Perception of Depth in Rotating Objects: 4. Fluctuating Stereokinetic Perceptual Variants

1968 ◽  
Vol 27 (1) ◽  
pp. 255-276 ◽  
Author(s):  
Roy B. Mefferd
Keyword(s):  
Steady State ◽  
Perceptual Organization ◽  
Phase 1 ◽  
Apparent Depth ◽  
Phase 2 ◽  
Basic System ◽  
Axis Of Rotation ◽  
Visual Systems ◽  
Processing Information ◽  
The One

There are a variety of stereokinetic percepts that fluctuate suddenly and unpredictably. On first viewing their sequence is predictable (Phase 1), but later it becomes unpredictable (Phase 2). A given percept results from the interplay of three independent visual systems: (1) the near-far mechanism (perspective reversals), (2) the one object-multiple object mechanism (degree of perceptual organization), and (3) the anchor point mechanism (apparent location of the axis of rotation). It was hypothesized that these fluctuating phenomena result from the operation of a basic system for repetitively sampling and pre-processing information on orientation, perceptual organization, and location of the axis of rotation and that a steady-state apparent-depth mechanism stabilizes the systems.

Evolution of the Slocan Syncline in south-central British Columbia

1968 ◽  
Vol 5 (4) ◽  
pp. 851-872 ◽  
Author(s):  
John V. Ross ◽  
P. Kellerhals
Keyword(s):  
British Columbia ◽  
Phase 1 ◽  
Granite Gneiss ◽  
Phase 2 ◽  
Phase 3 ◽  
The Core ◽  
South Central ◽  
Deformation Phase ◽  
Facies Metamorphism ◽  
The One

The Slocan Syncline, located in the center of the Kootenay Arc, south-central British Columbia, is outlined in its core by deformed Triassic sediments—the Slocan Group. These deformed sediments were originally deposited unconformably into a synform developed on the upward-facing limb of a recumbent, eastward-closing anticline, comprising Paleozoic and older rocks.The first phase of deformation resulted in the development of a recumbent anticline closing to the east. This anticline involved a sequence of rocks ranging in age from Windermere (late Precambrian—Horsethief Creek Group) up to Permian (Milford Group) and was originally developed along almost horizontal axes contained in an axial-plane having a shallow westerly dip. The core of this anticline contains granite gneiss, having a history pre-dating the deposition of the Horsethief Creek Group, which is in imbricate relation with the gneiss.Later, phase 2 deformation refolded this recumbent anticline into a synform and a westerly complementary antiform along shallow southeasterly axes contained within axial planes dipping southwesterly at about 45 degrees. Amphibolite-facies metamorphism (the "Shuswap Metamorphism") accompanied these phases of deformation and culminated in phase 2 time. Phase 1 and phase 2 deformation and metamorphism ate dated at post-Milford Group (Permian) and pre-Slocan Group (Triassic).Slocan Group (Triassic) sediments were deposited into the phase 2 synform, whose limbs consist of variable older rocks. A later non-metamorphic deformation, phase 3, along southeasterly striking axial planes dipping steeply to the northeast tightened the earlier phase 1 anticline and the phase 2 synform, and produced the Slocan Syncline. The Triassic sediments exhibit only phase 3 structures and are cut by the Nelson batholith dated at 171 × 106 years (Early Jurassic). Phase 3 deformation is then dated at post-Triassic and pre-Early Jurassic.Structural and stratigraphic evidence suggests that the phase 1 recumbent anticline herein described is but one of a set of nappes disposed structurally above and below the one presently described, and that the Kootenay Arc is an old structure perhaps resulting from interference of phase 1 and phase 2 deformations.

Fluctuations of Perceptual Organization and Orientation: Stochastic (Random) or Steady State (Satiation)?

1970 ◽  
Vol 31 (3) ◽  
pp. 739-749 ◽  
Author(s):  
Timothy G. Sadler ◽  
Roy B. Mefferd
Keyword(s):  
Steady State ◽  
Perceptual Organization ◽  
Fluctuation Phenomena ◽  
Published Data ◽  
Apparent Depth ◽  
Duration Data ◽  
Lateral Organization

Using flat drawings, intra-reversal times were obtained for two kinds of fluctuations, perspective reversals in a figure eliciting apparent depth and reversals of lateral organization in a figure not eliciting apparent depth. The durations of the alternate percepts (P1 and P2) between reversals early in a viewing session were compared with recently published data of the same type. In the latter study, P1 was found to be of longer duration than P2, both with a flat drawing and a rotating skeletal cube. These prior data were explained in terms of satiation theory; however, we found no significant differences between P1 and P2 with two different groups of Os and with two figures. Explanations for these differences in results were advanced. The use of grouped percept-duration data to support steady state (e.g., satiation) theories of perceptual fluctuation phenomena was criticized.

