Coinfection of goose parvovirus (GPV) and duck circovirus (DuCV) occurs commonly in field cases of short beak and dwarfism syndrome (SBDS). However, whether there is synergism between the two viruses ...in replication and pathogenicity remains undetermined.
We established a coinfection model of GPV and DuCV in Cherry Valley ducks. Tissue samples were examined histopathologically. The viral loads in tissues were detected by qPCR, and the distribution of the virus in tissues was detected by immunohistochemistry (IHC).
Coinfection of GPV and DuCV significantly inhibited growth and development of ducks, and caused atrophy and pallor of the immune organs and necrosis of the liver. GPV and DuCV synergistically amplified pathogenicity in coinfected ducks. In the early stage of infection, viral loads of both pathogens in coinfected ducks were significantly lower than those in monoinfected ducks (P < 0.05). With the development of the infection process, GPV and DuCV loads in coinfected ducks were significantly higher than those in monoinfected ducks (P < 0.05). Extended viral distribution in the liver, kidney, duodenum, spleen, and bursa of Fabricius was consistent with the viral load increases in GPV and DuCV coinfected ducks.
These results indicate that GPV and DuCV synergistically potentiate their replication and pathogenicity in coinfected ducks.
Simulation models are widely used to make predictions of crop growth and yield, and soil carbon and nutrient dynamics under various agricultural practices and soil-climatic conditions. An analytical ...model of soil carbon and nutrient dynamics, K-model, was expanded to include a plant sub-model (K-Model-P). This allows for the prediction of short- and long-term crop growth, and soil carbon and nitrogen dynamics. The simulations for a short-term experiment (2 growing seasons) with three nitrogen application rates showed that K-Model-P correctly predicted the growth processes of above-ground plant biomass and grain yields. Predicted and measured daily accumulative biomass were significantly correlated, and differences were statistically insignificant. The simulation results for long-term experiments (70 years) of two crop rotations with three soil amendments showed that predicted and measured annual straw and grain yields were significantly correlated, with the differences of less than 13%. Annual crop straw and grain yields can be estimated by the model without significant errors. The agreement between the predicted daily growth and annual yields and experimental data illustrated that the K-Model-P can be used to produce reliable predictions for daily and annual crop growth.
To assess the efficacy of left bundle branch pacing (LBBP) combined with either sacubitril/valsartan or enalapril in the treatment of chronic heart failure (CHF).
We retrospectively reviewed the ...records of 138 patients with CHF admitted to Dazhou Central Hospital between June 2020 and June 2022 to extract clinical data. We divided the data into two treatment groups for the analysis: 71 patients received LBBP combined with sacubitril/valsartan treatment (sacubitril/valsartan group), and 67 received LBBP combined with enalapril treatment (enalapril group). The levels of cardiac and cardiopulmonary function indicators, levels of myocardial injury markers, and the scores of the Minnesota Living with Heart Failure Questionnaire (MLHFQ) before and after the treatment were compared between the two groups.
After six months of treatment, patients in the sacubitril/valsartan group had lower myocardial injury markers, higher cardiopulmonary function indicators, and lower MLHFQ scores (
<0.05).
In CHF patients, the combination of LBBP with sacubitril/valsartan had a better therapeutic effect compared to LBBP with enalapril, with more effective improvement of the cardiopulmonary function, reduction of myocardial injury, and improvement in quality of life.
