348 research outputs found
Pseudo-Anosov flows in toroidal manifolds
We first prove rigidity results for pseudo-Anosov flows in prototypes of
toroidal 3-manifolds: we show that a pseudo-Anosov flow in a Seifert fibered
manifold is up to finite covers topologically equivalent to a geodesic flow and
we show that a pseudo-Anosov flow in a solv manifold is topologically
equivalent to a suspension Anosov flow. Then we study the interaction of a
general pseudo-Anosov flow with possible Seifert fibered pieces in the torus
decomposition: if the fiber is associated with a periodic orbit of the flow, we
show that there is a standard and very simple form for the flow in the piece
using Birkhoff annuli. This form is strongly connected with the topology of the
Seifert piece. We also construct a large new class of examples in many graph
manifolds, which is extremely general and flexible. We construct other new
classes of examples, some of which are generalized pseudo-Anosov flows which
have one prong singularities and which show that the above results in Seifert
fibered and solvable manifolds do not apply to one prong pseudo-Anosov flows.
Finally we also analyse immersed and embedded incompressible tori in optimal
position with respect to a pseudo-Anosov flow.Comment: 44 pages, 4 figures. Version 2. New section 9: questions and
comments. Overall revision, some simplified proofs, more explanation
Expected length of the longest common subsequence for large alphabets
We consider the length L of the longest common subsequence of two randomly
uniformly and independently chosen n character words over a k-ary alphabet.
Subadditivity arguments yield that the expected value of L, when normalized by
n, converges to a constant C_k. We prove a conjecture of Sankoff and Mainville
from the early 80's claiming that C_k\sqrt{k} goes to 2 as k goes to infinity.Comment: 14 pages, 1 figure, LaTe
Palliative care in interstitial lung disease: living well
Progressive fibrotic interstitial lung diseases (ILDs) are characterised by major reductions in quality of life and survival and have similarities to certain malignancies. However, palliative care expertise is conspicuously inaccessible to many patients with ILD. Unmet patient and caregiver needs include effective pharmacological and psychosocial interventions to improve quality of life throughout the disease course, sensitive advanced care planning, and timely patient-centred end-of-life care. The incorrect perception that palliative care is synonymous with end-of-life care, with no role earlier in the course of ILD, has created a culture of neglect. Interventions that aim to improve life expectancy are often prioritised without rigorous assessment of the individual's health and psychosocial needs, thereby inadvertently reducing quality of life. As in malignant disorders, radical interventions to slow disease progression and palliative measures to improve quality of life should both be prioritised. Efficient patient-centred models of palliative care must be validated, taking into account religious and cultural differences, as well as variability of resources. Effective implementation of palliative care for ILD will require multidisciplinary participation from clinicians, specialist nurses, psychologists, social workers, and, in some countries, non-governmental faith and community-based organisations with access to palliative care expertise
Genome-Wide Analysis of Subependymomas Shows Underlying Chromosomal Copy Number Changes Involving Chromosomes 6, 7, 8 and 14 in a Proportion of Cases
Subependymomas (SE) are slow-growing brain tumors that tend to occur within the ventricles of middle-aged and elderly adults. The World Health Organization classifies these tumors within the ependymoma group. Previous limited analysis of this tumor type had not revealed significant underlying cytogenetic abnormalities
Scents of Adolescence: The Maturation of the Olfactory Phenotype in a Free-Ranging Mammal
Olfaction is an important sensory modality for mate recognition in many mammal species. Odorants provide information about the health status, genotype, dominance status and/or reproductive status. How and when odor profiles change during sexual maturation is, however often unclear, particularly in free-ranging mammals. Here, we investigated whether the wing sac odorant of male greater sac-winged bats (Saccopteryx bilineata, Emballonuridae) differs between young and adults, and thus offers information about sexual maturity to potential mating partners. Using gas chromatography – mass spectrometry, we found differences in the odorants of young and adult males prior and during, but not after the mating period. The wing sac odorant of adult males consists of several substances, such as Pyrocoll, 2,6,10-trimethyl-3-oxo-6,10-dodecadienolide, and a so far unidentified substance; all being absent in the odor profiles of juveniles prior to the mating season. During the mating season, these substances are present in most of the juvenile odorants, but still at lower quantities compared to the wing sac odorants of adults. These results suggest that the wing sac odorant of males encodes information about age and/or sexual maturity. Although female S. bilineata start to reproduce at the age of half a year, most males of the same age postpone the sexual maturation of their olfactory phenotype until after the first mating season
Including Smart Architecture in environments for people with dementia
