1,092 research outputs found
Pressures and Preferences Affecting Willingness to Apply Beef Manure on Crops in the Colorado High Plains
Little is known about producers' willingness to use manure. Past studies have focused on substitutability for fertilizers. We surveyed crop producers in a cattle-dense region of the Colorado Plains about whether and why they apply manure, focusing on how pressures (like owning cattle) or preferences (pro and con) affect their adoption. Using logistic regression, findings show that pressure and preference (PS/PF) significantly affect adoption. A producer with high PS/PF was 10 times more likely to use manure than one with low PS/PF. Policy and decision makers can use such findings to inform education and policy aimed at increasing the land application of manure.cattle, economic benefits, economic costs, management, manure application, Crop Production/Industries,
Ammonia Emission BMP’s for Livestock Feeding: Identifying Benefits and Barriers to Adoption
Farm Management, Health Economics and Policy,
The effect of RO3201195 and a pyrazolyl ketone P38 MAPK inhibitor library on the proliferation of Werner syndrome cells
No description supplie
Occurrence of steroid sex hormones in the Cache la Poudre River: and pathways for the removal in the environment
November 2009.Includes bibliographical references.Some chemicals have the apparent ability to disrupt normal endocrine system functions after exposure to concentrations so small that they are difficult to detect in the environment. In recent years, these so-called "endocrine disruptors" have become the subject of intensive scientific research. In wildlife, most of the evidence for endocrine disruption has come from studies on species living in, or closely associated with, aquatic environments. Reported effects of endocrine disruption include abnormal blood hormone levels, masculinization of females, feminization of males, altered sex ratios, intersexuality, and reduced fertility and fecundity. Among suspected endocrine disruptors, exogenous steroid sex hormones generally have the highest potencies for disrupting normal steroid sex hormone functions. In a national reconnaissance study conducted by the U.S. Geological Survey (USGS) from 1999 to 2000, steroid sex hormones were detected at varying concentrations and frequencies in water samples from 139 stream sites located in 30 states. Other studies have detected steroid sex hormones in surface waters throughout the world, including Colorado. Potential sources of steroid sex hormones in the environment include sewage treatment plants, septic systems, animal feeding operations, rangeland grazing, paper mills, aquaculture, and agricultural operations where manure and biosolids are applied as fertilizers. The objectives of this study were to investigate the presence of steroid sex hormones in northern Colorado's Cache la Poudre River, to determine the potential for steroid sex hormone biodegradation and photodegradation under natural conditions, and to characterize the mobility of selected steroid sex hormones in agricultural fields using a rainfall simulator. The study determined that steroid sex hormones are present in the Cache la Poudre River, at concentrations ranging from 0.6 ng L−1 (epitestosterone) to 22.6 ng L−1 (estrone). The study also determined that testosterone, progesterone, and 17β-estradiol can be degraded by manure-borne bacteria, and that testosterone degradation is faster under aerobic conditions and at higher temperatures (i.e., 37°C vs. 22°C), but little affected by changes in pH (from 6 to 7.5) or glucose amendments. In ultraviolet light λ > 340 nm, the study observed direct photodegradation of testosterone and progesterone, and indirect photodegradation of testosterone and 17β-estradiol in the presence of Elliot soil humic acid. On the other hand, in ultraviolet light λ > 310 nm, direct photodegradation of androstenedione was substantially faster than direct photodegradation of testosterone in ultraviolet light λ > 310 nm, and no indirect photodegradation observed. The study detected and identified three testosterone biodegradation products (dehydrotestosterone, androstenedione, and androstadienedione), and detected several products of testosterone and androstenedione photodegradation which appear to retain their steroid structure, and possibly their endocrine disrupting potential. Finally, the study generally observed that androgen runoff concentrations follow runoff rates and decrease after successive rainfall events, while runoff concentrations of other analytes (e.g., estrone) peak after the maximum runoff rate and first rainfall event. Sample and data analysis from the study are continuing, and comprehensive finding and recommendations are expected after the date of this report.Financed in part by the U.S. Department of the Interior, Geological Survey, through the Colorado Water Institute
