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Hematopoietic stem cells (HSC) and downstream lineage-biased multipotent progenitors (MPP) tailor blood production and control myelopoiesis on demand. Recent lineage tracing analyses revealed MPPs to be major functional contributors to steady-state hematopoiesis. However, we still lack a precise resolution of myeloid differentiation trajectories and cellular heterogeneity in the MPP compartment. Here, we found that myeloid-biased MPP3 are functionally and molecularly heterogeneous, with a distinct subset of myeloid-primed secretory cells with high endoplasmic reticulum (ER) volume and FcγR expression. We show that FcγR+/ERhigh MPP3 are a transitional population serving as a reservoir for rapid production of granulocyte/macrophage progenitors (GMP), which directly amplify myelopoiesis through inflammation-triggered secretion of cytokines in the local bone marrow (BM) microenvironment. Our results identify a novel regulatory function for a secretory MPP3 subset that controls myeloid differentiation through lineage-priming and cytokine production and acts as a self-reinforcing amplification compartment in inflammatory stress and disease conditions.

In multiple types of cancer, decreased tumour cell apoptosis during chemotherapy is indicative of decreased chemosensitivity. Forkhead box K2 (FOXK2), which is essential for cell fate, regulates cancer cell apoptosis through several post‐translational modifications. However, FOXK2 acetylation has not been extensively studied. Here, we evaluated the effects of sirtiun 1 (SIRT1) on FOXK2 deacetylation. Our findings demonstrated that SIRT1 inhibition increased FOXK2‐induced chemosensitivity to cisplatin and that K223 in FOXK2 was acetylated. Furthermore, FOXK2 K223 deacetylation reduced chemosensitivity to cisplatin in vitro and in vivo. Mechanistically, FOXK2 was acetylated by the acetyltransferase cAMP response element binding protein and deacetylated by SIRT1. Furthermore, cisplatin attenuated the interaction between FOXK2 and SIRT1. Cisplatin or SIRT1 inhibition enhanced FOXK2 acetylation, thereby reducing the nuclear distribution of FOXK2. Additionally, FOXK2 K223 acetylation significantly affected the expression of cell cycle–related and apoptosis‐related genes in cisplatin‐stimulated cancer cells, and FOXK2 K223 hyperacetylation promoted mitotic catastrophe, which enhanced chemosensitivity to cisplatin. Overall, our results provided insights into the mechanisms of SIRT1‐mediated FOXK2 deacetylation, which was involved in chemosensitivity to cisplatin.

Hematopoietic aging is marked by a loss of regenerative capacity and skewed differentiation from hematopoietic stem cells (HSC) leading to dysfunctional blood production. Signals from the bone marrow (BM) niche dynamically tailor hematopoiesis, but the effect of aging on the niche microenvironment and the contribution of the aging niche to blood aging still remains unclear. Here, we characterize the inflammatory milieu in the aged marrow cavity that drives both stromal and hematopoietic remodeling. We find decreased numbers and functionality of osteogenic mesenchymal stromal cells (MSC) at the endosteum and expansion of pro-inflammatory perisinusoidal MSCs with deterioration of sinusoidal endothelium in the central marrow, which together create a degraded and inflamed old niche. Molecular mapping at single cell resolution confirms disruption of cell identities and enrichment of inflammatory response genes in niche populations. Niche inflammation, in turn, drives chronic activation of emergency myelopoiesis pathways in old HSCs and multipotent progenitors (MPP), which promotes myeloid differentiation at the expense of lymphoid and erythroid commitment and hinders hematopoietic regeneration. Remarkably, niche deterioration, HSC dysfunction and defective hematopoietic regeneration, can be improved by blocking inflammatory IL-1 signaling. Our results demonstrate that targeting niche inflammation is a tractable strategy to restore blood production during aging.

Recent lineage tracing analyses revealed multipotent progenitors (MPP) to be major functional contributors to steady-state hematopoiesis (1–6). However, we are still lacking a precise resolution of myeloid differentiation trajectories and cellular heterogeneity in MPPs. Here, we found that myeloid-biased MPP3 (2, 3) are functionally and molecularly heterogeneous, with a distinct subset of myeloid-primed secretory cells with high endoplasmic reticulum (ER) volume and FcγR expression. We show that FcγR+/ERhigh MPP3 are a transitional population for rapid production of granulocyte/macrophage progenitors (GMP), which directly amplify myelopoiesis through inflammation-triggered secretion of cytokines in the local bone marrow (BM) microenvironment. Our results identify a novel regulatory function for a subset of secretory MPP3 that controls myeloid differentiation through lineage-priming and cytokine production, and act as a self-reinforcing amplification compartment in stress and disease conditions.One-Sentence SummaryA secretory subset of multipotent hematopoietic progenitors augment myelopoiesis in stress and diseases conditions.

Shrub encroachment is very common in the semiarid regions of China. However, surprisingly little research has been conducted to evaluate the effects of shrubs on soil properties in these regions co...

