bluuebunny/crossref_metadata_2025_split huggingface dataset:
On explicit formulas of edge effect correction for Ripley'sK‐function
Authors: Goreaud François , Pélissier Raphaël 
Published: May 2006

Abstract.The analysis of spatial pattern in plant ecology usually implies the solution of some edge effect problems. We present in this paper some explicit formulas of edge effect correction that should enable plant ecologists to analyse a wider range of real field data.We consider the local correcting factor of edge effect for Ripley'sK‐function, that can also be used for other statistics of spatial analysis based on the counting of neighbours within a given distance. For both circular and rectangular study areas, we provide a review of explicit formulas and an extension of these formulas for long and narrow plots. In the case of irregular‐shaped study plots, we propose a generalization of the method that computes edge effect correction by excluding triangular surfaces from a simple (rectangular or circular) initial shape.An example in forest ecology, where the soil characteristics determine a study plot of complex shape, illustrates how this edge effect correction can be effective in avoiding misinterpretations.
Vegetation development in dune slacks: the role of persistent seed banks
Authors: Bekker R.M. , Lammerts E.J. , Schutter A. , Grootjans A.P. 
Published: May 2006

Abstract. The soil seed bank composition was determined at four sites in the dune slack ‘Koegelwieck’ on the Dutch Wadden Sea island of Terschelling. At three different sites in the slack, where sod‐cutting experiments down to the mineral sand had been carried out, the established vegetation and seed bank were assessed after 5, 9 and 39 yr of undisturbed development, respectively. In addition, a fourth site in the slack was investigated, where vegetation development had proceeded for 80 yr since plant colonization of bare soil and where nowadays a vegetation dominated by Calamagrostis epigejos and Salix repens occurs. Together these four sites can be regarded as a chronosequence of dune slack formation.Clear time sequences were detected in the seed bank data. Many late successional species showed a significant increase in the number of seeds during the succession. Some of the early successional basiphilous pioneer species such as Anagallis minima, Centaurium littorale, Littorella uniflora, Radiola linoides and Samolus valerandi, showed either a decrease during the time of succession or an optimum in the vegetation while remaining present in the seed bank in low but detectable numbers. They could, therefore, play a role in re‐establishment of the vegetation after sod‐cutting. One of the target species, Schoenus nigricans, established within a few years after removal of the sod. However, no seeds of this species have been detected in the soil below either of the successional stages. Based on the species disappearance from the established vegetation and based on the independent data of Thompson et al. (1997) an estimation of seed longevity could be made for several Red List species of wet dune slacks.
Response patterns of Vaccinium myrtillus and V. vitis‐idaea along nutrient gradients in boreal forest
Authors: Mäkipää Raisa 
Published: May 2006

Abstract. The relationships between biomass of dwarf shrub species and nutrient gradients of forest soils was studied under field conditions in boreal forests. The biomass‐response curves of Vaccinium myrtillus and V. vitis‐idaea were fitted against soil nutrient gradients using Generalized Linear Models (GLM). Ecological niches of Vaccinium myrtillus and V. vitis‐idaea were evaluated, and effects of nitrogen addition (manipulation of the nutrient gradient) on response function were tested.The Vaccinium species showed statistically significant Gaussian responses along soil nitrogen, phosphorus and calcium gradients, but not along other gradients (K and Mg). Furthermore, manipulation of the nitrogen gradient seemed to have a minor effect on response functions, i.e. addition of nitrogen did not change ecological niches of these species. Ecological optima of V. myrtillus and V. vitis‐idaea on the nutrient gradients were about the same. This study suggests that differences in dominance between Vaccinium myrtillus and V. vitis‐idaea in boreal forest is not determined by nutrient gradients, but may rather be explained by light conditions and/or moisture availability.
Species diversity, niche metrics and species associations in harvested and undisturbed bogs
Authors: Soro Antonella , Sundberg Sebastian , Rydin Håkan 
Published: May 2006

Abstract. Competition is considered an important force in structuring plant communities and in governing niche relations, but communities recovering from disturbance, may be less governed by species interactions and less orderly organized. To address this issue, we studied species richness, abundance and patterns of association between plant species at three spatial scales (1 m2, 1/25 m2, 1/625 m2) in two ombrotrophic mires in east‐central Sweden. One was at a secondary successional stage following peat extraction 50 yr ago and the other was undisturbed. Peat extraction leads to a change in hydrology which is slowly restored by the formation of new peat. Niche breadth and niche overlap along the gradient of height above the water table were calculated for the five common Sphagnum species occurring at both mires in an attempt to better understand differences in species co‐occurrence at each mire.Species cover differed between the mires, and the number of species per plot was higher in the undisturbed community at all scales, suggesting that the degree of species intermingling was greater than at the harvested site. At all scales, the number of non‐random associations was higher, and niche overlap lower among ecologically similar species (e.g. hollow Sphagnum species) in the undisturbed mire. These differences indicate that random events are important in colonization, and that biotic interactions between neighbours later result in a higher degree of non‐randomness.In addition, we surveyed a number of abandoned peat pit sites to test the effect of disturbance for species composition at a regional scale. Ombrotrophic peat pits contained several Sphagnum species normally associated with minerotrophic mires, and species of wooded mires occurred frequently in peat pits, making them more species‐rich than undisturbed bogs. There were also Sphagnum species new to, or rare in, this part of Sweden which indicates effective long‐distance dispersal. Even 50 yr after peat extraction had ceased, the vegetation had not recovered to its original composition.
A long‐term study of Pinus banksiana population dynamics
Authors: Kenkel N.C. , Hendrie M.L. , Bella I.E. 
Published: May 2006

