bluuebunny/crossref_metadata_2025 huggingface dataset:
SIEVE‐ELEMENT PLASTIDS, PHLOEM PROTEIN, AND EVOLUTION OF FLOWERING PLANTS: III. MAGNOLIIDAE
Authors: Behnke H.‐Dietmar
Published: April 2006

Two hundred sixty‐three species of the Magnoliidae distributed over the main genera of all its families were investigated with the TEM for ultrastructural characters from their sieve elements. Details from sieve‐element plastids (overall diameter, as well as qualitative and quantitative measurements of their starch and protein contents) provided the main data set for a putative phylogenetic arrangement of the families of Magnoliiflorae. The recording of the presence or absence of non‐dispersive protein bodies and nacreous wall thickenings yielded additional information.

Within the Magnoliiflorae sieve‐element plastids are proposed to have evolved from large‐sized S‐type plastids with high amount of starch to small‐sized, starch‐deficient P‐type or, at the other extreme, to So‐plastids. Along this line a basic group containing Austrobaileyaceae, Illiciaceae, Schisandraceae, Chloranthaceae, Myristicaceae, and Winteraceae is distinguished from four parallel and slightly advanced groups, the Annona‐, Aristolochia‐, Magnolia‐, and Monimia‐groups.

The Aristolochia‐group is held to represent one of the core groups of the Magnoliiflorae, incorporating the whole range of the different plastid forms from S‐type to So‐plastids or by several steps to form‐Pc and the monocotyledon form‐P2c plastids. Among the remaining five the Monimia‐group, only, shows a comparably broad range, while all other taxa are confined to one or two plastid forms (i.e., S‐type and/or form‐Psc resp. ‐Pcs plastids).
TERMINOLOGY FOR BRYOPHYTE SEXUALITY: TOWARD A UNIFIED SYSTEM
Authors: Wyatt Robert
Published: April 2006

There is no general consensus among bryologists as to the best system for describing sexual expression in mosses, liverworts, and hornworts. Existing schemes are not logically consistent: in some cases they emphasize functional considerations and in other cases, genetic considerations. Different authors, especially those working with mosses versus liverworts, use the same term to describe different sexual conditions. Lack of a set of terms collateral with those most widely used for other embryophytes has prevented cross‐comparisons to the detriment of understanding in both areas. This paper illustrates these problems and suggests an alternative system of terminology that is logical, consistent, and comprehensive and which coincides with usage for pteridophytes and seed plants.
ACCUMULATION OF NICKEL BY PSYCHOTRIA SPECIES FROM THE PACIFIC BASIN
Authors: Baker Alan J. M. , Brooks Robert R. , Kersten William J.
Published: April 2006

Thirty‐two Psychotria species from New Caledonia and 178 from other islands of the Pacific Basin were analyzed for nickel in order to identify hyperaccumulators (> 1000 μg/g dry mass) of nickel. P. douarrei was the only taxon which possessed this character and contained a mean concentration of 2.24% nickel in its leaves. This is higher than for any other known hyperaccumulator of nickel. Pot trials showed that P. douarrei can grow in substrates containing up to 1% plant‐available nickel. It is suggested that P. dourarrei is a neoendemic taxon possibly derived from P. baillonii which occupies complementary ecological niches on non‐nickeliferous soils adjacent to the ultramafic substrates supporting P. douarrei. Evolution may have proceeded via an intermediate nickel‐tolerant ecotype of P. baillonii which can still be found growing in association with P. douarrei.
MORPHOLOGY AND ALKALOID CHEMISTRY OF PAPAVER SETIGERUM DC. (PAPAVERACEAE)
Authors: Valva Vincenzo La , Sabato Sergio , Gigliano Gesualdo Siniscalco
Published: April 2006

Papaver setigerum DC. populations from Mediterranean France and Campania, southern Italy, have been studied morphologically and phytochemically. Papaver setigerum, whose circumscription is reported to be substantially the same as P. somniferum L., revealed to be a species morphologically distinct from the latter. Morphine, codeine, and thebaine, the major alkaloids of P. somniferum, are lacking in capsules of P. setigerum. Their absence supports also at the chemotaxonomical level that P. setigerum is a distinct species from P. somniferum.
THE PHYLLOCLADACEAE KENG—A CRITIQUE
Authors: Quinn Christopher J.
Published: April 2006

The interpretation of the phylloclade of Phyllocladus by Keng (1974) as an ancient link between lateral branch systems of progymnosperms and the simple leaves of modern conifers is critically examined in the light of patterns of vascularisation, and his erection of the monogeneric family Phyllocladaceae (Keng, 1973, 1978) is challenged.
A MOLECULAR EVOLUTIONARY CLOCK FOR ANGIOSPERMS
Authors: Martin P. G. , Dowd J. M.
Published: April 2006

Pairs of angiosperm species putatively separated by continental drift following the break‐up of Gondwanaland have been used to derive linear regressions relating macromolecular differences to time. Differences have been derived from N‐terminal amino acid sequences of the small subunit of rubisco from members of Proteaceae, Winteraceae, Nothofagus and Solarium. Alternative sets of times have been taken from the literature on plate tectonics and biogeography. Botanical criteria have been used to discriminate tentatively between the two regression lines. The rate of evolution corresponding to the preferred regression is one inferred nucleotide difference between two evolutionary lineages in seven million years. An estimate of the variance about the regression lines has been obtained and has allowed suggestions about which species disjunctions are likely to have originated more recently than the continental separations.
Saturated NaCI‐CTAB solution as a means of field preservation of leaves for DNA analyses
Authors: Rogstad Steven H.
Published: April 2006

Rogstad, S. H.: Saturated NaCI‐CTAB solution as a means of field preservation of leaves for DNA analyses. ‐ Taxon 41: 701‐708. 1992. ‐ ISSN 0040‐0262.

