643 research outputs found

    On Upward Drawings of Trees on a Given Grid

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    Computing a minimum-area planar straight-line drawing of a graph is known to be NP-hard for planar graphs, even when restricted to outerplanar graphs. However, the complexity question is open for trees. Only a few hardness results are known for straight-line drawings of trees under various restrictions such as edge length or slope constraints. On the other hand, there exist polynomial-time algorithms for computing minimum-width (resp., minimum-height) upward drawings of trees, where the height (resp., width) is unbounded. In this paper we take a major step in understanding the complexity of the area minimization problem for strictly-upward drawings of trees, which is one of the most common styles for drawing rooted trees. We prove that given a rooted tree TT and a WΓ—HW\times H grid, it is NP-hard to decide whether TT admits a strictly-upward (unordered) drawing in the given grid.Comment: Appears in the Proceedings of the 25th International Symposium on Graph Drawing and Network Visualization (GD 2017

    Phase I/II study of the deacetylase inhibitor panobinostat after allogeneic stem cell transplantation in patients with high-risk MDS or AML (PANOBEST trial)

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    Maintenance therapy after allogeneic hematopoietic stem cell transplantation (HSCT) for acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) is conceptually attractive to prevent relapse, but has been hampered by the limited number of suitable anti-leukemic agents. The deacetylase inhibitor (DACi) panobinostat demonstrated moderate anti-leukemic activity in a small subset of patients with advanced AML and high-risk MDS in phase I/II trials.1, 2 It also displays immunomodulatory activity3 that may enhance leukemia-specific cytotoxicity4 and mitigate graft versus host disease (GvHD), but conversely could impair T- and NK cell function.5, 6 We conducted this open-label, multi-center phase I/II trial (NCT01451268) to assess the feasibility and preliminary efficacy of prolonged prophylactic administration of panobinostat after HSCT for AML or MDS. The study protocol was approved by an independent ethics committee and conducted in compliance with the Declaration of Helsinki. All patients provided written informed consent. ..

    Algorithmic deformation of matrix factorisations

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    Branes and defects in topological Landau-Ginzburg models are described by matrix factorisations. We revisit the problem of deforming them and discuss various deformation methods as well as their relations. We have implemented these algorithms and apply them to several examples. Apart from explicit results in concrete cases, this leads to a novel way to generate new matrix factorisations via nilpotent substitutions, and to criteria whether boundary obstructions can be lifted by bulk deformations.Comment: 30 page

    A specific case in the classification of woods by FTIR and chemometric: discrimination of Fagales from Malpighiales

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    Fourier transform infrared (FTIR) spectroscopic data was used to classify wood samples from nine species within the Fagales and Malpighiales using a range of multivariate statistical methods. Taxonomic classification of the family Fagaceae and Betulaceae from Angiosperm Phylogenetic System Classification (APG II System) was successfully performed using supervised pattern recognition techniques. A methodology for wood sample discrimination was developed using both sapwood and heartwood samples. Ten and eight biomarkers emerged from the dataset to discriminate order and family, respectively. In the species studied FTIR in combination with multivariate analysis highlighted significant chemical differences in hemicelluloses, cellulose and guaiacyl (lignin) and shows promise as a suitable approach for wood sample classification

    Effective-Range Expansion of the Neutron-Deuteron Scattering Studied by a Quark-Model Nonlocal Gaussian Potential

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    The S-wave effective range parameters of the neutron-deuteron (nd) scattering are derived in the Faddeev formalism, using a nonlocal Gaussian potential based on the quark-model baryon-baryon interaction fss2. The spin-doublet low-energy eigenphase shift is sufficiently attractive to reproduce predictions by the AV18 plus Urbana three-nucleon force, yielding the observed value of the doublet scattering length and the correct differential cross sections below the deuteron breakup threshold. This conclusion is consistent with the previous result for the triton binding energy, which is nearly reproduced by fss2 without reinforcing it with the three-nucleon force.Comment: 21 pages, 6 figures and 6 tables, submitted to Prog. Theor. Phy

    Environmental Factors in the Relapse and Recurrence of Inflammatory Bowel Disease:A Review of the Literature