Abstract. The long‐term population dynamics of a pure, naturally‐established stand of Pinus banksiana (jack pine) in southeastern Manitoba, Canada is described. The study was initiated at stand age 15, when all 468 trees in a plot were mapped and their trunk diameter at breast height (DBH) measured. The plot was remeasured eight times — every five years (six years in one case) — and mortality and DBH changes recorded. Total mortality over the 41‐yr study period was ca. 84 %. Mortality was initially very low, increased once the stand entered the self‐thinning stage from ages 25–46, and declined at ages 46–56. Mortality was restricted to the smallest size classes throughout. The stand reached the self‐thinning line at ca. age 30. The self‐thinning slope was significantly less steep than the theoretically expected value of −0.5.The distribution of DBH values was initially symmetric, showed increasing positive skewness during the period of highest mortality, and became symmetric again at later stages. Size (DBH) inequality was highest just prior to the onset of density‐dependent mortality, and subsequently declined. Tree DBH values were positively autocorrelated both initially and at later stages of stand development, but were spatially independent during the period of highest density‐dependent mortality. The stand initially had a strongly clumped pattern at all spatial scales. Patterns of mortality were non‐random during stand development, however, resulting in increased spatial regularity over time. Mortality was initially restricted to high density patches of the stand, but occurred throughout the plot once the self‐thinning line was reached. Mortality during the self‐thinning stage deviated from random expectation at local spatial scales (1–2m radius), suggesting that individuals were competing with their immediate neighbours. It is argued that an integrated approach, incorporating both population size and spatial structures, is essential in improving our understanding of long‐term plant population dynamics.
Can we trust gradients extracted by Detrended Correspondence Analysis?
Authors: Ejrnæs Rasmus 
Published: May 2006

Abstract. In this study, data from dry temperate grassland vegetation in Denmark are used to compare the predictive power of gradients obtained by ordination. One of the problems of ordination methods based on weighted averaging, namely the assumption of symmetric, unimodal response curves, is investigated by smoothing species responses to simple and complex gradients respectively.It was found that species response types to a pH gradient are diverse and often deviate from a unimodal, symmetrical shape. Bimodal responses were also found, but they disappeared when more influential gradients were considered. Many species showed truncated responses with optima near gradient ends.In order to assess the impact of unrealistic response assumptions and reported problems with instability on the performance of DCA, the predictive potentials of measured variables and coenoclines extracted by DCA were compared. Despite field data violating the assumption of unimodal response, DCA was found to extract gradients predicting species abundance better than the environmental variables available. Shortcomings and advantages of indirect and direct methods in plant ecology are discussed.
An Editor Recalls Some Hopeless Papers
Authors: Hodges Wilfrid 
Published: May 2006

§1. Introduction. I dedicate this essay to the two-dozen-odd people whose refutations of Cantor's diagonal argument (I mean the one proving that the set of real numbers and the set of natural numbers have different cardinalities) have come to me either as referee or as editor in the last twenty years or so. Sadly these submissions were all quite unpublishable; I sent them back with what I hope were helpful comments. A few years ago it occurred to me to wonder why so many people devote so much energy to refuting this harmless little argument—what had it done to make them angry with it? So I started to keep notes of these papers, in the hope that some pattern would emerge.These pages report the results. They might be useful for editors faced with similar problem papers, or even for the authors of the papers themselves. But the main message to reach me is that there are several points of basic elementary logic that we usually teach and explain very badly, or not at all.In 1995 an engineer named William Dilworth, who had published a refutation of Cantor's argument in the Transactions of the Wisconsin Academy of Sciences, Arts and Letters, sued for libel a mathematician named Underwood Dudley who had called him a crank ([9] pp. 44f, 354).
Domains for Computation in Mathematics, Physics and Exact Real Arithmetic
Authors: Edalat Abbas 
Published: May 2006

