Protein folding dependence on selenoprotein M contributes to steady cartilage extracellular matrix repressing ferroptosis via PERK/ATF4/CHAC1 axis.

OBJECTIVE: Initiation of endoplasmic reticulum (ER) stress is pivotal to the advancement of osteoarthritis (OA). We aimed to explore the function of ER-resident selenoprotein M (SELM) in cartilage-forming chondrocytes, investigating how SELM participates in cartilage extracellular matrix (ECM) metabolism and ER stress modulation. METHODS: Articular cartilage samples with knee OA undergoing total knee arthroplasty were categorised into OA-smooth and OA-damaged groups, with primary chondrocytes extracted from smooth areas. Destabilization of the medial meniscus was induced in male C57BL6/J mice, with sham operations on the left knee as controls. After 8 weeks, knee joint tissues were collected for analysis. Histology and immunohistochemistry examined cartilage damage. Molecular biology techniques investigated how SELM affects ECM metabolism and ER stress regulation. RNA sequencing revealed the pathway changes after SELM intervention. AlphaFold demonstrated how SELM interacts with other molecules. Cultured cartilage explants helped determine the effects of SELM supplementation. RESULTS: SELM expression was reduced in the damaged cartilage. Increasing SELM levels positively impacted ECM equilibrium. Decreasing SELM expression activated genes linked to degenerative ailments and impaired the cellular response to misfolded proteins, initiating the PERK/P-EIF2A/ATF4 pathway and exacerbating GSH/GSSG imbalance via the ATF4/CHAC1 axis. SELM likely participated in protein folding and modification by leveraging its thioredoxin domains. In vitro SELM supplementation mitigated IL-1ß effects on damaged cartilage explants and suppressed beneficial chondrocyte phenotypes. CONCLUSIONS: Our results confirm the involvement of SELM in ER stress-induced cartilage damage as well as protein folding, pointing to new directions in molecular therapy for degenerative diseases.

Environmental determination of spring wheat yield in a climatic transition zone under global warming.

Understanding environmental determination of crop yield plays a critical role in agricultural. management in resource-limited areas. The climatic transition zone was a naturally ideal place to study. the relations between environmental factors and crop yield, due to its large annual variability of climatic factors and high speed of temperature increase under global warming. Our objectives were to identify the most critical environmental factor in determining spring wheat yield and analyze the convergence and divergence of water-yield relations for spring wheat in a typical climatic transition zone (semi-arid area). The study was conducted at two locations, Dingxi and Pengyang in Northwest China, with a long-term experiment (1987-2018) and two short-term irrigation experiments. Meanwhile, data of water use and spring wheat yield was collected from a series of previously published literature in the study area. The highest spring wheat yield was obtained under year pattern with higher soil water content at sowing (SWCS) and lower atmospheric dryness condition (ADC, the difference between reference evapotranspiration and precipitation during spring wheat growing season). SWCS was more important than precipitation during the growing season (PGS) in determining spring wheat yield in the study area. The relations between available water supply, water use, and spring wheat yield were convergence. However, SWCS had an impact on the relationship between yield and PGS and SWCS-yield relation was affected by ADC. We concluded that precipitation in 7 months before sowing was the dominant factor determining spring wheat yield in the climatic transition zone under global warming whereas the impact of high atmospheric evaporative demand resulted from the increasing temperature on crop yields and SWCS-yield relation must be taken into account for the analysis of environmental determination of spring wheat yield.

Multiplex Visualized Closed-Tube PCR with Hamming Distance 2 Code for 15 HPV Subtype Typing.

