Advances in aquatic ecology can be broadly separated into two contrasting approaches, synthetic vs. incremental. Synthesists study rivers at a holistic level and typically describe important processes in relative terms from headwater to river mouth or across regions. Incrementalists typically quantify relationships of stream flow quantity and quality to fisheries response and are often constrai...

A lunar outpost will involve a habitat with an integrated set of hardware and software that will maintain a safe environment for human activities. There is a desire for a paradigm shift whereby crew will be the primary mission operators, not ground controllers. There will also be significant periods when the outpost is uncrewed. This will require that significant automation software be resident...

We developed a demographic model to perform a population viability analysis (PVA) of the Blue-throated Macaw (Ara glaucogularis), a critically endangered species endemic to Bolivia. PVA simulations were run using individualbased (VORTEX 9.72) and cohort-based (RAMAS GIS 4.0) programs. A baseline simulation allowed for the assessment of the status of the species based on estimates of extinction ...

A shortage of salmonid spawning habitat on dammed and regulated rivers has led to the popularity of spawning habitat rehabilitation projects. Habitat heterogeneity is thought to be an important feature of aquatic ecosystems, but specific metrics for design and assessment are lacking. In August 2002, ~ 2,786 metric tons of spawning gravels and 7 large boulders were placed in a 155 meter reach on...

Theory predicts the occurrence of threshold levels of habitat in landscapes, below which ecological processes change abruptly. Simulation models indicate that below critical thresholds, fragmentation of habitat influences patch occupancy by decreasing colonization rates and increasing rates of local extinction. Uncovering such putative relationships is important for understanding the demography...

The Lunar Surface Operations Simulator (LSOS) is being developed to support planning and design of space missions to return astronauts to the moon. Vehicles, habitats, dynamic and physical processes and related environment systems are modeled and simulated in LSOS to assist in the visualization and design optimization of systems for lunar surface operations. A parametric analysis tool and a dat...

Please cite this article in press as: M. Boushab (2009), doi:10.1016/j.comnet.2009.07.015 In sensor networks, several applications such as habitat monitoring and moving objects tracking, require the knowledge of nodes positions. Position estimation most often includes errors due to the measurements of distance and incoming angles between neighbors. Erroneous positions are propagated from a node...

Presence–absence data are used widely in analysis of wildlife–habitat relationships. Failure to detect a species’ presence in an occupied habitat patch is a common sampling problem when the population size is small, individuals are difficult to sample, or sampling effort is limited. In this paper, the influence of non-detection of occurrence on parameter estimates of logistic regression models ...

The goal of this study was to identify and differentiate the influence of multiple habitat types that span a spectrum of suitability for Hyla squirella, a widespread frog species that occurs in a broad range of habitat types. We collected microsatellite data from 675 samples representing 20 localities from the southeastern USA and used machine-learning methodologies to identify significant habi...

Dams and water diversions can dramatically alter the hydraulic habitats of stream ecosystems. Predicting how water depth and velocity respond to flow alteration is possible using hydraulic models, such as Physical Habitat Simulation (PHABSIM); however, such models are expensive to implement and typically describe only a short length of stream (10m). If science is to keep pace with development, ...