bluuebunny/crossref_metadata_2025 huggingface dataset:
Gnu/Maverik: A Microkernel for Large-Scale Virtual Environments
Authors: Hubbold Roger , Cook Jon , Keates Martin , Gibson Simon , Howard Toby , Murta Alan , West Adrian , Pettifer Steve
Published: July 2002

This paper describes a publicly available virtual reality (VR) system, GNU/MAVERIK, which forms one component of a complete VR operating system. We give an overview of the architecture of MAVERIK, and show how it is designed to use application data in an intelligent way, via a simple, yet powerful, callback mechanism that supports an object-oriented framework of classes, objects, and methods. Examples are given to illustrate different uses of the system and typical performance levels.
Worldlets: 3-D Thumbnails for Wayfinding in Large Virtual Worlds
Authors: Elvins T. Todd , Nadeau David R. , Schul Rina , Kirsh David
Published: July 2002

Finding one's way to sites of interest on the Web can be problematic, and this difficulty has been recently exacerbated by widespread development of 3-D Web content and virtual-world browser technology using the Virtual Reality Modeling Language (VRML). Whereas travelers can often navigate 2-D Web sites based on textual and 2-D thumbnail image representations of the sites' content, finding one's way to destinations in 3-D environments is notoriously troublesome. Wayfinding literature provides clear support for the importance of landmarks in building a cognitive map and then using that map to navigate in a 3-D environment, be it real or virtual. Textual and 2-D image landmark representations, however, lack the depth and context needed for travelers to reliably recognize 3-D landmarks. This paper describes a novel 3-D thumbnail landmark affordance called a worldlet. Containing a 3-D fragment of a virtual world, worldlets offer travelers first-person, multi-viewpoint experience with faithful representations of potential destinations.

To facilitate an investigation into the comparative advantages of landmark affordances for wayfinding, worldlet capture algorithms were designed, implemented, and incorporated into two VRML-based virtual environment browsers. Findings from a psychological experiment using one of these browsers revealed that, compared to textual and image guidebook usage, worldlet guidebook usage: nearly doubled the time subjects spent studying the landmarks in the guidebook, significantly reduced the time required for subjects to reach landmarks, and reduced backtracking to almost zero. These results support the hypothesis that worldlets facilitate traveler landmark knowledge, expedite wayfinding in large virtual environments, and enable skilled wayfinding.
Assembly Planning Effectiveness Using Virtual Reality
Authors: Banerjee A. , Banerjee P. , Ye N. , Dech F.
Published: July 2002

Planning the sequence of components (or parts) to be assembled during manufacturing is an important application problem for virtual environments for three main reasons. First, it is a difficult combinatorial optimization but a highly visual problem. Second, a majority of assembly operations in factories (with the exception of simple pick-and-place operations) are still performed manually, because they are difficult to automate. Hence, it is an important problem involving human-machine interface. Third, there are a number of assembly operations which require dextrous operator training. Hence, it is also an important training problem. Recent research suggests a promising approach for assembly determination based on using heuristic rules to generate soft constraints in addition to the regular hard quantitative constraints due to part geometry and topology. We believe that the emergence of virtual environments can enable us to systematically use these soft constraints, which previously has not been possible. In this paper, we report results of experiments involving fifteen voluntary participants using a nonvirtual reality (VR) environment involving blueprints, a nonimmersive desktop VR environment, and an immersive projection-based VR environment to first teach participants skills in handling soft and hard constraints for assembly planning through examples, and then to measure the effectiveness of their learnt skills in solving a different example problem. We have classified soft constraints as infeasibility constraints, reorientation constraints, difficulty constraints, instability constraints, and dissimilarity constraints. A significant observation is that the participants could, on average, perform the assembly operations in approximately half the time in the immersive and nonimmersive VR environments than in the traditional environment using blueprints.
Evolving Learnable Neural Networks Under Changing Environments with Various Rates of Inheritance of Acquired Characters: Comparison of Darwinian and Lamarckian Evolution
Authors: Sasaki Takahiro , Tokoro Mario
Published: July 2002

The processes of adaptation in natural organisms consist of two complementary phases: learning, occurring within each individual's lifetime, and evolution, occurring over successive generations of the population. In this article, we study the relationship between learning and evolution in a simple abstract model, where neural networks capable of learning are evolved using genetic algorithms (GAs). Individuals try to maximize their life energy by learning certain rules that distinguish between two groups of materials: food and poison. The connective weights of individuals' neural networks undergo modification, that is, certain characters will be acquired, through their lifetime learning. By setting various rates for the heritability of acquired characters, which is a motive force of Lamarckian evolution, we observe adaptational processes of populations over successive generations. Paying particular attention to behaviors under changing environments, we show the following results. Populations with lower rates of heritability not only show more stable behavior against environmental changes, but also maintain greater adaptability with respect to such changing environments. Consequently, the population with zero heritability, that is, the Darwinian population, attains the highest level of adaptation to dynamic environments.
Anglo-American Nuclear Weapons Cooperation After the Nassau Conference: The British Policy of Interdependence
Authors: Middeke Michael
Published: July 2002

