Haplotype-resolved and chromosome-scale genomes provide insights into co-adaptation between the Amur tiger and Amur leopard

DEAR EDITOR,Big cats,such as Amur tigers(Panthera tigris altaica)and Amur leopards(P.pardus orientalis),are apex predator and have evolved specialized traits for hunting and carnivory(Moya et al.,2022),thus playing a crucial role in maintaining biodiversity and ecosystem integrity by regulating prey-predator dynamics.However,human-induced pressures,habitat fragmentation,and environmental alterations have restricted these species in small and isolated populations.Currently,all extant big cats are categorized as endangered or threatened according to their conservation status.Amur tigers and Amur leopards share overlapping geographic ranges,habitats,and certain prey species in the forests of Northeast Asia(Jiang et al.,2015).To reduce interspecies conflict,these carnivores exhibit differentiated dietary and temporal niches.Amur tigers predominantly prey on large ungulates,while Amur leopards hunt small to medium-sized animals(Sugimoto et al.,2016).Additionally,they occupy different temporal niches,with tigers being active at night and leopards more active during the day.Despite spatial and temporal niche partitioning,interspecific competition between these two species is inevitable.Tigers,benefiting from their greater size,have a competitive advantage over leopards,which can manifest in occasional leopard predation by tigers and declines in leopard populations with increasing tiger density(Jiang et al.,2015).Tigers also displace leopards from marginal habitats in nature reserves where they coexist.

The Ways to Improve the Efficiency of Maize Breeding

Referring to corn breeding literature at home and abroad,the possible ways to improve the efficiency of maize breeding were discussed.The results showed that through the summary and reflection on breeding objectives and strategies,and improvement and optimization of breeding techniques and methods,as well as adjustment and simplification of experimental design and implementation,the breeding cost would be greatly reduced,and the breeding efficiency would be improved.

Effective Ways to Improve Students'Interests in English Classes

Interest is the key role in English learning. Thus, English teachers should take effective ways to raise students'interests in teaching classes. Scientific investigation has proved that using effective approaches certainly helps arousing students'interests in English teaching.

Photodissociation Dynamics of 2-1odotoluene Investigated by Femtosecond Time-Resolved Mass Spectrometry

The photodissociation dynamics of 2-iodotoluene following excitation at 266 nm have been investigated employing femtosecond time-resolved mass spectrometry. The photofragments are detected by multiphoton ionization using an intense laser field centered at 800 nm. A dissociation time of 3804-50 fs was measured from the rising time of the co-fragments of toluene radical （C7H7） and iodine atom （I）, which is attributed to the averaged time needed for the C-I bond breaking for the simultaneously excited nσ and ππ＊ states by 266 nm pump light. In addition, a probe light centered at 298.23 nm corresponding to resonance wavelength of ground-state iodine atom is used to selectively ionize ground-state iodine atoms generated from the dissociation of initially populated hσ＊ and ππ＊ states. And a rise time of 4004-50 fs is extracted from the fitting of time-dependent I＋ transient, which is in agreement with the dissociation time obtained by multiphoton ionization with 800 nm, suggesting that the main dissociative products are ground-state iodine atoms.

Ways to Improve Students’Speaking Ability in English for Careers

English for Careers is a public course for non-English majors,whose objectives are to develop students’basic language skills for work-related activities:listening,reading,speaking,and writing.As far as the four skills are concerned,most students in higher vocational colleges have the very poor speaking ability.How to improve students’speaking ability is a hard and urgent task for English teachers.This article sets out to analyze the reasons for this problem in English for Careers.Then,based on the second language acquisition and current teaching theory,ways of improving students’speaking ability are suggested.

A gap-free and haplotype-resolved lemon genome provides insights into flavor synthesis and huanglongbing (HLB) tolerance

