bluuebunny/crossref_metadata_2025_split huggingface dataset:
Squaring the Circle: The Cultural Relativity of 'Good' Shape
Authors: Roberson Debi , Davidoff Jules , Shapiro Laura 
Published: July 2002

Abstract
The Gestalt theorists of the early twentieth century proposed a psychological primacy for circles, squares and triangles over other shapes. They described them as 'good' shapes and the Gestalt premise has been widely accepted. Rosch (1973), for example, suggested that shape categories formed around these 'natural' prototypes irrespective of the paucity of shape terms in a language. Rosch found that speakers of a language lacking terms for any geometric shape nevertheless learnt paired-associates to these 'good' shapes more easily than to asymmetric variants. We question these empirical data in the light of the accumulation of recent evidence in other perceptual domains that language affects categorization. A cross-cultural investigation sought to replicate Rosch's findings with the Himba of Northern Namibia who also have no terms in their language for the supposedly basic shapes of circle, square and triangle. A replication of Rosch (1973) found no advantage for these 'good' shapes in the organization of categories. It was concluded that there is no necessary salience for circles, squares and triangles. Indeed, we argue for the opposite because these shapes are rare in nature. The general absence of straight lines and symmetry in the perceptual environment should rather make circles, squares and triangles unusual and, therefore, less likely to be used as prototypes in categorization tasks. We place shape as one of the types of perceptual input (in philosophical terms, 'vague') that is readily susceptible to effects of language variation.
Structure of an anuran community in a montane meadow in southeastern Brazil: effects of seasonality, habitat, and predation
Authors: Sazima Ivan , Eterovick Paula Cabral 
Published: July 2002

AbstractIn order to assess the main factors influencing its structure, an anuran community was studied from August 1996 to July 1997, in a 1200 m high rocky meadow site at the Serra do Cipó, Minas Gerais, Brasil, a region with markedly seasonal climate. The study site included three temporary habitats: a stream, a puddle, and a swamp. Thirteen anuran species were recorded at the study site. Species of tadpoles differed in microhabitat as to their position in water column, annual occurrence period, and water flow in the occupied sites. Aquatic vegetation, depth and occupied habitat (stream, swamp, or puddle) were of secondary importance in telling species apart. Calling sites of males were distinguished based on occupied habitat and annual activity period. Most species started their reproductive activities at the onset of the rains, in an opportunistic way. Water availability in the habitat seems to be the most important factor affecting temporal distribution of reproductive activities in the anuran community. Competitive interactions could not be detected in the community. The most important tadpole predators recorded at the study site were belostomatid water bugs and dragonfly nymphs. Their abundance peaks occurred after those of tadpoles, as predicted for predator-prey populations with interconnected cycles. Mortality rates were high for tadpoles, and predation is the most likely cause. Differences recorded among species, considering time of occurrence, tadpole microhabitats, and male calling sites, may reflect distinct specific adaptations and preferences.
VOCAL COMMUNICATION AND INDIVIDUAL VARIATION IN BREEDING SOUTH AMERICAN SEA LIONS
Authors: Fernndez-Juricic Esteban , Campagna Claudio , Enriquez Victor , Ortiz Charles Leo 
Published: July 2002

AbstractThe purpose of this study was to analyse the structure, social contexts, and individual variation of South American sea lion (Otaria flavescens) airborne vocal communication during the breeding season. This is the first comprehensive analysis of the vocal repertoire of this species. Since breeding colonies are complex acoustic environments, we expect that male, female, and pup vocalizations would show individuality, and that individual variation would rely on several acoustic traits. We identified four calls for adult males: high pitched call or HPC (aggressive interactions, such as attack and retreat displays, and fights), bark (aggressive interactions, territory establishment, and usually combined with growls), growl (male-female interactions), and exhalation (after agonistic encounters); and two for adult females: mother primary call or MPC (female-pup interactions, such as after birth, during pup separation, and pup development), and grunt (agonistic interactions between females). Juveniles vocalized yearling primary calls or YPC (searching for their mothers or after being threatened by females), pups gave pup primary calls or PPC (in response to MPCs, when hungry, searching for their mothers, if nursing was interrupted, or when trying to nurse). Our results suggest that male's HPC and bark, female's MPC, and pup's PPC have acoustic features that support individuality. These calls are associated with contexts in which recognition of neighbours (HPC and bark) or relatives (MPC and PPC) may confer a relative advantage in reproductive performance. Individual variation depended on frequency, temporal, and intensity traits; such multi-trait individuality could be regarded as an adaptation to colonial life to overcome the high noise levels within pinniped breeding colonies.
Trans-specific nematicidal activity of Photorhabdus luminescens
Authors: Han Richou , Ehlers Ralf-Udo 
Published: July 2002

