766 research outputs found
On the degeneracies of the mass-squared differences for three-neutrino oscillations
Using an algebraic formulation, we explore two well-known degeneracies
involving the mass-squared differences for three-neutrino oscillations assuming
CP symmetry is conserved. For vacuum oscillation, we derive the expression for
the mixing angles that permit invariance under the interchange of two
mass-squared differences. This symmetry is most easily expressed in terms of an
ascending mass order. This can be used to reduce the parameter space by one
half in the absence of the MSW effect. For oscillations in matter, we derive
within our formalism the known approximate degeneracy between the standard and
inverted mass hierarchies in the limit of vanishing . This is done
with a mass ordering that permits the map .
Our techniques allow us to translate mixing angles in this mass order
convention into their values for the ascending order convention. Using this
dictionary, we demonstrate that the vacuum symmetry and the approximate
symmetry invoked for oscillations in matter are distinctly different.Comment: 5 pages, revised manuscrip
Atmospheric, long baseline, and reactor neutrino data constraints on
A new atmospheric neutrino oscillation tool which utilizes full three
neutrino oscillation probabilities and a full three neutrino treatment of the
MSW effect is combined with a standard analysis of the K2K, MINOS, and CHOOZ
data to examine the bounds on implied by existing data, including
the recent, more finely binned, Super-K atmospheric data. In the region
km/GeV, we have previously found that the sub-dominant
expansion does not converge and that terms linear in can be
significant. The current analysis confirms this and leads to the conclusion
that is bounded from above by the atmospheric data while CHOOZ
provides the lower bound. We trace the origin of this result to fully contained
data in the previously mentioned very long baseline region, to a combination of
a quadratic in term in and a linear term in
and their contribution to , a broad MSW resonance
for the solar mass-squared difference at 180 MeV, and an increase in
due to this resonant matter effect which alters the sign of the
linear in term. Assuming CP is conserved in the lepton sector, we
find , the asymmetry being a reflection of
the importance of the linear in terms.Comment: 4 pages, 5 figures, typos corrected, manuscript shortene
Repelling neoliberal world-making? How the ageing–dementia relation is reassembling the social
Growing old ‘badly’ is stigmatizing, a truism that is enrolled into contemporary agendas for the biomedicalization of ageing. Among the many discourses that emphasize ageing as the root cause of later life illnesses, dementia is currently promoted as an epidemic and such hyperbole serves to legitimate its increasing biomedicalization. The new stigma however is no longer contained to simply having dementia, it is failing to prevent it. Anti-ageing cultures of consumption, alongside a proliferation of cultural depictions of the ageing–dementia relation, seem to be refiguring dementia as a future to be worked on to eliminate it from our everyday life. The article unpacks this complexity for how the ageing–dementia relation is being reassembled in biopolitics in ways that enact it as something that can be transformed and managed. Bringing together Bauman’s theories of how cultural communities cope with the otherness of the other with theories of the rationale for the making of monsters – such as the figure of the abject older person with dementia – the article suggests that those older body-persons that personify the ageing–dementia relation, depicted in film and television for example, threaten the modes of ordering underpinning contemporary lives. This is not just because they intimate loss of mind, or because they are disruptive, but because they do not perform what it is to be ‘response-able’ and postpone frailty through managing self and risk
Ten steps or climbing a mountain: A study of Australian health professionals' perceptions of implementing the baby friendly health initiative to protect, promote and support breastfeeding
Background: The Baby Friendly Hospital (Health) Initiative (BFHI) is a global initiative aimed at protecting,
promoting and supporting breastfeeding and is based on the ten steps to successful breastfeeding. Worldwide,
over 20,000 health facilities have attained BFHI accreditation but only 77 Australian hospitals (approximately 23%)
have received accreditation. Few studies have investigated the factors that facilitate or hinder implementation of
BFHI but it is acknowledged this is a major undertaking requiring strategic planning and change management
throughout an institution. This paper examines the perceptions of BFHI held by midwives and nurses working in
one Area Health Service in NSW, Australia.
Methods: The study used an interpretive, qualitative approach. A total of 132 health professionals, working across four maternity units, two neonatal intensive care units and related community services, participated in 10 focus groups. Data were analysed using thematic analysis.
Results: Three main themes were identified: ‘Belief and Commitment’; ‘Interpreting BFHI’ and ‘Climbing a
Mountain’. Participants considered the BFHI implementation a high priority; an essential set of practices that would
have positive benefits for babies and mothers both locally and globally as well as for health professionals. It was
considered achievable but would take commitment and hard work to overcome the numerous challenges including a number of organisational constraints. There were, however, differing interpretations of what was required to attain BFHI accreditation with the potential that misinterpretation could hinder implementation.
A model described by Greenhalgh and colleagues on adoption of innovation is drawn on to interpret the findings.
