bluuebunny/crossref_metadata_2025 huggingface dataset:
Deletion of immunoglobulin β in developing B cells leads to cell death
Authors: Meffre Eric , Nussenzweig Michel C.
Published: September 2002

Inducible gene-targeting experiments have shown that Igμ expression is essential for maintaining survival of mature B cells, but the role of Igμ expression in immature B cell survival has not been determined. To assess whether continued B cell receptor (BCR) expression is required for bone marrow B cell precursor development and survival, we developed a method for conditional gene deletion in these cells. Recombination-activating gene regulatory elements were used to express Igβ cDNA as a transgene to complement Igβ
−/−
mice. Transgenic Igβ expression was found in proB and small preB cells and was extinguished in large preB and immature B cells. Igβ deletion from large preB cells and immature B cells resulted in cell death that could be rescued by transgenic bcl-2 expression. However, transgenic bcl-2 expression was unable to restore B cell development in the absence of Igβ. We conclude that Igβ expression is essential to maintain preB cell and immature B cell survival and to mediate B cell differentiation. In addition, complementation of null mutations with cDNAs under the control of heterologous bacterial artificial chromosomes is a useful method for cell-type-specific and developmentally regulated gene ablation
in vivo
.
ClpAP and ClpXP degrade proteins with tags located in the interior of the primary sequence
Authors: Hoskins Joel R. , Yanagihara Katsuhiko , Mizuuchi Kiyoshi , Wickner Sue
Published: September 2002

Clp/Hsp100 ATPases comprise a large family of ATP-dependent chaperones, some of which are regulatory components of two-component proteases. Substrate specificity resides in the Clp protein and the current thinking is that Clp proteins recognize motifs located near one or the other end of the substrate. We tested whether or not ClpA and ClpX can recognize tags when they are located in the interior of the primary sequence of the substrate. A protein with an NH
2
-terminal ClpA recognition tag, plasmid P1 RepA, was fused to the COOH terminus of green fluorescent protein (GFP). GFP is not recognized by ClpA or ClpX and is not degraded by ClpAP or ClpXP. We found that ClpA binds and unfolds the fusion protein and ClpAP degrades the protein. Both the GFP and RepA portions of the fusion protein are degraded. A protein with a COOH-terminal ClpX tag, MuA, was fused to the NH
2
terminus of GFP. ClpXP degrades MuA-GFP, however, the rate is 10-fold slower than that of GFP-MuA. The MuA portion but not the GFP portion of MuA-GFP is degraded. Thus, a substrate with an internal ClpA recognition motif can be unfolded by ClpA and degraded by ClpAP. Similarly, although less efficiently, ClpXP degrades a substrate with an internal ClpX recognition motif. We also found that ClpA recognizes the NH
2
-terminal 15 aa RepA tag, when it is fused to the COOH terminus of GFP. Moreover, ClpA recognizes the RepA tag in either the authentic or inverse orientation.
Chk2 regulates irradiation-induced, p53-mediated apoptosis in
Drosophila
Authors: Peters Malte , DeLuca Carmela , Hirao Atsushi , Stambolic Vuk , Potter Julia , Zhou Lily , Liepa Jennifer , Snow Bryan , Arya Sudha , Wong Jorge , Bouchard Denis , Binari Richard , Manoukian Armen S. , Mak Tak W.
Published: September 2002

The tumor suppressor function of p53 has been attributed to its ability to regulate apoptosis and the cell cycle. In mammals, DNA damage, aberrant growth signals, chemotherapeutic agents, and UV irradiation activate p53, a process that is regulated by several posttranslational modifications. In
Drosophila melanogaster
, however, the regulation modes of p53 are still unknown. Overexpression of
D. melanogaster
p53 (Dmp53) in the eye induced apoptosis, resulting in a small eye phenotype. This phenotype was markedly enhanced by coexpression with
D. melanogaster
Chk2 (DmChk2) and was almost fully rescued by coexpression with a dominant-negative (DN), kinase-dead form of DmChk2. DN DmChk2 also inhibited Dmp53-mediated apoptosis in response to DNA damage, whereas overexpression of Grapes (Grp), the
Drosophila
Chk1-homolog, and its DN mutant had no effect on Dmp53-induced phenotypes. DmChk2 also activated the Dmp53 transactivation activity in cultured cells. Mutagenesis of Dmp53 amino terminal Ser residues revealed that Ser-4 is critical for its responsiveness toward DmChk2. DmChk2 activates the apoptotic activity of Dmp53 and Ser-4 is required for this effect. Contrary to results in mammals, Grapes, the
Drosophila
Chk1-homolog, is not involved in regulating Dmp53. Chk2 may be the ancestral regulator of p53 function.
A nuclear export signal within the high mobility group domain regulates the nucleocytoplasmic translocation of SOX9 during sexual determination
Authors: Gasca Stéphan , Cañizares Joaquin , de Santa Barbara Pascal , Méjean Catherine , Poulat Francis , Berta Philippe , Boizet-Bonhoure Brigitte
Published: September 2002

