bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological Priming in Spanish Verb Forms: An ERP Repetition Priming Study
Authors: Rodriguez-Fornells Antoni , Münte Thomas F. , Clahsen Harald
Published: July 2002

The ERP repetition priming paradigm has been shown to be sensitive to the processing differences between regular and irregular verb forms in English and German. The purpose of the present study is to extend this research to a language with a different inflectional system, Spanish. The design (delayed visual repetition priming) was adopted from our previous study on English, and the specific linguistic phenomena we examined are priming relations between different kinds of stem (or root) forms. There were two experimental conditions: In the first condition, the prime and the target shared the same stem form, e.g., “ando—andar” [I walk—to walk], whereas in the second condition, the prime contained a marked (alternated) stem, e.g., “duermo— dormir” [I sleep—to sleep]. A reduced N400 was found for unmarked (nonalternated) stems in the primed condition, whereas marked stems showed no such effect. Moreover, control conditions demonstrated that the surface form properties (i.e., the different degree of phonetic and ortho-graphic overlap between primes and targets) do not explain the observed priming difference. The ERP priming effect for verb forms with unmarked stems in Spanish is parallel to that found for regularly inflected verb forms in English and German. We argue that effective priming is possible because prime target pairs such as “ando—andar” access the same lexical entry for their stems. By contrast, verb forms with alternated stems (e.g., “duermo”) constitute separate lexical entries, and are therefore less powerful primes for their corresponding base forms.
Spatial Processing and Hemispheric Asymmetry: Contributions of the Transient/Magnocellular Visual System
Authors: Roth Elizabeth Cowin , Hellige Joseph B.
Published: July 2002

Right-handed observers were presented with stimuli consisting of a line and two horizontally separated dots. A categorical spatial task required observers to indicate whether the dots were above or below the line, and a coordinate spatial task required observers to indicate whether the line could fit into the space between the two dots. For the coordinate task, reaction time was faster when the stimuli were presented to the left visual field (right hemisphere) than when the stimuli were presented to the right visual field (left hemisphere). The opposite hemispheric asymmetry was obtained for the categorical task. In addition, coordinate spatial processing took longer with stimuli presented on a red background than with stimuli presented on a green background. The opposite trend characterized categorical spatial processing. Because the color red attenuates processing in the transient/magnocellular visual pathway, these results suggest that coordinate spatial processing is more dependent on the transient/magnocellular pathway than is categorical spatial processing. However, manipulations of color condition had no effect on visual field (hemispheric) asymmetries, suggesting that the two hemispheres rely on the same visual information and on the same computational mechanisms as each other—although they do not always use that information with equal efficiency.
Categorical and Metric Spatial Processes Distinguished by Task Demands and Practice
Authors: Banich Marie T. , Federmeier Kara D.
Published: July 2002

In this study we examined Kosslyn's (1987) claim that the right hemisphere exhibits a relative superiority for processing metric spatial relations, whereas the left hemisphere exhibits a relative superiority for processing categorical spatial relations. In particular, we examined whether some failures to observe strong visual field (VF) advantages in previous studies might be due to practice effects that allowed individuals to process tasks in alternative manners (e.g., to process a metric task using a categorical strategy). We used two versions of a task previously employed by Hellige and Michimata (1989) in which individuals judge the metric (distance) or categorical (above/below) spatial relations between a bar and a dot. In one version, the position of the bar was held static. In another, the bar's position varied. This manipulation prevented participants from using the computer screen as a reference frame, forcing them to compute the spatial relationships on the basis of the relevant items only (i.e., the bar and the dot). In the latter, but not the former version of the task we obtained evidence supporting Kosslyn's hypothesis, namely, a significant right visual field (RVF) advantage for categorical spatial processing and a trend toward a left visual field (LVF) advantage for metric spatial processing. Furthermore, the pattern of results for trials on which information was presented centrally (CVF trials) was similar to that observed on RVF trials, whereas the pattern for trials in which identical information was presented in each visual field (BVF trials) was similar to that observed on LVF trials. Such a pattern is consistent with Kosslyn's suggestion that categorical processing is better suited for cells with small receptive fields and metric processing for cells with larger receptive fields.
Memory Lost and Regained Following Bilateral Hippocampal Damage
Authors: Henke Katharina , Kroll Neal E. A. , Behniea Hamraz , Amaral David G. , Miller Michael B. , Rafal Robert , Gazzaniga Michael S.
Published: July 2002

We present a longitudinal neuropsychological study (31 examinations over a period of 18 months) of patient DF. DF demonstrated bilateral atrophy of the hippocampal formation and globus pallidus resulting from carbon monoxide poisoning. Eighteen months after the event, the volume of the hippocampal formation was reduced by 42% on the left side and 28% on the right. The patient initially presented with a severe global amnesia. Then, he showed a gradual, yet selective recovery of episodic memory function. Verbal free recall and spatial memory performance remained reduced, whereas immediate word recall and recognition memory, as well as picture learning and memory, improved to levels at the lower range of normal performance. Interestingly, nonspatial associative learning was never much impaired and recovered completely by the end of testing. These data are taken as evidence that the human hippocampal formation does not equally support different forms of episodic memory.
Frontal Brain Activity during Episodic and Semantic Retrieval: Insights from Event-Related Potentials
Authors: Ranganath Charan , Paller Ken A.
Published: July 2002

