bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of fear conditioning on cerebellar LTP and LTD
Authors: Zhu Lan , Scelfo Bibiana , Hartell Nicholas A. , Strata Piergiorgio , Sacchetti Benedetto
Published: June 2007

Long‐term potentiation (LTP) and depression (LTD) at parallel fibre–Purkinje cell synapses have been described in vitro in the cerebellar cortex, but the physiological roles of these two forms of plasticity have not been well defined. Here we show that, in cerebellar slices taken from rats that had undergone fear conditioning, there was a significant occlusion of electrically induced LTP at parallel fibre–Purkinje cell synapses. This effect was long‐lasting and related to associative processes, as LTP was not occluded in unpaired animals. Notably, in conditioned animals the LTP‐inducing protocol produced LTD in some cells instead of LTP. Conversely, synaptic depression induced by conjunctive stimulation of parallel fibers and climbing fibres was impaired in tissue taken immediately following aversive stimulation in both paired and unpaired subjects. This effect was not, however, long‐lasting as the incidence and extent of LTD returned to normal levels 24 h after behavioural testing. These findings suggest that LTP takes part in the mechanisms underlying aversive associative memories in the cerebellum.
Deep propofol sedation for vacuum‐assisted bite‐block immobilization in children undergoing proton radiation therapy of cranial tumors
Authors: WEISS MARKUS , FREI MARTINA , BUEHRER SABIN , FEURER RITA , GOITEIN GUDRUN , TIMMERMANN BEATE
Published: June 2007

Background:  Vacuum‐assisted bite‐block immobilization of the head is a reliable technique for reproducible precise head positioning as used for proton radiation in adults. We report preliminary experience using deep propofol sedation without an artificial airway in children undergoing proton radiation of cranial tumors requiring vacuum‐assisted bite‐block immobilization.

Methods:  Sedation was started with a bolus of i.v. midazolam followed by repeated small boluses of propofol as required to tolerate bite‐block insertion and patient positioning. Sedation was maintained by continuous propofol infusion until removal of the bite block. Oxygen was administered by a nasal cannula. SpO2, endtidal CO2 taken at the nose and respiratory adverse events such as coughing, bucking, airway obstruction, regurgitation or aspiration were recorded. Data are mean ± sd.

Results:  Ten children aged 2.6 ± 0.8 years were treated to date. For each child, cumulative 26.7 ± 1.9 radiation fractions were administered. Propofol dose administered for induction, bite‐block insertion and patient positioning was 3.9 ± 0.5 mg·kg−1. Time from insertion to removal of the bite block lasted 48.3 ± 6.2 min. Endtidal CO2 values were 5.6 ± 0.8 kPa (43 ± 7 mmHg) and SpO2 values were 98.3 ± 1.9% with spontaneous breathing, supplemental oxygen and bite block inserted. No respiratory adverse events occurred during the 267 sedation procedures performed.

Conclusion:  Deep propofol sedation without the use of an artificial airway is an interesting technique for vacuum‐assisted bite‐block immobilization in young children undergoing precise radiation therapy of cranial tumors. However, simultaneous individual anesthetic challenges require pediatric anesthesiologists highly experienced with the pediatric airway, clinical alertness and closed monitoring.
Anaphylactic shock in a beta‐blocked child: usefulness of isoproterenol
Authors: MOMENI MONA , BRUI BARBARA , BAELE PHILIPPE , MATTA AMINE
Published: June 2007

Like adults, children taking beta‐blockers are at risk for serious hemodynamic instability in case of anaphylaxis. We report a case of severe bradycardia associated with anaphylactic shock after aprotinin in a beta‐blocked child, which was resistant to intravenous epinephrine and vascular filling but was treated successfully with isoproterenol.
Awareness during pediatric anesthesia – what is the position of European pediatric anesthesiologists?
Authors: ENGELHARDT THOMAS , PETROZ GUY C. , MCCHEYNE ALAN , BISSONNETTE BRUNO
Published: June 2007

Background:  The incidence of awareness in the pediatric population is reported as high as 1 : 125. An online survey was conducted about the current perception and practice of members of the British and French pediatric anesthesia societies regarding awareness during general anesthesia.

Methods:  Following the approval of the executive committees of the British and French pediatric anesthesia societies, members with a valid email contact address were invited to participate in a web‐based survey. Perceived risk factors, use of awareness monitors, pre‐ and postoperative discussions of awareness as well as personal experience were enquired.

Results:  A total of 302 (51%) responded to the email survey. More than 60% indicated that awareness is a problem in pediatric anesthesia with the majority estimating an incidence of 1 : 1000. Almost half (49%) the respondents believe that awareness is age‐dependent and 50% are not concerned below 1 month of age. More than 86% of respondents do not discuss the risk of awareness with the parents or actively look for awareness despite 27% reporting at least one episode in their practice. Intra‐operative monitoring almost exclusively consists of clinical signs and endtidal anesthetic concentrations. Bispectral index (BIS) monitoring is routinely used by approximately 10% of the surveyed members.