Cervical cancer is the fourth leading cause of death in women, especially in developing countries. Specific and economic methodologies for HPV typing are crucial in cancer diagnosis and further disease control. However, routine assays based on real-time polymerase chain reaction (qPCR) or DNA-chip hybridization are either incapable of offering detailed subtype information or involve tedious open-tube operations with the risk of cross-contamination from PCR amplicons. Herein, we proposed a multiplex visualized closed-tube PCR (Multi-Vision) for HPV typing. Using gold nanoparticle probes (AuNPs) as a color change indicator combined with a Hamming distance 2 coding scheme, 13 high-risk HPVs and two subtypes associated with high-incidence benign lesions were successfully typed by performing six closed-tube PCRs. The assay demonstrates high specificity with no cross-reaction among different subtypes under several artificial sample concentrations (from 100 to 103 copies per reaction) and enables highly sensitive detection of as low as 0.5 copies/µL. Further, 105 clinical samples were successfully analyzed using our method with a high concordance rate of 99.05% (104/105) compared to a HPV typing kit. The inconsistent sample was confirmed by sequencing to be consistent with the typing results determined by our method, indicating that Multi-Vision could be a useful tool for HPV detection, especially in resource-limited regions.

Automatic segmentation of esophageal cancer, metastatic lymph nodes and their adjacent structures in CTA images based on the UperNet Swin network.

OBJECTIVE: To create a deep-learning automatic segmentation model for esophageal cancer (EC), metastatic lymph nodes (MLNs) and their adjacent structures using the UperNet Swin network and computed tomography angiography (CTA) images and to improve the effectiveness and precision of EC automatic segmentation and TN stage diagnosis. METHODS: Attention U-Net, UperNet Swin, UNet++ and UNet were used to train the EC segmentation model to automatically segment the EC, esophagus, pericardium, aorta and MLN from CTA images of 182 patients with postoperative pathologically proven EC. The Dice similarity coefficient (DSC), sensitivity, and positive predictive value (PPV) were used to assess their segmentation effectiveness. The volume of EC was calculated using the segmentation results, and the outcomes and times of automatic and human segmentation were compared. All statistical analyses were completed using SPSS 25.0 software. RESULTS: Among the four EC autosegmentation models, the UperNet Swin had the best autosegmentation results with a DSC of 0.7820 and the highest values of EC sensitivity and PPV. The esophagus, pericardium, aorta and MLN had DSCs of 0.7298, 0.9664, 0.9496 and 0.5091. The DSCs of the UperNet Swin were 0.6164, 0.7842, 0.8190, and 0.7259 for T1-4 EC. The volume of EC and its adjacent structures between the ground truth and UperNet Swin model were not significantly different. CONCLUSIONS: The UperNet Swin showed excellent efficiency in autosegmentation and volume measurement of EC, MLN and its adjacent structures in different T stage, which can help to T and N stage diagnose EC and will save clinicians time and energy.

Risk assessment of severe postpartum hemorrhage after invasive placenta accreta based on three-dimensional reconstruction of magnetic resonance imaging.

Background: The aim of this study was to investigate the significance and feasibility of risk assessments based on the three-dimensional (3D) reconstruction of magnetic resonance imaging (MRI) of invasive placenta accreta (IPA) to create individualized surgical protocols and perioperative management plans in late pregnancy. Methods: MRI and clinical data of 36 pregnant women with IPA admitted to Southwest Hospital from January 2017 to June 2021 were retrospectively analyzed. The patients were divided into the following 4 groups: peripartum hysterectomy (PH), abdominal aortic balloon block (AABB), PH with AABB, and nonsurgical treatment. Each group was then divided into severe and nonsevere postpartum hemorrhage subgroups based on postpartum hemorrhage volumes of not more than 2,000 mL and more than 2,000 mL, respectively. The uteri, placentas, IPA, and urinary bladders in each group were segmented and 3-dimensionally reconstructed using Amira 5.2.2 (Visage Imaging, Richmond, Australia) software, and their surface areas and volumes were calculated. A multifactorial unconditional logistic regression analysis was performed to evaluate the 3D morphological parameters of postpartum hemorrhage and calculate the optimal threshold. Results: The bleeding volume, IPA area, placental area:uterine area ratio, IPA area:placental area ratio, maximum depth of IPA, placental position score, IPA position score, and implantation volume were greater in the severe postpartum hemorrhage subgroup than in the nonsevere postpartum hemorrhage subgroup of all groups. In the multifactorial regression analysis, the areas under the receiver operating characteristic curve of the implantation area, implantation volume, maximum depth of implantation, and implantation area:placental area ratio exceeded 0.9 and correlated strongly with severe postpartum hemorrhage, while those of the uterine area, uterine volume, placental area, placental volume, and placental area:uterine area ratio were between 0.5 and 0.7 and correlated with severe postpartum hemorrhage. The threshold (cutoff values) determining severe postpartum hemorrhage were 20,286.25 mm2 of the implantation area, 0.01271 of the implantation area:placental area ratio, 15.03 mm of the maximum depth of implantation, and 46,846 mm3 of the implantation volume. Conclusions: The MRI 3D reconstruction of IPA and its adjacent structures can accurately display the location, anatomical morphology, and spatial relationship of IPA, which can be used to improve the accuracy of IPA diagnosis, predict postpartum hemorrhage, and provide optimized treatment decisions for obstetricians.

