Showing papers by "University of Ottawa published in 2004"

Sirt1 promotes fat mobilization in white adipocytes by repressing PPAR-gamma.

Abstract: Calorie restriction extends lifespan in organisms ranging from yeast to mammals. In yeast, the SIR2 gene mediates the life-extending effects of calorie restriction. Here we show that the mammalian SIR2 orthologue, Sirt1 (sirtuin 1), activates a critical component of calorie restriction in mammals; that is, fat mobilization in white adipocytes. Upon food withdrawal Sirt1 protein binds to and represses genes controlled by the fat regulator PPAR-gamma (peroxisome proliferator-activated receptor-gamma), including genes mediating fat storage. Sirt1 represses PPAR-gamma by docking with its cofactors NCoR (nuclear receptor co-repressor) and SMRT (silencing mediator of retinoid and thyroid hormone receptors). Mobilization of fatty acids from white adipocytes upon fasting is compromised in Sirt1+/- mice. Repression of PPAR-gamma by Sirt1 is also evident in 3T3-L1 adipocytes, where overexpression of Sirt1 attenuates adipogenesis, and RNA interference of Sirt1 enhances it. In differentiated fat cells, upregulation of Sirt1 triggers lipolysis and loss of fat. As a reduction in fat is sufficient to extend murine lifespan, our results provide a possible molecular pathway connecting calorie restriction to life extension in mammals.

Constructing questionnaires based on the theory of planned behaviour: A manual for health services researchers

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Multiple Rare Alleles Contribute to Low Plasma Levels of HDL Cholesterol

Abstract: Heritable variation in complex traits is generally considered to be conferred by common DNA sequence polymorphisms. We tested whether rare DNA sequence variants collectively contribute to variation in plasma levels of highdensity lipoprotein cholesterol (HDL-C). We sequenced three candidate genes (ABCA1, APOA1, and LCAT) that cause Mendelian forms of low HDL-C levels in individuals from a population-based study. Nonsynonymous sequence variants were significantly more common (16% versus 2%) in individuals with low HDL-C ( 95th percentile). Similar findings were obtained in an independent population, and biochemical studies indicated that most sequence variants in the low HDL-C group were functionally important. Thus, rare alleles with major phenotypic effects contribute significantly to low plasma HDL-C levels in the general population.

Applying support vector machines to imbalanced datasets

Abstract: Support Vector Machines (SVM) have been extensively studied and have shown remarkable success in many applications. However the success of SVM is very limited when it is applied to the problem of learning from imbalanced datasets in which negative instances heavily outnumber the positive instances (e.g. in gene profiling and detecting credit card fraud). This paper discusses the factors behind this failure and explains why the common strategy of undersampling the training data may not be the best choice for SVM. We then propose an algorithm for overcoming these problems which is based on a variant of the SMOTE algorithm by Chawla et al, combined with Veropoulos et al's different error costs algorithm. We compare the performance of our algorithm against these two algorithms, along with undersampling and regular SVM and show that our algorithm outperforms all of them.

Predictions and tests of climate‐based hypotheses of broad‐scale variation in taxonomic richness

Abstract: Broad-scale variation in taxonomic richness is strongly correlated with climate. Many mechanisms have been hypothesized to explain these patterns; however, testable predictions that would distinguish among them have rarely been derived. Here, we examine several prominent hypotheses for climate–richness relationships, deriving and testing predictions based on their hypothesized mechanisms. The ‘energy–richness hypothesis’ (also called the ‘more individuals hypothesis’) postulates that more productive areas have more individuals and therefore more species. More productive areas do often have more species, but extant data are not consistent with the expected causal relationship from energy to numbers of individuals to numbers of species. We reject the energy–richness hypothesis in its standard form and consider some proposed modifications. The ‘physiological tolerance hypothesis’ postulates that richness varies according to the tolerances of individual species for different sets of climatic conditions. This hypothesis predicts that more combinations of physiological parameters can survive under warm and wet than cold or dry conditions. Data are qualitatively consistent with this prediction, but are inconsistent with the prediction that species should fill climatically suitable areas. Finally, the ‘speciation rate hypothesis’ postulates that speciation rates should vary with climate, due either to faster evolutionary rates or stronger biotic interactions increasing the opportunity for evolutionary diversification in some regions. The biotic interactions mechanism also has the potential to amplify shallower, underlying gradients in richness. Tests of speciation rate hypotheses are few (to date), and their results are mixed.

