An agent-based model of jaguar movement through conservation corridors

Wildlife corridors mitigate against habitat fragmentation by connecting otherwise isolated regions, bringing well established benefits to conservation both in principle and practice. Populations of large mammals in particular may depend on habitat connectivity, yet conservation managers struggle to optimise corridor designs with the rudimentary information generally available on movement behaviours. We present an agent-based model of jaguars (Panthera onca), scaled for fragmented habitat in Belize where proposals already exist for creating a jaguar corridor. We use a leastcost approach to simulate movement paths through alternative possible landscapes. Six different types of corridor and three control conditions differ substantially in their effectiveness at mixing agents across the environment despite relatively little difference in individual welfare. Our best estimates of jaguar movement behaviours suggest that a set of five narrow corridors may out-perform one wide corridor of the same overall area. We discuss the utility of ALife modelling for conservation management

Turnaround Strategies at an Underperforming Urban Elementary School: An Examination of Stakeholder Perspectives

In August of 2007, Los Angeles Unified School District embarked on a new journey under the leadership of Superintendent David Brewer toward improving the achievement of some of Los Angeles’ lowest performing schools. By establishing a partnership with the Mayor of Los Angeles, Antonio Villaraigosa, the goal of the improvements was to form a team of talented and experienced educators who would identify schools whose majority of teachers would be willing to be led and supported by these experienced educators under an umbrella organization called the Partnership for Los Angeles Schools in agreement with United Teachers of Los Angeles. The Deputy Mayor, Ramon Cortines, recruited me, the researcher of this study, to serve as Superintendent of Instruction of the Partnership in February of 2008. For two and a half years, I, along with 28 team members worked tenaciously to develop and implement a model that would accelerate achievement. While there were numerous initiatives and programs attempting to improve student performance in the lowest performing schools, no initiative in the district alleviated teachers from the day-to- day constraints of district policies and procedures. The reform model developed by the Partnership for Los Angeles Schools was the focus of this research. An analysis of the implementation of the Partnership Model at one particular site, Excellence Elementary School, yielded results that examined if the Partnership Model was able to successfully transform outcomes in an underperforming school

Spatially-explicit modelling of habitat permeability for mammalian wildlife

Least-cost and agent-based models present alternative approaches to modelling animal movements, at the population level and individual level respectively. This study introduces and tests a novel integration of adapted least-cost methods into agent-based simulations, in order to analyse connectivity and habitat preferences in two species of mammal. An initial proof-of-concept study built a set of empirically validated least-cost models of European hedgehogs (Erinaceus europaeus) into a simple agent based model. Agents most closely simulated natural behaviours of dispersing hedgehogs when their movements accounted for temporally-dependent habitat preferences in addition to least-cost pathways informed by the connectivity map. The fitness of these agents increased in more highly fragmented landscapes, in contrast to agents that took least-cost pathways without time-specific preferences. The integration of functional connectivity with individual behaviour combined the advantages of both modelling techniques. Quantitative analysis of the individual-level consequences of moving within different landscape scenarios provides a unique way of applying model outcomes to direct conservation action. A second conceptual study applied integrative methods to the construction of an agent-based simulation scaled for jaguars (Panthera onca) occupying fragmented landscape in Belize. This simulation tested alternative configurations of a wildlife corridor currently under development in Central Belize as part of the intercontinental Mesoamerican Biological Corridor. Six alternative corridor configurations and three control conditions differed substantially in their effectiveness at mixing agents across the environment, despite relatively little difference in individual welfare. Best estimates of jaguar movement behaviours suggested that a set of five narrow corridors may out perform one wide corridor of the same overall area. The first two studies set the framework for developing a detailed simulation of jaguar behaviour and population dynamics in a mixed forest and farmland landscape in the south of Belize. This more complex model drew on empirical data on resident jaguars in the region to simulate typical movement, feeding, reproduction and mortality events within a stable natural population. An overview of the construction and application of the model precedes detailed descriptions of its calibration, sensitivity analysis and validation with empirical data. Agents located inside protected forest reserves exhibited higher fitness, expressed in higher fecundity and lower energy- and habitat-related mortality, than agents located outside these reserves. Model validation showed similar patterns to field data in landscape utilisation and the spatial distribution of individuals. This approach to spatial modelling of population dynamics can provide novel insights into effective conservation strategies for large carnivores. Application of the model to the fragmented central corridor region of Belize sets the context for real-world conservation planning. Under current conditions, simulated jaguars formed a small but stable population with various levels of immigration. Implementation of wildlife corridors showed the largest tracts of physically connected reserves increased connectivity between spatially disconnected habitat patches but also increased vulnerability to environmental degradation

