The Effect of Hook Scarring on Angler Satisfaction on the West Fork of the Bitterroot River

Anglers in Montana are shifting towards a catch and release ethic. This shift is causing increased hook scarring in fish populations. Despite these increasing trends few studies have quantified the rate of hook scarring anglers observe, and their attitudes about hook scarring. We developed and conducted an angler survey on the West Fork of the Bitterroot, a section of river with over 30% scarring rates in Westslope Cutthroat in a 2014 Montana Fish, Wildlife and Parks (MFWP) electrofishing survey. We surveyed floating anglers as they pulled out at the end of the fishing day to get complete catch data, satisfaction information, observed hook scarring rates, attitudes about hook scarring, and equipment used. We surveyed 47 anglers of which 94% were fly-fishing and 72% were using barbless hooks. Anglers observed lower hook scarring rates than the previous MFWP electrofishing survey. On average anglers reported hook scarring rates to be very acceptable. There was no correlation between the rate of hook scarring anglers observed and satisfaction with their catch. As densities of anglers increase, more research is needed to understand the effects of angler gear type on hook scarring rates and the effect of hook scarring on angler satisfaction

Blurring Lines: Loot Boxes and Gambling in the Video Game Industry

A loot box is a consumable virtual item which, upon redemption, provides the player with a randomised assortment of further virtual items within a video game. They have been adopted by highly popular multiplayer games as an alternative source of revenue, but have been criticised. The controversy lies in the fact that the precise virtual item that is awarded to the player is solely dependent upon an element of chance, which suggests a strong similarity with traditional gambling services. This paper examines a specific subset of loot boxes, the ‘closed-loop’ mechanic (which effectively excludes the loot box from constituting a form of gambling under the Gambling Act 2005) and explores the impact this has on children and young people. We address the current regulatory framework governing the gambling industry in England and Wales and how loot boxes fit in, before examining why the use of loot boxes might be considered gambling activity. We outline the psychological landscape of loot box consumption and the effects it has on young people, before finally examining whether or not the current approach in England and Wales provides sufficient protection. We conclude that legislative reform in this area must be based on evidence-led policies

Modeling the Repertoire of True Tumor-Specific MHC I Epitopes in a Human Tumor

DNA replication has a finite measurable error rate, net of repair, in all cells. Clonal proliferation of cancer cells leads therefore to accumulation of random mutations. A proportion of these mutational events can create new immunogenic epitopes that, if processed and presented by an MHC allele, may be recognized by the adaptive immune system. Here, we use probability theory to analyze the mutational and epitope composition of a tumor mass in successive division cycles and create a double Pölya model for calculating the number of truly tumor-specific MHC I epitopes in a human tumor. We deduce that depending upon tumor size, the degree of genomic instability and the degree of death within a tumor, human tumors have several tens to low hundreds of new, truly tumor-specific epitopes. Parenthetically, cancer stem cells, due to the asymmetry in their proliferative properties, shall harbor significantly fewer mutations, and therefore significantly fewer immunogenic epitopes. As the overwhelming majority of the mutations in cancer cells are unrelated to malignancy, the mutation-generated epitopes shall be specific for each individual tumor, and constitute the antigenic fingerprint of each tumor. These calculations highlight the benefits for personalization of immunotherapy of human cancer, and in view of the substantial pre-existing antigenic repertoire of tumors, emphasize the enormous potential of therapies that modulate the anti-cancer immune response by liberating it from inhibitory influences

Synergistic effects of climate and invasions: a case study of juvenile Pacific salmon and their introduced freshwater predator (Esox lucius) in a changing Alaska river