Prostate zones and tumor morphological parameters on magnetic resonance imaging for predicting the tumor-stage diagnosis of prostate cancer.

PURPOSE: To determine whether the morphological parameters of prostate zones and tumors on magnetic resonance imaging (MRI) can predict the tumor-stage (T-stage) of prostate cancer (PCa) and establish an optimal T-stage diagnosis protocol based on three-dimensional reconstruction and quantization after image segmentation. METHODS: A dataset of the prostate MRI scans and clinical data of 175 patients who underwent biopsy and had pathologically proven PCa from January 2018 to November 2020 was retrospectively analyzed. The authors manually segmented and measured the volume, major axis, and cross-sectional area of the peripheral zone (PZ), transition zone, central zone (CZ), anterior fibromuscular stroma, and tumor. The differences were evaluated by the One-Way analysis of variance, Pearson's chi-squared test, or independent samples t-test. Spearman's correlation coefficient and receiver operating characteristic curve analyses were also performed. The cut-off values of the T-stage diagnosis were generated using Youden's J index. RESULTS: The prostate volume (PV), PZ volume (PZV), CZ volume, tumor's major axis (TA), tumor volume (TV), and volume ratio of the TV and PV were significantly different among stages T1 to T4. The cut-off values of the PV, PZV, CZV, TA, TV, and the ratio of TV/PV for the discrimination of the T1 and T2 stages were 53.63 cm3, 11.60 cm3, 1.97 cm3, 2.30 mm, 0.90 cm3, and 0.03 [area under the curves (AUCs): 0.628, 0.658, 0.610, 0.689, 0.724, and 0.764], respectively. The cut-off values of the TA, TV, and the ratio of TV/PV for the discrimination of the T2 and T3 stages were 2.80 mm, 8.29 cm3, and 0.12 (AUCs: 0.769, 0.702, and 0.688), respectively. The cut-off values of the TA, TV, and the ratio of TV/PV for the discrimination of the T3 and T4 stages were 4.17 mm, 18.71 cm3, and 0.22 (AUCs: 0.674, 0.709, and 0.729), respectively. CONCLUSION: The morphological parameters of the prostate zones and tumors on the MRIs are simple and valuable diagnostic factors for predicting the T-stage of patients with PCa, which can help make accurate diagnoses and lateral treatment decisions.

Could tumour volume and major and minor axis based on CTA statistical anatomy improve the pre-operative T-stage in oesophageal cancer?