In mammals, male sex determination starts when the Y chromosome
Sry
gene is expressed within the undetermined male gonad. One of the earliest effect of
Sry
expression is to induce up-regulation of
Sox9
gene expression in the developing gonad. SOX9, like SRY, contains a high mobility group domain and is sufficient to induce testis differentiation in transgenic XX mice. Before sexual differentiation, SOX9 protein is initially found in the cytoplasm of undifferentiated gonads from both sexes. At the time of testis differentiation and anti-Müllerian hormone expression, it becomes localized to the nuclear compartment in males whereas it is down-regulated in females. In this report, we used NIH 3T3 cells as a model to examine the regulation of SOX9 nucleo-cytoplasmic shuttling. SOX9-transfected cells expressed nuclear and cytoplasmic SOX9 whereas transfected cells treated with the nuclear export inhibitor leptomycin B, displayed an exclusive nuclear localization of SOX9. By using SOX9 deletion constructs in green fluorescent protein fusion proteins, we identified a functional nuclear export signal sequence between amino acids 134 and 147 of SOX9 high mobility group box. More strikingly, we show that inhibiting nuclear export with leptomycin B in mouse XX gonads cultured
in vitro
induced a sex reversal phenotype characterized by nuclear SOX9 and anti-Müllerian hormone expression. These results indicate that SOX9 nuclear export signal is essential for SOX9 sex-specific subcellular localization and could be part of a regulatory switch repressing (in females) or triggering (in males) male-specific sexual differentiation.
A phylogenetic analysis of myosin heavy chain type II sequences corroborates that Acoela and Nemertodermatida are basal bilaterians
Authors: Ruiz-Trillo I. , Paps J. , Loukota M. , Ribera C. , Jondelius U. , Baguñà J. , Riutort M.
Published: September 2002

Bilateria are currently subdivided into three superclades: Deuterostomia, Ecdysozoa, and Lophotrochozoa. Within this new taxonomic frame, acoelomate Platyhelminthes, for a long time held to be basal bilaterians, are now considered spiralian lophotrochozoans. However, recent 18S rDNA [small subunit (SSU)] analyses have shown Platyhelminthes to be polyphyletic with two of its orders, the Acoela and the Nemertodermatida, as the earliest extant bilaterians. To corroborate such position and avoid the criticisms of saturation and long-branch effects thrown on the SSU molecule, we have searched for independent molecular data bearing good phylogenetic information at deep evolutionary nodes. Here we report a phylogenetic analysis of DNA sequences from the myosin heavy chain type II (myosin II) gene from a large set of metazoans, including acoels and nemertodermatids. Our study demonstrates, both for the myosin II data set alone and for a combined SSU + myosin II data set, that Platyhelminthes are polyphyletic and that acoels and nemertodermatids are the extant earliest bilaterians. Hence, the common bilaterian ancestor was not, as currently held, large and complex but small, simple, and likely with direct development. This scenario has far-reaching implications for understanding the evolution of major body plans and for perceptions of the Cambrian evolutionary explosion.
Rescue of influenza B virus from eight plasmids
Authors: Hoffmann Erich , Mahmood Kutubuddin , Yang Chin-Fen , Webster Robert G. , Greenberg Harry B. , Kemble George
Published: September 2002

