bluuebunny/crossref_metadata_2025 huggingface dataset:
THE TAMING OF THE DUEL: MASCULINITY, HONOUR AND RITUAL VIOLENCE IN LONDON, 1660–1800
Authors: SHOEMAKER ROBERT B.
Published: November 2002

Over the course of the ‘long’ eighteenth century the nature and significance of duels fought in the London area changed dramatically. Pistols replaced swords, seconds took on a new role as mediators, and new conventions reduced the violence. Consequently, injuries and fatalities decreased significantly. The purpose of fighting duels also shifted from the defeat of one's antagonist to a demonstration of courage. Although duels continued to occur, growing opposition meant that the audience of people who supported duelling became increasingly limited and duels took place in places far from public view. At the same time, both the press and the courts provided alternative strategies for defending reputations. These changes cannot be attributed to technological developments, official attempts to prevent duelling, or the embourgeoisement of the duel. Rather, they resulted from a series of interlinked cultural changes, including an increasing intolerance of violence, new internalized understandings of elite honour, and the adoption of ‘polite’ and sentimental norms governing masculine conduct. These eighteenth-century changes shed new light on the reasons for the final end of duelling in England in 1852.
From Workshop to Wasteland: De-industrialization and Fragmentation of the Black Working Class on the East Rand (South Africa), 1990–1999
Authors: Barchiesi Franco , Kenny Bridget
Published: November 2002

In 1999 the South African government passed the Municipal Structures Act which established the Ekurhuleni Metropolitan Council and merged the East Rand towns of Alberton, Germiston, Brakpan, Benoni, Kempton Park, Springs, and Nigel under a common municipal authority. The new demarcation created a unified administrative structure for this region of approximately 2.5 million people living east of Johannesburg. It gave formal expression to long-standing processes of socioeconomic development that have defined the East Rand as a highly specific geographical entity. Between the 1950s and the 1970s the East Rand mapped itself on to South Africa's economic terrain as its industrial “workshop”, as manufacturing replaced mining as the major contributor to GDP. The administrative unification of the East Rand has taken place, however, at a moment when established patterns of economic and social integration based on manufacturing are undermined by the impact of restructuring encouraged by domestic and global forces.
The International Association of Machinists, Pratt & Whitney, and the Struggle for a Blue-Collar Future in Connecticut
Authors: Forrant Robert
Published: November 2002

Riding down Main Street in East Hartford, Connecticut toward the six smokestacks dominating the front of Pratt & Whitney's mammoth aircraft engine factory, one cannot help noticing numerous artifacts associated with rapid industrial decline: empty and trash-strewn lots, boarded-up storefronts, and vacated triple-deckers, once homes for Pratt & Whitney workers. A short drive away on the other side of the Connecticut River one can observe the dichotomies between East Hartford and downtown Hartford with its glittering insurance companies, banks, and the headquarters – known around Hartford as the “Gold Building” – of Pratt's parent, the United Technologies Corporation (UTC). The various social clubs, bars, and purveyors of fast food, ice cream, and fresh baked pies, that have served thousands of lunches and early suppers to members of the International Association of Machinists (IAM) are at risk.
On “De-industrialization” and the Crisis of Male Identities
Authors: Joshi Chitra
Published: November 2002

The last two decades in India have seen the decline of traditional factory industries and a growing process of informalization and casualization of labour. The crisis of industries like textiles and steel has meant a virtual decimation of a working class in old industrial centres. This paper will look at the phenomenon of de-industrialization and its implications for a labouring population whose lives were intimately connected with industrial work.
Epiphytic algal cover and sediment deposition as determinants of arthropod distribution and abundance on mangrove pneumatophores
Authors: Procheş Şerban , Marshall David J.
Published: November 2002

We report here an investigation on intertidal mangrove pneumatophores, examining the relationships between arthropod abundance (for ten taxa, mostly belonging to the meiofaunal size-class), algal biomass and sediment cover. There was a strong correlation between the mass of sediment and the mass of macroalgae, supporting the assumption that pneumatophore sediment cover depends on algal growth. These two components of pneumatophore cover were negatively related to elevation, an effect probably relating to desiccation-limited algal growth towards the pneumatophore tips. Total arthropod abundance and that of some taxa (particularly, Uropodidae (Acari), Metidae (Crustacea), Ceratopogonidae (Insecta) and Empidoidea (Insecta)), was negatively correlated with elevation and positively correlated with sediment and algal cover, suggesting a good relationship between abundance and habitat availability. Other arthropod taxa (particularly, Halacaridae (Acari)) however, showed the opposite pattern of relationships. When the pneumatophore cover was physically removed, in an experiment to assess assemblage recovery rates, some arthropod taxa (Halacaridae (Acari), Harpacticoidea (Crustacea) and Ceratopogonidae (Insecta)) had completely recovered by 25 weeks, while others (Tanaididae (Crustacea) and Empidoidea (Insecta)) only partially recovered.
Fecampia erythrocephala rediscovered: prevalence and distribution of a parasitoid of the European shore crab, Carcinus maenas
Authors: Kuris Armand M. , Torchin Mark E. , Lafferty Kevin D.
Published: November 2002

