Добірка наукової літератури з теми "Decorated sheaves"

Abstract In this paper, we will begin the systematic study of the influence of the choice of a faithful representation on the notion of (semi)stability for decorated principal bundles. We will prove boundedness for slope semistable quiver sheaves.

On the territory of the Perm cis-Urals during the Middle Ages wooden knife sheaths coated with metallic plates became popular. Most sheaths’ decorations were made of metal alloys with a high percentage of silver. Some specimens were decorated with grains, filigree, glass or stone encrustations, gild, and printed anthropomorphic and ornitomorphic images. The object of the article is to introduce into scientific discourse the sources and research results that will facilitate determining basic technological characteristics and individual features in the sheaths’ functions. Based on source collection and categorization, the authors reveal how diverse the items were, as well as the scale of their production. Coin material facilitated determining the period of the sheaths’ highest popularity, which is the 9th and the first half of the 10th centuries. Nevertheless, there are specimens dating back to the 11th century as well. The analysis of the features of the occurrence in burials, taking into account paleoanthropological data, allowed us to conclude that the sheaths with metal plates was part of a belt set and was used in women's costume as a symbolic and decorative element. Some items made their way from the Perm cis-Urals to the Udmurt cis-Urals (the Polom archaeological culture) and to the territory of Volga Bulgaria. It is possible that there were local production centres for these items in the Udmurt cis-Urals and on the territory of the ancient Mari people.

Medieval Church Barns in DenmarkThe subject of this article is medieval church barns within the area of present-day Denmark. A church barn (or tithe barn) is a building erected near a parish church and used for storing the crops that local peasants paid as tithes or taxes to the church. Constructed as functional buildings for the church, these barns have both a clerical and a secular context. In 1912 M. Mackeprang gave an account of relevant written sources and made a provisional list of barns preserved at that time. In this work the list has been revised to describe the present day situation and it is established that there are 31 church barns preserved today. There are a few additional buildings of which the original function is uncertain that could be added to this list (fig. 1). Since Mackeprang’s article no total account of Danish church barns has been compiled, and relevant information therefore had to be sought from various sources. The most important written sources for medieval and post-medieval times are the letters from the Chancellery (Kancelliets brevbøger) and church laws from the early Protestant period. Although these documents are not medieval, in this article they are used to give a probable picture of the condition of the medieval church barns. Another important source is the notebook that the Funen bishop Jacob Madsen made during his visitation of every parish in his diocese in the late 16th century. The bishop often mentions the condition of church barns and sometime adds some more information. His work is very reliable and gives an idea of the status of the Funen church barns approximately 50 years after the Reformation.All of the preserved barns are situated in the churchyard of the church to which they belong. Some are built at the periphery of the churchyard so that one of the walls forms part of the churchyard wall. Some church barns are free-standing within the churchyard (fig. 2), while a few are built as an extension of the actual church. This is the case of the preserved church barn in Voldum (fig. 3) and also of the now lost barn in Brønshøj. Jacob Madsen’s notes tell us that if the church was situated far from the village the church barn could be placed centrally in the village instead. All of the preserved church barns are made of stone. On Zealand they are mainly built of bricks but on the southern part of the island local limestone is also used to a great extent. (fig. 11). On Funen barns are built with both bricks and granite boulders (fig. 4). The few preserved barns in Jutland have plinths of granite boulders while the walls are built of brick. The fact that church barns are brick-built is surprising because secular barns in medieval Denmark were always wooden constructions. Perhaps many of the lost church barns were timbered or half-timbered buildings. This was certainly the case of some of the Funen barns which Jacob Madsen described. This can also be deduced from a document from the year 1573 in which a special licence was given to tear down all church barns in the Århus diocese that were not brick-built. This suggests that the remaining brick-built church barns may not be representative of the majority of the medieval barns.Judging from the remaining barns and reliable measurements from ruined barns the dimensions of these buildings are typically 14-16 m x 7-9 m. The biggest barn is that in Tranebjerg on the island of Samsø (21.5 m x 9 m) while the barn in Mogenstrup, no longer in existence, was only 8.5 m by 4.23 m. Thus the dimensions of the medieval barns seem to have varied greatly. Some of the existing barns have been reduced (Melby, fig. 10) or expanded (Mesinge, fig. 5) in size. It is difficult to determine what was used for roofing the medieval barns. It is unlikely, however, that a barn with a stepped gable would also have a thatched roof, since such a roof