Tangling with spaghetti : pedagogical lessons from games

International audienceGovernments are seeking to develop entrepreneurial competencies among today’s technology, science, and engineering graduates. However, the creation of “bilingual” graduates who have dual technical and managerial competencies is thwarted by students’ inferior teamwork and interpersonal skills. In education, what is taught is inextricably bound to how it is taught (Dewey, 1916). Current pedagogies in engineering education are insufficiently adapted to student learning style needs (Felder & Silverman, 1988), and the management component of engineering education remains underdeveloped. This problem is keenly felt in one French engineering school where students struggle with a team-based innovation project. We detail efforts made to equip students with teamwork skills by using games as a pedagogical device. Student teams compete to build weight resistant structures using only spaghetti sticks and sewing thread. Their written feedback forms the primary qualitative data for this study. Individual student interviews were subsequently carried out to further uncover potential learning outcomes. We found that students’ responses to the spaghetti game were overwhelmingly positive. Their commentary also illustrates concrete learning of many crucial teamwork processes. Finally, we discuss what makes this pedagogical innovation work and how it should be further studied.<br/

Ionogel-biosensor: novel ionogels based on ionic liquids as a platform to measure enzyme activity of glucose oxdase in real time

It is estimated that there are 170 million diabetics worldwide, and the number continues to rise alarmingly. The management of diabetes is therefore critical to future society, and this is driving demand for point-of-care (POC) glucose biosensors, and they play a central role in the management blood sugar levels in patients with diabetes. Glucose Oxidase (GOx) is a biorecognition enzyme, which recognises the glucose molecule and acts as a catalyst to produce gluconic acid and hydrogen peroxide in the presence of glucose and oxygen.[1] Ionic Liquids are organic salts, which are liquid at ambient temperature. Their non-volatile character and thermal stability makes them an attractive alternative to conventional organic solvents. We are interested in studying the characteristics of GOx in ionic liquids, and in polymer materials incorporating ionic liquids known as ionogels. Herein we report the enzyme activity of GOx in a biosensor fabricated using a novel hybrid ionogel. This approach potentially offers several advantages over conventional materials. For example, the ionogels can be chemically and physically tailored for a particular requirement. [3] The design of these ionogels ensures that the enzyme is effectively retained in the polymer, thus preventing leaching. The ionogel-biosensor has been incorporated into a compact, portable and low cost device, which allows the real time monitoring of enzyme activity of GOx. Based on this model, we project that this device will provide the platform for measuring the enzyme activity of a wide range of enzymes

A comparison of catabolic pathways induced in primary macrophages by pristine single walled carbon nanotubes and pristine graphene

Understanding the correlation between the physico-chemical properties of carbonaceous nanomaterials and how these properties impact on cells and subcelluar mechanisms is critical to their risk assessment and safe translation into newly engineered devices. Here the toxicity, uptake and catabolic response of primary human macrophages to pristine graphene (PG) and pristine single walled carbon nanotubes (pSWCNT) are explored, compared and contrasted. The nanomaterial toxicity was assessed using three complementary techniques (live-dead assay, real time impedance technique and confocal microscopic analysis), all of which indicated no signs of acute cytotoxicity in response to PG or pSWCNT. Transmission electron microscopy (TEM) demonstrated that PG was phagocytosed by the cells into single membrane lysosomal vesicles, whereas the primary macrophages exposed to pSWCNT contained many double membrane vesicles indicative of an autophagic response. These distinct catabolic pathways were further verified by biochemical and microscopic techniques. Raman spectroscopic mapping was used to explore the nanomaterial uptake and distribution. Based on the G-band, significant uptake and accumulation of the PG in discrete vesicles was recorded, whereas the pSWCNT were not taken up to the same extent. Thermogravimetric analysis (TGA) of the cells treated with PG revealed that ~ 20-30% of the remaining dry mass was made up of PG. No detectable amount of pSWCNT was recorded using TGA. TEM analysis confirmed that PG was still graphitic even after 24 hours of accumulation in the lysosomal compartments. In conclusion, these two nanomaterials with similar surface chemistries but unique geometries differ significantly in their uptake mechanisms and subsequently induced lysosomal and autophagic catabolic pathways in human primary macrophages

Real-time sweat pH monitoring based on a wearable chemical barcode micro-fluidic platform incorporating ionic liquids