The lemon(Citrus limon;family Rutaceae)is one of the most important and popular fruits worldwide.Lemon also tolerates huan-glongbing(HLB)disease,which is a devastating citrus disease.Here we produced a gap-free and haplotype-resolved chromosome-scale genome assembly of the lemon by combining Pacific Biosciences circular consensus sequencing,Oxford Nanopore 50-kb ultra-long,and high-throughput chromatin conformation capture technologies.The assembly contained nine-pair chromosomes with a contig N50 of 35.6 Mb and zero gaps,while a total of 633.0 Mb genomic sequences were generated.The origination analysis identified 338.5Mb genomic sequences originating from citron(53.5%),147.4Mb frommandarin(23.3%),and 147.1Mb frompummelo(23.2%).The genome included 30528 protein-coding genes,and most of the assembled sequences were found to be repetitive sequences.Several significantly expanded gene families were associated with plant-pathogen interactions,plant hormone signal transduction,and the biosynthesis of major active components,such as terpenoids and f lavor compounds.Most HLB-tolerant genes were expanded in the lemon genome,such as 2-oxoglutarate(2OG)/Fe(II)-dependent oxygenase and constitutive disease resistance 1,cell wall-related genes,and lignin synthesis genes.Comparative transcriptomic analysis showed that phloem regeneration and lower levels of phloem plugging are the elements that contribute to HLB tolerance in lemon.Our results provide insight into lemon genome evolution,active component biosynthesis,and genes associated with HLB tolerance.

High-quality haplotype-resolved genome assembly of cultivated octoploid strawberry

Cultivated strawberry(Fragaria×ananassa),a perennial herb belonging to the family Rosaceae,is a complex octoploid with high heterozygosity at most loci.However,there is no research on the haplotype of the octoploid strawberry genome.Here we aimed to obtain a high-quality genome of the cultivated strawberry cultivar,“Yanli”,using single molecule real-time sequencing and high-throughput chromosome conformation capture technology.The“Yanli”genome was 823 Mb in size,with a long terminal repeat assembly index of 14.99.The genome was phased into two haplotypes,Hap1(825 Mb with contig N50 of 26.70 Mb)and Hap2(808 Mb with contig N50 of 27.51 Mb).Using the combination of Hap1 and Hap2,we obtained for the first time a haplotype-resolved genome with 56 chromosomes for the cultivated octoploid strawberry.We identified a∼10 Mb inversion and translocation on chromosome 2-1.104957 and 102356 protein-coding genes were annotated in Hap1 and Hap2,respectively.Analysis of the genes related to the anthocyanin biosynthesis pathway revealed the structural diversity and complexity in the expression of the alleles in the octoploid F.×ananassa genome.In summary,we obtained a high-quality haplotype-resolved genome assembly of F.×ananassa,which will provide the foundation for investigating gene function and evolution of the genome of cultivated octoploid strawberry.

Ways to Improve Low-Benefit Black Locust Forests in Loess Plateau

This paper presents a general standard for the low-benefit black locust （Robinia pseudoacacia L.） torests m Loess Plateau based on defining the concept of “tri-low forest”, and emphasizes the major factors which result in low-benefit black locust, such as, lack of soil moisture of forest and nutrient, breaching the principle of matching tree species to sites, and high density of forests. Based on different characteristics of low-benefit forests, following the principle of “adjusting measures to local conditions, giving priority to ecological benefits, assisting with economic benefits”, the authors put forward some technical ways to reform low-benefit black locust forests, for example, taking measurements of collecting runoff and storing water, lowering the forest density, introducing mixed forests and transforming species, directive breeding and so on.

Disappearance of Superconductivity and a Concomitant Lifshitz Transition in Heavily Overdoped Bi_2Sr_2CuO_6 Superconductor Revealed by Angle-Resolved Photoemission Spectroscopy

By partially doping Pb to effectively suppress the superstructure in single-layered cuprate Bi_2Sr_2CuO_(6+δ)(Pb-Bi2201) and annealing them in vacuum or in high pressure oxygen atmosphere, a series of high quality Pb-Bi2201 single crystals are obtained with T_c covering from 17 K to non-superconducting in the overdoped region. High resolution angle resolved photoemission spectroscopy measurements are carried out on these samples to investigate the evolution of the Fermi surface topology with doping in the normal state. Clear and complete Fermi surfaces are observed and quantitatively analyzed in all of these overdoped Pb-Bi2201 samples. A Lifshitz transition from holelike Fermi surface to electron-like Fermi surface with increasing doping is observed at a doping level of ~0.35. This transition coincides with the change that the sample undergoes superconducting-to-non-superconducting states.Our results reveal the emergence of an electron-like Fermi surface and the existence of a Lifshitz transition in heavily overdoped Bi2201 samples. This provides important information in understanding the connection between the disappearance of superconductivity and the Lifshitz transition in the overdoped region.

