Investigating the effects of herbaceous root systems on the soil detachment process at the species level.

Plant root growth significantly affect soil detachment process, whereas the mechanism of how roots affect the soil detachment process by overland flow at species level is not fully understood. This study was conducted to investigate the soil detachment rate responds to plant-induce soil properties and root traits at species level. Two typical herbaceous plants, Bothriochloa ischcemum (Linn.). Keng (BI; fibrous root system) and Artemisia vestita Wall. ex Bess (AG; tap root system), from the Loess Plateau were studies for one year under six planted densities of 5 plants m-2, 10 plants m-2, 15 plants m-2, 20 plants m-2, 25 plants m-2, and 30 plants m-2. In total, 24 steel tanks were planted, and two plots were used as bare soil controls. Their soil detachment rates were tested under a constant overland flow (1.5 l s-1) on a 26.2 % slope. The results showed that soil detachment rate under the six planted densities ranged from 0.034 kg m2 s-1 to 0.112 kg m2 s-1 for BI and was ranged from 0.053 kg m2 s-1 to 0.132 kg m2 s-1 for AG, which all greatly reduced soil detachment rate and were 68.17 % to 92.33 % and 69.20 % to 87.27 % less than that of the control. In general, BI was more effective in reducing soil detachment rate than AG, achieving a mean soil detachment rate that was 23.75 % lower. With increasing plant density, soil detachment rate decreased as a power function. The overland flow hydraulic characteristics, soil properties and root traits influenced by plant density were positively or negatively correlated with soil detachment rate. Specifically, soil detachment rate decreased with velocity, bulk density, root length density, and increased with shear stress and Darcy-Weisbach friction factor as power or exponential functions. On this basis, the soil detachment rate (Dr) can be satisfactorily estimated by overland flow velocity (v), soil bulk density (BD) and root length density (RLD) as a power function (Dr = 63.03v0.174 × BD-20.712 × RLD-0.233R2 = 0.65; NSE = 0.60; p < 0.01).

[Influence of landscape pattern on elevation effect of δ18O in surface water in Hani Terrace]. / å“ˆå°¼æ¢¯ç”°æ™¯è§‚æ ¼å±€å¯¹åœ°è¡¨æ°´Î´18O海拔效应的影响.

With the Quanfuzhuang River basin located at Hani Rice Terrace core region as study area, we analyzed the isotopic composition and the effects of 12 surface water sampling sites for the forest landscape type and terrace landscape type from May 2015 to April 2016. The results showed that: 1) For the variation of isotope composition, both the average value and the variation range of δ18O in surface water under forest patches were smaller than that under terrace patches. 2) The overall elevation effect of the hydrogen and oxygen stable isotopes in surface water was obvious, except that in August and March, which could be expressed as the linear regression equation δ18O=-0.012H+13.84 (r=-0.83, n=12). 3) The altitude gradient of δ18O in surface water was -1.2‰·(100 m)-1, which was not the true altitude gradient affected by precipitation but by landscape gradient of δ18O in surface water between forest patches and terrace patches. 4) Under the "Forest-Terrace" landscape pattern, the δ18O differences in surface water between forest patches and terrace patches enhanced the elevation effect. Therefore, when landscape heterogeneity was strong, isotopic effect was strengthened, even with opposite isotope effect.

Comparison of survival, acute toxicities, and dose-volume parameters between intensity-modulated radiotherapy with or without internal target volume delineation method and three-dimensional conformal radiotherapy in cervical cancer patients: A retrospective and propensity score-matched analysis.

BACKGROUND: To evaluate whether the use of the internal target volume (ITV) delineation method improves the performance of intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3DCRT) in terms of survival, acute toxicities, and dose-volume parameters. METHODS: A total number of 477 cervical cancer patients who received concurrent chemoradiotherapy (CCRT) from January 2012 to December 2016 were retrospectively analyzed. They were divided into four groups: the non-ITV (N-ITV) + IMRT, ITV + IMRT, N-ITV + 3DCRT, and ITV + 3DCRT groups, with 76, 41, 327, and 33 patients, respectively. Survival analysis was performed with the Kaplan-Meier and the log-rank tests, and acute toxicity analysis was performed with the chi-squared test and the binary logistic regression test. Using the propensity score matching (PSM) method, 92 patients were matched among the four groups, and their dose-volume parameters were assessed with the Kruskal-Wallis method. RESULTS: The median follow-up time was 49 months (1-119) for overall survival (OS). The 5-year OS rate was 66.4%. The ITV delineation method was an independent prognostic factor for OS (HR [95% CI]: 0.52 [0.27, 0.98], p = 0.044) and progression-free survival (PFS) (HR [95% CI]: 0.59 [0.36, 0.99], p = 0.045). The ITV + IMRT group had the lowest incidence rate (22%) and the N-ITV + IMRT group had the highest incidence rate of grade ≥3 hematological toxicity (HT) (46.1%) among the four groups. The pelvic bone marrow relative V10, V20, and V30 in the N-ITV + IMRT group was higher than those in the ITV + IMRT and N-ITV + 3DCRT groups (p < 0.05). CONCLUSIONS: The use of ITV for IMRT treatment planning was associated with improved overall survival and progression-free survival, with lower HT rate.

Effects of root morphological traits on soil detachment for ten herbaceous species in the Loess Plateau.