The Anglo-American summit at Nassau in December 1962 did not strictly separate Britain's deterrent from the proposed Multilateral Force (MLF). As a result, Conservative governments in the 1960s tried to safeguard maximum British independence in nuclear relations with the United States. The British tried to thwart American initiatives on the mixed-manned MLF; some British officials even hoped to preserve an “independent British deterrent” through nuclear cooperation with France. For the United States, the British deterrent had political value in an intra-alliance or East-West context, but no military or political significance in itself. The MLF idea of bilateral nuclear cooperation with Britain and France was a means to contain French and German nuclear ambitions and to settle Cold War disputes with the Soviet Union. In London, however, leading officials believed that Britain's future as a great power was inextricably linked to the possession of an independent nuclear deterrent. When nuclear independence was lost, the appearance of independence became more important.
Confronting Consumption
Authors: Conca Ken
Published: July 2002

In affluent societies, evidence suggests that public concern and activism about “the consumption problem” is growing in many corners of everyday life—even in the paragon of the consumer society, the United States. These emerging concerns have an environmental dimension, but also embrace issues of community, work, meaning, freedom, and the overall quality of life. Yet the efforts of individuals, groups, and communities to confront consumption find little guidance or sympathy in policy-making, environmental, or academic circles—arenas dominated, perhaps as never before, by a deeply seated economistic reasoning and a politics of the sanctity of growth. Given our dissatisfaction with fragmentary approaches to consumption and its externalities, we highlight the elements of a provisional framework for confronting consumption in a more integrated fashion. We stress in particular the social embeddedness of consumption, the material and power-based linkages along commodity chains of resource use, and the hidden forms of consumption embedded in all stages of economic activity.
ADDE PRAEPUTIUM PRAEPUTIO MAGNUS ACERVUS ERIT: IF THE EXODUS AND CONQUEST HAD REALLY HAPPENED
Authors: Grabbe Lester
Published: July 2002

A lot of "what if" situations in history can be imagined, with interesting results. But an event often taken as history in the past is now regarded as a literary creation the exodus and conquest. When we begin to see the consequences of taking it as actual history-surprisingly, not done by supporters of this interpretation-it becomes even clearer why there never was such an event. If the exodus and conquest had actually occurred, the outcome could have changed the whole of the history of the Western world, and we would have a completely different Bible today.
WHAT IF JUDGES HAD BEEN WRITTEN BY A PHILISTINE?
Authors: Ackerman Susan
Published: July 2002

Judges 13-16, the saga of Samson, is a text that, in popular imagination, is typically described as depicting the exploits of the heroic Samson against the Philistine barbarians. But, in fact, as commentators have often pointed out, Samson, although endowed with superhuman strength in this tale, is otherwise something of a fool and a boor: posing an unfair riddle at his wedding feast, engaging again and again in acts of violent destruction, and revealing the secret of his uncut hair to Delilah even though she has made clear that she intends to summon the Philistines to seize him after rendering him powerless. Yet however stupid Samson and however forthright Delilah are depicted as being in their interactions together, popular imagination again has almost always remembered Delilah as the evil seductress who leads the helpless Samson astray. Philistine interpreters, though, might well have remembered Delilah as an equivalent of the Israelite hero Jael: as a woman who, in terms of ethnicity, seems to stand outside of the dispute in which she plays a role; as a woman who is not necessarily a part of the household of a father or husband; and as a women depicted in terms of erotic imagery that is primarily maternal in nature. From a Philistine point of view, that is, Delilah might well bear the epithet Israelite tradition awards to Jael in Judg. 5:24: "most blessed of women."
DAS BUCH ESTHER ALS METHODISCHES PROBLEM UND HERMENEUTISCHE HERAUSFORDERUNG: EINE SKIZZE
Authors: Wahl Harald Martin
Published: July 2002

Das Buch Esther ist in drei erheblich voneinander abweichenden Fassungen überliefert: Der hebräischen Fassung (M) steht eine griechische Kurzfassung (A), die mit c. 8 endet, und eine griechische Langfassung (B) zur Seite. Die Langfassung ist ihrerseits wiederum durch sechs Zusätze (ZusEst) um insgesamt 105 Verse erweitert worden. Die auffällige Fortschreibung und Interpretation des Buches führt zu methodischen und hermeneutischen Konsequenzen: Methodisch darf eine angemessene Auslegung des Stoffes vor allem die Septuaginta nicht ignorieren. Hermeneutisch zwingt die theologisch eigenständige griechische Tradition die Auslegung dazu, davon abzusehen, den hebräischen Text exklusiv zu behandeln. Die als Interpretationen entstandenen alternativen theologischen Traditionen verlangen nach einer angemessenen Deutung. Eine Auslegung, die wechselseitig die verschwisterte Tradition zur Deutung heranzieht und die originalen Fortschreibungen reflektiert, führt zu dem Verständnis eines für die Rezeption offenen Kanons.
Plato's Critique of the Democratic Character
Authors: Scott Dominic
Published: July 2002

