bluuebunny/crossref_metadata_2025 huggingface dataset:
Hyperexcitability of CA3 Pyramidal Cells in Mice Lacking the Potassium Channel Subunit Kv1.1
Authors: Lopantsev Valeri , Tempel Bruce L , Schwartzkroin Philip A.
Published: November 2003

Summary:  Purpose: To investigate further the membrane properties and postsynaptic potentials of the CA3 pyramidal cells in mice that display spontaneous seizures because of a targeted deletion of the Kcna1 potassium channel gene (encoding the Kv1.1 protein subunit).

Methods: Intracellular recordings were obtained from CA3 pyramidal cells in hippocampal slices prepared from Kcna1‐null and control littermates. CA3 pyramidal cells were activated: orthodromically, by stimulating mossy fibers; antidromically, by activating Schaffer collaterals; and by injecting intracellular pulses of current. Responses evoked under these conditions were compared in both genotypes in normal extracellular medium (containing 3 mM potassium) and in medium containing 6 mM potassium.

Results: Recordings from CA3 pyramidal cells in Kcna1‐null and littermate control slices showed similar membrane and action‐potential properties. However, in 33% of cells studied in Kcna1‐null slices bathed in normal extracellular medium, orthodromic stimulation evoked synaptically driven bursts of action potentials that followed a short‐latency excitatory postsynaptic potential (EPSP)‐inhibitory PSP (IPSP) sequence. Such bursts were not seen in cells from control slices. The short‐latency γ‐aminobutyric acid (GABA)A‐mediated IPSP event appeared similar in null and control slices. When extracellular potassium was elevated and excitatory synaptic transmission was blocked, antidromic activation or short pulses of intracellular depolarizing current evoked voltage‐dependent bursts of action potentials in the majority of cells recorded in Kcna1 null slices, but only single spikes in control slices.

Conclusions: Lack of Kv1.1 potassium channel subunits in CA3 pyramidal cells leads to synaptic hyperexcitability, as reflected in the propensity of these cells to generate multiple action potentials. The action‐potential burst did not appear to result from loss of GABAA receptor–mediated inhibition. This property of CA3 neurons, seen particularly when tissue conditions become abnormal (e.g., elevated extracellular potassium), helps to explain the high seizure susceptibility of Kcna1‐null mice.
The Anticonvulsant Effects of Progesterone and 5α‐dihydroprogesterone on Amygdala‐kindled Seizures in Rats
Authors: Lonsdale and Deborah , Burnham W. McIntyre
Published: November 2003

Summary:  Purpose: Progesterone has been shown to be anticonvulsant in several animal seizure models. The purpose of the present study was to investigate the anticonvulsant actions of progesterone and its primary metabolite 5α‐dihydroprogesterone in the amygdala kindling model.

Methods: Female Wistar rats were implanted in the right basolateral amygdala with a long‐term, bipolar electrode. The subjects were kindled to 30 stage 5 seizures and stability tested. Multiple doses of progesterone and 5α‐dihydroprogesterone were then tested for anticonvulsant activity against focal electrographic and generalized convulsive kindled seizures. The time course of progesterone's anticonvulsant action also was examined.

Results: Progesterone had a median effective dose (ED50) of 103 mg/kg against generalized convulsions at 15 min after injection. Subjects were not sedated at the time of seizure testing, although sedation developed later (40–60 min after injection). In time‐course experiments, it was found that 120 mg/kg of progesterone caused complete suppression of the generalized convulsion from 20 to 160 min after injection. Suppression of the focal discharge also was seen in some animals between 20 and 160 min. 5α‐dihydroprogesterone had an ED50 of 2.9 mg/kg against generalized kindled convulsions and an ED50 of 4.3 mg/kg against focal afterdischarge 15 min after injection. 5α‐dihydroprogesterone did not produce sedation 15 min after injection, or at any later time interval.

Conclusions: Progesterone is anticonvulsant only at high doses when tested against amygdala kindled seizures. 5α‐dihydroprogesterone is considerably more potent than progesterone. At low, nonsedative doses, it was effective against both the kindled amygdala focal afterdischarge and the generalized convulsion.
Taxonomic and biostratigraphical re‐assessments of Subterraniphyllum Elliott (Corallinales, Rhodophyta)
Authors: Bassi Davide , Woelkerling William J. , Nebelsick James H.
Published: November 2003

