bluuebunny/crossref_metadata_2025 huggingface dataset:
Critical Thinking, Epistemic Virtue, and the Significance of Inclusion: Reflections on Harvey Siegel's Theory of Rationality
Authors: Jay Kilby R.
Published: July 2004

Among proponents of critical thinking, Harvey Siegel stands out in his attempt to address fundamental epistemological issues. Siegel argues that discursive inclusion of diverse groups should not be confused with rational justification of the outcome of inquiry. He maintains that epistemic virtues such as inclusion are neither necessary nor sufficient for rational judgment, and that if we are to avoid falling prey to relativism, criteria are needed to distinguish which of these virtues are indeed rational. However, the author argues that at least some of Siegel's own rational criteria cannot pass the “necessary or sufficient” standard by which he measures epistemic virtues. Moreover, reliance upon criteria fails to settle conflict in cases of disagreement over what constitutes authoritative evidence. Jürgen Habermas's theory of communicative rationality can help us to overcome this impasse, because it provides a nonrelativistic basis for justifying inclusion and giving it a place of priority in practical reasoning.
Running in Circles: Chasing Dewey
Authors: Glassman Michael
Published: July 2004

This paper explores the impact of John Dewey on the field of educational psychology. Dewey raised issues and ideas, such as the role of context and the reapproximation of knowledge, that would come to haunt education and psychology for the next century. And yet soon after the turn of the twentieth century, Dewey abandoned psychology and redefined his role in education. This paper traces some of the reasons behind the schism between Dewey and his ideas and the fields of education and psychology. The demand for a methodological purity, pushed by G.S. Hall and his students into the mainstream of both fields, elbowed Dewey's ideas out to the distant margins and Dewey himself out altogether. I argue that because the ideas and issues Dewey raised were never resolved, they keep reemerging in different theoretical forms. In the second part of this paper I examine four theoretical models that, in many ways, mirror Dewey's early ideas: Piagetianism/constructivism, sociocultural theory, cultural historical activity theory, and postmodernism.
Immunohistochemical localization of the bone morphogenetic protein receptors in the porcine ovary
Authors: Quinn Ruth L. , Shuttleworth Gail , Hunter Morag G.
Published: July 2004

The bone morphogenetic protein (BMP) family is emerging as playing a crucial role in regulating normal follicle growth and determining ovulation rate. BMPs exert their effects via BMP receptors (BMPR‐IA, ‐IB and ‐II). However, there is a paucity of information relating to the expression of the BMPRs within the ovary of large polyovular species such as the pig. Furthermore, there is a lack of information on the expression of BMPRs by fetal ovaries of any species. The purpose of this study was to investigate temporal and spatial expression of the BMPRs in the porcine ovary, at different developmental stages. Immunohistochemistry for BMPR‐IA, BMPR‐IB and BMPR‐II was performed using sections from paraffin wax‐embedded ovaries, obtained from fetal (n = 15), prepubertal (n = 3) and cycling postpubertal (n = 4) pigs. Results confirmed the presence of all three receptors in the fetal egg nests and in the granulosa cell layer of follicles ranging from primordial to late antral stages. Immunostaining was also observed in oocytes, theca layer, corpus luteum and ovarian surface epithelium. The expression of BMPRs by fetal ovaries may be related to follicle formation, whereas expression in pre‐ and post‐pubertal animals indicates BMPs are involved in regulating porcine ovarian follicle growth.
Volume estimation from projections
Authors: WULFSOHN D. , GUNDERSEN H. J. G. , VEDEL JENSEN E. B. , NYENGAARD J. R.
Published: July 2004

We describe a new estimator of the volume of axially convex objects from total vertical projections with known position of the vertical axis. The estimator combines the Cavalieri method with the known formula for area in terms of the support function of a convex body. We examine the accuracy of the proposed estimator for ellipsoidal objects having exactly known support function and volume. In addition, we illustrate practical problems of accuracy by implementing the method for some biological products.
Characterization of crystallographic properties of SMC poly Si using electron backscattered diffraction
Authors: KIM D.‐I. , OH K. H. , LEE H.‐C. , CHANG Y. J. , SOHN W. S. , JANG J.
Published: July 2004

Crystallographic properties of silicide mediated crystallization (SMC) polycrystalline silicon (poly Si) and excimer laser annealing (ELA) poly Si were studied by electron backscattered diffraction. Large‐grain sized poly Si with a large fraction of low‐angle grain boundaries was acquired by SMC, and small‐grain sized poly Si with high‐angle grain boundaries especially around 60° was acquired by ELA. The thin film transistor (TFT) device characteristics were investigated in view of short‐range crystallinity (pattern quality) and long‐range crystallinity (misorientation distribution) of the specimens. Short‐range crystallinity did not significantly affect the TFT device characteristics, and long‐range crystallinity considering the low energy level of special boundaries could be better related to the TFT device characteristics of poly Si.
Exploring the use of soft X‐ray microscopy for imaging subcellular structures of the inner ear1
Authors: JOHANSSON GÖRAN A. , KHANNA SHYAM M. , NAIR AJIT , MANNSTRÖM PAULA , DENBEAUX GREG , ULFENDAHL MATS
Published: July 2004

