[Experimental Study on Soil Moisture Remote Sensing Based on Polarization Spectrum].

As a novel remote sensing technique, polarimetric detecting technology is a useful supplement to traditional hyperspectral remote sensing technology, which provides more information for remote sensing. By taking advantage of the polarization characteristics of the surface reflecting light of soil with different moisture, the polarization spectral method is applied to measure soil moisture. The spectropolarimeter was used to measure the polarized reflectance spectrum of different soil moisture. The correlation between soil moisture and polarization spectrum was analyzed. The polarization characteristics of soil surface reflecting light in different viewing angles were surveyed by experiments. The experimental results show that: in the higher soil moisture conditions, the polarization spectrum and soil moisture have a certain connection, especially in the 500～700 nm band and soil moisture is directly proportional to the degree of polarization; but in low soil moisture conditions, the correlation of polarization spectrum and soil moisture is not obvious; in addition, the polarization spectrum are influenced by viewing angles, for example, when the incident angle of source light is fixed at 50°, while the viewing angle of instrument is between 20° and 60°, the degree of polarization increases with the viewing angle. When the viewing angle becomes wider,, the degree of polarization changed more significantly with the soil moisture.

Genome-wide copy number variation study in anorectal malformations.

Anorectal malformations (ARMs, congenital obstruction of the anal opening) are among the most common birth defects requiring surgical treatment (2-5/10 000 live-births) and carry significant chronic morbidity. ARMs present either as isolated or as part of the phenotypic spectrum of some chromosomal abnormalities or monogenic syndromes. The etiology is unknown. To assess the genetic contribution to ARMs, we investigated single-nucleotide polymorphisms and copy number variations (CNVs) at genome-wide scale. A total of 363 Han Chinese sporadic ARM patients and 4006 Han Chinese controls were included. Overall, we detected a 1.3-fold significant excess of rare CNVs in patients. Stratification of patients by presence/absence of other congenital anomalies showed that while syndromic ARM patients carried significantly longer rare duplications than controls (P = 0.049), non-syndromic patients were enriched with both rare deletions and duplications when compared with controls (P = 0.00031). Twelve chromosomal aberrations and 114 rare CNVs were observed in patients but not in 868 controls nor 11 943 healthy individuals from the Database of Genomic Variants. Importantly, these aberrations were observed in isolated ARM patients. Gene-based analysis revealed 79 genes interfered by CNVs in patients only. In particular, we identified a de novo DKK4 duplication. DKK4 is a member of the WNT signaling pathway which is involved in the development of the anorectal region. In mice, Wnt disruption results in ARMs. Our data suggest a role for rare CNVs not only in syndromic but also in isolated ARM patients and provide a list of plausible candidate genes for the disorder.

Genome-wide association study identifies NRG1 as a susceptibility locus for Hirschsprung's disease.

Hirschsprung's disease (HSCR), or aganglionic megacolon, is a congenital disorder characterized by the absence of enteric ganglia in variable portions of the distal intestine. RET is a well-established susceptibility locus, although existing evidence strongly suggests additional loci contributing to sporadic HSCR. To identify these additional genetic loci, we carried out a genome-wide association study using the Affymetrix 500K marker set. We successfully genotyped 293,836 SNPs in 181 Chinese subjects with sporadic HSCR and 346 ethnically matched control subjects. The SNPs most associated with HSCR were genotyped in an independent set of 190 HSCR and 510 control subjects. Aside from SNPs in RET, the strongest overall associations in plausible candidate genes were found for 2 SNPs located in intron 1 of the neuregulin1 gene (NRG1) on 8p12, with rs16879552 and rs7835688 yielding odds ratios of 1.68 [CI(95%):(1.40, 2.00), P = 1.80 x 10(-8)] and 1.98 [CI(95%):(1.59, 2.47), P = 1.12 x 10(-9)], respectively, for the heterozygous risk genotypes under an additive model. There was also a significant interaction between RET and NRG1 (P = 0.0095), increasing the odds ratio 2.3-fold to 19.53 for the RET rs2435357 risk genotype (TT) in the presence of the NRG1 rs7835688 heterozygote, indicating that NRG1 is a modifier of HSRC penetrance. Our highly significant association findings are backed-up by the important role of NRG1 as regulator of the development of the enteric ganglia precursors. The identification of NRG1 as an additional HSCR susceptibility locus not only opens unique fields of investigation into the mechanisms underlying the HSCR pathology, but also the mechanisms by which a discrete number of loci interact with each other to cause disease.