Previous neuropsychological and neuroimaging results have implicated the prefrontal cortex in memory retrieval, although its precise role is unclear. In the present study, we examined patterns of brain electrical activity during retrieval of episodic and semantic memories. In the episodic retrieval task, participants retrieved autobiographical memories in response to event cues. In the semantic retrieval task, participants generated exemplars in response to category cues. Novel sounds presented intermittently during memory retrieval elicited a series of brain potentials including one identifiable as the P3a potential. Based on prior research linking P3a with novelty detection and with the frontal lobes, we predicted that P3a would be reduced to the extent that novelty detection and memory retrieval interfere with each other. Results during episodic and semantic retrieval tasks were compared to results during a task in which subjects attended to the auditory stimuli. P3a amplitudes were reduced during episodic retrieval, particularly at right lateral frontal scalp locations. A similar but less lateralized pattern of frontal P3a reduction was observed during semantic retrieval. These findings support the notion that the right prefrontal cortex is engaged in the service of memory retrieval, particularly for episodic memories.
Sampling Properties of the Spectrum and Coherency of Sequences of Action Potentials
Authors: Jarvis M. R. , Mitra P. P.
Published: July 2002

The spectrum and coherency are useful quantities for characterizing the temporal correlations and functional relations within and between point processes. This article begins with a review of these quantities, their interpretation, and how they may be estimated. A discussion of how to assess the statistical significance of features in these measures is included. In addition, new work is presented that builds on the framework established in the review section. This work investigates how the estimates and their error bars are modified by finite sample sizes. Finite sample corrections are derived based on a doubly stochastic inhomogeneous Poisson process model in which the rate functions are drawn from a low-variance gaussian process. It is found that in contrast to continuous processes, the variance of the estimators cannot be reduced by smoothing beyond a scale set by the number of point events in the interval. Alternatively, the degrees of freedom of the estimators can be thought of as bounded from above by the expected number of point events in the interval. Further new work describing and illustrating a method for detecting the presence of a line in a point process spectrum is also presented, corresponding to the detection of a periodic modulation of the underlying rate. This work demonstrates that a known statistical test, applicable to continuous processes, applies with little modification to point process spectra and is of utility in studying a point process driven by a continuous stimulus. Although the material discussed is of general applicability to point processes, attention will be confined to sequences of neuronal action potentials (spike trains), the motivation for this work.
Analysis and Neuronal Modeling of the Nonlinear Characteristics of a Local Cardiac Reflex in the Rat
Authors: Vadigepalli Rajanikanth , Doyle Francis J. , Schwaber James S.
Published: July 2002

Previous experimental results have suggested the existence of a local cardiac reflex in the rat. In this study, the putative role of such a local reflex in cardiovascular regulation is quantitatively analyzed. A model for the local reflex is developed from anatomical experimental results and physiological data in the literature. Using this model, a systems-level analysis is conducted. Simulation results indicate that the neuromodulatory mechanism of the local reflex attenuates the nonlinearity of the relationship between cardiac vagal drive and arterial pressure. This behavior is characterized through coherence analysis. Furthermore, the modulation of phase-related characteristics of the cardiovascular system is suggested as a plausible mechanism for the nonlinear attenuation. Based on these results, it is plausible that the functional role of the local reflex is highly robust nonlinear compensation at the heart, which results in less complex dynamics in other parts of the reflex.
The Scratch Orchestra and Visual Arts
Authors: Parsons Michael
Published: July 2002

The Scratch Orchestra, formed in London in 1969 by Cornelius Cardew, Michael Parsons and Howard Skempton, included visual and performance artists as well as musicians and other participants from diverse backgrounds, many of them without formal training. This article deals primarily with the earlier phase of the orchestra's activity, between 1969 and 1971. It describes the influence of the work of John Cage and Fluxus artists, involving the dissolution of boundaries between sonic and visual elements in performance and the use of everyday materials and activities as artistic resources. It assesses the conflicting impulses of discipline and spontaneity in the work of the Scratch Orchestra and in the parallel activity of the Portsmouth Sinfonia and other related groups. The emergence in the early 1970s of more controlled forms of compositional activity, in reaction against anarchic and libertarian aspects of the Scratch Orchestra's ethos, is also discussed.
Critical Art Ensemble, Tactical Media Practitioners
Authors: McKenzie Jon , Schneider Rebecca
Published: July 2002

The Critical Acts Ensemble, CAE for short, is a tightly knit group of artists exploring intersection between art, technology, critical theory, and political activism. We have given CAE a big chunk of space to present and explain their work. Added to that is a critical essay by TDR Contributing Editor Rebecca Schneider.
Multiring Fiducial Systems for Scalable Fiducial-Tracking Augmented Reality
Authors: Cho Youngkwan , Neumann Ulrich
Published: July 2002

In augmented reality (AR), a user can see a virtual world as well as the real world. To avoid registration problems between the virtual world and the real world, the user's viewing pose in both worlds should be kept the same. Fiducial-tracking AR is an attractive approach to the registration problem. However, most of the developed fiducialtracking AR systems have restricted workspaces. To provide a wide range of workspaces (from a small-scale desktop space to a large-scale space) and a wide range of views (from far views to detailed views), an AR system should have scalability.

