Zeitschriftenartikel: „Division by splitting“

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Krashen, Daniel, und Kelly McKinnie. „Distinguishing division algebras by finite splitting fields“. Manuscripta Mathematica 134, Nr. 1-2 (10.08.2010): 171–82. http://dx.doi.org/10.1007/s00229-010-0390-0.

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2

Beveridge, Terry J., Bob J. Harris, Girishchandra B. Patel und G. Dennis Sprott. „Cell division and filament splitting in Methanothrix concilii“. Canadian Journal of Microbiology 32, Nr. 10 (01.10.1986): 779–86. http://dx.doi.org/10.1139/m86-143.

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Cells of Methanothrix concilii do not possess rigid, shape-forming cell walls; they obtain their cellular form from the portions of the sheath and spacer plugs which enclose them. Electron microscopy has shown that cell division proceeds by the ingrowth of spacer plugs, like the closing of a camera iris, from select regions of the sheath; this process forces the cells to split in two. Therefore, each spacer plug which traverses the filament of cells is a completed division annulus. Spacer plugs are two-layered structures; one layer is an assembly of fine concentric rings and is the first to be laid down during the division ingrowth. The second layer consists of larger, raised, concentric ribbons which progressively follow the advance of the first layer during division. Although cells within the filament are typically 2.5 μm long, new daughter cells are ca. 1.0 μm and can grow to ca. 4.0 μm before division begins. Frequently, a developing spacer plug partitions a cell so that one daughter is a small, nonreplicating unit of protoplasm sandwiched between two completed plugs; eventually, this protoplasmic unit dies leaving a void in the chain of cells. The filament is susceptible to breakage at this juncture. In this instance, each of the two "void" plugs becomes a new terminal plug for the new ends of the split filament. This type of replication requires both cell division and filament splitting, and the series of structural events which are involved present a new form of prokaryotic division.

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Nizami Huseyn, Elcin, Emin Taleh Mammadov und Mohammad Hoseini. „A REVIEW ON THE DIVISION OF MAGNETIC RESONANT PROSTATE IMAGES WITH DEEP LEARNING“. NATURE AND SCIENCE 03, Nr. 01 (05.03.2021): 13–17. http://dx.doi.org/10.36719/2707-1146/06/13-17.

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Deep learning; it is often used in dividing processes on images in the biomedical field. In recent years, it has been observed that there is an increase in the division procedures performed on prostate images using deep learning compared to other methods of image division. Looking at the literature; It is seen that the process of dividing prostate images, which are carried out with deep learning, is an important step for the diagnosis and treatment of prostate cancer. For this reason, in this study; to be a source for future splitting operations; deep learning splitting procedures on prostate images obtained from magnetic resonance (MRI) imaging devices were examined. Key words: deep learning, image division, prostate cancer

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Amitsur, S. A. „Galois splitting fields of a universal division algebra“. Journal of Algebra 143, Nr. 1 (Oktober 1991): 236–45. http://dx.doi.org/10.1016/0021-8693(91)90262-7.

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5

Mecke, J. „A note on Cowan’s process of space division“. Advances in Applied Probability 21, Nr. 01 (März 1989): 235–36. http://dx.doi.org/10.1017/s0001867800017316.

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Mecke, J. „A note on Cowan’s process of space division“. Advances in Applied Probability 21, Nr. 1 (März 1989): 235–36. http://dx.doi.org/10.2307/1427209.

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7

Galindo, George R. B. „SPLITTING TWAIL?“ Windsor Yearbook of Access to Justice 33, Nr. 3 (01.05.2017): 37–56. http://dx.doi.org/10.22329/wyaj.v33i3.4886.

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Periodizations are political acts. They produce temporalities that do not necessarily coincide with chronology. TWAIL (Third World Approaches to International Law) scholars have generally endorsed the division of TWAIL into two generations. Whereas TWAIL I was composed by scholars that thought and wrote about international law during the decolonization process, TWAIL II began at the end of the 1990s. Although there are common features between the generations, a number of differences are also identified and emphasized by TWAIL II scholars. In this article, I advance the argument that such periodization is problematic for four reasons: anachronism, progressivism, a difficult self-identification of past third world legal scholars with TWAIL and the image made of TWAIL by non-TWAILers. Instead of periodizing TWAIL in two successive generations, I argue that identifying it as part of a larger tradition of third world international legal scholarship is more productive for the inner coherence of the intellectual movement and, consequently, for its success in the international legal academia.

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Tan Xuegong, 谭学功, 余顺争 Yu Shunzheng und 张宏滨 Zhang Hongbin. „Manycast Routing in Sparse Splitting Wavelength Division Multiplexing Networks“. Acta Optica Sinica 33, Nr. 7 (2013): 0706022. http://dx.doi.org/10.3788/aos201333.0706022.

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Lichtenstein, Bronwen, und Ida M. Johnson. „Splitting the Marital Home: Gendered Property Division and Postdivorce Foreclosure“. Journal of Divorce & Remarriage 60, Nr. 5 (20.11.2018): 346–61. http://dx.doi.org/10.1080/10502556.2018.1546065.

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Duke, w., und Á. Tóth. „The Splitting of Primes in Division Fields of Elliptic Curves“. Experimental Mathematics 11, Nr. 4 (Januar 2002): 555–65. http://dx.doi.org/10.1080/10586458.2002.10504706.

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Gao, Fu Qiang. „Failure Analysis and its Numerical Simulation on Impact-Damage Rock“. Advanced Materials Research 1010-1012 (August 2014): 1523–26. http://dx.doi.org/10.4028/www.scientific.net/amr.1010-1012.1523.

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Stress wave propagation effect and failure characteristics were studied by one-stage light-gas gun induced-plate impact experiment technology on limestone. The results show that dispersion effect and attenuation character are existed in impacting rock; failure division properties are analyzed by splitting cut observation, the results show that the failure specimen can be divided by three different failure divisions which are head failure zone, middle tension-compression failure zone and tail fracture failure zone. On this basis, impact-damaged process of rock is numerically simulated to analyze impact-damaged mechanism of limestone specimens.

