2,437 research outputs found
Constraints on Automorphic Forms of Higher Derivative Terms from Compactification
By dimensionally reducing the higher derivative corrections of
ten-dimensional IIB theory on a torus we deduce constraints on the E_{n+1}
automorphic forms that occur in d=10-n dimensions. In particular we argue that
these automorphic forms involve the representation of E_{n+1} with fundamental
weight \lambda^{n+1}, which is also the representation to which the string
charges in d dimensions belong. We also consider a similar calculation for the
reduction of higher derivative terms in eleven-dimensional M-theory.Comment: Minor corrections, to appear in JHE
Higher derivative type II string effective actions, automorphic forms and E11
By dimensionally reducing the ten-dimensional higher derivative type IIA
string theory effective action we place constraints on the automorphic forms
that appear in the effective action in lower dimensions. We propose a number of
properties of such automorphic forms and consider the prospects that E11 can
play a role in the formulation of the higher derivative string theory effective
action.Comment: 34 page
Effects of co-treatment of Rauwolfia vomitoria and Gongronema latifolium on neurobehaviour and the neurohistology of the cerebral cortex in mice
Rauwolfia vomitoria and Gongronema latifolium are medicinal plants with antioxidant, antidiabetic and analgesic properties among others. R. vomitoria is reported to possess adverse neural effects, which G. latifolium has shown the potential to address. This study therefore investigated the effects of co-treatment of R. vomitoria and G. latifolium on the neurobehaviour and histology of the cerebral cortex of female mice. Twenty female Wistar mice were divided into 4 groups (A, B, C and D). Group A designated as the control received 0.4 mL of 20 % Tween, while groups B, C and D received oral doses of 150 mg/kg of R. vomitoria (RV), 200 mg/kg of G. latifolium (GL) and a combination of 150 mg/kg of R. vomitoria and 200 mg/kg of G. latifolium (RV+GL), respectively for seven days. Light and dark field behaviour test was carried out on day 8 and the animals were immediately sacrificed. Their brains were excised and routinely processed by haematoxylin and eosin method. There was no difference in body and brain weights, and the behavioural parameters. Cellular cyto-architecture showed higher glial population with no apparent histopathology. The cellular population was higher (p<0.0001) in the RV and RV+GL groups, while the GL group was less (p<0.0001) populated all compared to the control.In conclusion, the reported treatment regimes, RV administered singly and in combination with GL may not affect some neurobehavioural activities, but may result in cellular increase in the cerebral cortex.KEY WORDS: Rauwolfia vomitoria; Gongronema latifolium; Cerebral cortex; Mic
Light-cone-like spreading of correlations in a quantum many-body system
How fast can correlations spread in a quantum many-body system? Based on the
seminal work by Lieb and Robinson, it has recently been shown that several
interacting many-body systems exhibit an effective light cone that bounds the
propagation speed of correlations. The existence of such a "speed of light" has
profound implications for condensed matter physics and quantum information, but
has never been observed experimentally. Here we report on the time-resolved
detection of propagating correlations in an interacting quantum many-body
system. By quenching a one-dimensional quantum gas in an optical lattice, we
reveal how quasiparticle pairs transport correlations with a finite velocity
across the system, resulting in an effective light cone for the quantum
dynamics. Our results open important perspectives for understanding relaxation
of closed quantum systems far from equilibrium as well as for engineering
efficient quantum channels necessary for fast quantum computations.Comment: 7 pages, 5 figures, 2 table
Meaning behind measurement : self-comparisons affect responses to health related quality of life questionnaires
Purpose The subjective nature of quality of life is particularly pertinent to the domain of health-related quality of
