Search results for "name"

Bone diagenesis in arid environments; An intra-skeletal approach

2014

Bone trace element content and isotopic composition are closely related to human nutrition. The investigation of archaeological bone geochemistry can help us to better understand the relationship between past populations and their environment alongside cultural practices as inferred from dietary reconstruction. However, dietary in- formation may be altered post-mortem by diagenetic processes in soil. In this study, bone mineralogy (Ca/P, sec- ondary minerals, organic matter content and bone apatite crystallinity), histology, element content (Mg, Na, F, Sr, Ba, Mn, Fe, La, Ce and U) and stable isotope composition (δ13Candδ18O carbonate) were investigated at the intra- individual scale in ord…

2020

Skeletal remains in archaeological strata are often assumed to be of similar ages. Here we show that combined Sr and O isotope analyses can serve as a powerful tool for assessing fish provenance and even for identifying fossil fish teeth in archaeological contexts. For this purpose, we established a reference Sr and O isotope dataset of extant fish teeth from major water bodies in the Southern Levant. Fossil shark teeth were identified within Iron Age cultural layers dating to 8–9th century BCE in the City of David, Jerusalem, although the reason for their presence remains unclear. Their enameloid 87Sr/86Sr and δ18OPO4 values [0.7075 ± 0.0001 (1 SD, n = 7) and 19.6 ± 0.9‰ (1 SD, n = 6), res…

Diversity of Fish Scales in Late Triassic deposits of Krasiejów (SW Poland)

2018

Abstract. Taxonomy of extinct fishes is mostly based on the shapes of their bodies, teeth and skeletons and sometimes the coverage of the body. Analysis of modern fishes shows that sometimes even single-scale morphology can also be used as a taxonomic tool. In spite of the fact that variation in scales character in one species can be broad, some specific features distinguish species of the same genus. Analysis of the fossilized scales of fishes found in the Late Triassic deposits of Krasiejow (SW Poland) shows that the microstructure of the external surface of scales can also be considered as a taxonomic tool in the fossil record. Description of the ornamentation pattern of several scales o…

Lonchidion derenzii, sp. nov., a new lonchidiid shark (Chondrichthyes, Hybodontiforms) from the Upper Triassic of Spain, with remarks on lonchidiid e…

2016

Lonchidiidae Herman, 1977, represents one of the most diverse and controversial families of Hybodontiformes, the sister group of Neoselachii (i.e., modern sharks, skates, and rays). It was initially erected as a monogeneric family including only Lonchidion Estes, 1964, a genus of small euryhaline hybodonts from the Mesozoic. Recently, Cappetta (2012) recognized up to eight genera within the family: Baharyodon, Diplolonchidion, Vectiselachos, Hylaeobatis, Isanodus, Parvodus,Lissodus, andLonchidion, although the content of the family is still under discussion (see, e.g., Rees, 2008; Khamha et al., 2016). Major discrepancies concern the phylogenetic relationships between Lonchidion and Lissodu…

A Model for ERD2 Function in Higher Plants

2020

ER lumenal proteins have a K(H)DEL motif at their C-terminus. This is recognized by the ERD2 receptor (KDEL receptor in animals), which localizes to the Golgi apparatus and serves to capture escaped ER lumenal proteins. ERD2-ligand complexes are then transported back to the ER via COPI coated vesicles. The neutral pH of the ER causes the ligands to dissociate with the receptor being returned to the Golgi. According to this generally accepted scenario, ERD2 cycles between the ER and the Golgi, although it has been found to have a predominant Golgi localization. In this short article, we present a model for the functioning of ERD2 receptors in higher plants that explains why it is difficult t…

Loss of Arabidopsis p24 function affects ERD2 traffic and Golgi structure and activates the unfolded protein response

2017

The p24 family of proteins (also known as the TMED family) are key regulators of protein trafficking along the secretory pathway, but very little is known about their functions in plants. A quadruple loss-of-function mutant affecting the p24 genes from the δ-1 subclass of the p24δ subfamily (p24δ3δ4δ5δ6) showed alterations in the Golgi, suggesting that these p24 proteins play a role in the organization of the compartments of the early secretory pathway in Arabidopsis Loss of p24δ-1 proteins also induced the accumulation of the K/HDEL receptor ERD2a (ER lumen protein-retaining receptor A) at the Golgi and increased secretion of BiP family proteins, ER chaperones containing an HDEL signal, pr…

Standardised spider (Arachnida, Araneae) inventory of Lammi, Finland

2020

In June 2019, an ecology field course of the University of Helsinki was held at Lammi Biological Station, Southern Finland. Within this course, the students familiarised themselves with field work and identification of spiders and explored the diversity of species in the area. Three sampling plots were chosen, one in grassland and two in boreal forest, to demonstrate the sampling techniques and, by applying a standardised protocol (COBRA), contribute to a global spider biodiversity project. The collected samples contained a total of 3445 spiders, of which 1956 (57%) were adult. Only adult spiders were accounted for in the inventory due to the impossibility of identification of juveniles. A …

Adaptive Evolution and Epigenetics

2023

Epigenetic changes, such as DNA methylation and certain histone modifications, can be inherited but in many cases they do not follow Mendelian inheritance patterns and their stability appears to be lower than for changes in DNA sequence. Adaptive evolution by natural selection requires that differences among individuals are heritable to some degree. Epigenetic changes can be incorporated into evolutionary theory, and given that properties of epigenetic variation are distinct from genetic variation, spontaneous epigenetic changes can affect evolutionary dynamics in interesting ways. In this chapter, I review the properties of epigenetic variation and how they relate to the main parameters of…

Simultaneous speciation in the European high mountain flowering plant genus Facchinia (Minuartia s.l., Caryophyllaceae) revealed by genotyping-by-seq…

2017

Understanding the relative importance of different mechanisms of speciation in a given lineage requires fully resolved interspecific relationships. Using Facchinia, a genus of seven species centred in the European Alps, we explore whether the polytomy found by Sanger sequencing analyses of standard nuclear (ITS) and plastid markers (trnQ-rps16) is a hard or soft polytomy by substantially increasing the amount of DNA sequence data, generated by genotyping-by-sequencing. In comparison to 142 phylogenetically informative sites in the Sanger sequences the GBS sequences yielded 3363 phylogenetically informative sites after exclusion of apparently oversaturated SNPs. Maximum parsimony, maximum li…

Loss of

2020

The early secretory pathway involves bidirectional transport between the endoplasmic reticulum (ER) and the Golgi apparatus and is mediated by coat protein complex I (COPI)-coated and coat protein complex II (COPII)-coated vesicles. COPII vesicles are involved in ER to Golgi transport meanwhile COPI vesicles mediate intra-Golgi transport and retrograde transport from the Golgi apparatus to the ER. The key component of COPI vesicles is the coatomer complex, that is composed of seven subunits (α/β/β'/γ/δ/ε/ζ). In Arabidopsis two genes coding for the β-COP subunit have been identified, which are the result of recent tandem duplication. Here we have used a loss-of-function approach to study the…