Details of a method for preserving leaves for subsequent DNA analyses using a solution that is saturated (obviating precise field weighing of chemicals) with both NaCl and CTAB are presented. Since the dry ingredients are easy to obtain and transport, the method can be utilized even at very remote sites. Results from fresh versus preserved leaves of Podophyllum, Polyalthia (3 spp.), and Taraxacum demonstrate that DNA suitable for restriction fragment analysis can be obtained from leaves that have been stored in the solution for up to one month at ambient temperatures and then frozen for over one year at ‐20°C (ultracold storage at ‐70°C is not necessary). Degradation of DNA with this new method appears to be less for some taxa than with previously proposed DNA extraction methods using dried leaves. Analyses of DNA from leaves collected at remote rain forest sites are demonstrated.
Nomenclatural notes on some Malvaceae species described by Cavanilles
Authors: Fuertes Javier , Fryxell Paul A.
Published: April 2006

Fuertes, J. & Fryxell, P. A.: Nomenclatural notes on some Malvaceae species described by Cavanilles. – Taxon 42: 661–664. 1993. – ISSN 0040‐0262.

Typifications or interpretations of ten of Cavanilles's new binomials in Malvaceae are presented, based on examination of original materials in the Madrid herbarium.
Ciadistics in taxonomic botany – master or servant?
Authors: Hedberg Olov
Published: April 2006

Hedberg, O.: Ciadistics in taxonomic botany – master or servant? – Taxon 44: 3‐11. 1995. – ISSN 0040‐0262.

Cladistics, a nowadays often computerized methodology for taxonomic research, is claimed by its proponents to be more advanced and less subjective than traditional evolutionary systematics. It offers a convenient method of combining factual character state distribution with assumptions on directions of evolutionary change, and of constructing hypothetic evolutionary trees. But its usefulness in taxonomic botany is hampered by difficulties in outgroup selection, frequency of parallelisms and reversals, and wide variation within taxa. Prudently used, cladistics may certainly be a useful tool to botanical taxonomists, but if pursued as an independent computer game it may be harmful to taxonomy and to biology as a whole.
REMARKS ON THE PUBLICATION DATES OF TENORE'S FLORA NAPOLITANA
Authors: Sabato Sergio
Published: April 2006

The dating of the Prodromus and its two first supplements in Tenore's Flora Napolitana has been re‐examined. The reconstruction of the fascicles of the first volume and the publication dates are assembled in a table.
The reinstatement of the genus Xiphotheca (Fabaceae)
Authors: Schutte Anne Lise , Van Wyk Ben‐Erik
Published: April 2006

Schutte, A. L. & Van Wyk, B‐E.: The reinstatement of the genus Xiphotheca (Fabaceae). ‐Taxon 42: 43‐49. 1993. ‐ ISSN 0040‐0262.

The reinstatement of the genus Xiphotheca Eckl. & Zeyh. (Fabaceae, tribe Liparieae) is proposed. A study of the morphology and alkaloids of the genus Priestleya DC. has shown remarkable differences between its two sections, P. sect. Priestleya and sect. Aneisothea DC. (= Xiphotheca). The latter differs in its geminate flowers, the non‐intrusive calyx, the obtuse and pocketed keel petals, the uniform anthers, the shortly petiolate and pinnately veined leaves and the unique combination of alkaloids. A brief synopsis of the genus, including nomenclature, synonymy and typification, is presented.
Gender of generic names, particularly those ending in ‐ma, in the ‘Names in current use’ list
Authors: Nicolson Dan H.
Published: April 2006

Nicolson, D. H.: Gender of generic names, particularly those ending in ‐ma, in the ‘Names in current use’ list. – Taxon 43: 97‐107. 1994. – ISSN 0040‐0262.

A historical review of the Code provisions concerning gender is given. Not all generic names ending in the letter “a” are feminine. Indeed, a majority of those ending in ‐ma are neuter. A general rule is that names ending with the same element have the same gender. Some guidelines are offered here and due consideration is given to generic names that break the pattern. Neither is it appropriate to blindly impose classical gender nor uncritically accept what the original author did. Major weight must be given to botanical usage. These principles have been applied to more than 1200 names appearing in the generic names in current use (NCU) list.
Typification of the names of Hawaiian Lobelioideae (Campanulaceae) published by Wilhelm Hillebrand or based upon his specimens
Authors: Lammers Thomas G.
Published: April 2006

Lammers, T. G.: Typification of the names of Hawaiian Lobelioideae (Campanulaceae) published by Wilhelm Hillebrand or based upon his specimens. – Taxon 43: 545‐572. 1994. – ISSN 0040‐0262.