Abstract
Mixed culture filtrates of Photorhabdus luminescens isolated from
Heterorhabditis bacteriophora H06 and from H. indica LN2 had a toxic effect
on axenic H. bacteriophora H06 dauer juveniles. Single culture filtrates had
no effect. When one filtrate originated from a secondary phase culture, the
toxic effect was lost. Heat treatment of one of the filtrates to 80°C
destroyed the effect. The toxin is probably synthesized de novo after mixing
the culture supernatants of these two P. luminescens symbionts. Dilution of
the filtrate reduced the effect, and it was lost when P. luminescens was
cultured for more than two days. Steinernema carpocapsae A24 was not
affected by the mixture, and was affected only by the filtrate of primary
phase P. luminescens H06. The toxic effect was recorded also when axenic
dauer juveniles of H. bacteriophora were inoculated into a mixed bacterial
culture of H06 and LN2. Inoculating monoxenic dauer juveniles of H.
bacteriophora H06 into P. luminescens LN2 or into mixtures containing LN2
bacteria resulted in significant dauer juvenile mortality. These
manifestations of the interaction of bacteria to produce toxic effects on
the non-symbiotic nematode (trans-specific activity) may have an impact on
competitive interactions when one insect host is infected by different
nematode species. Eine transspezifische nematizide Aktivitat von
Photorhabdus luminescens - Eine Mischung der Kulturfiltrate des Bakteriums
Photorhabdus luminescens, isoliert aus Heterorhabditis bacteriophora H06 mit
dem Filtrat des Symbionten aus H. indica LN2 wirkt toxisch auf axenische
Dauerlarven von H. bacteriophora H06. Die einzelnen Kulturfiltrate zeigten
keine Wirkung. Sofern ein Filtrat einer Sekundarformkultur entnommen wurde,
konnte kein Effekt erzielt werden. Eine Hitzebehandlung bei 80°C zerstorte
die Wirkung. Das Toxin wird wahrscheinlich de novo synthetisiert in dem
Moment, in dem die Kulturfiltrate dieser P. luminescens Symbionten gemischt
werden. Eine Verdunnung der Filtrate reduzierte die Wirkung. Sie ging ganz
verloren, wenn P. luminescens langer als zwei Tage kultiviert wurde. Die
Mischung hatte keine Wirkung auf axenische Steinernema carpocapsae. Dieser
Nematode wurde nur durch Filtrate der Primarform von P. luminescens H06
abgetotet. Die toxischen Effekte wurden auch festgestellt, wenn axenische
Dauerlarven von H. bacteriophora in Gemische von H06 und LN2
Bakterienkulturen inokuliert wurde. Bei Inokulation von monoxenischen
Dauerlarven von H. bacteriophora H06 in P. luminescens LN2 oder in Gemische,
die LN2 enthielten, wurde ebenfalls eine gesteigerte Mortalitat
festgestellt. Dieses Deutlichwerden von Wechselbeziehungen zwischen den
Bakterien bei Erzeugung toxischer Effekte auf den nicht-symbiontischen
Nematoden (trans-spezifische Aktivitat) konnte eine Auswirkung auf die
Konkurrenz bei Koinfektion eines Wirtsinsekts mit zwei Nematodenarten
haben.
Textural and structural modifications of saponite from Cerro del Aguila by acid treatment
Authors: Suárez Barrios M. , de Santiago Buey C. , García Romero E. , Martín Pozas J. M. 
Published: July 2002

