23 research outputs found
Relatório de estágio em farmácia comunitária
Relatório de estágio realizado no âmbito do Mestrado Integrado em Ciências Farmacêuticas, apresentado à Faculdade de Farmácia da Universidade de Coimbr
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Assessing the contribution of anadromous herring to largemouth bass growth
Juvenile anadromous river herring (alewife Alosa pseudoharengus and blueback herring A. aestivalis) spend the first 3 to 7 months of life in headwater lakes of coastal systems. Systems that support herring often produce trophy largemouth bass Micropterus salmoides. Even though biologists, managers, and anglers have speculated about the value of anadromous herring as a key prey for resident predators, the contribution that herring make to the diets of these predators has not been assessed. Herein, we quantified largemouth bass diets in two coastal lakes, Santuit and Coonamessett ponds, that contained anadromous herring, and we used bioenergetics modeling to evaluate the importance of herring prey to largemouth bass growth. During May through November 1994, largemouth bass diets consisted of various fish species, crayfish, and other invertebrates. Although not the most important prey overall, herring were the most important fish prey consumed in both lakes based on number of individuals consumed. In both lakes, herring were primarily eaten by largemouth bass that were fewer than 300 mm in total length after mid-August. Coonamessett Pond largemouth bass ate more herring and other fish prey and achieved better growth than did those in Santuit Pond. Bioenergetics modeling simulations revealed that water temperature does not explain the presence of trophy largemouth bass in southeastern Massachusetts. Because largemouth bass grow better on a diet that includes herring, we conclude that juvenile herring are an energetically valuable and a potentially key prey for largemouth bass. However, factors other than energetics mediate the use of herring by these resident predators. Further investigations into spatial dynamics, size structure, and foraging behavior are necessary to understand the mechanisms that drive interactions between largemouth bass and anadromous herring
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Mechanisms for migration of anadromous herring: An ecological basis for effective conservation
Land use planners have the challenge of incorporating biologically sound guidelines into development plans to balance human development with conservation of natural resources. Valued as an important component of the natural heritage of the northeastern United States, anadromous river herring (Alosa pseudoharengus, A. aestivalis) represent a model system to look at how ecological data can help conserve biological diversity in systems impacted by humans. Juvenile river herring spend 3–7 months in freshwater then migrate to the ocean. However, factors that trigger migration, and consequently influence distribution and abundance, are not well understood. Thus, our objectives in this study were to (1) describe juvenile river herring migration patterns, both “peak” (\u3e1000 fish/wk) and “all” (\u3e30 fish/wk) migration; (2) identify potential cues for this migration; (3) examine effects of one type of ecosystem alteration, low water levels, on river herring; and (4) suggest how this information can be incorporated into an effective conservation plan. Weekly during June–November 1994, we sampled both migrating and nonmigrating river herring and seven associated abiotic and biotic variables in one continuous and one intermittent flow system on Cape Cod, Massachusetts. We then used multiple logistic regression to predict when juvenile river herring migrate. In the continuous-flow system, juvenile river herring migration primarily occurred during the midday hours from July through early November, with the peaks of migration, comprising \u3e96% of all migrating fish observed in early July and early September. The peaks of migration occurred during the new moon, when Bosmina spp. density was low, and all periods of migration occurred when water visibility was low, during decreased amounts of rainfall. In the intermittent-flow system, juvenile river herring migration was frequently inhibited due to low water levels, and herring were on average 25 mm smaller than those in the continuous flow system. Using these results, managers can more effectively monitor river herring populations by identifying factors associated with migration and isolating critical flow periods when fish movement is likely to occur. Thus, we can detect changes in herring population size due to human impacts. Ultimately, these data can be incorporated into an ecologically sound conservation plan for juvenile anadromous herring that may help ensure their survival while balancing human needs for natural resources
Cell competition with normal epithelial cells promotes apical extrusion of transformed cells through metabolic changes
Recent studies have revealed that newly emerging transformed cells are often apically extruded from epithelial tissues. During this process, normal epithelial cells can recognize and actively eliminate transformed cells, a process called epithelial defence against cancer (EDAC). Here, we show that mitochondrial membrane potential is diminished in RasV12-transformed cells when they are surrounded by normal cells. In addition, glucose uptake is elevated, leading to higher lactate production. The mitochondrial dysfunction is driven by upregulation of pyruvate dehydrogenase kinase 4 (PDK4), which positively regulates elimination of RasV12-transformed cells. Furthermore, EDAC from the surrounding normal cells, involving filamin, drives the Warburg-effect-like metabolic alteration. Moreover, using a cell-competition mouse model, we demonstrate that PDK-mediated metabolic changes promote the elimination of RasV12-transformed cells from intestinal epithelia. These data indicate that non-cell-autonomous metabolic modulation is a crucial regulator for cell competition, shedding light on the unexplored events at the initial stage of carcinogenesis