Sex-determining region Y gene promotes liver fibrosis and accounts for sexual dimorphism in its pathophysiology.

BACKGROUND & AIMS: Men are more prone to develop and die from liver fibrosis than women. In this study, we aim to investigate how sex-determining region Y gene (SRY) in hepatocytes promotes liver fibrosis. METHODS: Hepatocyte-specific Sry knock-in (KI), Sry knockout (KO), and Sry KI with platelet-derived growth factor receptor α (Pdgfrα) KO mice were generated. Liver fibrosis was induced in mice by bile duct ligation for 2 weeks or carbon tetrachloride treatment for 6 weeks. In addition, primary hepatocytes, hepatic stellate cells (HSCs), and immortalized cell lines were used for in vitro studies and mechanistic investigation. RESULTS: Compared to females, the severity of toxin- or cholestasis-induced liver fibrosis is similarly increased in castrated and uncastrated male mice. Among all Y chromosome-encoded genes, SRY was the most significantly upregulated and consistently increased gene in fibrotic/cirrhotic livers in male patients and in mouse models. Sry KI mice developed exacerbated liver fibrosis, whereas Sry KO mice had alleviated liver fibrosis, compared to age- and sex-matched control mice after bile duct ligation or administration of carbon tetrachloride. Mechanistically, both our in vivo and in vitro studies illustrated that SRY in hepatocytes can transcriptionally regulate Pdgfrα expression, and promote HMGB1 (high mobility group box 1) release and subsequent HSC activation. Pdgfrα KO or treatment with the SRY inhibitor DAX1 in Sry KI mice abolished SRY-induced HMGB1 secretion and liver fibrosis. CONCLUSIONS: SRY is a strong pro-fibrotic factor and accounts for the sex disparity observed in liver fibrosis, suggesting its critical role as a potentially sex-specific therapeutic target for prevention and treatment of the disease. IMPACT AND IMPLICATION: We identified that a male-specific gene, sex-determining region Y gene (SRY), is a strong pro-fibrotic gene that accounts for the sex disparity observed in liver fibrosis. As such, SRY might be an appropriate target for surveillance and treatment of liver fibrosis in a sex-specific manner. Additionally, SRY might be a key player in the sexual dimorphism observed in hepatic pathophysiology more generally.

Supramolecular Structure and Photo-Thermo-Electric Property of Hydrogen-Bonded Liquid Crystalline Polymer Containing Poly(4-vinylpridine) and Cyanostilbene Side Chains.

A series of side-chain liquid crystalline polymers P4VP(CN-DBE)x , where x is the molar ratio of cyanostilbene (CN-DBE) to poly(4-vinylpyridine) (P4VP) repeating unit, was synthesized based on the intermolecular hydrogen bonding between P4VP and CN-DBE. Their luminescent property, liquid crystalline structure and photo-thermo-electric property were elucidated using photoluminescence spectra, X-ray diffraction, thermal imaging and thermoelectric experiments. With the increase of x, the supramolecular system can be changed from lamellar structure to hexagonal columnar structure. Moreover, the P4VP(CN-DBE)x polymer with columnar structure exhibits more efficient photothermal effect. The temperature of P4VP(CN-DBE)0.6 can rise to 130 °C within 10 s under the irradiation of ultraviolet lamp. In addition, the supramolecular system possesses unique photo-thermo-electric conversion ability, and 25 mA current can be detected in the circuit coupled with the thermoelectric module. This work broadens the potential applications of hydrogen-bonded polymer, and provides a simple and facile strategy to prepare liquid crystalline polymers with photo-thermo-electric property.

Blue-Emitting Zero-Dimensional Inorganic-Organic Hybrids Constructed from Beta-Diketonate Ligands and Bulky Organic Cations.

Two zero-dimensional inorganic-organic hybrids, namely, [C4mim][Cd(TCDPPA)3] (1) and [C4mpy][Cd(TCDPPA)3] (2), where (TCDPPA)- = 2,2,2-trichloro-N-(di(pyrrolidin-1-yl)phosphoryl)acetamide, (C4mim)+ = 1-butyl-3-methylimidazolium, and (C4mpy)+ = 1-butyl-4-methylpyridinium, have been synthesized via metathesis reactions and characterized systematically. These ionic cadmium-containing inorganic-organic hybrid compounds are assembled from a bulky organic cation and a complex anion constructed from the chelation of three TCDPPA ligands to one cadmium ion. These compounds possess wide band gaps and emit in the deep-blue region intensely with a quantum yield as high as 34.04%. The success of this work provides a new method for the design and fabrication of high-efficiency blue-emitting materials.