A taxonomic and biostratigraphical re‐assessment of Subterraniphyllum Elliott (Corallinales, Rhodophyta) is presented. Results from studies of the type collection and of newly collected material from north‐eastern Italy and northern Slovenia have shown that this taxon is not a geniculate coralline red alga as originally suggested by Elliott and most subsequent authors. Vegetatively, Subterraniphyllum most closely resembles certain living members of the Corallinales; however, the phenetic and phylogenetic relationships of Subterraniphyllum to other Corallinales cannot be determined with greater certainty. The exclusion of Subterraniphyllum from any group of Corallinaceae with genicula is based on unequivocal evidence that branch formation does not involve the occurrence of genicula. Subterraniphyllum seems to be restricted to the Oligocene. Reports of occurrences in Upper Eocene and Lower Miocene sediments cannot be substantiated. Subterraniphyllum, however, cannot be considered a useful stratigraphical marker until further data on its occurrence in well‐dated carbonate sequences are acquired. This study illustrates the problems associated with placing fossil coralline algal specimens into geniculate genera without the preservation of relevant morphological characters. This is especially true in the absence of the careful assessment of fossil material with respect to current taxonomic concepts of geniculate coralline genera, all of which are based on studies of living species. According to the current concepts for geniculate coralline genera, the placing of fossil specimens into geniculate genera without appropriate evidence must be avoided by grouping all potentially geniculate fragments under the informal group ‘Geniculate sensu lato’. Furthermore, for all those many fossil specimens where unequivocal evidence is not present, it is possible to utilize ‘form genera’ based on characters that are normally preserved. This leads to creating a consistent, workable system of applying names to most fossil corallines so that they can be reliably used in relation to stratigraphical and palaeoecological studies.
Opisthobranch molluscs from the Tertiary of the Aquitaine Basin (south‐western France), with descriptions of seven new species and a new genus
Authors: Valdés Ángel , Lozouet Pierre
Published: November 2003

An exceptionally well‐preserved collection of Tertiary opisthobranch molluscs from the Aquitaine Basin, France, includes species of the order Notaspidea [Umbraculum sanctipaulensis sp. nov., Tylodina perversa (Gmelin), Spiricella unguiculus Rang and Des Moulins, Berthella aquitaniensis sp. nov., Berthella ateles sp. nov.], of the order Anaspidea [Akera cf. bullata Mu¨ller, Floribella corrugata (Cossmann), Floribella cossmanni sp. nov., Floribella rozieri sp. nov., Limondinia ornata gen. et sp. nov.] and of the order Sacoglossa [Volvatella faviae sp. nov.]. BerthellaaquitaniensisB. atelesV. faviae are the first fossil records of the families Volvatellidae and Pleurobranchidae. Floribella plicifera (Cossmann) and F.corrugata, originally assigned to the genus Philine, belong to the genus Floribella and constitute the oldest records of this genus. The fossil evidence indicates that in Umbraculum laudunensis and U. sanctipaulensis the shell probably covered most of the animal, whereas in the Recent U. umbraculum the shell only covers the central portion of the body. Tylodina perversa could be an old species that appeared during the early Miocene, more than 21 Ma. The Recent shells of Akera bullata are indistinguishable from fossils as old as the mid Eocene, but it may be biologically unrealistic to consider them to be the same species. The European species of Floribella evolved from the bullomorph shells of the early Eocene forms to the elongate shells of the early Miocene. The genus Volvatella is another example of marine tropical disjoint distributions and an excellent ecological indicator.
The sonniniid ammonite Euhoploceras from the Middle Jurassic of south‐west England and southern Spain
Authors: Sandoval José , Chandler Robert B.
Published: November 2003

A biostratigraphical and taxonomic revision of the genus Euhoploceras is presented using new material collected from the Upper Aalenian–Lower Bajocian of south‐west England and the Betic Cordillera (Spain). Euhoploceras is shown to range from the uppermost Aalenian (Concavum Zone, Limitatum Subzone) to the Lower Bajocian (Laeviuscula Zone). S. S. Buckman's 69 species of Sonninia are grouped into three macroconch morphospecies: Euhoploceras acanthodes (Buckman), strongly ornamented, with tubercles and strong ribs throughout ontogeny; Euhoploceras marginatum (Buckman) with tuberculate inner whorls and relatively strong ribs persisting to the outer whorls, and Euhoploceras modestum (Buckman) with ribbed, sometimes slightly tuberculate inner whorls, becoming smooth or only slightly ornamented in later stages of coiling. Euhoploceras adicrum (Waagen) is a younger species with a type horizon in the Laeviuscula Zone. Dimorphism and possible polymorphism are present in both English and Spanish faunas. Euhoploceras subspinosum (Buckman) probably represents dwarf forms of E. acanthodes[M] and is included as a junior synonym of the latter; likewise, E. subdecoratum (Buckman) may belong with E. marginatum[M], although they are described separately herein. Some of the microconchs of Euhoploceras[M] are probably represented by Nannoceras. Similarities between English and Betic Euhoploceras confirm that during late Aalenian–earliest Bajocian times, the English and Spanish palaeobiogeographical regions were connected. The ammonite assemblages revised here come from the Concavum to Ovalis zones.
A near‐tetrapod from the Baltic Middle Devonian
Authors: Ahlberg Pererik , Lukševičs Ervins , Mark‐Kurik Elga
Published: November 2003

The tetrapodomorph sarcopterygian Livoniana multidentata gen. et sp. nov. is described on the basis of lower jaw fragments from the Middle Devonian(late Givetian) of Latvia and Estonia. It possesses a suite of derived characters previously only known from tetrapods, which first appear in the late Devonian (late Frasnian), and a phylogenetic analysis places it on the internode between Panderichthys and the base of the Tetrapoda. The analysis also reveals that the ‘Elpistostegalia’ are paraphyletic to Tetrapoda, with Elpistostege closer to tetrapods than is Panderichthys. Owing to incompleteness of the material, there is almost no overlap between the data sets for ElpistostegeLivoniana; the analysis places the two genera in an unresolved trichotomy. In addition to the tetrapod features, Livoniana has a strikingly autapomorphic dentary dentition comprising multiple tooth rows. It thus provides evidence both for the unexpectedly early evolution of tetrapod characteristics and for morphological radiation around the fish‐tetrapod transition.
A new specimen of the thyreophoran dinosaur cf. Scelidosaurus with soft tissue preservation
Authors: Martill David M. , Batten David J. , Loydell David K.
Published: November 2003

