Exploring the ecological meanings of temperature sensitivity of ecosystem respiration from different methods.

Temperature sensitivity (Q10) of ecosystem respiration (Re) is a critical parameter for predicting global terrestrial carbon dynamics and its response to climate warming. However, the determination of Q10 has been controversial. In this study, we scrutinized the underpinnings of three mainstream methods to reveal their relationships in estimating Q10 for Re in the Heihe River Basin, northwest China. Specifically, these methods are Q10 estimated from the long-term method (Q10_long), short-term method (Q10_short), and the low-frequency (Q10_lf) and high-frequency (Q10_hf) signals decomposed by the singular spectrum analysis (SSA) method. We found that: 1) Q10_lf and Q10_long are affected by the confounding effects caused by non-temperature factors, and are 1.8 ± 0.3 and 1.7 ± 0.3, respectively. 2) The high-frequency signals of the SSA method and short-term method have consistent roles in removing the confounding effects. Both Q10_short and Q10_hf reflect the actual response of respiration to temperature. 3) Overall, Q10_long has a larger variability (1.7 ± 0.3) across different biomes, whereas Q10_short and Q10_hf show convergence (1.4 ± 0.2 and 1.3 ± 0.1, respectively). These results highlight the fact that Q10 can be overestimated by the long-term method, whereas the short-term method and high-frequency signals decomposed by the SSA method can obtain closer and convergent values after removing the confounding effects driven by non-temperature factors. Therefore, it is recommended to use the Q10 value estimated by the short-term method or high-frequency signals decomposed by the SSA method to predict carbon dynamics and its response to global warming in Earth system models.

Integrating Genome-wide association and whole transcriptome analysis to reveal genetic control of leaf traits in Gossypium arboreum L.

Leaves are important organs for crop photosynthesis and transpiration, and their morphological characteristics can directly reflect the growth state of plants. Accurate measurement of leaf traits and mining molecular markers are of great significance to the study of cotton growth. Here, we performed a Genome-wide association study on 7 leaf traits in 213 Asian cotton accessions. 32 significant SNPs and 44 genes were identified. A field experiment showed significant difference in leaf hair and leaf area between DPL971 and its natural mutant DPL972. We also compared the leaf transcriptome difference between DPL971 and DPL972, and found a batch of differentially expressed genes and non-coding RNAs (including lncRNAs, microRNAs, and circRNAs). After integrating the GWAS and transcriptome results, we finally selected two coding genes (Ga03G2383 and Ga05G3412) and two microRNAs (hbr-miR156, unconservative_Chr03_contig343_2364) as the candidate for leaf traits. Those findings will provide important genomic resources for cotton leaf improvement breeding.

Modified Gant procedure for treatment of internal rectal prolapse in elderly women.

BACKGROUND: Although rectal prolapse is not a life-threatening condition, it can cause defecation disorders, anal incontinence, sensory abnormalities, and other problems that can seriously affect quality of life. AIM: To study the efficacy of the modified Gant procedure for elderly women with internal rectal prolapse. METHODS: Sixty-three elderly female patients with internal rectal prolapse underwent the modified Gant procedure. The preoperative and postoperative anal symptoms, Patient Assessment of Constipation Quality of Life (PAC-QOL), Wexner incontinence score, incontinence quality of life score, and complications (massive hemorrhage, infection, anorectal stenosis, and anorectal fistula) were compared. RESULTS: The improvement rates of postoperative symptoms were defecation disorders (84.5%), anal distention (69.6%), defecation sensation (81.4%), frequent defecation (88.7%), and anal incontinence (42.9%) (P < 0.05). All dimensions and total scores of the PAC-QOL after the procedure were lower than those before the operation (P < 0.05). The postoperative anal incontinence score and Wexner score were significantly lower than those before the procedure (P < 0.05). The quality of life and total scores of postoperative anal incontinence were significantly higher than those before the procedure (P < 0.05). There were no serious complications and no deaths. CONCLUSION: The modified Gant procedure has significant advantages in the treatment of elderly women with internal rectal prolapse.

Hydrogen sulfide attenuates renal I/R­induced activation of the inflammatory response and apoptosis via regulating Nrf2­mediated NLRP3 signaling pathway inhibition.

