2,290 research outputs found
Knockout of lysosomal enzyme-targeting gene causes abnormalities in mouse pup isolation calls
Humans lacking a working copy of the GNPTAB gene suffer from the metabolic disease Mucolipidosis type II (MLII). MLII symptoms include mental retardation, skeletal deformities and cartilage defects as well as a speech delay with most subjects unable to utter single words (Otomo et al., 2009; Cathey et al., 2010; Leroy et al., 2012). Here we asked whether mice lacking a copy of Gnptab gene exhibited vocal abnormities. We recorded ultrasonic vocalizations from 5 to 8 day old mice separated from their mother and littermates. Although Gnptab(−/−) pups emitted a similar number of calls, several features of the calls were different from their wild type littermates. Gnptab(−/−) mice showed a decrease in the length of calls, an increase in the intra-bout pause duration, significantly fewer pitch jumps with smaller mean size, and an increase in the number of isolated calls. In addition, Gnptab(−/−) mice vocalizations had less power, particularly in the higher frequencies. Gnptab(+/−) mouse vocalizations did not appear to be affected. We then attempted to classify these recordings using these features to determine the genotype of the animal. We were able to correctly identify 87% of the recordings as either Gnptab(−/−) or Gnptab(+/+) pup, significantly better than chance, demonstrating that genotype is a strong predictor of vocalization phenotype. These data show that deletion of genes in the lysosomal enzyme targeting pathway affect mouse pup isolation calls
A synchrotron study of Ba5Ta2Cl2O9
The structure of pentabarium ditantalum dichloride nonaoxide, Ba5Ta2Cl2O9, is isotypic with Ba5Ru1.6W0.4Cl2O9 and with one polymorph of Ba5Ru2Cl2O9. It is related to the perovskite structure and shows a ten-layer stacking of BaO3 and BaCl blocks along the c axis. The Ta cations occupy octahedral interstices, forming Ta2O9 dimers of distorted face-shared TaO6 octahedra. Except for one O atom, all atoms are situated on special positions: Ba1 (Wyckoff position (6) over bar m2), Ba2 and Ba3 (3m.), Ta (3m.), Cl (3m.) and O1 (mm2)
Information Management to Mitigate Loss of Control Airline Accidents
Loss of control inflight continues to be the leading contributor to airline accidents worldwide and unreliable airspeed has been a contributing factor in many of these accidents. Airlines and the FAA developed training programs for pilot recognition of these airspeed events and many checklists have been designed to help pilots troubleshoot. In addition, new aircraft designs incorporate features to detect and respond in such situations. NASA has been using unreliable airspeed events while conducting research recommended by the Commercial Aviation Safety Team. Even after significant industry focus on unreliable airspeed, research and other evidence shows that highly skilled and trained pilots can still be confused by the condition and there is a lack of understanding of what the associated checklist(s) attempts to uncover. Common mode failures of analog sensors designed for measuring airspeed continue to confound both humans and automation when determining which indicators are correct. This paper describes failures that have occurred in the past and where/how pilots may still struggle in determining reliable airspeed when confronted with conflicting information. Two latest generation aircraft architectures will be discussed and contrasted. This information will be used to describe why more sensors used in classic control theory will not solve the problem. Technology concepts are suggested for utilizing existing synoptic pages and a new synoptic page called System Interactive Synoptic (SIS). SIS details the flow of flight critical data through the avionics system and how it is used by the automation. This new synoptic page as well as existing synoptics can be designed to be used in concert with a simplified electronic checklist (sECL) to significantly reduce the time to configure the flight deck avionics in the event of a system or sensor failure
Evaluation of Technology Concepts for Energy, Automation, and System State Awareness in Commercial Airline Flight Decks
