Salient Phase Research Articles

Using the Art of Questioning as Classroom Assessment for Learning English in Pre-service Teaching

Practice teaching is a salient phase for students deployed in the real school settings while they pursue a degree from a Teacher Education Institution (TEI). This mixed-method research examined the types and levels of classroom questioning of pre-service teachers of elementary English in a TEI in Mindanao. It also explored their perceptions and practices in questioning anchored on Kolb's experiential learning theory. Through purposive sampling, 16 pre-service teachers taking-up Bachelor in English Education with certificate in teaching elementary participated in the study. Their actual classes were recorded and seven of them joined the 30-minute focus group discussion which was transcribed, translated, and analysed thematically. The identified questions were categorized according to the types of questions in classroom discourse and classified as to low and high levels through Bloom's Revised Taxonomy. Based on the findings, the types of questions were retrieval style and yes or no questions which belonged to low cognitive levels. The participants developed practices to mitigate the challenges of questioning as classroom assessment. A wider exploration to compare results with other pre-service programs in the focused TEI is recommended as the study had relevant implications to teacher development.

Using the Art of Questioning as Classroom Assessment for Learning English in Pre-service Teaching

Practice teaching is a salient phase for students deployed in the real school settings while they pursue a degree from a Teacher Education Institution (TEI). This mixed-method research examined the types and levels of classroom questioning of pre-service teachers of elementary English in a TEI in Mindanao. It also explored their perceptions and practices in questioning anchored on Kolb’s experiential learning theory. Through purposive sampling, 16 pre-service teachers taking-up Bachelor in English Education with certificate in teaching elementary participated in the study. Their actual classes were recorded and seven of them joined the 30-minute focus group discussion which was transcribed, translated, and analysed thematically. The identified questions were categorized according to the types of questions in classroom discourse and classified as to low and high levels through Bloom’s Revised Taxonomy. Based on the findings, the types of questions were retrieval style and yes or no questions which belonged to low cognitive levels. The participants developed practices to mitigate the challenges of questioning as classroom assessment. A wider exploration to compare results with other pre-service programs in the focused TEI is recommended as the study had relevant implications to teacher development.

Stability of bimanual finger tapping coordination is constrained by salient phases

In bimanual cyclical continuous movements, the relative timing of the most salient movement phase in each movement is a predominant constraint. This is the case for coordination when both movements have a single most salient phase (the relative-salience hypothesis). We tested whether the relative-salience hypothesis could explain results obtained for repetitive discrete movements, utilizing finger tapping. In experiment 1, participants performed unimanual alternate two-finger tapping with the metronome beat (i.e., one finger taps on the beat and the other finger taps off the beat). The stability of the tapping timing relative to the beat, which reflects the extent of salience, was higher in the index finger than the middle finger, and was lower in the ring finger than the middle finger. In experiment 2, participants performed four conditions of repetitive bimanual four-finger tapping (i.e., alternate two-finger tapping in each hand) without external pacing signals. Under all four conditions, a more stable pattern occurred when the timing of the more salient tapping in each hand was simultaneous rather than alternate, regardless of relative direction in the external space or movement coupling of the homologous fingers. The results indicated that bimanual four-finger tapping could be explained by the relative-salience hypothesis.

Efficient Synthesis of Asymmetric Miktoarm Star Polymers.

Asymmetric miktoarm star polymers comprising an unequal number of chemically-distinct blocks connected at a common junction produce unique material properties, yet existing synthetic strategies are beleaguered by complicated reaction schemes that are restricted in both monomer scope and yield. Here, we introduce a new synthetic approach coined "μSTAR" - Miktoarm Synthesis by Termination After Ring-opening metathesis polymerization - that circumvents these traditional synthetic limitations by constructing the block-block junction in a scalable, one-pot process involving (1) grafting-through polymerization of a macromonomer followed by (2) in-situ enyne-mediated termination to install a single mikto-arm with exceptional efficiency. This modular μSTAR platform cleanly generates AB n and A(BA') n miktoarm star polymers with unprecedented versatility in the selection of A and B chemistries as demonstrated using many common polymer building blocks: poly(siloxane), poly(acrylate), poly(methacrylate), poly(ether), poly(ester), and poly(styrene). The average number of B or BA' arms (n) is easily controlled by the molar equivalents of macromonomer relative to Grubbs catalyst in the initial ring-opening metathesis polymerization step. While these materials are characterized by dispersity in n that arises from polymerization statistics, they self-assemble into mesophases that are identical to those predicted for precise miktoarm stars as evidenced by small-angle X-ray scattering experiments and self-consistent field theory simulations. In summary, the μSTAR technique provides a significant boost in design flexibility and synthetic simplicity while retaining the salient phase behavior of precise miktoarm star materials.