Vegetation canopy interception (Ic) of precipitation is a considerable component of the global hydrological cycles. Although the measurement and modeling of canopy interception have been explored worldwide at the individual, stand or ecosystem scale, it is still unclear how to recognize this process at the regional or global scales within the context of global climate change. In this study, a revised Gash model was employed to estimate canopy interception based on remote sensing and meteorological data. The spatial and temporal variations in Ic were investigated and the main environmental factors were explored in China for the 2000–2018 period. The results showed that the revised Gash model performed well in modeling canopy interception at the regional scale compared with the PML_V2 dataset product and the in-situ measurements. The average annual Ic in China from 2000 to 2018 was 166.55 mm, with a significant decreasing spatial pattern from the Southeastern to the Northwestern regions. The ratio of canopy interception to precipitation (Ir) displayed a similar spatial pattern, with an average value of 22.30%. At the temporal scale, the mean annual Ic significantly increased at a rate of 1.79 mm yr−1 (p < 0.01) during the study period, and the increasing trend was more pronounced during the 2000–2009 period, at a rate of 3.34 mm yr−1 (p < 0.01). In most vegetation types, except for the deciduous broad-leaved forest and temperate desert, canopy interception showed a significant increasing trend (p < 0.01). Precipitation, temperature, and the normalized differential vegetation index (NDVI) were considered to be the main factors affecting the variations of Ic in China during the last two decades, with specific dominant factors varying in different areas. Specifically, precipitation was considered to control the variations of Ic in the Northwestern regions, temperature mainly influenced the Southern regions, and the NDVI was identified as the main factor in regions where significant ecological conservation projects are established, such as the Loess Plateau. Our findings are expected to not only contribute to the understanding of regional ecohydrological cycle but also provide valuable insights into the methodology of interception modeling at the regional and global scales.

Ho et al. demonstrate that old HSCs are extremely resistant to bloodborne systemic rejuvenation approaches and long-term exposure to a young BM niche microenvironment, maintaining a cell-intrinsic aged state. They also show that young HSCs are not affected by old blood or blood-derived factors, an important finding for transplantations in older patients and other emerging anti-aging interventions., While young blood can restore many aged tissues, its effects on the aged blood system itself and old hematopoietic stem cells (HSCs) have not been determined. Here, we used transplantation, parabiosis, plasma transfer, exercise, calorie restriction, and aging mutant mice to understand the effects of age-regulated systemic factors on HSCs and their bone marrow (BM) niche. We found that neither exposure to young blood, nor long-term residence in young niches after parabiont separation, nor direct heterochronic transplantation had any observable rejuvenating effects on old HSCs. Likewise, exercise and calorie restriction did not improve old HSC function, nor old BM niches. Conversely, young HSCs were not affected by systemic pro-aging conditions, and HSC function was not impacted by mutations influencing organismal aging in established long-lived or progeroid genetic models. Therefore, the blood system that carries factors with either rejuvenating or pro-aging properties for many other tissues is itself refractory to those factors., Graphical Abstract

To observe the effect of acupoint thread-embedding at "Zusanli" (ST 36) and "Fenglong" (ST 40) on the macrophage polarization of epididymis adipose tissue in obese mice, and to explore the action mechanism of acupoint thread-embedding on weight control.Among 30 male C57BL/6 mice, 10 mice were randomly selected and fed with normal diet, and the remaining 20 mice were fed with high-fat diet to establish the obesity model. Sixteen mice with successful obesity model were randomly divided into a model group and an acupoint thread-embedding group, 8 mice in each group. Eight mice were selected from mice which were fed with normal diet as the normal group. On the next day of successful modeling, acupoint thread-embedding was performed at "Zusanli" (ST 36) and "Fenglong" (ST 40) in the acupoint thread-embedding group, once every 10 days for 4 times. The body weight was recorded at 0, 8, 16, 24, 32, 40 days into intervention; the level of glucose metabolism was compared after intervention; the level of lipid metabolism and weight of epididymal adipose tissue were compared at the end of the intervention; the mRNA expression of M1 and M2 macrophage-related cytokines interleukin-10 (IL-6), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) were detected by real-time PCR; the mRNA and protein expression of M1 macrophage labeled inducible nitric oxide synthase (iNOS) and M2 macrophage labeled arginase-1 (Arg-1) were detected by real-time PCR and Western blot.Compared with the normal group, the body weight at 0, 8, 16, 24, 32, 40 days into intervention in the model group was increased (Acupoint thread-embedding at "Zusanli" (ST 36) and "Fenglong" (ST 40) may play a role in weight control by regulating the polarization of macrophages.

