bluuebunny/crossref_metadata_2025_split huggingface dataset:
A long-term record of human impacts on an urban ecosystem in the sediments of Töölönlahti Bay in Helsinki, Finland
Authors: TIKKANEN MATTI , KORHOLA ATTE , SEPPÄ HEIKKI , VIRKANEN JUHANI 
Published: July 2002

Ecological impacts of urbanization are receiving increasing scientific attention, yet few data sets permit long-term effects on terrestrial and aquatic ecosystems to be assessed. Töölönlahti Bay, in the centre of Helsinki, Finland, provided on opportunity to characterize recent human impacts especially by means of chemical and biostratigraphical analyses of a sediment core. Periods of coniferous forest, forest clearance, urbanization and the development of parks, can be distinguished in the pollen record of the core. Palynological diversity was highest before the forest clearance at the turn of the century. The character of the sediment and the water have changed substantially in response to rapid population growth, the construction of sewage systems and building within the catchment of the bay. This is reflected in marked increases in organic matter, phosphorus and heavy metal (Cd, Cu, Ni, Zn and Pb) concentrations between 1890 and 1960, accompanied by a rapid increase in diatom species indicative of eutrophication and a decline in diatom species diversity.Since the cessation of waste-water disposal in the 1960s, concentrations of a number of pollutants have declined and water quality has gradually improved, but conditions are still affected by internal and atmospheric loadings. As a consequence of land uplift (2 mm per year) and the rapid sedimentation rate (6 mm per year), the volume of the bay is decreasing. Within 200 years, the shallow bay, which is skirted by extensive parks and famous cultural buildings such as the Finlandia and the Opera Houses, will fill with sediment unless it is dredged.
The marsupial and monotreme thymus, revisited
Authors: Haynes Julie Irene 
Published: July 2002

AbstractThe anatomy and histology of the thymus in monotremes and marsupials were revisited and several new observations made. Tissues of the mediastinum and/or ventral neck of 134 animals altogether (12 Australian marsupial and monotreme species) were examined and the locations of thymic tissues documented. Descriptions not previously recorded include the gross anatomy of the thymus in monotremes, the bandicoot (Isoodon macrourus, Isoodon obesulus), the wombat (Lasiorhinus latifrons), and koala (Phascolarctos cinereus), as well as light and electron microscopic features in all species examined. In monotremes, thymic tissue was diffusely spread in the mediastinum and extended over the ventral surface of the pericardium. In the bandicoot, a small, deep cervical thymus was persistently present as well as the expected thoracic thymus and contrary to previous observations, a thoracic thymus was found in the wombat but not the koala. Both species also have a cervical thymus. In the marsupial species examined, additional thymic tissue was often present in the vicinity of the carotid bifurcations, in the deep ventral regions of the neck. In many animals, thymic tissue of deep cervical origin as well as thoracic thymus was mingled with parathyroid tissue. In several specimens, the two tissue types lacked intervening connective tissue barriers and at the electron microscopic level, attenuated processes of epithelial reticular cells were the only tissue components separating parathyroid and thymic tissues. The role of the cervical thymus in diprotodont marsupials remains to be elucidated. The presence of aberrant thymic tissue in marsupials is important in the interpretation of experiments involving thymectomy and immunological development because complete removal of thymic tissue may not occur. One aspect that has received little attention is the function of the thymic epithelial reticular cells in marsupial development and a suggestion is made that perhaps the extra thymic tissue found in marsupials provides extra epithelial reticular cells necessary for the production of cytokines and other secretions to sustain the development of immunological competence.
Censusing and monitoring black rhino (Diceros bicornis) using an objective spoor (footprint) identification technique
Authors: Jewell Zoë C. , Alibhai Sky K. , Law Peter R. 
Published: July 2002