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    The causes of relapse in patients with Crohn's disease (CD) and ulcerative colitis (UC) are largely unknown. This paper reviews the epidemiological and clinical data on how medications (non-steroidal anti-inflammatory drugs, estrogens and antibiotics), lifestyle factors (smoking, psychological stress, diet and air pollution) may precipitate clinical relapses and recurrence. Potential biological mechanisms include: increasing thrombotic tendency, imbalances in prostaglandin synthesis, alterations in the composition of gut microbiota, and mucosal damage causing increased permeability

    Dual FGF-2 and Intergrin Ξ±5Ξ²1 Signaling Mediate GRAF-Induced RhoA Inactivation in a Model of Breast Cancer Dormancy

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    Interactions with the bone marrow stroma regulate dormancy and survival of breast cancer micrometastases. In an in vitro model of dormancy in the bone marrow, we previously demonstrated that estrogen-dependent breast cancer cells are partially re-differentiated by FGF-2, re-express integrin Ξ±5Ξ²1 lost with malignant transformation and acquire an activated PI3K/Akt pathway. Ligation of integrin Ξ±5Ξ²1 by fibronectin and activation of the PI3K pathway both contribute to survival of these dormant cells. Here, we investigated mechanisms responsible for the dormant phenotype. Experiments demonstrate that integrin Ξ±5Ξ²1 controls de novo cytoskeletal rearrangements, cell spreading, focal adhesion kinase rearrangement to the cell perimeter and recruitment of a RhoA GAP known as GRAF. This results in the inactivation of RhoA, an effect which is necessary for the stabilization of cortical actin. Experiments also demonstrate that activation of the PI3K pathway by FGF-2 is independent of integrin Ξ±5Ξ²1 and is also required for cortical actin reorganization, GRAF membrane relocalization and RhoA inactivation. These data suggest that GRAF-mediated RhoA inactivation and consequent phenotypic changes of dormancy depend on dual signaling by FGF-2-initiated PI3K activation and through ligation of integrin Ξ±5Ξ²1 by fibronectin

    Cardiac rehabilitation adapted to transient ischaemic attack and stroke (CRAFTS): a randomised controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Coronary Heart Disease and Cerebrovascular Disease share many predisposing, modifiable risk factors (hypertension, abnormal blood lipids and lipoproteins, cigarette smoking, physical inactivity, obesity and diabetes mellitus). Lifestyle interventions and pharmacological therapy are recognised as the cornerstones of secondary prevention. Cochrane review has proven the benefits of programmes incorporating exercise and lifestyle counselling in the cardiac disease population. A Cochrane review highlighted as priority, the need to establish feasibility and efficacy of exercise based interventions for Cerebrovascular Disease.</p> <p>Methods</p> <p>A single blind randomised controlled trial is proposed to examine a primary care cardiac rehabilitation programme for adults post transient ischemic attack (TIA) and stroke in effecting a positive change in the primary outcome measures of cardiac risk scores derived from Blood Pressure, lipid profile, smoking and diabetic status and lifestyle factors of habitual smoking, exercise and healthy eating participation. Secondary outcomes of interest include health related quality of life as measured by the Hospital Anxiety and Depression Scale, the Stroke Specific Quality of Life scale and WONCA COOP Functional Health Status charts and cardiovascular fitness as measured by a sub-maximal fitness test.</p> <p>A total of 144 patients, over 18 years of age with confirmed diagnosis of ischaemic stroke or TIA, will be recruited from Dublin community stroke services and two tertiary T.I.A clinics. Exclusion criteria will include oxygen dependence, unstable cardiac conditions, uncontrolled diabetes, major medical conditions, claudication, febrile illness, pregnancy or cognitive impairment. Participants will be block-statified, randomly allocated to one of two groups using a pre-prepared computer generated randomisation schedule. Both groups will receive a two hour education class on risk reduction post stroke. The intervention group will receive a 10 week programme of supervised aerobic exercises (twice weekly) and individually tailored brief intervention lifestyle counselling. Both groups will be tested on week one and week ten of the programme. Follow-up at 1 year will assess longer term benefits. Analysis will test for significant changes in the key variables indicated.</p> <p>Discussion</p> <p>Application of the Cardiac Rehabilitation paradigm to patients with ischaemic stroke or TIA has not been explored despite the obvious overlap in aetiology. It is hoped the anticipated improvement in vascular risk factors and fitness resulting from such a programme will enhance health and social gain in this population.</p> <p>Trial Registration</p> <p>Current Controlled Trials ISCTRN90272638.</p
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