bluuebunny/crossref_metadata_2025 huggingface dataset:
Four proclamatory confrontations in scribal refraction
Authors: Brueggemann Walter
Published: October 2003

This paper offers a reflection upon the current preaching crisis in those parts of the United States church where old assumptions about preaching authority have collapsed. While preachers may have models of great confrontational authority available, in fact such authority for confrontation through preaching has largely evaporated. This paper explores new developments in OT studies that are related to canonical formulation, namely, that the biblical text as we have it is an outcome of belated editorial work whereby the text was reshaped with theological intentionality by scribes, a generative force in Judaism that transposed powerful memories into texts. Consequently, the great texts of confrontation between prophet and king, between truth and power, no longer offer dramatic confrontations but rather offer textual reflections upon remembered and perhaps constructed confrontations. The practical implication for preaching from this insight is that the preacher is not and need not be a player in confrontation as a prophet, but rather may be a scribe who keeps old texts available whereby the baptismal community may imagine its life differently. Four texts are considered wherein remembered dramatic confrontations have become textual resources.
Popular modernism? The ‘urban’ style of interwar Tin Pan Alley
Authors: Lindberg Ulf
Published: October 2003

The approach of this article complements those of previous critics that account for the rise of the ‘mature’ style of Tin Pan Alley chiefly in terms of the internal logic of the field of American popular music. It suggests that the so-called golden age of the Alley (ca. 1920–1940) should be considered in broader cultural terms, provided by modernisation and especially the growth of a ‘cool’, urban sensibility, representing a crucial reassessment of Victorian emotional style. In their contributions to this reassessment, the Alley greats stretched the conventions of popular song-writing in a number of ways, usually described vaguely in terms of ‘wit’, ‘sophistication’ and the like. Qualifying these concepts by lyrical analysis, the article suggests that the self-reflexive use of irony, linguistic play and ‘realist’ imperatives makes a number of songs approach contemporary ‘high’ literature in such a way that it makes sense to speak of a popular modernism.
Know history!: John Lydon, cultural capital and the prog/punk dialectic
Authors: Albiez Sean
Published: October 2003

Johnny Rotten / John Lydon was and remains the first voice of British punk and yet consistently refuses to identify with punk as a subculture. In revisiting his observations on his career with the Sex Pistols and Public Image Ltd (PiL) in the 1976–1980 period, this article considers how ‘narratives of self’ enable us to gain insights into individual subjectivity and the (trans) formation of identity. Through this material we can investigate the role of Lydon's idiosyncratic cultural capital in his creative process. It is suggested that this investigation requires us to consider ideas of cultural continuity and flow in relation to Lydon, the creative contexts within which he operated and the relationship between progressive music, punk and post-punk in the 1970s.
Implementation of a real-time moving object tracking system using visual
servoing
Authors: Tsai M-C. , Chen K-Y. , Cheng M-Y. , Lin K.C.
Published: October 2003

Due to the increasing popularity of surveillance and security systems, the problem of automatically tracking a moving target by visual servoing has become a research topic deserving more investigation. Nonetheless, the success of tracking a moving target in real-time primarily depends on the performance of the motion detection techniques
employed. This paper addresses visual tracking control of an unknown target that could be motional arbitrarily in the scene. A pan-tilt mechanism is used to gain the flexibility of tracking, and the so-called region-based matching method and motion energy method are modified and proposed in this study to detect a moving target based on the consecutive images acquired. A visual servo control scheme that adopts proportional control in the visual
loop for reducing the servo lagging is proposed using output disturbance feedforward compensation. Experimental results show the superiority of the proposed method in achieving high system bandwidth and tracking accuracy.
Undesirable aliens: factors determining the distribution of three invasive bird species in Singapore
Authors: Lim Haw Chuan , Sodhi Navjot S. , Brook Barry W. , Soh Malcom C. K.
Published: October 2003

Biological invasions are a major environmental concern due to their negative impacts on biodiversity and economics. We determined the population sizes and habitat-abundance relationships of the three most successful invasive bird species in Singapore: the house crow Corvus splendens, white-vented myna Acridotheres javanicus and common myna A. tristis. Estimated population sizes of the three species between February 2000 and February 2001 were between 106 000-176 000, 122 000-155 000 and 20 000-29 000, respectively. Population size of the house crow grew dramatically (>30-fold) in the last 15-16 y while that of the white-vented and common myna declined. Habitat-abundance relationships suggest that house crows are highly dependent on anthropogenic food. Their abundance was also positively related to proximity to coast. The common myna associated closely with agricultural areas while the white-vented myna probably preferred urban greenery among residential buildings. Our study shows that the three invasive bird species associated with different aspects of human-modified environment.
Les Mandariniers de la Rivière Huai: Le Réveil Religieux de la Chine.
By Benoît Vermander. [Paris: Desclée de Brouwer, 2002. 257 pp. €22.00. ISBN 2-220-05080-7.]
Authors: Laamann Lars Peter
Published: October 2003

