Talks by SRUK/CERU members – session I

Marta Pina, London South Bank University

On the search for fossils: the first step to know how life was in the past

Palaeontologists can get to know how fast a dinosaur could run; how much energy australopiths spent during bipedal walking; what was the last meal of an antelope species living in Spain around 12 million years ago; how sabre-toothed cats hunted their preys; or how the human lineage spread into different parts of the world. However, little is known by non-palaeontologists about the very first step to carry on those studies: recovering the fossil remains that are the base of their work. Can you imagine unearthing a fossil after millions of years covered by sediment and being the first person in seeing it after that amount of time? Palaeontologists spend weeks in the field every year to know how life was in the past. Pop culture has helped to create an image of what a palaeontologist does in the field, making science (from the field to the complex hypotheses and results) more accessible to the public. Nevertheless, movies like Jurassic Park or Indiana Jones have favoured confusing ideas about the palaeontologists’ figure and their work in the field. Far from the ideal belief of several people using a small brush while unearthing a whole and perfectly preserved dinosaur skeleton, palaeontological fieldwork is far from being alike that in the movies. Actually, taking the fossils out of the sediment is usually complex and requires varied techniques depending on their size, preservation, and the surrounding sediment. After that, fossils are prepared in specialised facilities before being studied by palaeontologists, who use a variety of methodologies and software to address different questions about the organisms that once inhabited the Earth.

Laura Guillardín, University of Oxford

From forest inventory to genotyping: How to increase forest diversity while timbering?

Thuja plicata (Western-redcedar), Tsuga heterophylla (Western hemlock) and Pseudotsuga menziesii (Douglas-fir) have been widely used in the UK for timber production. Some of these even-aged plantations are now being transformed into more diverse woodlands, which will rely on natural regeneration by establishing a Continuous Cover Forestry (CCF) approach as a way of management. However, as the primary canopy that was planted may not have high levels of genetic diversity, it can result in a poor gene pool being transmitted to the offspring. Thus, the ability of these forests to face ongoing environmental shifts, disease threats, and other stressors, because of anthropogenic climate change, may be compromised. We will estimate the gene pool transferred from the canopy trees toward naturally regenerated individuals by studying their genetic diversity levels to investigate this matter. To estimate how diverse these plantations are, we will perform a forestry inventory and will genotype several individuals by using molecular markers in each of the sites. We will use available Single Nucleotide Polymorphisms (SNPs) described previously in the literature for Douglas-fir and will develop an SNP discovery pre-step for Western-redcedar. Four sites were selected where leaves were collected and the DNA was extracted from adults and juveniles. Genotyping-by-Sequencing (GBS) has been applied in 80 redcedars chosen from the different sites resulting in a molecular marker discovery, which allowed us to describe several SNPs. Douglas-fir and Western-redcedar SNP databases were then filtered, and 96 SNPs were selected, respectively, for further genotyping analysis. An SNP genotyping approach was performed in a high-throughput microfluidic PCR system. The genotypic comparison between generations will shed light upon the vulnerability of such populations leading to the recommendation of comprehensive and effective genetic conservation strategies when needed.

Cristina Barrero Sicilia, University of Hertfordshire

“Lentejas y callos”: building up a duckweed

Duckweed (Lemnaceae), more commonly known as water lentils in Spain, is a promising alternative as a novel protein source for feed and food. In optimum conditions, this tiny aquatic plant can yield 30 ton/ha/yr with up to 45% of protein content. Furthermore, duckweeds can be used as biorefineries engineered to produce valuable chemicals in high-yield close bioreactors or consistent large-scale ponds.

Five years ago, just appointed as an early career lecturer in the UH, I unexpectedly started an amazing scientific journey to exploit the biotech potential of duckweeds. I had the contact of a start-up company called DryGro with a business plan to produce duckweeds for animal feed in Kenia. For maximising the genetic potential of duckweeds to convert nitrogen into proteins, we started a collaboration including a PhD student. The team was soon joined by researchers at Rothamsted Research and then we started to jointly receive Spanish undergraduate students funded by SRUK/CERU. We started a field sampling of UK ponds to build up a Lemna collection at the University of Hertfordshire. We developed a novel FT-MIR method to inexpensively measure total protein in our duckweeds. We started paving the way for a genetic transformation and CRISPR genome editing platform for duckweeds with experiments of in-vitro callus induction and Lemna regeneration that have already shown very promising results.

