197 research outputs found
Multi-taxa neo-taphonomic analysis of bone remains from barn owl pellets and cross-validation of observations: a case study from Dominica (Lesser Antilles)
Paleo- and neo-taphonomic analyses of bone assemblages rarely consider all the occurring taxa in a single study and works concerning birds of prey as accumulators of microvertebrate bone remains mostly focus on small mammals such as rodents and soricomorphs. However, raptors often hunt and consume a large range of taxa, including vertebrates such as small mammals, fishes, amphibians, squamates and birds. Bone remains of all these taxonomic groups are numerous in many paleontological and archaeological records, especially in cave deposits. To better characterize the predators at the origin of fossil and sub-fossil microvertebrate accumulations and the taphonomic history of the deposit, it is thus mandatory to conduct global and multi-taxa taphonomic approaches. The aim of this study is to provide an example of such a global approach through the investigation of a modern bone assemblage from a sample of pellets produced by the Lesser Antillean Barn Owl (Tyto insularis) in the island of Dominica. We propose a new methodology that allows us to compare different taxa (rodents, bats, squamates and birds) and to experiment with a cross-validation process using two observers for each taxonomic group to test the reliability of the taphonomic observations.1. Introduction 2. Materials and Methods 2.1. Owl Pellets Sampling 2.2. Prey Identification 2.3. Taphonomic Analysis 2.3.1. Anatomical Representation 2.3.2. Fragmentation 2.3.3. Surface Modifications 2.3.4. Size/Weight Classes of Preys 2.4. Cross-Validation of Observations 3. Results 3.1. Faunal Spectrum 3.2. Anatomical Representation 3.3. Fragmentation 3.4. Modifications of Bone Surface 4. Discussion 4.1. Diet of Tyto Insularis in Dominica 4.2. Taphonomic Impact of Tyto Insularis on Small Vertebrate Bone Assemblage 4.2.1. Remarks on the Size/Weight Classes of Preys 4.2.2. Anatomical Representation 4.2.3. Fragmentation 4.2.4. Digestion 4.3. Degree of Inter-Observer Differences and Potential Outcomes 4.4. Towards an “Inter-Taxa Calibration” 5. Conclusion
The use of paleoclimatic simulations to refine the environmental and chronological context of archaeological/paleontological sites
To reconstruct the paleoenvironmental and chronological context of archaeological/paleontological sites is a key step to understand the evolutionary history of past organisms. Commonly used method to infer paleoenvironments rely on varied proxies such as faunal assemblages and isotopes. However, those proxies often show some inconsistencies. Regarding estimated ages of stratigraphic layers, they can vary depending on the dating method used. In this paper, we tested the potential of paleoclimate simulations to address this issue and contribute to the description of the environmental and chronological context of archaeological/paleontological sites. We produced a set of paleoclimate simulations corresponding to the stratigraphy of a Late-Pleistocene Holocene site, El Harhoura 2 (Morocco), and compared the climatic sequence described by these simulations to environmental inferences made from isotopes and faunal assemblages. Our results showed that in the studied site combined US-ESR ages were much more congruent with paleoenvironmental inferences than OSL ages. In addition, climatic variations were found to be more consistent with isotopic studies than faunal assemblages, allowing us to discuss unresolved discrepancies to date. This study illustrates the strong potential of our approach to refine the paleoenvironmental and chronological context of archaeological and paleontological sites.1 Introduction 2 Material and methods 2.1 El Harhoura 2 cave 2.2 Paleoclimate simulations 2.2.1 Pre-existing ensemble of simulations 2.2.2 Model 2.2.3 Sea-surface boundary conditions 2.3 Climate variations through EH2 sequence 3 Results 3.1 Paleoclimate simulations 3.2 Climate variations through EH2 sequence 4 Discussion 5 Conclusio
The use of paleoclimate simulations to refine the environmental and chronological context of archaeological/paleontological sites
This study illustrates the strong potential of combining paleoenvironmental reconstructions and paleoclimate modeling to refine the paleoenvironmental and chronological context of archaeologicaland paleontological sites. We focus on the El Harhoura 2 cave (EH2), an archeological site located on the North-Atlantic coast of Morocco that covers a period from the Late Pleistocene to the mid-Holocene. On several stratigraphic layers, inconsistencies are observed between species- and isotope-based inferences used to reconstruct paleoenvironmental conditions. The stratigraphy of EH2 also shows chronological inconsistencies on older layers between age estimated by Optical Stimulated Luminescence (OSL) and Combination of Uranium Series and Electron Spin Resonance methods (combined US-ESR). We performed paleoclimate simulations to infer the global paleoclimate variations over the EH2 sequence in the area, and we conducted a consistency approach between paleoclimatereconstruction estimated from simulations and available from EH2 paleoenvironmental inferences. Our main conclusion show that the climate sequence based on combined US-ESR ages is more consistent with paleoenvironmental inferences than the climate sequence based on OSL ages. We also evidence