新农科背景下“无机及分析化学”创新教学与实践

在新农科建设背景下,涉农高校“无机及分析化学”课程改革势在必行。为培养品德优良、基础扎实、能力过硬的新型农林人才,本课程进行了线上线下混合式教学改革与探索,通过深耕教材挖掘具有新农科特色的教学元素,实现农科知识与化学知识高度融合,并通过科教融合、专创融入拓展教学资源,创新教学方法有效提高学生学习能力、思辨能力和创新实践能力。

Stability analysis for an Euler-Bernoulli beam under local internal control and boundary observation

An Euler-Bernoulli beam system under the local internal distributed control and boundary point observation is studied. An infinite-dimensional observer for the open-loop system is designed. The closed-loop system that is non- dissipative is obtained by the estimated state feedback. By a detailed spectral analysis, it is shown that there is a set of generalized eigenfunctions, which forms a Riesz basis for the state space. Consequently, both the spectrum-determined growth condition and exponential stability are concluded.

Demonstration of Faraday anomalous dispersion optical filter with reflection configuration

A narrow linewidth Faraday anomalous dispersion optical filter(FADOF)with reflection configuration is achieved for the first time based on the cesium(Cs)ground state 6S_(1/2) to the excited state 6P_(3/2) transition at 852 nm.Compared with the conventional FADOF with transmission configuration,reflection-type FADOF can greatly improve the transmittance of optical filter under the same experimental parameters,because it allows signal light to go and return through the atomic vapor cell.In our experiment,peak transmittance at Cs 6S_(1/2) F=4-6P_(3/2) transition is 81%for the reflection-type FADOF,and while 54%for the transmission-type FADOF when the temperature of Cs vapor cell and the axial magnetic field are 60℃and 19 G.The idea of this reflection-type FADOF design has the potential to be applied to the FADOF operating between two excited states to obtain higher transmittance.

Increased leucine-rich repeats and immunoglobulin- like domains 1 expression enhances chemosensitivity in glioma

Leucine-rich repeats and immunoglobulin-like domains 1 （LRIG1） is an anti-oncogene. LRIG1 is correlated with Bcl-2 in ependymomas. Decreased Bcl-2 and manganese superoxide dismutase expression can improve the chemosensitivity of glioma. In the present study, a tissue microarray of human brain astrocytomas was constructed. To investigate the relationship of LRIG1 with Bcl-2 and manganese superoxide dismutase, LRIG1, Bcl-2 and manganese superoxide dismutase expression in our tissue microarray was determined using immunohistochemistry. In addition, we constructed the LRIG1-U251 cell line, and its responses to doxorubicin and temozolomide were detected using the MTT assay. Results showed that LRIG1 expression was significantly negatively correlated with Bcl-2 and manganese superoxide dismutase expression in glioma. Also, proliferation of LRIG1-U251 cells exposed to doxorubicin or temozolomide was significantly inhibited, i.e. in the LRIG1-U251 cell line, the chemosensitivity to doxorubicin and temozolomide was increased. This indicates that increased LRIG1 expression produces a chemosensitivity in glioma.

Stabilization of the Cascaded ODE-Schrödinger Equations Subject to Observation With Time Delay

This paper focuses on the stabilization of the cascaded Schrodinger-ODE equations subject to the observation with time delay.Both observer and predictor systems are designed to estimate the state variable on the time interval[0,t-τ]when the observation is available,and to predict the state variable on the time interval[t-τ,t]when the observation is not available,respectively.Based on the estimated state variable and the output feedback stabilizing controller using the backstepping method,it is shown that the closed-loop system is exponentially stable.

Mutations with Hair Shape Phenotypes Abnormalities—The Morphogenetic Waves and Related Diseases

Hair morphology is one of the most conspicuous features of human variation. The hair follicle has attracted significant attention as a model for the investigation of diverse biological problems. Whereas, very little is known about the genes influencing the morphology and structure of the hair shaft. Curly hair is very common character of hair phenotypes of human, while most congenital curl occurs owing to genetic factors and some are closely related with genetic diseases. This review highlights current related genes reported affecting hair curliness and human diseases which are due to gene mutations.

