Fine-Scale Plant Species Identification in a Poor Fen and Integration of Techniques and Instrumentation in a Classroom Setting

Refining carbon flux measurements in the carbon cycle is an ongoing challenge. This study attempted to identify plant species in Sallie’s Fen, a nutrient-poor fen in Barrington, New Hampshire, at a fine scale in order to better model and understand carbon exchange between plants and the atmosphere in this type of ecosystem. A protocol for estimating percent cover of species in plots via ground measurements was developed. The next stage of this project was to compare these measurements with measurements derived from spectral images using ImageJ computer software. Statistical tests of the ground measurement data revealed that patterns of seasonal defoliation had a strong effect on the apparent species richness, evenness, and biodiversity of plants as seen aerially. The presence of Sphagnum mosses excluded the presence of other species, but the presence of other plants only excluded the visibility of Sphagnum since it resides in the understory of the layered community. A regression comparing percent cover of the vascular plant functional group and fractal dimensions from a digital camera was statistically significant, indicating that ground and aerial measurements agree and that spectral imaging can be used to save time in the field in place of ground measurements. Additionally, since ecosystem science is such an interdisciplinary field, it provides the perfect platform around which students can apply their scientific knowledge and understanding. Modifications to this project were suggested so that it can be carried out in a secondary school classroom setting while aligning with the Next Generation Science Standards

Large-scale sequencing identifies multiple genes and rare variants associated with Crohn’s disease susceptibility

peer reviewe

The Human Connectome Project and beyond: Initial applications of 300mT/m gradients

The engineering of a 3T human MRI scanner equipped with 300 mT/m gradients – the strongest gradients ever built for an in vivo human MRI scanner – was a major component of the NIH Blueprint Human Connectome Project (HCP). This effort was motivated by the HCP’s goal of mapping, as completely as possible, the macroscopic structural connections of the in vivo healthy, adult human brain using diffusion tractography. Yet, the 300 mT/m gradient system is well suited to many additional types of diffusion measurements. Here, we present three initial applications of the 300mT/m gradients that fall outside the immediate scope of the HCP. These include: 1) diffusion tractography to study the anatomy of consciousness and the mechanisms of brain recovery following traumatic coma; 2) q-space measurements of axon diameter distributions in the in vivo human brain and 3) postmortem diffusion tractography as an adjunct to standard histopathological analysis. We show that the improved sensitivity and diffusion-resolution provided by the gradients is rapidly enabling human applications of techniques that were previously possible only for in vitro and animal models on small-bore scanners, thereby creating novel opportunities to map the microstructure of the human brain in health and disease