Assessing the effects of manure application rate and timing on nitrous oxide emissions from managed grasslands under contrasting climate in Canada

It is uncertain whether process-based models are currently capable of simulating the complex soil, plant, climate, manure management interactions that influence soil nitrous oxide (N₂O) emissions from perennial cropping systems. The objectives of this study were (1) to calibrate and evaluate the DeNitrification DeComposition (DNDC) model using multi-year datasets of measured nitrous oxide (N₂O) fluxes, soil moisture, soil inorganic nitrogen, biomass and soil temperature from managed grasslands applied with manure slurry in contrasting climates of Canada, and (2) to simulate the impact of different manure management practices on N₂O emissions including slurry application i) rates (for both single vs. split); and ii) timing (e.g., early vs. late spring). DNDC showed "fair" to "excellent" performance in simulating biomass (4.7% ≤ normalized root mean square error (NRMSE) ≤ 29.8%; -9.5% ≤ normalized average relative error (NARE) ≤ 16.1%) and "good" performance in simulating soil temperature (13.2% ≤ NRMSE ≤ 18.1%; -0.7% ≤ NARE ≤ 10.8%) across all treatments and sites. However, the model only showed "acceptable" performances in estimating soil water and inorganic N contents which was partially attributed to the limitation of a cascade water sub-model and inaccuracies in simulating root development/uptake. Although, the DNDC model only demonstrated "fair" performance in simulating daily N₂O fluxes, it generally captured the impact of the timing and rate of slurry application and soil texture (loam vs. sandy loam) on total N₂O emissions. The DNDC model simulated N₂O emissions from spring better than split manure application (fall and spring) at the Manitoba site partially due to the overestimation of available substrates for microbial denitrification from fall application during the wet spring periods. Although DNDC performed adequately for simulating most of the manure management impacts considered in this study we recommend improvements in the simulation of soil freeze-thaw cycles, manure decomposition dynamics, soil water storage, rainfall canopy interception, and microbial denitrification and nitrification activities in grasslands.

Thyroid profile during the alternative Sunitinib dosing 2/1 schedule in metastatic renal cell carcinoma

PURPOSE

Hypothyroidism is a common side effect of Sunitinib (SUN) treatment in metastatic renal cell carcinoma (mRCC) patients. We aimed to evaluate thyroid profile during the alternative 2/1 SUN treatment schedule and to assess the predictive value of hypothyroidism in terms of survival.

METHODS

We performed a prospective observational study enrolling 42 consecutive mRCC patients starting first-line alternative SUN dosing 2/1 schedule. Thyroid function was assessed at baseline and during the first three SUN cycles (1 cycle = 6 weeks = 2 ON/1 OFF + 2 ON/1 OFF), and then after 6 and 12 months. Thyroid ultrasound was performed at baseline and after 3, 6, and 12 months.

RESULTS

Subclinical hypothyroidism developed in 24% of patients during the first cycle; in other 24% in the second cycle and in 14% in the third cycle. The highest TSH values were reached during the second cycle, ON phase (6.58 ± 5.74 μI U/l). We observed a reduction in thyroid size, in echogenicity and in parenchymal perfusion in all patients. Progression-free survival (PFS) tended to be longer in patients with TSH ≥ 5 μI U/ml during the second cycle (p = 0.069). TSH level was an independent risk factor for PFS in men (p = 0.009) but not in women (p = 0.285).

CONCLUSIONS

This is the first study investigating functional and morphological effects on thyroid during the alternative 2/1 SUN schedule in mRCC patients. We detected an early onset of subclinical hypothyroidism, observing the association between TSH ≥ 5 μI U/ml and: (i) longer PFS in men; (ii) progressive decrease of thyroid size in absence of significant changes in autoimmune thyroid profile.

Home infusion program with enzyme replacement therapy for Fabry disease: The experience of a large Italian collaborative group