“The fruit of the mandarin trees growing south of the river Huai is sweet,” goes the Chinese parable, “but turns bitter when transplanted to other side.” In his latest book, the editor of Le Christ chinoisis again focusing on the cultural parameters determining the development of Christianity in China. As alluded to in the title, space is in the focus, and its relevance in the formation of human tradition, in particular religion, underlined from the beginning.
How Migrant Labor is Changing Rural China. By Rachel Murphy. [Cambridge: Cambridge University Press, 2002. 306 pp. Hard cover $70.00, ISBN 0-521-80901-0; paperback $25.00, ISBN 0-521-00530-2.]
Authors: Zhang Li
Published: October 2003

Mass rural–urban labour migration in post-Mao China has received a great deal of attention by scholars of different disciplines. The existing research has largely focused on the causes and processes of migration; the politics of migrant identities and settlements in the cities; changing modes of governance in managing the migrant population; the questions of urban citizenship; and the cultural experiences of migrant wage workers in the reform era. Yet, we know very little about the profound social, economic and cultural impact of migrant labour on Chinese rural life and society. Rachel Murphy's book provides a timely contribution to our understanding of what has happened in rural China as a result of this unprecedented labour migration. Based on extensive, in-depth fieldwork in three counties in Jiangxi province, this is an extraordinarily insightful and fresh account of the everyday socio-economic changes brought by migration in the origin areas. Moving away from the static analysis of migration by modernization and structuralist theories, Murphy emphasizes the critical role of human agency by treating rural migrants as social agents who actively pursue their goals and utilize resources while making sense of the rapidly changing social world in which they live. Her study convincingly shows that migrants are neither passive victims of structural changes nor actors completely free of structural constraints; rather they constantly adopt strategies to negotiate with and alter the larger social, economic and political environment.
Diet quality during pre‐laying and nestling periods influences growth and survival of Florida scrub‐jay (Aphelocoma coerulescens) chicks
Authors: Reynolds S. James , Schoech Stephan J. , Bowman Reed
Published: October 2003

Food availability is one of the most important determinants of successful reproduction in birds. In a previous study, it was shown that Florida scrub‐jays Aphelocoma coerulescens maintained a third egg mass when supplemented with a high fat and high protein diet during pre‐breeding, as opposed to birds that were not supplemented that laid third eggs markedly lighter in mass than first‐ and second‐laid eggs. Increases in egg quality promote chick growth and survival in many avian species. In this study, scrub‐jays were provided with supplements throughout the pre‐laying and nestling periods of 2001 and 2002 to investigate whether diet quality influenced growth and survival of chicks. Fledging success and survival to independence of unsupplemented chicks were higher for 2002 compared with 2001 indicating that breeding conditions (e.g. natural food availability) for jays were probably improved in the former year. Consistent growth patterns were found during the first 11 days post‐hatch between chicks on supplemented and those on unsupplemented territories. Of the three growth measures, only seventh primary feather growth tended to be greater for third‐hatched chicks on supplemented territories compared with third‐hatched chicks on control territories. Food supplementation influenced survival of chicks. Compared with chicks hatching on unsupplemented territories, fledging success of chicks hatching from second‐laid eggs was significantly greater in 2001, but not in 2002. Chicks from third‐laid eggs on supplemented territories also tended to survive better in 2001 compared with chicks from unsupplemented territories, but, again, no such effect was found in 2002. We conclude that food supplementation in the pre‐laying and nestling periods results in little measurable improvement in chick growth. However, improvements were found in survival of chicks that may be mediated through improvements in egg quality, but also may be the result of changes in foraging strategies of provisioning birds on supplemented territories. Chicks on supplemented territories might be in better body condition than those on unsupplemented ones. Methods other than morphometrics may be required to detect elevations in body condition of chicks raised on supplemented territories.
Sexual segregation in the activity patterns of European polecats (Mustela putorius)
Authors: Marcelli Manlio , Fusillo Romina , Boitani Luigi
Published: October 2003

A typical feature in members of the mustelid family is sexual size dimorphism, related to the different reproductive strategies of the sexes. As a consequence sexual divergence in many ecological and behavioural traits is expected, including temporal strategies. In line with this prediction, sex differences in the diel activity pattern of the European polecat Mustela putorius, a dimorphic mustelid, were quantified and tested. Twenty‐eight polecats were captured in a rural area of central Italy (Abruzzo region) and 10 males and six females were monitored in the field using radio‐telemetry techniques for 81–621 days each. Males and females showed a pronounced dimorphism in size (males/females mass ratio=1.6) within the known range for the species. Multivariate analysis of diel time preference shows that temporal behaviour differed significantly and markedly between the sexes. Males exhibited a regular and constant nocturnal pattern in every season, preferring the time ranging from 20:00 to 06:00; activity was lower at dawn and dusk, and scarce during daylight hours. Females were significantly diurnal and crepuscular but individuals revealed flexibility in activity pattern, including polyphasic or arrhythmic patterns without apparent temporal organization. The constraints of small body size and reproduction on female activity, and the sex segregation in activity timing are discussed in the context of intrasexual territoriality.
Phylogenetic relationships of Chinese antelopes (sub family Antilopinae) based on mitochondrial Ribosomal RNA gene sequences
Authors: Lei Runhua , Jian Zhigang , Hu Zhiang , Yang Wanlong
Published: October 2003

