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1.
Pollen profiles, based cores taken in Lake Kahala and from the adjoining mire, were used to establish general vegetation history
and to reconstruct the extent and types of land-use over most of the Holocene. Modern pollen deposition was studied using
moss polsters and the results were used in the interpretation of the fossil pollen data in terms of former land-use practices.
The modern-day samples are from settlements, hay meadow and pasture, and overgrown pasture. Indications of human activity
can be traced back to the Stone Age. At ca. 6400 cal. B.C., the first indications of possible woodland utilisation by humans
are recorded. This may have involved grazing within the forests. From 4200 cal. B.C. onwards, animal husbandry with changing
intensity was practised. Arable farming, involving cereals, was introduced to the area at ca. 1800 cal. B.C., but it was only
at ca. 500 cal. B.C. that it assumed an important role in the farming economy.Secale cereale (rye) was introduced during the Roman Iron Age, intensive rye cultivation started at the end of the Iron Age, at ca. cal.
A.D. 800. Ever increasing farming pressures triggered the formation of openalvars. Open landscape similar to that of today has persisted, with minor forest regeneration phases, since at least 500 cal. B.C. 相似文献
2.
Michael Wille Henry Hooghiemstra Hermann Behling Klaas van der Borg Alvora Jose Negret 《Vegetation History and Archaeobotany》2001,10(2):61-77
We present a reconstruction of forest history and climatic change based on 11 pollen records from eight sites, all located
in the lower montane forest belt of the northern Andes in Colombia. We compared records from the Popayán area in southern
Colobia, Timbio (1750 m), Genagra (1750 m) and Pitalito (1300 m) and the new Piagua (1700 m) record with the records from
Lusitania (1500 m), Libano (1820 m), Pedro Palo (2000 m) and Ubaqué (2000 m) from Central Colombia. The changes of the altitudinal
position of the lower/upper montane (= subandean/Andean, S/At) forest belt transition were used to estimate temperature change
for the last 50 kyr. We infer a Last Glacial Maximum (LGM) temperature drop of 6°–7°C at 1700 m, and a steeper LGM lapse rate
of 0.76°C/100 m compared to today (ca. 0.6°C/100 m). Around 50 uncal. kyr B.P. the temperature at 1700 m was ca. 3°C lower
than today. Until 20 uncal. kyr B.P. the temperature oscillated and gradually decreased. During the LGM, temperature was down
to ca. 6°–7°C lower than today. After the LGM, temperature increased and ca. 14 uncal. kyr B.P. it was 2°–3°C lower than today
(S/At at ca. 1800 m, 500 m below present elevation; Susacá interstadial). An unquantified cooling (Ciega stadial) followed.
During ca. 12.3–11.7 uncal. kyr B.P. the S/At shifted upslope to 2100 m indicating a temperature of 1°–2°C cooler than today
(Guantiva interstadial). From 11.7–10.9 uncal. kyr B.P. the S/At was at 1800 m indicating that the temperature was ca. 3°C
lower than today and wet conditions prevailed (partly coinciding with the El Abra stadial). The period 10.9–9 uncal. kyr B.P.
was also cool, but drier. During 9–7.5 uncal. kyr B.P. temperature was ca. 1°C warmer relative to today (mid Holocene hypsithermal).
During the last 5 kyr the presence of cultivated plants demonstates human colonization of the lower montane zone in Colombia.
Received June 14, 2000 / Accepted December 19, 2000 相似文献
3.
The influence of pre-industrial animal husbandry on the boreal forest in south-central Sweden has been studied by pollen
and charcoal analyses of peat profiles from two mires in the vicinity of a shieling site. The impact of farming on the local
vegetation development is demonstrated from cal. A. D. 1300–1500 in three ways: forest clearance and cultivation of cereals
at the local shieling site; alterations of hydrology and vegetation, such as an increase in Cyperaceae, at mires used for
hay production; changes in the composition in the surrounding forest, with decreasing proportions of Betula, Picea and boreo-nemoral broadleaved trees and a consequent increase in Pinus, due to grazing and a change of fire regime. Similar alterations to the forest vegetation are noted at other sites in central
and northern Sweden during the last thousand years, when the system of using shielings became more widespread. Hence, early
animal husbandry is demonstrated to have had a regional impact on the long-term boreal forest development, replacing the original
mixed deciduous-coniferous forest with Pinus dominated forest.
