986 research outputs found
Ergodipotent maps and commutativity of elements in noncommutative rings and algebras with twisted intertwining
AbstractA property of algebraic dependence between two commuting elements is shown to hold in a more general setting than that in which it has previously been established. Key conditions are identified and some methods for establishing them are given.Moreover the class of algebras with a generalised Weyl structure, generalising the so-called Generalised Weyl Algebras (GWAs) or hyperbolic rings, is introduced and studied. We also present an interesting class of algebras which are not GWAs but share many of their properties by virtue of their generalised Weyl structure. For these classes of algebras, centralisers and algebraic dependence are investigated
UK Criteria for Uterus Transplantation: A Review
Absolute Uterine Factor Infertility (AUFI) is the final hurdle for assisted reproductive
treatments. Uterus transplant trials are happening worldwide; in order to advance the
debate around uterine transplantation (UTx) this article considers selection criteria for
clinical trials from a UK perspective and makes recommendations for future selection
criteria for UTx treatment. Recommendations advanced include the use of donor eggs,
access for single women and women in same-sex relationships, prohibiting
participation of women who are already mothers, and a preference for deceased
donors and bioengineered uteri. With UTx treatment on the horizon it is important to
proactively consider future selection criteria
Deformations of Lie Algebras using -derivations
In this article we develop an approach to deformations of the Witt and
Virasoro algebras based on -derivations. We show that -twisted
Jacobi type identity holds for generators of such deformations. For the
-twisted generalization of Lie algebras modeled by this construction,
we develop a theory of central extensions. We show that our approach can be
used to construct new deformations of Lie algebras and their central
extensions, which in particular include naturally the -deformations of the
Witt and Virasoro algebras associated to -difference operators, providing
also corresponding q-deformed Jacobi identities.Comment: 52 page
Fragmentation of exotic oxygen isotopes
Abrasion-ablation models and the empirical EPAX parametrization of projectile fragmentation are described. Their cross section predictions are compared to recent data of the fragmentation of secondary beams of neutron-rich, unstable 19,20,21O isotopes at beam energies near 600 MeV/nucleon as well as data for stable 17,18O beams
Visual onset expands subjective time
We report a distortion of subjective time perception in which the duration of a first interval is perceived to be longer than the succeeding interval of the same duration. The amount of time expansion depends on the onset type defining the first interval. When a stimulus appears abruptly, its duration is perceived to be longer than when it appears following a stationary array. The difference in the processing time for the stimulus onset and motion onset, measured as reaction times, agrees with the difference in time expansion. Our results suggest that initial transient responses for a visual onset serve as a temporal marker for time estimation, and a systematic change in the processing time for onsets affects perceived time
The effects of continued azacitidine treatment cycles on response in higher risk patients with myelodysplastic syndromes: an update
The international, phase III, multi-centre AZA-001 trial demonstrated azacitidine (AZA) is the first treatment to significantly extend overall survival (OS) in higher risk myelodysplastic syndromes (MDS) patients (Fenaux (2007) Blood 110 817). The current treatment paradigm, which is based on a relationship between complete remission (CR) and survival, is increasingly being questioned (Cheson (2006) Blood 108 419). Results of AZA-001 show CR is sufficient but not necessary to prolong OS (List (2008) Clin Oncol 26 7006). Indeed, the AZA CR rate in AZA-001 was modest (17%), while partial remission (PR, 12%) and haematological improvement (HI, 49%) were also predictive of prolonged survival. This analysis was conducted to assess the median number of AZA treatment cycles associated with achievement of first response, as measured by IWG 2000-defined CR, PR or HI (major + minor). The number of treatment cycles from first response to best response was also measured
Neutron recognition in the LAND detector for large neutron multiplicity
The performance of the LAND neutron detector is studied. Using an
event-mixing technique based on one-neutron data obtained in the S107
experiment at the GSI laboratory, we test the efficiency of various analytic
