site formation
Recently Published Documents


TOTAL DOCUMENTS

575
(FIVE YEARS 133)

H-INDEX

47
(FIVE YEARS 5)

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Haruna Fukuzaki ◽  
Junichiro Nakata ◽  
Shuko Nojiri ◽  
Yuki Shimizu ◽  
Toshiki Kano ◽  
...  

AbstractPeritoneal dialysis (PD) catheter exit-site care is critically important for the prevention of catheter-related infections (CRIs) and subsequent peritonitis. The postoperative management of the site is particularly essential because it has an open wound that is always adjacent to a PD catheter tube. This study aimed to examine the effectiveness of negative-pressure wound therapy (NPWT) for postoperative PD catheter exit sites. Thirty patients with end-stage renal disease who underwent simultaneous PD catheter insertion and exit-site formation were randomly assigned to receive NPWT (NPWT group) or conventional dressing (non-NPWT group) for the first seven postoperative days. The exit-site scores on the seventh postoperative day was lower in the NPWT group than in the non-NPWT group (p = 0.0049). Analysis of variance F statistic for the effect of NPWT over 180 days was highly significant (11.482595, p = 0.007). There were no statistically significant differences between the time to first CRI and PD-related peritonitis between the two groups. There was one case of CRI with relapsing peritonitis and catheter loss in the non-NPWT group. These findings demonstrate the association between NPWT and low exit-site score. NPWT can be recommended for the management of PD catheter exit sites in the early postoperative period.


Author(s):  
Carlos Enrich ◽  
Albert Lu ◽  
Francesc Tebar ◽  
Carles Rentero ◽  
Thomas Grewal

Membrane contact sites (MCS) are specialized small areas of close apposition between two different organelles that have led researchers to reconsider the dogma of intercellular communication via vesicular trafficking. The latter is now being challenged by the discovery of lipid and ion transfer across MCS connecting adjacent organelles. These findings gave rise to a new concept that implicates cell compartments not to function as individual and isolated entities, but as a dynamic and regulated ensemble facilitating the trafficking of lipids, including cholesterol, and ions. Hence, MCS are now envisaged as metabolic platforms, crucial for cellular homeostasis. In this context, well-known as well as novel proteins were ascribed functions such as tethers, transporters, and scaffolds in MCS, or transient MCS companions with yet unknown functions. Intriguingly, we and others uncovered metabolic alterations in cell-based disease models that perturbed MCS size and numbers between coupled organelles such as endolysosomes, the endoplasmic reticulum, mitochondria, or lipid droplets. On the other hand, overexpression or deficiency of certain proteins in this narrow 10–30 nm membrane contact zone can enable MCS formation to either rescue compromised MCS function, or in certain disease settings trigger undesired metabolite transport. In this “Mini Review” we summarize recent findings regarding a subset of annexins and discuss their multiple roles to regulate MCS dynamics and functioning. Their contribution to novel pathways related to MCS biology will provide new insights relevant for a number of human diseases and offer opportunities to design innovative treatments in the future.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Seiji Kadowaki ◽  
Toru Tamura ◽  
Risako Kida ◽  
Takayuki Omori ◽  
Lisa A. Maher ◽  
...  

AbstractThe Initial Upper Paleolithic (IUP) is a key chrono-cultural concept in our understanding of the cultural and population dynamics at the transition from the Middle Paleolithic to Upper Paleolithic period. This paper presents technological and chronological analyses of lithic assemblages from a rockshelter site at Tor Fawaz in the Jebel Qalkha area, southern Jordan, to provide accurate dating and detailed recognition of the IUP variability in the Levant. We present integrated micromorphological, phytolith, and dung spherulite analyses to evaluate formation and postdepositional processes of archaeological remains through high-resolution micro-contextual studies. As a result, the Tor Fawaz assemblages show general similarity to those of Boker Tachtit Level 4, Tor Sadaf A–B, and Wadi Aghar C–D1 that represent the late phase of the IUP in the southern Levant. Based on the detailed recognition of site-formation processes, we suggest ca. 45–36 ka as the age of IUP occupations at Tor Fawaz. More specifically, the IUP occupations at Tor Fawaz and Wadi Aghar, a nearby IUP site in the same area, may represent slightly different phases that show a lithic technological trend paralleling the IUP sequence at Tor Sadaf in southern Jordan, and possibly post-date Boker Tachtit Level 4. We also discuss the issue of partial chronological overlap between the late IUP and the Ahmarian and also argue for the geographically different trends in cultural changes from the late IUP to the Ahmarian.