Hematopoietic aging is marked by a loss of regenerative capacity and skewed differentiation from hematopoietic stem cells (HSC) leading to dysfunctional blood production. Signals from the bone marrow (BM) niche dynamically tailor hematopoiesis, but the effect of aging on the niche microenvironment and the contribution of the aging niche to blood aging still remains unclear. Here, we characterize the inflammatory milieu in the aged marrow cavity that drives both stromal and hematopoietic remodeling. We find decreased numbers and functionality of osteogenic mesenchymal stromal cells (MSC) at the endosteum and expansion of pro-inflammatory perisinusoidal MSCs with deterioration of sinusoidal endothelium in the central marrow, which together create a degraded and inflamed old niche. Molecular mapping at single cell resolution confirms disruption of cell identities and enrichment of inflammatory response genes in niche populations. Niche inflammation, in turn, drives chronic activation of emergency myelopoiesis pathways in old HSCs and multipotent progenitors (MPP), which promotes myeloid differentiation at the expense of lymphoid and erythroid commitment and hinders hematopoietic regeneration. Remarkably, niche deterioration, HSC dysfunction and defective hematopoietic regeneration, can be improved by blocking inflammatory IL-1 signaling. Our results demonstrate that targeting niche inflammation is a tractable strategy to restore blood production during aging.

To explore the effect of acupuncture on oxidative stress and apoptosis-related proteins of liver in obese mice induced by high-fat diet.A total of 45 male C57BL/6 mice were randomized into a control group (10 mice) and a model established group (35 mice). Mice in the model established group were fed with high-fat diet for 16 weeks to establish the obesity model. After model established, 30 mice were randomized into a model group, a non-acupoint group and an acupoint group, 10 mice in each one. Acupuncture was applied at "Guanyuan" (CV 4), " Zusanli" (ST 36), "Yishu" (EX-B 3) in the acupoint group and the points of 0.5 cm and 1 cm to the base of tail in the non-acupoint group, 15 min each time, once a day for 8 weeks. Mice in the control group were fed with normal diet, while mice in the other 3 groups were fed with high-fat diet continuously for 8 weeks. The body weight was measured at 0, 4th, 8th, 12th, 16th, 20th, 24th week in each group respectively. After 24-week intervention, the weight of white adipose tissue of epididymis and perirenal and liver was measured; the levels of serum alanine transaminase(ALT) and glutamic oxaloacetic aminotransferase (AST) were detected by automatic biochemical analyzer; liver homogenate was used to detect the level of malondialdehyde (MDA) and the activity of superoxide dismutase (SOD); the liver morphology was observed by HE staining; the expression of apoptosis-related proteins Bax and Bcl-2 were detected by Western blot.Compared with the control group, the body weight of mice in the model group, the acupoint group and the non-acupoint group was decreased on 16th week into experiment (before intervention,Acupuncture at "Guanyuan" (CV 4), "Zusanli" (ST 36) and "Yishu"(EX-B 3) can improve obesity and obesity related hepatic disorder by regulating oxidative stress and inhibiting apoptosis in liver.

Rainwater is altered hydrologically and chemically as it passes through tree canopies to reach the soil surface, but this aspect of urban forest ecosystems has received less attention than that of natural ecosystems. Hydrological partitioning and changes in solute composition of rainfall were examined in an urban forest within Guangzhou city, in southern China, with reference to three typical subtropical urban tree species (Roystonea regia, Ficus microcarpa, and Lagerstroemia speciosa) with large but morphologically distinct canopies. Three components of rainfall, namely throughfall, stemflow, and interception, were measured and sampled from September 2018 to September 2019. A canopy budget model was used for estimating the contribution of canopy exchange and dry deposition to net rainfall (throughfall + stemflow) solute flux. Being a palm, R. regia recorded the highest percentages of throughfall (72.60%) and stemflow (8.68%) whereas interception was higher in F. microcarpa (33.48%) and L. speciosa (30.54%). The concentrations of almost all the solutes (Ca2+, K+, Na+, Mg2+, Cl−, NO3−, and SO42−) in throughfall and stemflow were higher than those in rainfall, suggesting that water was enriched with these solutes as a result of passing through the canopy. The model of canopy budget also showed that whereas all the three species were similar in terms of the leaching of macronutrient cations, the species differed in term of anions: whereas R. regia and L. speciosa generally absorbed or retained anions on foliage, twigs, or trunks, F. microcarpa leached Cl− and NO3− (presumably because of its unique aerial root). These results can inform the design of urban forests. For example, the lack of NO3− uptake by F. microcarpa suggests that it would be less suitable for mitigating the problems of N deposition which are significant in southern China than the other two species; on other hand, the rainfall partitioning and canopy exchange characteristics of L. speciosa make it more suitable for intercepting rainwater as well as for alleviating the problem of N deposition. The findings of this study therefore have significant implications for the selection of urban tree species in similar subtropical regions worldwide.