Influenza B virus causes a significant amount of morbidity and mortality, yet the systems to produce high yield inactivated vaccines for these viruses have lagged behind the development of those for influenza A virus. We have established a plasmid-only reverse genetics system for the generation of recombinant influenza B virus that facilitates the generation of vaccine viruses without the need for time consuming coinfection and selection procedures currently required to produce reassortants. We cloned the eight viral cDNAs of influenza B/Yamanashi/166/98, which yields relatively high titers in embryonated chicken eggs, between RNA polymerase I and RNA polymerase II transcription units. Virus was detected as early as 3 days after transfection of cocultured COS7 and Madin–Darby canine kidney cells and achieved levels of 10
6
-10
7
plaque-forming units per ml of cell supernatant 6 days after transfection. The full-length sequence of the recombinant virus after passage into embryonated chicken eggs was identical to that of the input plasmids. To improve the utility of the eight-plasmid system for generating 6 + 2 reassortants from recently circulating influenza B strains, we optimized the reverse transcriptase–PCR for cloning of the hemagglutinin (HA) and neuraminidase (NA) segments. The six internal genes of B/Yamanashi/166/98 were used as the backbone to generate 6 + 2 reassortants including the HA and NA gene segments from B/Victoria/504/2000, B/Hong Kong/330/2001, and B/Hawaii/10/2001. Our results demonstrate that the eight-plasmid system can be used for the generation of high yields of influenza B virus vaccines expressing current HA and NA glycoproteins from either of the two lineages of influenza B virus.
VEGF-Trap: A VEGF blocker with potent antitumor effects
Authors: Holash Jocelyn , Davis Sam , Papadopoulos Nick , Croll Susan D. , Ho Lillian , Russell Michelle , Boland Patricia , Leidich Ray , Hylton Donna , Burova Elena , Ioffe Ella , Huang Tammy , Radziejewski Czeslaw , Bailey Kevin , Fandl James P. , Daly Tom , Wiegand Stanley J. , Yancopoulos George D. , Rudge John S.
Published: September 2002

Vascular endothelial growth factor (VEGF) plays a critical role during normal embryonic angiogenesis and also in the pathological angiogenesis that occurs in a number of diseases, including cancer. Initial attempts to block VEGF by using a humanized monoclonal antibody are beginning to show promise in human cancer patients, underscoring the importance of optimizing VEGF blockade. Previous studies have found that one of the most effective ways to block the VEGF-signaling pathway is to prevent VEGF from binding to its normal receptors by administering decoy-soluble receptors. The highest-affinity VEGF blocker described to date is a soluble decoy receptor created by fusing the first three Ig domains of VEGF receptor 1 to an Ig constant region; however, this fusion protein has very poor
in vivo
pharmacokinetic properties. By determining the requirements to maintain high affinity while extending
in vivo
half life, we were able to engineer a very potent high-affinity VEGF blocker that has markedly enhanced pharmacokinetic properties. This VEGF-Trap effectively suppresses tumor growth and vascularization
in vivo
, resulting in stunted and almost completely avascular tumors. VEGF-Trap-mediated blockade may be superior to that achieved by other agents, such as monoclonal antibodies targeted against the VEGF receptor.
RNA helicase-like protein as an early regulator of transcription factors for plant chilling and freezing tolerance
Authors: Gong Zhizhong , Lee Hojoung , Xiong Liming , Jagendorf André , Stevenson Becky , Zhu Jian-Kang
Published: September 2002

Susceptibility to chilling injury prevents the cultivation of many important crops and limits the extended storage of horticultural commodities. Although freezing tolerance is acquired through cold-induced gene expression changes mediated in part by the CBF family of transcriptional activators, whether plant chilling resistance or sensitivity involves the
CBF
genes is not known. We report here that an
Arabidopsis thaliana
mutant impaired in the cold-regulated expression of
CBF
genes and their downstream target genes is sensitive to chilling stress. Expression of
CBF3
under a strong constitutive promoter restores chilling resistance to the mutant plants. The mutated gene was cloned and found to encode a nuclear localized RNA helicase. Our results identify a regulator of
CBF
genes, and demonstrate the importance of gene regulation and the CBF transcriptional activators in plant chilling resistance.
Neural processing of emotional faces requires attention
Authors: Pessoa L. , McKenna M. , Gutierrez E. , Ungerleider L. G.
Published: September 2002

Attention gates the processing of stimuli relatively early in visual cortex. Yet, existing data suggest that emotional stimuli activate brain regions automatically, largely immune from attentional control. To resolve this puzzle, we used functional magnetic resonance imaging to first measure activation in regions that responded differentially to faces with emotional expressions (fearful and happy) compared with neutral faces. We then measured the modulation of these responses by attention, using a competing task with a high attentional load. Contrary to the prevailing view, all brain regions responding differentially to emotional faces, including the amygdala, did so only when sufficient attentional resources were available to process the faces. Thus, the processing of facial expression appears to be under top-down control.
Newly generated neurons in the amygdala and adjoining cortex of adult primates
Authors: Bernier Patrick J. , Bédard Andréanne , Vinet Jonathan , Lévesque Martin , Parent André
Published: September 2002

