Andrews University Communication under the COVID-19 Pandemic: Feedback Analysis of International Students

This research is an informative analysis of international students’ feedback on the Andrews University (AU) crisis communication during the COVID-19 pandemic in 2020. Participants were 21 years or older, on student visas, living on-campus or in student communities and had attended AU for at least 2 years. The theory informing this study is situational crisis communication theory (SCCT). The SCCT argues that the severity of the crisis defines which communicational crisis strategy will be more effective in minimizing attributions and adverse press while both maintaining and enhancing the organization\u27s credibility. The findings of this study indicated that 84 percent of the sample were either moderately or extremely satisfied with the AU crisis communication, which was essentially based on email communication. However, 16 percent of the participants found those emails ineffective. The study was significant to the researcher because, as a direct victim of the pandemic, he witnessed how the AU administration handled it. Participants provided insights based on their individual experiences. From a customer retention standpoint, higher education institutions will profit from the findings of this report. It will be a valuable tool for developing a new customer service chart in the likelihood that any higher educational institution, such as Andrews University, is expected to deal with a similar crisis in the future. However, further research should be undertaken to evaluate grade trends among foreign students who have no prior online learning experience but are now taking classes remotely due to the COVID-19 pandemic

Clustering-based Redshift Estimation: Comparison to Spectroscopic Redshifts

We investigate the potential and accuracy of clustering-based redshift estimation using the method proposed by M\'enard et al. (2013). This technique enables the inference of redshift distributions from measurements of the spatial clustering of arbitrary sources, using a set of reference objects for which redshifts are known. We apply it to a sample of spectroscopic galaxies from the Sloan Digital Sky Survey and show that, after carefully controlling the sampling efficiency over the sky, we can estimate redshift distributions with high accuracy. Probing the full colour space of the SDSS galaxies, we show that we can recover the corresponding mean redshifts with an accuracy ranging from $\delta$z=0.001 to 0.01. We indicate that this mapping can be used to infer the redshift probability distribution of a single galaxy. We show how the lack of information on the galaxy bias limits the accuracy of the inference and show comparisons between clustering redshifts and photometric redshifts for this dataset. This analysis demonstrates, using real data, that clustering-based redshift inference provides a powerful data-driven technique to explore the redshift distribution of arbitrary datasets, without any prior knowledge on the spectral energy distribution of the sources.Comment: 13 pages. Submitted to MNRAS. Comments welcom

The Eccentricity Distribution of Short-Period Planet Candidates Detected by Kepler in Occultation

We characterize the eccentricity distribution of a sample of ~50 short-period planet candidates using transit and occultation measurements from NASA's Kepler Mission. First, we evaluate the sensitivity of our hierarchical Bayesian modeling and test its robustness to model misspecification using simulated data. When analyzing actual data assuming a Rayleigh distribution for eccentricity, we find that the posterior mode for the dispersion parameter is $\sigma=0.081 \pm^{0.014}_{0.003}$. We find that a two-component Gaussian mixture model for $e \cos \omega$ and $e \sin \omega$ provides a better model than either a Rayleigh or Beta distribution. Based on our favored model, we find that $\sim90\%$ of planet candidates in our sample come from a population with an eccentricity distribution characterized by a small dispersion ($\sim0.01$), and $\sim10\%$ come from a population with a larger dispersion ($\sim0.22$). Finally, we investigate how the eccentricity distribution correlates with selected planet and host star parameters. We find evidence that suggests systems around higher metallicity stars and planet candidates with smaller radii come from a more complex eccentricity distribution.Comment: Accepted for publication in Ap

Morphological and molecular characterization of Isospora neochmiae n. sp. in a captive-bred red-browed finch (Neochmia temporalis) (Latham, 1802)