AbstractThe physicochemical properties of clays can be modified by acid treatment with inorganic acids. This treatment is usually referred to as ‘acid activation’, because it increases the specific surface area and the number of active sites of the solids. In the present study, the acid activation of saponite from Cerro del Aguila (Madrid, Spain) with HCl solutions was measured. Illite, quartz and small amounts of feldspar were found as impurities in the raw saponite.Acid treatments were carried out with different concentrations of HCl solutions. The samples obtained were characterized by mineralogical and chemical analyses, XRD, FT-IR spectroscopy, N2 adsorption-desorption isotherms and TEM. The acid attack, under the conditions employed, produced a progressive destruction of the structure of saponite by partial dissolution of the octahedral Mg(II) cations. Amorphous silica coming from the tetrahedral sheet of saponite was generated. The specific surface area of the most intensely treated sample (2.5% for 24 h) was doubled with respect to that of natural saponite. This increase in the surface area is due to the increase in both the external and internal surface areas.
An application of profile fitting and CLAY++ for the quantitative representation (QR) of mixed-layer clay minerals
Authors: Aparicio P. , Ferrell R. E. 
Published: July 2002

AbstractClay mineral quantification by XRD is difficult when mixed-layer clay minerals and discrete clay types are both present. New procedures for peak decomposition and pattern simulation offer increased opportunities to obtain mineral abundance estimates. This proposed methodological sequence, for quantitative representation (QR) of complex clay samples, involves: (1) determination of layer type, mixed-layer proportion and order (R); (2) simulation of XRD patterns using MULCALC, an adaptation of NEWMOD; and (3) interpretation of the clay assemblage by fitting the whole pattern with CLAY++, a statistical program. The product is a QR of individual phases or a summation of layer types. The absence of quantitative reference standards means results cannot be checked for accuracy, but the statistical fit is highly reproducible and less prone to operator error. The QRs may be obtained with simulated or actual reference mineral patterns in the database. Results for freshwater marsh samples illustrate the approach.
Layer-charge evaluation of expandable clays from a chronosequence of podzols in Finland using an alkylammonium method
Authors: Gillot F. , Righi D. , Räisänen M. L. 
Published: July 2002

AbstractSmectites from the E horizon of podzols dated at 1200–10,000 y in central and northern Finland were studied. Clay minerals in the fine (<0.1 μm) and coarse (0.1–2 μm) fractions were examined by X-ray diffraction. The distribution (octahedral or tetrahedral) and magnitude of the layer charge of expandable minerals were estimated using intercalation of alkylammonium ions (nC = 12) associated with the Hofmann & Klemen effect. In addition, charge alteration following desaturation (H+exchange) and autotransformation was investigated. Smectites from the E horizons of podzols are not homogeneous but constitute a mixture of several populations with various layer charges. Smectites with lower layer charge are present in podzols having a longer effective time of pedogenesis, suggesting alteration of the high-charge smectites with time. Experimental alteration of the smectites by autotransformation shows that a decrease of the layer charge is easily produced by desaturation of the smectite clays.
Structure and dynamics of silicate glasses and melts
Authors: Farnan I. , Dove M. T. 
Published: July 2002

A one-day meeting was held in the Department of Earth Sciences, University of Cambridge, on the theme of the ‘Structure and Dynamics of Silicate Glasses and Melts’. The meeting was sponsored by the Mineral Physics group of the Mineralogical Society, and was attended by ∼80 people. The objective of the meeting was to bring together experts from the glass community with members of the mineralogical community who are interested in glasses and melts. The scope of the talks considered structural details over length scales from nearest-neighbour coordinations up to 1–2 nm, and dynamics in both the slow relaxational and fast vibrational ranges. The talks also covered both experimental (particularly neutron scattering and NMR) and computer simulation methods.The meeting was organized into three groups of themes, namely structure and dynamics in glasses, structure and dynamics in melts, and vibrational dynamics in glasses.
Annealing experiments on CO2-bearing jadeite glass: an insight into the true temperature dependence of CO2 speciation in silicate melts
Authors: Morizet Y. , Kohn S. C. , Brooker R. A. 
Published: July 2002

AbstractThe thermodynamics and kinetics of CO2 speciation in silicate melts have been studied by measuring the concentration of CO2mol and carbonate in jadeite glass annealed at 575, 450 and 400°C. Assuming that the reaction is1where CO2mol..Obr represents a CO2 molecule weakly bonded to a bridging oxygen in the network and CO3 represents a bridging carbonate group with no net negative charge, ΔH for the reaction is –17 (+4/–8) kJ mol−1 and ΔS is –24 (+6/–9) J K−1 mol−1. The rate of equilibration of the species was measured at each temperature and the rate constants were deduced. The temperature dependence of the rate constants was used to determine the activation energy of the forward and reverse reactions which are 68 (+3/–31) kJ mol−1 and 86 (+1/–69) kJ mol−1 respectively. The data suggest that CO2mol may be much more abundant in silicate melts than previously assumed on the basis of studies of CO2-bearing glasses. Models of solubility, diffusion, and isotope fractionation should take this into account.
The petrology and petrogenesis of the North Motzfeldt Centre, Gardar Province, South Greenland
Authors: Finch A. A. , Goodenough K. M. , Salmon H. M. , Andersen T. 
Published: July 2002