AbstractAn objective, non‐invasive technique was developed for identifying individual black rhino from their footprints (spoor). Digital images were taken of left hind spoor from tracks (spoor pathways) of 15 known black rhino in Hwange National Park, Zimbabwe. Thirteen landmark points were manually placed on the spoor image and from them, using customized software, a total of 77 measurements (lengths and angles) were generated. These were subjected to discriminant and canonical analyses. Discriminant analysis of spoor measurements from all 15 known animals, employing the 30 measurements with the highest F‐ratio values, gave very close agreement between assigned and predicted classification of spoor. For individual spoor, the accuracy of being assigned to the correct group varied from 87% to 95%. For individual tracks, the accuracy level was 88%. Canonical analyses were based on the centroid plot method, which does not require pre‐assigned grouping of spoor or tracks. The first two canonical variables were used to generate a centroid plot with 95% confidence ellipses in the test space. The presence or absence of overlap between the ellipses of track pairs allowed the classification of the tracks. Using a new ‘reference centroid value’ technique, the level of accuracy was high (94%) when individual tracks were compared against whole sets (total number of spoor for each rhino) but low (35%) when tracks were compared against each other. Since tracks with fewer spoor were more likely to be misclassified, track sizes were then artificially increased by summing smaller tracks for the same rhino. The modified tracks in a pairwise comparison gave an accuracy of 93%. The advantages, limitations and practical applications of the spoor identification technique are discussed in relation to censusing and monitoring black rhino populations.
THE MANAGING EDITOR'S REPORT ON THE JOURNAL OF ZOOLOGY FOR 2000
Authors: Clutton‐Brock Juliet 
Published: July 2002

The Editors decided, during the year, that there was really little need for a Short Communications Section and it would be more effective to incorporate short papers into the body of the Journal. Great thanks therefore go to Martyn Gorman for his many years as Editor of the Communications from the Mammal Society and latterly for his editing of the Short Communications.By the end of 2000, the majority of the members of the Editorial Board had completed a five year term and an editorial decision was taken to replace the Board with a small team of international Editorial Consultants who would be asked to act as ambassadors for the Journal as well as giving advice on editorial matters. I should therefore like to thank all the retiring members of the Editorial Board for their work on the Journal and welcome the new Editorial Consultants whose names are given on the inside front cover of this issue.During 2000, 160 papers were published in the twelve monthly parts of volumes 250–252 and there was approximately eleven months between acceptance of a paper and its publication. Our aim is to reduce this time to a maximum of ten months from now on.Over the year, 286 manuscripts were submitted to the Journal and reports were written on them by 471 referees, whose names are listed below. As in previous years, I should like to make full acknowledgement of the generosity of these referees in both their time and expertise, without which the Journal could not survive. I should also like to thank all the authors who have sent in colour slides for possible reproduction on the covers.
A review of the comparative morphology and systematics of Utah Lake suckers (Catostomidae)
Authors: Cook A. Gaylon 
Published: July 2002

AbstractUtah Lake, Utah, U.S.A. harbours an endemic catostomid fish, the June sucker Chasmistes liorus, that is recognized as being endangered. Since 1981, post‐1935 representatives of the June sucker have generally been considered to be examples of a self‐propagating hybrid. Utah Lake has contained another endemic catostomid, the webug sucker Chasmistes fecundus that was regarded as a true species until 1981 when it was judged to be an extirpated sterile hybrid. Since then, fisheries biologists have not attempted to identify it. This review makes a comparative examination of the published descriptions of the internal and external anatomy of these two species, plus the third catostomid of Utah Lake, the Utah sucker Catostomus ardens. The Utah sucker purportedly crossed with a form of the June sucker that has supposedly since been expunged, to produce hybrids. On the basis of comparative morphology and the consideration of temporal changes in the habitat and piscifauna of Utah Lake, the authenticity of supposed hybridism in the webug sucker, and in the contemporary June sucker, is analysed. The conclusion is reached that there is insufficient evidence to deem these taxa hybrids, or the webug sucker, extinct.
Morphology and reproduction of Nipponomysella subtruncata (Yokoyama), a galeommatoidean bivalve commensal with the sipunculan Siphonosoma cumanense (Keferstein) in Japan
Authors: Lützen J. , Takahashi T. , Yamaguchi T. 
Published: July 2002

