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

Discerning and Developing Department Chairs as Instructional Leaders: A Case Study of a Large Suburban High School

Prevailing research on instructional leadership has primarily focused on school administration to fulfill this role. Growing accountability from state officials, increased departmentalization, and demands on administrations’ time and resources led to the need to study other avenues of leadership in secondary schools. In this qualitative case study, the researcher looked at the current perceptions and beliefs of administration, department chairs, and teachers concerning the department chair role. An understanding of department chairs’ instructional leadership capacity, distributed leadership in the school of study, and collective efficacy were investigated to determine the best ways to employ department chairs to support teacher development while impacting student performance. Interviews of administrators, department chairs, and teachers were solicited to provide their perceptions and beliefs regarding the position of department chair through the lens of instructional leadership. Similarities and differences were collected to develop descriptive themes designed to encompass department chair characteristics currently present in the school of study. The study findings indicated continuity in some aspects of the role of department chair while highlighting disparities between perceived and substantive characteristics. The major themes of collaboration, trust, traditional management, advocacy, mentorship, growth mindset, instruction, and distributed leadership were found throughout the participants’ responses. Perceptions and beliefs of how each group observed these themes regarding the research questions illustrated areas of inconsistencies for future analysis and study. As a consequence, a clearly defined job description and training program for the position of department chair and other lower-level positions such as professional learning community leads need to be considered to provide more opportunity for the role of departments to develop their instructional leadership capacity, to enhance teacher growth, and to increase student success. iv Keywords: administrators, collective efficacy, department chairs, distributed leadership, instructional leadershi

The Clustering Of Galaxies Around Radio-Loud AGNs

We examine the hypothesis that mergers and close encounters between galaxies can fuel AGNs by increasing the rate at which gas accretes towards the central black hole. We compare the clustering of galaxies around radio-loud AGNs with the clustering around a population of radio-quiet galaxies with similar masses, colors and luminosities. Our catalog contains 2178 elliptical radio galaxies with flux densities greater than 2.8 mJy at 1.4 GHz from the 6dFGS survey. We find that radio AGNs with more than 200 times the median radio power have, on average, more close (r<160 kpc) companions than their radio-quiet counterparts, suggestive that mergers play a role in forming the most powerful radio galaxies. For ellipticals of fixed stellar mass, the radio power is not a function of large-scale environment nor halo mass, consistent with the radio powers of ellipticals varying by orders of magnitude over billions of years.Comment: 12 pages, 6 figure

Juvenile gadoids habitat association and ontogenetic shift observations using stereo-video baited cameras

Understanding habitat variables affecting species distribution and survival is essential to their protection. This is especially important in areas where anthropogenic pressures can have a significant direct impact on not only the survival of the species but also damage their habitat. The Firth of Clyde, southwestern Scotland, was an important commercial fishing area for a variety demersal fish species up until 1973. However, stocks have since declined to near-zero despite fisheries measures put in place to aid recovery. Here we report on Stereo Baited Remote Underwater Video (SBRUV) surveys in the Firth of Clyde between June and September in 2013 and 2014 to determine the habitat of juvenile Atlantic cod Gadus morhua, haddock Melanogrammus aeglefinus, and whiting Merlangius merlangus. Habitat predictor variables explored included substratum type, depth, wave fetch, and bentho-demersal species diversity. G. morhua were most abundant in shallow, sheltered areas composed of gravel-pebble containing maerl. Ontogenetic shifts and density dependence were also observed. M. aeglefinus, and M. merlangus predominated over deeper sand and mud. Relative abundances of all three species were positively related to bentho-demersal diversity. This work demonstrates the potential of SBRUV as a non-destructive survey tool under northern-temperate conditions. Our results indicate that spatial conservation measures to benefit demersal fish should be advised by patterns of bentho-demersal diversity as well as physical substratum types

Survival of the fittest: explanations for gadoid imbalance in heavily fished seas