An ecological assessment of Fecampia erythrocephala, reporting its habitat distribution, abundance, host specificity, size-specific prevalence, frequency distribution among hosts, effect on host growth, and its site specificity within these hosts is presented. At the Isle of Man and near Plymouth, Fecampia erythrocephala cocoons were generally abundant on the undersides of rocks in the Ascophyllum and Fucus serratus zones. Infected crabs were also most common in these habitats. Both Carcinus maenas and Cancer pagurus were parasitized at similar prevalences, although the former species was relatively much more common in the habitats where the worm cocoons were abundant. Fecampia erythrocephala did not infect crabs larger than 11 mm carapace width, and prevalence decreased significantly with crab size. Prevalences reached 11% in areas where cocoons were abundant. Together with the large size of these worms relative to the size of the host crabs and the observations on worm emergence, these life history features indicate that F. erythrocephala is a parasitoid of young shore crabs. Fecampia erythrocephala cocoon abundance is often high in localized areas and size-prevalence information suggests that worms mature rapidly in these crabs. This suggests that F. erythrocephala is an important contributor to crab mortality and to the ecology of shore crabs at these sites.
The respiration and hypoxic tolerance of Nucula nitidosa and N. nucleus: factors responsible for determining their distribution?
Authors: Holmes Sebastian P. , Miller Nicola , Weber Anke
Published: November 2002

Measurement of the respiration of Nucula nitidosa and N. nucleus determined that N. nucleus had a respiration rate approximately a third greater than that of N. nitidosa, 215·28 and 135·64 μl O2 gdfw−1 h−1, respectively. This was calculated to be equivalent to a metabolic rate of 0·648 J individual−1 24 h−1 for N. nitidosa and 1·752 J individual−1 24 h−1 for N. nucleus. Estimation of the production of N. nucleus, from its respiration rate, revealed that for comparable populations, N. nucleus was approximately a third more productive than N. nitidosa, 30 kJ g dry flesh weight (dfw)−1 m−2 y−1 as opposed to 20 kJ gdfw−1 m−2 y−1. Examination of the Kleiber's constant (β) obtained for each species, demonstrated that for N. nitidosa β fell in the range 0·75–1 and that for N. nucleus β fell in the range 1–1·25. This suggests, in combination with other data, that N. nucleus adopts an ‘exploitative’ functional strategy as opposed to N. nitidosa, which can be regarded as adopting a ‘conservationist’ functional strategy.

Observations on the hypoxic tolerance of both N. nitidosa and N. nucleus revealed that N. nucleus had a hypoxic tolerance about twice that of N. nucleus. The mean survival time±standard error for N. nitidosa was 3·53±0·18 d in contrast to 7·72±0·21 d for N. nitidosa. The hypoxic tolerance of either species was not related to body size and was independent of any possible effects of starvation. These results are discussed with reference to their potential effects to determine the distribution of N. nitidosa and N. nucleus.
Reproductive indices and fecundity of Helicolenus dactylopterus dactylopterus (Teleostei: Scorpaenidae) in the Catalan Sea (western Mediterranean)
Authors: Muñoz M. , Casadevall M.
Published: November 2002

Various indices related to reproduction and the fecundity of Helicolenus dactylopterus dactylopterus (Teleostei: Scorpaenidae) were analysed. Sexual dimorphism does not occur in the population we studied and the sex ratio is always equal. The size of the species at sexual maturity is a standard length of 130 mm for males and 145 mm for females. The maximum gonadosomatic index values for males and females are temporally out of phase to a large degree, which explains the intra-ovarian storage of spermatozoa that occurs in this species. There are large hepatic reserves which are basically used in the synthesis of vitellogenin, while the mesentery fat reserves are not mobilized until the end of the maturation process of the oocytes. Multiple spawning takes place between January and February, consisting of between 11,000 and 87,000 eggs, of about 500 μm in diameter. The fecundity of the species is, with a high degree of correlation, determined by the size and weight of the individuals.
Diet of the harbour seals Phoca vitulina of Dundrum Bay, north-east Ireland
Authors: Wilson Susan C. , Pierce Graham J. , Higgins Catherine M. , Armstrong Michael J.
Published: November 2002

This study has shown that the main constituents of the diet of the harbour seals (Phoca vitulina) of Dundrum Bay, County Down, north-east Ireland, during the past few years (1995–2000) have been small flatfish and gadid fish, with the emphasis shifting from the beginning to the end of the study period from flatfish to gadids, principally whiting and haddock/pollack/saithe. During both 1995 and 1996 the diet of post-weaning pups consisted almost entirely of small gadid fish. The implications of this relatively poor diet, apparently deficient in oily fish, are considered—together with information on fish stocks in the north-west Irish Sea in recent years—in the context of an apparent decline both in the breeding population of harbour seals along the County Down coast and in the play behaviour of juvenile seals.
Estimation of body volume and body density in California sea lion pups
Authors: Luque Sebastián P. , Aurioles-Gamboa David
Published: November 2002