The subventricular zone remains mitotically active throughout life in rodents. Studies with tritiated thymidine, which is incorporated into the DNA of mitotic cells, have revealed that the rodent subventricular zone produces neuroblasts that migrate toward the olfactory bulb along the rostral migratory stream. A similar migratory stream has been documented in monkeys by using the thymidine analogue BrdUrd. The same approach showed that neurogenesis occurred in the dentate gyrus of adult primates, including humans. In the present study, experiments combining injections of BrdUrd and the dye 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindo-carbocyanine, with the immunostaining for molecular markers of neurogenesis (polysialylated neural cell adhesion molecule, β-tubulin-III, collapsin response mediator protein-4, neuronal nuclear protein) in New World (
Saimiri sciureus
) and Old World (
Macaca fascicularis
) monkeys have revealed that new neurons are produced in the amygdala, piriform cortex, and adjoining inferior temporal cortex in adult primates. These newborn neurons expressed the antiapoptotic protein Bcl-2 and formed a more-or-less continuous pathway that extended from the tip of the temporal ventricular horn to the deep portion of the temporal lobe. The production of newborn neurons in the amygdala, piriform cortex, and inferior temporal cortex seems to parallel the continuing addition of neurons in the olfactory bulb. These two concomitant phenomena may ensure structural stability and functional plasticity to the primate olfactory system and temporal lobe.
Dissociable prefrontal brain systems for attention and emotion
Authors: Yamasaki Hiroshi , LaBar Kevin S. , McCarthy Gregory
Published: September 2002

The prefrontal cortex has been implicated in a variety of attentional, executive, and mnemonic mental operations, yet its functional organization is still highly debated. The present study used functional MRI to determine whether attentional and emotional functions are segregated into dissociable prefrontal networks in the human brain. Subjects discriminated infrequent and irregularly presented attentional targets (circles) from frequent standards (squares) while novel distracting scenes, parametrically varied for emotional arousal, were intermittently presented. Targets differentially activated middle frontal gyrus, posterior parietal cortex, and posterior cingulate gyrus. Novel distracters activated inferior frontal gyrus, amygdala, and fusiform gyrus, with significantly stronger activation evoked by the emotional scenes. The anterior cingulate gyrus was the only brain region with equivalent responses to attentional and emotional stimuli. These results show that attentional and emotional functions are segregated into parallel dorsal and ventral streams that extend into prefrontal cortex and are integrated in the anterior cingulate. These findings may have implications for understanding the neural dynamics underlying emotional distractibility on attentional tasks in affective disorders.
Glutamatergic activity in the amygdala signals visceral input during taste memory formation
Authors: Miranda María Isabel , Ferreira Guillaume , Ramírez-Lugo Leticia , Bermúdez-Rattoni Federico
Published: September 2002

Conditioned taste aversion (CTA) is a learning paradigm in which an animal avoids a taste (conditioned stimulus) previously associated with visceral toxic effects [or unconditioned stimulus (US)]. Although many studies have implicated glutamate-mediated neurotransmission in memory consolidation of different types of learning tasks, including CTA, the exact role of this neurotransmitter system in memory formation is not known. Thus, we set out to determine whether glutamate mediates signaling of the US in CTA. We present evidence obtained by
in vivo
microdialysis that the US (i.p. injection of lithium chloride) induced a dramatic increase in glutamate release in the amygdala and a modest but significant release in the insular cortex. Moreover, CTA can be elicited by intra-amygdalar microinjections of glutamate; consequently, when glutamate is administered just before the presentation of a weak US, a clear CTA is induced. In contrast, the injection of glutamate alone or glutamate 2 h after the suboptimal US did not have any effect on the acquisition of CTA. These results indicate that glutamate activation of the amygdala can partially substitute the US in CTA, thus providing a clear indication that the amygdala conveys visceral information for this kind of memory.
Do advanced moral reasoners also show wisdom? Linking moral reasoning and wisdom-related knowledge and judgement
Authors: Pasupathi M. , Staudinger U. M.
Published: September 2002