would not fit tight against the gable but would have to overlap the top of it. The decorated gables of some of the barns are described in detail because these decorations can be used to date the barns (figs. 10-12). Caution has to be exercised, however, since these gables have often been restored freely, as for example in Strø (figs. 6 & 7). The church barn in Skårup has also been restored, but the reconstructed form of the gables is based on traces in the brickwork (figs. 8 & 9). In general the decorated gables of church barns seem to adopt local types of decoration that are also used in the churches. An example is the lost church barn in Ejby (fig. 20). It is not known whether church barns have existed in Denmark since the tithe regulations were introduced in the 12th century or if they are solely a late medieval phenomenon. Palle Lauring argues that Finderup Barn, in which King Erik Klipping was killed in 1289, was the village church barn. If this is true this would be the earliest mention of a Danish church barn. In Hjallese, Funen, remains of foundations have been interpreted as a church barn. This building is dated by two coins from the reign of Christoffer II (1320-1326). If this is correct it would be the oldest archaeologically dated church barn in Denmark. All of the preserved church barns are much later. These buildings date from 1450-1550, to judge from the decorated gables. The barn in Øster Egesborg is the only one to have been dendrochronologically dated. The trees used for its rafters were felled in approximately 1485-90. Even though church barns generally seem to be a medieval phenomenon it is apparent from written sources that church barns were also built in the second half of the 16th century and even as late as the beginning of the 17th century. However, in the attempt to make an account of the distribution of church barns in medieval Denmark it is often impossible to differentiate between barns built before 1536 and those built after. All references to church barns that could be found were therefore included for the purposes of the map (fig. 13). The main source of information about lost church barns on Zealand is Danmarks kirker, a series of descriptions of the Danish churches which now covers all of Zealand. Jacob Madsen is the main source for Funen , while information about church barns in Jutland is much more scarce and diffusely spread. The map of Jutland may not at the moment, therefore, give as true a picture of the medieval situation as the maps of Zealand and Funen. It is often claimed that church barns were a phenomenon concentrated in the eastern parts of Denmark (Zealand, Funen and Eastern Jutland) and generally this work supports this assumption. However, there have been church barns even in the northwest part of Jutland. On the other hand only one church barn is mentioned in the sources for the southern part of Jutland. In a church law from 1537 it is said that in every parish peasants should bring their crops to the church barns, but as the above shows there might not have been a church barn in every parish throughout the country. Possible explanations for the relatively few church barns in Jutland will be given later.Church barns also existed in the boroughs (fig. 15). The function of these buildings was to house the crops that came from the town’s fields, which were cultivated by the citizens. Furthermore the churches in the boroughs could function as parish churches for peasants in nearby villages.In theory tithe should be paid on all agricultural products, but in Denmark the crop tithe was by far the most important. In other European countries the tithe was divided into four portions: the vicar’s tithe, the bishop’s tithe, the tithe to keep the church well-maintained and equipped (the so-called fabrica), and finally one fourth of the tithe was given to the poor. In Denmark the tithe was only divided into three portions – leaving nothing to the poor. Even inside the Danish kingdom the practice of tithe varied greatly. A bishop’s tithe was introduced on Zealand, in Scania and in Slesvig in the late 12th century, but in the rest of Jutland and on Funen the bishop was paid a fixed amount of money (the “bishop’s gift”) that would often be much less than a third of the tithe. The dislike of the bishop’s tithe could among other things stem from the fact that this tithe should in theory be transported to the bishop’s town, which could be very far from the village. When the bishop’s tithe was introduced by law on Zealand is it said in the letter of the law that the tithe should only be brought to a place within the parish – probably to ease the acceptance of this new tax. Only in 1443 was the bishop’s tithe introduced in Jutland and on Funen, and it was much disliked. Which of the three parts of the tithe was stored in the church barns? In King Christian III’s church law from 1536 it is mentioned that the tithe should be brought to the church barn and then divided in three. On the other hand it is reasonable to assume that the vicar’s third of the tithe was brought directly to the vicarage, which was situated within the parish. One source indirectly points at this fact. In 1536 it is said that the peasants should be given two barrels of beer on the day they bring the tithe – and it is then added that this beer should not be consumed at the vicarage, as had often happened before. Maybe this is the reason a late 16th century barn beside the vicarage of Nimtofte in Eastern Jutland is called the church barn. So, did the church barns house the bishop’s tithe, the fabrica or both? As a result of the Reformation in 1536 the church’s