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Molecular parameters of post impact cooling in the Boltysh impact structure
Impact events have the potential to generate a number of long-term sources of heat that can lead to the initiation of hydrothermal systems when the impact occurs on a water- or ice-rich target. Such hydrothermal systems have been postulated as promising locations to search for evidence of past biological processes on Mars due to the prevalence of impact cratering as a surface process in Mars’s early history. In this study, we have used molecular parameters of the thermal maturity of organic matter combined with palynology and carbon isotope stratigraphy to study the post impact thermal history of crater fill sediments from the Boltysh crater, Ukraine
A Narrative Review of Medication-Related Clinical Decision Support
Objectives: A key element of the implementation and on-going use of an electronic prescribing (ePrescribing) system is ensuring that users are, and remain, sufficiently trained to use the system. Studies have suggested that insufficient training is associated with suboptimal use. However, it is not clear from these studies how clinicians are trained to use ePrescribing systems or the effectiveness of different approaches. We sought to describe the various approaches used to train qualified prescribers on ePrescribing systems and to identify whether users were educated about the pitfalls and challenges of using these systems. Methods: We performed a literature review, using a systematic approach across three large databases: Cumulative Index Nursing and Allied Health Literature (CINAHL), Embase and Medline were searched for relevant English language articles. Articles that explored the training of qualified prescribers on ePrescribing systems in a hospital setting were included. Key Findings: Our search of ‘all training’ approaches returned 1,155 publications, of which seven were included. A separate search of ‘online’ training found three relevant publications. Training methods in the ‘all training’ category included clinical scenarios, demonstrations and assessments. Regarding ‘online’ training approaches; a team at the University of Victoria in Canada developed a portal containing simulated versions of electronic health records, where individuals could prescribe for fictitious patients. Educating prescribers about the challenges and pitfalls of electronic systems was rarely discussed. Conclusions: A number of methods are used to train prescribers; however the lack of papers retrieved suggests a need for additional studies to inform training methods
High Speed Visible Light Communication Using Blue GaN Laser Diodes
GaN-based laser diodes have been developed over the last 20 years making them desirable for many security and defence applications, in particular, free space laser communications. Unlike their LED counterparts, laser diodes are not limited by their carrier lifetime which makes them attractive for high speed communication, whether in free space, through fiber or underwater. Gigabit data transmission can be achieved in free space by modulating the visible light from the laser with a pseudo-random bit sequence (PRBS), with recent results approaching 5 Gbit/s error free data transmission. By exploiting the low-loss in the blue part of the spectrum through water, data transmission experiments have also been conducted to show rates of 2.5 Gbit/s underwater. Different water types have been tested to monitor the effect of scattering and to see how this affects the overall transmission rate and distance. This is of great interest for communication with unmanned underwater vehicles (UUV) as the current method using acoustics is much slower and vulnerable to interception. These types of laser diodes can typically reach 50-100 mW of power which increases the length at which the data can be transmitted. This distance could be further improved by making use of high power laser arrays. Highly uniform GaN substrates with low defectivity allow individually addressable laser bars to be fabricated. This could ultimately increase optical power levels to 4 W for a 20-emitter array. Overall, the development of GaN laser diodes will play an important part in free space optical communications and will be vital in the advancement of security and defence applications
Vibrating Winding Branes, Wrapping Democracy and Stabilization of Extra Dimensions in Dilaton Gravity
We show that, in the context of dilaton gravity, a recently proposed
democratic principle for intersection possibilities of branes winding around
extra dimensions yield stabilization, even with the inclusion of momentum modes
of the wrapped branes on top of the winding modes. The constraints for
stabilization massaged by string theory inputs forces the number of observed
dimensions to be three. We also discuss consequences of adding ordinary matter
living in the observed dimensions.Comment: Added a section discussing the linear and non-linear stability of the
equilibrium point of the scale factors of the extra dimensions. Corrected a
typo in the original field equations and other typos. Added and changed
references. Final version appeared in JHE
Free-space and underwater GHz data transmission using AlGaInN laser diode technology
Laser diodes fabricated from the AlGaInN material system is an emerging technology for defence and security applications; in particular for free space laser communication. Conventional underwater communication is done acoustically with very slow data rates, short reach, and vulnurable for interception. AlGaInN blue-green laser diode technology allows the possibility of both airbourne links and underwater telecom that operate at very fast data rates (GHz), long reach (100’s of metres underwater) and can also be quantum encrypted. The latest developments in AlGaInN laser diode technology are reviewed for defence and security applications. The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from u.v., ~380nm, to the visible ~530nm, by tuning the indium content of the laser GaInN quantum well. Ridge waveguide laser diode structures are fabricated to achieve single mode operation with optical powers of <100mW. Visible light communications at high frequency (up to 2.5 Gbit/s) using a directly modulated 422nm Galliumnitride (GaN) blue laser diode is reported in free-space and underwate