AbstractWe present a survey of the recent applications of continuous domains for providing simple computational models for classical spaces in mathematics including the real line, countably based locally compact spaces, complete separable metric spaces, separable Banach spaces and spaces of probability distributions. It is shown how these models have a logical and effective presentation and how they are used to give a computational framework in several areas in mathematics and physics. These include fractal geometry, where new results on existence and uniqueness of attractors and invariant distributions have been obtained, measure and integration theory, where a generalization of the Riemann theory of integration has been developed, and real arithmetic, where a feasible setting for exact computer arithmetic has been formulated. We give a number of algorithms for computation in the theory of iterated function systems with applications in statistical physics and in period doubling route to chaos; we also show how efficient algorithms have been obtained for computing elementary functions in exact real arithmetic.
Recent discoveries in Eastern Cilicia
Authors: Bent J. Theodore 
Published: May 2006

Hearing of extensive and unidentified ruins on the banks of the river Jeihan (the ancient Pyramus) at a spot now called Bodroum to the east of the Cilician plain, just as the river enters the plain from the gorges of the Anti-Taurus, we determined to visit the site. The result of our explorations, made in the early months of this year, are as follows.Our route took us past the rock of Anazarba and Kars Bazaar, at which places we decided to spend a few days, and though the spots have both been previously described we were able to add a few points to the information concerning them, both epigraphical and topographical.Anazarba.—Caesarea penes Anazarbum, as Ptolemy calls it, was second only in importance to Tarsus of the cities of Cilicia during the days of imperial Rome, and was the metropolis of the eastern portion of the great plain. The town was built at the foot of a long rocky mountain, rising like an island out of the plain for the extent of three miles and attaining an altitude of 2,000 feet. The walls as they at present stand are of Armenian and Saracenic construction, enclosing a parallelogram, one side of which is protected by the mountain; but they contain many portions of Roman work, notably the great southern gate formed by a triumphal arch erected in the time of Justinian, when that emperor restored the town after it had been ruined by an earthquake.
The Homeric Talent, its Origin, Value, and Affinities
Authors: Ridgeway William 
Published: May 2006

This paper is an endeavour to discover (1) the origin, (2) the value, and (3) the affinity of the Talent of the Homeric Poems to other systems. In those Poems we find two systems of denominating value, the one by the ox (or cow), or the value of an ox, the other by the talent (τάλαντον). The former is the one which has prevailed and does still prevail in barbaric communities, such as the Zulus, where the sole or principal wealth consists in herds and flocks. For several reasons we may assign to it priority in age as compared with the talent. For as it represents the most primitive form of exchange, the barter of one article of value for another, before the employment of the precious metals as a medium of exchange, consequently the estimation of values by the ox is older than that by a talent or ‘weight’ of gold, or silver, or copper. Again in Homer all values are expressed in so many beeves, e.g. (Il. vi. 236.)The talent on the other hand is only mentioned in relation to gold; for we never find any mention of a talent of silver. But the names of monetary units hold their ground long after they themselves have ceased to be in actual use, as we observe in such common expressions as ‘bet a guinea,’ or ‘worth a crown,’ although these coins themselves are no longer in circulation.
Actors with Bird-Masks on Vases
Authors: Smith Cecil 
Published: May 2006

Plate XIV. B represents an unpublished vase of the British Museum, which originally formed part of the Burgon Collection: it appears to have been found in Italy in 1835. It is an oinochoè with black figures on a red panel, and may be assigned to a period between about 500 and 450 B.C.A representation upon an amphora published by Gerhard in his Trinkschalen, Pl. XXX. Figs. 1—3, so evidently relates to a similar subject, that it is here reproduced for comparison on the same plate (Fig. A). This picture shows us an auletes playing upon the double flutes in the presence of two grotesque-looking figures, apparently human, who are closely draped in long cloaks, himatia, and to whom his back is turned. That the heads of these two figures are intended to represent the heads of some sort of bird is evident from the beak-like conformation of the features, and by the purple crests which rise vertically from the crown. Gerhard, in publishing this vase, has for want of any better explanation described this scene as representing a parody or a mummery symbolical of a cock-fight. Viewed, however, in the light of the evidence afforded by the British Museum vase, this theory seems to me improbable: yet I am bound to say that I am unable to advance any explanation which seems entirely satisfactory.
A Summer in Phrygia: Part II
Authors: Anderson J. G. C. 
Published: May 2006