Plant root systems can greatly reduce soil loss, and their effects on soil erosion differ across species due to their varied root traits. The purpose of this study was to determine the effects of root morphology traits of herbaceous plants on the soil detachment process. Ten herbaceous plants (dominant species) in the Loess Plateau were selected, and 300 undisturbed soil samples (including living roots from the selected herbages) were scoured with flowing water to measure their soil detachment capacities under six levels of shear stress (4.98 to 16.37 Pa). Then, the root traits of each soil sample were measured, and the rill erodibility and critical shear stress were estimated based on the Water Erosion Prediction Project (WEPP) model. The results showed that root morphology traits varied greatly among the ten selected herbages. Accordingly, resulting variations in soil detachment capacity (0.030 to 3.297 kg m-2 s-1), rill erodibility (0.004 to 0.447 s m-1), and critical shear stress (4.73 to 1.13 Pa) were also observed. Plants with fibrous roots were more effective than those with tap roots in reducing soil detachment. Their mean soil detachment capacity and rill erodibility were 93.2% and 93.4% lower, respectively, and their mean critical shear stress was 1.15 times greater than that of the herbaceous plants with tap root systems. Of all the root traits, root surface area density (RSAD) was the primary root trait affecting the soil detachment, and it estimated the soil detachment capacity well (R2 = 0.91, normalized squared error (NSE) = 0.82). Additionally, an equation with few factors (soil aggregate and RSAD) was suggested to simulate the soil detachment capacity when the plant root parameters and soil properties were limited.

Sarcocystis eothenomysi n. sp. (Apicomplexa: Sarcocystidae) from the large oriental vole Eothenomys miletus (Thomas) (Cricetidae: Microtinae) from Anning, China.

Fifty-six oriental voles, Eothenomys miletus (Thomas), were collected in Anning prefecture of Yunnan Province (China) between March 2012 and December 2013 and examined for the presence of sarcocysts. Sarcosysts of a new species, Sarcocystis eothenomysi n. sp., were found in 14 out of 56 E. miletus (25%); they possessed a striated cyst wall, c.1-2 µm thick. Under transmission electron microscopy the cysts of S. eothenomysi exhibited numerous small, irregular protrusions, which may appear T-shaped in some sections. A phylogenetic analysis based on 18S rRNA gene sequences indicated that S. eothenomysi shares closest affinity with those species of Sarcocystis Lankester, 1982, which use cobra or viperid snakes as definitive hosts. We therefore, hypothesise that a venomous snake may serve as the definitive host for S. eothenomysi. This is the first species of Sarcocystis reported from Eothenomys spp.

[Capillaria hepatica infection in rodents from Anning Prefecture of Yunnan Province and experimental research on host animals].

OBJECTIVE: To investigate the prevalence of Capillaria hepatica in rodents from Anning Prefecture, Yunnan, and observe the susceptibility of C. hepatica to SD rats and KM mice. METHODS: Rodents were trapped in a cultivated filed of Wenquan Town, Annning from March 2010 to March 2012. The species of rodents were identified. The liver was examined and a microscopic examination of tissue was performed by the tissue press technique for the presence of the typical bipolar eggs, adults or larval stages. The prevalence of C. hepatica in rodents was calculated. C. hepatica eggs were collected and cultured in vitro. Each SD rat or KM mouse was orally infected with approximately 1 000 C. hepatica eggs. The control groups with 4 SD rats or 4 KM mice received only normal saline. The experimental animals were euthanized at the 30th and 80th day post infection. Collected liver samples were processed for gross pathological and histological section examination. RESULTS: A total of 115 rodents were captured and examined. C. hepatica eggs were found in 26 (22.6%) rodents. There was no significant difference in the prevalence between female (22.5%, 18/80) and males (22.9%, 26/115) (P > 0.05). The highest prevalence was found in Rattus norvegicus (10/11). Pathologi cal findings showed numerous white-yellow small nodules ranged from 0.1-0.2 cm in diameter. Under light microscope, C. hepatica eggs were ovoid [(50-65) microm x (25-30) microm]. At the 30th day post-infection, there were several adult worms and their eggs delimited by a fibrous capsule, and septal fibrosis formations occurred in the liver of SD rat. No worm or eggs were found in the mouse liver, but the liver presented inflammatory cell infiltration. At the 80th day post-infection, live worms disappeared from the focal lesions in the liver of SD rat, being replaced by partially calcified worm debris. Mature worms and eggs were seen in the KM mouse liver, however, septal fibrosis was absent. CONCLUSION: This study has documented a high prevalence of C. hepaticum in R. norvegicus from Anning Prefecture. SD rat and KM mouse are the susceptible hosts of C. hepatica.

Th1-type epitopes-based cocktail PDDV attenuates hepatic fibrosis in C57BL/6 mice with chronic Schistosoma japonicum infection.

Schistosomiasis is one of the world's major public health problems in terms of morbidity and mortality, which is characterized by a marked egg-induced CD4(+) T-cell programmed granulomatous inflammation and cumulative fibrosis. Here PDDV (peptide-DNA dual vaccine), a widely used non-viral gene delivery system, was applied. The cocktail PDDV, based on four Th1-type epitope peptides identified from Schistosoma japonicum vaccine candidates and CpG ODN1826, could induce dominant Th1-type response in C57BL/6J mice (P<0.05). The histopathological staging and collagen assessment for fibrosis showed that the cocktail PDDV presented an obvious down-regulation effect on hepatic fibrosis caused by chronic S. japonicum infection (P<0.05), and IFN-gamma, IL-4 and IL-13 mRNAs in liver detected by RT-PCR also showed that the cocktail PDDV represented the ability to up-regulate Th1-type responses, which paralleled with a decrease expression of alpha-SMA (P<0.05) and the up-regulated MMP9/TIMP1 balance (P<0.05) when compared to the control groups. Therefore, it is indicated that the cocktail PDDV can significantly attenuate hepatic fibrosis, in parallel with the decreased HSCs activation and the up-regulated MMP9/TIMP1 balance in favor of matrix degradation, which may be partially dependent on the increased Th1 response to restore the Th1/Th2 balance.