The partial mitochondrial 12S rRNA and 16S rRNA gene sequences (440 bp and 590 bp or so, respectively were determined of the Przewalski's gazelle Procapra przewalskii, Mongolian gazelle P. gutturosa, Tibetan gazelle P. picticaudata, goitered gazelle Gazella gutturosa, saiga Saiga tatarica, Tibetan antelope Pantholops hodgsoni, and thar Hemitragus jemlahicus. The average sequence divergence for all the species studied when both rRNA genes were combined was 8.4% (±0.7%), and the divergence values ranged from 0.5% to 13.3%. The average sequence divergence values for 16S rRNA gene and for 12S rRNA gene were 9.9% (±1.1%) and 6.3% (±1.1%), respectively. The sequence divergences among species of Procapra for 16S rRNA gene and for 12S rRNA gene were 1.4%(±0.5%) and 1.1% (±0.6%), respectively. Our phylogenetic analysis revealed the monophyly of the genus Procapra and that Przewalski's gazelle is more closely related to the Mongolian gazelle than to the Tibetan gazelle. We also found that the genus Procapra is closely related to Antilopini. We argued that the critically endangered Przewalski's gazelle should be treated as a species, not a subspecies of the Tibetan gazelle, which clearly warrants more attention from conservationists.
Swarming activity of temperate zone microchiropteran bats: effects of season, time of night and weather conditions
Authors: Parsons K. N. , Jones G. , Greenaway F.
Published: October 2003

Several species of vespertilionid bat gather at underground sites in temperate zones during late summer and early autumn for an activity called swarming. Up to many hundreds of bats may arrive and depart during a night. Bat activity was recorded automatically with a frequency division logging system at a swarming site in south‐east England for 415 nights between 1997 and 2001. In all 5 years, activity was highest between the beginning of August and the end of October (the swarming period), with a peak in September. Activity varied markedly from night to night and was affected by rainfall (which significantly suppressed swarming activity), and residual maximum ambient temperature (with which activity was positively correlated). Moon phase had no detectable influence on swarming activity. Activity was low in the first few hours after sunset of each night during the swarming period indicating that few bats emerged and that there was low daytime occupancy of the site. Activity increased to a peak between 6 and 7 h post‐sunset consistent with a large number of bats arriving after the first evening foraging bout. Activity then decreased gradually up to dawn as these bats departed again. Logged activity was positively correlated with the number of bats caught by harp‐trap, confirming that loggers are a reliable alternative to catching when monitoring a swarming site.
Movements and use of home range in the Iriomote cat (Prionailurus bengalensis iriomotensis)
Authors: Schmidt Krzysztof , Nakanishi Nozomi , Okamura Maki , Doi Teruo , Izawa Masako
Published: October 2003

Movement pattern of the Iriomote cat Prionailurus bengalensis iriomotensis was studied on Iriomote Island, Japan by radio‐tracking. The influence of sex and reproductive status of cats on their daily movement distance (DMD), straight‐line distance (SLD), daily movement range (DMR) and other relative indices of movements was estimated. DMD was longest in males (3.2 km) and shortest in females without kittens (1.9 km). Also, males moved faster than either females with or without kittens (0.34, 0.25 and 0.25 km/h, respectively). During the mating season, males moved faster and their DMRs were larger than during the rest of the year. The SLD/DMD ratio in males was similarly high in both seasons (0.29 and 0.33), which indicates that their daily routes were expanded over large areas year‐round, possibly to maintain a continuous control over their home range. In contrast, SLD/DMD varied seasonally in breeding females. It was low (0.09) during the lactating period, when females returned repeatedly to the den with kittens and it became high (0.32) out of the breeding season. Breeding females moved equally long DMDs in both seasons, whereas non‐breeding ones moved shorter distances during the breeding period. These differences may be related to seasonal changes of food abundance. Cats moved intensively, as indicated by long (812–1139 m) routes per km2 of their home range, and occasionally visited distant parts of their ranges in a short time (4–5 days). On the other hand, they showed a relatively slow increase of the patrolled area, from 10% to 36% of their home ranges, in the first and fifth day, respectively. Movement pattern of Iriomote cats showed no clear relation to active defence of home ranges.
Estimation of large herbivore densities in the tropical forests of southern India using distance sampling
Authors: Jathanna Devcharan , Karanth K. Ullas , Johnsingh A. J. T.
Published: October 2003

