History and evolution of Mesolithic landscapes in the Haut-Quercy (Lot, France): New charcoal data from archaeological contexts

The Holocene ◽  
2012 ◽  
Vol 23 (1) ◽  
pp. 127-136 ◽  
Author(s):  
Auréade Henry ◽  
Nicolas Valdeyron ◽  
Laurent Bouby ◽  
Isabelle Théry-Parisot
Keyword(s):  
Correspondence Analysis ◽  
Vegetation Dynamics ◽  
Local Environment ◽  
Charcoal Analysis ◽  
Hunter Gatherers ◽  
Palynological Data ◽  
The Stability ◽  
Late Mesolithic ◽  
Charred Wood ◽  
Original Type

Charred wood analyses have been performed on three Mesolithic sites located on the Causse de Gramat, a karstic plateau in southwestern France (Lot department): Les Fieux, les Escabasses and le Cuzoul de Gramat. The sites yielded occupations dating from the early to the late Mesolithic (9th to the 6th millennia cal. bc). In the absence of palynological data, charcoal analysis allowed us to characterise the woody environment exploited by Mesolithic hunter-gatherers. Our results point at the minor place of softwoods in the landscape and the local importance of Rosaceae prunoideae, marking an original type of pre-forest vegetation. In order to retrace the local vegetation dynamics, these results are synthesized and discussed thanks to a correspondence analysis, which includes previous anthracological data from Azilian and middle Mesolithic levels of two other sites of the Causse. The homogeneity of the results speaks in favour of the stability of the local environment and confirms the specific vegetation features of the area.

Vegetation dynamics drive the evolution of soil aggregate stability during the first 14,000 years of soil development in the Swiss alps

2021 ◽  
Author(s):  
Konrad Greinwald ◽  
Tobias Gebauer ◽  
Ludwig Treuter ◽  
Victoria Kolodziej ◽  
Alessandra Musso ◽  
...  
Keyword(s):  
Vegetation Dynamics ◽  
Plant Cover ◽  
Aggregate Stability ◽  
Root Traits ◽  
Soil Aggregate ◽  
Swiss Alps ◽  
Soil Aggregate Stability ◽  
Alpine Regions ◽  
The Stability ◽  
Positive Effect

<p><strong>Aims:</strong></p><p>The stability of hillslopes is an essential ecosystem service, especially in alpine regions with soils prone to erosion. One key variable controlling hillslope stability is soil aggregate stability. However, there is comparatively little knowledge about how vegetation dynamics affect soil aggregate stability during landscape evolution.</p><p><strong>Methods:</strong></p><p>We quantified soil aggregate stability by determining the Aggregate Stability Coefficient (ASC), which was developed for stone-rich soils. To reveal how hillslope aging and corresponding changes in vegetation affect the evolution of ASC, we measured plant cover, diversity, and root traits along two chronosequences in the Swiss Alps.</p><p><strong>Results:</strong></p><p>We found a significant positive effect of vegetation cover and diversity on ASC that was mediated via root traits. These relationships, however, developed in a time-depended manner: At young terrain ages, above- and belowground vegetation characteristics had a stronger effect on aggregate stability than species diversity, whereas these relationships were weaker at older stages.</p><p><strong>Conclusions:</strong></p><p>Our findings highlight the importance of vegetation dynamics for the evolution of aggregate stability and enhance our understanding of processes linked to hillslope stabilization, which is a key priority to avoid further soil degradation and connected risks to human safety in alpine areas.</p>

scholarly journals Climate and local environment structure asynchrony and the stability of primary production in grasslands

2020 ◽  
Vol 29 (7) ◽  
pp. 1177-1188 ◽  
Author(s):  
Benjamin Gilbert ◽  
Andrew S. MacDougall ◽  
Taku Kadoya ◽  
Munemitsu Akasaka ◽  
Joseph R. Bennett ◽  
...  
Keyword(s):  
Primary Production ◽  
Local Environment ◽  
The Stability

SALVAGING OIL IN THE SOUTH ATLANTIC1

2001 ◽  
Vol 2001 (2) ◽  
pp. 1333-1336
Author(s):  
Richard Tatner
Keyword(s):  
Oil Pollution ◽  
Local Environment ◽  
Weather Conditions ◽  
Structural Condition ◽  
Fuel Oil ◽  
The South ◽  
South Georgia ◽  
Specialized Equipment ◽  
The Stability ◽  
Oil Tanks

