An Inexpensive Microfluidic PDMS Chip for Visual Detection of Biofilm-forming Bacteria

Aims: Design and assembly of an inexpensive microfluidic PDMS chip for visual detection of cell adhesion and biofilm formation. Study Design: Three different styles of microchannels (2.6, 5.0, and 11.5 μl volumes) were designed, fabricated and tested for adhesion and biofilm formation in a microfluidic system. The pressure drop measurements system includes a bio-Ferrograph connected to the PDMS microchannel via a syringe and a pressure transducer. Methodology: Microfluidic chips were fabricated using Polydimethylsiloxane (PDMS) by means of soft lithography. Different cell densities of E.coli K12 cells were introduced to investigate adhesion and biofilm formation at different time intervals. Stabilization time and hydraulic resistance were obtained via a Bio-Ferrograph connected to a pressure transducer. Results: PDMS microfluidic volume (2.6 μl) failed to generate noticeable biofilm, while slight and greatest yield occurred with PDMS microchannels (5.0, and 11.5 μl), respectively, and could detect as low as 26 cells in 11.5 μl microchannel. As incubation time and/or initial cell density increases, cell adhesion increased, illustrated by crystal violet color intensity. High stabilization time (3 h) didn’t allow for bacterial attachment and cultivation inside the microchannel (2.6 μl) while lower stabilization time (10 min) yielded the highest capacity of cell adhesion in microchannel (11.5 μl). Conclusions: We developed a microfluidic chip with low stabilization time and hydraulic resistance, thus offering more volume for adhesion of bacterial cells and biofilm formation. It allowed bacterial cultivation without any addition of nutrients. The microfluidic chip provides a platform to monitor biofilm growth and can be integrated in situ investigations for biological systems, food biotechnology and other industrial biotechnology applications. This would allow a non-destructive and non-invasive monitoring of the biofilm-forming bacteria inside the PDMS microfluidic chip. This work opens opportunities for further investigations of pressure drop phenomena in microchannels that would otherwise go unnoticed in macro scale measurements

Efficiency for Large Fleets: An Analysis of How Industrial Customers Use Electric and Hybrid Vehicles

This paper presents methods and results which allow an analysis of relevant driving parameters of hybrid and electric vehicles. In order to gain crucial insights into how industrial customers use hybrid and electric vehicles, the paper investigates the following parameters: information about odometer, charging processes and battery charging levels. The data used for this purpose was provided by the Canadian fleet management company Geotab Inc. They were evaluated by means of ‘Google BigQuery’ and the statistics programme ‘IBM SPSS Statistics’. It turned out that correlations between ‘charging time’ and ‘battery charging level’ exist, as well as between ‘battery level’ and ‘distance per day’. One of the main questions in the present study asks whether long charging times of car batteries lead to decreased average battery charging levels. As a result of this study, the longer a hybrid vehicle is charged per day, the lower sink its average battery charging level. The findings of this research help managers of car fleets to enhance their existing fleet management for establishing more efficient fleets with respect to ecological and economical aspects. Our research is particularly significant as this will save money across such fleets worldwide, and at the same time, preserve the environment as much as possible. Keywords: fleet management, electric and hybrid vehicles, big data, battery charging DOI: 10.7176/ISDE/10-3-03 Publication date:March 31st 201

Die Lebensretterolympiade: Eine themen- und fächerübergreifende Möglichkeit zur Überprüfung des Lernerfolgs im Rahmen von Reanimations- und Gesundheitsunterricht

