NIR Spectral Inversion of Soil Physicochemical Properties in Tea Plantations under Different Particle Size States.

Soil fertility is vital for the growth of tea plants. The physicochemical properties of soil play a key role in the evaluation of soil fertility. Thus, realizing the rapid and accurate detection of soil physicochemical properties is of great significance for promoting the development of precision agriculture in tea plantations. In recent years, spectral data have become an important tool for the non-destructive testing of soil physicochemical properties. In this study, a support vector regression (SVR) model was constructed to model the hydrolyzed nitrogen, available potassium, and effective phosphorus in tea plantation soils of different grain sizes. Then, the successful projections algorithm (SPA) and least-angle regression (LAR) and bootstrapping soft shrinkage (BOSS) variable importance screening methods were used to optimize the variables in the soil physicochemical properties. The findings demonstrated that soil particle sizes of 0.25-0.5 mm produced the best predictions for all three physicochemical properties. After further using the dimensionality reduction approach, the LAR algorithm (R2C = 0.979, R2P = 0.976, RPD = 6.613) performed optimally in the prediction model for hydrolytic nitrogen at a soil particle size of 0.25~0.5. The models using data dimensionality reduction and those that used the BOSS method to estimate available potassium (R2C = 0.977, R2P = 0.981, RPD = 7.222) and effective phosphorus (R2C = 0.969, R2P = 0.964, RPD = 5.163) had the best accuracy. In order to offer a reference for the accurate detection of soil physicochemical properties in tea plantations, this study investigated the modeling effect of each physicochemical property under various soil particle sizes and integrated the regression model with various downscaling strategies.

Research on the Detection Method of Organic Matter in Tea Garden Soil Based on Image Information and Hyperspectral Data Fusion.

Soil organic matter is an important component that reflects soil fertility and promotes plant growth. The soil of typical Chinese tea plantations was used as the research object in this work, and by combining soil hyperspectral data and image texture characteristics, a quantitative prediction model of soil organic matter based on machine vision and hyperspectral imaging technology was built. Three methods, standard normalized variate (SNV), multisource scattering correction (MSC), and smoothing, were first used to preprocess the spectra. After that, random frog (RF), variable combination population analysis (VCPA), and variable combination population analysis and iterative retained information variable (VCPA-IRIV) algorithms were used to extract the characteristic bands. Finally, the quantitative prediction model of nonlinear support vector regression (SVR) and linear partial least squares regression (PLSR) for soil organic matter was established by combining nine color features and five texture features of hyperspectral images. The outcomes demonstrate that, in comparison to single spectral data, fusion data may greatly increase the performance of the prediction model, with MSC + VCPA-IRIV + SVR (R2C = 0.995, R2P = 0.986, RPD = 8.155) being the optimal approach combination. This work offers excellent justification for more investigation into nondestructive methods for determining the amount of organic matter in soil.

A binding site outside the canonical PDZ domain determines the specific interaction between Shank and SAPAP and their function.

Shank and SAPAP (synapse-associated protein 90/postsynaptic density-95-associated protein) are two highly abundant scaffold proteins that directly interact with each other to regulate excitatory synapse development and plasticity. Mutations of SAPAP, but not other reported Shank PDZ domain binders, share a significant overlap on behavioral abnormalities with the mutations of Shank both in patients and in animal models. The molecular mechanism governing the exquisite specificity of the Shank/SAPAP interaction is not clear, however. Here we report that a sequence preceding the canonical PDZ domain of Shank, together with the elongated PDZ BC loop, form another binding site for a sequence upstream of the SAPAP PDZ-binding motif, leading to a several hundred-fold increase in the affinity of the Shank/SAPAP interaction. We provide evidence that the specific interaction afforded by this newly identified site is required for Shank synaptic targeting and the Shank-induced synaptic activity increase. Our study provides a molecular explanation of how Shank and SAPAP dosage changes due to their gene copy number variations can contribute to different psychiatric disorders.

Injured adult retinal axons with Pten and Socs3 co-deletion reform active synapses with suprachiasmatic neurons.

