Mapping the potential distribution suitability of 16 tree species under climate change in northeastern China using Maxent modelling

Knowledge on the potential suitability of tree species to the site is very important for forest management planning.Natural forest distribution provides a good reference for afforestation and forest restoration.In this study,we developed species distribution model(SDM)for 16 major tree species with 2,825 permanent sample plots with natural origin from Chinese National Forest Inventory data collected in Jilin Province using the Maxent model.Three types of environmental factors including bioclimate,soil and topography with a total of 33 variables were tested as the input.The values of area under the curve(AUC,one of the receiver operating characteristics of the Maxent model)in the training and test datasets were between 0.784 and 0.968,indicating that the prediction results were quite reliable.The environmental factors affecting the distribution of species were ranked in terms of their importance to the species distribution.Generally,the climatic factors had the greatest contribution,which included mean diurnal range,annual mean temperature,temperature annual range,and iosthermality.But the main environmental factors varied with tree species.Distribution suitability maps under current(1950-2000)and future climate scenarios(CCSM4-RCP 2.6 and RCP 6.0 during 2050)were produced for 16 major tree species in Jilin Province using the model developed.The predicted current and future ranges of habitat suitability of the 16 tree species are likely to be positively and negatively affected by future climate.Seven tree species were found to benefit from future climate including B etula costata,Fraxinus mandshurica,Juglans mandshurica,Phellodendron amurense,Populus ussuriensis,Quercus mongolica and Ulmus pumila;five tree species will experience decline in their suitable habitat including B.platyphylla,Tilia mongolica,Picea asperata,Pinus sylvestris,Pinus koraiensis;and four(Salix koreensis,Abies fabri,Pinus densiflora and Larix olgensis)showed the inconsistency under RCP 2.6 and RCP 6.0 scenarios.The maps of the habitat suitability can be used as a basis for afforestation and forest restoration in northeastern China.The SDMs could be a potential tool for forest management planning.

Rethinking the image feature biases exhibited by deep convolutional neural network models in image recognition

In recent years,convolutional neural networks(CNNs)have been applied successfully in many fields.However,these deep neural models are still considered as“black box”for most tasks.One of the fundamental issues underlying this problem is understanding which features are most influential in image recognition tasks and how CNNs process these features.It is widely believed that CNN models combine low‐level features to form complex shapes until the object can be readily classified,however,several recent studies have argued that texture features are more important than other features.In this paper,we assume that the importance of certain features varies depending on specific tasks,that is,specific tasks exhibit feature bias.We designed two classification tasks based on human intuition to train deep neural models to identify the anticipated biases.We designed experiments comprising many tasks to test these biases in the Res Net and Dense Net models.From the results,we conclude that(1)the combined effect of certain features is typically far more influential than any single feature;(2)in different tasks,neural models can perform different biases,that is,we can design a specific task to make a neural model biased towards a specific anticipated feature.

Cerium oxide inclusion nucleation mechanism based on classical nucleation theory and two-step nucleation

It is challenging to assess the mechanism responsible for the nucleation of inclusions in metals at high temperatures.The present work therefore systematically investigates the nucleation of cerium oxide inclusions according to classical nucleation theory and a two-step nucleation mechanism.The nucleation rates and nucleation radii of these inclusions are obtained,and the results demonstrate a considerable difference between theoretical and experimental values.On the basis of a two-step nucleation mechanism,(CeO_(2))_(n) and(Ce_(2)O_(3))_(n)(n=1-6)clusters were constructed and the thermodynamic properties of both these clusters and of cerium oxide nanoparticles were analyzed.In addition,the entropies and heat capacity changes of cerium oxides were determined using first principles calculations and are found to be consistent with literature data.The present data indicate that the cerium oxide inclusion nucleation pathway can be summarized as[Ce]+[O]→(CeO_(2))n/(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(n)→(Ce_(2)O_(3))_(2)→core(Ce_(2)O_(3)crystal)-shell((Ce_(2)O_(3))_(2) cluster)nanoparticles→(Ce_(2)O_(3))bulk.