A novel hybrid genetic algorithm to reduce the peak-to-average power ratio of OFDM signals

Orthogonal frequency division multiplexing (OFDM) is an effective approach for high rate data transmission in telecommunication systems. The high peak-to-average power ratio (PAPR) is one of the main drawbacks of the OFDM systems. Partial transmit sequence (PTS) is an efficient method to decrease the PAPR of OFDM signals. But, the PTS technique needs an exhaustive search over all combinations of phase rotation factors and the computational complexity grows exponentially with the number of sub-blocks. To reduce the search complexity, we introduce a novel hybrid genetic algorithm (HGA) in the PTS technique. The important aspect of the proposed method is the choice of salient phase factors to reduce the high PAPR. The proposed HGA-PTS approach incorporates novel local search operations that are designed and embedded in the genetic algorithm to explore the optimum phase factors. Numerical simulations are performed for 16-QAM modulated symbols and the obtained results show that the HGA-PTS significantly reduces both the PAPR and search complexity.

Reconstruction of chronic Achilles tendon rupture with Achilles tendon allograft

This study presented an extensive analysis of the influence of chord-to-thickness ratios on unsteady behaviors of the separated flow and their coupling with wall-pressure fluctuations at the Reynolds number ReD=1.58×104. Three systems with different chord-to-thickness ratios were chosen for comparison: L/D = 3.0, 6.0, and 9.0. The separated flow fields and wall-pressure fluctuations were measured using planar Particle Image Velocimetry (PIV) operating at 1 Hz and a microphone array sampling at 1 kHz, respectively. The distributions of the turbulent kinetic energy and the reverse-flow intermittency indicated that the shortest plate (L/D = 3.0) was subjected to full coverage of the separated flow. In the moderate system (L/D = 6.0), the time-averaged reattachment station was determined to be x/D = 4.75, while in 7% of all realizations the fluid close to the trailing edge surface remained slightly reversed due to the unsteady reattachment of the separated shear layer to the trailing edge and to irregular trailing edge vortex shedding. However, the separated flow always reattached on the plate’s surface in the longest system L/D = 9.0. The measured wall-pressure fluctuations demonstrated combinative influences of hydrodynamic pressure of the large-scale vortical structures above the plate and acoustic excitation propagated by the energetic unsteady wake. This resulted in the salient phase changeover characteristics of the correlative patterns near x/D = 1.5 in the shortest system, L/D = 3.0. Close to the leading edge, the wall-pressure fluctuations in the L/D = 6.0 system were over-exposed to acoustic excitation propagated by the unsteady wake behind the trailing edge, while in the longest system, L/D = 9.0, such influences were relatively attenuated. Proper Orthogonal Decomposition (POD) analysis was performed on the down-sampled wall-pressure fluctuations paired with the flow fields, resulting in a series of energetic flow structures and their corresponding wall-pressure fluctuation profiles. Subsequently, the conditional averaging technique was applied to determine the relationship between the spatial characteristics of the large-scale vortical structures and profiles of the wall-pressure fluctuations.

Separated flow over blunt plates with different chord-to-thickness ratios: Unsteady behaviors and wall-pressure fluctuations

This study presented an extensive analysis of the influence of chord-to-thickness ratios on unsteady behaviors of the separated flow and their coupling with wall-pressure fluctuations at the Reynolds number ReD=1.58×104. Three systems with different chord-to-thickness ratios were chosen for comparison: L/D=3.0, 6.0, and 9.0. The separated flow fields and wall-pressure fluctuations were measured using planar Particle Image Velocimetry (PIV) operating at 1Hz and a microphone array sampling at 1kHz, respectively. The distributions of the turbulent kinetic energy and the reverse-flow intermittency indicated that the shortest plate (L/D=3.0) was subjected to full coverage of the separated flow. In the moderate system (L/D=6.0), the time-averaged reattachment station was determined to be x/D=4.75, while in 7% of all realizations the fluid close to the trailing edge surface remained slightly reversed due to the unsteady reattachment of the separated shear layer to the trailing edge and to irregular trailing edge vortex shedding. However, the separated flow always reattached on the plate’s surface in the longest system L/D=9.0. The measured wall-pressure fluctuations demonstrated combinative influences of hydrodynamic pressure of the large-scale vortical structures above the plate and acoustic excitation propagated by the energetic unsteady wake. This resulted in the salient phase changeover characteristics of the correlative patterns near x/D=1.5 in the shortest system, L/D=3.0. Close to the leading edge, the wall-pressure fluctuations in the L/D=6.0 system were over-exposed to acoustic excitation propagated by the unsteady wake behind the trailing edge, while in the longest system, L/D=9.0, such influences were relatively attenuated. Proper Orthogonal Decomposition (POD) analysis was performed on the down-sampled wall-pressure fluctuations paired with the flow fields, resulting in a series of energetic flow structures and their corresponding wall-pressure fluctuation profiles. Subsequently, the conditional averaging technique was applied to determine the relationship between the spatial characteristics of the large-scale vortical structures and profiles of the wall-pressure fluctuations.

