bluuebunny/crossref_metadata_2025 huggingface dataset:
Country of Origin Regulation in Cross-Border Media: One Step Beyond the Freedom to Provide Services?
Authors: Hörnle Julia
Published: December 2004

The E-commerce Directive1has introduced a country of origin rule2for the provision of online services (‘information society services’). This means in principle that service providers are only subject to the rules of their country of origin or home country, ie the country where they are established. The country to which they are providing the services to, the country of destination, must refrain from applying its regulations. For regulators this means that they must not applytheir national regulations to services provided from another Member State3(‘incoming services’).Likewise they must extend national regulation to services provided to residents in another MemberState (‘outgoing services’).
German‐learning infants’ ability to detect unstressed closed‐class elements in continuous speech
Authors: Höhle Barbara , Weissenborn Jürgen
Published: December 2004

The paper reports on two experiments with the head turn preference method which provide evidence that already at 7 to 9 months, but not yet at 6 months, German‐learning infants do recognize unstressed closed‐class lexical elements in continuous speech. These findings support the view that even preverbal children are able to compute at least phonological representations for closed‐class functional elements. They also suggest that these elements must be available to the language learning mechanisms of the child from very early on, allowing the child to make use of the distributional properties of closed‐class lexical elements for further top‐down analysis of the linguistic input, e.g. segmentation and syntactic categorization.
Children extend both words and non‐verbal actions to novel exemplars
Authors: Childers Jane B. , Tomasello Michael
Published: December 2004

Markson and Bloom (1997) found that some learning processes involved in children's acquisition of a new word are also involved in their acquisition of a new fact. They argued that these findings provided evidence against a domain‐specific system for word learning. However, Waxman and Booth (2000) found that whereas children quite readily extend newly learned words to novel exemplars within a category, they do not do this with newly learned facts. They therefore argued that because children did not extend some facts in a principled way, word learning and fact learning may result from different domain‐specific processes. In the current study, we argue that facts are a poor comparison in this argument since facts vary in whether they are tied to particular individuals. A more appropriate comparison is a conventional non‐verbal action on an object –‘what we do with things like this’– since they are routinely generalized categorically to new objects. Our study shows that 21/2‐year‐old children extend novel non‐verbal actions to new objects in the same way that they extend novel words to new objects. The findings provide support for the view that word learning represents a unique configuration of more general learning processes.
A Spoken Dialogue System for Navigation in Non‐Immersive Virtual Environments
Authors: McNeill M.D.J. , Sayers H. , Wilson S. , Mc Kevitt P.
Published: December 2004

Navigation is the process by which people control their movement in virtual environments and is a corefunctional requirement for all virtual environment (VE) applications. Users require the ability to move, controllingorientation, direction of movement and speed, in order to achieve a particular goal within a VE. Navigation israrely the end point in itself (which is typically interaction with the visual representations of data) but applicationsoften place a high demand on navigation skills, which in turn means that a high level of support for navigationis required from the application. On desktop systems navigation in non‐immersive systems is usually supportedthrough the usual hardware devices of mouse and keyboard. Previous work by the authors shows that many usersexperience frustration when trying to perform even simple navigation tasks — users complain about getting lost,becoming disorientated and finding the interface `difficult to use'. In this paper we report on work in progressin exploiting natural language processing (NLP) technology to support navigation in non‐immersive virtualenvironments. A multi‐modal system has been developed which supports a range of high‐level (spoken) navigationcommands and indications are that spoken dialogue interaction is an effective alternative to mouse and keyboardinteraction for many tasks. We conclude that multi‐modal interaction, combining technologies such as NLP withmouse and keyboard may offer the most effective interaction with VEs and identify a number of areas where furtherwork is necessary.

ACM CSS: I.3.6 Computer Graphics Methodology and Techniques—Interaction and Techniques, I.3.7 Three‐DimensionalGraphics and Realism—Virtual Reality, I.2.7 Natural Language Processing—Speech Recognitionand Synthesis
Creation and Control of Real‐time Continuous Level of Detail on Programmable Graphics Hardware
Authors: Southern Richard , Gain James
Published: December 2004

Continuity in level of detail sequences is essential in hiding visual artefacts that occur when switching between discrete levels of detail. However, construction and implementation of these sequences is prohibitively complex. We present a new structure, the g‐mesh, which greatly simplifies the implementation of continuous level of detail in large scenes. We also introduce a novel greedy predictive level of detail control system suited to the g‐mesh. Finally we achieve a dramatic improvement in the rendering of morphing sequences by exploiting current graphics hardware.

