scholarly journals Ancient DNA, lipid biomarkers and palaeoecological evidence reveals construction and life on early medieval lake settlements

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
A. G. Brown ◽  
M. Van Hardenbroek ◽  
T. Fonville ◽  
K. Davies ◽  
H. Mackay ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Animal Husbandry ◽  
Lipid Biomarkers ◽  
Human Occupation ◽  
Early Medieval ◽  
Alternative Approach ◽  
Dna Metabarcoding ◽  
Site Chronology ◽  
A Site

AbstractDirect evidence of ancient human occupation is typically established through archaeological excavation. Excavations are costly and destructive, and practically impossible in some lake and wetland environments. We present here an alternative approach, providing direct evidence from lake sediments using DNA metabarcoding, steroid lipid biomarkers (bile acids) and from traditional environmental analyses. Applied to an early Medieval Celtic settlement in Ireland (a crannog) this approach provides a site chronology and direct evidence of human occupation, crops, animal farming and on-site slaughtering. This is the first independently-dated, continuous molecular archive of human activity from an archeological site, demonstrating a link between animal husbandry, food resources, island use. These sites are under threat but are impossible to preserve in-situ so this approach can be used, with or without excavation, to produce a robust and full site chronology and provide direct evidence of occupation, the use of plants and animals, and activities such as butchery.

scholarly journals Development of Fragility Curves for Piping and Slope Stability of River Levees

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 738
Author(s):  
Nicola Rossi ◽  
Mario Bačić ◽  
Meho Saša Kovačević ◽  
Lovorka Librić
Keyword(s):  
Slope Stability ◽  
Fragility Curves ◽  
Safety Margin ◽  
Water Levels ◽  
Flood Event ◽  
Soil Parameters ◽  
Design Code ◽  
A Site ◽  
Insight Into

The design code Eurocode 7 relies on semi-probabilistic calculation procedures, through utilization of the soil parameters obtained by in situ and laboratory tests, or by the means of transformation models. To reach a prescribed safety margin, the inherent soil parameter variability is accounted for through the application of partial factors to either soil parameters directly or to the resistance. However, considering several sources of geotechnical uncertainty, including the inherent soil variability, measurement error and transformation uncertainty, full probabilistic analyses should be implemented to directly consider the site-specific variability. This paper presents the procedure of developing fragility curves for levee slope stability and piping as failure mechanisms that lead to larger breaches, where a direct influence of the flood event intensity on the probability of failure is calculated. A range of fragility curve sets is presented, considering the variability of levee material properties and varying durations of the flood event, thus providing crucial insight into the vulnerability of the levee exposed to rising water levels. The procedure is applied to the River Drava levee, a site which has shown a continuous trend of increased water levels in recent years.

Diagnosis of spontaneous intracranial hypotension by using magnetic resonance myelography

2000 ◽  
Vol 92 (5) ◽  
pp. 873-876 ◽  
Author(s):  
Akira Matsumura ◽  
Izumi Anno ◽  
Hiroshi Kimura ◽  
Eiichi Ishikawa ◽  
Tadao Nose
Keyword(s):  
Magnetic Resonance ◽  
Intracranial Hypotension ◽  
Direct Evidence ◽  
Spontaneous Intracranial Hypotension ◽  
Content Type ◽  
Highly Sensitive ◽  
Csf Leakage ◽  
Leakage Site ◽  
A Site ◽  
Mr Myelography

✓ The authors describe a case of spontaneous intracranial hypotension in which the leakage site was determined by using magnetic resonance (MR) myelography. This technique demonstrated the route of cerebrospinal fluid (CSF) leakage, whereas other methods failed to show direct evidence of leakage. Magnetic resonance myelography is a noninvasive method that is highly sensitive in detecting CSF leakage. This is the first report in which a site of CSF leakage was detected using MR myelography.

scholarly journals Lipid biomarkers in Holocene and glacial sediments from ancient Lake Ohrid (Macedonia, Albania)

2010 ◽  
Vol 7 (11) ◽  
pp. 3473-3489 ◽  
Author(s):  
J. Holtvoeth ◽  
H. Vogel ◽  
B. Wagner ◽  
G. A. Wolff
Keyword(s):  
Organic Matter ◽  
Lipid Biomarkers ◽  
Lake Ohrid ◽  
Labile Organic Matter ◽  
Glacial Sediments ◽  
Plant Matter ◽  
Lipid Biomarker ◽  
First Results ◽  
Near Shore