A new specimen, comprising eight articulated caudal vertebrae in a cut slab of blue/grey carbonate mudstone, is comparable to the early thyreophoran dinosaur Scelidosaurus harrisonii Owen from the English Lower Jurassic. Palynological analysis indicates that the specimen is probably late Hettangian–Sinemurian (Early Jurassic), but the exact horizon and locality remain uncertain. The slab has been cut longitudinally in a parasagittal plane along the vertebral series and exposes several articulated centra, haemal arches, neural arches and osteoderms. An envelope of preserved soft tissue wraps around the vertebrae and includes osteoderms with organic material on both the upper and lower surfaces. Basal thyreophoran dinosaur osteoderms were covered by a horny sheath during life.
A new xeromorphic conifer from the Cretaceous of East China
Authors: Zhiyan Zhou , Thévénard Fredéric , Barale Georges , Guignard Gaetan
Published: November 2003

Newly discovered coniferous shoots from the Cretaceous of Nanjing are attributed to the xeromorphic coniferous genus Glenrosa Watson and Fisher, which is found in China as well as in Eurasia for the first time. G. nanjingensis sp. nov. is known from shoots bearing scale‐like leaves with thick epidermal cuticle and hypodermis. Stomata are confined to the abaxial surface deeply sunken in stomatal chambers which are filled with papillae. The cuticle, which has been sectioned for TEM, consists of an outer pale amorphous cuticle proper, usually with a peripheral polylamellate zone, and an inner dark cuticular layer containing reticulate fibrillae. G. nanjingensis sp. nov. bears a close resemblance to the type species G. texensis (Fontaine) Watson and Fisher from North America in gross morphology and especially in the characteristic stomatal chambers, but differs in phyllotaxis and in having the hypostomatic leaf with an obtuse apex. G. nanjingensis sp. nov. is believed to have grown near inland marshes or water bodies under hot and arid climates.
A cephalopod fauna from the middle Ordovician of Saudi Arabia
Authors: Evans David H.
Published: November 2003

A small collection of cephalopods from the middle Ordovician of the Tabuk region of Saudi Arabia consists entirely of orthoconic longicones tentatively referred to the actinocerid genus Mesaktoceras? and pseudorthocerid Sactoceras?. Both taxa have Australasian affinities. Circumpolar Gondwana cephalopod faunas in the mid Ordovician were of low diversity and dominated by orthocerids, whilst actinocerids were largely restricted to low palaeolatitudes. The presence of Mesaktoceras? and Sactoceras? in a benthonic fauna belonging to the Neseuretus community is regarded as anomalous. Comparison is made with the occurrence of Trocholites in middle Ordovician Iberian successions. It has been suggested that Trocholites may have arrived in the Iberian area from Baltica through the transfer of bodies of warm water in storm masses. Mesaktoceras? and Sactoceras? may have arrived (albeit temporarily) in Saudi Arabia from Australasia through a similar process.
Palaeoberesellids (Dasycladaceans) from the Upper Jurassic Arab‐D Reservoir, Saudi Arabia
Authors: Adams Anthony E. , Al‐Zahrani Mohamed S.
Published: November 2003

Palaeoberesellids, tubular septate dasycladacean algae hitherto only described from the Upper Palaeozoic, have been discovered in the Late Jurassic Arab‐D Reservoir from the Khurais Oilfield, Saudi Arabia. Material is referred to a new species, Kamaena khuraisensis. Specimens occur in the wackestones and packstones of the lower part of the reservoir, deposited in offshore shelf environments deeper than those containing most of the other described Arab Reservoir dasycladaceans.
The species taxonomy of the sauropodomorph dinosaurs from the Löwenstein Formation (Norian, Late Triassic) of Germany
Authors: Yates Adam M.
Published: November 2003

The species taxonomy of the sauropodomorph dinosaurs from the Löwenstein Formation of Germany is examined. Previous work has classified these into two taxa: Sellosaurus gracilis from a number of localities and the widespread Plateosaurus engelhardti from a single monospecific accumulation in the Löwenstein Formation, near the town of Trossingen. The current hypodigm of Sellosaurus gracilis is found to contain a substantial amount of variation. This includes differences in the dentition, structure of the skull, composition of the sacrum and the structure of the caudal vertebrae and pelvis. This variation was analysed using a specimen–based parsimony analysis of the sauropodomorphs from the Löwenstein Formation. It was found that two discrete taxa comprise the current hypodigm of Sellosaurus. The more common of these two is a plesiomorphic form for which the correct name is Efraasia minor comb. nov. The less common form (which includes the holotype of Sellosaurus gracilis) is found to share a number of synapomorphies with Plateosaurus engelhardti and is placed in this genus as Plateosaurus gracilis
Cabinet Government: An Elusive Ideal?
Authors: Weller Patrick
Published: November 2003