Although many aspects of blood production are well understood, the spatial organization of myeloid differentiation in the bone marrow remains unknown. Here we use imaging to track granulocyte/macrophage progenitor (GMP) behaviour in mice during emergency and leukaemic myelopoiesis. In the steady state, we find individual GMPs scattered throughout the bone marrow. During regeneration, we observe expanding GMP patches forming defined GMP clusters, which, in turn, locally differentiate into granulocytes. The timed release of important bone marrow niche signals (SCF, IL-1β, G-CSF, TGFβ and CXCL4) and activation of an inducible $\textit{Irf8}$ and β-catenin progenitor self-renewal network control the transient formation of regenerating GMP clusters. In leukaemia, we show that GMP clusters are constantly produced owing to persistent activation of the self-renewal network and a lack of termination cytokines that normally restore haematopoietic stem-cell quiescence. Our results uncover a previously unrecognized dynamic behaviour of GMPs $\textit{in situ}$, which tunes emergency myelopoiesis and is hijacked in leukaemia.

The authors have withdrawn this preprint from Research Square

The maintenance of a soil&rsquo, s infiltration rate (IR) and field-saturated hydraulic conductivity (Kfs) is crucial for the long-term sustainable functioning of wastewater-irrigated lands. However, an effective procedure for reliably measuring in situ soil Kfs remains elusive. To address this issue, this study investigated the dualhead infiltrometer (DHI), a novel instrument for automatically determining IR and Kfs, and compared it with a traditional double-ring infiltrometer (DRI) under various field conditions. In the initial phase, we optimized the procedure and settings for the DHIs in a cropland that was spray-irrigated with secondary-treated wastewater for decades in central Pennsylvania. Results showed that our optimized procedure, which used a single, long pressure cycle, yielded more robust measurements of IR than the originally recommended sequence of two short pressure cycles. The values of Kfs measured by the DHIs with optimized settings were similar to those measured by DRIs under many (but not all) field conditions, due to their differences in infiltration surface areas, operational procedures, length of infiltration time, and soil spatiotemporal variability. Viscosity-corrected Kfs on the irrigated cropland was 123.8 &plusmn, 94.0 mm∙h&minus, 1, higher than that on the adjacent non-irrigated cropland (103.2 &plusmn, 94.6 mm∙h&minus, 1), but the difference was not statistically significant, owing to the high degree of soil spatiotemporal variability and our limited number of measurements. Nevertheless, the higher Kfs values measured on irrigated cropland reflect observed changes in soil structure (e.g., soil pore characteristics) that resulted from decades of irrigation. Seasonal variations in Kfs values existed between winter and summer conditions, but IRs during all seasons remained much higher than the current spray-irrigation rate (4.25 mm∙h&minus, 1), suggesting that the soil is still capable of handling the routine irrigation, even during winter. However, the coefficients of variation exceeded 67.0% across the field sites investigated, and the time periods covered by our measurements were limited. As this specific site is permitted to discharge treated wastewater year-round, caution must still be exercised to ensure that soil Kfs remains high enough to prevent runoff generation, especially during winter frozen conditions.

The interactions between deep-rooted grass patches and soil hydrological processes are unclear. This study used the deep-rooted grass Achnatherum splendens as an indicator plant to evaluate the relationship between spatial distributions of A. splendens patches and dynamics of soil water and salt using electromagnetic induction (EMI) methods in Qinghai Lake watershed on Qinghai-Tibet Plateau in northwestern China. An experimental plot of size 60 m × 60 m was designed for collecting repeated apparent electrical conductivity (ECa) images. Vegetation and soil properties (e.g. soil water, salinity, hydraulic conductivity and particle composition) were investigated. Results showed that soils in A. splendens patches had greater macroporosity and higher unsaturated hydraulic conductivity compared to interpatch zones. Analysis of temporal stability of ECa images showed that locations near A. splendens patches had greater water and salt contents compared to interpatch zones, and these locations also showed the greater increasing magnitudes. This indicated that A. splendens patches acted as focal points for accumulating soil water since the high and dense crown could trap the aeolian sediments and then improve infiltration capacity of soils. Process of root water uptake of A. splendens promoted salt ions transporting into the root zone, which was thought to be the main reason for the salt accumulation. The deep-rooted A. splendens changed soil hydrological properties and affected the dynamics of soil water and salt, and these eco-hydrological processes were determined using the EMI. Our findings provide valuable insights in understanding the eco-hydrological processes of deep-rooted patchy vegetation.

Habitat degradation and loss threaten the survival of many species, especially vertebrates. The establishment of nature reserves is an efficient approach to protect biodiversity. However, fulfilling conservation targets depends largely on the effectiveness of these nature reserves in capturing the targeted species. In this study, we developed a distribution database of threatened terrestrial vertebrates in China, then explored the patterns of the threatened terrestrial vertebrates and evaluated the effectiveness of current nature reserves in terms of their conservation, further identified the conservation priorities for these species in China. We found 452 threatened terrestrial vertebrates widely distributed across China, especially in mountainous and forested regions in southern China. The current nature reserve network is inadequate to capture the threatened vertebrate species. The nature reserves were found to cover 30.47% of the hotspots and 38.65% of the ranges of these species on average, with quite a few conservation hotspot and species gaps. We further propose to either systematically plan and fix current nature reserves or add new protected areas in Yunnan Province and mountainous regions in southeast China.