AbstractNorth Motzfeldt is an intrusive igneous centre within the Igaliku (formerly spelt Igaliko) complex, Gardar Province, South Greenland. A detailed field description of the centre is given, with preliminary geochemical and isotopic data. The North Motzfeldt centre is intruded into Ketilidian granitoid basement rocks, and current exposure retains parts of the original roof against earlier Gardar eruptives and clastic sediments of the Eriksfjord formation. The unconformity between the Ketilidian and the overlying Eriksfjord is believed to have been crucial in the siting of the centre. The centre is subdivided into two major units, NM1 and NM2. This was followed by significant peralkaline nepheline microsyenite in sheets, characterized by rare element-rich accessory minerals including rinkite-mł sandrite, pyrochlore and låvenite. A significant microsyenite body is called NM3. A preliminary Rb-Sr isochron of 1226±27 Ma indicates a far younger age for the centre than previously thought (~;1350 Ma). Cross-cutting relationships between North Motzfeldt and rocks of the adjacent Motzfeldt centre require a reappraisal of the chronology of Motzfeldt magmatism. We suggest that rocks previously believed to comprise the Motzfeldt centre represent the products of multiple phases of magmatism from Early- to Mid-Gardar times.
Fluid processes during the exhumation of high-P metamorphic belts
Authors: Miller J. A. , Buick I. S. , Cartwright I. , Barnicoat A. 
Published: July 2002

AbstractFluids can play a direct role in exhumation by influencing exhumation mechanisms and the driving processes for these mechanisms. In addition, the process of exhumation leads to the development of fluid-related features that in themselves may not drive exhumation. Fluids involved in exhumation are generally derived from dehydration reactions occurring during decompression, but at shallower crustal levels may also involve the introduction of exotic fluids. The composition of fluids attending exhumation are generally saline – CO2 mixtures, but N2, CH4, H2O mixtures have also been recorded. Studies of fluid features related to exhumation have found that fluids may contribute to density changes and the initiation of partial melting during decompression, as well as the development of extensive vein systems. However, the preservation of geochemical signatures related to fluid processes occurring prior to high-P and ultrahigh-P metamorphism indicates that large-scale pervasive fluid flow systems, in general, do not operate at any stage during the exhumation history. Large-scale channelled fluid flow may have operated in detachment faults and shear zones related to exhumation, and this requires further study. The most significant role of fluids during exhumation appears to be their controlling influence on the preservation of high-P or ultrahigh-P rocks.
Manganvesuvianite and tweddillite, two new Mn3+-silicate minerals from the Kalahari manganese fields, South Africa
Authors: Armbruster T. , Gnos E. , Dixon R. , Gutzmer J. , Hejny C. , Döbelin N. , Medenbach O. 
Published: July 2002

AbstractThe new minerals manganvesuviante and tweddillite, both formed by hydrothermal alteration of primary manganese ores, are described from the Kalahari manganese fields (Republic of South Africa). In addition, single-crystal X-ray structure refinements of both new minerals are presented.Manganvesuvianite is a tetragonal vesuvianite mineral with the simplified formula Ca19Mn3+(Al,Mn3+,Fe3+)10(Mg,Mn2+)2Si18O69(OH)9, characterized by Mn3+ occupying the five-coordinated position (square pyramid). The crystals simple prismatic forms: {100}, {110} terminated by {101} and exhibit deep maroon red colour. With polarized light the crystals are strongly pleochroic, yellowish parallel to E and dark red to lilac parallel to O.Tweddillite is an epidote-group mineral (space group P21/m, a = 8.932(5), b = 5.698(4), c = 10.310(5) Å, β = 114.56(4), V = 477.3(8) Å3) with the simplified formula CaSr(Mn3+,Fe3+)2Al[Si3O12](OH), closely related to strontiopiemontite. The difference between strontiopiemontite and tweddillite is the concentration of octahedral Mn3+. Strontiopiemontite has Mn3+ mainly on the M3 site whereas tweddillite has Mn3+ with minor Fe3+ on M3 and M1. Tweddillite forms aggregates of very thin dark red {001} blades characterized by striking pleochroism. The crystals appear dark red parallel to b and orange-yellow parallel to a. Perpendicular to (001) the blades appear magenta to red.
Decrespignyite-(Y), a new copper yttrium rare earth carbonate chloride hydrate from Paratoo, South Australia
Authors: Wallwork K. , Kolitsch U. , Pring A. , Nasdala L. 
Published: July 2002