2021 ◽  
Author(s):  
Daryl Wesley ◽  
Mirani Litster ◽  
Ian Moffat ◽  
Sue O’Connor

Malarrak 1 is currently the northernmost excavated rockshelter on the Australian mainland, located in the Wellington Range in north western Arnhem Land. The site contains a rich late Holocene deposit, with extensive contact rock art, stone artefacts, shell, bone, contact materials, ancestral human remains, and other cultural material. Excavation of the Malarrak 1 rockshelter and analysis of its sediments revealed many impacts on site formation processes within the deposit. We attribute the disturbance to possible erosion or sediment deposition during periods of intense rainfall and also to the construction of timber structures within the site. This is supported by modern and historical observations and is the focus of this paper. The extent of the disturbance to Malarrak 1 provides a cautionary tale for other excavations in the region that may be affected by similar Indigenous site occupation, as these anthropogenic activities enhance the risk of further impacts arising from biological and geomorphological processes that can impinge on the stratigraphic integrity of the cultural deposits.


2021 ◽  
Author(s):  
Bruno David ◽  
Jean-Jacques Delannoy ◽  
Robert Gunn ◽  
Emilie Chalmin ◽  
Géraldine Castets ◽  
...  

IntroductionThe southern Arnhem Land plateau contains a rich mosaic of thousands of rock art sites located in outcrops of Proterozoic Marlgowa Sandstone of the Kombolgie formation (Carson et al. 1999) (Figure 11.1). Within this region in Jawoyn Country can be found Nawarla Gabarnmang, an impressive rockshelter exhibiting a gridded network of pillars that supports a thick ceiling of 10 cm to 40 cm thick cross-beds of hard sandstone and quartzite (Figures 11.2 and 11.3; see also Chapter 10). The inter-layer joints and fissures between these compact and poorly soluble quartz-rich sandstones and quartzites have witnessed geologically slow dissolution of the bedrock, resulting in a hollowing out of the rock in a process known as ‘ghost rock’ formation or ‘phantomisation’ (Quinif 2010), a particular cave-forming process causing the regular gridshaped structure of underground cavities and pillars (for details of site formation processes, see Chapter 13).The remnant pillars supporting ceiling rock strata at Nawarla Gabarnmang are an anthropic cave structure (Delannoy et al. 2013; see Chapter 10): in addition to the slow geological dissolution of the rock along layer planes and fissure lines, people have also entirely or partially removed individual pillars, and possibly ceiling strata, over a period commencing sometime after the site was first occupied around 50,000 years ago (e.g. David et al. 2011, completed manuscript). What catches one’s attention at Nawarla Gabarnmang are the voids between the pillars, typically c. 1–2 m apart in the southwestern corner of the site, but more than 8 m apart in the central eastern portion. In that noticeably more open central-eastern area, a large, sub-horizontal and flat ceiling is supported by some 20 sparsely distributed pillars. Here, as in most other parts of the site, the floor of the sheltered area is generally flat and sub-horizontal, consisting of ashy sand with sparsely scattered, relatively small blocks of rock originating from the ceiling but not in their original fallen positions (these blocks have all, without exception, been moved by people). Within the fill across the site are rich archaeological deposits including stone artefacts, ochre pieces and animal bones, as revealed in the archaeological excavations (David et al. 2011; Geneste et al. 2012). What we see today in the shelter are the results of tens of thousands of years of human occupation, modification of rock surfaces and site use that express well the notion of ‘dwelling’ and ‘inhabitation’ (e.g. David et al. 2013, 2014; Delannoy et al. 2013; Geneste et al. 2010; cf. Ingold 2000; Thomas 2008).


2021 ◽  
Author(s):  
Ingrid Ward ◽  
Piers Larcombe ◽  
Peter Ross ◽  
Chris Fandry