This paper tackles some issues arising from Plato's account of the democratic man in Rep. VIII. One problem is that Plato tends to analyse him in terms of the desires that he fulfils, yet sends out conflicting signals about exactly what kind of desires are at issue. Scholars are divided over whether all of the democrat's desires are appetites. There is, however, strong evidence against seeing him as exclusively appetitive: rather he is someone who satisfies desires from all three parts of his soul, although his rational and spirited desires differ significantly from those of the philosopher or the timocrat. A second problem concerns the question why the democrat ranks so low in Plato's estimation, especially why he is placed beneath the oligarch. My explanation is that Plato presents him as a jumble of desires, someone in whom order and unity have all but disintegrated. In this way he represents a step beyond the merely bipolarised oligarch. The final section of the paper focuses on the democrat's rational part, and asks whether it plays any role in shaping his life as a whole. For the disunity criticism to hold, Plato ought to allow very little global reasoning: if there were a single deliberating reason imposing a life plan upon his life, the fragmentation of life and character discussed earlier would only be superficial. I argue that Plato attributes very little global reasoning to the democrat. Aside from the fact that the text fails to mention such reasoning taking place, Plato's views on the development of character and his use of the state-soul analogy show that the democrat's lifestyle is determined just by the strength of the desires that he happens to feel at any one time.
Religion in the Making? Animality, Savagery, and Civilization in the Work of A. N. Whitehead
Authors: Palmer Clare
Published: July 2002

Constructions of the animal and animality are often pivotal to religious discourses. Such constructions create the possibility of identifying and valuing what is "human" as opposed to the "animal" and also of distinguishing human beliefs and behaviors that can be characterized (and often disparaged) as being animal from those that are "truly human." Some discourses also employ the concept of savagery as a bridge between the human and the animal, where the form of humanity but not its ideal beliefs and practices can be displayed. This paper explores the work of the influential scientist, philosopher, and theologian A. N. Whitehead in this context. His ideas of what constitutes "the animal," the "primitive" and the "civilized" are laid out explicitly in his now little-used history of religions text, Religion in the Making. This paper explores these ideas in this history and then considers how the same ideas permeate his currently more popular philosophical and theological writing Process and Reality. Drawing on some work in post-colonial theory, the paper offers a critique of this understanding of animality, savagery, and civilization and suggests that using Whitehead to underpin modern theological work requires considerable caution.
Taxonomy of the banded newt, Triturus vittatus: morphological and allozyme data
Authors: Arntzen  , Olgun Kurtulus
Published: July 2002

We studied the number of rib-bearing vertebrae, eight morphometric characters and 36 protein loci in three subspecies of the banded newt, Triturus vittatus from the Near and Middle East. The number of rib-bearing vertebrae ranged from 12 to 15. Modal count was 13 in T. v. cilicensis, T. v. vittatus and T. v. ophryticus in the western part of the range and 14 in the eastern part of the T. v. ophryticus range. Significant differences were found between groups (cilicensis plus vittatus, western ophryticus, eastern ophryticus). Significant differences in shape were observed comparing T. vittatus with T. karelinii and T. montandoni, but not among T. v. vittatus, T. v. cilicensis and T. v. ophryticus. Genetic differentiation within T. v. ophryticus reached DNei = 0.24, which was similar to the distance observed between T. v. vittatus and T. v. cilicensis (DNei = 0.18). The two groups clustered at DNei = 0.58. We discuss the question whether T. v. ophryticus should be raised to species level.
Systematics of the Ctenosaura group of lizards (Reptilia: Sauria: Iguanidae)
Authors: Schroth  , Streit  , Köhler
Published: July 2002

The phylogenetic relationships of the species of the genus Ctenosaura were analysed using two independent data sets derived from morpho-etho-ecological and genetic (RAPD) markers. The analysis of the data matrix based on morpho-etho-ecological characters yielded a consensus tree with the species of Ctenosaura forming three clades. The consensus tree based on the RAPD data is not as well resolved as the morphological tree. Subgeneric status is proposed for the three monophyletic subgroups within the monophyletic genus Ctenosaura.
Cryptic speciation in Pelobates fuscus (Anura, Pelobatidae): evidence from DNA flow cytometry
Authors: Rosanov  , Borkin  , Milto  , Litvinchuk
Published: July 2002

The amount of nuclear DNA in 173 specimens of Pelobates f. fuscus from 34 localities in Russia, Ukraine, Moldavia and Latvia was determined by DNA flow cytometry. Two distinct groups with different genome sizes were identified. The ranges of the genome size variation in the two groups did not overlap. Geographically, these groups with smaller or larger genome size are distributed in the west and in the east of eastern Europe, respectively.
THE EFFECT OF A TREMATODE PARASITE (MICROPHALLUS SP.) ON THE RESPONSE OF THE FRESHWATER SNAIL POTAMOPYRGUS ANTIPODARUM TO LIGHT AND GRAVITY
Authors: Levri  , Fisher
Published: July 2002

Parasites often influence the behavior of their hosts in ways that increase the probability of transmission of the parasite. The digenetic trematode Microphallus sp. has been demonstrated to alter the behavior of the New Zealand freshwater snail Potamopyrgus antipodarum in a way that increases the probability that infected snails will be eaten by the final host (waterfowl). Infected snails are found foraging on top of rocks more often in the early morning when waterfowl are feeding and less often in the afternoon when unsuitable hosts (fish) are feeding. The mechanism(s) that the parasite utilizes to produce this behavioral change is not known. The present study investigated three possible behaviors (phototaxis, geotaxis, and photokinesis) that the parasite could alter that may account for the behavioral change seen in the field. Infected and uninfected snails were assessed in terms of their orientation to light (phototaxis), orientation to gravity (geotaxis), and movement in response to light (photokinesis). There was no evidence of phototactic behaviors in either infected or uninfected snails. However, uninfected snails were found to positively orient towards gravity, while infected snails did not. Also, both infected and uninfected snails were found to be positively photokinetic (they move faster in the light than in the dark), but Microphallus infected snails were found to move more slowly than uninfected snails. The differences found between infected and uninfected snails may be part of the manipulative effort of the parasite, but by themselves the differences are not sufficient to explain the patterns observed in the field.
DEFINING DIVE BOUTS USING A SEQUENTIAL DIFFERENCES ANALYSIS
Authors: Mori Yoshihisa , Yoda Ken , Sato Katsufumi
Published: July 2002