Received November 27, 2001 / Accepted June 20, 2002
Correspondence to: Marie Emanuelsson 相似文献
4.
Palynological investigation and radiocarbon dating of a 6-m core from lake Durankulak, north-eastern Bulgaria, enables vegetation development and human occupation from ca. 5500–5300 cal. B.C. onwards to be traced. Steppe vegetation that included with groves of deciduous trees asQuercus, Ulmus, Carpinus belulus andCorylus changed to a forest-steppe after 4000 cal. B.C. The archaeopalynological record indicates three distinct phases of human activity as follows: (1) 5300–4200 cal. B.C. (late Neolithic and Eneolithic) during which farming, that included a substantial arable component, was pursued, (2) 3500–3000 cal. B.C. (transition to early Bronze Age) when stock rearing appears to have dominated, and (3) after 1300 cal. B.C. (late Bronze Age) when arable farming again assumed importance. The palynological data correlate well with the rich archaeological record for human settlement that is available for the region from late Neolithic times onwards. 相似文献
5.
Ahmed Gamal-Eldin Fahmy 《Vegetation History and Archaeobotany》2001,10(4):235-246
The Neolithic site at Hidden Valley, Farafra Oasis, Egypt (6028±150 – 5163±374 cal B. C.) on the shores of a playa (dry lake
basin in the desert), yielded a large quantity of carbonized plant remains from post-holes, hearths, querns and a corridor.
The plant remains could have become carbonised during food preparation, or when fuel included seeds. Rich and diverse floras
were retrieved from 40 soil samples, in all 534 seeds, grains, spikelets, culm fragments and leaflet fragments which were
attributed to 30 taxa in the flora of Egypt. Wild grasses from almost all samples represent 83% of the plant remains. Quantitative
correlation between plants remains and archaeological contexts is discussed. The highest density of plant remains was recorded
from pot-holes (in which pots were stood), while sediments recovered near querns show the lowest. The economy of the site
was apparently based mainly on herding associated with the gathering of grasses which suggests that the climate at Farafra
during the middle Holocene (6077–4511 cal B. C.) was wetter than today's, with winter and summer rainfall. A reconstruction
of the vegetation around the site comprises reed plant cover, aquatic and wetland plants and desert savanna.
Received March 8, 2001 / Accepted June, 2001 相似文献
6.
Marjeta Jeraj 《Vegetation History and Archaeobotany》2002,11(4):277-288
Archaeobotanical evidence is presented for early agriculture at southwestern Ljubljansko barje (Ljubljana Moor), Slovenia.
Archaeobotanical finds from the Eneolithic site at Hočevarica, and pollen records from an archaeological profile and from
a nearby core were analysed. Numerous charred grains of cultivated cereals together with fossil seeds of Chenopodium sp. demonstrate that during the occupation of the settlement at Hočevarica, agriculture was well established. The majority
of identified grains were of Hordeum vulgare (cultivated barley) and the rest were Triticum monococcum and T. turgidum ssp. dicoccum (cultivated wheats). Large amounts of cereal pollen and pollen of Chenopodiaceae also suggest strong human impact on the
surrounding vegetation and landscape. Pollen and archaeobotanical data from Hočevarica show a large consistency in timing
of the appearance of agriculture. In the pollen record from the core at Hočevarica a significant increase (up to 40%) in cereal
pollen was detected at 4881 ± 50 B.P. (3770-3630 cal B.C.). Charred cereal grains were dated to 4800 ± 40 B.P. (3650-3520
cal B.C.). The grains of cultivated cereals from Hočevarica represent the oldest archaeobotanical evidence for agriculture
in central Slovenia.
Received February 18, 2002 / Accepted October 21, 2002 相似文献
7.