In this paper, we present multiring color fiducial systems and a real-time fiducial detection method for scalable fiducial-tracking AR. We analyze the optimal ring width and develop formulas to obtain the optimal fiducial set with applicationspecific inputs. We develop a real-time ring-detection method that converts the five-DOF ellipse-detection problem to a series of simple steps with a 1-D segmentfilter and multithreshold segmentation. The results lead to a simple and inexpensive means of achieving scalable-area tracking for AR and an approach that is suitable as an optical tracking method for VR as well.
Complex Organization in Multicellularity as a Necessity in Evolution
Authors: Furusawa Chikara , Kaneko Kunihiko
Published: July 2002

By introducing a dynamical system model of a multicellular system, it is shown that an organism with a variety of differentiated cell types and a complex pattern emerges through cell-cell interactions even without postulating any elaborate control mechanism. Such an organism is found to maintain a larger growth speed as an ensemble, by achieving a cooperative use of resources, than do simple homogeneous cells, which behave “selfishly.” This suggests that the emergence of multicellular organisms with complex organization is a necessity in evolution. According to our theoretical model, there initially appear multipotent stem cells, which undergo stochastic differentiation to other cell types. With development and differentiation, both the chemical diversity and the complexity of intra-cellular dynamics are decreased, as a general consequence of our system. Robustness of the developmental process is also confirmed.
Four Puzzles About Life
Authors: Bedau Mark A.
Published: July 2002

To surmount the notorious difficulties of defining life, we should evaluate theories of life not by whether they provide necessary and sufficient conditions for our current preconceptions about life but by how well they explain living phenomena and how satisfactorily they resolve puzzles about life. On these grounds, the theory of life as supple adaptation gets support from the natural and compelling way it resolves the following four puzzles: (a) How are different forms of life at different levels of the vital hierarchy related? (b) Is there a continuum between life and nonlife? (c) Does life essentially concern a living entity's material composition or its form? (d) Are life and mind intrinsically connected?
DEUTERONOMISTIC ROYAL IDEOLOGY IN JUDGES 17–21
Authors: Mayes Andrew
Published: July 2002

The article contrasts two approaches to Judges 17–21, a historical-critical approach which studies the text as ideology, and a literary approach which treats the text within the framework of the Deuteronomistic History. The literary study is given further refinement in the light of some recent literary theory, which distinguishes between different viewpoints expressed in a text, particularly those of the implied author and the narrator. Judges 17–21 is found to express different views of the monarchy which may be characterizd as those of the narrator and of the implied author. When these chapters are studied also by a historicalcritical approach it is clear that there is a conformity with the literary approach in that the sources of the Deuteronomistic History express the view of the narrator while the Deuteronomistic Historian's perspective is that of the implied author.
Schools Of Law And Historical Context: Re-Examining The Formation Of The Hanbalī Madhhab
Authors: Hurvitz Nimrod
Published: July 2002

Scholarly investigations of the formative stages of the madhāhib (schools of law) have generated several interpretations but few substantive studies. One of the underlying assumptions of madhhab scholarship is that personal schools grew out of regional schools. In this essay, I (1) challenge the notion of regional schools, suggesting that greater attention should be paid to circles of masters and their disciples; (2) survey the scholarship that has dealt with the formation of Hanbalism, with special attention to Ibn Hanbal and his followers; and (3) examine how the Hanbalī moral outlook contributed to the growth of the Hanbalī circle and discuss the influence of this moral outlook on the internal dynamics of the circle.
DEVOIRS FISCAUX ET DROITS FONCIERS : LA CONDITION DES FELLAHS ÉGYPTIENS (13e-16e SIÈCLES)
Authors: Michel Nicolas
Published: July 2002

This paper sets out to reconsider the issue of the Egyptian fallāhs' conditions, by collecting the occurrences of the word fallāh in the administrative writings of the 12th-15th centuries and then rereading them in relation to two documents dating from the beginning of the Ottoman era: the Kānūnnāme-i Mısır (1525) and a partial copy of the 933/1527-1528 cadaster. Al-Maqrīzī asserted that the fallāhs' status had appeared at the beginning of the Ayyubid era, probably with the term itself of fallāh when the iqtā' was instituted in the rural areas; this study confirms his assertion. During the period under study, the word fallāh, used in its administrative meaning, signified the land-tax payer. Each year, the overall village tax was apportioned out between a few individuals who had been chosen according to their ability of relatively large tracts of arable lands. This paper examines three questions: were fallāhūn actually serfs who were bound to the glebe? Did they farm lands on behalf of state? Or did they exploit their own lands and enjoy the status of landowners? By studying the charges and duties weighing on the fallāhūn group, one is led to picture a more complex view of Egyptian rural society as well as of the policies implemented by the state in to ensure its fiscal income through the maintenance of effective land cultivation. Cet article se propose de reprendre la question de la condition des fellahs, en relevant les occurrences du terme fallāh dans la littérature administrative des 12e-15e siècles, et en les relisant à la lumière de deux documents du début de l'époque ottomane: le Kānūnnāme-i Mısır de 1525 et une copie partielle du cadastre de 933/1527-1528. L'étude confirme l'assertion d'al-Maqrīzī selon laquelle la condition du fallāh, et sans doute le terme même, apparurent au début de l'époque ayyoubide, avec l'instauration de l'iqtā' dans les campagnes. Dans son sens administratif, durant la période considérée le fallāh était le contribuable acquittant l'impôt foncier. La charge fiscale globale du village était répartie chaque année entre un petit nombre de personnes, choisies en fonction de leur capacité à mettre en valeur et à exploiter les terres arables, sur des superficies assez importantes. L'article examine trois questions: les fallāhūn étaient-ils des serfs attachés à la glèbe? cultivaient-ils des terres pour le compte de l'État? ou exploitaient-ils leurs propres terres, dont ils auraient été propriétaires? L'étude des charges et obligations pesant sur le groupe des fallāhūn conduit à un tableau plus complexe de la société rurale, comme des politiques mises en oeuvre par l'État pour assurer ses rentrées fiscales à travers le maintien de la mise en culture des terres.
IS THE RABSHAKEH ALSO AMONG THE PROPHETS? A RHETORICAL STUDY OF 2 KINGS XVIII 17-35
Authors: Rudman Dominic
Published: July 2002