Leeches are frequently used in traditional Chinese medicine. However, they are potentially hazardous to human and animal health by transmitting several pathogens. Studies of diseases transmitted by leeches are scarce. The purpose of this study was to analyze the pathogens carried in pond-farmed medicinal leech in China. Leeches were collected from 6 farms in Hubei Province in central China. DNA was extracted from the internal organ of leeches to analyze the origin of blood meal. Leech genera were confirmed through amplification of 18S rRNA and mitochondrial gene cytochrome oxidase I (COI) gene by PCR and host animal species were identified through amplification of mitochondrial cytochrome b gene. Species of Ehrlichia in the leech specimens were screened with PCR using specific primers. PCR amplification and DNA sequencing showed that 620 leeches were Hirudinaria sp. Ehrlichia DNA was detected in 39 specimens from 2 farms. We obtained a total of 65 sequences of the cytB gene from 620 leech internal organ samples including sequences of human (n = 5), rat (n = 1), domestic pig (n = 10), duck (n = 23), goose (n = 12) and buffalo (n = 14). Phylogenetic analysis of the rrs and groEL gene sequences showed that Ehrlichia detected in the study were closely related to Ehrlichia sp. in ticks from Korea and Japan. To the best of our knowledge, this is the first report on Ehrlichia DNA being detected from leeches. Our findings provided new data on Ehrlichia spp. and farmed leech species in China.

The yield of stemflow from vegetation is mostly affected by rainfall and canopy structure, but few past studies have paid attention to the dynamics of canopy structure during the growth season. Artemisia ordosica is a typical subshrub, very different from trees and shrubs. Assessing the influence of canopy structure and rainfall on stemflow yield in A. ordosica during the growth season will fill a knowledge gap in our understanding of stemflow yield from subshrub species. This study therefore examined the effects of those two factors on stemflow at two growth stages of A. ordosica, using 20 experimental individuals in the Mu Us sandy land of northern China. It demonstrated that the mean stemflow percentage of gross rainfall (SF%) for this subshrub was 8.56%, and the average funneling ratio was 75.80. The critical control factors of stemflow volumes were rainfall amount and canopy area, which varied greatly during the growth season. The SF% was significantly lower during the reproductive growth stage than during the vegetative growth stage, because of the rapid increase in leaf area index at the former stage. This evaluation of the effects of vegetation growth dynamics on stemflow yield will improve the accuracy of future hydrological models.

This meta-analysis compared the efficacy of laryngectomy and three larynx-preservation treatments in patients with advanced laryngeal cancer.Medline, Cochrane, EMBASE and Google Scholar databases were searched (until May 5, 2014) for studies that evaluated total laryngectomy followed by radiation and three larynx-preserving strategies in patients with advanced laryngeal cancer. The outcomes assessed were the 2- to 5-year overall survival (OS), disease-free survival (DFS), and laryngectomy-free survival (LFS) RESULTS: The search identified ten studies which were used for the meta-analysis (N = 2013 patients). The meta-analysis found that among different treatments, RT alone was associated with the highest rate of OS (71.6 %), DFS (57.8 %), and LFS (79.0 %). OS was similar among the following treatments: laryngectomy→RT vs. CT→RT [P = 0.402]; RT+CT vs. RT alone [P = 0.440]; and RT+CT vs CT→RT [P = 0.588]. DFS rate was higher in patients receiving laryngectomy→RT than CT→RT (P = 0.001) and was similar for RT+CT compared with CT→RT (P = 0.590).These findings suggest that of the larynx-preserving treatments, RT alone was associated with highest rates of OS, DFS, and LFS in patients with locally advanced cancer of the larynx and hypopharynx. Laryngectomy provided a better rate of DFS than CT and RT, but OS were similar across the different larynx-preserving treatments and laryngectomy.

The Qinghai–Tibet Plateau is a sensitive area of global climate changes, and riparian ecosystems are thought as “hotspots” for climate change adaptation, but little work has been conducted regarding the alpine riparian ecosystems on the Qinghai–Tibet Plateau. We measured evapotranspiration ( ET ) and surface energy fluxes over the riparian shrub Myricaria squamosa Desv., which is widely distributed on the Qinghai–Tibet Plateau but has not been studied until now. The results indicated that annual ET was 390 mm and 503 mm for the period of 2010 to 2011 and 2011 to 2012, respectively, which was higher than the amount of precipitation during the same period. Cumulative ET was lower than the cumulative reference evapotranspiration during the entire experimental period, whereas ET in August was higher than reference evapotranspiration. ET in the growing season occupied over 80% of annual ET with a maximum daily ET of 7.2 mm d − 1 , and the ET in the non-growing season was quite low because of the frozen soil. In general, temperature and net radiation were the key variables controlling daily ET rates for M. squamosa . Annual sensible heat flux ( H ) consumed 60% of net radiation ( R n ) and latent heat flux ( LE ) 40% during the three years of the study. LE occupied the main part of R n from July to September. H was the highest in May and June, then sunk in the mid-growing season, and rebounded the other peak at late September and early October. Daily ground heat flux was positive from April to mid-September, and it was an important heat source of land surface in the winter and spring. This study highlighted that as an alpine riparian ecosystem in a semiarid region, ET and surface energy partitioning of the M. squamosa community are strongly affected by the freeze–thaw cycle, groundwater fluctuation, precipitation pulses and soil water content. We speculate that climate warming has a significant impact on ET process and surface energy partitioning of the M. squamosa community by influencing the freeze–thaw cycle and soil water content.