scholarly journals The identification of intermediates in the reaction of pig heart lactate dehydrogenase with its substrates

1974 ◽  
Vol 139 (3) ◽  
pp. 677-697 ◽  
Author(s):  
J. R. Whitaker ◽  
D. W. Yates ◽  
N. G. Bennett ◽  
J. J. Holbrook ◽  
H. Gutfreund
Keyword(s):  
Steady State ◽  
Lactate Dehydrogenase ◽  
Rate Constant ◽  
Active Sites ◽  
Phase 1 ◽  
Lactate Concentration ◽  
Phenol Red ◽  
Phase 2 ◽  
Protein Fluorescence ◽  
Rapid Formation

Pig heart lactate dehydrogenase was studied in the direction of pyruvate and NADH formation by recording rapid changes in extinction, proton concentration, nucleotide fluorescence and protein fluorescence. Experiments measuring extinction changes show that there is a very rapid formation of NADH within the first millisecond and that the amplitude of this phase (phase 1) increases threefold over the pH range 6–8. A second transient rate (phase 2) can also be distinguished (whose rate is pH-dependent), followed by a steady-state rate (phase 3) of NADH production. The sum of the amplitudes of the first two phases corresponds to 1mol of NADH produced/mol of active sites of lactate dehydrogenase. Experiments that measured the liberation of protons by using Phenol Red as an indicator show that no proton release occurs during the initial very rapid formation of NADH (phase 1), but protons are released during subsequent phases of NADH production. Fluorescence experiments help to characterize these phases, and show that the very rapid phase 1 corresponds to the establishment of an equilibrium between ENADLactate ⇌ H+ENADHPyruvate. This equilibrium can be altered by changing lactate concentration or pH, and the H+ENADHPyruvate species formed has very low nucleotide fluorescence and quenched protein fluorescence. Phase 2 corresponds to the dissociation of pyruvate and a proton from the complex with a rate constant of 1150s-1. The observed rate constant is slower than this and is proportional to the position of the preceding equilibrium. The ENADH formed has high nucleotide fluorescence and quenched protein fluorescence. The reaction, which is rate-limiting during steady-state turnover, must then follow this step and be involved with dissociation of NADH from the enzyme or some conformational change immediately preceding dissociation. Several inhibitory complexes have also been studied including ENAD+Oxamate and ENADHOxamate' and the abortive ternary complex ENADHLactate. The rate of NADH dissociation from the enzyme was measured and found to be the same whether measured by ligand displacement or by relaxation experiments. These results are discussed in relation to the overall mechanism of lactate dehydrogenase turnover and the independence of the four binding sites in the active tetramer.

Long-Term Memory of Pigeons for Stimulus-Outcome Associations Involving Multiple Stimuli, each Seen in a Single Brief Trial

1992 ◽  
Vol 45 (2b) ◽  
pp. 81-98 ◽  
Author(s):  
Euan M. Macphail ◽  
Steve Reilly ◽  
Mark Good
Keyword(s):  
Recognition Memory ◽  
Phase 1 ◽  
Cycle Phase ◽  
Long Term Memory ◽  
Phase 2 ◽  
Phase 3 ◽  
Term Memory ◽  
The One ◽  
High Level

Experiment 1 explored performance of pigeons in two versions of a shortterm recognition memory procedure. In one version responding to entirely novel slides was rewarded, and responding to familiar slides (slides seen once, for 10 sec) was not rewarded; in the other version, responding to familiar slides was rewarded. Performance was initially below chance in both versions of the procedure. This result indicated that in this procedure associations were formed between the slides and the outcome (reward or non-reward) that followed their presentation. The result also suggested that the true capacity of pigeon recognition memory cannot be assessed using these procedures, as performance is inevitably disrupted by the bird's associative memory. The tendency of pigeons to form one-trial associations was exploited in Experiment 2. Phase 1 consisted of 16 two-session cycles: in Session 1 of each cycle, birds were shown 20 novel slides and were rewarded for responding to 10 of those slides; in Session 2, the same slides were shown again, with the same reinforcement contingencies. The birds showed significant overnight retention of the one-trial associations formed in Session 1 of each cycle. Phase 2 showed significant retention over periods of more than 20 days of associations involving 320 slides seen twice only. Phase 3 re-exposed for nine daily sessions one of the sets of 20 slides used in Phases 1 and 2; a high level of discrimination emerged rapidly and 4 (of 8) birds showed, by the end of training, no overlap in response rates to positive and negative slides. Comparative implications of the results are discussed.