The soft X‐ray microscope at the Lawrence Berkeley National Laboratory was developed for visualization of biological tissue. Soft X‐ray microscopy provides high‐resolution visualization of hydrated, non‐embedded and non‐sectioned cells and is thus potentially an alternative to transmission electron microscopy. Here we show for the first time soft X‐ray micrographs of structures isolated from the guinea‐pig inner ear. Sensory outer hair cells and supporting pillar cells are readily visualized. In the hair cells, individual stereocilia can easily be identified within the apical hair bundle. The underlying cuticular plate is, however, too densely composed or too thick to be clearly visualized, and thus appears very dark. The cytoplasmic structures protruding from the cuticular plates as well as the fibrillar material surrounding and projecting from the cell nuclei can be seen. In the pillar cells the images reveal individual microtubule bundles. Soft X‐ray images of the acellular tectorial membrane and thin two‐layered Reissner's membrane display a level of resolution comparable to low‐power electron microscopy.
Estimation of the number of stellate cells in a liver with the smooth fractionator
Authors: MARCOS R. , MONTEIRO R. A. F. , ROCHA E.
Published: July 2004

To better evaluate the activation and proliferative response of hepatic stellate cells (HSC) in hepatic fibrosis, it is essential to have sound quantitative data in non‐pathological conditions. Our aim was to obtain the first precise and unbiased estimate of the total number of HSC in the adult rat, by combining the optical fractionator, in a smooth sampling design, with immunocytochemistry against glial fibrillary acidic protein. Moreover, we wanted to verify whether there was sufficiently relevant specimen inhomogeneity that could jeopardize the high expected estimate precision when using the smooth fractionator design for HSC. Finally, we wanted to address the question of what sampling scheme would be advisable a priori for future studies. Microscopical observations and quantitative data provided no evidence for inhomogeneity of tissue distribution of HSC. Under this scenario, we implemented a baseline sampling strategy estimating the number (N̂) of HSC as 207E06 (CV = 0.17). The coefficient of error [CE(N̂)] was 0.04, as calculated by two formerly proposed approaches. The biological difference among animals contributed ≅ 95% to the observed variability, whereas methodological variance comprised the remaining 5%. We then carried out a half reduction of sampling effort, at the level of both sections and fields. In either occasion, the CE(N̂) values were low (≅ 0.05) and the biological variance continued to be far more important than methodological variance. We concluded that our baseline sampling (counting 650–1000 cells/rat) would be appropriate to assess the lobular distribution and the N̂ of HSC. However, if the latter is the only parameter to be estimated, around half of our baseline sampling (counting 250–600 cells/rat) would still generate precise estimates [CE(N̂) < 0.1], being in this case more efficient to reduce the number of sections than to reduce the sampled fields.
Direct observation of the asphaltene structure in paving‐grade bitumen using confocal laser‐scanning microscopy
Authors: BEARSLEY S. , FORBES A. , G. HAVERKAMP R.
Published: July 2004

The structure of the asphaltene phase in the bitumen is believed to have a significant effect on its rheological properties. It has traditionally been difficult to observe the asphaltene phase in unaltered samples of bitumen. The maltenes are thought to form a continuous phase in which the asphaltenes are ‘dispersed’. In this study, confocal laser‐scanning microscopy (CLSM) operating in fluorescence mode was used to examine the structure of paving‐grade Safaniya and San Joaquin bitumen. The asphaltene fraction fluoresces in the 515–545 nm wavelength range when irradiated with light with a wavelength of 488 nm. The major advantages of CLSM are that the bitumen sample requires little pretreatment or preparation that may affect the original dispersion of asphaltenes and the bitumen is observed at ambient temperature and pressure. This reduces the possibility of producing images that are not representative of the original material. CLSM was able to show the distribution of maltene and asphaltene components in bitumen. The asphaltene aggregates in the bitumen were observed to be 2–7 µm in size and formed a dispersed ‘sol’ structure in the continuous maltene matrix rather than a network ‘gel’ structure. Surprisingly, the structure and fluorescence of the asphaltene phase does not appear to alter radically upon oxidative ageing. The structure of the asphaltene phase of an AR4000 San Joaquin bitumen was found to be more homogeneous than that of Safaniya bitumen, illustrating the range of structures that can be observed in bitumens by this method.
Density estimation in live‐trapping studies
Authors: Efford Murray
Published: July 2004

Unbiased estimation of population density is a major and unsolved problem in animal trapping studies. This paper describes a new and general method for estimating density from closed‐population capture–recapture data. Many estimators exist for the size (N) and mean capture probability ( p̄) of a closed population. These statistics suffer from an unknown bias due to edge effect that varies with trap layout and home range size. The mean distance between successive captures of an individual () provides information on the scale of individual movements, but is itself a function of trap spacing and grid size. Our aim is to define and estimate parameters that do not depend on the trap layout. In the new method, simulation and inverse prediction are used to estimate jointly the population density (D) and two parameters of individual capture probability, magnitude (g0) and spatial scale (σ), from the information in, p̄ and. The method uses any configuration of traps (e.g. grid, web or line) and any choice of closed‐population estimator. It is assumed that home ranges have a stationary distribution in two dimensions, and that capture events may be simulated as the outcome of competing Poisson processes in time. The method is applied to simulated and field data. The estimator appears unusually robust and free from bias.
Coexistence of similar genotypes of Daphnia magna in intermittent populations: response to thermal stress
Authors: E. Mitchell S. , Halves J. , Lampert W.
Published: July 2004

We investigated the diversity and thermal response of a fitness related trait, juvenile growth rate, in seasonal population samples of Daphnia magna from two temperate ponds. Both populations were intermittent, i.e. they disappeared from the water body and recolonized seasonally by hatching from resting eggs in the sediment.