After exploring the north side of the Lycos valley, and before proceeding down the right bank of the Maeander towards Ortakche (see Part I. init.), we spent a short time in the Phrygo-Lydian borderland, seeking for some evidence to clear up the uncertainties attaching to the situation of Sala, Tralla, Aetos, Kallatebos, and Apollonos-Hieron. (See Plate IV.)In discussing this district, I enjoy the advantage of having before me the work of three previous explorers, Prof. Ramsay, Prof. Radet, and the late Dr. Karl Buresch. I have been careful to quote the opinions of these critics, though I must sometimes differ from them, because it is convenient for the reader to have before him all the views that are, or have been, held in regard to each town. Amid a few differences, I find myself in general agreement with Prof. Ramsay and Dr. Buresch. In the development of their views from the earliest to the latest stage there is, happily, a steady approximation towards the same results; and yet, by a strange accident, this approximation was quite unconscious, for Dr. Buresch knew only Prof. Ramsay's earliest views, while Prof. Ramsay in his latest work had only a very imperfect knowledge of Dr. Buresch's earliest opinions. I regret that I am obliged to differ more widely from the results reached by M. Radet, and, as some readers might put a wrong construction on such expressions of dissent, I would here record my appreciation of the value of his fresh and suggestive work. When a subject is in process of growth, every suggestion and every fresh point of view are valuable, and it is only by due consideration and open criticism of all proposed combinations that we can cherish the hope of ultimately reaching, or approximating to, the truth.
A Suggested Characteristic in Thukydides' Work
Authors: Grundy G. B. 
Published: May 2006

The matter of this paper has been a subject of consideration with me for some time past, and I venture to put forward the conclusion I have arrived at, not because I consider it to be a certain one, but as possibly affording a working hypothesis providing an explanation of what has been to me, and may have been to others, an obscure and difficult point. That the subject demands the earnest attention of those who study Thukydides will, I think, be generally admitted, and this, together with the fact that I have formed the conclusion on a certain amount of first-hand experience, may afford some excuse for the publication of my views.The vast majority of the incidents in the Peloponnesian War are treated by Thukydides with great brevity, in some cases with a brevity disproportionate to their importance. There are, however, according to the ordinary acceptation, three incidents into which he enters with a peculiar and striking amount of detail.
The Text of the Homeric Hymns: I
Authors: Allen T. W. 
Published: May 2006

This article is a sequel to the text of the Homeric Hymns published by the Clarendon Press in the year 1893. For that edition it was my duty to write a preface, which under the circumstances did no more than enumerate the manuscripts and summarize the views as to their relations held by the principal writers. Since that time I have studied the subject of the tradition of these Hymns at greater leisure, and I now present such conclusions as I have been able to attain.The reviewers of Mr. Goodwin's edition, while indulgent to the book as a whole, took exception to our neglect of modern criticism, the few conjectures that had been inserted in the text, and the scanty record of others, usually accepted, in the notes. As this circumstance, so far as it depended on myself, was the fruit of conviction, and since I have followed out the principle upon which I then acted more at length in this article, I may be allowed to spend a few words in explanation of the position which in these matters I take.
A Statue of a Hellenistic King
Authors: Edgar C. C. 
Published: May 2006

The statue reproduced on Pl. II. was found two years ago in the village of Atfih which lies about forty-five miles south of Cairo on the edge of the eastern desert. Atfih preserves the name and occupies the site of the ancient Per nebt tep aht, the city of the cow-headed goddess Hathor. The Greeks, who identified Hathor with their own Aphrodite, translated the name into Aphroditopolis. The ruins of the town are covered by the modern village, but in the adjoining desert is a large cemetery, mainly of the Ptolemaic period, which Mr. Johnson has recently excavated in search of Greek papyrus.The statue was found accidentally by a labourer digging in the village and was secured for the Cairo Museum by the local Inspector of the Antiquities Department. It is made of a block of rather soft limestone and is considerably more than life size, the height of the figure without the plinth being 2·5 m. Both forearms are missing. The right leg from knee to ankle and parts of the left leg are restored in plaster. The features are badly damaged. There are no remains of paint or gilding on the surface of the limestone.
Wrestling. II
Authors: Gardiner E. Norman 
Published: May 2006

The attitude adopted by the Greek wrestler before taking hold, as described by Heliodorus, and frequently represented in art, was very similar to that in use at the present day. Taking a firm stand with his feet somewhat apart and knees slightly bent, rounding (γυρώσας) his back and shoulders, his neck advanced but pressed down into his shoulder blades, and his waist drawn in (σφηκώσας), he tried to avoid giving any opening (λαβή) himself, while his outstretched hands were ready to seize any opportunity offered by his opponent.Various methods of attack are enumerated by Plutarch. Symp. ii. 4. μόνους δὲ τοὺς παλαιστὰς ὁρῶμεν ἀλλήλους ἀγκαλιζομένους καὶ περιλαμβάνοντας καὶ τὰ ολεῖστα τῶν ἀγωνισμάτων ἐμβολαὶ παρεμβολαίσυστάσεις παραθέσεις συνάγουσιν αὐτοὺς καὶ ἀναμίγνυνται ἀλλήλοις These terms, arranged in contrasted pairs, denote the various positions and movements of wrestlers before they take hold.