This article will explore the proposition that cabinet government is dead by examining the different ways in which cabinet government is conceptualized and by suggesting that the lack of precision in the debates has undermined much of the criticism. It will seek to draw the strands of research together in a way that can emphasize how cabinet government has evolved while remaining at the core of government. The article will draw evidence from three countries, Australia, Canada and Britain, in each of which, despite the common heritage, cabinet has evolved in different ways.
Fiscal Transparency: Concepts, Measurement and UK Practice
Authors: Heald David
Published: November 2003

Greater fiscal transparency is seen by its advocates as a means of improving economic governance arrangements in ways which, by promoting fiscal stability, will in turn improve the functioning of the government sector and facilitate improvements in the economic environment for the private sector. ‘Fiscal transparency’ is much acclaimed by policy‐makers, not only in the UK Treasury but also by the IMF and OECD. Fiscal transparency can have substance or can just be voguish incantation. This article explores the meaning of fiscal transparency, by examining its structure and evaluating criteria for assessing the degree of fiscal transparency attached to particular sets of circumstances. It explores the link between transparency and accountability, developing the distinction between event and process transparency. Consideration is given to the trade‐off between the value of sunlight (to employ an analogy) and the danger of over‐exposure. The performance of the United Kingdom against emerging international best practice is examined, with regard to both public expenditure and taxation. By international standards, UK fiscal transparency is high. Nevertheless, there is a major gap between UK rhetoric and practice, indicating a  divergence between nominal and effective transparency. This is evidenced by: frequent changes in public expenditure definitions; the non‐publication of important analyses; the location of certain liabilities ‘off‐balance sheet’; and a lack of candour about tax policy.
Public Scrutiny, Standards and the Planning System: Assessing Professional Values within a Modernized Local Government
Authors: Allmendinger Philip , Tewdwr‐Jones Mark , Morphet Janice
Published: November 2003

Since the 1990s there has been a long‐standing concern in government towards public sector accountability, management, efficiency and service delivery. A number of studies have attempted to analyse the multitude of individual changes and their manifestations through analyses based on a variety of institutional, policy and governmental distinctions. This paper attempts to specify the changes with particular reference to planning, and to consider the evolution of the public service ethic in planning towards more openness, scrutiny, transparency and efficiency with particular reference to the changing ethos of the professional employee. We first explore the  main impacts upon local government, the public service ethic and professional planning as a consequence of the Modernization agenda and freedoms and flexibilities initiative. We then look at how such changes have impacted upon the ethos and values in public service and planning. We draw on some evidence of Ombudsman cases to highlight issues of professional values in planning practice over the past decade before finally drawing these strands together in some conclusions. Our principal findings indicate that the much‐trumpeted decline of services and standards may not have been as apparent as is sometimes portrayed and that internal professional attitudes and values towards the external changes may not have significantly altered over the same period.
Administrative Traditions and Policy Change: When Policy Paradigms Matter. The Case of Italian Administrative Reform During the 1990s
Authors: Capano Giliberto
Published: November 2003

In recent years a growing number of scholars have developed cognitive and ideational theoretical frameworks for the analysis of policy‐making processes: their underlying belief is that ideas (conceived as beliefs, causal theories and paradigms) really do matter. The concept of policy paradigm has been particularly useful in studying both the contents and dynamics of policy change. The present paper takes this concept, partially reformulates Hall's definition in terms of the distinction between the hegemonic and dominant paradigm, and then uses it to come to terms with the contents and dynamics of the Italian administrative reforms implemented during the 1990s. Mixing the conceptual lenses offered by the ideational and cultural path taken in the field of public policy and by historical neo‐institutionalism, this article attempts to explain the Italian trajectory, and to underline how normative and cognitive elements represent an important influence on the ‘design’ and ‘strategy’ of policy change. Our analysis of the consistency of the reformers’ documents and policy strategy shows that, despite their claims, the contents and strategy of reform do not represent a paradigmatic about‐turn, but constitute an evolutionary adaptation to external pressures imposed by the hegemonic administrative paradigm.
Some implications for monetary policy of uncertain exchange rate pass‐through
Authors: Hunt Benjamin , Isard Peter
Published: November 2003

The paper uses MULTIMOD to examine the implications of uncertain exchange rate pass‐through for the conduct of monetary policy. From the policymaker's perspective, uncertainty about exchange rate pass‐through implies uncertainty about policy multipliers and the impact of state variables on stabilization objectives. When faced with uncertainty about the strength of exchange rate pass‐through, policymakers will make less costly errors by overestimating the strength of pass‐through rather than underestimating it. The analysis suggests that pass‐through uncertainty of the magnitude considered does not result in efficient policy response coefficients that are smaller than those under certainty.
The Exchange Rate and Inflation in the UK
Authors: Kara Amit , Nelson Edward
Published: November 2003

