From the help desk: It's all about the sampling

Effective estimation and inference, when the data are collected using complex survey designs, requires estimators that fully account for the sampling design. This article explores, by means of Monte Carlo simulations of the power of simple hypothesis tests, the consequences of parameter estimation and inference when naive estimators are employed with survey data. Copyright 2002 by Stata Corporation.cluster, design, power, strata, svy, svymean, svyset

Simulation synergy : expanding TRNSYS capabilities and usability

Developers of simulation packages are now able to take advantage of the increase in available desktop computing power to expand the capabilities and usability of their programs. This paper will illustrate these opportunities by discussing the different techniques the developers of the TRNSYS software package have used to try and create a synergy between TRNSYS and external programs and between the developers and users of the program

Molecular contrast optical coherence tomography: a pump-probe scheme using indocyanine green as a contrast agent

The use of indocyanine green (ICG), a U.S. Food and Drug Administration approved dye, in a pump-probe scheme for molecular contrast optical coherence tomography (MCOCT) is proposed and demonstrated for the first time. In the proposed pump-probe scheme, an optical coherence tomography (OCT) scan of the sample containing ICG is first acquired. High fluence illumination (∼190kJ/cm^2) is then used to permanently photobleach the ICG molecules—resulting in a permanent alteration of the overall absorption of the ICG. A second OCT scan is next acquired. The difference of the two OCT scans is used to determine the depth resolved distribution of ICG within a sample. To characterize the extent of photobleaching in different ICG solutions, we determine the cumulative probability of photobleaching, ϕ_(B,cum), defined as the ratio of the total photobleached ICG molecules to the total photons absorbed by the ground state molecules. An empirical study of ICG photobleaching dynamics shows that ϕ_(B,cum) decreases with fluence as well as with increasing dye concentration. The quantity ϕ_(B,cum) is useful for estimating the extent of photobleaching in an ICG sample (MCOCT contrast) for a given fluence of the pump illumination. The paper also demonstrates ICG-based MCOCT imaging in tissue phantoms as well as within stage 54 Xenopus laevis

Drivers and mechanisms of tree mortality in moist tropical forests

Tree mortality rates appear to be increasing in moist tropical forests (MTFs) with significant carbon cycle consequences. Here, we review the state of knowledge regarding MTF tree mortality, create a conceptual framework with testable hypotheses regarding the drivers, mechanisms and interactions that may underlie increasing MTF mortality rates, and identify the next steps for improved understanding and reduced prediction. Increasing mortality rates are associated with rising temperature and vapor pressure deficit, liana abundance, drought, wind events, fire and, possibly, CO2 fertilization-induced increases in stand thinning or acceleration of trees reaching larger, more vulnerable heights. The majority of these mortality drivers may kill trees in part through carbon starvation and hydraulic failure. The relative importance of each driver is unknown. High species diversity may buffer MTFs against large-scale mortality events, but recent and expected trends in mortality drivers give reason for concern regarding increasing mortality within MTFs. Models of tropical tree mortality are advancing the representation of hydraulics, carbon and demography, but require more empirical knowledge regarding the most common drivers and their subsequent mechanisms. We outline critical datasets and model developments required to test hypotheses regarding the underlying causes of increasing MTF mortality rates, and improve prediction of future mortality under climate change

The Grizzly, September 9, 1998

Campus Mourns Loss of Colleague and Friend • Ursinus Loses Distinguished Alum and Benefactor • New Additions to Corson • Ursinus Welcomes New Resident Directors, Dyess and Ray • Renowned Psychologist to Speak on Research • Black History Figure of the Week: Peter Salem (1750-1816) • Opinion: Bill Clinton and the Hype About Sexual Harassment • 10 + 29 = Bridge Success • UC Bio Rocks • Independence in Avignon • Labyrinth Brings Relaxation • Mice Research Helping Humans • Ursinus Football Off to Rocky Start • Field Hockey in Full Swing • This Week in Soccer • UC Volleyball Blanks Rosemonthttps://digitalcommons.ursinus.edu/grizzlynews/1422/thumbnail.jp