Structural and functional basis for pan-CoV fusion inhibitors against SARS-CoV-2 and its variants with preclinical evaluation

The COVID-19 pandemic poses a global threat to public health and economy.The continuously emerging SARS-CoV-2 variants present a major challenge to the development of antiviral agents and vaccines.In this study,we identified that EK1 and cholesterol-coupled derivative of EK1,EK1C4,as pan-CoV fusion inhibitors,exhibit potent antiviral activity against SARS-CoV-2 infection in both lung-and intestine-derived cell lines(Calu-3 and Caco2,respectively).They are also effective against infection of pseudotyped SARS-CoV-2 variants B.1.1.7(Alpha)and B.l.1.248(Gamma)as well as those with mutations in S protein,including N417T,E484K,N501Y,and D614G,which are common in South African and Brazilian variants.Crystal structure revealed that EK1 targets the HR1 domain in the SARS-CoV-2 S protein to block virus-cell fusion and provide mechanistic insights into its broad and effective antiviral activity.Nasal administration of EK1 peptides to hACE2 transgenic mice significantly reduced viral titers in lung and intestinal tissues.EK1 showed good safety profiles in various animal models,supporting further clinical development of EK1-based pan-CoV fusion inhibitors against SARS-CoV-2 and its variants.

Effective treatment of NR2F1-related epilepsy with perampanel

Background NR2F1 mutations are associated with Bosch-Boonstra-Schaaf optic atrophy syndrome(BBSOAS).Although~46.7%of BBSOAS patients present with epilepsy,which is always drug-resistant and associated with higher rates of behavioral and cognitive problems,the treatment and outcomes of NR2F1-related epilepsy have rarely been described.Here,we present new cases of BBSOAS-related epilepsy and summarize all previously reported cases to explore the effective treatment for this type of epilepsy.Methods We identified six new Chinese cases of BBSOAS with epilepsy.Five different de novo heterozygous NR2F1 mutations were identified in these cases,including two novel mutations c.365G>T,p.Cys122Phe and c.449G>T,p.Gly150Val.By combining the six cases and 14 previously reported cases,we analyzed the characteristics and treatment outcomes of NR2F1-related epilepsy.Results Twelve of the 20 patients(60%)had infantile epileptic spasms,while the other patients had generalized tonic/tonic-clonic,focal,myoclonic,absence,or unclassified seizures.Several anti-seizure medications,steroids,and a ketogenic diet were administered in these cases.However,seizures were controlled in only 50%of previously reported cases,while all of the six new cases became seizure-free after perampanel as an add-on treatment.The average time from the addition of perampanel to seizure control was 7.33±4.59 months(range,1–12 months).The median time to seizure freedom was 14 months(1–32 months,>19 months in 3 cases).The average dosage of perampanel needed for epilepsy control was 0.22±0.17 mg/kg per day.Conclusions In this paper,we comprehensively summarized the clinical characteristics,treatments and outcomes of NR2F1-related epilepsy for the first time.Perampanel exhibits dramatic efficacy for NR2F1-related epilepsy.This will help optimize the treatment of this type of epilepsy and provide clues for its pathogenic mechanisms.The two novel mutations expand the genotype spectrum of this disease.

原卟啉Ⅸ和维替泊芬在细胞水平和小鼠体内有效抑制新型冠状病毒的感染

新型冠状病毒(新冠病毒)引起的疫情当前仍在全球蔓延,因而研究有效的新冠病毒疫苗和抗病毒药物成为当务之急.本研究发现原卟啉Ⅸ(ProtoporphyrinⅨ)和维替泊芬(Verteporfin)这两种FDA批准的药物分别在1.25和0.31μmolL-1的浓度下,能在Vero E6细胞上完全抑制新冠病毒的感染,并阻止新冠病毒感染造成的细胞病变.同时,原卟啉IX和维替泊芬的选择性指数(Selectivity indices,SI)分别为952.74和368.93,表明其具有很广的安全用药范围.进一步利用表达人源ACE2(hACE2)的腺病毒(Ad5-h ACE2)建立新冠病毒小鼠感染模型后,发现原卟啉IX和维替泊芬可以完全阻断小鼠感染新冠病毒.通过药物–蛋白分子对接模拟、药物-蛋白互作实验,发现原卟啉IX和维替泊芬这两个具有卟啉环结构的化合物能够直接结合新冠病毒受体——ACE2,并干扰病毒S蛋白与受体ACE2之间的相互作用.本研究表明,原卟啉IX和维替泊芬在细胞水平和动物水平均能有效抗新冠病毒感染,为开发新型抗新冠病毒药物提供了新的思路.

Correction To:Ceftazidime is a potential drug to inhibit SARS-CoV-2 infection in vitro by blocking spike protein-ACE2 interaction

After online publication of the article1 we noticed an error in citations for affiliation in the supplementary materials published in this article.The citations for affiliation in the article were reordered during the production process to match the order of authors in the author group.Unfortunately,this was not reflected in the supplementary material.