Implementation of CsLIS/NES in linalool biosynthesis involves transcript splicing regulation in Camellia sinensis.

Volatile terpenoids produced in tea plants (Camellia sinensis) are airborne signals interacting against other ecosystem members, but also pleasant odorants of tea products. Transcription regulation (including transcript processing) is pivotal for plant volatile terpenoid production. In this study, a terpene synthase gene CsLIS/NES was recovered from tea plants (C. sinensis cv. "Long-Men Xiang"). CsLIS/NES transcription regulation resulted in 2 splicing forms: CsLIS/NES-1 and CsLIS/NES-2 lacking a 305 bp-fragment at N-terminus, both producing (E)-nerolidol and linalool in vitro. Transgenic tobacco studies and a gene-specific antisense oligo-deoxynucleotide suppression applied in tea leaves indicated that CsLIS/NES-1, localized in chloroplasts, acted as linalool synthase, whereas CsLIS/NES-2 localized in cytosol, functioned as a potential nerolidol synthase, but not linalool synthase. Expression patterns of the 2 transcript isoforms in tea were distinctly different and responded differentially to the application of stress signal molecule methyl jasmonate. Leaf expression of CsLIS/NES-1, but not CsLIS/NES-2, was significantly induced by methyl jasmonate. Our data indicated that distinct transcript splicing regulation patterns, together with subcellular compartmentation of CsLIS/NE-1 and CsLIS/NE-2 implemented the linalool biosynthesis regulation in tea plants in responding to endogenous and exogenous regulatory factors.

A high-density microelectrode-tissue-microelectrode sandwich platform for application of retinal circuit study.

BACKGROUND: Microelectrode array (MEA) devices are frequently used in neural circuit studies, especially in retinal prosthesis. For a high throughput stimulation and recording paradigm, it is desirable to obtain the responses of multiple surface RGCs initiated from the electrical signals delivered to multiple photoreceptor cells. This can be achieved by an high density MEA-tissue-MEA (MTM) sandwich configuration. However, the retina is one of the most metabolically active tissues, consumes oxygen as rapidly as the brain. The major concern of the MTM configuration is the supply of oxygen. METHODS: We aimed to develop a high density MTM sandwich platform which consists of stacks of a stimulation MEA, retinal tissue and a recording MEA. Retina is a metabolically active tissue and the firing rate is very sensitive to oxygen level. We designed, simulated and microfabricated porous high density MEAs and an adjustable perfusion system that electrical signals can be delivered to and recorded from the clipped retinal tissue. RESULTS: The porous high-density MEAs linked with stimulation or recording devices within a perfusion system were manufactured and the MTM platform was assembled with a retina slice inside. The firing rate remained constant between 25 and 55 min before dramatically declined, indicating that within certain period of time (e.g. 30 min after habituation), the retina condition was kept by sufficient oxygen supply via the perfusion holes in the MEAs provided by the double perfusion system. CONCLUSIONS: MTM sandwich structure is an efficient platform to study the retinal neural circuit. The material and arrangement of high density microelectrodes with porous design make this MEA appropriate for sub-retina prosthesis. Finding ways to prolong the recording time and reduce the signal-to-noise ratio are important to improve our MTM prototype.

A social diffusion model with an application on election simulation.

Issues about opinion diffusion have been studied for decades. It has so far no empirical approach to model the interflow and formation of crowd's opinion in elections due to two reasons. First, unlike the spread of information or flu, individuals have their intrinsic attitudes to election candidates in advance. Second, opinions are generally simply assumed as single values in most diffusion models. However, in this case, an opinion should represent preference toward multiple candidates. Previously done models thus may not intuitively interpret such scenario. This work is to design a diffusion model which is capable of managing the aforementioned scenario. To demonstrate the usefulness of our model, we simulate the diffusion on the network built based on a publicly available bibliography dataset. We compare the proposed model with other well-known models such as independent cascade. It turns out that our model consistently outperforms other models. We additionally investigate electoral issues with our model simulator.

Transcutaneous auricular vagus stimulation (taVNS) improves human working memory performance under sleep deprivation stress.