ACM CSS:I.3.5 Computational Geometry and Object Modeling—Geometric Transformations, Object Hierarchies, I.3.6 Methodology and Techniques—Graphics Data Structures
Quad/Triangle Subdivision
Authors: Stam Jos , Loop Charles
Published: December 2004

In this paper we introduce a new subdivision operator that unifies triangular and quadrilateral subdivision schemes. Designers often want the added flexibility of having both quads and triangles in their models. It is also well known that triangle meshes generate poor limit surfaces when using a quad scheme, while quad‐only meshes behave poorly with triangular schemes. Our new scheme is a generalization of the well known Catmull‐Clark and Loop subdivision algorithms. We show that our surfaces are

C
1

everywhere and provide a proof that it is impossible to construct such a

C
2

scheme at the quad/triangle boundary. However, we provide rules that produce surfaces with bounded curvature at the regular quad/triangle boundary and provide optimal masks that minimize the curvature divergence elsewhere. We demonstrate the visual quality of our surfaces with several examples.

ACM CSS: I.3.5 Computer Graphics—Curve, surface, solid, and object representations
Councils, memory and mills: the early development of the Peace of God in Catalonia
Authors: Bowman Jeffrey A.
Published: December 2004

The Peace councils which took place throughout west Francia from the late tenth century have long been recognized as complex political, social and ritual events. Discussions of the Peace, however, often neglect the local factors which informed these councils. The earliest councils in Catalonia were characterized by remarkable variety in both their organization and in their objectives. Some elements of these councils reflect longstanding regional traditions. Earlier provincial synods, for example, shared many of the same concerns expressed at Peace councils. Both synods and councils testify to an impressive level of regional episcopal co‐operation. The 1027 Council of Toulouges provides a rich opportunity to explore the microsocial and micropolitical alliances and animosities which motivated one council. The monastery of Sant Miquel de Cuixà, whose abbot organized this council and two others, had been developing a network of mills and irrigation canals near the council's site. The choice of the council's site was motivated, in part, by the desire to secure Cuixà's grip on these property rights. The mills near Toulouges are an example of the local impulses which informed early Peace councils; understanding these impulses can contribute to current debates about the Feudal Revolution.
Sale, price and valuation in Galicia and Castile–León in the tenth century
Authors: Davies Wendy
Published: December 2004

The number of sale transactions recorded by northern Spanish charters of the tenth century is very striking, especially in the 930s to 960s. A record of price paid was a consistent element of such documents, although words used to express price varied from silver solidi to goats, shirts and grain. Valuations, in solidi and in other units of account such as cattle, were often stated when objects were used as payment. While it looks as if some silver was really used in deals in urban León and its hinterland, using pieces of silver called argenzos, argenteos etc., elsewhere this was rare. Comparing the transactions in the three very different monastic collections of Celanova in the north–west, Sahagún in the central meseta and Cardeña in the foothills of the sierras in the north–east, regional difference is also striking. Sahagún is notable for the volume and early date of its sales and for increasing use of silver–based expressions of price and value. Round Celanova, by contrast, although there were also many sales, people used several modes of valuation simultaneously, but metal–based notions very rarely. Round Cardeña, close to urban Burgos, far fewer sales are recorded, and they come later in the century, but silver–based notions of value were the only ones used. This latter sub–urban context seems to have been much less commercially active than that of León and Sahagún, with exchange by gift and countergift a more prominent characteristic.
The Evolutionary Stability of Moral Objections to Free Riding
Authors: Güth W. , Nitzan S.
Published: December 2004

In this study we explore the endogenous determination of moral objections to free riding. We first derive the individually rational behavior for given preferences. The motivational structure is allowed to evolve evolutionarily based on the comparison of the relative reproductive success of all possible preference types. The tastes that emerge are not necessarily those assumed in models resorting to altruism or moral obligations. In general, an effective social conscience preventing free riding need not be evolutionarily stable. In the first model that we explore, moral objections to free riding and, in turn, voluntary contributions to the provision of public goods are not to be expected with one notable exception, namely unanimity games. In the second model that we explore, the evolutionarily stable probability that an individual develops social conscience is positive.
Rationality in a Political‐Economic Environment
Authors: Grafstein R.
Published: December 2004

This paper develops a rational expectations model of the circle of public opinion and policy implicit in working democracies. The executive branch of government, in particular, takes into account its own preferences and, indirectly, those of the voters, which are not constant but depend on the policy context in which they are formed. As a result, policies and voter preferences become interdependent stochastic processes rather than solutions of static optimization problems. This interdependence has specific implications for policy and opinion. Most striking, when citizens' opinions develop in this environment, the existence of rationally held belief systems is consistent with the pattern of opinion instability Converse attributes to nonattitudes.
On Misunderstanding Government: an Analysis of the Art of Policy Advice
Authors: Basu K.
Published: December 2004