Temporally isolated clones of Daphniamagna showed the typical asymmetric response for growth rate with temperature and a sharp decline after the maximum response at 26°C (TMR). There was no evidence for genetically adapted seasonal groups. Despite significant genetic variation among clones and for phenotypic plasticity (G×E interactions without genetic correlations), seasonal groups of clones showed no shift in TMR and mean temperature reaction norms were similar among groups and both populations. Heritabilities remained similar among temperatures despite a large increase in genetic variance at stressfully high temperatures of 29°C and 32°C, due to simultaneous increase in environmental variance. Further, heritabilities remained high among sample periods and were not eroded during several months of asexual reproduction.

Regular diapause, an intrinsic feature of intermittent Daphnia populations, may replace the need for physiological temperature adaptation and promote maintenance of diversity through phenotypic similarity by reducing the time over which competitive interactions occur. Such populations are unlikely to be directly affected by elevated temperatures. They have a large potential for phenotypic plasticity as their TMR is higher than the temperature normally encountered.
Frequent nest relocation in the antAphaenogaster araneoides: resources, competition, and natural enemies
Authors: McGlynn Terrence P. , Carr Ryan A. , Carson Johnny H. , Buma Johnathan
Published: July 2004

Sessile and vagile organisms differ from one another in some fundamental ways, including methods of resource acquisition and competition. Ant colonies are typically studied as sessile entities, even though a large fraction of ant species frequently relocate their nests in the course of their life history. Little is known about the causes and consequences of nest relocation, but it is likely that the costs and benefits of relocation are driven by nest quality, neighborhood competition, or resource availability. In this paper, we document several cycles of nest relocation in a population of the Central American antAphaenogaster araneoides. In our first experiment, we tracked the pattern of relocation, testing whether environmental characteristics and colony demography were associated with relocation behavior. In our second experiment, we manipulated resource availability by adding or subtracting leaf litter, which is known to predict colony growth. We found that colonies relocated their nests once per week on average and colonies often reoccupied nests from which they had once emigrated. Larger colonies relocated more frequently than smaller colonies, and quickly growing colonies utilized a greater number of nests within their home range compared to slowly growing colonies. Relocation events were most likely to occur in periods when vapor pressure deficits were greatest. Nearest neighbor distance and other measures of environmental conditions were not associated with relocation behavior and there was no significant effect of litter removal or supplementation. We found evidence that multiple natural enemies attackedA. araneoidescolonies. Based on the demographic correlates of relocation and our rejection of other plausible hypotheses, we propose that nest relocation is driven by the escape from natural enemies.
Burrowing owls and burrowing mammals: are ecosystem engineers interchangeable as facilitators?
Authors: Machicote Marcela , Branch Lyn C. , Villarreal Diego
Published: July 2004

Terrestrial vertebrates exhibit dynamic, positive interactions that form and dissolve under different circumstances, usually with multiple species as participants. Ecosystem engineers are important facilitators of other species because they cause physical changes in the environment that alter resource availability. Although a species can be associated with more than one partner, facilitators may not be interchangeable if they differ in abundance, behavioral characteristics, or interactions with other factors in ways that condition the outcome of the association. We examined interactions between burrowing owls (Athene cunicularia) and two burrowing mammals, hairy armadillos (Chaetophractus villosus) and plains vizcachas (Lagostomus maximus), and determined whether these ecosystem engineers are interchangeable for owls. We examined reproductive success for owls nesting in these mammal burrows, constructed a logistic regression model to identify habitat characteristics associated with owl nests, and examined the engineering activities of the mammals. Data on reproduction and habitat indicate that armadillos and vizcachas are not interchangeable for owls. Thirty‐five percent of the nests in vizcacha burrows produced fledglings; no fledglings were produced from nests outside vizcachas colonies, even though owls nest successfully in armadillo burrows in other parts of Argentina. Vizcachas facilitate burrowing owls by construction of burrows and by producing open understory vegetation through herbivory. In contrast, armadillos do not alter vegetation, and their burrows are suitable for nest sites only when they occur in recently burned areas or areas maintained by anthropogenic disturbance. Our habitat model also suggests that fire plays a key role in maintaining owl populations because fire is the only natural process that reduces shrubs to the level required by owls. Current management practices of eradication of vizcachas and fire suppression in shrublands could have strong negative consequences for burrowing owls.
Credit or debit? Resource input changes population dynamics of city‐slicker birds
Authors: Shochat Eyal
Published: July 2004