In the treatment of Lobelioideae (Campanulaceae) for his Flora of the Hawaiian Islands, Hillebrand described 21 new species and 13 new varieties, and proposed 15 new combinations (all but one at specific rank) plus one avowed substitute name (also at specific rank). In addition, Wawra described two new species and one new variety on the basis of specimens received from Hillebrand, and Rock described two species and 13 varieties on the basis of specimens in Hillebrand's herbarium. Thirty‐three lectotypes and two neotypes are designated for names that were inadequately typified. In each case, the typification effected supports current usage of the name in the literature.
First taxonomic assessment of George Forster's botanical artwork at Gotha (Thuringia, Germany)
Authors: Nicolson Dan H.
Published: April 2006

Nicolson, D. H.: First taxonomic assessment of George Forster's botanical artwork at Gotha (Thuringia, Germany). – Taxon 47: 581‐592. 1998. – ISSN 0040‐0262.

The three repositories of botanical art of G. Forster, artist and author of works underlying South Pacific botany, are reviewed. Identifications are given of the 6 paintings and 78 drawings held in Gotha.
Epipactis kleinii, a new name to replace the illegitimate E. parviflora (A. & C. Niesch.) E. Klein, non (Blume) A.A. Eaton (Orchidaceae, Neottieae)
Authors: Crespo Manuel B. , Lowe Michael R. , Piera Joan
Published: April 2006

Crespo, M. B., Lowe, M. R. & Piera, J.: Epipactis kleinii, a new name to replace the illegitimate E. parviflora (A. & C. Niesch.) E. Klein, non (Blume) A.A. Eaton (Orchidaceae, Neottieae). ‐ Taxon 50: 853–855. 2001. ‐ ISSN 0040‐0262.

The name Epipactis kleinii, nom nov., is proposed as an avowed substitute for E. parviflora (A. & C. Niesch.) E. Klein, an illegitimate later homonym of E. parviflora (Blume) A.A. Eaton (≡ Neottia parviflora Blume, non Sm.), itself an illegitimate name which is presently treated as synonym of Goodyera procera (Ker Gawl.) Hook. A brief history is presented of the names concerned, to justify the new proposal.
Nomenclatural notes on Ancistrocactus (Cactaceae)
Authors: Doweld Alexander , Greuter Werner
Published: April 2006

Doweld, A. & Greuter, W.: Nomenclatural notes on Ancistrocactus (Cactaceae). ‐ Taxon 50: 875–877. 2001. ‐ ISSN 0040‐0262.

Ancistrocactus, a name first published by Britton and Rose in 1923, is best treated as based on Schumann's Echinocactus subg. Ancistrocactus, not as the name of a new genus. Consequently, Britton and Rose's original type designation cannot stand, nor can the next subsequent published choice by Taylor in 1979, as neither is of an element included in Schumann's protologue. Echinocactus scheeri Salm‐Dyck is here proposed to provide the type of both the subgeneric and generic name. This choice conforms to the provisions of the ICBN and does not impinge on the application of the name Ancistrocactus, which, under the narrow generic concept currently again accepted by some, remains correct for Britton & Rose's genus.
Interpretation of plant names in a Late Medieval medicai treatise
Authors: Cristofolini Giovanni , Mossetti Umberto
Published: April 2006

Cristofolini, G. & Mossetti, U.: Interpretation of plant names in a Late Medieval medical treatise. – Taxon 47: 305‐319. 1998. – ISSN 0040‐0262.

The medical treatise written by Guilielmus of Saliceto around 1290 includes 13 chapters on renal affections, in which 133 plant species are mentioned. Almost all have been identified by means of comparison with 15th century herbals and 16th century herbaria and books. 39 % are native to Italy and were presumably collected in the wild, 42% are cultivated plants, either native to the Mediterranean region or introduced since Roman times, 4 % were introduced to Italy from E. Europe or the Middle East in the late Middle Ages, and 15% were imported from the east in the form of spices or drugs. Most of the plants mentioned by Guilielmus correspond entirely (56%) or in part (8%) with modern genera or species accepted with similar names or epithets in Linnaean nomenclature. 19% of Guilielmus' designations denote modern species or genera but did not enter Linnean nomenclature. Only some 17% of the Medieval names are of uncertain application or designated heterogeneous taxa; their use, if it persists, has substantially changed since the 16th century.
Notes on the taxonomy and nomenclature of Teline pallida (Poir.) G. Kunkel
Authors: del Arco Aguilar Marcelino
Published: April 2006

Del Arco Aguilar, M: Notes on the taxonomy and nomenclature of Teline pallida (Poir.) G. Kunkel. – Taxon 49: 17‐25. 2000. – ISSN 0040‐0262.

The Teline pallida complex is studied from a nomenclatural and taxonomic viewpoint, and some comments about chorological and ecological aspects are included. Teline pallida subsp. silensis subsp. nov. is described. A synoptic table of the differences between it and its nearest relatives, identification key, illustrations, and distribution map are shown.
The Sibthorpian Herbarium at Oxford – guidelines for its use
Authors: Lack H. Walter
Published: April 2006

Lack, H. W.: The Sibthorpian Herbarium at Oxford – guidelines for its use. – Taxon 46: 253‐263. 1997. – ISSN 0040‐0262.