The United Kingdom is a highly open economy, and has a monetary policy strategy of targeting inflation in consumer prices. In this paper, we look at the evidence from the UK on inflation behaviour, and examine the propositions from several theoretical models about inflation dynamics in an open economy, focusing in particular on the hypothesized connections between the exchange rate and consumer price inflation. Theoretical open‐economy macroeconomic models ‘cover the waterfront’ on this issue, ranging from ‘exchange rate disconnect’ to a rigid link between nominal exchange rate changes and inflation. We estimate on UK data the open‐economy Phillips curves implied by the alternative explanations. We argue that, of the alternatives considered, only a model where imports are modelled as an intermediate good, as in McCallum and Nelson (1999), provides a reasonable match with the data. Unlike the standard model, in which imports are treated as a final consumer good, the intermediate‐goods specification provides support for a policy of CPI inflation targeting.
Persistence, The Transmission Mechanism And Robust Monetary Policy
Authors: Angeloni Ignazio , Coenen Günter , Smets Frank
Published: November 2003

In this paper we first explore the impact of nominal and real persistence on the transmission process of various shocks in an estimated DSGE model of the euro area. We then analyse its impact on optimal monetary policy and investigate the performance of various monetary policies when the policy maker is uncertain about the degree of nominal and real persistence.
The effect of urbanization on the quality of remnant habitats for leaf‐mining Lepidoptera on Quercus agrifolia
Authors: K. Rickman Jancy , F. Connor Edward
Published: November 2003

Previous studies suggest that urbanization alters the abundance and species richness of native insects on remnant habitat patches. However, the effects of urbanization on biological communities caused by habitat loss and fragmentation have not been separated from effects caused by altered habitat quality within remnant habitats or by the nature of the urban matrix. To test for an effect of urbanization acting via altered habitat quality or matrix characteristics, we controlled for the effects of habitat loss and fragmentation by comparing remnant habitat patches in urban and agricultural regions experiencing similar levels of habitat loss and fragmentation. We studied the species richness and abundance of the community of leaf‐mining Lepidoptera on Quercus agrifolia in the San Francisco Bay Area. We measured the extent of five land‐use types within a 500 m radius of each study patch. We built generalized linear models to determine if the extent of any of the landscape variables was associated with the species richness and abundance of the leaf‐miner community. The extent of urbanization was not associated with species richness or total abundance. However, the abundance of three species of leaf‐mining moths was associated with the extent of urbanization, but not in a consistent pattern. The abundances of Stigmella variella and Bucculatrix albertiella were higher and the abundance of Dryseriocrania auricyanea was lower at highly urbanized sites. The absence of a consistent association between urban land‐use and both species richness and abundance indicates that the effects of urbanization on the community of leaf‐mining moths of Q. agrifolia do not differ from the effects of replacing and fragmenting habitats with similar amounts of agricultural land‐uses.
Broad‐scale geographical patterns in local stream insect genera richness
Authors: Vinson Mark R. , Hawkins Charles P.
Published: November 2003

Comprehensive global studies of stream invertebrate assemblages are rare and have produced contradictory results. To address this shortcoming, we compiled data from 495 published estimates of local genera richness for three orders of stream‐dwelling insects (Ephemeroptera, Plecoptera, Trichoptera) from throughout the world and used these data to describe global geographic patterns in stream insect genera richness and to address two questions: 1) does local stream insect richness vary more with regional historical factors or with local ecological factors?, and 2) to what extent have streams converged in the number of taxa they support?  Maximum genera richness varied sharply across the range of latitude examined from the south to north poles for all three orders of aquatic insects. Ephemeroptera richness showed 3 peaks (∼30°S, 10°N, and 40°N) with highest richness near 5–10°N and 40°N latitude. Plecoptera richness was distinctly highest at ∼40°N latitude with a similar peak at 40°S latitude. Trichoptera richness showed less latitudinal variation than the other taxa but was slightly higher near the equator and at 40°N and S latitude than at other latitudes. Genera richness generally declined with increasing elevation, except for Plecoptera. Maximum genera richness increased steadily with a measure of regional terrestrial net primary production and declined sharply with a measure of hydrologic disturbance for all orders. Richness varied widely among both biogeographical realms and biomes, although ca 2 times as much variation in richness was associated with biome as biogeographic realm. Richness for each order was highest in different biogeographic realms, but all orders had highest richness in broadleaf forest biomes. These latter results imply that spatial variation in local richness of stream insects is more strongly affected by contemporary ecological factors than by historical biogeography and that maintenance of intact forested landscapes may be critical to the conservation of stream invertebrate faunas.
Responses of arthropods to plant diversity: changes after pollution cessation
Authors: Perner Jörg , Voigt Winfried , Bährmann Rudolf , Heinrich Wolfgang , Marstaller Rolf , Fabian Bärbel , Gregor Karsten , Lichter Dorit , Sander Friedrich W. , Jones T. Hefin
Published: November 2003