A pilot-in-the-loop flight simulation study was conducted at NASA Langley Research Center to evaluate flight deck systems that (1) provide guidance for recovery from low energy states and stalls, (2) present the current state and expected future state of automated systems, and/or (3) show the state of flight-critical data systems in use by automated systems and primary flight instruments. The study was conducted using 13 commercial airline crews from multiple airlines, paired by airline to minimize procedural effects. Scenarios spanned a range of complex conditions and several emulated causal and contributing factors found in recent accidents involving loss of state awareness by pilots (e.g., energy state, automation state, and/or system state). Three new technology concepts were evaluated while used in concert with current state-of-the-art flight deck systems and indicators. The technologies include a stall recovery guidance algorithm and display concept, an enhanced airspeed control indicator that shows when automation is no longer actively controlling airspeed, and enhanced synoptic pages designed to work with simplified interactive electronic checklists. An additional synoptic was developed to provide the flight crew with information about the effects of loss of flight critical data. Data was collected via questionnaires administered at the completion of flight scenarios, audio/video recordings, flight data, head and eye tracking data, pilot control inputs, and researcher observations. This paper presents findings derived from the questionnaire responses and subjective data measures including workload, situation awareness, usability, and acceptability as well as analyses of two low-energy flight events that resulted in near-stall conditions
Usability Evaluation of Indicators of Energy-Related Problems in Commercial Airline Flight Decks
A series of pilot-in-the-loop flight simulation studies were conducted at NASA Langley Research Center to evaluate indicators aimed at supporting the flight crews awareness of problems related to energy states. Indicators were evaluated utilizing state-of-the-art flight deck systems such as on commercial air transport aircraft. This paper presents results for four technologies: (1) conventional primary flight display speed cues, (2) an enhanced airspeed control indicator, (3) a synthetic vision baseline that provides a flight path vector, speed error, and an acceleration cue, and (4) an aural airspeed alert that triggers when current airspeed deviates beyond a specified threshold from the selected airspeed. Full-mission high-fidelity flight simulation studies were conducted using commercial airline crews. Crews were paired by airline for common crew resource management procedures and protocols. Scenarios spanned a range of complex conditions while emulating several causal factors reported in recent accidents involving loss of energy state awareness by pilots. Data collection included questionnaires administered at the completion of flight scenarios, aircraft state data, audio/video recordings of flight crew, eye tracking, pilot control inputs, and researcher observations. Questionnaire response data included subjective measures of workload, situation awareness, complexity, usability, and acceptability. This paper reports relevant findings derived from subjective measures as well as quantitative measures
Designing a Locally Manufacturable Wheelchair for Nepal
People with disabilities in developing countries often lack the basic equipment needed to assist them in their daily lives. International Nepal Fellowship (INF) is a Christian medical organization located in Nepal that provides medical care and assistance to people with disabilities and other conditions. Currently, INF imports expensive wheelchairs that undergo a prolonged border process before being received. INF has reached out to the Collaboratory to design a wheelchair that can withstand the challenges of Nepal’s terrain and can be manufactured from local materials. The Nepal Wheelchair team has set out to design a wheelchair that can fulfill their needs. In previous work, the team researched wheelchair designs and took a trip to Nepal. From this trip, more information was gained, an initial prototype was constructed, and locally available materials and parts from Nepal were brought back. This year, as a result of knowledge gained through constructing the second prototype, many design changes were tested and implemented. The team researched standards and created testing procedures to ensure the changes to the rear wheel mount, caster wheel mount, footrest, and seat design would uphold the strength and durability of the wheelchair. These design changes have enhanced patient safety and experience in the wheelchair while still keeping the design easily manufacturable. The team also researched options for adding push rims and through using a roller bender were able to construct them. Moving forward, the team will continue to finalize manufacturing documentation and take a second trip to Nepal this May.
