RAD-seq data reveals robust phylogeny and morphological evolutionary history of Rhododendron

Rhododendron is famous for its high ornamental value.However,the genus is taxonomically difficult and the relationships within Rhododendron remain unresolved.In addition,the origin of key morphological characters with high horticulture value need to be explored.Both problems largely hinder utilization of germplasm resources.Most studies attempted to disentangle the phylogeny of Rhododendron,but only used a few genomic markers and lacked large-scale sampling,resulting in low clade support and contradictory phylogenetic signals.Here,we used restriction-site associated DNA sequencing(RAD-seq)data and morphological traits for 144 species of Rhododendron,representing all subgenera and most sections and subsections of this species-rich genus,to decipher its intricate evolutionary history and reconstruct ancestral state.Our results revealed high resolutions at subgenera and section levels of Rhododendron based on RAD-seq data.Both optimal phylogenetic tree and split tree recovered five lineages among Rhododendron.Subg.Therorhodion(cladeⅠ)formed the basal lineage.Subg.Tsutsusi and Azaleastrum formed cladeⅡand had sister relationships.CladeⅢincluded all scaly rhododendron species.Subg.Pentanthera(cladeⅣ)formed a sister group to Subg.Hymenanthes(cladeⅤ).The results of ancestral state reconstruction showed that Rhododendron ancestor was a deciduous woody plant with terminal inflorescence,ten stamens,leaf blade without scales and broadly funnelform corolla with pink or purple color.This study shows significant distinguishability to resolve the evolutionary history of Rhododendron based on high clade support of phylogenetic tree constructed by RAD-seq data.It also provides an example to resolve discordant signals in phylogenetic trees and demonstrates the application feasibility of RAD-seq with large amounts of missing data in deciphering intricate evolutionary relationships.Additionally,the reconstructed ancestral state of six important characters provides insights into the innovation of key characters in Rhododendron.

一种基于Quartet Puzzling和邻接法的进化树构建算法

最大似然法是目前较准确的一种进化树构建方法,但是其时间复杂度非常高.在实际应用中,用分治策略实现最大似然法的Quartet Puzzling(QP)得到了人们的关注.它首先估计Quartet拓扑结构集合Q,然后利用重组技术将Q中的信息合并到一起构成一个包含所有序列的进化树.研究表明,QP的准确性不像人们所期望的那样高.如何快速有效地将Q所包含的信息融合在一起仍然是QP所面临的一个问题.为了提高QP,结合邻接法提出一种新的进化树构建方法QPNJ.理论上,QPNJ与QP具有相同的时间复杂度.通过模拟实验将QPNJ与QP以及目前流行的进化树构建方法进行了比较.结果表明,QPNJ比QP和邻接法更准确,并且其性能不依赖于模型树的结构,从而证明了QPNJ的有效性.

以《第五弦乐四重奏》看谢尔西晚期“单一音”创作技法特征

文章以贾钦多·谢尔西(Giacinto Scelsi,1905-1988)的晚期代表作《第五弦乐四重奏》为例,通过对其单一音的设立、结构的划分、音区的转变和微分音的使用这四个方面的观测,尝试对谢尔西晚期的"单一音"创作技法特征进行归纳。并通过比较该技法在其成熟期的运用特征,尝试总结出作曲家在晚期创作阶段对"单一音"技法的进一步改变和完善。

The Structure of Essential Spectra and Discrete Spectrum of Three-Electron Systems in the Impurity Hubbard Model—Quartet State

We consider a three-electron system in the Impurity Hubbard model with a coupling between nearest-neighbors. Our research aim consists of studying the structure of essential spectrum and discrete spectra of the energy operator of three-electron systems in the impurity Hubbard model in the quartet state of the system in a v-dimensional lattice. We have reduced the study of the spectrum of the three-electron quartet state operator in the impurity Hubbard model to the study of the spectrum of a simpler operator. We proved the essential spectra of the three-electron systems in the Impurity Hubbard model in the quartet state is the union of no more than six segments, and the discrete spectrum of the system is consists of no more than four eigenvalues.

