Measurement of human pilot dynamic characteristics in flight simulation

Fast Fourier Transform (FFT) and Least Square Error (LSE) estimation techniques were applied to the problem of identifying pilot-vehicle dynamic characteristics in flight simulation. A brief investigation of the effects of noise, input bandwidth and system delay upon the FFT and LSE techniques was undertaken using synthetic data. Data from a piloted simulation conducted at NASA Ames Research Center was then analyzed. The simulation was performed in the NASA Ames Research Center Variable Stability CH-47B helicopter operating in fixed-basis simulator mode. The piloting task consisted of maintaining the simulated vehicle over a moving hover pad whose motion was described by a random-appearing sum of sinusoids. The two test subjects used a head-down, color cathode ray tube (CRT) display for guidance and control information. Test configurations differed in the number of axes being controlled by the pilot (longitudinal only versus longitudinal and lateral), and in the presence or absence of an important display indicator called an 'acceleration ball'. A number of different pilot-vehicle transfer functions were measured, and where appropriate, qualitatively compared with theoretical pilot- vehicle models. Some indirect evidence suggesting pursuit behavior on the part of the test subjects is discussed

Prediction and measurement of human pilot dynamic characteristics in a manned rotorcraft simulation

An analytical and experimental study of the human pilot control strategies in a manned rotorcraft simulation is described. The task simulated involves a low-speed, constant-altitude maneuvering task in which a head-down display is utilized to allow the pilot to track a moving hover point. The efficacy of the display law driving an acceleration symbol is determined and the manner in which the prediction and measurement of pilot/vehicle dynamics can be made part of man/machine system evaluations is demonstrated

Beyond the clinical team: evaluating the human factors-oriented training of non-clinical professionals working in healthcare contexts

Background: As clinical simulation has evolved, it is increasingly used to educate staff who work in healthcare contexts (e.g. hospital administrators) or frequently encounter clinical populations as part of their work (e.g. police officers) but are not healthcare professionals. This is in recognition of the important role such individuals play in the patients’ experience of healthcare, frequently being a patients’ first point of contact with health services. The aim of the training is to improve the ability of the team to communicate and co-ordinate their actions, but there is no validated instrument to evaluate the human factors learning of non-clinical staff. Our aim was to develop, pilot and evaluate an adapted version of the Human Factors Skills for Healthcare Instrument, for non-clinical professionals. Method: The 18-item instrument was developed reflecting the human factors skills of situation awareness, decision making, communication, teamwork, leadership, care and compassion and stress and fatigue management. The instrument was piloted pre- and post-training with non-healthcare professionals (n = 188) attending mental health simulation training within an 11-month period (June 2017–April 2018). Trainees were hospital/primary care administrators (n = 53, 28%), police officers (n = 112, 59%), probation officers (n = 13, 7%) and social workers (n = 10, 5%). Most participants were female (n = 110, 59%) and from White ethnic backgrounds (n = 144, 77%). Results: Six items were removed, five were not sufficiently sensitive to change (d  .7). Cluster analysis revealed that participants with lower pre-training scores showed the greatest improvement. Discussion: The Human Factors Skills for Healthcare Instrument-Auxiliary version (HuFSHI-A) provides a reliable and valid instrument for the evaluation of human factors skills learning following training of non-clinical populations working in healthcare contexts. Although this instrument has been developed and evaluated with training courses specifically focusing on mental health topics, HuFSHI-A is applicable for any training where teamwork and co-ordination between clinical and non-clinical professionals is considered

Exposure History of Lunar Meteorites Queen Alexandra Range 93069 and 94269

Cosmic-ray produced C-14 (t(sub 1/2) = 5730 years), 36Cl (3.01 x 10(exp 5 years), Al-26 (7.05 x 10(exp 5 years), and Be-10 (1.5 x 10(exp 6 years) in the recently discovered lunar meteorites Queen Alexandra Range 93069 (QUE 93069) and 94269 (QUE 94269) were measured by accelerator mass spectrometry. The abundance pattern of these four cosmogenic radionuclides and of noble gases indicates QUE 93069 and QUE 94269 were a paired fall and were exposed to cosmic rays near the surface of the Moon for at least several hundred million years before ejection. After the meteorite was launched from the Moon, where it had resided at a depth of 65-80 g/cm square, it experienced a short transition time, approximately 20-50 ka, before colliding with the Earth. The terrestrial age of the meteorite is 5-10 ka. Comparison ofthe cosmogenic nuclide concentrations in QUE 93069/94269 and MAC 88104/88105 clearly shows that these meteorites were not ejected by a common event from the Moon

Electron Tomography of Cryofixed, Isometrically Contracting Insect Flight Muscle Reveals Novel Actin-Myosin Interactions

BACKGROUND: Isometric muscle contraction, where force is generated without muscle shortening, is a molecular traffic jam in which the number of actin-attached motors is maximized and all states of motor action are trapped with consequently high heterogeneity. This heterogeneity is a major limitation to deciphering myosin conformational changes in situ. METHODOLOGY: We used multivariate data analysis to group repeat segments in electron tomograms of isometrically contracting insect flight muscle, mechanically monitored, rapidly frozen, freeze substituted, and thin sectioned. Improved resolution reveals the helical arrangement of F-actin subunits in the thin filament enabling an atomic model to be built into the thin filament density independent of the myosin. Actin-myosin attachments can now be assigned as weak or strong by their motor domain orientation relative to actin. Myosin attachments were quantified everywhere along the thin filament including troponin. Strong binding myosin attachments are found on only four F-actin subunits, the "target zone", situated exactly midway between successive troponin complexes. They show an axial lever arm range of 77°/12.9 nm. The lever arm azimuthal range of strong binding attachments has a highly skewed, 127° range compared with X-ray crystallographic structures. Two types of weak actin attachments are described. One type, found exclusively in the target zone, appears to represent pre-working-stroke intermediates. The other, which contacts tropomyosin rather than actin, is positioned M-ward of the target zone, i.e. the position toward which thin filaments slide during shortening. CONCLUSION: We present a model for the weak to strong transition in the myosin ATPase cycle that incorporates azimuthal movements of the motor domain on actin. Stress/strain in the S2 domain may explain azimuthal lever arm changes in the strong binding attachments. The results support previous conclusions that the weak attachments preceding force generation are very different from strong binding attachments

