Quickshift++: Provably Good Initializations for Sample-Based Mean Shift

We provide initial seedings to the Quick Shift clustering algorithm, which approximate the locally high-density regions of the data. Such seedings act as more stable and expressive cluster-cores than the singleton modes found by Quick Shift. We establish statistical consistency guarantees for this modification. We then show strong clustering performance on real datasets as well as promising applications to image segmentation.Comment: ICML 2018. Code release: https://github.com/google/quickshif

Transnational Student Identity Development through the Cosmopolite Lens: Benefits and Challenges of Straddling Cultures

Have you ever felt like you are completely alone, or stuck between worlds? In this age of globalization, there is an increasing number of students who were raised in multiple countries and cultures. Why do these students find it so difficult to answer the question, “Where are you from?” How do childhood experiences influence one’s sense of identity, social interaction patterns, relationship attachment styles, and worldview? This moral conversation explores the characteristics of transnational students, identifies benefits of their experiences, examines their unique challenges, and uncovers their associated life patterns from straddling cultures. Through my personal narrative as a self-defined “cosmopolite,” (koz-mop-uh-lahyt) I will shine light onto the silent struggles of this often invisible student population

Resilience Amidst Adversity: The Sine Qua Non Principle for Meaningful and Effective Leadership in Education

Have you ever encountered difficult moments that trigger you? Do you find it difficult to monitor your internal dialogue after a setback? Do you struggle to find meaning and purpose amidst all the hardship? As leaders in higher education, we must prioritize others, often giving ourselves away in the process only to find there is nothing left within. We might feel empty, beaten down, and exhausted as others need us to repeatedly and reliably show up as competent leaders. I believe the art of cultivating resilience is the antidote for us as leaders to be meaning-filled and effective at work and in life. Life is full of inevitable major adversities, setbacks, hurdles, and challenges that we cannot avoid. These obstacles often feel unbearable and like our world is caving in around us. We all face them. No one is exempt. Everyone can relate in some way or another, but rarely are we shown a strategic system to explicitly cultivate the art of overcoming these hurdles, recovering from setbacks, and transcending adversity. How do we continue to lead effectively while replenishing our own cups with meaning and purpose? Through the use of the Scholarly Personal Narrative methodology, this dissertation examines how I am able to transcend adversities encountered in life through practical tips and systems for cultivating resilience. This organic self-disclosure narrative draws upon personal challenges to explore the lessons learned, light bulb moments captured, and epiphanies acquired through a multitude of growing pains and adversities. Written specifically with higher education educators and leaders in mind, but also those who they want to influence, the gleaned value is organized into three sections: What is resilience? Why may resilience be important? How can we cultivate resilience? While sharing what has worked for me in my journey, I hope to engage, inspire, and empower educators and leaders in the process of becoming more resilient themselves. My goal is to better equip individuals with the tools, skills, and mindset needed to propel us through these inevitable and unavoidable challenges in life. The better we can become as individuals, the better we are as a collective. Resilience should be woven throughout the fabric of our foundation as people. It is an internal boost that enhances our abilities as educators, enriches our capacities as parents, and deepens our impact as leaders

Extending self-determination theory’s dual-process model to a new tripartite model to explain diminished functioning

In a three-study investigation, we pursued three purposes: (1) extend self-determination theory’s dual-process model to a new tripartite model—to recognize that environmental conditions sometimes render a psychological need dormant; (2) better explain adolescents’ diminished functioning; and (3) develop the Three States Questionnaire (TSQ). In Study 1, 402 high schoolers reported the satisfied, frustrated, and dormant state of their psychological needs (autonomy, competence, and relatedness) during classroom instruction to develop the TSQ. In Study 2, 320 high schoolers reported their satisfied, frustrated, and dormant states as well as 17 indicators of their effective, defiant, and diminished classroom functioning. The TSQ showed excellent psychometric properties, and the predictive power of the tripartite model was superior to that of the dual-process model in the prediction of all five indicators of diminished functioning (e.g., disengagement). In Study 3, 457 high schoolers’ perceived teachers’ motivating styles (supporting, controlling, and neglecting) predicted their three need states (satisfied, frustrated, and dormant), which predicted the quality of their classroom functioning (effective, defiant, and diminished). Overall, the dormant state was distinct from the other two states, it uniquely explained diminished functioning, and the tripartite model out-predicted the dual-process model

