Diversity study of 12 X-chromosomal STR loci in Hui ethnic from China.

X-chromosomal STRs (X-STRs) have been used as complements of autosomal STR application in recent years. In this work, we present population genetic data of 12 X-STRs including DXS101, DXS10159, DXS10162, DXS10164, DXS6789, DXS7133, DXS7423, DXS7424, DXS8378, DXS981, GATA165B12, and GATA31E08 loci in a sample of 231 unrelated healthy individuals from the Hui ethnic group in Ningxia Hui Autonomous Region, China. Allelic frequencies of the 12 X-STR loci and haplotypic frequencies of the reported linkage groups (DXS7424-DXS101 and DXS10159-DXS10164-DXS10162) were investigated in the group, respectively. No STR loci showed significant deviations from the Hardy-Weinberg equilibriums and no linkage disequilibriums of pairwise loci were found after Bonferroni correction, respectively. A combined power of discrimination in female individuals was 0.999999999985 and that in male individuals was 0.99999967, respectively. The combined mean exclusion chance in deficiency cases, normal trios and duo cases were 0.999934, 0.995754, and 0.999796, respectively. Significant differences were observed from 0 to 8 loci, when making comparisons between the data of Hui ethnic group and previously reported data from other 16 populations. The results indicated the new panel of 12 X-STR loci might be useful for forensic science application.

Antagonism of the histamine H4 receptor reduces LPS-induced TNF production in vivo.

OBJECTIVE: Antagonism of the histamine H4 receptor (H4R) has been shown to be anti-inflammatory in a number of preclinical disease models, however the exact mechanisms behind this are still being uncovered. In vitro, the receptor interacts with TLR and impacts inflammatory mediator production from a number of different cell types. Here it is shown that this interaction also occurs in vivo. MATERIALS AND METHODS: Wild-type and H4R deficient BALB/c mice received an i.p. injection of LPS in PBS in conjunction with p.o. JNJ 7777120 or JNJ 28307474 (H4R antagonists). Two hours later blood was collected and TNF was measured. RESULTS: Two different H4R antagonists inhibited LPS-induced TNF production in mice and this production was also reduced in H4R-deficient mice. The TNF mRNA analysis showed that the major source of the cytokine was the liver and not blood, and that the H4R antagonist only reduced the expression levels in the liver. Depletion or inactivation of macrophages reduced the TNF levels and eliminated the H4R sensitivity. Treatment with an H4R antagonist also reduced LPS-induced liver injury and blocked LPS-enhanced lung inflammation in mice. CONCLUSION: The data support an interaction between H4R and TLR activation in vivo that can drive inflammatory responses.

Evaluation of reading speed and contrast sensitivity in dry eye disease.

PURPOSE: Visual disturbance is a common symptom reported by patients with dry eye disease (DED). The purpose of this study was to evaluate visual performance, including reading speed and contrast sensitivity, in control and DED subjects. METHODS: Fifty-two DED patients (mild, n = 17; moderate, n = 22; severe, n = 13; based on corneal staining and the Ocular Surface Disease Index ≥ 20) and 20 control subjects (Ocular Surface Disease Index <13, no corneal staining) took part in this study. The age ranges for the control and DED patients were 18 to 45 years and 19 to 84 years, respectively. Contrast sensitivity was measured using the Holladay Automated Contrast Sensitivity System, and reading speed was determined using the Wilkins Rate of Reading Test. Analysis of covariance was conducted to compare clinical characteristics among subject groups while adjusting for age, sex, and study site. Partial correlation coefficients from linear regression were used to measure the linear relationship between contrast sensitivity and reading speed with DED parameters. RESULTS: The log of the minimum angle of resolution visual acuities and contrast sensitivity were not significantly different across subject groups. The DED patients (134.9 ± 4.95 words per minute) exhibited slower reading speeds than the control subjects (158.3 ± 8.40 words per minute, p = 0.046). As DED severity increased, the reading speed decreased (141.0 ± 7.96 words per minute, 136.8 ± 7.15 words per minute, and 127.0 ± 9.63 words per minute in mild, moderate, and severe groups, respectively). Reading rate was found to correlate weakly with corneal staining based on a partial correlation coefficient (-0.345, p < 0.001) but not with other DED parameters. CONCLUSIONS: The reading rate was lower in DED subjects than that in control subjects. As the DED severity increased, the reading rate decreased. This finding is consistent with patient-reported symptoms and provides direct evidence for the impact of DED on reading performance. These findings suggest that reading speed may be used to monitor treatment benefit in DED.