The underlying evolutionary mechanisms of urban bird populations have hardly been studied. High food density and low predation risk serve to explain the global pattern of extremely high urban bird population densities. Both these bottom‐up and top‐down effects are paradoxical since the per capita amount of food is small due to competition, and domestic predator density is high in cities. The bottom‐up paradox can be resolved by taking into account the high food resource‐predictability in cities. Concerning the top‐down effect, recent studies suggest that at least when it comes to nest predation the effect of cats is minor. I suggest that the combination of high food predictability and low predation risk in cities alter bird foraging behaviour, which in turn affects population dynamics. In terms of density, the result is that bird populations exceed the carrying capacity of the urban environment, costing heavily on body condition and/or life span. Under such conditions the population should consist of a few winners and many losers. Only the winners have sufficient access to food resources and the opportunity to reproduce. The highly predictable continuous input of food in the urban environment allows them to “live on their credit”. They may trade off between offspring body condition and clutch size. In the lack of predation, the losers among the fledglings may survive for a relatively long period, getting just enough energy to survive. Though they may never become healthy enough to reproduce, they will have a major contribution to the observed population density. Results of several case studies seem to support the credit card hypothesis and suggest that it can serve as a general rule for the evolution of animal populations and communities in highly predictable human managed environments.
Can the biotic nestedness matrix be used predictively?
Authors: Maron Martine , Mac Nally Ralph , M. Watson David , Lill Alan
Published: July 2004

The biotas of a suite of neighboring patches of remnant vegetation often form a series of nested sub‐sets, in which the species present in species‐poor patches are non‐random sub‐sets of those present in richer patches. There has been recent interest in ways in which this knowledge may be used to aid conservation. We focus here on whether nested patterns can be used predictively. If nestedness in a fragmented system increases over time through biotic relaxation, locations where particular species may become extinct or are likely to colonize might be predictable and this could be useful in threatened‐species management. We used the Temperature Calculator ofAtmar and Patterson (1995)to arrange a matrix of bird species’ occurrences in a series of bulokeAllocasuarina leuhmanniiwoodland remnants so that nestedness was maximized. Probability bands generated by the calculator were used to predict possible colonization and extinction events. We then re‐surveyed the avifauna of the fragments after a seven‐year interval to test these predictions. Although nestedness increased between the two survey periods, there was no linear relationship between the generated probability of extinctions or colonizations and the accuracy of the predictions. The predictions derived from the calculator were no more accurate than a second set of predictions generated by use of a simple non‐nested model. Despite the increase in nestedness, the arrangement of sites in each of the two maximally packed matrices was substantially different. For the nestedness matrix to generate accurate predictions, an increase in nestedness must be due to a minimization of unexpected species presences and absences rather than an extensive redistribution of species among remnants, as we found. The potential utility of nested patterns in predicting systematic colonization and extinction events should be further evaluated in other, less dynamic, fragmented systems such as those undergoing biotic relaxation.
Timing of reproduction in a Darwin's finch: temporal opportunism under spatial constraints
Authors: Hau Michaela , Wikelski Martin , Gwinner Helga , Gwinner Eberhard
Published: July 2004

In seasonally unpredictable habitats, organisms cannot anticipate and prepare for a regular yearly reproductive period. Therefore, they opportunistically breed at any time of year. Opportunistically breeding birds are thought to maintain an activated reproductive system all year around. However, always being prepared can be costly and we therefore examined whether an opportunistic breeding strategy is realized in birds that are confined to harsh, climatically unpredictable habitats from which they cannot escape. We studied temporal variations in reproductive activity in small ground finches (Geospiza fuliginosa) in the Galápagos archipelago, Ecuador, by determining gonad sizes and plasma luteinizing hormone (LH) concentrations. We compared populations from the arid coasts of St. Fé and St. Cruz islands with birds from the St. Cruz humid highlands. The population from the arid St. Fé island increased gonad sizes and LH concentrations at least four months earlier in a wet (El Niño) year compared to the following dry year, indicating high temporal flexibility and opportunistic breeding. However, birds had completely regressed gonads for about 10 months between breeding events during a period of drought. Long‐term changes in environmental factors such as ambient temperature, daylength and light intensity did not appear to influence reproductive activity. Instead, environmental signals more directly connected to the occurrence of rains such as humidity, barometric pressure, or rainfall itself may stimulate reproduction. Our data demonstrate that small ground finches regulate the onset of reproductive activity flexibly like other opportunistic breeders. However, they differ from those by their unusual long‐term quiescence of the reproductive system during dry periods, which might minimize costs. Our findings suggest that within the continuum from seasonal to opportunistic breeding strategies, organisms evolutionarily optimize reproductive strategies to match local ecological conditions.
The joint effect of temperature and host species induce complex genotype‐by‐environment interactions in the larval parasitoid of Drosophila, Leptopilina heterotoma (Hymenoptera: Figitidae)
Authors: Ris Nicolas , Allemand Roland , Fouillet Pierre , Fleury Frédéric
Published: July 2004

