A portable neutron spectroscope (NSPECT) for detection, imaging and identification of nuclear material

We have developed, fabricated and tested a prototype imaging neutron spectrometer designed for real-time neutron source location and identification. Real-time detection and identification is important for locating materials. These materials, specifically uranium and transuranics, emit neutrons via spontaneous or induced fission. Unlike other forms of radiation (e.g. gamma rays), penetrating neutron emission is very uncommon. The instrument detects these neutrons, constructs images of the emission pattern, and reports the neutron spectrum. The device will be useful for security and proliferation deterrence, as well as for nuclear waste characterization and monitoring. The instrument is optimized for imaging and spectroscopy in the 1-20 MeV range. The detection principle is based upon multiple elastic neutron-proton scatters in organic scintillator. Two detector panel layers are utilized. By measuring the recoil proton and scattered neutron locations and energies, the direction and energy spectrum of the incident neutrons can be determined and discrete and extended sources identified. Event reconstruction yields an image of the source and its location. The hardware is low power, low mass, and rugged. Its modular design allows the user to combine multiple units for increased sensitivity. We will report the results of laboratory testing of the instrument, including exposure to a calibrated Cf-252 source. Instrument parameters include energy and angular resolution, gamma rejection, minimum source identification distances and times, and projected effective area for a fully populated instrument

Optical Breath Gas Extravehicular Activity Sensor for the Advanced Portable Life Support System

The infrared gas transducer used during extravehicular activity (EVA) in the extravehicular mobility unit (EMU) measures and reports the concentration of carbon dioxide (CO2) in the ventilation loop. It is nearing its end of life and there are a limited number remaining. Meanwhile, the next generation advanced portable life support system (PLSS) now being developed requires CO2 sensing technology with performance beyond that presently in use. A laser diode (LD) spectrometer based on wavelength modulation spectroscopy (WMS) is being developed to address both applications by Vista Photonics, Inc. Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. Version 1.0 devices were delivered to NASA Johnson Space Center (JSC) in 2011. The sensors incorporate a laser diode based CO2 channel that also includes an incidental water vapor (humidity) measurement. The prototypes are controlled digitally with a field-programmable gate array (FPGA)/microcontroller architecture. Version 2.0 devices with improved electronics and significantly reduced wetted volumes were delivered to JSC in 2012. A version 2.5 upgrade recently implemented wavelength stabilized operation, better humidity measurement, and much faster data analysis/reporting. A wholly reconfigured version 3.0 will maintain the demonstrated performance of earlier versions while being backwards compatible with the EMU and offering a radiation tolerant architecture

Forecasting Player Behavioral Data and Simulating in-Game Events

Understanding player behavior is fundamental in game data science. Video games evolve as players interact with the game, so being able to foresee player experience would help to ensure a successful game development. In particular, game developers need to evaluate beforehand the impact of in-game events. Simulation optimization of these events is crucial to increase player engagement and maximize monetization. We present an experimental analysis of several methods to forecast game-related variables, with two main aims: to obtain accurate predictions of in-app purchases and playtime in an operational production environment, and to perform simulations of in-game events in order to maximize sales and playtime. Our ultimate purpose is to take a step towards the data-driven development of games. The results suggest that, even though the performance of traditional approaches such as ARIMA is still better, the outcomes of state-of-the-art techniques like deep learning are promising. Deep learning comes up as a well-suited general model that could be used to forecast a variety of time series with different dynamic behaviors

Combined growth hormone and insulin-like growth factor 1 rescues growth retardation in glucocorticoid-treated mdx mice but does not prevent osteopenia

Short stature and osteoporosis are common in Duchenne muscular dystrophy (DMD) and its pathophysiology may include an abnormality of the growth hormone/insulin-like growth factor-1 (GH/IGF-1) axis, which is further exacerbated by long-term glucocorticoid (GC) treatment. Hence, an agent that has anabolic properties and may improve linear growth would be beneficial in this setting and therefore requires further exploration. A 5-week-old x-linked muscular dystrophy (mdx) mice were used as a model of DMD. They were treated with prednisolone ± GH + IGF-1 for 4 weeks and then compared to control mdx mice to allow the study of both growth and skeletal structure. GC reduced cortical bone area, bone fraction, tissue area and volume and cortical bone volume, as assessed by micro computed tomography (CT) In addition, GC caused somatic and skeletal growth retardation but improved grip strength. The addition of GH + IGF-1 therapy rescued the somatic growth retardation and induced additional improvements in grip strength (16.9% increase, P  < 0.05 compared to control). There was no improvement in bone microarchitecture (assessed by micro-CT and static histomorphometry) or biomechanical properties (assessed by three-point bending). Serum bone turnover markers (Serum procollagen 1 intact N-terminal propeptide (P1NP), alpha C-terminal telopeptide (αCTX)) also remained unaffected. Further work is needed to maximise these gains before proceeding to clinical trials in boys with DMD