property was confiscated by the king. The king now became head of the church and the bishop’s tithe was now called the king’s tithe. Apparently in the first years after the Reformation this change was only in name and therefore the practices concerning the king’s tithe in the early Protestant period probably reflect how the bishop’s tithe was handled in the late medieval period. In 1546 it is said in a letter from the Chancellery that the vicar and the churchwarden were responsible for hiring two men to thresh the tithe and then divide it into two parts: the fabrica and the king’s tithe (fig. 17). In a letter from 1542 it is said that the Scanian peasants were to bring one third of the tithe (the king’s tithe) to the church barn. In the Middle Ages the churchwardens were responsible for the fabrica and probably also for the church barns. The church barn in Vedtofte, Funen, was built by the churchwardens in 1554 using the fabrica. Jacob Madsen suggested in 1589 that the church barn in Turup, Funen, could be used as a house for the vicar, but the churchwarden had the final word, which was no. It is thus plausible that the fabrica was stored in the church barns, but of course this crop might also have been brought to the farm of one of the churchwardens who lived in the parish. It is most likely that the bishop’s tithe was stored in the church barn until it could be picked up by the bishop’s men. Some twenty years after the Reformation new rules were introduced that the peasants were to bring the king’s tithe (formerly the bishop’s tithe) to the respective castles and not just to the churchyard as previously. In 1577 a general law for Zealand was made that the peasants should bring the tithe in sheaves to whoever owned it. It was no longer enough to bring it to the churchyard.The conclusion is that the vicar’s tithe was probably brought to the vicarage, the fabrica could be stored in the church barn or at the churchwarden’s house and the bishop’s tithe was most likely always stored in the church barn.A few of the largest church barns may have been drive-through buildings, meaning that wagons entered through a gate in one end of the building, the sheaves were unloaded inside the building, and the wagon left via a gate at the opposite end of the building. The church barn in Kalundborg (fig. 18) and possibly also that in Tranebjerg had this function. In the smaller barns the sheaves were simply carried into the barn (fig. 16) or passed in through a hole in the wall. The interiors of the barns have been radically changed everywhere but some have been archaeologically examined. The church barn in Flemløse had been divided into three rooms, one of which seems to have had a cellar. The finding of charcoal in Skårup church barn suggests that the building was also used for purposes other than storage. In Skårup there were also remains of a hard clay floor that would have been ideal for threshing. Since we know nothing about church barns until the last century of the Middle Ages it has been claimed that originally the church lofts were used to store the crops. When vaults were introduced in many parish churches in late medieval times, leaving no storage room in the lofts, it became necessary to build church barns. This could explain the few church barns in Jutland since many churches in that part of the country never had vaults built on. From post-medieval times we know that in several churches in Southern and Northern Jutland the lofts were used for storing crops. In Egen church a winch used for this purpose still exists and one can suppose that this also reflects the medieval practice (fig. 19). However, this poses the question of where the threshing would then have taken place, because it seems that the tithe was normally handed over in sheaves and not in the form of grain. Furthermore there does not seem to be a clear connection between vaults and church barns. All of the vault-less churches mentioned by Jacob Madsen also had church barns. Probably the church barns must be considered as part of the massive construction works that were undertaken in connection with the Danish churches in the last 150 years of the Middle Ages. Vaults, towers, porches, etc. were built. This building activity was most intensive in the eastern part of the country, while the western part of Jutland tended to follow at a much slower pace, and in the year 1536 the Reformation put an abrupt end to it all. Another reason for the lack of church barns in many parts of Jutland could be that they were wooden constructions. Most of the church barns we know about are mentioned in the sources when they are torn down and the bricks or boulders sold. Wooden constructions are less valuable in this sense and might be underrepresented in the written sources for this reason.Immediately after the Reformation the use of the church barns probably did not change dramatically. But in the late 16th century more church barns fell out of use. This was encouraged by law in 1643. As more and more churches became private property the landlord owned both church buildings and tithe. For the church owner it was more convenient to have the tithe brought directly to his own barn and as the church barns lost their original function the materials of which they were built could be used for restoring the churches – another matter for which the church owner was responsible. Many church barns were lost on this account in the 1660s. The few church barns that remain today survived because they were used for a new purpose soon after the Reformation. In the boroughs they were often used as schools (fig. 14) and in the country parishes they could be converted into workhouses for poor people (fig. 21). The church barns have not drawn as much attention to themselves as an object of research as have the medieval churches, but they are a unique group of medieval buildings and together with the churches they form a unity that dates back almost 500 years. Mikael Manøe BjerregaardAfdeling for MiddelalderarkæologiAarhus UniversitetMoesgård

