A Conceptual Design of a General Aviation Hands-on-Throttle and Stick (HOTAS) System.

In this project the concept of Hands-on-Throttle and Stick (HOTAS) was applied to a general aviation (GA) aircraft. HOTAS had seen limited use in GA aircraft, but nothing that would compare to its use in military or commercial aircraft. The purpose of incorporating HOTAS was to give the pilot the ability to quickly and efficiently operate specific functions of the aircraft’s avionics units without having to remove his/her hands from the stick (or control wheel) or throttle. This project followed the systems engineering approach to accomplish the conceptual design of the GA HOTAS system. Two representative GA aircraft were chosen along with the avionics units to be controlled. In-flight functions of the units were determined and broken down into their most basic functions. Hardware was identified for each function, and the best alternative was chosen for each function. A control layout was achieved and then integrated into the aircraft’s existing controls. The project resulted in a conceptual GA HOTAS system that could be integrated into existing GA aircraft with existing avionics. Throughout the course of this project, the design proceeded with the needs and abilities of the pilot in mind. The HOTAS system was designed to be operable by pilots of various sizes and experience levels. The system was meant to be intuitive so that any pilot with experience in the aircraft’s avionics could operate it; however, training and experience with the system was also require

A Viscous Flow Analog to Prandtl’s Optimized Lifting Line Theory Utilizing Rotating Biquadratic Bodies of Revolution

Prandtl’s lifting line theory expanded the Kutta-Joukowski theorem to calculate the lift and induced drag of finite wings. The circulation distribution about a real wing was represented by a superposition of infinitesimal vortex filaments. From this theory, the optimum distribution of circulation was determined to be elliptical. A consequence of this theory led to the prediction that the elliptical chord distribution on a real fixed wing would provide the elliptical circulation distribution. The author applied the same line of reasoning to lift-producing rotating cylinders in order to determine the cylindrical geometry that would theoretically produce an elliptical circulation distribution. The resulting geometry was the biquadratic body of revolution (BBOR). Water tunnel testing was conducted to compare force coefficients and ratios between a lifting arrangement incorporating BBORs and a lifting arrangement incorporating a more traditional cylindrical arrangement, the constant diameter circular cylinder (CDCC). As directed by the Navier-Stokes equation, testing was conducted at low Re, 102 [100] ≤ Re ≤ 104 [10,000], where viscous effects would become more pronounced. Results showed the BBOR arrangement to produce the highest lift to drag ratio within specific ranges of α [alpha], surface velocity to free stream velocity. Lift coefficients were shown to increase with α [alpha] and approach values an order of magnitude larger than known fixed wing lift coefficients at low Re

A Bioinspired Modification for UAS Propeller/Rotor Noise Reduction

This projects presents a bioinspired modification to UAS propellers/rotors for noise reduction. Sound pressure levels (SPL) and thrust for modified propellers were compared to a baseline propeller. The bioinspired modification yielded lower SPL with a requisite increase in rpm in order to maintain a chosen level of thrust

Risk reduction and diversification in UK commercial property portfolios

The issue of diversification in direct real estate investment portfolios has been one of the most widely studied topics in academic and practitioner literature. Most work, however, has been done using mean returns and risks for broad market segments as inputs to asset allocation models, or in a few cases using data from small sets of individual properties. This paper reports results from a comprehensive testing of asset allocation modelling drawing on records of 10,000+ UK properties tracked by Investment Property Databank. It provides for the first time robust estimates of the diversification gains attainable given return, risk and cross-correlations across individual properties actually available to fund managers. The discussion of results covers implications for the number of assets and amount of money needed to construct “balanced” portfolios by direct investment, or via indirect specialist vehicles.Publisher PD