A new Isospora (Apicomplexa: Eimeriidae) species is described from a single red-browed finch (Neochmia temporalis) (subspecies N. temporalis temporalis), that was part of a captive population in Western Australia. Sporulated oocysts of this isolate are spherical, 18.3 (18.2-18.9) × 18.2 (18.2-18.6) μm, with a shape index (length/width) of 1.0; and a smooth and bilayered oocyst wall, 1.2 μm thick (outer layer 0.9 μm, inner 0.3 μm). A polar granule is present, but the oocyst residuum and a micropyle are absent. The sporocysts are ovoid-shaped, 13.3 (9.5-16.4) × 8.6 (6.8-10.0) μm, with a shape index of 1.5. An indistinct Stieda body is present, but the substieda body is absent. A sporocyst residuum is present and composed of numerous granules of different size scattered among the sporozoites. Morphologically, the oocysts from this isolate are different from those of all known valid Isospora spp. Molecular analysis was conducted at 4 loci; the 18S and 28S ribosomal RNA (rRNA), the mitochondrial cytochrome oxidase (COI) gene and the heat shock protein 70 (hsp70) gene. At the 18S locus, this new isolate exhibited 99.9%, 99.8%, 99.7%, and 99.5% similarity to I. sp. MAH-2013a from a superb starling (Lamprotornis superbus), I. MS-2003 from a Southern cape sparrow (Passer melanurus), I. sp. Tokyo from a domestic pigeon (Columba livia domestica) and I. MS-2003 from a Surinam crested oropendula (Psarocolius decumanus). At the 28S locus, this new isolate exhibited 99.7% similarity to both an Isospora sp (MS-2003) from a Northern house sparrow (Passer domesticus) and an Isospora sp. (MS-2003) from a Southern cape sparrow. At the COI locus, this new isolate exhibited 98.9% similarity to an Isospora sp. ex Apodemus flavicollis. At the hsp70 locus, this new isolate exhibited 99% similarity to isolate MS-2003 (. AY283879) from a wattled starling (Creatophora cinerea). Based on morphological and molecular data, this isolate is a new species of Isospora, which is named Isospora neochmiae n. sp. after its host, the red-browed finch (Neochmia temporalis)

Antiproton triggered fusion propulsion for interstellar missions

Interstellar precursor missions have been the subject of recent investigations. Current proposals include a thousand and a ten thousand astronomical unit mission, both to be completed in fifty years. These interstellar precursor missions provide a means to develop payload, communication, guidance and propulsion systems that could ultimately send payloads to the stars. The one thousand astronomical unit mission could be completed by improvements in nuclear electric systems, but the ten thousand astronomical unit mission is considerably more difficult. Antiproton triggered fusion propulsion systems provide a means to develop fusion propulsion in the near term. These systems rely on antiprotons to fission a subcritical mass of uranium or plutonium. The energy released in the fission reaction is then used to trigger fusion in a pellet. A 1000 astronomical unit mission can be completed in 50 years with a mass ratio of 1.06, while for a 10,000 astronomical unit mission the ratio is 1.87. A flyby of the nearest star, at 270,000 astronomical units, requires a mass ratio of at least 64. © 1999 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87460/2/1333_1.pd

Future of Antiproton Triggered Fusion Propulsion

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76963/1/AIAA-2009-4871-470.pd

MICF: A fusion propulsion system for interstellar missions

A very promising propulsion device that could open up the solar system and beyond to human exploration is the Magnetically Insulated Inertial Confinement Fusion (MICF) system. This scheme combines the favorable aspects of inertial and magnetic fusion into one where physical containment of the hot plasma is provided by a metal shell while its thermal energy is insulated from this wall by a strong, self-generated magnetic field. The fusion nuclear reactions in this device can be triggered by a beam of antiprotons that enters the target through a hole and annihilates on the deuterium-tritium (DT) coated inner wall giving rise to the hot fusion plasma. In addition to thermally insulating the plasma, the magnetic field helps to contain the charged annihilation products and allows them to deposit their energy in the plasma to heat it to thermonuclear temperatures. Preliminary analysis given in this paper shows that an MICF propulsion system is capable of producing specific impulses on the order of 106106 seconds. Such capability makes not only the most distant planet in the solar system, but also the nearest star reachable in a human’s lifetime. It also shows that a robotic mission to 10,000 AU can readily be achieved in less than 50 years. © 2000 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87638/2/984_1.pd

A Newly Designed Baggage Transfer System Implemented Using Event-Based Simulations

This paper proposes a newly designed system for baggage transfer, which utilises the Nexus Metro system in Newcastle-Upon-Tyne by running a pendulum freight train system between the Haymarket and Newcastle Airport to carry travellers’ baggage. This system is capable of serving all passengers departing from Newcastle Airport in a day, with a capacity of 9750 bags across 26 freight train journeys. Following the initial solution two more solutions were designed with the aims of maximising the utilisation of the metro tracks by saturating the system with freight trains on a 24 hour system. All solutions have been replicated using models designed and validated by event based simulation using SIMUL8, a simulation modelling software package