Modification of the biological intercept model to account for ontogenetic effects in laboratory-reared delta smelt (Hypomesus transpacificus)*

We investigated age, growth, and ontogenetic effects on the proportionality of otolith size to fish size in laboratory-reared delta smelt (Hypomesus transpacificus) from the San Francisco Bay estuary. Delta smelt larvae were reared from hatching in laboratory mesocosms for 100 days. Otolith increments from known-age fish were enumerated to validate that growth increments were deposited daily and to validate the age of fish at first ring formation. Delta smelt were found to lay down daily ring increments; however, the first increment did not form until six days after hatching. The relationship between otolith size and fish size was not biased by age or growth-rate effects but did exhibit an interruption in linear growth owing to an ontogenetic shift at the postflexon stage. To back-calculate the size-at-age of individual fish, we modified the biological intercept (BI) model to account for ontogenetic changes in the otolith-size−fish-size relationship and compared the results to the time-varying growth model, as well as the modified Fry model. We found the modified BI model estimated more accurately the size-at-age from hatching to 100 days after hatching. Before back-calculating size-at-age with existing models, we recommend a critical evaluation of the effects that age, growth, and ontogeny can have on the otolith-size−fish-size relation

"Do You Comb Your Hair?”: Detangling First-Generation Black Student Experiences in Internships

Thesis advisor: Deborah PiatelliThis study contributes to the growing literature on the effectiveness of diversity and inclusion efforts in organizations. Previous studies focus on D&I efforts for full-time staff and employees. This qualitative and intersectional study examined first-generation black students in corporatized organizations that are predominantly white through interviews where they could share their experiences with organizational structures and cultures to determine the impact that it has on the performance and identity of black interns. This study assessed organizational cultures of three kinds: exclusive, transitional, and inclusive. Using these organizational cultures, the study determined the way that racism and whiteness culture affects the intern experience. The participants had various relationships with recruitment strategies, diversity discussions, navigating professional and personal networking, negotiating working identity and imposter syndrome, stereotype threat, microaggressions, and professional development. Overall, organizations are engaging in practices that alienate and suppress black student interns while encouraging assimilation. In inclusive organizations, black interns feel like they can be their authentic selves and progress more successfully because of the acceptance of their identity and their ability to share their experiences with that identity.Thesis (BA) — Boston College, 2020.Submitted to: Boston College. College of Arts and Sciences.Discipline: .Discipline: Departmental Honors.Discipline: Sociology

Beyond the Brim of the Hat: Kinematics of Globular Clusters out to Large Radius in the Sombrero Galaxy

We have obtained radial velocity measurements for 51 new globular clusters around the Sombrero galaxy. These measurements were obtained using spectroscopic observations from the AAOmega spectrograph on the Anglo-Australian Telescope and the Hydra spectrograph at WIYN. Combined with our own past measurements and velocity measurements obtained from the literature we have constructed a large database of radial velocities that contains a total of 360 confirmed globular clusters. Previous studies' analyses of the kinematics and mass profile of the Sombrero globular cluster system have been constrained to the inner ~9' (~24 kpc or ~5 effective radii), but our new measurements have increased the radial coverage of the data, allowing us to determine the kinematic properties of M104 out to ~15' (~41 kpc or ~9 effective radii). We use our set of radial velocities to study the GC system kinematics and to determine the mass profile and V-band mass-to-light profile of the galaxy. We find that the V-band mass-to-light ratio increases from 4.5 at the center to a value of 20.9 at 41 kpc (~9 effective radii or 15'), which implies that the dark matter halo extends to the edge of our available data set. We compare our mass profile at 20 kpc (~4 effective radii or ~7.4') to the mass computed from x-ray data and find good agreement. We also use our data to look for rotation in the globular cluster system as a whole, as well as in the red and blue subpopulations. We find no evidence for significant rotation in any of these samples.Comment: Accepted for publication in the Astronomical Journal; 23 pages, 14 figures, and 2 table

Oral History Conversation with Charlene Espinoza (Bosh Bosh)

This was an oral history conversation with Charlene Espinoza on March 28, 2017

Structure of the NDH-2 - HQNO inhibited complex provides molecular insight into quinone-binding site inhibitors.