that isotope-based inferences are more congruent with the paleoclimate sequence than species-based inferences. These results highlight the difference in scale between the information provided by each ofthese paleoenvironmental proxies. Our approach is transferable to other sites due to the increase number of available paleoclimate simulations.1 Introduction 2 Material and methods 2.1 El Harhoura 2 cave 2.1.1 Presentation of the site 2.1.2 Chronostratigraphy and dating hypotheses 2.1.3 Paleoenvironmental variables 2.2 Paleoclimate reconstruction 2.2.1 Climate model 2.2.2 Paleoclimate simulations 2.2.3 Sea-surface boundary conditions 2.2.4 A subset of key paleoclimate variables 2.3 Consistency analyses 3 Results 3.1. Simulated climate changes 3.2 Consistency between paleoclimate simulations and paleoenvironmental inferences 3.2.1 Association of paleoclimate simulations and stratigraphic layers 3.2.2 Consistency analyses 4 Discussion 4.1 Paleoclimate variation and underlying forcings 4.2 Paleoclimate simulations and chronostratigraphy 4.3 Paleoclimate simulations and paleoenvironmental inferences 5 Conclusion
An improved chronology for the Middle Stone Age at El Mnasra cave, Morocco
North African coastal Middle Stone Age (MSA) sites are key to study the development and expansion of early H. sapiens. El Mnasra cave on the Atlantic coast of Morocco (Témara region) is a crucial site associated with MSA archaeological materials considered advanced cognitive hallmarks of behavioural innovation, such as numerous Nassariidae perforated shells, hematite pigments, bones industry and coastal resources exploitation. We provide new trapped-charges dates (OSL and combined US-ESR ages). Our Bayesian modelling strengthens the new lithostratigraphic interpretation of the cave stratigraphic units (US) and we propose an updated chronostratigraphic model for the Middle Stone Age archaeo-sequence of El Mnasra Cave. We confirm a human presence between 124–104 ka, earlier than what the previous OSL and US-ESR data showed. Our time range intervals allowed us to also extend the age of the MSA occupations considerably to the MIS 4/3 (~62–30 ka), marked by the disappearance of the Nassariidae perforated shells. Outstandingly, our model pushed back the age of the largest record of Nassariidae perforated shells and placed the age of their use by the Aterian groups at El Mnasra from the MIS 5d-5b (~115–94 ka)
Pacific Northwest National Laboratory Site Environmental Report for Calendar Year 2011
The PNNL Site Environmental Report for Calendar Year 2011 was prepared pursuant to the requirements of Department of Energy (DOE) Order 231.1B, "Environment, Safety and Health Reporting" to provide a synopsis of calendar year 2011 information related to environmental management performance and compliance efforts. It summarizes site compliance with federal, state, and local environmental laws, regulations, policies, directives, permits, and orders and environmental management performance
Limpet Shells from the Aterian Level 8 of El Harhoura 2 Cave (Témara, Morocco): Preservation State of Crossed-Foliated Layers
International audienceThe exploitation of mollusks by the first anatomically modern humans is a central question for archaeologists. This paper focuses on level 8 (dated around * 100 ka BP) of El Har-houra 2 Cave, located along the coastline in the Rabat-Témara region (Morocco). The large quantity of Patella sp. shells found in this level highlights questions regarding their origin and preservation. This study presents an estimation of the preservation status of these shells. We focus here on the diagenetic evolution of both the microstructural patterns and organic components of crossed-foliated shell layers, in order to assess the viability of further investigations based on shell layer minor elements, isotopic or biochemical compositions. The results show that the shells seem to be well conserved, with microstructural patterns preserved down to sub-micrometric scales, and that some organic components are still present in situ. But faint taphonomic degradations affecting both mineral and organic components are nonetheless evidenced, such as the disappearance of organic envelopes surrounding crossed-foliated lamellae, combined with a partial recrystallization of the lamellae. Our results provide a solid case-study of the early stages of the diagenetic evolution of crossed-foliated shell layers. Moreover, they highlight the fact that extreme caution must be taken before using fossil shells for palaeoenvironmental or geochronological reconstructions. Without thorough investigation, the alteration patterns illustrated here would easily have gone unnoticed. However, these degradations are liable to bias any proxy based on the elemental, isotopic or biochemical composition of the shells. This study also provides significant data concerning human subsistence behavior: the presence of notches and the good preservation state of limpet shells (no dissolution/recrystallization, no bioerosion and no abrasion/fragmentation aspects) would attest that limpets were gathered alive with tools by Middle Palaeolithic (Aterian) populations in North Africa for consumption
Expanding phenotype of hereditary fibrosing poikiloderma with tendon contractures, myopathy, and pulmonary fibrosis caused by FAM111B mutations: Report of an additional family raising the question of cancer predisposition and a short review of early-onset poikiloderma.