Evaluating the effects of nacre on human skin and scar cells in culture

This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence.Pearl nacre, a biomineralisation product of molluscs, has growing applications in cosmetics, as well as dental and bone restoration, yet a systematic evaluation of its biosafety is lacking. Here, we assessed the biocompatibility of nacre with two human primary dermal fibroblast cell cultures and an immortalised epidermal cell line and found no adverse effects

Novel approaches to the development and assessment of an ovine model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common reproductive, endocrine and metabolic disorder present in women of reproductive age. Despite the widespread prevalence and heritability of PCOS, the heterogeneous and polygenic traits have made the successful identification of candidate genes difficult. Animal models have been developed on the premise that early exposure to sex steroids can programme epigenetic changes that predispose the fetus to the adult features of PCOS. Past research has modelled ovarian dysfunction, endocrine abnormalities and metabolic perturbances in rodent, non-human primate and sheep PCOS models, through the enhanced neonatal or prenatal exposure to the male sex hormone, testosterone. The modelling of PCOS in a large domestic species such as the sheep is advantageous due to similar biological reproductive function as the human. In this regard the sheep has been extensively used to model PCOS by the treatment of pregnant ewes from early to midgestation with androgens such as testosterone propionate (TP). These experiments have demonstrated the fetal programming effects of androgens on offspring that go on to develop PCOS-like characteristics in adulthood. One of the caveats of assessing steroid effects in this way is the effect of the placenta in mediating the transfer of these hormones. TP is an aromatisable androgen and thus some of its effects in the fetus may be attributable to placental by-products such as estrogens. This thesis describes the development and assessment of a novel model of prenatal androgenisation. Two models were compared: the indirect maternal exposure to TP (the current model) and the direct fetal injection of TP. In directly treating the fetus this allowed control over the dose of TP administered and avoidance of secondary effects that androgens may exert in the mother that could be transferred to the fetus. For the maternal model, pregnant Scottish Greyface ewes were administered TP twice weekly from day (d)62-102 of a 147 day gestation. For the fetal model, fetuses were injected twice while the ewe was anaesthetised with graded doses of TP during the same period of treatment as the maternal model. The effects of prenatal androgenisation were assessed in the female fetus shortly after treatment and also in young adult sheep. Fetal ovarian and adrenal steroidogenic gene expression was monitored and found to be altered in response to elevated levels of sex steroids. At d90 the morphology of the developing ovary was not changed by prenatal androgens. In the adult a detailed ovarian and endocrine assessment was undertaken, by examination of ovarian morphology, hormone levels, ovulatory cycles, hypothalamic pituitary ovarian function and follicle steroidogenesis, during the first breeding season. In addition, the metabolic effects of prenatal androgens were monitored by measuring body fat, insulin and glucose homeostasis and liver function. Neither maternal nor fetal prenatal androgenisation during mid-gestation resulted in a perturbed hormonal milieu or polycystic ovaries in young adults. These treatments did however programme a clear ovarian phenotype demonstrated by the increased capacity of follicles to secrete androgens, independently of an abnormal endocrine environment and disordered folliculogenesis. Furthermore, animals that were exposed maternally to TP developed fatty liver and had increased insulin secretion in response to glucose load. A major outcome of this study was the finding that the fetally injected control animals were phenotypically different than the maternal control animals. In fact, some of the reproductive and metabolic features of maternal TP exposure were found in the fetal control group. This unexpected finding has raised the possibility that it is the fetal exposure to stress, that is secondary to elevated maternal androgens, rather than androgens per se that is responsible for at least some of the multitude of anomalies encountered in PCOS

