Quantification of Nitric Oxide via Single-Walled Carbon Nanotubes

Nitric oxide (NO), a free radical present in biological systems, can have many beneficial and detrimental effects on the body. Due to NO’s short half-life, its detection and quantification is difficult. This inability to quantify NO has hindered researchers that are trying to understand NO’s impact in healthy and diseased conditions. Single-walled carbon nanotubes (SWNT), can become selective to various analytes when wrapped in specific single-stranded DNA strands. The presence of the analyte of interest can change the wavelength and/or intensity of the SWNT’s fluorescence, allowing the SWNT to be used as a sensor. One type of SWNT sensor, 6,5 SWNT wrapped with (AT)15, displays a selectivity towards NO, decreasing in fluorescence intensity in NO’s presence. We have discovered that SWNT’s decrease in florescence is related to the concentration of NO present, allowing for the quantification of NO based on the decrease in signal intensity. The ability to quantify NO will lead to many new areas of study, such as determination of the effects of specific concentrations of NO on the health of a biological system, as well as possible applications of artificially increasing or decreasing NO levels. Advisor: Nicole M. Iverso

How Does Shortage of Health IT Professionals Impact on the Digital Health Transformation?

Background: The need for software suppliers to react swiftly to the plethora of application requests and constantly shifting market requirements is one of the major problems facing the health IT business in the context of digital health transformation. This can only be achieved when the necessary staff and resources are available. Objectives: The objective of this work is to identify challenges health IT companies are confronted with related to personnel capacities and skilled workers. Methods: Using a questionnaire distributed through newsletters and social media among representatives of software companies and hospitals we collected information on current hurdles of health software providers and their strategies to overcome these in order to address the demands of the digital health transformation. Results: The main findings of the survey are that scarce resources in software development are among the reasons for not achieving strategic goals on time in the health IT sector and for not being able to react flexibly to market changes. A strategy to overcome missing expert knowledge and own resources without free capacity is to hire external resources. Conclusions: With the ever-changing landscape of digital health, it is essential to have skilled workers with knowledge on the peculiarities of clinical workflows. The existing shortage of skilled workers leads to a reduction of innovative power in the health IT sector, potentially slowing down the digital health transformation

The effect of heterogeneity on decorrelation mechanisms in spiking neural networks: a neuromorphic-hardware study

High-level brain function such as memory, classification or reasoning can be realized by means of recurrent networks of simplified model neurons. Analog neuromorphic hardware constitutes a fast and energy efficient substrate for the implementation of such neural computing architectures in technical applications and neuroscientific research. The functional performance of neural networks is often critically dependent on the level of correlations in the neural activity. In finite networks, correlations are typically inevitable due to shared presynaptic input. Recent theoretical studies have shown that inhibitory feedback, abundant in biological neural networks, can actively suppress these shared-input correlations and thereby enable neurons to fire nearly independently. For networks of spiking neurons, the decorrelating effect of inhibitory feedback has so far been explicitly demonstrated only for homogeneous networks of neurons with linear sub-threshold dynamics. Theory, however, suggests that the effect is a general phenomenon, present in any system with sufficient inhibitory feedback, irrespective of the details of the network structure or the neuronal and synaptic properties. Here, we investigate the effect of network heterogeneity on correlations in sparse, random networks of inhibitory neurons with non-linear, conductance-based synapses. Emulations of these networks on the analog neuromorphic hardware system Spikey allow us to test the efficiency of decorrelation by inhibitory feedback in the presence of hardware-specific heterogeneities. The configurability of the hardware substrate enables us to modulate the extent of heterogeneity in a systematic manner. We selectively study the effects of shared input and recurrent connections on correlations in membrane potentials and spike trains. Our results confirm ...Comment: 20 pages, 10 figures, supplement

Spectral Sequences in String Topology

In this paper, we investigate the behaviour of the Serre spectral sequence with respect to the algebraic structures of string topology in generalized homology theories, specificially with the Chas-Sullivan product and the corresponding coproduct and module structures. We prove compatibility for two kinds of fibre bundles: the fibre bundle $\Omega^n M \to L^n M \to M$ for an $h_*$-oriented manifold $M$ and the looped fibre bundle $L^n F \to L^n E \to L^n B$ of a fibre bunde $F \to E \to B$ of $h_*$-oriented manifolds. Our method lies in the construction of Gysin morphisms of spectral sequences. We apply these results to study the ordinary homology of the free loop spaces of sphere bundles and generalized homologies of the free loop spaces of spheres and projective spaces.Comment: 33 page