The Sibthorpian Herbarium is a historical collection kept in the Fielding‐Druce Herbarium, Oxford, comprising vascular and non‐vascular plants formerly owned by J. Sibthorp. This paper deals with the C. 2700 specimens of vascular plants, most of which originate from modern Greece, Turkey, Cyprus, Italy, Bulgaria, and Rumania, having been collected by J. Sibthorp, J. Hawkins, their assistants and an anonymous apothecary in 1786‐1798. Annotated in a fragmentary way, the Sibthorpian Herbarium comprises several hundred specimens that typify names validated in J. E. Smith's Prodromus florae graecae. Recommendations for the interpretation of the entries into this work and guidelines for the use of the Sibthorpian Herbarium are presented.
Comments on Art. 14, footnote 2: first place of publication for seed plant family names
Authors: Reveal James L.
Published: April 2006

Reveal. J. L.: Comments on Art. 14, footnote 2: first place of publication for seed plant family names. – Taxon 47: 851‐856. 1998. – ISSN 0400‐0262.

A list of 191 family names of Spermatophyta is presented, whose date of valid publication is earlier than the date given in App. IIB of the Code, and authorship usually different. Many of the names were published prior to the arbitrarily accepted but never legally sanctioned starting date for family names in Spermatophyta, 4 Aug 1789. The Code, “for the time being”, authorises maintenance of authorship and date for conserved names listed in App. IIB. The present list foreshadows changes that would ensue were this provisional derogation to be abolished, but a continued search of the literature will likely reveal even earlier names.
Quantitative assessment of corolla shape variation in Solanum sect. Petota by computer image analysis
Authors: van der Heijden Gerie W. A. M. , van den Berg Ronald G.
Published: April 2006

Heijden, G. W. A. M. van der & Berg, R. G. van den: Quantitative assessment of corolla shape variation in Solanum sect. Petota by computer image analysis. – Taxon 46: 49‐64. 1997. – ISSN 0040‐0262.

Computer image analysis was used to quantify the corolla shapes of Solanum species. Three approaches were applied, using global features, a selected number of points along the contour, and complete contour descriptions, the latter in three different variants. All permit quantification of corolla shape and are in fact generally applicable in taxonomy for studying two‐dimensional shapes. All image analysis methods gave comparable variation patterns: the observed variation of corolla shapes is continuous, which does not support the subdivision of S. subsect. Potatoe into two superseries on the base of corolla shape alone. The studied accession of S. tarijense (S. superser. Stellata) could not be distinguished on corolla shape from that of S. berthaultii (S. superser. Rotata).
Podostemum ricciiforme (Podostemaceae) rediscovered and redescribed
Authors: Retana Alejandro Novelo , Philbrick C. Thomas
Published: April 2006

Novelo Retana, A. & Philbrick, C. T.: Podostemum ricciiforme (Podostemaceae) rediscovered and redescribed. – Taxon 46: 451‐455. 1997. – ISSN 0040‐0262.

Marathrum ricciiforme was originally described by Liebmann in 1847, based on scanty, sterile material collected in 1841 in Puebla, Mexico, where it is now extinct. On the basis of vegetative features, the species was later transferred to Podostemum (where it indeed belongs), with a second (misidentified) sterile specimen from Costa Rica added. Fertile material was first collected in 1988, and subsequently in several other Mexican localities. The species is here fully described, illustrated, and mapped, and an epitype is designated for its name.
In defence of using adhesives and low‐temperature pest control for botanical specimens
Authors: Shchepanek Michael J.
Published: April 2006

Shchepanek, M. J.: In defence of using adhesives and low‐temperature pest control for botanical specimens. – Taxon 50: 169–173. 2001. – ISSN 0040‐0262.

I.M. Egenberg & D. Moe have suggested that herbarium specimens mounted with adhesive combined with the low temperature technique for pest eradication causes serious damage to specimens. Experiments carried out at the National Herbarium of Canada contradict these results and show that the techniques are safe when used properly.
Nomenclatural status of Carphobolus (Compositae: Vernonieae)
Authors: Strother John L.
Published: April 2006

Strother, J. L.: Nomenclatural status of Carphobolus (Compositae: Vernonieae). – Taxon 50: 191–192. 2001. – ISSN 0040‐0262.

The generic name Carphobolus dates from 1863 and is lectotypified by C. lucidus.
A note on Trachylejeunea chinensis (Hepaticae, Lejeuneaceae)
Authors: Rui‐Liang Zhu , Ling So May
Published: April 2006

Zhu, R.‐L. & So, M. L.: A note on Trachylejeunea chinensis (Hepaticae, Lejeuneaceae). – Taxon 48: 489‐492. 1999. – ISSN 0040‐0262.

The name Trachylejeunea chinensis Herzog is lectotypified, and the species transferred to the genus Lejeunea based on the following diagnostic features: a lejeuneoid gynoecial innovation, lack of ocelli in the leaf lobe, non‐papillose leaf cells, and an obovate, smooth perianth. The genus Trachylejeunea is excluded from China and Asia by this transfer.
Aethiocarpa reduced to Harmsia (Malvaceae, Dombeyoideae)
Authors: Jenny Matthias , Bayer Clemens , Dorr Laurence J.
Published: April 2006

Jenny, M., Bayer, C. & Dorr, L. J.: Aethiocarpa reduced to Harmsia (Malvaceae, Dombeyoideae). – Taxon 48: 3‐6. 1999. – ISSN 0040‐0262.