Environments which aim to promote human well-being must address both functional and psychosocial needs. This paper comprises a description of a framework for a smart home environment, which aims to comprehensively address issues of environmental fit, in particular for a person with cognitive impairment associated with dementia, by means of introducing sensing of user affect as a factor in system management of a smart personal life space, and in generation of environmental response, adapting to changing user need. The introduction of affective computing into an intelligent system managing environmental response and adaptation is seen as a critical component in successfully realizing an interactive personal life-space, where a continuous feedback loop operates between user and environment, in real time. The overall intention is to maximize environmental congruence for the user, both functionally and psychosocially, by factoring in adjustment to changing user status. Design thinking, at all scales, is perceived as being essential to achieving a coherent smart environment, where architecture is reframed as interaction design
Phase I Randomised Clinical Trial of an HIV-1CN54, Clade C, Trimeric Envelope Vaccine Candidate Delivered Vaginally
We conducted a phase 1 double-blind randomised controlled trial (RCT) of a HIV-1 envelope protein (CN54 gp140) candidate vaccine delivered vaginally to assess immunogenicity and safety. It was hypothesised that repeated delivery of gp140 may facilitate antigen uptake and presentation at this mucosal surface. Twenty two healthy female volunteers aged 18–45 years were entered into the trial, the first receiving open-label active product. Subsequently, 16 women were randomised to receive 9 doses of 100 µg of gp140 in 3 ml of a Carbopol 974P based gel, 5 were randomised to placebo solution in the same gel, delivered vaginally via an applicator. Participants delivered the vaccine three times a week over three weeks during one menstrual cycle, and were followed up for two further months. There were no serious adverse events, and the vaccine was well tolerated. No sustained systemic or local IgG, IgA, or T cell responses to the gp140 were detected following vaginal immunisations. Repeated vaginal immunisation with a HIV-1 envelope protein alone formulated in Carbopol gel was safe, but did not induce local or systemic immune responses in healthy women
In Vivo Carbon-13 Dynamic MRS and MRSI of Normal and Fasted Rat Liver with Hyperpolarized 13C-Pyruvate
BACKGROUND: The use of in vivo (13)C nuclear magnetic resonance spectroscopy in probing metabolic pathways to study normal metabolism and characterize disease physiology has been limited by its low sensitivity. However, recent technological advances have enabled greater than 50,000-fold enhancement of liquid-state polarization of metabolically active (13)C substrates, allowing for rapid assessment of (13)C metabolism in vivo. The present study applied hyperpolarized (13)C magnetic resonance spectroscopy to the investigation of liver metabolism, demonstrating for the first time the feasibility of applying this technology to detect differences in liver metabolic states. PROCEDURES: [1-(13)C]pyruvate was hyperpolarized with a dynamic nuclear polarization instrument and injected into normal and fasted rats. The uptake of pyruvate and its conversion to the metabolic products lactate and alanine were observed with slice-localized dynamic magnetic resonance spectroscopy and 3D magnetic resonance spectroscopic imaging (3D-MRSI). RESULTS: Significant differences in lactate to alanine ratio (P < 0.01) between normal and fasted rat liver slice dynamic spectra were observed. 3D-MRSI localized to the fasted livers demonstrated significantly decreased (13)C-alanine levels (P < 0.01) compared to normal. CONCLUSIONS: This study presents the initial demonstration of characterizing metabolic state differences in the liver with hyperpolarized (13)C spectroscopy and shows the ability to detect physiological perturbations in alanine aminotransferase activity, which is an encouraging result for future liver disease investigations with hyperpolarized magnetic resonance technology
Integrating Clinical Probability into the Diagnostic Approach to Idiopathic Pulmonary Fibrosis: An International Working Group Perspective
Background. When considering the diagnosis of idiopathic pulmonary fibrosis (IPF), experienced
clinicians integrate clinical features that help to differentiate IPF from other fibrosing interstitial lung
diseases, thus generating a “pre-test” probability of IPF. The aim of this international working group
perspective was to summarize these features using a tabulated approach similar to chest HRCT and
histopathologic patterns reported in the international guidelines for the diagnosis of IPF, and to help
formally incorporate these clinical likelihoods into diagnostic reasoning to facilitate the diagnosis of
IPF.
Methods. The committee group identified factors that influence the clinical likelihood of a diagnosis
of IPF, which was categorized as a pre-test clinical probability of IPF into “high” (70-100%),
“intermediate” (30-70%), or “low” (0-30%). After integration of radiological and histopathological
features, the post-test probability of diagnosis was categorized into “definite” (90-100%), “high
confidence” (70-89%), “low confidence” (51-69%), or “low” (0-50%) probability of IPF.
Findings. A conceptual Bayesian framework was created, integrating the clinical likelihood of IPF
(“pre-test probability of IPF”) with the HRCT pattern, the histopathology pattern when available,
and/or the pattern of observed disease behavior into a “post-test probability of IPF”. The diagnostic
probability of IPF was expressed using an adapted diagnostic ontology for fibrotic interstitial lung
diseases.
Interpretation. The present approach will help incorporate the clinical judgement into the diagnosis
of IPF, thus facilitating the application of IPF diagnostic guidelines and, ultimately improving
diagnostic confidence and reducing the need for invasive diagnostic techniques
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