Density matrix for the kink ground state of the ferromagnetic XXZ chain

The exact expression for the density matrix of the kink ground state of the ferromagnetic XXZ chain is obtained. Utilizing this, we exactly calculate various correlation functions such as the longitudinal and transverse spin-spin correlation functions, and the ferromagnetic and antiferromagnetic string formation probabilities. The asymptotic behaviors of these correlation functions are also analyzed. As a consequence, we find that the spin-spin correlation functions decay exponentially for large distances, while the string formation probabilities exhibit Gaussian decay for large strings. We also evaluate the entanglement entropy, which shows interesting behaviors due to the lack of the translational invariance of the state.Comment: 7 pages, 9 figure

Reflection equation for the N=3 Cremmer-Gervais R-matrix

We consider the reflection equation of the N=3 Cremmer-Gervais R-matrix. The reflection equation is shown to be equivalent to 38 equations which do not depend on the parameter of the R-matrix, q. Solving those 38 equations. the solution space is found to be the union of two types of spaces, each of which is parametrized by the algebraic variety $\mathbb{P}^1(\mathbb{C}) \times \mathbb{P}^1(\mathbb{C}) \times \mathbb{P}^2(\mathbb{C})$ and $\mathbb{C} \times \mathbb{P}^1(\mathbb{C}) \times \mathbb{P}^2(\mathbb{C})$.Comment: 28 pages, revised versio

On the problem of calculation of correlation functions in the six-vertex model with domain wall boundary conditions

The problem of calculation of correlation functions in the six-vertex model with domain wall boundary conditions is addressed by considering a particular nonlocal correlation function, called row configuration probability. This correlation function can be used as building block for computing various (both local and nonlocal) correlation functions in the model. The row configuration probability is calculated using the quantum inverse scattering method; the final result is given in terms of a multiple integral. The connection with the emptiness formation probability, another nonlocal correlation function which was computed elsewhere using similar methods, is also discussed.Comment: 15 pages, 2 figure

An application of incomplete pairwise comparison matrices for ranking top tennis players

Pairwise comparison is an important tool in multi-attribute decision making. Pairwise comparison matrices (PCM) have been applied for ranking criteria and for scoring alternatives according to a given criterion. Our paper presents a special application of incomplete PCMs: ranking of professional tennis players based on their results against each other. The selected 25 players have been on the top of the ATP rankings for a shorter or longer period in the last 40 years. Some of them have never met on the court. One of the aims of the paper is to provide ranking of the selected players, however, the analysis of incomplete pairwise comparison matrices is also in the focus. The eigenvector method and the logarithmic least squares method were used to calculate weights from incomplete PCMs. In our results the top three players of four decades were Nadal, Federer and Sampras. Some questions have been raised on the properties of incomplete PCMs and remains open for further investigation.Comment: 14 pages, 2 figure

Factors predisposing 6 to 11-year old children in the first stage of orthodontic treatment to temporomandibular disorders

INTRODUCTION: The etiology of temporomandibular disorders (TMD's) is currently considered multifactorial, involving psychological factors, oral parafunctions, morphological and functional malocclusion. OBJECTIVES: In keeping with this reasoning, we evaluated children who seek preventive orthodontic treatment, to better understand their grievances and to assess the prevalence of TMD signs and symptoms in these patients. METHODS: Two examiners evaluated 65 children aged 6 to 11 years. RESULTS: In our sample, bruxism featured the highest prevalence rate, whereas atypical swallowing displayed the highest rate among predisposing factors. CONCLUSION: We therefore recommend that the evaluation of possible TMD signs and symptoms in children be adopted as routine in the initial clinical examination.INTRODUÇÃO: atualmente, considera-se multifatorial a etiologia da desordem temporomandibular (DTM), na qual fatores psicológicos, parafunções orais, má oclusão morfológica e funcional constituem possíveis causas para o desenvolvimento dessa disfunção. OBJETIVO: avaliar as crianças que procuram por tratamento ortodôntico preventivo, visando compreender melhor suas queixas e avaliar a prevalência de sinais e sintomas de desordem temporomandibular. MÉTODOS: sessenta e cinco crianças, com idades variando entre 6 e 11 anos, foram avaliadas por dois examinadores. RESULTADOS: o bruxismo foi o sintoma que apresentou o maior índice de prevalência na amostra estudada e a deglutição atípica apresentou o maior índice dentre os fatores predisponentes. CONCLUSÃO: recomenda-se que a avaliação dos possíveis sinais e sintomas da DTM em crianças seja adotada como rotina durante o exame clínico inicial.UMESPEPM UNIFESPUNIFESP-EPM Departamento de FonoaudiologiaUniversidade Metodista de São Paulo Faculdade de OdontologiaUNIFESP, EPM, UNIFESP, EPM Depto. de FonoaudiologiaSciEL

Simultaneous disruption of two DNA polymerases, Polη and Polζ, in Avian DT40 cells unmasks the role of Polη in cellular response to various DNA lesions