The unispecific genus Aethiocarpa was distinguished from Harmsia principally on the basis of ovary and fruit structure: one‐seeded, unilocular ovaries and indehiscent fruit versus two‐seeded, bilocular ovaries and tardily dehiscent fruit, respectively. A critical re‐examination of ovary characters, however, reveals that both genera share biovulate unilocular ovaries, which are unique within subfamily Dombeyoideae (Malvaceae). Differences in indumentum, inflorescence morphology, and number of seed per fruit, which were cited as ancillary characters distinguishing Aethiocarpa from Harmsia, do not appear to justify the recognition of two different genera. Aethiocarpa is therefore considered to be a synonym of Harmsia and the new combination H. lepidota is proposed.
Corsinopteris, a new substitute name for Orthotheca (Marattiales‐Marattiopsida)
Authors: McNeill John , Doweld Alexander B.
Published: April 2006

Doweld, A. B.: Corsinopteris, a new substitute name for Orthotheca (Marattiales–Marattiopsida). – Taxon 50: 1097–1099. 2001. ‐ ISSN 0040–0262.

The later homonym Orthotheca P. Corsin, 1951 [fossil foliage] (non S. E. Bridel, 1827 [Musci] nee Pichon, 1946 [Bignoniaceae]) is replaced by a new generic name Corsinopteris. All four species described under Orthotheca P. Corsin. are transferred to the new genus.
Wave-length and amplitude in Gaussian noise
Authors: Lindgren Georg
Published: April 2006

We give moment approximations to the density function of the wavelength, i. e., the time between “a randomly chosen” local maximum with heightuand the following minimum in a stationary Gaussian process with a given covariance function. For certain processes we give similar approximations to the distribution of the amplitude, i. e., the vertical distance between the maximum and the minimum. Numerical examples and diagrams illustrate the results.
Ergodicity of age structure in populations with Markovian vital rates. II. General states
Authors: Cohen Joel E.
Published: April 2006

The age structure of a large, unisexual, closed population is described here by a vector of the proportions in each age class. Non-negative matrices of age-specific birth and death rates, called Leslie matrices, map the age structure at one point in discrete time into the age structure at the next. If the sequence of Leslie matrices applied to a population is a sample path of an ergodic Markov chain, then: (i) the joint process consisting of the age structure vector and the Leslie matrix which produced that age structure is a Markov chain with explicit transition function; (ii) the joint distribution of age structure and Leslie matrix becomes independent of initial age structure and of the initial distribution of the Leslie matrix after a long time; (iii) when the Markov chain governing the Leslie matrix is homogeneous, the joint distribution in (ii) approaches a limit which may be easily calculated as the solution of a renewal equation. A numerical example will be given in Cohen (1977).
First-passage percolation on the square lattice. I
Authors: Smythe R. T. , Wierman John C.
Published: April 2006

We consider several problems in the theory of first-passage percolation on the two-dimensional integer lattice. Our results include: (i) a mean ergodic theorem for the first-passage time from (0,0) to the linex = n; (ii) a proof that the time constant is zero when the atom at zero of the underlying distribution exceedsC, the critical percolation probability for the square lattice; (iii) a proof of the a.s. existence of routes for the unrestricted first-passage processes; (iv) a.s. and mean ergodic theorems for a class of reach processes; (v) continuity results for the time constant as a functional of the underlying distribution.
Occupation measures for Markov chains
Authors: Pitman J. W.
Published: April 2006

An occupation measure describes the expected amount of time a stochastic process spends in different parts of its state space prior to a given random time. It is shown that a basic identity involving occupation measures provides a unified approach to a variety of moment identities for Markov chains, and some connections with potential theory are made.
Generalised birth and death queueing processes: recent results
Authors: Conolly B. W. , Chan J.
Published: April 2006

The systems considered are single-server, though the theory has wider application to models of adaptive queueing systems. Arrival and service mechanisms are governed by state (n)-dependent mean arrival and service rates λn and µn. It is assumed that the choice of λn and µn leads to a stable regime. Formulae are sought that provide easy means of computing statistics of effectiveness of systems. A measure of traffic intensity is first defined in terms of ‘effective’ service time and inter-arrival intervals. It is shown that the latter have a renewal type connection with appropriately defined mean effective arrival and service rates λ∗ and µ∗ and that in consequence the ratio λ∗/µ∗ is the traffic intensity, equal moreover to where is the stable probability of an empty system, consistent with other systems. It is also shown that for first come, first served discipline the equivalent of Little's formula holds, where and are the mean waiting time of an arrival and mean system size at an arbitrary epoch. In addition it appears that stable regime output intervals are statistically identical with effective inter-arrival intervals. Symmetrical moment formulae of arbitrary order are derived algebraically for effective inter-arrival and service intervals, for waiting time, for busy period and for output.
Some explicit formulas for the steady-state behavior of the queue with semi-Markovian service times
Authors: Neuts Marcel F.
Published: April 2006

This paper discusses a number of explicit formulas for the steady-state features of the queue with Poisson arrivals in groups of random sizes and semi-Markovian service times. Computationally useful formulas for the expected duration of the various busy periods, for the mean numbers of customers served during them, as well as for the lower order moments of the queue lengths, both in discrete and in continuous time, and of the virtual waiting time are obtained. The formulas are recursive matrix expressions, which generalize the analogous but much simpler results for the classical M/G/1 model.
Asymptotic behaviour of immigration-branching processes with general set of types. I: Critical branching part
Authors: Hering H.
Published: April 2006