Greenhouse gas emissions from solid and liquid organic fertilizers applied to lettuce
Improper application of nitrogen (N) fertilizer and environmental factors can cause the loss of nitrous oxide (N2O) to the environment. Different types of fertilizers with different C/N ratios may have different effects on the environment. The focus of this study was to evaluate the effects of environmental factors and four organic fertilizers (feather meal, blood meal, fish emulsion, and cyano-fertilizer) applied at different rates (0, 28, 56, and 112 kg N ha−1) on N2O emissions and to track CO2 emissions from a lettuce field (Lactuca sativa L.). The study was conducted in 2013 and 2014 and compared preplant-applied solid fertilizers (feather meal and blood meal) and multiple applications of liquid fertilizers (fish emulsion and cyano-fertilizer). Three days a week, N2O and CO2 emissions were measured twice per day in 2013 and once per day in 2014 using a closed-static chamber, and gas samples were analyzed by gas chromatography. Preplant-applied solid fertilizers significantly increased cumulative N2O emissions as compared with control, but multiple applications of liquid fertilizers did not. Emission factors for N2O ranged from 0 to 0.1% for multiple applications of liquid fertilizers and 0.6 to 11% for preplant-applied solid fertilizers, which could be overestimated due to chamber placement over fertilizer bands. In 2014, solid fertilizers with higher C/N ratios (3.3–3.5) resulted in higher CO2 emissions than liquid fertilizers (C/N ratio, 0.9–1.5). Therefore, organic farmers should consider the use of multiple applications of liquid fertilizers as a means to reduce soil greenhouse gas emissions while maintaining high yields
Prevalence and lameness-associated risk factors in Alberta feedlot cattle
Lameness in cattle is a health and welfare concern; however, limited information is available on risk factors and the relationship between lameness and common diseases like bovine respiratory disease (BRD). Therefore, the objectives of this study were to: 1) identify prevalence of lameness in feedlot cattle and related risk factors of cattle diagnosed as lame; and 2) determine associations between BRD occurrence and lameness. Feedlot cattle health records were available from 28 feedlots for 10 yr. The data set consisted of 663,838 cattle records, with 13.9% (92,156) diagnosed with a disease, including 32.3%, 46.0%, and 22.0% with lameness, BRD, and other diagnoses, respectively. Lameness was classified into four categories: foot rot (FR), joint infections (JI), lame with no visible swelling (LNVS), and injuries (INJ), with a prevalence of 74.5%, 16.1%, 6.1%, and 3.1%, respectively. Lameness was compared across cattle types (arrival date and weight) as well as age classification (calf vs. yearling), gender (steer vs. heifer), and season of placement in the feedlot (spring, summer, fall, and winter). Within the disease-diagnosed population, lameness represented 28.5% of treated fall-placed calves, 38.5% of winter-placed calves, and 40.8% of treated yearlings. Foot rot was the most common diagnosis with 74.5% of all lameness diagnoses, with winter- and fall-placed calves more likely to be diagnosed with FR compared to yearlings (OR: 1.19, 95% CI: 1.10–1.30 and OR: 1.46, 95% CI: 1.38–1.55, respectively). Joint infections were the second most common diagnosis (16.1%). Compared to yearlings, fall-placed calves had a higher odds (OR: 3.64, 95% CI: 3.12–4.24) for JI. Injuries and LNVS were the least common but again fall-placed calves had higher odds of this diagnosis compared to yearlings (OR: 2.26, 95% CI: 1.70–2.99 and OR: 9.10, 95% CI: 6.26–13.2, respectively). Gender was significantly different for JI as steers were less likely affected compared to heifers (OR: 0.687, 95% CI: 0.545–0.867), and more likely affected by LNVS (OR: 2.46, 95% CI: 1.57–3.84). Of all lameness-associated deaths, JI accounted for almost 50%. Finally, cattle diagnosed with BRD were subsequently more likely to be diagnosed with INJ, JI, or LNVS (P < 0.001 for all comparisons). In conclusion, animal type and gender were associated with type of lameness diagnoses, allowing feedlots to allocate resources to groups at highest risk and focus on early intervention strategies.info:eu-repo/semantics/publishedVersio
A new era of wide-field submillimetre imaging: on-sky performance of SCUBA-2
SCUBA-2 is the largest submillimetre wide-field bolometric camera ever built.
