It is three days to Christmas Day and I am in digital detox [see ‘Digital detox with a deep vacation’ on August 10th, 2016] after a long term. So, only a picture this week of ice on Lake Michigan near Traverse City in December 2004. Happy Holidays to all of my readers!
![figure 1 from [1] with text explanation](https://realizeengineering.blog/wp-content/uploads/2021/12/giorgi-et-al-rsos-8-210068.jpg)
While many of us are being jabbed in the arm to deliver an agent that stimulates our immune system to recognize the coronavirus SARS-CoV-2 as a threat and destroy it, my research group has been working, in collaboration with colleagues at the European Commission Joint Research Centre, on the dynamics of nanoparticles [1] [see ‘Size matters‘ on October 23rd, 2019] which could be used as carriers for the targeted delivery of therapeutic, diagnostic and imaging agents in the human body [2]. The use of nanoparticles to mechanically stimulate stem cells to activate signalling pathways and modulate their differentiation also has some potential [3]. In studies of the efficacy of nanoparticles in these biomedical applications, the concentration of nanoparticles interacting with the cell is a primary factor influencing both the positive and negative effects. Such studies often involve exposing a monolayer of cultured cells adhered to the bottom of container to a dose of nanoparticles and monitoring the response over a period of time. Often, the nominal concentration of the nanoparticles in biological medium supporting the cells is reported and used as the basis for determining the dose-response relationships. However, we have shown that this approach is inaccurate and leads to misleading results because the nanoparticles in solution are subject to sedimentation due to gravity, Brownian motion [see ‘Slow moving nanoparticles‘ on December 13th, 2017] and inter-particle forces [see ‘ Going against the flow‘ on February 3rd, 2021] which affect their transport within the medium [see graphic] and the resultant concentration adjacent to the monolayer of cells. Our experimental results using the optical method of caustics [see ‘Holes in fluids‘ on October 22nd, 2014] have shown that nanoparticle size, colloidal stability and solution temperature influence the distribution of nanoparticles in solution. For particles larger than 60 nm in diameter (about one thousandth of the diameter of a human hair) the nominal dose differs significantly from the dose experienced by the cells. We have developed and tested a theoretical model that accurately describes the settling dynamics and concentration profile of nanoparticles in solution which can be used to design in vitro experiments and compute dose-response relationships.
References
[1] Giorgi F, Macko P, Curran JM, Whelan M, Worth A & Patterson EA. 2021 Settling dynamics of nanoparticles in simple and biological media. Royal Society Open Science, 8:210068.
[2] Daraee H, Eatemadi A, Abbasi E, Aval SF, Kouhi M, & Akbarzadeh A. 2016 Application of gold nanoparticles in biomedical and drug delivery. Artif. Cells Nanomed. Biotechnol. 44, 410–422. (doi:10.3109/21691401.2014.955107)
[3] Wei M, Li S, & Le W. 2017 Nanomaterials modulate stem cell differentiation: biological
interaction and underlying mechanisms. J. Nanobiotechnol. 15, 75. (doi:10.1186/s12951-
017-0310-5)
Two weeks ago I used two infographics to illustrate the dominant role of energy use in generating greenhouse gas emissions and the disportionate production of greenhouse gas emission by the rich [see ‘Where we are and what we have‘ on November 24th, 2021]. Energy use is responsible for 73% of global greenhouse gas emissions and 16% of the world’s population are responsible for 38% of global CO2 emissions. Today’s infographics illustrate the energy flows from source to consumption for the USA (above), UK and Europe (thumbnails below). In the USA fossil fuels (coal, natural gas and petroleum) are the source of nearly 80% of their energy, in the UK it is a little more than 80% and the chart for Europe is less detailed but the proportion looks similar. COP 26 committed countries to ending ‘support for the international unabated fossil fuel energy sector by the end of 2022’ and recognised ‘investing in unabated fossil-related energy projects increasingly entails both social and economic risks, especially through the form of stranded assets, and has ensuing negative impacts on government revenue, local employment, taxpayers, utility ratepayers and public health.’ However, to reduce our dependency on fossil fuels we need a strategy, a plan of action for a fundamental change in how we power industry, heat our homes and propel our vehicles. A hydrogen economy requires the production of hydrogen without using fossil fuels, electric cars and electric domestic heating requires our electricity generating capacity to be at least trebled by 2050 in order to hit the net zero target. This scale and speed of transition to zero-carbon sources is such that it will have to be achieved using an integrated blend of green energy sources, including solar, wind and nuclear energy. For example, in the UK our current electricity generating capacity is about 76 GW and 1 GW is equivalent to 3.1 million photovoltaic (PV) panels, or 364 utility scale wind turbines [www.energy.gov/eere/articles/how-much-power-1-gigawatt] so trebling capacity from one of these sources alone would imply more than 700 million PV panels, or one wind turbine every square mile. It is easy to write policies but it is much harder to implement them and make things happen especially when transformational change is required. We cannot expect things to happen simply because our leaders have signed agreements and made statements. Now, national plans are required to ween us from our addiction to fossil fuels – it will be difficult but the alternative is that global warming might cause the planet to become uninhabitable for us. It is time to stop ‘making thermodynamic whoopee with fossil fuels’ to quote Kurt Vonnegut [see ‘And then we discovered thermodynamics‘ on February 3rd, 2016].
Sources:
Kurt Vonnegut, A Man without a Country, New York: Seven Stories Press, 2005. He wrote ‘we have now all but destroyed this once salubrious planet as a life-support system in fewer than two hundred years, mainly by making thermodynamic whoopee with fossil fuels’.
US Energy flow chart: https://flowcharts.llnl.gov/commodities/energy
EU Energy flow chart: https://ec.europa.eu/eurostat/web/energy/energy-flow-diagrams
UK Energy flow chart: https://www.gov.uk/government/collections/energy-flow-charts#2020
It is easy for ideas or plans for transformational change to transition into transactional processes that deliver only incremental change. Transformational change is about major shifts in culture, strategy or technology that causes substantial alterations in structure, organisation, behaviour and performance; whereas transactional changes occur within the existing structure and organisation. Leading transformational change is hard and requires courage, vision, a willingness to listen to all stakeholders, decisiveness and communication, i.e. procedural justice and fair processes [see ‘Advice to abbots and other leaders‘ on November 13th, 2019]. If any of these components are absent, especially courage, vision and decisiveness, then transformational change can transition to a transactional process with incremental outcomes. When the need to change becomes urgent due to existential threats, the focus should be on disruptive change [see ‘The disruptive benefit of innovation‘ on May 23rd 2018] but there is a tendency to avoid such transformations and retreat into transactional processes that provide the illusion of progress. Perhaps this is because transformational change requires leaders to be selfless, courageous and to do the right thing not just the easy thing [see ‘Inspirational leadership‘ on March 22nd, 2017]; whereas transactional processes occur within existing frameworks and hence minimise psychological entropy and stress [see ‘Psychological entropy increased by ineffectual leaders‘ on February 10th, 2021]. This tendency to avoid disruptive change happens at all levels in society from individual decisions about lifestyle, through product development in companies, to global conferences on climate change [see ‘Where we are and what we have‘ on November 24th, 2021].
Image: Ink drawing by Zahrah Resh, 2005. See ‘Seasons Greetings in 2020‘ on December 23rd, 2020.
Acknowledgement: thank you to a regular reader of this blog for the stimulating this post with a comment about transformational change left to the last minute becoming transactional.
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