Bout analysis searches for a bout-ending criterion (BEC) to determine whether successive events are part of the same bout. Methods widely used for finding the BEC are logsurvivorship, log-frequency, and log-normal analyses. These analyses are based on the assumption that frequency distributions of event intervals can be described by two or three random distributions, and that the mean interval within a bout is common to all other bouts. Diving typically occurs in bouts. Since a dive bout is a sequence of complex behaviours in which the duration, depth, and interval between dives may all be adapted for optimal foraging, it is unreasonable to assume that the mean dive interval within a bout is common to all other dive bouts. Furthermore, one should not assume that dives might be split into bouts based only on dive interval without considering other characteristics, such as dive depth. Here we propose a new method, the sequential differences analysis, to find the BEC for dive bout analysis. This method has two features: (1) the frequency of differences in dive characteristics between two successive dives is used instead of the frequency of dive intervals, and (2) along with the dive interval, other characteristics are used to determine the BEC. Compared with the log-frequency analysis using dive intervals, the sequential differences analysis results in bouts with less variation (i.e. a smaller coefficient of variation) in dive characteristics, and a smaller number of dives within a bout. This suggests that our method splits dive sequences into bouts at a finer scale than the existing method. The sequential differences analysis is useful for dividing a sequence of complex behaviours with several characteristics into more meaningful bouts.
THE EFFECTS OF CONTEXT, SEX, AND BODY SIZE ON STAGED SOCIAL INTERACTIONS IN JUVENILE MALE AND FEMALE GREEN ANOLES (ANOLIS CAROLINENSIS)
Authors: Lovern Matthew , Jenssen Thomas
Published: July 2002

We documented the ontogeny of headbobbing display use in green anoles (Anolis carolinensis) by determining the effects of social context, sex, and body size on juvenile social interactions. Juveniles only gave displays in social interactions (never while isolated), and activity levels in general were much higher during interactions than during isolation. Neither social context (consexual or heterosexual) nor sex affected the type or quantity of displays and related behaviors (perch shifts, display modifiers, color changes, and approaches or retreats). Interactions always appeared to be aggressive in nature and qualitatively similar to interactions between adult females. Both males and females tended to increase overall activity during interactions with body size, including the use of displays and related behaviors, and large juvenile males performed more headbobbing displays than did large juvenile females. These results suggest that juvenile social interactions are agonistic in nature and that they function to defend both immediate and future resources (prospective resource hypothesis). It is likely that resource protection confers the immediate benefits of suitable habitat for foraging, thermoregulation, and predator avoidance, and it is hypothesized that the primary future benefit is the acquisition of the eventual breeding territory that juveniles will hold as adults.
A LONG TERM STUDY ON INITIAL ORIENTATION IN SAND MARTINS (RIPARIA RIPARIA)
Authors: Baldaccini Natale Emilio , Giunchi Dimitri , Mongini Emanuele
Published: July 2002

Over a period of 18 years sand martins (Riparia riparia) were displaced from their breeding colonies and released to investigate the relationship between distance of displacement and initial orientation. The results show significant homeward orientation at the shortest distances of displacement (7.1-18.2 km, series A), but not over longer distances (49-180 km, series B and C). Birds displaced over 49 km from their breeding colonies only seldom show homeward directedness, while pseudo-pooling and second order analysis of their directional choices seem to indicate the tendency to fly in a given compass direction. Possible causal factors that can induce this behaviour in sand martins are discussed, taking into account not only local biasing factors but also the existence of a so called preferred compass direction. These data show that sand martins are able to determine the correct homing direction inside a probably familiar area. The response over longer distances indicates difficulties in determining the appropriate homing course at takeoff.
ACTIVE DISPERSAL OF STENASELLUS VIREI BOUI MAGNIEZ (ISOPODA) THROUGH THE ALLUVIAL SEDIMENTS OF A PYRENEAN STREAM (SOUTHERN FRANCE)
Authors: Rouch Raymond , Danielopol Dan
Published: July 2002