We consider immigration-branching processes constructable from an inhomogeneous Poisson process, a sequence of population probability distributions, and a homogeneous branching transition function. The set of types is arbitrary, and the process parameter is allowed to be discrete or continuous. For the branching part a weak form of positive regularity, criticality, and the existence of second moments are assumed. Varying the conditions on the immigration law, we obtain several results concerning asymptotic extinction, the rate of extinction, and limiting distribution functions of properly normalized, vector-valued counting processes associated with the immigration branching process. The proofs are based on the generating functional method.
An index of genealogical relatedness
Authors: Lloyd Stuart P.
Published: April 2006

The inner product associated with the l2 analog of the Mycielski-Ulam l1 genealogical distance serves to quantify the notion of genealogical relatedness in a fairly natural way. The expected value of the relatedness is obtained for certain random population models with stratified generations, including the Mycielski-Ulam model.
Exit problem for a spectrally positive process
Authors: Emery D. J.
Published: April 2006

The joint distributions of the exit time and exit value of a spectrally positive process, from semi-infinite and finite intervals, are derived in the form of Fourier-Laplace transforms. Also the probability that such a process makes its first exit from a finite interval via the lower end point is obtained explicitly.
Weak convergence in queueing theory
Authors: Iglehart Donald L.
Published: April 2006

In the last ten years the theory of weak convergence of probability measures has been used extensively in studying the models of applied probability. By far the greatest consumer of weak convergence has been the area of queueing theory. This survey paper represents an attempt to summarize the experience in queueing theory with the hope that it will prove helpful in other areas of applied probability. The paper is organized into the following sections: queues in light traffic, queues in heavy traffic, queues with a large number of servers, continuity of queues, rates of convergence, and special queueing models.
Selection by three loci
Authors: Feldman Marcus W. , Franklin Ian , Thomson Glenys J.
Published: April 2006

The three-locus symmetric viability model has been analysed. The symmetric equilibria, namely those with equality of complementary chromosomes and hence with all allele frequencies equal to ½, have been found and their local stability studied. It was shown that there are fifteen symmetric equilibria, of which six may be stable for a given set of selection and recombination parameters.
Assortative mating
Authors: Smith Cedric A. B. , Vetta Atam
Published: April 2006

Various attempts have been made to develop a theory of the genetical effects of assortative mating, using various models. The earliest and most famous is that of Fisher (1918). However, this has run into a difficulty in that his paper is far from easy to understand even despite the efforts of Kempthorne (1957) and Moran and Smith (1966) to simplify his presentation. A key paragraph is the following (which we give in abbreviated form).
Sampling of pedigrees
Authors: Stene Jon
Published: April 2006

Effects of sampling procedures on the probability distributions of pedigrees are illustrated. Elimination of these effects by suitable conditioning is demonstrated.
Functional limit theorems for stochastic processes based on embedded processes
Authors: Serfozo Richard F.
Published: April 2006

The techniques used by Doeblin and Chung to obtain ordinary limit laws (central limit laws, weak and strong laws of large numbers, and laws of the iterated logarithm) for Markov chains, are extended to obtain analogous functional limit laws for stochastic processes which have embedded processes satisfying these laws. More generally, it is shown how functional limit laws of a stochastic process are related to those of a process embedded in it. The results herein unify and extend many existing limit laws for Markov, semi-Markov, queueing, regenerative, semi-stationary, and subordinated processes.
On record and inter-record times for a sequence of random variables defined on a Markov chain
Authors: Lee Guthrie Gary , Holmes Paul T.
Published: April 2006

The familiar three theorems of Rényi concerning the record times in an i.i.d. sequence of random variables are extended to the record times and inter-record times of a sequence of dependent, non-identically distributed random variables defined on a finite Markov chain. These theorems are the Central Limit Theorem (C.L.T.), the Strong Law of Large Numbers (S.L.L.N.) and the Law of the Iterated Logarithm (L.I.L.). Similar results are also obtained for m-record times, inter-m-record times, and for the continuous parameter situation when observations are taken at the epochs of a Poisson process.
Bang-bang controls of point processes
Authors: Brémaud P.
Published: April 2006

In this paper, we consider the problem of controlling the intensity of a point process in order to maximize the probability that the number of points in a fixed interval equals a given integer, under the constraint that the intensity belong to some closed interval of R+.

The problem is stated as a problem of optimization on the set of probabilities over the basic measurable space of point processes, and shown to be equivalent to a problem of deterministic control. Structural results concerning the set of optimal solutions are given. The existence of the latter is proven; the control is shown to be bang-bang and a complete solution can be obtained by application of Pontryagin's Maximum Principle.
Criteria for classifying general Markov chains
Authors: Tweedie R. L.
Published: April 2006

The aim of this paper is to present a comprehensive set of criteria for classifying as recurrent, transient, null or positive the sets visited by a general state space Markov chain. When the chain is irreducible in some sense, these then provide criteria for classifying the chain itself, provided the sets considered actually reflect the status of the chain as a whole. The first part of the paper is concerned with the connections between various definitions of recurrence, transience, nullity and positivity for sets and for irreducible chains; here we also elaborate the idea of status sets for irreducible chains. In the second part we give our criteria for classifying sets. When the state space is countable, our results for recurrence, transience and positivity reduce to the classical work of Foster (1953); for continuous-valued chains they extend results of Lamperti (1960), (1963); for general spaces the positivity and recurrence criteria strengthen those of Tweedie (1975b).
On generalising the notion of upcrossings to random fields
Authors: Adler Robert J.
Published: April 2006