tools used to determine the multiplicity and kinematic properties of detected
neutrons. A new algorithm developed recently for recognizing neutron showers
from spectator decays in the ALADIN experiment S254 is described in detail. Its
performance is assessed in comparison with other methods. The properties of the
observed neutron events are used to estimate the detection efficiency of LAND
in this experiment.Comment: 16 pages, 8 figure
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Biases in the perceived timing of perisaccadic perceptual and motor events
Subjects typically experience the temporal interval immediately following a saccade as longer than a comparable control interval. One explanation of this effect is that the brain antedates the perceptual onset of a saccade target to around the time of saccade initiation. This could explain the apparent continuity of visual perception across eye movements. Thisantedating account was tested in three experiments in which subjects made saccades of differing extents and then judged either the duration or the temporal order of key events. Postsaccadic stimuli underwent subjective temporal lengthening and had early perceived onsets. A temporally advanced awareness of saccade completion was also found, independently of antedating effects. These results provide convergent evidence supporting antedating and differentiating it from other temporal biases
Seniors' experiences of living in special housing accommodation
This article presents a hermeneutic phenomenological analysis of interview material in which 12 seniors living in Special Housing Accommodation (SHA) facilities reflect on the experience of living in such facilities. Of particular interest in the analysis is living in a SHA as a phenomenon. The finding shows that the phenomenon of lived experience in a SHA seems to be a state of ambiguity regarding one's existence, which is made up of several constituents (elements of meaning). The analysis contributes to the understanding of how the phenomenon of SHA living is coming into existence as a need, due to an individual's failing health; however, the SHA is not considered to be a true home. Accordingly, this has consequences to the subject position for the seniors in that they have to navigate between existing and not existing. The seniors learn to cope with living in the SHA by lowering their expectations of life and existence while the SHA provides the prerequisites for their existence. An implication for promoting care is to support the seniors to enable a full existence of life within SHA living
Randomized Control Trial of Postnatal rhIGF-1/rhIGFBP-3 Replacement in Preterm Infants: Post-hoc Analysis of Its Effect on Brain Injury
Background: Postnatal insulin-like growth factor-1 (IGF-1) replacement with recombinant human (rh)IGF-1 and IGF binding protein-3 (rhIGF-1/rhIGFBP-3) is being studied as a potential treatment to reduce comorbidities of prematurity. We have recently reported on a phase II, multicenter, randomized, controlled trial comparing postnatal rhIGF-1/rhIGFBP-3 replacement with standard of care (SOC) in extremely preterm infants (NCT01096784). Maximum severity of retinopathy of prematurity was the primary endpoint of the trial and presence of GMH-IVH/PHI one of the pre-specified secondary endpoints. Infants therefore received serial cranial ultrasound scans (CUS) between birth and term age. In this post-hoc analysis we present a detailed analysis of the CUS data of this trial and evaluate the effect of postnatal rhIGF-1/rhIGFBP-3 replacement on the incidence of different kinds of brain injury in extremely preterm infants.
Methods: This report is an exploratory post-hoc analysis of a phase II trial in which infants <28 weeks gestational age were randomly allocated to rhIGF-1/rhIGFBP-3 or SOC. Serial cranial ultrasounds were performed between birth and term-equivalent age. Presence of germinal matrix hemorrhage and intraventricular hemorrhage (GMH-IVH), periventricular hemorrhagic infarction (PHI), post-hemorrhagic ventricular dilatation, and white matter injury (WMI) were scored by two independent masked readers.
Results: The analysis included 117 infants; 58 received rhIGF-1/rhIGFBP-3 and 59 received SOC. A trend toward less grade II–III GMH-IVH and PHI was observed in treated infants vs. SOC. A subanalysis of infants without evidence of GMH-IVH at study entry (n = 104) showed reduced progression to GMH-IVH in treated infants (25.0% [13/52] vs. 40.4% [21/52]; not significant). No effects of rhIGF-1/rhIGFBP-3 on WMI were observed.
Conclusion: The potential protective effect of rhIGF-1/rhIGFBP-3 on the occurrence of GMH-IVH/PHI appeared most pronounced in infants with no evidence of GMH-IVH at treatment start
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