Body volume was measured directly by the water displacement method and using three different geometric models, consisting of a series of cones and truncated cones, in California sea lion (Zalophus californianus) pups from the Gulf of California. Volume is required for the estimation of density, an indicator of the ratio of fat to lean mass. A model consisting of two cones and four truncated cones predicted body volume with greatest accuracy (volume=1·11+1·06&;estimated volume, r2=0·90, P<0·001, SEE=0·673, N=274). This model, however, was not adequate to estimate absolute pup body density (mass to volume ratio), as it yielded values poorly correlated with observed body density (r=0·14, P=0·02). However, the regression line of mass on volume indicated that density decreased with volume, so the mass to volume ratio is a biased estimate of density and is not appropriate for comparing whole body density among sea lion pups. The direct analysis of the relationship between body mass and body volume (observed or estimated) through analysis of covariance provided a better tool to compare the relative density among pups of different sex, populations, or born in different years. The results from such analyses are consistent with previous evidence of sex and age effects on body composition.
A simple and inexpensive device to measure immersion times in wave exposed shores
Authors: Venegas Roberto M. , Navarrete Sergio A. , Finke Gerhard R.
Published: November 2002

An inexpensive and easy to build and deploy device to measure immersion times is described. The device consists of an LCD timer mounted in a small waterproof PVC housing. Time is recorded and integrated when seawater creates a connection between two stainless steel contacts. The device was tested in the laboratory and under field conditions on a wave swept shore. Under laboratory and field conditions, the device gave precise estimates of immersion times with maximum error of less than 4%. Applicability of this device in ecological and physiological studies is discussed and compared to other methods proposed in the literature.
Cirrate octopods from Greenland and Iceland waters
Authors: Collins Martin A.
Published: November 2002

Three species of cirrate octopod are reported from deep-sea collections around the coasts of Greenland and Iceland in the North Atlantic. Twenty-one specimens of Stauroteuthis syrtensis were caught from east and west Greenland at depths of 258–1321 m, representing a considerable geographic and bathymetric extension of the range. Nine specimens of a putative new species of the genus Opisthoteuthis are reported, and are the first records of this genus in the area. Nineteen specimens of the circum-Arctic species Cirroteuthis muelleri add significantly to our knowledge of the distribution this species. Latitudinal patterns in the bathymetric distribution of C. muelleri and S. syrtensis suggest temperature is the principal controlling factor.
On the shape of foregut lumen in sea spiders (Arthropoda: Pycnogonida)
Authors: Miyazaki Katsumi
Published: November 2002

The shape of foregut lumen in both the pharyngeal and the oesophageal regions has been examined from serial histological sections in 16 species of pycnogonids covering all extant families. Each species has a Y-shaped foregut lumen in transverse section. This result shows that some previous authors misoriented the lumen as inverted Y-shaped. The triradiate Y-shaped foregut lumen has been found among ecdysozoans including tardigrades, onychophorans and scatteringly arthropods. At present, it is not clear whether the Y-shaped state of the characteristic in pycnogonids is convergent or symplesiomorphy with that in tardigrades and onychophorans.
Tolerance range and osmoregulation in hypersaline conditions in the European sea bass (Dicentrarchus labrax)
Authors: Varsamos Stamatis
Published: November 2002

The tolerance of the European sea bass to high salinities was determined through abrupt and gradual transfers to different hyperosmotic media. Mortality rate reached roughly 50% in fish abruptly transferred to 70 psu salinity and in fish gradually adapted to 90 psu salinity. All fish abruptly transferred to 90 psu salinity expired in less than three hours. A crisis and regulation type osmoregulatory pattern, related to the range of the osmotic shock, was recorded following abrupt transfers to the tolerable experimental media. The lethal level of blood osmolality in sea bass was determined.
Private Pension Planning: The Rhetoric of Responsibility,
The Reality of Insecurity
Authors: ROWLINGSON KAREN
Published: November 2002

Over the last twenty years, policy-makers have placed increasing emphasis
on individual planning, particularly in relation to pensions. Planning
for one's own future, and that of one's family, is increasingly upheld as a
morally responsible activity. This article explores the assumptions made
by policy-makers in this area. It begins with a discussion of how the
rhetoric from policy-makers and policy-commentators makes considerable
reference to individual planning and responsibility. The policies
themselves, however, sometimes act as disincentives to make private provision
and do relatively little to provide security for people's future retirement.
The article then draws on empirical research including recent
qualitative findings to emphasise the limited nature of private pension
planning and the constraints people face in relation to this activity.
The Silver Age of the Welfare State: Perspectives on
Resilience
Authors: TAYLOR-GOOBY PETER
Published: November 2002

The circumstances which favoured the expansion of state welfare in the
post-war ‘golden age’ – secure growth, full employment, moderate
welfare needs and national politico-economic autonomy – have been
reversed in the ‘silver age’ of labour market restructuring, demographic
transition and economic globalisation. Most researchers argue that the
European welfare settlement is (so far) surprisingly resilient in the face of
current challenges. This article argues that analysis of welfare states has
been approached from two basic directions – quantitative analysis and
comparative case study – and that each approach has its merits and difficulties.
Using the example of pensions policy it show that quantitative
methods tend to produce findings which place greater emphasis on continuity
and resilience, while case studies focus attention more on political
processes. The latter approach is likely to provide greater insight into
shifts that may lead to new policy directions in the immediate future. The
picture presented by the quantitative method tends to predominate in
comparative cross-national studies of the response of welfare states to
current pressures, and this may overemphasise stability and resilience
against discontinuity and change.
Modified Smith Predictor with DeMenthon-Horaud pose estimation algorithm for 3D
dynamic visual servoing
Authors: Sim T. P. , Hong G. S. , Lim K. B.
Published: November 2002

