Hasil untuk "physics.ed-ph"

D. Perrin, B. Dempsey

B. Poole, S. Ohkuma

The spectral characteristics of dextran, labeled with fluorescein, depend upon pH. We have loaded the lysosomes of mouse peritoneal macrophages with this fluorescence probe and used it to measure the intralysosomal pH under various conditions. The pH of the medium has no effect on the intralysosomal pH. Weakly basic substances in the medium cause a concentration-dependent increase in the intralysosomal pH. However, the concentration of base necessary to produce a significant change in the intralysosomal pH varies over a wide range for different bases. The active form of the base is the neutral, unprotonated form. Although most of these weak bases cause an increase in the volume of the lysosomes, increase in lysosomal volume itself causes only a minor perturbation of the intralysosomal pH. This was demonstrated in cells whose lysosomes were loaded with sucrose, and in cells vacuolated as a demonstrated in cells whose lysosomes were loaded with sucrose, and in cells vacuolated as a consequence of exposure to concanavalin A. The results of these studies are interpreted in terms of energy-dependent lysosomal acidification and leakage of protons out of the lysosomes in the form of protonated weak bases.

J. Skehel, P. Bayley, E. Brown et al.

J. Raven, F. A. Smith

W. Busa, R. Nuccitelli

B. S. Stein, B. S. Stein, S. D. Gowda et al.

K. J. Ellis, J. Morrison

I. H. Madshus

Matthew Szydagis

Claims of the retrieval of crashed craft or vehicles from non-human intelligence(s) (NHI) abound in the popular culture and media. For this article, the number of unsubstantiated claims is utilized to estimate the time expected until a "catastrophic disclosure" occurs. The term was defined at the 2023 Sol Foundation's inaugural conference as an accidental disclosure of strong evidence of the existence of NHI. The phrase refers to this occurring outside the control of major human institutions, such as governments and militaries. One possible example of this is the crash of a piloted (space)craft or ET probe in the middle of a busy metropolis (such as the New York City Times Square). The distribution of humans across the Earth's surface, the population as a function of time, and the fraction of individuals owning a camera-phone, also versus time, are each taken into consideration as a foundation for a rigorous statistical analysis. This author adopts a skeptical and agnostic approach and does not conclude NHI or ET are real, but applies standard statistical distributions as educational examples of critical thinking to an issue which captures the imagination of the public as almost no other issue does. Making the extraordinary assumptions that sentient species other than humans exist, are capable of constructing vehicles for transportation, and are sufficiently fallible that their technology can malfunction, it becomes possible to quantify some potential answers to the question of how long it might be before smartphone imagery and/or video evidence appears on the web and becomes irrevocable via classification in the modern era. Results of simulations of numerous potential scenarios with varying degrees of optimism indicate that, if NHI are real, catastrophic disclosure may actually happen accidentally rather soon, with the mean expected year being 2040 +/- 20 under the default assumptions.

Idil Ismail, Shayantan Chaudhuri, Dylan Morgan et al.

This article is intended as a guide for new graduate students in the field of computational science. With the increasing influx of students from diverse backgrounds joining the ever-popular field, this short guide aims to help students navigate through the various computational techniques that they are likely to encounter during their studies. These techniques span from Bash scripting and scientific programming to machine learning, among other areas. This paper is divided into ten sections, each introducing a different computational method. To enhance readability, we have adopted a casual and instructive tone, and included code snippets where relevant. Please note that due to the introductory nature of this article, it is not intended to be exhaustive; instead, we direct readers to a list of references to expand their knowledge of the techniques discussed within the paper. It is likely that this article will continue to evolve with time, and as such, we advise readers to seek the latest version. Finally, readers should note this article serves as an extension to our student-led seminar series, with additional resources and videos available at \url{https://computationaltoolkit.github.io/} for reference.

R. Naidu, N. Bolan, R. Kookana et al.

Nicolas Misdariis, Elif Özcan, Massimo Grassi et al.