Abstract. Organic matter preserved in Lake Ohrid sediments originates from aquatic and terrestrial sources. Its variable composition reflects climate-controlled changes in the lake basin's hydrology and related organic matter export, i.e. changes in primary productivity, terrestrial plant matter input and soil erosion. Here, we present first results from lipid biomarker investigations of Lake Ohrid sediments from two near-shore settings: site Lz1120 near the southern shore, with low-lying lands nearby and probably influenced by river discharge, and site Co1202 which is close to the steep eastern slopes. Variable proportions of terrestrial n-alkanoic acids and n-alkanols as well as compositional changes of ω-hydroxy acids document differences in soil organic matter supply between the sites and during different climate stages (glacial, Holocene, 8.2 ka cooling event). Changes in the vegetation cover are suggested by changes in the dominant chain length of terrestrial n-alkanols. Effective microbial degradation of labile organic matter and in situ contribution of organic matter derived from the microbes themselves are both evident in the sediments. We found evidence for anoxic conditions within the photic zone by detecting epicholestanol and tetrahymanol from sulphur-oxidising phototrophic bacteria and bacterivorous ciliates and for the influence of a settled human community from the occurrence of coprostanol, a biomarker for human and animal faeces (pigs, sheep, goats), in an early Holocene sample. This study illustrates the potential of lipid biomarkers for future environmental reconstructions using one of Europe's oldest continental climate archives, Lake Ohrid.

Green rust as a precursor for magnetite: an in situ synchrotron based study

2008 ◽  
Vol 72 (1) ◽  
pp. 201-204 ◽  
Author(s):  
A. Sumoondur ◽  
S. Shaw ◽  
I. Ahmed ◽  
L. G. Benning
Keyword(s):  
Direct Evidence ◽  
Green Rust ◽  
Stable Phase ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Subsequent Transformation ◽  
Rapid Formation ◽  
Reaction Proceeds

AbstractIn this study, direct evidence for the formation of magnetite via a green rust intermediate is reported. The Fe(II) induced transformation of ferrihydrite, was quantified in situ and under O2-free conditions using synchrotron-based time-resolved energy dispersive X-ray diffraction. At pH 9 and Fe(II)/Fe(III) ratios of 0.5 and 1, rapid growth (6 min) of sulphate green rust and its subsequent transformation to magnetite was observed. Electron microscopy confirmed these results, showing the initial rapid formation of hexagonal sulphate green rust particles, followed by the corrosion of the green rust as magnetite growth occurred, indicating that the reaction proceeds via a dissolution-reprecipitation mechanism. At pH 7 and Fe(II)/Fe(III) ratio of 0.5, sulphate green rust was the stable phase, with no transformation to magnetite.

scholarly journals Serous Tubal Intraepithelial Carcinoma or Not? Metastases to Fallopian Tube Mucosa Can Masquerade as In Situ Lesions

2017 ◽  
Vol 141 (10) ◽  
pp. 1313-1315 ◽  
Author(s):  
Reena Singh ◽  
Kathleen R. Cho
Keyword(s):  
Fallopian Tube ◽  
De Novo ◽  
Data Sources ◽  
High Grade ◽  
Serous Tubal Intraepithelial Carcinoma ◽  
Different Types ◽  
Intraepithelial Carcinoma ◽  
A Site ◽  
Immunohistochemical Stains

Context.— Nonuterine high-grade serous carcinomas (HGSCs) are believed to arise most often from precursors in the fallopian tube referred to as serous tubal intraepithelial carcinomas (STICs). A designation of tubal origin has been suggested for all cases of nonuterine HGSC if a STIC is identified. Objective.— To highlight that many different types of nongynecologic and gynecologic carcinomas, including HGSC, can metastasize to the tubal mucosa and mimic de novo STIC. Data Sources.— A mini-review of several recently published studies that collectively examine STIC-like lesions of the fallopian tube. Conclusions.— The fallopian tube mucosa can be a site of metastasis from carcinomas arising elsewhere, and pathologists should exercise caution in diagnosing STIC without first considering the possibility of metastasis. Routinely used immunohistochemical stains can often be used to determine if a STIC-like lesion is tubal or nongynecologic in origin. In the context of uterine and nonuterine HGSC, STIC may represent a metastasis rather than the site of origin, particularly when widespread disease is present.

