Use of genetic data to assess the uncertainty in stock assessments due to the assumed stock structure: the case of albacore (Thunnus alalunga) from the Atlantic Ocean

Stock assessments can be problematic because of uncertainties associated with the data or because of simplified assumptions made when modeling biological processes (Rosenberg and Restrepo, 1995). For example, the common assumption in stock assessments that stocks are homogeneous and discrete (i.e., there is no migration between the stocks) is not necessarily true (Kell et al., 2004a, 2004b)

Phenotypic evolution in microalgae: a dramatic morphological shift in Dictyosphaerium chlorelloides (Chlorophyta) after exposure to TNT

Phenotypic evolution in microalgae: a dramatic morphological shift in Dictyosphaerium chlorelloides (Chlorophyta) after exposure to TNT. The occurrence of rapid morphological evolution in the microalga Dictyosphaerium chlorelloides (Chlorophyta) was induced after exposure of the wild strains of the alga to the potent algal poison 2,4,6-trinitrotoluene (TNT). After exposing a wildtype population (consisted of representative spherical-ellipsoidal cells) to doses of TNT that were lethal for most of the cells, a TNT-resistant spindle-shaped mutant was able to proliferate. This spindleshaped mutant appeared spontaneously by rare mutations before the selective treatment: in deed, it was already present in the wild population. The frequency of the mutants within the ancestral population seemed to be determined by the balance between the rate of accumulation by recurrent mutation and the rate of elimination by selection (ranging 10-102 spindle-shaped mutants per 106 cells). We hypothesize that clone selection could take place in asexual populations of microalgae by selection of rare, pre-selective genotypes, driven by a drastic selective pressure subsequent to a catastrophic environmental changeEvolucion fenotípica en microalgas: un cambio morfológico espectacular en Dictyosphaerium chlorelloides (Chlorophyta) tras la exposición a TNT. Un cambio morfológico muy rápido tiene lugar en Dictyosphaerium chlorelloides (Chlorophyta) tras la exposición de cepas salvajes al potente alguicida 2,4,6 trinitrotolueno (TNT). Las cepas salvajes, sensibles al TNT, tienen una morfología típica esférico-elipsoidal. Tras exponer dichas cepas a dosis letales de TNT, solamente sobreviven células resistentes al tóxico cuya silueta es fusiforme. Estos resistentes fusiformes aparecen como consecuencia de mutaciones espontáneas que tienen lugar antes de exponer las cepas salvajes al agente selectivo (TNT): es decir, las células fusiformes estaban presentes en la población salvaje. La frecuencia de mutantes fusiformes en las poblaciones salvajes está definida por el equilibrio entre la tasa de acumulación de mutantes y la tasa en que son eliminados por tener una eficiencia biológica menor (10-102 mutantes fusiformes por 106 células salvajes). Se propone que la selección de clones podría ser un mecanismo de evolución adaptativa en poblaciones de microalgas asexuales. Este evento opera mediante la selección de genotipos pre-selectivos que aparecen como consecuencia del incremento de la presión de selección como fruto de eventos catastróficos en el medio ambient

Fringes of the empire: diet and cultural change at the Roman to post-Roman transition in NW Iberia

A growing number of paleodiet investigations over recent years have begun to reveal the stark dietary differences that existed between regions of the Roman Empire, as well as significant changes in subsistence strategies after its fall. The present study explores the dietary changes at the Roman to post-Roman (Germanic) transition in the Northwest Iberian Peninsula, in order to improve our understanding of the changes that occurred at end of the Roman Empire in different regions across Europe and to also consider the influence of climate had on them. The carbon and nitrogen stable isotope investigation in bone collagen from A Lanzada, NW Spain (100–700 AD), which was an important commercial, coastal settlement has been presented. A human sample of 59 individuals, 6 of them subadults, is compared with 31 faunal specimens, which include a number of marine fish. Isotope data for the terrestrial fauna reveal the influence of the sea on the local isotope baseline. Analysis of the human samples indicates a mixed marine-terrestrial diet. A shift in mean human δ13C values from −16.7‰ to −14.3‰ provides clear evidence for a significant change in diet in the post-Roman period, probably through the intensification of both marine resources exploitation and C4-plant consumption (presumably millet). A deterioration of paleoenvironmental conditions, together with a poor socioeconomic situation and the arrival of new people, the Sueves, who brought a new political and socioeconomic system have been discussed as the main causes for the dietary modification in post-Roman times

