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Stochastic fluctuations of chemical reactions are particularly prominent in small systems such as cells. Such fluctuations of cellular signal processes have been observed directly by single-molecule imaging. Recent theoretical studies have also revealed that stochastic cellular reactions generate fluctuations in the number of a molecule, which can be related to their functioning such as amplification of signals. Here, we study how large each signal reaction generates and amplifies the stochastic fluctuations. The general framework of fluctuation response relation in non-equilibrium physics throws light upon this problem. The result has been applied to the chemotactic signal processing of eukaryotic cell, such as Dictyostelium cell, revealing that the accuracy of chemotaxis is determined by the signal to noise ratio in the signal of the reaction between G-protein and G-protein coupled receptor. [ABSTRACT FROM AUTHOR]

We investigate the damping of fluctuations of order parameters in a two-band model of superconductivity in dependence on intra- and interband interactions. The relevant free energy and kinetic equations have been derived. On the basis of these equations one can distinguish two different time scales in the relaxation of superconducting fluctuations. The considerable non-monotonic temperature dependence of the relaxation times has been established below the phase transition point. The behavior is caused by the certain competition between intra- and interband couplings and it allows one to estimate the ratio of these interactions. [ABSTRACT FROM AUTHOR]

The Doñana Natural Area includes a large array of wetlands with the highest degree of environmental protection in Spain, and so it has long attracted many studies. We present a cumulative list of zooplankton taxa (Copepods and Branchiopods) based on a collection of 18 publications (1964–2007) and 4 unpublished studies. Seventy-eight taxa have been recorded in a set of 55 ponds, and 72 taxa at 38 sites spread over the Doñana marshland. In total, 96 taxa have been recorded, including 50% of all branchiopod species reported for the whole Iberian Peninsula. Taxa composition was significantly segregated between ponds and marshland during floods (ANOSIM test, R = 0.929, P < 0.01), but this segregation disappeared at a larger spatio-temporal scale when a non-metric MDS ordination produced a gradient from ponds to marshland (ANOSIM test, R = 0.272, P < 0.01). The lack of segregation between ponds and marshland sites, and among ponds with different hydroperiods, was not due to a large number of cosmopolitan species, but to a random distribution of a large number of low-occurrence species (67% of total taxa occurred with a frequency <15%). Long-hydroperiod ponds occupy a key position among the Doñana wetlands in terms of biodiversity as these ponds accumulated a high crustacean richness over time. They also supported a significantly higher cumulative number of cladoceran and harpacticoid taxa, while short-hydroperiod ponds accumulated the lowest number of diaptomid taxa. Our data indicate the need for recording biodiversity in the long term as richness on a short-temporal scale is not a good indicator of the number of crustacean species that would be encountered with a longer sampling period in Mediterranean temporary wetlands. [ABSTRACT FROM AUTHOR]

The process of hearing can be understood as one arising through the action of a number of nonlinear elements operating near dynamical instabilities in an environment subject to fluctuations. The sound detector in the inner ear, the mechanoelectrical transducer hair cell can be modelled as a forced Hopf oscillator. When such a system is additionally equipped with a regulatory feedback mechanism which ensures that the system always remains self tuned to operate very close to the bifurcation, then the presence of weak noise can assist in enhancing hugely the amplification of weak stimuli. The fast variable gets phase-locked with the external stimulus for all values of the signal amplitude, showing that the phenomenon is distinct from stochastic resonance. Drawing upon some interesting results obtained for a generic nonlinear system, some speculations can be made in the context of hearing. We suggest a plausible explanation for the hitherto unexplained source of the peaks in the spontaneous otoacoutic emission spectra of various organisms. [ABSTRACT FROM AUTHOR]

The multiplicity fluctuations in nucleus-nucleus collisions at SPS and RHIC energies within the HSD transport approach and statistical model have been studied. Both energy and system size dependences of the scaled variances have been analyzed for proton–proton and central nucleus–nucleus collisions. The importance of rigid centrality trigger has been discussed additionally. [ABSTRACT FROM AUTHOR]