Despite advances in promoting axonal regeneration after adult central nervous system injury, elicitation of a large number of lesion-passing axons reform active synaptic connections with natural target neurons remains limited. By deleting both Pten and Socs3 in retinal ganglion cells, we report that optic nerve axons after prechiasm lesion robustly reinnervate the hypothalamus, form new synapses with neurons in the suprachiasmatic nucleus (SCN), and re-integrate with the existing circuitry. Photic or electric stimulation of the retinal axons induces neuronal response in SCN. However both the innervation pattern and evoked responses are not completely restored by the regenerating axons, suggesting that combining with other strategies is necessary to overcome the defective rewiring. Our results support that boosting the intrinsic growth capacity in injured neurons promotes axonal reinnervation and rewiring.

Shootin1 Regulates Retinal Ganglion Cell Neurite Development: Insights From an RGC Direct Somatic Cell Reprogramming Model.

Purpose: Retinal ganglion cells (RGCs) connect the retina to the brain. Proper development of the axons and dendrites of RGCs is the basis for these cells to function as projection neurons to deliver visual information to the brain. The purpose of this study was to investigate the function of Shtn1 (which encodes shootin1) in RGC neurite development. Methods: Immunofluorescence (IF) was used to characterize the expression pattern of marker genes. An in vitro direct somatic cell reprogramming system was used to generate RGC-like neurons (iRGCs), which was subsequently used to study the function of Shtn1. Short-hairpin RNAs (shRNAs) were used to knock down Shtn1, and the coding sequence (CDS) of Shtn1 was used to overexpress the gene. Lentiviruses were used to deliver shRNAs or CDSs into iRGCs. The patch clamp technique was used to measure the electrophysiological properties of the iRGCs. RNA sequencing (RNA-seq) was used to examine transcriptome expression. Results: Using IF, we demonstrated that shootin1 is distinctively expressed in RGCs during the period in which RGCs actively develop and adjust the connections of their neurites with upstream and downstream neurons. Using the iRGC system, we demonstrated that Shtn1 promotes the growth and complexity of neurites and thus the electrophysiological maturation, of iRGCs. RNA-seq analyses showed that Shtn1 may also regulate gene expression and neurogenesis in iRGCs. Conclusions: Shtn1 promotes RGC neurite development. These findings improve our understanding of the molecular machinery governing RGC neurite development and may help to optimize future RGC regeneration methods.

Retinal Ganglion Cell Fate Induction by Ngn-Family Transcription Factors.

Purpose: Retinal ganglion cells (RGCs) are the projection neurons of the retina. Loss of RGCs is the cellular basis for vision loss in patients with glaucoma. Finding ways to regenerate RGCs will aid in the development of regenerative therapies for patients with glaucoma. The aim of this study was to examine the ability of Ngn-family transcription factors (TFs) to induce RGC regeneration through reprogramming in vitro and in vivo. Methods: In vitro, lentiviruses were used to deliver Ngn-TFs into mouse embryonic fibroblasts (MEFs). In vivo, mouse pup retina electroporation was used to deliver Ngn-TFs into late-stage retinal progenitor cells (RPCs). Immunofluorescence staining and RNA sequencing were used to examine cell fate reprogramming; patch-clamp recording was used to examine neuronal electrophysiologic functions. Results: In vitro, all three Ngn-TFs, Ngn1, Ngn2, and Ngn3, were able to work alone to reprogram MEFs into RGC-like neurons that resembled RGCs at the transcriptome level, exhibited typical neuronal membrane electrophysiologic properties, and formed functional synaptic communications with retinal neurons. In vivo, Ngn-TFs reprogrammed the differentiation-competent state of late-stage RPCs to generate RGCs. Conclusions: Ngn-TFs are effective in inducing an RGC-like fate both in vitro and in vivo and might be explored further in the future for glaucoma translational applications.

[Nondestructive measurement of sugar content of Hami melon based on diffuse reflectance hyperspectral imaging technique].