\u27Living cantilever arrays\u27 for characterization of mass of single live cells in fluids

The size of a cell is a fundamental physiological property and is closely regulated by various environmental and genetic factors. Optical or confocal microscopy can be used to measure the dimensions of adherent cells, and Coulter counter or flow cytometry ( forward scattering light intensity) can be used to estimate the volume of single cells in a flow. Although these methods could be used to obtain the mass of single live cells, no method suitable for directly measuring the mass of single adherent cells without detaching them from the surface is currently available. We report the design, fabrication, and testing of \u27living cantilever arrays\u27, an approach to measure the mass of single adherent live cells in fluid using silicon cantilever mass sensor. HeLa cells were injected into microfluidic channels with a linear array of functionalized silicon cantilevers and the cells were subsequently captured on the cantilevers with positive dielectrophoresis. The captured cells were then cultured on the cantilevers in a microfluidic environment and the resonant frequencies of the cantilevers were measured. The mass of a single HeLa cell was extracted from the resonance frequency shift of the cantilever and was found to be close to the mass value calculated from the cell density from the literature and the cell volume obtained from confocal microscopy. This approach can provide a new method for mass measurement of a single adherent cell in its physiological condition in a non-invasive manner, as well as optical observations of the same cell. We believe this technology would be very valuable for single cell time-course studies of adherent live cells

The catalytic core of DEMETER guides active DNA demethylation in Arabidopsis.

The Arabidopsis DEMETER (DME) DNA glycosylase demethylates the maternal genome in the central cell prior to fertilization and is essential for seed viability. DME preferentially targets small transposons that flank coding genes, influencing their expression and initiating plant gene imprinting. DME also targets intergenic and heterochromatic regions, but how it is recruited to these differing chromatin landscapes is unknown. The C-terminal half of DME consists of 3 conserved regions required for catalysis in vitro. We show that this catalytic core guides active demethylation at endogenous targets, rescuing dme developmental and genomic hypermethylation phenotypes. However, without the N terminus, heterochromatin demethylation is significantly impeded, and abundant CG-methylated genic sequences are ectopically demethylated. Comparative analysis revealed that the conserved DME N-terminal domains are present only in flowering plants, whereas the domain architecture of DME-like proteins in nonvascular plants mainly resembles the catalytic core, suggesting that it might represent the ancestral form of the 5mC DNA glycosylase found in plant lineages. We propose a bipartite model for DME protein action and suggest that the DME N terminus was acquired late during land plant evolution to improve specificity and facilitate demethylation at heterochromatin targets

Target gene selectivity of the myogenic basic helix–loop–helix transcription factor myogenin in embryonic muscle

AbstractThe myogenic regulatory factors MyoD and myogenin are crucial for skeletal muscle development. Despite their importance, the mechanisms by which these factors selectively regulate different target genes are unclear. The purpose of the present investigation was to compare embryonic skeletal muscle from myogenin+/+ and myogenin−/− mice to identify genes whose expression was dependent on the presence of myogenin but not MyoD and to determine whether myogenin-binding sites could be found within regulatory regions of myogenin-dependent genes independent of MyoD. We identified a set of 140 muscle-expressed genes whose expression in embryonic tongue muscle of myogenin−/− mice was downregulated in the absence of myogenin, but in the presence of MyoD. Myogenin bound within conserved regulatory regions of several of the downregulated genes, but MyoD bound only to a subset of these same regions, suggesting that many downregulated genes were selective targets of myogenin. The regulatory regions activated gene expression in cultured myoblasts and fibroblasts overexpressing myogenin or MyoD, indicating that expression from exogenously introduced DNA could not recapitulate the selectivity for myogenin observed in vivo. The results identify new target genes for myogenin and show that myogenin's target gene selectivity is not based solely on binding site sequences