Introduction: a variety of urban political forms The political history of towns in early modern Europe is conventionally depicted in terms of their growing subservience to the expanding state which underpinned the consolidation of oligarchy, the displacement of merchants and craftsmen on town councils by royal officeholders and the penetration of civic government by the rural elites. It is a model which has proved influential in approaching the history of towns in the British archipelago. The later seventeenth century, in particular, is seen as a period when calculations of parliamentary electoral advantage led the crown and rural elites into massive interventions in urban affairs which curbed their autonomy. However, many of the assumptions underpinning the model have been under attack. In view of the weakness of its own resources the power of the centre could only advance by means of compromises with local groups; likewise municipal magistrates could only hope to implement their policies by involving craftsmen and tradesmen in local administration; and changes in our understanding of patronage relationships have led to the realisation that interventions by the rural elites often occurred at the instigation of townsfolk anxious to exploit the relationship with outsiders to their own ends. Civic ideals may well have retained more strength in 1700 than is often recognised, and this chapter will argue that they remained an important force in blunting the very real ideological divisions released by the Reformation and reinforced by the legacies of the conflicts of the Civil Wars and the Exclusion Crisis. [ABSTRACT FROM AUTHOR]

The sixteenth-century pattern In the early sixteenth century Scotland was undoubtedly less urbanised than England. Data on the population size of Scottish towns are very rare before the middle decades of the seventeenth century but Jan de Vries has calculated that in 1550 1.4 per cent of the Scottish population lived in towns of 10,000 inhabitants or more compared to 3.5 per cent in England and Wales. Another estimate, by Ian Whyte, suggests that 2.5 per cent of Scots were dwelling in towns of over 2,000 in population in 1550 whereas in 1600 8.7 per cent of the population of England were living in towns of this size or bigger. Not only was Scotland an overwhelmingly rural society in this period, more akin to countries such as Ireland and Denmark than to England or Holland, it was also one where urban development was very regionally concentrated. Whole areas, especially in the Highlands and southern Uplands, lacked any urban focus and were distant from any developed marketing centre. In the main, the Scottish towns of the sixteenth century were located in the central Lowlands, especially around the estuaries of the Forth, Tay and Clyde, along the east coast from Edinburgh to Aberdeen and in the lower Tweed valley to the south. These were regions of relatively dense population and rich arable land. It is also the case that in some of these areas town development was extensive and contrasted with the national pattern of very modest urban growth. Recent demographic research on the seventeenth-century hearth taxes has shown that the five counties around the River Forth, East Lothian, Midlothian, Fife, Clackmannan and West Lothian, had by far the highest percentage of town dwellers in Scotland with a level of urbanisation which could be compared to parts of the Netherlands. [ABSTRACT FROM AUTHOR]

Writing home to the Doge and Senate, those crusty patricians ensconced in their colonnaded palace on St Mark's Square, Venetian ambassadors to the Tudor Court hymned the praises of London as one of the principal cities of Europe, but ignored or dismissed almost all the remaining English towns. Other sixteenth-century visitors from the great continental states were equally critical. Only travellers from the more remote central European countries found anything remarkable in English provincial towns. Scottish and Welsh towns barely figure in foreign reports: Edinburgh on one occasion was compared to a French country town. Yet by the late eighteenth century British towns – not just London but provincial towns – were the envy of the civilised world, admired in the many travellers' accounts which rehearsed details of their affluence, manufactures, vigorous club life, bustling, friendly shops, well-lit, orderly streets, and much else. Whereas at the start of our period only a minority of English people, maybe 15 per cent or so (and a much lower proportion in Scotland and Wales) resided in cities and towns, by the accession of Queen Victoria nearly half the British population was urban. Not only was there an increasingly integrated national system of towns, but British towns became notable as centres of economic and social innovation, of political discourse and cultural enlightenment, their advance having a growing impact on national society and beyond. Hitherto located on the European periphery in terms of urban development, analogous to regions like Scandinavia and central Europe with their low urban populations and localised towns, from the eighteenth century Britain emerged as the chief laboratory of a modernising world. [ABSTRACT FROM AUTHOR]

