Uncertainties in landslide susceptibility prediction:Influence rule of different levels of errors in landslide spatial position

The accuracy of landslide susceptibility prediction(LSP)mainly depends on the precision of the landslide spatial position.However,the spatial position error of landslide survey is inevitable,resulting in considerable uncertainties in LSP modeling.To overcome this drawback,this study explores the influence of positional errors of landslide spatial position on LSP uncertainties,and then innovatively proposes a semi-supervised machine learning model to reduce the landslide spatial position error.This paper collected 16 environmental factors and 337 landslides with accurate spatial positions taking Shangyou County of China as an example.The 30e110 m error-based multilayer perceptron(MLP)and random forest(RF)models for LSP are established by randomly offsetting the original landslide by 30,50,70,90 and 110 m.The LSP uncertainties are analyzed by the LSP accuracy and distribution characteristics.Finally,a semi-supervised model is proposed to relieve the LSP uncertainties.Results show that:(1)The LSP accuracies of error-based RF/MLP models decrease with the increase of landslide position errors,and are lower than those of original data-based models;(2)70 m error-based models can still reflect the overall distribution characteristics of landslide susceptibility indices,thus original landslides with certain position errors are acceptable for LSP;(3)Semi-supervised machine learning model can efficiently reduce the landslide position errors and thus improve the LSP accuracies.

Analysis on Pigment and Photosynthetic Characteristics of Leaves of New Strain of Rehmannia glutinosa

Through the analysis on the leaf color and photosynthetic characteristics of new strains and main cultivars of Rehmannia glutinosa,it is expected to provide theoretical basis for breeding of new varieties. Chlorophyll,anthocyanin,and net photosynthetic rate（Pn）,stomatal conductance（Cond）,transpiration rate（Tr）,and intercellular CO2concentration（Ci） in 8 varieties of Rehmannia glutinosa were measured by spectrophotometer and LI-6400 XT Portable Photosynthesis System. The results showed that the chlorophyll content of Huaidijin 8（2. 84 mg/g）,Huaidi 81（2. 71 mg/g）,Huaidi 85-5（2. 69 mg/g）,Jinjiu（2. 66 mg/g） and Huaidi 83（2. 63 mg/g） was higher; the anthocyanin content of Jinjiu（0. 169） and Huaidijin 8（0. 165） was higher,while the anthocyanin content Huaidi 83（0. 060） was the lowest; Pn of Huaidi81[2. 41 μmol/（m2·s） ],Huaidi 83[2. 37 μmol/（m2·s） ]and Huaidijin 8[2. 25 μmol/（m2·s） ]was higher,and the anthocyanin content was positively correlated with Pn,while the anthocyanin content was negatively correlated with Pn; Huaidijin 8 and Huaidi 83 showed dominant advantages in single plant fresh weight,indicator component,and resistance over the main cultivars. This indicates that the new variety Huaidijin 8 and Huaidi 83 have excellent comprehensive traits and can be properly popularized.

Assessment of causal effects of physical activity on neurodegenerative diseases:A Mendelian randomization study

Background:Physical activity has been hypothesized to play a protective role in neurodegenerative diseases.However,effect estimates previously derived from observational studies were prone to confounding or reverse causation.Methods:We performed a two-sample Mendelian randomization(MR)analysis to explore the causal association of accelerometer-measured physical activity with 3 common neurodegenerative diseases:Alzheimer’s disease(AD),Parkinson’s disease(PD),and amyotrophic lateral sclerosis(ALS).We selected genetic instrumental variants reaching genome-wide significance(p<5×10^(-8))from 2 largest meta-analyses of about 91,100 UK Biobank participants.Summary statistics for AD,PD,and ALS were retrieved from the up-to-date studies in European ancestry led by the international consortia.The random-effect,inverse-variance weighted MR was employed as the primary method,while MR pleiotropy residual sum and outlier(MR-PRESSO),weighted median,and MR-Egger were implemented as sensitivity tests.All statistical analyses were performed using the R programming language(Version 3.6.1;R Foundation for Statistical Computing,Vienna,Austria).Results:Primary MR analysis and replication analysis utilized 5 and 8 instrumental variables,which explained 0.2%and 0.4%variance in physical activity,respectively.In each set,one variant at 17q21 was significantly associated with PD,and MR sensitivity analyses indicated them it as an outlier and source of heterogeneity and pleiotropy.Primary results with the removal of outlier variants suggested odds ratios(ORs)of neurodegenerative diseases per unit increase in objectively measured physical activity were 1.52 for AD(95%confidence interval(95%CI):0.88-2.63,p=0.13)and 3.35 for PD(95%CI:1.32-8.48,p=0.01),while inconsistent results were shown in the replication set for AD(OR=1.06,95%CI:1.01-1.12,p=0.02)and PD(OR=0.99,95%CI:0.88-0.12,p=0.97).Similarly,the beneficial effect of physical activity on ALS(OR=0.51,95%CI:0.29-0.91,p=0.02)was not confirmed in the replication analysis(OR=0.96,95%CI:0.91-1.02,p=0.22).Conclusion:Genetically predicted physical activity was not robustly associated with risk of neurodegenerative disorders.Triangulating evidence across other studies is necessary in order to elucidate whether enhancing physical activity is an effective approach in preventing the onset of AD,PD,or ALS.