During a 13 month project Stenasellus virei boui Magniez, 1968, living in the alluvial sediments of the Nert stream (near Saint Girons, Ariege), were sampled monthly in an area of 30 m2 at depths of 0.6 and 1.0 m. Isopods were found over the whole area at low frequencies: 91% of the samples contained 1-5 specimens and a total of 140 individuals was caught. After each sampling series, the sites were baited and re-sampled the next day. The isopods aggregated rapidly (up to 148 specimens/sample) around the bait, especially in interstitial areas with high permeability, and more than 2,000 additional individuals were caught with this technique. The experiment documents that S. virei boui is represented in the field by an unexpectedly large perennial population, even in superficial sediments. The animals actively react to chemical cues, moving rapidly through the interstitial space. The data also point out that the interstitial habitat and the isopods that are adapted to live within it, together build a complex ecological system. Lors d'une etude poursuivie pendant treize mois, Stenasellus virei boui Magniez, 1968, qui vit dans les sediments alluviaux du Nert (pres de Saint-Girons, Ariege), a fait l'objet de prelevements mensuels sur une aire de 30 m2, a 0,6 m et 1,0 m de profondeur. Cet Isopode a ete recolte sur la totalite de l'aire prospectee mais avec une frequence peu elevee: 91% des prelevements contenaient 1 a 5 specimens et un total de 140 individus ont ete recoltes. Apres chaque serie de prelevements, les sites etudies ont ete appates puis preleves a nouveau le jour suivant. Les Isopodes se rassemblaient rapidement autour des appats (jusqu'a 148 individus par site), essentiellement dans les zones a permeabilite elevee. Plus de 2000 individus additionnels ont ete captures par cette technique. Les donnees obtenues montrent que S. virei boui peut former des populations abondantes dans des sediments relativements superficiels; les animaux repondent activement aux informations chimiques en se deplacant rapidement dans les espaces interstitiels. Ainsi est suggere le fait que l'habitat interstitiel et les Isopodes qui lui sont adaptes forment un systeme ecologique plus complexe qu'on ne le pensait.
Pristionchus pacificus: a satellite organism in evolutionary developmental biology
Authors: Jungblut Benno , Silva André Pires-Da , Eizinger Andreas , Lee Kwang-Zin , Srinivasan Jagan , Grandien Kaj , Sommer Ralf , Carmi Ilil , Sigrist Carola , Schlak Isabel , Nguyen Hanh
Published: July 2002

Pristionchus pacificus has been described as a satellite organism, for functional comparative studies with Caenorhabditis elegans. Like C. elegans, P. pacificus is also easily cultured in the laboratory on a lawn of E. coli bacteria. P. pacificus is a hermaphroditic species with a 4-day life cycle, but unlike most nematodes which pass through four juvenile stages during their development, P. pacificus has only three juvenile stages. The combination of genetic, molecular and cell-biological studies have made P. pacificus a model system in the new field of evolutionary developmental biology. One process that has been studied in detail is the development of the vulva. Genetic and molecular studies revealed that the function of several genes involved in vulva development differs between P. pacificus and C. elegans. Here, we review our genetic and molecular studies of P. pacificus. We show that P. pacificus is well-suited as a satellite organism not only for understanding the cellular and genetic aspects of evolutionary change, but also for addressing questions of molecular evolution at the genomic level. Pristionchus pacificus wurde vor mehrerern Jahren als “Satelitten-Organism” für funktionelle-vergleichende Studien mit dem Modellorganismus C. elegans beschrieben. P. pacificus ist eine hermaphroditische Art mit einer Generationszeit von 4 Tagen und kann auf E. coli gezüchtet werden. Die Analyse des Lebenszyklus hat gezeigt dass diese Art im Gegensatz zu den meisten Nematoden nur drei Juvenilstadien durchläuft. Da in P. pacificus genetische, molekular-biologische und zelluläre Methoden in ähnlicher Weise zum Einsatz kommen können wie in C. elegans, ist diese Art ein ideales Modellsystem für evolutionäre entwicklungsbiologische Fragestellungen. Ein besonders detailliert analysierter Entwicklungsprozess ist die Bildung der Vulva. Genetische und molekulare Arbeiten haben gezeigt dass einige in beiden Arten an der Vulva-Bildung beteiligte homologen Gene, sich in ihrer detaillierten Funktion deutlich voneinander unterscheiden. Die vorliegende Arbeit gibt einen Überblick über die genetischen und molekularen Aspekte der Vulva-Entwicklung in P. pacificus und zeigt die Potenzen der Art auch für zukünftige molekulare und genomische Untersuchungen.
Capture of nematodes using antiserum and lectin-coated magnetised beads
Authors: Robertson Lee , Blok Vivian , Chen Qing , Brown Derek , Jones John , Phillips Mark
Published: July 2002

Plant-parasitic nematodes are small and extremely difficult to identify. Previous studies have demonstrated the potential for lectin- or antibody-assisted identification of nematodes. We present an extension of this technology, using antibody- or lectin-coated magnetic beads (Dynabeads) to recover target nematodes from mixtures of specimens. Lectins and antisera that bound specifically and reproducibly to the whole surface of second stage juveniles of Globodera rostochiensis and Meloidogyne arenaria were identified. These were then used as probes bound to Dynabeads to recover nematodes from test suspensions. While both types of probe isolated nematodes from suspension, antibody-coated beads recovered them more efficiently than beads coated with lectins. Other factors that affected the efficiency of recovery, such as the age of the nematode samples, were analysed. This study revealed that Dynabeads coated with a probe of suitable specificity could be used to extract nematodes from mixtures of species. This technology may ultimately be useful in 'non-expert systems' for routine detection and quantification of nematode species.
Occurrence of dopamine in Panagrellus redivivus and Meloidogyne incognita
Authors: Stewart Graham , Perry Roland , Wright Denis
Published: July 2002

Dopamine-like immunoreactivity was detected in various parts of the nervous system of adult males and females of the free-living nematode Panagrellus redivivus , including the nerve ring and some cephalic processes, the ventral nerve cord, and the tail region. Positive immunoreactivity for dopamine was not found in infective second stage juveniles (J2) of the root-knot nematode Meloidogyne incognita. This putative neurotransmitter was detected by HPLC in homogenates of both species, the dopamine content in P.redivivus being eight times greater than in M. incognita. No other catecholamine compounds were detected in these species by HPLC. The development of a more sensitive immunocytochemical assay for dopamine will be required to determine the location of dopamine in the nervous system of M. incognita J2.
Isolation and characterisation of Heterorhabditis spp. (Nematoda: Heterorhabditidae) from Hungary, Estonia and Denmark
Authors: Griffin Christine T. , Dix Ilona , Joyce Susan A. , Burnell Ann M. , Downes Martin J.
Published: July 2002