Ecological densities of large herbivores were estimated using the line transect method in the tropical moist forests of Bhadra Tiger Reserve, southern India, during November 2000. The species of interest were chital Axis axis, sambar Cervus unicolor, muntjac Muntiacus muntjak, gaur Bos gaurus and Hanuman langur Presbytes entellus. Six permanent transects, ranging from 2.6 to 3.6 km (totalling 18.2 km) were each walked 26 times. A total of 473 km were walked during the surveys. Numbers of detections were generally low (51, 25, 68, 17 and 302 for chital, sambar, muntjac, gaur and langur, respectively). Mean estimated densities of different species were[D (± SE)]: 4.51 (±1.05) chital km−2, 0.89 (±0.23) sambar km−2, 3.64 (±0.63) muntjac km−2, 1.48 (±0.63) gaur km−2 and 22.62 (±2.64) langur km−2. Possible shortcomings of our estimates are considered and suggestions made for improving future surveys. A comparison with densities estimated for these species in other well‐protected parks showed that the chital, gaur and sambar densities in Bhadra were extremely low. The main causal factors for these low densities seem to be poaching and livestock grazing.
The in vitro and in vivo development of goat embryos produced by intracytoplasmic sperm injection using tail-cut spermatozoa
Authors: Wang Bin , Baldassarre H. , Pierson J. , Cote F. , Rao K.M. , Karatzas C.N.
Published: October 2003

The objective of this study was to assess the efficacy of a novel intracytoplasmic sperm injection (ICSI) procedure, as well as the in vitro and in vivo developmental competence of goat embryos produced by ICSI. Oocyte-cumulus complexes recovered by LOPU from donors stimulated with gonadotrophins were matured in vitro. Fresh goat semen was used for ICSI following Percoll gradient washing. Tail-cut spermatozoa were microinjected into the ooplasm of goat oocytes using a piezo micropipette-driving system (PiezoDrill). In order to assess developmental competence, the ICSI-derived zygotes were cultured in one of two media systems (mTALP-mKSOM vs G1.3-G2.3) for in vitro development or were transferred into recipients for full-term development. The results suggest that cutting sperm tails using the oocyte-holding pipette coupled with the PiezoDrill is an efficient approach for goat ICSI in terms of oocyte survival, pronuclear development and initial cleavage. The mTALP-mKSOM culture system was more suitable for in vitro development of ICSI-derived goat embryos than G1.3-G2.3. This first report of full-term development of an ICSI-derived goat embryo suggests that ICSI can be applied to assisted reproduction in goats.
Potential amplification of early pregnancy signals by ovarian follicular cells in suspension within the Fallopian tube
Authors: Hunter R.H.F. , Einer-Jensen N.
Published: October 2003

That a mammalian embryo might influence the maternal
endocrinological and/or immunological systems
whilst still in the Fallopian tube has long seemed possible
(Fig. 1). Under normal circumstances, the embryo
contains a full diploid complement of genetic information
and thus the point at issue is just how soon instructions
in the genome are expressed for trophic purposes.
It could be argued from several points of view
that it would be biologically prudent for an embryo to
influence the mother whilst still at an early stage of
development. Consideration of the extremely intimate
apposition of the zona pellucida and the tubal epithelium
- perhaps best appreciated in scanning electron
micrographs (Fig. 2) - also suggests scope for a mutual
exchange of signals. Even so, one of the earliest
recorded maternal responses to a developing embryo
is the change in permeability of the capillary bed of the
uterus that precedes implantation in rodents: this can
be demonstrated by the Pontamine blue reaction, a
series of bands of dye in the uterine wall corresponding
to the location of individual embryos, and is
detectable in rats on the fourth day after mating
(Psychoyos, 1960, 1973).
Nucleolus in apoptosis-induced mouse preimplantation embryos
Authors: Baran V. , Fabian D. , Rehak P. , Koppel J.
Published: October 2003

Apoptosis may occur in early embryos in which the execution of essential developmental events has failed. Thus the initiation of the apoptotic mechanism may be related to activation of the embryonic genome. In this way, developmentally incompetent cells or whole embryos are eliminated. It is likely that some link exists between failed resumption of rRNA synthesis and the incidence of apoptosis in cleaving embryos. In this context, decreased developmental potential in cleaving nucleotransferred embryos is consistent with cell loss, and very likely due to programmed cell death. The effects of apoptosis inducers on cleaving embryos have not been characterised in comparable detail to that in the case of somatic cells. Early embryos provide a very good model for study of these processes because of the specificity of rRNA transcription resumption after fertilization. In our experiments three apoptosis inducers (staurosporin 10 mM, actinomycin D 0.05 mg/ml and camptothecin 0.1 mg/ml) were used in a culture medium for 15 h at the 4-cell stage (day 2) of mouse embryos, followed by further development in a pure culture medium until fixation on days 3, 4 and 5. In staurosporin-induced embryos, light microscopy immunostaining of nucleolar proteins (fibrillarin, Nopp140, protein B23) did not reveal changes in nucleolar morphology on day 3. On days 4 and 5, more compact (roundish) nucleoli (in comparison with controls) were observed. The embryos treated with camptothecin displayed a similar staining pattern to those with staurosporin at each day. In actinomycin-D-treated embryos, marked changes in nucleolar appearance were visible as early as day 3. These changes in nucleolar morphology consisted of loss of the reticulation appearance and fragmentation of nucleoli. In addition to nucleolar changes, significantly decreased cell proliferation was observed. The induced embryos did not reach the blastocyst stage. The number of blastomeres was decreased, and staining with Hoechst 33342 revealed a significant percentage of apoptotic nuclei (condensed/fragmented nuclei) from day 4.
Identity/Crisis
Authors: Joffe Alexander H.
Published: October 2003