Schulen stehen im Fokus als eine geeignete Institution, um Erste-Hilfe-Wissen zur Laienreanimation, zur Gesundheit und zur Prävention zu unterrichten und so sukzessive in der Gesellschaft zu etablieren. Die Implementierung einer solchen Thematik wurde in den letzten Jahren intensiv diskutiert und empfohlen. Dieser Beitrag ist darauf ausgerichtet, eine unterrichtspraktische Möglichkeit aufzuzeigen, wie der Lernabschluss von Reanimations- sowie Gesundheitsunterricht im schulischen Biologie- bzw. Sportunterricht gestaltet werden könnte. Dabei wird eine alternative Überprüfungsform, eine „Lebensretterolympiade“, genutzt. Mit der Konzeption der Lebensretterolympiade sollen zwei Bereiche verbunden werden: Es sollen Handlungskompetenz und Sicherheit im Umgang mit Notfallsituationen und zudem mit Blick auf das Thema der eigenen Herz-Kreislauf-Gesundheit gefordert und gefördert werden. Spielerisch und dennoch in realitätsnahen Szenarien und Aufgaben überprüfen die Schüler*innen ihr Wissen und ihre Handlungsfähigkeit. Wie funktioniert und adaptiert sich das menschliche Herz-Kreislauf-System? Worauf kommt es bei der Wiederbelebung an und wie arbeite ich im Team? Wie erkenne ich akute Kreislaufstörungen und wie reagiere ich darauf? Diese im vorhergehenden Unterricht thematisierten Fragen greift die Olympiade beispielhaft auf und ist daher auch anschlussfähig an Inhalte und Kompetenzziele von Lehrplänen etwa in Sport und Biologie. Der Beitrag ordnet das Material in einen didaktisch-empirischen Kontext ein und präsentiert die Unterrichtsmaterialien zusammen mit Hinweisen für die Nutzung durch Lehrkräfte

Motivations and Needs of Older People for Work and Active Lifestyle

The article presents the results of a poll of older people on the example of a particular region (The Tomsk Region) to identify the need for an active lifestyle and penchant for productive work. The system ofhypotheses under article issues is tested. The aim of the work is to analyze problems of older people which affect their labor activity.The empirical base for the study was the results of the survey (sample frame 400 pers.). The respondents were older people living in urban and rural areas of the Tomsk Region. To test the generated hypothesesstatistical methods (analysis of variance, correlation analysis, etc.) are used. There are three main problems the elderly related to their needs and inclinations to work. It was determined that the formationof a stable demand of older people in productive work and active lifestyle will help to solve a number of problems of socio-psychological and economic nature at the present stage of social development inRussia and abroad

Microstructure, mechanical, and thermogravimetric characterization of cellulosic by-products obtained from biomass seeds

The microstructural, thermal, and nanomechanical characterization of biomass by-products coming from the food industry were studied. Scanning electron microscopy showed a microstructure formed by polygonal grains. The thermal behavior of seeds, evaluated by thermogravimetric analysis, revealed three main components (hemicellulose, cellulose, and lignin). Walnut shell showed the highest thermal stability and also the highest amount of lignin. The nanomechanical aspects were evaluated by nanoindentation. Samples with higher amount of cellulose presented minor modulus values. In accordance with the thermal stability, the highest modulus and hardness were observed in walnut. These by-products could be useful as reinforcement materials for biodegradable plastic industry.This work has been supported by the Spanish Ministry of Science and Innovation (MAT2011-28468-C02-02) and the Autonomous Government of Valencia (Spain) through the research program Geronimo Forteza (62/2010, 9 de Junio DOCV no 6291). M.P. Arrieta is granted by Santiago Grisolia program (GRISOLIA/2011/007).Rayón Encinas, E.; Ferrándiz Bou, S.; Rico Beneito, MI.; López Martínez, J.; Arrieta, MP. (2015). Microstructure, mechanical, and thermogravimetric characterization of cellulosic by-products obtained from biomass seeds. International Journal of Food Properties. 18(6):1211-1222. https://doi.org/10.1080/10942912.2014.884578S1211122218

How to score alternatives when criteria are scored on an ordinal scale

International audienceWe address in this paper the problem of scoring alternatives when they are evaluated with respect to several criteria on a finite ordinal scale $E$. We show that in general, the ordinal scale $E$ has to be refined or shrunk in order to be able to represent the preference of the decision maker by an aggregation operator belonging to the family of mean operators. The paper recalls previous theoretical results of the author giving necessary and sufficient conditions for a representation of preferences, and then focusses on describing practical algorithms and examples

From 10 Kelvin to 10 TeraKelvin: Insights on the Interaction Between Cosmic Rays and Gas in Starbursts

