Recent Advances in Polymeric Materials Used as Electron Mediators and Immobilizing Matrices in Developing Enzyme Electrodes

Different classes of polymeric materials such as nanomaterials, sol-gel materials, conducting polymers, functional polymers and biomaterials have been used in the design of sensors and biosensors. Various methods have been used, for example from direct adsorption, covalent bonding, crossing-linking with glutaraldehyde on composites to mixing the enzymes or use of functionalized beads for the design of sensors and biosensors using these polymeric materials in recent years. It is widely acknowledged that analytical sensing at electrodes modified with polymeric materials results in low detection limits, high sensitivities, lower applied potential, good stability, efficient electron transfer and easier immobilization of enzymes on electrodes such that sensing and biosensing of environmental pollutants is made easier. However, there are a number of challenges to be addressed in order to fulfill the applications of polymeric based polymers such as cost and shortening the long laboratory synthetic pathways involved in sensor preparation. Furthermore, the toxicological effects on flora and fauna of some of these polymeric materials have not been well studied. Given these disadvantages, efforts are now geared towards introducing low cost biomaterials that can serve as alternatives for the development of novel electrochemical sensors and biosensors. This review highlights recent contributions in the development of the electrochemical sensors and biosensors based on different polymeric material. The synergistic action of some of these polymeric materials and nanocomposites imposed when combined on electrode during sensing is discussed

Validation and reliability of Filipino Colorado Learning Attitudes about Science Survey (CLASS)

Assessment is an essential aspect of effective instruction. Assessment of students\u27 performance, attitudes, perceptions, and others is observed using standard tests. In the Philippines, although the medium of instruction is English, most high school students show low competence in this subject. Thus, there is a strong possibility that their scores in assessments administered in English do not reflect the actual values. This study involves translating the Colorado Learning Attitude about Science Survey (CLASS), determining its psychometric properties, and identifying different factors that describe the students\u27 attitude towards learning Physics. CLASS was translated into the Filipino language using direct and conceptual translation. Filipino teachers and Physics experts validated this first version based on the translation\u27s semantics, grammar, and syntax. Another translation was done after the initial revision considering conceptual equivalence. After a successful pilot testing to 28 STEM- students of the final version, the Filipino CLASS was administered to 679 STEM students from representative public high schools in Metro Manila. Confirmatory factor analysis showed a difference in the structural model of original CLASS and Filipino CLASS. Further factor analysis identified a different factor model that would fit Filipino CLASS. The removal of non-categorical and non- correlational items finalized the factor model. The final structure model comprises four categories: Problem Solving- and Learning, Personal Interest and Real World Connection, Sense-Making/Effort, and Applied Conceptual Understanding. The result showed that the Filipino translation done in CLASS had different factors that affect students\u27 learning attitudes towards Physics

The Disconnect Between the Tuning of the Eardrum and the Brain in the Treefrog Litoria caerulea

Frogs rely on acoustic communication for mating but they tend to hear within a narrow frequency range. The tuning of their hearing matches that of their vocal folds, allowing for the reception of conspecific signals. Similarly, vibrations at the ear drum are maximal within the same frequencies as neurological data recorded from the midbrain. We measured the hearing performance of 10 male Indonesian White\u27s treefrogs (Litoria caerulea) at both ends of the auditory pathway (eardrums and brain). Using laser vibrometry, we quantified the tympanic membrane response to sound. We compared these data with neural responses recorded by a tungsten electrode in the torus semicircularis, within the optic lobe. We found that the eardrum’s peak response occurs around twice the frequency of the peak brain sensitivity, which is a closer match to the main frequency in the species’ call. These results were obtained with the same protocol that recently revealed a very close match in the tuning of calls, eardrums and brain of gray treefrogs (Hyla versicolor). We hypothesize that: 1) The larger females have their ears tuned to the male calls, but males remain out of tune for having both small body size and ears; 2) This species might produce an undocumented behavioral adjustment of tuning, which did not occur under anesthesia in our measurements

The Disconnect Between the Tuning of the Eardrum and the Brain in the Treefrog Litoria caerulea

Frogs rely on acoustic communication for mating but they tend to hear within a narrow frequency range. The tuning of their hearing matches that of their vocal folds, allowing for the reception of conspecific signals. Similarly, vibrations at the ear drum are maximal within the same frequencies as neurological data recorded from the midbrain. We measured the hearing performance of 10 male Indonesian White\u27s treefrogs (Litoria caerulea) at both ends of the auditory pathway (eardrums and brain). Using laser vibrometry, we quantified the tympanic membrane response to sound. We compared these data with neural responses recorded by a tungsten electrode in the torus semicircularis, within the optic lobe. We found that the eardrum’s peak response occurs around twice the frequency of the peak brain sensitivity, which is a closer match to the main frequency in the species’ call. These results were obtained with the same protocol that recently revealed a very close match in the tuning of calls, eardrums and brain of gray treefrogs (Hyla versicolor). We hypothesize that: 1) The larger females have their ears tuned to the male calls, but males remain out of tune for having both small body size and ears; 2) This species might produce an undocumented behavioral adjustment of tuning, which did not occur under anesthesia in our measurements

Título de la portada adicional: Simulacro ejecutado por la tropas que guarnecen el Distrito Militar de Galicia

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