The Audible Universe project aims at making dialogue between two scientific domains investigating two distinct research objects, briefly said, Stars and Sound. It has been instantiated within a collaborative workshop that started to mutually acculturate both communities, by sharing and transmitting respective knowledge, skills and practices. One main outcome of this exchange was a global view on the astronomical data sonification paradigm that allowed to observe either the diversity of tools, uses and users (including visually-impaired people), but also the current limitations and potential ways of improvement. From this perspective, the current paper presents basic elements gathered and contextualised by sound experts in their respective fields (sound perception / cognition, sound design, psychoacoustics, experimental psychology), in order to anchor sonification for astronomy in a more well-informed, methodological and creative process.

Ketevi A. Assamagan, Breese Quinn, Kenneth Bloom et al.

This is the summary report of the Community Engagement Frontier for the Snowmass 2021 study of the future of particle physics. The report discusses a number of general issues of importance to the particle physics community, including (1) the relation of universities, national laboratories, and industry, (2) career paths for scientists engaged in particle physics, (3) diversity, equity, and inclusion, (4) physics education, (5) public education and outreach, (6) engagement with the government and public policy, and (7) the environmental and social impacts of particle physics.

Li-Heng Henry Chang, Shea Roccaforte, Ziyu Xu et al.

The Bloch Sphere visualization of the possible states of a single qubit has proved a useful pedagogical and conceptual tool as a one-to-one map between qubit states and points in a 3-D space. However, understanding many important concepts of quantum mechanics, such as entanglement, requires developing intuitions about states with a minimum of two qubits, which map one-to-one to unvisualizable spaces of 6 dimensions and higher. In this paper we circumvent this visualization issue by creating maps of subspaces of 1- and 2-qubit systems that quantitatively and qualitatively encode properties of these states in their geometries. For the 1-qubit case, the subspace approach allows one to visualize how mixed states relate to different choices of measurement in a basis-independent way and how to read off the entries in a density matrix representation of these states from lengths in a simple diagram. For the 2-qubit case, a toroidal map of 2-qubit states illuminates the non-trivial topology of the state space while allowing one to simultaneously read off, in distances and angles, the level of entanglement in the 2-qubit state and the mixed-state properties of its constituent qubits. By encoding states and their evolutions through quantum logic gates with little to no need of mathematical formalism, these maps may prove particularly useful for understanding fundamental concepts of quantum mechanics and quantum information at the introductory level. Interactive versions of the visualizations introduced in this paper are available at https://quantum.bard.edu/.

J. Jamieson, H. Stein, T. Demeester et al.

Hector Jose Morrell, Anika Zaman, Hiu Yung Wong

After learning basic quantum computing concepts, it is desirable to reinforce the learning using an important and relatively complex algorithm through which the students can observe and appreciate how the qubits evolve and interact with each other. Harrow-Hassidim-Lloyd (HHL) quantum algorithm, which can solve Linear System Problems with exponential speed-up over the classical method and is the basic of many important quantum computing algorithms, is used to serve this purpose. The HHL algorithm is explained analytically followed by a 4-qubit numerical example in bra-ket notation. Matlab code corresponding to the numerical example is available for students to gain a deeper understanding of the HHL algorithm from a pure matrix point of view. A quantum circuit programmed using qiskit is also provided which can be used for real hardware execution in IBM quantum computers. After going through the material, students are expected to have a better appreciation of the concepts such as basis transformation, bra-ket and matrix representations, superposition, entanglement, controlled operations, measurement, Quantum Fourier Transformation, Quantum Phase Estimation, and quantum programming. To help readers review these basic concepts, brief explanations augmented by the HHL numerical examples in the main text are provided in the Appendix.

J. Elliott, Mara L Macdonald, J. Nie et al.

Yan-Li Zhao, Zongxi Li, Sanaz Kabehie et al.

B. Zaid, D. Saidi, A. Benzaid et al.

Marcos Daniel Caballero, Morten Hjorth-Jensen

In this contribution we discuss how to develop a physics curriculum for undergraduate students that includes computing as a central element. Our contribution starts with a definition of computing and pertinent learning outcomes and assessment studies and programs. We end with a discussion on how to implement computing in various physics courses by presenting our experiences from Michigan State University in the USA and the University of Oslo in Norway.