Conclusion: Despite strong support for BFHI, the principles of this global strategy are interpreted differently by
health professionals and further education and accurate information is required. It may be that the current
processes used to disseminate and implement BFHI need to be reviewed. The findings suggest that there is a
contradiction between the broad philosophical stance and best practice approach of this global strategy and the
tendency for health professionals to focus on the ten steps as a set of tasks or a checklist to be accomplished. The
perceived procedural approach to implementation may be contributing to lower rates of breastfeeding
continuation
Large Magnetoresistance Oscillations in Mesoscopic Superconductors Due to Current-Excited Moving Vortices
We show in the case of a superconducting Nb ladder that a mesoscopic
superconductor typically exhibits magnetoresistance oscillations whose
amplitude and temperature dependence are different from those stemming from the
Little-Parks effect. We demonstrate that these large resistance oscillations
(as well as the monotonic background on which they are superimposed) are due to
{\it current-excited moving vortices}, where the applied current in competition
with the oscillating Meissner currents imposes/removes the barriers for vortex
motion in increasing magnetic field. Due to the ever present current in
transport measurements, this effect should be considered in parallel with the
Little-Parks effect in low- samples, as well as with recently proposed
thermal activation of dissipative vortex-antivortex pairs in high-
samples
Understanding health-care outcomes of older people with cognitive impairment and/or dementia admitted to hospital: a mixed-methods study
BACKGROUND:
Cognitive impairment is common in older people admitted to hospital, but previous research has focused on single conditions.
OBJECTIVE: This project sits in phase 0/1 of the Medical Research Council Framework for the Development and Evaluation of Complex Interventions. It aims to develop an understanding of current health-care outcomes. This will be used in the future development of a multidomain intervention for people with confusion (dementia and cognitive impairment) in general hospitals. The research was conducted from January 2015 to June 2018 and used data from people admitted between 2012 and 2013.
DESIGN:
For the review of outcomes, the systematic review identified peer-reviewed quantitative epidemiology measuring prevalence and associations with outcomes. Screening for duplication and relevance was followed by full-text review, quality assessment and a narrative review (141 papers). A survey sought opinion on the key outcomes for people with dementia and/or confusion and their carers in the acute hospital (n = 78). For the analysis of outcomes including cost, the prospective cohort study was in a medical admissions unit in an acute hospital in one Scottish health board covering 10% of the Scottish population. The participants (n = 6724) were older people (aged ≥ 65 years) with or without a cognitive spectrum disorder who were admitted as medical emergencies between January 2012 and December 2013 and who underwent a structured nurse assessment. ‘Cognitive spectrum disorder’ was defined as any combination of delirium, known dementia or an Abbreviated Mental Test score of < 8 out of 10 points. The main outcome measures were living at home 30 days after discharge, mortality within 2 years of admission, length of stay, re-admission within 2 years of admission and cost.
DATA SOURCES:
Scottish Morbidity Records 01 was linked to the Older Persons Routine Acute Assessment data set.
RESULTS: In the systematic review, methodological heterogeneity, especially concerning diagnostic criteria, means that there is significant overlap in conditions of patients presenting to general hospitals with confusion. Patients and their families expect that patients are discharged in the same or a better condition than they were in on admission or, failing that, that they have a satisfactory experience of their admission. Cognitive spectrum disorders were present in more than one-third of patients aged ≥ 65 years, and in over half of those aged ≥ 85 years. Outcomes were worse in those patients with cognitive spectrum disorders than in those without: length of stay 25.0 vs. 11.8 days, 30-day mortality 13.6% vs. 9.0%, 1-year mortality 40.0% vs. 26.0%, 1-year mortality or re-admission 62.4% vs. 51.5%, respectively (all p < 0.01). There was relatively little difference by cognitive spectrum disorder type; for example, the presence of any cognitive spectrum disorder was associated with an increased mortality over the entire period of follow-up, but with different temporal patterns depending on the type of cognitive spectrum disorder. The cost of admission was higher for those with cognitive spectrum disorders, but the average daily cost was lower.
LIMITATIONS:
A lack of diagnosis and/or standardisation of diagnosis for dementia and/or delirium was a limitation for the systematic review, the quantitative study and the economic study. The economic study was limited to in-hospital costs as data for social or informal care costs were unavailable. The survey was conducted online, limiting its reach to older carers and those people with cognitive spectrum disorders.
CONCLUSIONS: Cognitive spectrum disorders are common in older inpatients and are associated with considerably worse health-care outcomes, with significant overlap between individual cognitive spectrum disorders. This suggests the need for health-care systems to systematically identify and develop care pathways for older people with cognitive spectrum disorders, and avoid focusing on only condition-specific pathways.
FUTURE WORKS:
Development and evaluation of a multidomain intervention for the management of patients with cognitive spectrum disorders in hospital.
STUDY REGISTRATION:
This study is registered as PROSPERO CRD42015024492.