Archaeology has an identity problem. At least three factors are involved. The postmodern view of radical instability has collided with processual aversions towards ‘meaning’, resulting in a stalemate regarding the past. Modern problems with identity, including the role of the past and archaeology itself, have generated additional confusion. Identity is a hall of mirrors which parallels other epistemological debates in archaeology, all of which revolve around the divide between realism and idealism. Archaeology cannot resolve this problem. The solution is not, however, to become either better technicians or more strident ideologues, but to become more informed contributors to larger debates in the human sciences and philosophy, in an atmosphere of civility and pluralism.
Post-processualism, professionalization and archaeological methodologies. Towards reflective and radical practice
Authors: Chadwick Adrian
Published: October 2003

In recent years the gap between archaeological theory and practice has been closing, but although there have been calls for ‘reflexivity’, there has been little critical examination of its meanings. Proposed reflexive methodologies still perpetuate many traditional hierarchies of power, and fail to consider the creative nature of excavation and post-excavation. Much archaeological work in Britain, Europe and North America also takes place within the commercial sphere, and post-processual ideas cannot advance archaeological practice unless they can be implemented in contract archaeology. This paper examines theoretical considerations of reflexivity, representation, subjectivity and sensual engagement to highlight their relevance to everyday archaeological practice, and their political potential to undermine existing hierarchies of power within commercial archaeology.
Fear‐potentiated startle and posttraumatic stress symptoms in urban police officers
Authors: Pole Nnamdi , Neylan Thomas C. , Best Suzanne R. , Orr Scott P. , Marmar Charles R.
Published: October 2003

We studied the effects of increasing threat conditions on self‐reported emotion, eyeblink electromyogram, and skin conductance responses to startling sounds in 55 police officers who endorsed a range of PTSD (posttraumatic stress disorder) symptoms. We found that contextual threat affected both physiologic and self‐reported emotional responses. Greater PTSD symptom severity was related to greater physiologic responses under the low and medium but not under the high threat condition. The relationship between PTSD symptoms and physiologic responses was neither explained by self‐reported emotional responses nor preexisting reported exaggerated startle symptoms. Our results emphasize the importance of contextual threat and suggest that laboratory measures of startle improve upon self‐reported exaggerated startle alone in indexing PTSD symptom severity in urban police officers.
Neuroleptic malignant syndrome in juvenile neuronal ceroid lipofuscinosis associated with low‐dose risperidone therapy
Authors: Vercammen L. , Buyse G. M. , Proost J. E. F. , Van Hove J. L. K.
Published: October 2003

Summary:#We present a patient with juvenile neuronal ceroid lipofuscinosis who developed a neuroleptic malignant syndrome when treated for hallucinations with a very low dose of risperidone, an atypical neuroleptic medication with usually few extrapyramidal side‐effects. The loss of dopaminergic neurons in this condition may make these patients more vulnerable to this severe adverse effect.
Prenatal diagnosis for arginase deficiency: A case study
Authors: Hewson S. , Clarke J. T. R. , Cederbaum S.
Published: October 2003

Arginase deficiency is a rare, autosomal recessive, disorder of the urea cycle characterized by mild hyperammonaemia, hyperargininaemia, dibasic aminoaciduria and orotic aciduria, associated with progressive spastic tetraplegia, seizures, psychomotor retardation, and growth failure. We report a family who presented with their daughter at 4 years 11 months of age with an acute encephalopathy. Initial laboratory results revealed hyperammonaemia (160 µmol/L; normal 0–34), hyperargininaemia (512 µmol/L; normal 23–86) and orotic aciduria. A diagnosis of arginase deficiency was confirmed by enzyme assay, and treatment with a modified protein‐restricted diet along with sodium benzoate therapy was initiated. Over time, intellectual development has been normal, but the child developed spasticity in her lower extremities. Subsequently, the mother presented at 6 weeks of pregnancy seeking prenatal diagnosis. Prenatal testing for arginase deficiency has only been reported in one other case. Arginase is not expressed in cultured amniotic fluid cells or chorionic villus samples. Testing for arginase activity assay in red blood cells, isolated by cordocentesis, was performed and predicted an unaffected fetus. The result was confirmed by postnatal enzyme analysis of red cells from the newborn. On the basis of our experience, prenatal diagnosis of arginase deficiency by cord red blood cell arginase activity assay appears possible.
Dynamic fluid kinetic (DyFK) simulation of auroral ion transport: Synergistic effects of parallel potentials, transverse ion heating, and soft electron precipitation
Authors: Wu X.‐Y. , Horwitz J. L. , Tu J.‐N.
Published: October 2003

