Lake Champlain 2010: A summary of recent research and monitoring initiatives

Lake Champlain shares a geological history with the Great Lakes and, as part of the St. Lawrence drainage, also shares biological and ecological similarities. The complex bathymetry and extensive shoreline provide a variety of lacustrine habitats, from deep oligotrophic areas to shallow bays that are highly eutrophic. The large basin:lake ratio (19:1) makes Lake Champlain vulnerable to impacts associated with land use, and in some parts of the lake these impacts are further exacerbated by limited water exchange among lake segments due to both natural and anthropogenic barriers. Research in Lake Champlain and the surrounding basin has expanded considerably since the 1970s, with a particularly dramatic increase since the early 1990s. This special issue of the Journal of Great Lakes Research brings together 16 reports from recent research and monitoring efforts in Lake Champlain. The papers cover a variety of topics but primarily focus on lake hydrodynamics; historical and recent chemical changes in the lake; phosphorus loading; recent changes in populations of phytoplankton, zooplankton, and fishes; impacts of invasive species; recreational use; and the challenges of management decision-making in a lake that falls within the legal jurisdictions of two U.S. states, one Canadian province, two national governments, and the International Joint Commission. The papers provide not only evaluations of progress on some critical management issues but also valuable reference points for future research.     

MODIS NDVI time-series allow the monitoring of Eucalyptus plantation biomass

The use of remote sensing is necessary for monitoring forest carbon stocks at large scales. Optical remote sensing, although not the most suitable technique for the direct estimation of stand biomass, offers the advantage of providing large temporal and spatial datasets. In particular, information on canopy structure is encompassed in stand reflectance time series. This study focused on the example of Eucalyptus forest plantations, which have recently attracted much attention as a result of their high expansion rate in many tropical countries. Stand scale time-series of Normalized Difference Vegetation Index (NDVI) were obtained from MODIS satellite data after a procedure involving un-mixing and interpolation, on about 15,000 ha of plantations in southern Brazil. The comparison of the planting date of the current rotation (and therefore the age of the stands) estimated from these time series with real values provided by the company showed that the root mean square error was 35.5 days. Age alone explained more than 82% of stand wood volume variability and 87% of stand dominant height variability. Age variables were combined with other variables derived from the NDVI time series and simple bioclimatic data by means of linear (Stepwise) or nonlinear (Random Forest) regressions. The nonlinear regressions gave r-square values of 0.90 for volume and 0.92 for dominant height, and an accuracy of about 25 m³/ha for volume (15% of the volume average value) and about 1.6 m for dominant height (8% of the height average value). The improvement including NDVI and bioclimatic data comes from the fact that the cumulative NDVI since planting date integrates the interannual variability of leaf area index (LAI), light interception by the foliage and growth due for example to variations of seasonal water stress. The accuracy of biomass and height predictions was strongly improved by using the NDVI integrated over the two first years after planting, which are critical for stand establishment. These results open perspectives for cost-effective monitoring of biomass at large scales in intensively-managed plantation forests.     

A novel approach to the prediction of musculotendon paths

One of the most important aspects of the modelling of musculoskeletal systems is the determination of muscle moment arms which are dependent upon the paths of the muscles. These paths are often required to wrap around passive structures that can be modelled as simple geometric shapes. A novel technique for the prediction of the paths of muscles modelled as strings when wrapping around smooth analytical surfaces is presented. The theory of geodesics is used to calculate the shortest path of the string on the surface and a smoothness constraint is used to determine the correct solutions for the string path between insertions. The application of the technique to tapered cylinders and ellipsoids is presented as an extension of previous work on right-circular cylinders and spheres. The technique is assessed with reference to a particular biomechanical scenario; string lengths and moment arms are calculated and compared with alternative approximate methods. This illustrates the potential of the technique to provide more accurate muscle moment arm predictions.     

Successful treatment of childhood onset symptomatic dystonia with levodopa

Three patients with childhood onset symptomatic dystonia responded to levodopa. None fulfilled criteria for a diagnosis of "dopa responsive dystonia" (Segawa's disease). One may have had athetoid cerebral palsy for almost 25 years. All obtained dramatic and sustained benefit from levodopa therapy. A therapeutic trial of levodopa is advised in all patients in whom dystonia has developed in childhood or early adult life, regardless of suspected aetiology or duration of symptoms.     

Correlations of Regional Cerebral Metabolism With Memory Performance and Executive Function in Patients With Herpes Encephalitis or Frontal Lobe Lesions.