Immunomodulatory effect of the topical ophthalmic Janus kinase inhibitor tofacitinib (CP-690,550) in patients with dry eye disease.

OBJECTIVE: To evaluate the immunomodulatory effect of topical ophthalmic tofacitinib (CP-690,550) after an 8-week treatment period in patients with dry eye disease (DED). DESIGN: Biomarker substudy of a phase 1/2 prospective, randomized, vehicle- and comparator-controlled clinical trial (NCT00784719). PARTICIPANTS: A total of 82 patients with moderate to severe DED enrolled. METHODS: Patients received 1 of 5 doses of tofacitinib (0.0003%, 0.001%, 0.003%, or 0.005% twice daily [BID] or 0.005% once daily [QD]), active comparator (cyclosporine ophthalmic emulsion, 0.05% [Restasis, Allergan Inc., Irvine, CA]), or vehicle control BID for 8 weeks. Conjunctival impression cytology and tear fluid samples were collected at baseline and after an 8-week treatment period. Conjunctival cells were analyzed by flow cytometry for human leukocyte antigen DR-1 (HLA-DR). Tear fluids were analyzed by microsphere-based immunoassays for tear levels of cytokines and inflammation markers. MAIN OUTCOME MEASURES: Reduction in inflammation assessed by change from baseline in conjunctival cell surface level of HLA-DR and tear level of cytokines and inflammation markers. RESULTS: At week 8, a decrease in conjunctival cell surface expression of HLA-DR was observed in patients treated with tofacitinib 0.005% QD and 0.003% BID: 71% and 67% of baseline, respectively, compared with 133% of baseline in patients treated with vehicle (P=0.023 and P=0.006, compared with vehicle, respectively). Matrix metalloproteinase (MMP)-3 in tears was reduced from baseline at week 8 (40% of baseline, P=0.035) in the tofacitinib 0.005% QD group, whereas the vehicle group showed 77% of baseline (P>0.20). Interleukin (IL)-1ß in tears was 36% of baseline (P=0.053) in the tofacitinib 0.005% QD group and 95% of baseline (P > 0.20) in the vehicle group. Several other cytokines and inflammation markers in tears, including MMP-9, IL-15, IL-17A, and IL-12p70, were markedly reduced in the tofacitinib 0.005% QD group but not the vehicle group. There was an association between the changes in HLA-DR and the tear inflammation markers (P<0.05): HLA-DR with IL-12p70 (r=0.49) and IL-1ß (r=0.46), IL-12p70 with IL-1ß (r=0.90), and IL-17A with MMP-9 (r=0.82). CONCLUSIONS: Topical ophthalmic tofacitinib may act as an immunomodulator in patients with DED. Treatment for 8 weeks showed a promising reduction of conjunctival cell surface HLA-DR expression and tear levels of proinflammatory cytokines and inflammation markers.

Tear Cytokines as Biomarkers for Acute Ocular Graft-Versus-Host Disease.

PURPOSE: The purpose of this study was to analyze tear cytokine and complement levels in patients diagnosed with acute ocular graft-versus-host disease (oGVHD) and examine the consistency of these levels with the severity of clinical manifestations. METHODS: Ten patients with acute oGVHD (20 eyes) were enrolled for the assessment of tear cytokine levels and ocular surface parameters, and 18 healthy people (36 eyes) were selected as the control group. The tear cytokine and complement levels were measured using microsphere-based immunoassay analysis. RESULTS: The main clinical manifestations of acute oGVHD include eye redness, a large amount of purulent exudate, eye pain, and even false membranes. The levels of intercellular cell adhesion molecule-1, interleukin 6 (IL-6), interleukin 1 beta (IL-1ß), interleukin 8, epidermal growth factor (EGF), interleukin 7 (IL-7), B-cell activating factor, granulocyte-macrophage colony-stimulating factor (GM-CSF), and complement in patients with acute oGVHD showed significant differences compared with those in normal people. Furthermore, the levels of IL-6, IL-1ß, EGF, GM-CSF, IL-7, and C3a showed a stronger correlation with ocular surface parameters. CONCLUSIONS: Our study was the first to enroll patients with acute oGVHD to assess tear cytokine levels as a method contributing to the diagnosis of acute oGVHD. In addition, it has been demonstrated that certain tear cytokines, including intercellular cell adhesion molecule-1, IL-6, IL-1ß, interleukin 8, B-cell activating factor, GM-CSF, IL-7, EGF, and complement, may be new diagnostic biomarkers for acute oGVHD.

