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- Nannochloropsis lipids and polyunsaturated fatty acids: potential applications and strain improvementPublication . Navalho, Sofia; Narcis Ferrer-Ledo; Maria J. Barbosa; Varela, JoãoThe genus Nannochloropsis comprises a group of oleaginous microalgae that accumulate polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA). These molecules are essential for the correct development and health of humans and animals. Thanks to their attractive lipid profile, Nannochloropsis is mainly marketed as a feed ingredient in aquaculture. In microalgae of this genus, contents and cellular location of PUFAs are affected by the growth conditions and gene expression. Strain improvement through non-recombinant approaches can generate more productive strains and efficient bioprocesses for PUFA production. Nevertheless, the lack of specific markers, detection methods, and selective pressure for isolating such mutants remains a bottleneck in classical mutagenesis approaches or lipid quality assessment during cultivation. This review encompasses the importance of PUFAs and lipid classes from Nannochloropsis species and their potential applications. Additionally, a revision of the different ways to increase PUFA content in Nannochloropsis sp. by using classical mutagenesis and adaptive laboratory evolution is also presented, as well as various methods to label and quantify lipids and PUFAs from Nannochloropsis microalgae.
- What can lithics tell us about hominin technology's ‘primordial soup’? an origin of stone knapping via the emulation of mother naturePublication . Eren, Metin I.; Lycett, Stephen J.; Bebber, Michelle R.; Key, Alastair; Buchanan, Briggs; Finestone, Emma; Benson, Joseph; Gürbüz, Rebecca Biermann; Cebeiro, Adela; Garba, Roman; Grunow, Anne; Lovejoy, C. Owen; MacDonald, Danielle; Maletic, Erica; Miller, G. Logan; Ortiz, Joseph D.; Paige, Jonathan; Pargeter, Justin; Proffitt, Tomos; Raghanti, Mary Ann; Riley, Teal; Rose, Jeffrey Ian; Singer, David M.; Walker, Robert S.The use of stone hammers to produce sharp stone flakes—knapping—is thought to represent a significant stage in hominin technological evolution because it facilitated the exploitation of novel resources, including meat obtained from medium-to-large-sized vertebrates. The invention of knapping may have occurred via an additive (i.e., cumulative) process that combined several innovative stages. Here, we propose that one of these stages was the hominin use of ‘naturaliths,’ which we define as naturally produced sharp stone fragments that could be used as cutting tools. Based on a review of the literature and our own research, we first suggest that the ‘typical’ view, namely that sharp-edged stones are seldom produced by nonprimate processes, is likely incorrect. Instead, naturaliths can be, and are being, endlessly produced in a wide range of settings and thus may occur on the landscape in far greater numbers than archaeologists currently understand or acknowledge. We then explore the potential role this ‘naturalith prevalence’ may have played in the origin of hominin stone knapping. Our hypothesis suggests that the origin of knapping was not a ‘Eureka!’ moment whereby hominins first made a sharp flake by intention or by accident and then sought something to cut, but instead was an emulative process by hominins aiming to reproduce the sharp tools furnished by mother nature and already in demand. We conclude with a discussion of several corollaries our proposal prompts, and several avenues of future research that can support or question our proposal.