Laser transmitter for cubesat-class applications

Laser communications onboard CubeSats is an emerging technology for enabling high-speed space-based communication links. In this paper we present the development of a 25 cm 3 and second iteration 0.3 U CubeSat-class laser transmitter operating at data rates of up to 500 Mbps using OOK modulation and an output power of up to 300 mW over the entire C-band. We present results of the development and characterization of the transmitter. From this testing the design will be demonstrated up to TRL 4/5 with the view for future qualification work and electronics integration

Modular coherent photonic-aided payload receiver for communications satellites

Ubiquitous satellite communications are in a leading position for bridging the digital divide. Fulfilling such a mission will require satellite services on par with fibre services, both in bandwidth and cost. Achieving such a performance requires a new generation of communications payloads powered by large-scale processors, enabling a dynamic allocation of hundreds of beams with a total capacity beyond 1 Tbit s−1. The fact that the scale of the processor is proportional to the wavelength of its signals has made photonics a key technology for its implementation. However, one last challenge hinders the introduction of photonics: while large-scale processors demand a modular implementation, coherency among signals must be preserved using simple methods. Here, we demonstrate a coherent photonic-aided receiver meeting such demands. This work shows that a modular and coherent photonic-aided payload is feasible, making way to an extensive introduction of photonics in next generation communications satellites

The Importance of Human FcγRI in Mediating Protection to Malaria

The success of passive immunization suggests that antibody-based therapies will be effective at controlling malaria. We describe the development of fully human antibodies specific for Plasmodium falciparum by antibody repertoire cloning from phage display libraries generated from immune Gambian adults. Although these novel reagents bind with strong affinity to malaria parasites, it remains unclear if in vitro assays are predictive of functional immunity in humans, due to the lack of suitable animal models permissive for P. falciparum. A potentially useful solution described herein allows the antimalarial efficacy of human antibodies to be determined using rodent malaria parasites transgenic for P. falciparum antigens in mice also transgenic for human Fc-receptors. These human IgG1s cured animals of an otherwise lethal malaria infection, and protection was crucially dependent on human FcγRI. This important finding documents the capacity of FcγRI to mediate potent antimalaria immunity and supports the development of FcγRI-directed therapy for human malaria

Nomogram-based Prediction of Overall Survival in Patients with Metastatic Urothelial Carcinoma Receiving First-line Platinum-based Chemotherapy: Retrospective International Study of Invasive/Advanced Cancer of the Urothelium (RISC)

The available prognostic models for overall survival (OS) in patients with metastatic urothelial carcinoma (UC) have been derived from clinical trial populations of cisplatin-treated patients

Quantification of Visual Field Loss in Age-Related Macular Degeneration

Background An evaluation of standard automated perimetry (SAP) and short wavelength automated perimetry (SWAP) for the central 10–2 visual field test procedure in patients with age-related macular degeneration (AMD) is presented in order to determine methods of quantifying the central sensitivity loss in patients at various stages of AMD. Methods 10–2 SAP and SWAP Humphrey visual fields and stereoscopic fundus photographs were collected in 27 eyes of 27 patients with AMD and 22 eyes of 22 normal subjects. Results Mean Deviation and Pattern Standard Deviation (PSD) varied significantly with stage of disease in SAP (both p<0.001) and SWAP (both p<0.001), but post hoc analysis revealed overlap of functional values among stages. In SWAP, indices of focal loss were more sensitive to detecting differences in AMD from normal. SWAP defects were greater in depth and area than those in SAP. Central sensitivity (within 1°) changed by −3.9 and −4.9 dB per stage in SAP and SWAP, respectively. Based on defect maps, an AMD Severity Index was derived. Conclusions Global indices of focal loss were more sensitive to detecting early stage AMD from normal. The SWAP sensitivity decline with advancing stage of AMD was greater than in SAP. A new AMD Severity Index quantifies visual field defects on a continuous scale. Although not all patients are suitable for SWAP examinations, it is of value as a tool in research studies of visual loss in AMD

Multi-trait genome-wide association study identifies new loci associated with optic disc parameters.

Funder: All funders per study are acknowledged in the Supplementary FileA new avenue of mining published genome-wide association studies includes the joint analysis of related traits. The power of this approach depends on the genetic correlation of traits, which reflects the number of pleiotropic loci, i.e. genetic loci influencing multiple traits. Here, we applied new meta-analyses of optic nerve head (ONH) related traits implicated in primary open-angle glaucoma (POAG); intraocular pressure and central corneal thickness using Haplotype reference consortium imputations. We performed a multi-trait analysis of ONH parameters cup area, disc area and vertical cup-disc ratio. We uncover new variants; rs11158547 in PPP1R36-PLEKHG3 and rs1028727 near SERPINE3 at genome-wide significance that replicate in independent Asian cohorts imputed to 1000 Genomes. At this point, validation of these variants in POAG cohorts is hampered by the high degree of heterogeneity. Our results show that multi-trait analysis is a valid approach to identify novel pleiotropic variants for ONH

Genome-wide association meta-analysis of corneal curvature identifies novel loci and shared genetic influences across axial length and refractive error