Wisdom and morality are both discussed as developmental ideals. They are often associated in theoretical contexts but the nature of their empirical relation is still an open question. We hypothesised that moral reasoning (one facet of morality), would be related to wisdom-related knowledge and judgement, but that the two represent different facets of high level psychological functioning. A sample of 220 adults ranging in age from 20 to 87 years completed measures of wisdom-related performance, moral reasoning, and a battery of cognitive and personality measures. As predicted, moral reasoning was positively associated with wisdom-related performance, although we also found evidence for divergent validity of these two constructs. This association was mediated by person characteristics (e.g., personality, intelligence, and additional measures). In addition, as predicted by a threshold model, very high levels of wisdom-related performance were unlikely among those with very low moral reasoning performance. In line with neo-Piagetian conceptions, exploratory analyses suggested that higher age was associated with higher levels of wisdom-related knowledge and judgement only for those with high levels of moral reasoning. Results are discussed in terms of a lifespan model of wisdom-related knowledge and judgement.
Are hormone levels and cognitive ability related during early adolescence?
Authors: Davison Kirsten Krahnstöver , Susman Elizabeth J.
Published: September 2002

The present study assessed the longstanding question of whether there is a relationship between sex hormones and cognitive ability in young adolescent girls and boys. Three “theories” of the relationship between hormone levels and cognition were identi” ed from a broad literature base and were used to formulate hypotheses regarding the relationship between sex hormones and cognitive ability in early adolescents. Fifty-six boys, aged 10-14, and 52 girls, aged 9-14, completed two standardised spatial ability tests and one standardised test of verbal ability. Three blood samples, at 20-minute intervals, were obtained to determine levels of estradiol and testosterone. Data were collected on three occasions for all measures at 6-month intervals. A positive linear relationship between testosterone and spatial ability was identi” ed for boys at each time of measurement for both measures of spatial ability (i.e., mental rotation and block design). For girls, a positive linear relationship was identi” ed between testosterone and mental rotation only at time 3. In addition, longitudinal relationships were identi” ed between change in testosterone levels and change in spatial ability for both girls and boys. The conclusion was that testosterone is related to cognitive functioning during pubertal development for boys and to a lesser extent for girls.
The role of parental perceived control in child development: A longitudinal study
Authors: Hagekull Berit , Bohlin Gunilla , Hammarberg Annie
Published: September 2002

The study investigated the role of parental perceived control in child development. A discussion of the conceptual bases of two parental locus-of-control scales led to differential predictions as regards their relations with parent experiences during infancy and child problems and competencies at 4 and 9 years. The Parental Control of Child’s Behaviour scale was suggested to measure perceived control and to be related to infancy factors and child outcomes. The Parental Responsibility scale was tentatively seen as measuring a stereotypic view, and associations with infancy aspects and child outcomes were not predicted. In a normal longitudinal sample of 103 families, mothers’ and fathers’ control ratings were obtained at ages 33 months and 9 years. In contrast to parental responsibility ratings, parental control ratings were predicted by child difficultness and parental adaptation during infancy, and more perceived control was associated with fewer problems and more competence both longitudinally and concurrently. Both fathers’ and mothers’ perceived control was important. It was further concluded that the Parental Control scale could function as a psychometrically adequate measure of how parents perceive their actual control in the rearing situation.
Relation of maternal intelligence and schooling to offspring nutritional intake
Authors: Wachs Theodore D. , McCabe George
Published: September 2002

For parents and children living in less developed countries the contributions of maternal education level to child survival and growth has been well established. What is less clear is the mechanism through which more education for women in less developed countries translates into positive child outcomes. Given evidence linking education to adult intellectual performance, and evidence linking children’s dietary quality to development, we hypothesised that more educated or more intelligent women in less developed countries may be providing a more nutritionally adequate diet to their offspring. This hypothesis was tested on a sample of 76 Egyptian mothers and their toddlers and a sample of 57 Egyptian mothers and their school age children living in an agricultural village outside of Cairo. Our predictor variables consisted of family demographics, maternal years of education, and maternal performance on four subscales from the Egyptian WAIS-R plus the Raven’s Matrices. Over a 12-month period dieticians collected monthly data on offspring dietary intake, including macronutrients (protein, calories), and micronutrients (trace minerals and vitamins). After controlling for family socioeconomic status, total caloric intake, and maternal educational level, results indicated that maternal intelligence was a unique predictor of toddler dietary quality intake. For school age children, after partialling, maternal educational level rather than maternal intelligence was found to be a better predictor of offspring nutritional intake. Implications of these results for understanding variability in children’s food intake are discussed.
Long-term socialisation goals and the construction of infants’ social networks among middle class Anglo and Puerto Rican mothers
Authors: Miller Amy M. , Harwood Robin L.
Published: September 2002

