Long-term mental wellbeing and functioning after surgery for cauda equina syndrome

INTRODUCTION: Cauda Equina Syndrome (CES) can cause persisting life-changing dysfunction. There is scarce literature regarding the long-term assessment of CES symptoms, and rarer still is the impact of these symptoms on mental wellbeing investigated. This study assessed the long-term patient reported mental wellbeing outcomes of post-operative CES patients. METHODS: Patients who underwent surgery for CES between August 2013 and November 2014 were identified using an ethically approved database. They then completed validated questionnaires over the telephone assessing their mental and physical functioning (Short-Form 12 Questionnaire), generating the Physical Component Summary (PCS) and Mental Component Summary (MCS). Bladder, bowel and sexual function were also assessed using validated questionnaires. MCS scores were compared to both the Scottish mean and previously published cut-offs indicating patients at risk of depression. Correlations of MCS with bladder, bowel, sexual and physical dysfunction were examined and multifactorial regression to predict MCS from these variables analysed. Independent t-tests assessed the mean difference in MCS between patients presenting with incomplete CES (CES-I) and CES with retention (CES-R) and between those with radiologically confirmed and impending CES. RESULTS: Forty-six participants with a mean follow-up time of 43 months completed the study. The mean (±SD) MCS was 49 (±11.8) with 22% demonstrating poor mental health related quality of life in comparison to the Scottish mean. Overall, 37% had scores consistent with being at risk for depression with in the last 30 days, and 45% within the last 12 months. MCS was significantly correlated with Urinary Symptoms Profile (USP) score (-0.608), NBDS score (-0.556), ASEX score (-0.349) and PCS score (0.413) with worse bladder, bowel, sexual and physical dysfunction associated with worse MCS score. Multifactorial regression analysis demonstrated both urinary (USP score p = 0.031) and bowel function (NBDS score p = 0.009) to be significant predictive variables of mental health related quality of life. There were no significant mean differences in MCS between those presenting with CES-I and CES-R or those with radiologically complete and impending CES. DISCUSSION: This study demonstrates a high frequency of being at risk for depression in patients with CES and identifies outcome measures (physical, sexual and more so bladder and bowel dysfunction) associated with poorer mental wellbeing. Our large cohort and long follow-up highlight that CES patients should be considered at risk of depression, and the need to consider mental health outcomes following CES surgery

Survivorship Patterns of Larval Amphibians Exposed to Low Concentrations of Atrazine

Amphibians can be exposed to contaminants in nature by many routes, but perhaps the most likely route is agricultural runoff in amphibian breeding sites. This runoff results in high-level pulses of pesticides. For example, atrazine, the most widely used pesticide in the United States, can be present at several parts per million in agricultural runoff. However, pesticide levels are likely to remain in the environment at low levels for longer periods. Nevertheless, most studies designed to examine the impacts of contaminants are limited to short-term (~ 4 days) tests conducted at relatively high concentrations. To investigate longer-term (~ 30 days) exposure of amphibians to low pesticide levels, we exposed tadpoles of four species of frogs—spring peepers (Pseudacris crucifer), American toads (Bufo americanus), green frogs (Rana clamitans), and wood frogs (Rana sylvatica)—at early and late developmental stages to low concentrations of a commercial preparation of atrazine (3, 30, or 100 ppb; the U.S. Environmental Protection Agency drinking water standard is 3 ppb). We found counterintuitive patterns in rate of survivorship. Survival was significantly lower for all animals exposed to 3 ppb compared with either 30 or 100 ppb, except the late stages of B. americanus and R. sylvatica. These survival patterns highlight the importance of investigating the impacts of contaminants with realistic exposures and at various developmental stages. This may be particularly important for compounds that produce greater mortality at lower doses than higher doses, a pattern characteristic of many endocrine disruptors

Design and implementation of an instrumented pedal for cycling biomechanics research

Cycling is a common, low-impact activity used for recreation, exercise, and rehabilitation. Knee joint loading can be predicted using inverse dynamic analyses of pedal load cell and kinematic data measured during cycling biomechanics experiments. Several studies have successfully measured foot loading at the pedals, e.g. by using custom instrumented pedal spindles outfitted with strain gauges and a potentiometer to measure crank angle [1-3]. Such designs are relatively complex, requiring difficult machining and component fabrication, and require post-processing of strain gauge data. The long-term goal of this study is to calculate knee joint loading and, ultimately, cartilage tissue stress to provide evidence-based prescriptions for rehabilitative and fitness sustainment exercises for those who are at high risk for knee osteoarthritis. The objective of this project was to design, fabricate, and implement an instrumented pedal system using existing load cells for use in cycling biomechanics research. Measured data retrieved from the load cells during cycling experiments will be compared to similar studies to verify that this project was successful