Renal ischemia/reperfusion (I/R) injury can lead to acute renal failure, delayed graft function and graft rejection. Nucleotide­binding oligomerization domain NOD­like receptor containing pyrin domain 3 (NLRP3)­mediated inflammation participates in the development of renal injury. Nrf2 accelerates NLRP3 signaling pathway activation and further regulates the inflammatory response. In addition, hydrogen sulfide serves a protective role in renal injury; however, the detailed underlying mechanism remains poorly understood. The present study investigated whether Nrf2 and NLRP3 pathway participate in hydrogen sulfide­regulated renal I/R­induced activation of the inflammatory response and apoptosis. Wild­type and Nrf2­knockout (KO) mice underwent surgery to induce renal I/R via clamping of the bilateral renal pedicles. A total of 20 mg/kg MCC950 (an NLRP3 inhibitor) was injected intraperitoneally daily for 14 days prior to surgery. Renal tissue and blood were collected from the I/R model mice to analyze NLRP3 and Nrf2 mRNA expression levels, NLRP3, PYD and CARD domain containing, caspase­1, IL­1ß, Nrf2 and heme oxygenase 1 protein expression levels, cell apoptosis, the secretion of tumor necrosis factor­α, IL­1ß and IL­6 cytokines and renal histopathology and function. Renal I/R activated the NLRP3 and Nrf2 signaling pathways. Conversely, MCC950 treatment inhibited activation of the NLRP3 signaling pathway, and prevented I/R­induced renal injury, release of cytokines and apoptosis in renal I/R model mice. Sodium hydrosulfide (NaHS) not only alleviated upregulation of NLRP3 protein expression levels, but also relieved renal injury, release of cytokines and cell apoptosis induced by renal I/R in wild­type mice, but not in Nrf2­KO mice. NaHS alleviated NLRP3 inflammasome activation, renal injury, the inflammatory response and cell apoptosis via the Nrf2 signaling pathway in renal I/R model mice.

Flooding constrains tree water use of a riparian forest in the lower Heihe River Basin, Northwest China.

Riparian forests in floodplains are occasionally or regularly submerged by flooding. However, controversy exists regarding the effects of flooding on water use in riparian forests, and this controversy severely restricts our ability to better utilize limited water resources to restore damaged riparian forests in arid regions.The evapotranspiration (Et) and transpiration (T) of riparian P. euphratica forests in the arid regions of northwestern China were determined using eddy covariance and sap flow technology across a 3-year period. Fortunately, the flooding introduced by ecological water diversion was occurred in 2014 and 2016 but not in 2015. Our results showed that the magnitude and seasonal pattern of Et across 3 years was comparable (approximately 900 mm), but the T was higher in 2015 (431 mm) than in the other two years (288 mm in 2014 and 290 mm in 2016). The interannual patterns in the transpiration were consistent with the net ecosystem productivity at the site. Given the similar meteorological conditions (e.g. net radiation, temperature, relative humidity, and vapor pressure deficit) among the 3 years, two aspects may contributed to the suppressed tree water use and productivity under flooding: 1) the increased soil salinity reduce the roots water uptake from soil by increasing root water potential via osmotic adjustment; and 2) the depressed tree growth (e.g. the leaf area) via suspended water upward transport along soil-plant-atmosphere continuum. Although flooding is widely known beneficial for the regeneration, we suggest that it is not appropriate for the rejuvenation of phreatophyte (e.g., Populus spp.) in arid regions. Our results were drawn from only three years of measurement and therefore longer time series are needed to confirm or refine those conclusions.

Construction and application of urinary system model with functional bladder module.

In order to study the construction and application of urinary system model with functional bladder module, bladder model was designed, and appropriate materials was selected to make it, and its performance was studied. The results showed that in the analysis of pressure performance of bladder model, more detrusor instability was found in the model than in the urodynamic test, and there was significant statistical difference (P < 0.01). In the analysis of bladder safety capacity, it was found that the bladder safety capacity in the model was much larger than that measured by urodynamics, and there was significant statistical difference (P < 0.01). In the analysis of detrusor workmanship and contraction rate, it was found that the normal model group was significantly smaller than the obstruction group, and there was significant statistical difference (P < 0.01). Comparing the detrusor contraction rate of the two groups, it was found that the normal group and the obstruction group had significant difference at t3, and there was no statistical difference between the other two groups. Therefore, through this study, it is found that the understanding of urinary system can be enhanced by building bladder model, and the basic operating skills of medical staff can be improved more easily by using bladder model, which achieves the expected results of the experiment. Although some shortcomings have been found in the course of the study, it still provides experimental reference for the clinical study of bladder in the future.

The influences of canopy species and topographic variables on understory species diversity and composition in coniferous forests.

Understanding the factors that influence the distribution of understory vegetation is important for biological conservation and forest management. We compared understory species composition by multi-response permutation procedure and indicator species analysis between plots dominated by Qinghai spruce (Picea crassifolia Kom.) and Qilian juniper (Sabina przewalskii Kom.) in coniferous forests of the Qilian Mountains, northwestern China. Understory species composition differed markedly between the forest types. Many heliophilous species were significantly associated with juniper forest, while only one species was indicative of spruce forest. Using constrained ordination and the variation partitioning model, we quantitatively assessed the relative effects of two sets of explanatory variables on understory species composition. The results showed that topographic variables had higher explanatory power than did site conditions for understory plant distributions. However, a large amount of the variation in understory species composition remained unexplained. Forward selection revealed that understory species distributions were primarily affected by elevation and aspect. Juniper forest had higher species richness and α-diversity and lower ß-diversity in the herb layer of the understory plant community than spruce forest, suggesting that the former may be more important in maintaining understory biodiversity and community stability in alpine coniferous forest ecosystems.

Seasonal fluctuations and temperature dependence in photosynthetic parameters and stomatal conductance at the leaf scale of Populus euphratica Oliv.