Stemflow is an important hydrological process of rainfall partitioning, but it has rarely been studied in the alpine riparian shrub Myricaria squamosa in the Qinghai–Tibet Plateau. This study aimed to measure and model the stemflow of the unstudied M. squamosa and to identify the key controlling factors of stemflow yield. Correlations and stepwise regression analysis between stemflow and five meteorological and ten biological factors indicated that the rainfall amount and the aboveground biomass were the best variables for modelling and predicting stemflow. We used the best model to estimate annual and stand stemflow, as well as rainfall threshold for stemflow generation. Annual stemflow accounted for 2.3 to 10.2% of the annual rainfall amount, varying with different vegetation coverage and leaf area index. The annual stemflow percentage increased linearly with the annual total rainfall amount of events > 7.3 mm. For M. squamosa stands, branches with diameters of 10 to 25 mm were less frequent but contributed much more stemflow than branches with diameters smaller than 10 mm. The stemflow percentage increased sharply with increasing rainfall amounts when the rainfall amounts were less than 4, 8 or 13 mm for the M. squamosa stands with coverage of 32.6, 47.6 or 56.1%, respectively, but increased gently when the rainfall amounts were greater than these values. The rainfall threshold for stemflow generation decreased as the branch aboveground biomass increased, and the estimated median value of the rainfall threshold was 0.8 mm for M. squamosa stands, with a range of 3.0 to 0.4 mm for branches weighing 10 to 300 g, respectively. Copyright © 2014 John Wiley & Sons, Ltd.

Riparian zones are vulnerable to water regimes, which alter soil water availability and impact the persistence of riparian plants. However, little is known about the water use patterns of alpine riparian shrubs (e.g., Myricaria squamosa) in response to changes in soil water availability on the Qinghai–Tibet Plateau. This study examined the water-use patterns of M. squamosa along a zone of gradual degradation (light, moderate, and severe), located in the lower reaches of the Shaliu River in the Qinghai Lake watershed. Stable water isotopes (δ2H and δ18O) in xylem water, soil water and groundwater, as well as leaf water potential were monitored during the growing seasons from 2012 to 2013, and quantified the water-use proportions via MixSIAR model. Results showed significant differences in the isotopic signatures of M. squamosa from the light, moderate, and severe degradation sites across seasons, suggesting that M. squamosa exploited different water sources. MixSIAR results also revealed that M. squamosa used high proportions of shallow soil water in the light degradation site (35.4%) compared with the severe degradation sites (13.4%). By contrast, M. squamosa exhibited an ability to shift its water sources and to rely more on groundwater in the severe degradation site across seasons. The contrasting water-use patterns of M. squamosa along the gradual degradation zone were closely linked with the distributions of active root zones when competing for water. Higher predawn leaf water potential (Ψpd) of M. squamosa (mean Ψpd = −2.29 ± 0.7 MPa) was found in the light degradation site and lower Ψpd values in the severe degradation site (mean Ψpd = −3.3 ± 0.8 MPa), suggesting that M. squamosa depended on a high degree of flexible plasticity in water use to alleviate water stress along the gradual degradation. These results linked to water-use patterns and ecophysiological characteristics (e.g., Ψpd) of plants responding to changes in available water are important for informing decision-making management strategies designed to prevent ecological degradation.

Many arid grasslands around the world are affected by shrub encroachment. However, the transition states of shrub-encroached ecosystems are still poorly known, and the effects of human disturbances are difficult to quantify during the transition process. This study investigated plant biomass, community characteristics, and water capturing capability of the shrub and interspace grass patches during the different transition states of Caragana microphylla Lam-encroached grassland in response to the intensity of anthropogenic disturbances. The results indicate that the number of plant species increased with the disturbance intensity at the shrub patches and that the total aboveground biomass (AB) significantly decreased from the slightly disturbed site to the moderately disturbed site, then significantly increased from the moderately disturbed site to the seriously disturbed site. The total belowground biomass (BB) was much greater in the shrub patches than the interspace grass patches at the above three sites. The results also suggest that grass or shrub dominance were alternative stable states in the processes of shrub encroachment but that a threshold existed during state transition. Dye tracing experiments showed that shrubs had higher water capturing capability than grass. The shrubs could capture and transport water to the deeper soil layers in the shrub patches. We speculate that the competitive advantage for biomass and water by shrubs could be reversed for grass if the disturbance intensity does not exceed a threshold value. A continual increase of anthropogenic disturbance would further lower the water capturing capability of grasses, leading to an increase of biomass and the size of shrub patches and a shift in the landscape to a shrub-dominated state, which would be irreversible.

