205 research outputs found

    Ocean acidification alters predator behaviour and reduces predation rate

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    Ocean acidification poses a range of threats to marine invertebrates; however, the emerging and likely widespread effects of rising carbon dioxide (CO₂) levels on marine invertebrate behaviour are still little understood. Here, we show that ocean acidification alters and impairs key ecological behaviours of the predatory cone snail Conus marmoreus. Projected near-future seawater CO₂ levels (975 ”atm) increased activity in this coral reef molluscivore more than threefold (from less than 4 to more than 12 mm min⁻Âč) and decreased the time spent buried to less than one-third when compared with the present-day control conditions (390 ”atm). Despite increasing activity, elevated CO₂ reduced predation rate during predator–prey interactions with control-treated humpbacked conch, Gibberulus gibberulus gibbosus; 60% of control predators successfully captured and consumed their prey, compared with only 10% of elevated CO₂ predators. The alteration of key ecological behaviours of predatory invertebrates by near-future ocean acidification could have potentially far-reaching implications for predator–prey interactions and trophic dynamics in marine ecosystems. Combined evidence that the behaviours of both species in this predator–prey relationship are altered by elevated CO₂ suggests food web interactions and ecosystem structure will become increasingly difficult to predict as ocean acidification advances over coming decades

    Ocean acidification alters predator behaviour and reduces predation rate

    Get PDF
    Ocean acidification poses a range of threats to marine invertebrates; however, the emerging and likely widespread effects of rising carbon dioxide (CO₂) levels on marine invertebrate behaviour are still little understood. Here, we show that ocean acidification alters and impairs key ecological behaviours of the predatory cone snail Conus marmoreus. Projected near-future seawater CO₂ levels (975 ”atm) increased activity in this coral reef molluscivore more than threefold (from less than 4 to more than 12 mm min⁻Âč) and decreased the time spent buried to less than one-third when compared with the present-day control conditions (390 ”atm). Despite increasing activity, elevated CO₂ reduced predation rate during predator–prey interactions with control-treated humpbacked conch, Gibberulus gibberulus gibbosus; 60% of control predators successfully captured and consumed their prey, compared with only 10% of elevated CO₂ predators. The alteration of key ecological behaviours of predatory invertebrates by near-future ocean acidification could have potentially far-reaching implications for predator–prey interactions and trophic dynamics in marine ecosystems. Combined evidence that the behaviours of both species in this predator–prey relationship are altered by elevated CO₂ suggests food web interactions and ecosystem structure will become increasingly difficult to predict as ocean acidification advances over coming decades

    Characterization of body weight and composition changes during the sophomore year of college

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    <p>Abstract</p> <p>Background</p> <p>Years spent in college represents a critical time for obesity development though little information is known regarding how body weight and composition changes beyond the first year of college. The aim of this study was to investigate changes in body weight and composition and the factors influencing those changes among sophomore females.</p> <p>Methods</p> <p>Body composition by dual energy X-ray absorptiometry was obtained in participants beginning during their freshman year and continued through their sophomore year.</p> <p>Results</p> <p>No difference was observed between sophomore year fall and spring visits for body weight (60.4 versus 60.6 kg) or fat mass (19.3 versus 18.7 kg). However, a significant (<it>P </it>≀ 0.05) decrease was observed for body fat (31.9 versus 30.9 %fat) and a significant increase was observed for fat-free mass (37.7 versus 38.4 kg). Participants living off campus significantly (<it>P </it>≀ 0.05) declined in body fat (33.0 versus 31.0 %fat) and fat mass (19.4 versus 18.2 kg) and increased in fat-free mass (36.1 versus 37.2 kg) with no differences in those living on campus.</p> <p>Conclusion</p> <p>No change in body weight was observed in females during their sophomore year. However, an increase in fat-free mass accompanied with a decrease in fat mass resulted in a decrease in body fat. Participants living off campus had favorable changes in their body composition by means of decreasing %fat and fat mass while increasing fat-free mass. Participants living on campus did not demonstrate these favorable changes.</p

    Using Social Network Analysis to Assess Professional Network Development among AGE\u3ci\u3eSW\u3c/i\u3e Pre-Dissertation Fellowship Program Participants

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    Professional networks are important for the success of doctoral students and early career faculty members, yet there is little research about what types of experiences help emerging scholars develop these networks. Social network analysis may be an ideal method for studying the effectiveness of training programs in nurturing network development among emerging scholars. We describe one application of this method, which was used to examine the professional networks formed through participation in the Association of Gerontological Education in Social Work (AGESW)’s Pre-Dissertation Fellowship Program (PDFP). Alumni (n = 12) from the first three cohorts of the program (2010–2012) reported meeting an average of 20 scholars (SD = 13.2) through AGESW, which led to potential professional interactions and collaborations on conference presentations and manuscripts. Although challenges with missing data limited the conclusions that can be drawn, we find that this method holds promise for helping to identify key factors that facilitate professional network development in pre-dissertation training programs such as the PDFP