Genetic diversities of 21 non-CODIS autosomal STRs of a Chinese Tibetan ethnic minority group in Lhasa.

In the present study, we investigated 21 short tandem repeat (STR) loci (D6S474, D12ATA63, D22S1045, D10S1248, D1S1677, D11S4463, D1S1627, D3S4529, D2S441, D6S1017, D4S2408, D19S433, D17S1301, D1GATA113, D18S853, D20S482, D14S1434, D9S1122, D2S1776, D10S1435, D5S2500), which are not included in the Combined DNA Index System and Amelogenin locus in 104 randomly selected healthy autochthonous individuals from the Tibetan ethnic minority group residing in the Lhasa region, Tibet Autonomous Region of China. Allelic frequencies, common forensic statistical parameters, and the Hardy-Weinberg equilibrium in this population were calculated with a modified PowerState V12.xls. A total of 143 alleles were found in the Tibetan group with corresponding allelic frequencies ranging from 0.005 to 0.582. The observed heterozygosity, the expected heterozygosity, the power of discrimination, the power of exclusion, and the polymorphic information content ranged from 0.615 to 0.817, 0.559 to 0.787, 0.727 to 0.926, 0.310 to 0.632, and 0.488 to 0.760, respectively. Chi-square tests of the observed genotype frequencies and expected genotype frequencies in the samples showed no departure from the Hardy-Weinberg equilibrium at all loci except for D5S2500. Our results demonstrate that these 21 STRs are highly polymorphic and suitable for anthropological research, population genetics, and forensic paternity testing and human individual identification in this region, and can enrich Chinese ethnical genetic informational resources.

Genetic polymorphism analysis of 15 STR loci in Chinese Hui ethnic group residing in Qinghai province of China.

In the present study, we investigated the diversity distributions of allelic frequencies of 15 short tandem repeats (STRs) loci in a sample of Chinese Hui ethnic group in the Ningxia Hui Autonomous Region. The allelic frequencies of the 15 STR loci (D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818 and FGA) were obtained from 2975 unrelated healthy Hui individuals. The STR genotyping data of all the samples were generated by DNA extraction, multiple amplification, GeneScan and genotype analysis. The genetic distances among different populations were calculated by using Nei's method and a phylogenetic tree was constructed based on the allelic frequencies of the same 15 STR loci using the neighbor-joining method. A total of 185 alleles were observed in the Hui population, with the corresponding allelic frequencies ranging from 0.0002 to 0.5322. Chi-Square tests showed that all STR loci were in Hardy-Weinberg equilibrium. The forensic statistical parameters of all the loci showed high values. The population data in this study were compared with the previously published population data from other ethnics or areas. The Hui population showed significant differences from the Minnan Han, Uigur, Ewenki, Yi, Tibetan, Maonan and Malay ethnic minority groups in some loci, and from the South Morocco population and the Moroccan population in all the loci. Our results are valuable for human individual identification and paternity testing in the Chinese Hui population and are expected to enrich the genetic information resources of Chinese populations.

Impaired visual performance in patients with dry eye.

Patients with dry eye disease (DED) often complain about poor vision, which is not easily quantifiable. This review assesses the current understanding of clinical evaluations of visual function in patients with DED. Several noninvasive techniques for the assessment of visual performance have been utilized in patients with DED, and these are critically reviewed in relation to the visual symptoms experienced by these patients. It is clear that none of the current techniques is ideal, and there is not one appropriate, simple, clinical test that can be used for assessing visual impairment in patients with DED. Evidence from a comprehensive literature search combined with clinical experience have been used to identify which tests are currently of most benefit and to highlight the future development of a more specific clinical test for visual impairment in the dry eye patient.

