Targeted Optical Neural Stimulation: A New Era for Personalized Medicine

Targeted optical neural stimulation comprises infrared neural stimulation and optogenetics, which affect the nervous system through induced thermal transients and activation of light-sensitive proteins, respectively. The main advantage of this pair of optical tools is high functional selectivity, which conventional electrical stimulation lacks. Over the past 15 years, the mechanism, safety, and feasibility of optical stimulation techniques have undergone continuous investigation and development. When combined with other methods like optical imaging and high-field functional magnetic resonance imaging, the translation of optical stimulation to clinical practice adds high value. We review the theoretical foundations and current state of optical stimulation, with a particular focus on infrared neural stimulation as a potential bridge linking optical stimulation to personalized medicine.

Thermal Lens Technique as a Potential Optical Tool

The spectroscopic characterization of materials involves the use of various optical tools. Spectrometers, interferometers etc, are some of the examples of optical tools. Thermal lens technique is one of the potential optical tools for the thermal characterization of different materials. The thermal lens effect is a photothermal effect which results when energy from a laser beam is absorbed by a sample, causing heating of the sample along the beam path. In this paper an overview of thermal lensing, its significance as potential optical tool and its applications are discussed. Index Terms: Optical tool, Photothermal spectroscopy, TLS application, Thermal diffusivity

Desain augmented reality laboratory based implement optical physics sebagai media pembelajaran fisika

In the end of 2019, as a new period for the emergence of Corona Virus Disease 2019 (COVID-19) has made the world including Indonesia, limit movement in the social, economic, and even educational spheres. Indonesia has implemented PSBB (Large-Scale Social Restrictions) which resulted in activities such as being stopped working from being a WFH (Work From Home), and study from home. This learning media can help teachers to be more creative in delivering material so that it is not boring. Utilizing used goods as optical tools to make it easier for students to see objects or objects that are not necessarily visible to the eye. The purpose of this research is to develop learning media based on augmented reality, especially in the discussion of physics, namely optical tools that will make it easier for students during a pandemic, where physics practicum activities use used goods as a medium that will be made by students. Because, the pandemic has become an obstacle for students to carry out practical work directly in the laboratory.

PENGEMBANGAN PERANGKAT PEMBELAJARAN MODEL INKUIRI TERBIMBING PADA MATERI ALAT-ALAT OPTIK UNTUK MENINGKATKAN PENGUASAAN KONSEP FISIKA