OBJECTIVES: To statistically study the 3D shape of oesophageal cancer (EC) and its spatial relationships based on computed tomography angiography (CTA) 3D reconstruction, to determine its relationship with T-stages, and to create an optimal T-stage diagnosis protocol based on CTA calculation. METHODS: Pre-operative CTA images of 155 patients with EC were retrospectively collected and divided into four groups: T1-T4. We used Amira software to segment and 3D reconstruct the EC, oesophagus, aorta, pericardium and peripheral lymph nodes and measured their surface area, volume, major axis, minor axis, longitudinal length, roughness and relationship to the aorta of the EC. One-way ANOVA, independent sample t-test, ROC, etc., were performed and critical values between different T-stages were calculated. We also invited two radiologists to evaluate the measurements. RESULTS: There were no significant differences in EC longitudinal length, roughness score and relationship with the aorta between the different T-stages of EC. There were significant differences in EC surface area, EC volume and mean major and minor axis among the different T-stages. The volumes of the T1-T4 tumours were 12,934.36 ± 7739.25, 23,095.27 ± 14,975.67, 37,577.98 ± 36,085.64 and 58,579.25 ± 41,073.96 mm3 separately (p < 0.05), and the T1-T4 volume cut-off values were 11,712.00, 19,809.00 and 44,103.50 mm3 separately. For comparison with radiologists, the AUC value of our measurements was 0.704, which was higher than the radiologists of AUC = 0.630. CONCLUSIONS: EC volume, major and minor axis can be used as important factors for surgeons in the T-stage diagnosis of EC, which helps to improve prognosis and treatment decisions after CTA.

Multiplex-invasive reaction-assisted qPCR for quantitatively detecting the abundance of EGFR exon 19 deletions in cfDNA.

Exon 19 deletions (19-Del) on the epidermal growth factor receptor (EGFR) gene are vital biomarkers for guiding tyrosine kinase inhibitor (TKI) treatment and the diagnosis of non-small cell lung cancer (NSCLC). However, it is difficult for conventional qPCR to quantitatively detect all 19-Del targets of EGFR, especially for cfDNA samples. Herein, a multiplex invasive reaction-assisted qPCR was proposed by employing a multiplex invasive reaction to distinguish 19-Del DNA targets from wild DNA targets and report them with different fluorescence signals in each PCR cycle. As all 19-Del targets have the same amplification efficiency and very similar invasive reaction efficiencies, the 19-Del abundance in a sample could be quantified by using the difference between the Ct values (ΔCt) of the deletion targets and the wild targets without the requirement of a standard calibration curve. Combining the high sensitivity of PCR and the high specificity of the invasive reaction, this method can detect 10 copies of the deletion targets and lower than 0.1% deletion abundance. The results were 100% consistent with ARMS-PCR for the 38 tumor tissues tested and were in good agreement with next-generation sequencing for quantifying the abundance of EGFR 19-Del in 15 cfDNA samples, showing the great potential of the method for liquid biopsies.

A measurement, quantitative identification and estimation method(QINRW) of non-rainfall water component by lysimeter.

Non-rainfall water (NRW) has an important impact on the ecosystem, especially in arid and semi-arid areas. It is also an important component in the surface water cycle. Currently, there is not any instrument that can directly measure NRW and it can only be estimated by observation data. Presently, there is no standard method available to estimate each constituents of NRW. With some research not distinguishing each component of NRW, this inaccurate methodology will consequently lead to a greater scope for statistical error. Naturally, this compounds the difficulty in evaluating the role of NRW on the ecosystem and land surface water cycle. Therefore, this paper proposes a new methodology for separating NRW components, which is called QINRW(A Quantitative Identification method for NRW). Based on lysimeter data and combined with meteorological data, this method distinguishes the physical properties of each component of NRW. Consequently, the amount of NRW can be obtained. It is also suitable for microlysimeter data to be applied in QINRW. The advantages of QINRW are three points: •It is more accurate for excluding the precipitation and dry deposition information from lysimeter data, which was not mentioned in previous studies;•It can obtain each component of NRW;•The identification process is more rigorous and clear in theory so far.

[Effects of air temperature increase and precipitation change on grain yield and quality of spring wheat in semiarid area of Northwest China].