journal article2017 Mar2017 03 19importedHereditary fibrosing poikiloderma with tendon contractures, myopathy, and pulmonary fibrosis (POIKTMP [MIM#615704]) is an extremely rare syndromic form of autosomal dominant poikiloderma. This genetic disorder was first identified in a South African family in 2006.1 To date, 3 families and 9 independent sporadic cases have been reported.2-4 Here we report an additional family of POIKTMP and expand the clinical spectrum. We describe, for the first time to our knowledge, a pancreatic cancer in the clinical course in 1 patient
BBS proteins interact genetically with the IFT pathway to influence SHH-related phenotypes
There are numerous genes for which loss-of-function mutations do not produce apparent phenotypes even though statistically significant quantitative changes to biological pathways are observed. To evaluate the biological meaning of small effects is challenging. Bardet–Biedl syndrome (BBS) is a heterogeneous autosomal recessive disorder characterized by obesity, retinopathy, polydactyly, renal malformations, learning disabilities and hypogenitalism, as well as secondary phenotypes including diabetes and hypertension. BBS knockout mice recapitulate most human phenotypes including obesity, retinal degeneration and male infertility. However, BBS knockout mice do not develop polydacyly. Here we showed that the loss of BBS genes in mice result in accumulation of Smoothened and Patched 1 in cilia and have a decreased Shh response. Knockout of Bbs7 combined with a hypomorphic Ift88 allele (orpk as a model for Shh dysfuction) results in embryonic lethality with e12.5 embryos having exencephaly, pericardial edema, cleft palate and abnormal limb development, phenotypes not observed in Bbs7−/− mice. Our results indicate that BBS genes modulate Shh pathway activity and interact genetically with the intraflagellar transport (IFT) pathway to play a role in mammalian development. This study illustrates an effective approach to appreciate the biological significance of a small effect
A Novel Mutation Involving the Initiation Codon of FGF3 in a Family Described with Complete Inner Ear Agenesis, Microtia and Major Microdontia (LAMM Syndrome)
LAMM syndrome (OMIM #610706) is a rare autosomal recessive syndrome characterized by the association of Michel aplasia, microdontia and malformation of the external ear. Different mutations in FGF3 gene were reported in several families presenting with this syndrome. Clinical features and genetic results observed in a family with LAMM syndrome are reported. The diagnosis of isolated Michel aplasia was initially made in this family composed of two affected children. Microtia and microdontia was recently evidenced in both patients suggesting the diagnosis of LAMM syndrome. New auditory and orodental iconography was performed permitting to describe the patients’ phenotype in depth and to report rare findings of LAMM syndrome. The sequencing of FGF3 gene identified a novel missense mutation (c.2T>G), substituting the first initiator methionine in arginine, in the fibroblast growth factor 3 (FGF3) at the homozygous state in both patients. LAMM syndrome was confirmed and appropriate genetic counseling performed
Mutations in the latent TGF-beta binding protein 3 (LTBP3) gene cause brachyolmia with amelogenesis imperfecta
Inherited dental malformations constitute a clinically and genetically heterogeneous group of disorders. Here, we report on four families, three of them consanguineous, with an identical phenotype, characterized by significant short stature with brachyolmia and hypoplastic amelogenesis imperfecta (AI) with almost absent enamel. This phenotype was first described in 1996 by Verloes et al. as an autosomal recessive form of brachyolmia associated with AI. Whole-exome sequencing resulted in the identification of recessive hypomorphic mutations including deletion, nonsense and splice mutations, in the LTBP3 gene, which is involved in the TGF-beta signaling pathway. We further investigated gene expression during mouse development and tooth formation. Differentiated ameloblasts synthesizing enamel matrix proteins and odontoblasts expressed the gene. Study of an available knockout mouse model showed that the mutant mice displayed very thin to absent enamel in both incisors and molars, hereby recapitulating the AI phenotype in the human disorder
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