Data collected from three different polluted sites in the vicinity of a phosphate fertilizer factory that was closed in 1990 are used to test with Mantel tests and smoothing techniques whether the rapid increase of plant species richness following cessation of pollution enhanced associated arthropod assemblage diversity. 132 plant species (between 1990 and 1999) and 66 413 individuals of 680 arthropod species (using sweep net sampling between 1990 and 1996) were recorded. Using top soil pH as a representative pollution parameter we detected an increase of plant species richness, effective diversity and evenness of plant community with decreasing pH both in space and time. While the richness of all studied functional groups of herbivores increased with plant species richness, only the richness of one carnivore functional group showed a similar pattern. Plant species richness was significantly correlated to the abundance patterns of two herbivore and two carnivore groups. But contrary to theoretical predictions consumer abundance tended to decrease with increasing plant diversity only between a plant species richness range of 10 to ca 35. Our results support the findings of previous studies that highlight how increased plant species and functional group richness may result in higher herbivore species richness, and that carnivore richness may be influenced by herbivore and detritivore richness. The functional group approach used in this study has enabled us to detected the very individual interaction patterns that occur between different groups within the same trophic level.
Diet selection of lesser white‐fronted geese Anser erythropus at a spring staging area
Authors: Markkola Juha , Niemelä Marika , Rytkönen Seppo
Published: November 2003

We studied diet selection of the globally threatened lesser white‐fronted goose Anser eythropus at a spring staging area on the island of Hailuoto (64°00′N, 24°45′E), off the western coast of Finland. We determined the diet using droppings, which were collected in late May, when the geese had left the area and migrated northwards. The sample potentially comprised of ejecta from 31 different individuals. Plant idengification was based on visual determination of epidermal fragments. A total of 100 droppings were sampled using a point quadrat method. We calculated the percentage of each idengified taxon in each dropping and related this to the availability of the corresponding taxon in the meadow. We measured preference for each taxon using Chesson's electivity index (ɛi) and tested them by bootstrap resampling. The diet contained 9 taxa of the ca 40 available. Almost all dietary items were Monocotyledons (99.9%), mostly grasses (88.7%) including Festuca rubra (43%), Phragmites australis (30%) and Calamagrostis stricta (13%). Only Phragmites (ɛ=0.73, p=0.000), Festuca (ɛ=0.52, p=0.004) and possibly Triglochin palustris (ɛ=0.70, p=0.125) were preferred, all other species were avoided. All preferred species were quite common and other goose species exploit them too. The lesser white‐fronted geese preferred large natural meadows that were five times broader than an “average” Bothnian Bay meadow. All forms of mowing and grazing management benefit the restoration of lesser white‐fronted goose habitats at the landscape level. Festuca and especially Triglochin benefit from such management. Reeds, Phragmites, whose spread has been the main cause of coastal meadow deterioration, can be controlled by management, but can also be maintained among other vegetation if mowing is less frequent or grazing not too intensive.
Influence of environmental and spatial variables on regional distribution of forest plant species in a fragmented and changing landscape
Authors: Jacquemyn Hans , Butaye Jan , Hermy Martin
Published: November 2003

During the past several centuries, forests in Europe and large parts of North America have been subject to extensive forest clearance. The last several decades, however, numerous new forest patches have been established onto former agricultural land. As a result, the present forest area often consists of a mixture of small forest patches of different age, area, habitat quality and connectivity embedded within a hostile agricultural landscape. In these patchy landscapes, distribution patterns of plant species may be affected by both regional and local factors, although the relative importance of both is still poorly understood. In this study, we investigated distribution patterns of 113 forest plant species in a fragmented landscape. Species abundances at the regional scale conformed to a clearly unimodal abundance distribution which we believe to be related to 1) environmental heterogeneity due to succession and 2) inequality in migration rates. Patch incidence was significantly related to life form, which in turn was correlated to seed mass and dispersal mechanism. Multiple logistic regressions showed that presence/absence of 59 species studied was significantly affected by patch connectivity, patch area and age for 35, 30 and 34 species, respectively. The results of this study indicate that distribution patterns of forest plant species are influenced by both local and regional factors. Moreover, they also demonstrate that next to spatial aspects of fragmentation, temporal patterns of landscape change may have far‐reaching effects on presence/absence patterns of plant species and therefore should be incorporated in studies dealing with regional population structures of plants.
Diversity and abundance patterns of phytophagous insect communities on alien and native host plants in the Brassicaceae
Authors: Frenzel Mark , Brandl Roland
Published: November 2003

The herbivore load (abundance and species richness of herbivores) on alien plants is supposed to be one of the keys to understand the invasiveness of species. We investigate the phytophagous insect communities on cabbage plants (Brassicaceae) in Europe. We compare the communities of endophagous and ectophagous insects as well as of Coleoptera and Lepidoptera on native and alien cabbage plant species. Contrary to many other reports, we found no differences in the herbivore load between native and alien hosts. The majority of insect species attacked alien as well as native hosts. Across insect species, there was no difference in the patterns of host range on native and on alien hosts. Likewise the similarity of insect communities across pairs of host species was not different between natives and aliens. We conclude that the general similarity in the community patterns between native and alien cabbage plant species are due to the chemical characteristics of this plant family. All cabbage plants share glucosinolates. This may facilitate host switches from natives to aliens. Hence the presence of native congeners may influence invasiveness of alien plants.
Considerations for the use of SADIE statistics to quangify spatial patterns
Authors: Xu Xiangming , Madden Laurence V.
Published: November 2003

