Search for: All records

Cellular heterogeneity, an inherent feature of biological systems, plays a critical role in processes such as development, immune response, and disease progression. Human mesenchymal stem cells (hMSCs) exemplify this heterogeneity due to their multi-lineage differentiation potential. However, their inherent variability complicates clinical use, and there is no universally accepted method for detecting and quantifying cell population heterogeneity. Dielectrophoresis (DEP) has emerged as a powerful electrokinetic technique for characterizing and manipulating cells based on their dielectric properties, offering label-free analysis capabilities. Quantitative information from the DEP spectrum, such as transient slope, measure cells’ transition between negative and positive DEP behaviors. In this study, we employed DEP to estimate transient slope of various cell populations, including relatively homogeneous HEK-293 cells, heterogeneous hMSCs, and cancer cells (PC3 and DU145). Our analysis encompassed hMSCs derived from bone marrow, adipose, and umbilical cord tissue, to capture tissue-specific heterogeneity. Transient slope was assessed using two methods, involving linear trendline fitting to different low-frequency regions of the DEP spectrum. We found that transient slope serves as a reliable indicator of cell population heterogeneity, with more heterogeneous populations exhibiting lower transient slopes and higher standard deviations. Validation using cell morphology, size, and stemness further supported the utility of transient slope as a heterogeneity metric. This label-free approach holds promise for advancing cell sorting, biomanufacturing, and personalized medicine. 

The history of astronomy has shown that advances in sensing methods open up new windows to the Universe and often lead to unexpected discoveries. Quantum sensor networks in combination with traditional astronomical observations are emerging as a novel modality for multimessenger astronomy. Here we develop a generic analysis framework that uses a data-driven approach to model the sensitivity of a quantum sensor network to astrophysical signals as a consequence of beyond-the-standard model (BSM) physics. The analysis method evaluates correlations between sensors to search for BSM signals coincident with astrophysical triggers, such as black hole mergers, supernovae, or fast radio bursts. Complementary to astroparticle approaches that search for particlelike signals (e.g., weakly interacting massive particles), quantum sensors are sensitive to wavelike signals from exotic quantum fields. This analysis method can be applied to networks of different types of quantum sensors, such as atomic clocks, matter-wave interferometers, and nuclear clocks, which can probe many types of interactions between BSM fields and standard model particles. We use this analysis method to carry out the first direct search utilizing a terrestrial network of precision quantum sensors for BSM fields emitted during a black hole merger. Specifically, we use the global network of optical magnetometers for exotic physics (GNOME) to perform a search for exotic low-mass field (ELF) bursts generated in coincidence with a gravitational-wave signal from a binary black hole merger (GW200311_115853) detected by LIGO/Virgo on the March 11, 2020. The associated gravitational wave heralds the arrival of the ELF burst that interacts with the spins of fermions in the magnetometers. This enables GNOME to serve as a tool for multimessenger astronomy. Our search found no significant events and, consequently, we place the first lab-based limits on combinations of ELF production and coupling parameters. 

This RESEARCH paper examines faculty perceptions regarding the use of Scrum for departmental operations. Scrum is an agile methodology that applies processes and procedures that encourage transparency, inspection, and adaptation in the creation of a product. Across the literature for engineering education change, there has been a focus on identifying the barriers and affordances to cultural change in engineering departments. The objective of this paper is to examine the driving factors and barriers to implementing Scrum for departmental operations. The paper will specifically address how a group of faculty about to adopt Scrum perceive the impact of that adoption on potential changes to departmental operations and culture. Findings indicate concerns with the traditional barriers of time and workload. However, they also indicate that there is some expectation for Scrum to decrease elements of the faculty workload and reduce time to complete tasks. These findings also build on the understanding of how faculty collaboration is perceived as both a barrier and affordance to departmental change. 

Study explores Scrum, a comprehensive team performance process based on Agile engineering principles, through an I/O lens. Study focuses on impact of Scrum implementation on team performance, organizational culture, and change management. Role of I/O in implementing engineering process improvement programs is discussed, as well as need for greater I/O involvement in engineering process management. 