The research on nondestructive test for detecting the sugar content of Hami melon by the technology of hyperspectral imaging was put forward. The research used the hyperspectral imaging system to get the diffuse reflective spectrum information (400 - 1 000 nm) of anilox class Hami melon sugar content, chose effective whole wavelength (500 - 820 nm)to do the modeling regression analysis the sugar content of Hami melon. The research compared the correction method of MSC and SNV, and also compared the influence of accuracy of modeling in terms of the spectrum pretreatment methods of original spectrum, first order differential, second order differential; Using the methods of PLS, SMLR and PCR, the comparative analysis of sugar content detection model effect with skin Hami melon and peel Hami melon was conducted. The results showed that after the original spectrum being processed by MSC and first order differential spectrum, modeling effect could be very good using the method of PLS and SMLR. Synthesizing correction set correlation coefficient and forecast modeling effect, it's feasible to detect the sugar content of skin Hami melon by the PLS method, with a correction sample correlation coefficient (R(c)) of 0.861 and the lower root mean square errors of correction (RMSEC) of 0.627, and a prediction sample correlation coefficient (R(p)) of 0.706 and root mean square errors of prediction (RMSEP) of 0.873. The best effect to detecti the sugar content of peel Hami melon was obtained by the SMLR method with a correction sample correlation coefficient (R(c)) of 0.928 and the lower root mean square errors of correction (RMSEC) of 0.458, with a Prediction sample correlation coefficient (R(p)) of 0.818 and root mean square errors of prediction (RMSEP) of 0.727. The results of this study indicate that the technology of hyperspectral imaging can be used to predict the sugar content of Hami melon.

m6A epitranscriptomic modification regulates neural progenitor-to-glial cell transition in the retina.

N 6-methyladenosine (m6A) is the most prevalent mRNA internal modification and has been shown to regulate the development, physiology, and pathology of various tissues. However, the functions of the m6A epitranscriptome in the visual system remain unclear. In this study, using a retina-specific conditional knockout mouse model, we show that retinas deficient in Mettl3, the core component of the m6A methyltransferase complex, exhibit structural and functional abnormalities beginning at the end of retinogenesis. Immunohistological and single-cell RNA sequencing (scRNA-seq) analyses of retinogenesis processes reveal that retinal progenitor cells (RPCs) and Müller glial cells are the two cell types primarily affected by Mettl3 deficiency. Integrative analyses of scRNA-seq and MeRIP-seq data suggest that m6A fine-tunes the transcriptomic transition from RPCs to Müller cells by promoting the degradation of RPC transcripts, the disruption of which leads to abnormalities in late retinogenesis and likely compromises the glial functions of Müller cells. Overexpression of m6A-regulated RPC transcripts in late RPCs partially recapitulates the Mettl3-deficient retinal phenotype. Collectively, our study reveals an epitranscriptomic mechanism governing progenitor-to-glial cell transition during late retinogenesis, which is essential for the homeostasis of the mature retina. The mechanism revealed in this study might also apply to other nervous systems.

The retina is a layer in the eye that converts light into electrical signals, which allows us to see. It is a part of the central nervous system and is made of brain cells, such as neurons and supporting cells called glia. These supporting cells protect neurons, supply them with nutrients and maintain steady surrounding conditions. The retina shares many characteristics with other neural tissues, so it is useful for biologists to study these structures. One way for cells to control the activity of genes is by chemically modifying messenger RNA molecules. These alterations can affect various aspects of mRNA and the proteins that are ultimately produced. The most common mRNA modification, referred to as m⁶A, plays a key role in the development and healthy performance of various tissues. However, it is unclear whether m⁶A is involved in how glial cells in the retina develop. To address this question, Xin et al. studied the impact of blocking m⁶A in the retina of mice. These genetically modified mice displayed abnormalities as the retina developed. Analysis of the mRNA produced in single cells and the pattern of modifications revealed that m⁶A is involved in the development of glia. In particular, m⁶A helps to remove the mRNA associated with early-stage proto-glia, allowing the cells to mature and transition to their final form. The finding by Xin et al. that the m⁶A RNA modification is an essential part of retina development could help to understand eye diseases. In addition, this discovery may apply to other brain regions, and, in time, such work could lead to new treatments for neurodegenerative diseases.

Characterization, immunostimulatory and antitumor activities of a ß-galactoglucofurannan from cultivated Sanghuangporus vaninii under forest.

