Measuring physical activity levels in people with mild cognitive impairment or mild dementia

Measuring physical activity (PA) in people with mild cognitive impairment (MCI) or dementia can be difficult. The aim was to investigate the validity and acceptability of three different PA measurement methods.The mixed-method analysis included 49 participants with MCI or dementia who completed a daily calendar recording PA, the International Physical Activity Questionnaire (IPAQ), the LASA Physical Activity Questionnaire and wore a Misfit Shine accelerometer. The quantitative analysis showed equal completion rates for the IPAQ questionnaire and the accelerometer but a lower completion rate for the calendar. Correlations between outcome measures were moderate or strong. The qualitative analysis indicated that all measures were acceptable, though help to complete the calendars or fasten the accelerometers was required for some participants. The study supported the validity of these methods for people with MCI and mild dementia. Using accelerometers and completing calendars might increase motivation to be active for some people

Predicting 30-day mortality after hip fracture surgery: Evaluation of the National Hip Fracture Database case-mix adjustment model.

OBJECTIVES: The National Hip Fracture Database (NHFD) publishes hospital-level risk-adjusted mortality rates following hip fracture surgery in England, Wales and Northern Ireland. The performance of the risk model used by the NHFD was compared with the widely-used Nottingham Hip Fracture Score. METHODS: Data from 94 hospitals on patients aged 60 to 110 who had hip fracture surgery between May 2013 and July 2013 were analysed. Data were linked to the Office for National Statistics (ONS) death register to calculate the 30-day mortality rate. Risk of death was predicted for each patient using the NHFD and Nottingham models in a development dataset using logistic regression to define the models' coefficients. This was followed by testing the performance of these refined models in a second validation dataset. RESULTS: The 30-day mortality rate was 5.36% in the validation dataset (n = 3861), slightly lower than the 6.40% in the development dataset (n = 4044). The NHFD and Nottingham models showed a slightly lower discrimination in the validation dataset compared with the development dataset, but both still displayed moderate discriminative power (c-statistic for NHFD = 0.71, 95% confidence interval (CI) 0.67 to 0.74; Nottingham model = 0.70, 95% CI 0.68 to 0.75). Both models defined similar ranges of predicted mortality risk (1% to 18%) in assessment of calibration. CONCLUSIONS: Both models have limitations in predicting mortality for individual patients after hip fracture surgery, but the NHFD risk adjustment model performed as well as the widely-used Nottingham prognostic tool and is therefore a reasonable alternative for risk adjustment in the United Kingdom hip fracture population.Cite this article: Bone Joint Res 2017;6:550-556

Electron multiplication CCD detector technology advancement for the WFIRST-AFTA coronagraph

The WFIRST-AFTA (Wide Field InfraRed Survey Telescope-Astrophysics Focused Telescope Asset) is a NASA space observatory. It will host two major astronomical instruments: a wide-field imager (WFI) to search for dark energy and carry out wide field near infrared (NIR) surveys, and a coronagraph instrument (CGI) to image and spectrally characterize extrasolar planets. In this paper, we discuss the work that has been carried out at JPL in advancing Electron Multiplying CCD (EMCCD) technology to higher flight maturity, with the goal of reaching a NASA technology readiness level of 6 (TRL-6) by early-to-mid 2016. The EMCCD has been baselined for both the coronagraph's imager and integral field spectrograph (IFS) based on its sub-electron noise performance at extremely low flux levels - the regime where the AFTA CGI will operate. We present results from a study that fully characterizes the beginning of life performance of the EMCCD. We also discuss, and present initial results from, a recent radiation test campaign that was designed and carried out to mimic the conditions of the WFIRST-AFTA space environment in an L2 orbit, where we sought to assess the sensor's end of life performance, particularly degradation of its charge transfer efficiency, in addition to other parameters such as dark current, electron multiplication gain, clock induced charge and read noise

Functional colour genes and signals of selection in colour polymorphic salamanders

