The Status Of Content Revisited

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138325/1/papq00404.pd

Perception and satisfaction level of students regarding the teaching practices during the COVID-19 pandemic

The COVID-19 pandemic caused an unanticipated shift in the way classes were delivered. Institutions moved towards online teaching as the only way to provide lectures and laboratory work. Both instructors and students had to quickly adapt to this challenging change. The objective of this study was to examine students’ perspectives and levels of satisfaction in food-related majors regarding the teaching practices adopted. A questionnaire was created and distributed through professional networks and universities that offer food-related degrees worldwide. Participants were asked to rate their degree of satisfaction with virtual classes through a five-point Likert scale ranging from 1 «strongly disagree», 2 «disagree», 3 «neither agree nor disagree», 4 «agree» to 5 «strongly agree». Out of 388 student participants, about 49% were satisfied with the general formats of their online classes. Completing a discipline remotely took more effort than if it was taught in a face-to-face modality was felt by 66% of participants, and 56% were not motivated to attend the online classes. About 34% believed that remote learning would negatively affect their professional future, whilst 24% alleged the opposite. Additionally, about 52% of students shared that it would be better for some disciplines to be remotely taught in the future.info:eu-repo/semantics/publishedVersio

An engineering analysis of natural and biomimetic self-repair processes for solar energy harvesting

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 191-201).Plants have evolved highly sophisticated mechanisms of self-repair to regenerate proteins that become photo-damaged over time. Key to this self-repair process is the reversible self-assembly of protein complexes, which is characterized by the molecular recognition of parts, kinetic trapping of meta-stable thermodynamic states, and chemical signaling to switch between states. In this thesis, we mimic such regenerative mechanisms in an effort to develop biological light-harvesting devices with prolonged lifetimes. We demonstrate the first synthetic photoelectrochemical cell capable of mimicking key aspects of the self-repair process. Surfactant addition and removal was used to signal between the disassembly and re-assembly of a photoactive complex demonstrating photo-conversion efficiencies of 40%. These dynamic complexes consist of lipid bilayer disks housing photoactive reaction centers (RCs) that align along the length of a single-walled carbon nanotube (SWNT). Application of a regeneration cycle that reversibly signals between the assembled and disassembled states extends the lifetime of the photoelectrochemical cell indefinitely and increases cell efficiency by over 300% over 168 hours. We modeled the kinetic and thermodynamic forces that drive the reversible self-assembly, and we fit this model to spectrofluorimetric measurements that monitor complex formation. The bestfit rate constants for lipid bilayer and bilayer-nanotube complex formation are 79 mM-Is'Iand 5.4x 10 mM-1 s- 1, respectively. We find that these reactions do not occur under diffusioncontrolled conditions, and the phase diagram predicts a locally optimal surfactant removal rate of 8 x 10-4 s-1. This model was subsequently fit to cyclic complex assembly and disassembly measurements, demonstrating that the forces modeled in this study may form the basis for synthetic and natural photoactive complexes capable of dynamic component repair. In an effort to extend our scope to study natural regeneration mechanisms, we established a platform for quantifying reactive oxygen species (ROS) generation in isolated chloroplasts capable of autonomous regeneration. ROS generation from illuminated chloroplasts from S. oleracea was examined in the presence of dextran-wrapped nanoceria (dNC), cerium ions (Ce3 ), fullerenol, and DNA-wrapped SWNTs. ROS concentrations were evaluated using the oxidative dyes, 2',7'- dichlorodihydrofluorescein diacetate (H2DCF-DA) and 2,3-bis(2-methoxy-4-nitro-5- sulfophenyl)-2H-tetrazolium-5-carboxanilide sodium salt (XTT). Chloroplast photoactivity was monitored throughout the illumination period using chloroplast fluorescence and the artificial, photosynthetic electron accepting dye, dichloroindophenol (DCPIP). The results of this study indicate that dNC offers a promising mechanism for effective ROS scavenging whilst preserving chloroplast photoactivity at concentrations below 5 [tM. We have also established several platforms for studying the glucose production of isolated chloroplasts for biofuel cell applications. We developed an algorithm to quantify single-molecule efflux measurements from individual, photoactive chloroplasts. Near-infrared fluorescing SWNTs have been used in previous studies to report single-molecule binding events via stochastic fluctuations in fluorescence. In this thesis, we develop and compare several algorithms for extracting concentration-dependent rates from the stochastic fluctuations. Overall, the birthand- death model most accurately predicts the rate constants, whereas the moment analysis is more accurate at large forward rates (>10-3 s-1). Glucose efflux from chloroplasts was characterized using a glucose oxidase assay, high-pressure liquid chromatography (HPLC), and a biofuel cell. Calculated export rates of 1.9 and 6 tmol/(mg chlorophyll hr) were measured using the HPLC and fuel cell, respectively. Maximum power densities of 110 pW/cm 2 were achieved with alginate encapsulated chloroplasts. In the presence of regenerative materials, such as dNC, this biofuel cell setup provides a promising platform for demonstrating a biological lightharvesting construct capable of autonomous regenerationby Ardemis A. Boghossian.Ph.D

