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During the third millennium cal BC, there were major changes in many aspects of Cypriot material culture, technology and economy which characterize the division between the Chalcolithic and early Bronze Age on the island. Many innovations can be traced to Anatolian antecedents. These include a very wide array of domestic as well as agricultural and industrial technologies. Their nature and range make it possible to argue strongly for the movement of people to the island, rather than for other mechanisms of technology transfer and culture change. This identification of an intrusive group, with distinctive patterns of behaviour (habitus), opens up questions of prehistoric ethnicity, and the processes by which the initial maintenance of different lifeways by indigenous and settler communities eventually gave way to a common cultural system.
Excavations at the small Chalcolithic site of Politiko-Kokkinorotsos in central Cyprus show that it was occupied around 2880–2670 cal BC. Fallow deer (Dama mesopotamica) form the major component of the substantial faunal assemblage. The structure of the animal population suggests a seasonal hunting site, an interpretation consistent with the lack of formal architecture and the range of stone tools. In this study, independent odontochronological analyses of deer and caprine are used to test and confirm the model of seasonal culling in spring and summer based on more general indicators. The results suggest a pattern of varied, specialized site-types and activities in different parts of the island and in different ecological zones, and add considerably to our understanding of cultural systems on the island in the early third millennium BC.
The Pleistocene to Holocene transition is both a reality of climate history, and a notion of the prehistorian. A century of approaches to Australian archaeology guides the frameworks of the issue today.
When fire swept through a workshop at Ambelikou Aletri on Cyprus in the nineteenth or twentieth century BC it brought a sudden halt to pottery production, leaving the latest batch of recently fired vessels. The remains of the kiln and its immediate surroundings provide a rare opportunity to gain direct insight into the technology and organisation of a Middle Bronze Age pottery workshop in the eastern Mediterranean. Analysis of the batch of cutaway-mouthed jugs adjacent to the kiln reveals a level of standardisation focused more on vessel shape than capacity, and shows that at a detailed level, no two jugs were alike. This pottery production site provides vital background for the study of contemporary pottery assemblages on Cyprus and elsewhere in the broader region.
Recent excavations at a small Chalcolithic site in central Cyprus show that it was occupied about 2880–2670 cal BC. Fallow deer form the major component of the substantial faunal sample: both these and other animals were hunted. The chipped stone, too, fits with a model of intensive meat exploitation. The lack of formal architecture supports the general model of a seasonally or intermittently used hunters' village. Plant remains and a limited array of ground stone tools, however, indicate that domesticated plants were processed and consumed, although probably not harvested at the site, while large quantities of pottery also show a wider range of activities. These data and observations can be explained by several models, which emphasise either broad processes and historical developments or more local patterns of varied site-types and activities in different parts of the island or in different ecological zones, providing an important insight into the diversity and complexity of cultural systems in the early 3rd millennium BC.
Koongine is a sizeable limestone cave set in a low ridge some 4 km from the sea in the lower South-east of South Australia. It was used for about 2000 years at the transition from the Pleistocene to Holocene, and then again during the last millennium. The sequence at this site exposes issues of the appropriate scale and form of explanation for changes in site use. The stratified deposits of stone artefacts provide an opportunity to define for the first time the nature of the ‘Gambieran’ Industry. This spatially and temporally restricted industry characterised by large convex scrapers made on large, often asymmetrical, flakes is otherwise known mainly from older surface collections. The formal definition of this local industry adds to the growing evidence of considerable variation in the earlier stone tools of Australia, and provides an additional basis for rejecting the concept of a widespread Core Tool and Scraper Tradition, and replacing it with a model which recognises a mosaic of different tool-making traditions embedded in local social, economic, and technological contexts.
Bone-forming cells fabricate a highly ordered collagen matrix (osteoid) which subsequently mineralizes. A variety of cell culture systems exist for osteogenic cells, yet none of these is optimal for the organized formation of a mineralized matrix. We have generated collagen substrates which have different degrees of fibrillar orientation, and have cultured osteogenic cells on these matrices. In this format, von Kossa-stained sections show that highly oriented collagen matrix starts to calcify in 6–7 days, while a random fibrillar matrix does not mineralize even after 21 days. Mineral has been detected only within the collagen matrix with a narrow, unmineralized region between the cells and the mineral.
We have used transmitted polarized light microscopy to examine the fluid contents of silk glands taken from Bombyx mori silkworms and Nephila clavipes orb-weaving spiders. In the absence of shear, the secretions are optically isotropic. As the concentration is allowed to increase by evaporation, microstructures typical of the nematic liquid crystalline state are observed. Thus it appears that naturally spun silk becomes liquid crystalline en route to solidifying into fiber - which is advantageous to introducing and retaining global molecular alignment. This will facilitate the formation of strong, stiff fibers without the need for a significant post-spinning draw. We have also found that natural silk does not exhibit the defects in molecular alignment that are typical of synthetic polymer fibers spun from liquid crystalline solutions or melts.
The use of enzymes in organic solvents has enabled two distinct polymer syntheses to be performed. The first is the enzyme-catalyzed polycondensation of sucrose with an adipic acid derivative in pyridine. Taking advantage of the extremely high regioselectivity of proleather, an alkaline protease, sucrose has been polymerized with 6 and 1' ester linkages. The result is a highly water-soluble product with sucrose an integral part of the polymer backbone. The polyester is degraded by the proleather in aqueous solution, thereby suggesting that the polymer is biodegradable. The second polymer synthesis is the free-radical polymerization of phenols using horseradish peroxidase in dioxane-water mixtures. Molecular weights in excess of 25,000 have been produced. The scope of polymerization can be predicted based on enzyme kinetics in organic media and using a Monte Carlo simulation. Astonishingly accurate simulations have been run that suggest that the high degree of control afforded by enzymatic catalysis over conventional chemical catalysts can be usedpredictively in polymer synthesis. This is of great importance in process control of polymer syntheses.