Conclusions:  This survey demonstrates that European pediatric anesthesiologists perceive awareness as a major problem. However, none seems to address the issue openly or looks for its presence routinely. The vast majority of pediatric anesthesiologists rely almost exclusively on clinical monitoring and endtidal anesthetic concentrations for its detection.
Combined spinal – epidural anesthesia in major abdominal surgery in high‐risk neonates and infants
Authors: SOMRI MOSTAFA , TOME RIAD , YANOVSKI BORIS , ASFANDIAROV ELDAR , CARMI NURIT , MOGILNER JOERGE , DAVID BADER , GAITINI LUIS A.
Published: June 2007

Background:  Combined spinal‐epidural anesthesia (CSE‐A) is reportedly safe and effective for the pediatric population in infraumbilical surgery. Our main purpose was to describe our experience of this technique in neonates and infants undergoing elective major upper abdominal surgery.

Methods:  Spinal anesthesia was performed in 28 neonates and infants with isobaric bupivacaine 0.5%, 1 mg·kg−1 followed by placement of a caudal epidural catheter to thoracic spinal segments. The catheter tip position was confirmed radiographically. Respiratory and hemodynamic data were collected before and after the CSE‐A and throughout the operation, as a measure of anesthetic effectiveness. Complications related to the anesthesia technique were collected as a measure of the anesthetic technique safety.

Results:  Satisfactory surgical anesthesia was achieved in 24 neonates and infants, four patients were converted to general anesthesia. Respiratory and hemodynamic variables did not change significantly during surgery, compared with baseline values: oxygen saturation (P = 0.07), systolic and diastolic blood pressures (P = 0.143, P = 0.198 respectively), heart rate (P = 0.080) and respiratory rate (P = 0.127). However, twenty infants were fussy during the surgical procedures and were calmed with intravenous midazolam; our patients required oxygen supplementation and transient manual ventilation intraoperatively.

Conclusions:  Combined spinal‐epidural anesthesia could be considered as an effective anesthetic technique for elective major upper abdominal surgery in awake or sedated neonates and infants, and could be used cautiously by a pediatric anesthesiologist as an alternate to general anesthesia in high‐risk neonates and infants undergoing upper gastrointestinal surgery.
Clinical and diagnostic imaging findings predict anesthetic complications in children presenting with malignant mediastinal masses
Authors: ANGHELESCU DORALINA L. , BURGOYNE LAURA L. , LIU TIEBIN , LI CHIN‐SHANG , PUI CHING‐HON , HUDSON MELISSA M. , FURMAN WAYNE L. , SANDLUND JOHN T.
Published: June 2007

Background:  The presence of a mediastinal mass in a child poses significant anesthesia‐related risks including death. To optimize outcome clinicians must be able to predict which patients are at highest risk of anesthetic complications.

Methods:  We conducted a retrospective review of 118 pediatric patients who presented with mediastinal masses. We investigated their medical records for clinical symptoms and signs at presentation and reviewed their chest radiographs, computed tomography scans, and echocardiograms and electrocardiograms when available. We then conducted analyses to identify clinical and diagnostic imaging features associated with anesthesia‐related complications.

Results:  Eleven of 117 [9.4%, 95% confidence interval (CI) 4.1–14.7%] patients experienced an anesthesia‐related complication. Four preoperative features were significantly associated with anesthetic complications: orthopnea (P = 0.033, odds ratio (OR) 5.31, 95% CI, 1.15–24.56), upper body edema (P = 0.035, OR 8.00, 95% CI, 1.16–55.07), great vessel compression (P = 0.037, OR 5.41, 95% CI, 1.11–26.49), and main‐stem bronchus compression (P = 0.044, OR 5.11, 95% CI, 1.05–24.92). The presence of pleural effusion (P = 0.060, OR 4.53, 95% CI, 0.94–21.96) or tracheal compression (P = 0.061, OR 5.09, 95% CI, 0.93–27.81) also appeared to be risk factors. Although the rate of anesthesia‐related complications detected in our cohort was comparable with that found in earlier studies, the events were less severe.

Conclusions:  Patients who present with orthopnea, upper body edema, great vessel compression and main stem bronchus compression are at risk of anesthesia‐related complications. The low severity of complications in our series may reflect a combination of factors: use of the least invasive method such as interventional radiology to obtain tissue for diagnosis, completion of a thorough preoperative assessment and minimal anesthesia intervention.
Conifer phenolic resistance markers are bark beetle antifeedant semiochemicals
Authors: Faccoli Massimo , Schlyter Fredrik
Published: June 2007

1 Phenols are important in conifer resistance to fungi associated with bark beetles and as markers for resistance to beetle mass‐attacks. However, the mechanism of phenolic activity in conifer resistance to Ips typographus bark beetle remains unclear.

2 By a new bioassay, we tested the effect on host acceptance and tunnelling of male and female I. typographus in an artificial gallery (13 mm long) for 4 h (no‐choice test). To the artificial diet, an aliquot of host (catechin, taxifolin, or resveratrol) or nonhost (E‐conophthorin) compounds was added, singly tested at doses close to those of tree bark. Host acceptance and tunnelling was measured by the amount of diet removed by the insects.