Thesis (M.S.) University of Alaska Fairbanks, 2024Climate change and invasive species are major individual drivers of declines in freshwater productivity and diversity, yet the potential for these factors to interact is poorly understood. I explored the synergistic effects of climate change and invasion to better understand observed changes in a freshwater community comprised of socially valuable salmonid fishes. I modeled daily predation and annual consumption of juvenile salmon by an introduced apex predator, Northern Pike (Esox lucius), as a function of time, streamflow, water temperature, and Northern Pike demography in a rapidly warming system in Southcentral Alaska. I hypothesized that Northern Pike predation would shift from juvenile salmon to alternative prey as a function of progressed invasion and that salmon predation would peak during species-specific out migrations. I also hypothesized that predation on juvenile salmon would be positively correlated with streamflow because high water would cause juvenile salmon to seek refuge in off-channel habitats instigating interaction with Northern Pike. Daily predation and annual consumption of Northern Pike in this system have shifted away from salmon-dominated to dominated by resident fishes over the past decade (2011 to 2022). Streamflow was positively correlated with daily predation on juvenile Chinook Salmon and total Oncorhynchus species in diets. Between 2011-2012 and 2021-2022 the population of Northern Pike shifted to younger individuals with increased growth. Estimates revealed that annual consumption of Chinook Salmon and Coho Salmon by Northern Pike decreased between time periods. Bioenergetic simulations revealed increases of 6 to 12.5% in total per capita consumption of prey by Northern Pike under end of century scenarios. These findings collectively suggest that Northern Pike have switched to alternative fish prey as salmon declined. Seasonal high streamflows and increased water temperature consistent with observed and predicted climate change in Southcentral Alaska appear to increase predation rates on juvenile Chinook Salmon by Northern Pike, while patterns in predation for juvenile Coho Salmon are more uncertain. Predicted future temperatures may increase total consumption of Northern Pike enough to appreciably increase mortality of salmon exacerbating changes in species composition and community structure and further jeopardizing struggling salmon runs. These findings suggest that invasive predators may also become more impactful in other systems undergoing rapid climate change.Chapter 1: Introduction -- 1.1. References. Chapter 2: Patterns of seasonal predation of salmon by a novel freshwater predator (Esox lucius) in Southcentral Alaska and the associations with streamflow -- 2.1. Abstract -- 2.2. Introduction -- 2.3. Methods -- 2.3.1. Study site -- 2.3.2. Sampling -- 2.3.3. Streamflow -- 2.3.4. Analytical approach -- 2.4. Results -- 2.4.1. Annual changes of Northern Pike diet diversity -- 2.4.2. Juvenile salmon across years -- 2.4.3. Seasonal effects on predation -- 2.4.4. Streamflow relationship -- 2.5. Discussion -- 2.6. References -- 2.7. Tables and Figures. Chapter 3: Salmon declines coincide with climate mediated increases in consumption by a novel predator -- 3.1. Abstract -- 3.2. Introduction -- 3.3. Methods -- 3.3.1. Study site and history of invasion -- 3.3.2. Sampling -- 3.3.3. Cohort construction for consumption estimates -- 3.3.4. Bioenergetics modeling -- 3.3.5. Diet proportions -- 3.3.6. Water temperature -- 3.3.7. Scenarios of future warming -- 3.4. Results -- 3.4.1. Changes in predator demography -- 3.4.2. Changes in predator consumption -- 3.4.3. Consumption under future temperature scenarios -- 3.5. Discussion -- 3.5.1. Northern Pike demographic shift -- 3.5.2. Diet shift -- 3.5.3. Decreased salmon consumption -- 3.5.4. Consumption under future temperature scenarios -- 3.5.5. Study Limitations -- 3.5.6. Implications for native range of Northern Pike -- 3.5.7. Broader application -- 3.5.8. Future directions -- 3.6. References -- 3.7. Tables and Figures. Chapter 4: Discussion -- 4.1. Findings -- 4.1.1. Diet and consumption changes over time -- 4.1.2. Effects of streamflow on predation -- 4.1.3. Northern Pike demographic shifts -- 4.1.4. Present and future consumption -- 4.2. Impacts and considerations -- 4.3. Habitat overlap and expansion -- 4.4. Northern Pike and salmon management in Alaska and beyond -- 4.5. Research Recommendations -- 4.6. Management implications -- 4.7. Implications for other systems and invasion ecology -- 4.8. References. Appendix A. Diet proportions for 2021-2022 bioenergetics models by prey species, season, and Northern Pike age class and Wet weight (g) and sample size (n) of common prey items (n>5) from Northern Pike diets 2021-2022. Appendix B. Energy value and sources for prey items used for bioenergetics estimates based on Sepulveda 2015. Appendix C. 1. Water temperature map indicating May averaged instantaneous mid - water column temperature in sampling sites on the Deshka River, Alaska, USA. Appendix C. 2. Water temperature maps indicating late July averaged instantaneous mid - water column temperature in sampling sites on the Deshka River, Alaska, USA. Appendix C.3. Water temperature maps indicating August averaged instantaneous mid - water column temperature in sampling sites on the Deshka River, Alaska, USA. Appendix D.1. 2021 ADFG issued Aquatic Resource permit # SF2021-109. Appendix D.2. 2022 ADFG issued Aquatic Resource Permit #SF2022-137