This work presents the fabrication, characterisation and the performance of a wearable, robust, flexible and disposable chemical barcode device based on a micro-fluidic platform that incorporates ionic liquid polymer gels (ionogels). The device has been applied to the monitoring of the pH of sweat in real time during an exercise period. The device is an ideal wearable sensor for measuring the pH of sweat since it does not contents any electronic part for fluidic handle or pH detection and because it can be directly incorporated into clothing, head- or wristbands, which are in continuous contact with the skin. In addition, due to the micro-fluidic structure, fresh sweat is continuously passing through the sensing area providing the capability to perform continuous real time analysis. The approach presented here ensures immediate feedback regarding sweat composition. Sweat analysis is attractive for monitoring purposes as it can provide physiological information directly relevant to the health and performance of the wearer without the need for an invasive sampling approac

Industrial grade 2D Molybdenum Disulphide (MoS2): An in-vitro exploration of the impact on cellular uptake, cytotoxicity, and inflammation

The recent surge in graphene research, since its liquid phase monolayer isolation and characterization in 2004, has led to advancements which are accelerating the exploration of alternative 2D materials such as molybdenum disulphide (MoS2), whose unique physico-chemical properties can be exploited in applications ranging from cutting edge electronic devices to nanomedicine. However, to assess any potential impact on human health and the environment, the need to understand the bio-interaction of MoS2 at a cellular and sub-cellular level is critical. Notably, it is important to assess such potential impacts of materials which are produced by large scale production techniques, rather than research grade materials. The aim of this study was to explore cytotoxicity, cellular uptake and inflammatory responses in established cell-lines that mimic different potential exposure routes (inhalation, A549; ingestion, AGS; monocyte, THP-1) following incubation with MoS2 flakes of varying sizes (50 nm, 117 nm and 177 nm), produced by liquid phase exfoliation. Using high content screening (HCS) and live/dead assays, it was established that 1 μg/ml (for the three different MoS2 sizes) did not induce toxic effects on any of the cell-lines. Confocal microscopy images revealed a normal cellular morphology in all cases. Transmission electron microscopy (TEM) confirmed the uptake of all MoS2 nanomaterials in all the cell-lines, the MoS2 ultimately locating in single membrane vesicles. At such sub-lethal doses, inflammatory responses are observed, however, associated, at least partially, with the presence of lipopolysaccharide endotoxin in nanomaterial suspensions and surfactant samples. Therefore, the inflammatory response of the cells to the MoS2 or endotoxin contamination was interrogated using a 10-plex ELISA which illustrates cytokine production. The experiments carried out using wild-type and endotoxin hyporesponsive bone marrow derived dendritic cells confirmed that the inflammatory responses result from a combination of endotoxin contamination, the MoS2 nanomaterials themselves, and the stabilizing surfactant

Label-free Screening of Biochemical Changes in Macrophage-like Cells Following MoS2 Exposure Using Raman Micro-spectroscopy

The emergence of large scale production techniques for 2D particulate materials has dramatically increased their applications potential. Understanding the interactions of biological cells with such particulate material is therefore of paramount importance, both for toxicological assessment and potential biomedical applications. Conventional in-vitro cytological assays commonly record only a single colorimetric end-point, and do not provide an in-depth analysis of how such materials are uptaken and processed within cells. To demonstrate its potential as an alternative, label free approach, confocal Raman micro-spectroscopy has been used to profile the cellular response of macrophage-like immune cells as a result of exposure to a sub-lethal dose of particulate MoS2, as an example novel 2D material. Particles were seen to be uptaken and trafficked in sub-cellular vesicles, and this sensitive technique allows differences in the biochemical composition of the vesicles to be assessed and monitored as a function of time. Untreated macrophage-like cells contain lipidic vesicles which are found to be relatively rich in the membrane lipid sphingomyelin, key to the process of cell membrane regeneration. After exposure to MoS2, the particulate material is seen to be invaginated in similar vesicles, the most prominent of which now, however, have spectroscopic signatures which are dominated by those of phosphatidyl family lipids, consistent with the phagocytotic pathway. The lipidic content of cells is seen to increase at all time-points (4, 24 and 72 h). although vesicles composed of sphingomyelin become more prominent again following a prolonged incubation of 72 h to a sub-lethal dose of MoS2, as the immune cell has processed the particulate material and initiates recovery to a normal/untreated state. This study reveals Raman micro-spectroscopy is an effective method for monitoring cellular responses and evolution of organelle compositions in response to MoS2 exposure. The additional benefit of using this technique is that cells can be monitored as a function of time, while it can also be used for screening other micro/nano materials for toxicology and/or establishing cell responses