Skeletal remains of human perinatal individuals from the fortified Iberian Period settlement of Ca n’Oliver ( 6th century to 50 years BCE)

Burial customs in the Iberian Period (Iron Age II) included cremation. Only perinatal and newborn infants were buried directly beneath floor settlement. These infants represent the very few unburned human remains recovered from Iberian sites. The interpretation of these infant burials is in debate, focusing on whether they are unnatural or natural deaths. Our aim is to infer mortality patterns and developmental conditions of these individuals, in order to respond if infanticide was present in these assemblages. A large perinatal human skeletal sample from the Ca n’Oliver site (sixth century to 50 years BCE) from the Iberian Period of the northeast of the Iberian Peninsula was analysed, combining osteological methods together with tooth histology and aDNA analysis. Combining osteological and odontological estimates indicated ages between 22 and 42 weeks of gestation for 47 out of a total of 48 individuals. The remaining individual died at about 6 months after birth. Tooth height and enamel histology indicated in 9 out of a subgroup of 13 individuals a low probability of live birth. The remaining 4 individuals possibly survived birth for less than 2 months. According to morphological and molecular results, the sex ratio of this sample is approximately 1:1 male to female. The mortality distribution is consistent with natural mortality. These perinatal deaths were probably spontaneous abortions and neonatal deaths, reflecting an endogenous mortality profile due to genetic and maternal influences. The present study will serve to broaden our knowledge on perinatal individuals of the Iberian Period.The City Council of Cerdanyola del Vallès, BarcelonaKnut and Alice Wallenberg Foundation (1000 Ancient Genomes Project Grant 2016)Swedish Research Council (2013-4959)Riksbankens Jubileumsfond (P16-0553:1)JIN-2019 Postdoctoral fellowship Spanish (PID2019-111683RJ-I00)Ministerio de Ciencia e InnovaciónGrupos de Referencia Competitiva (ED431C 2021/32) by Xunta de GaliciaSGR Evolució social, cultural i biològica al Pleistocè (StEP), Ref: 2021 SGR 0123

Intuition and experimentation as teaching tools: physical and interactive computational models

Structural design and analysis is generally not the favourite subject among architecture students, who find it hard to assimilate abstract structural concepts expressed in complex formulae, whose translation to specific structural phenomena and application are not clear to them. This paper presents a teaching innovation project that seeks to include intuition and experimentation in the learning of concepts related to the buildings’ structural behaviour. Direct experimentation allows a better understanding and assimilation of concepts and increases motivation. The idea is to “take the laboratory to the classroom” through physical models that the students can build and test. These models are specially designed for the visual, intuitive, and clear explanation of one or several structural concepts. The combination of these physical models with the development of interactive, computational structural models based on graphic statics allows the students to predict the behaviour of the proposed structure and immediately check the correction of their prediction with the physical model. The geometry-based approach to the teaching of the structures through graphic statics, together with the use of the parametric models and the experimentation with physical models result in an intuitive, interactive and easy-to-understand method for the teaching of structures. Furthermore, the experimental and visual character of these teaching activities makes them more appealing for architecture students and results in a higher motivation and participation in the classes, which, in turn, comes with higher academic performance and grades.Peer ReviewedPostprint (published version

Adaptation of cyanobacteria and microalgae to extreme environmental changes derived from anthropogenic pollution