Phenotypic plasticity and genotype‐by‐environment interactions are usually studied by testing environmental factors separately. However, several environmental factors may vary simultaneously across the geographic range of a species, and thus interact to drive phenotypic and genotypic evolution. Here, we address the question of the interaction between two environmental factors in the case of a koinobiont parasitoid of Drosophila, Leptopilina heterotoma (Hymenoptera: Figitidae). Using two allopatric parasitoid lines, we analysed the joint effect of developmental temperature and host species on two major fitness components (pre‐imaginal survival and fecundity) of emerged parasitoids. Our results indicate that both environmental factors strongly interact to shape the parasitoid phenotype. Moreover, complex genotype‐by‐environment interactions appeared that can even invert the relative fitness of the two parasitoid lines.
A New Genus of Fossil Sand Crab (Anomura: Albuneidae) from the Oligocene of Italy
Authors: Boyko Christopher B.
Published: July 2004

The recently described fossil albuneid Paralbunea galantensis De Angeli and Marangon differs from the type of the genus Paralbunea Serène and is herein made the type species of a new genus, Harryhausenia, which is closely related to Zygopa Serène and Umali. A discussion is given on the relationships between the new genus and Zygopa, as well as between Zygopa and other albuneid taxa.
An Unusually Diverse Llandovery (Silurian) Diplograptid Fauna from the Southern Urals of Russia and Its Evolutionary Significance
Authors: Koren' T. N. , Rickards R. B.
Published: July 2004

This vesiculosus Biozone assemblage of chemically‐isolated graptolites from the Orenburg District of Russia was obtained from limestones associated with pillow lavas of the Sakmara Formation of Silurian–Early Devonian age. It comprises 30 species, of which 24 are described. Nine are new, one is a new subspecies, and eight are left under open nomenclature. The assemblage is unique in its diversity of minute biserial graptolites referable to the genera ‘Glyptograptus’, Normalograptus, Sudburigraptus, and Metaclimacograptus; and is unusual in that well‐preserved graptolite faunas are rare at this stratigraphical level, which is fixed by the occurrence of Cystograptus vesiculosus (Nicholson) s.l. and Paraclimacograptus innotatus (Nicholson). The following new forms are described: ‘Glyptograptus’tamariscus praecursor subsp. nov., G. mazovoensis sp. nov., G. nikitini sp. nov., G. pavlinovi sp. nov., G. telarius sp. nov., G. zimai sp. nov., Normalograptus legrandi sp. nov., N. melchini sp. nov., N. sobolevskayae sp. nov., and Metaclimacograptus bjerreskovae sp. nov. Five evolutionary lineages are defined within the ‘Glyptograptus’tamariscus (Nicholson) plexus, modifying and extending the pioneer work of Packham (1962). The diverse ‘Glyptograptus’ faunas are considered to be a replacement for the Normalograptus fauna which peaked in the late Ordovician and early Silurian. Metaclimacograptus, although reasonably diverse in its speciation, exhibits a conservative style of evolution with little fundamental change throughout the Llandovery. It is suggested that cortical bandages have species‐specific dimensions and micro‐features. Some problematical micro‐ and ultrastructural features are described, notably fibrillar textures, parallel to the fusellar margins, in several species.
JOB MOBILITY IN BRITAIN: ARE THE SCOTS DIFFERENT? EVIDENCE FROM THE BHPS†
Authors: Heitmueller Axel
Published: July 2004

The Scottish extension‐sample of the British Household Panel Study (BHPS) is used to shed light on differences in job mobility patterns in England and Scotland for both men and women. Based on probit estimates of the overall mobility rate, a new decomposition technique is applied to distinguish between explained and unexplained differences. Furthermore, exploiting data on the number of job changes, a zero inflated Poisson model is estimated to provide information on possible differences in the expected number of job changes. Overall, there is evidence that suggests significant differences in mobility patterns south and north of the Borders; however, this is confined to men. Yet, whether this suffices to justify a heterogeneous regional labour market remains to be seen.
REVENUE DIVERGENCE AND COMPETITIVE BALANCE IN A DIVISIONAL SPORTS LEAGUE
Authors: Dobson Stephen , Goddard John
Published: July 2004

The North American model of resource allocation in professional sports leagues is adapted for English (association) football. Comparisons are drawn between the equilibrium allocations of playing talent under objective functions of profit maximisation and win percent maximisation subject to a financial constraint. Empirical revenue functions are reported for 1926–1999. These indicate a shift in the composition of demand favouring big‐city teams and an increase in the sensitivity of revenue to performance. An analysis of match results in the FA Cup suggests an increase in competitive imbalance between teams at different levels of the league's divisional hierarchy, as the theory suggests.
FINANCIAL MARKET INTEGRATION AND BUSINESS CYCLE VOLATILITY IN A MONETARY UNION
Authors: Pierdzioch Christian
Published: July 2004

This paper uses a dynamic general equilibrium two‐country sticky‐price model to analyze the implications of financial market integration for the propagation of asymmetric productivity and government spending shocks in a monetary union. Financial market integration has a small effect on the propagation of these shocks if households can only trade in risk‐free bonds. However, financial market integration has a more substantial effect on the propagation of these shocks in a monetary union with a complete market for state‐contingent claims. This result indicates that it may be important to account for threshold effects in empirical analyses of the impact of financial market integration on business cycle volatility in a monetary union.
RE‐ESTIMATING FEMALE DOMESTIC WORK: BASED ON THE BRITISH SURVEY EVIDENCE FROM 1986–7
Authors: Prodromídis Pròdromos‐Ioànnis
Published: July 2004