AbstractThe shell and anatomy of Nipponomysella subtruncata is described. The bivalve is attached singly or in groups of up to nine on Siphonosoma cumanense, a burrowing intertidal sipunculan in south‐west Japan. The species is a protandrous hermaphrodite. Specimens 1.4–2.5 mm long are males, which between 2.1 and 3 mm in length reverse sex and remain females. Reproduction peaks in summer and the annual number of clutches is small. Ripe oocytes, 84–88 μm diameter, are spawned into the suprabranchial cavity where they develop into 107‐μm‐long straight‐hinged veligers. Following a planktotrophic period of unknown duration, the c. 360‐μm‐long spat normally settle upon and attach to the shells of larger, predominantly female, individuals. At a length of 1–1.6 mm they detach again and live separately thereafter. Sperm are transferred in spermatophores and stored within paired, mushroom‐shaped receptacles located posteriorly in the female's suprabranchial cavity. The receptacles first appear in large males or in specimens in the process of reversing sex. Stored sperm probably survive long enough to fertilize more than one clutch. The anatomy of Nipponomysella is characteristic of the Montacutidae, and is of especial interest because of the unique structure of the sperm receptacles.
Birds of paradise (Paradisaeidae) and bowerbirds (Ptilonorhynchidae): regional levels of biodiversity and terrane tectonics in New Guinea
Authors: Heads Michael 
Published: July 2002

AbstractMost species of birds of paradise (Paradisaeidae) are endemic in the rainforests of New Guinea. There are also a few species in the northern Moluccas and in northern Australia. Bowerbirds (Ptilonorhynchidae) are centred in New Guinea but are more widespread in Australia. The two families have often been regarded as sister groups, but in recent studies Paradisaeidae appear as sister to Corvidae, a worldwide family which is notably depauperate in New Guinea and Australia. This indicates vicariance of a worldwide ancestor, rather than invasion of New Guinea. Other families in the superfamily Corvoidea include Ptilonorhynchidae (basal), Campephagidae (Africa to New Guinea and Fiji), and Cracticidae (Australia to New Guinea). Biodiversity levels in Paradisaeidae and Ptilonorhynchidae were assessed from literature records by counting numbers of species in grid cells 1° latitude by 1° longitude. Birds of paradise are equally diverse in the Mendi square and the Mount Hagen–Wahgi Valley–Jimi Valley square. Bowerbirds are most diverse in the Mount Hagen–Wahgi Valley–Jimi Valley square. This area lies on one of the main tectonic boundaries in New Guinea, the former margin of the Australian craton, and is geologically distinctive in having several diverse accreted terranes juxtaposed there, including an ophiolite complex. It also includes the western slopes of Mount Wilhelm, one of the highest mountains in the New Guinea orogen. Paradisaeidae have secondary centres of diversity in the southern part of the New Guinea orogen (south of the former craton margin), while Ptilonorhynchidae have secondary centres north of the craton margin on the accreted terranes, and also in eastern Australia. Within New Guinea the two distributions correlate closely with the geological interpretation of the orogen as comprising southern (craton) and northern (accreted terrane) components. Within Australia, Paradisaeidae have two species per degree square in northern Cape York Peninsula (on the old Australian craton), and only one elsewhere in eastern Australia, whereas Ptilonorhynchidae have a clear Australian massing further south in Queensland, on the accreted terranes of the Tasman orogen.
The place of beta-adrenoreceptor-blocking drugs in the treatment of congestive heart failure in elderly people: review of current opinion
Authors: Woosnam L , Hasan M 
Published: July 2002

The clinical syndrome of heart failure affects more than 1% of the population, and its prevalence increases steeply with advancing age, especially after 75, where it reaches approximately 10%. It is one of the commonest reasons for the admission of elderly people to hospital.Despite recent advances in treatment of heart failure with angiotensin-converting enzyme (ACE) inhibitors, which were proven to provide survival benefit, the rates of morbidity and mortality from heart failure remain high, and new therapeutic strategie
s are needed.
Lagrangians of Hypergraphs
Authors: TALBOT J. M. 
Published: July 2002

How large can the Lagrangian of an r-graph with m edges be? Frankl and Füredi [1]

conjectured that the r-graph of size m formed by taking the first m sets in the colex

ordering of N(r) has the largest Lagrangian of all r-graphs of size m.