Coloration has been associated with multiple biologically relevant traits that drive adaptation and diversification in many taxa. However, despite the great diversity of colour patterns present in amphibians the underlying molecular basis is largely unknown. Here, we use insight from a highly colour-variable lineage of the European fire salamander (Salamandra salamandra bernardezi) to identify functional associations with striking variation in colour morph and pattern. The three focal colour morphs—ancestral black-yellow striped, fully yellow and fully brown—differed in pattern, visible coloration and cellular composition. From population genomic analyses of up to 4,702 loci, we found no correlations of neutral population genetic structure with colour morph. However, we identified 21 loci with genotype–phenotype associations, several of which relate to known colour genes. Furthermore, we inferred response to selection at up to 142 loci between the colour morphs, again including several that relate to coloration genes. By transcriptomic analysis across all different combinations, we found 196 differentially expressed genes between yellow, brown and black skin, 63 of which are candidate genes involved in animal coloration. The concordance across different statistical approaches and ‘omic data sets provide several lines of evidence for loci linked to functional differences between colour morphs, including TYR, CAMK1 and PMEL. We found little association between colour morph and the metabolomic profile of its toxic compounds from the skin secretions. Our research suggests that current ecological and evolutionary hypotheses for the origins and maintenance of these striking colour morphs may need to be revisited.This research was supported by a Natural Environment Research Council; a Royal Society Research Grant; a Glasgow Natural History Society grant; a Wellcome Trust ISSF Catalyst Grant and a Spanish Ministry of Science Grant

Predicting 30-day mortality after hip fracture surgery

Objectives The National Hip Fracture Database (NHFD) publishes hospital-level risk-adjusted mortality rates following hip fracture surgery in England, Wales and Northern Ireland. The performance of the risk model used by the NHFD was compared with the widely-used Nottingham Hip Fracture Score. Methods Data from 94 hospitals on patients aged 60 to 110 who had hip fracture surgery between May 2013 and July 2013 were analysed. Data were linked to the Office for National Statistics (ONS) death register to calculate the 30-day mortality rate. Risk of death was predicted for each patient using the NHFD and Nottingham models in a development dataset using logistic regression to define the models’ coefficients. This was followed by testing the performance of these refined models in a second validation dataset. Results The 30-day mortality rate was 5.36% in the validation dataset (n = 3861), slightly lower than the 6.40% in the development dataset (n = 4044). The NHFD and Nottingham models showed a slightly lower discrimination in the validation dataset compared with the development dataset, but both still displayed moderate discriminative power (c-statistic for NHFD = 0.71, 95% confidence interval (CI) 0.67 to 0.74; Nottingham model = 0.70, 95% CI 0.68 to 0.75). Both models defined similar ranges of predicted mortality risk (1% to 18%) in assessment of calibration. Conclusions Both models have limitations in predicting mortality for individual patients after hip fracture surgery, but the NHFD risk adjustment model performed as well as the widely-used ­Nottingham prognostic tool and is therefore a reasonable alternative for risk adjustment in the United Kingdom hip fracture population

Validation of NIEL for >1MeV electrons in silicon using the CCD47-20

For future space missions that are visiting hostile electron radiation environments, such as ESA’s JUICE mission, it is important to understand the effects of electron irradiation on silicon devices. This paper outlines a study to validate and improve upon the Non-Ionising Energy Loss (NIEL) model for high energy electrons in silicon using Charge Coupled Devices (CCD), CMOS Imaging Sensors (CIS) and PIPS photodiodes. Initial results of radiation effects in an e2v technologies CCD47-20 after irradiation to 10 krad of 1 MeV electrons are presented with future results and analysis to be presented in future publications