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Motiee, Mehran. „On the non-existence of cyclic splitting fields for division algebras“. Forum Mathematicum 30, Nr. 2 (01.03.2018): 385–95. http://dx.doi.org/10.1515/forum-2016-0121.

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AbstractLetDbe a division algebra over its centerFof degreen. Consider the group{\mu_{Z}(D)=\mu_{n}(F)/Z(D^{\prime})}, where{\mu_{n}(F)}is the group of all then-th roots of unity in{F^{*}}, and{Z(D^{\prime})}is the center of the commutator subgroup of the group of units{D^{*}}ofD. It is shown that if{\mu_{Z}(D\otimes_{F}L)\neq 1}for someLcontaining all the primitive{n^{k}}-th roots of unity for all positive integersk, thenDis not split by any cyclic extension ofF. This criterion is employed to prove that some special classes of division algebras are not cyclically split.

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CHAI, LEI, DAHUI WANG, JIAWEI CHEN, MENGHUI LI und ZENGRU DI. „CLUSTER SPLITTING TRANSITION IN A MARKOV CHAIN MODEL FOR LABOR DIVISION“. International Journal of Bifurcation and Chaos 18, Nr. 02 (Februar 2008): 593–98. http://dx.doi.org/10.1142/s0218127408020513.

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A Markov chain model is constructed to simulate pattern formation arising from an evolutionary population of interactive homogeneous agents. In the structure of optimal evolution and stochastic properties, the model exhibits emergent properties with rich dynamical diagrams. We study the cluster splitting transition with the coarsening period-adding phenomena shown by the model, which gives an example of pattern formation in the evolution of complex system and reveals dynamical behavior of the Markov chain process.

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Малов, Илья, und Iliy Malov. „Applicability investigations of laser-controlled thermo-splitting technology for manufacturing elements of thermo-optical coating for spacecraft radiators“. Science intensive technologies in mechanical engineering 2, Nr. 12 (13.12.2017): 36–39. http://dx.doi.org/10.12737/article_5a313b650da070.69097320.

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In view of a responsible destination and hard operation conditions strong technical requirements are made to glass ele-ments of a thermo-optical coating for spacecraft radiators where a basic requirement of them is absence of chips and micro-cracks. There are carried out investigations of the influence of laser radiation parameters upon end face quality in the in glass element obtained through the method of controlled thermo-splitting. A quality considerable increase is shown in the surfaces of division at the use of the method of the end-to-end laser controlled thermo-splitting in comparison with the methods of part-through laser controlled thermo-splitting and scribing with a diamond cutter with the further after-break.

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Fisher, Brent, und John Biddle. „Luminescent spectral splitting: Efficient spatial division of solar spectrum at low concentration“. Solar Energy Materials and Solar Cells 95, Nr. 7 (Juli 2011): 1741–55. http://dx.doi.org/10.1016/j.solmat.2011.01.043.

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16

Cowan, Richard. „A mosaic of triangular cells formed with sequential splitting rules“. Journal of Applied Probability 41, A (2004): 3–15. http://dx.doi.org/10.1017/s0021900200112161.

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The iterative division of a triangle by chords which join a randomly-selected vertex of a triangle to the opposite side is investigated. Results on the limiting random graph which eventuates are given. Aspects studied are: the order of vertices; the fragmentation of chords; age distributions for elements of the graph; various topological characterisations of the triangles. Different sampling protocols are explored. Extensive use is made of the theory of branching processes.

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Cowan, Richard. „A mosaic of triangular cells formed with sequential splitting rules“. Journal of Applied Probability 41, A (2004): 3–15. http://dx.doi.org/10.1239/jap/1082552186.

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The iterative division of a triangle by chords which join a randomly-selected vertex of a triangle to the opposite side is investigated. Results on the limiting random graph which eventuates are given. Aspects studied are: the order of vertices; the fragmentation of chords; age distributions for elements of the graph; various topological characterisations of the triangles. Different sampling protocols are explored. Extensive use is made of the theory of branching processes.

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Kumar, Megha, Kumari Pushpa und Sivaram V. S. Mylavarapu. „Splitting the cell, building the organism: Mechanisms of cell division in metazoan embryos“. IUBMB Life 67, Nr. 7 (Juli 2015): 575–87. http://dx.doi.org/10.1002/iub.1404.

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de Ville de Goyet, J., F. di Francesco, V. Sottani, C. Grimaldi, A. E. Tozzi, L. Monti und P. Muiesan. „Splitting livers: Trans-hilar or trans-umbilical division? Technical aspects and comparative outcomes“. Pediatric Transplantation 19, Nr. 5 (09.06.2015): 517–26. http://dx.doi.org/10.1111/petr.12534.

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20

Hosoki, Takashi, und Daisuke Kimura. „Micropropagation of Centaurea macrocephala Pushk. ex Willd. by Shoot-axis Splitting“. HortScience 32, Nr. 6 (Oktober 1997): 1124–25. http://dx.doi.org/10.21273/hortsci.32.6.1124.

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Micropropagation of Centaurea macrocephala Pushk. ex Willd. was achieved by subculturing of vertically split shoots and division of axillary buds on MS-based medium with 0.44 μm BA. A proliferation rate of 2.0 per 16-day culture period was obtained. Seventy percent of microcuttings obtained through in vitro culture could be rooted on a modified Hyponex medium with 25 μM IBA. All plantlets were readily acclimatized and grown in a greenhouse. Chemical names used: benzylaminopurine (BA); indole-3-butyric acid (IBA).

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K M, Delphin Raj, Sun-Ho Yum, Eunbi Ko, Soo-Young Shin, Jung-Il Namgung und Soo-Hyun Park. „Multi-Media and Multi-Band Based Adaptation Layer Techniques for Underwater Sensor Networks“. Applied Sciences 9, Nr. 15 (05.08.2019): 3187. http://dx.doi.org/10.3390/app9153187.