A regional water quality model designed for a range of users and for retrofit and re-use
We discuss the motivations for, and software design concepts underpinning, the development of a regional water quality model. The Environmental Management Support System (EMSS) was developed to predict daily fluxes of runoff, total suspended sediment, total nitrogen and total phosphorous through a large-scale river network. It was built using a custom environmental modelling framework called Tarsier, founded on the Borland C++ Builder rapid application development environment. Three autonomous models are integrated within the EMSS, but are loosely coupled so that alternative models could be retrofitted into the system if desired. The three models share common data handling and visualisation routines resident in the Tarsier modelling environment and used in other modelling applications. The EMSS was designed for use by a range of stakeholders with varying levels of computer and technical proficiency. To satisfy their varying needs, we built three different interfaces, suited to ‘expert’, ‘intermediate’ and ‘basic’ users. The interfaces for the latter two groups were developed using interface prototyping methods, resulting in software that suited the user requirements. The object-oriented design employed in the coding of the EMSS has enhanced the extendibility and re-useability of the software. The EMSS development was part of a larger hydrologic modelling initiative aimed at reducing duplication in model building and standardising approaches to model design and delivery. The lessons learned during development of the EMSS have informed our future model development strategy
T and S dualities and The cosmological evolution of the dilaton and the scale factors
Cosmologically stabilizing radion along with the dilaton is one of the major
concerns of low energy string theory. One can hope that T and S dualities can
provide a plausible answer. In this work we study the impact of S and T duality
invariances on dilaton gravity. We have shown various instances where
physically interesting models arise as a result of imposing the mentioned
invariances. In particular S duality has a very privileged effect in that the
dilaton equations partially decouple from the evolution of the scale factors.
This makes it easy to understand the general rules for the stabilization of the
dilaton. We also show that certain T duality invariant actions become S duality
invariance compatible. That is they mimic S duality when extra dimensions
stabilize.Comment: Corrected a misleading interpretation of the S duality transformation
and a wrong comment on d=10. I thank A.Kaya for pointing this out to me in
time. So the new version is dealing with d=10 only. Added references and
corrected some typos. Minor re-editing. Omitted a section for elaboration in
a further study. Corrected further typo
Fixing the conformal window in QCD
A physical characterization of Landau singularities is emphasized, which
should trace the lower boundary N_f^* of the conformal window in QCD and
supersymmetric QCD. A natural way to disentangle ``perturbative'' from
``non-perturbative'' contributions to amplitudes below N_f^* is suggested.
Assuming an infrared fixed point persists in the perturbative part of the QCD
coupling even below N_f^* leads to the condition \gamma(N_f^*)=1, where \gamma
is the critical exponent. Using the Banks-Zaks expansion, one gets 4<N_f^*<6.
This result is incompatible with the existence of an analogue of Seiberg
duality in QCD. The presence of a negative ultraviolet fixed point is required
both in QCD and in supersymmetric QCD to preserve causality within the
conformal window. Evidence for the existence of such a fixed point in QCD is
provided.Comment: 10 pages, 1 figure, extended version of a talk given at the
QCDNET2000 meeting, Paris, September 11-14 2000; main new material added is
evidence for negative ultraviolet fixed point in QC
Supersymmetry Breaking and Dilaton Stabilization in String Gas Cosmology
In this Note we study supersymmetry breaking via gaugino condensation in
string gas cosmology. We show that the same gaugino condensate which is
introduced to stabilize the dilaton breaks supersymmetry. We study the
constraints on the scale of supersymmetry breaking which this mechanism leads
to.Comment: 11 page
A literature review of the training offered to qualified prescribers to use electronic prescribing systems: why is it so important?
Objectives A key element of the implementation and ongoing use of an electronic prescribing (ePrescribing) system is ensuring that users are, and remain, sufficiently trained to use the system. Studies have suggested that insufficient training is associated with suboptimal use. However, it is not clear from these studies how clinicians are trained to use ePrescribing systems or the effectiveness of different approaches. We sought to describe the various approaches used to train qualified prescribers on ePrescribing systems and to identify whether users were educated about the pitfalls and challenges of using these systems. Methods We performed a literature review, using a systematic approach across three large databases: Cumulative Index Nursing and Allied Health Literature, Embase and Medline were searched for relevant English language articles. Articles that explored the training of qualified prescribers on ePrescribing systems in a hospital setting were included. Key findings Our search of ‘all training’ approaches returned 1155 publications, of which seven were included. A separate search of ‘online’ training found three relevant publications. Training methods in the ‘all training’ category included clinical scenarios, demonstrations and assessments. Regarding ‘online’ training approaches; a team at the University of Victoria in Canada developed a portal containing simulated versions of electronic health records, where individuals could prescribe for fictitious patients. Educating prescribers about the challenges and pitfalls of electronic systems was rarely discussed. Conclusions A number of methods are used to train prescribers; however, the lack of papers retrieved suggests a need for additional studies to inform training methods
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