Deterministic networks for probabilistic computing

Neural-network models of high-level brain functions such as memory recall and reasoning often rely on the presence of stochasticity. The majority of these models assumes that each neuron in the functional network is equipped with its own private source of randomness, often in the form of uncorrelated external noise. However, both in vivo and in silico, the number of noise sources is limited due to space and bandwidth constraints. Hence, neurons in large networks usually need to share noise sources. Here, we show that the resulting shared-noise correlations can significantly impair the performance of stochastic network models. We demonstrate that this problem can be overcome by using deterministic recurrent neural networks as sources of uncorrelated noise, exploiting the decorrelating effect of inhibitory feedback. Consequently, even a single recurrent network of a few hundred neurons can serve as a natural noise source for large ensembles of functional networks, each comprising thousands of units. We successfully apply the proposed framework to a diverse set of binary-unit networks with different dimensionalities and entropies, as well as to a network reproducing handwritten digits with distinct predefined frequencies. Finally, we show that the same design transfers to functional networks of spiking neurons.Comment: 22 pages, 11 figure

How to develop health-promoting food supplements by using single-use bioreactors

There is currently considerable interest in alternative and sustainable production methods for healthy foods. The cultivation of plant cell cultures in suitable bioreactors instead of growing whole plants on the field may be a solution. In this way, the cell cultures of interesting plant species can be established independent of the location. Furthermore, secondary metabolism can be specifically controlled during mass propagation of the cells. In other words, the expression of compounds promoting health and wellbeing can be supported, and the formation of substances with adverse health effects can be suppressed. We used this approach to make cacao powder and to produce a ‘cell culture chocolate’ by growing suspension cells from Theobroma cacao in a Flexsafe RM 20L bag with a screw cap from a BIOSTAT RM 20/50. The cell line (dark culture) was established from a well-growing and friable callus clone, and has a doubling time of 4 days. It provided up to 40% higher concentrations of the polyphenols epicatechine, procyanidine B1, B2 and C1, and cinnamtannine A2 than cocoa beans from pods grown in Puerto Rico. The alkaloids caffeine and theobromine were absent in the cell culture grown in MS-medium. On day 16, about 300 g biomass (fresh weight) was harvested from the wave-mixed single-use bioreactor operated in feeding mode. Addition of an antifoam agent and pH-regulator was not required. The biomass was freeze-dried, resulting in in vitro cacao powder that was roasted and milled before adding sugar, lecithin and cocoa butter. 3 blocks of dark chocolate (70%) were produced, which provided the experts on the ZHAW`s sensory panel with a unique taste experience. The flavour was intensive and complex, citric and berry flavours being predominant. The results demonstrate the suitability of wave-mixed bioreactors for the development of plant cell-based health-promoting food and food ingredients. Subsequent studies will focus on the influence of power input and shear stress on polyphenol formation, and the development of a scalable low-cost bioreactor

Prescription Rates, Polypharmacy and Prescriber Variability in Swiss General Practice—A Cross-Sectional Database Study

Purpose: The frequency of medication prescribing and polypharmacy has increased in recent years in different settings, including Swiss general practice. We aimed to describe patient age- and sex-specific rates of polypharmacy and of prescriptions of the most frequent medication classes, and to explore practitioner variability in prescribing.Methods: Retrospective cross-sectional study based on anonymized electronic medical records data of 111 811 adult patients presenting to 116 Swiss general practitioners in 2019. We used mixed-effects regression analyses to assess the association of patient age and sex with polypharmacy (≥5 medications) and with the prescription of specific medication classes (second level of the Anatomical Therapeutic Chemical Classification System). Practitioner variability was quantified in terms of the random effects distributions.Results: The prevalence of polypharmacy increased with age from 6.4% among patients aged 18–40 years to 19.7% (41–64 years), 45.3% (65–80 years), and 64.6% (81–92 years), and was higher in women than in men, particularly at younger ages. The most frequently prescribed medication classes were antiinflammatory and antirheumatic products (21.6% of patients), agents acting on the renin-angiotensin system (19.9%), analgesics (18.7%), and drugs for acid related disorders (18.3%). Men were more often prescribed agents targeting the cardiovascular system, whereas most other medications were more often prescribed to women. The highest practitioner variabilities were observed for vitamins, for antiinflammatory and antirheumatic products, and for mineral supplements.Conclusion: Based on practitioner variability, prevalence, and risk potential, antiinflammatory drugs and polypharmacy in older patients appear to be the most pressing issues in current drug prescribing routines

Importance of different electronic medical record components for chronic disease identification in a Swiss primary care database: a cross-sectional study