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In the last few decades, underwater communication systems have been widely used for the development of navy, military, business, and safety applications, etc. However, in underwater communication systems, there are several challenging issues, such as limitations in bandwidth, propagation delay, 3D topology, media access control, routing, resource utilization, and power constraints. Underwater communication systems work under severe channel conditions such as ambient noise, frequency selectivity, multi-path and Doppler shifts. In order to collect and transmit the data in effective ways, multi-media/multi-band-based adaptation layer technology is proposed in this paper. The underwater communication scenario comprises of Unmanned Underwater Vehicles (UUVs), Surface gateways, sensor nodes, etc. The transmission of data starts from sensor nodes to surface gateway in a hierarchical manner through multiple channels. In order to provide strong and reliable communication underwater, the adaptation layer uses a multi-band/multi-media approach for transferring data. Hence, in this paper, existing techniques for splitting the band such as Orthogonal Frequency-Division Multiple Access (OFDMA), Frequency-Division Multiple Access (FDMA), or Orthogonal Frequency-Division Multiplexing (OFDM) are used for splitting the frequency band, and the medium selection mechanism is proposed to carry the signal through different media such as Acoustic, Visible Light Communication (VLC), and Infrared (IR) signals in underwater. For the channel selection mechanism, two phases are involved: 1. Finding the distance of near and far nodes using Manhattan method, and 2. Medium selection and data transferring algorithm for choosing different media.

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Cui, Wei, Wei Wang, Jie Zhang und Jungang Yang. „Multicore structures and the splitting and merging of eddies in global oceans from satellite altimeter data“. Ocean Science 15, Nr. 2 (15.04.2019): 413–30. http://dx.doi.org/10.5194/os-15-413-2019.

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Abstract. This study investigated the statistics of eddy splitting and merging in the global oceans based on 23 years of altimetry data. Multicore structures were identified using an improved geometric closed-contour algorithm of sea surface height. Splitting and merging events were discerned from continuous time series maps of sea level anomalies. Multicore structures represent an intermediate stage in the process of eddy evolution, similar to the generation of multiple nuclei in a cell as a preparatory phase for cell division. Generally, splitting or merging events can substantially change (by a factor of 2 or more) the eddy scale, amplitude, and eddy kinetic energy. Specifically, merging (splitting) generally causes an increase (decrease) of eddy properties. Multicore eddies were found to tend to split into two eddies with different intensities. Similarly, eddy merging is not an interaction of two equal-intensity eddies, and it tends to manifest as a strong eddy merging with a weaker one. A hybrid tracking strategy based on the eddy overlap ratio, considering both multicore and single-core eddies, was used to confirm splitting and merging events globally. The census revealed that eddy splitting and merging do not always occur most frequently in eddy-rich regions; e.g., their frequencies of occurrence in the Antarctic Circumpolar Current and western boundary currents were found to be greater than in midlatitude regions (20–35∘) to the north and south. Eddy splitting and merging are caused primarily by an unstable configuration of multicore structures due to obvious current– or eddy–topography interaction, strong current variation, and eddy–mean flow interaction.

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Tseng, Kuo-Bin. „Efficient multicast routing in wavelength-division-multiplexing networks with light splitting and wavelength conversion“. Optical Engineering 44, Nr. 4 (01.04.2005): 045003. http://dx.doi.org/10.1117/1.1886846.

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Leventhal, A., S. Ault und D. Vitek. „The nasotemporal division in primate retina: the neural bases of macular sparing and splitting“. Science 240, Nr. 4848 (01.04.1988): 66–67. http://dx.doi.org/10.1126/science.3353708.

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Uehara, Tsuyoshi, Thuy Dinh und Thomas G. Bernhardt. „LytM-Domain Factors Are Required for Daughter Cell Separation and Rapid Ampicillin-Induced Lysis in Escherichia coli“. Journal of Bacteriology 191, Nr. 16 (12.06.2009): 5094–107. http://dx.doi.org/10.1128/jb.00505-09.

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ABSTRACT Bacterial cytokinesis is coupled to the localized synthesis of new peptidoglycan (PG) at the division site. This newly generated septal PG is initially shared by the daughter cells. In Escherichia coli and other gram-negative bacteria, it is split shortly after it is made to promote daughter cell separation and allow outer membrane constriction to closely follow that of the inner membrane. We have discovered that the LytM (lysostaphin)-domain containing factors of E. coli (EnvC, NlpD, YgeR, and YebA) are absolutely required for septal PG splitting and daughter cell separation. Mutants lacking all LytM factors form long cell chains with septa containing a layer of unsplit PG. Consistent with these factors playing a direct role in septal PG splitting, both EnvC-mCherry and NlpD-mCherry fusions were found to be specifically recruited to the division site. We also uncovered a role for the LytM-domain factors in the process of β-lactam-induced cell lysis. Compared to wild-type cells, mutants lacking LytM-domain factors were delayed in the onset of cell lysis after treatment with ampicillin. Moreover, rather than lysing from midcell lesions like wild-type cells, LytM− cells appeared to lyse through a gradual loss of cell shape and integrity. Overall, the phenotypes of mutants lacking LytM-domain factors bear a striking resemblance to those of mutants defective for the N-acetylmuramyl-l-alanine amidases: AmiA, AmiB, and AmiC. E. coli thus appears to rely on two distinct sets of putative PG hydrolases to promote proper cell division.

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Kawamoto, Manabu, Akiko Fujiwara, Shin-ichi Kuno und Ikuo Yasumasu. „Changes in the activities of protein phosphatase type 1 and type 2A in sea urchin embryos during early development“. Zygote 8, S1 (Dezember 1999): S68—S69. http://dx.doi.org/10.1017/s0967199400130370.