This 43 square arc-minute field-of-view instrument operates at two wavelengths
(850 and 450 microns) and has been installed on the James Clerk Maxwell
Telescope on Mauna Kea, Hawaii. SCUBA-2 has been successfully commissioned and
operational for general science since October 2011. This paper presents an
overview of the on-sky performance of the instrument during and since
commissioning in mid-2011. The on-sky noise characteristics and NEPs of the 450
and 850 micron arrays, with average yields of approximately 3400 bolometers at
each wavelength, will be shown. The observing modes of the instrument and the
on-sky calibration techniques are described. The culmination of these efforts
has resulted in a scientifically powerful mapping camera with sensitivities
that allow a square degree of sky to be mapped to 10 mJy/beam rms at 850 micron
in 2 hours and 60 mJy/beam rms at 450 micron in 5 hours in the best weather.Comment: 18 pages, 15 figures.SPIE Conference series 8452, Millimetre,
Submillimetre and Far-infrared Detectors and Instrumentation for Astronomy VI
201
Fat and Carbohydrate Interact to Potentiate Food Reward in Healthy Weight but Not in Overweight or Obesity
Prior work suggests that actual, but not estimated, energy density drives the reinforcing value of food and that energy from fat and carbohydrate can interact to potentiate reward. Here we sought to replicate these findings in an American sample and to determine if the effects are influenced by body mass index (BMI). Thirty participants with healthy weight (HW; BMI 21.92 ± 1.77; M ± SD) and 30 participants with overweight/obesity (OW/OB; BMI 29.42 ± 4.44) rated pictures of common American snacks in 120-kcal portions for liking, familiarity, frequency of consumption, expected satiety, healthiness, energy content, energy density, and price. Participants then completed an auction task where they bid for the opportunity to consume each food. Snacks contained either primarily carbohydrate, primarily fat, or roughly equal portions of fat and carbohydrate (combo). Replicating prior work, we found that participants with HW bid the most for combo foods in linear mixed model analyses. This effect was not observed among individuals with OW/OB. Additionally, in contrast with previous reports, our linear regression analyses revealed a negative relationship between the actual energy density of the snacks and bid amount that was mediated by food price. Our findings support altered macronutrient reinforcement in obesity and highlight potential influences of the food environment on the regulation of food reward
Organic fertilizer source and application method impact ammonia volatilization
Ammonia (NH3) volatilization from fertilizer applications reduces efficiency and poses environmental hazards. This study used semi-open static chambers to measure NH3 volatilization from organic fertilizers (feather meal, blood meal, fish emulsion, cyano-fertilizer) to evaluate the impacts of fertilizer source, application method, and rate on NH3 volatilization. In 2014, two application rates (28 and 56 kg N ha−1) were applied to lettuce (Lactuca sativa L.). Solid fertilizers (feather meal, blood meal) were preplant applied in a subsurface band, whereas liquid fertilizers (fish emulsion, cyano-fertilizer) were applied weekly through drip irrigation beginning two weeks after transplanting. In 2015, a single application rate (28 kg N ha−1) was applied to cucumber (Cucumis sativus L.). Solid fertilizers were applied in either subsurface or surface bands. There was a significant difference in NH3 volatilization among fertilizers, but there was little difference between application rates. Liquid fertilizers had lower NH3 emissions than solid fertilizers due to their timing and placement. In 2014, blood meal at 56 kg N ha−1 and feather meal at both rates had the highest NH3 fluxes. In 2015, surface-banded blood and feather meal had the highest NH3 fluxes. Fertilizer decisions for organic systems should consider NH3 emission losses and practices for their reduction
The relative ineffectiveness of bibliographic search engines
Author Posting. © American Institute of Biological Sciences, 2005. This article is posted here by permission of American Institute of Biological Sciences for personal use, not for redistribution. The definitive version was published in Bioscience 55 (2005): 688–692, doi:10.1641/0006-3568(2005)055[0688:TRIOBS]2.0.CO;2.The increasing number of scientific publications has made bibliographic search engines essential tools in all disciplines. These software-based devices, however, are far from perfect. Comparisons of software-based bibliographic search engines with complete lists of three authors' publications showed that reference citations were not generally available before 1970, and that the effectiveness of recovery was improving but was quite variable, yielding on average 36 percent of the publications. There was marked year-to-year inconsistency in the recovery of titles. The inconsistency could not be explained by differences in indexing due to journal reputation: there was no evident relationship between search effectiveness and journal impact factor, but the percentage of recovered citations was higher for indexed journals. Search engines are widely used in bibliographic searches performed for evaluating researchers, awarding promotions, or assessing journal performance. Given the ineffectiveness of search engines, their use in making such important personal and institutional decisions needs careful consideration
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