Type II NADH:quinone oxidoreductase (NDH-2) is a proposed drug-target of major pathogenic microorganisms such as Mycobacterium tuberculosis and Plasmodium falciparum. Many NDH-2 inhibitors have been identified, but rational drug development is impeded by the lack of information regarding their mode of action and associated inhibitor-bound NDH-2 structure. We have determined the crystal structure of NDH-2 complexed with a quinolone inhibitor 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO). HQNO is nested into the slot-shaped tunnel of the Q-site, in which the quinone-head group is clamped by Q317 and I379 residues, and hydrogen-bonds to FAD. The interaction of HQNO with bacterial NDH-2 is very similar to the native substrate ubiquinone (UQ1) interactions in the yeast Ndi1-UQ1 complex structure, suggesting a conserved mechanism for quinone binding. Further, the structural analysis provided insight how modifications of quinolone scaffolds improve potency (e.g. quinolinyl pyrimidine derivatives) and suggests unexplored target space for the rational design of new NDH-2 inhibitors

Leveraging Public-Private Partnerships During COVID-19: Providing Virtual Field Opportunities for Student Learners and Addressing Social Isolation in Older Adults

While preventive and management measures are important to mitigate the spread of COVID-19, strategies like social distancing can have devastating effects on older adults who are already at risk for social isolation and loneliness. In response, two Colleges of Health Professions (Social Work and Nursing) at a large public University leveraged a partnership with a national health and wellbeing company to address social isolation and loneliness in Houston area older adults during the COVID-19 pandemic. This intergenerational linkage initiative involved 707 older adults and 177 graduate social work and nursing students. This study describes the process of developing a virtual educational opportunity for students while also meeting the needs of vulnerable older adults in Houston, the third largest, and one of the most diverse cities in the U.S. Findings include student/learner outcomes, as well as self-reported improvements in loneliness scores, and unhealthy physical and mental health days among enrolled older adults

WIYN Imaging of the Globular Cluster Systems of the Spiral Galaxies NGC891 and NGC4013

We present results from a WIYN 3.5m telescope imaging study of the globular cluster (GC) systems of the edge-on spiral galaxies NGC891 and NGC4013. We used the 10' x 10' Minimosaic Imager to observe the galaxies in BVR filters to projected radii of ~20 kpc from the galaxy centers. We combined the WIYN data with archival and published data from WFPC2 and ACS on the Hubble Space Telescope to assess the contamination level of the WIYN GC candidate sample and to follow the GC systems further in toward the galaxies' centers. We constructed radial distributions for the GC systems using both the WIYN and HST data. The GC systems of NGC891 and NGC4013 extend to 9+/-3 kpc and 14+/-5 kpc, respectively, before falling off to undetectable levels in our images. We use the radial distributions to calculate global values for the total number (N_GC) and specific frequencies (S_N and T) of GCs. NGC4013 has N_GC = 140+/-20, S_N = 1.0+/-0.2 and T = 1.9+/-0.5; our N_GC value is ~40% smaller than a previous determination from the literature. The HST data were especially useful for NGC891, because the GC system is concentrated toward the plane of the galaxy and was only weakly detected in our WIYN images. Although NGC891 is thought to resemble the Milky Way in its overall properties, it has only half as many GCs, with N_GC = 70+/-20, S_N = 0.3+/-0.1 and T = 0.6+/-0.3. We also calculate the galaxy-mass-normalized number of blue (metal-poor) GCs in NGC891 and NGC4013 and find that they fall along a general trend of increasing specific frequency of blue GCs with increasing galaxy mass. Given currently available resources, the optimal method for studying the global properties of extragalactic GC systems is to combine HST data with wide-field, ground-based imaging with good resolution. The results here demonstrate the advantage gained by using both methods when possible.Comment: 43 pages, 11 figures 6 tables; accepted to The Astronomical Journal. Online AJ version at http://iopscience.iop.org/1538-3881/140/2/430

The efficacy of interventions for behaviourally inhibited preschool-aged children: A meta-analysis

