In pursuit of reconstructing missing human handsOA

<正>Human beings are the most intelligent living beings on Earth.Creating reconstructions of missing human limbs that can be naturally integrated into the human body is a lofty ambition and faces challenges in neuroscience,information science,mechanical and electronic engineering,and many other disciplines.Based on the development history of robotic prosthetic hands over the past 70 years,     

An action plan for the agri-food sector at the time of the climate and biodiversity crisesOA

<正>Land areas on our planet are facing unprecedented levels of stress.More than70%of the global ice-free land has been affected by human activities,30%of the land is threatened by degradation,biodiversity and other ecosystem services(ESs) are declining,and climate change is altering ecosystem functioning [1].Currently,agriculture is the dominant form of land use,with grazing land comprising27%and cropland 12%(and more than half of the cropland is used to produce animal feed).Agriculture is...     

Photodegradable polar-functionalized polyethylenesOA

The degradation of plastics has attracted much attention from the global community.Polyethylenes(PEs),as the most abundant synthetic plastics,are most frequently studied.PE is non-degradable and non-polar because of the sole presence of the pure hydrocarbon components.Concurrent incorporation of both in-chain cleavable and functional groups into the PE chain is an effective pathway to overcome the non-degradable and non-polar issue;however,the method for achieving this pathway remains elusive.He...     

Multi-region calcium imaging in freely behaving mice with ultra-compact head-mounted fluorescence microscopesOA

To investigate the circuit-level neural mechanisms of behavior, simultaneous imaging of neuronal activity in multiple cortical and subcortical regions is highly desired. Miniature head-mounted microscopes offer the capability of calcium imaging in freely behaving animals. However, implanting multiple microscopes on a mouse brain remains challenging due to space constraints and the cumbersome weight of the equipment.Here, we present TINIscope, a Tightly Integrated Neuronal Imaging microscope opti...     

China Enters New Phasein Space Exploration

China successfully launched itsfourth unmanned test space-craft (Shenzhou-4) into orbit on lastDecember 30. It signifies that Chinais one step closer to a manned flight.The spacecraft was jointly manufac-tured by the Chinese Research In-stitute of Space Technology and theShanghai Research Institute of As-tronomical Technology, with scien-tific experiments developed by theChinese Academy of Sciences in co-operation with other domesticinstitutions.The spacecraft touched downsuccessfully in…     

蜘蛛抱蛋属(百合科)的细胞分类学研究(1)——四川七个种的核型

In the work mitotic chromosomes in root-tips of 7 species native to Sichuan Pro- vince were examined and their karyotypes were analysed based on 7-8 cells at mitotic meta- phase, using Levan et al.'s (1964) nomenclature. The list of species and origin of the materials used in this work are provided in the appendix.  The micrographs of mitotic metaphase of all the materials are shown in Plates 1 and 2; the idiograms in Fig. 1, 1-9, and the parameters of chromosomes are provided in Tables 1-9.  All the chromosome countings and karyotypes in this paper are reported for the first time.      Characteristics of the karyotypes may be summarized as follows:      1.  2n=38 are found in all the materials except A. sichuanensis, which has 3 cytotypes, i.e, 2n=38+5B, 2n=38+lB and 2n=38+OB (Plate 2, 1-2, Fig. 1, 5-6).      2.  The karyotypes are of two major types: the karyotype of A. flaviflora falls into 3C in Stebbins's (1958, 197l) classification of karyotypes and those of all the other species into 2C. The two types are also different from each other in the number of large and medium-sized chromosomes pairs and morphology of the first pair of chromosomes (compare Plate 2, 5, Fig. 1, 9 with the other micrographs and idiograms).A. flaviflora with the karyotype 3C also differs from the other species in a series of gross morphological characters: the species is of a yellow and campanulate corolla.      3.  The species with caespitose leaves (A. caespitosa and A. omeiensis) have essentially the same karyotype, which is rather different from those of the species with scattered leaves. There are two pairs of small sm chromosomes (arm ratio ≥1.90) in the former karyotype (Tables 1 and 3), but all the small chromosomes are m or sm with arm ratio <1.80 in the latter karyotypes.     

Testing flexible polymer solar cells in near-spaceOA

<正>Since the big success of the Vanguard1 mission,being the first solar-powered satellite,the use of solar cells in space developed very rapidly.Today,conventional solar cell technologies for space are based on silicon and GaAs modules.If significantly higher power conversion efficiencies (PCEs) are required,     

A teraflop computer with Loongson inside

On 26 December, 2007, the KD-50-1, the first computer capable of teraflop speeds based on the Loongson （formerly named Godson） processor series and other home-grown components, equipment and technologies, passed the accreditation by a panel of expels led by Prof. WANG Shoujue, a renowned expert on information science and a CAS Member.     

诺·达格瑞(R．Dahlgyen)被子植物分类系统介绍和评注

The present paper aims at introducting Dahlgren’s system of classification of the angiosperms.  Phenetic and phylogenetic classifications are discussed.  The basic principles and methods used by Dahlgren are explained.  Dahlgren’s opinions on some important problems,  such as the origin of angiosperms,  the flowers of primitive angiosperms,  the relation between the dicotyledons and monocotyledons,  the origin of the monocotyledons,  the treatment of the “Amentiferae” and of the orders of the “Sympetalae”,  are all expressed.  A brief comparison between Dahlgren’s system and three other current systems,  viz. those of Takhtajan,  Cronquist and Thorne is also given.     