3 All tested chemicals decreased the tunnelling activity of I. typographus, with an antifeedant effect stronger in males and increasing with dose. No mortality was recorded. The nonhost volatile spiroketal, E‐conophthorin, had the highest antifeedant activity both in males and females. Among host compounds, effects and dose–response were weak in females. Both catechin and E‐conophthorin gave a 50% reduction of tunnelling at a concentration of 0.1% for males, the pioneering (host selecting) sex in Ips. The threshold of activity for host compounds to males was at concentrations of 0.03–0.1%, which corresponds to, or is less than, the concentrations reported from spruce host bark.

4 The results allow us to support the hypothesis of a direct behavioural antifeedant mechanism for resistance from those phenols that are particularly active for the pioneering males during tree attack.
Global survey of diversity among environmental saltwater Bacteriovoracaceae
Authors: Pineiro Silvia A. , Stine O. Colin , Chauhan Ashvini , Steyert Susan R. , Smith Richard , Williams Henry N.
Published: June 2007

Halophilic Bacteriovorax (Bx), formerly known as the marine Bdellovibrio, are Gram‐negative, predatory bacteria found in saltwater systems. To assess their genetic diversity and geographical occurrence, the small subunit rRNA (ssu‐rRNA) gene sequences were analysed from 111 marine, salt lake and estuarine isolates recovered from 27 locations around the world. Phylogenetic analysis of these isolates using Geobacter as the outgroup revealed eight distinct ribotype clusters each with at least two isolates. Each cluster was composed of isolates with ≥ 96.5% similarity in ssu‐rRNA sequences. Three single isolate outliers were observed. Many of the Bx ribotypes were widely dispersed among different types of ecosystems (e.g. cluster III was recovered from the Great Salt Lake, the Atlantic Ocean, Pacific Ocean, Chesapeake Bay and gills of aquarium fish). However, cluster V was only recovered from a single ecosystem, estuaries. Cluster V was originally detected in the Chesapeake Bay and subsequently in the Pamlico Sound/Neuse River system. Principal coordinate analysis revealed that the sequences of the isolates from different environments were distinct from each other. The results of this study reveal the saltwater Bx to be phylogenetically and environmentally more diverse than was previously known.
Sperm ultrastructure of five species of the Neotropical ant genusPseudomyrmex(Hymenoptera: Formicidae)
Authors: Moya J. , Mancini K. , Lino‐Neto J. , Delabie J. , Dolder H.
Published: June 2007

The seminal vesicles of adult males of five species ofPseudomyrmexwere prepared for light and transmission electron microscopy. ThePseudomyrmexspermatozoa are long and slender with similar morphology. The head region has an acrosome and a nucleus. In all the studied species, two morphologically distinct types of acrosomal vesicles were observed, a long structure, as observed in all known ants, and a pear‐shaped one, never before observed in ants. The nucleus is elongated and both condensed and loose chromatin are present. The flagellum has an axoneme, a centriolar adjunct, two mitochondrial derivatives and two accessory bodies. The centriolar, the mitochondrial derivatives and the accessory bodies are similar to observations in most ant species that have been studied. The axoneme presents an uncommon 9 + 9 + 1 microtubule arrangement and the central microtubule has 13 protofilaments. The acrosomal dimorphism and the different levels of chromatin organization are exclusive characteristics ofPseudomyrmex. Furthermore, the 9 + 9 + 1 microtubule arrangement is different from all Hymenoptera, as well as from most insects, which present a 9 + 9 + 2 arrangement. These new morphological characters that are specific toPseudomyrmex, are valuable synapomorphies of the genus and can be used in taxonomic characterization of the Pseudomyrmecinae subfamily and in phylogenetic analyses in Formicidae family.
Ultrastructural, histochemical and cytochemical characterization of intestinal epithelial cells in Aplysia depilans (Gastropoda, Opisthobranchia)
Authors: Lobo‐da‐Cunha Alexandre , Batista‐Pinto Carla
Published: June 2007

To improve the current knowledge about the digestive system in opisthobranchs, light and electron microscopy methods were used to characterize the epithelial cells in the mid‐intestine of Aplysia depilans. This epithelium is mainly formed by columnar cells intermingled with two types of secretory cells, named mucous cells and granular cells. Columnar cells bear microvilli on their apical surface and most of them are ciliated. Mitochondria, multivesicular bodies, lysosomes and lipid droplets are the main components of the cytoplasm in the region above the nucleus of these cells. Peroxisomes are mainly found in middle and basal regions, usually close to mitochondria. Mucous cells are filled with large secretory vesicles containing thin electron‐dense filaments surrounded by electron‐lucent material in which acidic mucopolysaccharides were detected. The basal region includes the nucleus, several Golgi stacks and many dilated rough endoplasmic reticulum cisternae containing tubular structures. The granular cells are characterized by very high amounts of flat rough endoplasmic reticulum cisternae and electron‐dense spherical secretory granules containing glycoproteins. Enteroendocrine cells containing small electron‐dense granules are occasionally present in the basal region of the epithelium. Intraepithelial nerve fibres are abundant and seem to establish contacts with secretory and enteroendocrine cells.
Morphology of the male reproductive system and spermatophore formation in the freshwater ‘red claw’ crayfish Cherax quadricarinatus (Von Martens, 1898) (Decapoda, Parastacidae)
Authors: López Greco Laura S. , Vazquez Fernanda , Rodríguez Enrique M.
Published: June 2007