Helicobacter pylori uses a cluster of polar, sheathed flagella for swimming motility. A search for homologs of H. pylori proteins that were conserved in Helicobacter species that possess flagellar sheaths but were underrepresented in Helicobacter species with unsheathed flagella identified several candidate proteins. Four of the identified proteins are predicted to form part of a tripartite efflux system that includes two transmembrane domains of an ABC transporter (HP1487 and HP1486), a periplasmic membrane fusion protein (HP1488), and a TolC-like outer membrane efflux protein (HP1489). Deleting hp1486/hp1487 and hp1489 homologs in H. pylori B128 resulted in reductions in motility and the number of flagella per cell. Cryo-electron tomography studies of intact motors of the Δhp1489 and Δhp1486/hp1487 mutants revealed many of the cells contained a potential flagellum disassembly product consisting of decorated L and P rings, which has been reported in other bacteria. Aberrant motors lacking specific components, including a cage-like structure that surrounds the motor, were also observed in the Δhp1489 mutant. These findings suggest a role for the H. pylori HP1486-HP1489 tripartite efflux system in flagellum stability. Three independent variants of the Δhp1486/hp1487 mutant with enhanced motility were isolated. All three motile variants had the same frameshift mutation in fliL, suggesting a role for FliL in flagellum disassembly.

In this study, a composite ring spinning via feeding filaments in front of the front roller nip method was developed as a novel, effective way to form yarn surface looped fancy wrappings. The novel method was theoretically demonstrated to produce fil-wrap yarn with tight filament wrappings and periodic filament loop decorations on the surface. Tight filament wrappings fasten staple fibers firmly onto the yarn stem to achieve excellent anti-friction, while filament loops decorate the yarn surface to yield a fancy appearance. However, intensive bending of looped and wrapping filaments are likely sheared down to decrease the yarn’s tensile strength. The novel method was combined with corefil spinning to produce a fil-clamp yarn with enhanced structural fastness and strength. Experiments were conducted to validate the approach. Experimental results proved that the novel fil-wrap and fil-clamp yarns had periodic filament looped and tight wrappings, resulting in eliminated hairiness and increased fancy loops after comparison with conventional sirofil and corefil yarns. respectively. The fil-wrap yarn with only surface-bending filament wrappings was weaker, but more friction-resistant than conventional sirofil and corefil yarns. Yarn strength and anti-friction were enhanced after burying straight filaments in the fil-wrap yarn body to form a fil-clamp yarn. The fil-clamp yarn with fancy and anti-frictional structure is expected to endow fabrics with improved fluffiness, softness and anti-frictional properties.

The article deals with relatively rare but important for Scythians animal style repertoire image of a wild boar. The sources of iconography and style of the image are analyzed, as well as his inner evolution and external influences from Central Asia, Near East, Iran and Greece. Full figure image of a wild boar in the Northern Black Sea region in archaic period are very rare unlike Central Asia and Southern Seberia, where these images were quite popular. Nevertheless some typical Asian styled figures (in a «sudden stop» pose or standing «on a hoof tips») are represented in Kuban’ and Dniepr Forrest-Steppe regions. Obviously they connected to Central Asia tradition and may be an evidence of migration process from eastern region to the Northern Black Sea in VII—VI centuries BC. The article notes, that already in archaic period in Scythians burials being discovered artifacts with typical Greek and Middle East images of a wild boar as well as Celtic imports from Central Europe. In classical period the situation is changing. A new wild boar image iconography appears: with bent legs. At the current stage of research it’s impossible to unambiguously determine a geographical source of such image: was it Central Asia or Near East. The images with new iconography performed mostly in gold and decorated most often the weapons (bow cases, sword sheaths), ritual and cult items (bowls, rhytons, headdress). At the same time the image of a separate wild boar head appears. It became more popular than full figures and gained wider distribution from the late VI — early V century BC. It being developed in two stylistic directions: laconic, connected with Sauromathian impact and realistic-decorative, as a result of further development of this image by Bosporus artisans. The article also deals with semantics of the image. Many researchers associated the image of a wild boar with the embodiments of gods of war and victory — Indo-Iranian Veretragna and Scythians Ares. Author argues that a wild boar could be associated also with a chthonic destructive power and victory over him made the winning warrior a real hero, equal to his «cosmic» rival. Two new artefacts with a wild boar images from the territory of Crimea peninsula are introduced into scientific circulation.

