Innovative school-level quantitative chemistry experimental technique (III): A conductivity meter designed for micro-scale use in schools

The paper is a continuation of Part (II) of the article [1] published in AJCE Vol 10 No.2, July, 2020. It also advocates the use of “DMM display” technique in which a single piece of instrument, a digital multi-meter (DMM), is used as a terminal display for more than one type of experiment. Sensor circuit design aims at providing a “unit-free” display situation in which students feel less threatening, i.e. a “user-friendly” situation for school-level experimentation. The designed electronic sensor, coupled with an innovative miniature conductivity probe, a combo-well plate and a commercial DMM, is able to numerically display electrical conductivity of aqueous solutions ranging from non-conductive like deionized water as 0 to highly conductive such as 1M H2SO4 as 81, with a complete conductance calibrated at 100. The design allows digital display of conductivity measurement of aqueous solutions without the conventional reading unit of “μS/cm”

Innovative school-level quantitative chemistry experimental technique (i): pH measurement by antimony electrode

This paper introduces the principles of pH measurement by antimony/copper(II) combination electrodes, use of an innovative mini “salt-plug” and details for the construction of the electrodes and an electronic sensor. Raw e.m.f. signals generated by the combination electrode are amplified by the sensor which is pre-set to give an analogue output voltage of 10 mV per pH. The voltage displayed by a commercial low-cost digital multimeter (DMM) can be treated as the pH value. The “DMM display” technique works for measurements of conductance and colour intensity as well as pH, provided that suitable sensors are used

Innovative techniques in school level micro-scale chemistry experiments part (I) Collection of Distillate at the Source (CDS) technique [1]

Traditional distillation setup collects distillate at a certain distance from the boiling source. This results in loss of product and the situation  could be very serious if micro-scale method is employed. By using an innovative design, it is possible to collect nascent distillate immediately after vapor condensation at the boiling source. This is the rationale of designing the Collection of Distillate at the Source (“CDS”) technique. The design not only significantly improves product yield, because cooling water used for condensation can be  dispensed with or recycled. This offers a helpful means to enhance students’ “Green awareness”. Two designs using the “CDS” technique are introduced, namely (i) Micro-scale water-less reflux and distillation and (ii) Micro-scale recycled coolant and all-glass reflux and distillation. The first design can be totally homemade with local resources and by acquiring decent workshop skills, details of construction of its various components are provided

Effect of farnesol on Candida dubliniensis morphogenesis

Cell–cell signalling in Candida albicans is a known phenomenon and farnesol was identified as a quorum sensing molecule determining the yeast morphology. The aim of this work was to verify if farnesol had a similar effect on Candida dubliniensis, highlighting the effect of farnesol on Candida spp. morphogenesis. Methods and Results: Two different strains of C. dubliniensis and one of C. albicans were grown both in RPMI 1640 and in serum in the presence of absence of farnesol. At 150 μmol l -1 farnesol the growth rate of both Candida species was not affected. On the contrary, farnesol inhibited hyphae and pseudohyphae formation in C. dubliniensis. Conclusion: Farnesol seems to mediate cell morphology in both Candida species. Significance and Impact of the Study: The effect of farnesol on C. dubliniensis morphology was not reported previously.Fundação para a Ciência e a Tecnologia (FCT

Targeted nasal vaccination provides antibody-independent protection against Staphylococcus aureus.

Despite showing promise in preclinical models, anti-Staphylococcus aureus vaccines have failed in clinical trials. To date, approaches have focused on neutralizing/opsonizing antibodies; however, vaccines exclusively inducing cellular immunity have not been studied to formally test whether a cellular-only response can protect against infection. We demonstrate that nasal vaccination with targeted nanoparticles loaded with Staphylococcus aureus antigen protects against acute systemic S. aureus infection in the absence of any antigen-specific antibodies. These findings can help inform future developments in staphylococcal vaccine development and studies into the requirements for protective immunity against S. aureus

Editorial overview: Relational values: what are they, and what's the fuss about?

Relational values as preferences, principles and virtues about human-nature relationships have attracted a great deal of attention in recent years. The term has been used to include concepts and knowledge from a wide range of social sciences and humanities, e.g., importantly making space for qualitative approaches often neglected within environmental management and science. Meanwhile, crucial questions have emerged. What counts as a relational value, and what does not? How do relational values (RVs) compare with other value categories and terms, including held, assigned, instrumental, moral, shared, social, and non-material values (e.g., associated with cultural ecosystem services)? In this article, we address these issues, partly by providing context about how the RV term originated and how it has evolved to date. Most importantly, because of their somewhat unique combination of groundedness and moral relevance, positive relational values may offer important opportunities for the evolution of values that may be necessary for transformative change towards sustainability. The special issue includes contributions that contemplate particular concepts (e.g., care, stewardship, eudaimonia human flourishing), applications (e.g., environmental assessment, environmental policy design), and the history of relevant scholarship in various intellectual traditions (e.g., ecological economics, human ecology, environmental education). Together with this suite of thought-provoking papers, we hope that the clarification we provide here facilitates a broad and productive interdisciplinary exchange to create and refine a reflective but powerful tool for sustainability and justice. © 2018We have been funded by a Canadian SSHRC Insight Grant (#435-2017-1071) and a UBC Killam Research Fellowship (KC)