Digestive and locomotor capacity show opposing responses to changing food availability in an ambush predatory fish

Metabolic rates vary widely within species, but little is known about how variation in the “floor” (i.e. standard metabolic rate in ectotherms; SMR) and “ceiling” (maximum metabolic rate; MMR) for an individual's aerobic scope (AS) are linked with the digestive and locomotor function. Any links among metabolic traits and aspects of physiological performance may also be modulated by fluctuations in food availability. This study followed changes in SMR, MMR, and digestive and locomotor capacity in Southern catfish (Silurus meridionalis) throughout 15 days of food deprivation and 15 days of refeeding. Individuals down-regulated SMR during food deprivation and showed only a 10% body mass decrease during this time. While critical swim speed (Ucrit), was robust to food-deprivation, digestive function decreased after fasting with a reduced peak oxygen uptake during specific dynamic action (SDA) and prolonged SDA duration. During refeeding, individuals displayed rapid growth and digestive function recovered to pre-fasting levels. However, refed fish showed a lower Ucrit than would be expected for their increased body length and in comparison to measures at the start of the study. Reduced swimming ability may be a consequence of compensatory growth: growth rate was negatively correlated with changes in Ucrit during refeeding. Southern catfish down-regulate digestive function to reduce energy expenditure during food deprivation, but regain digestive capacity during refeeding, potentially at the cost of decreased swimming performance. The plasticity of maintenance requirements suggests that SMR is a key fitness trait for in this ambush predator. Shifts in trait correlations with food availability suggest that the potential for correlated selection may depend on context

Functional Integration of Ecological Networks through Pathway Proliferation

Large-scale structural patterns commonly occur in network models of complex systems including a skewed node degree distribution and small-world topology. These patterns suggest common organizational constraints and similar functional consequences. Here, we investigate a structural pattern termed pathway proliferation. Previous research enumerating pathways that link species determined that as pathway length increases, the number of pathways tends to increase without bound. We hypothesize that this pathway proliferation influences the flow of energy, matter, and information in ecosystems. In this paper, we clarify the pathway proliferation concept, introduce a measure of the node--node proliferation rate, describe factors influencing the rate, and characterize it in 17 large empirical food-webs. During this investigation, we uncovered a modular organization within these systems. Over half of the food-webs were composed of one or more subgroups that were strongly connected internally, but weakly connected to the rest of the system. Further, these modules had distinct proliferation rates. We conclude that pathway proliferation in ecological networks reveals subgroups of species that will be functionally integrated through cyclic indirect effects.Comment: 29 pages, 2 figures, 3 tables, Submitted to Journal of Theoretical Biolog

Post

\u27Post\u27 deals with issues regarding the act of reading, writing, and the inevitability of imaginative erasure. Using two distinct, yet fundamentally related, narratives, \u27Post\u27 splits the reader\u27s focus between a dysfunctional kid in an unfriendly city, trying to uncover the origins of a mysterious list of addresses, and the creator of said list, a misanthropic collector, who hopes to conceal the absences and injuries of his past by mimicking, and living through, the lives of his others (i.e. people who share his name). By erasing certain facts that contradict their perspectives, and by projecting themselves onto the people/objects/events they investigate, both characters portray the acts of reading and writing as always already flawed pursuits, prompting the reader to question the very means by which he or she processes texts

Volume 7, Number 1

Fire Fighters Strike, Food: A Special 17-Page Section, Paraquat & Pothttps://thekeep.eiu.edu/post_amerikan/1074/thumbnail.jp

Volume 7, Number 10

Cops Go Berserk in Jail Shakedown, Food Stamps--How to Get \u27Emhttps://thekeep.eiu.edu/post_amerikan/1083/thumbnail.jp

Vendor-managed inventory in fresh-food supply chains

This thesis focuses on vendor-managed inventory (VMI) in fresh-food supply chains. VMI is a well-known example of supply chain collaboration, often applied to reduce inventory and improve demand fulfillment in retail supply chains. The thesis shows that VMI is a versatile combination of instruments and can be used in multiple ways to improve the performance of a supply chain. How VMI can be used best depends strongly on the products, processes and organizations of the suppliers involved. Because these characteristics can differ strongly also implementation of VMI can result in different (positive) outcomes. This way, the research emphasizes the importance of allowing suppliers the freedom to really take control of the supply chain. Meanwhile, coaching from the retailer can help to prevent disillusions caused by over or under investment

Volume 4, Number 11

Tales from the Naked Bureaucracy, 3 Secret Reports, Narc Pix, Abortion Protest, E.R.A., Beichs, Free Food, County Board, V.D., Day Carehttps://thekeep.eiu.edu/post_amerikan/1049/thumbnail.jp