The aim of the current paper is twofold. Primarily we wish to extend some of our earlier results on excursions of random fields and introduce a more powerful technique for obtaining the mean value of a certain characteristic of these excursions. Since these results can also be used to tie together the scattered results of previous authors we also include a full review of earlier work in this field.
Limit theorems for stochastic growth models. II
Authors: Kesten Harry
Published: April 2006

We consider d-dimensional stochastic processes which take values in (R+)d These processes generalize Galton-Watson branching processes, but the main assumption of branching processes, independence between particles, is dropped. Instead, we assume for some

Here τ:(R+)d→R +, |x| = σ1d |x(i)|, A {x ∈(R+)d: |x| 1} and T: A→A. Under various assumptions on the maps τ and T it is shown that with probability one there exists a ρ > 1, a fixed point p ∈ A of T and a random variable w such that limn→∞Zn|ρnwp. This result is a generalization of the main limit theorem for supercritical branching processes; note, however, that in the present situation both ρ and ρ are random as well. The results are applied to a population genetical model for zygotic selection without mutation at one locus.
On a fundamental identity in the theory of semi-Markov processes
Authors: Arjas E.
Published: April 2006

A fundamental identity, due to Miller (1961a), (1962a, b) and Kemperman (1961), is generalized to semi-Markov processes. Thus the identity applies to processes defined on a Markov chain with discrete state space and random walks with Markov dependent steps (Section 2). Wald's identity is discussed briefly in Section 3. Section 4 is a study of the maxima of partial sums, and Section 5 of maxima in a semi-Markov process.
Rates of convergence for queues in heavy traffic. II: Sequences of queueing systems
Authors: Kennedy Douglas P.
Published: April 2006

Estimates are given for the rates of convergence in functional central limit theorems for the queue length process in a sequence of general multiple channel queues. The situation is considered where the traffic intensity in the nth. queue, ρn, tends to ρ ≧ 1 as n approaches infinity. This extends previous work by the author, [6], in which the traffic intensity was fixed ≧ 1.
Sur une caractérisation des vidanges fortes
Authors: Dion Jean-Guy
Published: April 2006

This paper is concerned with a discrete Markov process related to an underlying weighted graph. With this graph we associate an urn containing p types of balls which correspond to the p vertices of the graph, and such that the number of balls of each type is proportional to the weight of the related vertex. A drawing scheme from the urn is defined which leads to Markovian non-homogeneous transition probabilities. Many kinds of weighted graphs are found to have a strong convergence property; this is that the number of balls drawn from the urn at the end of any single draw converges in probability to the total number of balls in the urn, as this tends to infinity.
The theory of periodic screening I: Lead time and proportion detected
Authors: Prorok Philip C.
Published: April 2006

A stochastic model for a periodic screening program is presented in which the natural history of a chronic disease is assumed to follow a progressive path from a preclinical state to a clinical state. The sampling of preclinical state sojourn times by screening examinations generates bounds on the preclinical state recurrence times. The distribution of the bounded forward recurrence time is derived and used to obtain the distribution and mean of the lead time, and relationships for calculating the proportion of preclinical cases detected. These expressions are derived in terms of the preclinical state sojourn-time distribution and adjustible parameters important in the design of a periodic screening program.
Markov decision chains with unbounded costs and applications to the control of queues
Authors: Robinson D. R.
Published: April 2006

A discrete-time Markov decision model with a denumerable set of states and unbounded costs is considered. It is shown that the optimality equation of dynamic programming along with some additional, easily checked, conditions may be used to establish the optimality or ∊ -optimality of policies with respect to the average expected cost criterion. The results are used to derive optimal policies in two queueing examples.
Optimal control of batch service queues with switching costs
Authors: Deb Rajat K.
Published: April 2006

We consider a batch service queue which is controlled by switching the server on and off, and by controlling the batch size and timing of services. These batch sizes cannot exceed a fixed number Q, which we call the service capacity. Costs are charged for switching the server on and off, for serving customers and for holding them in the system. Viewing the system as a semi-Markov decision process, we show that the policies which minimize the expected continuously discounted cost and the expected cost per unit time over an infinite time horizon are of the following form: at a review point if the server is off, leave the server off until the number of customers x reaches an optimal level M, then turn the server on and serve min (x, Q) customers; and when the server is on, serve customers in batches of size min(x, Q) until the number of customers falls below an optimal level m(m ≦ M) and then turn the server off. An example for computing these optimal levels is also presented.
Point processes generated by transitions of Markov chains
Authors: Rudemo Mats
Published: April 2006

For a continuous time Markov chain the time points of transitions, belonging to a subset of the set of all transitions, are observed. Special cases include the point process generated by all transitions and doubly stochastic Poisson processes with a Markovian intensity. Equations are derived for the conditional distribution of the state of the Markov chain, given observations of the point process. This distribution may be used for prediction. For the forward recurrence time of the point process, distributions corresponding to synchronous and asynchronous sampling are also derived. The Palm distribution for the point process is specified in terms of the corresponding initial distribution for the Markov chain. In examples the point processes of arrivals and departures in a queueing system are studied. Two biological applications deal with estimation of population size and detection of epidemics.
Detection of spatial pattern at several scales simultaneously
Authors: Mead Roger
Published: April 2006

