Effects of prostaglandin F₂α on in vitro and in vivo development of preimplantation rat embryos

Two experiments were conducted to determine the effect of prostaglandin F2α, (PGF2α) on in vitro and in vivo development of preimplantation rat embryos. In Trial 1 of the first experiment, seven-hundred-twenty three 8-cell embryos from superovulated female Sprague-Dawley rats were collected four days after natural mating. Embryos were cultured in alpha- Minimum Essential Medium (αMEM) supplemented with 0.1% polyvinyl alcohol (control;n=179) or control medium supplemented with one of the following levels of prostaglandin F2α 1) 0.1 ng/ml(n=176) , 2) 1.0 ng/ml(n=176) or 3) 10 ng/ml(n=162). After 24 hours of incubation in their respective treatments, stages of embryonic development were recorded and morphologically normal embryos were transferred to control media for an additional 24 h. Following 24 h of culture, 63% of control embryos had continued development to the morula or blastocyst stage. However, only 20, 15, and 16% of the embryos treated with 0.1, 1.0, and 10 ng/ml PGF2α, respectively, continued development to the morula and blastocyst stage. All levels of prostaglandin F2α decreased the number of embryos developing to the expanded blastocyst stage after 48 h of culture (p\u3c0.01). Furthermore, a second trial was performed in which embryos were placed with corpora lutea in 2 of 4 treatments, consisting of the following: 1)control (αMEM;n=30), 2)control-luteal (corpora lutea + αMEM;n=30), 3)PGF-luteal (corpora lutea + 10 ng/ml PGF2α;n=30) and 4)PGF-control (10ng/ml PGF2α +αMEM;n=41). The percentage of embryos in the CL + αMEM treatment that reached the blastocyst stage (43.3%) was not statistically different from the controls (37.8%;p\u3e.10). However, the co-culture of corpora lutea and PGF2α tended (p\u3c0.07) to increase the negative effects of PGFzc, on blastocyst development (19%) when compared to the PGF2α group. To investigate the effects of PGF2a on in vivo development of preimplantation embryos, prostaglandin F2α (0.5 and 1 mg) was administered to rats twice daily during Days 4-7 of pregnancy. All animals were also injected with 4 mg/day of progesterone from Days 4-11 of treatment. On Day 11, animals were euthanized by CO2 overdose and the number of implantation sites determined. Prostaglandin F2α, was not effective in terminating pregnancy or reducing litter size. These data suggest that increased levels of prostaglandin F2α, have a direct negative effect on in vitro embryonic development. However, exogenous PGF2α, had no effect on embryonic survival, suggesting that PGF2α may not attain embryotoxic concentrations within the uterus, possibly because of conversion to PGE2

The Use of Narratives and Social Media in Arts & Culture Nonprofit Crisis Communication During COVID-19

The COVID-19 pandemic interrupted established communication practices for organizations across the globe. While much attention focused on the adaptability of large corporations, less attention has been paid to how nonprofit organizations have responded. At a time when the COVID-19 pandemic was creating ripple effects in social service needs, nonprofit organizations that did not directly address public health still fulfilled urgent missions and needed to communicate their legitimacy to assist with community resilience efforts. This study discovered the roles narratives and social media played in nonprofit organizational crisis communication during the COVID-19 pandemic through interviews with 12 participants. Using situational crisis communication and narrative theories, the study found that nonprofits engaged with different and diverse crisis communication strategies that extended far beyond those theorized. Nonprofit organizations successfully used narratives on social media during crisis communication to support and advance their missions in online spaces and encourage emotional identification with the organization. Most significantly, NPOs seemed concerned with appearing competent and in control throughout the crisis, and the use of narratives in crisis communication allowed nonprofits to preserve and promote organizational reputation

Low-Energy Electron-Track Imaging for a Liquid Argon Time-Projection-Chamber Telescope Concept using Probabilistic Deep Learning

The GammaTPC is an MeV-scale single-phase liquid argon time-projection-chamber gamma-ray telescope concept with a novel dual-scale pixel-based charge-readout system. It promises to enable a significant improvement in sensitivity to MeV-scale gamma-rays over previous telescopes. The novel pixel-based charge readout allows for imaging of the tracks of electrons scattered by Compton interactions of incident gamma-rays. The two primary contributors to the accuracy of a Compton telescope in reconstructing an incident gamma-ray's original direction are its energy and position resolution. In this work, we focus on using deep learning to optimize the reconstruction of the initial position and direction of electrons scattered in Compton interactions, including using probabilistic models to estimate predictive uncertainty. We show that the deep learning models are able to predict locations of Compton scatters of MeV-scale gamma-rays from simulated pixel-based data to better than 0.6 mm RMS error, and are sensitive to the initial direction of the scattered electron. We compare and contrast different deep learning uncertainty estimation algorithms for reconstruction applications. Additionally, we show that event-by-event estimates of the uncertainty of the locations of the Compton scatters can be used to select those events that were reconstructed most accurately, leading to improvement in locating the origin of gamma-ray sources on the sky

Results of the MAJORANA DEMONSTRATOR's Search for Double-Beta Decay of 76Ge to Excited States of 76Se

The MAJORANA DEMONSTRATOR is searching for double-beta decay of 76Ge to excited states (E.S.) in 76Se using a modular array of high purity Germanium detectors. 76Ge can decay into three E.S.s of 76Se. The E.S. decays have a clear event signature consisting of a ββ-decay with the prompt emission of one or two γ-rays, resulting in with high probability in a multi-site event. The granularity of the DEMONSTRATOR detector array enables powerful discrimination of this event signature from backgrounds. Using 21.3 kg-y of isotopic exposure, the DEMONSTRATOR has set world leading limits for each E.S. decay, with 90% CL lower half-life limits in the range of (0.56 2.1) ⋅ 1024 y. In particular, for the 2v transition to the first 0+ E.S. of 76Se, a lower half-life limit of 0.68 ⋅ 1024 at 90% CL was achieved

ADC Nonlinearity Correction for the Majorana Demonstrator

Imperfections in analog-to-digital conversion (ADC) cannot be ignored when signal digitization requirements demand both wide dynamic range and high resolution, as is the case for the Majorana Demonstrator 76Ge neutrinoless double-beta decay search. Enabling the experiment's high-resolution spectral analysis and efficient pulse shape discrimination required careful measurement and correction of ADC nonlinearities. A simple measurement protocol was developed that did not require sophisticated equipment or lengthy data-taking campaigns. A slope-dependent hysteresis was observed and characterized. A correction applied to digitized waveforms prior to signal processing reduced the differential and integral nonlinearities by an order of magnitude, eliminating these as dominant contributions to the systematic energy uncertainty at the double-beta decay Q value

Contamination Control and Assay Results for the Majorana Demonstrator Ultra Clean Components

The MAJORANA DEMONSTRATOR is a neutrinoless double beta decay experiment utilizing enriched Ge-76 detectors in 2 separate modules inside of a common solid shield at the Sanford Underground Research Facility. The DEMONSTRATOR has utilized world leading assay sensitivities to develop clean materials and processes for producing ultra-pure copper and plastic components. This experiment is now operating, and initial data provide new insights into the success of cleaning and processing. Post production copper assays after the completion of Module 1 showed an increase in U and Th contamination in finished parts compared to starting bulk material. A revised cleaning method and additional round of surface contamination studies prior to Module 2 construction have provided evidence that more rigorous process control can reduce surface contamination. This article describes the assay results and discuss further studies to take advantage of assay capabilities for the purpose of maintaining ultra clean fabrication and process design.Comment: Proceedings of Low Radioactivity Techniques (LRT May 2017, Seoul