Jenkins and O'Leary (SJPE, 1997) estimated unpaid work using some of the variables collected in the 1986–7 SCEL Initiative. However, the discovery of low filial effects should be attributed to the specification of their model, especially to the inclusion of proxies for contemporaneous paid work aiming to capture population heterogeneity. It seems that the two researchers could have utilised other data from people's past work histories (which were also solicited in the survey) to construct alternative paid‐work proxies and avoid the simultaneity problem altogether. The introduction of such proxies preserves the structure of the Jenkins/O'Leary model, and yields both lower full‐time and part‐time employment effects on unpaid work, and higher children‐effects. In fact the children‐effects remain pronounced even if one drops all paid work regressors or introduces a non‐selection hazard from the probit on paid work participation, instead.
Spatially structured herbivory and primary succession at Mount St Helens: field surveys and experimental growth studies suggest a role for nutrients
Authors: Fagan William F. , Bishop John G. , Schade John D.
Published: July 2004

Abstract.  1. The 1980 eruption of Mount St Helens (Washington, U.S.A.) created a 60‐km2 region of primary successional habitat. Since colonising in 1981, the spatial spread of the legume Lupinus lepidus at Mount St Helens, Washington, U.S.A., has afforded intriguing opportunities to study the effect of trophic dynamics on primary succession.

2. Insect herbivory on this lupine has exhibited striking spatial structure for over a decade, with inverse density‐dependent damage patterns occurring over both small (10–100 m) and large (1–10 km) spatial scales.

3. Hypothesising that lupine nutritional chemistry might underlie the spatial patterns in herbivory, the distribution of elemental macronutrients (nitrogen, phosphorus) across the landscape was characterised.

4. Samples of soil and lupine tissue (roots and leaves) were collected from sites along both local and regional gradients in lupine density. On both large and small spatial scales, lupine leaves from low‐density conditions were significantly more nutrient rich.

5. In addition, in a laboratory growth study native lepidopteran herbivores that specialise on lupines (Gelechiidae: Filatima sp.) performed better when fed leaves from low‐density, high‐nutrient lupines than on diets of low‐nutrient lupine leaves from high‐density areas a few metres away.

6. These data suggest that spatial heterogeneity in lupine nutrient chemistry may underlie the remarkable herbivory gradients witnessed at Mount St Helens.
Movement and disappearance of mountain birch defoliators are influenced by the interactive effects of plant architecture and induced resistance
Authors: Kaitaniemi Pekka , Vehviläinen Harri , Ruohomäki Kai
Published: July 2004

Abstract.  1. Changes in herbivore movement and feeding behaviour may determine the efficacy of induced plant resistance by affecting the location of damage within the foliage and by modifying the vulnerability of herbivores to predators.

2. Observations of larval feeding sites were used to test whether induced resistance increased the movement of free‐living Epirrita autumnata Borkh. (Lepidoptera, Geometridae) larvae feeding on mountain birch [Betula pubescens ssp. czerepanovii (Orlova) Hämet‐Ahti]. The amount of defoliation at different canopy parts was measured to test the associated changes in the spread of damage within the foliage.

3. The architectural complexity of trees was measured to test its association with the disappearance of larvae from their hosts. The underlying hypothesis was that the architectural traits of the host plant could affect disappearance by influencing the frequency of herbivores encountering predators.

4. Distance between the consecutive feeding positions, the number of leaves damaged, and consumption of long shoot leaves all increased in trees with induced resistance.

5. Disappearance of larvae depended on the architectural complexity of trees. The effect of complexity differed between defoliation treatments, and may depend on the activity and number of predators in relation to the canopy size.

6. Accordingly, this study suggested that the interactive effects of plant architecture, induced resistance, and herbivore behaviour can determine the performance of herbivores on their host plant.
Anoxia tolerance in high Arctic terrestrial microarthropods
Authors: Hodkinson Ian D. , Bird Jeremy M.
Published: July 2004

Abstract.  1. Ten Arctic species of Collembola and two species of cryptostigmatic mites survived anoxia at 5 °C over periods ranging from 1 to 36 days.

2. Highly active, surface‐dwelling collembolans such as Isotoma anglicana, Isotoma tschernovi, and Sminthurides malmgreni were the most susceptible to anoxia. Mites and Collembola living deeper in the soil or in wet habitats, such as Camisia anomia and Hypogastrura viatica, were most tolerant. Tolerance, however, appears more closely linked to taxonomic relatedness than to ecological groupings per se, although the two may coincide.

3. Implications for life‐history strategies, including metabolic cold adaptation in its broadest sense, are discussed.
Conflict between optimal clutch size for mothers and offspring in the leaf miner, Leucoptera sinuella
Authors: Kagata Hideki , Ohgushi Takayuki
Published: July 2004

Abstract.  1. Clutch size in a leaf‐mining moth, Leucoptera sinuella (Reutti), was examined to determine whether the clutch size in natural populations meets the prediction of an optimal strategy, through comparisons between the optimal clutch sizes for offspring and for a mother.

