Molecular recording of mammalian embryogenesis.

Ontogeny describes the emergence of complex multicellular organisms from single totipotent cells. This field is particularly challenging in mammals, owing to the indeterminate relationship between self-renewal and differentiation, variation in progenitor field sizes, and internal gestation in these animals. Here we present a flexible, high-information, multi-channel molecular recorder with a single-cell readout and apply it as an evolving lineage tracer to assemble mouse cell-fate maps from fertilization through gastrulation. By combining lineage information with single-cell RNA sequencing profiles, we recapitulate canonical developmental relationships between different tissue types and reveal the nearly complete transcriptional convergence of endodermal cells of extra-embryonic and embryonic origins. Finally, we apply our cell-fate maps to estimate the number of embryonic progenitor cells and their degree of asymmetric partitioning during specification. Our approach enables massively parallel, high-resolution recording of lineage and other information in mammalian systems, which will facilitate the construction of a quantitative framework for understanding developmental processes

The Grizzly, February 24, 2005

Spring Break Closing Information • Board of Trustees Meet to Discuss Issues on Campus • Fundraising Facts: Numbers Increase for Airband and Tsunami Relief Effort • Negro Spirituals Celebrate Black History Month • The Face in the Mirror: A Groundbreaking New Play for Ursinus • Competing Condoms: Consumer Reports Rates the Efficacy of Various Brands • Opinions: On the Look-out for a Boat Anchor?; Does UC Give Enough Charitable Support? • Wrestlers Grapple Conferences and Nationals • Bears Clinch Playoff Berthhttps://digitalcommons.ursinus.edu/grizzlynews/1579/thumbnail.jp

The Grizzly, April 28, 2005

Commencement 2005 • Students Protest Laptop Buyback • Got Talent? • Kaleidoscope Opens • Diversity Week a Success • Ursinus Dancers Preview Work in the Scope • Students Prove Educational Value in Buffy • How to Have a Great Summer • Let the Art Speak for Itself : Preview of the Annual Art Exhibition • Opinions: Most Controversial; Thoughts of a Rising Senior; Turn from Intolerance • Road to the Playoffs in Sight • Lacrosse Team Denied First Conference Win • Intramural Sports Becoming a Popular Alternativehttps://digitalcommons.ursinus.edu/grizzlynews/1585/thumbnail.jp

ZERO-G EXPERIMENTS OF THE BIONICWINGSAT - A 2U-CUBESAT WITH DEPLOYABLE, BIOLOGICALLY-INSPIRED WINGS

In this paper, recent testing of a novel deployable structure with several potential applications in space will be described, with the focus on performed deployment experiments in a DLR Zero-g flight campaign and in ground tests. Through a cooperative effort of the German Aerospace Center (DLR) and the National Aeronautics and Space Administration (NASA), a biologically-inspired structurally-integrated membrane featuring distributed functional elements has been developed and integrated into the 2U CubeSat called BionicWingSat. Such a membrane structure could be useful for all sorts of applications in which a relatively flat area is desirable such as solar sails, drag sails, or solar shades. For SmallSats and CubeSats, the design proposed also has the desirable property of being self-deploying without the need for powered deployment mechanisms. Building on previous work inspired by the wings of earwigs, the research presented in this paper focuses on testing of developed design concepts for such structural systems. To do so 24 fully integrated wings on two BionicWingSats in 2U Cubesat format were experimentally deployed in a microgravity environment during a dedicated DLR Zero-g flight campaign in 2021. The results of these experiments, the built hardware and test articles, the test arrangement, as well as a comparison to ground tests are discussed in this paper

Design and Testing of the BionicWingSat in a Zero-g Flight Campaign - A 2U-CubeSat with Deployable, BiologicallyInspired Wings

In this paper, recent developments in the design, manufacturing, and testing of a novel deployable structure with several potential applications in space will be described. Through a cooperative effort of the German Aerospace Center (DLR) and the National Aeronautics and Space Administration (NASA), a biologically inspired structurally integrated membrane featuring distributed functional elements has been developed and tested in a 2U CubeSat called BionicWingSat. Such a membrane structure could be useful for several applications in which a relatively flat area is desirable such as solar sails, drag sails, or solar shades. For SmallSats and CubeSats, the design proposed also has the desirable property of being self-deploying without the need for powered deployment mechanisms. Building on previous work inspired by the wings of earwigs, the research presented in this paper includes structural design of self-deploying hinges, a survey of various advanced additive layer manufacturing (ALM) methods for making hinges, mechanical characterization of the hinges, and finite element analysis (FEA) of the hinges. In this work, the conflicting goals of maximizing deployed structural stiffness, maximizing deployed area, maximizing stowed packaging efficiency, and maximizing resistance to creep when stowed must be considered. The resulting design concept is a gossamer structure that cannot support its own weight in gravity. For this reason, a focus in this paper is on a parabolic flight test campaign in which 24 fully integrated wings on two BionicWingSats were tested in a microgravity environment. From this test campaign, several lessons were learned regarding the wing design and procedures for carrying out microgravity tests of this manner

The Grizzly, February 3, 2005

Students Videoconference with Sri Lanka • Forensics Team Coach-less • Where Have All the Trees Gone? • It\u27s Cold in Here • Learning the Roots and Aspects of Freedom of Expression: Special Topic Course • Contraception and the Y Chromosome: Male Birth Control Options • Influenza: How to Survive the Yearly Epidemic • Where in the World is Your Study Abroad Application? • Opinions: Random Rantings of Racial Relations; Law Should not Justify Artificial Survival • Gymnastics Team Ranked First in Nation • Fourth Time\u27s the Charm • Gaining Ground in the Ranks of the Collegiate Wrestling Worldhttps://digitalcommons.ursinus.edu/grizzlynews/1576/thumbnail.jp

The Grizzly, February 17, 2005

UC Students Tour Washington D.C. to Prepare for Model UN • Wismer Music Makes a Comeback • Problems with New Member Education • Ursinus Students Sprint into SPINT Housing • Leaders Wanted: Do You Have What it Takes? • Sexual Physical Fitness • Dramaturgy: New Course for Theater • Philadelphia Gets Closer for Ursinus Students • Opinions: Speak Up, It\u27s Your Right; God in the Government: Can we Escape Him?; What Rules the Media, Entertainment or Information? • Track and Field Team Headed in Right Direction • Lady Bears Dominate Bryn Mawr • Murray Helps Wrestling Team Remain Undefeatedhttps://digitalcommons.ursinus.edu/grizzlynews/1578/thumbnail.jp

Entangled-Photon Generation from Parametric Down-Conversion in Media with Inhomogeneous Nonlinearity

We develop and experimentally verify a theory of Type-II spontaneous parametric down-conversion (SPDC) in media with inhomogeneous distributions of second-order nonlinearity. As a special case, we explore interference effects from SPDC generated in a cascade of two bulk crystals separated by an air gap. The polarization quantum-interference pattern is found to vary strongly with the spacing between the two crystals. This is found to be a cooperative effect due to two mechanisms: the chromatic dispersion of the medium separating the crystals and spatiotemporal effects which arise from the inclusion of transverse wave vectors. These effects provide two concomitant avenues for controlling the quantum state generated in SPDC. We expect these results to be of interest for the development of quantum technologies and the generation of SPDC in periodically varying nonlinear materials.Comment: submitted to Physical Review