[Research on extraction method of water body with DS spectral enhancement based on HJ-1 images].

Natural disaster is one of the major global issues, and it is an important premise for disaster prevention and reduction to monitor it. In the present paper, multi-temporal HJ-1 images pre- and posto-typhoon Morakot were used. First, radiometric calibration and registration were done, then, decorrelation stretch (DS) was applied, and finally, maximum likelihood classification (MLC) was adopted to extract water body and monitor change of water body caused by typhoon Morakot. The results show that after DS spectral enhancement, the correlations among bands decrease and spectral differences increase, and it is helpful to identify surface features. The accuracy assessment demonstrates that the overall accuracies and Kappa coefficients of four phases are higher, above 96.0% and 0.94 respectively, than that of direct MLC without DS spectral enhancement. It is beneficial to scheduling flood discharge and ensuring the safety of reservoir downstream by comparing extracted multi-temporal water bodies.

[GIS-based measurement of Haloxylon ammodendron tree ring]. / 基于GIS的梭梭年轮测量方法.

Tree ring data is of significance for reconstructing climate and predicting environmental dynamics. In order to accurately measure spacing and other parameters of Haloxylon ammodendron tree ring, we first assigned coordinate system to the scanned H. ammodendron disc PS images based on GIS, and then completed the H. ammodendron tree ring spacing measurement by using ENVI image classification software and GIS measuring tool. The measurement accuracy was proved by WinDENDRO tree ring analysis system. The results showed that there was no significant difference between those two methods (P=0.63), and that the difference of paired mean value was 0.87 µm, indicating that the measured results were accurate and reliable. The constructed method in this study could be used to measure the spacing of H. ammodendron tree ring, which lay the foundation for the automatic measurement of tree ring parameters such as area and perimeter. Our method could replace the current professional tree ring analysis system for some ring parameter measurement. The study would contribute to the dendroclimatology analysis and the investigation on age structure of H. ammodendron population.

[Discrimination and spectral response characteristic of stress leaves infected by rice Aphelenchoides besseyi Christie].

An ASD Field Spec Pro Full Range spectrometer was used to acquire the spectral reflectance of healthy and diseased leaves infected by rice Aphelenchoides besseyi Christie, which were cut from rice individuals in the paddy field. Firstly, foliar pigment content was investigated. As compared with healthy leaves, the total chlorophyll and carotene contents (mg x g(-1)) of diseased leaves decreased 18% and 22%, respectively. The diseased foliar content ratio of total chlorophyll to carotene was nearly 82% of the healthy ones. Secondly, the response characteristics of hyperspectral reflectance of diseased leaves were analyzed. The spectral reflectance in the blue (450-520 nm), green (520-590 nm) and red (630-690 nm) regions were 2.5, 2 and 3.3 times the healthy ones respectively due to the decrease in foliar pigment content, whereas in the near infrared (NIR, 770-890 nm) region was 71.7 of the healthy ones because of leaf twist, and 73.7% for shortwave infrared (SWIR, 1 500-2 400 nm) region, owing to water loss. Moreover, the hyperspectral feature parameters derived from the raw spectra and the first derivative spectra were analyzed. The red edge position (REP) and blue edge position (BEP) shifted about 8 and 10 nm toward the short wavelengths respectively. The green peak position (GPP) and red trough position (RTP) shifted about 8.5 and 6 nm respectively toward the longer wavelengths. Finally, the area of the red edge peak (the sum of derivative spectra from 680 to 740 nm) and red edge position (REP) as the input vectors entered into C-SVC, which was an soft nonlinear margin classification method of support vector machine, to recognize the healthy and diseased leaves. The kernel function was radial basis function (RBF) and the value of punishment coefficient (C) was obtained from the classification model of training data sets (n = 138). The performance of C-SVC was examined with the testing sample (n = 126), and healthy and diseased leaves could be successfully differentiated without errors. This research demonstrated that the response feature of spectral reflectance was obvious to disease stress in rice leaves, and it was feasible to discriminate diseased leaves from healthy ones based on C-SVC model and hyperspectral reflectance.