2. A field experiment revealed that premature leaf abscission, egg dropping, and larval competition were important selective forces in determining the clutch size of this leaf miner on its host plant, Salix miyabeana. Then, optimal clutch size was predicted using the theoretical model of Weis et al. (1983), from the data obtained in the field experiment.

3. The model predicts that the clutch size that maximises offspring fitness is two, and that the clutch size that maximises reproductive success of the female varies from two to four, depending on the female's survival rate between oviposition events. The predicted clutch size (two) was identical to the clutch size observed most frequently in the field, assuming > 95% survival rate of females. Suitability of the model of Weis et al. (1983) was discussed based on these results.
The mid‐season crash in aphid populations: why and how does it occur?
Authors: Karley A. J. , Parker W. E. , Pitchford J. W. , Douglas A.E.
Published: July 2004

Abstract. 1. Aphid populations on agricultural crops in temperature regions collapse over a few days from peak numbers to local extinction soon after mid‐summer (e.g. mid‐July in the U.K.). The populations recover 6–8 weeks later. There is anecdotal or incidental evidence of an equivalent mid‐season population crash of aphids on grasses and forbs in natural vegetation.

2. The ecological factors causing the mid‐season population crash of aphids include a decline in plant nutritional quality and increased natural enemy pressure as the season progresses. Extreme weather events, e.g. severe rainstorms, can precipitate the crash but weather conditions are not a consistent contributory factor.

3. The population processes underlying the crash comprise enhanced emigration, especially by alate (winged) aphids, depressed performance resulting in reduced birth rates, and elevated mortality caused by natural enemies.

4. Mathematical models, previously applied to aphid populations on agricultural crops, have great potential for studies of aphid dynamics in natural vegetation. In particular, they can help identify the contribution of various ecological factors to the timing of the population crash and offer explanations for how slow changes in population processes can result in a rapid collapse of aphid populations.
Release of phylogenetic constraints through low resource heterogeneity: the case of gall‐inducing sawflies
Authors: Price Peter W. , Ohgushi Takayuki , Roininen Heikki , Ishihara Michihiro , Craig Timothy P. , Tahvanainen Jorma , Ferrier Sharon M.
Published: July 2004

Abstract.  1. A group of six unusual sawfly species, which do not conform to the phylogenetic constraints hypothesis as it has been applied to sawflies, was examined in natural populations. All species were in the genus Pontania (Hymenoptera: Tenthredinidae), which induce galls on leaves of willow species (Salicaceae). An understanding of these non‐conformist species was important as a test of the validity of the general hypothesis.

2. The six species of sawfly, Pontania mandshurica, P. cf. arcticornis, P. aestiva, P. arcticornis, P. pacifica, and P. nr. pacifica, showed no oviposition preference for long, vigorous shoots, in contrast to 37 documented tenthredinid species that have demonstrated such a preference. Rather, the non‐conformist species attacked the shortest shoot length classes more frequently and larval establishment in galls was successful.

3. The evident escape from the phylogenetic constraint, which commonly limits sawfly attack to the most vigorous shoots in a willow population, resulted from low apparent heterogeneity of the resources exploited by these Pontania species. At the time of female oviposition, shoots and leaves were too uniform to allow discrimination by females among shoot length classes, resulting in random, or near random attack of shoots.

4. The unusual relative uniformity of resources to which sawflies were exposed resulted from several characteristics. (1) Females emerged early relative to shoot growth phenology, making discrimination among shoot length and vigour difficult or impossible. (2) Low heterogeneity in leaf length resulted in resource similarity independent of shoot length. (3) Abscission of leaves occurred after emergence of larvae from leaf galls so that differential abscission of leaves in relation to shoot length became irrelevant. (4) In some cases, low variance in shoot lengths was evident in old ramets lacking long, vigorous shoots. Probably as a result of low resource heterogeneity, larvae survived well across all shoot length classes, revealing no ovipositional preference and larval performance linkage related to the exploitation of the longest shoot length classes in a population of willows, as in the conformist species. Therefore, larval survival did not provide positive feedback on female preferential behaviour for long shoots, as in the conformist species studied.
Tracing the Effects of WTO Accession on Policy‐making in Sovereign States: Preliminary Lessons from the Recent Experience of Transition Countries
Authors: Drabek Zdenek , Bacchetta Marc
Published: July 2004

We examine in this paper the effects of WTO Accession on policy‐making and institutional reforms in transition countries. This is done by looking at the experience of those transition countries which are already Members of the WTO and/or which have recently acceded. We start by trying to distinguish between effects of accession negotiations and from those which are the results of autonomous policy initiatives. The areas of domestic policy‐making which are considered in the analysis include market access, governance, government budget, structural reforms, trade and investment arrangements with regional partners and macroeconomic management. We find that no precise blueprint of accession conditions can be ascertained and argue that the WTO played a role, albeit not an exclusive one, in the process of liberalisation. We also find that the costs of WTO Accession are not negligible, but that the benefits of WTO Membership are significant in terms of improved, more predictable, market access and its stability, improved governance and a recourse to better economic policies without significant loss to government revenues.
Pricing Efficiency in a Thin Market with Competitive Market Makers: Box Spread Strategies in the Hang Seng Index Options Market
Authors: Fung Joseph K. W. , Mok Henry M. K. , Wong Kenneth C. K.
Published: July 2004