The morphology of the male reproductive system was studied in Cherax quadricarinatus. The testes and vasa deferentia were dissected, fixed, cut and stained. Testes appear as two parallel and opalescent strands; they present many testicular lobes, each lobe containing cells in the same stage of the spermatogenic cycle. A vas deferens arises from the external side of each testis and three parts were clearly distinguished: proximal vas deferens (PVD), middle vas deferens (MVD) and distal vas deferens (DVD). The PVD is opalescent and highly convoluted, the MVD is pale white in colour and convoluted, but wider in diameter than the PVD, while the DVD shows the widest diameter, is straight and is white in colour. A single‐layered epithelium is recognized in the vas deferens; with cylindrical cells in the PVD and cuboid cells in the MVD and DVD. The formation of the spermatophore starts at the PVD, while the secondary layer of the spermatophore seems to be added at the MVD. At the DVD, the highly coiled spermatophore is surrounded by the periodic acid Schiff‐positive sticky components of the secondary layer. Many aspects of spermatophore formation in C. quadricarinatus differ from those of other Astacida. The applied aspects of this study for aquaculture purposes are discussed.
Early development of the aplacophoran mollusc Chaetoderma
Authors: Nielsen Claus , Haszprunar Gerhard , Ruthensteiner Bernhard , Wanninger Andreas
Published: June 2007

The early development of the trochophore larva of the aplacophoran Chaetoderma nitidulum (Mollusca: Caudofoveata = Chaetodermomorpha) is described using scanning and transmission electron microscopy and using fluorescence staining and confocal laser scanning microscopy of the muscle system. The most important features include the presence of a prototroch and a telotroch, serially arranged glandular cells (spiculoblasts) at the dorsal mantle, the occurrence of a ventral suture as a possible remnant of a former foot sole, and the presence of a pair of protonephridia. The development of the early anlagen of the circular body wall muscles does not show the anterior–posterior mode of formation that is typical for annelids, thus strengthening the hypothesis of a non‐segmented ancestry of Mollusca.
Interspecific variation of sperm morphology in the Australian rodent genus Zyzomys
Authors: Breed William G. , Leigh Chris M. , Robertson Helen , Mantellato Lisa , Lambert Cathy , Jequier Anne , Matson Phillip
Published: June 2007

The sperm head morphology and tail length of two species of Australian rock rats, Zyzomys argurus and Zyzomys pedunculatus, are presented. In Z. argurus the sperm head has an apical hook together with two ventral processes extending from the upper concave surface that are largely composed of cytoskeletal material, and the sperm tail is about 135 µm in length. By contrast, in Z. pedunculatus the sperm head is paddle‐shaped with the nucleus capped by an acrosome that has a large apical segment and is surrounded by a thin layer of cytoskeletal material, and the sperm tail is only around 85 µm in length. Since the structure of the spermatozoon of Z. argurus is similar to that of most of the old endemic Australian rodents it is presumed to be the ancestral condition within the Zyzomys genus with that of Z. pedunculatus being highly derived and showing convergence with the sperm structure in some other orders of mammals.
Spatial autocorrelation and the selection of simultaneous autoregressive models
Authors: Kissling W. Daniel , Carl Gudrun
Published: June 2007

Aim Spatial autocorrelation is a frequent phenomenon in ecological data and can affect estimates of model coefficients and inference from statistical models. Here, we test the performance of three different simultaneous autoregressive (SAR) model types (spatial error = SARerr, lagged = SARlagand mixed = SARmix) and common ordinary least squares (OLS) regression when accounting for spatial autocorrelation in species distribution data using four artificial data sets with known (but different) spatial autocorrelation structures.

Methods We evaluate the performance of SAR models by examining spatial patterns in model residuals (with correlograms and residual maps), by comparing model parameter estimates with true values, and by assessing their type I error control with calibration curves. We calculate a total of 3240 SAR models and illustrate how the best models [in terms of minimum residual spatial autocorrelation (minRSA), maximum model fit (R2), or Akaike information criterion (AIC)] can be identified using model selection procedures.

Results Our study shows that the performance of SAR models depends on model specification (i.e. model type, neighbourhood distance, coding styles of spatial weights matrices) and on the kind of spatial autocorrelation present. SAR model parameter estimates might not be more precise than those from OLS regressions in all cases. SARerrmodels were the most reliable SAR models and performed well in all cases (independent of the kind of spatial autocorrelation induced and whether models were selected by minRSA,R2or AIC), whereas OLS, SARlagand SARmixmodels showed weak type I error control and/or unpredictable biases in parameter estimates.

Main conclusions SARerrmodels are recommended for use when dealing with spatially autocorrelated species distribution data. SARlagand SARmixmight not always give better estimates of model coefficients than OLS, and can thus generate bias. Other spatial modelling techniques should be assessed comprehensively to test their predictive performance and accuracy for biogeographical and macroecological research.
Ecological correlates of geographical range occupancy in North American birds
Authors: Hurlbert Allen H. , White Ethan P.
Published: June 2007

Aim The degree to which a species is predictably encountered within its range varies tremendously across species. Understanding why some species occur less frequently within their range than others has important consequences for conservation and for analyses of ecological patterns based on range maps. We examined whether patterns in geographical range occupancy can be explained by species‐level traits.