Testing for Multigroup Invariance Using AMOS Graphics: A Road Less Traveled

Abstract: The purpose of this article is to illustrate the steps involved in testing for multigroup invariance using Amos Graphics. Based on analysis of covariance (ANCOV) structures, 2 applications are demonstrated, each of which represents a different set of circumstances. Application 1 focuses on the equivalence of a measuring instrument and tests for its invariance across 3 teacher panels, given baseline models that are identical across groups. Application 2 centers on the equivalence of a postulated theoretical structure across adolescent boys and girls in light of baseline models that are differentially specified across groups. Taken together, these illustrated examples should be of substantial assistance to researchers interested in testing for multigroup invariance using the Amos program.

A Multiple Resampling Method for Learning from Imbalanced Data Sets

Abstract: Resampling methods are commonly used for dealing with the class-imbalance problem. Their advantage over other methods is that they are external and thus, easily transportable. Although such approaches can be very simple to implement, tuning them most effectively is not an easy task. In particular, it is unclear whether oversampling is more effective than undersampling and which oversampling or undersampling rate should be used. This paper presents an experimental study of these questions and concludes that combining different expressions of the resampling approach is an effective solution to the tuning problem. The proposed combination scheme is evaluated on imbalanced subsets of the Reuters-21578 text collection and is shown to be quite effective for these problems.

Family caregiver burden: results of a longitudinal study of breast cancer patients and their principal caregivers

Abstract: Background: The vital role played by family caregivers in supporting dying cancer patients is well recognized, but the burden and economic impact on caregivers is poorly understood. We prospectively examined the psychosocial, occupational and economic impact of caring for a person with a terminal illness. Methods: We studied 89 caregivers of women with advanced breast cancer receiving care at either the Ottawa or Hamilton regional cancer centres in Ontario. Patients were followed until their death or study completion at 3 years. Patients identified a principal caregiver to participate in the study. The Karnofsky Performance Status (KPS) index, the Medical Outcomes Study 36-item Short Form (SF-36), the Hospital Anxiety and Depression Scale, the Zarit Burden Inventory, FAMCARE and the Medical Outcomes Study Social Support Survey were administered during follow-up. Economic data were collected by means of a questionnaire administered by an interviewer. Assessments were conducted every 3 months during the palliative period (KPS score > 50) and every 2 weeks during the terminal period (KPS score ≤ 50). Results: Over half of the caregivers were male (55%) and the patient9s spouse or partner (52%), with a mean age of 53 years. At the start of the palliative period, the caregivers9 mean physical functioning score was better than the patients9 (51.3 v. 35.1, 95% confidence interval [CI] 13.3–20.0); there were similar mean mental functioning scores (46.6 and 47.1 respectively); similar proportions were depressed (11% and 12%); and significantly more caregivers than patients were anxious (35% v. 19%, p = 0.009). More caregivers were depressed (30% v. 9%, p = 0.02) and had a higher level of perceived burden (26.2 v. 19.4, p = 0.02) at the start of the terminal period than at the start of the palliative period. Burden was the most important predictor of both anxiety and depression. Of employed caregivers, 69% reported some form of adverse impact on work. In the terminal period 77% reported missing work because of caregiving responsibilities. Prescription drugs were the most important component of financial burden. Interpretation: Caregivers9 depression and perceived burden increase as patients9 functional status declines. Strategies are needed to help reduce the psychosocial, occupational and economic burden associated with caregiving.

The Practice of Emotionally Focused Couple Therapy: Creating Connection

Abstract: Introduction. The Field of Couple Therapy and EFT. An Attachment View of Love: The EFT Philosophy. The EFT Theory of Change: Within and Between. The Basics of EFT: Tasks and Interventions. Expanding Experience and Shaping Dances. Defining the Dance and Listening to Music. EFT: Steps 1 and 2 . Changing the Music - Towards De-escalation. EFT: Steps 3 and 4. Deepening Engagement. EFT: Steps 5 and 6. Emotional Engagement, Enactments and Bonding . EFT: Step 7 and Change Events. The Consolidation of a Secure Base. EFT: Steps 8 and 9. Key Clinical Issues and Solutions. Becoming an EFT Therapist. Emotionally Focused Family Therapy. Restructuring Attachment. Relationship Traumas: Addressing attachment injuries. Forgiveness and Reconciliation. An EFT Session - Micro-analysis of a Change Event. A Second EFT Session - Micro-analysis of a Change Event. Epilogue.