Using a box spread arbitrage strategy, we examine the pricing efficiency of the emerging, thinly traded Hang Seng Index options market in Hong Kong, where market makers operate under a competitive open outcry system. In 20 months of tick‐by‐tick bid‐ask and transaction quotes we find very few arbitrage opportunities. Our examination of the reporting time of quotes shows that in effect, all the apparent mispricings are deceptive and could be explained by stale quotes. The absence of real arbitrage opportunities supports the pricing rationality hypothesis in the Hong Kong options market.
An International Investigation of the Factors that Determine Conditional Gold Betas
Authors: Faff Robert , Hillier David
Published: July 2004

We investigate the unconditional and conditional gold betas of four country‐based gold industry portfolios. First, we document the similarity of unconditional gold betas across countries. Second, we find that the factors affecting conditional gold betas are different in the Australian and South African gold sectors relative to their North American counterparts. Only the gold bullion return volatility shows a negative association with conditional gold betas in Australian and South African gold mining firms. Moreover, gold price does not appear to play a systematic role in determining Australian or South African conditional gold betas. We discuss possible explanations for these findings.
Characterization of hair follicles induced in implanted, cultured rat keratinocyte sheets
Authors: Miyashita H. , Hakamata Y. , Kobayashi E. , Kobayashi K.
Published: July 2004

Abstract:  Cultured rat keratinocyte sheets form hair follicles in combination with rat vibrissa dermal papillae when they are transplanted subcutaneously in syngeneic rats and athymic mice. In the present study, the histologic details of these induced follicles were analyzed by preparing cultured sheets mixed with normal rat keratinocytes and green fluorescent protein (GFP)‐transgenic rat keratinocytes. Histologic examination demonstrated that some induced follicles maintained their size and morphology for at least 18 weeks, whereas others decreased in size and others totally differentiated into cornified structures between 3 and 6 weeks. The percentage of the grafts with GFP‐positive cells decreased during the same period. This finding suggests that some GFP‐positive cells were transient‐amplifying cells that turned into terminally differentiated cells and were lost during this period. Some large follicles and some small follicles maintained their hair‐producing ability and the proliferative activity in their hair matrix for 18 weeks. In addition, one 6‐week‐old follicle contained label‐retaining cells in the outer root sheath. Seven of 25 follicles induced from chimera epithelium contained both GFP‐positive cells and GFP‐negative cells. These results suggest that stem cells are present in the induced follicle and the induced follicle consists of polyclonally derived cells. The presence of early anagen‐like large follicles at week 6 and 9 and a telogen‐like small follicle at week 18 also suggests that hair‐growth cycle phases proceeded in the induced follicles. In conclusion, the follicles induced in the cultured keratinocyte sheets maintained hair‐producing ability and proliferative activity for at least 18 weeks. This and the presence of label‐retaining cells suggest that there are stem cells in the induced follicles, which seem to have a hair‐growth cycle.
Multilineage progression of genetically unstable tumor subclones in cutaneous T‐cell lymphoma
Authors: Rübben Albert , Kempf Werner , Kadin Marshall E. , Zimmermann Dieter R. , Burg Günter
Published: July 2004

Abstract:  Molecular analysis of solid malignant tumors has suggested multilineage progression of genetically unstable subclones during early stages of tumorigenesis as a common mechanism of tumor cell evolution. We have investigated whether multilineage progression is a feature of cutaneous T‐cell lymphoma (CTCL). To identify individual tumor cell subclones, we determined the pattern of mutations within microsatellite DNA obtained from multiple histomorphologically confined tumor cell nests of mycosis fungoides (MF) and lymphomatoid papulosis (LyP) lesions. Tumor cells were isolated by laser microdissection, and allelotypes were determined at microsatellite markers D6S260, D9S162, D9S171, D10S215, TP53.PCR15, and D18S65. Nine cases of MF and one patient with anaplastic large cell lymphoma (ALCL) originating from LyP were analyzed at 277 different microdissected areas obtained from 31 individual lesions. Three specimens of cutaneous lichen planus microdissected at 26 areas served as the control tissue. Microsatellite instability in microdissected tissue [MSI(md‐tissue)] was detected in tumor tissues of all CTCL patients. One hundred and fifty‐seven of 469 analyzed polymerase chain reaction (PCR) amplifications contained mutated microsatellite alleles (34%). In lichen planus, MSI(md‐tissue) was seen in only four of 76 PCR products (5%) (P < 0.0001). The distribution of allelotypes in tumor cells from different disease stages was consistent with multilineage progression in five MF cases, as well as in the LyP/ALCL patient. Our results suggest that CTCL may evolve by multilineage progression and that tumor subclones in MF can be detected in early disease stages by mutation analysis of microsatellite DNA obtained from multiple microdissected areas.