In the traditional economics literature government is treated as an agent exogenous to the economy. When economists confront situations where individuals cannot sign binding contracts, they invoke government as the “third party” that can enforce the contracts; after studying the macroeconomic problems of a country, economists frequently go on to tell what government should do to improve the outcome. It is argued in this paper that this is an erroneous view of government and is the reason why the advice of economists and other social scientists have had so little impact on government behavior. The difficulties of advising an endogenous government are highlighted by developing a new game, the Cheater's Roulette. It demonstrates that even when the adviser and the politician have very similar objectives, there may be no straightforward way to transmit the knowledge of the adviser to the politician. Having analysed the subject of advising government, the paper goes on to discuss, more speculatively, some general issues concerning the modeling of an endogenous government.
Economic Policy, Model Uncertainty and Elections
Authors: Letterie Wilko , Swank Otto H.
Published: December 2004

We analyse a game theoretical model in which policy makers have superior knowledge about the working of the economy relative to voters. We show that parties increase their chances of reelection by basing their policies on the model that best fits in with their preferences. Moreover, we show that if parties care much about holding office, they may deliberately base their policies on a model that is electorally attractive, even if this model does not describe the working of the economy correctly. Our paper provides an explanation for the observation that different political parties subscribe to different economic philosophies.
Electoral Rules, Political Systems, and Institutional Quality
Authors: Ugo
Published: December 2004

This paper explores the links between political rules and institutional quality. The paper concentrates on two political measures: the presence of checks and balances in the political system and an index of political particularism that measures the incentives for politicians to build personal support bases. The paper finds a positive correlation between checks and balances and institutional quality. It also finds that intermediate levels of particularism are associated with higher institutional quality.
Wy are the transition paths in China and Eastern Europe different?
Authors: Brezis Elise S. , Schnytzer Adi
Published: December 2004

The purpose of this paper is to provide a framework linking communist regime collapse and privatizing economic reforms. The framework permits us to explain why certain communist regimes lost their monopoly of political power while others have not. We show that the essential difference between those communist regimes which survived economic reform and those which did not, lies in the nature of the privatization reform introduced by the communist leadership. The privatization that we call ‘Market‐Leninist’, was implemented in China and Vietnam while the second type of privatization, termed ‘Embezzlement for a rainy day’ was the type of privatization implemented in Eastern Europe. We show, in the context of a game between rulers and the population, that the size of the repressive apparatus is the key element determining the type of privatization chosen by the rulers.

JEL classification: P2, P3.
Consumption smoothing in Russia
Authors: Skoufias Emmanuel
Published: December 2004

This paper uses panel data from rounds V–IX of the Russian Longitudinal Monitoring Survey (RLMS) to examine the extent to which households are able to protect their consumption from fluctuations in their income.

It is found that consumption is only partially protected from idiosyncratic shocks to income with food consumption being better protected than non‐food consumption expenditures. This suggests that adjustments in non‐food expenditures may be an important component of the risk management tools of Russian households. The analysis also provides evidence on the extent and nature of the coping strategies adopted by households. It is demonstrated that households complement their self‐insurance strategies, of borrowing, adjusting their labour supply, and selling assets, with informal risk sharing arrangements with households within their community. An examination of the role of sample selection confirmed that these findings are quite robust to this potential source of bias. Furthermore, accounting for the role of measurement and imputation errors in the measure of household income revealed that OLS estimates may yield a misleading picture about the extent to which urban and rural households are insured from idiosyncratic income shocks.

JEL classification: D1, R2, P5.
Optimal dynamics of environmental quality in economies in transition1
Authors: Chimeli Ariaster B.
Published: December 2004

Environmental pressures in the transition economies of the post‐Soviet era affect not only the quality of life for local populations, but also other key economic issues such as privatization and employment by posing obstacles to their progress. Most studies addressing the environment in transition economies are empirical or analyze the effect of environmental protection on economic variables without first establishing an underlying framework together with the optimal path of environmental quality during the transition. This paper presents such a framework and a policy rule for attainment of the optimal balance between capital and environmental quality in economies in transition. Furthermore, the model shows that pollution taxes or tradable pollution permits are by themselves insufficient to implement the social optimum in a decentralized economy. The results of the model are consistent with depressed economic activity in those economies during an initial phase, and with the diversity of environmental policies in both Central and Eastern Europe (CEE) countries and the Newly Independent States (NIS).

