8,553 research outputs found
Simulating Hamiltonian dynamics using many-qudit Hamiltonians and local unitary control
When can a quantum system of finite dimension be used to simulate another
quantum system of finite dimension? What restricts the capacity of one system
to simulate another? In this paper we complete the program of studying what
simulations can be done with entangling many-qudit Hamiltonians and local
unitary control. By entangling we mean that every qudit is coupled to every
other qudit, at least indirectly. We demonstrate that the only class of
finite-dimensional entangling Hamiltonians that aren't universal for simulation
is the class of entangling Hamiltonians on qubits whose Pauli operator
expansion contains only terms coupling an odd number of systems, as identified
by Bremner et. al. [Phys. Rev. A, 69, 012313 (2004)]. We show that in all other
cases entangling many-qudit Hamiltonians are universal for simulation
Power system technologies for the manned Mars mission
The high impulse of electric propulsion makes it an attractive option for manned interplanetary missions such as a manned mission to Mars. This option is, however, dependent on the availability of high energy sources for propulsive power in addition to that required for the manned interplanetary transit vehicle. Two power system technologies are presented: nuclear and solar. The ion thruster technology for the interplanetary transit vehicle is described for a typical mission. The power management and distribution system components required for such a mission must be further developed beyond today's technology status. High voltage-high current technology advancements must be achieved. These advancements are described. In addition, large amounts of waste heat must be rejected to the space environment by the thermal management system. Advanced concepts such as the liquid droplet radiator are discussed as possible candidates for the manned Mars mission. These thermal management technologies have great potential for significant weight reductions over the more conventional systems
Relay I trapped radiation measurements
Radiation measurements of geomagnetically trapped electrons by instruments on Relay I satellite in 196
Perceptions of the cancer care left undone in primary and community services: A mixed methods evaluation
This is the peer reviewed version of the following article: Lawler,J., Lofton,L., and Leary, A. (2020) Perceptions of the cancer care left undone in primary and community
services: a mixed methods evaluation, Health and Social Care in the Community which will be published in final form at https://onlinelibrary.wiley.com/journal/13652524. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions."
Primary and community care in the United Kingdom are under increasing workforce and time pressures. How these pressures effect the delivery of cancer care has rarely been explored. This service evaluation aimed to elucidate some of the views of the workforce in this sector of what work in cancer care is left undone, and what they would like to be able to offer more of. An exploratory sequential design was taken including a questionnaire and interviews asking primary and community care staff in London about their workload in cancer care. Surveys were analysed using descriptive statistics. The evaluation revealed a perception from primary and community care that there is work in cancer care that is currently being left undone. 64% of the workforce across all professions reported that they worked 10 or more hours of unpaid overtime per week. Respondents identified psychological care for people with cancer, and bereavement care for families and carers of people with cancer as the most common areas that were left undone. They would like to do more proactive work, in place of the current reactive “fire-fighting” they are doing. For example, signposting available services to people with cancer and access to nutritional support. There was a desire for acknowledgement of the time and workforce pressures in primary and community care, and how these are hindering the delivery of care for people with cancer
Preparation and characterization of rufinamide HP-β-cyclodextrin complexes prepared by the kneading method for solubility enhancement
ACKNOWLEDGEMENT:
The author(s) are thankful to Ramanbhai Patel College of Pharmacy, Gujarat for providing facility to carry out research work.Aims: The present investigation concerns the preparation and characterization of Rufinamide HP-β-cyclodextrin complexes prepared by the kneading method.
Material & methods: Rufinamide was procured as a gift sample from Torrent Pharmaceuticals limited. HP-β-cyclodextrin (HP-β-CD) was purchased from Himedia, India. Methanol and Hydrochloric Acid were purchased from S. D. Fine Chem. Pvt. Ltd., India. kneading method was selected to prepare inclusion complexation of Rufinamide. Phase solubility study was performed to check formation of inclusion complex. Prepared complex were characterize by different methods like DSC study, FTIR study, X-RPD study & in-vitro dissolution study
Results: It was found that there is a formation of 1:1 inclusion complex between HP-β-CD as stability constant was found to be 221.27 M-1. DSC study, FTIR study had given supporting data for formation of inclusion complex. Amorphous nature of the complex was confirmed from the X-RPD study.
Conclusions: From in-vitro dissolution study it was found that 1:1.5 complex showed around 50% drug released in 30 min & more than 70% of Drug release in 60 mins.Objetivos: La presente investigación se refiere a la preparación y caracterización de complejos de rufinamida HP-β-ciclodextrina preparados por el método de amasado.
Material y métodos: La rufinamida fue donada por la empresa Torrent Pharmaceuticals limitado. HP-β-ciclodextrina (HP-β-CD) se adquirió de Himedia, India. Metanol y ácido clorhídrico se obtuvieron de SD Fine Chem. SA. Ltd., India. Se utilizó el método de amasado para preparar complejos de inclusión de rufinamida. El estudio de la fase de solubilidad se realizó para comprobar la formación de complejos de inclusión. Los complejos preparados se caracterizaron por diferentes métodos como DSC, FTIR, X-RPD y ensayo de disolución in vitro.
Resultados: Se encontró que se producían formación de complejos en la relación 1:1. La constante de estabilidad encontrada fue de 221,27 M-1. Los estudios de DSC, FTIR confirmaron la formación del complejo de inclusión. Mediante X-RPD se confirmó la naturaleza amorfa del complejo.