Simultaneous determination of captopril and hydrochlorothiazide by time-resolved chemiluminescence with artificial neural network calibration

The combined use of chemometrics and chemiluminescence（CL）measurements,with the aid of the stopped-flow mixing technique,developed a simple time-resolved CL method for the simultaneous determination of captopril（CPL）and hydrochlorothiazide（HCT）.The stopped-flow technique in a continuous-flow system was employed in this work in order to emphasize the kinetic differences between the two analytes in cerium（IV）-rhodamine 6G CL system.After the flow was stopped,an initial rise of CL signal was observed for HCT standards,while a direct decay of CL signal was obtained for CPL standards.The mixed CL signal was monitored and recorded on the whole process of continuous-flow/stopped-flow,and the obtained data were processed by the chemometric approach of artificial neural network.The relative prediction error（RPE）of CPL and HCT was 5.9% and 8.7%,respectively.The recoveries of CPL and HCT in tablets were found to fall in the range between 95% and 106%.The proposed method was successfully applied to the simultaneous determination of CPL and HCT in a compound pharmaceutical formulation.

An Optimization Approach of Rotor Contour for Variable Reluctance Resolver

An effective approach for optimizing the rotor contour for variable reluctance(VR)resolver is presented.Using this approach,the procedure for optimizing the rotor is divided into two parts:the establishment of initial shape curve,and then computation for the optimization.In order to simplify the process of the former,a shape function is constructed.And the latter is carried out by Taguchi optimization method and finite element method(FEM).An example of a 3-10 VR resolver is used to present the procedure of the optimization,and the testing results confirmed the effectivity of the approach.

Hepatitis B virus reactivation and hepatitis in diffuse large B-cell lymphoma patients with resolved hepatitis B receiving rituximab-containing chemotherapy:risk factors and survival

Introduction:Hepatitis B virus(HBV) reactivation has been reported in B-cell lymphoma patients with resolved hepatitis B(hepatitis B surface antigen[HBsAg]-negative and hepatitis B core antibody[HBcAb]-positive).This study aimed to assess HBV reaaivation and hepatitis occurrence in diffuse large B-cell lymphoma(DLBCL) patients with resolved hepatitis B receiving rituximab-containing chemotherapy compared with HBsAg-negative/HBcAb-negative patients to identify risk factors for HBV reaaivation and hepatitis occurrence and to analyze whether HBV reaaivation and hepatitis affect the survival of DLBCL patients with resolved hepatitis B.Methods:We reviewed the clinical data of 278 patients with DLBCL treated with rituximab-containing therapy between January 2004 and May 2008 at Sun Yat-sen University Cancer Center,China.Prediaive faaors for HBV reaaivation,hepatitis development,and survival were examined by univariate analysis using the chi-square or Fisher's exact test and by multivariate analysis using the Cox regression model.Results:Among the 278 patients,165 were HBsAg-negative.Among these 165 patients,6(10.9%) of 55 HBcAb-positive(resolved HBV infeaion) patients experienced HBV reactivation compared with none(0%) of 110 HBcAb-negative patients(P=0.001).Patients with resolved hepatitis B had a higher hepatitis occurrence rate than HBsAg-negative/HBcAb-negative patients(21.8%vs.8.2%,P = 0.013).HBcAb positivity and elevated baseline alanine aminotransferase(ALT) levels were independent risk factors for hepatitis.Among the 55 patients with resolved hepatitis B,patients with elevated baseline serum ALT or aspartate aminotransferase(AST) levels were more likely to develop hepatitis than those with normal serum ALT or AST levels(P = 0.037,P = 0.005,respeaively).An elevated baseline AST level was an independent risk factor for hepatitis in these patients.Six patients with HBV reactivation recovered after immediate antiviral therapy,and chemotherapy was continued.HBcAb positivity,HBV reactivation,or hepatitis did not negatively affect the survival of DLBCL patients.Conclusions:DLBCL patients with resolved hepatitis B may have a higher risk of developing HBV reaaivation and hepatitis than HBsAg-negative/HBcAb-negative patients.Close monitoring and prompt antiviral therapy are required in these patients.

A comparison of single shot nanosecond and femtosecond polarization-resolved laser-induced breakdown spectroscopy of Al

Aluminum samples have been analyzed by femtosecond polarization-resolved laser-induced breakdown spectroscopy （fs-PRLIBS）. We compare the obtained spectra with those obtained from nanosecond PRLIBS （ns-PRLIBS）. The main specific features of fs-PRLIBS are that a lower plasma temperature leads to a low level of continuum and no species are detected from the ambient gas. Furthermore, signals obtained by fs-PRLIBS show a higher stability than those of ns-PRLIBS. However, more elements are detected in the ns-PRLIBS spectra.