The Grizzly, September 22, 1998

Ursinus Gears Up for Family Day • Dr. Fouts Gives Lecture on Chimpanzee Research • Freshman Class Election Results • Opinion: Ursinus\u27 Movement Towards Diversity; In Response to Has America Sunk to the Level of Terrorists? • Presentations on Family Day • Help is out There • Old Dogs Don\u27t Need New Tricks • Big, Big Band: Big, Big Success • Theater Life • Field Hockey Wrap-Up • UC Volleyball Evens Out at 2-2 • Bears Recognized in Centennial Conference Honor Roll • Lady Bears Suffer Conference Losses • Men\u27s Soccer Split Games • Football Falls in Conference Opener • Flo Jo Dies at 38 • Ripken Ends Streakhttps://digitalcommons.ursinus.edu/grizzlynews/1424/thumbnail.jp

The Grizzly, September 29, 1998

Construction Begins for New Bookstore • Ursinus Students Named Smith Scholars • Econ. Students Apply Classroom Knowledge • Opinion: Terrorist Debate Continues; Ursinus Keeps up With the Times; Students Vote Two Thumbs up for Co-ed Living • Is Home the way you Left it? • Students Spending Weekends Differently • Hugs Help Pottstown Hospital • Family Day \u2798 = Success • Kelley on Photography • Berman Exhibits Not Well Attended • Volleyball Hit With Key Injury • UC Football Gets Terrorized • Men\u27s Soccer Drops Two • Women\u27s Soccer Shuts-Out Dickinson • Who\u27s in Charge Here? • Women\u27s Rugby Overpowered by Lock Haven University • Centennial Conference Newshttps://digitalcommons.ursinus.edu/grizzlynews/1425/thumbnail.jp

Expressions 1988

https://openspace.dmacc.edu/expressions/1031/thumbnail.jp

Skunk River Review September 1989, vol 1 no 1

https://openspace.dmacc.edu/skunkriver/1004/thumbnail.jp

Histone H3K9 Trimethylase Eggless Controls Germline Stem Cell Maintenance and Differentiation

Epigenetic regulation plays critical roles in the regulation of cell proliferation, fate determination, and survival. It has been shown to control self-renewal and lineage differentiation of embryonic stem cells. However, epigenetic regulation of adult stem cell function remains poorly defined. Drosophila ovarian germline stem cells (GSCs) are a productive adult stem cell system for revealing regulatory mechanisms controlling self-renewal and differentiation. In this study, we show that Eggless (Egg), a H3K9 methyltransferase in Drosophila, is required in GSCs for controlling self-renewal and in escort cells for regulating germ cell differentiation. egg mutant ovaries primarily exhibit germ cell differentiation defects in young females and gradually lose GSCs with time, indicating that Egg regulates both germ cell maintenance and differentiation. Marked mutant egg GSCs lack expression of trimethylated H3K9 (H3k9me3) and are rapidly lost from the niche, but their mutant progeny can still differentiate into 16-cell cysts, indicating that Egg is required intrinsically to control GSC self-renewal but not differentiation. Interestingly, BMP-mediated transcriptional repression of differentiation factor bam in marked egg mutant GSCs remains normal, indicating that Egg is dispensable for BMP signaling in GSCs. Normally, Bam and Bgcn interact with each other to promote GSC differentiation. Interestingly, marked double mutant egg bgcn GSCs are still lost, but their progeny are able to differentiate into 16-cell cysts though bgcn mutant GSCs normally do not differentiate, indicating that Egg intrinsically controls GSC self-renewal through repressing a Bam/Bgcn-independent pathway. Surprisingly, RNAi-mediated egg knockdown in escort cells leads to their gradual loss and a germ cell differentiation defect. The germ cell differentiation defect is at least in part attributed to an increase in BMP signaling in the germ cell differentiation niche. Therefore, this study has revealed the essential roles of histone H3K9 trimethylation in controlling stem cell maintenance and differentiation through distinct mechanisms