Traditionally, discussion of the account of the siege of Jerusalem in 2 Kgs. xviii 13-xix 37 has focussed on historical or source-critical questions. This article approaches the account from a literary perspective, focussing in particular on the rhetorical content of Rabshakeh's speech to the defenders of Jerusalem in 2 Kgs. xviii 19-35 (//Isa. xxxvi 4-20). The Rabshakeh couches his mixture of threats, admonitions and promises in "prophetic" language, aiming thereby to make the Jerusalemites abandon their covenant with Yahweh to form a new one with Sennacherib. Thus, the narrator of the siege account depicts a confrontation between the Assyrian king as false god and Yahweh as true God, mediated by their respective "prophets", the Rabshakeh and Isaiah. Caught in the middle of these duelling antagonists is Hezekiah, whose choice will determine whether the remnant of Judah will remain Yahweh's people, or follow Israel into oblivion.
Behavioural responses by hatchling racers (Coluber constrictor) from two geographically distinct populations to chemical stimuli from potential prey and predators
Authors: Burghardt Gordon , Cooper William , Brown William
Published: July 2002

In experiments on responses to chemical food stimuli by previously unfed hatchlings from widely separated populations of the colubrid snake Coluber constrictor in the United States, strong responses were elicited by items important in the local diet. These differed between populations, suggesting that response has been adjusted to local diet by natural selection. Coluber constrictor priapus from South Carolina tongue-flicked at elevated rates to cues from lizards, snakes, and frogs, and bit only in response to a preferred lizard prey. They responded more strongly to the sympatric lizard Anolis carolinensis than to A. sagrei, an allopatric congener. Strong response to cues from the ophidiophagous snake Lampropeltis triangulum might reflect motivation for predator avoidance or for feeding, depending on relative snake sizes. Coluber constrictor mormon, for which insects and mammals are the most important foods, responded most strongly to stimuli from sympatric insects, mammals, and a lizard, as well as a bird.
MASKING BEHAVIOUR IN A COMMENSAL SHRIMP, METAPONTONIA FUNGIACOLA BRUCE, 1967 THAT USES THE SOFT TISSUES OF THE HOST CORAL (DECAPODA, PALAEMONIDAE, PONTONIINAE)
Authors: Yamashiro Hideyuki
Published: July 2002

Masking behaviour was observed in a commensal pontoniine shrimp, Metapontonia fungiacola, living on the discs of fungiid corals (Scleractinia, Fungiidae). When the coral was disturbed, the shrimp moved to and situated itself between the coral septa, and then performed masking behaviour. The shrimp thus hid itself under host tissues by "hooking" soft tissues of the coral with the dactyli of three pairs of pereiopods (i.e., the third to the fifth) in such a way, that these approached each other on the shrimp's back, like drawing curtains. Le comportement de camouflage a ete observe chez la crevette commensale Pontoniinae, Metapontonia fungiacola, vivant sur les disques de coraux Fungiidae (Scleractinia). Quand ces derniers sont inquietes, la crevette vient se placer entre les cloisons coralliaires et developpe alors son comportement de camouflage. La crevette se cache sous les tissus mous de l'hote en s'y accrochant a l'aide des dactyles de trois paires de pereiopodes (troisieme a cinquieme paire) de telle facon que lorsqu'ils se rapprochent, les tissus se referment comme si on tirait des rideaux.
Early development of nematode embryos: differences and similarities
Authors: Schierenberg Einhard
Published: July 2002