Analysis of Microstructural Changes in the Heat-Affected Zone and Fusion Zone of a Fiber Laser Welded DP980 Steel

Dual phase (DP) steels are designed to consist of hard martensite dispersed in a relatively soft ferrite matrix, which offers a favorable combination of high strength with good deformability. Fiber laser welding (FLW) is becoming increasingly important for joining advanced materials due to its flexibility and deep penetration. In this study, the microstructure of a DP steel, DP980, welded by FLW technique was carefully analyzed. Gleeble thermo-mechanical simulation coupled with analytical transmission electron microscopy revealed that the FLW process produced significant microstructural changes in a narrow heat-affected zone (HAZ) and fusion zone (FZ), which can result in dramatic changes in mechanical properties. This is reflected in the micro-hardness profile obtained across the welded material. The salient phase transitions induced by the FLW, including the formation of new martensite grains in the upper-critical HAZ and FZ, are discussed.

Activity enhancement in cyanation of aryl halides through confinement of ionic liquid in the nanospaces of SBA-15-supported Pd complex

A novel and practical ionic-liquid mediated route for the synthesis of various aromatic nitriles has been developed via the cyanation of aryl halides with K4[Fe(CN)6] as a low cost, non-toxic and easily handled cyanating reagent in the presence of SBA-15 functionalized palladium complex partially confined with ionic liquids (IL@SBA-15-Pd) as the catalyst. Among the various ionic liquids tested in the cyanation reaction, 1-butyl-3-methylimidazolium hexafluorophosphate was found to provide the best medium for Pd-catalyzed cyanation of aryl halides. A variety of electron-rich and electron-poor aryl iodides and bromides gave the corresponding benzonitrile derivatives in good yield. Moreover, the catalyst was reused in four consecutive cycles with consistent catalytic activity. It was found that the presence of ionic liquid in the mesochannels of the mesoporous support not only provides a means of stabilizing Pd nanoparticles during the reaction but also the salient phase transfer feature of the imidazolium moieties may also serve as handles for faster penetration of Fe(CN)63− into the system pores to achieve highly concentrated reaction sites in close proximity to the catalytic (Pd NPs) centers, which resulted in an enhancement of the catalyst activity performance.

Methods, markers and mechanisms for protective immunity in the controlled human malaria infection model

A unique tool to study malaria immunology and efficacy of immunization strategies form Controlled Human Malaria Infections (CHMI) and has proved to be a reproducible, predictable and safe method of inducing Plasmodium falciparum (Pf ) malaria. An efficient method for induction of complete protection in humans was achieved by us in a CHMI setting by exposing human subjects to Pf-infected mosquitoes while taking blood-stage suppressive chloroquine prophylaxis. When tested in clinical trials, this protocol induced clinical and parasitological protection against a standard homologous and heterologous CHMI. In addition, we showed that CPS-induced protection was long lasting and primarily mediated by immunity to sporozoite and liver stages rather than to asexual blood-stages. Cellular responses to Plasmodium falciparum parasites, in particular interferon-gamma (IFNγ) production, CD107a CD4 cells and Granzyme producing CD8 cells, play an important role in anti-malarial immunity. Our approach appears to utilize the Pf parasite’s clinically salient replicative phase of liver stage development to induce fully protective immune response against sporozoites and liver stages. It opens opportunities to explore mechanisms of protective immunity, allowing the search for immune correlates/signatures of protection and clinical development of a whole sporozoite based vaccine.