This study examined the relation between mothers’ long-term socialisation goals and the social networks they construct for their infants. Middle class Anglo (n = 32) and Puerto Rican (n = 28) mothers were interviewed regarding: (a) their long-term socialisation goals; (b) how often their infants’ typically have contact with friends and family members; and (c) specific family circumstances which might influence contact with relatives, including geographic distance, maternal employment status, and child care arrangements. Study results indicated that mothers’ long-term socialisation goals were correlated with the type and frequency of social contacts they structured for their infants. Moreover, limited evidence was found for the influence of group membership on frequency of contact with relatives, despite individual variations in family circumstances. Results are interpreted as illuminating one aspect of the interface between cultural beliefs and socialisation practices within the constructs of individualism/sociocentrism.
Development of concepts of interrelationships among duration, distance, and speed
Authors: Matsuda Fumiko
Published: September 2002

The main purpose of this study was to clarify the developmental processes of understanding of interrelationships among the three concepts, duration, distance, and speed. In Experiment 1, ” ve developmental phases were found based on data of 222 four- to eleven-year-old children. In the ” rst phase, children displayed an implicit understanding of the direct relationships between duration and distance, and between distance and speed. This phase was most common among 4-year-olds. Second, children occasionally understood the inverse relation between duration and speed. Third, all of the two direct relations and the inverse relation were almost correctly understood, although the third dimension was still rather ignored. Fourth, children made their judgements based on the duration-distance-speed system, but were not fully conscious of it. Finally, children judged consciously based on this system. About half of the 11-year-olds reached this phase. In Experiment 2, 29 children repeatedly participated in the same experiment six or eight times once a year till 6th grade. Generally, their understanding developed along the process that emerged in Experiment 1, although there was facilitation of a transfer from the coordination of two-by-two relations to the duration-distance-speed system. Theoretical and educational implications of these ” ndings were discussed.
School competence in young adolescence: Links to early attachment relationships beyond concurrent self-perceived competence and representations of relationships
Authors: Aviezer Ora , Resnick Gary , Sagi Abraham , Gini Motti
Published: September 2002

Predictive associations of infant attachment to mothers and fathers with later school functioning, beyond the contribution of contemporaneous representations of relationships and circumstances of caregiving, were examined in 66 young adolescents who were raised in infancy in Israeli kibbutzim with collective sleeping. The Strange Situation Procedure was used to evaluate early attachment to mother and father, the Separation Anxiety Test was used to assess contemporaneous representation of relationships, and teachers’ reports evaluated school functioning. Circumstances of caregiving included parental reports of quality of marital relations and a change from collective sleeping to home sleeping for children. Results showed that infant attachment to mother, but not to father, contributed significant additional variance to the prediction of children’s scholastic skills and emotional maturity beyond the contribution of concurrent representations of relationships and changes in circumstances of caregiving. The results support the secure base construct as an organising concept of longitudinal investigations of attachment.
The specific mediating paths between economic hardship and the quality of parenting
Authors: Leinonen Jenni A. , Solantaus Tytti S. , Punamäki Raija-Leena
Published: September 2002

Finland, one of the welfare states of northern Europe, faced an exceptionally deep economic recession at the beginning of the 1990s. Based on the Family Stress Model (Conger & Elder, 1994) we studied specific mediating paths between economic hardship and the different domains of parenting in 527 mother-father-child triads. The results show that economic hardship created economic pressures for both parents. For fathers, both the general and specific pressures were further associated with symptoms of anxiety and social dysfunction, whereas for mothers, only the specific economic pressures were negatively reflected in mental health by increasing depressing mood and anxiety symptoms. Paternal anxiety was then associated with hostile marital interaction, perceived by the wife, and maternal anxiety with low marital support, perceived by the husband. The negative marital interaction finally was associated with poor parenting, especially among the fathers. Fathers’ anxiety was also directly related to their punitive and noninvolved fathering, and social dysfunction to noninvolved fathering. Depressive symptoms in mothers were negatively reflected in authoritative mothering. Finally, the results revealed that supportive and nonhostile marital interaction was able to moderate the negative impact of economic hardship on parenting. The findings suggest that mothers and fathers fulfil gendered roles in dealing with the family economy and relationships.
What does it Mean to be ‘Critical’ in is Research?
Authors: Brooke Carole
Published: September 2002

