927 research outputs found
List precoloring extension in planar graphs
A celebrated result of Thomassen states that not only can every planar graph
be colored properly with five colors, but no matter how arbitrary palettes of
five colors are assigned to vertices, one can choose a color from the
corresponding palette for each vertex so that the resulting coloring is proper.
This result is referred to as 5-choosability of planar graphs. Albertson asked
whether Thomassen's theorem can be extended by precoloring some vertices which
are at a large enough distance apart in a graph. Here, among others, we answer
the question in the case when the graph does not contain short cycles
separating precolored vertices and when there is a "wide" Steiner tree
containing all the precolored vertices.Comment: v2: 15 pages, 11 figres, corrected typos and new proof of Theorem
3(2
On EPR paradox, Bell's inequalities and experiments which prove nothing
This article shows that the there is no paradox. Violation of Bell's
inequalities should not be identified with a proof of non locality in quantum
mechanics. A number of past experiments is reviewed, and it is concluded that
the experimental results should be re-evaluated. The results of the experiments
with atomic cascade are shown not to contradict the local realism. The article
points out flaws in the experiments with down-converted photons. The
experiments with neutron interferometer on measuring the "contextuality" and
Bell-like inequalities are analyzed, and it is shown that the experimental
results can be explained without such notions. Alternative experiment is
proposed to prove the validity of local realism.Comment: 27 pages, 8 figures. I edited a little the text and abstract I
corrected equations (49) and (50
Relational legacies impacting on veteran transition from military to civilian life: trajectories of acquisition, loss and re-formulation of a sense of belonging
The veteran cohort has been inextricably linked in the general public's mind by media generated
perceptions of high risk and fear of crime, echoed in wider contemporary debates linking issues of
place, social identity, social exclusion (Pain 2000) and a loss of belonging in wider communities
(Walklate 1998). Despite the growing interest in the longer term outcomes of transition from
military to civilian life from policy-makers, practitioners and academics, few qualitative studies
explore the social and relational impacts of this transitional experience on those who have
experienced it. Tensions and frustrations expressed by ex-forces personnel, engaging in addictions
services with a history of engagement in the criminal justice sector, are explored through the lens
of belongingness, loss and related citizenship frameworks to expose temporal impacts on the
acquisition, loss and reformulation of a sense of belonging across the life course. The relevance of
a significant loss of belonging in the transition from military to civilian life is useful, given the
widely accepted damaging consequences of having this need thwarted. This paper concludes that
a broader understanding of this largely disenfranchised grief (Doka, 2002) can enable more
informed reflexive opportunities to facilitate a valued military veteran citizenship status and
thereby contribute to the formulation of current policy debates concerning the veteran question
Pregnancy and childbirth in English prisons : institutional ignominy and the pains of imprisonment
Š 2020 The Authors. Sociology of Health & Illness published by John Wiley & Sons Ltd on behalf of Foundation for SHIL.With a prison population of approximately 9000 women in England, it is estimated that approximately 600 pregnancies and 100 births occur annually. Despite an extensive literature on the sociology of reproduction, pregnancy and childbirth among women prisoners is underâresearched. This article reports an ethnographic study in three English prisons undertaken in 2015â2016, including interviews with 22 prisoners, six women released from prison and 10 staff members. Pregnant prisoners experience numerous additional difficulties in prison including the ambiguous status of a pregnant prisoner, physical aspects of pregnancy and the degradation of the handcuffed or chained prisoner during visits to the more public setting of hospital. This article draws on Erving Goffman's concepts of closed institutions, dramaturgy and mortification of self, Crewe et al.'s work on the gendered pains of imprisonment and Crawley's notion of âinstitutional thoughtlessnessâ, and proposes a new concept of institutional ignominy to understand the embodied situation of the pregnant prisoner.Peer reviewe
The Amateur Sky Survey Mark III Project
The Amateur Sky Survey (TASS) is a loose confederation of amateur and
professional astronomers. We describe the design and construction of our Mark
III system, a set of wide-field drift-scan CCD cameras which monitor the
celestial equator down to thirteenth magnitude in several passbands. We explain
the methods by which images are gathered, processed, and reduced into lists of
stellar positions and magnitudes. Over the period October, 1996, to November,
1998, we compiled a large database of photometric measurements. One of our
results is the "tenxcat" catalog, which contains measurements on the standard
Johnson-Cousins system for 367,241 stars; it contains links to the light curves
of these stars as well.Comment: 20 pages, including 4 figures; additional JPEG files for Figures 1,
2. Submitted to PAS
Evolution of a unique predatory feeding apparatus: functional anatomy, development and a genetic locus for jaw laterality in Lake Tanganyika scale-eating cichlids
