Polarization compensator for optical communications

An optical data communication system is provided whereby two orthogonal polarization states of a light beam carrier correspond to digital states. In such a system, automatic polarization compensation is provided by applying a dither modulating voltage to a cell exhibiting the electro-optic effect. The cell controls the relative phase of electric field components of an input light beam enabling the dither frequency component of the difference of the instantaneous powers in the two polarization states to be coherently detected. A signal derived from the coherent detection process is fed back to the cell via an integrator to form polarization bias compensating servo loop ot Type 1

Channel simulation for direct detection optical communication systems

A technique is described for simulating the random modulation imposed by atmospheric scintillation and transmitter pointing jitter on a direct detection optical communication system. The system is capable of providing signal fading statistics which obey log normal, beta, Rayleigh, Ricean or chi-squared density functions. Experimental tests of the performance of the Channel Simulator are presented

The Art of Refusal: Promising Practice for Grant Makers and Grant Seekers

The full report of this research project provides the findings of a study of communication experiences and practices, at the point of grant refusal, among selected grant making and grant seeking organisations. Its context was the frustration and disappointment being experienced by many grant seekers in a period of enhanced competition for funding, alongside the multiple pressures facing grant makers, in responding to grant seekers' needs and in meeting their own range of obligations. The overall purpose of the research was to support learning and improvement in policy and practice among grant makers and grant seekers. A summary of the findings from the qualitative research undertaken for the project is provided at the end of this paper. In this practice paper, we focus on the direct learning question posed by the research - 'what promising practices in grant refusal communications may be identified from grant makers' and grant seekers' perspectives on their experiences?' Many respondents during the research process highlighted what were, for them, preferred and promising practices in communicating and managing grant refusal among grant seekers and grant makers. These were sometimes their own approaches and sometimes those which they had observed and welcomed. These insights, examples and possibilities are now distilled and presented below as promising practice learning and action points, illustrated by anonymous quotations taken from our research respondents

Bioconjugation of Green Fluorescent Protein via an Unexpectedly Stable Cyclic Sulfonium Intermediate

Bioconjugation of superfolder GFP involving the formation of an unusually stable, and unprecedented, cyclic sulfonium species is described. This sulfonium can undergo smooth reaction with a range of nucleophiles to give sulfur-, selenium- and azide-modified GFP derivatives in high conversions

Dynamic polarization compensating system for optical communications receiver

Electro-optic cell is located in optical path of input light beam. Cell includes crystal for controlling phase between two polarization states. Cell axes are rotated 45 deg to receiver axes defined by vertical and horizontal polarization states. Voltage across cell compensates for bias by introducing different phase retardation along crystal axes

Retrodirective modulator Patent

Optical retrodirective modulator with focus spoiling reflector driven by modulation signa

Do medical students want to learn about global health?

Conflicts of interest and funding: We declare that we have no conflicts of interest. A grant from the Partnership of Maternal, Newborn and Child Health funded this studyPeer reviewedPublisher PD

Artificial intelligence in cardiology : applications, benefits and challenges

Evidently, the potential benefits of AI in cardiology are enormous. However, such benefits are not without challenges. First, there are clear benefits for improving work productivity. There are currently fewer physicians to care for an ever - increasing aging population (WHO 2016). AI can support, rather than replace physicians, generating time - and cost - saving benefits for them and their patients and enabling more compassionate and thorough interactions. However, as more tasks become automated, there are possibilities that fewer physicians will be required to work or that fewer will do so on a full - time basis, since many tasks could be delivered through platforms by part-time, freelancer physicians. This may impact the relationship between patients, physicians and administrative staff in healthcare systems