Advanced Cardiac Life Support in Out-of-Hospital Cardiac Arrest

Abstract: background The Ontario Prehospital Advanced Life Support (OPALS) Study tested the incremental effect on the rate of survival after out-of-hospital cardiac arrest of adding a program of advanced life support to a program of rapid defibrillation. methods This multicenter, controlled clinical trial was conducted in 17 cities before and after advanced-life-support programs were instituted and enrolled 5638 patients who had had cardiac arrest outside the hospital. Of those patients, 1391 were enrolled during the rapid-defibrillation phase and 4247 during the subsequent advanced-life-support phase. Paramedics were trained in standard advanced life support, which includes endotracheal intubation and the administration of intravenous drugs. results From the rapid-defibrillation phase to the advanced-life-support phase, the rate of admission to a hospital increased significantly (10.9 percent vs. 14.6 percent, P<0.001), but the rate of survival to hospital discharge did not (5.0 percent vs. 5.1 percent, P=0.83). The multivariate odds ratio for survival after advanced life support was 1.1 (95 percent confidence interval, 0.8 to 1.5); after an arrest witnessed by a bystander, 4.4 (95 percent confidence interval, 3.1 to 6.4); after cardiopulmonary resuscitation administered by a bystander, 3.7 (95 percent confidence interval, 2.5 to 5.4); and after rapid defibrillation, 3.4 (95 percent confidence interval, 1.4 to 8.4). There was no improvement in the rate of survival with the use of advanced life support in any subgroup. conclusions The addition of advanced-life-support interventions did not improve the rate of survival after out-of-hospital cardiac arrest in a previously optimized emergency-medical-services system of rapid defibrillation. In order to save lives, health care planners should make cardiopulmonary resuscitation by citizens and rapid-defibrillation responses a priority for the resources of emergency-medical-services systems.

Physical activity/exercise and type 2 diabetes.

Abstract: For decades, exercise has been considered a cornerstone of diabetes management, along with diet and medication. However, high-quality evidence on the importance of exercise and fitness in diabetes was lacking until recent years. The last American Diabetes Association (ADA) technical review of exercise and type 2 diabetes (formerly known as non–insulin dependent diabetes) was published in 1990. The present work emphasizes the advances that have occurred since the last technical review was published. Major developments since the 1990 technical review include: Based on this new evidence, we have refined the recommendations on the desired types, amounts, and intensities of aerobic physical activity for people with diabetes. Resistance training will now be recommended in a broader group of patients and at a broader range of intensity than done previously. There are other areas in which new evidence is lacking, but we feel that previous recommendations may have been more conservative than necessary. These areas include indications for exercise stress test before beginning an exercise program and precautions regarding …

Motor rehabilitation using virtual reality.

Abstract: Virtual Reality (VR) provides a unique medium suited to the achievement of several requirements for effective rehabilitation intervention. Specifically, therapy can be provided within a functional, purposeful and motivating context. Many VR applications present opportunities for individuals to participate in experiences, which are engaging and rewarding. In addition to the value of the rehabilitation experience for the user, both therapists and users benefit from the ability to readily grade and document the therapeutic intervention using various systems. In VR, advanced technologies are used to produce simulated, interactive and multi-dimensional environments. Visual interfaces including desktop monitors and head-mounted displays (HMDs), haptic interfaces, and real-time motion tracking devices are used to create environments allowing users to interact with images and virtual objects in real-time through multiple sensory modalities. Opportunities for object manipulation and body movement through virtual space provide frameworks that, in varying degrees, are perceived as comparable to similar opportunities in the real world. This paper reviews current work on motor rehabilitation using virtual environments and virtual reality and where possible, compares outcomes with those achieved in real-world applications.

Class imbalances versus small disjuncts

Abstract: It is often assumed that class imbalances are responsible for significant losses of performance in standard classifiers. The purpose of this paper is to the question whether class imbalances are truly responsible for this degradation or whether it can be explained in some other way. Our experiments suggest that the problem is not directly caused by class imbalances, but rather, that class imbalances may yield small disjuncts which, in turn, will cause degradation. We argue that, in order to improve classifier performance, it may, then, be more useful to focus on the small disjuncts problem than it is to focus on the class imbalance problem. We experiment with a method that takes the small disjunct problem into consideration, and show that, indeed, it yields a performance superior to the performance obtained using standard or advanced solutions to the class imbalance problem.

