Outbreak of an undetected invasive species triggered by a climate anomaly

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ecosphere 7 (2016): e01628, doi:10.1002/ecs2.1628.When an invasive species appears at a new location, we typically have no knowledge of the population dynamics leading up to that moment. Is the establishment of invasive propagules closely followed by the appearance of the population? Or alternatively, was there an established low-density population that was released from a constraint and crossed the detection threshold? The early stages of the invasion process are a critical gap in our knowledge, yet vitally important for the detection and management of invasions. Here, we present multiple lines of evidence supporting the lag scenario for an invasive species outbreak. The invasive predatory zooplankton, spiny water flea (Bythotrephes longimanus), was detected in Lake Mendota, Wisconsin (USA), in summer of 2009 and rapidly reached and sustained exceptionally high densities. To evaluate whether Bythotrephes' outbreak immediately followed introduction or erupted from an established low-density population, we constructed a population model of Bythotrephes in Lake Mendota. In the model, Bythotrephes persisted indefinitely at low levels until favorable thermal conditions in 2009, the coolest July since at least 1895, allowed it to erupt to high densities and establish a large egg bank in the lake sediments. The egg bank stabilized the population in the high-density state despite a return to nonfavorable thermal conditions, which is further supported by demographic data suggesting a constant contribution from the egg bank during the year. The prolonged lag scenario is corroborated by the detection of two individual Bythotrephes in pre-2009 archived samples, and the detection of Bythotrephes spines in lake sediment core layers dating back to 1994 (±5 yr). Together, our results suggest that Bythotrephes persisted for at least a decade below the detection limit, until optimal thermal conditions triggered a population outbreak. This work highlights the potential for environmental conditions to trigger invasive species outbreaks from low-density populations.NSF North Temperate Lakes Long-Term Ecological Research Program Grant Numbers: DEB-0217533, DEB-1440297; Wisconsin Department of Natural Resource

The internal validity of the school-level comparative interrupted time series design: evidence from four new within-study comparisons

Comparative interrupted time series (CITS) designs evaluate impact by modeling the relative deviation from trends among a treatment and comparison group after an intervention. The broad applicability of the design means it is widely used in education research. Like all non-experimental evaluation methods however, the internal validity of a given CITS evaluation depends on assumptions that cannot be directly verified. We provide an empirical test of the internal validity of CITS by conducting four within-study comparisons of school-level interventions previously evaluated using randomized controlled trials. Our estimate of bias across these four studies is 0.03 school-level (or 0.01 pupil-level) standard deviations. The results suggest well-conducted CITS evaluations of similar school-level education interventions are likely to display limited bias

The semiquinone radical anion of 1,10-phenanthroline-5,6-dione: synthesis and rare earth coordination chemistry

Reduction of 1,10-phenanthroline-5,6-dione (pd) with CoCpR2 resulted in the first molecular compounds of the pd˙− semi-quinone radical anion, [CoCpR2]+[pd]˙− (R = H, (1); R = Me4, (2)). Furthermore compounds 1 and 2 were reacted with [Y(hfac)3(thf)2] (hfac = 1,1,1-5,5,5-hexafluoroacetylacetonate) to synthesise the rare earth-transition metal heterometallic compounds, [CoCpR2]+[Y(hfac)3(N,N′-pd)]˙− (R = H, (3); R = Me4, (4))

The Potential Role of Exercise Training and Mechanical Loading on Bone-Associated Skeletal Nerves

: The spatial distribution, innervation, and functional role of the bone-associated skeletal nerves have been previously reported in detail. However, studies examining exercise-induced associations between skeletal nerves and bone metabolism are limited. This review introduces a potential relationship between exercise and the skeletal nerves and discusses how it can contribute to exercise-induced bone anabolism. First, the background and current understanding of nerve fiber types and their functions in the skeleton are provided. Next, the influence of exercise and mechanical loading on the skeletal nervous system is elaborated. Effective synthesis of recent studies could serve as an established baseline for the novel discovery of the effects of exercise on skeletal nerve density and bone anabolic activity in the future. Therefore, this review overviews the existing evidence for the neural control of bone metabolism and the potential positive effects of exercise on the peripheral skeletal nervous system. The influence of exercise training models on the relationships of sensory nerve signals with osteoblast-mediated bone formation and the increased bone volume provides the first insight on the potential importance of exercise training in stimulating positive adaptations in the skeletal nerve-bone interaction and its downstream effect on bone metabolism, thereby highlighting its therapeutic potential in a variety of clinical populations