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Serine/threonine protein phosphatases expected to participate in the process of signal transduction, cell movement such as cell division and gene expression (Kinoshita et al., 1990; Healy et al., 1991; Mayer-Jaekel et al., 1993; Mumby & Walter, 1993), are classified into type 1 (PP1), type 2A (PP2A), type 2B and type 2C in mammalian cells. PP1 and PP2A are known to be strongly inhibited by okadaic acid (OA) (Tachibana et al., 1981; Bialojan Takai, 1988), a polyether fatty acid isolated from the marine sponge Halicondria okadai (Haystead et al., 1989). OA is also known to inhibit PP2A at lower concentrations than that to block PP1 in mammalian cells, but does not inhibit the activities of other phosphatase species (Ishihara et al., 1989).The p-nitrophenyl phosphate (pNPP) splitting activity in the extract obtained from eggs of the sea urchin Hemicentrotus pulcherrimus was found to be inhibited by OA and calyculin A (CLA), potent inhibitors of PP1 and PP2A. OA-sensitive phosphatases are known to catalyse pNPP splitting (Takai & Mieskes, 1991), in the same manner as other OA-insensitive phosphatases.Four peaks of the pNPP splitting activity were obtained by QAE-Toyopearl chromatography in the extract of sea urchin eggs. In two of these four peaks, pNPP splitting reactions were strongly inhibited by OA and CLA at quite low concentration. High sensitivities of the pNPP splitting reaction to OA and CLA in these two peaks suggest that pNPP splitting results from the reaction catalysed by PP2A. The molecular masses of proteins exhibiting OA-sensitive pNPP splitting activities in these two peaks were found to be about 160 kDa by Superdex 200HR, and were similar to that of mammalian PP2A trimeric holoenzyme. By immunoblot analyses with anti-human PP2A catalytic subunit antibody, an immunoreactive 36 kDa protein was found by SDS-PAGE in a peak of OA-sensitive pNPP splitting activity obtained by QAE-Toyopearl chromatography. Sea urchin eggs have at least two PP2A-like enzymes with similar molecular masses to that of mammalian PP2A, and one of them contains human-type catalytic subunit.

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Shillcock, Richard, und Padraic Monaghan. „The Computational Exploration of Visual Word Recognition in a Split Model“. Neural Computation 13, Nr. 5 (01.05.2001): 1171–98. http://dx.doi.org/10.1162/08997660151134370.

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We argue that the projection of the visual field to the cortex constrains and informs the modeling of visual word recognition. On the basis of anatomical and psychological evidence, we claim that the higher-level cognition involved in word recognition does not completely transcend initial foveal splitting. We present a schematic connectionist model of word recognition that instantiates the precise splitting of the visual field and the contralateral projection of the two hemifields. We explore the special nature of the exterior (i.e., first and last) letters of words in reading. The model produces the correct behavior spontaneously and robustly. We analyze this behavior of the model with respect to words and random patterns and conclude that the systematic division of the visual input has predictable, general informational consequences and is chiefly responsible for the exterior letters effect.

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Beveridge, Terry J., Bob J. Harris und G. Dennis Sprott. „Septation and filament splitting in Methanospirillum hungatei“. Canadian Journal of Microbiology 33, Nr. 8 (01.08.1987): 725–32. http://dx.doi.org/10.1139/m87-126.

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Methanospirillum hungatei GP1 consists of chains of rod-shaped cells separated from one another by "cell spacers" comprised of two spacer plugs sandwiching a loose, amorphous material. The chain is encased within a highly ordered sheath to form a cylindrical, multicelled filament about 5 to 10 cells long under our growth conditions. Cells within the filament divide by septation in a manner similar to gram-positive eubacteria; the plasma membrane and wall grow inward to partition the cell in two. Yet, unlike gram-positive eubacteria, the wall is flexible, since cells round up when extruded from the sheath; the shape-maintaining structures are the sheath and spacer plugs. After septation and daughter cell separation, the cell spacer grows between the new cells. Initially, the growth of a spacer plug is detected by electron microscopy as the addition of electron-dense layers, exhibiting an 18.0-nm periodicity, at the surface of one new cell pole. Usually three layers develop at this pole before plug assembly is initiated at the opposite pole. As assembly proceeds, the two newly formed plugs separate from each other to form the loose, amorphous central zone of the spacer. Presumably, cell and cell spacer elongation requires sheath extension, since filament growth is observed. The amorphous cell spacer zone continues to expand as the spacer grows larger until lesions appear in the sheath near the zone's midpoint. Usually, the largest spacer zones are found towards each filament's centre and the lesions split the chain in two. Consequently, M. hungatei requires two separate events for filament division: cell replication which is a septation process and filament splitting which is a "cell spacer" breakage.

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Derom, Catherine, Evert Thiery, Bart P. F. Rutten, Hilde Peeters, Marij Gielen, Esmée Bijnens, Robert Vlietinck und Steven Weyers. „The East Flanders Prospective Twin Survey (EFPTS): 55 Years Later“. Twin Research and Human Genetics 22, Nr. 6 (09.09.2019): 454–59. http://dx.doi.org/10.1017/thg.2019.64.

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AbstractThe East Flanders Prospective Twin Survey (EFPTS) is a registry of multiple births in the province of East Flanders, Belgium. Since its start in 1964, over 10,000 twin-pairs have been registered. EFPTS has several unique features: it is population-based and prospective, with the possibility of long-term follow-up; the twins (and higher order multiple births) are recruited at birth; basic perinatal data are recorded; chorion type and zygosity are established; since 1969, placental biopsies have been taken and frozen at –20°C for future research. Since its origin, the EFPTS has included placental data and allows differentiation of three subtypes of monozygotic twins based on the time of the initial zygotic division: the dichorionic–diamniotic pairs (early, with splitting before the fourth day after fertilization), the monochorionic–diamniotic pairs (intermediate, splitting between the fourth- and the seventh-day postfertilization) and the monochorionic–monoamniotic pairs (late, splitting after the eighth day postfertilization). Studies can be initiated taking into account primary biases, those originating ‘in utero’. Such studies could throw new light on the consequences of early embryological events and the gene–environment interactions as far as periconceptional and intrauterine environment are concerned.

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Blickstein, Isaac, und Louis G. Keith. „On the Possible Cause of Monozygotic Twinning: Lessons From the 9-Banded Armadillo and From Assisted Reproduction“. Twin Research and Human Genetics 10, Nr. 2 (01.04.2007): 394–99. http://dx.doi.org/10.1375/twin.10.2.394.