Radioelements on Vesta: An Update

The main-belt asteroid 4 Vesta is the putative parent body of the howardite, eucrite, and diogenite (HED) meteorites. Because these achondrites have similar petrology, geochemistry, chronology, and O-isotope compositions, it is thought that most HEDs originated from a single parent body. The connection to Vesta is supported by a close spectroscopic match between Vesta and the HEDs and a credible mechanism for their delivery to Earth. Studies of the HEDs show that Vesta underwent igneous differentiation, forming a Fe-rich core, ultramafic mantle, and basaltic crust. Here we present the results of peak analyses applied to a gamma ray difference spectrum to determine the absolute abundances of K and Th. Data are compared to meteorite whole-rock compositions and other inner solar system bodies. The results, while preliminary, represent our present best estimates for these elements. Because the element signatures are near detection limits and not fully resolved, further analysis (e.g. using spectral unmixing) will be required for improved accuracy and to characterize systematic errors

Structural Changes in Isometrically Contracting Insect Flight Muscle Trapped following a Mechanical Perturbation

The application of rapidly applied length steps to actively contracting muscle is a classic method for synchronizing the response of myosin cross-bridges so that the average response of the ensemble can be measured. Alternatively, electron tomography (ET) is a technique that can report the structure of the individual members of the ensemble. We probed the structure of active myosin motors (cross-bridges) by applying 0.5% changes in length (either a stretch or a release) within 2 ms to isometrically contracting insect flight muscle (IFM) fibers followed after 5–6 ms by rapid freezing against a liquid helium cooled copper mirror. ET of freeze-substituted fibers, embedded and thin-sectioned, provides 3-D cross-bridge images, sorted by multivariate data analysis into ∼40 classes, distinct in average structure, population size and lattice distribution. Individual actin subunits are resolved facilitating quasi-atomic modeling of each class average to determine its binding strength (weak or strong) to actin. ∼98% of strong-binding acto-myosin attachments present after a length perturbation are confined to “target zones” of only two actin subunits located exactly midway between successive troponin complexes along each long-pitch helical repeat of actin. Significant changes in the types, distribution and structure of actin-myosin attachments occurred in a manner consistent with the mechanical transients. Most dramatic is near disappearance, after either length perturbation, of a class of weak-binding cross-bridges, attached within the target zone, that are highly likely to be precursors of strong-binding cross-bridges. These weak-binding cross-bridges were originally observed in isometrically contracting IFM. Their disappearance following a quick stretch or release can be explained by a recent kinetic model for muscle contraction, as behaviour consistent with their identification as precursors of strong-binding cross-bridges. The results provide a detailed model for contraction in IFM that may be applicable to contraction in other types of muscle

Prevention Of Xerophthalmia By Oral Massive Dose Vitamin A: (A Preliminary Report)

Untuk menilai efektivitas pemberian vitamin A dosis tinggi (200.000 IU vitamin A dan 40 IU vitamin E) secara masai dalam USAha pencegahan xerophthalmia, dilakukan penelitian terhadap seluruh anak umur 1-5 tahun di tujuh RK kotamadya Salatiga dan lima desa kabupaten Semarang, oleh suatu team ophthalmologi. Pada pemeriksaan awal ditemukan 132 penderita xerophthalmia diantara 2812 anak (4,7 persen). Kepada 2680 anak yang tidak menderita xerophthalmia sebagian diberi kapsul vitamin A dosis tinggi dan sebagian lain diberi kapsul placebo yang identik, secara "double-blind" diperiksa ulang sesudah enam bulan. Ternyata bahwa 7 diantara 1286 anak penerima vitamin A yang diperiksa (0,5 persen) menunjukkan tanda-tanda xerophthalmia. Sedang diantara 1183 anak penerima placebo yang diperiksa ternyata terdapat 43 penderita xerophthalmia (3,6 persen). Secara statistik bedanya amat bermakna. Tanda-tanda utama yang ditemukan adalah kombinasi dari buta-senja, xerosis conjunctiva, dan bercak Bitot. Kedua tanda yang terakhir ini terdapat pada 90 persen dari penderita, sedang buta-senja hanya 15 persen. Pada pemeriksaan ulang 132 anak penderita xerophthalmia yang telah diberi kapsul vitamin A dosis tinggi ternyata bahwa 91 persen dari yang diperiksa tidak lagi memperlihatkan tanda-tanda xerophthalmia. Jumlah anak yang tidak dapat diperiksa kembali jauh dibawah angka perkiraan. Sebagian besar karena telah pindah alamat, sebagian kecil meninggal. Antara golongan placebo dan vitamin, jumlah anak yang tidak dapat diperiksa kembali ini sama besar. Penelitian ini membuktikan bahwa kapsul vitamin A dosis tinggi efektip sekali untuk mencegah timbulnya xerophthalmia dan menyembuhkan gejala-gejala xerophthalmia ringan