The absence of known prehistoric underwater cultural heritage (UCH) sites on the inner continental shelf of Australia stands in stark contrast to the thousands of sites revealed elsewhere in the world. Two recent claims – Dortch et al. (D2019) and Benjamin et al. (B2020) – put forward the first in situ (i.e., primary context) marine UCH sites in the shallow waters of the Dampier Archipelago, NW Australia, each arguing the stone artefact scatters are at least 7000 years old and are now submerged because of post-glacial sea-level rise. From the data published in D2019 and B2020, we assess the explicit and implicit assumptions and uncertainties of these claims. We include new results of hydrodynamic modelling, new data on coastal erosion and new bathymetric data of northern Flying Foam Passage, leading to a reinterpretation of the archaeology and the sites' sedimentary settings.Whilst the presented lithic material of D2019 and B2020 clearly includes cultural artefacts, we find that the arguments for the sites being of primary context and reflecting early Holocene land surfaces do not stand up to scrutiny and that the available evidence is insufficient to establish the facts. In describing the assumptions and uncertainties in D2019 and B2020, we include example tests to help resolve them. On balance, it appears that these sites are intertidal, and many or all artefacts are likely to have been reworked. These and similar sites would benefit from a thorough appraisal of past and present coastal processes to produce a defensible understanding of site formation processes before it is possible to determine their true nature and significance, noting that, even as secondary sites, they would still inform our understanding of process and change. Such work would support more powerful contributions to submerged prehistory than attempts to seek the first, the earliest, the oldest or deepest.


2021 ◽  
Vol 97 ◽  
pp. 1-196
Author(s):  
Caroline Wickham-Jones ◽  
Richard Bates ◽  
Alison Cameron ◽  
Ann Clarke ◽  
Diane Collinson ◽  
...  

This volume presents the results of archaeological fieldwork undertaken along the River Dee, Aberdeenshire, north-east Scotland, by the Mesolithic Deeside voluntary community archaeology group between 2017 and 2019. A total of 42 fields were investigated, from which over 11,000 lithics were recovered, representing at least 15 archaeological sites and a span of human activity covering some 10,000 years from around 12,000 BC to c 2000 BC. Finds from the Late Upper Palaeolithic, Mesolithic, Neolithic and Bronze Age were present. Work comprised fieldwalking, test pitting, specialist analysis, and small-scale excavation. The investigation described here is significant not just for the light it throws on the early prehistoric populations along the River Dee but also for the methodology by which investigation was undertaken, as this provides a potential model for work in other areas. Both aspects are covered in the report. The River Dee flows between postglacial gravel and sand terraces, the structure of which has played an important role for the early settlers of the area, and this is covered in some detail in order to provide the physical background framework for the sites. There are also sections on more specialised geophysical and geoscience techniques where these were undertaken, together with a summary of research on the palaeoenvironmental conditions throughout the millennia of prehistory. The artefactual evidence comprises lithic assemblages which were all catalogued as fieldwork progressed; the contents of each site are presented, together with more detailed analysis of the finds from test pitted sites. Finally, given the rich archaeological record from the area, the results of the present project are set into the wider context of the evidence for prehistoric settlement along the river, and there is consideration of future directions for further fieldwork. While all authors have contributed to the whole volume, individual sections that present specialist work by specific teams have been attributed. The distribution maps and GIS are the work of Irvine Ross. Dates given are calibrated BC dates. The Nethermills Farm NM4 dates are calibrated using the Oxford Radiocarbon Accelerator Unit calibration program OxCal 4 (Bronk Ramsey 2009) and their date ranges are calibrated using the IntCal13 atmospheric calibration curve (Reimer et al 2013). Optically stimulated luminescence (OSL) was used to profile sediment accumulations on some of the sites and obtain information relating to site formation, but it was not used for dating in any of the projects.


Quaternary ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 33
Author(s):  
Loïc Lebreton ◽  
Eugène Morin ◽  
Brad Gravina ◽  
Alexandre Michel ◽  
François Bachellerie ◽  
...  

As micromammals are highly sensitive to changes in their habitat, variations in species representation are often used to reconstruct local environmental conditions. However, taphonomic aspects of micromammals are often overlooked, despite the fact that they can provide important information for our understanding of archaeological sites. La Roche-à-Pierrot, Saint-Césaire, is a major archaeological site for our understanding of the Middle-to-Upper Palaeolithic transition in Western Europe. Clearly documenting site formation processes, the post-depositional reworking of deposits and the sequence of human occupations is fundamental for providing a secure archaeostratigraphic context of the site. The exceptionally large accumulation of micromammals from recently excavated stratigraphic units at the site makes it possible to track variations in the density of micromammals across the stratigraphic sequence. The taphonomic analysis of micromammals demonstrates these variations are not related to a change in the main accumulation agent or post-depositional phenomena. A negative correlation between small mammal remains and archaeological material suggests that peaks in micromammal densities can potentially be correlated with periods when the site was abandoned or when human occupation was less intense, and therefore provide new data for interpreting the Saint-Césaire stratigraphic sequence.


Sign in / Sign up

Export Citation Format

Share Document