Anna Maria Mercuri Carla Alberta Accorsi Marta Bandini Mazzanti 《Vegetation History and Archaeobotany》2002,11(4):263-276
The cores from the Albano and Nemi lakes, near Rome, were studied within the European Union funded PALICLAS project and provided
high resolution records of the Late-glacial and Holocene. Pollen evidence of increasing human influence on vegetation was
recorded in the Holocene parts of both diagrams, and the Cannabis (hemp) curve was one of the major signs. In this paper we present unambiguous pollen evidence from the Cannabaceae records
for the cultivation of hemp in central Italy by the Romans. The oldest records of Cannabis and Humulus (hop) date from to the Late-glacial. Hop pollen values rise during the mid Holocene, while hemp pollen becomes more abundant
from ca. 3000 cal B.P. onwards. The highest earliest hemp peak (21%) is dated to the 1st century A.D. This ‘Cannabis phase’, with the abrupt rise of hemp pollen soon after the rise of cultivated trees (Castanea, Juglans and Olea) is associated with the increase in cereals and ruderal plants. This unambiguous proof of cultivation by Romans around 2000
B.P. occurs as well as a long lasting pre-Roman presence of hemp in the area, which is natural and possibly also anthropogenic.
Subsequent clear episodes of cultivation in the medieval period were found.
Received February 4, 2002 / Accepted September 13, 2002
Correspondence to: Anna Maria Mercuri, e-mail: mercuri.annamaria@unimo.it 相似文献
8.
Leif Björkman 《Vegetation History and Archaeobotany》2001,10(4):201-210
A pollen record from a small peatland located on Kullaberg in northwestern Sk?ne, southern Sweden, revealed that grazing
pressure might have been the major disturbance agent controlling the vegetation, at least from ca. 1500 B. C. until the latter
part of the nineteenth century. The pollen data also indicate a step-by-step increase in grazing pressure, expressed as a
marked increase in non-arboreal pollen representation at ca. 1500 B. C., A. D. 650 and A. D. 1650. The increase at A. D. 650
probably indicates a more regular and intensive use of the area, resulting in a forest structure that was much more open than
earlier, together with an expansion of Fagus, which rapidly replaced Quercus as the local forest dominant. At about this time the first patches of heath vegetation originated, but they probably only
covered a small part of Kullaberg. Larger areas with an intensively grazed Calluna heath, as shown by eighteenth century maps, probably evolved around ca. A. D. 1650, when much of Kullaberg seems to have
been deliberately deforested.
Received February 20, 2001 / Accepted September 12, 2001 相似文献
9.
Aims Our aim is to reconstruct decadal scale development of historical landscapes during the last 1000 years by means of fossil pollen analysis of annually laminated lake sediments, and detailed historical maps and documents. Location Lake Rõuge Tõugjärv (Estonia), a small lake with annually laminated lake sediments situated in a dense prehistoric setting. Methods The chronology of the palaeodata is based on the annual laminations supported by AMS 14C and 210Pb dating and 137Cs, 241Am, and spheroidal carbonaceous particle marker horizons. The time‐scale and resolution allows fine sampling (the pollen samples generally comprise 3.5 years) and vegetation change reconstruction. Relevant source area of pollen (RSAP) of the lake was estimated, and the statistical zonation, rate of change, palynological richness, and DCA and PCA ordinations were generated on the basis of the pollen data. The historical calibration data set (maps, numerical information on population, domestic stock, farmland division, etc.) is based on archival material preserved in the Estonian Historical Archives. Results The topmost part (0–180 cm) of the sediment column of Lake Rõuge Tõugjärv, covering the last 1000 years, is visibly laminated carbonaceous gyttja. The varve chronology extends from ad 2000 to ad 1339, with a cumulative ± 9‐year error estimate. Beyond this the chronology is extrapolated using the 14C date and varve age–depth estimations. The simulation of the RSAP of Lake Tõugjärv shows that the major portion of the pollen loading originating from local vegetation is derived from plants growing within 2000 m of the sampling site. The pollen record divides into five statistically significant subgroups, which fall on the PCA plot into three clusters reflecting the general openness–closedness of the landscape. During the period between ad 1000 and 1200 (RT 1) the Rõuge area was generally wooded with birch, spruce and pine forests. The advancement of extensive farming gradually opened up the landscape between ad 1200 and 1650 (RT 2 and RT 3). The maximum openness of the landscape was reached between ad 1650 and 1875 (RT 4), with the most open period in the late eighteenth century. Historical maps from 1684 and 1870–99 and available quantitative data on population, domestic stock, farmland division, etc. show the same trend. The pollen data covering the last 125 years, and maps from 1935 and 1995, show the reduction of arable land in RSAP of the lake under investigation and the reduction of open land to an extent comparable with the end of the seventeenth century. Main conclusions The formation and development of the cultural landscape at Rõuge over the last 1000 years is characterized by rapid changes in floristic richness and rates of vegetation change attributed to certain historic processes in the RSAP. Five phases of landscape and social development are clearly distinguished during the last 1000 years. The decadal scale vegetation response to human‐induced forcing agrees with historical maps and documents and could be used for past landscapes prior to the period with solid historical data. 相似文献
10.
