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Corbicula fluminea Effects on Survival, Growth, and Drift of Juvenile Lampsilis siliquoidea in Laboratory Exposures
No full textThe Asian clam, Corbicula fluminea, is an invasive species that is abundant and often co-occurs with native freshwater mussels. Corbicula is widely suspected of having negative effects on native mussels, but few studies have empirically tested this hypothesis. I used laboratory experiments to evaluate how adult Corbicula affected the survivorship, growth, and drift of juvenile Lampsilis siliquoidea. Survival and growth of newly metamorphosed mussels were tested in downwelling flow-through chambers with glass-bead substrate. Treatments were control (no clams), small adult clams, or large adult clams. After 28 days, large clams slightly but significantly reduced the number of juveniles recovered from the substrate. The proportion recovered alive did not change, suggesting that the missing juveniles were eaten and the shells digested. Small clams did not affect juvenile recovery or survival. Mussels grew nearly threefold in length over 4 weeks. Corbicula had small and inconsistent effects on growth. Mussels exposed to large clams grew 3% larger than the control group at the end of the 4 weeks. In contrast, mussels exposed to small clams grew 3% less than the control group. Tests on drift were carried out in small raceways with glass bead substrate. Drifting behavior (wash-out) of 2-week (0.5 mm) and 6-week-old (1.5 mm) mussels was tested with and without Corbicula over 3 days. Mussel drift increased with increasing clam density: 19%, 33% and 47% of 2-week-old mussels drifted at 0, 500 or 2000 clams/m2, respectively. Drift of 6-week-old mussels increased only at the highest clam density, with 42% of mussels displaced, versus 5% and 8% in the control and low-density treatments. Interactions between Corbicula and native juvenile mussels could help explain why mussel populations continue to decline across the United States
Pollinator effectiveness is affected by intraindividual behavioral variation
No full textVariation in pollinator quality is fundamental to the evolution of plant-pollinator mutualisms and such variation frequently results from differences in foraging behavior. Surprisingly, despite substantial intraindividual variation in pollinator foraging behavior, the consequences for pollen removal and deposition on flowers are largely unknown. We asked how two pollen foraging behaviors of a generalist pollinator (Bombus impatiens) affect removal and deposition of heterospecific and conspecific pollen, key aspects of pollinator quality, for multiple plant species. In addition, we examined how bee body size and pollen placement among body parts shaped pollen movement. We manipulated foraging behavior types using artificial flowers, which donated pollen that captive bees then deposited on three recipient plant species. While body size primarily affected donor pollen removal, foraging behavior primarily affected donor pollen deposition. How behavior affected donor pollen deposition depended on the plant species and the quantity of donor pollen on the bee\u27s abdomen. Plant species with smaller stigmas received significantly less pollen and fewer bees successfully transferred pollen to them. For a single plant species, heterospecific pollen interfered with conspecific pollen deposition, such that more heterospecific pollen on the bee\u27s abdomen resulted in less conspecific pollen deposition on the flower. Thus, intraindividual variation in foraging behavior and its interaction with the amount and placement of acquired pollen and with floral morphology can affect pollinator quality and may shape plant fitness via both conspecific and heterospecific pollen transfer
Social work students\u27 experiences of ethical difficulties in field placements: A qualitative study in China
No full textField placements provide social work students with opportunities to learn to handle ethical difficulties in a professional manner. In many developed countries, field staff are generally employed to supervise social work students\u27 field placements. \u27Code of Ethics\u27 and other ethics documents have also been developed to guide students\u27 professional activities. However, there is a lack of field staff, \u27Code of Ethics\u27 and other ethics documents in China, which may lead to ethical difficulties amongst students during their field placements. Based on the interviews of twenty-four social work students who completed field placements in 2016 at a university in China, this research revealed that students encountered many ethical difficulties in field placements. They tried to handle the difficulties in the beginning, but gradually adapted to the difficulties passively due to the lack of support. Most students also reported that they adhered to social work values and ethics in field placements and learned from field placements. The findings suggested that social work profession associations, Departments or Schools of Social Work, social work agencies and social work academia in China need to collaborate to create a more professional and supportive environment for students\u27 field placements
The impact of online learning tools on student success in college of business core finance classes
No full textThe authors examine the impact of a new online learning system on student performance in a core finance course required of all business majors. They find that the online learning system significantly reduces the number of students that withdraw from the course prior to course completion. Additionally, the benefits of a lower withdrawal rate transcend all modalities of course delivery and are greatest for students with declared majors outside of finance. Finally, though use of the online learning system reduces the withdrawal rate of students, it does not appear to result in significant grade inflation among those students completing the course
Hypervigilance, Allostatic Load, and Migraine Prevention: Antibodies to CGRP or Receptor