This paper presents
an attractive position-based visual servoing approach for camera-in-hand robotic systerns.
The major contribution of this work is in devising an
elegant and pragmatic approach for 3D visual tracking, which yielded
good target tracking performance. It differs from the other known
techniques, in its approach for image interpretation and the introduction
of a Smith-like predictor control structure to overcome the inherent
multi-rate time delayed nature of the visual servoing system. A
complete description is made of the proposed MSP-DH visual servoing
system. Experiments on the target tracking performance on XY planar
motion using an AdeptOne robotic system are presented to illustrate
the controller performance. In addition, experimental results have clearly shown
the capability of the MSP-DH visual servoing system in performing
3D-dynamic visual servoing.
Parameter estimation and upper bounding adaptation in adaptive-robust control approaches
for trajectory control of robots
Authors: Uzmay Ibrahim , Burkan Recep
Published: November 2002

In this paper a new robust adaptive control law
for n-link robot manipulators with parametic uncertainties is derived using
the Lyapunov theory thus guaranteed the stability of an uncertain
system. The novelty of the adaptive robust control algorithm is
that manipulator parameters and adaptive upper bounding functions are estimated
to control the system properly, and the adaptive robust control
law is also updated as an exponential function of manipulator
kinematics, inertia parameters and tracking errors. The proposed adaptive control
input includes a parameter estimation law as an adaptive controller
and an additional control input vector as a robust controller.
The developed approach has the advantages of both adaptive and
robust control laws, without their discolour tags.
Online stress detection using psychophysiological signals for implicit human-robot cooperation
Authors: Rani Pramila , Sims Jared , Brackin Robert , Sarkar Nilanjan
Published: November 2002

Robots are expected to be pervasive in the society in
a not too distant future where they will work extensively
as assistants of humans in various activities. With this in
view, a novel affect-sensitive architecture for human-robot cooperation is presented
in this paper where the robot is expected to recognize
human psychological states. As a demonstration, an online heart rate
variability analysis to infer the mental stress of a human
engaged in a task is presented. This technique involves real-time
heart rate monitoring, signal processing using both Fourier Transforrn and
Wavelet Transform, and inferring the stress condition based on the
level of activation of the sympathetic and parasympathetic nervous systems
using fuzzy logic. Results from human subject trials are presented
to validate the presented methodology. This stress detection technique is
expected to be useful in the future human-robot cooperation activities,
where the robot will recognize human stress and respond appropriately.
A comparative study of stability margins for walking machines
Authors: Garcia Elena , Estremera Joaquin , de Santos Pablo Gonzalez
Published: November 2002

Several static and dynamic stability criteria have been defined in the course of walking robot history. Nevertheless, different applications may require different stability criteria and, to the authors' best knowledge, there is no qualitative classification of such stability measurements. Using the wrong stability criterion to control a robot gait may prevent the task from succeeding. Furthermore, if the optimum criterion is found, the robot gait can also be optimized. In this paper, the stability criteria that have been applied to walking robots with at least four legs are examined in terms of their stability margins in different static and dynamic situations. As a result, a qualitative classification of stability criteria for walking machines is proposed so that the proper criterion can be chosen for every desired application.
There is no evidence for a ‘no overt subject’ stage in early child Spanish: a note on Grinstead (2000)
Authors: AGUADO-OREA JAVIER , PINE JULIAN M.
Published: November 2002

Grinstead (2000) argues that there is a stage in both Spanish and Catalan children's grammatical development when they are restricted to using verbs without overt subjects. However, the evidence for a ‘no overt subject’ stage in early child Spanish is based on very thin data from a single child: Juan between the ages of 1;7 and 2;1. In the present note we reanalyse the data from Juan and compare it with data from another child María at 1;7 and 1;8. Our results show that Juan produces his first overt subject during the same session as his first non-imperative verb form, and that María produces a relatively high proportion of verbs with overt subjects in both of her first two transcripts. They thus provide no support for the claim that there is a ‘no overt subject’ stage in early child Spanish.
Does preemption help children learn verb transitivity?
Authors: BROOKS PATRICIA J. , ZIZAK OTTO
Published: November 2002

Children's acquisition of the transitivity status of novel verbs was examined to test whether preemption helps children learn to avoid non-conventional uses of verbs. Given that many English verbs alternate between transitive and intransitive usage (e.g. break, roll), how do children learn the fixed transitive status of verbs such as hit or the fixed intransitive status of verbs such as fall? 48 four-year-olds and 48 six- and seven-year-olds learned two novel verbs, with one verb modelled as transitive and the other as intransitive. Exposure conditions varied the occurrence and type of preemptive evidence potentially facilitating learning of the verbs' transitivity status. In comparison to a No Preemption group, only six- to seven-year-olds exposed to novel verbs in alternative constructions (that allowed them to talk about the actions from the perspective of the agent or patient without changing the verbs' assigned transitivity) produced fewer utterances violating the verbs' fixed transitivity. The results identify limits in children's usage of indirect negative evidence in acquiring verb argument structure constructions.
Patterns of spontaneous production of novel words and gestures within an experimental setting in children ages 1;6 and 2;2
Authors: NAMY LAURA L. , WAXMAN SANDRA R.
Published: November 2002