We prove the first ‘interesting’ case of this conjecture, namely that the 3-graph with

(t3) edges and largest Lagrangian is [t](3).

We also prove that this conjecture is true for 3-graphs of several other sizes.For general r-graphs we prove a weaker result: for t sufficiently large, the r-graph of

size (tr) supported on t + 1 vertices and with largest

Lagrangian, is [t](r).
Intersecting Chains in Finite Vector Spaces
Authors: CZABARKA ÉVA 
Published: July 2002

We prove an Erdős–Ko–Rado-type theorem for
intersecting k-chains of subspaces of a finite
vector space. This is the q-generalization of earlier results of
Erdős, Seress and Székely for intersecting k-chains of subsets
of an underlying set. The proof hinges on the author's
proper generalization of the shift technique from extremal set theory to finite vector spaces,
which uses a linear map to define the generalized shift operation. The theorem is the
following.For c = 0, 1, consider k-chains of subspaces of an
n-dimensional vector space over GF(q), such that the smallest
subspace in any chain has dimension at least c, and the
largest subspace in any chain has dimension at most n − c. The
largest number of such k-chains under the condition that any two share
at least one subspace as an element of the chain, is achieved by the
following constructions:(1) fix a subspace of dimension c and take all k-chains containing it,(2) fix a subspace of dimension n − c and take all
k-chains containing it.
Conservation genetics of the endangered Shenandoah salamander (Plethodon shenandoah, Plethodontidae)
Authors: Carpenter Daniel W. , Jung Robin E. , Sites Jack W. 
Published: July 2002

AbstractThe Shenandoah salamander (Plethodon shenandoah) is restricted to three isolated talus outcrops in Shenandoah National Park, VA, USA and has one of the smallest ranges of any tetrapod vertebrate. This species was listed as endangered under the US Endangered Species Act in 1989 over concern that direct competition with the red‐backed salamander (Plethodon cinereus), successional habitat changes, and human impacts may cause its decline and possible extinction. We address two issues herein: (1) whether extensive introgression (through long‐term hybridization) is present between the two species and threatens the survival of P. shenandoah, and (2) the level of population structure within P. shenandoah. We provide evidence from mtDNA haplotypes that shows no genetic differentiation among the three isolates of P. shenandoah, suggesting that their fragmentation is a geologically recent event, and/or that the isolates are still connected by occasional gene flow. There is also no evidence for extensive introgression of alleles in either direction between P. cinereus and P. shenandoah, which suggests that P. shenandoah may not be in danger of being genetically swamped out through hybridization with P. cinereus.
Microhabitat use by a translocated population of St Lucia whiptail lizards (Cnemidophorus vanzoi)
Authors: Dickinson Hannah C. , Fa John E. , Lenton Stuart M. 
Published: July 2002

AbstractMicrohabitat use studies of translocated species are crucial to assess their adaptation to the new environment. A total of 42 St Lucia whiptail lizards (Cnemidophorus vanzoi), an endemic to two islets (Maria Major, 10.2 ha and Maria Minor, 1.8 ha) off St Lucia in the Lesser Antilles, were translocated from Maria Major to Praslin Island (1.1 ha) in 1995. Three years after the release, we studied the abundance, density and distribution of the translocated lizard population in the prevailing five habitat types on the island. Habitats varied from more exposed open grasslands to tall, continuously canopied woodlands. Although lizards were distributed throughout the island, some habitats were used more than predicted with respect to availability. Habitat utilization showed a seasonal shift in distribution. Line transect sampling estimated a population of 145 ± 23 lizards on Praslin Island. There were significant seasonal differences in estimated lizard abundance indicating a change in activity during the dry season. Lizard density was significantly correlated with general habitat characteristics, rather than with any specific microhabitat variable measured. Factors affecting distribution (thermo‐regulation, food resources and competitive exclusion) are discussed and it is suggested that habitat use during the dry season may be best explained by thermal constraint. These results will help managers choose future translocation sites.
Conservation breeding for reintroductions: assessing survival in a captive flock of houbara bustards
Authors: van Heezik Yolanda , Ostrowski Stéphane 
Published: July 2002