Targeted surveys were conducted for the entomopathogenic nematode
Heterorhabditis in areas of Denmark, Estonia and Hungary. Isolates were
identified by IEF, PCR and cross-fertility tests as belonging to three
distinct taxonomic groups: H. bacteriophora, the north-west European (NWE)
type of H. megidis and the Irish type of Heterorhabditis. The Irish and NWE
types of Heterorhabditis were both present in Denmark (at six and four
sites, respectively), while only the NWE type was recovered in Estonia. H.
bacteriophora was the dominant heterorhabditid identified in Hungary (ten
sites), but the Irish type was also detected at two sites. This is the first
report of the Irish type of Heterorhabditis on continental Europe.
Co-occurrence of two Heterorhabditis types at a single site was noted in
Denmark (Irish and NWE) and in Hungary (Irish and H. bacteriophora).
Heterorhabditis was recovered at 38.5% of sites (n = 26) in Denmark (north
coast of Sjaelland), 27.3% of the coastal sites (n = 22) in Estonia, and
32.6% of sites (n = 46) in Hungary. Isolation et caracterisation d'especes
d'Heterorhabditis (Nematoda: Heterorhabditidae) originaires de Hongrie,
d'Estonie et du Danemark - Des prospections ciblees ont ete effectuees dans
certaines regions du Danemark, d'Estonie et de Hongrie pour rechercher les
nematodes du genre Heterorhabditis. Les souches, identifiees par les
methodes de concentration isoelectrique, de PCR et d'hybridation,
appartiennent aux trois groupes taxinomiques d'Heterorhabditis : H.
bacteriophora, le groupe de l'Europe du nord-ouest (NWE) de H. megidis et le
groupe irlandais d'Heterorhabditis. Le groupe irlandais et le groupe NWE
sont tous les deux presents au Danemark (dans six et quatre sites,
respectivement), mais seul le dernier groupe a ete rencontre en Estonie. H.
bacteriophora, present dans dix sites, est l'espece dominante
d'Heterorhabditis en Hongrie, mais le groupe irlandais a ete egalement
detecte dans deux sites. C'est la premiere fois que le groupe irlandais est
rencontre en Europe continentale. La presence simultanee de deux types
d'Heterorhabditis est signalee au Danemark (groupe irlandais et groupe NWE)
et en Hongrie (groupe irlandais et H. bacteriophora). Des Heterorhabditis
ont ete collectes sur 38.5% des 26 sites du Danemark (cote nord de
Sjaelland), 27.3% des 22 sites du littoral estonien et 32.6% des 46 sites de
Hongrie.
The flow cytometric analysis of telomere length in antigen-specific CD8+ T cells during acute Epstein-Barr virus infection
Authors: Plunkett Fiona J. , Soares Maria Vieira D. , Annels Nicola , Hislop Andrew , Ivory Kamal , Lowdell Mark , Salmon Mike , Rickinson Alan , Akbar Arne N.
Published: July 2002

Acute infectious mononucleosis (AIM) induced by Epstein-Barr virus (EBV) infection is characterized by extensive expansion of antigen-specific CD8+ T cells. One potential consequence of this considerable proliferative activity is telomere shortening, which predisposes the EBV-specific cells to replicative senescence. To investigate this, a method was developed that enables the simultaneous identification of EBV specificity of the CD8+ T cells, using major histocompatibility complex (MHC) class I/peptide complexes, together with telomere length, which is determined by fluorescence in situ hybridization. Despite the considerable expansion, CD8+ EBV-specific T cells in patients with AIM maintain their telomere length relative to CD8+ T cells in normal individuals and relative to CD4+ T cells within the patients themselves and this is associated with the induction of the enzyme telomerase. In 4 patients who were studied up to 12 months after resolution of AIM, telomere lengths of EBV-specific CD8+ T cells were unchanged in 3 but shortened in one individual, who was studied only 5 months after initial onset of infection. Substantial telomere shortening in EBV-specific CD8+ T cells was observed in 3 patients who were studied between 15 months and 14 years after recovery from AIM. Thus, although telomerase activation may preserve the replicative potential of EBV-specific cells in AIM and after initial stages of disease resolution, the capacity of these cells to up-regulate this enzyme after restimulation by the persisting virus may dictate the extent of telomere maintenance in the memory CD8+ T-cell pool over time.
Characterization of a novel autosomal dominant bleeding disorder in a large kindred from east Texas
Authors: Kuang Shao-Qing , Hasham Sumera , Phillips Martin D. , Wolf David , Wan Ying , Thiagarajan Perumal , Milewicz Dianna M.
Published: July 2002