Introduction

This collection of newly commissioned essays, edited by NYU philosophers Paul Boghossian and Christopher Peacocke, resumes the current surge of interest in the proper explication of the notion of a priori. The authors discuss the relations of the a priori to the notions of definition, meaning, justification, and ontology, explore how the concept figured historically in the philosophies of Leibniz, Kant, Frege, and Wittgenstein, and address its role in the contemporary philosophies of logic, mathematics, mind, and science. The editors’ Introduction familiarizes the reader with the issues that are to be explored in detail in later parts of the anthology

Analytical Approaches for Monitoring DNA–Protein Interactions

DNA–protein interactions play a critical role in cellular regulation. We herein review existing analytical methods for investigating these interactions, highlighting methods such as chromatin immunoprecipitation and yeast-one-hybrid that are used to identify undiscovered DNA–protein interactions. We summarize the most common approaches for characterizing known interactions based on DNA–protein structure, thermodynamic and kinetic measurements, and dynamic binding assays. We discuss techniques in optical imaging as well as representative methods, such as eletrophoretic mobility shift assay and surface plasmon resonance. The advantages and disadvantages of these techniques are used to assess a proposed optical platform based on single-walled carbon nanotube (SWCNT) fluorescence

Thermosonication applied to kiwi peel: a healthy source of nutrients

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Thermosonication applied to kiwi peel: impact on nutritional and microbiological indicators

The peels of many fruits are rich sources of nutrients, although they are not commonly consumed. If they are properly decontaminated, they can be used as healthy food ingredients reducing food waste. The objective was to apply thermosonication processes to kiwi peel and evaluate the impact on Listeria innocua survival (a non-pathogenic surrogate of L. monocytogenes) and key nutrients and quality indicators: proteins, fibers, minerals (Ca, K, Mg, Na, and P), chlorophylls, and phenolic contents. Kiwi peels were artificially inoculated with L. innocua and thermal and thermosonication treatments were performed at 55 °C and 60 °C for 30 and 15 min maximum, respectively. Bacteria were enumerated through treatment time, and quality indicators were assessed before and at the end of treatments. A Weibull model with a decimal reduction time (D-value) was successfully used in L. innocua survival data fits. Results showed that coupling temperature to ultrasound had a synergistic effect on bacteria inactivation with significant decreases in D-values. Thermosonication at 60 °C was the most effective in terms of protein, fiber, chlorophylls, and phenolics retention. Minerals were not significantly affected by all treatments. Applying thermosonication to kiwi peel was more effective for decontamination than thermal treatments at the same temperature while allowing the retention of healthy compounds.info:eu-repo/semantics/publishedVersio