The Thermal Electrical Conductivity Probe (TECP) for Phoenix

The Thermal and Electrical Conductivity Probe (TECP) is a component of the Microscopy, Electrochemistry, and Conductivity Analyzer (MECA) payload on the Phoenix Lander. TECP will measure the temperature, thermal conductivity and volumetric heat capacity of the regolith. It will also detect and quantify the population of mobile H2O molecules in the regolith, if any, throughout the polar summer, by measuring the electrical conductivity of the regolith, as well as the dielectric permittivity. In the vapor phase, TECP is capable of measuring the atmospheric H2O vapor abundance, as well as augment the wind velocity measurements from the meteorology instrumentation. TECP is mounted near the end of the 2.3 m Robotic Arm, and can be placed either in the regolith material or held aloft in the atmosphere. This paper describes the development and calibration of the TECP. In addition, substantial characterization of the instrument has been conducted to identify behavioral characteristics that might affect landed surface operations. The greatest potential issue identified in characterization tests is the extraordinary sensitivity of the TECP to placement. Small gaps alter the contact between the TECP and regolith, complicating data interpretation. Testing with the Phoenix Robotic Arm identified mitigation techniques that will be implemented during flight. A flight model of the instrument was also field tested in the Antarctic Dry Valleys during the 2007-2008 International Polar year.

COVID-19-exploring the implications of long-term condition type and extent of multimorbidity on years of life lost : a modelling study

Grant Information: David A. McAllister is wholly supported via an intermediate clinical fellowship from the Wellcome Trust (201492). Peter Hanlon is funded through a Clinical Research Training Fellowship from the Medical Research Council (MR/S021949/1).Background: COVID-19 is responsible for increasing deaths globally. As most people dying with COVID-19 are older with underlying long-term conditions (LTCs), some speculate that YLL are low. We aim to estimate YLL attributable to COVID-19, before and after adjustment for number/type of LTCs, using the limited data available early in the pandemic. Methods: We first estimated YLL from COVID-19 using WHO life tables, based on published age/sex data from COVID-19 deaths in Italy. We then used aggregate data on number/type of LTCs in a Bayesian model to estimate likely combinations of LTCs among people dying with COVID-19. We used routine UK healthcare data from Scotland and Wales to estimate life expectancy based on age/sex/these combinations of LTCs using Gompertz models from which we then estimate YLL. Results: Using the standard WHO life tables, YLL per COVID-19 death was 14 for men and 12 for women. After adjustment for number and type of LTCs, the mean YLL was slightly lower, but remained high (11.6 and 9.4 years for men and women, respectively). The number and type of LTCs led to wide variability in the estimated YLL at a given age (e.g. at ≥80 years, YLL was >10 years for people with 0 LTCs, and <3 years for people with ≥6). Conclusions: Deaths from COVID-19 represent a substantial burden in terms of per-person YLL, more than a decade, even after adjusting for the typical number and type of LTCs found in people dying of COVID-19. The extent of multimorbidity heavily influences the estimated YLL at a given age. More comprehensive and standardised collection of data (including LTC type, severity, and potential confounders such as socioeconomic-deprivation and care-home status) is needed to optimise YLL estimates for specific populations, and to understand the global burden of COVID-19, and guide policy-making and interventions.Peer reviewe

Open conversion in laparoscopic cholecystectomy and bile duct exploration: subspecialisation safely reduces the conversion rates

Background: Open conversion rates during laparoscopic cholecystectomy vary depending on many factors. Surgeon experience and operative difficulty influence the decision to convert on the grounds of patient safety but occasionally due to technical factors. We aim to evaluate the difficulties leading to conversion, the strategies used to minimise this event and how subspecialisation influenced conversion rates over time. Methods: Prospectively collected data from 5738 laparoscopic cholecystectomies performed by a single surgeon over 28 years was analysed. Routine intraoperative cholangiography and common bile duct exploration when indicated are utilised. Patients undergoing conversion, fundus first dissection or subtotal cholecystectomy were identified and the causes and outcomes compared to those in the literature. Results: 28 patients underwent conversion to open cholecystectomy (0.49%). Morbidity was relatively high (33%). 16 of the 28 patients (57%) had undergone bile duct exploration. The most common causes of conversion in our series were dense adhesions (9/28, 32%) and impacted bile duct stones (7/28, 25%). 173 patients underwent fundus first cholecystectomy (FFC) (3%) and 6 subtotal cholecystectomy (0.1%). Morbidity was 17.3% for the FFC and no complications were encountered in the subtotal cholecystectomy patients. These salvage techniques have reduced our conversion rate from a potential 3.5% to 0.49%. Conclusion: Although open conversion should not be seen as a failure, it carries a high morbidity and should only be performed when other strategies have failed. Subspecialisation and a high emergency case volume together with FFC and subtotal cholecystectomy as salvage strategies can reduce conversion and its morbidity in difficult cholecystectomies