JEL classification: Q20, P20, O13.
Acquiring a Community: The Acquis and the Institution of European Legal Order
Authors: Lindahl Hans
Published: December 2004

Abstract: The theme ‘law and disorganised civil society’ raises the fundamental question concerning the junction between legal order and disorder, hence the passage from instituted legal order to the institution of legal order. The emblematic manifestation of this passage, in the framework of the European legal order, is the acquis communautaire: what is the nature of the process that leads from acquired community to acquiring a community? In a first, preparatory, step, it will be argued that determinate conceptions of truth, time and the giving and taking of reason underlie the process of acquiring a European community. These findings are confronted, in a second step, with Antonio Negri's theory of the multitude as a constituent power, which opposes revolutionary self‐determination to representation. Deconstructing this massive opposition, this paper explores three ways in which representation is at work in revolutionary self‐determination. As will become clear in the course of the debate, instituting (European) community turns on the interval linking and separating law ‘and’ disorganised civil society.
Democratic Global Internet Regulation? Governance Networks, International Law and the Shadow of Hegemony
Authors: Von Bernstorff Jochen
Published: December 2004

Abstract: The field of global Internet Regulation serves as a prime example for the rise of global ‘a‐centric’ and ‘self regulatory’ governance structures. The most prominent private organisation in this field is the Internet Corporation of Assigned Names and Numbers (ICANN). ICANN was founded as a private non‐profit organisation comprising private and public actors that run the Internet domain name system, a crucial part of the Internet technical infrastructure. It claims to be a participatory network that enables deliberation among the ‘relevant’ commercial and non‐profit actors in the Internet field. This normative aspiration of a legitimate sectoral polity beyond governmental and intergovernmental policymaking can also be isolated as the driving force behind a certain strand within the literature on global governance. The paper undertakes a critical analysis of this claim within the ICANN context.
Grammatical analysis of Hindi sentences using connectionist approach
Authors: Prakash Nupur , Garg Kumkum
Published: December 2004

Abstract:
This paper presents a simple connectionist approach to parsing of a subset of sentences in the Hindi language, using Rule based Connectionist Networks (RBCN) as suggested by Fu in 1993. The basic grammar rules representing Kernel Hindi sentences have been used to determine the initial topology of the RBCN. The RBCN is based on a multilayer perceptron, trained using the backpropagation algorithm. The terminal symbols defined in the language structure are mapped onto the input nodes, the non‐terminals onto hidden nodes and the start symbol onto the single output node of the network structure. The training instances are sentences of arbitrary, but fixed maximum length and fixed word order.

A neural network based recognizer is used to perform grammaticality determination and parse tree generation of a given sentence. The network is exposed to both positive and negative training instances, derived from a simple context‐free‐grammar (CFG), during the training phase. The trained network recognizes seen sentences (sentences present in the training set) with 98–100% accuracy. Since a neural net based recognizer is trainable in nature, it can be trained to recognize any other CFG, simply by changing the training set. This results in reducing programming effort involved in parser development, as compared to that of the conventional AI approach. The parsing time is also reduced to a great extent as compared to that of a conventional parser, as a result of the inherent parallelism exhibited by neural net architecture.
ESAS: A case‐based approach to business planning and monitoring
Authors: Frangou Andreas J. , Wan Yan , Antony Jiju , Kaye Mike
Published: December 2004

Abstract:
Creating and sustaining a competitive advantage in today’s turbulent world markets is a formidable business challenge. For many organisations, operating within an inherently unstable external environment has resulted in the need for a cultural rethink. Business complacency, brought about by corporate industry monopolisation, the reliance on reputation, brand identity, and customer allegiance, is no longer a recipe for sustained market growth. Companies have realised that being market focused could provide them with a competitive edge within the marketplace. To achieve this organisations have turned to the ‘Quality movement’, embracing the Total Quality Management (TQM) philosophy and its inherent tools (auditing frameworks, concept of quality systems etc.) as a means to recapture lost ground.

ESAS (Enterprise Strategic Advisory System) is a prototype intelligent system that utilises a case‐ based approach to address the issues raised above, by providing organisations with advice on market‐ led quality and competitive strategy. This paper explores the philosophy and ideas behind the ESAS concept, and describes the development of an ESAS prototype.
Scale of Operations and Locus of Control in Market‐ Versus Mission‐Oriented Charter Schools*
Authors: Brown Heath , Henig Jeffrey , Lacireno‐Paquet Natalie , Holyoke Thomas T.
Published: December 2004

Objective.The objective of this article is to investigate two distinct strands in the charter school movement: one that emphasizes school‐based management and another that emphasizes market efficiency. We were interested in whether charter schools that were founded or co‐founded by for‐profit education management organizations (EMOs) tend to pursue economies of scale and are less likely than others to implement school‐level decision making in key areas.

Methods.The analysis uses data drawn from a survey we conducted of the population of charter schools in Arizona, Michigan, Pennsylvania, and Washington, DC.