Learning from imbalanced data sets with boosting and data generation: the DataBoost-IM approach

Abstract: Learning from imbalanced data sets, where the number of examples of one (majority) class is much higher than the others, presents an important challenge to the machine learning community. Traditional machine learning algorithms may be biased towards the majority class, thus producing poor predictive accuracy over the minority class. In this paper, we describe a new approach that combines boosting, an ensemble-based learning algorithm, with data generation to improve the predictive power of classifiers against imbalanced data sets consisting of two classes. In the DataBoost-IM method, hard examples from both the majority and minority classes are identified during execution of the boosting algorithm. Subsequently, the hard examples are used to separately generate synthetic examples for the majority and minority classes. The synthetic data are then added to the original training set, and the class distribution and the total weights of the different classes in the new training set are rebalanced. The DataBoost-IM method was evaluated, in terms of the F-measures, G-mean and overall accuracy, against seventeen highly and moderately imbalanced data sets using decision trees as base classifiers. Our results are promising and show that the DataBoost-IM method compares well in comparison with a base classifier, a standard benchmarking boosting algorithm and three advanced boosting-based algorithms for imbalanced data set. Results indicate that our approach does not sacrifice one class in favor of the other, but produces high predictions against both minority and majority classes.

The Effectiveness of Whole-School Antibullying Programs: A Synthesis of Evaluation Research

Abstract: Bullying is a serious problem in schools, and school authorities need effective solutions to resolve this problem. There is growing interest in the whole- school approach to bullying. Whole-school programs have multiple components that operate simultaneously at different levels in the school community. This ar- ticle synthesizes the existing evaluation research on whole-school programs to determine the overall effectiveness of this approach. The majority of programs evaluated to date have yielded nonsignificant outcomes on measures of self-re- ported victimization and bullying, and only a small number have yielded positive outcomes. On the whole, programs in which implementation was systematically monitored tended to be more effective than programs without any monitoring.

Towards a quantum programming language

Abstract: We propose the design of a programming language for quantum computing. Traditionally, quantum algorithms are frequently expressed at the hardware level, for instance in terms of the quantum circuit model or quantum Turing machines. These approaches do not encourage structured programming or abstractions such as data types. In this paper, we describe the syntax and semantics of a simple quantum programming language with high-level features such as loops, recursive procedures, and structured data types. The language is functional in nature, statically typed, free of run-time errors, and has an interesting denotational semantics in terms of complete partial orders of superoperators.

The health of primary caregivers of children with cerebral palsy: how does it compare with that of other Canadian caregivers?