To determine whether embryogenesis of Caenorhabditis elegans is typical for nematodes in general, we started to analyse in comparison several aspects of development in various nematode species. The differences we observed can be subdivided into two classes, those visible in the intact embryo and those requiring experimental interference. Particularly obvious differences of both types were revealed between C. elegans (Rhabditidae) and Acrobeloides nanus (Cephalobidae). Not only does the spatial and temporal pattern of early events differ but also that of intercellular communication and cell specification. Our data suggest that some developmental variations are characteristic for certain nematode groups and therefore may be useful as phylogenetic markers. In contrast, we detected little evidence so far for environmental influence on early developmental processes. Pour déterminer dans quelle mesure l’embryogenèse de Caenorhabditis elegans est une caractéristique générale des nématodes, nous avons commencé l’analyse de plusieurs aspects du développement chez différentes espèces de nématodes. Les différences observées peuvent être divisées en deux catégories: celles observables chez l’embryon intact et celles nécessitant une intervention expérimentale. En particulier, des différences nettes entre les deux catégories ont été mises en évidence chez C. elegans (Rhabditidae) et Acrobeloides nanus (Cephalobidae). Diffèrent non seulement le schéma spatio-temporel des évènements précoces, mais également la communication intercellulaire et la différenciation cellulaire. Nos données suggèrent que certaines variations du développement sont caractéristiques de certains groupes de nématodes et pourraient donc être utiles comme marqueurs phylogénétiques. A contrario, une influence de l’environnement sur les processus précoces du développement n’a pas, jusqu’à présent, été détectée.
Development of the entomopathogenic nematode Heterorhabditis megidis strain NLH-E 87.3 in Galleria mellonella
Authors: Boff Mari , Smits Peter , Gerritsen Lonne , Wiegers Gerrie
Published: July 2002

Increasing densities of Heterorhabditis megidis strain NLH-E 87.3 infective juveniles (IJ) affected invasion, reproduction, length and time to first emergence of the nematodes in larvae of the greater wax moth, Galleria mellonella. Although the number of nematodes that invaded the host increased with increasing dose, percentage of invasion declined. The number of progeny produced per host initially increased with dose. The highest production of IJ per cadaver was reached at a dose of 300 IJ per host, at that dose 62 ± 3.4 IJ were established per cadaver. Production decreased again significantly at higher densities. The smallest IJ were produced at a dose of 1000 IJ per host and the largest at a dose of 300 IJ per host. Time to first emergence of juveniles was generally shorter when the number of IJ inoculated was large (300-3000 IJ/host).Des densités croissantes de juvéniles infestants (IJ) d'Heterorhabditis megidis souche NLH-E 87.3 ont affecté la pénétration, la reproduction, la longueur du corps et la date de la première émergence des nématodes des larves de Galleria mellonella. Bien que le nombre de nématodes ayant pénétré dans l'hôte ait augmenté avec l'inoculum, le pourcentage de pénétration a décru. L'importance de la descendance produite par hôte a initialement augmenté avec l'inoculum. La production la plus forte d'IJ par cadavre a été atteinte à un taux d'inoculum de 300 IJ par hôte; à ce taux d'inoculum, 62 ± 3.4 IJ par cadavre avaient pénétré. La production d'IJ a de nouveau diminué significativement aux taux d'inoculum plus élevés. Les IJ les plus petits ont été obtenus au taux d'inoculum de 1000 IJ par hôte. Le temps écoulé jusqu'à la première sortie des juvéniles hors de l'insecte a été généralement plus court lorsque le taux d'inoculum était élevé (300-3000 IJ/hôte).
Longidorus dalmassoi sp. n. (Nematoda: Dorylaimoidea) from France
Authors: Peneva Vlada , Loof Pieter A.A. , Brown Derek J.F.
Published: July 2002

A description is provided of Longidorus dalmassoi sp. n., a bisexual species
associated with grasses in France. The species is characterised by a body
length of 6.9-7.8 mm, slightly expanded and anteriorly flattened head
region, symmetrically bilobed amphidial pouches, long odontostyle (152-163
mu m), spear guiding system with compensation sacks, conoid tail (39-52.5 mu
m) with narrow, rounded terminus, males with short spicules (50-51 mu m) and
a row of 15 or 16 supplements. Longidorus dalmassoi sp. n. (Nematoda:
Longidoridae) provenant de France - Description est donnee de Longidorus
dalmassoi sp. n., espece bisexuee associee a une vegetation herbacee, en
France. Cette espece est caracterisee par une longueur du corps de 6,9-7,8
mm, une extremite anterieure legerement elargie et aplatie a l'avant, des
poches amphidiennes symetriques et bilobees, un odontostyle long (152-163 mu
m), un systeme de guidage du stylet comportant des sacs de compensation, une
queue conoide (39-52,5 mu m) a extremite etroite et arrondie, des males a
spicules courts (20-51 mu m) et pourvus d'une rangee de 15 ou 16
supplements.
National Mythologies and Ethnic Cleansing: The Expulsion of Czechoslovak Germans in 1945
Authors: Glassheim Eagle
Published: July 2002

Beginning in January of 1946, trains filled with Sudeten Germans—forty wagons, thirty passengers per wagon—left Czechoslovakia daily for the American Zone of occupied Germany. By the end of 1946, the Czechoslovak government completed the “organized transfer” of almost 2 million Germans, and it did so in a manner that in many respects fulfilled the mandate of the Potsdam agreement that the resettlement be “orderly and humane.” But a focus on these regularized trainloads of human cargo obscures the extent of the humanitarian disaster facing Germans during the summer months of 1945, immediately after the Nazi capitulation. By the end of 1945, Czech soldiers, security forces, and local militias had already expelled over 700,000 Sudeten Germans to occupied Germany and Austria. As many as 30,000 Germans died on forced marches, in disease-filled concentration camps, in summary executions, and massacres.
Geological factors controlling clay mineral patterns across the Cretaceous-Tertiary boundary in Mediterranean and Atlantic sections
Authors: Ortega M. , Palomo I. , Martinez F. , Gonzalez I.
Published: July 2002