Results.We find that charter schools that were founded or co‐founded by EMOs tend to be larger and areless likelyto exhibit decision‐making control at the school level.

Conclusions.Our analysis underscores the importance of disaggregating the charter school phenomenon into its distinct constituent parts in order to draw meaningful lessons from this evolving and significant experiment in alternative education delivery mode.
Culture Wars in State Education Policy: A Look at the Relative Treatment of Evolutionary Theory in State Science Standards*
Authors: Gibson M. Troy
Published: December 2004

Objectives. Students of public policy have recognized that not all policies are completely or mostly shaped by socioeconomic factors. Some policies, known as morality policies, derive from the deeply held values and beliefs of effective participants in the policy‐making process. To better understand this distinct policy category and where it exists, policy analysts must test for the impact of both socioeconomic forces and explanatory factors developed in morality politics theory (particularly religious contexts). This study attempts to explain differences in state science education standards with regard to stipulated instruction in evolutionary theory as morality policy.

Methods. A cross‐sectional study of the American states employing ordinary least squares and logistic regression analysis assesses the impact of popular evangelical adherence over the presence of evolution‐friendly state science standards, ceteris paribus.

Results. Socioeconomic factors inadequately explain the variation in state science standards. Furthermore, these standards are morality policies with clearly defined religious implications and are better explained by state religious divisions than by other cultural forces such as state ideological context.

Conclusion. This study demonstrates that some policies have clear implications for religious beliefs and may represent a subcategory of morality policy. These kinds of policies are better explained by religious contexts than other political and cultural determinants of morality policies.
Guns, Hollywood, and School Safety: Defining the School‐Shooting Problem Across Public Arenas*
Authors: Lawrence Regina G. , Birkland Thomas A.
Published: December 2004

Objective. Research in agenda setting has demonstrated that dramatic news events can drive particular issues to the top of the media and governmental agendas. The objective of this study is to analyze how different aspects of an event‐driven problem compete for attention in those arenas.

Methods. The method is content analysis of media coverage and congressional legislative activity following the 1999 Columbine High School shootings.

Results. The results show that while both agendas converged on the gun‐control aspect of the problem, they substantially diverged on other understandings of what kind of problem the Columbine shooting represented and how to address it.

Conclusions. We conclude that the differing institutional structure and incentives of the news media and Congress can create or inhibit interinstitutional positive feedback in the problem‐defining process. Agenda divergences are amplified when prominent politicians cue the media to follow particular story lines that depart from actual legislative activity.
Latinos and School Vouchers: Testing the “Minority Support” Hypothesis*
Authors: Leal David L.
Published: December 2004

Objectives. Voucher proponents, as well as some researchers, argue that minorities and individuals of relatively low socioeconomic status (SES) particularly favor school vouchers. Little work has specifically explored Latino attitudes, with the focus typically on African‐American opinions. This article will therefore examine whether Latinos hold unique attitudes toward vouchers.

Methods. Ordinal probit regression analysis of a recent national survey of Latinos, African Americans, and Anglos (non‐Latino whites).

Results. In the aggregate, Latinos and African Americans are more likely than Anglos to support vouchers. The Latino population variable is statistically insignificant, however, while the African‐American measure is significant and positive. When the aggregate Latino variable is disaggregated into four major Latino national‐origin groups, Puerto Ricans are shown to hold uniquely favorable opinions about vouchers. In addition, there are no opinion differences by income and education.

Conclusions. When Catholicism is taken into account, the voucher opinions of Latinos and Anglos are generally indistinct. This suggests that aggregate Latino support for vouchers may drop if Catholic affiliation further declines.
The SAT II: Minority/Majority Test‐Score Gaps and What They Could Mean for College Admissions*
Authors: Thomas M. Kathleen
Published: December 2004

Objective. Although most colleges and universities do not currently use SAT II subject tests to make admissions decisions, changing sentiment against aptitude tests could lead to more widespread use of the SAT II. This study examines score gaps on the SAT II between white and minority students.

Methods. Using data from the Texas Schools Microdata Panel, I estimate the influence of race/ethnicity on SAT II writing scores after controlling for sample selection.

Results. This study shows that although the average white student performs better than the average minority student on the SAT II writing exam, Asian and black students outperform white students when controlling for academic performance, family background, and high school fixed effects, while allowing different returns to characteristics.

Conclusions. These score gaps reverse only if the average minority student is given the same characteristics as the average white student. Unequal incomes and educational environments virtually ensure these score gaps will endure well into the future.
Anticipating Likely Consequences of Lottery‐Based Affirmative Action*
Authors: Grofman Bernard , Merrill Samuel
Published: December 2004

Objectives. To better understand the consequences of whole or partial reliance on test scores as a screening mechanism for college or university admissions or for job placement or promotion.