A combined model to simulate CO2 and H2O gas exchange at the leaf scale was parameterized using data obtained from in situ leaf-scale observations of diurnal and seasonal changes in CO2 and H2O gas exchange. The Farquhar et al.-type model of photosynthesis was parameterized by using the Bayesian approach and the Ball et al.-type stomatal conductance model was optimized using the linear least-squares procedure. The results show that the seasonal physiological changes in photosynthetic parameters (e.g., V(cmax25), J(max25), R(d25) and g(m25)) in the biochemical model of photosynthesis and m in the stomatal conductance model should be counted in estimating long-term CO2 and H2O gas exchange. Overall, the coupled model successfully reproduced the observed response in net assimilation and transpiration rates.

[Expressions of neurotrophic factors and their receptors in prostate cancer].

OBJECTIVE: To investigate the expressions of neurotrophic factors (NTFs) and their receptors in prostate cancer. METHODS: We detected the expressions of the nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and their receptors TrkA, TrkB and p75 in 35 specimens of prostate cancer by Western blotting, and included 10 specimens of normal prostate tissue from young males that died accidentally. RESULTS: Compared with the control group, the expressions of NGF and p75 were significantly decreased (P < 0.01), while those of BDNF, TrkA and TrkB significantly increased in prostate cancer (P < 0.05). CONCLUSION: The changes in the expressions of NTFs and their receptors were related with the pathogenesis and progression of prostate cancer, which may be considered as reference indexes for the diagnosis of the disease.

Estimation of parameters of a biochemically based model of photosynthesis using a genetic algorithm.

Photosynthesis response to carbon dioxide concentration can provide data on a number of important parameters related to leaf physiology. The genetic algorithm (GA), which is a robust stochastic evolutionary computational algorithm inspired by both natural selection and natural genetics, is proposed to simultaneously estimate the parameters [including maximum carboxylation rate allowed by ribulose 1.5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (V(cmax)), potential light-saturated electron transport rate (J(max)), triose-phosphate utilization (TPU), leaf dark respiration in the light (R(d)) and mesophyll conductance (g(m))] of the photosynthesis models presented by Farquhar, von Caemmerer and Berry, and Ethier and Livingston. The results show that by properly constraining the parameter bounds the GA-based estimate methods can effectively and efficiently obtain globally (or, at least near globally) optimal solutions, which are as good as or better than those obtained by non-linear curve fitting methods used in previous studies. More complicated problems such as taking the g(m) variation response to CO(2) into account can be easily formulated and solved by using GA. The influence of the crossover probability (P(c)), mutation probability (P(m)), population size and generation on the performance of GA was also investigated.

[Analysis of the spatial and temporal changes in soil CO2 efflux and its related factors from alpine meadow in Qilian Mountains].

Continuous field experiment was carried out on alpine meadow along different elevation gradient in Qilian Mountains during the growing season of 2004 using a soil respiration chamber (Li-6400-09) connected to a portable photosynthesis system (Li-6400). The possible effect of water-heat factors and root parameter on characteristics of alpine meadow soil respiration was statistically analyzed. The results indicate that soil CO2 efflux has apparent spatial variation laws. Spatial variation patterns of soil respiration from different alpine meadow along elevation gradient are gradually decreased and its coefficient of variation increases gently. The curves of day change of soil CO2 efflux have a simple peak value, and it is low at night, with lowest at 02:00-06:00, and starts to rise rapidly during 07:00-08:30, and then descends during 16:00 -18:30. The peak CO2 efflux appears during 11:00-16:00. The diurnal average of soil CO2 efflux is between (0.56 +/- 0.32) - (2.53 +/- 0.76) micromol x (m2 x s)(-1). As for seasonal variation, soil CO2 fluxes of various are relatively high in summer and autumn but relatively low in spring and winter. The maximum of average soil CO2 efflux occurrs in July and August [4.736 micromol (m2 x s)(-1), and the second is in June and September, and the third is in May and October. Soil CO2 efflux of alpine meadow during growth season is positively correlated with soil temperature, root biomass and soil water content at depths of 10 cm to different degrees. These results indicate that the temperature, soil moisture and root biomass have great effects on the spatial variation of soil CO2 efflux in the area.

[Temporal variation of soil respiration on sloping pasture of Heihe River basin and effects of temperature and soil moisture on it].

Employing LiCor 6400 gas exchange analyzer and soil respiration chamber attachment (LiCor Inc., Lincoln, NE, USA), this paper continuously measured the soil surface CO2 effluxes on the sloping pasture of Heihe River basin from early April to late October 2003 to investigate the soil CO2 efflux rate and its feedback to the changes of climate and land use. The results showed that from May to October, the diurnal variation of soil respiration was low at night, the lowest at 7:00, 6:30, 5:30, 6:00 and 7:00, raised rapidly at 7:00 - 8:30, and then descended at 16:00 - 18:30. The maximum soil CO2 efflux appeared at 15:00, 14:30, 14:30, 13:30, 14:00 and 15:00. The mean daily soil respiration rate was 0.31 - 6.98 micromol m(-2) s(-1), with the maximum in July and August, the second in May and September, and nearly consistent in April and October. Soil respiration rate had an exponential and power correlation with temperature and soil moisture, respectively.