[Investigation of polarization characteristics of soil surface with low vegetation cover and different soil moisture].

Compared with the spectral detection method, polarization detection could obtain more information of the target. For example, the polarization detection could be applied to interpret the refractive index and the surface roughness of the object, or retrieve the soil moisture, etc. Polarization detection provides a new approach to quantitative retrieval of soil moisture, and this is very important in agriculture, hydrology, meteorology and ecology. The polarization characteristics of soil surface with low vegetation cover,which is a example of mixed pixel in remote sensing, were researched with experiments, and the relationship between the polarization characteristics and soil moisture was also explored. The results showed that the polarization characteristics of soil surface with low vegetation cover are mainly determined by the area of bare soil, and are strongly relevant with the soil moisture. For the results of experiments in this paper, the IDOLP of soil surface with low vegetation cover increased with increasing soil moisture when the viewing angle of instrument was between 20 degree and 60 degree, while the incident angle of light source was fixed at 40 degree. This paper offered a new method to retrieve moisture content of soil with low vegetation cover.

[Measurement and analysis of blue-violet light emitting spectrum on tiny cubic boron nitride crystal].

The electroluminescence effect can be observed by the micro N-type wide-gap CBN semiconductor crystal under the condition of static eletric field. The micro N-type CBN crystal was fixed on the focus of the parabolic reflector of grating monochromator, and the maximum value of transmission ratio and the ideal signal-noise ratio can be obtained. Under the condition of static ectric-field intensity (4.7 x 10(6) V x cm(-1)), the blue-violet light-emitting spectrum of the CBN crystal was measured in the range from 350 to 450 nm. The construction of the CBN energy band, which was calculated with the First-principles method, the nonlinear relationship between current density and the ectric-field intensity that was measured and the phenomenon of electrical break-down were considered together to enable us to discuss the luminescence mechanism. Finally, the authors came up with the luminescence mechanism concerning electron migration from gamma energy valley to X energy valley. The large number of excited electrons we talked about were generated by polarization and breakdown of defect dipole before avalanche breakdown occurred.

Mapping of a Hirschsprung's disease locus in 3p21.

Hirschsprung's disease (HSCR) is a congenital disorder in which ganglion cells are absent in variable portions of the lower digestive tract according to which patients are classified. The RET gene is the major HSCR gene, although reduced penetrance of RET mutations and variable expression of HSCR phenotype indicates that more than one gene is required. An unidentified RET-dependent modifier on 3p21 appears to be necessary for transmission of the short HSCR (S-HSCR) phenotype. We investigated 6 Mb of the 3p21 region on a quest for the HSCR-susceptibility locus. Fifty-eight S-HSCR case-parent trios were genotyped using Sequenom technology for 214 tag single nucleotide polymorphisms (SNPs) distributed along 6 Mb of the 3p21 region. A five-marker haplotype, spanning a 118 kb gene-rich region, was found to be overtransmitted to affected offspring. The associated haplotype encompasses three genes involved in neurological phenotypes. Importantly, this association was replicated in an independent sample of 172 S-HSCR cases and 153 unrelated controls. Ranking markers by proximity to candidate genes or by expected functional consequences could be used in follow-up studies to finally pinpoint this HSCR locus.

Mutational analysis of SHH and GLI3 in anorectal malformations.

BACKGROUND: Anorectal malformations (congenital absence of the anal opening) are among the most common pediatric surgical problems and carry a significant chronic morbidity. METHODS: Direct sequencing was used to screen 88 anorectal malformations patients for mutations and polymorphisms in SHH and GLI3. These genes were chosen according to the phenotype presented by mutant mice and their expression patterns. RESULTS: We report on 10 GLI3 variants (IVS3+141C>G, T183A, IVS4+124T>C, IVS7+17G>A, IVS8+1 G>C, N503N, P941P, P998L, A1005A, A1039A) and four SHH mutation/variants (IVS1-49C>T, IVS2+111A>C, L214L, G290D). CONCLUSIONS: These variants are not over-represented in the healthy population and most are predicted to be benign. This study conveys the problematic assessment of the pathogenic role in disease of rare point mutations and variants.

[Accuracy analysis on a sort of polarized measurement in remote sensing].

