This paper briefly explores the roles of empiricism and determinism in science and engineering. From this analysis, I conclude that the intellectual exercise that we call “science” is best described as the transition from empiricism (i.e., from what we can observe) to determinism, which is the philosophy that the future can be predicted from the past on the basis of the natural laws that are condensations of all previous scientific knowledge. Thus, “science” is enacted by formulating theories to explain the observations and models, based on those theories, are developed to predict new phenomena. Accordingly, models are the computational arms of theories. Importantly, all models must possess a theoretical basis but not all theories need to predict. The structure of a deterministic model is that it must contain an input, a model “engine”, and an output, that are all linked by a feedback loop that permits the continual updating of the model parameters and a means of assessing predictions against new observations. This latter feature, in essence, enables the application of the “scientific method” of cyclical modification/assessment that continues until the model no longer accounts for new observations. At that point, the model (and possibly the theory, as well) must be discarded and a new theory/model developed. Again, importantly, no amount of successful prediction can “prove” a theory/model to be “correct”, because theories and models are merely the figments of our imagination as developed through imperfect senses and imperfect intellect. Accordingly, all theories and models are wrong at some level of detail. Contrariwise, a single failure of a model to predict an observation invalidates the theory/model unequivocally. The principal impediment to model building is complexity and it is the reason why a compromise must always be made between physical reality and mathematical tractability.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The software "BaseBuddy" (basebuddy.lbl.gov) is a user-friendly web app designed for codon optimization of heterologous genes. Codon optimization is a widely used technique to enhance the expression levels of non-native genes. Our app is built on the DNA Chisel Python library (Zulkower and Rosser, 2020), which offers highly customizable and transparent gene optimization. Unlike DNA Chisel, which is a command-line interface software with numerous optional functions, our web app simplifies the process for users. Additionally, while DNA Chisel relies on the outdated Kazusa codon usage database, our app introduces the option to utilize the most recent version of the CoCoPUTs database (Athey et al., 2017). By incorporating CoCoPUTs, we also expand the range of target organisms and maintain up-to-date sequencing data for more accurate codon optimization results.
The first use of ether protecting groups in the design of imaging systems based on substituted poly(hydroxystyrenes) is reported. Polymers containing 4-(2-cyclohexenyloxy) or 4-(1-phenylethyloxy) derivatives of 4-vinylphenol or 3,5-dimethyl-4-vinylphenol have been prepared from the corresponding monomers. Due to their design, which allows for facile elimination or rearrangement reactions, the ether protecting groups can be removed easily by acidolysis, or thermolysis, or a combination thereof. In some instances, the protecting groups can be split quantitatively from the polymers, while in others a thermal Claisen rearrangement or an acid-catalyzed alkylation occur with the formation of some alkylated phenolic moieties. Application of the design to imaging systems is achieved through the use of triarylsulfonium salts as photochemical triggers. Exposure of films of poly[4-(2-cyclohexenyloxy)-3,5-dimethyl-styrene] containing some of the onium salt to irradiation at 254 nm results in the formation of acid in the exposed areas which catalyzes the polymer deprotection and allows for the development of images in either positive or negative mode through a differential dissolution process.
Physician practices that intended to join the early ACO programs had greater capabilities and experience to manage risk than those practices that decided not to join. The early ACO programs thus attracted the more capable physician practices, but those practices still fell short of implementing key recommended behaviors. The findings have implications for future physician practice selection into ACOs.
ADVERTISEMENT RETURN TO ISSUEPREVViewpointNEXTLiquid Sunlight: The Evolution of Photosynthetic BiohybridsPeidong Yang*Peidong YangDepartment of Chemistry, Materials Science and Engineering, University of California, Berkeley, California United StatesMaterials and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California United StatesKavli Energy NanoSciences Institute at the University of California, Berkeley, California United States*Email: [email protected]More by Peidong Yanghttps://orcid.org/0000-0003-4799-1684Cite this: Nano Lett. 2021, 21, 13, 5453–5456Publication Date (Web):July 2, 2021Publication History Published online2 July 2021Published inissue 14 July 2021https://pubs.acs.org/doi/10.1021/acs.nanolett.1c02172https://doi.org/10.1021/acs.nanolett.1c02172editorialACS PublicationsCopyright © Published 2021 by American Chemical Society. This publication is available under these Terms of Use. Request reuse permissions This publication is free to access through this site. Learn MoreArticle Views8965Altmetric-Citations16LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail PDF (1 MB) Get e-AlertscloseSUBJECTS:Bacteria,Charge transfer,Interfaces,Semiconductors,Solar energy Get e-Alerts
The assembly, organization and function of the photosynthetic apparatus was investigated in wild type and a chlorophyll (Chl) b-less mutant of the unicellular green alga Chlamydomonas reinhardtii, generated via DNA insertional mutagenesis. Comparative analyses were undertaken with cells grown photoheterotrophically (acetate), photomixotrophically (acetate and HCO 3 - ) or photoautotrophically (HCO 3 - ). It is shown that lack of Chl b diminished the photosystem-II (PSII) functional Chl antenna size from 320 Chl ( a and b) to about 95 Chl a molecules. However, the functional Chl antenna size of PSI remained fairly constant at about 290 Chl molecules, independent of the presence of Chl b. Western blot and kinetic analyses suggested the presence of inner subunits of the Chl a-b light-harvesting complex of PSII (LHCII) and the entire complement of the Chl a-b light-harvesting complex of PSI (LHCI) in the mutant. It is concluded that Chl a can replace Chl b in the inner subunits of the LHCII and in the entire complement of the LHCI. Growth of cells on acetate as the sole carbon source imposes limitations in the photon use efficiency and capacity of photosynthesis. These are manifested as a lower quantum yield and lower light-saturated rate of photosynthesis, and as a lower variable to maximal (Fv/Fmax) chlorophyll fluorescence yield ratios. This adverse effect probably originates