Background While bilaterality is a defining characteristic of triploblastic animals, several assemblages have managed to break this symmetry in order to exploit the adaptive peaks garnered through the lateralization of behaviour or morphology. One striking example of an evolved asymmetry in vertebrates comes from a group of scale-eating cichlid fishes from Lake Tanganyika. Members of the Perissodini tribe of cichlid fishes have evolved dental and craniofacial asymmetries in order to more effectively remove scales from the left or right flanks of prey. Here we examine the evolution and development of craniofacial morphology and laterality among Lake Tanganyika scale-eating cichlids. Results Using both geometric and traditional morphometric methods we found that the craniofacial evolution in the Perissodini involved discrete shifts in skeletal anatomy that reflect differences in habitat preference and predation strategies. Further, we show that the evolutionary history of the Perissodini is characterized by an accentuation of craniofacial laterality such that certain taxa show elaborate sided differences in craniofacial shape consistent with the sub-partitioning of function between sides of the head during attacks. Craniofacial laterality in the scale-eating specialist Perissodus microlepis was found to be evident early in development and exhibited a unimodal distribution, which is contrary to the adult condition where jaw laterality has been described as a discrete, bimodal antisymmetry. Finally, using linkage and association analyses we identified a conserved locus for jaw handedness that segregates among East African cichlids. Conclusions We suggest that, during the evolution of the Perissodini, selection has accentuated a latent, genetically determined handedness of the craniofacial skeleton, enabling the evolution of jaw asymmetries in order to increase predation success. Continued work on the developmental genetic basis of laterality in the Perissodini will facilitate a better understanding of the evolution of this unique group of fishes, as well as of left-right axis determination among vertebrates in general
Deletion of chromosome 11q predicts response to anthracycline-based chemotherapy in early breast cancer
Despite the recent consensus on the eligibility of adjuvant
systemic therapy in patients with lymph nodeânegative breast
cancer (NNBC) based on clinicopathologic criteria, specific
biological markers are needed to predict sensitivity to the
different available therapeutic options.W e examined the feasibility
of developing a genomic predictor of chemotherapy
response and recurrence risk in 185 patients with NNBC using
assembled arrays containing 2,460 bacterial artificial chromosome
clones for scanning the genome for DNA copy number
changes.Aft er surgery, 90 patients received anthracyclinebased
chemotherapy, whereas 95 did not.T amoxifen was administered
to patients with hormone receptorâpositive tumors.
The association of genomic and clinicopathologic data and
outcome was computed using Cox proportional hazard models
and multiple testing adjustment procedures.Analysis of NNBC
genomes revealed a common genomic signature.Specific DNA
copy number aberrations were associated with hormonal
receptor status, but not with other clinicopathologic variables.
In patients treated with chemotherapy, none of the genomic
changes were significantly correlated with recurrence.In
patients not receiving chemotherapy, deletion of eight bacterial
artificial chromosome clones clustered to chromosome 11q
was independently associated with relapse (disease-free survival
at 10 years F SE, 40% F 14% versus 86% F 6%; P < 0.0001).
The 54 patients with deletion of 11q (29%) did not present more
aggressive clinicopathologic features than those without 11q
loss.The adverse influence of 11q deletion on clinical outcome
was confirmed in an independent validation series of 88
patients with NNBC.Our data suggests that patients with NNBC
with the 11q deletion might benefit from anthracycline-based
chemotherapy despite other clinical, pathologic, or genetic
features.However , these initial findings should be evaluated
in randomized clinical trials
Interplay between telecommunications and face-to-face interactions - a study using mobile phone data
In this study we analyze one year of anonymized telecommunications data for
over one million customers from a large European cellphone operator, and we
investigate the relationship between people's calls and their physical
location. We discover that more than 90% of users who have called each other
have also shared the same space (cell tower), even if they live far apart.
Moreover, we find that close to 70% of users who call each other frequently (at
least once per month on average) have shared the same space at the same time -
an instance that we call co-location. Co-locations appear indicative of
coordination calls, which occur just before face-to-face meetings. Their number
is highly predictable based on the amount of calls between two users and the
distance between their home locations - suggesting a new way to quantify the
interplay between telecommunications and face-to-face interactions
The Cyprinodon variegatus genome reveals gene expression changes underlying differences in skull morphology among closely related species
Genes in durophage intersection set at 15 dpf. This is a comma separated table of the genes in the 15 dpf durophage intersection set. Given are edgeR results for each pairwise comparison. Columns indicating whether a gene is included in the intersection set at a threshold of 1.5 or 2 fold are provided. (CSV 13ĂÂ kb
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