Ruth Drescher-Schneider Jacques-Louis de Beaulieu Michel Magny Anne-Véronique Walter-Simonnet Gilles Bossuet Laurent Millet Elisabetta Brugiapaglia Anton Drescher 《Vegetation History and Archaeobotany》2007,16(4):279-299
Interdisciplinary studies of the sediments of Lago dell’Accesa started in 2001. We present here results from the palynological
study. The pollen diagram provides a record of vegetation and climatic change spanning over 15,000 years. The oldest pollen
spectra show a late-glacial steppe vegetation typical of central and southern Italy during this period. The Late-glacial Interstadial,
interrupted by two cooling events, is dominated by open deciduous oak forests. The Younger Dryas is represented by 150 cm
of sediment and shows the presence of steppic vegetation. The Holocene vegetation is characterised by alternating dominance
of deciduous oaks and Quercus ilex. The three zones characterised by Q. ilex are accompanied by peat layers marking lake-level lowering at ca. 8600–7900, 4600–4300 and 3700–2800 cal b.p. Between approximately 9000 and 6000 cal b.p. extensive Abies-forests existed on the Colline Metallifere located 15–20 km to the north and northeast of the lake. Local fir populations
may also have existed by the lake. Human impact starts at approximately 8000 cal b.p. during the Neolithic period, and increases at ca. 4300 cal b.p.
Castanea and Juglans pollen is recorded from ca. 2800 cal b.p. The impact of the Etruscan settlement near the lakeshore is shown in the increasing values of arable crops, species of secondary
forest canopy (Ericaceae, Pinus, Pistacia, Myrtus) and anthropogenic indicators (Chenopodiaceae, Plantago lanceolata, Rumex etc). 相似文献
11.
Agnieszka Wacnik 《Vegetation History and Archaeobotany》2009,18(3):187-203
Early and mid Holocene local vegetational history, with special reference to woodland communities, was revealed by pollen
analysis of a radiocarbon dated lake sediment profile from Lake Miłkowskie (Jezioro Miłkowskie) in northeastern Poland. The
main factor controlling the dynamics of woodland composition changes until ca. 1950 b.c. was climate. After that, the role of human activity became increasingly important. The results of high-resolution pollen
analyses provide evidence for early woodland disturbances caused by Mesolithic people at ca. 6950 b.c. Several episodes of human impact, differing in scale, and separated by subsequent episodes of woodland regeneration/stabilization
were noted. The first traces of local crop farming, shown by the presence of Cerealia pollen, were recorded at ca. 3800 b.c. in the Paraneolithic/Neolithic period. Animal husbandry as well as cereal cultivation played only a marginal role in the
economy, which was traditionally based on hunting, fishing and gathering through the Neolithic and the early Bronze Age. The
change in economic strategies from foraging towards farming, starting around 3750 b.c., was a long-lasting process. An increase of productive economy took place in the middle Bronze Age at ca. 1400 b.c. 相似文献
12.
Aldona Bieniek 《Vegetation History and Archaeobotany》2002,11(1-2):33-40
Neolithic settlements in the Kujawy region of central Poland are represented by seven archaeological sites which have botanical
material archaeologically dated to the Linear Pottery culture (LBK) (ca. 5400-5000 cal. B.C.) and the Lengyel culture (ca.