Abstract: Background. Caring for any child involves considerable resources, but the demands for these resources are often increased when caring for a child with a disability. These demands have implications for the psychologic and physical health of the caregiver (CG). Although a number of recent trends in health care stress the importance of studying and promoting the health of CGs of children with disabilities, the literature in this area exhibits 2 major weaknesses, ie, most studies draw conclusions from relatively small, potentially biased, clinic-based samples and the majority of work has focused on the psychologic health of CGs, whereas little research has been undertaken to study their physical well-being. The goal of this study was to compare the physical and psychologic health of CGs of children with cerebral palsy (CP) with that of the general population of CGs. Methods. Data on the physical and psychologic health of 468 primary CGs of children with CP, drawn from 18 of 19 publicly funded children9s rehabilitation centers in Ontario, Canada, were collected with a self-completed questionnaire and a face-to-face interview. Identical items and scales had been administered previously to nationally representative samples of the Canadian population in 2 large-scale Canadian surveys, ie, the National Population Health Survey (NPHS) and the National Longitudinal Study of Children and Youth (NLSCY). Subsamples of those data, restricted to adult residents of the province of Ontario who were parents, allowed a comparison of our sample of CGs of children with CP with parent samples from both the NLSCY ( n = 2414) and the NPHS ( n = 5549). Outcome Measures. Demographic variables included CG age, gender, education, income, and work-related variables. Psychologic health and support variables included social support, family functioning, frequency of contacts, distress, and emotional and cognitive problems. Physical health variables included the number and variety of chronic conditions, vision, hearing, and mobility problems, and experience of pain. Results. CGs of children with CP had lower incomes than did the general population of CGs (proportion with income over $60 000: CG: 40.9%; NLSCY: 51.4%), despite the absence of any important differences in education between the 2 samples. Results showed that CGs of children with CP were less likely to report working for pay (CG: 66%; NLSCY: 81.2%), less likely to be engaged in full-time work (CG: 67.5%; NLSCY: 73.2%), and more likely to list caring for their families as their main activity (CG: 37.2%; NLSCY: 28.4%). Measures of support showed no difference in reported social support (CG: mean score: 14.5; SD: 3.4; NLSCY: mean score: 14.3; SD: 2.7) or family functioning (CG: mean score: 8.6; SD: 5.6; NLSCY: mean score: 9.0; SD: 4.9) between the 2 samples, although the CG sample did report a statistically greater number of support contacts (CG: mean score: 4.5; SD: 0.7; NPHS: mean score: 4.2; SD: 0.9). Measures of psychologic health showed greater reported distress (CG: mean score: 4.7; SD: 4.4; NPHS: mean score: 2.2; SD: 2.7), chronicity of distress (CG: mean score: 5.5; SD: 1.4; NPHS: mean score: 5.2; SD: 1.1), emotional problems (CG: 25.3% indicating problems; NPHS: 13.7%), and cognitive problems (CG: 38.8%; NPHS: 14.3%) among CGs of children with CP. They also reported a greater likelihood of a variety of physical problems, including back problems (CG: 35.5% reporting the condition; SE: 2.2%; NLSCY: 12.2%; SE: 0.7%), migraine headaches (CG: 24.2%; SE: 2.0%; NLSCY: 11.2%; SE: 0.7%), stomach/intestinal ulcers (CG: 8.4%; SE: 1.3%; NLSCY: 1.7%; SE: 0.3%), asthma (CG: 15.8%; SE: 1.7%; NLSCY: 6.3%; SE: 0.5%), arthritis/rheumatism (CG: 17.3%; SE: 1.8%; NLSCY: 7.3%; SE: 0.5%), and experience of pain (CG: 28.8%; SE: 2.1%; NPHS: 11.0%; SE: 0.5), as well as a greater overall number of chronic physical conditions (CG: 24.1% reporting no chronic conditions; NLSCY: 55.2%). Conclusions. Although many families cope well despite the added challenges of caring for a child with a disability, our findings suggest that the demands of their children9s disabilities can explain differences in the health status of parents and that parents of children with CP are more likely to have a variety of physical and psychologic health problems. Many of these findings are consistent with a stress process model, in which stress from caregiving can directly or indirectly affect a variety of measures of health, although some of the findings (asthma and arthritis) seem to strain this hypothesis. Alternate interpretations of these findings include the possibility that parents who are in regular contact with the health care system may have more opportunities to discuss and receive attention for their own health concerns than do comparison adults or that the greater number of health issues reported by CGs is related to the nature of our study, perhaps leading these parents to focus on their health and well-being in more depth than is usually feasible in a population survey. CGs of children with CP also had lower incomes, despite the absence of any important differences in education. The findings are consistent with the idea that the financial burden of caring for a child with a disability results in part from a reduced availability of these parents to work for pay. Implications for Service Providers. Physicians and other health care professionals should be aware of the important relationship between child disability and CG health. Family-centered policies and services that explicitly consider CG health are likely to benefit the well-being of both CGs and their families. Future work should address the extent to which the family-centeredness of services, as experienced by CGs, is associated with better health outcomes for parents and their families.

The Relationship between Impaired Glucose Tolerance, Type 2 Diabetes, and Cognitive Function

Abstract: The present review integrates findings of published studies that have evaluated the cognitive function of treated and untreated type 2 diabetic patients and provides a detailed overview of the neuropsychological assessments conducted. Cognitive deficits are observed in older people with glucose intolerance or untreated diabetes but these deficits appear to be attenuated by treatments that improve glycemic control. Cognitive decrements in treated type 2 diabetic patients are most consistently observed on measures of verbal memory (35% of the measures) and processing speed (45% of the measures) while preserved function is observed on measures of visuospatial, attention, semantic and language function. Some studies suggest that deficits in cognitive functions are associated with poorer glycemic control. A number of other factors, such as depression, cardiovascular and cerebrovascular disease, increase these deficits. We conclude that, in diabetic patients who achieve and maintain good glycemic control, type 2 diabetes only has a small impact on cognitive functions before the age of 70 years. However, early onset of type 2 diabetes, poor glycemic control and the presence of micro- and macrovascular disease may interact to produce early cognitive deficits. In older adults (70 years and over), diabetes likely interacts with other dementing processes such as vascular disease and Alzheimer's disease to hasten cognitive decline.