Location North America.

Methods We used survey data from 1993 to 2002 from the North American Breeding Bird Survey along with digital range maps produced by NatureServe to calculate range occupancy for 298 species of terrestrial birds. We tested whether species traits explained variation in range occupancy values using linear regression techniques.

Results We found three species traits that together explained more than half of the variation in range occupancy. Population density and niche breadth were positively correlated with occupancy, while niche position was negatively correlated with occupancy.

Main conclusions Our results suggest that high range occupancy will occur in species that are common at sites on which they occur, that tolerate a relatively wide range of ecological conditions and that tend to have ranges centred on areas with common environmental conditions. Furthermore, it appears that niche‐based characteristics may explain patterns of distribution and abundance from local habitats up to the scale of geographical ranges.
Soil nitrogen and carbon heterogeneity in woodlands and grasslands: contrasts between temperate and tropical regions
Authors: Pärtel Meelis , Laanisto Lauri , Wilson Scott D.
Published: June 2007

Aim  Soil resource heterogeneity is linked to several ecological processes including invasion of woody species into grasslands. Studies from the temperate zone have demonstrated greater soil heterogeneity beneath woody vegetation than beneath grasslands. Woody species have a more widespread and coarser root system than herbaceous species, and may have a competitive advantage in relatively heterogeneous soils. We tested the global generality of greater soil heterogeneity beneath woody vegetation.

Location  Global.

Methods  We used data from published literature for soil nitrogen and carbon heterogeneity from paired woodland and grassland sites around the world.

Results  Woodland and grassland soil heterogeneities from paired observations were strongly correlated. There was, however, significant geographical variability in the relationship. Soils were more heterogeneous in woodlands than grasslands in temperate areas, but the opposite was true for tropical habitats. Grassland soils were more heterogeneous at lower than higher latitudes. Woodland soil heterogeneity did not vary with latitude.

Main conclusions  The previously described high soil heterogeneity in woody vegetation compared to grasslands holds only for temperate regions. Consequently, the relationship between soil resource heterogeneity and vegetation type is dependent on the study region. Macroecological studies should test the generality of relationships between soil and vegetation at the global scale.
Small fish, big fish, red fish, blue fish: size‐biased extinction risk of the world's freshwater and marine fishes
Authors: Olden Julian D. , Hogan Zeb S. , Zanden M. Jake Vander
Published: June 2007

Aim  In light of the current biodiversity crisis, there is a need to identify and protect species at greatest risk of extinction. Ecological theory and global‐scale analyses of bird and mammal faunas suggest that small‐bodied species are less vulnerable to extinction, yet this hypothesis remains untested for the largest group of vertebrates, fish. Here, we compare body‐size distributions of freshwater and marine fishes under different levels of global extinction risk (i.e. listed as vulnerable, endangered or critically endangered according to the IUCN Red List of Threatened Species) from different major sources of threat (habitat loss/degradation, human harvesting, invasive species and pollution).

Location  Global, freshwater and marine.

Methods  We collated maximum body length data for 22,800 freshwater and marine fishes and compared body‐size frequency distributions after controlling for phylogeny.

Results  We found that large‐bodied marine fishes are under greater threat of global extinction, whereas both small‐ and large‐bodied freshwater species are more likely to be at risk. Our results support the notion that commercial fishing activities disproportionately threaten large‐bodied marine and freshwater species, whereas habitat degradation and loss threaten smaller‐bodied marine fishes.

Main conclusions  Our study provides compelling evidence that global fish extinction risk does not universally scale with body size. Given the central role of body size for trophic position and the functioning of food webs, human activities may have strikingly different effects on community organization and food web structure in freshwater and marine systems.
CONSOLATIONS FOR THE ECONOMIST: THE FUTURE OF ECONOMIC ORTHODOXY1
Authors: George Donald A.R.
Published: June 2007

Abstract This paper sets the contributions to this volume in the context of widespread and serious doubts expressed by economists about the mainstream of their subject. Orthodox economics is increasingly dominated by sterile formalism, which refers only to itself. But the methodology of orthodox economics is under attack, and many economists are proposing an alternative agenda for the subject. This paper argues that there is a valid future for economics, but to reach it economists will have to abandon sterile formalism, stop invoking notions of ‘rigour’ which they do not understand, adopt pluralism and learn from cognate disciplines instead of trying to colonise them.
AXIOMATIZATION AND FORMALISM IN ECONOMICS
Authors: Boylan T.A. , O'Gorman P.F.
Published: June 2007

Abstract In this paper we address a number of issues in the historiography and methodology of the formalization of economics in the twentieth century. We argue that Debreu's approach to formalism pursuing his Bourbakist programme was based on Hilbert's version of finitism. The latter project attempted to retain its place in Cantor's ‘paradise’ and in so doing bequeathed serious methodological consequences. There was, however, at the turn of the twentieth century an alternative version of finitism available, that provided by Poincaré, which if adopted by economics would have led to a radically different approach to economic theorizing and modelling. We argue that these reflections must be embedded in an alternative larger methodological framework.
VARIETY OF METHODOLOGICAL APPROACH IN ECONOMICS
Authors: Dow Sheila C.
Published: June 2007