In order to predict effects of climate changing on growth, quality and grain yields of spring wheat, a field experiment was conducted to investigate the effects of air temperature increases (0 °C, 1.0 °C, 2.0° C and 3.0°) and precipitation variations (decrease 20%, unchanging and increase 20%) on grain yields, quality, diseases and insect pests of spring wheat at the Dingxi Arid Meteorology and Ecological Environment Experimental Station of the Institute of Arid Meteorology of China Meteorological Administration (35°35' N ,104°37' E). The results showed that effects of precipitation variations on kernel numbers of spring wheat were not significant when temperature increased by less than 2.0° C , but was significant when temperature increased by 3.0° C. Temperature increase enhanced kernel numbers, while temperature decrease reduced kernel numbers. The negative effect of temperature on thousand-kernel mass of spring wheat increased with increasing air temperature. The sterile spikelet of spring wheat response to air temperature was quadratic under all precipitation regimes. Compared with control ( no temperature increase), the decreases of grain yield of spring wheat when air temperature increased by 1.0°C, 2.0°C and 3.0°C under each of the three precipitation conditions (decrease 20%, no changing and increase 20%) were 12.1%, 24.7% and 42.7%, 8.4%, 15.1% and 21.8%, and 9.0%, 15.5% and 22.2%, respectively. The starch content of spring wheat decreased and the protein content increased with increasing air temperature. The number of aphids increased when air temperature increased by 2.0°C , but decreased when air temperature increased by 3.0°CT. The infection rates of rust disease increased with increasing air temperature.

[Effects of increasng field temperature on growth, development and yield of spring wheat in semi-arid area].

A field infrared temperature-increasing simulation experiment was conducted to investi- gate the effects of air temperature increases (0, 1 and 2 °C ) on growth, development and yield of spring wheat at the Dingxi Arid Meteorology and Ecological Environment Experimental Station of the Institute of Arid Meteorology of China Meteorological Administration. The results showed that the growth period of spring wheat was shortened by 7-11 d when the temperature increased by 1-2 °C. The plant height and leaf area index increased at early growth stage, decreased after entering the jointing stage, and warming 2 °C had a higher effect than warming 1 °C. Warming treatment induced an obvious decrease in chlorophyll content, especially from late grain filling stage to milk ripe stage. Compared with the control, increasing temperature by 1-2 °C decreased the spring wheat yield by 25.4%-45.5%, mainly due to obvious decreases in number of grains and grain mass per panicle. Water consumption of 0-100 cm soil horizons increased with the increase of temperature, while the variation tendency of water consumption of 100-160 cm soil horizons was not obvious.

A novel edge detection in medical images by fusing of multi-model from different spatial structure clues.

Edge detection has been widely used in medical image processing, automatic diagnosis, et al. A novel edge detection algorithm, based on the fusion model, is proposed by combination with the two proposed models as follows: the matrix of most probable distribution of edge point and the matrix of the difference weight of each point. The most probable distribution of edge point can be obtained by analyzing the variance among 4-connected neighborhood points around each pixel under estimation in the image to label the all candidate edge points in the image. The difference weight of each point can be gotten by analyzing the brightness difference between the neighborhood point and the under-estimating pixel to represent the probability of being edge. The two matrices gotten from the different descriptions of spatial structure are fused together and derive from the final edge image with thresholding method on the fusion matrix. The experiments are performed based on the public diabetic retinopathy database DRIVE. According to the edge images obtained, the proposed method is subjectively analyzed to be complete and close to the Ground Truth image with very low noise in comparison with the Sobel, Canny and LOG edge detectors. The F1 measure, ROC measure and PFOM measure are separately adopted to make quantitative evaluation of the proposed edge detection algorithm. Experimental results show that the proposed method is able to improve the effect of edge detection on medical images.

Evapotranspiration measurement and crop coefficient estimation over a spring wheat Farmland ecosystem in the Loess Plateau.

