From the Dinner Pot to Smoking Pot; How a Better Understanding of Cannabidiol in Crayfish could Alleviate Anxiety and Modulate Hunger

Anxiety affects approximately 1/3 of the US population and presents in many different forms, ranging from social to panic disorders. It also presents with high comorbidity for other mental disorders. One treatment is Selective Serotonin Reuptake Inhibitors (SSRIs) which allow for increased activation of serotonin (5-HT) receptors. SSRIs come with an extensive list of side effects, which can fail to maintain quality of life. Cannabidiol (CBD) is a cannabis derived compound which has been shown to decrease anxiety by activation of multiple subtype 5-HT amine receptors. CBD has few side effects, is not psychoactive, and exhibits anti-psychotic properties. The current understanding of CBD\u27s mechanisms is limited specifically in invertebrates, where to date limited published research involves behavior and cannabinoids. Decapod crustaceans, such as crayfish, have emerged as a novel approach to studying drugs of abuse. Within the neural structures of the crayfish tails are 5-HT receptors that control tail-flips, a withdraw reflex when placed into a fight. Serotonin has also been linked to aggression and decision making for engaging in fights with other crayfish. Additionally, evidence currently suggests CB1 receptors are present at neuromuscular junctions (NMJ) and may have an impact on motility. For this thesis, crayfish were administered either CBD, 5-HT, or a vehicle control. Analysis of motility by percent of time moving or rest, amount of food consumed, and aggression in paired fights were conducted. No statistical significance was found for CBD influencing motility and hunger. However, the duration of fights significantly increased when injected with CBD and when paired with 5-HT injected crayfish. This evidence supports the main hypothesis that CBD increases serotonin receptor activity in crayfish as seen with SSRIs, thus could be of use in treating anxiety

Review on the conversion of thermoacoustic power into electricity

Thermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently into electric power. This article provides a review of the four main methods to convert the (thermo)acoustic power into electricity. First, loudspeakers and linear alternators are discussed in a section on electromagnetic devices. This is followed by sections on piezoelectric transducers, magnetohydrodynamic generators, and bidirectional turbines. Each segment provides a literature review of the given technology for the field of thermoacoustics, focusing on possible configurations, operating characteristics, output performance, and analytical and numerical methods to study the devices. This information is used as an input to discuss the performance and feasibility of each method, and to identify challenges that should be overcome for a more successful implementation in thermoacoustic engines. The work is concluded by a comparison of the four technologies, concentrating on the possible areas of application, the conversion efficiency, maximum electrical power output and more generally the suggested focus for future work in the field.Comment: The following article appeared in J. Acoust. Soc. Am 143(2) and the final version in a proper two-column format may be found at: http://scitation.aip.org/content/asa/journal/jasa/143/2/10.1121/1.502339

Proximal Soil Sensing – A Contribution for Species Habitat Distribution Modelling of Earthworms in Agricultural Soils?

Earthworms are important for maintaining soil ecosystem functioning and serve as indicators of soil fertility. However, detection of earthworms is time-consuming, which hinders the assessment of earthworm abundances with high sampling density over entire fields. Recent developments of mobile terrestrial sensor platforms for proximal soil sensing (PSS) provided new tools for collecting dense spatial information of soils using various sensing principles. Yet, the potential of PSS for assessing earthworm habitats is largely unexplored. This study investigates whether PSS data contribute to the spatial prediction of earthworm abundances in species distribution models of agricultural soils

General practitioners' approaches to prostate-specific antigen testing in the north-east of the Netherlands

BACKGROUND: There is wide variation in clinical practice for the early detection of prostate cancer, not least because of the ongoing debate about the benefits of prostate-specific antigen (PSA) testing. In this study, we aimed to assess the approaches, attitudes, and knowledge of general practitioners (GPs) regarding PSA testing in primary care in the Netherlands, particularly regarding recommendations for prostate cancer. METHODS: Questionnaire surveys were sent to 179 GPs in the north-east of the Netherlands, of which 65 (36%) were completed and returned. We also surveyed 23 GPs attending a postgraduate train-the-trainer day (100%). In addition to demographic data and practice characteristics, the 31-item questionnaire covered the attitudes, clinical practice, adherence to PSA screening recommendations, and knowledge concerning the recommendations for prostate cancer early detection. Statistical analysis was limited to the descriptive level. RESULTS: Most GPs (95%; n = 82) stated that they had at least read the Dutch GP guideline, but just half (50%; n = 43) also stated that they knew the content. Almost half (46%; n = 39) stated they would offer detailed counseling before ordering a PSA test to an asymptomatic man requesting a test. Overall, prostate cancer screening was reported to be of minor importance compared to other types of cancer screening. CONCLUSIONS: Clinical PSA testing in primary care in this region of the Netherlands seems generally to be consistent with the relevant guideline for Dutch GPs that is restrictive to PSA testing. The next step will be to further evaluate the effects of the several PSA testing strategies