AbstractIt has been argued by some that the distinction between orthodox economics and heterodox economics does not fit the growing variety in economic theory, unified by a common methodological approach. On the other hand, it remains a central characteristic of heterodox economics that it does not share this methodological approach, but rather represents a range of alternative methodological approaches. The paper explores the evidence, and arguments, for variety in economics at different levels, and a range of issues which arise. This requires in turn a discussion of the meaning of variety in economics at the different levels of reality, methodology, method and theory. It is concluded that there is scope for more, rather than less, variety in economic methodologies, as well as within methodologies. Further, if variety is not to take the form of ‘anything goes’, then critical discussion by economists of different approaches to economics, and of variety itself, is required.
VARIATIONS ON THE THEME OFCONNINGaINMATHEMATICAL ECONOMICS
Authors: Velupillai K. Vela
Published: June 2007

AbstractThe mathematization of economics is almost exclusively in terms of the mathematics of real analysis which, in turn, is founded on set theory (and the axiom of choice) and orthodox mathematical logic. In this paper I try to point out that this kind of mathematization is replete with economic infelicities. The attempt to extract these infelicities is in terms of three main examples and one general discussion: dynamics, policy and rational expectations and learning are the examples; a game theory without ‘subjectivism’, based on the axiom of determinateness, is discussed in general terms. The focus is on the role and reliance of standard fixed‐point theorems in orthodox mathematical economics.
THE SOCIOLOGICAL APPROACH TO FINANCIAL MARKETS
Authors: Preda Alex
Published: June 2007

AbstractAs a part of the renaissance and growth of economic sociology during the past two decades, and in response to processes such as economic globalization, financial markets have been increasingly scrutinized by sociologists. Their investigation is seen as relevant with respect to understanding the structure and dynamics of advanced societies, the dynamics of social development, as well as fundamental aspects of human behaviour. This paper charts recent developments in the sociology of financial markets; its starting point is the treatment of the concept of information within three sociological orientations: the social‐structural approach, sociological neo‐institutionalism and the newer social studies of finance. By highlighting their different assumptions about information and market behaviour, I discuss how these approaches conceptualize financial markets, the methodological implications and the ways in which they contribute to the study of financial exchanges.
WORKERS' SAVINGS AND THE RIGHT TO MANAGE
Authors: George Donald A.R.
Published: June 2007

Abstract Most Western capitalist institutions are islands of fascism in a sea of democracy. But democracy can be introduced from the political to the economic sphere by re‐assigning the right to manage from capital owners to workers, thereby creating a sector consisting of self‐managed firms. Such firms require external finance for efficiency; this can be supplied via a new form of financial asset (performance bonds), to be held by wage‐earners' investment funds. Reforms such as these could improve productivity and the quality of working life, strengthen the role of markets and help to deal with the so‐called pensions crisis. These reforms would threaten the interests of private capital owners and would therefore require decisive political action: they can thus be differentiated sharply from voluntary, enterprise‐level schemes for introducing profit‐sharing, employee share‐ownership or industrial democracy.
A NEW VISION OF THE KNOWLEDGE ECONOMY
Authors: Chi‐ang Lin Brian
Published: June 2007

AbstractTo date, more than half of the output in the major OECD countries has been knowledge based. This paper argues, however, that the current growth‐oriented exposition of the knowledge economy rooted in the conventional concept of free competition is insufficient for promoting the long‐term development of human societies. Although we now live in a knowledge economy, most countries have been concurrently characterized by serious phenomena such as environmental degradation and growing economic inequality. The prospect of meeting global commitments, for instance, to reducing inequality, as outlined in the 1995 World Summit for Social Development in Copenhagen and endorsed in the United Nations Millennium Declaration, is bleak and the global society as a whole has become less and less sustainable. Indeed, the world is better seen as composed of numerous (but finite) knowledge economies. To take up the challenge of sustainable development of human societies, we have to develop a pluralistic perspective of the knowledge economy and fully acknowledge the characteristics of each unique knowledge system (such as indigenous knowledge possessed by a small tribe). Once we can help each individual knowledge system develop into a specific set of economic institutions that freely exchange concepts and beliefs with each other in a global environment, we will be able to develop a global economy that embodies a value‐committed basis that assures a sustainable path of development on earth.
EVOLUTIONARY AND NEW GROWTH THEORIES. ARE THEY CONVERGING?
Authors: Castellacci Fulvio
Published: June 2007