4400-4000 cal. B.C.). The composition of plant remains suggests that Stipa pennata s.l. played a certain role in the economy of the Neolithic settlers. The presence of this xerothermic grass is best explained
by local gathering rather than distant transport or coming into the sediment by chance. The finding of Hierochlo? cf. australis grains represents the first identification of this plant in archaeobotanical material from Poland. This, now rare, plant
contains coumarin and for this reason could have been useful in prehistory. Other plants such as Bromus spp., Chenopodium album type, Fallopia convolvulus and Galium spp. were found in large quantities, and although common weeds now, they could also have been collected by the Neolithic
settlers. Plants such as Corylus avellana and Vaccinium vitis-idaea that are typically considered to be collected as foods are present in the studied material but in very small quantities.
Received September 17, 2001 / Accepted March 13, 2002 相似文献
13.
The cultural landscape development of a farming community in western Norway was investigated through pollen analyses from
a lake and a peat/soil profile. The pollen record from the lake indicates that there was a decrease in arboreal pollen (AP)
by the end of the Mesolithic period (ca. 4200 cal b.c.), and that a substantial forest clearance occurred during the Bronze Age (ca. 1500 cal b.c.). The latter, together with grazing indicators and cereals, suggests a widespread establishment of farming. At the beginning
of the Roman Iron Age there is an increase in heath communities. The pollen diagram from the peat/soil profile shows the forest
clearance in the Bronze Age more clearly than the lake profile. This local pollen diagram is compared with modern pollen samples
from mown and grazed localities in western Norway. Both analogue matching and ordination (PCA) indicate that the site was
characterised by pastures and cereal fields from the Late Bronze Age to the Late Iron Age. An expansion of cereal cultivation
took place during the Pre-Roman Iron Age, and an arable field was established at the site after ca. a.d. 800. This investigation illustrates the potential of selecting pollen sites reflecting different spatial scales, and complements
the cultural history of the area as inferred from archaeological and historical records. 相似文献
14.
Irmeli Vuorela Matti Saarnisto Terttu Lempiäinen Jussi-Pekka Taavitsainen 《Vegetation History and Archaeobotany》2001,10(3):121-138
The village of Pegrema in Karelia may be regarded as a Stone Age innovation centre in the large Lake Onega area. Two pollen
and plant macrofossil diagrams are presented which represent the first contribution to the study of human impact in the area
using anthropogenic pollen indicators. A continuous but sporadic human presence from the Mesolithic onwards is demonstrated.
While there is no archaeological evidence relating to the period 4200–3000 B.P., the pollen data suggest continuous, though
rather sparse human presence. The data do not support any natural catastrophes in Pegrema as has been suggested elsewhere.
Cerealia pollen is recorded earlier than expected (c. 5000 B.P.=. In the Bronce Age and Iron Age, the settlement of the Zaonezhye
peninsula is reflected by a slight increase in herb pollen representation, sporadic Cerealia pollen and several periods of
regression in Picea. The long introductory period of agriculture to the area, as well as the similarities and discrepancies between different
sources of evidence (palaeoecological, archaeological and historical) are discussed at some length. The start of land clearance
for permanent cultivation in the profile Pegrema S was dated to the late 13th century. The beginning of more intensive field cultivation in the 15th century is clearly seen in the pollen succession at both localities. The fluctuation in anthropogenic indicators can be related
to population density based on historical data. The village of Pegrema was depopulated in 1956 which is reflected in a distinct
decline in settlement indicators.
Received February 17 / Accepted May 19, 2000 相似文献
15.
Susanne Jahns 《Vegetation History and Archaeobotany》1993,2(4):187-203
Palynological investigations have been carried out on a sediment core from ancient Lake Lerna, a former fresh water lagoon in the western part of the Argive plain, Peloponnese, southern Greece. The sequence starts at 6800 B.P. (5700 cal B.C.). The lowest part of the pollen diagram shows a period of open deciduous oak woods, which may have been influenced by human impact already (Zone I). It is followed by a period of dense deciduous oak woods (Zone II), which lasted until the beginning of the Bronze Age ca. 4800 B.P. (3500 cal B.C.). Later, the diagram indicates strong human influence such as woodland clearance, the spread of maquis, phrygana and pine in Zones IIIa-IV. During the Archaic, Geometric and Classical periods after ca. 2700 B.P. (800 cal B.C.) there is evidence of a phase of extensive olive farming (Zone IIIb). In the same zone, after a period of scattered finds, there is an almost continuous Juglans curve. Zone IV is characterised by high pine values. In Zones I-II the evidence of evergreen Mediterranean plants is surprisingly small. In times with no discernible human influence (Zone II), deciduous oaks dominate, with no evidence for a climax vegetation of the Oleo-Ceratonion alliance. Olea europaea is the only species of that alliance traceable by its pollen in the diagram, while Ceratonia pollen is totally absent. 相似文献
16.
