The first stars of the Rho Ophiuchi Dark Cloud. XMM-Newton view of Rho Oph and its neighbors

Star formation in molecular clouds can be triggered by the dynamical action of winds from massive stars. Furthermore, X-ray and UV fluxes from massive stars can influence the life time of surrounding circumstellar disks. We present the results of a 53 ks XMM-Newton observation centered on the Rho Ophiuchi A+B binary system. Rho Ophiiuchi lies in the center of a ring of dust, likely formed by the action of its winds. This region is different from the dense core of the cloud (L1688 Core F) where star formation is at work. X-rays are detected from Rho Ophiuchi as well as a group of surrounding X-ray sources. We detected 89 X-ray sources, 47 of them have at least one counterpart in 2MASS + All-WISE catalogs. Based on IR and X-ray properties, we can distinguish between young stellar objects (YSOs) belonging to the cloud and background objects. Among the cloud members, we detect 3 debris disk objects and 22 disk-less / Class III young stars. We show that these stars have ages in $5-10$ Myr, and are significantly older than the YSOs in L1688. We speculate that they are the result of an early burst of star formation in the cloud. An X-ray energy of $\ge5\times10^{44}$ ergs has been injected into the surrounding medium during the past $5$ Myr, we discuss the effects of such energy budget in relation to the cloud properties and dynamics.Comment: 17 pages, 9 figures, 7 tables. Accepted for publication to Astronomy & Astrophysic

SIGNAL: SCUBA-Integrated Gear for Noiseless Audio and Lighting

SCUBA divers, both recreational and professional, need an effective way to communicate underwater, but there are drawbacks to all of the existing methods. Hand signals can easily be misinterpreted, and devices that use ultrasonic waves can disturb the underwater environment. This project explores using visible light as the signal canier instead of ultrasonic waves because it minimally disturbs the environment with a single beam of light instead of bouncing ultrasonic waves throughout the water. It also has virtually no harmful effects on the environment, and most divers already cany a light with them during a dive. The prototype costs $464.46 to build, less expensive than current underwater communication systems, and consists of a transmitter unit, a receiver unit, a set of bone conduction headphones, and a microphone. These parts are all waterproof except for the microphone, which will be enclosed in the diver\u27s full-face mask. The device uses an analog transmission scheme where the intensity of an array of four light-emitting diodes (LEDs) in the transmitter directly conesponds to the voice that the microphone captures. The photodiode in the receiver then picks up these changes in intensity, and the headphones play back the speaker\u27s voice. The receiver is powered by a single 9 V battery, while the transmitter is powered by two 9 V batteries: one for the printed circuit board (PCB) and one for the microphone. Since it is difficult to observe the circuit on a PCB with standard lab equipment due to its size, several signal tests are conducted with breadboard prototypes. According to the power consumption tests, if both the transmitter and receiver are powered by a single 9 V battery, the estimated battery life would be 2 hours and 43 minutes, which meets the 1 hour goal stated in the project charter. The project charter also states that the signal-to-noise ratio (SNR) of the headphone output must be at least 14 dB and operate at least 4 m apart. Depending on the lighting conditions, the SNR ratio varies considerably. The test results clearly show that the design cannot function at a distance of 4 m no matter what the lighting conditions. With respect to noise expected in an outdoor, underwater environment, the design achieves at least 14 dB up to a distance of around 0.61 m (2 ft) depending on the lighting conditions. The frequency response shows that the circuit passes frequencies between 25 Hz and 7 kHz, which encompasses the entire range of human voice and rejects most of the other frequencies within human hearing. Since the design is only intended to transmit human voice, any frequencies outside of human speech are not necessary. Outdoor and environmental testing with the breadboard prototype also shows that the design works in non-laboratory settings. The design works outside, provided the photodiode is not in direct sunlight. The sunlight\u27s DC current saturates the photodiode, rendering it incapable of detecting changes in LED intensity. To ensure clarity of the system alone, soundproof rooms with clear doors are also used in tests to isolate the listener from the speaker. These qualitative tests indicate that the system transmits voice clearly on its own. As expected, water attenuates the signal more than air, and greater distances produce greater differences in attenuation. The design described in this report can be improved in several ways. The design has not been properly tested on the PCB, and the transmitter and receiver should be condensed into a single unit powered by a single battery. More LEDs should also be used to improve SNR at a farther distance. All of the devices should also be waterproofed for common SCUBA diving depths. However, this design serves as a successful proof of concept for an underwater visible light communication system for SCUBA divers

Conjugation to polymeric chains of influenza drugs targeting M2 ion channels partially restores inhibition of drug-resistant mutants

By attaching multiple copies of the influenza M2 ion channel inhibitors amantadine (1) and rimantadine (2) to polymeric chains, we endeavored to recover their potency in inhibiting drug-resistant influenza viruses. Depending on loading densities, as well as the nature of the drug, the polymer, and the spacer arm, polymer-conjugated drugs were up to 30-fold more potent inhibitors of drug-resistant strains than their monomeric parents. In particular, a 20% loading density and a short linker group on the negatively charged poly-l-glutamate resulted in one of the most potent inhibitors for 2's conjugates against drug-resistant influenza strains. Although full recovery of the inhibitory action against drug-resistant strains was not achieved, this study may be a step toward salvaging anti-influenza drugs that are no longer effective.Martin Family Society of Fellows for SustainabilityNational Institutes of Health (U.S.) (Grant U01-AI074443