ABSTRACT Oil Spill Response Limited (OSRL) was contracted by the South Georgia and South Sandwich Islands (SGSSI) government to conduct an investigation into the stability and potential oil pollution problem of three ex-whale/seal catcher vessels. The three vessels sunken/semisubmerged at their moorings are located in Grytviken Harbour on the Island of South Georgia located over 900 miles south east of the Falkland Islands. The purpose of the survey was threefold: (1) to corroborate previous surveys and quantify the amount of oil remaining in the three vessels; (2) to recommend a remedial solution whilst simultaneously looking into putting together the logistic to tangibly rectify the problem long term; and (3) finally and most importantly, to complete all of this without upsetting this fragile environment and ecology of the harbor and more over the Island of South Georgia. The ex-whale catch Petrel was the primary interest. A report was required on the vessels structural condition and content of her fuel oil tanks in respect to there being an imminent risk of more oil escaping from a damaged fuel oil tank into the marine environment and having an environmental impact. Recommendations were required on the feasibility of removing the oil and stabilizing the vessel. This brief applied equally to the ex-whale/seal catchers Albatross and Dias. The investigation revealed the quantity of fuel oil contained within the Petrel to be less than expected. In addition, the oil had not deteriorated as might have been expected considering the number of years in the tanks. A sample of fuel oil was taken and sent for analysis on return. The potential risk of a large spill from the damaged tank and the threat to the local environment were found to be negligible. Removal of the fuel oil from the tanks is considered to be fairly straightforward given the correct equipment and weather conditions. The investigation of the Albatross and Dias found these two vessels to be in worse structural condition by comparison with the Petrel. The two vessels were found to be more difficult to examine due to the greater percentage of their structure being below water. Examination of their fuel tanks to determine contents was not possible because of the fuel tank hatches being permanently submerged. Investigation and removal of any oil found within the tanks of the two vessels is possible, but, unlike the Petrel, specialized equipment would be required (Figure I).

Regulation, Location and Activity of Plasminogen Activator Inhibitor 2 (PAI-2) in Peripheral Blood Monocytes, Macrophages and Foam Cells

1997 ◽  
Vol 77 (06) ◽  
pp. 1168-1173 ◽  
Author(s):  
Helen Ritchie ◽  
Alec Jamieson ◽  
Nuala A Booth
Keyword(s):  
Local Environment ◽  
Plasminogen Activator Inhibitor ◽  
Plasminogen Activators ◽  
Foam Cells ◽  
Major Product ◽  
Blood Monocytes ◽  
Peripheral Blood Monocytes ◽  
Detergent Treatment ◽  
The Stability ◽  
Activator Inhibitor

SummaryMonocytes, macrophages and foam cells are central to atherogenesis. We have examined the potential ability of monocytes, macrophages and foam cells to affect the stability of deposited fibrin, characteristic of the atherosclerotic plaque, by their production of plasminogen activators and their inhibitors. Monocytes respond to thrombin and LPS by up-regulation of PAI-2 synthesis, and PAI-2 is their major product among the plasminogen activators/inhibitors. In contrast, macrophages and foam cells, while they did produce PAI-2, did not respond to thrombin and LPS by an increase in its synthesis. All PAI-2 produced by macrophages and foam cells was accumulated intracellularly, whereas monocytes also secreted PAI-2. Secreted PAI-2 was active as an inhibitor of u-PA, whereas intracellular PAI-2 required detergent treatment to generate activity. Thus monocytes, but not macrophages or foam cells, produce and secrete active PAI-2, thus potentially affecting fibrin stability in the local environment.

scholarly journals Temporal species turnover and plant community changes across different habitats in the Lake Engure Nature Park, Latvia

2014 ◽  
Vol 68 (1-2) ◽  
pp. 68-79 ◽  
Author(s):  
Solvita Rūsiņa ◽  
Ģertrūde Gavrilova ◽  
Ieva Roze ◽  
Viesturs Šulcs
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Vegetation Dynamics ◽  
Species Turnover ◽  
Dry Forest ◽  
Latitudinal Gradients ◽  
Nature Park ◽  
The Stability ◽  
Window Approach ◽  
Temporal Species Turnover

Abstract Simultaneous monitoring of vegetation dynamics in different ecosystems has been rarely conducted but can provide important insights into mechanisms of vegetation dynamics in relation to vegetation structure and patterns. We compared the herb layer dynamics, species turnover, and species-time relationships across different habitats in a 12-year period in the ILTER monitoring station of the Lake Engure Nature Park, Latvia. Temporal species turnover was defined as diference in species composition in a community between two times. Species-time relationships were assessed using a sliding window approach. Species richness, cumulative species richness, and diversity changed more in species-rich non-forest habitats than in forests. Species turnover was highly different among habitats, and was not associated with the stability of habitats, as reported from other studies. The species-time relationship of six habitats was much lower than that reported in the literature. This could be explained by latitudinal gradients in species diversity and temporal turnover. At higher latitudes both species diversity and turnover is lower, and the mentioned habitats represent typical boreal vegetation. Vegetation dynamics in acidic grassland, dune slack, fen, and dune forest were interpreted as fluctuations. Vegetation changes in moist forest, dry forest, and coastal grassland showed clear signs of succession (xerophytisation and overgrowing). Vegetation dynamics of the beach community exhibited features of both natural succession and anthropogenic fluctuation.