Replicative DNA polymerases are frequently stalled by DNA lesions. The resulting replication blockage is released by homologous recombination (HR) and translesion DNA synthesis (TLS). TLS employs specialized TLS polymerases to bypass DNA lesions. We provide striking in vivo evidence of the cooperation between DNA polymerase η, which is mutated in the variant form of the cancer predisposition disorder xeroderma pigmentosum (XP-V), and DNA polymerase ζ by generating POLη−/−/POLζ−/− cells from the chicken DT40 cell line. POLζ−/− cells are hypersensitive to a very wide range of DNA damaging agents, whereas XP-V cells exhibit moderate sensitivity to ultraviolet light (UV) only in the presence of caffeine treatment and exhibit no significant sensitivity to any other damaging agents. It is therefore widely believed that Polη plays a very specific role in cellular tolerance to UV-induced DNA damage. The evidence we present challenges this assumption. The phenotypic analysis of POLη−/−/POLζ−/− cells shows that, unexpectedly, the loss of Polη significantly rescued all mutant phenotypes of POLζ−/− cells and results in the restoration of the DNA damage tolerance by a backup pathway including HR. Taken together, Polη contributes to a much wide range of TLS events than had been predicted by the phenotype of XP-V cells

Multiply-refined enumeration of alternating sign matrices

Four natural boundary statistics and two natural bulk statistics are considered for alternating sign matrices (ASMs). Specifically, these statistics are the positions of the 1's in the first and last rows and columns of an ASM, and the numbers of generalized inversions and -1's in an ASM. Previously-known and related results for the exact enumeration of ASMs with prescribed values of some of these statistics are discussed in detail. A quadratic relation which recursively determines the generating function associated with all six statistics is then obtained. This relation also leads to various new identities satisfied by generating functions associated with fewer than six of the statistics. The derivation of the relation involves combining the Desnanot-Jacobi determinant identity with the Izergin-Korepin formula for the partition function of the six-vertex model with domain-wall boundary conditions.Comment: 62 pages; v3 slightly updated relative to published versio

TPXL-1 activates Aurora A to clear contractile ring components from the polar cortex during cytokinesis

During cytokinesis, a signal from the central spindle that forms between the separating anaphase chromosomes promotes the accumulation of contractile ring components at the cell equator, while a signal from the centrosomal microtubule asters inhibits accumulation of contractile ring components at the cell poles. However, the molecular identity of the inhibitory signal has remained unknown. To identify molecular components of the aster-based inhibitory signal, we developed a means to monitor the removal of contractile ring proteins from the polar cortex after anaphase onset. Using this assay, we show that polar clearing is an active process that requires activation of Aurora A kinase by TPXL-1. TPXL-1 concentrates on astral microtubules coincident with polar clearing in anaphase, and its ability to recruit Aurora A and activate its kinase activity are essential for clearing. In summary, our data identify Aurora A kinase as an aster-based inhibitory signal that restricts contractile ring components to the cell equator during cytokinesis.We thank the Caenorhabditis Genetic Center (funded by the National Institutes of Health Office of Research Infrastructure Programs P40 OD010440) for strains. This work was supported by grants to K. Oegema (National Institutes of Health; GM074207), E. Zanin (Deutsche Forschungsgemeinschaft, ZA619/3-1), and A.X. Carvalho (European Research Council; 640553–ACTOMYO). T. Kim was supported by a grant to Arshad Desai (National Institutes of Health; GM074215). K. Oegema receives salary and other support from the Ludwig Institute for Cancer Research. S. Mangal is a member of International Max Planck Research School for Molecular Life Sciences, and J. Sacher is a member of the Life Science Munich graduate program; both thank their programs for support

Third Report on Chicken Genes and Chromosomes 2015

Following on from the First Report on Chicken Genes and Chromosomes [Schmid et al., 2000] and the Second Report in 2005 [Schmid et al., 2005], we are pleased to publish this long-awaited Third Report on the latest developments in chicken genomics. The First Report highlighted the availability of genetic and physical maps, while the Second Report was published as the chicken genome sequence was released. This report comes at a time of huge technological advances (particularly in sequencing methodologies) which have allowed us to examine the chicken genome in detail not possible until now. This has also heralded an explosion in avian genomics, with the current availability of more than 48 bird genomes [Zhang G et al., 2014b; Eöry et al., 2015], with many more planned

Coupling changes in cell shape to chromosome segregation

Animal cells undergo dramatic changes in shape, mechanics and polarity as they progress through the different stages of cell division. These changes begin at mitotic entry, with cell–substrate adhesion remodelling, assembly of a cortical actomyosin network and osmotic swelling, which together enable cells to adopt a near spherical form even when growing in a crowded tissue environment. These shape changes, which probably aid spindle assembly and positioning, are then reversed at mitotic exit to restore the interphase cell morphology. Here, we discuss the dynamics, regulation and function of these processes, and how cell shape changes and sister chromatid segregation are coupled to ensure that the daughter cells generated through division receive their fair inheritance