Many human activities require high cognitive performance over long periods, while impairments induced by sleep deprivation influence various aspects of cognitive abilities, including working memory (WM), attention, and processing speed. Based on previous research, vagal nerve stimulation can modulate cognitive abilities, attention, and arousal. Two experiments were conducted to assess the efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) to relieve the deleterious effects of sleep deprivation. In the first experiment, 35 participants completed N-back tasks at 8:00 a.m. for two consecutive days in a within-subject study. Then, the participants received either taVNS or earlobe stimulation (active control) intervention in two sessions at random orders after 24 h of sustained wakefulness. Then, they completed the N-back tasks again. In the second experiment, 30 participants completed the psychomotor vigilance task (PVT), and 32 completed the N-back tasks at 8:00 a.m. on the first and second days. Then, they received either taVNS or earlobe stimulation at random orders and finished the N-back and PVT tasks immediately after one hour. In Experiment 1, taVNS could significantly improve the accuracy rate of participants in spatial 3-back tasks compared to active control, which was consistent with experiment 2. However, taVNS did not specifically enhance PVT performance. Therefore, taVNS could be a powerful intervention for acute sleep deprivation as it can improve performance on high cognitive load tasks and is easy to administer.

Thermally induced morphology evolution of pit-patterned Si substrate and its effect on nucleation properties of Ge dots.

We demonstrate the effect of the pre-growth heat treatment process on the nucleation properties of Ge dots grown on pit-patterned Si(001) substrates. The prefabricated 200 nm diameter pits inherently evolve into truncated inverted pyramids (TIPs) with (110) base edges and a 7°-9° sidewall slope during heat treatment; this morphology transformation is robust against variations in shape and orientation of the pit patterns. Uniform Ge dots with an areal density of 4 × 10(9) cm(-2) were obtained on the Si substrates having TIPs. Each TIP contains four aligned Ge dots locating symmetrically with respect to (110). These dots exhibit an elliptical dome shape with major axis oriented along (100). The nucleation position, shape and spatial orientation of these Ge dots coincide with the calculated surface chemical potential distribution of the TIP.

[A fixation frame for acupuncture and moxibustion of Shu-Mu acupoint combination in rats].

Shu-Mu acupoint combination is commonly employed in acupuncture and moxibustion treatment. In animal experiments, it is difficult to implement such combination because of the uncontrollable features of animals. Therefore, there is an urgent need to design an experimental device to facilitate the operation of acupuncture and moxibustion at Shu-Mu acupoints in rats. The present study designed a device equipped with a fixed plate and a moxibustion frame for rats. The fixed plate and the moxibustion frame with detachable connection can allow acupuncture on the back, chest, and abdomen of rats to meet the requirements of the Shu-Mu acupoint combination. The moxibustion frame is made of universal hose and equipped with moxa clip, which ensures moxibustion in any direction and performs moxibustion on acupoints in the back, chest, and abdomen simultaneously. This device is unique in structure and convenient in operation, with safety and reliability. It is beneficial to the development of animal experiments related to acupuncture and moxibustion of Shu-Mu acupoint combination in the future.

Relationship between carotid artery stiffness and total serum homocysteine in coronary slow flow phenomenon: a high-resolution echo-tracking study.

Background: Coronary slow flow phenomenon (CSFP) is not uncommon in conventional coronary angiography. A disorder of serum homocysteine (tHcy) metabolism may play a role in the pathogenesis of slow coronary flow. Moreover, elevated tHcy concentration is closely associated with atherosclerosis. We aimed to evaluate the relationship between carotid artery stiffness and serum tHcy levels in patients with CSFP. Methods: This was a case-control study. The study population comprised 146 patients with newly diagnosed stable angina, including 73 patients with CSFP and 73 patients with normal coronary flow. All participants underwent conventional coronary angiography, carotid ultrasonography, and biochemical examination. Results: The carotid artery stiffness parameters of ß index (ß), pressure-strain elastic modulus (Ep), and local pulse wave velocity (PWV) in the CSFP group were significantly higher than those in the control group (ß: 10.75±2.16 vs. 9.02±2.11, P=0.007; Ep: 147.41±41.22 vs. 116.21±39.21, P=0.004; PWV: 7.45±1.23 vs. 6.16±1.20, P=0.003), However, arterial compliance (AC) was lower in the CSFP group than the control group (0.52±0.11 vs. 0.69±0.24, P=0.008). The mean thrombolysis in myocardial infarction (TIMI) frame count and the tHcy concentration in the CSFP group were significantly higher than those in the control group (48.60±1.30 vs. 24.50±3.80, P=0.001; 19.95±4.00 vs. 9.12±2.72, P=0.009). The tHcy concentration was positively correlated with ß (R value =0.494, P<0.0001), Ep (R value =0.469, P<0.0001), and PWV (R value =0.436, P<0.0001), but negatively correlated with AC (R value =-0.230, P=0.022). The predictors of CSFP were tHcy concentration, left PWV, right PWV, left ß index, and right ß index. Among them, the left ß index and right ß index were the best indictors for predicting CSFP. The cutoff values of left ß index, right ß index, left PWV, and right PWV were 9.3, 9.3, 6.7, and 6.6, respectively. Conclusions: Our data showed that serum tHcy levels were elevated in patients with CSFP compared with the control group. Carotid artery stiffness parameters were correlated with tHcy. The best predictors of CSFP were left ß index and right ß index. These findings may contribute to a better understanding of systemic vascular disorders in patients with coronary slow flow, rather than simply attributing such disorders to a single and isolated lesion of the epicardial coronary artery.