Textual enhancements and comprehension with adult readers of English is China

The present study utilizes texts from social psychology to examine the effects of textual enhancements on reading comprehension with 185 native adult Chinese speakers learning English in China. Participants read two different vignettes, either with or without an adjunct. Each adjunct consisted of a ‘what’ question along with instructions to either ‘pause and consider’ or ‘pause and write.’ Participants also completed written recall, sentence completion, multiple-choice, and a topic familiarity question. Across passages, findings revealed significant effects of passage version on comprehension as measured via recall and sentence completion and no significant effects of passage version on multiple-choice questions. Participants scored almost the same on recall and sentence completion for versions with no adjuncts and versions with ‘pause and consider’ adjuncts, and they scored significantly lower on these assessment tasks for the version with pause and write adjuncts. Participants scored the same on multiple-choice questions for all three versions of both passages

Polygenic risk-tailored screening for prostate cancer: A benefit-harm and cost-effectiveness modelling study.

BACKGROUND: The United States Preventive Services Task Force supports individualised decision-making for prostate-specific antigen (PSA)-based screening in men aged 55-69. Knowing how the potential benefits and harms of screening vary by an individual's risk of developing prostate cancer could inform decision-making about screening at both an individual and population level. This modelling study examined the benefit-harm tradeoffs and the cost-effectiveness of a risk-tailored screening programme compared to age-based and no screening. METHODS AND FINDINGS: A life-table model, projecting age-specific prostate cancer incidence and mortality, was developed of a hypothetical cohort of 4.48 million men in England aged 55 to 69 years with follow-up to age 90. Risk thresholds were based on age and polygenic profile. We compared no screening, age-based screening (quadrennial PSA testing from 55 to 69), and risk-tailored screening (men aged 55 to 69 years with a 10-year absolute risk greater than a threshold receive quadrennial PSA testing from the age they reach the risk threshold). The analysis was undertaken from the health service perspective, including direct costs borne by the health system for risk assessment, screening, diagnosis, and treatment. We used probabilistic sensitivity analyses to account for parameter uncertainty and discounted future costs and benefits at 3.5% per year. Our analysis should be considered cautiously in light of limitations related to our model's cohort-based structure and the uncertainty of input parameters in mathematical models. Compared to no screening over 35 years follow-up, age-based screening prevented the most deaths from prostate cancer (39,272, 95% uncertainty interval [UI]: 16,792-59,685) at the expense of 94,831 (95% UI: 84,827-105,630) overdiagnosed cancers. Age-based screening was the least cost-effective strategy studied. The greatest number of quality-adjusted life-years (QALYs) was generated by risk-based screening at a 10-year absolute risk threshold of 4%. At this threshold, risk-based screening led to one-third fewer overdiagnosed cancers (64,384, 95% UI: 57,382-72,050) but averted 6.3% fewer (9,695, 95% UI: 2,853-15,851) deaths from prostate cancer by comparison with age-based screening. Relative to no screening, risk-based screening at a 4% 10-year absolute risk threshold was cost-effective in 48.4% and 57.4% of the simulations at willingness-to-pay thresholds of GBP£20,000 (US$26,000) and £30,000 ($39,386) per QALY, respectively. The cost-effectiveness of risk-tailored screening improved as the threshold rose. CONCLUSIONS: Based on the results of this modelling study, offering screening to men at higher risk could potentially reduce overdiagnosis and improve the benefit-harm tradeoff and the cost-effectiveness of a prostate cancer screening program. The optimal threshold will depend on societal judgements of the appropriate balance of benefits-harms and cost-effectiveness

Heart failure care in low-and middle-income countries: a systematic review and meta-analysis

In a systematic review and meta-analysis, Kazem Rahimi and colleagues examine the burden of heart failure in low- and middle-income countries. Please see later in the article for the Editors' Summar

High-throughput bioprinting of the nasal epithelium using patient-derived nasal epithelial cells.