A large east Texas family with autosomal dominant inheritance of a novel bleeding disorder has been identified. The disorder is characterized clinically by easy bruising, life-threatening bleeding with trauma or surgery, and menorrhagia in affected women. Laboratory studies demonstrated prolongation of the prothrombin time and activated partial thromboplastin time in affected individuals. Paradoxically, assays of known coagulation factors are all within normal limits. To determine the molecular basis of this disease, a candidate gene linkage analysis in this kindred was done. Initially it was hypothesized that the cause of the disease in this family could be an antithrombin III (AT3) mutation that resulted in a constitutively active AT3 in the absence of heparin binding. Linkage studies using DNA from the family and an intragenic polymorphic marker within the AT3 gene showed that the disease mapped to this locus. The coding region and intron/exon junctions of AT3were sequenced using the proband's DNA, but this analysis failed to identify a mutation. Additional family members were recruited for the study, and 16 polymorphic markers around the AT3 gene were analyzed. Using 2 recombinants, the critical interval for the defective gene was narrowed to approximately 1.5 Mb, centromeric toAT3. The factor V (FV) gene was mapped into the disease interval and sequenced; there were no mutations found. Elucidation of the genetic defect causing the bleeding disorder in this family may reveal a novel protein involved in the coagulation cascade.
Adverse Pregnancy Outcomes in Solid Organ Transplant Recipients
Authors: Yo Jennifer H. , Fields Neville , Li Wentao , Anderson Alice , Marshall Sarah A. , Kerr Peter G. , Palmer Kirsten R.
Published: August 2024

Importance

Transplant recipients experience high rates of adverse pregnancy outcomes; however, contemporary estimates of the association between solid organ transplantation and adverse pregnancy outcomes are lacking.

Objective

To evaluate the association between solid organ transplantation and adverse pregnancy outcomes and to quantify the incidence of allograft rejection and allograft loss during pregnancy.

Data Sources

PubMed/MEDLINE, EMBASE and Scopus databases were searched from January 1, 2000, to June 20, 2024, and reference lists were manually reviewed.

Study Selection

Cohort and case-control studies that reported at least 1 adverse pregnancy outcome in pregnant women with solid organ transplantation vs without solid organ transplant or studies that reported allograft outcomes in pregnant women with solid organ transplantation were included following independent dual review of abstracts and full-text articles.

Data Extraction and Synthesis

Two investigators abstracted data and independently appraised risk of bias using the Newcastle Ottawa Scale. A random-effects model was used to calculate overall pooled estimates using the DerSimonian-Laird estimator. Reporting followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) reporting guideline.

Main Outcomes and Measures

Primary pregnancy outcomes were preeclampsia, preterm birth (<37 weeks), and low birth weight (<2500 g). Secondary pregnancy outcomes were live birth rate, gestation, very preterm birth (<32 weeks), very low birth weight (<1500 g), and cesarean delivery. Allograft outcomes were allograft loss and rejection during pregnancy.

Results

Data from 22 studies and 93 565 343 pregnancies (4786 pregnancies in solid organ transplant recipients) were included; 14 studies reported adverse pregnancy outcomes, and 13 studies provided data for allograft outcomes. Pregnancies in organ transplant recipients were associated with significantly increased risk of preeclampsia (adjusted odds ratio [aOR], 5.83 [95% CI, 3.45-9.87]; I2 = 77.4%), preterm birth (aOR, 6.65 [95% CI, 4.09-12.83]; I2 = 81.8%), and low birth weight (aOR, 6.51 [95% CI, 2.85-14.88]; I2 = 90.6%). The incidence of acute allograft rejection was 2.39% (95% CI, 1.20%-3.96%; I2 = 68.5%), and the incidence of allograft loss during pregnancy was 1.55% (95% CI, 0.05%-4.44%; I2 = 69.2%).

Conclusions and Relevance

In this systematic review and meta-analysis, pregnancies in recipients of a solid organ transplant were associated with a 4 to 6 times increased risk of preeclampsia, preterm birth, and low birth weight during pregnancy. There was a low overall risk of graft rejection or loss during pregnancy.
Progress in Ionizing Radiation Shielding Materials
Authors: Wu Yanhe , Wang Zhengke
Published: August 2024

The continuous development of ionizing radiation in medical imaging and treatment, nuclear reactors, food irradiation, and other fields is accompanied by potential risks. It protects related equipment and personnel by adopting radiation shielding materials to reduce irradiation. Due to the advancement of science and technology, many high‐performance radiation protection materials have been reported. Ionizing radiation is a complex environment involving X‐ray imaging, radiation therapy, nuclear power operation, and space radiation. Irradiation energy, irradiation type, and the measurement of shielding material have essential effects on shielding efficiency. However, there has not been a general review of the preparations and properties of ionizing radiation shielding materials in the light of different matrixes in recent years. Herein, a comprehensive overview of recent advancements in radiation shielding materials, categorized into alloys, concretes, glasses and ceramics, and polymer composites, is presented. Furthermore, the synthesis methods employed for these materials and their respective radiation shielding properties are discussed. Finally, the current research gap and possible future scope of radiation shielding materials are proposed.
Intrinsic Bipolar Head‐Direction Cells in the Medial Entorhinal Cortex
Authors: Long Xiaoyang , Wang Xiaoxia , Deng Bin , Shen Rui , Lv Sheng‐Qing , Zhang Sheng‐Jia
Published: August 2024