Methods. We introduce a simple hurdles/threshold model to study one particular mechanism that has been recently proposed to generate a “compromise” between race‐normed or gender‐normed standards for acceptance, on the one hand, and the decision to select those with the highest score regardless of race or gender, on the other—a method we call lottery‐based rules with minimum thresholds of acceptance.

Results. We show the factors that determine how close acceptance rates for the disadvantaged group under lottery‐based methods will be to the acceptance rates under either race‐normal or pretest‐score‐based mechanisms.

Conclusions. We argue that the likely consequences of using this method are not nearly as attractive as they might first appear to reformers.
Pregnancy‐induced sympathetic overactivity: a precursor of preeclampsia*
Authors: Fischer T. , Schobel H. P. , Frank H. , Andreae M. , Schneider K. T. M. , Heusser K.
Published: December 2004

Background  Preeclampsia has been shown to constitute a state of sympathetic overactivity. However, it remains unclear if the sympathetic activity precedes preeclampsia or represents only a secondary phenomenon. To further investigate this issue, we performed a prospective study in pregnant women considered to be at increased risk for preeclampsia owing to preeclampsia during a preceding pregnancy.

Materials and methods  Twenty‐two women with a history of preeclampsia were longitudinally studied on three occasions: twice during pregnancy (M1: 22 ± 4, M2: 33 ± 5 weeks) and once postpartum (M3: 26 ± 6 weeks postpartum). We measured muscle sympathetic nerve activity (MSNA), forearm blood flow, and blood pressure at rest and during reactive hyperaemia after forearm occlusion.

Results  At M1 and M2, none of the subjects was hypertensive, however, muscle sympathetic nerve activity levels were significantly augmented, compared with their postpartum values (M1: 21 ± 9, M2: 29 ± 14, M3: 9 ± 5 bursts min−1; P < 0·05). Forearm vascular resistance did not significantly change from M1 through M3 (M1: 16 ± 9, M2: 15 ± 7, M3: 16 ± 7 U; P = NS). Gestational muscle sympathetic nerve activity values did not differ significantly among the subjects with subsequent preeclampsia compared with those who remained normotensive [with preeclampsia (n = 6): M1: 21 ± 5, M2: 27 ± 6, M3: 7 ± 4 bursts min−1; without preeclampsia (n = 16): M1: 21 ± 11, M2: 30 ± 16, M3: 9 ± 6 bursts min−1; P = NS].

Conclusion  Invariably, all women at risk for preeclampisa showed a pregnancy‐induced increase in MSNA (pregnancy‐induced sympathetic overactivity, PISO), which normalized after delivery. Most importantly, PISO is not necessarily associated with peripheral vasoconstriction and hypertension. Furthermore, only a subset of patients developed preeclampsia later on. Therefore, we hypothesize that PISO constitutes a precursor of preeclampsia which is physiologically compensated for by vasodilating mechanisms, leading to preeclampsia only when they fail.
Long‐term variation in the abundance of the brown shrimp Crangon crangon (L.) population of the German Bight and possible causes for its interannual variability
Authors: SIEGEL V. , GRÖGER J. , NEUDECKER T. , DAMM U. , JANSEN S.
Published: December 2004

Time series on Crangon crangon densities in the German Wadden Sea show a considerable degree of interannual variability, for the entire region in spring and in autumn as well as for three subareas, North Frisia, East Frisia and Elbe estuary. Across the entire survey area C. crangon density was inversely related to water depth. In autumn after the recruitment, settlement shrimp densities are correlated across a larger spatial scale (>100 km longshore), whereas in spring the overwintering adult spawning stock is uncorrelated across subareas. Interannually, extreme density variations can develop even over a short time span of 1 yr. On a large spatial scale shrimp abundance in autumn was correlated with year‐to‐year changes in physical environmental and biological parameters, winter water temperature, autumn river runoff and the winter NAO index. On a regional scale (North Frisia), density of gadoid predators was an additional component affecting shrimp stock abundance. No correlations to such parameters could be detected for the C. crangon stock in spring. Possible causes for the spring situation and additional sources for variability are discussed.
Using commercial landings data to identify environmental correlates with distributions of fish stocks
Authors: SUNDERMEYER MILES A. , ROTHSCHILD BRIAN J. , ROBINSON ALLAN R.
Published: December 2004