Shrub encroachment occurs in arid grasslands worldwide, however, little experimental works on shrub encroachment has been conducted in China. Moreover, interactions and feedbacks between soil moisture/temperature and woody plants remain poorly investigated in arid and semiarid regions. We continuously measured soil water content and soil temperature at 10-min intervals beneath shrub canopy and inter-space grass at different topographic positions of a hillslope in Caragana microphylla encroached grassland of Inner Mongolia in north China from June 2009 to April 2011. The findings of this study revealed that, contrary to most previous results, soil moisture was not always greater in shrub patches than that in the inter-space grass patches, but was strongly affected by precipitation size and calcic layers. Significant higher soil water content and quicker response to summer rainstorm in the shallow soil layer (0–20 cm) for grass patches than the adjacent shrub patches, however, spatial distribution of the deeper soil water (40–100 cm) in the profile was controlled by the position of calcic horizon functioned as a ‘dam’ to store water in wet period and release water to plant in drought period, highlighting positive feedbacks between shrub establishment and CaCO 3 horizons. Diurnal soil temperature and daily soil temperature was significantly higher for shrub than grass in winter, but the trend was reversed in summer. The summer soil cooling and winter soil warming effects would favor shrub to resist drought and freeze damage ensuring continuing shrub growth and survival under arid and clod conditions. These evidences suggest that feedbacks between C. microphylla and soil moisture/temperatur were overall positive.

Rainfall partitioning is a key process of ecosystem water cycle which has not get enough attention in the alpine deciduous shrub. Moreover，there is no apposite analytical model that suits to estimate the rainfall redistribution of the deciduous shrub with great changes in coverage and leaf storage capacity due to foliation and defoliation. Field and laboratory experiments to assess these processes and to determine vegetation and atmospheric parameters were established for deciduous Potentilla fruticosa shrub on the Qinghai-Tibet Plateau. Based on the experimental data, a variable parameter Gash model especially for deciduous shrub rainfall partitioning which is adapted from the revised Gash model was developed to represent these processes. The performance of the variable parameters Gash model in modelling the rainfall partitioning of the deciduous shrub patches is better than that of the original model. The variable parameters Gash model treated the water captured by the stem as that captured by leaf canopy considering the low height of shrub and its low coverage in leafless period. Thus, the model developed here were perfect to represent the rainfall partitioning processes. It was found that the interception, throughfall and stemflow accounted for 21.44 %, 29.26 % and 49.30 % of gross rainfall in the shrub patches during the growing season of 2012, respectively. 42.6 % of the interception was loss by evaporation from the saturated leaf canopy during rainfall events. The results indicate that adaptations of the analytical model in this paper improved its performance and provide hypotheses more near the realities in the deciduous shrub.

One-dimensional V2O5 nanowires have been synthesized inside the channels of mesoporous silica SBA-15 through chemical approach, which involves aminosilylation of silanol groups on the silica surface, anchoring of isopoly acid, H6V10O28. by neutralization of basic amine groups, and thermal decomposition. The formation and physicochemical properties of the nanowires were monitored and studied by TG-DTA, variable temperature in situ XRD, TEM, N2 sorption measurements and UV-Vis DRS. The results indicate that V2O5 nanowires formed within SBA-15 channels belong to orthorhombic polycrystal domains. The oxygen-to-metal charge transfer band of V2O5 nanowires shows a blue shift in comparison with bulk V2O5, which clearly exhibits the quantum size effect of nanowires.

The effects of the L-type Ca 2+ channel blocker nimodipine on the spectrum of the spontaneous neural noise (SNN) and the waveform of the gross sound-evoked compound action potential (CAP) were investigated by perilymphatic perfusion in the guinea pig cochlea. Both the SNN and the CAP were reversibly suppressed by nimodipine. The percentage reduction in SNN was dose-dependent in a manner very similar to the results obtained with the measures of CAP threshold changes. The reduction in the peak SNN caused by 10 μM nimodipine was the same as that caused by 500 μM kainic acid, which totally eliminated any neural responses. For 1 μM nimodipine there was an apparent dissociation between the SNN and CAP changes such that the SNN could be markedly suppressed with only very small changes in CAP thresholds. These results imply that spontaneous release of neurotransmitter from the inner hair cell is more sensitive to block of calcium channels than evoked release. There was no evidence for any marked shift caused by nimodipine, in the position of the main (900 Hz) spectral peak in the SNN. Comparison of the CAP waveform before and after nimodipine perfusion showed that the CAP waveforms were unchanged despite the change in sensitivity. These data do not support the notion of any significant postsynaptic site of action of nimodipine. The data hence provide further support for an exclusively presynaptic role for L-type Ca 2+ channels in the regulation of both evoked and spontaneous neurotransmitter release from inner hair cells.

