Tes perseptual motorik untuk anak usia 5-6 tahun

Penelitian dan pengembangan ini bertujuan untuk menghasilkan tes perseptual motorik untuk anak usia 5-6 tahun. Prosedur pengembangannya mengadaptasi model Borg and Gall, yaitu: (1) tahap studi pendahuluan dan perencanaan, (2) tahap pengembangan produk, (3) tahap validasi ahli, (4) tahap uji coba, dan (5) revisi produk. Subjek uji coba menggunakan 10 anak usia 5-6 tahun. Data yang digunakan dalam penelitian ini berupa data kuantitatif dan kualitatif. Data kuantitatif diperoleh dari hasil validasi draf tes perseptual motorik dan uji coba. Data kualitatif diperoleh dari hasil kuesioner yang berupa masukan dan saran dari para ahli materi dan praktisi. Instrumen pengumpulan data menggunakan pedoman kuesioner. Kuesioner digunakan untuk mendapatkan masukan dari para ahli materi dan praktisi. Produk dapat dikatakan dapat diterima dan digunakan harus dilakukan uji validitas dan reliabilitas. Uji validasi ahli materi berdasarkan validitas isi dan pengujian reliabilitas menggunakan reliabilitas pengamatan dengan Alpha Cronbach. Hasil produk yang dikembangkan menujukkan bahwa tes perseptual motorik untuk anak usia 5-6 tahun dapat diterima dan sesuai dengan aspek dalam unsur perseptual motorik. Hasil uji reliabilitas tes adalah 0,930. Perceptual Motor Test for Children Aged 5-6 Years Old Abstract This research and development aim to produce perceptual-motor tests for children aged 5-6 years. The development procedure is to adapt the Borg and Gall model, namely: (1) preliminary study and planning stages, (2) product development stage, (3) expert validation stage, (4) trial phase, and (5) product revision. The data used in this research are quantitative and qualitative data. Quantitative data were obtained from the results of the validation of the perceptual-motor test draft and trial test. Qualitative data were obtained from the results of the questionnaire in the form of input and advice from material experts and practitioners. Data collection instruments using questionnaire guidelines. The questionnaire was used to obtain input from material experts and practitioners. Products that can be said to be acceptable and used must be tested for validity and reliability. Material expert validation test based on content validity and reliability testing using observational reliability with Alpha Cronbach. The results of the product developed show that perceptual-motor tests for children aged 5-6 years are acceptable and in accordance with aspects in the perceptual-motor element. The reliability test results are 0.930.

The cochlear outer hair cell speed paradox

Cochlear outer hair cells (OHCs) are among the fastest known biological motors and are essential for high-frequency hearing in mammals. It is commonly hypothesized that OHCs amplify vibrations in the cochlea through cycle-by-cycle changes in length, but recent data suggest OHCs are low-pass filtered and unable to follow high-frequency signals. The fact that OHCs are required for high-frequency hearing but appear to be throttled by slow electromotility is the “OHC speed paradox.” The present report resolves this paradox and reveals origins of ultrafast OHC function and power output in the context of the cochlear load. Results demonstrate that the speed of electromotility reflects how fast the cell can extend against the load, and does not reflect the intrinsic speed of the motor element itself or the nearly instantaneous speed at which the coulomb force is transmitted. OHC power output at auditory frequencies is revealed by emergence of an imaginary nonlinear capacitance reflecting the phase of electrical charge displacement required for the motor to overcome the viscous cochlear load.

Controlling motor neurons of every muscle for fly proboscis reaching

We describe the anatomy of all the primary motor neurons in the fly proboscis and characterize their contributions to its diverse reaching movements. Pairing this behavior with the wealth of Drosophila’s genetic tools offers the possibility to study motor control at single-neuron resolution, and soon throughout entire circuits. As an entry to these circuits, we provide detailed anatomy of proboscis motor neurons, muscles, and joints. We create a collection of fly strains to individually manipulate every proboscis muscle through control of its motor neurons, the first such collection for an appendage. We generate a model of the action of each proboscis joint, and find that only a small number of motor neurons are needed to produce proboscis reaching. Comprehensive control of each motor element in this numerically simple system paves the way for future study of both reflexive and flexible movements of this appendage.

The yeast dynein Dyn2-Pac11 complex is a dynein dimerization/processivity factor: structural and single-molecule characterization

Cytoplasmic dynein is the major microtubule minus end–directed motor. Although studies have probed the mechanism of the C-terminal motor domain, if and how dynein's N-terminal tail and the accessory chains it binds regulate motor activity remain to be determined. Here, we investigate the structure and function of the Saccharomyces cerevisiae dynein light (Dyn2) and intermediate (Pac11) chains in dynein heavy chain (Dyn1) movement. We present the crystal structure of a Dyn2-Pac11 complex, showing Dyn2-mediated Pac11 dimerization. To determine the molecular effects of Dyn2 and Pac11 on Dyn1 function, we generated dyn2Δ and dyn2Δpac11Δ strains and analyzed Dyn1 single-molecule motor activity. We find that the Dyn2-Pac11 complex promotes Dyn1 homodimerization and potentiates processivity. The absence of Dyn2 and Pac11 yields motors with decreased velocity, dramatically reduced processivity, increased monomerization, aggregation, and immobility as determined by single-molecule measurements. Deleting dyn2 significantly reduces Pac11-Dyn1 complex formation, yielding Dyn1 motors with activity similar to Dyn1 from the dyn2Δpac11Δ strain. Of interest, motor phenotypes resulting from Dyn2-Pac11 complex depletion bear similarity to a point mutation in the mammalian dynein N-terminal tail (Loa), highlighting this region as a conserved, regulatory motor element.