Modeling system states in liver cells: Survival, apoptosis and their modifications in response to viral infection

<p>Abstract</p> <p>Background</p> <p>The decision pro- or contra apoptosis is complex, involves a number of different inputs, and is central for the homeostasis of an individual cell as well as for the maintenance and regeneration of the complete organism.</p> <p>Results</p> <p>This study centers on Fas ligand (FasL)-mediated apoptosis, and a complex and internally strongly linked network is assembled around the central FasL-mediated apoptosis cascade. Different bioinformatical techniques are employed and different crosstalk possibilities including the integrin pathway are considered. This network is translated into a Boolean network (74 nodes, 108 edges). System stability is dynamically sampled and investigated using the software SQUAD. Testing a number of alternative crosstalk possibilities and networks we find that there are four stable system states, two states comprising cell survival and two states describing apoptosis by the intrinsic and the extrinsic pathways, respectively. The model is validated by comparing it to experimental data from kinetics of cytochrome c release and caspase activation in wildtype and Bid knockout cells grown on different substrates. Pathophysiological modifications such as input from cytomegalovirus proteins M36 and M45 again produces output behavior that well agrees with experimental data.</p> <p>Conclusion</p> <p>A network model for apoptosis and crosstalk in hepatocytes shows four different system states and reproduces a number of different conditions around apoptosis including effects of different growth substrates and viral infections. It produces semi-quantitative predictions on the activity of individual nodes, agreeing with experimental data. The model (SBML format) and all data are available for further predictions and development.</p

Simulation-based model selection for dynamical systems in systems and population biology

Computer simulations have become an important tool across the biomedical sciences and beyond. For many important problems several different models or hypotheses exist and choosing which one best describes reality or observed data is not straightforward. We therefore require suitable statistical tools that allow us to choose rationally between different mechanistic models of e.g. signal transduction or gene regulation networks. This is particularly challenging in systems biology where only a small number of molecular species can be assayed at any given time and all measurements are subject to measurement uncertainty. Here we develop such a model selection framework based on approximate Bayesian computation and employing sequential Monte Carlo sampling. We show that our approach can be applied across a wide range of biological scenarios, and we illustrate its use on real data describing influenza dynamics and the JAK-STAT signalling pathway. Bayesian model selection strikes a balance between the complexity of the simulation models and their ability to describe observed data. The present approach enables us to employ the whole formal apparatus to any system that can be (efficiently) simulated, even when exact likelihoods are computationally intractable.Comment: This article is in press in Bioinformatics, 2009. Advance Access is available on Bioinformatics webpag

A red/far-red light-responsive bi-stable toggle switch to control gene expression in mammalian cells

Growth and differentiation of multicellular systems is orchestrated by spatially restricted gene expression programs in specialized subpopulations. The targeted manipulation of such processes by synthetic tools with high-spatiotemporal resolution could, therefore, enable a deepened understanding of developmental processes and open new opportunities in tissue engineering. Here, we describe the first red/far-red light-triggered gene switch for mammalian cells for achieving gene expression control in time and space. We show that the system can reversibly be toggled between stable on- and off-states using short light pulses at 660 or 740 nm. Red light-induced gene expression was shown to correlate with the applied photon number and was compatible with different mammalian cell lines, including human primary cells. The light-induced expression kinetics were quantitatively analyzed by a mathematical model. We apply the system for the spatially controlled engineering of angiogenesis in chicken embryos. The system's performance combined with cell- and tissue-compatible regulating red light will enable unprecedented spatiotemporally controlled molecular interventions in mammalian cells, tissues and organism