Hughes abdominal closure versus standard mass closure to reduce incisional hernias following surgery for colorectal cancer: the HART RCT

BackgroundIncisional hernias can cause chronic pain and complications and affect quality of life. Surgical repair requires health-care resources and has a significant associated failure rate. A prospective, multicentre, single-blinded randomised controlled trial was conducted to investigate the clinical effectiveness and cost-effectiveness of the Hughes abdominal closure method compared with standard mass closure following surgery for colorectal cancer. The study randomised, in a 1 : 1 ratio, 802 adult patients (aged ≥ 18 years) undergoing surgical resection for colorectal cancer from 28 surgical departments in UK centres.InterventionHughes abdominal closure or standard mass closure.Main outcome measuresThe primary outcome was the incidence of incisional hernias at 1 year, as assessed by clinical examination. Within-trial cost-effectiveness and cost–utility analyses over 1 year were conducted from an NHS and a social care perspective. A key secondary outcome was quality of life, and other outcomes included the incidence of incisional hernias as detected by computed tomography scanning.ResultsThe incidence of incisional hernia at 1-year clinical examination was 50 (14.8%) in the Hughes abdominal closure arm compared with 57 (17.1%) in the standard mass closure arm (odds ratio 0.84, 95% confidence interval 0.55 to 1.27; p = 0.4). In year 2, the incidence of incisional hernia was 78 (28.7%) in the Hughes abdominal closure arm compared with 84 (31.8%) in the standard mass closure arm (odds ratio 0.86, 95% confidence interval 0.59 to 1.25; p = 0.43). Computed tomography scanning identified a total of 301 incisional hernias across both arms, compared with 100 identified by clinical examination at the 1-year follow-up. Computed tomography scanning missed 16 incisional hernias that were picked up by clinical examination. Hughes abdominal closure was found to be less cost-effective than standard mass closure. The mean incremental cost for patients undergoing Hughes abdominal closure was £616.45 (95% confidence interval –£699.56 to £1932.47; p = 0.3580). Quality of life did not differ significantly between the study arms at any time point.LimitationsAs this was a pragmatic trial, the control arm allowed surgeon discretion in the approach to standard mass closure, introducing variability in the techniques and equipment used. Intraoperative randomisation may result in a loss of equipoise for some surgeons. Follow-up was limited to 2 years, which may not have been enough time to see a difference in the primary outcome.ConclusionsHughes abdominal closure did not significantly reduce the incidence of incisional hernias detected by clinical examination and was less cost-effective at 1 year than standard mass closure in colorectal cancer patients. Computed tomography scanning may be more effective at identifying incisional hernias than clinical examination, but the clinical benefit of this needs further research.Future workAn extended follow-up using routinely collected NHS data sets aims to report on incisional hernia rates at 2–5 years post surgery to investigate any potential mortality benefit of the closure methods. Furthermore, the proportion of incisional hernias identified by a computed tomography scan (at 1 and 2 years post surgery), but not during clinical examination (occult hernias), proceeding to surgical repair within 3–5 years after the initial operation will be explored.Trial registrationThis trial is registered as ISRCTN25616490

Exquisite, apart: remoteness and/as resistance.

It has become routine to characterise digital art as indicative of an assumed universal shift from ‘traditional’ practic-es towards novel forms of cultural pro-duction, interaction and consumption. Frequently, running parallel to this is the assertion that space, time and distance have been compressed, subsumed, aug-mented, eliminated or are unable to resist being replaced by relations, experiences or symbolic values. This collective paper is based on a panel presentation at ISEA 2013. It discussed five different research approaches that address theoretical, practical, philosophical and artistic possibili-ties of engaging with the realities of distance, remoteness or ‘exquisite apartness’ as locii of resistance

Exquisite, apart: remoteness and/as resistance.