    Replication Study: Biomechanical remodeling of the microenvironment by stromal caveolin-1 favors tumor invasion and metastasis

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    As part of the Reproducibility Project: Cancer Biology we published a Registered Report (Fiering et al., 2015) that described how we intended to replicate selected experiments from the paper ‘Biomechanical remodeling of the microenvironment by stromal caveolin-1 favors tumor invasion and metastasis’ (Goetz et al., 2011). Here we report the results. Primary mouse embryonic fibroblasts (pMEFs) expressing caveolin 1 (Cav1WT) demonstrated increased extracellular matrix remodeling in vitro compared to Cav1 deficient (Cav1KO) pMEFs, similar to the original study (Goetz et al., 2011). In vivo, we found higher levels of intratumoral stroma remodeling, determined by fibronectin fiber orientation, in tumors from cancer cells co-injected with Cav1WT pMEFs compared to cancer cells only or cancer cells plus Cav1KO pMEFs, which were in the same direction as the original study (Supplemental Figure S7C; Goetz et al., 2011), but not statistically significant. Primary tumor growth was similar between conditions, like the original study (Supplemental Figure S7Ca; Goetz et al., 2011). We found metastatic burden was similar between Cav1WT and Cav1KO pMEFs, while the original study found increased metastases with Cav1WT (Figure 7C; Goetz et al., 2011); however, the duration of our in vivo experiments (45 days) were much shorter than in the study by Goetz et al. (2011) (75 days). This makes it difficult to interpret the difference between the studies as it is possible that the cells required more time to manifest the difference between treatments observed by Goetz et al. We also found a statistically significant negative correlation of intratumoral remodeling with metastatic burden, while the original study found a statistically significant positive correlation (Figure 7Cd; Goetz et al., 2011), but again there were differences between the studies in terms of the duration of the metastasis studies and the imaging approaches that could have impacted the outcomes. Finally, we report meta-analyses for each result

    Sustainable Polymers: New 4-H STEM Curricula

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    There are many environmental issues surrounding the global production and use of plastics. Three science curricula (Grades K-2, 3-5, and 6-8) were developed to introduce youth to the past, present, and future of plastics. Designed using research-based methods and grounded in effective science pedagogy, the curricula provide young people opportunities to explore viable alternatives to plastics and develop knowledge and skills necessary to help mitigate environmental impacts associated with the production, use and disposal of plastics. Evaluation results demonstrated that youth improved their understanding of polymers and intention to help reduce impacts of plastics on the environment

    Activity of immunoproteasome inhibitor ONX-0914 in acute lymphoblastic leukemia expressing MLL–AF4 fusion protein

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    Proteasome inhibitors bortezomib and carfilzomib are approved for the treatment of multiple myeloma and mantle cell lymphoma and have demonstrated clinical efficacy for the treatment of acute lymphoblastic leukemia (ALL). The t(4;11)(q21;q23) chromosomal translocation that leads to the expression of MLL–AF4 fusion protein and confers a poor prognosis, is the major cause of infant ALL. This translocation sensitizes tumor cells to proteasome inhibitors, but toxicities of bortezomib and carfilzomib may limit their use in pediatric patients. Many of these toxicities are caused by on-target inhibition of proteasomes in non-lymphoid tissues (e.g., heart muscle, gut, testicles). We found that MLL–AF4 cells express high levels of lymphoid tissue-specific immunoproteasomes and are sensitive to pharmacologically relevant concentrations of specific immunoproteasome inhibitor ONX-0914, even in the presence of stromal cells. Inhibition of multiple active sites of the immunoproteasomes was required to achieve cytotoxicity against ALL. ONX-0914, an inhibitor of LMP7 (ß5i) and LMP2 (ß1i) sites of the immunoproteasome, and LU-102, inhibitor of proteasome ß2 sites, exhibited synergistic cytotoxicity. Treatment with ONX-0914 significantly delayed the growth of orthotopic ALL xenograft tumors in mice. T-cell ALL lines were also sensitive to pharmacologically relevant concentrations of ONX-0914. This study provides a strong rationale for testing clinical stage immunoproteasome inhibitors KZ-616 and M3258 in ALL

    Unidentified EGRET Sources and the Extragalactic Gamma-Ray Background

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    The large majority of EGRET point sources remain to this day without an identified low-energy counterpart. Whatever the nature of the EGRET unidentified sources, faint unresolved objects of the same class must have a contribution to the diffuse gamma-ray background: if most unidentified objects are extragalactic, faint unresolved sources of the same class contribute to the background, as a distinct extragalactic population; on the other hand, if most unidentified sources are Galactic, their counterparts in external galaxies will contribute to the unresolved emission from these systems. Understanding this component of the gamma-ray background, along with other guaranteed contributions from known sources, is essential in any attempt to use gamma-ray observations to constrain exotic high-energy physics. Here, we follow an empirical approach to estimate whether a potential contribution of unidentified sources to the extragalactic gamma-ray background is likely to be important, and we find that it is. Additionally, we comment on how the anticipated GLAST measurement of the diffuse gamma-ray background will change, depending on the nature of the majority of these sources.Comment: 6 pages, 3 figures, to appear in proceedings of "The Multi-Messenger Approach to High Energy Gamma-Ray Sources", Barcelona, 4-7 July 2006; comments welcom

