Global sensitivity analysis of an end-to-end marine ecosystem model of the North Sea : factors affecting the biomass of fish and benthos

Comprehensive analysis of parameter and driver sensitivity is key to establishing the credibility of models of complex systems. This is especially so for models of natural systems where experimental manipulation of the real-world to provide controlled validation data is not possible. Models of marine ecosystems fall into this category, but despite the interest in these models for evaluating the effects of climate change and fishing on nutrient fluxes and the abundances of flora and fauna, none have yet been subjected to global sensitivity analysis. Here we present results of both local ‘one-at-a-time’ (OAT), and variance based global sensitivity analyses (GSA) of the fish and fishery aspects of StrathE2E, an end-to-end (nutrients to birds and mammals) ecosystem model of the North Sea. The sensitivity of the model was examined with respect to internal biological parameters, and external drivers related to climate and human activity. The OAT Morris method was first used to screen for factors most influential on model outputs. The Sobol GSA method was then used to calculate quantitative sensitivity indices. The results indicated that the fish and shellfish components of the model (demersal and pelagic fish, filter/deposit and scavenge/carnivore feeding benthos) were influenced by different sets of factors. Harvesting rates were directly influential on demersal and pelagic fish biomasses. Suspension/deposit feeding benthos were directly sensitive to changes in temperature, while the temperature acted indirectly on pelagic fish through the connectivity between model components of the food web. Biomass conversion efficiency was the most important factor for scavenge/carnivorous feeding benthos. The results indicate the primacy of fishing as the most important process affecting total fish biomass, together with varying responses to environmental factors which may be relevant in the context of climate change. The non-linear responses and parameter interactions identified by the analysis also highlight the necessity to use global rather than local methods for the sensitivity analysis of ecosystem models

Phosphorylation State-Dependent Regulation of SAPAP3 and mGluR5 Association

poster abstractThis study aims to characterize the interaction between SAP90/PSD-95-associated protein 3 (SAPAP3) and metabotropic Glutamate Receptor 5 (mGluR5); specifically focusing on how SAPAP3 phosphorylation state modulates association. SAPAP3 is a scaffolding protein localized to the postsynaptic density (PSD) of striatal neurons and SAPAP3 knockout mice have Obsessive-Compulsive Disorder-like symptoms. Here, we hypothesize that spinophilin modulates SAPAP3 phosphorylation and alterations in SAPAP3 phosphorylation regulate SAPAP3 binding to mGluR5. We will use in vitro and ex vivo studies to characterize the interaction between spinophilin and SAPAP3 and to determine the functional implications of SAPAP3 phosphorylation on mGluR5 binding. These data will enhance our understanding of molecular mechanisms that regulate SAPAP3 and mGluR5 function, two proteins with known roles in obsessive-compulsive disorder

A Comparative Study of Qualitative and Quantitative Courses Across Three Educational Delivery Modalities

This study investigated differences in student satisfaction between qualitative and quantitative courses across three modalities: online, on ground and blended. With 21,000 respondents results indicate there are significant differences in student satisfaction between qualitative and quantitative courses. Satisfaction was higher for qualitative courses across all three modalities; it was highest for the online modify for both qualitative and quantitative courses

Mechanisms Regulating the Association of Protein Phosphatase 1 with Spinophilin and Neurabin

Protein phosphorylation is a key mediator of signal transduction, allowing for dynamic regulation of substrate activity. Whereas protein kinases obtain substrate specificity by targeting specific amino acid sequences, serine/threonine phosphatase catalytic subunits are much more promiscuous in their ability to dephosphorylate substrates. To obtain substrate specificity, serine/threonine phosphatases utilize targeting proteins to regulate phosphatase subcellular localization and catalytic activity. Spinophilin and its homologue neurabin are two of the most abundant dendritic spine-localized protein phosphatase 1 (PP1) targeting proteins. The association between spinophilin and PP1 is increased in the striatum of animal models of Parkinson's disease (PD). However, mechanisms that regulate the association of spinophilin and neurabin with PP1 are unclear. Here, we report that the association between spinophilin and PP1α or PP1γ1 was increased by CDK5 expression and activation in a heterologous cell system. This increased association is at least partially due to phosphorylation of PP1. Conversely, CDK5 expression and activation decreased the association of PP1 with neurabin. As with dopamine depletion, methamphetamine (METH) abuse causes persistent alterations in dopamine signaling which influence striatal medium spiny neuron function and biochemistry. Moreover, both METH toxicity and dopamine depletion are associated with deficits in motor control and motor learning. Pathologically, we observed a decreased association of spinophilin with PP1 in rat striatum evaluated one month following a binge METH paradigm. Behaviorally, we found that loss of spinophilin recapitulates rotarod pathology previously observed in dopamine-depleted and METH-treated animals. Together, these data have implications in multiple disease states associated with altered dopamine signaling such as PD and psychostimulant drug abuse and delineate a novel mechanism by which PP1 interactions with spinophilin and neurabin may be differentially regulated

Understanding the synthesis and reactivity of ADORable zeolites using NMR spectroscopy