Head‐direction (HD) cells are a fundamental component in the hippocampal‐entorhinal circuit for spatial navigation and help maintain an internal sense of direction to anchor the orientation in space. A classical HD cell robustly increases its firing rate when the head is oriented toward a specific direction, with each cell tuned to only one direction. Although unidirectional HD cells are reported broadly across multiple brain regions, computation modelling has predicted the existence of multiple equilibrium states of HD network, which has yet to be proven. In this study, a novel HD variant of bipolar HD cells in the medial entorhinal cortex (MEC) are identified that exhibit stable double‐peaked directional tuning properties. The bipolar patterns remain stable in the darkness and across environments of distinct geometric shapes. Moreover, bipolar HD cells co‐rotate coherently with unipolar HD cells to anchor the external visual cue. The discovery reveals a new spatial cell type of bipolar HD cells, whose unique activity patterns may comprise a potential building block for a sophisticated local neural circuit configuration for the internal representation of direction. These findings may contribute to the understanding of how the brain processes spatial information by shedding light on the role of bipolar HD cells in this process.
SARS‐CoV‐2 Evolution: Immune Dynamics, Omicron Specificity, and Predictive Modeling in Vaccinated Populations
Authors: Zhang Xiaohan , Li Mansheng , Zhang Nana , Li Yunhui , Teng Fei , Li Yongzhe , Zhang Xiaomei , Xu Xingming , Li Haolong , Zhu Yunping , Wang Yumin , Jia Yan , Qin Chengfeng , Wang Bingwei , Guo Shubin , Wang Yajie , Yu Xiaobo
Published: August 2024

Host immunity is central to the virus's spread dynamics, which is significantly influenced by vaccination and prior infection experiences. In this work, we analyzed the co‐evolution of SARS‐CoV‐2 mutation, angiotensin‐converting enzyme 2 (ACE2) receptor binding, and neutralizing antibody (NAb) responses across various variants in 822 human and mice vaccinated with different non‐Omicron and Omicron vaccines is analyzed. The link between vaccine efficacy and vaccine type, dosing, and post‐vaccination duration is revealed. The classification of immune protection against non‐Omicron and Omicron variants is co‐evolved with genetic mutations and vaccination. Additionally, a model, the Prevalence Score (P‐Score) is introduced, which surpasses previous algorithm‐based models in predicting the potential prevalence of new variants in vaccinated populations. The hybrid vaccination combining the wild‐type (WT) inactivated vaccine with the Omicron BA.4/5 mRNA vaccine may provide broad protection against both non‐Omicron variants and Omicron variants, albeit with EG.5.1 still posing a risk. In conclusion, these findings enhance understanding of population immunity variations and provide valuable insights for future vaccine development and public health strategies.
Anisotropic Spin Fluctuations Induced by Spin‐Orbit Coupling in a Misfit Layer Compound (LaSe)1.14(NbSe2)
Authors: Shan Min , Li Shunjiao , Yang Ye , Zhao Dan , Li Jian , Nie Linpeng , Wu Zhimian , Zhou Yanbing , Zheng Lixuan , Kang Baolei , Wu Tao , Chen Xianhui
Published: August 2024

Spin‐orbit coupling (SOC) has significant effects on the superconductivity and magnetism of transition metal dichalcogenides (TMDs) at the 2D limit. Although 2D TMD samples possess many exotic properties different from those of bulk samples, experimental characterization in this field is still limited, especially for magnetism. Recent studies have revealed that bulk misfit layer compounds (MLCs) with (LaSe)1.14(NbSe2)n = 1,2 exhibit an Ising superconductivity similar to that of heavily electron‐doped NbSe2 monolayers. This offers an opportunity to study the effect of SOC on the magnetism of 2D TMDs. Here, the possible SOC effect in (LaSe)1.14(NbSe2) is investigated by measuring nuclear magnetic resonance (NMR) and electrical transport. It is found that the LaSe layer not only functions as a charge reservoir for transferring electrons into the NbSe2 layer but also remarkably influences the local electronic environment around the 93Nb nuclei. More importantly, the significant SOC induces both a weak antilocalization (WAL) effect and anisotropic spin fluctuations in noncentrosymmetric NbSe2 layers. The present work contributes to a deep understanding of the role of the SOC effect in 2D TMDs and supports MCLs as an intriguing platform for exploring exotic physical properties within the 2D limit.
Unveiling Intercalation Chemistry via Interference‐Free Characterization Toward Advanced Aqueous Zinc/Vanadium Pentoxide Batteries
Authors: Li Xianjin , Xu Yue , Chen Xiaoqin , Yang Xiaofei , Zhang Guohui , Li Xianfeng , Fu Qiang
Published: August 2024

Aqueous Zn/V2O5 batteries are featured for high safety, low cost, and environmental compatibility. However, complex electrode components in real batteries impede the fundamental understanding of phase transition processes and intercalation chemistry. Here, model batteries based on V2O5 film electrodes which show similar electrochemical behaviors as the real ones are built. Advanced surface science characterizations of the film electrodes allow to identify intercalation trajectories of Zn2+, H2O, and H+ during V2O5 phase transition processes. Protons serve as the vanguard of intercalated species, facilitating the subsequent intercalation of Zn2+ and H2O. The increase of capacity in the activation process is mainly due to the transition from V2O5 to more active V2O5·nH2O structure caused by the partial irreversible deintercalation of H2O rather than the increase of active sites induced by the grain refinement of electrode materials. Eventually, accumulation of Zn species within the oxide electrode results in the formation of inactive (Zn3(OH)2V2O7·2H2O) structure. The established intercalation chemistry helps to design high‐performance electrode materials.