Funding for this work provided by The Collaboratory for Strategic Partnerships and Applied Research.https://mosaic.messiah.edu/engr2022/1012/thumbnail.jp
Designing a Locally Manufacturable Wheelchair for Nepal
Persons with disabilities in developing countries often lack the basic equipment needed to assist them in their daily lives. International Nepal Fellowship (INF) is a Christian medical organization located in Nepal that provides medical care and assistance to people with disabilities and other conditions. Currently, INF imports expensive wheelchairs that undergo a prolonged border process before being received. INF has reached out to the Collaboratory to design a wheelchair that can withstand the challenges of Nepal’s terrain and can be manufactured from local materials. The Nepal Wheelchair team accepted this challenge and set out to design a wheelchair that can fulfill their needs. The team began by researching wheelchair models for inspiration and eventually settled on two preliminary designs. In January 2020, the team traveled to Pokhara, Nepal to gain feedback from the staff at INF and select a final design based on their comments. During this trip, the team acquired and brought back locally available materials and parts available in Nepal in order to construct a prototype. This year, prototyping has been completed for the following elements: the central frame, wheel lock, footrest, wheel mounting assemblies and armrest fixtures. As a result of knowledge gained during prototyping, some design changes to the wheelchair have been made. Moving forward, the team will test the overall prototype for durability and prepare a manufacturing manual for INF.https://mosaic.messiah.edu/engr2021/1010/thumbnail.jp
Characterizing the Cool KOIs II. The M Dwarf KOI-254 and its Hot Jupiter
We report the confirmation and characterization of a transiting gas giant
planet orbiting the M dwarf KOI-254 every 2.455239 days, which was originally
discovered by the Kepler mission. We use radial velocity measurements, adaptive
optics imaging and near infrared spectroscopy to confirm the planetary nature
of the transit events. KOI-254b is the first hot Jupiter discovered around an
M-type dwarf star. We also present a new model-independent method of using
broadband photometry to estimate the mass and metallicity of an M dwarf without
relying on a direct distance measurement. Included in this methodology is a new
photometric metallicity calibration based on J-K colors. We use this technique
to measure the physical properties of KOI-254 and its planet. We measure a
planet mass of Mp = 0.505 Mjup, radius Rp = 0.96 Rjup and semimajor axis a =
0.03 AU, based on our measured stellar mass Mstar = 0.59 Msun and radius Rstar
= 0.55 Rsun. We also find that the host star is metal-rich, which is consistent
with the sample of M-type stars known to harbor giant planets.Comment: AJ accepted (in press
A crossover randomised controlled trial of oral mandibular advancement devices for obstructive sleep apnoea-hypopnoea (TOMADO)
Rationale Mandibular advancement devices (MADs)
are used to treat obstructive sleep apnoea-hypopnoea
syndrome (OSAHS) but evidence is lacking regarding
their clinical and cost-effectiveness in less severe disease.
Objectives To compare clinical- and cost-effectiveness
of a range of MADs against no treatment in mild to
moderate OSAHS.
Measurements and methods This open-label,
randomised, controlled, crossover trial was undertaken at
a UK sleep centre. Adults with Apnoea-Hypopnoea Index
(AHI) 5–<30/h and Epworth Sleepiness Scale (ESS) score
≥9 underwent 6 weeks of treatment with three nonadjustable
MADs: self-moulded (SleepPro 1; SP1);
semi-bespoke (SleepPro 2; SP2); fully-bespoke MAD
(bMAD); and 4 weeks no treatment. Primary outcome
was AHI scored by a polysomnographer blinded to
treatment. Secondary outcomes included ESS, quality of
life, resource use and cost.
Main results 90 patients were randomised and 83
were analysed. All devices reduced AHI compared with
no treatment by 26% (95% CI 11% to 38%, p=0.001)
for SP1, 33% (95% CI 24% to 41%) for SP2 and 36%
(95% CI 24% to 45%, p<0.001) for bMAD. ESS was
1.51 (95% CI 0.73 to 2.29, p<0.001, SP1) to 2.37
(95% CI 1.53 to 3.22, p<0.001, bMAD) lower than no
treatment (p<0.001 for all). Compliance was lower for
SP1, which was the least preferred treatment at trial exit.
All devices were cost-effective compared with no
treatment at a £20 000/quality-adjusted life year (QALY)
threshold. SP2 was the most cost-effective up to
£39 800/QALY.
Conclusions Non-adjustable MADs achieve clinically
important improvements in mild to moderate OSAHS and
are cost-effective
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