AbstractDecrespignyite-(Y) is a new copper yttrium rare earth carbonate chloride hydrate from the Paratoo copper mine, near Yunta, Olary district, South Australia. Decrespignyite-(Y) occurs as blue crusts, coatings and fillings in thin fissures on the slatey country rock. Individual pseudohexagonal platelets are typically 10–50 µm in maximum dimension and are often curved. Associated minerals include caysichite-(Y), donnayite-(Y), malachite and kamphaugite-(Y). Electron microprobe and CHN analyses gave: Y2O3 42.2; La2O3 0.1; Pr2O3 0.1; Nd2O3 1.3; Sm2O3 1.0; Gd2O3 4; Tb2O3 0.4; Dy2O3 3.7; Ho2O3 2.6; Er2O3 2.5; CaO 0.5; CuO 10.9; Cl 3.0; CO2 19.8; H2O 10.8, yielding an empirical formula of (Y3.08Gd0.22Dy0.16Ho0.11Er0.10Nd0.06Sm0.05Tb0.02La0.02Pr0.01Ca0.08)∑3.91Cu1.12(CO3)3.70-Cl0.7(OH)5.79·2.4H2O. The simplified formula is (Y,REE)4Cu(CO3)4Cl(OH)5·2H2O. The mineral is royal blue to turquoise-blue in colour, transparent, with a pearly to vitreous lustre and a pale blue streak. No cleavage was observed but the morphology suggests that cleavage would be on [010]. The Mohs' hardness is estimated to be 4. The strongest lines in the X-ray powder pattern are {dobs (Iobs) (hkl)} 22.79 (30) (010); 7.463 (30) (001); 7.086 (50) (011); 6.241 (100) (021); 4.216 (30) (12); 3.530 (40) (022); 3.336 (30) (032); 2.143 (30) (222, 01). The powder diffraction pattern was indexed on a monoclinic cell with a = 8.899(6), b = 22.77(2), c = 8.589(6)Å, β = 120.06(5)°, V = 1506.3(7) Å3 and Z = 4. The structure of the new mineral could not be determined but powder diffraction data indicate the space group is P2, Pm or P2/m. The measured density is 3.64(2) g/cm3 and the calculated density is 3.645 g/cm3. Decrespignyite-(Y) is biaxial negative with α = 1.604(4) and γ = 1.638(3) with β very close to γ pleochroism is medium strong; X very pale bluish, Y and Z bluish (with greenish tint). Decrespignyite-(Y) is a supergene mineral which precipitated from mildly basic carbonated ground waters. The mineral is named after Robert Champion de Crespigny, a prominent figure in the Australian mining industry and chancellor of the University of Adelaide.
Accurate quantification of the modal mineralogy of rocks when image analysis is difficult
Authors: Schofield P. F. , Knight K. S. , Covey-Crump S. J. , Cressey G. , Stretton I. C. 
Published: July 2002

AbstractThe volume proportions of the mineral phases in two strongly deformed olivine-orthopyroxene rocks have been quantified by whole-pattern stripping of fixed geometry X-ray powder diffraction data. The results were compared with the phase proportions as determined by Rietveld refinement of time-of-flight neutron powder diffraction data, and were shown to be in excellent agreement. The X-ray technique not only provides a very rapid and cost-effective method of determining phase proportions, but it also circumvents several of the problems associated with obtaining this information by image analysis. Moreover, the technique is particularly advantageous in strongly textured rocks or in rocks that contain significant residual strains. As such it offers a powerful technique for analysing the mineralogical composition of fine-grained and/or deformed experimental run products, which makes it of considerable potential for monitoringin situthe progress of mineral reactions during laboratory experiments.