The SADIE methodology has recently been developed to quangify spatial patterns, particularly in determining the randomness of observed patterns, estimating patches and gaps, and quangifying correlation between species. We used argificially generated data sets to investigate the relationship of the SADIE pattern and association statistics with patch number and spatial positions of the patches. Results showed that SADIE statistics are critically dependent on the absolute positions of quadrat counts, and not just on their relative positions. In particular, degree of patchiness increased as the patch was displaced away from the centre. Therefore, the dependence of SADIE statistics on absolute sampling positions should be taken into consideration when using and interpreting SADIE‐based results.
Cost of reproduction, T‐lymphocyte mediated immunocompetence and health status in female and nestling barn swallowsHirundo rustica
Authors: Pap Péter L. , Márkus Róbert
Published: November 2003

We investigate the trade‐off between reproductive effort, health status and T‐lymphocyte acquired immunity in female and nestling barn swallowsHirundo rusticausing a brood size manipulation experiment. Maternal and total feeding effort increased with experimental brood size. Parents did not fully compensate for the increased food demand of the enlarged broods and as a consequence the per capita feeding rate of nestlings decreased with increasing experimental brood size. Body mass and a measure of T‐cell mediated immunity in 12 days old nestlings also decreased with increasing experimental brood size. Different leucocyte concentrations and the heterophile/lymphocyte ratio – an index of stress – of nestlings did not change in relation to experimental brood size, suggesting that within brood competition did not affect stress to nestlings. The brood size manipulation had a significant effect on maternal T‐cell mediated immunity, measured by the phytohemagglutinin skin test, but not on maternal body mass, haematocrit or differential or total white blood cell counts. Our results seem to support the prediction that under mild work stress females respond first by reducing the energetically expensive acquired immunity. Different leucocyte types and the heterophile/lymphocyte ratio appear less sensitive to parental workload.
Experimental dissociation of the effects of diet, age and breeding experience on primary reproductive effort in zebra finchesTaeniopygia guttata
Authors: Williams Tony D. , Christians Julian K.
Published: November 2003

Reproductive performance varies with age in a wide range of organisms, and increasingly such patterns are interpreted in terms of state‐dependent models. We sought to characterise ‘state’ with regards to age‐related variation in clutch size, egg mass and timing of breeding in captive zebra finchesTaeniopygia guttata, focusing on the roles of diet quality, age and breeding experience. Females on a high‐quality diet laid larger clutches of larger eggs than did females on a low‐quality diet. The effect of age on reproductive performance was examined by comparing females breeding (i.e. paired) for the first time at either 3‐ and/or 6‐months of age. Clutch size increased with age but on the low‐quality diet only, not on the high‐quality diet. Furthermore, clutch sizedecreasedbetween 3‐ and 6‐months of age in birds bred first on the high‐quality diet and then on the low‐quality diet. Age did not affect egg mass but older birds had shorter laying intervals. Reproductive performance did not differ between females breeding at 6‐months of age for the first or second time: the effects of age were not due to ‘training’ effects or experience specific to breeding (e.g. undergoing the physiological process of egg formation). In conclusion, nutritional condition (diet) emerged as a central component of state that could strongly influence, and even reverse, any age‐dependent increase in primary reproductive performance.
Experimental evidence for the influence of food availability on incubation attendance and hatching asynchrony in the Australian reed warbler Acrocephalus australis
Authors: Eikenaar Cas , Berg Mathew L. , Komdeur Jan
Published: November 2003

The amount of time a bird allocates to incubation is likely to be limited by energetic constraints. If food is abundant, energetic constraints may be reduced and the time spent incubating (incubation attendance) may increase. Moreover, the onset of incubation in relation to clutch completion may be advanced, resulting in a higher degree of hatching asynchrony. We measured the effect of experimentally increased food availability on incubation attendance and an estimate of hatching asynchrony in the Australian reed warbler Acrocephalus australis. Supplementary food was provided every other day, from a few days before the start of egg laying until just prior to hatching. Incubation attendance was measured with temperature loggers at nests receiving supplementary food and control nests. Hatching asynchrony was inferred from mass and size differences between siblings shortly after hatching. We found that 1) food supplementation resulted in an increase in incubation attendance, when comparing both nests receiving supplementary food to control nests as well as feeding to non‐feeding days in nests receiving supplementary food, and 2) food supplementation resulted in a greater hatching asynchrony, without affecting clutch size, average egg volume or the likelihood of eggs hatching. This suggests that food availability acts in a proximate way to modify the extent of incubation attendance and hatching asynchrony. We discuss the adaptive significance of increased incubation attendance and a shift in the degree of hatching asynchrony in relation to food availability.
Honesty in host‐parasite communication signals: the case for begging by fledgling brown‐headed cowbirds Molothrus ater
Authors: Hauber Mark E. , Ramsey Caitlin K.
Published: November 2003

