A taxonomic revision of Camptocerus Dejean (Coleoptera: Curculionidae: Scolytinae)

The Neotropical ambrosia beetle genus Camptocerus Dejean was revised. Monophyly of the genus was tested using 66 morphological characters in a cladistic analysis. Camptocerus was recovered as monophyletic and 31 species were recognized. Six new synonyms were discovered: C. auricomus Blandford 1896 (= C. striatulus Hagedorn 1905), C. inoblitus (Schedl) 1939 (= C. morio (Schedl) 1952), C. niger (Fabricius) 1801 (= C. tectus Eggers 1943), C. opacicollis (Eggers) 1929 (= C. infidelis Wood 1969; = C. uniseriatus Schedl 1972), C. suturalis (Fabricius) 1801 (= C. cinctus Chapuis 1869). Two species were removed from synonymy: C. charpentierae Schedl and C. hirtipennis Schedl. Twelve new species of Camptocerus were described: C. coccoformus (Brazil, Ecuador), C. distinctus (Ecuador), C. doleae (Ecuador), C. igniculus (Brazil), C. mallopterus (Ecuador), C. noel (widely distributed across Amazonia), C. petrovi (Ecuador), C. pilifrons (Ecuador), C. pseudoangustior (widely distributed across Amazonia), C. satyrus (Brazil), C. unicornus (Brazil) and C. zucca (Ecuador). Lectotypes are here designated for the following species: Camptocerus auricomus Blandford, Camptocerus squammiger Chapuis, Hylesinus gibbus Fabricius, Hylesinus suturalis Fabricius, Hylesinus fasciatus Fabricius. A key, diagnosis, distribution, host records and images were provided for each species

Impurity transport in a mixed-collisionality stellarator plasma

A potential threat to the performance of magnetically confined fusion plasmas is the problem of impurity accumulation, which causes the concentration of highly charged impurity ions to rise uncontrollably in the center of the plasma and spoil the energy confinement by excessive radiation. It has long been thought that the collisional transport of impurities in stellarators always leads to such accumulation (if the electric field points inwards, which is usually the case), whereas tokamaks, being axisymmetric, can benefit from "temperature screening", i.e., an outward flux of impurities driven by the temperature gradient. Here it is shown, using analytical techniques supported by results from a new numerical code, that such screening can arise in stellarator plasmas too, and indeed does so in one of the most relevant operating regimes, where the impurities are highly collisional whilst the bulk plasma is in any of the low-collisionality regimes.Comment: 11 pages, 3 figure

Barriers to graduation: an examination of first-generation college students

Thesis (M.A.) University of Alaska Fairbanks, 2012The college experience of first- generation college students is unique in comparison to their peers. Many students do not have the support from their family and require help in the navigation of college life. Student Support Services, a federally funded TRIO program helps students successfully graduate with a bachelor's degree. Qualitative interviews were conducted on ten undergraduate students at UAF who were labeled as first-generation college students. All ten students were active participants in Student Support Services at the University of Alaska Fairbanks during the time of the interview. A thematic analysis produced six emergent themes. It was found that students utilized communicative strategies based on Orbe's co-cultural communication theory. First-generation college students, a non-dominant part of society, tried to negotiate through the University system, the dominant section of society. Through this negotiation, a co-cultural group was formed.1. Introduction -- 1.1. Rationale for study -- 2. Literature review -- 2.1. First generation students -- 2.2. Supporting university students -- 2.2.1. Student support services -- 2.2.2. Advising programs -- 2.3. Theoretical framework -- 2.3.1. Standpoint theory -- 2.3.2. Co-cultural communication theory -- 2.4. Research questions -- 3. Methodology -- 3.1. Theoretical framework -- 3.2. Theoretical perspectives -- 3.3. Research methodology -- 3.4. Methods -- 3.4.1. Objectivity and researcher as instrument -- 3.4.2. Validity -- 3.4.3. Reliability -- 3.4.4. Lived experience and generation of knowledge -- 3.5. Procedures -- 3.6. Participants -- 3.7. Analysis -- 4. Results -- 4.1. Nicole's conversational interview -- 4.2. Jamie's conversational interview --4.3. Carolyn's conversational interview -- 4.4. Robert's conversational interview -- 4.5. Brian's conversational interview -- 4.6. Elizabeth's conversational interview -- 4.7. Alex's conversational interview -- 4.8. Emily's conversational interview -- 4.9. Samantha's conversational interview -- 4.10. Mandi's conversational interview -- 5. Analysis & discussion -- 5.1. I should be at home tucking in my kids -- 5.1.1. Financial -- 5.1.2. Family -- 5.2. "First generation? We're all alone. Nobody likes us."-Alex -- 5.2.1. First generation -- 5.2.2. Non-traditional students -- 5.2.3. Low self-confidence -- 5.3. "There's this part that your family, they just never understood."-Mandi -- 5.3.1. Disconnect -- 5.3.2. Lack of Support -- 5.4. I' think I'll just change my major -- 5.4.1. Dominant is disconnected -- 5.4.2. Dominant don't care -- 5.5. Thanks for making an effort -- 5.5.1. Advisors -- 5.5.2. Teachers -- 5.5.3. I will help my community -- 5.6. "I probably would've given up because I was already in the mindset ... to fail."-Nicole -- 5.7. Summary and suggestions for further research -- Works cited