On the relationship between gonadal development and response time to photostimulation of sticklebacks living under natural conditions and under constant short-day conditions for long periods of time

1989 ◽  
Vol 67 (1) ◽  
pp. 126-135 ◽  
Author(s):  
Bertha Baggerman
Keyword(s):  
Cell Activation ◽  
Gasterosteus Aculeatus ◽  
Response Times ◽  
Phase 1 ◽  
Late Summer ◽  
Gonadal Development ◽  
Phase 2 ◽  
Short Day ◽  
Two Phases ◽  
The One

In the threespine stickleback, Gasterosteus aculeatus L., gonadal development proceeds in two phases, each occurring in a different season. Phase 1 (spermatogenesis, endogenous vitellogenesis) begins in late summer and is completed during winter. Phase 2 (Leydig cell activation, exogenous vitellogenesis) does not start before late February and is completed in April; the breeding season lasts from April to August. These different developmental phases are also characterized by differences in response times to the stimulating influence of a long photoperiod, 16L:8D at 20 °C. As long as phase 1 was not complete, the response times (number of days until complete sexual maturity is attained) were longer than 34 ± 6 days in males and 33 ± 5 days in females. From the time phase 2 was initiated, the response times became progressively shorter. When sticklebacks were raised from the egg stage, or from within 3 months after hatching in an outdoor pond, under constant short-day conditions (8L:16D at 20 °C), only phase 1 was completed, whereas no development in phase 2 took place; the response times of these fish were comparable to those given above. Only small numbers of these short-day animals attained maturity spontaneously under the experimental photoperiod. The fish matured in June and July of the year following the one in which they hatched in June. These results suggest an endogenous annual reproductive rhythm.

Rationalization and internalization

2001 ◽  
Vol 60 (4) ◽  
pp. 215-230 ◽  
Author(s):  
Jean-Léon Beauvois
Keyword(s):  
Phase 1 ◽  
Facilitatory Effect ◽  
Phase 2 ◽  
Causal Explanations ◽  
Reduction Effect ◽  
Dissonance Reduction

After having been told they were free to accept or refuse, pupils aged 6–7 and 10–11 (tested individually) were led to agree to taste a soup that looked disgusting (phase 1: initial counter-motivational obligation). Before tasting the soup, they had to state what they thought about it. A week later, they were asked whether they wanted to try out some new needles that had supposedly been invented to make vaccinations less painful. Agreement or refusal to try was noted, along with the size of the needle chosen in case of agreement (phase 2: act generalization). The main findings included (1) a strong dissonance reduction effect in phase 1, especially for the younger children (rationalization), (2) a generalization effect in phase 2 (foot-in-the-door effect), and (3) a facilitatory effect on generalization of internal causal explanations about the initial agreement. The results are discussed in relation to the distinction between rationalization and internalization.

PENERAPAN MODEL QUANTUM LEARNING UNTUK MENINGKATKAN HASIL BELAJAR AUTOCAD SISWA KELAS X TEKNIK PEMESINAN SMK NEGERI 1 STABAT

2013 ◽  
Vol 5 (1) ◽  
Author(s):  
Abdul Hasan Saragih
Keyword(s):  
Positive Response ◽  
Phase 1 ◽  
First Grade ◽  
Learning Model ◽  
Second Phase ◽  
Phase 2 ◽  
Phase 3 ◽  
The Third ◽  
Third Phase ◽  
Quantum Learning

This classroom research was conducted on the autocad instructions to the first grade of mechinary class of SMK Negeri 1 Stabat aiming at : (1) improving the student’ archievementon autocad instructional to the student of mechinary architecture class of SMK Negeri 1 Stabat, (2) applying Quantum Learning Model to the students of mechinary class of SMK Negeri 1 Stabat, arising the positive response to autocad subject by applying Quantum Learning Model of the students of mechinary class of SMK Negeri 1 Stabat. The result shows that (1) by applying quantum learning model, the students’ achievement improves significantly. The improvement ofthe achievement of the 34 students is very satisfactory; on the first phase, 27 students passed (70.59%), 10 students failed (29.41%). On the second phase 27 students (79.41%) passed and 7 students (20.59%) failed. On the third phase 30 students (88.24%) passed and 4 students (11.76%) failed. The application of quantum learning model in SMK Negeri 1 Stabat proved satisfying. This was visible from the activeness of the students from phase 1 to 3. The activeness average of the students was 74.31% on phase 1,81.35% on phase 2, and 83.63% on phase 3. (3) The application of the quantum learning model on teaching autocad was very positively welcome by the students of mechinary class of SMK Negeri 1 Stabat. On phase 1 the improvement was 81.53% . It improved to 86.15% on phase 3. Therefore, The improvement ofstudent’ response can be categorized good.