BACKGROUND Primary care databases collect electronic medical records with routine data from primary care patients. The identification of chronic diseases in primary care databases often integrates information from various electronic medical record components (EMR-Cs) used by primary care providers. This study aimed to estimate the prevalence of selected chronic conditions using a large Swiss primary care database and to examine the importance of different EMR-Cs for case identification. METHODS Cross-sectional study with 120,608 patients of 128 general practitioners in the Swiss FIRE ("Family Medicine Research using Electronic Medical Records") primary care database in 2019. Sufficient criteria on three individual EMR-Cs, namely medication, clinical or laboratory parameters and reasons for encounters, were combined by logical disjunction into definitions of 49 chronic conditions; then prevalence estimates and measures of importance of the individual EMR-Cs for case identification were calculated. RESULTS A total of 185,535 cases (i.e. patients with a specific chronic condition) were identified. Prevalence estimates were 27.5% (95% CI: 27.3-27.8%) for hypertension, 13.5% (13.3-13.7%) for dyslipidaemia and 6.6% (6.4-6.7%) for diabetes mellitus. Of all cases, 87.1% (87.0-87.3%) were identified via medication, 22.1% (21.9-22.3%) via clinical or laboratory parameters and 19.3% (19.1-19.5%) via reasons for encounters. The majority (65.4%) of cases were identifiable solely through medication. Of the two other EMR-Cs, clinical or laboratory parameters was most important for identifying cases of chronic kidney disease, anorexia/bulimia nervosa and obesity whereas reasons for encounters was crucial for identifying many low-prevalence diseases as well as cancer, heart disease and osteoarthritis. CONCLUSIONS The EMR-C medication was most important for chronic disease identification overall, but identification varied strongly by disease. The analysis of the importance of different EMR-Cs for estimating prevalence revealed strengths and weaknesses of the disease definitions used within the FIRE primary care database. Although prioritising specificity over sensitivity in the EMR-C criteria may have led to underestimation of most prevalences, their sex- and age-specific patterns were consistent with published figures for Swiss general practice

The price of nicotine dependence: A comparison of the cost of nicotine across products in Switzerland, Germany, USA, Sweden, France and the UK, in 2019 [short report].

INTRODUCTION Tobacco cigarette taxes aim at reducing smoking, but smokers are still dependent on nicotine and need safe and cheap alternatives. As the costs play a role in the product chosen, we compared standardized nicotine costs across products and countries. METHODS We gathered prices of tobacco cigarettes, heated tobacco products (HTP), pharmaceutical nicotine replacement therapy (pNRT) gums, snus, and open and closed electronic nicotine delivery systems (ENDS) in 6 countries (Switzerland, Germany, USA, Sweden, France, UK) in 2019. We compared the cost of a pack of cigarettes in Switzerland to the cost of equivalent doses of nicotine delivered by other products and across countries, normalizing to purchasing power GDP per capita to compute relative adjusted costs (RACs). RESULTS Adjusted tobacco cigarette cost was lowest in Switzerland, Germany, and Sweden; RAC for pNRT was 1.1 in Switzerland and 1.0 in Germany. In France and the UK, RACs for cigarettes were 1.5 and 2.1, while for pNRT they were cheaper (RAC: 0.04). In Switzerland, snus/nicotine pouches were the cheapest form of nicotine delivery (RAC: 0.2), open ENDS were a low-cost option for nicotine delivery in all countries (RAC: 0.2-0.3), and HTP cost more than regular tobacco products in most countries. CONCLUSIONS We found broad differences in costs of nicotine according to countries and products. This should be considered in future studies on smoking prevalence and in public health efforts

The EIVE CubeSat - Developing a Satellite Bus for a 71-76 GHz E-Band Transmitter Payload

A high-speed data downlink system provides many challenges for a CubeSat design. Two major aspect are an adequate power management as well as the thermal implications of the dissipated power. The goal of the 6U CubeSat EIVE is to prove the feasibility of an E-band link at 71-76 GHz and explore the influence of different atmospheric conditions on the link quality. The requirements of the E-band transmitter in terms of mass, volume, power and pointing accuracy outline the specific constraints imposed on the design of the satellite bus. The major design drivers of the system are the peak power demand of 60 W for the payload itself and the required pointing accuracy of less than 1◦. To cope with these demands, general design considerations, the choice of the orbit and the operation of the satellite are discussed. A special focus is the power generation and consumptions by means of a dynamic attitude and power simulation. The thermal simulation is verified by building a detailed structural and thermal replica of the satellite to investigate the heat dissipation. An overview of the current EIVE CubeSat platform design concludes this paper