Tetraphenylethylene sulfonate derivative as turn-on fluorescent sensor for berberine chloride detection in aqueous solution.

A negatively-charged tetraphenylethylene derivative (TPE-SE) was designed and synthesized as turn-on fluorescent sensor for berberine chloride (BBC) detection in aqueous solution. The fluorescent property and detection mechanism were elucidated by UV-vis absorption spectra, photoluminescence spectra, dynamic light scattering experiments. The results reveal that the BBC can lead to aggregation-induced emission of TPE-SE due to the electrostatic interactions, endowing TPE-SE with excellent turn-on detecting ability, high selectivity and sensitivity to BBC. The detection limit is as low as 6.58 × 10-6M. These results should be applicable to fabricate special turn-on fluorescent sensors towards various antibiotics, and it is crucially important for achieving reasonable control and intake of small biomolecules.

Pheromone antagonism in Plu tella xylostella (Linnaeus) by sex pheromones of two sympatric noctuid moths.

BACKGROUND: Responses to sex pheromones are commonly antagonized by pheromone components of closely related species. Pheromone antagonism has not been widely explored for phylogenetically distant species that have completely different pheromone components. Yet, pheromone components of sympatrically occurring species may also interfere with each other even if these species are distantly related. Here, the effects of heterospecific pheromones on electrophysiology (electroantennogram, EAG) and behavioral responses were tested on the diamondback moth Plutella xyloslella (Plutellidae) and two sympatric noctuid moth species, Spodoptera litura and Spodoptera exigua, whose larvae also feed on Brassica crops. RESULTS: The sex pheromone blend of P. xyloslella, and its components, did not elicit EAG responses in males of the two noctuid species, while sex pheromone components of the noctuid moths elicited significant EAG responses in P. xyloslella males. In wind tunnel bioassays, both (Z, E)-9, 12-tetradecadienyl acetate (ZE-9,12-14:OAc) and (Z, E)-9, 11-tetradecadienyl acetate (ZE-9,11-14:OAc), sex pheromone components from the noctuid moths, inhibited the upwind flight behavior of P. xyloslella males toward an intraspecific pheromone odor source. In Brassica fields, sex pheromone lures of P. xyloslella did not influence trap catches of the noctuid moths, while P. xyloslella pheromone lures baited with either ZE-9,11-14:OAc or ZE-9,12-14:OAc decreased trap catches of P. xyloslella males in a dose-dependent manner. Trap catches of P. xylostella males were also affected by the proximity of ZE-9,11-14:OAc or ZE-9,12-14:OAc to P. xylostella lures. CONCLUSION: The uni-directional pheromone antagonism by ZE-9,11-14:OAc and ZE-9,12-14:OAc suggests innovative semiochemical-based strategies for the management of P. xyloslella and other economically important pests in Brassica fields. © 2021 Society of Chemical Industry.

Assessing the Effect of Simultaneous Combining of Transcranial Direct Current Stimulation and Transcutaneous Auricular Vagus Nerve Stimulation on the Improvement of Working Memory Performance in Healthy Individuals.

A previous study found that combining transcranial direct current stimulation (tDCS) and transcutaneous auricular vagus nerve stimulation (taVNS) could evoke significantly larger activation on a range of cortical and subcortical brain regions than the numerical summation of tDCS and taVNS effects. In this study, two within-subject experiments were employed to investigate its effects on working memory (WM). In experiment 1, the WM modulatory effects of tDCS over the left dorsolateral prefrontal cortex (DLPFC), taVNS, and simultaneous joint simulation of tDCS over the left DLPFC and taVNS (SJS-L) were compared among 60 healthy subjects. They received these three interventions between the baseline test and post-test in a random manner three times. In spatial 3-back task, there was a significant interaction between time and stimulations in the accuracy rate of matching trials (mACC, p=0.018). MACCs were significantly improved by SJS (p = 0.001) and taVNS (p = 0.045), but not by tDCS (p = 0.495). Moreover, 41 subjects in the SJS group showed improvement, which was significantly larger than that in the taVNS group (29 subjects) and tDCS group (26 subjects). To further investigate the generalization effects of SJS, 72 students were recruited in experiment 2. They received tDCS over the right DLPFC, taVNS, simultaneous joint simulation of tDCS over the right DLPFC and taVNS (SJS-R), and sham stimulation in a random manner four times. No significant results were found, but there was a tendency similar to experiment 1 in the spatial 3-back task. In conclusion, combining tDCS and taVNS might be a potential non-invasive neuromodulation technique which is worthy of study in future.

