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