Evapotranspiration (ET) is an important component of the surface energy balance and hydrological cycle. In this study, the eddy covariance technique was used to measure ET of the semi-arid farmland ecosystem in the Loess Plateau during 2010 growing season (April to September). The characteristics and environmental regulations of ET and crop coefficient (Kc) were investigated. The results showed that the diurnal variation of latent heat flux (LE) was similar to single-peak shape for each month, with the largest peak value of LE occurring in August (151.4 W m(-2)). The daily ET rate of the semi-arid farmland in the Loess Plateau also showed clear seasonal variation, with the maximum daily ET rate of 4.69 mm day(-1). Cumulative ET during 2010 growing season was 252.4 mm, and lower than precipitation. Radiation was the main driver of farmland ET in the Loess Plateau, which explained 88% of the variances in daily ET (p<0.001). The farmland Kc values showed the obvious seasonal fluctuation, with the average of 0.46. The correlation analysis between daily Kc and its major environmental factors indicated that wind speed (Ws), relative humidity (RH), soil water content (SWC), and atmospheric vapor pressure deficit (VPD) were the major environmental regulations of daily Kc. The regression analysis results showed that Kc exponentially decreased with Ws increase, an exponentially increased with RH, SWC increase, and a linearly decreased with VPD increase. An experiential Kc model for the semi-arid farmland in the Loess Plateau, driven by Ws, RH, SWC and VPD, was developed, showing a good consistency between the simulated and the measured Kc values.

[Characteristics of evapotranspiration and crop coefficient of agroecosystems in semi-arid area of Loess Plateau, Northwest China].

Evapotranspiration (ET) is an important component of ground surface energy balance and water balance, and closely related to water cycle. By using eddy covariance technique, this paper studied the ET characteristics of agroecosystems in the semi-arid area of Loess Plateau in growth season (from April to September), 2010, and analyzed the relationships between crop coefficient and environmental factors. During the observation period, the diurnal variation of latent heat flux (LE) in each month was similar to single-peak curve, and the peak value (151.4 W x m(-2)) occurred in August. The daytime energy partitioning manner showed a significant seasonal variation, with LE/R(n) < H/R(n) (R(n) was net radiation, and H was sensible heat flux) from April to June, and LE/R(n) > H/R(n) from July to September. The daily ET rate also showed a significant seasonal variation, with the maximum of 4.69 mm x d(-1). The wind speed (W(s)), relative humidity (RH), soil water content (theta), and atmospheric vapor pressure deficit (D) were the major factors affecting the crop coefficient K(c) which was exponentially decreased with increasing W(s), exponentially increased with increasing RH and theta, and linearly decreased with increasing D.

[Effects of climate warming on oil flax growth and water use efficiency in semi-arid region of Loess Plateau, Northwest China].

By using the site-specific observation data of oil flax growth and related meteorological records in semi-arid region of Loess Plateau, this paper studied the effects of climate change on the oil flax growth, and analyzed the relationships between the oil flax water use efficiency and meteorological condition. In this region, the annual precipitation displayed a decreasing trend, and its climatic trend rate was -15.80 mm (10 a)(-1), with an annual periodic change of 3 a and 6 a, whereas the annual air temperature had an increasing trend, and its climatic trend rate was 0.36 degrees C (10 a)(-1). In crop growth period, the aridity index displayed a marked increasing trend, its climatic trend rate was 0.12 (10 a)(-1), and the aridity tendency was more obvious from the beginning of 1990s to the year 2009. From sowing to maturation, oil flax needed 120-150 d, 1700-2100 degrees C d of > or = 0 degrees C accumulated temperature, 200-250 mm precipitation, and 1000-1300 h sunshine hours. The main meteorological factors affecting the oil flax growth in the region were air temperature and precipitation. The increase of air temperature shortened the prophase vegetative growth stage, whereas the increase of air temperature and the decrease of precipitation extended the reproductive growth stage, causing the extension of the whole growth period of the oil flax. The air temperature in the oil flax whole growth period except at seeding stage and maturing stage had negative effect on the yield formation, being more obvious at squaring stage, whereas the precipitation in the whole growth period except at blooming stage had positive effect on the yield formation, being more obvious at seeding stage. The water use efficiency of the oil flax was significantly positively correlated with the air temperature and sunshine hours at seeding stage as well as the aridity index from squaring stage to maturing stage, and negatively correlated with the precipitation from squaring stage to maturing stage. In the study region, the aridity index from May to July was the key factor affecting the water use efficiency of oil flax.

