Green burial focuses on the interment of the body of a dead person in a fashion that supports decomposition so that the body can be naturally recycled. Green burial has grown exponentially within the past ten years and are now offered by hundreds of providers across the U.S., making it an increasingly popular alternative to conventional funerary customs, such as casket burial and cremation. While recent research has explored the conditions under which the green burial industry has become normalized and competitive, and the types of predictors of green burial support, we know little about the experience of participants and the characteristics of green burial ritual. To what extent have funeral participants internalized the industry’s goals of conservation and fostering an emotional bond with nature? Do green burial rites reinforce community among the living as with conventional funeral rites? Or does the ritual appeal mostly to participants sympathetic to environmentalism? To answer these questions, I conducted ethnographic interviews with green burial workers and participants and observations of green burial rituals. The results of my study furthered our understanding of the green burial as a growing social movement and new meaning making enterprise and revealed how supporters derived distinctive meaning within green burial.

The modern human longitudinal arch is a structural adaptation to bipedal locomotion, rigid enough to be a propulsive lever but flexible enough to stabilize a large body mass over a relatively small base of support. Early hominins appear to have a low or absent longitudinal arch—a condition equivalent to human pes planus. The morphology of the calcaneocuboid joint (CCJ) has been suggested to play a critical role in the stability of the longitudinal arch, but the relationship between articular shape and arch height has yet to be tested empirically. This study examines the covariation of the shape of the CCJ with arch height, via calcaneal inclination angle (CIA). Eleven calcaneal measurements and CIA were measured on weight-bearing radiographs of 103 patients from an urban US trauma center. An equation to predict CIA was determined using stepwise regression analysis using Böehler’s angle, plantar and distal angles of the calcaneal tuber, anterior angle, and the angle of inclination of the posterior talar facet (all p’s<0.01, R2=0.67). Landmark data were obtained from 3D surface scans of the CCJ of 24 calcanei from lower limbs amputated due to infection or acute ischemia. Individuals with bony pathology were excluded from analysis. Data were analyzed in R using Procrustes ANOVA with principal components analysis to explore patterns of variation within the sample. No significant associations were found between CCJ shape and CIA (p=0.51, R2=0.03, F=0.91). Consequently, calcaneocuboid joint shape may not be a useful for interpreting the longitudinal arch morphology of fossil hominin pedal remains.

Spinal cord injuries (SCI), unlike other injuries, often exhibit limited recovery. Patients with SCI often face major detriments to quality of life and health due to impaired motor control, sensation, and homeostatic regulation. In SCI patient surveys, regaining hand function is consistently among the highest priorities. We use a rat model of cervical SCI to develop therapies that restore motor function for reaching and grasping. We have shown that rats that receive targeted, activity-dependent spinal stimulation (TADSS) at a single spinal site for forelimb reaching exhibited enhanced recovery compared to physical retraining or open-loop electrical stimulation. Spinal stimulation is delivered to the injured forelimb of the rat when muscular activity, during reaching and grasping, is displayed. We used the single pellet grasping (SPG) task to assess forelimb function. Our hypothesis was that modifying the TADSS protocol to include stimulation of multiple motor pathways (MTADSS) for reaching and grasping will produce greater recovery than single site TADSS. In the current project, male and female Long-Evans rats were injured with a unilateral C4-C5 spinal hemi-contusion which primarily impairs the dominant forelimb. Four weeks after injury, the animals were implanted with spinal stimulation wires and wires for recording the muscle activity of the impaired forelimb. MTADSS and unstimulated control rats, underwent fourteen weeks of daily SPG, lever pull, which measures pull strength, and two other functional assessments, which will be reported elsewhere. MTADSS rats show recovery in SPG and a principal component analysis of lever pull showed that mean peak force (MPF), explains 84% of the variance between control rats and therapy rats at week 7 of therapy. The increased MPF among MTADSS rats suggests increased muscle recovery due to therapy. Taken together, MTADSS therapy seems to promote recovery in multiple measures of forelimb function compared to physical retraining alone.

The existence of 'checkpoints' in the mitotic cell cycle is well characterized; however, much less is known about the possible existence of checkpoints controlling re-entry of terminally differentiated cells into mitosis. We are exploring this possibility in Chlamydomonas reinhardtii, a unicellular eukaryotic green alga that, in the presence of visible light, differentiates back and forth from an actively dividing 'vegetative' state to a non-dividing 'gametic' state depending on the presence or absence of nitrogen in the culture medium. The work of previous students in our group suggests that gametes of wildtype C. reinhardtii show a growth delay of about 12 hours after nitrogen is added to nitrogen-deficient media; UV exposure immediately prior to nitrogen addition significantly increases the length of this delay. This is consistent with the working hypothesis of a dedifferentiation checkpoint in this organism. However, the visible light requirement for dedifferentiation confounds this result, because C. reinhardtii also uses visible light for photoreactivation subsequent to UV exposure. To control for this, we are taking a genetic approach. We expect to find an even longer post-UV dedifferentiation lag for a photorepair-deficient mutant of C. reinhardtii compared to wildtype, which would strengthen the case for a dedifferentiation checkpoint in this organism. Of particular interest in the present study is our use of two parallel statistical approaches to analyze our experimental data: (1) a 'traditional' timepoint-by-timepoint statistical analysis, and (2) statistical comparison of logistic curves fitted to the same data. We have written programs that facilitate execution and comparison of the outcomes of both methods of analysis, and expect both methods to agree in confirming our hypothesis. This insight into the inner workings of cell cycle dedifferentiation, as well as the validation of the second, novel statistical approach could be beneficial to a broad variety of ecological and biomedical experimental contexts.