The most fundamental goal of the synthetic chemist is control of molecular architecture. With respect to small molecules (i.e., those of molecular weight less than a few thousand), this means absolute control of chemical connectivity and stereochemistry – complete specification of molecular structure. But in macromolecular chemistry, controlled architecture has meant something quite different. Because polymerizations are in general statistical processes, conventional polymeric materials are characterized by substantial heterogeneity in chain length, sequence and stereochemistry . Control is exercised in a statistical sense only, and considerable skill is required to control even the average properties of the chain population and the dispersity in those properties.
Is a cemetery that has been robbed and pillaged for generations worthy of systematic research? It certainly is, given the application of a well conceived and executed project design. The authors show that the precise investigation of tomb architecture and identification of residual pottery can allow the detailed mapping of funerary practice over large areas of space and periods of time. Here they develop a narrative of increasing population and funerary investment through the Bronze Age in central north Cyprus. And having recorded 1286 pillaged tombs they call attention to the value of what still remains and the dangers that such monuments still face. The fact that a cemetery has been damaged is no reason to sacrifice it to the bulldozer.
This paper shows the remarkable level of social history that can be drawn from the high quality excavation and analysis of a well-preserved stratigraphic sequence. A Bronze Age settlement in Cyprus could be defined as a series of households, comprising dwellings, outbuildings and courtyards that were established, extended, replaced or abandoned over some 500 years. The authors' interpretation offers intimate access to the private lives of the inhabitants over a period in which their settlement grew from a village to a town and then reverted to a deserted ruin.
Age- and gender-specific suicide rates in England and Wales have changed considerably since 1950.
To assess whether cohort effects underlie some of these changes.
Graphical displays to assess age–period–cohort effects on suicide for the period 1950–1999.
Successive male birth cohorts born after 1940 carried with them, as they aged, a greater risk of suicide than their predecessors although this effect diminished for the 1975 and 1980 birth cohorts. There was less clear evidence of any increased risk of suicide in post-war female birth cohorts.
Succeeding generations of males born in the post-war years have experienced increasing rates of suicide at all ages, an observation in keeping with patterns seen in other countries. If these trends continue into middle- and old-age they will lead to a great increase in overall male suicide rates.
Synchronisation of motor unit discharges is commonly seen in hand muscles of normal man but is absent following neurologically complete spinal cord injury and reduced after stroke. These findings support the notion that some corticospinal inputs to motoneurones are shared and contribute to the observed synchrony of discharge. In this study we have examined motor unit discharge in hand muscles below the level of an incomplete spinal cord injury in an attempt to relate strength of synchrony to the integrity of the corticospinal tract. Eight patients with incomplete spinal cord injury (neurological level C3-C7) and eight control subjects took part in the study. The patients had sustained injury 14-191 weeks prior to the recordings and had since regained good motor function in their hands. Two concentric needle electrodes were inserted into the first dorsal interosseus muscle which subjects were instructed to contract weakly so that potentials from individual motor units could be reliably identified on both recordings. Synchrony was detected by constructing cross-correlograms between the discharges of pairs of individual motor units. The amount of synchronous firing was determined from the magnitude of any peak in the cross-correlogram, as the probability above chance (XP) of one motor unit firing with respect to the other and vice versa. The degree of synchrony was lower (P < 0·05) in the patient group (mean XP 0·06) than in the control group (mean XP 0·09). The incidence of significant synchrony was lower in the patient group (41·8 %) than in the control group (92·9 %). The mean (± S.E.M.) frequency of motor unit discharge was slightly lower (P < 0·05) in patients (9·7 ± 0·4 impulses s-1) than controls (10·8 ± 0·5 impulses s-1). The mean width of synchrony peaks was narrower (P < 0·05) in patients (11·4 ± 1·1 ms) than controls (13·2 ± 0·6 ms). We conclude that the weaker synchrony of motor unit discharge in incomplete spinal cord injury may reflect permanent damage to some corticospinal axons.
The influence of the macro-economic climate on suicide is unclear. During the recent recession, rates have increased in young males but declined in females.
To investigate associations between unemployment and suicide in 15 – to 44-year-old men and women over a period spanning two major economic recessions (1921–1995). To minimise confounding by changes in method availability, analyses are restricted to suicides using methods other than poisons and gases.
Time-series analysis using routine mortality and unemployment data.
There were significant associations between unemployment and suicide in both males and females. Associations were generally stronger at younger ages.
Secular trends in youth suicide may be influenced by unemployment or other factors associated with changes in the macroeconomic climate. These factors appear to affect women to the same extent as men. Although it is not possible to draw firm aetiological conclusions from time-trend data, our findings are in keeping with those of person-based studies.
A known result holds that capital taxes should be high in the short run and low or
zero in the long-run steady state. This paper studies the
dynamics of optimal capital taxation during the transition, when a high
rate is no longer optimal but the economy is still in flux. The main
result is that capital should be taxed whenever the sum of the
elasticities of marginal utility with respect to consumption and labor
supply are rising
and subsidized whenever this sum is falling. If the
utility function displays increasing relative risk aversion, this
paradoxically implies that capital should be taxed when the capital stock
is below the modified golden-rule level and subsidized whenever it exceeds
this level. Thus, savings incentives sometimes can be more desirable when
the capital stock is large than when it is small.