The modular synthesis of rare earth-transition metal heterobimetallic complexes utilizing a redox-active ligand

We report a robust and modular synthetic route to heterometallic rare earth-transition metal complexes. We have used the redox-active bridging ligand 1,10-phenathroline-5,6-dione (pd), which has selective N,N′ or O,O′ binding sites as the template for this synthetic route. The coordination complexes [Ln(hfac)3(N,N’-pd)] (Ln = Y [1], Gd [2]; hfac = hexafluoroacetylacetonate) were synthesised in high yield. These complexes have been fully characterised using a range of spectroscopic techniques. Solid state molecular structures of 1 and 2 have been determined by X-ray crystallography and display different pd binding modes in coordinating and non-coordinating solvents. Complexes 1 and 2 are unusually highly coloured in coordinating solvents, for example the vis-NIR spectrum of 1 in acetonitrile displays an electronic transition centred at 587 nm with an extinction coefficient consistent with significant charge transfer. The reaction between 1 and 2 and VCp2 or VCpt2 (Cpt = tetramethylcyclopentadienyl) resulted in the isolation of the heterobimetallic complexes, [Ln(hfac)3(N,N′-O,O′-pd)VCp2] (Ln = Y [3], Gd [4]) or [Ln(hfac)3(N,N′-O,O′-pd)VCpt2] (Ln = Y [5], Gd [6]). The solid state molecular structures of 3, 5 and 6 have been determined by X-ray crystallography. The spectroscopic data on 3–6 are consistent with oxidation of V(II) to V(IV) and reduction of pd to pd2− in the heterobimetallic complexes. The spin-Hamiltonian parameters from low temperature X-band EPR spectroscopy of 3 and 5 describe a 2A1 ground state, with a V(IV) centre. DFT calculations on 3 are in good agreement with experimental data and confirm the SOMO as the dx2−y2 orbital localised on vanadium

Design and rheological performance of microgel suspensions and microgel stabilised emulsions

This thesis describes the fabrication, characterization and applications of pectin based microgels. A variety of techniques commonly used to characterize colloidal and soft matter systems (i.e., particle size analysis, microscopy techniques and shear rheometry) were used throughout. Microgel suspensions were prepared in large quantities using a simple and scalable ‘top-down’ technique. This involved the fabrication of crosslinked ‘parent’ pectin hydrogels which were subsequently combined with a suitable solvent and subjected to mechanical disruption to yield microgel suspensions. Such systems are promising candidates as novel food additives for purposes of rheology modification and emulsification. It was shown that the rheological properties (viscosity and elasticity) of microgel suspensions can be tailored by varying the elasticity and effective volume fraction of microgel particles. The former is easily controlled via the elasticity of parent hydrogels, which in turn depends on the crosslinking density. The use of microgel suspensions as rheology modifiers is shown to provide distinct benefits over native polymer solutions and crosslinked polymer gels respectively. The ability to engineer desirable flow behaviour is likely to be a significant advantage to the manufacturerwhen developing new products or processes. Converting pectin to pectin microgels also improved their functional properties when such systems were used as stabilizers of oil-in-water emulsions. Microgel stabilized emulsions were more resistant against droplet coarsening on prolonged storage and when subjected to temperature cycling as compared to native pectin stabilized emulsions. Furthermore, the particulate nature of the microgels resulted in emulsions with enhanced rheological properties at the same overall biopolymer concentration

Outerwall and Beyond

In 2013, Outerwall (parent company of Coinstar and RedBox) acquired ecoATM, an automated e-waste recycling station. As a disruptive technology in the e-recycling business, ecoATM has demonstrated significant potential for triple-bottom-line success. Outerwall has struggled with negative press related to law-enforcement belief that these kiosks are “a motivator for the criminal element.” This CSR mini-case provides students an opportunity to work creatively to solve a public relations and perception problem in order to fully realize a company’s full potential for positive social, environmental and economic impact