Polyphase Multipole Resolvers for Improving Ripple Torque

The configuration of a brushless DC torque motor is introduced. According to the fundamental relation of the armature winding current and the air gap flux density, the ripple torque caused by the electrical errors of a resolver is approached. And a polyphase multipole resolver is developed in the brushless DC torque motor. Finally, the experimental results are presented to illustrate the improvement of ripple torque in the brushless DC torque motor with the polyphase multipole resolver.

Angle-resolved photoemission spectroscopy study on iron-based superconductors

Angle-resolved photoemission spectroscopy （ARPES） has played an important role in determining the band structure and the superconducting gap structure of iron-based superconductors. In this paper, from the ARPES perspective, we briefly review the main results from our group in recent years on the iron-based superconductors and their parent compounds, and depict our current understanding on the antiferromagnetism and superconductivity in these materials.

Numerical stability of solution to delay differential equations under resolvent condition for Runge-Kutta methods

Deals with the application of Kreiss resolvent condition in the error growth analysis of numerical methods, and studies the stability of Runge Kutta method in respect of Kreiss resolvent condition with emphasis on the study on the subclass of collocation methods with abscissas in [0,1] by applying the methods to the test equation U′(t)=λU(t)+μU(t-τ)τ>0 with complex constraints μ and λ, and proves under some assumptions on the R K methods that the error growth is uniformly bounded in the stability region.

A New Method to Resolve Overlapped Voltammetric Peaks

A new method called spline convolution (SC) for resolving overlapped peaks was proposed in this paper. The differential pulse voltammetric overlapped peaks of mixtures of Pb(II) and Tl(I) were investigated by this method, and satisfactory results were obtained. The results show excellent correlation between peak areas of the processed signals and the concentrations.

g-η-Monotone mapping and resolvent operator technique for solving generalized implicit variational-like inclusions

A new class of g-η-monotone mappings and a class of generalized implicit variational-like inclusions involving g-η-monotone mappings are introduced. The resolvent operator of g-η-monotone mappings is defined and its Lipschitz continuity is presented, An iterative algorithm for approximating the solutions of generalized implicit wriational- like inclusions is suggested and analyzed. The convergence of iterative sequences generated by the algorithm is also proved,

Ways to Improve English Listening and Speaking Skills

With the fast development of science and technology, English is becoming more and more important. Concerning English learning, we should focus our attention on listening, speaking, reading, writing and translating. Comparatively speaking, listening and speaking skills are more practical. But how to improve these skills? Everyone knows that the only effective way to improve language skills is to use the language. In reality, however, we know that there are many reasons why people don’t want to speak in another language——they are afraid of making mistakes, they can’t express their real meaning easily, they are shy, they are afraid people will laugh at them. We feel this way sometimes, but if you are sure that you really want to improve your English, try some of the suggestions that have been made here.

Effective Atomic Number Measurement with Energy-Resolved Computed Tomography Using Two-Dimensional “transXend” Detector

Introduction: We have previously developed an effective atomic number (Zeff) measurement method using linear attenuation coefficients (LACs) obtained by energy-resolved computed tomography (CT) with one-dimensional (1D) detector. The energy-resolved CT was performed with a “transXend” detector, which measured X-rays as electric current and then gave X-ray energy distribution with unfolding analysis using pre-estimated response function (RF). The purpose of this study is to measure Zeff by the energy-resolved CT using a flat panel detector (FPD). Methods: To demonstrate a 2D transXend detector, we developed the stripe absorbers for the FPD. Eleven human tissue-equivalent material rods which were grouped into four material categories were measured by X-rays with 120 kVp tube voltage, 2.3 mA tube current, and 1.0 s exposure time. Zeff is measured by the ratio of LACs with two different pseudo-monochromatic X-ray energies. RFs of each rod material were estimated by numerical calculation. First, we employed the RF estimated for the same rod material (self-RF scenario). Second, we employed the RF estimated for the different rod materials in the same material category (cross-RF scenario). The purpose of the cross-RF scenario was to find representative rod materials in each material category. Results: Upon the self-RF scenario, measured Zeffs were systematically underestimated. Median relative error to theoretical Zeff was -6.92% (range: -7.89% - -4.60%). After normalizing measured Zeffs to the theoretical one for Breast, median relative error improved to -0.75% (range: -1.79% - +1.73%). Upon the cross-RF scenario, the representative rod materials were found in two material categories. Conclusion: Zeff measurements were performed by energy-resolved CT using 2D transXend detector with numerically-estimated RF data. Normalized Zeffs for all rod materials in the self-RF scenario were in good agreement with the theoretical ones.