Avian leukosis virus subgroup J (ALV‐J) was isolated in meat‐type breeder chickens for the first time in 1988 in the United Kingdom. Due to the application of an eradication program, there were fewer ...reports related to myelocytomatosis or ALV‐J in China after 2013. However, there was another breakout almost simultaneously in six provinces of China in February 2018. On‐site, 15‐ to 20‐week‐old broiler breeder chickens showed depression, paralysis and weight loss. Mortality for certain flocks reached 15%. Sick chickens showed numerous yellow–white neoplasms growing in the sternum, rib and lumbar vertebra and had hepatic and renal metastasis. Histopathological observation showed all neoplasms were myelocytomas, and there were massive myelocyte‐like tumour cells in the liver, kidney and bone marrow. To explore the aetiology of this re‐outbreak of myelocytomatosis in China, we collected tumour‐bearing chickens and isolated six strains of ALV‐J (GM0209‐1 to ‐6). Phylogenetic analysis of gp85 and gp37 showed GM0209 strains were clearly distinct from the prototype strain of ADOL‐7501, HPRS‐103 and NX0101, and there was a mutation, R176G, in the conserved region between hr1 and hr2 regions of gp85, which was not found in other 44 ALV‐J strains. The 3′UTR nucleotide sequences of GM0209 isolates showed there was a signature deletion of 11 nt that was also present in 3′UTR sequences of SCDY1 and NHH, two isolates that have a reported association with haemangioma, indicating this deletion could not determine the tumour type induced by ALV‐J. Although the eradication program of ALV‐J has been successfully applied in China, the outbreak of ALV‐J still occurred, and the virus strain spread quickly. Thus, the biocharacteristics and pathogenesis of mutational ALV‐J should be further studied.
•N fertilization and tillage reversal increased organic C more for soil with low C.•Macroaggregates were the most important fraction for C storage.•N fertilization and tillage reversal enhanced ...macroaggregate formation in topsoils.•Tillage reversal did not offset N fertilization-increased C storage in topsoils.
Nitrogen (N) fertilization and reversing land management from long-term no tillage (NT) to conventional tillage (tillage reversal; TR) may markedly alter soil carbon (C) dynamics. We studied the impact of N fertilization, N applied at 100 kg ha−1 yr−1 (N100) vs. no N application (N0), and tillage reversal (NT vs. TR) on soil aggregation and aggregate-associated C in top- (0–10) and subsoils (50–60 cm) in a Black Chernozem and a Gray Luvisol. Our results showed that soil organic C content was greater in N100 (1.74 g C kg−1) than in N0 (1.29 g C kg−1), and in TR (1.71 g C kg−1) than in NT (1.32 g C kg−1) only in the topsoil of the Gray Luvisol. Nitrogen fertilization and tillage reversal improved topsoil, but not subsoil mean weight diameter or the amount of large macroaggregates (>2000 μm). Topsoil aggregate-associated C was only increased (P < 0.01) with N fertilization. Microaggregate-associated C in the topsoil of the Black Chernozem was 70.6 g C kg−1 sand-free water-stable aggregate in N100, which was 13.8% higher (P < 0.01) than that in N0. However, C associated with all aggregate fractions in the topsoil was increased (P < 0.05) by N fertilization in the Gray Luvisol. In the Black Chernozem, the physical protection for C in the subsoil was decreased by N fertilization and tillage reversal, as indicated by decreased large macroaggregate and microaggregate-associated C (P = 0.04 and < 0.001, respectively). Subsoil aggregate-associated C was not influenced by N fertilization or tillage reversal in the Gray Luvisol. We conclude that N fertilization and/or tillage reversal improved topsoil aggregation; only N fertilization improved the physical protection for C in the topsoil. The adoption of tillage reversal (2 years) did not offset the benefit of N fertilization on soil aggregation and soil C concentration.