Bernd Wagner Martin Melles Fabien Kenig Roberto Pierau 《Palaeogeography, Palaeoclimatology, Palaeoecology》2006,241(2):320-337
A 9.14 m long sediment sequence was recovered from Lake Fryxell, Taylor Valley, southern Victoria Land, Antarctica, and investigated for its chronology and sedimentological, mineralogical, and biogeochemical changes. The basal part of the sequence is dominated by coarse clastic matter, i.e., mainly sand. The sediment composition suggests that a lake existed in Fryxell basin during the Middle Weichselian by ca. 48,000 cal. year BP. After a short period of lake-level lowstand ca. 43,000 cal. year BP, lower Taylor Valley became occupied by the proglacial Lake Washburn, which was at least partly supplied by meltwater and sediments from the Ross Ice Sheet that was advanced to the mouth of Taylor Valley. Evaporation of Lake Washburn to lower levels started during the Last Glacial Maximum at ca. 22,000 cal. year BP, long before the Ross Ice Sheet retreated significantly. Lake-level lowering was discontinuous with a series of high and low stands. From ca. 4000 cal. year BP environmental conditions were similar to those of today and lower Fryxell basin was occupied by a small lake. This lake evaporated to a saline or hypersaline pond between ca. 2500 and 1000 cal. year BP and refilled subsequently. 相似文献
17.
Juan Carlos Berrío Arnoud Boom Pedro José Botero Luisa Fernanda Herrera Henry Hooghiemstra Freddy Romero Gustavo Sarmiento 《Vegetation History and Archaeobotany》2001,10(3):161-174
An environmental reconstruction of the last 10,000 14C years of a frequently flooded wetland ecosystem in the lower Magdalena valley in northern Colombia is presented, on the
basis of a multi-disciplinary study of the sediments of the upper 15 m of the core from Boquillas (74°33'E, 9°7'N; 20 m a.
s. l.). We used the following studies: pollen, lithology, organic structures, clay mineralogy, soil and sediment geochemistry,
and δ13C values. The chronology is based on 13 AMS radiocarbon dates; the humic acid fractions were used in the case of seven samples.
Pollen from local origin (swamps, open grass-rich vegetation, and gallery forest) show the development of the wetland area.
River-transported pollen from a greater distance (dry forest, montane forest, Alnus) show changes in river activity and reflect large-scale changes of climatic conditions in the Momposina basin. From c. 10,010
to 9370 uncal B. P. (zone BQS-Ia) the river system was of high energy, as inferred by the lithological changes. The landscape
was dominated by open grass-rich vegetation with gallery forest along the streams. A marked representation of Alnus and montane forest taxa indicate significant water transport and river dynamics. Climatic conditions were dry. From c. 9370-8430
uncal B. P. (zone BQS-Ib) wetlands were isolated from the main river system, and clayey sediments with kaolinite, smectite
and illite as the main minerals accumulated in a lower-energy environment. Climatic conditions were dry and changes in the
seasonal precipitation favoured the expansion of the gallery forest. From c. 8430 to 8040 uncal B. P. (zone BQS-Ic) low values
of river-transported pollen indicate dry climatic conditions and open vegetation became more abundant. The flooding frequency
of the Boquillas site diminished. From 8040 to 4900 uncal B. P. (zone BQS-Id) the Boquillas site was dominated by open vegetation
with patches of gallery forest along the streams. Supply of river-transported allochthonous pollen (from many sources) was
minimal. Clay minerals from the sediments suggest variable temperature and precipitation. From c. 4900 to 1550 uncal B. P.