Fabry disease (FD) [OMIM 301500] is an X-linked lysosomal storage disorder caused by a deficiency of the lysosomal enzyme alpha-galactosidase A, resulting in progressive multisystem accumulation of globotriaosylceramide (Gb3). Although the introduction of Enzyme Replacement Therapy (ERT) resulted in a variety of clinical benefits, life-long intravenous (IV) treatment with ERT with an every other week schedule, may interfere with daily life activities and impact on QoL. We report here a multicentric, observational, longitudinal data analysis on a large cohort of 85 Italian FD patients (45 males, 40 females) from 11 out of 20 Italian regions, who received a cumulative number of 4269 home infusions of agalsidase alfa. For the whole cohort, the average duration of home therapy was 1 year and 11 months (range 3 months–4 years and 6 months), and during this period, compliance to treatment (number of infusions performed vs scheduled) reached 100%. The EQ-5 VAS scale was administered to patients to evaluate the self-reported QoL, 58% of patients showing an increase of EQ-5 VAS score at follow up compared to baseline (home treatment start) or remaining stable. A mild increase of average disease severity, measured through Mainz Severity Score Index (MSSI), was found during hospital treatment (p < 0,007), while it remained stable between the first home therapy infusion and last follow up. Interestingly, 4 out of 7 (57%) patients, showing an improvement in FD-related clinical status after starting home therapy, had previously a sub-optimal compliance to treatment during the period of hospital treatment management. Only 4 adverse non serious reactions (0,093%) were reported totally in 2 patients during home treatment.

We conclude that home infusions in eligible patients with FD are safe, contribute to improve treatment compliance and therapeutic clinical outcomes, and may have a positive impact on self-perceived QoL.

Phosphorus Mobilization from Manure-Amended and Unamended Alkaline Soils to Overlying Water during Simulated Flooding

Anaerobic soil conditions resulting from flooding often enhance release of phosphorus (P) to overlying water. Enhanced P release is well documented for flooded acidic soils; however, there is little information for flooded alkaline soils. We examined the effect of flooding and anaerobic conditions on P mobilization using 12 alkaline soils from Manitoba that were either unamended or amended with solid cattle manure. Pore water and floodwater were analyzed over 8 wk of simulated flooding for dissolved reactive P (DRP), Ca, Mg, Fe, and Mn. As expected, manured soils had significantly greater pore and floodwater DRP concentrations than unamended. Flooding increased pore water DRP concentrations significantly in all soils and treatments except one manured clay in which concentrations increased initially and then decreased. Floodwater DRP concentrations increased significantly by two- to 15-fold in 10 soils regardless of amendment treatment but remained relatively stable in the two soils with greatest clay content. Phosphorus release at the onset of flooding was associated with the release of Ca, Mg, and Mn, suggesting that P release may be controlled by the dissolution of Mg and Ca phosphates and reductive dissolution of Mn phosphates. Thereafter, P release was associated with release of Fe, suggesting the reductive dissolution of Fe phosphates. Differences in pore water and floodwater DRP concentrations among soils and amendment treatments and the high variability in P mobilization from pore water to floodwater among soils indicate the need to further investigate chemical reactions responsible for P release and mobility under anaerobic conditions.

Pasture productivity, cattle productivity and metabolic status following fertilization of a grassland with liquid hog manure: A three-year study

Forage yield and quality, cattle and pasture productivity, and enteric methane (CH4) emissions were determined from grass pastures receiving liquid hog manure. Three treatments were evaluated: grass pastures receiving no manure (Control), grass pastures receiving liquid hog manure applied as a single application of 142 ± 20 kg available N ha-1 in the spring (Single) or a split application of 70 ± 6 kg available N ha-1 in both the spring and autumn (Split). Each treatment was represented by two paddocks. The study was carried out over three grazing seasons, from 2004 to 2006, with each grazing season divided into three, 28-d periods. Growing steers (338 ± 32 kg) were introduced into pastures in early summer (May-June) of each year. Standing biomass, measured using quadrats, averaged 1.2, 2.6, and 2.0 ± 0.44 t dry matter (DM) ha-1 for Control, Split and Single pastures, respectively, and was not influenced (P = 0.13) by liquid hog manure application. Liquid hog manure application caused a shift in pasture grasses resulting in a predominance of quackgrass [Elytrigia repens (L.) Nevski]. Nutrient profiles of forage samples collected by hand plucking showed no treatment response for forage gross energy (GE; P = 0.18) and neutral detergent fibre (NDF; P = 0.19), but forage crude protein (CP) (P = 0.027) as well as ash (P = 0.002), K (P = 0.001), P (P = 0.001), and Mg (P = 0.001) concentrations increased with manure application. Liquid hog manure application did not influence dry matter intake (DMI) (P = 0.56), GE intake (P = 0.58), and NDF intake (P = 0.79) of grass forages. Higher CP intake of steers on Split and Single pastures resulted in higher (P = 0.001) serum urea N (5.7 and 5.9 ± 0.42 mmol L-1, respectively) compared with steers grazing Control pastures, 2.5 ± 0.42 mmol L-1. Enteric CH4 emissions (L d-1) tended to be lower (P = 0.09) in cattle grazing the Split pasture treatment. Though application of liquid hog manure did not improve individual animal gains, pasture carrying capacity increased (P = 0.001) from 89 to 324 grazing days ha-1 and liveweight gain increased (P = 0.001) from 100 to 329 kg ha-1 in Control and manured pastures, respectively. Application of liquid hog manure to grasslands generated significant benefits through improved forage quality and pasture productivity measured as carrying capacity and liveweight gain. Split liquid hog manure application may have a further benefit in terms of improved carrying capacity and lower enteric CH4 emissions. Key words: Liquid hog manure, enteric methane, beef cattle, carrying capacity, serum urea nitrogen