The authors would like to thank the ERC (EU FP7 Consolidator Grant 614290 EXONMR and Advanced Grant 787073 ADOR) and EPSRC (EP/N509759/1) for a studentship for CMR. The research data (and/or materials) supporting this publication can be accessed at https://doi.org/10.17630/d82e58e4-b4a0-40b3-8156-5cbf80eeea72Zeolites remain one of the most important class of industrial catalyst used today, and with the urgent drive for transition from petrochemical to renewable feedstocks there is a renewed interest in developing new types of zeolite. Recent synthetic advances in the field have included the development of the Assembly-Disassembly-Organisation-Reassembly (ADOR) method. In this short review we will discuss how solid-state NMR experiments can be used to probe the mechanism of the process by characterising the structure of the intermediates and products, show how 17O NMR spectroscopy can be used to probe the reactivity of ADORable zeolites and explain how this in turn can lead to fundamental questions of how zeolites behave in the presence of liquid water.Publisher PDFPeer reviewe

Bighead Carp effects on the growth, abundance, and survival of larval Bluegill

Bighead Carp (Hypophthalmichthys nobilis) are an invasive planktivore, native to Asia, that have established successful populations in the Mississippi and Illinois River systems after their unintentional introduction in the 1980’s. Their ability to efficiently consume zooplankton, has generated enormous concern for the native fishes in these ecosystems and those in connected water bodies yet to be invaded. Current research on their competitive interactions with native fishes, especially facultative planktivores, is not well documented and inconsistent. Furthermore, inquiries into their effect on the larval stages of native fishes have yet to be made. The objective of my thesis was to test for competitive interactions between Bighead Carp and a facultative planktivore as they relate to larval growth, abundance, and survival. Moreover, I aimed to compare the competitive effects of Bighead Carp to those of a native planktivore. I conducted two experiments at different spatial scales involving Bighead Carp, Golden Shiners (Notemigonus crysoleucas), and larval Bluegill (Lepomis macrochirus). My first experiment involved investigating the growth of larval Bluegill at varying densities of either Bighead Carp or Golden Shiners in a controlled mesocosm setting. The results of this experiment inconsistently suggested that Bighead Carp reduce the growth of larval Bluegill to a greater extent than Golden Shiners. My second experiment was at a larger scale in 0.4 hectare ponds and aimed to examine the recruitment success of Bluegill when either Bighead Carp or Golden Shiners were present. This experiment consistently showed that Bighead Carp reduce the daily growth rate, and ultimately recruitment efficiency, of larval Bluegill to a greater extent than Golden Shiners. Effects observed in both studies correlated with greater decreases in zooplankton by Bighead Carp compared to Golden Shiners. These results begin to indicate that an invasive planktivore may negatively affect the growth of larval Bluegill, and other native fishes with similar life-histories, to a greater extent than a native planktivore. My results help to further understand the effects Asian Carp are having on the Illinois and Mississippi River systems and provide insight into their potential impacts on aquatic systems yet to be invaded

Cambrian suspension-feeding tubicolous hemichordates

The combination of a meager fossil record of vermiform enteropneusts and their disparity with the tubicolous pterobranchs renders early hemichordate evolution conjectural. The middle Cambrian Oesia disjuncta from the Burgess Shale has been compared to annelids, tunicates and chaetognaths, but on the basis of abundant new material is now identified as a primitive hemichordate

Brain neuropeptide Y and CCK and peripheral adipokine receptors: Temporal response in obesity induced by palatable diet

Objective: Palatable food disrupts normal appetite regulation, which may contribute to the etiology of obesity. Neuropeptide Y (NPY) and cholecystokinin play critical roles in the regulation of food intake and energy homeostasis, while adiponectin and carnitine palmitoyltransferase (CPT) are important for insulin sensitivity and fatty acid oxidation. This study examined the impact of short- and long-term consumption of palatable high-fat diet (HFD) on these critical metabolic regulators. Methods: Male C57BL/6 mice were exposed to laboratory chow (12% fat), or cafeteria-style palatable HFD (32% fat) for 2 or 10 weeks. Body weight and food intake were monitored throughout. Plasma leptin, hypothalamic NPY and cholecystokinin, and mRNA expression of leptin, adiponectin, their receptors and CPT-1, in fat and muscles were measured. Results: Caloric intake of the palatable HFD group was 2-3 times greater than control, resulting in a 37% higher body weight. Fat mass was already increased at 2 weeks; plasma leptin concentrations were 2.4 and 9 times higher than control at 2 and 10 weeks, respectively. Plasma adiponectin was increased at 10 weeks. Muscle adiponectin receptor 1 was increased at 2 weeks, while CPT-1 mRNA was markedly upregulated by HFD at both time points. Hypothalamic NPY and cholecystokinin content were significantly decreased at 10 weeks. Conclusion: Palatable HFD induced hyperphagia, fat accumulation, increased adiponectin, leptin and muscle fatty acid oxidation, and reduced hypothalamic NPY and cholecystokinin. Our data suggest that the adaptive changes in hypothalamic NPY and muscle fatty acid oxidation are insufficient to reverse the progress of obesity and metabolic consequences induced by a palatable HFD. © 2008 Nature Publishing Group All rights reserved