We examined the efficacy of using commercial landings data to identify potential environmental correlates with fish distributions. Historical landings data for two commercially important species, Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus), were used along with historical conductivity, temperature, and depth (CTD) data to infer monthly mean spatial distributions of catch per unit effort (CPUE), temperature, salinity, density, and stratification over Georges Bank. Relationships between CPUE and these environmental variables plus bottom sediment type and bottom depth were examined on seasonal, annual, and interannual time scales. Empirical analysis suggests that both cod and haddock are found preferentially in water temperatures of approximately 5°C in winter/spring, and as high as 10–11°C during late fall. Both species are also found preferentially over coarse sand and gravel as opposed to fine sand, and in water depths between 60 and 70 m. These preferences appear to vary seasonally. The above results are consistent with findings of previous investigators using semi‐annual research trawl survey data, and suggest that commercial landings data, despite their known errors and biases, can be used effectively to infer associations between fish and their environment.
Assessing the variability of hydrographic processes influencing the life cycle of the Sicilian Channel anchovy, Engraulis encrasicolus, by satellite imagery
Authors: LAFUENTE JESÚS GARCÍA , VARGAS JUAN MIGUEL , CRIADO FRANCISCO , GARCÍA ALBERTO , DELGADO JAVIER , MAZZOLA SALVATORE
Published: December 2004

Three oceanographic surveys carried out in the Sicilian Channel during the spawning season (June to July) of anchovy (Engraulis encrasicolus) showed a close relationship between anchovy reproductive strategy and important hydrographic structures. A time series of satellite‐derived sea surface temperature images of the Sicilian Channel were analysed by means of empirical orthogonal functions and the dominant empirical modes were studied in detail. The first empirical mode captured much of the original variance and reproduced the trajectory of the Atlantic Ionian Stream (AIS), the principal hydrodynamic feature of the area. The time coefficients of modes 1 and 2 had seasonal signals which, when combined, accounted for the enhancement of the thermal front, clearly visible off Cape Passero (southernmost coast of Sicily) during summer. As the area constituted the principal nursery ground of the Sicilian Channel anchovy, the combination of the time coefficients of these modes was considered a potential indicator of the food particle concentration usually associated with oceanic fronts, which provided the energy requirements for larval growth. Mode 3 described the north/south displacements of the mean AIS trajectory, which modified the surface temperature regime of the anchovy spawning habitat. Therefore, the time coefficients of this mode were used as a potential indicator of anchovy spawning habitat variability. The capability of time coefficients of modes 2 and 3 to modify the main pattern depicted by mode 1 were tested successfully against in situ oceanographic observations.
ANNA: A new prediction method for bioassessment programs
Authors: Linke Simon , Norris Richard H. , Faith Daniel P. , Stockwell David
Published: December 2004

1. Cluster analysis of reference sites with similar biota is the initial step in creating River Invertebrate Prediction and Classification System (RIVPACS) and similar river bioassessment models such as Australian River Assessment System (AUSRIVAS). This paper describes and tests an alternative prediction method, Assessment by Nearest Neighbour Analysis (ANNA), based on the same philosophy as RIVPACS and AUSRIVAS but without the grouping step that some people view as artificial.

2. The steps in creating ANNA models are: (i) weighting the predictor variables using a multivariate approach analogous to principal axis correlations, (ii) calculating the weighted Euclidian distance from a test site to the reference sites based on the environmental predictors, (iii) predicting the faunal composition based on the nearest reference sites and (iv) calculating an observed/expected (O/E) analogous to RIVPACS/AUSRIVAS.

3. The paper compares AUSRIVAS and ANNA models on 17 datasets representing a variety of habitats and seasons. First, it examines each model's regressions for Observed versus Expected number of taxa, including the r2, intercept and slope. Second, the two models’ assessments of 79 test sites in New Zealand are compared. Third, the models are compared on test and presumed reference sites along a known trace metal gradient. Fourth, ANNA models are evaluated for western Australia, a geographically distinct region of Australia. The comparisons demonstrate that ANNA and AUSRIVAS are generally equivalent in performance, although ANNA turns out to be potentially more robust for the O versus E regressions and is potentially more accurate on the trace metal gradient sites.

4. The ANNA method is recommended for use in bioassessment of rivers, at least for corroborating the results of the well established AUSRIVAS‐ and RIVPACS‐type models, if not to replace them.
Effects of increased flow in the main stem of the River Rhine on the invertebrate communities of its tributaries
Authors: Beckmann Melanie C. , Schöll Franz , Matthaei Christoph D.
Published: December 2004

1. We hypothesised that increased flow in the main stem of the River Rhine would influence the invertebrate communities of its tributaries and therefore investigated the invertebrate fauna of six tributaries over 2 years.

2. We collected quantitative invertebrate samples at three sites in each tributary: in the tributary mouth (influenced by Rhine water whenever flow in the Rhine exceeded mean annual level), in the zone reached by average floods (return period 1.5 years) in the Rhine (average flood level sites), and immediately upstream of the range of extreme Rhine floods (reference sites). Samples were taken in spring, summer and autumn of each year, at different flow levels of the Rhine. We also compared substratum composition at the three sites.