[Analysis on urban vegetations reflectance characteristics in Shanghai].

The spectral features of ground objects are not only the brief contents of mechanism of remote sensing, but also the important basis in remote sensing application. As one of main components of terrestrial ecosystems, urban forest plays a key role in maintaining urban ecosystem balance. In the present paper, the authors adopted FieldSpec 3 portable spectroscope made by American ASD Company, and investigated or examined some spots in the Kangjian park of Shanghai, China. The spectra of euonymus japonicus L. cv, hypericum monogynum, sabina chinensis, ophiopogon japonicus, viburnum awabuki, and buxus sinica were measured. According to the actual conditions, the authors analyzed the data noise characteristic of the spectrum and got rid of the noise with Savitzky Golay method. Meanwhile, differential spectrum technology was used to remove the environmental background influence. Then the authors analyzed their features and variation of these spectral curves from the vegetation canopy and leaf level respectively. The research on spectral reflectance characteristics for urban vegetations is very significant. And the result of this research can be used for the study of physical chemistry performances of urban vegetation, remote sensing retrieval, vegetation classification, vegetation survey and environmental monitoring in urban area.

[Spatiotemporal variation of growing season length of vegetation in China.] / 中国植被生长期的时空变化.

We analyzed the variation trend of growing season length (GSL) of different periods in provinces (regions) of China and the corresponding movement velocity of GSL isolines at 150, 200, 250, 300 and 350 days, based on daily mean temperature data of 822 meteorological stations from 1951 to 2017. In this study, the definition of GSL given by the world meteorological organization was adopted, together with Slope, Hurst and Mann-Kendall indices. The results showed that the GSL in northern China changed significantly during 1951-2017. The extension of GSL was faster in the north than the south, and faster in high-altitude areas than low-altitude ones. The trend of future GSL change in most regions of China converged with the current extension trend. The extension of GSL in northern provinces (regions) was generally 0.1-0.2 d·a-1, of which the fastest was Tibet with a speed of 0.44 d·a-1. The period 1981-2000 was the most changeable time of GSL in Chinese provinces (regions). The growing season start (GSS) of all provinces (regions) contributed more to the GSL extension, except for Xinjiang, whose GSL extension was dominated by the growing season end (GSE). In the high-latitude or high-altitude provinces, GSL was more sensitive to the change of mean annual temperature. The higher the mean annual temperature, the longer the GSL. Since 1951, China's GSL isolines of 150, 200, 250, 300 and 350 days showed notable variations. The fastest movement velocity was the 200 days isoline in Northeast China with an average northward movement velocity of 6.11 km·a-1. The general principle of the movement of China's GSL isoline was that the higher the value of the isoline, the slower the northward movement, with even a southward shift in part of the 350 days isoline. The extension of GSL in China would result in the northward shift of crop planting boundary and the extension of natural vegetation growth period. However, the specific impacts of this change on the quality, crop yield, and ecosystem carbon sequestration need further research.

[Normalized difference ratio pigment index for estimating chlorophyll and cartenoid contents of in leaves of rice].

The objective of the present study was (1) to construct new pigment indices based on making full use of all the spectral bands in the 350-2,500 nm region and (2) to compare the performance of these new pigment indices with that of the published normalized difference ratio pigment indices in estimating pigment content of rice. The 252 leaves of rice were sampled at different development stages, representing a wide range of pigment contents. The hyperspectral reflectance of leaves of rice and the corresponding chlorophyll contents and carotenoid contents were measured. A rigorous method using all the wavebands in the range of 350-2,500 nm was applied to generate all possible two-band normalized difference pigment indices, and then the linear models between these indices and chlorophyll and carotenoid contents were constructed. Finally, the index with the highest determination coefficients was selected as the optimal index for corresponding pigment. The model was tested and these selected indices were compared with the published indices. The result indicated that the indices [(R1729-R707)/(R1729+R707), (R1554-R572)/(R1554+R572), (R1729-R706)/(R1729+R706)), (R1536-R707)/(R1536+R707)] can relatively accurately estimate chlorophyll and cartenoid contents. The reference bands of the these new indices are mainly located in short wave infrared spectral region, which indicate that the spectral bands in the short wave infrared region are significant to construct normalized ratio pigment index, while the index bands of these indices are mostly in the region near 700 nm, and the longer bands of green region in the next place. Compared to the published indices, in general, the new indices give more accurate estimation of chlorophyll and carotenoid contents, or they behave the same as the best published index.

