Spacecraft health and environmental monitoring from a CubeSat platform

The uncertainties in the outgassing/offgassing, dust/debris, and radiation environments within and surrounding spacecraft regularly lead to operational problems with technical, scientific and ultimately economically deleterious consequences. In this paper we present the outputs of a study into a small modular spacecraft health and environmental monitoring package deployed in a standard 3U CubeSat platform that will provide real time measurements of a spacecraft's immediate environment to inform operators and on-board systems of threats to spacecraft or payload "health" via a comprehensive and correlated dataset of many related environmental parameters. We also demonstrate a mission concept with this platform deployed in LEO orbit

C3D – an imaging radiation damage experiment on UKUBE-1

The Open University, in collaboration with e2v technologies Ltd and XCAM Ltd, have been selected to fly an experimental payload on board the UK Space Agency's UKube-1 pilot Cubesat programme. Cubesat payloads offer a unique opportunity to rapidly build and fly space hardware for minimal cost, providing easy access to the space environment. The proposed payload incorporated new imaging technology using a CMOS image sensor into a combined Earth Observation (EO) technology demonstrator and in-orbit radiation damage characterisation instrument, to help raise the TRL of the sensor technology. Based around the e2v 1.3 MPixel 0.18 micron process “eye-on-Si” CMOS devices, the instrument consists of 3 distinct image sensors; one devoted to radiation damage monitoring (RDM), as well as a narrow field imager (NFI) and a wide field imager (WFI). The narrow and wide field imagers are expected to achieve resolutions of 25 m and 350 m respectively from a 650 km orbit, providing sufficient swathe widths of 30 and 450 km respectively. The radiation damage experiment has been designed to verify and reinforce ground based testing that has been conducted on the e2v eye-on-Si family of devices and includes a TEC for temperature control as well as RADFETs for in-orbit dosimetry. Of particular interest are Single Event Effects (SEEs); Single Event Upset (SEU) and Single Event Latchup (SEL) effects etc. and the experiment contains operating modes to evaluate these during SAA passage. The novel instrument design allows for a wide range of capabilities the within highly constrained mass (170g), power (1W) and space budgets providing a model for future use on similarly constrained missions, such as planetary rovers. Scheduled for launch in June 2014, this project should not only provide valuable data helping to raise the TRL of the technology to prove flight heritage for future missions, but also provide outreach opportunities demonstrating the capabilities of such payloads

The noise performance of electron-multiplying charge-coupled devices at X-ray energies

Electron-multiplying charge-coupled devices (EMCCDs) are used in low-light-level (L3) applications for detecting optical, ultraviolet, and near-infrared photons (10–1100 nm). The on-chip gain process is able to increase the detectability of any signal collected by the device through the multiplication of the signal before the output node. Thus, the effective readout noise can be reduced to subelectron levels, allowing the detection of single photons. However, this gain process introduces an additional noise component due to the stochastic nature of the multiplication. In optical applications, this additional noise has been characterized. The broadening of the detected peak is described by the excess noise factor. This factor tends to a value of √2 at high gain (>100x). In X-ray applications, the situation is improved by the effect that Fano factor f has on the shot noise associated with X-ray photon detection (f ≈ 0.12 at X-ray energies). In this paper, the effect of the detection of X-ray photons in silicon is assessed both analytically and through a Monte Carlo model of the gain amplification process. The excess noise on the signal is predicted (termed the modified Fano factor) for photon detection in an EM-CCD at X-ray energies. A hypothesis is made that the modified Fano factor should tend to 1.115 at high levels of gain (>10x). In order to validate the predictions made, measurements were taken using an 55 Fe source with Mn k-alpha X-ray energy of 5898 eV. These measurements allowed the hypothesis to be verified

The use of EM-CCDs on high resolution soft x-ray spectrometers

Charge-Coupled Devices (CCDs) have been traditionally used on high resolution soft X-ray spectrometers, but with their ability to increase the signal level in the detector before the readout noise of the system is added, Electron-Multiplying CCDs (EM-CCDs) have the potential to offer many advantages in soft X-ray detection. Through this signal multiplication an EM-CCD has advantages over conventioanl CCDs of increased signal, suppressed noise, faster readout speeds for the same equivalent readout noise and an increased inmmunity to Electro-Magnetic Intereference. This paper will look at present and future spacel applications for high resolution soft X-ray spectrometers and assess the advantages and disadvantage of using EM-CCDs in these applications

The noise performance of electron-multiplying charge-coupled devices at soft X-ray energy values