Ion outflow processes along auroral field lines are simulated with a dynamic fluid kinetic (DyFK) model which couples a comprehensive fluid ionospheric (120–1100 km altitude) model to a semikinetic treatment for the topside through 3 RE region. Using a simplified electron description, large‐scale extended parallel electrical fields driven by anisotropic hot plasma distributions have been incorporated in addition to the soft auroral electron precipitation and wave‐driven ion‐heating processes previously simulated [Wu et al., 1999]. Simulations show that auroral ionospheric ion outflows involve initial evacuation, ion‐heating, and replenishment phases. The ionospheric ion supply is effectively elevated by the soft electron precipitation to topside altitudes, where the wave‐driven transverse ion heating pumps ions upward. The altitude distribution and duration of wave heating and potential drop largely affect the “pressure cooker” ion trap formation. With comparable and persistent downward potential drop and wave heating, the pressure cooker produces slow and dense suprathermal ion outflows. The ion velocity distribution evolves in an extended ion trap from bowl and counterstreaming suprathermal conic distributions at lower altitudes into mirrored conics and finally toroidal distributions at the top of the pressure cooker. The wave heating is less effective for H+ ions, owing partly to their fast transit through the wave‐heating region. The H+ ion trap tends to be lower but more extended in altitudinal extent than the O+ ion trap. H+ flux and total flow are about a third to half of those of O+. Some of the toroidal distributions and ion species variations of beam and conic energies in these simulations qualitatively resemble satellite observations of such ion distributions.
Imaging riometer observations on energetic electron precipitation at SANAE IV, Antarctica
Authors: Wilson A. , Stoker P. H.
Published: October 2003

The expansion phase of a substorm on the evening of 1 May 1997 was studied from recordings of all‐sky optical aurora and a 64‐beam imaging riometer at the Antarctic base SANAE IV (L = 4.1). Digitized all‐sky, low‐level white light images of auroral optical emissions were mapped onto the angular directivity functions of the 64‐beam imaging riometer. During the period of investigation, several optical arcs appeared and disappeared, while a persistent absorption structure appeared in the south (poleward). This and new structures changed only slowly in time. The differences in morphologies of optical emissions and absorption regions, together with temporal differences, imply that there are two categories of energetic auroral electrons: the softer electrons (<10 keV) causing optical emissions in the E and F regions of the ionosphere and the harder (>10 keV) electrons ionizing down into the D region for cosmic radio noise absorption (CRNA). Optical emissions tend to lead the appearance of cosmic radio noise absorptions by 0–60 s in a specific region of ionospheric space. Furthermore, in the all‐sky optical data, westward traveling surges (WTS) were observed coincident with a CRNA WTS and leading the CRNA WTS by ∼30–50 s. In the CRNA data the WTS was ribbon‐like, traveling westward at a speed of 2.3 km s−1. These observations suggest that the softer electrons, causing E and F region optical emissions, may be injected onto drift paths closer to Earth than the more energetic electrons, ionizing down into the D region for cosmic radio noise absorption. The harder electrons could have been accelerated by, for instance, an increasing dawn‐to‐dusk electric field for later precipitation.
Sea ice kinematics and surface properties from RADARSAT synthetic aperture radar during the SHEBA drift
Authors: Stern Harry L. , Moritz Richard E.
Published: October 2003

Satellite data are important for providing the large‐scale context of the Surface Heat Budget of the Arctic Ocean (SHEBA) station and for characterizing the spatial variability of the sea ice in its vicinity. The Canadian RADARSAT satellite collected 195 synthetic aperture radar (SAR) images of the SHEBA site over the course of the 1 year drift. The RADARSAT Geophysical Processor System (RGPS) used these images to compute the spatial pattern of ice motion within 100 km of the SHEBA station by tracking features in sequential images. From the ice motion data the divergence and shear of the pack ice are estimated. The divergence is large from November to January, followed by a gradual convergence from February through July. The character of the ice motion changes at the end of July, from piecewise rigid motion to free drift. The ice motion reverts to its winterlike character in late September. Thus the “kinematic” summer runs from late July to late September. The radar backscatter also goes through seasonal transitions, capturing the abrupt onset of melt (29 May) and freeze‐up (15 August). The concentration of multiyear ice is about 94% in the fall, and its backscatter signature remains stable through spring. Multiyear and first‐year ice cannot be distinguished during the summer melt season, when the mean backscatter is negatively correlated with the surface air temperature. The “thermodynamic” summer runs from late May to mid‐August.
Electrostatic plasma turbulence in the topside equatorial F region ionosphere
Authors: Hysell D. L. , Shume E. B.
Published: October 2003

Two‐dimensional, turbulent plasma flows in the topside equatorial F region ionosphere associated with fully developed equatorial spread F are analyzed and simulated numerically. In the inertially dominated flow regime, the governing equations of motion resemble the Navier Stokes equation but are cubicly nonlinear. Large amplitude density irregularities are prerequisite for inertial effects to be important, but when these are present, the third‐order nonlinear effects become significant, mean‐squared velocity and vorticity cease to be conserved by nonlinear mode coupling, and the foundations of the turbulent cascade theory of Kraichnan [1967] are undermined. Nonetheless, one‐dimensional, angle‐averaged velocity spectra computed from simulated flows exhibit similarity ranges with k−5/3 and k−3 power laws, resembling inertial ranges and suggesting turbulent cascades. Invariants of the flow (quantities conserved by nonlinear mode coupling) are found which are generalizations of the quadratic forms of kinetic energy and enstrophy and which are dimensionally equivalent to them. Statistical properties of the flow appear to permit turbulent cascades to arise.
Consequences of current interruption for plasma sheet dynamics
Authors: Pritchett P. L. , Coroniti F. V.
Published: October 2003