Identification of optimal hyperspectral bands for estimation of rice biophysical parameters.

The present study aims to identify the narrow spectral bands that are most suitable for characterizing rice biophysical parameters. The data used for this study come from ground-level hyperspectral reflectance measurements for five rice species at three levels of nitrogen fertilization during the growing period. Reflectance was measured in discrete narrow bands between 350 and 2,500 nm. Observed rice biophysical parameters included leaf area index (LAI), wet biomass and dry biomass. The stepwise regression method was applied to identify the optimal bands for rice biophysical parameter estimation. This research indicated that combinations of four narrow bands in stepwise regression models explained 69% to 83% variability for LAI, 56% to 73% for aboveground wet biomass and 70% to 83% for leaf wet biomass. An overwhelming proportion of rice information was in a particular portion of near infrared (NIR) (1,100-1,150 nm), red-edge (700-750 nm), and a longer portion of green (550-600 nm). These were followed by the moisture-sensitive NIR (950-1,000 nm), the intermediate portion of shortwave infrared (SWIR) (1 650-1,700 nm), and another portion of NIR (1,000-1,050 nm).

Assessing the response of seasonal variation of net primary productivity to climate using remote sensing data and geographic information system techniques in Xinjiang.

Net primary productivity (NPP) is a key component of energy and matter transformation in the terrestrial ecosystem, and the responses of NPP to global change locally and regionally have been one of the most important aspects in climate-vegetation relationship studies. In order to isolate causal climatic factors, it is very important to assess the response of seasonal variation of NPP to climate. In this paper, NPP in Xinjiang was estimated by NOAA/AVHRR Normalized Difference Vegetation Index (NDVI) data and geographic information system (GIS) techniques. The impact of climatic factors (air temperature, precipitation and sunshine percentage) on seasonal variations of NPP was studied by time lag and serial correlation ageing analysis. The results showed that the NPP for different land cover types have a similar correlation with any one of the three climatic factors, and precipitation is the major climatic factor influencing the seasonal variation of NPP in Xinjiang. It was found that the positive correlation at 0 lag appeared between NPP and precipitation and the serial correlation ageing was 0 d in most areas of Xinjiang, which indicated that the response of NPP to precipitation was immediate. However, NPP of different land cover types showed significant positive correlation at 2 month lag with air temperature, and the impact of which could persist 1 month as a whole. No correlation was found between NPP and sunshine percentage.

Quantifying biochemical variables of corn by hyperspectral reflectance at leaf scale.

To further develop the methods to remotely sense the biochemical content of plant canopies, we report the results of an experiment to estimate the concentrations of three biochemical variables of corn, i.e., nitrogen (N), crude fat (EE) and crude fiber (CF) concentrations, by spectral reflectance and the first derivative reflectance at fresh leaf scale. The correlations between spectral reflectance and the first derivative transformation and three biochemical variables were analyzed, and a set of estimation models were established using curve-fitting analyses. Coefficient of determination (R2), root mean square error (RMSE) and relative error of prediction (REP) of estimation models were calculated for the model quality evaluations, and the possible optimum estimation models of three biochemical variables were proposed, with R2 being 0.891, 0.698 and 0.480 for the estimation models of N, EE and CF concentrations, respectively. The results also indicate that using the first derivative reflectance was better than using raw spectral reflectance for all three biochemical variables estimation, and that the first derivative reflectances at 759 nm, 1954 nm and 2370 nm were most suitable to develop the estimation models of N, EE and CF concentrations, respectively. In addition, the high correlation coefficients of the theoretical and the measured biochemical parameters were obtained, especially for nitrogen (r=0.948).

Optimal waveband identification for estimation of leaf area index of paddy rice.