Progenitor human nasal epithelial cells (hNECs) are an essential cell source for the reconstruction of the respiratory pseudostratified columnar epithelium composed of multiple cell types in the context of infection studies and disease modeling. Hitherto, manual seeding has been the dominant method for creating nasal epithelial tissue models through biofabrication. However, this approach has limitations in terms of achieving the intricate three-dimensional (3D) structure of the natural nasal epithelium. 3D bioprinting has been utilized to reconstruct various epithelial tissue models, such as cutaneous, intestinal, alveolar, and bronchial epithelium, but there has been no attempt to use of 3D bioprinting technologies for reconstruction of the nasal epithelium. In this study, for the first time, we demonstrate the reconstruction of the nasal epithelium with the use of primary hNECs deposited on Transwell inserts via droplet-based bioprinting (DBB), which enabled high-throughput fabrication of the nasal epithelium in Transwell inserts of 24-well plates. DBB of progenitor hNECs ranging from one-tenth to one-half of the cell seeding density employed during the conventional cell seeding approach enabled a high degree of differentiation with the presence of cilia and tight-junctions over a 4 weeks air-liquid interface culture. Single cell RNA sequencing of these cultures identified five major epithelial cells populations, including basal, suprabasal, goblet, club, and ciliated cells. These cultures recapitulated the pseudostratified columnar epithelial architecture present in the native nasal epithelium and were permissive to respiratory virus infection. These results denote the potential of 3D bioprinting for high-throughput fabrication of nasal epithelial tissue models not only for infection studies but also for other purposes, such as disease modeling, immunological studies, and drug screening

Examining the epistemology of impact and success of educational interventions using a reflective case study of university bursaries

This paper engages with the continuing emphasis given to evidence-based policy and ‘what works’ approaches in educational research, highlighting some of the continuing epistemological challenges from a post-positivist perspective. To illustrate these, it uses the case of bursaries awarded by universities to improve outcomes for students from disadvantaged backgrounds as an example of an education intervention designed to address structural inequality. The paper then discusses critical reflections arising from a project commissioned by the Office for Fair Access in England, which aimed to enable universities to evaluate the impact of the bursaries that they award. These reflections provide a lens to explore the limitations of experimental and quasi-experimental designs in complex social fields. The paper concludes that we lack a strong understanding of the relationship between financial and educational disadvantage prior to and during higher education, and this undermines efforts to ‘prove’ that certain interventions will ‘level the playing field’

Optimal spatiotemporal scales to aggregate satellite ocean color data for nearshore reefs and tropical coastal waters: two case studies

Remotely sensed ocean color data are useful for monitoring water quality in coastal environments. However, moderate resolution (hundreds of meters to a few kilometers) satellite data are underutilized in these environments because of frequent data gaps from cloud cover and algorithm complexities in shallow waters. Aggregating satellite data over larger space and time scales is a common method to reduce data gaps and generate a more complete time series, but potentially smooths out the small-scale, episodic changes in water quality that can have ecological influences. By comparing aggregated satellite estimates of Kd(490) with related in-water measurements, we can understand the extent to which aggregation methods are viable for filling gaps while being able to characterize ecologically relevant water quality conditions. In this study, we tested a combination of six spatial and seven temporal scales for aggregating data from the VIIRS instrument at several coral reef locations in Maui, Hawai‘i and Puerto Rico and compared these with in situ measurements of Kd(490) and turbidity. In Maui, we found that the median value of a 5-pixels, 7-days spatiotemporal cube of satellite data yielded a robust result capable of differentiating observations across small space and time domains and had the best correlation among spatiotemporal cubes when compared with in situ Kd(490) across 11 nearshore sites (R2 = 0.84). We also found long-term averages (i.e., chronic condition) of VIIRS data using this aggregation method follow a similar spatial pattern to onshore turbidity measurements along the Maui coast over a three-year period. In Puerto Rico, we found that the median of a 13-pixels, 13-days spatiotemporal cube of satellite data yielded the best overall result with an R2 = 0.54 when compared with in situ Kd(490) measurements for one nearshore site with measurement dates spanning 2016–2019. As spatiotemporal cubes of different dimensions yielded optimum results in the two locations, we recommend local analysis of spatial and temporal optima when applying this technique elsewhere. The use of satellite data and in situ water quality measurements provide complementary information, each enhancing understanding of the issues affecting coastal ecosystems, including coral reefs, and the success of management efforts