Nowadays are living in a global extinction period consequence of human activities that are altering biosphere-level processes. Microalgal populations are being exposed to by-products of human activities for the first time and little is known about their mechanisms of adaptation. Cyanobacteria and microalgae could to adapt to novel environments through selection on spontaneous mutations or through individual responses (i.e. resistant organisms arising by mutations occurring randomly prior to selective agent exposure or by direct and specific adaptation in response to selective agent). We are working on mechanisms of adaptation of these organisms to catastrophic environmental changes coming from residual materials of water pollution. Fluctuation analysis is the procedure to study this adaptive process. Cyanobacteria and microalgal species exposed to several pollutants (herbicides, antibiotics, heavy metals, sulphureous waters and others) showed resistant variants arise from rare spontaneous pre-selective mutations occurring prior to pollutant exposition. Spontaneous mutations seem to be enough to assure the adaptation of large microalgal populations. However, resistant mutants show diminished growth and photosynthesis.Estamos en un periodo de extinción global consecuencia de las actividades humanas y que están alterando los procesos de la biosfera. Las poblaciones de microalgas estan siendo expuestas por primera vez a estos productos fruto de la actividad antropogénica y sus mecanismos de adaptación son muy poco conocidos. Las cianobacterias y microalgas pueden adaptarse a nuevas condiciones ambientales a través de mutaciones espontáneas o a través de respuestas individuales (p.e. los organismos resistentes se pueden producir por mutaciones que ocurren antes de la exposición al agente selectivo, o por una respuesta específica y directa al contaminante). Nosotros hemos trabajado en los mecanismos de adaptación de estos organismos al cambio ambiental brusco debido a contaminantes del agua. El análisis de fluctuación es el procedimiento adecuado para el estudio del proceso adaptativo. Las especies de cianobacterias y microalgas expuestas a distintos contaminantes (herbícidas, antibióticos, metales pesados, aguas sulfurosas y otros…) muestran variantes resistentes que se producen por raras mutaciones espontáneas que ocurren antes de la exposición al contaminante. Estos mutantes resistentes mostraron una disminución del crecimiento y de la fotosíntesis respecto a la población sensible. Las mutaciones espontáneas pueden ser suficientes para asegurar la adaptación en las enormes poblaciones de microalgas

Linking structural and compositional changes in archaeological human bone collagen: an FTIR-ATR approach

Collagen is the main structural and most abundant protein in the human body, and it is routinely extracted and analysed in scientific archaeology. Its degree of preservation is, therefore, crucial and several approaches are used to determine it. Spectroscopic techniques provide a cost-effective, non-destructive method to investigate the molecular structure, especially when combined with multivariate statistics (chemometric approach). In this study, we used FTIR-ATR spectroscopy to characterise collagen extracted from skeletons recovered from necropoleis in NW Spain spanning from the Bronze Age to eighteenth century AD. Principal components analysis was performed on a selection of bands and structural equation models (SEM) were developed to relate the collagen quality indicators to collagen structural change. Four principal components represented: (i) Cp1, transformations of the backbone protein with a residual increase in proteoglycans; (ii) Cp2, protein transformations not accompanied by changes in proteoglycans abundance; (iii) Cp3, variations in aliphatic side chains and (iv) Cp4, absorption of the OH of carbohydrates and amide. Highly explanatory SEM models were obtained for the traditional collagen quality indicators (collagen yield, C, N, C:N), but no relationship was found between quality and δ13C and δ15N ratios. The observed decrease in C and N content and increase in C:N ratios is controlled by the degradation of protein backbone components and the relative preservation of carbon-rich compounds, proteoglycans and, to a lesser extent, aliphatic moieties. Our results suggest that FTIR-ATR is an ideal technique for collagen characterization/pre-screening for palaeodiet, mobility and radiocarbon researchThis research was partially funded by the projects “Galician Paleodiet” (ED481D 2017/014), Consiliencia network (ED 431D2017/08), GPC (ED341B 2018/20) and “Antropoloxía dos restos óseos humanos de Galicia” (Dirección Xeral de Patrimonio Histórico), Xunta de Galicia. OLC is funded by Plan Galego I2C mod.B (ED481D 2017/014) and by Ministerio de Ciencia e Innovación (JIN project PID2019-111683RJ-100)S

Biological histories of an elite: Skeletons from the Royal Chapel of Lugo Cathedral (NW Spain)

