocks. Based on evidence of synchrony from these analyses, we used Bayesian hierarchical models to relate recruitment to environmental covariates for groups of stocks that may be similarly influenced by environmental processes based on their life histories. There were consistent relationships among stocks to the covariates, especially within the Gulf of Alaska and California Current. The best Gulf of Alaska model included Northeast Pacific sea surface height as a predictor of recruitment, and was particularly strong for stocks dependent on cross‐shelf transport during the larval phase for recruitment. In the California Current the best‐fit model included San Francisco coastal sea level height as a predictor, with higher recruitment for many stocks corresponding to anomalously high sea level the year before spawning and low sea level the year of spawning. The best Eastern Bering Sea and Aleutian Islands model included several environmental variables as covariates and there was some consistent response across stocks to these variables. Future research may be able to utilize these across‐stock environmental influences, in conjunction with an understanding of ecological processes important across early life history stages, to improve identification of environmental drivers of recruitment.  相似文献   

Extracted sweet corn tassels as a renewable alternative to peat in greenhouse substrates     

Steven F. Vaughn  Nathan A. DeppeDebra E. Palmquist  Mark A. Berhow 《Industrial Crops and Products》2011,33(2):514-517

Soilless substrates are primarily used in the production of containerized greenhouse and nursery crops. Sphagnum peat moss is a primary constituent of these substrates and its harvest from endangered ecosystems has become a worldwide concern. Ethanol-extracted, coarse-ground corn (Zea mays L. ‘Silver Queen’) tassels were used as a peat replacement for potting substrates. Replacing peat moss with increasing levels of ground tassel (up to 50%, v/v) elevated pH and electrical conductance, while having variable effects on substrate physical properties (bulk density, percent solids, air porosity, container capacity, and total porosity). Two identical greenhouse experiments separated by time were conducted using tomato (Solanum lycopersicum L. ‘Red Robin’) plants grown in 6.0-L pots. In the first experiment, all substrates were similar for total tomato yield per plant and number of fruit per plant, with only the 50% tassel substrate having significantly lower values. There were no differences for plant height or average fruit weight among substrates. No differences were found for any of these variables in the second experiment. This research indicates that extracted ground tassels may be utilized as a suitable replacement for peat in greenhouse substrates for tomatoes.  相似文献   

Metal accumulation in House Sparrow (Passer domesticus) from Thohoyandou,Limpopo province,South Africa     

Nathan J Baker  Simone Dahms  Ruan Gerber  John Maina  Richard Greenfield 《African Zoology》2017,52(1):43-53

Studies on metal pollution (cadmium, cobalt, chromium, copper, manganese and nickel) in South African terrestrial environments are severely lacking. Due to being relatively unaffected by industrialisation, the Thohoyandou region may provide data on natural levels of metals for use as baseline data. The House Sparrow (Passer domesticus) was chosen as a bio-indicator of metal pollution due to its abundance, non-migratory lifestyle and close association with humans. The aims were to determine the viability of using feathers as a non-lethal bio-indicator tissue compared with muscle. Plume feathers, flight feathers and muscle tissue were analysed using ICP-OES techniques. Analyses of tissue metal concentrations identified the following trend: plume feather > flight feather > muscle tissue. Within the Thohoyandou region, Magondi, which was affected by anthropogenic activities at the time of sampling, had significantly higher concentrations (p ≤ 0.05) for each of the metals, indicating potential metal contamination from various sources. Alternatively, Makonde had the lowest metal concentrations and may be an important reference site for future comparative studies. The results showed that the House Sparrow can be used as a bio-indicator organism in South African terrestrial environments. The plume feathers indicate that they are a good non-lethal tissue for determining metal pollution levels on a temporal scale, indicating recent metal exposure.  相似文献   

Response of Winter Manure Application on Surface Runoff Water Quantity and Quality from Small Watersheds in South Dakota     

Shikha Singh  Nathan Brandenburg  Laurent Ahiablame  Arturo Gonzalez  Jeppe Kjaersgaard  Todd P. Trooien  Sandeep Kumar 《Water, air, and soil pollution》2017,228(10):389