This paper undertakes a preliminary review of the state of critical thinking in the fields of information systems and organizational analysis. It begins by addressing the question ‘what is critical research?’ showing how the definition has changed and broadened over time. Two key themes emerge from this discussion: our understanding of emancipation and the nature of unequal power relations in the workplace. The paper then goes on to identify a recent emerging tendency towards the use of Habermas in the specific area of critical IS inquiry. It considers some of the reasons for this apparent trend and warns against becoming locked into a particular discourse. The paper concludes with some thoughts on how we can continue to broaden our frameworks of thinking, illustrating this with reference to the work of Foucault.
Following Successfully: Followership and Technology Adoption
Authors: Hall Peter , Densten Iain L.
Published: September 2002

Most firms in most countries find themselves taking up new technology in the wake of pioneers or first-movers. A central question is how (and whether) such firms can make a success of being followers--in the time-related sense of adopting subsequently. We take a novel approach to this question by drawing on the literature of leadership and followership within organisations. This literature employs characteristics in two dimensions to build a taxonomy of types of follower--in the hierarchical sense of working for and with an organisational superior. Using this approach, we generate hypotheses about the sorts of firms which are likely to prove more or less successful as early and later technology adopters. From the analysis, we are also able to identify ways in which the emerging followership literature requires strengthening.
Is there a Bin Laden in the Audience? Considering the Events of September 11 as a Possible Boomerang Effect of the Globalization of US Mass Communication
Authors: Ravault René-Jean
Published: September 2002

The images of America exported by entertainment and information media companies have created very high expectations in foreign audiences. Some recipients overhearing American media want to immigrate to the US and/or study in Western universities. In the process, a few of them encounter difficulties deceiving their high expectations. Their frustrations have been exploited by some fanatic ideologues for their own agendas, resulting in anti-American terrorism. The American media should be aware of the unintended consequences of their global exhibition of media, and more careful attention should be given to the way immigrants or graduate students sojourning in the US live their day-to-day encounters.
Media Use During a Crisis
Authors: Carey John
Published: September 2002

After learning about the crisis of September 11, Americans overwhelmingly turned to television for more information. However, people used multiple sources of information. The Web and e-mail appear to have played important but secondary roles to television and the telephone. Overall, the media functioned well in meeting the extraordinary demands for information and communication.
Something's Happened: Fictional Media as a Coping Mechanism
Authors: Mcnee Fiona
Published: September 2002

By the afternoon of September 11, entertainment executives were rushing to remove media products containing 'inappropriate' references from American television and movie screens. While references to terrorism were the starting point, their caution extended to themes of war and threats against America, all in the name of 'public sensitivity' and 'respect for the victims'. Simultaneously, uninterrupted news coverage was brimming with scenes of devastation and heartbreak. What makes fiction inappropriate when the equivalent fact is not? Can fiction help the viewer process fact, and if so, should it?
Live Television's Disaster Marathon of September 11 and its Subversive Potential
Authors: Blondheim Menahem , Liebes Tamar
Published: September 2002

Television's coverage of the tragic events of September 11 can be viewed and understood as a paradigmatic disaster marathon. The salience of the attack's visual images, their exclusivity on the screen for a protracted period, and the invisibility of their perpetrators enhanced the attack's effectiveness. The paper highlights a number of problems that the September 11 disaster marathon poses to the profession of journalism and to society, and points out possible remedies for the future. It ends with a short discussion of the ways in which television's coverage of the event both resembled and differed from the media-event model, and of theoretical aspects of its unique dimensions as a disaster marathon.
Preface
Authors: Noll A. Michael
Published: September 2002

This issue of the journal Prometheus includes an edited collection of papers by communication and media scholars from around the globe treating the social and societal aspects of the use of telecommunication and mass media tied to the tragic events that occurred in the United States on September 11, 2001.
For Different Audiences, Different Arguments: Economic Rhetoric at the Beginning of the Latin American School
Authors: Bianchi Ana Maria
Published: September 2002

This paper consists of a rhetorical interpretation of two essays published fifty years ago, at the beginning of the so-called “Latin American economic school.” Both were written by the Argentinean economist Raúl Prebisch (1901–1986), who was then working at the United Nations Economic Commission for Latin America (ECLA). As the most prominent Latin American economist, Prebisch fostered the construction of a theoretical framework that heavily influenced Latin American development policies after World War II.
There are Many Alternatives: Margaret Thatcher in the History of Economic Thought
Authors: Bateman Bradley W.
Published: September 2002