Introduction The main purpose of this book is to investigate in detail long-term variations in the length of the day, or equivalently, changes in the Earth's rate of rotation, using pre-telescopic observations of eclipses. Such variations are mainly produced by lunar and solar tides, but non-tidal mechanisms are also significant. Despite its historical bias, this subject has become an important topic in modern geophysics. In studying changes in the length of the day which have occurred in recent centuries (since the invention of the telescope), more accurate data than eclipses are available. These include occultations of stars by the Moon up to 1955 and systematic monitoring of the Earth's rotation relative to the atomic time-scale since that date. However, observations of eclipses provide by far the most consistent and reliable source of information on variations in the terrestrial rate of rotation during the pre-telescopic period. Although numerous early accounts of eclipses are to be found in astronomical works, many others are scattered in a variety of writings – for example the Greek and Latin classics, imperial annals of China and monastic chronicles of Europe. Observations recorded in these works are often extremely crude by modern standards, but the lengthy time-scale covered is highly suited to the detection of long-term trends which are not apparent from more recent data. The investigation of this diverse material adds a whole new dimension to what might otherwise have been a somewhat narrow scientific discipline. [ABSTRACT FROM AUTHOR]

You should propose that the scientific investigations shall be accompanied by a practical exposé of the steps to be taken in order to bring the exercise of sea fishing more in accord with the natural conditions regulating the growth and increase of fish, and thus permanently increase the supply of fish in the markets of the countries adjoining the North Sea. Throughout the 1880s and the 1890s many conferences were held with the goal of promoting international cooperation between the nations of Europe. Some of these conferences were mundane but important for regulation of international trade and commerce, such as the ‘North Sea Convention’ of 1882, which defined ‘territorial waters’ and agreed upon a vessel identification and marking scheme. Others failed to reach agreement, but helped to define what would be needed, such as the National Sea Fisheries Protection Association's conferences on international cooperation in fishing during the 1890s (see chapter 3), and the 1892 Peace Congress in Berne. Of the many conferences of this period, two held late in the century are of particular interest, each in its own realm. In 1897 Nicolas II, Tzar of Russia, proposed an arms limitation conference, a proposal that shocked the world and prompted a skeptical poem by Kipling, from which came the famous phrase ‘the bear that walks like a man.’ [ABSTRACT FROM AUTHOR]

[T]he fluctuation of year classes [is] a prominent, perhaps the predominating factor determining fluctuations in the fisheries. Hjort's conclusions that the fluctuations in the catches were due, at least in part, to the large variability in the numbers of young herring and cod surviving from each year's spawning were accepted by almost all scientists by 1920. While D. W. Thompson continued to argue that herring scales could not reveal age precisely, and hence could not be relied on to reveal fluctuating age compositions as Hjort claimed, many other scientists began to demonstrate similar fluctuations in age frequency distributions for other species of fish. Armed with Hjort's answer to the question posed to Sars now more than a half century earlier, and with the results of the ‘War Experiment’ demonstrating the effects of reducing fishing intensity, scientists entered the 1920s with a sense of optimism. One cause of the fluctuations of fish populations was known, and the possibility ‘of turning our knowledge to the practical guidance of the fishermen’ (Thompson, H. 1929) by predicting future catches began to attract the interest of several biologists working in the North Sea and in North America. Three approaches were taken. One was based on monitoring the varying age distributions by directly sampling the commercial catches or, using research vessels, sampling the population itself. This approach achieved moderate success for the North Sea haddock and East Anglia herring fisheries. [ABSTRACT FROM AUTHOR]

Ecosystems result from the integration of populations of different species in a common environment. They rarely remain steady for long, and fluctuations lie in the very essence of the ecosystems and of every one of the … populations. The truth of Margalef's observation was not apparent to scientists, fishermen, or politicians in the 1860s. The conclusion that ecosystems vary, and also the concepts used (population, environment, steady state, and even ecosystem) were virtually unknown. At that time, it was apparent only that catches varied from year to year despite the best efforts of the fishermen. The reality of this variation was painfully apparent. The amount of fish caught, and hence available as food, was much less in some years, leading at times to hunger. However, in other years the amount of fish caught was so high that prices plummeted and much went to waste, leading to economic difficulties. Catches might increase steadily for several years, encouraging investment in fishing gear and processing equipment, and leading to relocation of work forces, only to subsequently decline. Investments were lost, and people's economic plans and security compromised. The value of resources that are so variable is lessened. As Hugh Miller pointed out in an 1829 description of a Scottish herring fishery in the Inverness Courier: Its value must therefore be estimated in the same way that Directors of an insurance office would calculate upon that of the life of one who had a hereditary tendency to apoplexy. [ABSTRACT FROM AUTHOR]