ABSTRAKPerangkat pembelajaran merupakan bagian terpenting dalam proses pembelajaran, dimana proses pembelajaran berjalan efisien, efektif dan juga terstruktur karena adanya perangkat pembelajaran. Perangkat pembelajaran yang dikembangkan berupa perangkat pembelajaran model inkuiri terbimbing yang terdiri dari silabus, RPP, LKPD, instrument tes penguasaan konsep. Tujuan penelitian ini yaitu untuk mengembangkan perangkat pembelajaran fisika yang valid, efektif, dan efisien dengan menggunakan model inkuiri terbimbing pada materi alat-alat optik untuk meningkatkan penguasaan konsep. Penelitian ini menggunakan jenis penelitian Research and Development (R&D) dengan model 4D yang terdiri dari empat tahapan yaitu Define, Design, Develop, dan Disseminate. Perangkat yang dikembangkan pada penelitian ini adalah silabus, RPP, LKPD, dan instrumen tes penguasaan konsep. Kevalidan perangkat yang dikembangkan diperoleh berdasarkan penilaian angket dari enam validator yaitu tiga validator ahli dan tiga validator praktisi, kemudian kevalidan perangkat dianalisis dengan menggunakan skala Likert. Keefektifan perangkat diperoleh berdasarkan analisis lembar observasi keterlaksanaan RPP dari tiga orang observer yang kemudian ditentukan dengan menggunakan perhitungan Interjudge Agreement (IJA) dan perolehan nilai N-Gain. Selanjutnya, keefisienan perangkat didapatkan dari hasil uji coba terbatas pada peserta didik kelas XI yang kemudian ditentukan dari respon guru dan peserta didik. Maka dapat disimpulkan perangkat pembelajaran yang dikembangkan efektif. Terakhir, dari respon guru dan peserta didik didapatkan beberapa kendala dari pembelajaran yang telah dilakukan sehingga perangkat pembelajaran model inkuiri terbimbing kurang efisien untuk digunakan dalam pembelajaran. Kata Kunci : perangkat pembelajaran; inkuiri terimbing; penguasaan konsep ABSTRACTLearning tools are the most important part of the learning process, where the learning process runs efficiently, effectively and is structured because of the learning tools. The learning tools developed are in the form of guided inquiry learning models which are based on the syllabus, lesson plans, student worksheet, and concept mastery test instruments. The purpose of this research is to develop valid, effective, and efficient physics learning tools by using guided inquiry models on the material of optical tools to improve concept mastery. This study uses a Research and Development (R&D) type of research with a 4D model consisting of four stages, namely Define, Design, Develop, and Disseminate. The tools developed in this study were the syllabus, lesson plans, student worksheet, and concept mastery test instruments. The validity of the developed device was obtained based on a questionnaire assessment of six validators, namely three expert validators and three practitioner validators, then the validity of the devices was analyzed using a Likert scale. The effectiveness of the device was obtained based on the analysis of the RPP implementation observation sheet from three observers which was then determined using the calculation of the Interjudge Agreement (IJA) and the acquisition of the N-Gain value. Furthermore, the efficiency of the device was obtained from the limited trial results for class XI students which was then determined from the responses of the teacher and students. So it can be concluded that the learning tools developed are effective. Finally, from the responses of teachers and students, there are several obstacles from the learning that has been done so that the guided inquiry learning model is less efficient for use in learning. Key Word : Learning tools; guided inquiry learning; mastery of concepts

Chemosensory signal transduction in Caenorhabditis elegans

Chemosensory neurons translate perception of external chemical cues, including odorants, tastants, and pheromones, into information that drives attraction or avoidance motor programs. In the laboratory, robust behavioral assays, coupled with powerful genetic, molecular and optical tools, have made Caenorhabditis elegans an ideal experimental system in which to dissect the contributions of individual genes and neurons to ethologically relevant chemosensory behaviors. Here, we review current knowledge of the neurons, signal transduction molecules and regulatory mechanisms that underlie the response of C. elegans to chemicals, including pheromones. The majority of identified molecules and pathways share remarkable homology with sensory mechanisms in other organisms. With the development of new tools and technologies, we anticipate that continued study of chemosensory signal transduction and processing in C. elegans will yield additional new insights into the mechanisms by which this animal is able to detect and discriminate among thousands of chemical cues with a limited sensory neuron repertoire.

Cone mitochondria act as microlenses to enhance light delivery and confer Stiles-Crawford-like direction sensitivity

Sensory systems that efficiently transduce physical energy into neural signaling are advantageous for survival. The vertebrate retina poses a challenge to such efficiency, featuring an inverted structure with multiple neural layers through which photons must pass, risking premature absorption or scattering. Moreover, mammalian photoceptors aggregate an unusual amount of mitochondria in the ellipsoid region immediately before the light-sensitive outer segments (OS). While these mitochondria are required to support the high metabolic demands of phototransduction, it is yet unknown their impact on light transmission. Here we demonstrate via direct live-imaging and computational modeling that such tightly packed mitochondria concentrate light to enter the OS for detection. Intriguingly, this “microlens”-like feature of cone mitochondria delivers light with an angular dependence akin to the Stiles-Crawford effect, an essential visual phenomenon that improves resolution. We thus establish an unconventional optical function for cone mitochondria, energy-producing organelles, providing insight into their role in the interpretation of noninvasive optical tools for vision research and ophthalmology clinics.