Sondage national des résidents en médecine et directeurs de programme canadiens sur le congé parental durant la résidence

Background: Despite the advantages of having a child as a medical resident, the transition back to residency after parental leave can be challenging. This study is the first to investigate this issue using a nation-wide Canadian sample of both residents and program directors. Method: A questionnaire was developed and made available online. Respondents included 437 female residents, 33 male residents, and 172 residency program directors. The mean length of parental leave was nine months for female residents and six weeks for male residents. Almost all female residents (97.5%) breastfed with an average duration of 12 months. The top challenges reported by residents were feeling guilty for being away from their family, long and unpredictable work hours, sleep deprivation, and finding time to study. When female residents and program directors were matched to both school and program (N = 99 pairs), there was no difference in the total number of challenges reported, but program directors reported offering significantly more accommodations than female residents reported being offered, t(196) = 13.06, p < .001. Results: Our data indicate there is a need for better communication between resident parents and program directors, as well as clear program-specific parental leave policies, particularly for supporting breastfeeding mothers as they return to work

3-Dimensional Kinematics in low foreground extinction windows of the Galactic Bulge: Radial Velocities for 6 bulge fields

The detailed structure of the Galactic bulge still remain uncertain. The strong difficulties of obtaining observations of stars in the Galactic bulge have hindered the acquisition of a kinematic representation for the inner kpc of the Milky Way. The observation of the 3-d kinematics in several low foreground extinction windows can solve this problem. We have developed a new technique, which combines precise stellar HST positions and proper motions with integral field spectroscopy, in order to obtain reliable 3-d stellar kinematics in crowded fields of the Galactic center. In addition, we present results using the new techniques for six fields in our project. A significant vertex deviation has been found in some of the fields in agreement with previous determinations. This result confirms the presence of a stellar bar in the Galactic bulge.Comment: 14 pages, 15 figures, Accepted for publication in A&

The chemical abundances in the Galactic Centre from the atmospheres of Red Supergiants

The Galactic Centre (GC) has experienced a high degree of recent star-forming activity, as evidenced by the large number of massive stars currently residing there. The relative abundances of chemical elements in the GC may provide insights into the origins of this activity. Here, we present high-resolution $H$-band spectra of two Red Supergiants in the GC (IRS~7 and VR~5-7), and in combination with spectral synthesis we derive abundances for Fe and C, as well as other $\alpha$-elements Ca, Si, Mg Ti and O. We find that the C-depletion in VR~5-7 is consistent with the predictions of evolutionary models of RSGs, while the heavy depletion of C and O in IRS~7's atmosphere is indicative of deep mixing, possibly due to fast initial rotation and/or enhanced mass-loss. Our results indicate that the {\it current} surface Fe/H content of each star is slightly above Solar. However, comparisons to evolutionary models indicate that the {\it initial} Fe/H ratio was likely closer to Solar, and has been driven higher by H-depletion at the stars' surface. Overall, we find $\alpha$/Fe ratios for both stars which are consistent with the thin Galactic disk. These results are consistent with other chemical studies of the GC, given the precision to which abundances can currently be determined. We argue that the GC abundances are consistent with a scenario in which the recent star-forming activity in the GC was fuelled by either material travelling down the Bar from the inner disk, or from the winds of stars in the inner Bulge -- with no need to invoke top-heavy stellar Initial Mass Functions to explain anomalous abundance ratios.Comment: 23 pages, 5 figs. Accepted for publication in Ap