Mortality of Pratylenchus penetrans by Volatile Fatty Acids from Liquid Hog Manure

As part of our research program assessing the use of liquid hog manure (LHM) to control root-lesion nematodes, Pratylenchus penetrans, a series of acute toxicity tests was conducted to: (i) examine if non-ionized forms of volatile fatty acids (VFA) are responsible for the mortality of P. penetrans exposed to LHM under acidic conditions, (ii) determine if Caenorhabditis elegans can be a surrogate for P. penetrans in screening tests by comparing their sensitivities to VFA, (iii) characterize the nematicidal effect of individual VFA in LHM to P. penetrans, and (iv) determine whether individual VFA in LHM interact in their toxicity to P. penetrans. LHM was significantly (P Collapse

Key Words

• bioassay
• caenorhabditis elegans
• lhm
• liquid hog manure
• lsm
• liquid swine manure
• management
• nematode
• potato
• pratylenchus penetrans
• root-lesion nematode
• vfa
• volatile fatty acids

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Affiliation(s)

A Mahran Departments of Soil Science, Plant Science, and Environment and Geography, University of Manitoba, Winnipeg, MB Canada R3T 2N2. Canada Research Chair in Applied Soil Ecology, University of Manitoba, Winnipeg, MB Canada R3T 2N2
M Tenuta
M L Hanson
F Daayf

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Chemical-Mediated Toxicity of N-Viro Soil to Heterodera glycines and Meloidogyne incognita

N-Viro Soil (NVS) is an alkaline-stabilized municipal biosolid that has been shown to lower population densities and reduce egg hatch of Heterodera glycines and other plant-parasitic nematodes; but the mechanism(s) of nematode suppression of this soil amendment are unknown. This study sought to identify NVS-mediated changes in soil chemical properties and their impact upon H. glycines and Meloidogyne incognita mortality. N-Viro Soil was applied to sand in laboratory assays at 0.5%, 1.0%, 2.0%, and 3.0% dry w/w with a nonamended treatment as a control. Nematode mortality and changes in sand-assay chemical properties were determined 24 hours after incubation. Calculated lethal concentration (LC(90)) values were 1.4% w/w NVS for second-stage juveniles of both nematode species and 2.6 and >3.0% w/w NVS for eggs of M. incognita and H. glycines, respectively. Increasing rates of NVS were strongly correlated (r(2) = 0.84) with higher sand solution pH levels. Sand solution pH levels and, to a lesser extent, the production of ammonia appeared to be the inorganic chemical-mediated factors responsible for killing plant-parasitic nematodes following amendment with NVS.

Growth hormone secretion after baclofen administration in different phases of the menstrual cycle in healthy women

AIM

The aim of this study was to investigate the effect of baclofen administration on growth hormone (GH) secretion during different phases of the menstrual cycle.

METHODS

Twelve healthy women (33.6 +/- (SD) 2.8 years; range 23-40 years) with regular menstrual cycles were enrolled. The phases of the menstrual cycle were determined using transvaginal ultrasonography (TV-US) and detecting hormonal serum levels. Plasma GH levels were evaluated during the early follicular, periovulatory and luteal phases of the cycle before and after the baclofen challenge test.

RESULTS

After acute baclofen administration, GH levels increased significantly (p < 0.001) compared to basal values during the periovulatory and luteal phases, while no significant variation was detected during the early follicular phase. In addition, plasma GH levels resulted significantly (p < 0.001) higher during the luteal phase than during the periovulatory phase.

CONCLUSION

Acute baclofen administration induces a significant increase in plasma GH levels in healthy females during the periovulatory and luteal phases, but not during the early follicular phase. These data suggest a modulator role of plasma sex steroids levels on GH release induced by baclofen.