Abstract. At laboratory timescales, rock salt samples with different composition and microstructure show variance in steady-state creep rates, but it is not known if and how this variance is manifested at low strain rates and corresponding deviatoric stresses. Here, we aim to quantify this from the analysis of multilayer folds that developed in rock salt over geological timescale in the Ocnele Mari salt mine in Romania. The formation is composed of over 90 % of halite, while distinct multiscale layering is caused by variation in the fraction of impurities. Regional tectonics and mine-scale fold structure are consistent with deformation in a shear zone after strong shearing in a regional detachment, forming over 10 m scale chevron folds of a tectonically sheared sedimentary layering, with smaller folds developing on different scales in the hinges. Fold patterns at various scales clearly indicate that during folding, the sequence was mechanically stratified. The dark layers contain more impurities and are characterised by a more regular layer thickness compared to the bright layers and are thus inferred to have higher viscosities. Optical microscopy of gamma-decorated samples shows a strong shape-preferred orientation of halite grains parallel to the foliation, which is reoriented parallel to the axial plane of the folds studied. Microstructures indicate dislocation creep, together with extensive fluid-assisted recrystallisation and strong evidence for solution–precipitation creep. This provides support for linear (Newtonian) viscous rheology as a dominating deformation mechanism during the folding. Deviatoric stress during folding was lower than during shearing in the detachment at around 1 MPa. We investigate fold development on various scales in a representative multilayer package using finite-element numerical models, constrain the relative layer thicknesses in a selected outcrop, and design a numerical model. We explore the effect of different Newtonian viscosity ratios between the layers on the evolving folds on different scales. By comparing the field data and numerical results, we estimate that the effective viscosity ratio between the layers was larger than 10 and up to 20. Additionally, we demonstrate that the considerable variation of the layer thicknesses is not a crucial factor to develop folds on different scales. Instead, unequal distribution of the thin layers, which organise themselves into effectively single layers with variable thickness, can control deformation on various scales. Our results show that impurities can significantly change the viscosity of rock salt deforming at low deviatoric stress and introduce anisotropic viscosity, even in relatively pure layered rock.

Specialized proton-secreting cells known collectively as mitochondria-rich cells are found in a variety of transporting epithelia, including the kidney collecting duct (intercalated cells) and toad and turtle urinary bladders. These cells contain a population of characteristic tubulovesicles that are believed to be involved in the shuttling of proton pumps (H+ATPase) to and from the plasma membrane. These transporting vesicles have a dense, studlike material coating the cytoplasmic face of their limiting membranes and similar studs are also found beneath parts of the plasma membrane. We have recently shown that this membrane coat does not contain clathrin. The present study was performed to determine the structure of this coat in rapidly frozen and freeze-dried tissue, and to determine whether the coat contains a major membrane protein transported by these vesicles, a proton pumping H+ATPase. The structure of the coat was examined in proton-secreting, mitochondria-rich cells from toad urinary bladder epithelium by rapidly freezing portions of apical membrane and associated cytoplasm that were sheared away from the remainder of the cell using polylysine-coated coverslips. Regions of the underside of these apical membranes as large as 0.2 micron2 were decorated by studlike projections that were arranged into regular hexagonal arrays. Individual studs had a diameter of 9.5 nm and appeared to be composed of multiple subunits arranged around a central depression, possibly representing a channel. The studs had a density of approximately 16,800 per micron2 of membrane. Similar arrays of studs were also found on vesicles trapped in the residual band of cytoplasm that remained attached to the underside of the plasma membrane, but none were seen in adjacent granular cells. To determine whether these arrays of studs contained H+ATPase molecules, we examined a preparation of affinity-purified bovine medullary H+ATPase, using the same technique, after incorporation of the protein eluted from a monoclonal antibody affinity column into phospholipid liposomes. The affinity-purified protein was shown to be capable of ATP-dependent acidification. In such preparations, large paracrystalline arrays of studs identical in appearance to those seen in situ were found. The dimensions of the studs as well as the number per square micrometer of membrane were identical to those of toad bladder mitochondria-rich cells: 9.5 nm in diameter, 16,770 per micron2 of membrane.(ABSTRACT TRUNCATED AT 400 WORDS)

This thesis is devoted to the study of semistability condition of type t=(a,b,c,N) decorated bundles and sheaves in order to better understand and simplify it. We approach the problem in two different ways: on one side we “enclose” the above semistability condition between a stronger semistability condition (\epsilon-semistability) and a weaker one (k-semistability), on the other side we try, and succeed for the case of a = 2, to bound the length of weighted filtrations on which one checks the semistability condition.