QUARTET突变四倍体拟南芥的获得与表型分析

为了将四分子分析应用于多倍体遗传重组的研究,本研究从qrt1基因突变的二倍体Columbia(Col)与Landsberg erecta(Ler)生态型拟南芥出发,利用秋水仙素诱导核基因组加倍,利用流式细胞技术及荧光原位杂交技术筛选出成功加倍的qrt1基因突变的四倍体Col与Ler生态型拟南芥。并对其进行营养及生殖相关表型分析。首先qrt1突变抑制了侧根数量、基部侧枝数量以及莲座叶片面积。其次,四倍体莲座叶片面积、花粉、花药以及种子更大,侧根及茎基部分枝减少,抽薹时间推迟,每株果荚数与每果荚种子数更少,但种子发芽率都接近100%。倍性还对某些表型的影响具有背景依赖性,如对主茎分支数量、最终株高以及果荚长度的影响在Col与Ler生态型中表现不同。

Structure of Essential Spectrum and Discrete Spectra of the Energy Operator of Five-Electron Systems in the Hubbard Model. Third and Fourth Doublet States

We consider a five-electron system in the Hubbard model with a coupling between nearest-neighbors. The structure of essential spectrum and discrete spectrum of the systems in the third and fourth doublet states in a v-dimensional lattice is investigated. We prove that the essential spectrum of the system in a third doublet state consists is the union of at most four segments, and discrete spectrum of the system is empty. We show that the essential spectrum of the system in a fourth doublet state consists of the union of at most seven segments, and discrete spectrum of the system consists of no more than one point.

Factors affecting improvement of fluorescence intensity of quartet and doublet state of NO diatomic molecule excited by glow discharge

We report on the observation of new fluorescence emission spectral transitions obtained from NO diatomic molecule in the region from ultraviolet （UV） to near infrared （NIR） in a low power glow discharge system. This glow discharge electronic excitation populates different quartet and doublet states of NO in its proximity such as the A2Z （/9 = 2）, b4∑- （υ= 3）, B2М （1） = 4）, and X2Л （u= 33-32） states. Due to inter-system crossing, emission lines originating from these levels to lower lying states are recorded and spectral line assignments are performed. The observed systems include b4∑- a4∏, B21∏-a4∏, a4∏-X2I∏, A2∑X2∏, X2∏-X2∏ （33-15）, X2∏-X2∏ （33-17）, X2∏-X2∏ （33-20）, and X2∏-X2∏ （33- 18）. This new information will conduce to the better understanding of the interesting features of NO molecule. Such parameters that affect the recording of low density of NO molecules are also discussed In addition to the factors such as the time evolution, argon gas concentration relative to NO mixture, the percentage of NO molecular gas concentration, discharge electric current signals and discharge applied voltage are studied. Those factors would enhance the fluorescence signal intensity of NO molecules. The recent results might be significant as reference data for optimizing the glow discharge spectrometer and diagnostics of NO gas.

Local Particle-Ghost Symmetry

We study the quantization of systems with local particle-ghost symmetries. The systems contain ordinary particles including gauge bosons and their counterparts obeying different statistics. The particle-ghost symmetries are new type of fermionic symmetries between ordinary particles and their ghost partners, different from the space-time supersymmetry and the BRST symmetry. There is a possibility that they are useful to explain phenomena of elementary particles at a more fundamental level, by extension of our systems. We show that our systems are formulated consistently or subsidiary conditions on states guarantee the unitarity of systems, as the first step towards the construction of a realistic fundamental theory.

爵土123之QUARTET：在音乐里“玩桥牌”

纸牌是许多人喜欢玩的一种益智类游戏，世界上不同的国家地区，不同的民族都有着自己独特的纸牌文化和游戏规则。在纸牌的玩法中最高雅的一种就是人们非常熟悉的桥牌。现代桥牌的起源是从惠斯特桥牌开始的，这是十七世纪以后流行于英国的一种四人扑克牌打法。

KRIFS Quartet Model Improving Livelihoods and Fueling Tourism in Kitagwenda District, Western Uganda

Kyabwanswa Rural Integrated Farming Systems(KRIFS)is a Community Based Organization(CBO)with its Head Office in Kitagwenda Town Council.KRIFS quartet model involves emphasis of integrating four agricultural activities namely:Apiculture,agro-forestry,coffee and at least one type of livestock.The paper utilizes data obtained from January 2017 surveys,interviews,focus group discussions and observations by the authors.The authors observe that the four activities are symbiotic income generating enterprises.The quartet model has greatly contributed in reducing poverty,increasing agricultural productivity,facilitating value addition,conserving the environment,halting biodiversity loss and mitigating climate change.The model is strongly hinged on training of farmers in organized groups more especially the youth and the women.The involvement of KRIFS in integrated farming that involves introducing new innovations to improve production and productivity in agriculture through improved breeds of livestock and crops as well as environmental conservation being pivotal in its operations,has culminated to agro-tourism in the district.The authors recommend that the model be implemented in the whole of Uganda.Apiculture should be included in the priority commodity list for the parish model.Agro-tourism is yet another economic activity that should be exploited to reduce unemployment,conserve the environment and reduce effects of climate change.