Role of AIF in caspase-dependent and caspase-independent cell death

Abstract: The major challenge in treating cancer is that many tumor cells carry mutations in key apoptotic genes such as p53, Bcl family proteins or those affecting caspase signaling Such defects render treatment with traditional chemotherapeutic agents ineffective Many studies have demonstrated the importance of caspase-independent cell death pathways in injury, degenerative diseases and tumor tissue It is now recognized that in addition to their critical role in the production of cellular energy, mitochondria are also the source of key proapoptotic molecules involved in caspase activation More recently, it has been discovered that in response to apoptotic stimuli, mitochondria can also release caspase-independent cell death effectors such as AIF and Endonuclease G In this review, we examine the role of Bcl family proteins and poly(ADP-ribose) polymerase-1 signaling in the regulation of these apoptotic pathways and address the ongoing controversies in this field Continued study of the mechanisms of apoptosis including caspase-independent death processes are likely to reveal novel therapeutic targets for the treatment of diverse human pathologies including cancer, neurodegenerative diseases and acute injuries such as stroke or myocardial infarction

Arsenic Behavior in Paddy Fields during the Cycle of Flooded and Non-flooded Periods

Abstract: The behavior of As in paddy fields is of great interest considering high As contents of groundwater in several Asian countries where rice is the main staple. We determined the concentrations of Fe, Mn, and As in soil, soil water, and groundwater samples collected at different depths down to 2 m in an experimental paddy field in Japan during the cycle of flooded and non-flooded periods. In addition, we measured the oxidation states of Fe, Mn, and As in situ in soil samples using X-ray absorption near-edge structure (XANES) and conducted sequential extraction of the soil samples. The results show that Fe (hydr)oxide hosts As in soil. Arsenic in irrigation waters is incorporated in Fe (hydr)oxide in soil during the non-flooded period, and the As is quickly released from soil to water during the flooded period because of reductive dissolution of the Fe (hydr)oxide phase and reduction of As from As(V) to As(III). The enhancement of As dissolution by the reduction of As is supported by high As/Fe ratios of soil water during the flooded period and our laboratory experiments where As(III) concentrations and As(III)/As(V) ratios in submerged soil were monitored. Our work, primarily based on data from an actual paddy field, suggests that rice plants are enriched in As because the rice grows in flooded paddy fields when mobile As(III) is released to soil water.

Implementing clinical guidelines: current evidence and future implications.

Abstract: One of the most common findings from health services research is a failure to routinely translate research findings into daily practice. Previous systematic reviews of strategies to promote the uptake of research findings suffered from a range of methodologic problems that have been addressed in a more recent systematic review of guideline dissemination and implementation strategies. Changes in practitioner behavior; in the desired direction, were reported in 86% of the comparisons made. The median effect size overall was approximately 10% improvement in absolute terms. The review suggests that interventions that were previously thought to be ineffective (e.g., dissemination of educational materials) may have modest but worthwhile benefits. Also, multifaceted interventions, previously thought to be more effective than single interventions, were found to be no more effective than single interventions. Overall, there is an imperfect evidence base for decision makers to work from. Many studies had methodologic weaknesses, and reporting of this kind of research is generally poor, making the generalizability of study findings frequently uncertain. A better theoretical underpinning of studies would make this body of research more useful.

Big questions, small worlds: microbial model systems in ecology

Abstract: Although many biologists have embraced microbial model systems as tools to address genetic and physiological questions, the explicit use of microbial communities as model systems in ecology has traditionally been more restricted. Here, we highlight recent studies that use laboratory-based microbial model systems to address ecological questions. Such studies have significantly advanced our understanding of processes that have proven difficult to study in field systems, including the genetic and biochemical underpinnings of traits involved in ecological interactions, and the ecological differences driving evolutionary change. It is the simplicity of microbial model systems that makes them such powerful tools for the study of ecology. Such simplicity enables the high degrees of experimental control and replication that are necessary to address many questions that are inaccessible through field observation or experimentation.