scholarly journals Exploring the Utility of Compound-Specific Isotope Analysis for Assessing Ferrous Iron-Mediated Reduction of RDX in the Subsurface

2020 ◽  
Author(s):  
Yiran Tong ◽  
Matthew J. Berens ◽  
Bridget A. Ulrich ◽  
Jakov Bolotin ◽  
Jennifer H. Strehlau ◽  
...  
Keyword(s):  
Groundwater Contamination ◽  
Ferrous Iron ◽  
Chemical Reduction ◽  
Isotope Analysis ◽  
Enrichment Factors ◽  
Isotope Enrichment ◽  
Compound Specific Isotope Analysis ◽  
A Site ◽  
Mediated Reduction

This work determines isotope enrichment factors for RDX during reduction by iron minerals. The values determined are used to assess the transformation of RDX at a site with groundwater contamination and in laboratory column reactors simulating in situ chemical reduction treatment.

Initial Stages of InAs Quantum Dots Evolution in GaAs/AlAs Matrixes

2002 ◽  
Vol 749 ◽  
Author(s):  
Michael Yakimov ◽  
Vadim Tokranov ◽  
Alex Katnelson ◽  
Serge Oktyabrsky
Keyword(s):  
Quantum Dots ◽  
Direct Evidence ◽  
Matrix Material ◽  
Single Layer ◽  
High Energy ◽  
Inas Quantum Dots ◽  
Auger Signal ◽  
The Matrix ◽  
Growth Evolution

ABSTRACTWe have studied the first phases of post-growth evolution of InAs quantum dots (QDs) using in-situ Auger electron spectroscopy in conjunction with Reflection High Energy Electron Diffraction (RHEED). Direct evidence for InAs intermixing with about 6ML (monolayers) of the matrix material is found from Auger signal behavior during MBE overgrowth of InAs nanostructures. Re-establishment of 2D growth mode by overgrowth with GaAs or AlAs was monitored in single-layer and multi-layer QD structures using RHEED. Decay process of InAs QDs on the surface is found to have activation energy of about 1.1 eV that corresponds to In intermixing with the matrix rather than evaporation from the surface.

scholarly journals Benthic nutrient fluxes and sediment oxygen consumption in a full-scale facultative pond in Patagonia, Argentina

2013 ◽  
Vol 68 (8) ◽  
pp. 1770-1777 ◽  
Author(s):  
M. Faleschini ◽  
J. L. Esteves
Keyword(s):  
Oxygen Consumption ◽  
Advanced Degree ◽  
Benthic Fluxes ◽  
Temperate Region ◽  
Benthic Metabolism ◽  
Mineralization Of Organic Matter ◽  
A Site ◽  
Water Bottom ◽  
Raw Wastewater

The study of benthic metabolism is an interesting tool to understand the process that occurs in bottom water at wastewater stabilization ponds. Here, rates of benthic oxygen consumption and nutrient exchange across the water–sludge interface were measured in situ using a benthic chamber. The research was carried out during autumn, winter, and summer at a municipal facultative stabilization pond working in a temperate region (Puerto Madryn city, Argentina). Both a site near the raw wastewater inlet (Inlet station) and a site near the outlet (Outlet station) were sampled. Important seasonal and spatial patterns were identified as being related to benthic fluxes. Ammonium release ranged from undetectable (autumn/summer – Inlet station) to +30.7 kg-NH4+ ha−1 d−1 (autumn – Outlet station), denitrification ranged from undetectable (winter – in both sites) to −4.0 kg-NO3− ha−1 d−1 (autumn – Outlet station), and oxygen consumption ranged from 0.07 kg-O2ha−1 d−1 (autumn/summer – Outlet station) to 0.84 kg-O2ha−1 d−1 (autumn – Inlet station). During the warmer months, the mineralization of organic matter from the bottom pond acts as a source of nutrients, which seem to support the important development of phytoplankton and nitrification activity recorded in the surface water. Bottom processes could be related to the advanced degree and efficiency of the treatment, the temperature, and probably the strong and frequent wind present in the region.

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