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AbstractAvailable hypotheses proposed to explain the mechanism of zygotic splitting fail to explain why monozygotic twins are more prevalent after all methods of assisted reproduction and which structure is likely to control this phenomenon. Arguably, a small proportion of oocytes might have an inborn propensity to undergo splitting upon fertilization leading to the constant prevalence of spontaneous monozygotic conceptions among different populations. Ovarian stimulation would then predictably increase the number of available splitting-prone oocytes and consequently would increase the chance for such oocytes to develop into monozygotic twins, leading to a ‘dose’-dependent relationship between monozygosity rates and the combined effect of infertility treatment. Embryonic division into 2 distinct cell lines begins and accommodates within an intact zona pellucida that controls the process by preventing ill-timed hatching. Human fertilized oocytes are able to undergo 2 binary fissions, just as is the case for the 9-banded armadillo (the only other mammal that produces monozygotic quadruplets) and to give rise to a variety of combinations of monozygotic pregnancies. This hypothetical explanation does not negate the already existing and genetically sound hypotheses, but places them into a broader perspective that respects recent observations from modern infertility treatment.

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Herranz, Gonzalo. „The timing of monozygotic twinning: a criticism of the common model“. Zygote 23, Nr. 1 (05.06.2013): 27–40. http://dx.doi.org/10.1017/s0967199413000257.

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SummaryIn the dominant model, monozygotic (MZ) twinning is universally accepted as a post-fertilization event resulting from splitting of the embryo along its first 2 weeks of development. The stage at which splitting occurs determines chorionicity and amnionicity. A short history on how the model was built is presented, stressing the role played by some embryologists, in particular George Corner, in its completion and final success. Strikingly, for more than 60 years no deep criticisms have been raised against the model, which, in virtue of its rational and plausible character, enjoys the status of undisputed truth. At close examination, the embryological support of the model shows some important weak points, particularly when dealing with late splitting. In the author's view, the model not only has contributed to ‘suspend’ our knowledge on the timing of MZ twinning, but seems indefensible and claims to be substituted. That factor could imply relevant consequences for embryology and bioethics. As an alternative to the model, a new theory to explain the timing of MZ twinning is proposed. It is based on two premises. First, MZ twinning would be a fertilization event. In that case, due to an alteration of the zygote–blastomere transition, the first zygotic division, instead of producing two blastomeres, generates twin zygotes. Second, monochorionicity and monoamnionicity would not depend on embryo splitting, but on fusion of membranes. Some support for this theory can be found in recent embryological advances and also in some explanations of old.

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Derom, Catherine, Evert Thiery, Hilde Peeters, Robert Vlietinck, Paul Defoort und Jean-Pierre Frijns. „The East Flanders Prospective Twin Survey (EFPTS): An Actual Perception“. Twin Research and Human Genetics 16, Nr. 1 (29.10.2012): 58–63. http://dx.doi.org/10.1017/thg.2012.75.

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The East Flanders Prospective Twin Survey (EFPTS) is a prospective, population-based registry of multiple births in the province of East-Flanders, Belgium. EFPTS has several unique features: it is population-based and prospective, with the possibility of long-term follow-up; the twins (and higher order multiple births) are recruited at birth; basic perinatal data recorded; chorion type and zygosity established; and since 1969 placental biopsies have been taken and frozen at −20 °C for later determination of genetic markers. The EFPTS is the only large register that includes placental data and allows differentiation of three subtypes of monozygotic (MZ) twins based on the time of the initial zygotic division: the dichorionic–diamnionic pairs (early, with splitting before the fourth day after fertilization), the monochorionic–diamnionic pairs (intermediate, splitting between the fourth and the seventh day post-fertilization), and the monochorionic–monoamnionic pairs (late, splitting after the eighth day post-fertilization). Studies can be initiated taking into account primary biases, those originating ‘in utero’. Such studies could throw new light on the controversy over the validity of the classic twin method, the consequences of early embryological events, and the gene–environment interactions as far as periconceptional and intrauterine environment are concerned.

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Mayor, Thibault, York-Dieter Stierhof, Kayoko Tanaka, Andrew M. Fry und Erich A. Nigg. „The Centrosomal Protein C-Nap1 Is Required for Cell Cycle–Regulated Centrosome Cohesion“. Journal of Cell Biology 151, Nr. 4 (13.11.2000): 837–46. http://dx.doi.org/10.1083/jcb.151.4.837.

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Duplicating centrosomes are paired during interphase, but are separated at the onset of mitosis. Although the mechanisms controlling centrosome cohesion and separation are important for centrosome function throughout the cell cycle, they remain poorly understood. Recently, we have proposed that C-Nap1, a novel centrosomal protein, is part of a structure linking parental centrioles in a cell cycle–regulated manner. To test this model, we have performed a detailed structure–function analysis on C-Nap1. We demonstrate that antibody-mediated interference with C-Nap1 function causes centrosome splitting, regardless of the cell cycle phase. Splitting occurs between parental centrioles and is not dependent on the presence of an intact microtubule or microfilament network. Centrosome splitting can also be induced by overexpression of truncated C-Nap1 mutants, but not full-length protein. Antibodies raised against different domains of C-Nap1 prove that this protein dissociates from spindle poles during mitosis, but reaccumulates at centrosomes at the end of cell division. Use of the same antibodies in immunoelectron microscopy shows that C-Nap1 is confined to the proximal end domains of centrioles, indicating that a putative linker structure must contain additional proteins. We conclude that C-Nap1 is a key component of a dynamic, cell cycle–regulated structure that mediates centriole–centriole cohesion.

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Bertoin, Jean, und Alexander R. Watson. „Probabilistic aspects of critical growth-fragmentation equations“. Advances in Applied Probability 48, A (Juli 2016): 37–61. http://dx.doi.org/10.1017/apr.2016.41.

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AbstractThe self-similar growth-fragmentation equation describes the evolution of a medium in which particles grow and divide as time proceeds, with the growth and splitting of each particle depending only upon its size. The critical case of the equation, in which the growth and division rates balance one another, was considered in Doumic and Escobedo (2015) for the homogeneous case where the rates do not depend on the particle size. Here, we study the general self-similar case, using a probabilistic approach based on Lévy processes and positive self-similar Markov processes which also permits us to analyse quite general splitting rates. Whereas existence and uniqueness of the solution are rather easy to establish in the homogeneous case, the equation in the nonhomogeneous case has some surprising features. In particular, using the fact that certain self-similar Markov processes can enter (0,∞) continuously from either 0 or ∞, we exhibit unexpected spontaneous generation of mass in the solutions.