Per1 gene polymorphisms influence the relationship between brain white matter microstructure and depression risk.

Background: Circadian rhythm was involved in the pathogenesis of depression. The detection of circadian genes and white matter (WM) integrity achieved increasing focus for early prediction and diagnosis of major depressive disorder (MDD). This study aimed to explore the effects of PER1 gene polymorphisms (rs7221412), one of the key circadian genes, on the association between depressive level and WM microstructural integrity. Materials and methods: Diffusion tensor imaging scanning and depression assessment (Beck Depression Inventory, BDI) were performed in 77 healthy college students. Participants also underwent PER1 polymorphism detection and were divided into the AG group and AA group. The effects of PER1 genotypes on the association between the WM characteristics and BDI were analyzed using tract-based spatial statistics method. Results: Compared with homozygous form of PER1 gene (AA), more individuals with risk allele G of PER1 gene (AG) were in depression state with BDI cutoff of 14 (χ2 = 7.37, uncorrected p = 0.007). At the level of brain imaging, the WM integrity in corpus callosum, internal capsule, corona radiata and fornix was poorer in AG group compared with AA group. Furthermore, significant interaction effects of genotype × BDI on WM characteristics were observed in several emotion-related WM tracts. To be specific, the significant relationships between BDI and WM characteristics in corpus callosum, internal capsule, corona radiata, fornix, external capsule and sagittal stratum were only found in AG group, but not in AA group. Conclusion: Our findings suggested that the PER1 genotypes and emotion-related WM microstructure may provide more effective measures of depression risk at an early phase.

[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.

Field-effect pump: liquid dielectrophoresis along a virtual microchannel with source-gate-drain electric fields.

We investigate liquid dielectrophoresis (LDEP) to implement field-effect pumps (FEPs) that drive liquids from source, via gate, toward drain electric fields between parallel plates without external pumps or the problem of dead volume. The appropriate gate electric field establishes a wall-less virtual microchannel to transfer the liquid from source to drain with an adjustable flow rate (Q) controlled by the difference of the square of the electric field strength (ΔE2DS). Analogous to field-effect transistors (FETs), the FEPs can operate in a "linear", "transition" or "saturation" region depending on ΔE2GD and ΔE2DS. With a sufficient ΔE2GD and a small ΔE2DS, the FEPs operated in the linear region where Q was linearly proportional to ΔE2DS and inversely proportional to the flow resistance R that was mainly determined by the length (L), width (W) and height (H) of a stable and fully-occupied virtual microchannel. With an insufficient ΔE2GD and a moderate to large ΔE2DS, narrowing, tapering and even pinch-off of virtual microchannels were observed, which increased R and changed the operation into the transition or saturation region. A field-effect stream merger regulating two streams was built based on two FEPs with shared gate and drain electrodes. The versatility of FEPs was demonstrated with preliminary studies on whole blood and particle solutions.

[Rule mining of acupoint and medication selection of acupoint application therapy for functional constipation].

OBJECTIVE: To analyze the rules of acupoint and medication selection of acupoint application therapy for functional constipation (FC) by data mining technology. METHODS: The clinical research literature regarding acupoint application therapy for FC from published to February 26, 2020 was searched in CNKI, VIP, Wanfang, SinoMed and PubMed. The prescriptions were extracted, and by using SPSS24.0 and SPSS Modeler14.0 software, the use of high-frequency acupoints and medication was summarized. The association rule analysis, cluster analysis and core prescription analysis of acupoints and medication were analyzed. RESULTS: A total of 122 prescriptions of acupoint application therapy were included, involving 32 acupoints. The core prescription of acupoints was Tianshu (ST 25), Dachangshu (BL 25), Shenque (CV 8) and Guanyuan (CV 4). The high-frequency meridians mainly included conception vessel, yangming stomach meridian of foot and taiyang bladder meridian of foot. The core prescription of medication was rheum officinale, mirabilite, immature bitter orange, mangnolia officinalis, common aucklandia root and borneol. CONCLUSION: The use of local acupoint and regulating-qi and purgating medication is an important principle of acupoint application therapy for FC.

[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).