With its origin dating back to as early as the 500 BC, the ukkil forms part of a centuries-old woodcarving art and tradition of the Suluk, one of the many indigenous ethnic groups of Nusantara (Southeast Asia). Suluk ukkil bears striking resemblance to the Malay ukir, both featuring similar patterns and motifs. The ukkil is often used to decorate jewellery, boats, houses, grave markers, and mosques. It is also used to decorate the hilts and sheaths of bladed weapons such as the barung. The barung refers to the thick, leaf-shaped sword of the Suluk. A barung with beautifully carved hilt and sheath, especially those using expensive wood, is considered high value and usually reserved for Suluk aristocrats. This book narrates the expressions, motifs and meanings behind ukkil carved on the barung. It is based on the results of a two-year field research conducted in different districts of Sabah. It presents data gathered through various interviews with owners, elders, and subject-matter experts. It also presents data from direct observations of heirloom barung that are still found in the hands of a few Suluk and individuals from other indigenous ethnic groups. It presents new insights from analysis made using the Theory of Iconology, a framework of analyzing art popularized by German art historian Erwin Panofsky. The predominant themes of ukkil found on ancient barung in Sabah are Islamic; zoomorphic such as birds, lizards, snakes, and squids; plantomorphic such as vines, flowers, and leaves; and cultural such as those depicting local myths, culture, values and traditions of the Suluk. Each of these images and themes represent realities that shaped the daily lives of the Suluk from the past until today, including the wind, the ocean waves and sea currents, all of which are essential for travel and navigation. They also depict concepts, beliefs and practices important to the Suluk such as freedom, livelihood, aristocracy, harmony within the community, leadership, spirituality, and Islamic principles. The Suluk are a sea-faring people who have a deep relationship with their immediate environment, especially the sea. Suluk carvers draw inspiration from nature, the environment around them, their local culture, their religious practices, and their own values and ideals in life. Both the ukkil and the barung are an embodiment of their rich past, their livelihood, creativity, their faith, their principles and their values in life. Sadly, the practice of ukkil-carving is fast declining nowadays, with only very few practitioners left and so few individuals interested in learning about it. The barung too, where the ukkil is often carved on, is no longer being produced in large numbers. As the ukkil, like all forms of art, constitute an integral part of a nation’s culture and identity, it is important for it to be understood, preserved, and protected. This book provides fresh knowledge and insights that will help the Suluk and other indigenous tribes of Malaysia and Nusantara in the understanding and preservation of the ukkil as an essential aspect of their country’s or their region’s culture and heritage. This book offers historical background that will help explain the identity of the Suluk as a culturally and artistically advanced people with deep interconnection with other indigenous ethnic groups in Malaysia and the rest of Nusantara as early as the pre-colonial period. Knowledge about the ukkil can help people connect and correct their thoughts about the Suluk while at the same time promote cultural awareness and diversity among Malaysians and other people in Southeast Asia. This book will hopefully pave the way for more research to be done on the arts and culture, not just of the Suluk but also of other indigenous ethnic groups in the region as well. That knowledge will serve as a medium for keeping harmony and cultural links among each and every Malaysian and Nusantaran.