Interactions between lakes and the atmosphere at high-altitudes are still poorly understood due to difficulty in accessibility of direct measurements. This is particularly true for the Qinghai–Tibet Plateau (QTP), where approximately 50% of the lakes in China are located. Continuous direct measurements of the water flux and surface energy budget were made over the largest high-altitude saline lake in China, Qinghai Lake on the northeastern QTP, using the eddy covariance (EC) method from 11 May, 2013 through 10 May, 2015. Results indicated that annual evaporation of Qinghai Lake was 832.5 mm for 2013/2014 and 823.6 mm for 2014/2015, respectively. The surface energy budget and evaporation showed a strong seasonal pattern, with peaks in the latent and sensible heat flux observed in autumn and early winter. There was a 2–3 month delay between the maximum net radiation and maximum latent and sensible heat fluxes. Intraseasonal and seasonal variations in latent and sensible heat flux were strongly affected by different air masses. Westerly cold and dry air masses increased evaporation while southeast moist air mass suppressed evaporation, suggesting that the lakes might serve as an 'air-conditioner' to modify the temporal heat and water flux in the QTP.

Nifedipine (NDP) is used extensively for the clinical treatment of a number of cardiovascular diseases. Herein, the interaction between human serum albumin (HSA) and NDP and the influence of flavonoids, rutin and baicalin, on their binding properties were investigated in vitro by means of fluorescence and absorption spectroscopy. The fluorescence of HSA was quenched remarkably by NDP and the quenching mechanism was considered as static quenching by forming a complex. The results of thermodynamic parameters indicate that both hydrogen bonds and hydrophobic interactions play the main role in the binding process and the binding process was spontaneous. The binding distance between the amino acid residue of HSA and NDP is 2.608 nm, which indicates that the energy transfer from HSA to NDP can occur with high probability. The decreased association constants and the increased binding distance of NDP binding to HSA in the presence of flavonoids were both due to their competitive binding to the site I of HSA. The results obtained from synchronous fluorescence and three-dimensional fluorescence spectra showed that the interaction between HSA and NDP caused the conformational changes of HSA and the synergism effects of NDP and flavonoids induced the further conformational changes of HSA.

Tea tree oil shows promise as an effective treatment for a number of micro-organisms commonly associated with otitis externa and otitis media, but its possible ototoxicity has not been previously assessed. The ototoxicity of tea tree oil was examined in the guinea pig by measuring the thresholds of the compound auditory nerve action potential (CAP) to tone bursts before and after instillation of the oil into the middle ear. After 30 min of instillation, 100% tea tree oil caused a partial CAP threshold elevation at 20 kHz. A lower concentration of oil [2% tea tree oil dissolved in saline using 0.5% detergent (Tween-80)] did not cause any significant lasting threshold change after middle ear instillation for the same period of time. The latter concentration of oil is greater than the minimum inhibitory concentration reported for most micro-organisms in the effective spectrum of the oil and this suggests that this concentration may be safe and effective provided only short exposures (about 30 min) are used. The results suggest that high concentrations of tea tree oil applied to the round window for a relatively short time are to some extent ototoxic to the high-frequency region of the cochlea. Hence further study is needed to establish whether tea tree oil can be used with safety in the treatment of external and middle ear infections.

Intracochlear perfusion and gross potential recording of sound-evoked neural and hair cell responses were used to study the site of action of the L-type Ca2+channel blocker nimodipine in the guinea pig inner ear. In agreement with previous work nimodipine (1–10 μM) caused changes in both the compound auditory nerve action potential (CAP) and the DC component of the hair cell receptor potential (summating potential, or SP) in normal cochleae. For 20-kHz stimulation, the effect of nimodipine on the CAP threshold was markedly greater than the effect on the threshold of the negative SP. This latter result was consistent with a dominant action of nimodipine at the final output stage of cochlear transduction: either the release of transmitter from inner hair cells (IHCs) or the postsynaptic spike generation process. In animals in which the outer hair cells (OHCs) had been destroyed by prior administration of kanamycin, nimodipine still caused a large change in the 20-kHz CAP threshold, but even less change was observed in the negative SP threshold than in normal cochleae. When any neural contamination of the SP recording in kanamycin-treated animals was removed by prior intracochlear perfusion with TTX, nimodipine caused no significant change in SP threshold. Some features of the data also suggest a separate involvement of nimodipine-sensitive channels in OHC function. Perfusion of the cochlea with solutions containing Ni2+(100 μM) caused no measurable change in either CAP or SP. These results are consistent with, but do not prove, the notion that L-type channels are directly involved in controlling transmitter release from the IHCs and that T-type Ca2+channels are not involved at any stage of cochlear transduction.