AbstractConservation breeding for reintroduction is becoming a popular option for restoring threatened populations. Whereas post‐release results are widely reported in the conservation literature, little empirical information is presented on the captive populations that often make such releases possible, even though fecundity, fertility and survival rates can have an impact on the outcome and cost of wild population re‐establishment. We present results of survival analyses carried out on a captive population of houbara bustards to determine peak periods of mortality, and by identifying sources of variations in mortality to recognize the potential impact of management practices on productivity. There were two main mortality peaks: during incubation (53% survival of fertile eggs), and by 6 months post‐hatching (75% survival of hatchlings). Management‐related variables influencing survival of eggs and chicks included the year when laid, the cohort of females laying them, and possibly sex. Most post‐hatching deaths were due to trauma and infectious diseases. Trauma‐related deaths usually follow collisions with cages, and imply selection for the captive environment, an undesirable trend in populations maintained for reintroductions. Reducing losses during incubation would have the largest impact on production of birds for reintroduction, enabling the release of more birds, and reducing the overall costs of the project.
Inhibitors of Serine/Threonine Phosphoprotein Phosphatases Alter Circadian Properties in Gonyaulax polyedra
Authors: Comolli J. , Taylor W. , Rehman J. , Hastings J. W. 
Published: July 2002

Abstract
Protein serine/threonine phosphatases were implicated in the regulation of circadian rhythmicity in the marine dinoflagellate Gonyaulax polyedra based on the effects of three inhibitors specific for protein phosphatases 1 and 2A (okadaic acid, calyculin A, and cantharidin). Chronic exposure to okadaic acid resulted in a significant period lenghtening, as measured by the bioluminescent glow rhythm, whereas cantharidin and calyculin A caused large phase delays but no persistent effect on period. Short pulses of the phosphatase inhibitors resulted in phase delays that were greatest near subjective dawn. Unlike 6-dimethylaminopurine, a protein kinase inhibitor, okadaic acid, calyculin A, and cantharidin did not block light-induced phase shifts. The inhibitors tested also increased radiolabeled phosphate incorporation into Gonyaulax proteins in vivo and blocked protein phosphatase 1 and 2A activities in Gonyaulax extracts. This study indicates that protein dephosphorylation catalyzed by protein serine/threonine phosphatases is necessary for proper functioning of the circadian system.
Tissue-Specific and Developmental Regulation of Cotton Gene FbL2A (Demonstration of Promoter Activity in Transgenic Plants)
Authors: Rinehart J. A. , Petersen M. W. , John M. E. 
Published: July 2002

Abstract
A gene (FbL2A) that is preferentially expressed in cotton (Gossypium barbadense L. cv Sea Island) fiber was isolated and characterized. Genomic and cDNA analyses suggest multiple FbL2A genes in cotton. The gene is developmentally regulated and is activated during late primary and early secondary wall synthesis stages. FbL2A encodes a polypeptide of 43.4 kD and a predicted isoelectric point of 5.97. The nucleotide-derived protein is highly hydrophilic except for a hydrophobic N terminus and has a compositional bias for glutamic acid (26.3 mol%) and lysine (18.9 mol%). Sixty-two percent of the putative protein is composed of repeat motifs. A 55-amino-acid peptide region is repeated four times in a concatenate fashion within the protein. The function of the protein in the fiber cells is not known. A 2.3-kb DNA fragment 5[prime] from the FbL2A gene is shown to direct expression of heterologous proteins in transgenic cotton in a fiber-specific and developmentally regulated fashion. The FbL2A promoter was used to express in transgenic cotton genes encoding acetoacetyl-coenzyme A reductase and polyhydroxyalkanoic acid synthase, which are involved in the synthesis of the thermoplastic polymer polyhydroxybutyric acid. Transgenic plants containing both enzymes produced polyhydroxybutyric acid in fiber. Thus, the FbL2A promoter is useful in genetic engineering schemes to modify cotton fiber.