3. Tributary mouth sites had the finest substratum, the lowest total invertebrate density and the lowest taxon richness. At average flood level and reference sites, these three parameters were similar.

4. Taxa known to prefer larger rivers were mostly confined to the tributary mouth sites, and species preferring upland streams dominated at the average flood level and reference sites.

5. Multivariate analyses confirmed the influence of the Rhine on the tributary mouth sites. Invasive invertebrate species, which usually appear only in the Rhine itself, were found at the tributary mouth sites but not further up in the tributaries.

6. Our study shows that increased flow in the main stem of the Rhine influenced substratum composition and invertebrate communities at the tributary mouth sites. These results imply that the relationship between the main stem of a river and its tributaries is not one‐way (from tributary to main stem), but rather a two‐way interaction.
Are populations of mayflies living in adjacent fish and fishless streams genetically differentiated?
Authors: Peckarsky Barbara L. , Hughes Jane M. , Mather Peter B. , Hillyer Mia , Encalada Andrea C.
Published: December 2004

1. Conspecific populations living in habitats with different risks of predation often show phenotypic variation in defensive traits. Traits of two species of mayflies (Baetidae: Baetis bicaudatus and Baetis sp. nov.) differ between populations living in fish and fishless streams in a high altitude drainage basin in western Colorado, U.S.A. We tested for genetic differentiation between mayfly populations in these two habitat types, assuming that lack of genetic differentiation would be consistent with the hypothesis that those traits are phenotypically plastic.

2. Previous work has shown that larvae of both species behave differently and undergo different developmental pathways in adjacent fish and fishless streams. These phenotypic differences in behaviour and development have been induced experimentally, suggesting that populations from fishless streams have the genetic capability to respond to fish.

3. During summer 2001 we collected Baetis larvae from several fish and fishless streams, and from fish and fishless sections of the same streams. We used allozymes and a fragment of the cytochrome oxidase subunit 1 mitochondrial gene to examine genetic variation of Baetis individuals within and among streams.

4. Results showed that genetic variation exists among populations of the same species of Baetis from different streams, but none of that variation was associated with the presence or absence of fish. These data confirm that populations of Baetis living in fish and fishless streams are not genetically distinct, and are consistent with the hypothesis that traits associated with environments of different risk are phenotypically plastic.
Determinants of macrophyte palatability to the pond snailLymnaea stagnalis
Authors: ELGER A. , LEMOINE D.
Published: December 2004

Summary1. This study aimed to identify the chemical and structural determinants of macrophyte palatability to the pond snailLymnaea stagnalis. Eleven macrophyte species were investigated, and one of them (Potamogeton lucens) was collected at four sites, on two different dates in the year, to study palatability determinants at an intra‐specific level.

2. Plant palatability toL. stagnaliswas determined through non‐choice feeding assays. Dry matter content (DMC), total phenolic content and protein content were measured for each macrophyte species. These parameters, and soluble carbohydrate content, were also measured for each sample ofP. lucens.

3. The palatability of macrophytes was positively related to their protein content (between species only) and negatively related to their DMC (both between species and withinP. lucens). No simple relationship was found between the palatability of macrophytes and their phenolic content, but highly palatable macrophytes consistently exhibited a low phenolic content.

4. These results emphasise that macrophyte palatability is a multifactorial attribute, potentially depending on both structural and chemical traits. Because some of these traits were correlated, further investigations are required to assess their respective influence on macrophyte palatability.
Hide, rest or die: a light‐mediated diapause response in Daphnia magna to the threat of fish predation
Authors: Ślusarczyk Mirosław , Dawidowicz Piotr , Rygielska Ewa
Published: December 2004

1. In a laboratory batch culture experiment, a diapause response of Daphnia magna to a simulated threat of fish predation was tested at various light intensities, which under natural conditions determine potential vulnerability of Daphnia to visual planktivorous fish.

2. Under moderate light intensity (1.4 μmol m−2 s−1) that allows effective predation by fish, the proportion of females producing dormant eggs was significantly higher than under dim light conditions (0.001 μmol m−2 s−1) that are not favourable for visual detection of prey. Production of dormant eggs was not observed in complete darkness or in treatments missing fish kairomones, irrespective of tested light conditions.

3. The observed phenomenon is interpreted as a flexible response of prey to the conditional risk of predation assessed by Daphnia according to the presence of fish‐derived cues on the one hand and the presence of dark refugia on the other. Irrespective of the presence of fish kairomones, Daphnia may not produce resting eggs as long as a safe, dark, bottom zone is accessible.