The clay mineral associations in the Cretaceous-Tertiary Boundary (KTB) and in the Danian and Maastrichtian levels of sections from the Mediterranean and the Atlantic Domains have been studied. The Mediterranean sections have a single mineral association consisting of smectiteiltite and kaolinite, whereas the Atlantic sections have several associations: illite-chlorite, illite-R1 I-S-kaolinite and illite-R 1 I-S-chlorite. Data are presented relating to the influence of K-feldspars and Fe oxide sphemles on the clay mineral associations. Study of rare-earth elements shows that regional geological factors affect the clay mineralogy of the KTB, examples showing significant anthigenesis in the Mediterranean sections, and important detrital supply in all the Atlantic sections. We propose that the KTB studied in these marine sections is equivalent to the uppermost layer of the two-layered clay unit originating in a cloud of a vapourized bolide. Regional tectonic conditions have been responsible for differences in clay sedimentation in these geological domains and among the stratigraphic sections of the Atlantic Domain.
Effect of heating and acid pre-treatment on pore size distribution of sepiolite
Authors: Balci S.
Published: July 2002

Due to its channels of molecular dimensions and a high specific surface area, sepiolite has many industrial applications which require high resistance to thermal effects in addition to a large surface area. On heating, sorbed water molecules are removed causing changes in the pore size distribution. In this study, the effects of thermal treatment on the pore structure of sepiolite and the acid-treated sepiolite samples were investigated. The solid density of sepiolite, measured by a He displacement technique, was 2.08 g cm-3 and total porosity was ~0.58. Both of these values showed an increase at 100°C, then decreased with further temperature increase due to crystal deformation and channel plugging which occurred at elevated temperatures. The BET surface area of the original sepiolite was 148 m2 g-1, and increased to 263 m2 g-1 at 100°C and then started to decrease. Approximately 16% of the total volume was in the micropores at 100°C. The acid pre-activation caused restrictions in possible crystal deformation during thermal treatment. The micropore volume increased to 20% and BET surface area reached values >500 m2 g-1 for the acid-treated samples.
Iron-rich saponite: dissolution reactions and Cr uptake
Authors: Brigatti M. F. , Lugli C. , Poppi L. , Venturelli G.
Published: July 2002

To gain a deeper understanding of the geochemical processes involved in the interactions between ionic solutions and clay minerals in natural systems, the dissolution rate of an Fe-rich saponite from Mt. Prinzera (Taro Valley, Italy) was measured as a function of pH and time at 25°C. Also, its ability to adsorb Cr was studied at varying metal concentrations (3.22, 5.50, 8.50 mEq l-1) and with different competing anions (CH3COO-, Cl-, NO3-). It was found that there is a correlation between the experimentally determined release rate constant (k), as defined by the relase of Si, and pH. In acidic solutions, the k values correlate negatively with pH, whereas the opposite occurs for basic solutions. The extent of Cr uptake was measured by analysis of the liquid portion separated by centrifugation after a controlled period of exposure. The Cr adsorbed for different concentrations and anionic environments shows the dependence of Cr uptake on the initial metal concentration and on accompanying anions in the order CH3COO-, Cl-, NO3-.
A fluid inclusion study of an amethyst deposit in the Cretaceous Kyongsang Basin, South Korea
Authors: Yang K. H. , Yun S. H. , Lee J. D.
Published: July 2002

The Eonyang amethyst deposit is thought to be spatially and temporally associated with the biotite granite of the Cretaceous Kyongsang Basin, South Korea. The euhedral quartz crystals in cavities in the aplite which intrudes biotite granite are colour-zoned from white at the base to amethystine at the top. Fluid inclusions from rock-forming quartz in granitic rocks and euhedral quartz crystals in cavities were examined. Three types of primary inclusions were observed and three isochores for inclusions representing each type are constructed to constrain the trapping conditions and fluid evolution involved during the formation of the amethyst. The intersection of the isochore representing the early fluid inclusions with solidus temperature of the host granite indicates initial quartz formation at ~600°C and 1.0–1.5 kbar. Intermediate quartz formation, associated with the high-salinity inclusions, occurred at somewhat lower temperatures (400°C) and pressures of ~1 kbar. The amethystine quartz formed from H2O–CO2–NaCl fluids at temperatures between 280 and 400°C, and pressures of ~1 kbar. Based on the texture and mineralogy of host minerals and on the fluid inclusion characteristics, the euhedral quartz began growing at near solidus conditions of the granite and the pressure did not vary significantly until the end of crystallization of amethystine quartz crystals in cavities. Early quartz in cavities formed from moderately saline fluids that either exsolved from or were in equilibrium with the granite, whereas the amethystine quartz apparently grew from fluids of at least partial sedimentary origin. The granite crystallized at considerable depth under relatively low water pressures probably in the root zones of porphyry-type systems. Hydrothermal activities, fluid compositions and erosion factors combined to provide favourable conditions for the formation of the Eonyang amethyst deposit and its presence near the Earth's surface today.
Differentiation of natrocarbonatite magma at Oldoinyo Lengai volcano, Tanzania
Authors: Gittins J. , Jago B. C.
Published: July 2002