Using OpenSim to predict knee joint moments during cycling

Cycling is a relatively low impact activity conventionally recommended as a rehabilitative or fitness sustaining exercise for patients at a high risk for knee osteoarthritis (OA) [1,2]. Expanding our understanding of knee joint loads is necessary to develop and improve evidence-based prescriptions for cycling as a rehabilitative and fitness therapy that limits the risk for knee OA. OpenSim (www.simtk.org) is an open source biomechanical analysis software that can partition predictions of external joint loads (or net muscle moments) into muscle and joint contact loads [3]. Joint contact loads more accurately represent cartilage tissue loading and hence risk for cartilage damage and/or OA [4]. As a first step towards predicting knee joint contact loads during cycling, we hypothesized that OpenSim can predict external knee joint moments that are consistent with published data [5,6]. To address this hypothesis, we conducted cycling experiments and used OpenSim’s scale tool, inverse kinematics (IK) solver, and inverse dynamics (ID) solver to model the recorded activity

Changes in tree community structure in defaunated forests are not driven only by dispersal limitation

Bushmeat hunting has reduced population sizes of large frugivorous vertebrates throughout the tropics, thereby reducing the dispersal of seeds. This is believed to affect tree population dynamics, and therefore community composition, because the seed dispersal of large-seeded trees depends upon large-bodied vertebrates.We report on a long-running study of the effect of defaunation on a tropical tree community. In three censuses over 11 years, we compared sapling recruitment between a hunted and a nonhunted site, which are nearby and comparable to one another, to determine the extent to which species composition has changed through time following defaunation. We expected to find a reduced abundance of tree species that rely on large frugivores for dispersal at the hunted site and altered community structure as a consequence.Although community composition at the hunted site diverged from that at the nonhunted site, the changes were independent of dispersal syndrome, with no trend toward a decline in species that are dispersed by large, hunted vertebrates. Moreover, the loss of large-bodied dispersers did not generate the changes in tree community composition that we hypothesized. Some species presumed to rely on large-bodied frugivores for dispersal are effectively recruiting despite the absence of their dispersers.Synthesis: The presumption that forests depleted of large-bodied dispersers will experience rapid, directional compositional change is not fully supported by our results. Altered species composition in the sapling layer at the hunted site, however, indicates that defaunation may be connected with changes to the tree community, but that the nature of these changes is not unidirectional as previously assumed. It remains difficult to predict how defaunation will affect tree community composition without a deeper understanding of the driving mechanisms at play

Changes in tree community structure in defaunated forests are not driven only by dispersal limitation

1. Bushmeat hunting has reduced population sizes of large frugivorous vertebrates throughout the tropics, thereby reducing the dispersal of seeds. This is believed to affect tree population dynamics, and therefore community composition, because the seed dispersal of large‐seeded trees depends upon large‐bodied vertebrates. 2. We report on a long‐running study of the effect of defaunation on a tropical tree community. In three censuses over 11 years, we compared sapling recruitment between a hunted and a nonhunted site, which are nearby and comparable to one another, to determine the extent to which species composition has changed through time following defaunation. We expected to find a reduced abundance of tree species that rely on large frugivores for dispersal at the hunted site and altered community structure as a consequence. 3. Although community composition at the hunted site diverged from that at the nonhunted site, the changes were independent of dispersal syndrome, with no trend toward a decline in species that are dispersed by large, hunted vertebrates. Moreover, the loss of large‐bodied dispersers did not generate the changes in tree community composition that we hypothesized. Some species presumed to rely on large‐bodied frugivores for dispersal are effectively recruiting despite the absence of their dispersers. 4. Synthesis: The presumption that forests depleted of large‐bodied dispersers will experience rapid, directional compositional change is not fully supported by our results. Altered species composition in the sapling layer at the hunted site, however, indicates that defaunation may be connected with changes to the tree community, but that the nature of these changes is not unidirectional as previously assumed. It remains difficult to predict how defaunation will affect tree community composition without a deeper understanding of the driving mechanisms at play

Volume 12

Introduction, Dr. Roger A. Byrne, Dean From the Editor, Dr. Larissa Kat Tracy From the Designers, Rachel English, Rachel Hanson Immortality in the Mortal World: Otherworldly Intervention in Lanval and The Wife of Bath\u27s Tale by Haleigh James Analysis of Phenolic Compounds in Moroccan Olive Oils by HPLC by Hannah Meyls Art by Hope Irvin The Effects of Cell Phone Use on Gameplay Enjoyment and Frustration by Megan E. Hlavaty, Samara L. Gall, and Austin J. Funk Care, No Matter What: Planned Parenthood\u27s Use of Organizational Rhetoric to Expand its Reputation by Karyn Keane Analysis of Petroleum Products for Forensic and Environmental Applications by Sarah Ghali, Antonio Harvey, and Katelynn McCrillis Art by Andrew Jones The Triangle Shirtwaist Factory Fire by Rachel Hazelwood Art by Madison Schmitz Ercilla y la imitacion: Araucanos al estilo europeo by Marija Venta Design by Haley Tebo Design by Jeremiah Gilmer White Supremacist\u27s Appropriation of the Persuasion of Passivity in Marvel\u27s Captain America by Bridget Dunn Design by Benjamin Sullivan Art by McKenzie Johnso