The objectives of the study were to select suitable wavebands for rice leaf area index (LAI) estimation using the data acquired over a whole growing season, and to test the efficiency of the selected wavebands by comparing them with feature positions of rice canopy spectra. In this study, the field experiment in 2002 growing season was conducted at the experimental farm of Zhejiang University, Hangzhou, China. Measurements of hyperspectral reflectance (350 approximately 2500 nm) and corresponding LAI were made for a paddy rice canopy throughout the growing season. And three methods were employed to identify the optimal wavebands for paddy rice LAI estimation: correlation coefficient-based method, vegetation index-based method, and stepwise regression method. This research selected 15 wavebands in the region of 350~2 500 nm, which appeared to be the optimal wavebands for the paddy rice LAI estimation. Of the selected wavebands, the most frequently occurring wavebands were centered around 554, 675, 723, and 1 633 nm. They were followed by 444, 524, 576, 594, 804, 849, 974, 1 074, 1 219, 1 510, and 2 194 nm. Most of them made physical sense and had their counterparts in spectral known feature positions, which indicates the promising potential of the 15 selected wavebands for the retrieval of paddy rice LAI.

[Predicting nitrogen concentrations from hyperspectral reflectance at hyperspectral reflectance at leaf and canopy for rape].

An experiment was designed to determine whether nitrogen concentrations could be predicted from reflectance (R) spectra of rape leaves in laboratory, and, if so, whether the predictive spectral features could be correlated with nitrogen concentration of simple canopies of rape. The best predictors for nitrogen in leaves appeared with first-difference transformations of R, and the bands selected were similar to those found in other studies. Shortwave infrared bands were best predictors for nitrogen. In the shortwave infrared region, however, the absolute differences in reflectance at critical bands were extremely small, and the bands of high correlation were narrow. High spectral and radiance resolution are required to resolve these differences accurately. Variability in canopy reflectance in shortwave infrared region was at least an order of magnitude beyond that necessary to detect signals from chemicals. The variability in first-difference R and log 1/R on canopy scales were related to the arrangement of trees with respect to direct solar radiation, instrument noise, leaf fluttering, and small change in atmospheric moisture. The first-difference of reflectance R based regressions prediction of nitrogen concentration at canopy level gets a good fitness.

[Wavebands selection for rice information extraction based on spectral bands inter-correlation].

The hyperspectral remote sensing data usually involve hundreds or even thousands of narrow bands, which may be crucial for providing additional information with significant improvements over broad bands in quantifying biophysical and biochemical variables of agricultural crop. However, the huge data generated by hyperspectral systems, and the problems this presents for storage and analysis, have far prevented the routine use of such data. The objective of the present research was to identify the spectral bands in the visible and near-infrared range that were suitable for the study of rice. The hyperspectral reflectance of canopy in different development stages was measured in experimental field using a 1 nm-wide spectroradiometer but was aggregated to 10 nm-wide bandwidths to match the first spaceborne hyperspectral sensor, Hyperion. The correlation coefficients(r) between all the combinations of spectral bands were computed, and then they were converted to R2 , which constituted R2 matrices. The matrices were plotted against wavebands. The criterion of band selection is that the lower the R2 value, the less the redundancy between two wavebands while the higher R2 indicates that there is redundant information between two wavebands. According to the criterion, the wavebands corresponding to the first 100 minimum R2 values were selected from all canopy spectra collected on different dates. And then these bands were analyzed. The results indicate that the visible and infrared (NIR and SWIR) themselves contain redundant information. The wavebands containing abundant information of rice are located in specific bands in the longer wavelength portion of the visible region, with secondary clusters in red edge region, in strongly reflective near-infrared region with relatively higher reflectance, in one particular section of short wave near-infrared (SWIR) (1 530 nm) and in the second maximum reflectance region of SWIR (2 215 nm). Compared with the selected bands with other vegetation, rice seems to have three spectral regions of 400-410 nm, 630-650 nm and 1 520-1 540 nm, which exclusively depict the characteristics of rice. Moreover, this research identified 17 spectral bands in the visible and near-infrared region, which were 405, 565, 585, 605, 620, 640, 660, 680, 695, 705, 720, 740, 865, 910, 1 085, 1 530 and 2 215 nm. These bands contain the majority of the rice information content. A reduction in band number without significant information loss is important because it makes it possible to achieve fine spatial resolution without sacrificing the ability to characterize rice status.