This study presents an analysis of children's spontaneous production of words and gestures during an experimental symbol learning task. Namy & Waxman (1998) previously reported that children aged 1;6 interpreted novel arbitrary words (e.g. blicket) and manual gestures (e.g. a dropping motion) as names for object categories (e.g. fruit) but that at 2;2, children interpreted words as names more readily than gestures. Based on this finding and other observational evidence of gesture use, it has been suggested that the younger infants have an initial general symbolic capacity that encompasses both words and gestures. Over time, as infants acquire greater experience with language, words begin to take on a greater priority in the infant's communicative repertoire. The current study examines this hypothesis by analyzing children's spontaneous production of the novel symbols in Namy & Waxman's original task. At 1;6, children rarely produced either the novel words or gestures. At 2;2, children frequently produced both symbolic forms; however, words were produced in a referential manner while gestures were produced in a non-referential manner. These findings are consistent with the argument that over time, words supplant gestures as a symbolic medium.
Early lexical development in German: a study on vocabulary growth and vocabulary composition during the second and third year of life
Authors: KAUSCHKE CHRISTINA , HOFMEISTER CHRISTOPH
Published: November 2002

This paper focuses on aspects of early lexical acquisition in German. There have been conflicting results in the literature concerning both the pattern of vocabulary growth and the composition of the early lexicon. Our study describes the development of various categories of words and questions the preponderance of nouns in spontaneous speech. 32 children were studied longitudinally through recordings made at age 1;1, 1;3, 1;9 and 3;0. The following properties of the data were investigated: vocabulary size in relation to age, frequency of word use, and distribution of word categories. The results show that use of both types and tokens increases with time. A trend analysis indicates an exponential increase in vocabulary production in the second year, followed by a further expansion. This vocabulary spurt-like pattern can be observed in the use of word types and tokens. The findings in regard to vocabulary composition illustrate the dynamics present in the development of word categories. In the beginning, children use mostly relational words, personal-social words and some onomatopoeic terms. These categories are gradually complemented with nouns, verbs, function words and other words so that we see a balanced lexicon by 3;0. Trend analyses clarify characteristic developmental patterns in regard to certain word categories. Our spontaneous speech data does not support a strong noun-bias hypothesis.
Comparison, basic-level categories, and the teaching of adjectives
Authors: MANDERS KATHERINE , HALL D. GEOFFREY
Published: November 2002

We tested 24 caregivers of preschool children to determine whether their strategies for teaching novel adjectives are consistent with children's demonstrated abilities to learn these words (e.g. Waxman & Klibanoff, 2000). On each of four trials, caregivers had to select one of two cards, both of which showed a familiar object bearing an unfamiliar property. On the within-basic card, the object was accompanied by a second object from the same basic-level category; on the across-basic card, this second object came from a different basic-level category. Caregivers' task was to choose the card that would be more helpful to teach a novel adjective for the unfamiliar property. If the second object differed from the first in terms of a novel target property, caregivers (N = 12) stated a strong preference for the within-basic card. If the two objects agreed in terms of the novel property, caregivers (N = 12) indicated a clear preference for the across-basic card. The findings offer new insight into the speed and efficiency of lexical development, by revealing that word teachers, like word learners (cf. Waxman & Klibanoff, 2000), are sensitive to the conditions under which certain contrasts (in property or in basic-level category) are effective in promoting the successful acquisition of novel adjectives.
The Wiener Index of Random Trees
Authors: NEININGER RALPH
Published: November 2002

The Wiener index is analysed for random recursive trees and random binary search trees
in uniform probabilistic models. We obtain expectations, asymptotics for the variances, and
limit laws for this parameter. The limit distributions are characterized as the projections
of bivariate measures that satisfy certain fixed point equations. Covariances, asymptotic
correlations, and bivariate limit laws for the Wiener index and the internal path length are
given.
Involvement of estrogen receptor β in terminal differentiation of mammary gland epithelium
Authors: Förster Carola , Mäkela Sari , Wärri Anni , Kietz Silke , Becker David , Hultenby Kjell , Warner Margaret , Gustafsson Jan-Åke
Published: November 2002