life (HRQOL) research. The extent to which participantsâ responses are affected by subjective information and personal reference frames is unknown. This study investigated how an elderly population living with a chronic metabolic bone disorder evaluated self-reported quality of life. Methods Participants (n = 1,331) in a multi-centre randomised controlled trial for the treatment of Pagetâs disease completed annual HRQOL questionnaires, including the SF-36, EQ-5D and HAQ. Supplementary questions were added to reveal implicit reference frames used when making HRQOL evaluations. Twenty-one participants (11 male, 10 female, aged 59â91 years) were interviewed retrospectively about their responses to the supplementary questions, using cognitive interviewing techniques and semi-structured topic guides. Results The interviews revealed that participants used complex and interconnected reference frames to promote response shift when making quality of life evaluations. The choice of reference frame often reflected external factors unrelated to individual health. Many participants also stated that they were unclear whether to report general or disease-related HRQOL. Conclusions It is important, especially in clinical trials, to provide instructions clarifying whether âquality of lifeâ refers to disease-related HRQOL. Information on selfcomparison reference frames is necessary for the interpretation of responses to questions about HRQOL.The Chief Scientist Office of the Scottish Government Health Directorates,
The PRISM funding bodies (the Arthritis Research Campaign, the National Association for the Relief of Pagetâs disease and the Alliance for Better Bone Health)Peer reviewedAuthor final versio
Extremely high reflection of solar wind protons as neutral hydrogen atoms from regolith in space
We report on measurements of extremely high reflection rates of solar wind
particles from regolith-covered lunar surfaces. Measurements by the Sub-keV
Atom Reflecting Analyzer (SARA) instrument on the Indian Chandrayaan-1
spacecraft in orbit around the Moon show that up to 20% of the impinging solar
wind protons are reflected from the lunar surface back to space as neutral
hydrogen atoms. This finding, generally applicable to regolith-covered
atmosphereless bodies, invalidates the widely accepted assumption that regolith
almost completely absorbs the impinging solar wind.Comment: 2 figure
Actinopolyspora algeriensis sp. nov., a novel halophilic actinomycete isolated from a Saharan soil
A halophilic actinomycete strain designated H19T, was isolated from a Saharan soil in the Bamendil region (Ouargla province, South Algeria) and was characterized taxonomically by using a polyphasic approach. The morphological and chemotaxonomic characteristics of the
strain were consistent with those of members of the genus
Actinopolyspora, and 16S rRNA gene sequence analysis confirmed that strain H19T was a novel species of the genus
Actinopolyspora. DNAâDNA hybridization value between strain H19T and the nearest Actinopolyspora species, A. halophila, was clearly below the 70 % threshold. The genotypic and phenotypic data showed that the organism represents a novel species of the genus Actinopolyspora for which the name Actinopolyspora algeriensis sp. nov. is proposed, with the type strain H19T (= DSM 45476T = CCUG 62415T)
The role of the combination of bone and fall related risk factors on short-term subsequent fracture risk and mortality
BACKGROUND: We analysed whether a combination of bone- and fall-related risk factors (RFs) in addition to a recent non-vertebral fracture (NVF) contributed to subsequent NVF risk and mortality during 2-years in patients who were offered fall and fracture prevention according to Dutch fracture- and fall-prevention guidelines. METHODS: 834 consecutive patients aged â„50 years with a recent NVF who were included. We compared subgroups of patients according to the presence of bone RFs and/or fall RFs (group 1: only bone RFs; group 2: combination of bone and fall RFs; group 3: only fall RFs; group 4: no additional RFs). Univariable and multivariable Cox regression analyses were performed adjusted for age, sex and baseline fracture location (major or minor). RESULTS: 57 (6.8%) had a subsequent NVF and 29 (3.5%) died within 2-years. Univariable Cox regression analysis showed that patients with the combination of bone and fall RFs had a 99% higher risk in subsequent fracture risk compared to all others (Hazard Ratio (HR) 1.99; 95% Confidence Interval (CI) 1.18-3.36) Multivariable analyses this was borderline not significant (HR 1.70; 95% CI: 0.99-2.93). No significant differences in mortality were found between the groups. CONCLUSION: Evaluation of fall RFs contributes to identifying patients with bone RFs at highest immediate risk of subsequent NVF in spite of guideline-based treatment. It should be further studied whether earlier and immediate prevention following a NVF can decrease fracture risk in patients with a combination of bone and fall RFs
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