No full textMigraine involves brain hypersensitivity with episodic dysfunction triggered by behavioral or physiological stressors. During an acute migraine attack the trigeminal nerve is activated (peripheral sensitization). This leads to central sensitization with activation of the central pathways including the trigeminal nucleus caudalis, the trigemino-thalamic tract, and the thalamus. In episodic migraine the sensitization process ends with the individual act, but with chronic migraine central sensitization may continue interictally. Increased allostatic load, the consequence of chronic, repeated exposure to stressors, leads to central sensitization, lowering the threshold for future neuronal activation (hypervigilance). Ostensibly innocuous stressors are then sufficient to trigger an attack. Medications that reduce sensitization may help patients who are hypervigilant and help to balance allostatic load. Acute treatments and drugs for migraine prevention have traditionally been used to reduce attack duration and frequency. However, since many patients do not fully respond, an unmet treatment need remains. Calcitonin gene-related peptide (CGRP) is a vasoactive neuropeptide involved in nociception and in the sensitization of peripheral and central neurons of the trigeminovascular system, which is implicated in migraine pathophysiology. Elevated CGRP levels are associated with dysregulated signaling in the trigeminovascular system, leading to maladaptive responses to behavioral or physiological stressors. CGRP may, therefore, play a key role in the underlying pathophysiology of migraine. Increased understanding of the role of CGRP in migraine led to the development of small-molecule antagonists (gepants) and monoclonal antibodies (mAbs) that target either CGRP or the receptor (CGRP-R) to restore homeostasis, reducing the frequency, duration, and severity of attacks. In clinical trials, US Food and Drug Administration-approved anti-CGRP-R/CGRP mAbs were well tolerated and effective as preventive migraine treatments. Here, we explore the role of CGRP in migraine pathophysiology and the use of gepants or mAbs to suppress CGRP-R signaling via inhibition of the CGRP ligand or receptor
Cold Tolerance of Mountain Stoneflies (Plecoptera: Nemouridae) from the High Rocky Mountains
No full textHow aquatic insects cope with cold temperatures is poorly understood. This is particularly true for high-elevation species, which often experience a seasonal risk of freezing. In the Rocky Mountains, nemourid stoneflies (Plecoptera: Nemouridae) are a major component of mountain stream biodiversity and are typically found in streams fed by glaciers and snowfields, which are rapidly receding due to climate change. Predicting the effects of climate change on mountain stoneflies is difficult because their thermal physiology is largely unknown. We investigated cold tolerance of several alpine stoneflies (Lednia tumana, Lednia tetonica, and Zapada spp.) from the Rocky Mountains, USA. We measured the supercooling point (SCP) and tolerance to ice enclosure of late-instar nymphs collected from a range of thermal regimes. SCPs varied among species and populations, with the lowest SCP measured for nymphs from an alpine pond, which was much more likely to freeze solid in winter than flowing streams. We also show that L. tumana cannot survive being enclosed in ice, even for short periods of time (h) at relatively mild temperatures (-0.5°C). Our results indicate that high-elevation stoneflies at greater risk of freezing may have correspondingly lower SCPs, and despite their common association with glacial meltwater, these stoneflies appear to be living near their lower thermal limits
Occupancy of Small Mammals in Missouri’s Fragmented Prairies
No full textPrairies once extended across much of Missouri, but now are dwindling and often surrounded by agriculture or other developed land. This has resulted in a mosaic-like landscape made up of small patches that are often isolated and distant from other patches. The theory of Island Biogeography posits that species richness of habitat patches exists as a dynamic equilibrium between colonization and extinction rates and that larger islands should contain more species than smaller islands. The purpose of this study is to examine how occupancy of a small mammal prairie specialist, the prairie vole, Microtus ochrogaster, and other small mammal species, such as the deer mouse, Peromyscus maniculatus, and the hispid cotton rat, Sigmodon hispidus, are affected by patch size, fragmentation, and isolation of prairie patches from other similar habitats. This study will be conducted by trapping small mammals using transects surveys with Sherman live traps (a standard in the field) and individuals will be marked with a unique ear tag. Small prairie fragments throughout Missouri were used as a model system, to analyze community characteristics of these patches, I 1) created single season multi-species occupancy models to determine effects of habitat characteristics such as area, isolation, and perimeter, on small mammal occupancy, and 2) compared observed species richness to area, perimeter, and isolation. Six species of small mammals were found over the course of this study. Prairie area, perimeter, or isolation were not found to have an impact on occupancy or species richness. An unknown mechanism seems to be driving small mammal community composition and further data collection is needed to find the mechanism causing these variations
Creating Democratic Spaces for Addressing Racism on College Campuses: The Example of Dialogue to Change at Oklahoma State University
No full textPolarizing rhetoric, racist violence, and racial inequality continue to cast a dark shadow over democracy and threaten to further divide our communities. How our country moves forward in this time is under consideration by practitioners, scholars, and everyday people alike. This article begins by reviewing the Dialogue to Change approach Everyday Democracy has developed to expand opportunities for the people of our country to grapple with racism together, across racial backgrounds, and then work with each other and public officials to create positive, equitable change at local, state, and national levels. The second part of the article looks at the research and analysis of the dialogue to change efforts at The Center for Public Life at Oklahoma State University and finds it noteworthy for the ways in which they build on and advance lessons about creating and sustaining democratic discourse on racism. While campuses-as-communities are not democracies in and of themselves, they have an essential role to play in our larger democracy
Nationalism, Patriotism, and Support for the European Union
No full textDoes attachment to a nation enhance or dampen support for the European Union (EU)? Using the 2003 and 2013 ISSP national-identity modules, we isolate and provide multi-item measures of two distinct types of national attachment—nationalism and patriotism. We find that they are positively related yet have divergent effects. We validate the measures showing that nationalism increases, and patriotism decreases, support for nationalistic policies (anti-immigration and protectionism) as expected. We then test the effects of nationalism and patriotism on EU attitudes and find that nationalism increases, and patriotism decreases, opposition to the EU. The presence of a neo-nationalist political party enhanced the effects of nationalism on opposition to the EU, underscoring the importance of political rhetoric in shaping nationalistic EU opposition. In further support of the rhetoric hypothesis, the most-educated nationalists are most likely to oppose the EU in countries with a neo-nationalist political party and vote for such parties when present