It has become routine to characterise digital art as indicative of an assumed universal shift from ‘traditional’ practic-es towards novel forms of cultural pro-duction, interaction and consumption. Frequently, running parallel to this is the assertion that space, time and distance have been compressed, subsumed, aug-mented, eliminated or are unable to resist being replaced by relations, experiences or symbolic values. This collective paper is based on a panel presentation at ISEA 2013. It discussed five different research approaches that address theoretical, practical, philosophical and artistic possibili-ties of engaging with the realities of distance, remoteness or ‘exquisite apartness’ as locii of resistance

Effects of sample handling and storage on quantitative lipid analysis in human serum

There is sparse information about specific storage and handling protocols that minimize analytical error and variability in samples evaluated by targeted metabolomics. Variance components that affect quantitative lipid analysis in a set of human serum samples were determined. The effects of freeze-thaw, extraction state, storage temperature, and freeze-thaw prior to density-based lipoprotein fractionation were quantified. The quantification of high abundance metabolites, representing the biologically relevant lipid species in humans, was highly repeatable (with coefficients of variation as low as 0.01 and 0.02) and largely unaffected by 1-3 freeze-thaw cycles (with 0-8% of metabolites affected in each lipid class). Extraction state had effects on total lipid class amounts, including decreased diacylglycerol and increased phosphatidylethanolamine in thawed compared with frozen samples. The effects of storage temperature over 1week were minimal, with 0-4% of metabolites affected by storage at 4°C, −20°C, or −80°C in most lipid classes, and 19% of metabolites in diacylglycerol affected by storage at −20°C. Freezing prior to lipoprotein fractionation by density ultracentrifugation decreased HDL free cholesterol by 37% and VLDL free fatty acid by 36%, and increased LDL cholesterol ester by 35% compared with fresh samples. These findings suggest that density-based fractionation should preferably be undertaken in fresh serum samples because up to 37% variability in HDL and LDL cholesterol could result from a single freeze-thaw cycle. Conversely, quantitative lipid analysis within unfractionated serum is minimally affected even with repeated freeze-thaw cycle

Assessing individual metabolic responsiveness to a lipid challenge using a targeted metabolomic approach

The development of assessment techniques with immediate clinical applicability is a priority for resolving the growing epidemic in metabolic disease. Many imbalances in diet-dependent metabolism are not detectable in the fasted state. Resolving the high inter-individual variability in response to diet requires the development of techniques that can detect metabolic dysfunction at the level of the individual. The intra- and inter-individual variation in lipid metabolism in response to a standardized test meal was determined. Following an overnight fast on three different days, three healthy subjects consumed a test meal containing 40% of their daily calories. Plasma samples were collected at fasting, and 1, 3, 6, and 8h after the test meal. Plasma fatty acid (FA) concentrations within separated lipid classes and lipoprotein fractions were measured at each time point. The intra-individual variation within each subject across three days was lower than the inter-individual differences among the three subjects for over 50% of metabolites in the triacylglycerol (TG), FA, and phosphatidylcholine (PC) lipid classes at 6h, and for 25-50% of metabolites across lipid classes at 0, 1, 3, and 8h. The consistency of response within individuals was visualized by principal component analysis (PCA) and confirmed by ANOVA. Three representative metabolites that discriminated among the three individuals in the apolipoprotein B (ApoB) fraction, TG16:1n7, TG18:2n6, and PC18:3n3, are discussed in detail. The postprandial responses of individuals were unique within metabolites that were individual discriminators (ID) of metabolic phenotype. This study shows that the targeted metabolomic measurement of individual metabolic phenotype in response to a specially formulated lipid challenge is possible even without lead-in periods, dietary and lifestyle control, or intervention over a 3-month period in healthy free-living individual

The Role of Counselor Educators in Preparing Active Duty Military Students Utilizing Online Courses: An Initial Primer

Given today’s diverse educational opportunities afforded through online courses, the implications for counselor educators working with active military students are examined. A literature review is presented summarizing current research addressing online education as well as meeting the specific needs of active duty military students. Suggested best practices for preparing these students to be competent counselors are presented, addressing their unique situations taking online courses while serving in active military roles. Recommendations for future research are also presented