Nestling parasites typically beg more intensively than do host nestlings yet these exaggerated displays are also honest in that they are modulated by hunger and age. We hypothesized that honesty was also maintained in the food solicitation behaviors of fledgling brood parasites because the benefits and costs of their begging displays are similar to those of nestling parasites. Begging displays of hand‐reared 14–32 days old brown‐headed cowbirds Molothrus ater that had experimentally manipulated nutritional needs were recorded to analyze variation in the peak frequency, duration, and rate of fledglings’ begging bouts. Peak frequency of bouts decreased with greater age and was lower for females. Bout rate was greater with increasing hunger levels of fledgling parasites but did not vary with age. Consistent and predictable variation of acoustic begging displays with age, sex, and hunger‐level indicates honesty in host‐parasite communication systems through conveying truthful information about the many possible needs of parasitic fledglings.
Explaining annual fluctuations in breeding density of fieldfares Turdus pilaris– combined influences of factors operating during breeding, migration and wintering
Authors: Hogstad Olav , Selås Vidar , Kobro Sverre
Published: November 2003

In a subalpine birch forest in Central Norway, the breeding population of fieldfare Turdus pilaris varied from 3 to 63 pairs per km2 during 1966–2000. For the period 1971–1995, the breeding density was negatively related to the number of days with >75% snow covered ground in April, presumably because snow cover reduce the availability of earthworms. In a multiple regression model for the period 1974–1995, snow cover in spring, the number of migrating fieldfares observed at two ornithological stations at the southern coast of Norway in April, the mean temperature in November in the preceding year, winter temperatures, rowanberry production in the previous autumn, and the interaction effect of the two latter variables (high value of one of these variables reduced the negative effect of a low value of the other) explained 80% of the variation in fieldfare breeding density. Autumn and winter temperatures, as well as rowanberry production, contributed through a positive effect, probably because these factors affected the number of fieldfare present in Norway throughout winter, which in some years may constitute a significant proportion of the overall fieldfare population.
The effects of light characteristics on avian mortality at lighthouses
Authors: Jones Jason , Francis Charles M.
Published: November 2003

The generation of artificial light by human activity can have far‐reaching detrimental impacts upon a wide variety of organisms. A great deal of attention has been paid to well‐lit buildings, television towers, and communication towers as sources of mortality for nocturnally migrating songbirds. However, despite being among the first human structures known to generate migratory bird kills, little is known about the current impact of lighthouses on birds, or the impact of light design. We examined the impact of a lighthouse on nocturnal avian migrants at Long Point, Lake Erie, Ontario, Canada. From 1960–1989, mean annual kills were 200 birds in spring, and 393 in autumn, with kills of up to 2000 birds in a single night. In 1989, the Long Point lighthouse was automated, with a simultaneous change in beam characteristics – the new beam is narrower and less powerful. This change brought about a drastic reduction in avian mortality at the lighthouse to a mean of only 18.5 birds per year in spring, and 9.6 in autumn from 1990–2002. Our results highlight the effectiveness of simple changes in light signatures in reducing avian light attraction and mortality during migration.
Chemical warfare? Effects of uropygial oil on feather‐degrading bacteria
Authors: Shawkey Matthew D. , Pillai Shreekumar R. , Hill Geoffrey E.
Published: November 2003

Anti‐microbial activity is a commonly suggested but rarely tested property of avian uropygial oil. Birds may defend themselves against feather‐degrading and other potentially harmful bacteria using this oil. We preliminarily identified 13 bacterial isolates taken from the plumage of wild house finches Carpodacus mexicanus, measured bacterial production of the enzyme keratinase as an index of feather‐degrading activity, and used the disc‐diffusion method to test bacterial response to uropygial oil of house finches. For comparison, we performed the same tests on a type strain of the known feather‐degrading bacterium Bacillus licheniformis. Uropygial oil inhibited the growth of three strongly feather‐degrading isolates (including Bacillus licheniformis), as well as one weakly feather‐degrading isolate and one non‐feather‐degrading isolate. Uropygial oil appeared to enhance the growth of one weakly feather‐degrading isolate. Growth of the remaining isolates was unaffected by uropygial oil. These results suggest that birds may defend themselves against some feather‐degrading bacteria using uropygial oil.
Symposium: Imperial Dreams: Can the Middle East Be Transformed?
Authors: Pollack Kenneth , Hawthorne Amy , Lang W. Patrick , Wilcox, Jr. Philip C.
Published: November 2003

The following is an edited transcript of the thirty‐fourth in a series of Capitol Hill conferences convened by the Middle East Policy Council. The meeting was held on October 3, 2003, in the Rayburn House Office Building with Chas. W. Freeman, Jr., moderating.
Age, Cohort, and the Slump in Job Satisfaction among West German Workers
Authors: Jürges Hendrik
Published: November 2003

Abstract.  Using German panel data, I examine the long‐term development in satisfaction with work from 1984 until 2001. As was the case for many other industrialized countries, Germany witnessed a sharp decline in workers’ self‐reported job satisfaction in the late 1980s and 1990s, the reason of which is yet unknown. I present a cohort analysis of job satisfaction using various identifying assumptions to examine several explanations for this phenomenon: pure cohort effects, a decrease in self‐reported job security, an increase in stress at work and a deterioration in other job conditions, and possible survey artefacts such as interviewer or repeated measurement effects. However, none of these can explain the overall decline in job satisfaction.