Abstract: Corneal curvature, a highly heritable trait, is a key clinical endophenotype for myopia - a major cause of visual impairment and blindness in the world. Here we present a trans-ethnic meta-analysis of corneal curvature GWAS in 44,042 individuals of Caucasian and Asian with replication in 88,218 UK Biobank data. We identified 47 loci (of which 26 are novel), with population-specific signals as well as shared signals across ethnicities. Some identified variants showed precise scaling in corneal curvature and eye elongation (i.e. axial length) to maintain eyes in emmetropia (i.e. HDAC11/FBLN2 rs2630445, RBP3 rs11204213); others exhibited association with myopia with little pleiotropic effects on eye elongation. Implicated genes are involved in extracellular matrix organization, developmental process for body and eye, connective tissue cartilage and glycosylation protein activities. Our study provides insights into population-specific novel genes for corneal curvature, and their pleiotropic effect in regulating eye size or conferring susceptibility to myopia

Multi-trait genome-wide association study identifies new loci associated with optic disc parameters

A new avenue of mining published genome-wide association studies includes the joint analysis of related traits. The power of this approach depends on the genetic correlation of traits, which reflects the number of pleiotropic loci, i.e. genetic loci influencing multiple traits. Here, we applied new meta-analyses of optic nerve head (ONH) related traits implicated in primary open-angle glaucoma (POAG); intraocular pressure and central corneal thickness using Haplotype reference consortium imputations. We performed a multi-trait analysis of ONH parameters cup area, disc area and vertical cup-disc ratio. We uncover new variants; rs11158547 in PPP1R36-PLEKHG3 and rs1028727 near SERPINE3 at genome-wide significance that replicate in independent Asian cohorts imputed to 1000 Genomes. At this point, validation of these variants in POAG cohorts is hampered by the high degree of heterogeneity. Our results show that multi-trait analysis is a valid approach to identify novel pleiotropic variants for ONH

Next generation optical communications for satellites

This thesis was previously held under moratorium from 12/11/2020 to 15/11/2022The amount of data being generated and communicated in space is ever increasing. With radio frequency systems becoming increasingly strained under technological and regulatory problems, laser communications has been identified as a key technology in leading a paradigm shift within satellite communications. When compared to traditional radio satellite communications, laser communication techniques show greater performance in terms of available data rates, but also improvements in areas such as a reduction in the size, weight and power of the communication subsystem. Historically, laser communications has been demonstrated on large satellites but their current use upon small satellites (≤ 10 kg) is limited. Within this thesis we address this problem by providing a trade-off analysis for a laser transmitter within space and assess the unique environment in which these laser systems will operate. 3 new classes of optical component not previously assessed for space use are tested. A polarisation maintaining hybrid and non-polarisation maintaining hybrid component are shown to suitable for use within a low-Earth orbit environment whilst a compact 1 µm isolator needs to be assessed further. Additionally, a selection of double-clad ErYb-doped fibers are tested to select the most suitable fiber for use within future high-power applications. With a new set of parts tested, the thesis turns towards novel module development. The first module presented is a technology readiness level 5/6 design for a 0.2 W, 1 Gbps laser transmitter designed for CubeSat applications. The optical design is modelled and verified over a temperature range of -5 °C to +50 °C. Finally a multi-channel optical amplifier used for photonic-based radio frequency beam-forming is presented. This amplifier utilises a novel photonic-crystal fiber which was then integrated into a module and performance verified. Having demonstrated the potential for laser communications in small satellite applications. This thesis has helped to provide a technological base on which the nextgeneration of compact, optical communication payloads can be built.The amount of data being generated and communicated in space is ever increasing. With radio frequency systems becoming increasingly strained under technological and regulatory problems, laser communications has been identified as a key technology in leading a paradigm shift within satellite communications. When compared to traditional radio satellite communications, laser communication techniques show greater performance in terms of available data rates, but also improvements in areas such as a reduction in the size, weight and power of the communication subsystem. Historically, laser communications has been demonstrated on large satellites but their current use upon small satellites (≤ 10 kg) is limited. Within this thesis we address this problem by providing a trade-off analysis for a laser transmitter within space and assess the unique environment in which these laser systems will operate. 3 new classes of optical component not previously assessed for space use are tested. A polarisation maintaining hybrid and non-polarisation maintaining hybrid component are shown to suitable for use within a low-Earth orbit environment whilst a compact 1 µm isolator needs to be assessed further. Additionally, a selection of double-clad ErYb-doped fibers are tested to select the most suitable fiber for use within future high-power applications. With a new set of parts tested, the thesis turns towards novel module development. The first module presented is a technology readiness level 5/6 design for a 0.2 W, 1 Gbps laser transmitter designed for CubeSat applications. The optical design is modelled and verified over a temperature range of -5 °C to +50 °C. Finally a multi-channel optical amplifier used for photonic-based radio frequency beam-forming is presented. This amplifier utilises a novel photonic-crystal fiber which was then integrated into a module and performance verified. Having demonstrated the potential for laser communications in small satellite applications. This thesis has helped to provide a technological base on which the nextgeneration of compact, optical communication payloads can be built