A three‐dimensional, fully electromagnetic particle simulation model is used to explore the upper limits to the physical effects which might be produced by the onset of anomalous resistance within the substorm growth phase thin near‐Earth current sheet. This is accomplished by blocking a local portion of the cross‐tail current at regular intervals of ≈2ωpe−1. The blocking leads to an enhancement of the cross‐tail electric field and to the formation of a localized reconnection region. Within the blocking region the in‐plane (xz) current system is dominated by the reconnection Hall currents. On the earthward side of the X line, the Hall currents flow into (out of) the ionosphere at higher (lower) latitude, thus forming a coaxial sheet current system. The field‐aligned currents that originate from the diversion of the cross‐tail current are likewise dominated by the reconnection Hall currents, with the “substorm current wedge” involving only a relatively small fraction of the total field‐aligned current. This study suggests that the sudden onset of a very strong anomalous resistance can, in principle, disrupt the near‐Earth current sheet and produce a diversion of a portion of the cross‐tail current onto an ionospheric closure path. Whether such a current sheet disruption is, in fact, responsible for substorm onset is still unclear.
Comment on “Model of ionic charge states of impulsive solar energetic particles in solar flares” by M. Dolores Rodríguez‐Frías, Luis del Peral, and Jorge Pérez‐Peraza
Authors: Kovaltsov Gennadi A. , Kartavykh Yulia Y. , Kocharov Leon , Ostryakov Valery M. , Torsti Jarmo
Published: October 2003

Attention is drawn to the fact that the numerical code ESCAPE by Rodríguez‐Frías et al. [2001] is in conflict with other models of charge‐changing processes in solar corona, including the most reliable model by Arnaud and Raymond [1992]. We find in the >0.1 MeV nucleon−1 energy range a tendency of the ESCAPE code to overestimate the ionic charge of iron. This implies an underestimation of the density × acceleration‐time product in the ion acceleration region in solar corona.
Dayside pulsed aurora intensifications, observed by ITACA during constant interplanetary magnetic field Bz ∼ 0 and By ≪ 0
Authors: Massetti S. , Orsini S. , Candidi M. , Kauristie K.
Published: October 2003

On 30 November 1999, the Italian all‐sky camera ITACA (Ny‐Ålesund, Svalbard), observed one of the strongest dayside aurora events occurred during the 1999/2000 winter season. In the postnoon, the red auroral activity was characterized mainly by four quasiperiodic pulsed activations, with brightness, period and latitudinal extent increasing monotonically with time. During this period, the Wind satellite was well positioned upstream in the solar wind and measured a IMF Bz close to zero, together with a constantly negative IMF By ∼ −10 nT. A detailed description of the phenomenon is presented, together with a preliminary analysis of the data. This work underlines that it is difficult to identify, among the parameters usually involved in the solar wind–magnetosphere coupling, the source of the modulation(s) observed in the aurora development.
Anhysteretic remanent magnetization of fine magnetic particles
Authors: Egli R. , Lowrie W.
Published: October 2003

Various magnetic parameters are in common use for estimating the grain size of magnetic particles. Among these, the ratio of the intensity of anhysteretic remanent magnetization (ARM) to that of isothermal remanent magnetization, as well as their alternating field (AF) demagnetization curves are used as an indicator of the domain state of the particles. Several models have been proposed to describe physically the acquisition of ARM in a biased AF field. Jaep [1969] first developed a semiquantitative theory based entirely on the thermal fluctuation analysis developed by Néel [1949, 1954, 1955]. Significant discrepancies were found between his model and experimental results on magnetite. A new, general theory of ARM based on the work of Jaep is presented here, with particular regard to the influence of various parameters like grain size, coercivity, and mineralogy on ARM intensity. An analytical expression for ARM intensity in the special case of very fine particles was derived from this theory, and a good agreement with experimental results and data from the literature was found. A new estimation of the atomic reorganization time was obtained from ARM measurements on a sample of the Yucca Mountain Tuff, which has well‐known mineralogy and grain‐size distribution. The results are in agreement with the value proposed by McNab et al. [1968] for magnetite. Some authors considered magnetic interactions as the key to understand the ARM in fine particles, and this is certainly true for strongly interacting samples. In this case, ARM would be useless for the characterization of magnetic grains. However, many sediments have a very low concentration of well‐distributed magnetic grains. For these samples, the explanation of an ARM in terms of intrinsic properties of the grains, as qualitatively proposed by other authors, is more suitable.
Model estimates of M2 internal tide energetics at the Hawaiian Ridge
Authors: Merrifield Mark A. , Holloway Peter E.
Published: October 2003