An endophytic fungus interacts with the defensinlike protein OsCAL1 to regulate cadmium allocation in rice

Defensin-like proteins are conserved in multicellular organisms and contribute to innate immune re-sponses against fungal pathogens.In rice,defensins play a novel role in regulating cadmium(Cd)efflux from the cytosol.However,whether the antifungal activity of defensins correlates with Cd-efflux function remains unknown.In this study,we isolated an endophytic Fusarium,designed Fo1o,by a comparative mi-crobiome analysis of rice plants grown in a paddy contaminated with Cd.Fo10 is tolerant to high levels of Cd,but is sensitive to the defensin-like protein OsCAL1,which mediates Cd efflux to the apoplast.We found that Fo10 symbiosis in rice is regulated by OsCAL1 dynamics,and Fo10 coordinates multiple plant pro-cesses,including Cd uptake,vacuolar sequestration,efflux to the environment,and formation of Fe pla-ques in the rhizosphere.These processes are dependent on the salicylic acid signaling pathway to keep Cd levels low in the cytosol of rice cells and to decrease Cd levels in rice grains without any yield penalty.Fo10 also plays a role in Cd tolerance in the poaceous crop maize and wheat,but has no observed effects in the eudicot plants Arabidopsis and tomato.Taken together,these findings provide insights into the mech-anistic basis underlying how afungal endophyte and host plant interact to control Cd accumulation in host plants by adapting defense responses to promotethe establishment ofa symbiosis that permits adaptation to high-Cd environments.

Control of Rice Embryo Development, Shoot Apical Meristem Maintenance, and Grain Yield by a Novel Cytochrome P450

Angiosperm seeds usually consist of two major parts： the embryo and the endosperm. However, the molec- ular mechanism（s） underlying embryo and endosperm development remains largely unknown, particularly in rice, the model cereal. Here, we report the identification and functional characterization of the rice GIANT EMBRYO （GE） gene. Mutation of GE resulted in a large embryo in the seed, which was caused by excessive expansion of scuteUum cells. Post-embryonic growth of ge seedling was severely inhibited due to defective shoot apical meristem （SAM） mainte- nance. Map-based cloning revealed that GE encodes a CYP78A subfamily P450 monooxygenase that is localized to the endoplasmic reticulum. GE is expressed predominantly in the scutellar epithelium, the interface region between embryo and endosperm. Overexpression of GE promoted cell proliferation and enhanced rice plant growth and grain yield, but reduced embryo size, suggesting that GE is critical for coordinating rice embryo and endosperm development. Moreover, transgenic Arabidopsis plants overexpressing AtCYP78AlO, a GE homolog, also produced bigger seeds, implying a con- served role for the CYP78A subfamily of P450s in regulating seed development. Taken together, our results indicate that GE plays critical roles in regulating embryo development and SAM maintenance.

Denitrification and phosphorus uptake by DPAOs using nitrite as an electron acceptor by step-feed strategies

把亚硝酸根用作一个电子领受人的从的磷积累有机体(DPAO ) 能减少更多的精力。然而，亚硝酸根被报导了在从上有抑制磷移动。在这研究，步喂策略被建议完成低亚硝酸根集中，它能避免或减轻亚硝酸根抑制。结果证明那 denitrification 率，磷举起率和到亚硝酸根的磷 uptaken 的比率从(缺氧的 P/N 比率) 当亚硝酸根集中是 15 mg 时。

Dietary butyrate,lauric acid and stearic acid improve gut morphology and epithelial cell turnover in weaned piglets