)zone BQS-II) the site was within the reach of the main river system as is the case today. Frequent flooding, coinciding with
peaks of river-transported grains of Alnus and high sediment supply, point to high precipitation in the composite catchment area of the Magdalena, Cauca, San Jorge,
and Cesár rivers. High values of phosphorous in the upper part of the core point to the presence of a pre-Hispanic civilization,
approximately from 2000 uncal B. P. onward. Construction of an extensive drainage system allowed irrigation as well as drainage
depending the annual cycle of precipitation. The landscape was significantly modified and allowed an extensive crop production
on a system of raised fields.
Received May 18, 2001 / Accepted June 15, 2001 相似文献
18.
Detailed pollen analytical investigations at a Neolithic lake dwelling site on Lake Chalain, Jura, France, show very characteristic variation in the Plantago lanceolata and P. major/media pollen curves in the period during which settlements are recorded (3030–2630 cal. B.C.). At first, P. lanceolata is the more important taxon but P. major/media representation gradually rises, to become the more important taxon in the uppermost settlement phase. After considering the present day ecology and phytosociology of the Plantago species in question, i.e. P. lanceolata, P. major and P. media, and the available archaeozoological and archaeological information, it is suggested that the changes in the representation of these two pollen taxa are the result of a change in the farming economy, at ca. 2800 cal. B.C., which involved a substantial rise in the numbers of domesticated grazing animals and more intensive land use. 相似文献
19.
The paper presents a set of two-dimensional experiments that utilize direct 13C detection to provide proton–carbon, carbon–carbon and carbon–nitrogen correlations in the bases of nucleic acids. The set
includes a 13C-detected proton–carbon correlation experiment for the measurement of 13C–13C couplings, the CaCb experiment for correlating two quaternary carbons, the HCaCb experiment for the 13C–13C correlations in cases where one of the carbons has a proton attached, the HCC-TOCSY experiment for correlating a proton
with a network of coupled carbons, and a 13C-detected 13C–15N correlation experiment for detecting the nitrogen nuclei that cannot be detected via protons. The IPAP procedure is used
for extracting the carbon–carbon couplings and/or carbon decoupling in the direct dimension, while the S3E procedure is preferred in the indirect dimension of the carbon–nitrogen experiment to obtain the value of the coupling constant.
The experiments supply accurate values of 13C and 15N chemical shifts and carbon–carbon and carbon–nitrogen coupling constants. These values can help to reveal structural features
of nucleic acids either directly or via induced changes when the sample is dissolved in oriented media.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.
The human formyl peptide receptor like 1 (FPRL-1) is a variant of the Gi-coupled formyl-peptide receptor. Functional FPRL-1 is endogenously expressed in the U87 astrocytoma cell line and there is
accumulating evidence to suggest that FPRL-1 may be involved in neuroinflammation associated with the pathogenesis of Alzheimer’s
disease. In this study, we examined the ability of FPRL-1 to mobilize intracellular Ca2+ in U87 astrocytoma cells, as well as in Chinese hamster ovary (CHO) cells stably expressing FPRL-1. We showed that Trp–Lys–Tyr–Met–Val–Met–NH2 (WKYMVM), a specific agonist for FPRL-1, stimulated Ca2+ influx in both U87 and FPRL-1/CHO cells. These effects can be inhibited by the FPRL-1 selective antagonist, WRW4. Involvement of Gi proteins was demonstrated with the use of pertussis toxin, while inhibitors of store-operated channels (SOC) including 1-[2-(4-methoxyphenyl)]-2-[3-(4-methpxyphenyl)propoxy]ethyl-1H-imidazole hydrochloride (SKF96365) and 2-aminoethoxydiphenyl borate (2-APB) were found to abolish the WKYMVM-induced Ca2+ increase. However, intracellular Ca2+ mobilization in both cell lines were unaffected by the phospholipase Cβ inhibitor U73122 or selective ryanodine receptor
inhibitors. Our data demonstrated that activation of Gi-coupled FPRL-1 can lead to Ca2+ influx possibly via SOCs in U87 and FPRL-1/CHO cells. 相似文献