The use of electron-multiplying charge-coupled devices (CCDs) for high-resolution soft X-ray spectroscopy has been proposed in previous studies, and the analysis that followed experimentally identified and verified a modified Fano factor for X-ray detection using an 55Fe X-ray source. However, further experiments with soft X-rays at 1000 eV were less successful, attributed to excessive split events. More recently, through the use of deep-depletion e2v CCD220 and on-chip binning, it has been possible to greatly reduce the number of split events, allowing the result for the modified Fano factor at soft X-ray energy values to be verified. This paper looks at the earlier attempt to verify the modified Fano factor at 1000 eV with e2v CCD97 and shows the issues created by splitting of the charge cloud between pixels. It then compares these earlier results with new data collected using e2v CCD220, investigating how split-event reduction allows the modified Fano factor to be verified for low-energy X-rays

Cardiac Deletion of Smyd2 Is Dispensable for Mouse Heart Development

Chromatin modifying enzymes play a critical role in cardiac differentiation. Previously, it has been shown that the targeted deletion of the histone methyltransferase, Smyd1, the founding member of the SET and MYND domain containing (Smyd) family, interferes with cardiomyocyte maturation and proper formation of the right heart ventricle. The highly related paralogue, Smyd2 is a histone 3 lysine 4- and lysine 36-specific methyltransferase expressed in heart and brain. Here, we report that Smyd2 is differentially expressed during cardiac development with highest expression in the neonatal heart. To elucidate the functional role of Smyd2 in the heart, we generated conditional knockout (cKO) mice harboring a cardiomyocyte-specific deletion of Smyd2 and performed histological, functional and molecular analyses. Unexpectedly, cardiac deletion of Smyd2 was dispensable for proper morphological and functional development of the murine heart and had no effect on global histone 3 lysine 4 or 36 methylation. However, we provide evidence for a potential role of Smyd2 in the transcriptional regulation of genes associated with translation and reveal that Smyd2, similar to Smyd3, interacts with RNA Polymerase II as well as to the RNA helicase, HELZ

Class dynamics of development: a methodological note

This article argues that class relations are constitutive of developmental processes and central to understanding inequality within and between countries. In doing so it illustrates and explains the diversity of the actually existing forms of class relations, and the ways in which they interplay with other social relations such as gender and ethnicity. This is part of a wider project to re- vitalise class analysis in the study of development problems and experiences

Identifying mortality risks in patients with opioid use disorder using brief screening assessment:Secondary mental health clinical records analysis

BACKGROUND: Risk assessments are widely used, but their ability to predict outcomes in opioid use disorder (OUD) treatment remains unclear. Therefore, the aim was to investigate if addiction-specific brief risk screening is effective in identifying high mortality risk groups and if subsequent clinical actions following risk assessment impacts on mortality levels.  METHODS: Opioid use disorder (OUD) patients were identified in the South London and Maudsley Case Register. Deaths were identified through database linkage to the national mortality dataset. Cox and competing-risk regression were used to model associations between brief risk assessment domains and all-cause and overdose mortality in 4488 OUD patients, with up-to 6-year follow-up time where 227 deaths were registered. Data were stratified by admission to general mental health services.  RESULTS: All-cause mortality was significantly associated with unsafe injecting (HR 1.53, 95% CI 1.10-2.11) and clinically appraised likelihood of accidental overdose (HR 1.48, 95% CI 1.00-2.19). Overdose-mortality was significantly associated with unsafe injecting (SHR 2.52, 95% CI 1.11-5.70) and clinically appraised suicidality (SHR 2.89, 95% CI 1.38-6.03). Suicidality was associated with a twofold increase in mortality risk among OUD patients who were not admitted to mental health services within 2 months of their risk assessment (HR 2.03, 95% CI 1.67-3.24).  CONCLUSIONS: Diagnosis-specific brief risk screening can identify OUD patient subgroups at increased risk of all-cause and overdose mortality. OUD patients, where suicidality is evident, who are not admitted into services are particularly vulnerable

“At ‘Amen Meals’ It’s Me and God” Religion and Gender: A New Jewish Women’s Ritual

New ritual practices performed by Jewish women can serve as test cases for an examination of the phenomenon of the creation of religious rituals by women. These food-related rituals, which have been termed ‘‘amen meals’’ were developed in Israel beginning in the year 2000 and subsequently spread to Jewish women in Europe and the United States. This study employs a qualitative-ethnographic methodology grounded in participant-observation and in-depth interviews to describe these nonobligatory, extra-halakhic rituals. What makes these rituals stand out is the women’s sense that through these rituals they experience a direct con- nection to God and, thus, can change reality, i.e., bring about jobs, marriages, children, health, and salvation for friends and loved ones. The ‘‘amen’’ rituals also create an open, inclusive woman’s space imbued with strong spiritual–emotional energies that counter the women’s religious marginality. Finally, the purposes and functions of these rituals, including identity building and displays of cultural capital, are considered within a theoretical framework that views ‘‘doing gender’’ and ‘‘doing religion’’ as an integrated experience

Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans

Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in 25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16 regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP, while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium (LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region. Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa, an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent signals within the same regio