The mammary glands of prepubertal estrogen receptor (ER)β−/− mice are morphologically indistinguishable from those of WT littermates. It appears that, although ERβ is expressed in the mouse mammary gland, it is not involved in ductal growth of the gland. In this study, we examined the possibility that ERβ has a role in the differentiated function of the mammary gland. Pregnancy is rare in ERβ−/− mice, but an intensive breeding program produced seven pregnant ERβ−/− mice, of which five did not eat their offspring and continued to successful lactation. Histomorphological comparison of lactating glands revealed that alveoli were larger and there was less secretory epithelium in ERβ−/− than in WT mice. Ultrastructural analysis showed abundant milk droplets and normal apical villi in the luminal epithelial cells, but the extracellular matrix and lamina basalis were reduced, and very frequently the interepithelial cell space was increased. Levels of the adhesion molecules, E-cadherin, connexin 32, occludin, and integrin α2 were reduced, and no zona occludens was detectable. In addition, there was widespread expression of the proliferation marker, Ki-67, in luminal epithelial cells in ERβ−/− but not in WT mice. These findings suggest a role for ERβ in organization and adhesion of epithelial cells and hence for differentiated tissue morphology. We speculate that, because a reduced risk for breast cancer is conferred on women who breast-feed at an early age, ERβ could contribute to this risk reduction by facilitating terminal differentiation of the mammary gland.
Invisible liposomes: Refractive index matching with sucrose enables flow dichroism assessment of peptide orientation in lipid vesicle membrane
Authors: Ardhammar Malin , Lincoln Per , Nordén Bengt
Published: November 2002

Valuable information on protein–membrane organization may in principle be obtained from polarized-light absorption (linear dichroism, LD) measurement on shear-aligned lipid vesicle bilayers as model membranes. However, attempts to probe LD in the UV wavelength region (<250 nm) have so far failed because of strong polarized light scattering from the vesicles. Using sucrose to match the refractive index and suppress the light scattering of phosphatidylcholine vesicles, we have been able to detect LD bands also in the peptide-absorbing region (200–230 nm). The potential of refractive index matching in vesicle LD as a general method for studying membrane protein structure was investigated for the membrane pore-forming oligopeptide gramicidin incorporated into the liposome membranes. In the presence of sucrose, the LD signals arising from oriented tryptophan side chains as well as from n→π* and π→π* transitions of the amide chromophore of the polypeptide backbone could be studied. The observation of a strongly negative LD for the first exciton transition (≈204 nm) is consistent with a membrane-spanning orientation of two intertwined parallel gramicidin helices, as predicted by coupled-oscillator theory.
Testing neoclassical competitive market theory in the field
Authors: List John A.
Published: November 2002

This study presents results from a pilot field experiment that tests predictions of competitive market theory. A major advantage of this particular field experimental design is that my laboratory is the marketplace: subjects are engaged in buying, selling, and trading activities whether I run an exchange experiment or am a passive observer. In this sense, I am gathering data in a natural environment while still maintaining the necessary control to execute a clean comparison between treatments. The main results of the study fall into two categories. First, the competitive model predicts reasonably well in some market treatments: the expected price and quantity levels are approximated in many market rounds. Second, the data suggest that market composition is important: buyer and seller experience levels impact not only the distribution of rents but also the overall level of rents captured. An unexpected result in this regard is that average market efficiency is lowest in markets that match experienced buyers and experienced sellers and highest when experienced buyers engage in bargaining with inexperienced sellers. Together, these results suggest that both market experience and market composition play an important role in the equilibrium discovery process.
Parallel phenotypic analysis of sporulation and postgermination growth in
Saccharomyces
cerevisiae
Authors: Deutschbauer Adam M. , Williams Roy M. , Chu Angela M. , Davis Ronald W.
Published: November 2002

We have quantitatively monitored the sporulation and germination efficiencies of ≈4,200 yeast deletion strains in parallel by using a molecular bar coding strategy. In a single study, we doubled the number of genes functionally implicated in sporulation to ≈400, identifying both positive and negative regulators. Our set of 261 sporulation-deficient genes illustrates the importance of autophagy, carbon utilization, and transcriptional machinery during sporulation. These general cellular factors are more likely to exhibit fitness defects when deleted and less likely to be transcriptionally regulated than sporulation-specific genes. Our postgermination screening assay identified recombination/chromosome segregation genes, aneuploid strains, and possible germination-specific factors. Finally, our results facilitate a genome-wide comparison of expression pattern and mutant phenotype for a developmental process and suggest that 16% of genes differentially expressed during sporulation confer altered efficiency of spore production or defective postgermination growth when disrupted.
Identification of phosphorylated residues that affect the activity of the mitotic kinase Aurora-A
Authors: Littlepage Laurie E. , Wu Hua , Andresson Thorkell , Deanehan Julia K. , Amundadottir Laufey T. , Ruderman Joan V.
Published: November 2002