And of course, we had our own eureka moments! We were wondering how to maintain our ever-growing duckweed collection in the UH. Unfortunately, duckweeds won’t easily produce seeds. Maintaining alive cultures of each clone in the collection is unmanageable. Cryopreservation protocols are expensive and still in their infancy. Just by chance we discovered a method for the resuscitation of frozen duckweed individuals… Want to know how? Come and see my talk at the symposium!

Iago Grobas, University of Oxford

Bacteria form liquid crystals under extreme confinement

In nature, bacteria are not necessarily free in their environment but rather they navigate through complex topologies such as porous materials, rough surfaces or wounds.  In this study, we use a mutant of Bacillus subtilis that lack flagella as a model organism to study bacteria assembly and liquid crystal formation in extreme confinement. The confinement is micropatterned using an adaptation of a soft lithography-based method. The desired patterns are situated at the bottom of a deep well (2 cm in height) which acts as a reservoir for a solution containing the immotile bacteria. These bacteria precipitate over time, forming a dense liquid crystalline layer at the bottom of the well. The confinement of bacteria leads to the formation of complex nematic phases whose topological defects are pattern-dependent and can be resolved at single cell resolution using laser scanning confocal microscopy. This characterization allows the comparison with more simple systems of hard rod-shaped colloidal particles and of soft fd rod-shaped viruses which, unlike bacteria, do not undergo cell replication. This additional factor may lead to different states that would not be possible when particles are just precipitating. We discovered that under confinement in a thin annulus structure, the bacteria nematic phase can transit into a quasi-smquasi/sectic phase, an unexpected transition due to the bacteria low and polydisperse aspect ratio.

Francisco Romera, Falmouth University & Eugenie le Bigot (University of Caen, France)

Understanding sustainable tourism. Insights from Spain

This contribution examines the perceptions and level of awareness of Generation Z, also known as Gen Z, ‘post-millennials’, or ‘Centennials’, among others. The results obtained are compared with their previous cohort, Generation Y, also known as Millennials. The role this generation has to play in the future of tourism and sustainable development has been the subject of recent interest among academics and practitioners. However, there is a need for studies that investigate how the personal factors, or the human side influence their relation to sustainable practices in the field of tourism. To provide an answer to this question, this research work is based on a quantitative approach. A sample of 266 Spanish individuals was collected. The data were collected between February and March 2022. The results show that Millennials and Generation Z are aware of the role they have to play when it comes to responsible tourism. Thus, there are certain differences between Generation Z and its predecessor. Generation Z also shows a greater commitment towards responsible practices. As a matter of fact, it is observed that individual profiles have an impact on this relationship. At the same time, although this generation has made progress towards sustainable development, there are still challenges to be faced to achieve responsible and sustainable tourism practices.

Iago Díez, University of Exeter

Tailoring the radiation of nanolasers

Lasers based on whispering-gallery modes have proved to be excellent systems for biosensing and optical communications. Due to their circular geometry, their radiation is emitted in-plane and isotropically, and that is why they require external elements like integrated mirrors or grating couplers to extract the light out of the chip for analysis. Here we present whispering-gallery nanodisc lasers that were inverse-designed to directly emit out-of-plane along their axial direction and whose laser beam shape and polarisation can be selected by the cavity geometry. We experimentally demonstrate the validity of the inverse design method by designing three cavities emitting into different radiation modes. Their emission was analysed by photoluminescence confocal spectroscopy, Fourier microscopy and k-space polarimetry.

Violeta Menéndez González, University of Surrey

Computer vision: can machines see behind objects?

Computer vision studies how machines can interpret and generate images. In this work we explore the capability of machines to see behind objects. We train a Machine Learning model to reconstruct missing image areas in stereoscopic images caused by object disocclusions. This can be useful in media production, virtual reality, 3D animation of still images, and the removal of unwanted objects in pictures.