Spinal cord injury (SCI) is a debilitating condition that impairs motor function and overall quality of life. We have previously shown that Targeted Activity-Dependent Spinal Stimulation (TADSS) improves motor function in a rodent cervical SCI model. The hypothesized mechanism underlying TADSS is Spike-Timing Dependent Plasticity (STDP). During STDP, the strength of the synapse, or connection, between two neurons depends on the spiking behavior of a presynaptic neuron (A) relative to the postsynaptic neuron (B) within an optimal delay window. A synapse strengthens if A spikes less than 50 ms before B. Conversely, a synapse weakens if A fires less than 50 ms after B. It is currently unclear if TADSS strengthens corticospinal tract (CST) input into cervical spinal cord. In this project, we investigated the efficacy of TADSS therapy in inducing STDP in the rodent CST. TADSS therapy involved behavioral retraining of injured animals, with treated animals receiving concurrent spinal stimulation and control animals receiving no stimulation. In separate weekly sessions, the synaptic strength between motor cortex and spinal cord was assessed by measuring spinal cord evoked potentials (EPs) during test electrical stimulation. Test electrical stimulation involved current application to the forelimb region of motor cortex and recording of the EP response in cervical spinal cord caudal to the site of injury. After 3 weeks of TADSS, we observed larger EPs in TADSS animals and smaller EPs in injured control animals. In the weeks that followed, TADSS animals exhibited improved motor function while control animals exhibited declined motor function. Our results indicate increased connectivity between the motor cortex and spinal cord which precedes behavioral improvement -- this possibly suggests that strengthening the synaptic connectivity of the descending CST input to spinal cord is incorporated in the mechanism of TADSS-induced motor recovery.

Spinal cord injury (SCI) affects the lives of over 294,000 individuals in the United States alone. Therefore, there is an urgency for development of therapies for SCI. We are exploring the role of environmental enrichment in promoting motor recovery from chronic cervical SCI that produces partial to complete forelimb paralysis in adult rats. Novelty, a major component of our environmental enrichment, has been associated with memory consolidation which could be related to the release of plasticity-related products (PRPs). PRPs are a key component of lasting plasticity changes in vitro, which could prove to be vital to motor learning after spinal cord injury. Throughout a 6-week therapy period during which the rats are exposed to environmental enrichment, motor function of the impaired forelimb is assessed using behavioral scores on a reach-and-grasp pellet-retrieval task. Our project will utilize environmental enrichment to enhance the effectiveness of our physical training paradigm. Environmental enrichment will include access to toys that provide opportunities for physical exercise, socialization, and social learning. The toys will be changed each week to promote novelty. We predict that environmental enrichment will have an additive effect in promoting recovery of the impaired forelimb when combined with physical therapy. We hope these results will help inform how neural plasticity can be deployed for design of effective therapies for promoting motor recovery after chronic SCI.

The NMS, a physiological structure where neurons stimulate muscles via release of acetylcholine, is specifically organized to ensure efficient transmission of neural information by minimizing the diffusion distance of acetylcholine from the presynaptic neuron to the postsynaptic muscle cell. This is accomplished through the precise creation of ‘active zones’, which are neural cytosolic structures that anchor acetylcholine-containing vesicles directly across from acetylcholine-gated ion channels in the muscle cell. A failure to form active zones hampers synaptic transmission, causing muscle weakness disorders. Prior research has elucidated that active zone formation is predicated on the binding of the L5_III extracellular loop of presynaptic Ca_v2.1 to the beta-2 chain of laminin (a synaptic protein). My project is to create an improved assay measuring Ca_v2.1/beta-2 laminin binding. The eventual aim is to use the improved assay to elucidate the amino acids residues of the L5_III extracellular loop critical for binding laminin. To implement this assay, I created a beta-2 laminin construct (tagged with a red fluorescent protein) and built-up stocks of HEK 293 cells that can be transfected with DNA encoding Ca_v2.1 (tagged with the green fluorescent protein EGFP). Next, I cultured transfected cells and incubated them with 1 micrometer beads coated with the laminin protein construct. Using fluorescence microscopy, I then confirmed that beta-2 laminin does indeed bind to the Ca_v2.1 expressing cells by observing the co-localization of red and green fluorescence. Additionally, I have built up the necessary reagents to perform this binding assay with cells transfected with different Ca_v2.1 DNA constructs containing single amino acid mutations in the L5_III loop. If binding is no longer observed, the mutated amino acid(s) in the L5_III loop will be identified as being responsible for binding laminin. In conclusion, this project has paved the way for a greater understanding of the critical Ca_v2.1/beta-2 laminin interaction.