The activity of the kinase Aurora-A (Aur-A) peaks during mitosis and depends on phosphorylation by one or more unknown kinases. Mitotic phosphorylation sites were mapped by mass spec sequencing of recombinant Aur-A protein that had been activated by incubation in extracts of metaphase-arrested
Xenopus
eggs. Three sites were identified: serine 53 (Ser-53), threonine 295 (Thr-295), and serine 349 (Ser-349), which are equivalent to Ser-51, Thr-288, and Ser-342, respectively, in human Aur-A. To ask how phosphorylation of these residues might affect kinase activity, each was mutated to either alanine or aspartic acid, and the recombinant proteins were then tested for their ability to be activated by M phase extract. Mutation of Thr-295, which resides in the activation loop of the kinase, to either alanine or aspartic acid abolished activity. The S349A mutant had slightly reduced activity, indicating that phosphorylation is not required for activity. The S349D mutation completely blocked activation, suggesting that Ser-349 is important for either the structure or regulation of Aur-A. Finally, like human Aur-A, overexpression of
Xenopus
Aur-A transformed NIH 3T3 cells and led to tumors in nude mice. These results provide further evidence that
Xenopus
Aur-A is a functional ortholog of human Aur-A and, along with the recently described crystal structure of human Aur-A, should help in future studies of the mechanisms that regulate Aur-A activity during mitotic progression.
Progesterone receptor knockout mice have an improved glucose homeostasis secondary to β-cell proliferation
Authors: Picard Frédéric , Wanatabe Mitsuhiro , Schoonjans Kristina , Lydon John , O'Malley Bert W. , Auwerx Johan
Published: November 2002

Gestational diabetes coincides with elevated circulating progesterone levels. We show that progesterone accelerates the progression of diabetes in female
db/db
mice. In contrast, RU486, an antagonist of the progesterone receptor (PR), reduces blood glucose levels in both female WT and
db/db
mice. Furthermore, female, but not male, PR−/− mice had lower fasting glycemia than PR+/+ mice and showed higher insulin levels on glucose injection. Pancreatic islets from female PR−/− mice were larger and secreted more insulin consequent to an increase in β-cell mass due to an increase in β-cell proliferation. These findings demonstrate an important role of progesterone signaling in insulin release and pancreatic function and suggest that it affects the susceptibility to diabetes.
Structure of factor-inhibiting hypoxia-inducible factor 1: An asparaginyl hydroxylase involved in the hypoxic response pathway
Authors: Dann Charles E. , Bruick Richard K. , Deisenhofer Johann
Published: November 2002

Precise regulation of the evolutionarily conserved hypoxia-inducible transcription factor (HIF) ensures proper adaptation to variations in oxygen availability throughout development and into adulthood. Oxygen-dependent regulation of HIF stability and activity are mediated by hydroxylation of conserved proline and asparagine residues, respectively. Because the relevant prolyl and asparginyl hydroxylases use O
2
to effect these posttranslational modifications, these enzymes are implicated as direct oxygen sensors in the mammalian hypoxic response pathway. Here we present the structure of factor-inhibiting HIF-1 (FIH-1), the pertinent asparaginyl hydroxylase involved in hypoxic signaling. Hydroxylation of the C-terminal transactivation domain (CTAD) of HIF by FIH-1 prevents CTAD association with transcriptional coactivators under normoxic conditions. Consistent with other structurally known hydroxylases, FIH-1 is comprised of a β-strand jellyroll core with both Fe(II) and the cosubstrate 2-oxoglutarate bound in the active site. Details of the molecular contacts at the active site of FIH-1 have been elucidated and provide a platform for future drug design. Furthermore, the structure reveals the presence of a FIH-1 homodimer that forms in solution and is essential for FIH activity.
A general population genetic theory for the evolution of developmental interactions
Authors: Rice Sean H.
Published: November 2002

The development of most phenotypic traits involves complex interactions between many underlying factors, both genetic and environmental. To study the evolution of such processes, a set of mathematical relationships is derived that describe how selection acts to change the distribution of genetic variation given arbitrarily complex developmental interactions and any distribution of genetic and environmental variation. The result is illustrated by using it to derive models for the evolution of dominance and for the evolutionary consequences of asymmetry in the distribution of genetic variation.
Polκ protects mammalian cells against the lethal and mutagenic effects of benzo[
a
]pyrene
Authors: Ogi Tomoo , Shinkai Yoichi , Tanaka Kiyoji , Ohmori Haruo
Published: November 2002

Several low-fidelity DNA polymerases have recently been discovered that are able to bypass DNA lesions during DNA synthesis
in vitro
. The efficiency and accuracy of lesion bypass is, however, both polymerase and lesion specific. For example,
in vitro
studies revealed that human DNA polymerase κ (Polκ) is unable to insert a base opposite a
cis-syn
thymine-thymine dimer or cisplatin adduct, yet can bypass some DNA lesions such as abasic site and acetylaminofluorene-adducted guanine in an error-prone manner. More importantly, Polκ is able to bypass benzo[
a
]pyrene (B[
a
]P)-adducted guanine accurately and efficiently. To investigate the biological function of Polκ, we have generated mouse embryonic stem (ES) cells deficient in the
Polk
gene encoding the enzyme.
Polk
-deficient ES cells grow normally and their sensitivities to UV and x-ray radiation are only slightly affected. In contrast, the mutant cells are highly sensitive to both killing and mutagenesis induced by B[
a
]P. Furthermore, the spectrum of mutations recovered in the
Polk
-deficient cells is different from that in the wild-type cells. Thus, our results indicate that Polκ plays an important role in suppressing mutations at DNA lesions generated by B[
a
]P.
Non-Lipschitz minimizers of smooth uniformly convex functionals
Authors: Sverák Vladimír , Yan Xiaodong
Published: November 2002