Natrocarbonatite magma, erupted as lava flows in the Tanzanian volcano Oldoinyo Lengai in June and November of 1988, has evolved chemically since its formation. The June and November flows of 1988 display increasing Cl, F, Ba, K, Mg and Mn, concomitantly with Na, Ca and P depletion. Furthermore, the June magma, at the time of eruption, had higher Cl, F, Ba and K contents and lower Ca than the November magma and evolved to higher levels of Cl, F, Ba and K content and lower Ca, Na and P. The mineralogy of the lavas reflects these trends. Crystallization of fluorite and halite–sylvite solid solution, usually as a symplectic intergrowth, occurs when Cl and F concentrations reach the critical value necessary to stabilize both minerals and explains why neither occurs as a phenocryst phase. Natrocarbonatite magma has undergone considerable and rapid magmatic evolution, probably in small and separate magma chambers. Two minerals, nyerereite and gregoryite, have dominated the crystallization history of natrocarbonatite magma, and many lavas are phenocryst-rich. However, because most of the lavas are composed principally of these two minerals, crystal accumulation has not greatly changed their composition and, consequently, we suggest that the bulk composition of the lavas closely approximates that of the parental magma.
Interleukin-6 dimers produced by endothelial cells inhibit apoptosis of B-chronic lymphocytic leukemia cells
Authors: Moreno Ana , Villar Marı́a Luisa , Cámara Carmen , Luque Rosario , Cespón Constantino , González-Porqué Pedro , Roy Garbiñe , López-Jiménez Javier , Bootello Alfredo , Santiago Ernesto Roldán
Published: July 2002

Tumoral lymphocytes from patients with B-chronic lymphocytic leukemia (B-CLL) are long-lived cells in vivo, but they die rapidly by apoptosis in vitro. Here, it is reported that endothelial cells (ECs) inhibit the apoptosis of B-CLL cells, as determined by 4 different flow cytometric methods, and that this antiapoptotic effect is mediated mainly by soluble factor(s), as can be deduced from the following findings. First, EC-conditioned medium (ECCM) inhibited the apoptotic rate in B-CLL to approximately 50% of control. Second, the antiapoptotic effect mediated by EC/B-CLL cell contact was more apparent than real; using a fluorescence-based phagocytosis assay, it was demonstrated that this effect was due to the phagocytic capacity of ECs, which internalized apoptotic cells. Third, the protective effect of ECCM was associated neither with proliferation nor differentiation signals. Fourth, the survival factor was a dimeric form of IL-6 because anti–IL-6 antibodies completely neutralized the antiapoptotic effect mediated not only by the crude ECCM but also by the 45- to 55-kd active fractions obtained after gel filtration, which contained high levels of IL-6. These IL-6 dimers (IL-6D) were noncovalently associated. Sixth, human recombinant IL-6D(hrIL-6D) inhibited B-CLL apoptosis, whereas hrIL-6 monomers (hrIL-6M) did not. Binding and functional competition experiments showed not only that monomers and dimers had similar affinity for the IL-6R, but also that hrIL-6Minhibited the antiapoptotic activity of hrIL-6D. These data suggest that IL-6D derived from ECs promote the survival of B-CLL cells.
Inhibitory effect of the mi transcription factor encoded by the mutant mi allele on GA binding protein–mediated transcript expression in mouse mast cells
Authors: Morii Eiichi , Ogihara Hideki , Oboki Keisuke , Sawa Chika , Sakuma Takahiko , Nomura Shintaro , Esko Jeffrey D. , Handa Hiroshi , Kitamura Yukihiko
Published: July 2002

The mi transcription factor (MITF) is a basic-helix-loop-helix leucine zipper (bHLH-Zip) transcription factor that is important for the development of mast cells. Mast cells ofmi/mi genotype express normal amounts of abnormal MITF (mi-MITF), whereas mast cells of tg/tg genotype do not express any MITFs. The synthesis of heparin is abnormal in the skin mast cells of mi/mi mice. Because N-deacetylase/N-sulfotransferase 2 (NDST-2) is essential for the synthesis of heparin, the amount of NDST-2 messenger RNA (mRNA) was compared among cultured mast cells (CMCs) of +/+,mi/mi, and tg/tg genotypes. The NDST-2 mRNA was detected by in situ hybridization in the skin mast cells of +/+ andtg/tg mice, but not in the skin mast cells ofmi/mi mice. The amount of NDST-2 mRNA decreased significantly in CMCs derived from mi/mi mice when compared to the values of +/+ and tg/tg mice, suggesting that the defective form of MITF inhibited the expression of the NDST-2 transcript. The expression of NDST-2 transcript was mediated by the GGAA motif located in the 5′-untranslated region. GA binding protein (GABP) bound the GGAA motif and increased the amount of NDST-2 transcript. The mi-MITF appeared to inhibit the ability of GABP to express NDST-2 transcript by disturbing its nuclear localization. This is the first study to show that expression of an abnormal form of a bHLH-Zip transcription factor can dramatically alter the intracellular location of another DNA/RNA binding factor, which in turn brings about profound and unexpected consequences on transcript expression.
Effect of the PlA2 alloantigen on the function of β3-integrins in platelets
Authors: Bennett Joel S. , Catella-Lawson Francesca , Rut Andrew R. , Vilaire Gaston , Qi Weiwei , Kapoor Shiv C. , Murphy Scott , FitzGerald Garret A.
Published: July 2002