Direccion Xeral de Patrimonio Historico de Galicia; Xunta de Galicia, Grant/Award Numbers: ED431B 2018/20, ED 431D2017/08, ED481D 2017/014; Spanish Ministerio de Ciencia e Innovacion and Beca Leonardo a Investigadores y Creadores Culturales 2020 de la Fundacion BBVA, Grant/Award Number: PID2019-111683RJ-I00This study aims to reconstruct the biological histories of the people buried at the Royal Chapel of Lugo Cathedral, an important religious center of NW Spain, by using anthropological, geochemical, and historical perspectives. We conducted a macroscopic and radiographic study on 955 skeletal elements, a multi-isotope (δ13Ccol, δ15N, δ34Scol, δ13Cap, δ18Oap) analysis of human (n = 12) and animal (n = 4) samples, and the study of 1407 documents from the cathedral archives. There was a minimum of 15 individuals, including six subadults (<7 years), seven mature males, and one possible female. Several traumatic healed injuries, a pelvis osteochondroma, and a case of DISH have been detected. Males were enriched in 15N (up to 15.7‰, Δhumananimal avg = 5.1‰) suggesting consumption of animal protein including freshwater fish. Cathedral documents reflect fora payments in the form of rye, eggs, poultry, sheep, pigs, and eels as well as the hiring of two physicians. All individuals, except one, lived between the 14th and the early 15th centuries and show characteristics of high standard of living. Males were likely members of the cathedral—chaplains, administrators, sacristans, but not bishops—or noblemen relatives of the former according to preserved documents. Isotopic and paleopathological study suggest that they had an active and traveling life and at least one of them had connections with Central Spain. Children were local and possibly connected to the nobility. Lugo Cathedral is a prime example about the possibilities of transdisciplinary research in the identification of lifestyle in past populations.Direccion Xeral de Patrimonio Historico de GaliciaXunta de Galicia European Commission ED431B 2018/20 ED 431D2017/08 ED481D 2017/014Spanish Ministerio de Ciencia e Innovacion and Beca Leonardo a Investigadores y Creadores Culturales 2020 de la Fundacion BBVA PID2019-111683RJ-I0

Eating in silence: Isotopic approaches to nuns’ diet at the convent of Santa Catalina de Siena (Belmonte, Spain) from the sixteenth to the twentieth century

Advances in geochemical and physical anthropological studies have provided new tools to reconstruct ancient lifestyles, especially of those minorities not commonly mentioned in historical texts. In comparison to males, little is known about everyday life in female monastic communities, and how it has changed over time. In this paper, we present a paleodietary (δ13C and δ15N in bone collagen) study of human (n = 58) and animal (n = 13) remains recovered from the former Convent of Santa Catalina de Siena in Belmonte (Cuenca, central Spain). Two funerary areas used by Dominican nuns were sampled: one dated to the sixteenth (n = 34) and the seventeenth (n = 15) centuries, and the other dated in the nineteenth and twentieth (n = 9) centuries. The isotopic values for sheep (n = 7) suggest the animals consumed at the convent came from diverse ecosystems or were raised under a range of management strategies. The human samples reflect a terrestrial diet, and those from the nineteenth to twentieth century, in some cases, reveal the presence of C4 plants (millet, corn or sugar cane). Due to their religious practice, the consumption of terrestrial animal protein was restricted, and although they were allowed to eat fish, the isotopic signatures show little evidence of this. The individuals from the sixteenth and seventeenth century show a continuous shift in δ15N (9.7–12.7‰), with few significant differences in relation to the period, age, or pathologies (osteoporosis, periostitis, and brucellosis). The nineteenth- to twentieth-century samples can be divided into two groups: (a) one that fits the trend of previous centuries, albeit with a higher δ15N, possibly related to extensive access to animal protein; and (b) a second group with elevated δ13C values (up to − 15.7‰). Different customs in the assumed homogeneous monastic life are discussed as possible sources of isotopic variation, including access to luxury products such as animal protein or sugar, or the practice of periods of food abstinence, which were especially popular with these communities, according to historical recordsThe isotopic study was carried out with funding from the CONSILIENCIA network (R2014/001; ED 431D2017/08) of the Consolidation and Structuring Programme of Research Units of the Xunta de Galicia, and a consolidating grant of the Xunta de Galicia for emerging research groups to the group CULXEO (GPC2015/024). OLC is funded by Plan Galego I2C mod.B (ED481D 2017/014)