480 research outputs found
Backward Evolving Quantum States
The basic concept of the two-state vector formalism, which is the time
symmetric approach to quantum mechanics, is the backward evolving quantum
state. However, due to the time asymmetry of the memory's arrow of time, the
possible ways to manipulate a backward evolving quantum state differ from those
for a standard, forward evolving quantum state. The similarities and the
differences between forward and backward evolving quantum states regarding the
no-cloning theorem, nonlocal measurements, and teleportation are discussed. The
results are relevant not only in the framework of the two-state vector
formalism, but also in the framework of retrodictive quantum theory.Comment: Contribution to the J.Phys. A special issue in honor of GianCarlo
Ghirard
Wfs1 Is Expressed In Dopaminoceptive Regions Of The Amniote Brain And Modulates Levels Of D1-Like Receptors
During amniote evolution, the construction of the forebrain has diverged across different lineages, and accompanying the structural changes, functional diversification of the homologous brain regions has occurred. This can be assessed by studying the expression patterns of marker genes that are relevant in particular functional circuits. In all vertebrates, the dopaminergic system is responsible for the behavioral responses to environmental stimuli. Here we show that the brain regions that receive dopaminergic input through dopamine receptor D1 are relatively conserved, but with some important variations between three evolutionarily distant vertebrate linesâhouse mouse (Mus musculus), domestic chick (Gallus gallus domesticus) / common quail (Coturnix coturnix) and red-eared slider turtle (Trachemys scripta). Moreover, we find that in almost all instances, those brain regions expressing D1-like dopamine receptor genes also express Wfs1. Wfs1 has been studied primarily in the pancreas, where it regulates the endoplasmic reticulum (ER) stress response, cellular Ca2+ homeostasis, and insulin production and secretion. Using radioligand binding assays in wild type and Wfs1-/- mouse brains, we show that the number of binding sites of D1-like dopamine receptors is increased in the hippocampus of the mutant mice. We propose that the functional link between Wfs1 and D1-like dopamine receptors is evolutionarily conserved and plays an important role in adjusting behavioral reactions to environmental stimuli
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The role of the international cocoa germplasm database and the international cocoa quarantine centre in information management and distribution of cocoa genetic resources
A range of physiological parameters (canopy light transmission, canopy shape, leaf size, flowering and flushing intensity) were measured from the International Clone Trial, typically over the course of two years. Data were collected from six locations, these being: Brazil, Ecuador, Trinidad, Venezuela, CĂŽte dâIvoire and Ghana. Canopy shape varied significantly between clones, although it showed little variation between locations. Genotypic variation in leaf size was differentially affected by the growth location; such differences appeared to underlie a genotype by environment interaction in relation to canopy light transmission. Flushing data were recorded at monthly intervals over the course of a year. Within each location, a significant interaction was observed between genotype and time of year, suggesting that some genotypes respond to a greater extent than others to environmental stimuli. A similar interaction was observed for flowering data, where significant correlations were found between flowering intensity and temperature in Brazil and flowering intensity and rainfall in CĂŽte dâIvoire. The results demonstrate the need for local evaluation of cocoa clones and also suggest that the management practices for particular planting material may need to be fine-tuned to the location in which they are cultivated
Changes in performance and bio-mathematical model performance predictions during 45 days of sleep restriction in a simulated space mission
Lunar habitation and exploration of space beyond low-Earth orbit will require small crews to live in isolation and confinement while maintaining a high level of performance with limited support from mission control. Astronauts only achieve approximately 6 h of sleep per night, but few studies have linked sleep deficiency in space to performance impairment. We studied crewmembers over 45 days during a simulated space mission that included 5 h of sleep opportunity on weekdays and 8 h of sleep on weekends to characterize changes in performance on the psychomotor vigilance task (PVT) and subjective fatigue ratings. We further evaluated how well bio-mathematical models designed to predict performance changes due to sleep loss compared to objective performance. We studied 20 individuals during five missions and found that objective performance, but not subjective fatigue, declined from the beginning to the end of the mission. We found that bio-mathematical models were able to predict average changes across the mission but were less sensitive at predicting individual-level performance. Our findings suggest that sleep should be prioritized in lunar crews to minimize the potential for performance errors. Bio-mathematical models may be useful for aiding crews in schedule design but not for individual-level fitness-for-duty decisions
Asymmetric Dark Matter and Dark Radiation
Asymmetric Dark Matter (ADM) models invoke a particle-antiparticle asymmetry,
similar to the one observed in the Baryon sector, to account for the Dark