    Now or Later? An fMRI study of the effects of endogenous opioid blockade on a decision-making network

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    Previously, we found that distinct brain areas predict individual selection bias in decisions between small immediate (“Now”) and larger delayed rewards (“Later”). Furthermore, such selection bias can be manipulated by endogenous opioid blockade. To test whether blocking endogenous opioids with Naltrexone (NTX) alters brain activity during decision-making in areas predicting individual bias, we compared fMRI BOLD signal correlated with Now versus Later decision-making after acute administration of NTX (50 mg) or placebo. We tested abstinent alcoholics and control subjects in a double-blind two-session design. We defined regions of interest (ROI) centered on activation peaks predicting Now versus Later selection bias. NTX administration significantly increased BOLD signal during decision-making in the right lateral orbital gyrus ROI, an area where enhanced activity during decision-making predicts Later bias. Exploratory analyses identified additional loci where BOLD signal during decision-making was enhanced (left orbitofrontal cortex, left inferior temporal gyrus, and cerebellum) or reduced (right superior temporal pole) by NTX. Additional analyses identified sites, including the right lateral orbital gyrus, in which NTX effects on BOLD signal predicted NTX effects on selection bias. These data agree with opioid receptor expression in human frontal and temporal cortices, and suggest possible mechanisms of NTX’s therapeutic effects

    Cytokine Response to Traditional and Cluster Sets in Resistance-trained Women

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    Resistance exercise that incorporates intra-set rest between repetition blocks (i.e., cluster sets [CS]) can produce a smaller metabolic stress and endocrine response than traditional sets (TS). PURPOSE: To examine the effect of CS on the acute cytokine response in resistance trained women. METHODS: 12 resistance-trained women (mean ± SE; 23.7 ± 1.1 years; 160.1 ± 1.5 cm; 62.5 ± 1.7 kg; 5 ± 1 years training) completed 3 sessions in the follicular phase. One-repetition maximum (1RM) back squat (BS) (98.7 ± 4.1 kg), and BS:body mass (1.6 ± 0.1) were determined in Session 1. For Session 2 (3 days post Session 1) and Session 3 (7 days post Session 2), subjects were randomly assigned to either 4 sets of 10 reps with 120 seconds (s) inter-set rest (TS) or 4 x (2 x 5 reps) with 30s intra-set rest and 90s inter-set rest (CS). All performed both protocols at 70% 1RM BS. Instructions were to perform every rep “as explosively as possible”. Blood was collected pre-exercise (PRE), immediately after sets 1, 2, 3, 4 (IP), and at 5 (+5), 15 (+15), 30 (+30), and 60 (+60) min post-exercise and analyzed for interleukin (IL)-1ÎČ, IL-2, IL-6, IL-8, IL 10, and IL-15. Data were analyzed using repeated measures ANOVAs (2 × 9). RESULTS: A significant main effect of time (p\u3c0.05) was found for IL-1ÎČ, IL-2, IL-8, IL-10, and IL-15. Concentration of IL-1ÎČ was smaller at +5 (3.9 ± 0.4 ng/mL), +15 (3.6 ± 0.4) +30 (3.5 ± 0.3), and +60 (3.7 ± 0.4) compared to IP (4.1 ± 0.4). IL-2 was greater after set 1 (10.8 ± 1.0 ng/mL), and set 2 (11.0 ± 1.2) compared to PRE (10.2 ± 1.0), and smaller at +30 (9.9 ± 1.0) compared to IP (11.0 ± 1.0). IL-8 was greater after set 1 (8.4 ± 0.6 ng/mL), set 2 (8.6 ± 0.7), and set 3 (8.5 ± 0.7) compared to PRE (8.0 ± 0.6). IL-10 was smaller at +30 (31.3 ± 7.4 ng/mL) compared to PRE (34.0 ± 7.4), and also smaller at +15 (32.6 ± 7.9) +30 (31.3 ± 7.4), and +60 (33.4 ± 8.6) compared to IP (38.0 ± 8.6). IL-15 was greater at IP (15.5 ± 4.0 ng/mL) compared to PRE (13.4 ± 3.5), and smaller at PRE (13.4 ± 3.5), +30 (11.9 ± 3.3), and +60 (11.6 ± 3.2) compared to IP (15.5 ± 4.0). No condition × time point effects were observed. CONCLUSION: Both TS and CS induced an acute cytokine response in resistance-trained women; incorporating intra-set rest (CS) did not appear to affect this cytokine response
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