[Effects of climate change on potato growth in semi-arid region of Loess Plateau, China].

Based on the 1988-2008 located observation and 2007-2008 encrypted observation of potato growth and the 1957-2008 meteorological observation in semi-arid region of Loess Plateau, this paper studied the effects of climate change on the potato growth in this region. In 1957-2008, the annual precipitation in this region had a descending trend, with a linear fitting rate of the annual precipitation change curves being - 13.359 mm x (10 a)(-1), while the annual mean temperature displayed an ascending trend, with a linear fitting rate of the annual mean temperature change curves being 0.239 degrees C x (10 a)(-1). During potato growth period, the aridity index displayed a marked ascending trend, and the linear fitting rate of the aridity index change curves was 0.102 x (10 a)(-1). The growth rate of potato tuber became faster from the 96th day after sowing, reached the maximum on the 110th day, and turned slower from the 124th day. The interval from sowing to seedling emergence was shortened by 1-2 d x (10 a)(-1), and that from inflorescence formation to reaping and of whole growth period was lengthened by 9-10 d x (10 a) (-1). In the study region, climate warming shortened the vegetative growth stage, but lengthened the reproductive growth stage and whole growth period of potato.

[Responses of subalpine meadow Poa botryoides to climate change].

Based on the field plot observation and related meteorological data, the effects of climate change in 1985-2005 on the growth and development of subalpine meadow Poa botryoides in Maqu County of Gansu Province were analyzed. The results showed that during study period, the annual precipitation in the Maqu County had a decreasing trend, with a rate of -9.895 mm x (10 a)(-1) and a cycle of 3 years, while the annual air temperature had an increasing trend, with a rate of 0.341 degrees C x (10 a)(-1). The aridity index of P. botryoides in growth season had an obvious increasing trend, with a rate of 0.036 x (10 a)(-1), and the tendency was more markedly from the beginning of the 1990s to 2005. The period from reviving to ripeness of P. botryoides was 140-150 d, and the requirements of accumulated temperature above 0 degree C, precipitation, and sunshine duration in this period were 1000 degrees C-1200 degrees C, 400-450 mm, and 1000-1100 h, respectively. The growth rate of P. botryoides turned to higher at 54 d after reviving, reached the highest at 80 d after reviving, and became lower at 104 d after reviving. Under the effects of climate warming, the phenophase of P. botryoides was advanced by 15 d x (10 a)(-1) at heading stage, 7-8 d x (10 a)(-1) at flowering stage, 8-9 d x (10 a)(-1) at ripeness stage, and 3 d x (10 a)(-1) at withering stage. Climate change made the P. botryoides yield in study area have greater variation and higher unsteadiness.

[Effects of air temperature change on spring wheat growth at different altitudes in northwest arid area].

Based on the 1981-2006 observation data from agricultural meteorological stations at Minle (high altitude) and Zhangye (low altitude) in northwest arid area, the effects of air temperature change at the two altitudes on the growth and yield of spring wheat were studied. It was shown that during study period, the air temperature at the two altitudes had an increasing trend, and the increment was greater at high altitude than at low altitude. At high altitude, the growth duration of spring wheat shortened but the grain yield increased; while at low altitude, the growth duration shortened and the yield decreased. When the mean daily air temperature during spring wheat growth period increased by 1 degrees C, the growth duration shortened by 8.3 days at high altitude and by 3.8 days at low altitude. The growth duration and grain yield of spring wheat at high altitude had a slight increase when the maximum air temperature during growth period was below 30.4 degrees C, but decreased when the maximum air temperature was above 30.4 degrees C.