A primitive equation model is used to examine the structure and energetics of M2 internal tides generated at the Hawaiian Ridge. Recent estimates based on altimeter data suggest that 20 GW of barotropic tidal dissipation occurs at the ridge, with conversion to internal tides believed to be the dominant dissipation mechanism. The model simulates an internal tide that accounts for 9.7 GW of radiated energy away from the ridge in the northeast and southwest directions. The strongest generation occurs at three sites where enhanced barotropic currents flow across elongated topographic features. The depth‐integrated baroclinic energy flux and energy densities at these sites are on the order of 104 W m−1 and 104 J m−2, respectively. A modal decomposition indicates that 62% of the outgoing energy flux is accounted for by the first internal mode, 15% is accounted for by the second mode, and less than 5% is accounted for by each subsequent higher mode. The tidal dissipation due to bottom friction along the ridge is estimated to be 0.1 GW. The level of turbulent dissipation near the ridge owing to tidal energy conversion remains to be determined to assess fully the barotropic‐baroclinic energy budget.
Geomagnetic effects due to an eclipse‐induced low‐conductivity ionospheric spot
Authors: Hvoždara M. , Prigancová A.
Published: October 2003

The solar eclipse on 11 August 1999 was quite unique due to its totality belt coverage of the territory of central Europe where the facilities for the geophysical monitoring are most dense. Ionospheric and geomagnetic observations during the eclipse allowed us to study the eclipse‐induced effects more precisely. A mathematical model based on the classical Ashour‐Chapman model is considered to show that the decrease (up to 40%) of the ionospheric total electron content in the region of the totality belt leads finally to geomagnetic disturbances quantitatively dependent on the position of both the quasi‐circular spot of the ionospheric conductivity decrease and given geomagnetic observatory location. The model is generalized for the anisotropic ionosphere. The theoretical estimates are compared with observational data from European geomagnetic observatories: Fürstenfeldbruck, Nagycenk, Tihany, and Hurbanovo, the last one being nearby the totality belt.
Average characteristics and activity dependence of the subauroral polarization stream
Authors: Foster J. C. , Vo H. B.
Published: October 2003

Data from the Millstone Hill incoherent scatter radar taken over two solar cycles (1979–2000) are examined to determine the average characteristics of the disturbance convection electric field in the midlatitude ionosphere. Radar azimuth scans provide a regular database of ionospheric plasma convection observations spanning auroral and subauroral latitudes, and these scans have been examined for all local times and activity conditions.We examine the occurrence and characteristics of a persistent secondary westward convection peak which lies equatorward of the auroral two‐cell convection. Individual scans and average patterns of plasma flow identify and characterize this latitudinally broad and persistent subauroral polarization stream (SAPS), which spans the nightside from dusk to the early morning sector for all Kp greater than 4. Premidnight, the SAPS westward convection lies equatorward of L = 4 (60° invariant latitude, Λ), spans 3°–5° of latitude, and has an average peak amplitude of >900 m/s. In the predawn sector, SAPS is seen as a region of antisunward convection equatorward of L = 3 (55° Λ), spanning ∼3° of latitude, with an average peak amplitude of 400 m/s.
Polarity reversal of the solar magnetic field during cycle 23
Authors: Wang Y.‐M. , Sheeley N. R. , Andrews M. D.
Published: October 2003

Using magnetograph data, coronagraph observations, and source surface extrapolations, we examine the evolution of the photospheric magnetic field from 1996 through the 2000–2001 polarity reversal and show how this evolution is reflected in coronal holes, coronal streamers, the heliospheric current sheet (HCS), and the solar wind. The photospheric polarity reversal is completed in the more active Northern Hemisphere in late 2000 and then in the Southern Hemisphere in 2001. The polar coronal holes disappear in 2000 and start to re‐form in 2001; during this interval, most of the open magnetic flux resides in the active region latitudes, where small coronal holes with strong footpoint fields generate predominantly slow solar wind. The nondipolar nature of the large‐scale coronal field at sunspot maximum gives rise to complex streamer/HCS topologies, in which a four‐sector structure and even a secondary, detached current sheet with cylindrical geometry are sometimes present. Comparison of the potential field extrapolations with coronagraph and Ulysses observations suggests that the magnetograph measurements may have underestimated the strength of the south polar field during late 2000.
A fault constitutive relation accounting for thermal pressurization of pore fluid
Authors: Andrews D. J.
Published: October 2003

The heat generated in a slip zone during an earthquake can raise fluid pressure and thereby reduce frictional resistance to slip. The amount of fluid pressure rise depends on the associated fluid flow. The heat generated at a given time produces fluid pressure that decreases inversely with the square root of hydraulic diffusivity times the elapsed time. If the slip velocity function is crack‐like, there is a prompt fluid pressure rise at the onset of slip, followed by a slower increase. The stress drop associated with the prompt fluid pressure rise increases with rupture propagation distance. The threshold propagation distance at which thermally induced stress drop starts to dominate over frictionally induced stress drop is proportional to hydraulic diffusivity. If hydraulic diffusivity is 0.02 m2/s, estimated from borehole samples of fault zone material, the threshold propagation distance is 300 m. The stress wave in an earthquake will induce an unknown amount of dilatancy and will increase hydraulic diffusivity, both of which will lessen the fluid pressure effect. Nevertheless, if hydraulic diffusivity is no more than two orders of magnitude larger than the laboratory value, then stress drop is complete in large earthquakes.