AbstractThis paper presents a critical review of evolutionary and new growth theories. The purpose is to discuss the often‐made claim that the two approaches, both inspired by Schumpeter's seminal work, are becoming more and more similar in terms of the sources and mechanisms of the growth process on which they focus. According to this argument, some kind oftheoretical convergencebetween the two paradigms is taking place. Differently from previous surveys of the field, this paper compares evolutionary and new growth theories by focusing on their major theoretical foundations. The discussion leads to the conclusion that the two approaches greatly differ with respect to all of their main theoretical building blocks, and that no convergence between the two paradigms is therefore taking place. This finding should be welcomed by both evolutionary and new growth scholars, because it is the process of interaction and the fruitful exchange of ideas between different approaches that lead to advances in growth theory, not their convergence to a common paradigm.
REPETITION AND FINANCIAL INCENTIVES IN ECONOMICS EXPERIMENTS
Authors: Lee Jinkwon
Published: June 2007

AbstractWhile experimental methods have been an effective tool for economic research, there have been controversies on the methodological aspects. The reason why we need to care about it is clear: if the method in an experiment is not valid, the results from that experiment cannot be valid too. Among other things, the methodological issues of financial incentives and repetition, which are norms in experimental economics, have been at the centre of many debates. While there are previous reviews that investigate financial incentives and repetition separately, our view is that the effects of these two factors are interdependent rather than independent. Thus, our review here is more specific and more conditional, that is, we are interested in the answer to the question, ‘Do we need to use financial incentives conditional on the use of repetition?’ After we discuss the relationship between financial incentives and repetition, we argue, from a review of 44 experimental studies, that using financial incentives would be more necessary to improve the validity of experimental results if an experimenter needs to use repetition.
Efficiency of gene silencing in Arabidopsis: direct inverted repeats vs. transitive RNAi vectors
Authors: Filichkin Sergei A. , DiFazio Stephen P. , Brunner Amy M. , Davis John M. , Yang Zamin K. , Kalluri Udaya C. , Arias Renee S. , Etherington Elizabeth , Tuskan Gerald A. , Strauss Steven H.
Published: June 2007

We investigated the efficiency of RNA interference (RNAi) in Arabidopsis using transitive and homologous inverted repeat (hIR) vectors. hIR constructs carry self‐complementary intron‐spliced fragments of the target gene whereas transitive vectors have the target sequence fragment adjacent to an intron‐spliced, inverted repeat of heterologous origin. Both transitive and hIR constructs facilitated specific and heritable silencing in the three genes studied (AP1, ETTIN and TTG1). Both types of vectors produced a phenotypic series that phenocopied reduction of function mutants for the respective target gene. The hIR yielded up to fourfold higher proportions of events with strongly manifested reduction of function phenotypes compared to transitive RNAi. We further investigated the efficiency and potential off‐target effects of AP1 silencing by both types of vectors using genome‐scale microarrays and quantitative RT‐PCR. The depletion of AP1 transcripts coincided with reduction of function phenotypic changes among both hIR and transitive lines and also showed similar expression patterns among differentially regulated genes. We did not detect significant silencing directed against homologous potential off‐target genes when constructs were designed with minimal sequence similarity. Both hIR and transitive methods are useful tools in plant biotechnology and genomics. The choice of vector will depend on specific objectives such as cloning throughput, number of events and degree of suppression required.
Measuring Heterogeneous Preferences for Cattle Traits among Cattle‐Keeping Households in East Africa
Authors: Ouma Emily , Abdulai Awudu , Drucker Adam
Published: June 2007

This study employs mixed logit and latent class models to examine preferences for cattle traits with a focus on heterogeneity among cattle keepers, using choice experiment data of 506 cattle‐keeping households in Kenya and Ethiopia. The findings indicate the existence of preference heterogeneity based on cattle production systems. Highly valued cattle traits for the cropping systems include traction fitness and trypanotolerance, while traits associated with herd increase are considered important in pastoral systems. Considering heterogeneity within population segments provides a framework for adapting breeding policy interventions to specific producer segments, by integrating preferred traits in a breed improvement program.
Aggregation of Price Risk over Commodities: An Economic Index Number Approach
Authors: Coyle Barry T.
Published: June 2007

This article extends the economic theory of index numbers to the aggregation of price risk over commodities in production. Superlative indexes of aggregate price risk are related to Tornqvist and Fisher—type output quantity indexes. An application to major crops in Manitoba illustrates the empirical importance of the analysis.
Willingness to Pay versus Expected Consumption Value in Vickrey Auctions for New Experience Goods
Authors: Alfnes Frode
Published: June 2007

Over the past two decades, Vickrey auctions have been widely used to elicit willingness to pay for new food products. This article shows that in a multiperiod context, it can be optimal for consumers to bid higher than the expected consumption value for a new experience good to obtain information about how the new good fits into their preference set. The degree of uncertainty about the consumption value, the purchasing frequency, and expected future market prices affect both the expected value of the quality information and the subgame perfect bidding strategy in Vickrey auctions for new experience goods.
Willingness to Pay for Agricultural Land Preservation and Policy Process Attributes: Does the Method Matter?
Authors: Johnston Robert J. , Duke Joshua M.
Published: June 2007

This article examines relationships between willingness to pay for land preservation and policy process attributes. The approach departs from traditional welfare assessments in that it does not constrain attributes of the policy process to be utility‐neutral. Results indicate policy process attributes may influence utility in some circumstances, even after controlling for the influence of land use outcomes often correlated with specific policy techniques. Results further imply that in some cases, even comprehensive specification of land use outcomes by stated preference instruments may be insufficient to prevent systematic shifts in willingness to pay related to unspecified, yet assumed, policy process attributes.
The Matching Problem (and Inventories) in Private Negotiation
Authors: Menkhaus Dale J. , Phillips Owen R. , Bastian Christopher T. , Gittings Lance B.
Published: June 2007