The current systematic review and meta-analyses examined the efficacy of psychological interventions targeting behavioural inhibition and anxiety in preschool-aged children, evaluated within randomised controlled trials. Web of Science, MEDLINE, PsycINFO and CINAHL were systematically searched from inception to March 2021. Ten studies (N = 1475 children, aged 3 – 7 years) were included in the current review. Separate analyses were conducted for behavioural inhibition, anxiety symptoms, and anxiety diagnosis as reported by parents, teachers, and observer-ratings. Pooled outcomes ranged from post-intervention to 12-month follow-up due to the limited number of studies. Meta-analyses revealed that intervention did not reduce behavioural inhibition as assessed by independent observers (SMD = -.13, 95% CI = -.63 to.38), but did reduce behavioural inhibition as reported by parents (SMC = -.64, 95% CI = -1.00 to -.27) and teachers (SMD = -.69, 95% CI = -1.02 to -.36). Additionally, intervention appeared to reduce the risk of anxiety disorders (RR =.75, 95% CI =.62 to.90), and parent-report anxiety symptoms (SMC = -.47, 95% CI = -.83 to -.12) in preschool-aged children. Intervention may be efficacious in reducing anxiety in preschool-aged behaviourally inhibited children. It is less clear whether intervention leads to change in BI

HAWAII ALGAL BIOFUEL

This report investigates the feasibility and affordability of producing algae-derived biofuel in Hawaii for military aviation. The authors evaluated methods for cultivation of algae, investigated the processes necessary to locally refine bio-oil into bio-kerosene, researched the environmental impacts of cultivation and refinement facilities in Hawaii, and studied the resultant cost per gallon of bio-kerosene production. Based on the current state of technology and the proposed system of systems architecture, this report estimates that bio-kerosene can be produced for $8.00 - 22.87/gal, indicating that although this system is technically feasible, it is unlikely to be affordable at current fuel prices without ongoing subsidy or further technical innovation.http://archive.org/details/hawaiialgalbiofu109453289

SEM-EDS investigation on PM10 data collected in Central Italy: Principal Component Analysis and Hierarchical Cluster Analysis

<p>Abstract</p> <p>Background</p> <p>Combined Heat and Power (CHP) systems can provide a range of benefits to users with regards to efficiency, reliability, costs and environmental impact. Furthermore, increasing the amount of electricity generated by CHP systems in the United States has been identified as having significant potential for impressive economic and environmental outcomes on a national scale. Given the benefits from increasing the adoption of CHP technologies, there is value in improving our understanding of how desired increases in CHP adoption can be best achieved. These obstacles are currently understood to stem from regulatory as well as economic and technological barriers. In our research, we answer the following questions: Given the current policy and economic environment facing the CHP industry, what changes need to take place in this space in order for CHP systems to be competitive in the energy market?</p> <p>Methods</p> <p>We focus our analysis primarily on Combined Heat and Power Systems that use natural gas turbines. Our analysis takes a two-pronged approach. We first conduct a statistical analysis of the impact of state policies on increases in electricity generated from CHP system. Second, we conduct a Cost-Benefit analysis to determine in which circumstances funding incentives are necessary to make CHP technologies cost-competitive.</p> <p>Results</p> <p>Our policy analysis shows that regulatory improvements do not explain the growth in adoption of CHP technologies but hold the potential to encourage increases in electricity generated from CHP system in small-scale applications<it>.</it> Our Cost-Benefit analysis shows that CHP systems are only cost competitive in large-scale applications and that funding incentives would be necessary to make CHP technology cost-competitive in small-scale applications.</p> <p>Conclusion</p> <p>From the synthesis of these analyses we conclude that because large-scale applications of natural gas turbines are already cost-competitive, policy initiatives aimed at a CHP market dominated primarily by large-scale (and therefore already cost-competitive) systems have not been effectively directed. Our recommendation is that for CHP technologies using natural gas turbines, policy focuses should be on increasing CHP growth in small-scale systems. This result can be best achieved through redirection of state and federal incentives, research and development, adoption of smart grid technology, and outreach and education.</p