Lateralization of Huggins pitch

The Huggins pitch is a sensation of pitch generated from a broadband noise having a narrowband boundary region where the interaural phase difference varies rapidly as a function of frequency. Models of binaural hearing predict that the pitch image should be well lateralized. A direct psychophysical experimental method was used to estimate the lateral positions of Huggins pitch images with two different forms of phase boundaries, linear phase and stepped phase. A third experiment measured the lateral positions of sine tones with controlled interaural phase differences. The results showed that the lateralization of Huggins pitch stimuli was similar to that of the corresponding sine tones and that the lateralizations of the two forms of Huggins pitch phase boundaries were even more similar to one another. Both Huggins pitches and sine tones revealed strong laterality compression (exponent approximately 0.5). Ambiguous stimuli, with an interaural phase difference of 180 degrees , were consistently lateralized on one side or the other according to individual asymmetries-an effect called "earedness." An appendix to this article develops a new first-order lateralization model, the salient phase density model, which combines attributes of previous models of dichotic pitch lateralization.

Social Development: a Psychobiological Perspective

Social development from a psychobiological perspective is part of evolutionary biology. From a functional standpoint two major interrelated themes can be discerned in the evolution of behavior: Wanting (referring collectively to the vital needs of an organism) and Knowing (referring collectively to the organism's knowledge or skill for meeting its vital needs). The social development of the immature primate involves the integration of these themes in two distinct but overlapping phases. In the initially most salient phase, the manifestations of wanting and knowing are focused on constructing an effective relationship with the mother (mother-directed). One of the most important achievements during this phase is the formation of an emotional attachment (probably based on a psychoneuroendocrine core) to a specific object in which elements of both wanting and knowing are intimately involved. The second phase becomes increasingly prominent as development proceeds. The salient manifestations of this phase are focused on relations with the world beyond the mother (other-directed), and involve a new integration of the motivational and emotional components of wanting and knowing, characterized by attraction to novelty, exploration, social interaction and acquisition of knowledge and skills in the contexts of foods, predators and other members of the species.

Salient phase density model for the lateralization of binaural pitches

Binaural pitches are sensations of pitch generated from a broadband noise having a narrowband boundary region where the interaural phase difference varies rapidly as a function of frequency. These pitch sensations are perceived to be lateralized in the head. A binaural model, the Salient Phase Density model, has been derived to predict the lateralizations. The model begins by separating the boundary from the background. Because the boundary is narrow, the boundary components can be represented statistically by a density. Components of the boundary with phases similar to the background are discounted in the density as not salient. The density is then used to compute the cross-correlation function of the boundary region. The predicted lateralization is based on the interaural time difference of a template that best matches the cross-correlation of the boundary. The model was tested against psychoacoustical experiments using four types of Huggins pitch boundary-linear phase, stepped phase, uncorrelated phase, and π-shifted linear phase. The model was further tested against other binaural pitches: Binaural edge pitch and binaural coherence edge pitch. The experiments supported the model. [Work supported by the NIDCD, Grant No. DC00181.]

Planet(oid) core crystallisation and fractionation—evidence from the Agpalilik mass of the Cape York iron meteorite shower

Metallographic and chemical study of the Agpalilik mass (20 t) of the Cape York iron meteorite shower (totalling > 58 t), which belongs to the most populous group IIIAB, reveals evidence of the mode of crystallisation and fractionation of key elements consistent with a dentritic solidification of at least part of the once fully molten meteorite parent body metallic core. We assess systematic chemical gradients displayed by Ir and Au across an 85 cm section that is inferred to be perpendicular to the parent body gravitational field; these gradients are too large to be part of the fractionation resulting from the general fractional crystallisation radially outward of the IIIAB core. They are interpreted as representing a dendritic growth mode also explaining the characteristic elongated and orientated sulphide nodules found in Agpalilik and which signify trapped liquid of the late(st) stage(s) of crystallisation. Detailed mineralogic and chemical characterisation of the Agpalilik liquid-solid transformation products allow modelling of the entire crystallisation history commencing with dendritic metal precipitation through an ultimate troilite-taenite-Cu eutectic, representing a crystallisation range spanning approx. 1350-700°C. This constitutes a model system of the maximum potential fractionation of the parent body core, being a ‘telescoped’ forecasting of possible later events in the solidifying supernascent core pool. Adequate description of the salient phase relations requires the quaternary FeNiSP system; the essentials of the major element fractionation can be encompassed by the residual system FeNiS. Viewed as a study in analogo of possible ways of crystallisation-fractionation of the cores of other inner solar system bodies, a broader scope can be attached to these findings. Provided the case can be made for comparable chemistry with the modelled system, which is the case for most iron meteorite groups, for the Earth at least some evidence for a match is at hand, taking into consideration the inherent large ambient pressure differences. Some aspects of the present inner/outer core solidification/fractionation of the Earth's core would appear to be susceptible to interpretation within the confines of the principles of the present planet(oid) core crystallisation-fractionation model.