In-vitro Localisation and Degradation of Few-layer MoS2 Submicrometric Plates in Human Macrophage-like Cells: a Label Free Raman Micro-spectroscopic Study

Monitoring the uptake, micro-environment and fate of micro or nano scaled particulate materials in cells is of paramount importance for the emerging fields of toxicology and medicine. Such particulate materials are known to interfere with colorimetric assays and many such assays record only a single end-point. Therefore, there is a need for a label-free, cost effective technique with little or no inference from the particulate materials. Raman micro-spectroscopy was used to simultaneously interrogate the integrity of few-layer MoS2 submicrometric plates in human macrophage-like cells, in-vitro, as well as the biochemical characteristics of the local micro-environment in which they are encompassed. Firstly, the degradation profile of MoS2 plates induced by hydrogen peroxidase was established using UV-Vis absorption and Raman micro-spectroscopy. Raman micro-spectroscopic maps interrogated all aspects of the cell, including the nucleus, cytoplasm and perinuclear region, and the location/distribution of MoS2 was monitored as a function of time (4, 24 and 72 h). Whereas only pristine MoS2 was detectable after 4 and 72 periods, degradation in-vitro was confirmed following a 24 h incubation. Analysis of the MoS2 micro-environments revealed the presence of both phosphatidyl lipidic vesicles and enzymatic regions containing lysozyme, the former being most associated with the MoS2 degradation. There was an increase and saturation of cytosolic neutral lipids detected following a 24 h incubation with MoS2, which reduces following a prolonged incubation of 72 h. This study reveals that macrophage-like cells perform degradation of the material in-vitro within lipidic vesicles subsequent to phagocytosis, which manifest as an increase in the production of lipid bodies as a mechanism of defense following exposure to industrial grade MoS2

The effect of hypoglycaemia during hospital admission on health-related outcomes for people with diabetes: a systematic review and meta-analysis

Aims: To assess the health-related outcomes of hypoglycaemia for people with diabetes admitted to hospital; specifically, hospital length of stay and mortality.Methods: We conducted a systematic review and meta-analysis of studies relating to inpatient hypoglycaemia (<4 mmol/L) for hospitalised adults (≥16 years) with diabetes reporting the primary outcomes of interest, hospital length of stay or mortality. Final papers for inclusion were reviewed in duplicate and the adjusted results of each were pooled, using a random effects model then undergoing further prespecified subgroup analysis.Results: 15 studies were included in the meta-analysis. The pooled mean difference in length of stay for ward-based inpatients exposed to hypoglycaemia was 4.1 days longer (95% confidence interval [CI], 2.36-5.79; IÇ = 99%) compared to inpatients without hypoglycaemia. This association remained robust across the pre-specified subgroup analyses. The pooled relative risk (RR) of in-hospital mortality was greater for inpatients exposed to hypoglycaemia 2.09 (95% CI, 1.64 to 2.67; IÇ = 94%, n=7 studies) but not in intensive care unit mortality RR 0.75 (0.49 to 1.16; IÇ =0%, n=2 studies).Conclusion: There is an association between inpatient hypoglycaemia and longer length of stay and greater in-hospital mortality. Studies examining this association were heterogenous in terms of both clinical populations and effect size, but the overall direction of the association was consistent. Therefore, glucose concentration should be considered a potential tool to aid the identification of patients at risk of poor health-related outcomes

Simple barcode system based on ionogels for real time pH-sweat monitoring

This paper presents the fabrication, characterization and the performance of a wearable, robust, flexible and disposable barcode system based on novel ionic liquid polymer gels (ionogels) for monitoring in real time mode the pH of the sweat generated during an exercise period. Up to now sweat analysis has been carried out using awkward methods of collecting sweat followed by laboratory analysis. The approach presented here can provide immediate feedback regarding sweat composition. The great advantage of sweat analysis is the fact that it is a completely non-invasive means of analyzing the wearer's physiological state and ensuring their health and well-being