scholarly journals Influence of pH modifiers on the dissolution and stability of hydrochlorothiazide in the bi- and three-layer tablets

2015 ◽  
Vol 65 (4) ◽  
pp. 383-397 ◽  
Author(s):  
Sandra Urek Blatnik ◽  
Rok Dreu ◽  
Stanko Srčič
Keyword(s):  
Dissolution Rate ◽  
Local Environment ◽  
Demographic Shift ◽  
The Past ◽  
Related Substances ◽  
Significant Difference ◽  
Treatment Of Hypertension ◽  
Model Drug ◽  
The Stability ◽  
Influence Of Ph

Abstract During the past few years, the studies of bi- and multi-layered tablets increased due to the consumption of several different drugs per day by a patient and requests for appropriate patient compliance. The demographic shift toward older population increases the use of combination therapy as polypharmacy. Hydrochlorothiazide (HCTZ), as a model drug, is most commonly used in the treatment of hypertension, congestive heart failure and as a diuretic. The aim of the present study is to investigate the effect of the local environment on dissolution and stability behaviour of HCTZ in fixed multilayered tablet combinations, which are commonly used in polypharmacy. For this purposes, three different systems were introduced: (i) two conventional tablets (HCTZ and pH modifying placebo), (ii) 2-layer tablets (HCTZ, pH modifying placebo) and (iii) 3-layer tablets (HCTZ, barrier and pH modifying placebo). Disintegration of tablets, dissolution of HCTZ from tablets and HCTZ related substances were monitored for all systems. Results showed that there was a significant difference between dissolution profiles of the conventional two-tablet system (HCTZ tablet and pH modifying tablet) and the 2-layer and 3-layer tablets, which include the pH modifying layer. In the case of the conventional two-tablets system, 85 % of HCTZ was dissolved in less than 15 minutes. The dissolution profiles of HCTZ from 2-layered and 3-layered tablets showed a decrease in the dissolution rate. In addition, during the stability studies, it has been confirmed that the typical degradation product of HCTZ is formed, impurity B (4-amino-6-chloro-1,3-benzenedisulfonamide), which implies formation of formaldehyde as hydrolytic impurity not reported in the Ph. Eur. (16). Both impurities are particularly raised in 2-layered tablets with alkaline and neutral placebo layers. Stability of HCTZ was improved in the case of the 3-layer tablet, where the intermediate separation layer of glycerol monostearate was present. It is presumed that the HCTZ dissolution rate was decreased due to formation of non-soluble substances as a result of HCTZ degradation in the presence of alkaline layer.

scholarly journals CHRONOLOGY OF THE BURIAL ACTIVITY OF THE LAST HUNTER-GATHERERS IN THE SOUTHWESTERN IBERIAN PENINSULA, PORTUGAL

Radiocarbon ◽  
2020 ◽  
pp. 1-35
Author(s):  
R Peyroteo-Stjerna
Keyword(s):  
Iberian Peninsula ◽  
Environmental Changes ◽  
Human Bone ◽  
Social Structures ◽  
Human History ◽  
Funerary Practices ◽  
Hunter Gatherers ◽  
Bayesian Mixing Model ◽  
Burial Grounds ◽  
Late Mesolithic

ABSTRACT For most of human history, funerary burial has been unusual. Archaeology shows a shift in funerary practices in postglacial hunter-gatherers, in parts of Europe during the Late Mesolithic. This is documented by the burial grounds in the Tagus and Sado valleys in the southwestern Iberian Peninsula, Portugal, where ca. 376 burials were excavated. This study presents a chronology for the burial activity in these sites and contextualizes the start and end activity phases within regional environmental changes and cultural developments. The dataset consists of 76 14C dates on human bone (19 new, 57 published) including new dates from contexts in Portugal outside these valleys. Bayesian chronological models were defined in OxCal, and protein carbon contributions of marine foods were estimated by the Bayesian mixing model FRUITS. The results indicate a broader timeframe for the Late Mesolithic in Portugal, than previously suggested, starting during a period of significant environmental changes, ca. 8500–8300 cal BP, and ending ca. 7000 cal BP. The burial activity decreased during the establishment of Neolithic farmers in southwestern Iberia from ca. 7450 cal BP, however, these burial grounds continued to be used by Mesolithic hunter-gatherers, showing that diverse social structures and worldviews coexisted for several generations.

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