Matter (DM) abundance. Both asymmetries are usually generated by the same
mechanism and generally related, thus predicting DM masses around 5 GeV in
order to obtain the correct density. The main challenge for successful models
is to ensure efficient annihilation of the thermally produced symmetric
component of such a light DM candidate without violating constraints from
collider or direct searches. A common way to overcome this involves a light
mediator, into which DM can efficiently annihilate and which subsequently
decays into Standard Model particles. Here we explore the scenario where the
light mediator decays instead into lighter degrees of freedom in the dark
sector that act as radiation in the early Universe. While this assumption makes
indirect DM searches challenging, it leads to signals of extra radiation at BBN
and CMB. Under certain conditions, precise measurements of the number of
relativistic species, such as those expected from the Planck satellite, can
provide information on the structure of the dark sector. We also discuss the
constraints of the interactions between DM and Dark Radiation from their
imprint in the matter power spectrum.Comment: 22 pages, 5 figures, to be published in JCAP, minor changes to match
version to be publishe
End-of-life care in UK care homes: a systematic review of the literature
Background The number of people requiring end-of-life care provision in care homes has grown significantly. There is a need for a systematic examination of individual studies to provide more comprehensive information about contemporary care provision. Aim The aim of this study was to systematically review studies that describe end-of-life care in UK care homes. Method A systematic PRISMA review of the literature published between 2008 and April 2017 was carried out. A total of 14 studies were included in the review. Results A number of areas of concern were identified in the literature in relation to the phases of dying during end-of-life care: end-of-life pre-planning processes; understandings of end-of-life care; and interprofessional end-of-life care provision. Conclusions Given that the problems identified in the literature concerning end-of-life care of residents in care homes are similar to those encountered in other healthcare environments, there is logic in considering how generalised solutions that have been proposed could be applied to the specifics of care homes. Further research is necessary to explore how barriers to good end-of-life care can be mitigated, and facilitators strengthened
Increasing incidence of EpsteinâBarr virusârelated nasopharyngeal carcinoma in the United States
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152902/1/cncr32517_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152902/2/cncr32517.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152902/3/cncr32517-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152902/4/cncr32517-sup-0002-FigS2.pd
Honor-Based Abuse in England and Wales: Who Does What to Whom?
Key findings are presented from an empirical study profiling 1,474 cases of honor-based abuse (HBA) known to police and victim services in England and Wales. Thematic and quantitative (regression) analyses were used to investigate whether and how HBA differed from other forms of domestic abuse and forced marriage. A new typology of HBA is proposed, based principally on the relationship(s) between victim and perpetrator(s). Interpreted within an overarching lens of gender-based violence, it is argued that Type 1 (partner abuse) and Type 3 (partner plus family abuse) are culturally specific forms of domestic abuse, whereas Type 2 (family abuse) is distinct
Clinical decision making in the recognition of dying: a qualitative interview study
BACKGROUND: Recognising dying is an essential clinical skill for general and palliative care professionals alike. Despite the high importance, both identification and good clinical care of the dying patient remains extremely difficult and often controversial in clinical practice. This study aimed to answer the question: "What factors influence medical and nursing staff when recognising dying in end-stage cancer and heart failure patients?" METHODS: This study used a descriptive approach to decision-making theory. Participants were purposively sampled for profession (doctor or nurse), specialty (cardiology or oncology) and grade (senior vs junior). Recruitment continued until data saturation was reached. Semi-structured interviews were conducted with NHS medical and nursing staff in an NHS Trust which contained cancer and cardiology tertiary referral centres. An interview schedule was designed, based on decision-making literature. Interviews were audio-recorded and transcribed and analysed using thematic framework. Data were managed with Atlas.ti. RESULTS: Saturation was achieved with 19 participants (7 seniors; 8 intermediate level staff; 4 juniors). There were 11 oncologists (6 doctors, 5 nurses) and 8 cardiologists (3 doctors, 5 nurses). Six themes were generated: information used; decision processes; modifying factors; implementation; reflecting on decisions and related decisions. The decision process described was time-dependent, ongoing and iterative, and relies heavily on intuition. CONCLUSIONS: This study supports the need to recognise the strengths and weaknesses of expertise and intuition as part of the decision process, and of placing the recognition of dying in a time-dependent context. Clinicians should also be prepared to accept and convey the uncertainty surrounding these decisions, both in practice and in communication with patients and carers
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