What might it mean to be an agile academic department? An agile college? An agile university? “Agile”, as used here, refers to practices and frameworks in software development and deployment, such as Scrum, Extreme Programming, and Crystal Clear. The Agile movement’s founding documents, the Agile Manifesto and its accompanying Agile Principles [https://agilemanifesto.org/], were published by leading software engineering researchers in February of 2001. The Manifesto staked out distinction with the prevailing software development approach at the time, called planned development and otherwise known as waterfall. The Agile Manifesto states, "We are uncovering better ways of developing software by doing it and helping others do it. Through this work we have come to value: "Individuals and interactions over processes and tools Working software over comprehensive documentation Customer collaboration over contract negotiation Responding to change over following a plan "That is, while there is value in the items on the right, we value the items on the left more.” Since the Manifesto’s publication, Agile use has expanded from its then primarily application in software development into a wide range of activities, from rocket motors (Space X), to race car development (Wikispeed), to finance (World Bank), to human resources (ING). Denning postulates Three Laws of the Agile Mindset: (1) The Law of the Small Team, in which small cross-functions teams work in short iterations receiving regular customer feedback; (2) The Law of the Customer, in which delighting the customer is taken as the ultimate purpose for any enterprise; and (3) The Law of the Network, in which networks of small teams act, having trust in the competency of each other, act like small teams in themselves [The Age of Agile: How Smart Companies Are Transforming the Way Work Gets Done. AMACOM, 2018]. Academic enterprises have unique attributes — recurring, months long, instructional terms; “customers” (students) whose short-term dissatisfaction can be part of the path to long-term success; industrial stakeholders who influence program direction and focus to satisfy hiring needs; generation of new knowledge, often with financial support from government agencies and industry; service to the profession and to our institutions. Using Denning’s Laws as a framing, we present possible approaches to employing agile within an academic department and discuss potential expansion of such to the level of a college and even an entire university. 

Context. TOI-732 is an M dwarf hosting two transiting planets that are located on the two opposite sides of the radius valley. Inferring a reliable demographics for this type of systems is key to understanding their formation and evolution mechanisms. Aims. By doubling the number of available space-based observations and increasing the number of radial velocity (RV) measurements, we aim at refining the parameters of TOI-732 b and c. We also use the results to study the slope of the radius valley and the density valley for a well-characterised sample of M-dwarf exoplanets. Methods. We performed a global Markov chain Monte Carlo analysis by jointly modelling ground-based light curves and CHEOPS and TESS observations, along with RV time series both taken from the literature and obtained with the MAROON-X spectrograph. The slopes of the M-dwarf valleys were quantified via a support vector machine (SVM) procedure. Results. TOI-732b is an ultrashort-period planet (P= 0.76837931_-0.00000042^+0.0000039days) with a radiusR_b= 1.325_-0.058^+0.057R_⊕, a massM_b= 2.46 ± 0.19M_⊕, and thus a mean densityρ_b= 5.8_-0.8^+1.0g cm^-3, while the outer planet atP= 12.252284 ± 0.000013 days hasR_c= 2.39_-0.11^+0.10R_⊕,M_c= 8.04_-0.48^+0.50M_⊕, and thusρ_c= 3.24_-0.43^+0.55g cm^-3. Even with respect to the most recently reported values, this work yields uncertainties on the transit depths and on the RV semi-amplitudes that are smaller up to a factor of ~1.6 and ~2.4 for TOI-732 b and c, respectively. Our calculations for the interior structure and the location of the planets in the mass-radius diagram lead us to classify TOI-732 b as a super-Earth and TOI-732 c as a mini-Neptune. Following the SVM approach, we quantified d logR_p,valley/ d logP= -0.065_-0.013^+0.024, which is flatter than for Sun-like stars. In line with former analyses, we note that the radius valley for M-dwarf planets is more densely populated, and we further quantify the slope of the density valley as d log ρ^_valley/ d logP= -0.02_-0.04^+0.12. Conclusions. Compared to FGK stars, the weaker dependence of the position of the radius valley on the orbital period might indicate that the formation shapes the radius valley around M dwarfs more strongly than the evolution mechanisms.