Soil dry aggregate size distribution (DASD) and surface roughness are important factors affecting wind erodibility. This study monitored overwinter changes in DASD and surface roughness and ...identified relationships with climatic variables in the chinook‐dominated region of southern Alberta. A different site was monitored in each of three winters (18 Sept. 1992 to 12 May 1993; 26 Oct. 1993 to 29 Apr. 1994; 30 Aug. 1994 to 24 May 1995) on Dark Brown Chernozemic clay loams (fine‐loamy, mixed, Typic Haploborolls). The DASD was expressed as geometric mean diameter (GMD) and wind erodible fraction (EF). The GMD ranged from 1.88 to 0.08 mm in 1992‐1993, from 9.05 to 1.17 mm in 1993‐1994, and from 4.71 to 0.80 mm in 1994‐1995. The EF ranged from 38.9 to 74.0% in 1992‐1993, from 12.6 to 43.7% in 1993‐1994, and 31.3 to 55.0% in 1994‐1995. Surface roughness was measured parallel (Cpar) to tillage direction on two of the sites. Using the chain method, Cpar ranged from 15.1 to 3.7% in 1993‐1994 and from 14.4 to 3.3% in 1994‐1995. Regression analysis with time revealed significant exponential decay for GMD (R2 = 0.57 in 1992‐1993, 0.97 in 1993‐1994, and 0.78 in 1994‐1995) and Cpar (R2 = 0.98 in 1993‐1994, 0.91 in 1994‐1995) and a positive linear fit for EF (R2 = 0.57 in 1992‐1993, 0.91 in 1993‐1994, and 0.62 in 1994‐1995). Three overwinter periods, differentiated by the timing and form of precipitation and designated as “fall rain/snow”, “winter snow”, and “spring snow/rain”, were used to assess the changes in EF using cumulative freeze–thaw cycles, precipitation, and snow cover variables. Results indicated that precipitation, which directly influences soil water content, is necessary for freeze–thaw cycles to be effective in disrupting soil aggregates. Snowmelt and spring rainfall appear capable of reducing wind erodibility on these clay loam soils by promoting soil crusting. Our study showed that overwinter soil properties affecting wind erodibility are highly transitory and that the timing and form of precipitation played a major role in determining wind erosion risk in southern Alberta.
There is a strong demand for accurate estimates of long-term changes in soil organic carbon (SOC) with different agricultural practices under different soil and climate conditions. A process and ...analytic model, K-model, including a non-compartmental algorithm of soil carbon decomposition, was developed to simulate the changes of SOC under different cropping and soil management practices. This study evaluates the performance of K-model by comparing its predictions on SOC with measurements and predictions of CENTURY model, which is widely used for the similar purposes. Both K-model and CENTURY can predict the dynamics of SOC when site-specific soil and climate data are used to initialize simulations. Very similar annual carbon decomposition rates were simulated by the single carbon pool K-model and the 3-carbon pool CENTURY model. However, compared with experimental measurements of SOC, K-model produces relative smaller errors than CENTURY (<0.1 kg C m"2 vs. 0.08-0.48 kg C m"2, and within plus or minus 5% vs. plus or minus 5%-45%), mainly resulting from smaller biases of predicted crop production. When detailed site-specific soil and climate data are not available for initialization and feeding the running of model, K-model can still reasonably predict the dynamics of SOC with its auto-correction function, but CENTURY produces poor results. In comparison with measurements, K-model has improved capacities to predict the effects of chemical fertilizer, manure application, residue management and fallow on SOC dynamics.
Low soil water potential and low or high root temperatures are important stresses affecting carbon allocation in plants. This study examines the effects of these stresses on carbon allocation from ...the perspective of whole plant mass balance. Sixteen-day old spring wheat seedlings were placed in a growth room under precisely controlled root temperatures and soil water potentials. Five soil water potential treatments, from -0.03 MPa to -0.25 MPa, and six root temperature treatments, from 12 to 32°C were used. A mathematical model based on mass balance considerations was used, in combination with experimental measurements of rate of net photosynthesis, leaf area, and shoot/root dry masses to determine photosynthate allocation between shoot and root. Partitioning of photosynthates to roots was the lowest at 22-27°C root temperature regardless soil water potential, and increased at both lower and higher root temperatures. Partitioning of photosynthates to the roots increased with decreasing soil water potential. Under the most favourable conditions, i.e. at -0.03 MPa soil water potential and 27°C root temperature, the largest fraction, 57%, of photosynthates was allocated to the shoots. Under the most stressed conditions, i.e. at -0.25 MPa soil water potential and 32°C root temperature, the largest fraction, more than 80%, of photosynthates was allocated to roots.
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