FUNDING:
This project was funded by the National Institute for Health Research (NIHR) Health Services and Delivery Research programme and will be published in full in Health Services and Delivery Research; Vol. 9, No. 8. See the NIHR Journals Library website for further project information
Tocopherols, Phylloquinone, Ascorbic Acid, and Sugar Contents in Hydroponically Grown Lettuce
Growing vegetables in controlled environments (CEs), such as hydroponics, aquaponics, and vertical structures, is a rapidly expanding industry in Florida and the United States, especially in nearby urban areas. Although lettuce (Lactuca sativa) is still mostly produced in fields, growing in CEs proximal to urban areas has become increasingly popular because it may facilitate reduced transportation time and associated postharvest degradation. Lettuce is among the top-most consumed vegetables in the United States and could provide some of the nutrition missing in the US diet. This research was planned to understand the levels of some vitamins that are key for human health, including vitamin E (tocopherols), vitamin K1 (phylloquinone), and vitamin C (ascorbic acid), in lettuce grown in greenhouse hydroponics. Lettuce germplasm was grown using the hydroponic nutrient film technique system in three greenhouse experiments: at the beginning, middle, and end of the Florida, USA, growing season (from Aug 2020 to Mar 2021). Genetic variation for these vitamins were found among the germplasm tested in the four morphological types of lettuce, romaine, Boston, Latin, and leaf. In addition, a sugar analysis was conducted in this germplasm, of which fructose was the most abundant sugar. A significant genotype × environment (G × E) interaction was observed, indicating that the levels of these compounds, especially vitamins, was environment dependent. However, the presence of certain non-crossover G × E interactions indicates that selecting lettuce in a representative environment could result in new cultivars with higher vitamin content. This research marks the initial steps to improve lettuce for these vitamins, which can contribute to better health of US consumers, not for the highest amount of these compounds in lettuce but for the offset due to its high consumption
Towards connecting biodiversity and geodiversity across scales with satellite remote sensing
Issue
Geodiversity (i.e., the variation in Earth\u27s abiotic processes and features) has strong effects on biodiversity patterns. However, major gaps remain in our understanding of how relationships between biodiversity and geodiversity vary over space and time. Biodiversity data are globally sparse and concentrated in particular regions. In contrast, many forms of geodiversity can be measured continuously across the globe with satellite remote sensing. Satellite remote sensing directly measures environmental variables with grain sizes as small as tens of metres and can therefore elucidate biodiversity–geodiversity relationships across scales. Evidence
We show how one important geodiversity variable, elevation, relates to alpha, beta and gamma taxonomic diversity of trees across spatial scales. We use elevation from NASA\u27s Shuttle Radar Topography Mission (SRTM) and c. 16,000 Forest Inventory and Analysis plots to quantify spatial scaling relationships between biodiversity and geodiversity with generalized linear models (for alpha and gamma diversity) and beta regression (for beta diversity) across five spatial grains ranging from 5 to 100 km. We illustrate different relationships depending on the form of diversity; beta and gamma diversity show the strongest relationship with variation in elevation. Conclusion
With the onset of climate change, it is more important than ever to examine geodiversity for its potential to foster biodiversity. Widely available satellite remotely sensed geodiversity data offer an important and expanding suite of measurements for understanding and predicting changes in different forms of biodiversity across scales. Interdisciplinary research teams spanning biodiversity, geoscience and remote sensing are well poised to advance understanding of biodiversity–geodiversity relationships across scales and guide the conservation of nature
On Heisenberg Uncertainty Relationship, Its Extension, and the Quantum Issue of Wave-Particle Duality
Within the path integral Feynman formulation of quantum mechanics, the fundamental Heisenberg Uncertainty Relationship (HUR) is analyzed in terms of the quantum fluctuation influence on coordinate and momentum estimations. While introducing specific particle and wave representations, as well as their ratio, in quantifying the wave-to-particle quantum information, the basic HUR is recovered in a close analytical manner for a large range of observable particle-wave Copenhagen duality, although with the dominant wave manifestation, while registering its progressive modification with the factor
1-n2, in terms of magnitude n∈[0,1]. of the quantum fluctuation, for the free quantum evolution around the exact wave-particle equivalence. The practical implications of the present particle-to-wave ratio as well as of the free-evolution quantum picture are discussed for experimental implementation, broken symmetry and the electronic localization function
Topology by Design in Magnetic nano-Materials: Artificial Spin Ice
Artificial Spin Ices are two dimensional arrays of magnetic, interacting
nano-structures whose geometry can be chosen at will, and whose elementary
degrees of freedom can be characterized directly. They were introduced at first
to study frustration in a controllable setting, to mimic the behavior of spin
ice rare earth pyrochlores, but at more useful temperature and field ranges and
with direct characterization, and to provide practical implementation to
celebrated, exactly solvable models of statistical mechanics previously devised
to gain an understanding of degenerate ensembles with residual entropy. With
the evolution of nano--fabrication and of experimental protocols it is now
possible to characterize the material in real-time, real-space, and to realize
virtually any geometry, for direct control over the collective dynamics. This
has recently opened a path toward the deliberate design of novel, exotic
states, not found in natural materials, and often characterized by topological
properties. Without any pretense of exhaustiveness, we will provide an
introduction to the material, the early works, and then, by reporting on more
recent results, we will proceed to describe the new direction, which includes
the design of desired topological states and their implications to kinetics.Comment: 29 pages, 13 figures, 116 references, Book Chapte
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