Impurity transport and bulk ion flow in a mixed collisionality stellarator plasma

The accumulation of impurities in the core of magnetically confined plasmas, resulting from standard collisional transport mechanisms, is a known threat to their performance as fusion energy sources. Whilst the axisymmetric tokamak systems have been shown to benefit from the effect of temperature screening, that is an outward flux of impurities driven by the temperature gradient, impurity accumulation in stellarators was thought to be inevitable, driven robustly by the inward pointing electric field characteristic of hot fusion plasmas. We have shown in Helander et. al. (2017b) that such screening can in principle also appear in stellarators, in the experimentally relevant mixed collisionality regime, where a highly collisional impurity species is present in a low collisionality bulk plasma. Details of the analytic calculation are presented here, along with the effect of the impurity on the bulk ion flow, which will ultimately affect the bulk contribution to the bootstrap current

Optimization of flux-surface density variation in stellarator plasmas with respect to the transport of collisional impurities

Avoiding impurity accumulation is a requirement for steady-state stellarator operation. The accumulation of impurities can be heavily affected by variations in their density on the flux-surface. Using recently derived semi-analytic expressions for the transport of a collisional impurity species with high-$Z$ and flux-surface density-variation in the presence of a low-collisionality bulk ion species, we numerically optimize the impurity density-variation on the flux-surface to minimize the radial peaking factor of the impurities. These optimized density-variations can reduce the core impurity density by $0.75^Z$ (with $Z$ the impurity charge number) in the Large Helical Device case considered here, and by $0.89^Z$ in a Wendelstein 7-X standard configuration case. On the other hand, when the same procedure is used to find density-variations that maximize the peaking factor, it is notably increased compared to the case with no density-variation. This highlights the potential importance of measuring and controlling these variations in experiments.Comment: 19 figures, 17 pages. Accepted into Nuclear Fusio

The Threat of Returning to “Normal”: Resisting Ableism in the Post-COVID Classroom

The abrupt switch to online learning during the COVID-19 pandemic highlighted pervasive ableism; accommodations that had been “impossible” were suddenly available. This critical commentary draws from interviews with 16 students and our own ethnographic accounts as student/professor to understand how COVID shaped disabled experiences in the classroom. As a student with a disability, Elizabeth was hyperaware of her vulnerability to illness, but also experienced herself as less impaired online. She could control her learning environment to minimize sensory and mobility challenges. Additionally, professors’ flexible policies helped her to manage energy, time, and symptoms. However, Elizabeth and her peers feared an uncritical return to “normal.” As we witness students’ struggles for inclusion, how might professors resist returning to rigid, ableist practices

Relational altruism and giving in social groups

Much fundraising is done by individuals within existing social groups. Exploiting a unique dataset, we demonstrate (i) a positive relationship between social group size and the number of donations; (ii) a negative relationship between group size and the size of individual donations; (iii) no clear relationship between group size and the total amount raised. Free riding with respect to the activity being funded cannot explain the relationship between group size and donation size, since the number of social group members is only a subset of total contributors. Instead, the findings are consistent with the notion that giving in social groups is motivated by “relational altruism”