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Gontar, Anastasia, Vladimir Plotnikov, Nadezda Chernovanova und Elena Yagupova. „The use of accounting information for assessing the economic security of commercial banks“. E3S Web of Conferences 91 (2019): 08065. http://dx.doi.org/10.1051/e3sconf/20199108065.

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The authors studied the use of accounting information for assessing the level of economic security of commercial banks. The article substantiates the choice of financial indicators of credit institutions as input parameters of the neural network. The analytical platform Deductor Studio Academic was chosen as the instrumental environment for assessing the level of economic security of banks. With its help, cluster analysis was performed. The division of the initial set of credit institutions into subsets (economic security classes) used the k-means method with splitting into three clusters: cluster 0 - “Optimal level of economic security”, cluster 1 -“Conditionally optimal level of economic security”, cluster 2 - “Low level of economic security”. The proposed data model with the results of the division of credit institutions into clusters according to the financial indicators of International Financial Reporting Standards made it possible to draw conclusions about the level of economic security of credit institutions and justify the choice of accounting information indicators for implementing a neural network approach to banking research.

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Jones, Laura A., Cécile Villemant, Toby Starborg, Anna Salter, Georgina Goddard, Peter Ruane, Philip G. Woodman, Nancy Papalopulu, Sarah Woolner und Victoria J. Allan. „Dynein light intermediate chains maintain spindle bipolarity by functioning in centriole cohesion“. Journal of Cell Biology 207, Nr. 4 (24.11.2014): 499–516. http://dx.doi.org/10.1083/jcb.201408025.

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Cytoplasmic dynein 1 (dynein) is a minus end–directed microtubule motor protein with many cellular functions, including during cell division. The role of the light intermediate chains (LICs; DYNC1LI1 and 2) within the complex is poorly understood. In this paper, we have used small interfering RNAs or morpholino oligonucleotides to deplete the LICs in human cell lines and Xenopus laevis early embryos to dissect the LICs’ role in cell division. We show that although dynein lacking LICs drives microtubule gliding at normal rates, the LICs are required for the formation and maintenance of a bipolar spindle. Multipolar spindles with poles that contain single centrioles were formed in cells lacking LICs, indicating that they are needed for maintaining centrosome integrity. The formation of multipolar spindles via centrosome splitting after LIC depletion could be rescued by inhibiting Eg5. This suggests a novel role for the dynein complex, counteracted by Eg5, in the maintenance of centriole cohesion during mitosis.

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Li, Wenzhi, Mostafa M. Abd El-Samie, Shuang Zhao, Jianqing Lin, Xing Ju und Chao Xu. „Division methods and selection principles for the ideal optical window of spectral beam splitting photovoltaic/thermal systems“. Energy Conversion and Management 247 (November 2021): 114736. http://dx.doi.org/10.1016/j.enconman.2021.114736.

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MORENO-TERNERO, JUAN D. „PROPORTIONALITY AND NON-MANIPULABILITY IN BANKRUPTCY PROBLEMS“. International Game Theory Review 08, Nr. 01 (März 2006): 127–39. http://dx.doi.org/10.1142/s0219198906000825.

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We explore the relationship between proportionality and manipulation (via merging or splitting agents' claims) in bankruptcy problems. We provide an alternative proof to the well-known result that, in an unrestricted domain, immunity to manipulation is equivalent to requiring proportional division. We show that this result also holds for restricted (but sufficiently rich) domains, such as the domain of simple problems and the domain of zero-normalized problems. Finally, we characterize two adjustments of the proportional rule by combining non-manipulabilty on these domains and the usual axioms of independence of claims truncation and composition from minimal rights.

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Heredia, Jorge David Figueroa, Jose Ildefonso U. Rubrico, Shouhei Shirafuji und Jun Ota. „Teaching Tasks to Multiple Small Robots by Classifying and Splitting a Human Example“. Journal of Robotics and Mechatronics 29, Nr. 2 (20.04.2017): 419–33. http://dx.doi.org/10.20965/jrm.2017.p0419.

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[abstFig src='/00290002/14.jpg' width='300' text='Two robots performing the task of opening the folding chair lying on the floor' ] In this study, we present a novel framework to address the problem of teaching manipulation tasks performed by a single human to a set of multiple small robots in a short period. First, we focused on classifying the manipulation style used during a human-performed task. An allocator process is proposed to determine the type and number of robots to be taught based on the capabilities of available robots. Then, according to the detected task requirements, robot behaviors are generated to create robot programs by splitting human demonstration data. Small robots were used to evaluate our approach in four defined tasks that were taught by a single human. Experiments demonstrated the efficiency of the method to classify and judge whether the division of a task is necessary or not. Moreover, robot programs were generated for manipulating selected objects either individually or in a cooperative manner.

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Sluder, G., und D. A. Begg. „Experimental analysis of the reproduction of spindle poles“. Journal of Cell Science 76, Nr. 1 (01.06.1985): 35–51. http://dx.doi.org/10.1242/jcs.76.1.35.

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We have investigated the functional properties of the mechanisms that control the reproduction of spindle poles in fertilized sea-urchin eggs. By prolonging mitosis by three independent means, we show that a spindle pole can split during mitosis into two functional poles of normal appearance. However, these poles have only half the normal reproductive capacity; each daughter cell that receives a split pole, always forms a monopolar spindle at the next division. Each monopolar spindle appears to be exactly half of a spindle because two of them can come together to form a functional bipolar spindle of normal appearance. The poles of such spindles show normal reproduction in subsequent divisions. By following the development of individual cells with monopolar spindles, we show that such a cell can stay in mitosis longer than normal, and the single pole splits into two asters, which move apart to give a functional bipolar spindle. The poles of such a spindle have only half the normal reproductive capacity, because the two daughters of the cell always form monopolar spindles at the next mitosis. This novel cycle of development is often repeated. The occurrence of such phenomena does not depend upon the method used to induce monopolar spindles. These results show that each normal pole has two polar determinants. The results also demonstrate that the reproduction of spindle poles consists of three distinct events: splitting of the polar determinants, physical separation of the two determinants, and duplication of the determinants to return the pole to a duplex state. Splitting and duplication are distinct events because they can be experimentally put out of phase with each other for several cell cycles.