Neither Fluorocarbons nor Silicones:Hydrocarbon-Based Water-Borne Healable Supramolecular Elastomer with Unprecedent Dual Resistance to Water and Organic Solvents

Except for fluorocarbons and silicones,few artificial materials display both water and organic solvent resistance.Herein,we report an artificial hydrocarbonbased supramolecular elastomer that displays unprecedented dual resistance to both water and organic solvents.This elastomer is formed in water with two water soluble components,folic acid(FA)and branched poly(ethylene imine)(b-PEI).The hydrogen bonding between the two components occurs immediately,which further promotes the hydrogen bonding between the FA,yielding folate quartets and theirπ-πstacking.These multiple noncovalent interactions work synergistically,leading to a hydrophobic,transparent,stretchable,healable,notchinsensitive,and recyclable elastomer that resists both water and organic solvents.The elastomer remains intact after storage in high humidity and organic solvents for months.Films generated by stretching the elastomer are very hydrophobic,and the contact angle of water on the elastomer is up to 112.3°.The damaged elastomers also exhibit water-assisted healable behavior.This work discloses a new paradigm of material synthesis that can inspire the fabrication of robust nonfluorocarbon and silicone-based materials with green strategies.

Radical induced quartet photosensitizers with high ^(1)O_(2) production for in vivo cancer photodynamic therapy

Singlet oxygen(^(1)O_(2)) is a strong oxidant which plays important roles in photodynamic therapy(PDT). The exploitation of photosensitizers with high ^(1)O_(2) production is crucial to improve PDT efficiency. In this study, a radical labeled quartet photosensitizer Cy-DENT is reported with high singlet oxygen quantum yield(Φ_(Δ)=32.3%) due to a radical enhanced inter-system crossing(ISC) process. After the introduction of 2,2,6,6-tetramethylpiperidinyloxy(TEMPO) radical, quartet state ^(4)[R,T] of CyDENT could be formed to give an over 20-fold enhancement of singlet oxygen quantum yield compared to Cy-DEN(without TEMPO radical) under irradiation of near infrared(NIR) light. In addition, the ^(1)O_(2 )production is well controlled by varying the electron-donating ability of the terminal substituent group. Cy-DENT possesses good cell permeability and is localized in mitochondria. Under the irradiation of 700 nm light, Cy-DENT can produce high levels of ROS to destroy the mitochondria membrane potential and induce cell apoptosis. Through the encapsulation of PEG-SS-PCL micelle, Cy-DENT can be effectively delivered to tumors and suppresses the tumor growth after PDT treatment.

Recent progress in multiple chiral doublet bands

Recent progress regarding multiple chiral doublet bands(MχD)is reviewed from the experimental and theoretical perspectives.In particular,the experimental findings,theoretical predictions,selection rule for electromagnetic transitions,MχD with octupole correlations,and some related topics are highlighted.Based on these discussions,it is of great scientific interest to search for the other MχD,as well as possible chiral wobblers,chirality-parity quartet bands,and chirality-pseudospin triplet(or quartet)bands in the nuclear system.

Possible candidate nuclei for chirality-parity quartet bands

The potential energy surfaces of the even-even 68-92Se, 112-150Ba, and 208-230Ra isotopes are calculated using the macroscopic-microscopic method in a multidimensional space {αλ,μ} including quadrupole （λ=2, μ=0, 2） and octupole （λ=3, μ=0, 1, 2, 3） degrees of freedom. The calculated results show that the even-even isotopes 92Se, 112,114,144-150Ba and 220-228Ra can exhibit the coexistence of triaxial and octupole deformations, thereby leading to simultaneous chiral and reflected symmetry breaking. Therefore, chirality-parity quartet bands are expected in these and their neighboring odd-A/odd-odd nuclei.

A Harmonious Quartet

BRIC nations voice shared concerns over global issues at their second summit When Goldman Sachs firstcoined the BRIC concept adecade ago, the internationalinvestment and securities

Quartet:一曲致敬夕阳的《四重唱》

2012年,年过七旬的老牌影帝Dustin Hoffman作为一个"菜鸟"级的导演携其首次执导的影片《四重唱》亮相于众。这部姗姗来迟的导演处女作和Dustin后期参演的影片一样,拥有着小众化的"小清新"风格。如今,老年题材的影片已不再沉重,夕阳下、轮椅上、那遥望窗外的孤独背影,虽已不是主流,但依旧有感染力,那种在生命即将走到尽头却依旧具备自身的价值更是值得关注。影片那并未过分狗血和满是同情心的轻喜剧手段,不仅使人深受感动,同时还有了更多的思考——当时光飞逝,直至年老体衰之时。