Toxic effects of coal fly ash on wheat seedlings.

We studied heavy metal (HM) stress on wheat seedlings (AK-58) with and without coal fly ash (CFA) exposure. Three CFA spray rates were used to simulate air quality of the second level. Results show airborne particulates can directly enter plant leaves, affecting the whole plant. HM deposition decreases seedling size and mass and reduces activities of the chlorophyll family, photosynthesis enzymes (RuBP and PEPC), and photosynthesis efficiency. In leaves, HM deposition increases with the CFA spray rate. In roots, however, CFA exposure seems to reduce HM deposition, compared with the control without CFA exposure. A possible reason is that HM deposition in leaves from airborne particulates hinders photosynthesis, weakens the whole physiology of the seedlings, and consequently reduces root absorption of HMs from soil. CFA leads to chloroplast expansion, layer-stack disorder of grana, plastoglobule increase, and even chlorophyll membrane damage.

Temporal dynamics and vertical variations in stem CO2 efflux of Styphnolobium japonicum.

CO2 efflux (ECO2) from stems and branches is highly variable within trees. To investigate the mechanisms underlying the temporal dynamics and vertical variations in ECO2, we measured the stem ECO2 by infrared gas analysis (IRGA) and meteorological conditions at 10 different heights from 0.1 to 3.7 m aboveground on two consecutive days every month for 1 year in six Styphnolobium japonicum trees with a similar size. The results indicated that the seasonal change in ECO2 roughly followed the seasonal variations in woody tissue temperature (TW) and stem radial diameter increment (Di). Together, TW and Di explained the monthly change in ECO2, and the contributions of TW and Di changed with the stem positions and growth stages. The diurnal patterns of ECO2 differed greatly between the growing and dormant season, showing a bimodal distribution with an obvious midday depression in the former and a unimodal distribution in the latter. The strong vertical variation in the day-time ECO2 of the growing season was mainly caused by the vertical gradients of TW, Di and difference in sapwood volume per unit of the stem surface along the trunk. The temperature-sensitivity coefficient (Q10) was not constant, as assumed in some models, but was instead vertically altered and highly dependent on the measurement temperature. For all stem positions, the highest Q10 value appeared at approximately 5 °C, and both higher and lower temperatures decreased Q10. Our study demonstrated that application of a constant Q10 would cause an estimation error when scaling up chamber-based measurements to annual carbon budgets at the whole-stem level.

Regulation on air temperature by residential area morphology: A case study in Xuzhou City, China.

Due to woodlands and farmlands being replaced by residential areas in cities, continuous urbanization resulting in frequent urban heat island effects, especially in summer when high temperature seriously threaten health and lives of citizens. Although scientists realized that reasonable residential area morphology could effectively regulate air temperature and improve microclimate, it is lack of air temperature regulation-oriented specifications and requirements on morphology of residential areas. In this study, we used three types of morphological parameters of 15 residential areas in Xuzhou City and air temperature data via field investigation to analyze air temperature regulation caused by residential area morphology. The results showed that key morphological parameters of residential areas were different in morning and afternoon. In morning, independent effects of mean building height, street aspect ratio, and complete aspect ratio contributed 15.4%, 7.3%, and 6.8%, while those of building density, sky view factor, and the ratio of building surface area to floor area were 21.1%, 23.1%, and 6.9% in afternoon, respectively. Threshold values of efficiency of morphological parameters of residential areas were different between morning and afternoon. There were significant correlations between some morphological parameters of residential area. The results could provide data support and methodological reference for residential areas design in Xuzhou and surrounding cities.

[Urban thermal environment effects based on visual indices: A case study in Xuzhou City, China]. / 基于视觉指数的城市热环境效应­­ä»¥å¾å·žå¸‚为例.

Urban thermal environments are closely related to habitats, citizens' health, and sustainable development. Based on green view index (GVI), we proposed two new visual indices, construction view index (CVI) and imperious surface view index (R&PVI). Mobile observation was used to obtain urban thermal environment data, images and coordinates synchronously in Xuzhou City in late summer, including urban area (U), scenic area (S), exterior of university campus (E), and university campus inside (CUMT). We analyzed the impacts of the urban composition represented by the visual index on the urban thermal environment. The results showed that, along the sampling line, mean air temperature (Ta) was highest (30.42 ℃) and mean relative humidity (RH) was lowest (40.7%) in urban area, while mean Ta was lowest (29.35 ℃) and mean RH was highest (48.4%) in scenic area. The situation of mean wind-chill temperature (TaW) was the highest (32.95 ℃) in the urban area and the lowest (31.93 ℃) in the scenic area. As for CVI, urban area, university campus inside, exterior of university campus and scenic area ranked in descending order, while GVI showed an opposite pattern. CVI was significantly positively correlated to Ta and TaW, but negatively to RH. GVI was significantly negatively correlated to Ta and TaW, but positively to RH. R&PVI was significantly positively correlated to Ta and TaW, but not correlated to RH. CVI and GVI influenced Ta significantly, with the independent effects being 10.4% and 18.9%, and joint effects being 7.8% and 11.3%, respectively. As for RH, CVI and GVI contributed significantly as well, independent effects were 37.5% and 15.7%, and joint effects were 51.4% and 30.2%, respectively. As for TaW, the three visual indices contributed significantly, but independent and joint effects were lower than those on Ta. Moreover, visual indices contributed more on RH than Ta or TaW. The results could provide ideas for optimizing urban thermal environments and mitigating urban heat island effects, and have practical implications for urban renewal and improvement of the quality of human living environment.