Predicting 30-day mortality after hip fracture surgery

Objectives The National Hip Fracture Database (NHFD) publishes hospital-level risk-adjusted mortality rates following hip fracture surgery in England, Wales and Northern Ireland. The performance of the risk model used by the NHFD was compared with the widely-used Nottingham Hip Fracture Score. Methods Data from 94 hospitals on patients aged 60 to 110 who had hip fracture surgery between May 2013 and July 2013 were analysed. Data were linked to the Office for National Statistics (ONS) death register to calculate the 30-day mortality rate. Risk of death was predicted for each patient using the NHFD and Nottingham models in a development dataset using logistic regression to define the models’ coefficients. This was followed by testing the performance of these refined models in a second validation dataset. Results The 30-day mortality rate was 5.36% in the validation dataset (n = 3861), slightly lower than the 6.40% in the development dataset (n = 4044). The NHFD and Nottingham models showed a slightly lower discrimination in the validation dataset compared with the development dataset, but both still displayed moderate discriminative power (c-statistic for NHFD = 0.71, 95% confidence interval (CI) 0.67 to 0.74; Nottingham model = 0.70, 95% CI 0.68 to 0.75). Both models defined similar ranges of predicted mortality risk (1% to 18%) in assessment of calibration. Conclusions Both models have limitations in predicting mortality for individual patients after hip fracture surgery, but the NHFD risk adjustment model performed as well as the widely-used ­Nottingham prognostic tool and is therefore a reasonable alternative for risk adjustment in the United Kingdom hip fracture population

Development of in-situ trap characterisation techniques for EMCCDs

The "trap pumping" technique has seen considerable use over recent years as a means to probe the intrinsic properties of silicon defects that can impact charge transfer performance within CCD-based technologies. While the theory behind the technique is reasonably well understood, it has to date only been applied to relatively simple pixel designs where the motion of charge between pixel phases is fairly easy to predict. For some devices, the intrinsic pixel architecture is more complex and can consist of unequal phase sizes and additional implants that deform the electronic potential. Here, we present the implementation of the trap pumping technique for the CCD201-20, a 2-phase Teledyne e2v EMCCD. Clocking schemes are presented that can provide the location of silicon defects to sub-micron resolution. Experimental techniques that allow determination of trap energy levels and emission cross sections are presented. These are then implemented on an irradiated CCD201-20 to determine the energy level and emission cross section for defects thought to be the double acceptor state of the silicon divacancy (VV--) and carbon-phosphorus (CiPs) pairs. An improvement in charge transfer performance through optimised parallel clock delay is demonstrated and found to correlate with the properties of defects found using the trap pumping technique

Development of in-situ trap characterisation techniques for EMCCDs

The "trap pumping" technique has seen considerable use over recent years as a means to probe the intrinsic properties of silicon defects that can impact charge transfer performance within CCD-based technologies. While the theory behind the technique is reasonably well understood, it has to date only been applied to relatively simple pixel designs where the motion of charge between pixel phases is fairly easy to predict. For some devices, the intrinsic pixel architecture is more complex and can consist of unequal phase sizes and additional implants that deform the electronic potential. Here, we present the implementation of the trap pumping technique for the CCD201-20, a 2-phase Teledyne e2v EMCCD. Clocking schemes are presented that can provide the location of silicon defects to sub-micron resolution. Experimental techniques that allow determination of trap energy levels and emission cross sections are presented. These are then implemented on an irradiated CCD201-20 to determine the energy level and emission cross section for defects thought to be the double acceptor state of the silicon divacancy (VV--) and carbon-phosphorus (CiPs) pairs. An improvement in charge transfer performance through optimised parallel clock delay is demonstrated and found to correlate with the properties of defects found using the trap pumping technique

Allopatric diversification and evolutionary melting pot in a North African Palearctic relict: the biogeographic history of Salamandra algira

North Africa is a climatically and topographically complex region with unique biotic assemblages resulting from the combination of multiple biogeographic realms. Here, we assess the role of climate in promoting intra-specific diversification in a Palearctic relict, the North African fire salamander, Salamandra algira, using a combination of phylogenetic and population genetic analyses, paleoclimatic modelling and niche overlap tests. We used mitochondrial DNA (Cyt-b), 9838 ddRADseq loci, and 14 microsatellite loci to characterize patterns of genetic diversity and population structure. Phylogenetic analyses recover two major clades, each including several lineages with mito-nuclear discordances suggesting introgressive patterns between lineages in the Middle Atlas, associated with a melting pot of genetic diversity. Paleoclimatic modelling identified putative climatic refugia, largely matching areas of high genetic diversity, and supports the role of aridity in promoting allopatric diversification associated with ecological niche conservatism. Overall, our results highlight the role of climatic microrefugia as drivers of populations’ persistence and diversification in the face of climatic oscillations in North Africa, and stress the importance of accounting for different genomic regions when reconstructing biogeographic processes from molecular markers