Study on HAM coupling migration of complex air-tightness defect structure caused by air leakage

The airtightness defects in building components are mainly composed of thin air gaps caused by porous materials and assembly tolerances.Indoor and outdoor air leakage,as well as risks such as condensation and mold growth in the structure,will result in significant heat loss.In this paper,a numerical model of heat,air and moisture transfer(commonly called HAM transfer)between the air channel and the porous material is proposed.The model adopts a single-domain modeling strategy without considering the migration coefficient of the interface.A benchmark experiment of the dilution buffer model is used to further validate the model,and the results indicate good consistency.The condensation risk of a two-dimensional complex building structural component in air infiltration and seepage scene was tested,and it was shown that the existence of air passage would prolong the time for the periodic equilibrium of water in the building structure and significantly change the temperature as well as the humidity distribution in the structure.In addition,the impact of an airtightness defect on the heat flux of the structure’s internal boundary was analyzed qualitatively,and it was found that the infiltration scene has a larger effect on heat loss than the seepage scene.

Dynamic-Change Laws of the Porosity and Permeability of Low-to Medium-Rank Coals under Heating and Pressurization Treatments in the Eastern Junggar Basin,China

Deep coalbed methane exists in high-temperature and high-pressure reservoirs. To elucidate the dynamic-change laws of the deep coal reservoir porosity and permeability characteristics in the process of coalbed methane production, based on three pieces of low- to medium-rank coal samples in the eastern Junggar Basin, Xinjiang, we analyse their mercury-injection pore structures. We measured the porosity and permeability of the coal samples at various temperatures and confining pressures by high-temperature and confining pressure testing. The results show that the porosity of a coal sample decreases exponentially with increasing effective stress. With increasing temperature, the initial porosity increases for two pieces of relatively low-rank coal samples. The increased rate of porosity decreases with increasing confining pressure. With increasing temperature, the initial porosity of a relatively high-rank coal sample decreases, and the rate of change of the porosity become faster. An exponential relationship exists between the porosity and permeability. With increasing coal rank, the initial porosity and permeability decrease. The change rate of the permeability decreases with increasing porosity.

Pharmacological modulation of autophagy for Alzheimer's disease therapy:Opportunities and obstacles

Alzheimer's disease(AD)is a prevalent and deleterious neurodegenerative disorder characterized by an irreversible and progressive impairment of cognitive abilities as well as the formation of amyloidβ(Aβ)plaques and neurofibrillary tangles(NFTs)in the brain.By far,the precise mechanisms of AD are not fully understood and no interventions are available to effectively slow down progression of the disease.Autophagy is a conserved degradation pathway that is crucial to maintain cellular homeostasis by targeting damaged organelles,pathogens,and disease-prone protein aggregates to lysosome for degradation.Emerging evidence suggests dysfunctional autophagy clearance pathway as a potential cellular mechanism underlying the pathogenesis of AD in affected neurons.Here we summarize the current evidence for autophagy dysfunction in the pathophysiology of AD and discuss the role of autophagy in the regulation of AD-related protein degradation and neuroinflammation in neurons and glial cells.Finally,we review the autophagy modulators reported in the treatment of AD models and discuss the obstacles and opportunities for potential clinical application of the novel autophagy activators for AD therapy.

Glide symmetry protected higher-order topological insulators from semimetals with butterfly-like nodal lines

Most topological insulators(TIs)discovered today in spinful systems can be transformed from topological semimetals(TSMs)with vanishing bulk gap via introducing the spin-orbit coupling(SOC),which manifests the intrinsic links between the gapped topological insulator phases and the gapless TSMs.Recently,we have discovered a family of TSMs in time-reversal invariant spinless systems,which host butterfly-like nodal-lines(NLs)consisting of a pair of identical concentric intersecting coplanar ellipses(CICE).In this Communication,we unveil the intrinsic link between this exotic class of nodal-line semimetals(NLSMs)and a Z_(4)=2 topological crystalline insulator(TCI),by including substantial SOC.We demonstrate that in three space groups(i.e.,Pbam(No.55),P4/mbm(No.127),and P4_(2)/mbc(No.135)),the TCI supports a fourfold Dirac fermion on the(001)surface protected by two glide symmetries,which originates from the intertwined drumhead surface states of the CICE NLs.The higher order topology is further demonstrated by the emergence of one-dimensional helical hinge states,indicating the discovery of a higher order topological insulator protected by a glide symmetry.