A biomacromolecule, named as ß-galactoglucofurannan (SVPS2), was isolated from the cultivated parts of Sanghuangporus vaninii under the forest. Its primary and advanced structure was analyzed by a series of techniques including GC-MS, methylation, NMR, MALS as well as AFM. The results indicated that SVPS2 was a kind of 1, 5-linked ß-Glucofurannan consisting of ß-glucose, ß-galactose and α-fucose with 23.4 KDa. It exhibited a single-stranded chain with an average height of 0.72 nm in saline solution. The immunostimulation test indicated SVPS2 could facilitate the initiation of the immune reaction and promote the secretion of cytokines in vitro. Moreover, SVPS2 could mediate the apoptosis of HT-29 cells by blocking them in S phase. Western blot assay revealed an upregulation of Bax, Cytochrome c and cleaved caspase-3 by SVPS2, accompanied by a downregulation of Bcl-2. These results collectively demonstrate that antitumor mechanism of SVPS2 may be associated with enhancing immune response and inducing apoptosis of tumor cells in vitro. Therefore, SVPS2 might be utilized as a promising therapeutic agent against colon cancer and functional food with immunomodulatory activity.

Quick Commitment and Efficient Reprogramming Route of Direct Induction of Retinal Ganglion Cell-like Neurons.

Direct reprogramming has been widely explored to generate various types of neurons for neurobiological research and translational medicine applications, but there is still no efficient reprogramming method to generate retinal ganglion cell (RGC)-like neurons, which are the sole projection neurons in the retina. Here, we show that three transcription factors, Ascl1, Brn3b, and Isl1, efficiently convert fibroblasts into RGC-like neurons (iRGCs). Furthermore, we show that the competence of cells to enter iRGC reprogramming route is determined by the cell-cycle status at a very early stage of the process. The iRGC reprogramming route involves intermediate states that are characterized by a transient inflammatory-like response followed by active epigenomic and transcriptional modifications. Our study provides an efficient method to generate iRGCs, which would be a valuable cell source for potential glaucoma cell replacement therapy and drug screening studies, and reveals the key cellular events that govern successful neuronal fate reprogramming.

Delta Subunit-Containing Gamma-Aminobutyric Acid A Receptor Disinhibits Lateral Amygdala and Facilitates Fear Expression in Mice.

BACKGROUND: Maintaining gamma-aminobutyric acidergic (GABAergic) inhibition in the amygdala within a physiological range is critical for the appropriate expression of emotions such as fear and anxiety. The synaptic GABA type A receptor (GABAAR) is generally known to mediate the primary component of amygdala inhibition and prevent inappropriate expression of fear. However, little is known about the contribution of the extrasynaptic GABAAR to amygdala inhibition and fear. METHODS: By using mice expressing green fluorescent protein in interneurons (INs) and lacking the δ subunit-containing GABAAR (GABAA(δ)R), which is exclusively situated in the extrasynaptic membrane, we systematically investigated the role of GABAA(δ)R in regulating inhibition in the lateral amygdala (LA) and fear learning using the combined approaches of immunohistochemistry, electrophysiology, and behavior. RESULTS: In sharp contrast to the established role of synaptic GABAAR in mediating LA inhibition, we found that either pharmacological or physiological recruitment of GABAA(δ)R resulted in the weakening of GABAergic transmission onto projection neurons in LA while leaving the glutamatergic transmission unaltered, suggesting disinhibition by GABAA(δ)R. The disinhibition arose from IN-specific expression of GABAA(δ)R with its activation decreasing the input resistance of local INs and suppressing their activation. Genetic deletion of GABAA(δ)R attenuated its role in suppressing LA INs and disinhibiting LA. Importantly, the GABAA(δ)R facilitated long-term potentiation in sensory afferents to LA and permitted the expression of learned fear. CONCLUSIONS: Our findings suggest that GABAA(δ)R serves as a brake rather than a mediator of GABAergic inhibition in LA. The disinhibition by GABAA(δ)R may help to prevent excessive suppression of amygdala activity and thus ensure the expression of emotion.