Men nurses: job opportunities in nursing

Thesis (M.S.)--Boston Universit

Pirates for Academic Success

ECU reported in 2019 that the school had an overall retention rate of 83%. Although this percentage seems high, it is nothing compared to UNC Chapel Hill’s overall retention rate of 97.2% or Duke’s rate of 97.6%, (both reported from 2013-2017.) Because of this our group decided to research why ECU’s retention rate was so much lower than surrounding universities and provide resources and information to take a step forward in solving these problems. After spending our first year conducting interviews among students, it was clear that most students were not aware of the resources offered to them on campus. Some were not even aware of their style of learning and how to effectively study for upcoming exams or quizzes. From this we created Pirates for Academic Success. Our goal was to make videos explaining not only what resources were available on campus that you may not know about but also explain different studying techniques and how discovering your style of learning can lead to a more effective study pattern. Doing this allows students who do not know ECU campus that well or who do not know many other students a way to find resources in a less intimidating way. This can lead to higher grades, more confidence in coursework and classes, and a higher chance of students staying at ECU for a second year. “Confident students develop relationships with faculty that can lead to participation in research and other developmental activities...this leads further to potential future connections, letters of recommendation, internships, future work, or graduate school� (Croskey, 2021). Our group has set up a Vimeo containing videos ranging from how to use different online homework platforms such as Cengage to resources at the library students may not be aware of and how to effectively use them. Through this we have established a relationship with the library, marketing our videos and receiving exclusive access to the library to make more videos using their equipment

The Stellar Ages and Masses of Short GRB Host Galaxies: Investigating the Progenitor Delay Time Distribution and the Role of Mass and Star Formation in the Short GRB Rate

[Abridged] We present optical and NIR observations of 19 short GRB host galaxies, aimed at measuring their stellar masses and population ages. The goals of this study are to evaluate whether short GRBs track the stellar mass distribution of galaxies, to investigate the progenitor delay time distribution, and to explore any connection between long and short GRB progenitors. Using single stellar population models we infer masses of log(M/M_sun)=8.8-11.6 and population ages of tau=0.03-4.4 Gyr. We further infer maximal masses of log(M/M_sun)=9.7-11.9 by assuming stellar population ages equal to the age of the universe at each host's redshift. Comparing the distribution of stellar masses to the general galaxy mass function we find that short GRBs track the cosmic stellar mass distribution only if the late-type hosts generally have maximal masses. However, there is an apparent dearth of early-type hosts compared to the equal contribution of early- and late-type galaxies to the cosmic stellar mass budget. These results suggest that stellar mass may not be the sole parameter controlling the short GRB rate, and raise the possibility of a two-component model with both mass and star formation playing a role. If short GRBs in late-type galaxies indeed track the star formation activity, the resulting typical delay time is ~0.2 Gyr, while those in early-type hosts have a typical delay of ~3 Gyr. Using the same stellar population models we fit the data for 22 long GRB hosts and find that they have lower masses and younger population ages, with =9.1 and =0.06 Gyr, respectively; their maximal masses are similarly lower, =9.6. Most importantly, the two host populations remain distinct even if we consider only the star-forming hosts of short GRBs, supporting our previous findings that the progenitors of long GRBs and short GRBs in late-type galaxies are distinct.Comment: Submitted to ApJ; 20 pages, 3 tables, 8 figure

Making adaptable systems work for mission operations: A case study

The Advanced Multimission Operations System (AMMOS) at NASA's Jet Propulsion Laboratory is based on a highly adaptable multimission ground data system (MGDS) for mission operations. The goal for MGDS is to support current flight project science and engineering personnel and to meet the demands of future missions while reducing associated operations and software development costs. MGDS has become a powerful and flexible mission operations system by using a network of heterogeneous workstations, emerging open system standards, and selecting an adaptable tools-based architecture. Challenges in developing adaptable systems for mission operations and the benefits of this approach are described

Effective interactions in the colloidal suspensions from HNC theory

The HNC Ornstein-Zernike integral equations are used to determine the properties of simple models of colloidal solutions where the colloids and ions are immersed in a solvent considered as a dielectric continuum and have a size ratio equal to 80 and a charge ratio varying between 1 and 4000. At an infinite dilution of colloids, the effective interactions between colloids and ions are determined for ionic concentrations ranging from 0.001 to 0.1 mol/l and compared to those derived from the Poisson-Boltzmann theory. At finite concentrations, we discuss on the basis of the HNC results the possibility of an unambiguous definition of the effective interactions between the colloidal molecules.Comment: 26 pages, 15 figure

The impact of mass-loss on the evolution and pre-supernova properties of red supergiants

The post main-sequence evolution of massive stars is very sensitive to many parameters of the stellar models. Key parameters are the mixing processes, the metallicity, the mass-loss rate and the effect of a close companion. We study how the red supergiant lifetimes, the tracks in the Hertzsprung-Russel diagram (HRD), the positions in this diagram of the pre-supernova progenitor as well as the structure of the stars at that time change for various mass-loss rates during the red supergiant phase (RSG), and for two different initial rotation velocities. The surface abundances of RSGs are much more sensitive to rotation than to the mass-loss rates during that phase. A change of the RSG mass-loss rate has a strong impact on the RSG lifetimes and therefore on the luminosity function of RSGs. At solar metallicity, the enhanced mass-loss rate models do produce significant changes on the populations of blue, yellow and red supergiants. When extended blue loops or blue ward excursions are produced by enhanced mass-loss, the models predict that a majority of blue (yellow) supergiants are post RSG objects. These post RSG stars are predicted to show much smaller surface rotational velocities than similar blue supergiants on their first crossing of the HR gap. The position in the HRD of the end point of the evolution depends on the mass of the hydrogen envelope. More precisely, whenever, at the pre-supernova stage, the H-rich envelope contains more than about 5\% of the initial mass, the star is a red supergiant, and whenever the H-rich envelope contains less than 1\% of the total mass the star is a blue supergiant. For intermediate situations, intermediate colors/effective temperatures are obtained. Yellow progenitors for core collapse supernovae can be explained by the enhanced mass-loss rate models, while the red progenitors are better fitted by the standard mass-loss rate models.Comment: 19 pages, 11 figures, 6 tables, accepted for publication in Astronomy and Astrophysic

Molecular Density Functional Theory of Water describing Hydrophobicity at Short and Long Length Scales

We present an extension of our recently introduced molecular density functional theory of water [G. Jeanmairet et al., J. Phys. Chem. Lett. 4, 619, 2013] to the solvation of hydrophobic solutes of various sizes, going from angstroms to nanometers. The theory is based on the quadratic expansion of the excess free energy in terms of two classical density fields, the particle density and the multipolar polarization density. Its implementation requires as input a molecular model of water and three measurable bulk properties, namely the structure factor and the k-dependent longitudinal and transverse dielectric susceptibilities. The fine three-dimensional water structure around small hydrophobic molecules is found to be well reproduced. In contrast the computed solvation free-energies appear overestimated and do not exhibit the correct qualitative behavior when the hydrophobic solute is grown in size. These shortcomings are corrected, in the spirit of the Lum-Chandler-Weeks theory, by complementing the functional with a truncated hard-sphere functional acting beyond quadratic order in density. It makes the resulting functional compatible with the Van-der-Waals theory of liquid-vapor coexistence at long range. Compared to available molecular simulations, the approach yields reasonable solvation structure and free energy of hard or soft spheres of increasing size, with a correct qualitative transition from a volume-driven to a surface-driven regime at the nanometer scale.Comment: 24 pages, 8 figure