Recent work has both illuminated and mystified our attempts to understand cosmic rays (CRs) in starburst galaxies. I discuss my new research exploring how CRs interact with the ISM in starbursts. Molecular clouds provide targets for CR protons to produce pionic gamma rays and ionization, but those same losses may shield the cloud interiors. In the densest molecular clouds, gamma rays and Al-26 decay can provide ionization, at rates up to those in Milky Way molecular clouds. I then consider the free-free absorption of low frequency radio emission from starbursts, which I argue arises from many small, discrete H II regions rather than from a "uniform slab" of ionized gas, whereas synchrotron emission arises outside them. Finally, noting that the hot superwind gas phase fills most of the volume of starbursts, I suggest that it has turbulent-driven magnetic fields powered by supernovae, and that this phase is where most synchrotron emission arises. I show how such a scenario could explain the far-infrared radio correlation, in context of my previous work. A big issue is that radio and gamma-ray observations imply CRs also must interact with dense gas. Understanding how this happens requires a more advanced understanding of turbulence and CR propagation.Comment: Conference proceedings for "Cosmic-ray induced phenomenology in star-forming environments: Proceedings of the 2nd Session of the Sant Cugat Forum of Astrophysics" (April 16-19, 2012). 16 pages, 5 figure

Ears of the Armadillo: Global Health Research and Neglected Diseases in Texas

Neglected tropical diseases (NTDs) have\ud been recently identified as significant public\ud health problems in Texas and elsewhere in\ud the American South. A one-day forum on the\ud landscape of research and development and\ud the hidden burden of NTDs in Texas\ud explored the next steps to coordinate advocacy,\ud public health, and research into a\ud cogent health policy framework for the\ud American NTDs. It also highlighted how\ud U.S.-funded global health research can serve\ud to combat these health disparities in the\ud United States, in addition to benefiting\ud communities abroad

Bone Density, Microstructure and Strength in Obese and Normal Weight Men and Women in Younger and Older Adulthood

Obesity is associated with greater areal BMD (aBMD) and is considered protective against hip and vertebral fracture. Despite this, there is a higher prevalence of lower leg and proximal humerus fracture in obesity. We aimed to determine if there are site‐specific differences in BMD, bone structure, or bone strength between obese and normal‐weight adults. We studied 100 individually‐matched pairs of normal (body mass index [BMI] 18.5 to 24.9 kg/m2) and obese (BMI >30 kg/m2) men and women, aged 25 to 40 years or 55 to 75 years. We assessed aBMD at the whole body (WB), hip (TH), and lumbar spine (LS) with dual‐energy X‐ray absorptiometry (DXA), LS trabecular volumetric BMD (Tb.vBMD) by quantitative computed tomography (QCT), and vBMD and microarchitecture and strength at the distal radius and tibia with high‐resolution peripheral QCT (HR‐pQCT) and micro–finite element analysis. Serum type 1 procollagen N‐terminal peptide (P1NP) and collagen type 1 C‐telopeptide (CTX) were measured by automated electrochemiluminescent immunoassay (ECLIA). Obese adults had greater WB, LS, and TH aBMD than normal adults. The effect of obesity on LS and WB aBMD was greater in older than younger adults (p < 0.01). Obese adults had greater vBMD than normal adults at the tibia (p < 0.001 both ages) and radius (p < 0.001 older group), thicker cortices, higher cortical BMD and tissue mineral density, lower cortical porosity, higher trabecular BMD, and higher trabecular number than normal adults. There was no difference in bone size between obese and normal adults. Obese adults had greater estimated failure load at the radius (p < 0.05) and tibia (p < 0.01). Differences in HR‐pQCT measurements between obese and normal adults were seen more consistently in the older than the younger group. Bone turnover markers were lower in obese than in normal adults. Greater BMD in obesity is not an artifact of DXA measurement. Obese adults have higher BMD, thicker and denser cortices, and higher trabecular number than normal adults. Greater differences between obese and normal adults in the older group suggest that obesity may protect against age‐related bone loss and may increase peak bone mass