A feasibility assessment of installation, operation and disposal options for nuclear reactor power system concepts for a NASA growth space station

A preliminary feasibility assessment of the integration of reactor power system concepts with a projected growth space station architecture was conducted to address a variety of installation, operational disposition, and safety issues. A previous NASA sponsored study, which showed the advantages of space station - attached concepts, served as the basis for this study. A study methodology was defined and implemented to assess compatible combinations of reactor power installation concepts, disposal destinations, and propulsion methods. Three installation concepts that met a set of integration criteria were characterized from a configuration and operational viewpoint, with end-of-life disposal mass identified. Disposal destinations that met current aerospace nuclear safety criteria were identified and characterized from an operational and energy requirements viewpoint, with delta-V energy requirement as a key parameter. Chemical propulsion methods that met current and near-term application criteria were identified and payload mass and delta-V capabilities were characterized. These capabilities were matched against concept disposal mass and destination delta-V requirements to provide the feasibility of each combination

Tests of Sample-recovery Models of Cued Recall

Sample-recovery models are a predominant class of episodic memory models that seek to explain why sometimes the representation of an experienced event is not retrieved or retrieved incorrectly. In these models, a correct retrieval occurs if the correct target item was sampled among the alternative studied item, then recovered correctly. In cued recall, participants output the representation of a single experienced event, a target, given a presented test stimulus and some defined relationship between the stimulus and the target. This relationship depends on the kind of cued recall and can rely on either studied or pre-experimental relationships. Sample-recovery models of this task share common testable properties related to both sampling and recovery, which we do across two experiments. Experiment 1 tests the property that sampling in sample-recovery models of cued recall is one process: they combine information about test stimulus and its relationship to the target into a single value and sample in a way consistent with the Luce choice rule. We test this assumption by testing whether manipulating the strengths of these relationships generates differential influence on performance in kinds of cued recall where different relationships between test stimulus and response are probed. The pattern of data is inconsistent with one sample process but is consistent with a sampling procedure that separately samples for a cue given the stimulus and a target given a cue. Experiment 2 tests the assumption that recovery performance is independent of other studied items. We allow some cue and target words to be related to some other untested studied words. Targets with a related word on the study list were associated with more correct responses than targets without one. This suggests that recovery in some way uses the memory for the other studied items to help retrieve. We consider how various models of sample-recovery may be adapted to account for these findings, with a particular focus on the Retrieving Effectively from Memory model

Tests Of Sample-recovery Models Of Cued Recall

Sample-recovery models are a predominant class of episodic memory models that seek to explain why sometimes the representation of an experienced event is not retrieved or retrieved incorrectly. In these models, a correct retrieval occurs if the correct target item was sampled among the alternative studied item, then recovered correctly. In cued recall, participants output the representation of a single experienced event, a target, given a presented test stimulus and some defined relationship between the stimulus and the target. This relationship depends on the kind of cued recall and can rely on either studied or pre-experimental relationships. Sample-recovery models of this task share common testable properties related to both sampling and recovery, which we do across two experiments. Experiment 1 tests the property that sampling in sample-recovery models of cued recall is one process: they combine information about test stimulus and its relationship to the target into a single value and sample in a way consistent with the Luce choice rule. We test this assumption by testing whether manipulating the strengths of these relationships generates differential influence on performance in kinds of cued recall where different relationships between test stimulus and response are probed. The pattern of data is inconsistent with one sample process but is consistent with a sampling procedure that separately samples for a cue given the stimulus and a target given a cue. Experiment 2 tests the assumption that recovery performance is independent of other studied items. We allow some cue and target words to be related to some other untested studied words. Targets with a related word on the study list were associated with more correct responses than targets without one. This suggests that recovery in some way uses the memory for the other studied items to help retrieve. We consider how various models of sample-recovery may be adapted to account for these findings, with a particular focus on the Retrieving Effectively from Memory model

Written information for patients (or parents of child patients) to reduce the use of antibiotics for acute upper respiratory tract infections in primary care