This study was to evaluate the effects of the supplementation of saturated fatty acids with different chain lengths on growth performance,intestinal morphology,epithelial cell proliferation,differentiation and apoptosis in weaned piglets.Thirty-two weaned piglets(Duroc×Landrace×Yorkshire,BW=7.81±0.26 kg)were weaned at 21 d and randomly assigned to 1 of 4 experimental treatments:(1)a basal diet(control);(2)control+0.3% butyrate(BT);(3)control+0.3%lauric acid(LA);(4)control+0.3% stearic acid(SA).All piglets were then slaughtered for tissue sampling after having been fed experimental diets for 28 d after weaning.Supplementation of BT increased the gain-to-feed ratio(G:F)(P<0.05)compared to piglets fed the control diet from 14 to 28 d.In addition,the villus height(VH)to crypt depth(CD)ratio(VH:CD ratio)of the ileum were higher in the BT and LA diets than that of the control diet(P<0.05).The SA-supplemented diet increased ileal VH(P<0.05),whereas the BT-supplemented diet increased jejunal CD(P<0.05).Compared to the control,diets supplemented with BT,LA,or SA all tended to increase jejunal proliferation(Ki67/crypt positive cells)(P=0.190);diets supplemented with BT or SA significantly increased the number of ki67-positive cells in the ileal crypt(P<0.05).Furthermore,in the jejunum,the protein expression of activated caspase 3 and villin were increased in piglets fed BT,LA,or SA diets compared to those on the control diet(P<0.05).In the ileum,compared with the control diet,the BT diet tended to increase the protein level of mammalian phosphorylation target of rapamycin(p-m TOR,P<0.10);LA or SA diets significantly increased p-m TOR protein expression(P<0.05).These results show that dietary supplementation of BT,LA,or SA promotes jejunal cell renewal in weaned piglets.At the same time,increased proliferation of ileal crypt cells by promoting p-m TOR expression has beneficial effects on ileal morphology in weaned piglets.

Elimination of a Retrotransposon for Quenching Genome Instability in Modern Rice

Transposable elements(TEs)constitute the most abundant portions of plant genomes and can dramatically shape host genomes during plant evolution.They also play important roles in crop domestication.However,whether TEs themselves are also selected during crop domestication has remained unknown.Here,we identify an active long terminal repeat(LTR)retrotransposon,HUO,as a potential target of selection during rice domestication and breeding.HUO is a low-copy-number LTR retrotransposon,and is active under natural growth conditions and transmitted through male gametogenesis,preferentially inserting into genomic regions capable of transcription.HUO exists in all wild rice accessions and about half of the archaeological rice grains(1200–7000 years ago)and landraces surveyed,but is absent in almost all modern varieties,indicating its gradual elimination during rice domestication and breeding.Further analyses showed that HUO is subjected to strict gene silencing through the RNA-directed DNA methylation pathway.Our results also suggest that multiple HUO copies may trigger genomic instability through altering genome-wide DNA methylation and small RNA biogenesis and changing global gene expression,resulting in decreased disease resistance and yield,coinciding with its elimination during rice breeding.Together,our study suggests that negative selection of an active retrotransposon might be important for genome stability during crop domestication and breeding.

Narrow linewidth two-color polarization spectroscopy due to the atomic coherence effect in a ladder-type atomic system

An experimental investigation of two-color polarization spectroscopy(TCPS) is presented based on the cesium 6 S1/2– 6P3/2– 8S1/2(852.3 nm + 794.6 nm) ladder-type system in a room-temperature vapor cell. The dependency of line shapes of TCPS on the power of a 852.3 nm pump and a 794.6 nm probe laser is measured in detail, and we confirm that the linewidth of TCPS in a counter-propagating configuration between the pump and probe laser beams is obviously narrower than that of a co-propagating configuration, due to the atomic coherence effect. It is helpful for laser stabilization of the excited state transition using TCPS without frequency modulation.

End-to-End Fusion of Hyperspectral and Chlorophyll Fluorescence Imaging to Identify Rice Stresses

Herbicides and heavy metals are hazardous substances of environmental pollution,resulting in plant stress and harming humans and animals.Identification of stress types can help trace stress sources,manage plant growth,and improve stress-resistant breeding.In this research,hyperspectral imaging(HSI)and chlorophyll fluorescence imaging(Chl-FI)were adopted to identify the rice plants under two types of herbicide stresses(butachlor(DCA)and quinclorac(ELK))and two types of heavy metal stresses(cadmium(Cd)and copper(Cu)).

Boundary feedback stabilization of a Schrdinger equation interconnected with a heat equation

In this paper, we study stabilization for a Schoedinger equation, which is interconnected with a heat equation via boundary coupling. A direct boundary feedback control is adopted. By a detailed spectral analysis, it is found that there are two branches of eigenvalues： one is along the negative real axis, and the other is approaching to a vertical line, which is parallel to the imagine axis. Moreover, it is shown that there is a set of generalized eigenfunctions, which forms a Riesz basis for the energy state space. Finally, the spectrum-determined growth condition is held and the exponential stability of the system is then concluded.