Electro-Muscle-to-Muscle Transfer

The Electro Muscle to Muscle Transfer (EMMT) system will entail designing, manufacturing, and providing a wearable device that stimulates paralyzed muscles in the hand by sampling and amplifying muscles from the forearm. With further development, the system may be capable of using different muscle inputs other than the forearm muscles along with different stimulated muscle outputs other than the hand. The system functions as a rehabilitative device for spinal cord injuries, irreparable nerve loss and/or damage, and improper neuromuscular function. It is not for total treatment nor for curing of the disabilities listed above but to alleviate the side effects of the disability and help reduce muscular dysfunction

Stress Testing for Diastolic Dysfunction: An Old Approach to a New Question

BACKGROUND: Currently, conventional cycle echocardiography is the recommended method for diagnosing diastolic dysfunction in patients with unexplained dyspnea upon exertion. However, this method has several underlying limitations including movement and respiratory artifact. These limitations are often exaggerated in patients who are obese and suffer from exertional dyspnea, and therefore limit its application in clinical diagnosis. Our group recently demonstrated that isometric handgrip echocardiography is a powerful sub-clinical diastolic discriminator that avoids the limitations of conventional cycle echocardiography and that can be easily implemented in the clinic. PURPOSE: However, to date it remains unclear how these two methodologies compare, and thus was the focus of the present investigation. We hypothesized that isometric handgrip echocardiography would be a more robust method for unmasking exercise induced diastolic dysfunction compared to conventional cycle echocardiography, due to its markedly different hemodynamic load. METHODS: To test this hypothesis, we recruited 24 individuals from the community (9 male, 15 female, age range: 18 - 80), who all performed 3 minutes of isometric handgrip echocardiography followed by 3 minutes of dynamic cycle exercise (20 W). At rest and during the final minute of each exercise protocol heart rate (HR), mean arterial pressure (MAP) and Doppler derived E/e’ were recorded. Consistent with our previous work, and that of others, individuals who had a change in E/e’ from rest to exercise of \u3e1.5 (ΔE/e’ \u3e 1.5) were defined as responders, while non-responders were defined as ΔE/e’ \u3c 1.5. RESULTS: Both isometric handgrip and low-intensity cycle exercise resulted in a similar rise in HR (ΔHR: 22 ± 13 vs. 25 ± 7, handgrip vs. cycle exercise, P \u3e 0.05), while isometric handgrip resulted in a larger increase in MAP (ΔMAP: 28 ± 14 vs. 16 ± 12, handgrip vs. cycle exercise, P = 0.0003). Remarkably, the increased afterload stress experienced by the myocardium during isometric handgrip exercise was more robust at unmasking sub-clinical diastolic dysfunction in asymptomatic elderly individuals compared to conventional cycle exercise (handgrip: n = 14 vs. n = 10; and cycle: n = 10 vs. n = 14, responders vs. non-responders). CONCLUSION: Taken together, these data highlight the usefulness of isometric handgrip echocardiography at isolating myocardial diastolic relaxation abnormalities in community dwelling individuals, beyond that of dynamic cycle exercise. Future work should focus on confirming the sensitivity of this method in individuals at risk for or with diagnosed heart failure

Echocardiographic Assessment of Myocardial Deformation during Exercise

The human heart is an asymmetrical structure that consists of oblique, circumferential, and transmural fibers, as well as laminae and sheets. Sequential electrical activation of all the muscle fibers ultimately results in a coordinated contraction of the heart muscle also referred to as “deformation.” This is immediately followed by myocardial relaxation, when the preceding deformation is reversed, and the ventricles fill with blood. Given the complexity of these repetitive motions, it is not surprising that there is great diversity in the myocardial deformation between different individuals and between distinct populations. Exercise presents a natural challenge to determine the full capacity of an individual’s heart, and modern imaging technologies allow for the non-invasive assessment of myocardial deformation during exercise. In this chapter, the most relevant anatomical basis for myocardial deformation is summarized and definitions of the most relevant parameters are provided. Then, the general cardiac responses to exercise are highlighted before the current knowledge on myocardial deformation during exercise is discussed. The literature clearly indicates that the echocardiographic evaluation of myocardial deformation during exercise holds great promise for the identification of sub-clinical disease. Future studies should aim to determine the mechanisms of differential expression of myocardial deformation during exercise in health and disease