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Turner, Erin E., Debra L. Junk und Susan B. Empson. „Research, Reflection, Practice: The Power of Paper–Folding Tasks: Supporting Multiplicative Thinking and Rich Mathematical Discussion“. Teaching Children Mathematics 13, Nr. 6 (Februar 2007): 322–29. http://dx.doi.org/10.5951/tcm.13.6.0322.

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Building understanding of multiplicative relationships is a key goal of mathematics instruction in the upper elementary and middle grades. Multiplicative thinking includes comparing numbers through many processes: multiplication and division (rather than addition and subtraction), ratio, proportions, stretching and shrinking, magnification, scaling, and splitting. Research has shown that multiplicative thinking develops slowly in children, over long periods of time (Clark and Kamii 1996; Vergnaud 1988). Initially, children tend to reason additively about multiplicative situations, and this additive thinking is often resistant to change (Hart 1984). Students need practice with tasks that help develop multiplicative thinking—in particular, tasks that help them recognize and reason about multiplicative relationships.

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Zhang, Guangwen, Seppo Honkanen, Ari Tervonen, Chun-Meng Wu und S. Iraj Najafi. „Glass integrated optics circuit for 148/155- and 130/155-μm-wavelength division multiplexing and 1/8 splitting“. Applied Optics 33, Nr. 16 (01.06.1994): 3371. http://dx.doi.org/10.1364/ao.33.003371.

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Lippincott, J., K. B. Shannon, W. Shou, R. J. Deshaies und R. Li. „The Tem1 small GTPase controls actomyosin and septin dynamics during cytokinesis“. Journal of Cell Science 114, Nr. 7 (01.04.2001): 1379–86. http://dx.doi.org/10.1242/jcs.114.7.1379.

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Cytokinesis in budding yeast involves an actomyosin-based ring which assembles in a multistepped fashion during the cell cycle and constricts during cytokinesis. In this report, we have investigated the structural and regulatory events that occur at the onset of cytokinesis. The septins, which form an hour-glass like structure during early stages of the cell cycle, undergo dynamic rearrangements prior to cell division: the hourglass structure splits into two separate rings. The contractile ring, localized between the septin double rings, immediately undergoes contraction. Septin ring splitting is independent of actomyosin ring contraction as it still occurs in mutants where contraction fails. We hypothesize that septin ring splitting may remove a structural barrier for actomyosin ring to contract. Because the Tem1 small GTPase (Tem1p) is required for the completion of mitosis, we investigated its role in regulating septin and actomyosin ring dynamics in the background of the net1-1 mutation, which bypasses the anaphase cell cycle arrest in Tem1-deficient cells. We show that Tem1p plays a specific role in cytokinesis in addition to its function in cell cycle progression. Tem1p is not required for the assembly of the actomyosin ring but controls actomyosin and septin dynamics during cytokinesis.

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Chevrier, Véronique, Matthieu Piel, Nora Collomb, Yasmina Saoudi, Ronald Frank, Michel Paintrand, Shuh Narumiya, Michel Bornens und Didier Job. „The Rho-associated protein kinase p160ROCK is required for centrosome positioning“. Journal of Cell Biology 157, Nr. 5 (28.05.2002): 807–17. http://dx.doi.org/10.1083/jcb.200203034.

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The p160–Rho-associated coiled-coil–containing protein kinase (ROCK) is identified as a new centrosomal component. Using immunofluorescence with a variety of p160ROCK antibodies, immuno EM, and depletion with RNA interference, p160ROCK is principally bound to the mother centriole (MC) and an intercentriolar linker. Inhibition of p160ROCK provoked centrosome splitting in G1 with the MC, which is normally positioned at the cell center and shows little motion during G1, displaying wide excursions around the cell periphery, similar to its migration toward the midbody during cytokinesis. p160ROCK inhibition late after anaphase in mitosis triggered MC migration to the midbody followed by completion of cell division. Thus, p160ROCK is required for centrosome positioning and centrosome-dependent exit from mitosis.

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Evans, Tucker, und Feng Fu. „Opinion formation on dynamic networks: identifying conditions for the emergence of partisan echo chambers“. Royal Society Open Science 5, Nr. 10 (Oktober 2018): 181122. http://dx.doi.org/10.1098/rsos.181122.

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Modern political interaction is characterized by strong partisanship and a lack of interest in information sharing and agreement across party lines. It remains largely unclear how such partisan echo chambers arise and how they coevolve with opinion formation. Here, we explore the emergence of these structures through the lens of coevolutionary games. In our model, the payoff of an individual is determined jointly by the magnitude of their opinion, their degree of conformity with their social neighbours and the benefit of having social connections. Each individual can simultaneously adjust their opinion and the weights of their social connections. We present and validate the conditions for the emergence of partisan echo chambers, characterizing the transition from cohesive communities with a consensus to divisive networks with splitting opinions. Moreover, we apply our model to voting records of the US House of Representatives over a timespan of decades to understand the influence of underlying psychological and social factors on increasing partisanship in recent years. Our work helps elucidate how the division of today has come to be and how cohesion and unity could otherwise be attained on a variety of political and social issues.

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Byle, Philip A. F. „Brood Division and Parental Care in the Period Between Fledging and Independence in the Dunnock (Prunella Modularis)“. Behaviour 113, Nr. 1-2 (1990): 1–19. http://dx.doi.org/10.1163/156853990x00419.