Retrospective Study Examining Obesity Hypoventilation Syndrome in COVID+ Patients

Purpose: Coronavirus disease 2019 (COVID-19) has affected millions of people all over the world with worse proven outcomes in those with certain comorbid conditions, such as diabetes, cardiovascular disease, and pulmonary complications. The Rio Grande Valley located in South Texas with a largely Hispanic population has been hit especially hard during this pandemic with over 3,200 virus-related deaths. This region’s high population of diabetic and obese patients is likely correlated with the especially high mortality rate. While it is understood the impact that obesity has on worsening health outcomes, further research is needed to better understand whether more adverse COVID-19 outcomes are correlated with an underdiagnosis of Obesity Hypoventilation Syndrome (OHS) amongst obese patients. Patients and Methods: Using an observational database from Valley Baptist Medical Center (VBMC) in Harlingen, TX, we gathered a list of COVID+ patients admitted between March 19, 2020 and September 25, 2020. COVID-19 was diagnosed based on World Health Organization (WHO) guidance. The official database is still a work-in-progress, as we are still working on manual data-entry for co-existing conditions and lab values for these patients. Once the database is completed, evaluation guidelines as listed in the American Journal of Respiratory and Critical Care Medicine will be used as a screening method to identify OHS in COVID+ patients. COVID-19 outcomes including hospitalization length, ICU transfer/admission, intubation count, in-hospital death will then be evaluated. Results: Of the 1114 patients with COVID-19+ included in our database, we have completed chart review on 112 patients. Once the database is completed, statistical analysis will be performed using Python to see if there is a higher percentage of adverse COVID-19+ outcomes in OHS-suspected patients compared to obese patients who don’t meet the criteria for OHS. Further analysis will also be done to compare these outcomes to the remaining admitted COVID+ patients. Conclusion: Database still in progress and no conclusion can be drawn at this time

CK1 is required for a mitotic checkpoint that delays cytokinesis

Failure to accurately partition genetic material during cell division causes aneuploidy and drives tumorigenesis [1]. Cell-cycle checkpoints safeguard cells from such catastrophes by impeding cell-cycle progression when mistakes arise. FHA-RING E3 ligases, including human RNF8 [2] and CHFR [3] and fission yeast Dma1 [4], relay checkpoint signals by binding phosphorylated proteins via their FHA domains and promoting ubiquitination of downstream targets [5]. Upon mitotic checkpoint activation, S. pombe Dma1 concentrates at spindle pole bodies (SPBs) in an FHA-dependent manner and ubiquitinates Sid4, a scaffold of Polo kinase, to suspend cytokinesis [6]. However, the kinase or kinases that phosphoprime Sid4 for Dma1-mediated ubiquitination are unknown. Here, we report that the highly conserved protein kinase CK1 transmits the signal necessary to stall cytokinesis by phosphopriming Sid4 for Dma1-mediated ubiquitination. Like Dma1, CK1 accumulates at SPBs during a mitotic arrest and associates stably with SPB components, including Sid4. Our results establish CK1 as an integral component of a mitotic, ubiquitin-mediated checkpoint pathway. © 2013 Elsevier Ltd

Animal Print: The Literary Production of Humane America.

This dissertation considers how humane literary texts mediate animal-human relationships and how these relationships, in turn, shape the expressive modes in which they are rendered. In studies of three popular animal-protection genres from the late-nineteenth century, it reconstructs print media’s role in establishing a kindness-to-animals ethic in the United States. It then carries its topic forward in time with an examination of animal-human relationships in mystery fiction. The first chapter, a literary-historical inquiry into Anna Sewell’s Black Beauty (1877) and its North American “sequels,” establishes a link between children’s literacy and the production of humane subjects. Focusing on George Thorndike Angell and the Massachusetts Society for the Prevention of Cruelty to Animals, this discussion explores the epistemological challenges confronting animal advocates who came of age in the moral-reform and abolitionist cultures of antebellum New England. A close examination of Elizabeth Stuart Phelps’s antivivisection novels, in the second chapter, suggests that imaginative literature infused the American humane movement with a sense of urgency by exploiting the formal properties of the classic romance plot. Phelps’s stolen-pet narratives revealed, in ways that other discursive forms did not, how vivisection threatened to corrode the nation’s happy homes. The third chapter, which is devoted to a discussion of fin de siècle field guides, argues that tensions between the emerging science of ornithology and the recreational practice of birdwatching generated new cultural ideas about the place of birds and natural-history study in American life. Revising earlier ornithological histories focused on the museum and the wilderness, this discussion centers the home and the backyard as the hubs of ornithological knowledge production in the nineteenth century. The fourth chapter serves as an investigation into a contemporary mass-market animal genre: the cat mystery. By exploring the interplay between narrative technique and mass-marketing strategy, this discussion acknowledges the genre’s ailurophilic readers as co-producers of their favorite series as well as targets of territorial mystery purists. The dissertation concludes with a consideration of the interrelation between literacy, childhood, and animals in contemporary Reading Education Assistance Dogs (R.E.A.D.) programs.PHDAmerican CultureUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/102418/1/alyssasc_1.pd