This study examines laboratory market outcomes under alternative matching risk scenarios and advance production. Limited access and/or asymmetry in the number of buyers and sellers cause a matching problem. When sellers hold inventory before sale and there is buyer concentration, prices are about 23% below the competitive level and close to the predicted monopsony price. The bargaining advantage shifts to buyers in this market environment. Sellers can benefit by creating alliances or cooperatives to increase their bargaining position for price and overcome poor access to buyers.
Genetics, Dementia, and the Elderly
Authors: Gatz Margaret
Published: June 2007

Whether or not an individual develops dementia is powerfully influenced by genes. For Alzheimer's disease, the most common type of dementia, one susceptibility gene with major effects has been identified, but progress finding other susceptibility genes has stalled. Twin studies have revealed that nongenetic risk also plays an important role, as there are many monozygotic twin pairs in which only one individual has dementia. Scientists have argued that gene-by-environment interactions will be key to understanding vulnerability to Alzheimer's disease; but to date, few substantial gene-by-environment interactions have been replicated. Often, too, the nongenetic or lifestyle factor appears to have a protective effect only for those individuals not carrying the risky version of the gene, not for those individuals who are at genetic risk.
Cell-Phone–Induced Driver Distraction
Authors: Strayer David L. , Drews Frank A.
Published: June 2007

Our research examined the effects of hands-free cell-phone conversations on simulated driving. We found that even when participants looked directly at objects in the driving environment, they were less likely to create a durable memory of those objects if they were conversing on a cell phone. This pattern was obtained for objects of both high and low relevance, suggesting that very little semantic analysis of the objects occurs outside the restricted focus of attention. Moreover, in-vehicle conversations do not interfere with driving as much as cell-phone conversations do, because drivers are better able to synchronize the processing demands of driving with in-vehicle conversations than with cell-phone conversations. Together, these data support an inattention-blindness interpretation wherein the disruptive effects of cell-phone conversations on driving are due in large part to the diversion of attention from driving to the phone conversation.
Mirror Neurons and the Evolution of Embodied Language
Authors: Fogassi Leonardo , Ferrari Pier Francesco
Published: June 2007

Mirror neurons are a class of neurons first discovered in the monkey premotor cortex that activate both when the monkey executes an action and when it observes the same action made by another individual. These neurons enable individuals to understand actions performed by others. Two subcategories of mirror neurons in monkeys activate when they listen to action sounds and when they observe communicative gestures made by others, respectively. The properties of mirror neurons could constitute a substrate from which more sophisticated forms of communication evolved; this would make sense, given the anatomical and functional homology between part of the monkey premotor cortex and Broca's area (the “speech” area of the brain) in humans. We hypothesize that several components of human language, including some aspects of phonology and syntax, could be embedded in the organizational properties of the motor system and that a deeper knowledge of this system could shed light on how language evolved.
Recall in Infancy
Authors: Bauer Patricia J.
Published: June 2007

Relations between developments in neural structures and changes in memory in infancy are a relatively recent focus of research. Greater knowledge about brain development, as well as methodological advances such as combined use of behavioral and electrophysiological techniques, have led to the generation and testing of specific hypotheses regarding sources of age-related change. Theory and data converge to suggest that the early-stage processes of encoding and consolidation are a significant source of age-related variability in memory early in life. Additional research is needed to determine how these processes change and interact with myriad other determinants of recall.
Decision Neuroscience
Authors: Sanfey Alan G.
Published: June 2007

Investigations of decision making have historically been undertaken by different disciplines, each using different techniques and assumptions, and few unifying efforts have been made. Economists have focused on precise mathematical models of normative decision making, psychologists have examined how decisions are actually made based on cognitive constraints, and neuroscientists have concentrated on the detailed operation of neural systems in simple choices. In recent years, however, researchers in these separate fields have joined forces in an attempt to better specify the foundations of decision making. This interdisciplinary effort has begun to use decision theory to guide the search for the neural bases of reward value and predictability. Concurrently, these formal models are beginning to incorporate processes such as social reward and emotion. The combination of these diverse theoretical approaches and methodologies is already yielding significant progress in the construction of more comprehensive decision-making models.
Common Representations of Abstract Quantities
Authors: Cordes Sara , Williams Christina L. , Meck Warren H.
Published: June 2007

Representations of abstract quantities such as time and number are essential for survival. A number of studies have revealed that both humans and nonhuman animals are able to nonverbally estimate time and number; striking similarities in the behavioral data suggest a common magnitude-representation system shared across species. It is unclear, however, whether these representations provide animals with a true concept of time and number, as posited by Gallistel and Gelman (2000) . In this article, we review the prominent cognitive and neurobiological models of timing and counting and explore the current evidence suggesting that nonhuman animals represent these quantities in a modality-independent (i.e., abstract) and ordered manner. Avenues for future research in the area of temporal and mathematical cognition are also discussed.