Manure application on frozen soil, which is a common practice in the upper Midwest of USA, results in degraded soil and water quality. During snowmelt or precipitation events, water runoff carries nutrients into nearby streams and impairs the water quality. There is a need, therefore, to identify improved management of manure application in the soils. This study was conducted to assess water quality impacts associated following manure application during winter months when soil is completely covered with snow. The study site included three watersheds, named south (SW), east (CW), and north (NW) managed with a corn (Zea mays L.)-soybean (Glycine max L.) rotation located in South Dakota. The SW and NW were used as treatment, and CW as the control watershed. The treatments included manure application on the upper half of the SW and lower half of the NW, and CW received no manure application. This study showed that manure improved soil properties including infiltration rate and organic matter. Nitrogen and phosphorus losses in the surface runoff were higher from NW compared to that of SW. The CW had similar nutrient losses compared to the NW with slight differences. It can be concluded that maintaining a setback distance can help in improving the environmental quality as well as managing the agricultural wastes during the winter months.  相似文献   

What's Your Diagnosis?     

Nathan Phillip Charlton  Mairin Smith  Christopher Peter Holstege 《The Forestry Chronicle》2010,21(2):164-165

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Potato production in Florida as influenced by soil acidity and nitrogen sources     

G. M. Volk  Nathan Gammon 《American Journal of Potato Research》1954,31(3):83-92

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Paramedian incisional complications after prophylactic laparoscopy-assisted gastropexy in 411 dogs     

Jessica K. Baron DVM  DACVS-SA  Sue A. Casale DVM  DACVS  Eric Monnet DVM  PhD  FAHA  DACVS  DECVS  Philipp D. Mayhew BVM&S  DACVS  Jeffrey J. Runge DVM  DACVS  Christelle M. Follette DVM  Kevin Phipps DVM  Margaret E. Powell DVM  Alicja I. Reczynska DVM  Nathan T. Squire VMD  Bruce A. Barton PhD  John Berg DVM  DACVS 《Veterinary surgery : VS》2020,49(Z1):O148-O155

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Removal of Metaldehyde Through Photocatalytic Reactions Using Nano-Sized Zinc Oxide Composites     

Doria  F. C.  Borges  A. C.  Kim  J. K.  Nathan  A.  Joo  J. C.  Campos  L. C. 《Water, air, and soil pollution》2013,224(2):1-9

In this study, we have reported the synthesis of new amino-substituted p-tert-butylcalix[4]arene (3) and its application for the removal of two carcinogenic azo dyes, i.e., Chicago Sky Blue (CSB) and Tropaeolin 000 (TP) from aqueous environment. The newly synthesized calix–ligand 3 is characterized by FT-IR and ¹H NMR spectroscopy as well as elemental analysis. The extraction efficiency of newly calix–ligand 3 for CSB and TP dyes from aqueous media was evaluated through liquid–liquid extraction experiments. The newly synthesized calix–ligand 3 showed outstanding extraction percentage and maximum percent extraction, i.e., 97 and 96 % of CSB and TP dyes was achieved at pH 9, respectively. During the extraction process, effect of various parameters was monitored and found that extraction is highly dependent on pH and salinity. Moreover, cyclic structure, cavity size, functional groups of the calixarene derivative, hydrophobicity, and the ionic property of guest molecules also affect the extraction efficiency. The comparative data prop up calix–ligand 3 as an effective extractant for both CSB and TP dyes.  相似文献   

Larvicidal and growth inhibition of the malaria vector Anopheles stephensi by triterpenes from Dysoxylum malabaricum and Dysoxylum beddomei     

Nathan SS  Hisham A  Jayakumar G 《Fitoterapia》2008,79(2):106-111

Secondary metabolites from Dysoxylum malabaricum and Dysoxylum beddomei were tested against mature and immature stage of the mosquito vector Anopheles stephensi under laboratory conditions. The triterpenes 3beta,24,25-trihydroxycycloartane and beddomeilactone from D. malabaricum and D. beddomei showed strong larvicidal, pupicidal and adulticidal activity. They also affected the reproductive potential of adults by acting as oviposition deterrents. The highest concentration tested (10 ppm) of both compounds evoked more than 90% mortality and oviposition deterrence.  相似文献