Cerebral [1?F]fluorodeoxyglucose positron emission tomography (1?FDG-PET) data from patients suffering amnesia following herpes encephalitis (n = 7) or frontal lobe pathology (n = 14) were compared with data from age-matched nonamnesic subjects (n = 10). All subjects received structural MRI, resting 1?FDG-PET scans, and neuropsychological evaluation. PET data were analyzed using complementary statistical parametric mapping and region-of-interest methods. Differential patterns of hypometabolism were found in patients relative to healthy controls. Factor analysis of the neuropsychological data revealed that memory performance was associated with retrosplenial and medial temporal metabolism, and executive function was associated with dorsolateral frontal metabolism. The association between memory performance and retrosplenial metabolism remained statistically significant after accounting for measures of cerebral atrophy using MRI. The significance of the retrosplenium as a major relay station between the thalamus and the medial temporal and frontal lobes--sensitive to changes in either--is discussed in the light of the findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Internet and DSS: massive,real-time data availability is changing the DSS landscape

Absract The Internet can serve as a source of massive, micro-level data. We discuss the opportunities and challenges in capturing and utilizing real-time data off the Internet, intranets, or extranets. Emphasis is placed on developing dynamic decision support systems (DSSs) in our new data-enabled environment. Illustrations of real-time data capture and potential DSS use are provided from work on online auctions, e-retailing, piracy, and intellectual property. This article is part of the “Handbook on Decision Support Systems” edited by Frada Burstein and Clyde W. Holsapple (2008) Springer.     

Reduction of Microbial Counts at a Commercial Beef Koshering Facility

Effectiveness of a water soaking, salting, and water rinsing (koshering) process in reducing microbial counts was examined. Beef briskets (30) were sampled at four stages in the plant, viz. prewashing, postwashing, after 24 h chilling, and after koshering. Quantitative aerobic plate, coliforms, and Escherichia colicounts, and qualitative analysis for Salmonella were determined. PROC MIXED and GLM procedures were applied to determine statistical differences among least square means (LSM) at p.0.05. Microbial counts did not always decrease from prewashing to postwashing, after 24 h chilling, or after koshering but koshering reduced APC, coliforms, and E. coli from initial counts. Salmonella were also reduced.     

Predation on emergent lake trout fry in Lake Champlain

The rehabilitation of extirpated lake trout (Salvelinus namaycush) in the Great Lakes and Lake Champlain has been hindered by various biological and physiological impediments. Efforts to restore a lake trout fishery to Lake Champlain include hatchery stocking and sea lamprey control. Despite these management actions, there is little evidence of recruitment of naturally-produced fish in annual fall assessments. Spawning occurs at multiple sites lake-wide in Lake Champlain, with extremely high egg and fry densities, yet sampling for juvenile lake trout has only yielded fin-clipped fish. To investigate this recruitment bottleneck, we assessed predation pressure by epi-benthic fish on emergent fry on two spawning reefs and the subsequent survival and dispersal of fry in potential nursery areas. Epi-benthic predators were sampled with 2-h gillnet sets at two small, shallow sites in Lake Champlain throughout the 24-h cycle, with an emphasis on dusk and dawn hours. In total, we documented seven different species that had consumed fry, with consumption rates from 1 to 17 fry per stomach. Rock bass and yellow perch dominated the near-shore fish community and were the most common fry predators. Predator presence and consumption of fry was highest between 19:00 and 07:00. Predators only consumed fry when fry relative abundance was above a threshold of 1 fry trap^− 1 day^− 1. We used an otter trawl to sample for post-emergent fry adjacent to the reef, but did not capture any age-0 lake trout. Due to the observed predation pressure by multiple littoral, species on shallow spawning reefs, lake trout restoration may be more successful at deep, offshore sites.     

Involving users in the design and usability evaluation of a clinical decision support system

AIM: To design and evaluate a clinical decision support system (CDSS) to support cardiovascular risk prevention in type 2 diabetes. METHODS: A preliminary requirements specification and three prototype CDSS interface designs were developed. Seven patients and seven clinicians conducted 'usability tests' on five different task scenarios with the CDSS prototypes to test its effectiveness, efficiency and 'user-friendliness'. Structured, qualitative questions explored their preferences for the different designs and overall impressions of clinical usefulness. RESULTS: Patients and clinicians were enthusiastic about the CDSS and used it confidently after a short learning period. Some patients had difficulty interpreting clinical data, but most were keen to see the CDSS used to help them understand their diabetes, provided a clinician explained their results. Clinicians' main concern was that the CDSS would increase consultation times. Changes suggested by users were incorporated into the final interface design. CONCLUSION: We have successfully incorporated patients' and clinicians' views into the design of a CDSS, but it was an arduous process.