Detection of the different scales of pattern in plant communities is an important area of plant ecological research, and various tests of pattern have been devised. The method of pattern detection which is ecologically most meaningful is that due to Greig-Smith (1952) but, until now, this has suffered from the lack of valid tests of significance for the individual scales of pattern, once the overall departure from a random distribution has been established. Various tests which partially or completely overcome this deficiency are discussed and exemplified and their small sample distributional properties examined. It is concluded that a set of tests, based on randomisation arguments, provides a fully valid method of testing simultaneously for pattern at various scales.
The cell kinetics of the prostate of the testosterone-stimulated castrated mouse
Authors: Appleton D. R.
Published: April 2006

Cell kinetics deals with experiments and theories designed to determine the proportion of cells in a tissue which are engaged in replication, and the times they take to pass through the various stages of their reproductive cycle.
The general bulk queue as a matrix factorisation problem of the Wiener-Hopf type. Part I.
Authors: Dagsvik John
Published: April 2006

The relationship between the Wiener-Hopf factorisation of matrices and the solution of systems of certain operator equations is discussed in an algebraic setting. It is shown that the study of the waiting time process of thenth arriving group of the general single server bulk queue leads to equations of that type. This system of equations may be considered as an extension of Lindley's waiting-time equation.
Controlled queues in heavy traffic
Authors: Rath John H.
Published: April 2006

This paper studies a controlled queueing system in which the decisionmaker may change servers according to rules which depend only on the queue length. It is proved that for a given control policy a properly normalised sequence of these controlled queue length processes converges weakly to a controlled diffusion process as the queueing systems approach a state of heavy traffic.
Mathematical methods of chronic diseases study in 1970
Authors: Meshalkin L. D.
Published: April 2006

This report is based mainly on the research conducted in 1969–70 in the Division of Research in Epidemiology and Communications Science of the World Health Organization, and gives a short résumé of methods elaborated for concise descriptions of what has been observed for prognosis of subsequent development of disease, and for the planning of new studies.
Information science approach to biomathematics and its implications to ecology and quantitative epidemiology
Authors: Kitagawa Tosio
Published: April 2006

The paper consists of three parts A, B and C. In part A, “A contribution to the methodology of biomathematics”, general considerations on mathematical analysis and automaton theory are given in order to show how and why new approaches for biomathematics are required from the standpoint of information science. In fact three requirements are mentioned: (1°) general system approach; (2°) historical approach; (3°) three indispensable constituent fields of biological science. Regarding (1°), the author refers to his work on the logic of information science explained in 1968 at the CAS Seminar in Dubrovnik and published in 1969 in a Japanese monograph. Regarding (2°), reference is made to his paper “A contribution to the methodology of futurology” published in International Conference on Futurology, April 1970, Kyoto. The three indispensable constitutent fields are given by (a) theoretical, (b) experimental and (c) engineering biologies. In view of these three requirements, characteristic features of biomathematics in connection with an information science approach are (1°) discrete, (2°) combinatorial, (3°) dynamical, (4°) evolutionary, and (5°) design mathematics.
Multidimensional right-shift processes
Authors: Severo Norman C.
Published: April 2006

Let v be a positive integer and for each k = 1, · · ·, v let mk and Nk be a positive and a non-negative integer, respectively. Denote by S'Nk,mk the set of (mk + 1) -tuples rk = (rk,mk, · · ·, rk,1, rk,0) having non-negative components summing to Nk, and by Xk(t) = (Xk,mk(t), · · ·, Xk,1(t), Xk,0(t)) an (mk + 1)-tuple random variable taking on values only from the set S′Nk,mk.
Asymptotic behavior of a generalization of Bailey's simple epidemic
Authors: Weiss George H. , Dishon Menachem
Published: April 2006

It has been shown that for many epidemic models, the stochastic theory leads to essentially the same results as the deterministic theory provided that one identifies mean values with the functions calculated from the deterministic differential equations (cf. [1]). If one considers a generalization of Bailey's simple epidemic for a fixed population of size N, represented schematically by where I refers to an infected, S refers to a susceptible, and α and β are appropriate rate constants, then it is evident that at time t = ∞, the expected number of infected individuals must be zero provided that β > 0. If x(t) denotes the number of infected at time t, then the deterministic model is summarized by
Simulation of stochastic discrete-time epidemic models for two agents
Authors: Elveback Lila R.
Published: April 2006

Three simulation models for stochastic discrete-time epidemics involving two competing and interfering viruses in highly structured communities were presented.
Random wear models in reliability theory
Authors: Reynolds David S. , Savage I. Richard
Published: April 2006

Gaver (1963) and Antelman and Savage (1965) have proposed models for the distribution of the time to failure of a simple device exposed to a randomly varying environment. Each model represents cumulative wear as a specified function of a non-negative stochastic process with independent increments, and assumes that the reliability of the device is conditioned upon realizations of this process. From these models are derived the corresponding unconditional joint distributions for the random failure time vector of n independent, identical devices exposed to the same realization of the wear process. It is shown that the identical failure time distribution for one component can arise from each model. In the Gaver model simultaneous failure times occur with positive probability. The probabilities of specific tie configurations are developed.

For an interesting class of Gaver models involving a time scale parameter, the maximum likelihood estimates from several devices in one environment are examined. In that case the tie configuration probability does not depend on the parameter. For the corresponding Antelman-Savage models a consistent sequence of estimators is obtained; the maximum likelihood theory did not appear tractable.