In situ deteriorating patient simulation in general practice

2020 ◽  
Vol 70 (suppl 1) ◽  
pp. bjgp20X711425
Author(s):  
Joanna Lawrence ◽  
Petronelle Eastwick-Field ◽  
Anne Maloney ◽  
Helen Higham
Keyword(s):  
Life Support ◽  
Early Recognition ◽  
Phase 1 ◽  
Patient Simulation ◽  
Medical Emergency ◽  
Phase 2 ◽  
Action Plans ◽  
Integrated Simulation ◽  
Deteriorating Patient

BackgroundGP practices have limited access to medical emergency training and basic life support is often taught out of context as a skills-based event.AimTo develop and evaluate a whole team integrated simulation-based education, to enhance learning, change behaviours and provide safer care.MethodPhase 1: 10 practices piloted a 3-hour programme delivering 40 minutes BLS and AED skills and 2-hour deteriorating patient simulation. Three scenarios where developed: adult chest pain, child anaphylaxis and baby bronchiolitis. An adult simulation patient and relative were used and a child and baby manikin. Two facilitators trained in coaching and debriefing used the 3D debriefing model. Phase 2: 12 new practices undertook identical training derived from Phase 1, with pre- and post-course questionnaires. Teams were scored on: team working, communication, early recognition and systematic approach. The team developed action plans derived from their learning to inform future response. Ten of the 12 practices from Phase 2 received an emergency drill within 6 months of the original session. Three to four members of the whole team integrated training, attended the drill, but were unaware of the nature of the scenario before. Scoring was repeated and action plans were revisited to determine behaviour changes.ResultsEvery emergency drill demonstrated improved scoring in skills and behaviour.ConclusionA combination of: in situ GP simulation, appropriately qualified facilitators in simulation and debriefing, and action plans developed by the whole team suggests safer care for patients experiencing a medical emergency.

Clinical Drug Development for the Treatment of Pulmonary Arterial Hypertension: Collaboration With the Pharmaceutical Industry and Regulatory Agencies

2010 ◽  
Vol 9 (4) ◽  
pp. 214-219
Author(s):  
Robyn J. Barst
Keyword(s):  
Clinical Trials ◽  
Pulmonary Arterial Hypertension ◽  
Drug Development ◽  
Phase 1 ◽  
Preclinical Studies ◽  
Phase 2 ◽  
Phase 3 ◽  
Preclinical Testing ◽  
New Drug ◽  
Pulmonary Arterial

Drug development is the entire process of introducing a new drug to the market. It involves drug discovery, screening, preclinical testing, an Investigational New Drug (IND) application in the US or a Clinical Trial Application (CTA) in the EU, phase 1–3 clinical trials, a New Drug Application (NDA), Food and Drug Administration (FDA) review and approval, and postapproval studies required for continuing safety evaluation. Preclinical testing assesses safety and biologic activity, phase 1 determines safety and dosage, phase 2 evaluates efficacy and side effects, and phase 3 confirms efficacy and monitors adverse effects in a larger number of patients. Postapproval studies provide additional postmarketing data. On average, it takes 15 years from preclinical studies to regulatory approval by the FDA: about 3.5–6.5 years for preclinical, 1–1.5 years for phase 1, 2 years for phase 2, 3–3.5 years for phase 3, and 1.5–2.5 years for filing the NDA and completing the FDA review process. Of approximately 5000 compounds evaluated in preclinical studies, about 5 compounds enter clinical trials, and 1 compound is approved (Tufts Center for the Study of Drug Development, 2011). Most drug development programs include approximately 35–40 phase 1 studies, 15 phase 2 studies, and 3–5 pivotal trials with more than 5000 patients enrolled. Thus, to produce safe and effective drugs in a regulated environment is a highly complex process. Against this backdrop, what is the best way to develop drugs for pulmonary arterial hypertension (PAH), an orphan disease often rapidly fatal within several years of diagnosis and in which spontaneous regression does not occur?

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