Conclusiones: El estudio de disolución in vitro mostró que la proporción 1:1.5 liberaba alrededor de 50% de fármaco en 30 min y a los 60 minutos se consiguió una liberación del 70%
Dysregulation of Na+/K+ ATPase by amyloid in APP+PS1 transgenic mice
BACKGROUND: The pathology of Alzheimer's disease (AD) is comprised of extracellular amyloid plaques, intracellular tau tangles, dystrophic neurites and neurodegeneration. The mechanisms by which these various pathological features arise are under intense investigation. Here, expanding upon pilot gene expression studies, we have further analyzed the relationship between Na+/K+ ATPase and amyloid using APP+PS1 transgenic mice, a model that develops amyloid plaques and memory deficits in the absence of tangle formation and neuronal or synaptic loss. RESULTS: We report that in addition to decreased mRNA expression, there was decreased overall Na+/K+ ATPase enzyme activity in the amyloid-containing hippocampi of the APP+PS1 mice (although not in the amyloid-free cerebellum). In addition, dual immunolabeling revealed an absence of Na+/K+ ATPase staining in a zone surrounding congophilic plaques that was occupied by dystrophic neurites. We also demonstrate that cerebral Na+/K+ ATPase activity can be directly inhibited by high concentrations of soluble Aβ. CONCLUSIONS: The data suggest that the reductions in Na+/K+ ATPase activity in Alzheimer tissue may not be purely secondary to neuronal loss, but may results from direct effects of amyloid on this enzyme. This disruption of ion homeostasis and osmotic balance may interfere with normal electrotonic properties of dendrites, blocking intraneuronal signal processing, and contribute to neuritic dystrophia. These results suggest that therapies aimed at enhancing Na+/K+ ATPase activity in AD may improve symptoms and/or delay disease progression
Dynamics of Rumor Spreading in Complex Networks
We derive the mean-field equations characterizing the dynamics of a rumor
process that takes place on top of complex heterogeneous networks. These
equations are solved numerically by means of a stochastic approach. First, we
present analytical and Monte Carlo calculations for homogeneous networks and
compare the results with those obtained by the numerical method. Then, we study
the spreading process in detail for random scale-free networks. The time
profiles for several quantities are numerically computed, which allow us to
distinguish among different variants of rumor spreading algorithms. Our
conclusions are directed to possible applications in replicated database
maintenance, peer to peer communication networks and social spreading
phenomena.Comment: Final version to appear in PR
Development and testing of a risk indexing framework to determine field-scale critical source areas of faecal bacteria on grassland.
This paper draws on lessons from a UK case study in the management of diffuse microbial pollution from grassland farm systems in the Taw catchment, south west England. We report on the development and preliminary testing of a field-scale faecal indicator organism risk indexing tool (FIORIT). This tool aims to prioritise those fields most vulnerable in terms of their risk of contributing FIOs to water. FIORIT risk indices were related to recorded microbial water quality parameters (faecal coliforms [FC] and intestinal enterococci [IE]) to provide a concurrent on-farm evaluation of the tool. There was a significant upward trend in Log[FC] and Log[IE] values with FIORIT risk score classification (r2 =0.87 and 0.70, respectively and P<0.01 for both FIOs). The FIORIT was then applied to 162 representative grassland fields through different seasons for ten farms in the case study catchment to determine the distribution of on-farm spatial and temporal risk. The high risk fields made up only a small proportion (1%, 2%, 2% and 3% for winter, spring, summer and autumn, respectively) of the total number of fields assessed (and less than 10% of the total area), but the likelihood of the hydrological connection of high FIO source areas to receiving watercourses makes them a priority for mitigation efforts. The FIORIT provides a preliminary and evolving mechanism through which we can combine risk assessment with risk communication to end-users and provides a framework for prioritising future empirical research. Continued testing of FIORIT across different geographical areas under both low and high flow conditions is now needed to initiate its long term development into a robust indexing tool
21st century fisheries management: a spatio-temporally explicit tariff-based approach combining multiple drivers and incentivising responsible fishing
Abstract
Kraak, S. B. M., Reid, D. G., Gerritsen, H. D., Kelly, C. J., Fitzpatrick, M., Codling, E. A., and Rogan, E. 2012. 21st century fisheries management: a spatio-temporally explicit tariff-based approach combining multiple drivers and incentivising responsible fishing. – ICES Journal of Marine Science, 69: 590–601. Traditionally fisheries management has focused on biomass and mortality, expressed annually and across large management units. However, because fish abundance varies at much smaller spatio-temporal scales, fishing mortality can potentially be controlled more effectively if managed at finer scale. The ecosystem approach requires more indicators at finer scales as well. Incorporating ecosystem targets would need additional management tools with potentially conflicting results. We present a simple, integrated, management approach that provides incentives for “good behaviour”. Fishers would be given a number of fishing-impact credits, called real-time incentives (RTIs), to spend according to spatio-temporally varying tariffs per fishing day. RTI quotas and tariffs could be based on commercial stocks and ecosystem targets. Fishers could choose how to spend their RTIs, e.g. by limited fishing in high-catch or sensitive areas or by fishing longer in lower-catch or less sensitive areas. The RTI system does not prescribe and forbid, but instead allows fishers to fish wherever and whenever they want; ecosystem costs are internalized and fishers have to take them into account in their business decisions. We envisage no need for traditional landings or catch quotas for the fleets while operating under the scheme. The approach could facilitate further devolution of responsibility to industry.</jats:p
- …