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Abstract1. Brood division was observed in 12 out of the 21 broods of dunnocks. It was stable over the whole period of fledging to independence. 2. Undivided broods were significantly more likely to occur earlier in the season than divided broods. 3. Brood size had no significant effect on the age at which chicks reached independence. 4. The weight (on day 6) of chicks in undivided broods influenced the age at which they reached independence, but no significant relationship was found in divided broods. 5. The provision of extra food significantly reduced the age at which fledglings reached independence, indicating that territory quality may affect the timing of independence. The effects of extra food on brood division were unclear. 6. There was no differential splitting of the brood between the dominant male and the female in polyandry and polygynandry or between a monogamous male and his female. Males and females fed the chicks at similar rates. 7. Beta males who had helped to feed the nestlings were more likely to continue to help feed fledglings in larger broods. 8. There was a tendency for male parents to care for male offspring and female parents to care for female offspring.

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Gardner, Shea N. „Scheduling Chemotherapy: Catch 22 between Cell Kill and Resistance Evolution“. Journal of Theoretical Medicine 2, Nr. 3 (2000): 215–32. http://dx.doi.org/10.1080/10273660008833047.

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Dose response curves show that prolonged drug exposure at a low concentration may kill more cells than short exposures at higher drug concentrations, particularly for cell cycle phase specific drugs. Applying drugs at low concentrations for prolonged periods, however, allows cells with partial resistance to evolve higher levels of resistance through stepwise processes such as gene amplification. Models are developed for cell cycle specific (CS) and cell cycle nonspecific (CNS) drugs to identify the schedule of drug application that balances this tradeoff.The models predict that a CS drug may be applied most effectively by splitting the cumulative dose into many (>40) fractions applied by long-term chemotherapy, while CNS drugs may be better applied in fewer than 10 fractions applied over a shorter term. The model suggests that administering each fraction by continuous infusion may be more effective than giving the drug as a bolus, whether the drug is CS or CNS. In addition, tumors with a low growth fraction or slow rate of cell division are predicted to be controlled more easily with CNS drugs, while those with a high proliferative fraction or fast cell division rate may respond better to CS drugs.

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Zomeni, Maria, und Ioannis N. Vogiatzakis. „Roads and Roadless Areas in Cyprus: Implications For The Natura 2000 Network“. Journal of Landscape Ecology 7, Nr. 1 (01.01.2014): 75–90. http://dx.doi.org/10.2478/jlecol-2014-0010.

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Abstract The road network in Cyprus has seen an 88% increase in the last 20 years. This expansion has not been followed by any kind of assessment on the effects of the network on nature conservation. This is the first island-wide quantitative assessment of the size, character (surface types), pervasiveness and distribution of the road system with particular reference to Natura 2000 network on the island. We mapped roadless areas (i.e. areas at least one km away from nearest road) for the whole island and examined the spatial distribution with respect to Natura 2000. We tested the relationship between overall road density and road density of different road categories within terrestrial Natura 2000 sites to four zones which were defined on the basis of landform, principal land use and ownership. We employed three indices i.e. effective mesh size, splitting and division to measure fragmentation caused by the road network within Natura 2000 and investigated the relationship between road density and the above fragmentation metrics. Mean road density in Cyprus is 2.3 km/km2 which is comparable to road density values recorded in other Mediterranean countries such as France, Spain and Italy, which have much larger area and population. Roadless areas cover 4.5% of the island, and despite being scattered 80% is found within Natura 2000, which demonstrates the added value of the network for nature conservation. Road expansion has taken place throughout the island with the same intensity irrespectively of the zones examined. Fragmentation has been lower in sites on mountainous areas where sites are larger and under state ownership. Road density is negatively correlated (r = - 0.383, p = 0.05) with effective mesh size and positively correlated with both landscape division (r = 0.376, p = 0.05) and splitting index (r = 0.376, p = 0.05). Results corroborate that spatial configuration is an important property of the road network in addition to traffic load, length and density.With the shift from site based conservation to landscape level there is a challenge for integrating technical, human and ecological requirements into infrastructure planning.

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Sivatski, A. S. „Central simple algebras of prime exponent and divided power operations“. Journal of K-Theory 11, Nr. 1 (15.01.2013): 113–23. http://dx.doi.org/10.1017/is013001008jkt197.

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AbstractLet p be a prime and F a field of characteristic different from p. Suppose all p-primary roots of unity are contained in F. Let α ∈ pBr(F) which has a cyclic splitting field. We prove that γi(α) = 0 for all i ≥ 2, where γi : pBr(F) → K2i(F)/pK2i(F) are the divided power operations of degree p. We also show that if char F ≠ 2, √−1 ∈ F*. D ∈2 Br(F), indD = 8 and a ∈ F* such that ind DF(√a) = 4, then γ3(D) = {a,s}γ2(D) for some s ∈ F*. Consequently, we prove that if D, considered as a division algebra, has a subfield of degree 4 of certain type, then γ3(D) = 0. At the end of the paper we pose a few open questions.

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Chen, Chun-Ti, und Marc-Jan Gubbels. „TgCep250 is dynamically processed through the division cycle and is essential for structural integrity of the Toxoplasma centrosome“. Molecular Biology of the Cell 30, Nr. 10 (Mai 2019): 1160–69. http://dx.doi.org/10.1091/mbc.e18-10-0608.

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The apicomplexan centrosome has a unique bipartite structure comprising an inner and outer core responsible for the nuclear cycle (mitosis) and budding cycles (cytokinesis), respectively. Although these two cores are always associated, they function independently to facilitate polyploid intermediates in the production of many progeny per replication round. Here, we describe the function of a large coiled-coil protein in Toxoplasma gondii, TgCep250, in connecting the two centrosomal cores and promoting their structural integrity. Throughout the cell cycle, TgCep250 localizes to the inner core but, associated with proteolytic processing, is also present on the outer core during the onset of cell division. In the absence of TgCep250, stray centrosome inner and outer core foci were observed. The detachment between centrosomal inner and outer cores was found in only one of the centrosomes during cell division, indicating distinct states of mother and daughter centrosomes. In mammals, Cep250 processing is required for centrosomal splitting and is mediated by Nek phopsphorylation. However, we show that neither the nonoverlapping spatiotemporal localization of TgNek1 and TgCep250 nor the distinct phenotypes upon their respective depletion support conservation of this mechanism in Toxoplasma. In conclusion, TgCep250 has a tethering function tailored to the unique bipartite centrosome in the Apicomplexa.

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