Angular error of polarizer in polarimetric measurement is an important element affecting the measurement accuracy of degree of polarization, so angular error of polarizer should be considered in remote sensing of high-accuracy quantitative polarization. Simulation study shows that polarimetric measurement is relative to the polarization state (polarization angle or degree of polarization) of incident light in a specific measurement system of polarization. In the measurement mode of polarizer setting (0 degree, 60 degrees, 120 degrees), there is a maximum error of polarization measurement at the 0 degree or 180 degrees polarization angle while a minimum error at the 30 degrees, 90 degrees and 150 degrees polarization angle; In the measurement mode of polarizer setting (0 degree, 45 degrees, 90 degrees), there is a maximum error of polarization measurement near the 45 degrees polarization angle while a minimum error at the 0 degree, 90 degrees and 135 degrees polarization angle. The larger degree of polarization of incident light often contributes to the bigger measurement error except for incident light with several polarization angles. So the polarization measurement may be evaluated by the average degree of polarizatioo of linearly polarized light introduced in this paper. It is indicated that the measurement mode of polarizer setting (0 degree, 60 degrees, 120 degrees) is better than that of (0 degree, 45 degrees, 90 degrees).

[Magnetic resonance imaging of children with fecal incontinence after anoplasty for anorectal malformation and its clinical significance].

OBJECTIVE: To study the development of pelvic floor muscle, morphology and location of rectum and anal canal as well as morphology of spinal cord and sacrum based on pelvic magnetic resonance imaging(MRI) of children with fecal incontinence after anoplasty for anorectal malformation and to provide information on management of fecal incontinence. METHODS: Clinical and MRI data of 34 children with fecal incontinence after anoplasty for anorectal malformation in the Second Hospital of Shangdong University from September 2009 to December 2011 were analyzed retrospectively. There were 21 males and 13 females with the age of 3 to 14 years old. All the children underwent MRI detection. The morphology of external anal sphincter, puborectalis, ani levator, rectum and anal canal as well as the development of spinal cord and sacrum were observed using 1.5T MR scanner, including routine axial view, coronal view and sagittal view. RESULTS: MRI revealed that dysplasia of external anal sphincter, puborectalis and anilavatory were found in 18, 23 and 27 children, respectively. MRI also showed ectopia of rectum(n=6), dilation of rectum(n=12), increased anorectal angle(n=11), fat tissue around the anal canal(n=5), tethered cord syndrome(n=2), Currarino syndrome(n=2), sacrum dysplasia(n=11); and rectourethral fistula(n=2). The above MRI findings were confirmed by operation and clinical practice. CONCLUSIONS: MRI can provide clear morphology of external anal sphincter, puborectalis and ani lavatory, and location of rectum and anal canal as well as the development of spinal cord and sacrum. MRI is a valuable method to evaluate the children with fecal incontinence after anoplasty.

The effects of biofeedback training of pelvic floor muscles on fecal incontinence.

OBJECTIVE: The purpose of this study is to discuss the effect of pelvic floor muscle training on fecal incontinence. METHODS: A retrospective study was performed on patients who received pelvic floor muscle training from March 2002 to April 2007. There were 55 patients with fecal incontinence (male, 32 cases; female, 23 cases; mean age, 9.4 years old from 6 to 14), including 39 cases of anorectal malformation and 16 cases of Hirschsprung's disease. Pelvic floor muscle training was performed using biofeedback for 2 weeks in hospital, 2 times each day, and 30 minutes each time. The patients were then instructed to carry out self-training at home without the biofeedback device daily and received training evaluations in the hospital outpatient department monthly. All patients completed the training regimen and were followed up for 1 year. Anal manometry and clinical score were evaluated before and after training. RESULTS: Anal continence of 30 patients had satisfactory improvement, but not for the other 25 cases after training. The mean anal squeeze pressures of the group that had good results and the group that had poor results were 98.4 +/- 7.3 and 47.4 +/- 13.6 mm Hg, respectively, before training. There were 31 patients whose anal squeeze pressures were above 80 mm Hg, and 26 of these had satisfactory anal continence improvement, including all patients with Hirschsprung's disease. On the contrary, only 4 of 24 cases whose anal squeeze pressure was below 80 mm Hg acquired satisfactory anal continence improvement. CONCLUSIONS: Pelvic floor muscle training could achieve good results in some patients with fecal incontinence. Baseline measurements during anorectal manometry appear to provide good prediction of prognosis and effective management.