The polymorphism responsible for the PlA2 alloantigen on the β3-component of β3-containing integrins is reported to be a risk factor for coronary thrombosis. This study examined the effect of PlA2 on the function of β3-integrins using platelets from subjects homozygous and heterozygous for PlA1 and PlA2. There was overlap in the distribution of the dissociation constant (Kd) and maximum fibrinogen binding (Bmax) values for fibrinogen binding to αIIbβ3 on platelets from PlA1 and PlA2 homozygotes and PlA1/PlA2 heterozygotes. However, whereas there was no statistical difference in these values for the PlA1homozygotes and PlA2 heterozygotes, the Kd for the PlA2 homozygotes was significantly lower than that for the PlA1/PlA2 heterozygotes, but was not statistically different from that for the PlA1 homozygotes. No differences were detected in ADP sensitivity between platelets from PlA1 homozygotes and PlA1/PlA2heterozygotes, in the IC50 for RGDS inhibition of fibrinogen binding to αIIbβ3, in the αvβ3-mediated adhesion of platelets to osteopontin and vitronectin, and in the phorbol ester-stimulated adhesion to fibrinogen of B lymphocytes expressing αIIbβ3 containing either the PlA1 or the PlA2 polymorphism. Finally, no differential effects of PlA2 on turbidometric platelet aggregation, platelet secretion, or platelet thrombus formation were found as measured in the PFA-100. Because no differences were detected in the ability of β3-integrins to interact with ligands based on the presence or absence of the PlA2 polymorphism, the results suggest that factors unrelated to β3-integrin function may account for the reported association of the PlA2 allele with coronary thrombosis.
Preconditioning with fetal cord blood facilitates engraftment of primary childhood T-cell acute lymphoblastic leukemia in immunodeficient mice
Authors: Dialynas Deno P. , Lee Mi-Jeong , Gold Daniel P. , Shao Li-en , Yu Alice L. , Borowitz Michael J. , Yu John
Published: July 2002

Childhood T-cell acute lymphoblastic leukemia (T-ALL) is one of the most common childhood cancers. It is reported that preconditioning sublethally irradiated immunodeficient NOD/SCID (nonobese diabetic/X-linked severe combined immunodeficient) mice with human cord blood mononuclear cells facilitates the engraftment, expansion, and dissemination in these mice of primary T-ALL cells obtained from patients at the time of diagnosis. Cells recovered from mouse bone marrow or spleen resembled the original leukemia cells from patients with respect to surface lineage markers and T-cell receptor Vβ gene rearrangements. Moreover, the pattern of leukemia dissemination in mouse tissues, resulting in universally fatal leukemia, is reminiscent of the human clinical disease. In addition, the fidelity of the model to the human disease is documented with regard to the presence of morphologically identifiable human leukemia cells in mouse bone marrow and blood and the maintenance of leukemia-initiating capacity within the leukemia-engrafted mouse. Therefore, several lines of independent approaches are used to suggest that the engrafted cells are of human leukemia origin and are not derived from cord blood. The in vivo model described here should enable the study of the growth properties of primary T-ALL cells obtained from patients and should prove useful in evaluating the potential efficacy of therapeutic strategies directed toward T-ALL.
Breakage and fusion of the TEL (ETV6) gene in immature B lymphocytes induced by apoptogenic signals
Authors: Eguchi-Ishimae Minenori , Eguchi Mariko , Ishii Eiichi , Miyazaki Sumio , Ueda Kazuhiro , Kamada Nanao , Mizutani Shuki
Published: July 2002

TEL-AML1 fusion resulting from the t(12;21)(p13;q22) is one of the most common genetic abnormalities in childhood acute lymphoblastic leukemia. Recent findings that site-specific cleavage of the MLL gene can be induced by chemotherapeutic agents such as topoisomerase-II inhibitors suggest that apoptogenic agents can cause chromosomal translocations in hematopoietic cells. This study demonstrates a possible relationship between exposure to apoptogenic stimuli, TEL breaks, and the formation ofTEL-AML1 fusion in immature B lymphocytes. Short-term culture of immature B cell lines in the presence of apoptogenic stimuli such as serum starvation, etoposide, or salicylic acid induced double-strand breaks (DSBs) in intron 5 of the TEL gene and intron 1 of the AML1 gene. TEL-AML1fusion transcripts were also identified by reverse transcriptase–polymerase chain reaction (RT-PCR) analysis in cell lines treated by serum starvation or aminophylline. DSBs within theTEL gene were also associated with fusion to other unknown genes, presumably as a result of chromosomal translocation. We also examined 67 cord blood and 147 normal peripheral blood samples for the existence of in-frame TEL-AML1 fusion transcripts. One cord blood sample (1.5%) and 13 normal peripheral blood samples (8.8%) were positive as detected by nested RT-PCR. These data suggest that breakage and fusion of TEL andAML1 may be relatively common events and that sublethal apoptotic signals could play a role in initiating leukemogenesis via the promotion of DNA damage.