Climbing robots for manufacturingOA

Robotized intelligent manufacturing is a growing trend in the manufacturing of large and complex components in aviation,aerospace,marine engineering and other industries.With their expansive workspaces and flexible deployment,climbing manufacturing robots can create a revolutionary manufacturing paradigm for large and complex components.This paper defines the climbing manufacturing robot based on the application status of climbing robots and then analyzes four key technical re quirements:adhesio...     

Challenges and opportunities for modeling coupled human and natural systemsOA

<正>The Earth is a very large and complex system that consists of human and natural components interacting bidirectionally with each other,thus forming coupled human and natural systems (CHANS)[1].The increasing dominance of human impacts,especially after the 1950s [2],marked a new era for the Earth,the Anthropocene,which means humans have become the main drivers of the evolution of changes in the Earth system.Therefore,modeling CHANS is essential for understanding the emergent system prope...     

Microbes in mass extinction: an accomplice or a savior?OA

<正>Microbes include various types of organisms that are invisible to the naked eye,e.g. bacteria, archaea and microeukaryotes. Although the precise number remains largely unknown, microbes are recognized as the unseen majority of our biosphere [1]. As a group of organisms classified by body size, microbes cover a considerable spectrum of metabolisms,     

白芷的核型研究及其分类意义

The present paper deals mainly with the karyotype analysis of five materials in Angelica dahurica collected in Yanbian of Jilin, Anguo of Hebei, Yuxian of Henan, Hangzhou of Zhejiang and Suining of Sichuan.  They are under the names “Dongbeidahuo”, “Qibaizhi”, “Yubaizhi”, ”Hangbaizhi” and “Chuanbaizhi” respe- ctively.  Among then “Dongbeidahuo” is a wild plant, which occurs in  northeastern China, and the others are cultivated as important crude drugs in some provinces. “Qi- Baizhi” and “Yubaizhi” have been identified as conspecific with the wild Baizhi-“Do- Ngbeidahuo” (A. dahurica) according to the external morphological features, whereas the other cultivated ones, “Hangbaizhi” and “Chuanbaizhi”, treated as a variety (A. dahu- rica var. formosana).      The results of karyotype analysis are shown in Plate 1, 2, with the formula 2n=22 =12 m+2 mSAT+4sm+4st. The karyotypes described here are constantly characterized by satellites attached to the fourth pair of metacentric chromosomes and differ from the pu- blished reports on the other species of the genus.  It is reasonable to say that the five materials collectively named “Baizhi” are taxonomically closely related to each other and could be regarded as conspecific.  Since the second chromosome pair is submetacen- tric in “Dongbeidahuo”, it may be justifiable to separate the wild plant from the cul- tivated ones and treat them as two separate varieties.     

Scientific misconducts in the darkening gray zone

<正>Much atention has been given to three forms of scientiic misconducts known as falsiication,fabrication and plagiarism(FFP).Outright cases of FFP are rare,and once exposed,the consequences are severe.More frequent and hard to detect are questionable conducts in the gray zone,such as inappropriate data selection,analysis and presentation,misbehaviors in scientiic review and communication,and undue credit allocation in publications or other forms of research products.Some of these     

How variable progenitor clones construct a largely invariant neocortexOA

The neocortex contains a vast collection of diverse neurons organized into distinct layers. While nearly all neocortical neurons are generated by radial glial progenitors(RGPs), it remains largely unclear how a complex yet organized neocortex is constructed reliably and robustly. Here, we show that the division behavior and neuronal output of RGPs are highly constrained with patterned variabilities to support the reliable and robust construction of the mouse neocortex. The neurogenic process of ...     

Modular Design and Genome-wide Association Analysis Will Become Important Means of Molecular Breeding in Future

<正>In recent years,with the rapid development of interdisciplinary studies such as molecular biology,genomics and systems biology,and with the breakthroughs in genome sequencing and other technologies,molecular marker-assisted selection and transgenic technology gradually became two important means of plant/animal breeding.Despite of the achievements,however,there are a number of problems in molecular breeding that need to be addressed immediately.As the major agronomic and economic traits of plants or animals are usually very complex and controlled by multiple genes,the modifi cation of a single or several functional genes is inadequate for the overall improvement of the target’s complex traits.Thus efficient,targeted and     

Figs,Wasps, Carrots and Sticks? A New Theoretical Approach to Understanding the Origin and Nature of Mutualisms and Symbiotic Relationships

<正>Mutualisms—relationships where by two organisms live in tandem with one another,each providing a service to the other—are among the most interesting and complex relationships in nature.These kinds of relationships are generally considered cooperative interactions,whereby each of the organisms incurs substantial cost in trading services with its partner in order for each of them to gain some benefit and increase their chances of survival and evolutionary fitness.While     

Level pinning of anti-PT-symmetric circuits for efficient wireless power transferOA

Wireless power transfer(WPT) technology based on magnetic resonance(a basic physical phenomenon)can directly transfer energy from the source to the load without wires and other physical contacts, and has been successfully applied to implantable medical devices, electric vehicles, robotic arms and other fields.However, due to the frequency splitting of near-field coupling, the resonant WPT system has some unique limitations, such as poor transmission stability and low efficiency. Here, we propose...     

An Aircraft Navigation System Fault Diagnosis Method Based on Optimized Neural Network Algorithm

Air data and inertial reference system （ADIRS） is one of the complex sub-system in the aircraft navigation system and it plays an important role into the flight safety of the aircraft. This paper propose an optimize neural network algorithm which is a combination of neural network and ant colony algorithm to improve efficiency of maintenance engineer job task.