BackgroundAcute upper respiratory tract infections (URTIs) are frequently managed in primary care settings. Although many are viral, and there is an increasing problem with antibiotic resistance, antibiotics continue to be prescribed for URTIs. Written patient information may be a simple way to reduce antibiotic use for acute URTIs. ObjectivesTo assess if written information for patients (or parents of child patients) reduces the use of antibiotics for acute URTIs in primary care. Search methodsWe searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, Web of Science, clinical trials.gov, and the World Health Organization (WHO) trials registry up to July 2016 without language or publication restrictions. Selection criteriaWe included randomised controlled trials (RCTs) involving patients (or parents of child patients) with acute URTIs, that compared written patient information delivered immediately before or during prescribing, with no information. RCTs needed to have measured our primary outcome (antibiotic use) to be included. Data collection and analysisTwo review authors screened studies, extracted data, and assessed study quality. We could not meta-analyse included studies due to significant methodological and statistical heterogeneity; we summarised the data narratively. Main resultsTwo RCTs met our inclusion criteria, involving a total of 827 participants. Both studies only recruited children with acute URTIs (adults were not involved in either study): 558 children from 61 general practices in England and Wales; and 269 primary care doctors who provided data on 33,792 patient-doctor consultations in Kentucky, USA. The UK study had a high risk of bias due to lack of blinding and the US cluster-randomised study had a high risk of bias because the methods to allocate participants to treatment groups was not clear, and there was evidence of baseline imbalance. In both studies, clinicians provided written information to parents of child patients during primary care consultations: one trained general practitioners (GPs) to discuss an eight-page booklet with parents; the other conducted a factorial trial with two comparison groups (written information compared to usual care and written information plus prescribing feedback to clinicians compared to prescribing feedback alone). Doctors in the written information arms received 25 copies of two-page government-sponsored pamphlets to distribute to parents. Compared to usual care, we found moderate quality evidence (one study) that written information significantly reduced the number of antibiotics used by patients (RR 0.53, 95% CI 0.35 to 0.80; absolute risk reduction (ARR) 20% (22% versus 42%)) and had no significant effect on reconsultation rates (RR 0.79, 95% CI 0.47 to 1.32), or parent satisfaction with consultation (RR 0.95, 95% CI 0.87 to 1.03). Low quality evidence (two studies) demonstrated that written information also reduced antibiotics prescribed by clinicians (RR 0.47, 95% CI 0.28 to 0.78; ARR 21% (20% versus 41%); and RR 0.84, 95% CI 0.81 to 0.86; 9% ARR (45% versus 54%)). Neither study measured resolution of symptoms, patient knowledge about antibiotics for acute URTIs, or complications for this comparison. Compared to prescribing feedback, we found low quality evidence that written information plus prescribing feedback significantly increased the number of antibiotics prescribed by clinicians (RR 1.13, 95% CI 1.09 to 1.17; absolute risk increase 6% (50% versus 44%)). Neither study measured reconsultation rate, resolution of symptoms, patient knowledge about antibiotics for acute URTIs, patient satisfaction with consultation or complications for this comparison. Authors' conclusionsCompared to usual care, moderate quality evidence from one study showed that trained GPs providing written information to parents of children with acute URTIs in primary care can reduce the number of antibiotics used by patients without any negative impact on reconsultation rates or parental satisfaction with consultation. Low quality evidence from two studies shows that, compared to usual care, GPs prescribe fewer antibiotics for acute URTIs but prescribe more antibiotics when written information is provided alongside prescribing feedback (compared to prescribing feedback alone). There was no evidence addressing resolution of patients' symptoms, patient knowledge about antibiotics for acute URTIs, or frequency of complications. To fill evidence gaps, future studies should consider testing written information on antibiotic use for adults with acute URTIs in high- and low-income settings provided without clinician training and presented in different formats (such as electronic). Future study designs should endeavour to ensure blinded outcome assessors. Study aims should include measurement of the effect of written information on the number of antibiotics used by patients and prescribed by clinicians, patient satisfaction, reconsultation, patients' knowledge about antibiotics, resolution of symptoms, and complications.</p

Fabrication methods for creating flexible polymer substrate sensor tags

The authors describe the design, fabrication, and testing of a passive wireless sensor platform utilizing low-cost commercial surface acoustic wave filters and sensors. Polyimide and polyethylene terephthalate sheets are used as substrates to create a flexible sensor tag that can be applied to curved surfaces. A microfabricated antenna is integrated on the substrate in order to create a compact form factor. The sensor tags are fabricated using 315 MHz surface acoustic wave filters and photodiodes and tested with the aid of a fiber-coupled tungsten lamp. Microwave energy transmitted from a network analyzer is used to interrogate the sensor tag. Due to an electrical impedance mismatch at the SAW filter and sensor, energy is reflected at the sensor load and reradiated from the integrated antenna. By selecting sensors that change electrical impedance based on environmental conditions, the sensor state can be inferred through measurement of the reflected energy profile. Testing has shown that a calibrated system utilizing this type of sensor tag can detect distinct light levels wireless and passively. The authors also demonstrate simultaneous operation of two tags with different center passbands that detects light. Ranging tests show that the sensor tags can operate at a distance of at least 3.6 m