We construct non-Lipschitz minimizers of smooth, uniformly convex functionals of type
I
(
u
) = ∫
Ω
f
(
Du
(
x
))
dx.
Our method is based on the use of null Lagrangians.
Elliptic Yang–Mills equation
Authors: Tian Gang
Published: November 2002

We discuss some recent progress on the regularity theory of the elliptic Yang–Mills equation. We start with some basic properties of the elliptic Yang–Mills equation, such as Coulomb gauges, monotonicity, and curvature estimates. Next we discuss singularity of stationary Yang–Mills connections and compactness theorems on Yang–Mills connections with bounded
L
2
norm of curvature. We also discuss in some detail self-dual solutions of the Yang–Mills equation and describe a compactification of their moduli space.
A computational method for resequencing long DNA targets by universal oligonucleotide arrays
Authors: Pe'er Itsik , Arbili Naama , Shamir Ron
Published: November 2002

Universal arrays contain all possible oligonucleotides of a certain length, typically 6–10 bases. They can determine in a single experiment all substrings of that length that occur along a target sequence. That information, also called the spectrum of the sequence, is not sufficient to uniquely reconstruct a sequence longer than a few hundred bases. We have devised a polynomial algorithm that reconstructs the sequence, given the spectrum and an additional reference sequence, homologous to the target sequence. Such a reference is available, for example, in the identification of single-nucleotide polymorphisms. The algorithm can handle errors in the spectrum as well as substitutions, insertions, and deletions in the target sequence. We present extensive simulation results, which show that the algorithm correctly reconstructs target sequences of >2,000 nucleotides from error-prone 8-mer spectra when realistic levels of single-nucleotide polymorphisms are present.
High incidence of epithelial cancers in mice deficient for DNA polymerase δ proofreading
Authors: Goldsby Robert E. , Hays Laura E. , Chen Xin , Olmsted Elise A. , Slayton William B. , Spangrude Gerry J. , Preston Bradley D.
Published: November 2002

Mutations are a hallmark of cancer. Normal cells minimize spontaneous mutations through the combined actions of polymerase base selectivity, 3′ → 5′ exonucleolytic proofreading, mismatch correction, and DNA damage repair. To determine the consequences of defective proofreading in mammals, we created mice with a point mutation (D400A) in the proofreading domain of DNA polymerase δ (polδ, encoded by the
Pold1
gene). We show that this mutation inactivates the 3′ → 5′ exonuclease of polδ and causes a mutator and cancer phenotype in a recessive manner. By 18 months of age, 94% of homozygous

Pold1
D400A/D400A

mice developed cancer and died (median survival = 10 months). In contrast, only 3–4% of

Pold1
+/D400A

and

Pold1
+/+

mice developed cancer in this time frame. Of the 66 tumors arising in 49

Pold1
D400A/D400A

mice, 40 were epithelial in origin (carcinomas), 24 were mesenchymal (lymphomas and sarcomas), and two were composite (teratomas); one-third of these animals developed tumors in more than one tissue. Skin squamous cell carcinoma was the most common tumor type, occurring in 60% of all

Pold1
D400A/D400A

mice and in 90% of those surviving beyond 8 months of age. These data show that polδ proofreading suppresses spontaneous tumor development and strongly suggest that unrepaired DNA polymerase errors contribute to carcinogenesis. Mice deficient in polδ proofreading provide a tractable model to study mechanisms of epithelial tumorigenesis initiated by a mutator phenotype.
Conformational-relaxation models of single-enzyme kinetics
Authors: Lerch Hans-Philipp , Mikhailov Alexander S. , Hess Benno
Published: November 2002

Fluorescent spectroscopy experiments with single-enzyme molecules yield a large volume of statistical data that can be analyzed and interpreted using stochastic models of enzyme action. Here, we present two models, each based on the mechanism that an enzyme molecule must pass through a sequence of conformational transformations to complete its catalytic turnover cycle. In the simplest model, only one path leading to the release of product is present. In contrast to this, two different catalytic paths are possible in the second considered model. If a cycle is started from an active state, immediately after the previous product release, it follows a different conformational route and is much shorter. Our numerical investigations show that both models generate non-Markovian molecular statistics. However, their memory landscapes and distributions of cycle times are significantly different. The memory landscape of the double-path model bears strong similarity to the recent experimental data for horseradish peroxidase.
Mitotic chromosomes are chromatin networks without a mechanically contiguous protein scaffold
Authors: Poirier Michael G. , Marko John F.
Published: November 2002

Isolated newt (
Notophthalmus viridescens
) chromosomes were studied by using micromechanical force measurement during nuclease digestion. Micrococcal nuclease and short-recognition-sequence blunt-cutting restriction enzymes first remove the native elastic response of, and then to go on to completely disintegrate, single metaphase newt chromosomes. These experiments rule out the possibility that the mitotic chromosome is based on a mechanically contiguous internal non-DNA (e.g., protein) “scaffold”; instead, the mechanical integrity of the metaphase chromosome is due to chromatin itself. Blunt-cutting restriction enzymes with longer recognition sequences only partially disassemble mitotic chromosomes and indicate that chromatin in metaphase chromosomes is constrained by isolated chromatin-crosslinking elements spaced by ≈15 kb.