[A review of research on the urban thermal environment effects of green quantity]. / ç»¿é‡çš„åŸŽå¸‚çƒ­çŽ¯å¢ƒæ•ˆåº”ç ”ç©¶çŽ°çŠ¶ä¸Žå±•æœ›.

The regulative function of green quantity in urban thermal environment is an important topic in urban studies. Here, we reviewed the concepts and developments of green quantity, the measurements of green quantity and urban thermal environment, the relevance between green quantity and urban thermal environment, and its implications for urban planning. After summarizing domestic and international research processes, we put forward four prospective directions: 1) improving the methods for three-dimensional investigation of green quantity, 2) developing means for urban thermal environment monitoring and forecasting, 3) establishing an index system for three-dimensional pattern of urban green quantity, and 4) creating three-dimensional analytical methods to quantify the relationship between green quantity and urban thermal environment. It was expected to provide a three-dimensional spatial perspective for exploring the relevance between green quantity and urban thermal environment. It was proposed to deeply examine three-dimensional patterns of urban green quantity, in order to balance urban thermal environment and multiple ecological benefits, and to provide scientific basis for urban green space planning and design, as well as to form theoretical supports for adaptation to climate change and regulation of urban thermal environments.

Dynamic spatial patterns of leaf traits affect total respiration on the crown scale.

Temporal and spatial variations of leaf traits caused conflicting conclusions and great estimating errors of total carbon budget on crown scales. However, there is no effective method to quantitatively describe and study heterogeneous patterns of crowns yet. In this study, dynamic spatial patterns of typical ecological factors on crown scales were investigated during two sky conditions, and CEZs (crown ecological zones) method was developed for spatial crown zoning, within which leaf traits were statistically unchanged. The influencing factors on hourly and spatial variations of leaf dark respiration (Rd) were analysed, and total crown respiration (Rt) was estimated based on patterns of CEZs. The results showed that dynamic spatial patterns of air temperature and light intensity changed significantly by CEZs in special periods and positions, but not continuously. The contributions of influencing factors on variations of Rd changed with crown depth and sky conditions, and total contributions of leaf structural and chemical traits were higher during sunny days than ecological factors, but lower during cloudy days. The estimated errors of Rt may be obviously reduced with CEZs. These results provided some references for scaling from leaves to crown, and technical foundations for expanding lab-control experiments to open field ones.

Horizontal Heat Impact of Urban Structures on the Surface Soil Layer and Its Diurnal Patterns under Different Micrometeorological Conditions.

The temperature of the surface soil layer around different orientation walls was investigated horizontally along several construction-soil micro-gradients in Beijing, China. On a diurnal scale, similar fluctuating trends in T0 and T50 (temperature of surface soil layer, 0 and 0.5 m from the building baseline) adjacent to the external walls of buildings with the same orientation usually appeared under similar micrometeorological conditions. The difference between T0 and T50 (ΔT 0-50) can be considered an indicator of the intensity of the horizontal heat effects: higher ΔT 0-50 values correspond to greater intensities. The values of ΔT 0-50 for south-, north-, east- and west-facing sides of buildings were highest on sunny days in summer and exhibited values of 6.61 K, 1.64 K, 5.93 K and 2.76 K, respectively. The scope of horizontal heat impacts (Sh) changed on a diurnal scale between zero and the maximum, which fluctuated with the micrometeorological conditions. The maximum values of Sh were 0.30, 0.15, 0.20 and 0.20 m for south-, north-, east-, and west-facing walls. The ΔT 0-50 was related to solar radiation, horizontal heat flux, relative humidity, wind speed, soil moisture differences and air temperature; the relative importance of these factors was 36.22%, 31.80%, 19.19%, 2.67%, 3.68% and 6.44%, respectively.

Cell adhesion downregulates the expression of Homer1b/c and contributes to drug resistance in multiple myeloma cells.

Previous studies have demonstrated that Homer1b/c plays an important pro-apoptotic role through classical mitochondrial apoptotic pathway. The present study was undertaken to determine the expression and functional significance of Homer1b/c in multiple myeloma (MM). We found that Homer1b/c was lowly expressed in MM cell apoptotic model induced by doxorubicin. The positive role of Homer1b/c in cell apoptosis was further confirmed by knocking down Homer1b/c. Further study confirmed that Homer1b/c was able to affect the CAM-DR via pro-apoptotic activity regulating the ability of cell adhesion. Collectively, these data indicate that Homer1b/c may represent a good candidate for pursuing clinical trial in MM.

Poor response to platinum-based chemotherapy is associated with KRAS mutation and concomitant low expression of BRAC1 and TYMS in NSCLC.

OBJECTIVE: To evaluate treatment response, survival, and the associations between KRAS mutation status and tumour expression levels of BRCA1, TYMS and SRC retrospectively in a cohort of patients with non-small cell lung cancer (NSCLC), treated exclusively with conjunctive platinum-based doublet chemotherapy. METHODS: KRAS mutation status was determined via amplification refractory mutation and multiple quantitative polymerase chain reaction (PCR) analysis. Tumour expression levels of BRCA1, TYMS and SRC were determined via real time quantitative PCR. RESULTS: Patients with KRAS mutations (n = 3) had significantly shorter survival duration than patients with wild type KRAS (n = 42). Tumour expression levels of BRCA1 and TYMS, but not SRC, were significantly lower in patients with, than in those without, KRAS mutations. Tumour expression level of BRCA1 was positively correlated with survival duration. CONCLUSIONS: KRAS mutation status and BRCA1 tumour expression are potential biomarkers for tailoring chemotherapy and predicting clinical outcome.