1. Anthropogenic activities have caused the degradation of the world's ecosystems, accelerating the loss of biodiversity. In marine ecosystems, fishing has had strong impacts on fish populations and their habitats; however, not all species have responded equally to fishing pressure. 2. Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and whiting (Merlangius merlangus) are of high commercial value throughout the North Atlantic. Despite having relatively similar life cycles, the state of stocks of these three species varies enormously, with whiting faring better than cod. Within the Firth of Clyde (south‐west Scotland), this imbalance is especially accentuated, where small whiting now make up the greater proportion of the biomass. 3. In this study, cod, haddock, and whiting recruitment to coastal areas, growth, and bait attraction were explored within a marine protected area (MPA) in the Firth of Clyde. Over the course of the summers of 2013 and 2014, whiting and haddock arrived at coastal areas earlier than cod, and grew more quickly. Cod were on average the smallest gadoid observed, and whiting the largest. Whiting also had more predominant scavenging behaviour. 4. These results, in combination with other life‐history traits, indicate that whiting may be at a competitive advantage over cod, and this may partly explain the imbalance of gadoids in the Firth of Clyde. This study highlights the importance of considering life‐history differences in multi‐species fisheries management, and how appropriately managed MPAs could help to restore fish population and assemblage structure

Real-Time Simulation of Ares I Launch Vehicle

The Ares Real-Time Environment for Modeling, Integration, and Simulation (ARTEMIS) has been developed for use by the Ares I launch vehicle System Integration Laboratory (SIL) at the Marshall Space Flight Center (MSFC). The primary purpose of the Ares SIL is to test the vehicle avionics hardware and software in a hardware-in-the-loop (HWIL) environment to certify that the integrated system is prepared for flight. ARTEMIS has been designed to be the real-time software backbone to stimulate all required Ares components through high-fidelity simulation. ARTEMIS has been designed to take full advantage of the advances in underlying computational power now available to support HWIL testing. A modular real-time design relying on a fully distributed computing architecture has been achieved. Two fundamental requirements drove ARTEMIS to pursue the use of high-fidelity simulation models in a real-time environment. First, ARTEMIS must be used to test a man-rated integrated avionics hardware and software system, thus requiring a wide variety of nominal and off-nominal simulation capabilities to certify system robustness. The second driving requirement - derived from a nationwide review of current state-of-the-art HWIL facilities - was that preserving digital model fidelity significantly reduced overall vehicle lifecycle cost by reducing testing time for certification runs and increasing flight tempo through an expanded operational envelope. These two driving requirements necessitated the use of high-fidelity models throughout the ARTEMIS simulation. The nature of the Ares mission profile imposed a variety of additional requirements on the ARTEMIS simulation. The Ares I vehicle is composed of multiple elements, including the First Stage Solid Rocket Booster (SRB), the Upper Stage powered by the J- 2X engine, the Orion Crew Exploration Vehicle (CEV) which houses the crew, the Launch Abort System (LAS), and various secondary elements that separate from the vehicle. At launch, the integrated vehicle stack is composed of these stages, and throughout the mission, various elements separate from the integrated stack and tumble back towards the earth. ARTEMIS must be capable of simulating the integrated stack through the flight as well as propagating each individual element after separation. In addition, abort sequences can lead to other unique configurations of the integrated stack as the timing and sequence of the stage separations are altered

Observation of ultrafast internal conversion in fullerene anions in solution

The ultrafast decay rates of photoexcited View the MathML source ions have been measured in the condensed phase. The mechanism for decay is internal conversion, and the decay rate is a strong function of the charge on the ion. A bottleneck in the ground state recovery has also been detected, and its interpretation is discussed

Real-Time Hardware-in-the-Loop Simulation of Ares I Launch Vehicle

The Ares Real-Time Environment for Modeling, Integration, and Simulation (ARTEMIS) has been developed for use by the Ares I launch vehicle System Integration Laboratory at the Marshall Space Flight Center. The primary purpose of the Ares System Integration Laboratory is to test the vehicle avionics hardware and software in a hardware - in-the-loop environment to certify that the integrated system is prepared for flight. ARTEMIS has been designed to be the real-time simulation backbone to stimulate all required Ares components for verification testing. ARTE_VIIS provides high -fidelity dynamics, actuator, and sensor models to simulate an accurate flight trajectory in order to ensure realistic test conditions. ARTEMIS has been designed to take advantage of the advances in underlying computational power now available to support hardware-in-the-loop testing to achieve real-time simulation with unprecedented model fidelity. A modular realtime design relying on a fully distributed computing architecture has been implemented

Supplemental data for "Bear encounters with seismic stations in Alaska and northwestern Canada"

This collection is established as a supplement to a published manuscript, "Bear encounters with seismic stations in Alaska and northwestern Canada".This project was supported by the National Science Foundation, Grant EAR-1352688