The last twenty-five years of the twentieth century were freighted with important moments for historians of economic thought: the collapse of the Keynesian consensus, the rise (and fall) of monetarism, the collapse of the former Soviet Union and the other Marxist-Leninist states in central and eastern Europe, the rise of neo-liberalism, and arguments over the possible emergence of a “New Economy” following the internet investment boom at the end of the 1990s. Each of these moments will require its own history as we slowly move away from the tumult of the times and begin to weigh them for their own significance. But several of the moments have a common iconic face in Margaret Thatcher, the Prime Minister of Great Britain from 1979 to 1990. Few other individuals so readily embody the sense of the times. Thatcher's election—a full year and a half before Ronald Reagan's—marks for many people the moment when Keynesian policies finally and irretrievably lost their legitimacy. Likewise, the timing of her election, just two months before Paul Volcker's selection as the chair of the Federal Reserve Board of Governors in the United States, also means that for many people Thatcher's is the public face of monetarism's ascendancy. Finally, there is probably no one person whose name is so clearly associated with the rise of free market thinking and neo-liberalism during the end of the twentieth century.
Margaret Thatcher's Place in History: Two Views
Authors: Clarke Peter
Published: September 2002

It is not every literary novice, blushing diffidently over her first manuscript, who easily finds a publisher, still less one prepared to pay an advance of several million pounds. But not every first author has such a story to tell as Margaret Thatcher, the longest-serving British prime minister of the twentieth century. It was the previous record holder, Asquith, who first established the notion that retired prime ministers write their memoirs, and he did so under a twin motivation which was not peculiar to himself. He sought vindication and he was after the money.
Elevated C‐met in Thymic Dendritic Cells of New Zealand Black Mice
Authors: Okada Tomoyuki , Lian Zhe-Xiong , Hsu Tom , Naiki Mitsuru , Ansari Aftab A. , Robinson Dan , Kung Hsing-Jien , Boyd Richard , Gershwin M. Eric
Published: September 2002

New Zealand Black (NZB) mice are a well‐known animal model of human autoimmune disease. Although the mechanism for development of autoimmunity is unclear, NZB mice are well known for severe thymic microarchitecture abnormalities. It is thought that thymic dendritic cells (DC) may play a role in thymic education and contribute to the autoimmune process. To address this issue and, in particular, that qualitative and/or quantitative differences exist in thymic DC, we took advantage of a novel restriction analysis system that allow definition of differences in the expression of tyrosine kinases using highly enriched populations of thymic DC from NZB compared to BALB/c and C57BL/6 mice. The method chosen, restriction analysis of gene expression, allowed the determination of protein tyrosine kinase transcription profiles. We report herein that NZB mice have a significant upregulation of C‐met compared to the control strains. The abnormality of the C‐met transcription was confined to thymic DC. We believe that its abnormal expression reflects the resistance of thymic cells to apoptosis, which will ultimately lead to defects and/or abnormal signaling by the interaction of thymic DC and thymocytes. Further studies involving such interactions are under way.
Ontogenic Development of Th1 and Th2 Cytokine Capabilities in Random Bred Mice
Authors: Fagoaga Omar R. , Nehlsen-Cannarella Sandra L.
Published: September 2002

Neonatal mouse Th1 capabilities mature by postnatal day 5. Neonatal T cells have been reported to exhibit a bias towards Th2 cytokine production when co‐cultured with adult antigen presenting cells (APC). We studied mouse T cells co‐cultured with contemporary APC to evaluate neonatal cytokine production capabilities. In response to allogeneic stimulation, T cells co‐cultured with contemporary APC from day 5 pups produced 37‐fold greater IFNγ and 1.4‐fold greater IL‐2 levels than day 20 weanling mice. After CD3 ligation, cells from day 5 pups produced 4‐ (IL‐2) and 10‐fold (IFNγ) greater levels than adults (day 45), and concentrations were 27‐ (IL‐2) and 18‐fold (IFNγ) higher than with allogeneic stimulation alone. On average, the percent difference in concentrations was 418 (IL‐4), 286 (IL‐2) and 1140% (IFNγ) higher in unseparated spleen cells than in isolated splenic CD4 cells and APC. These results demonstrate that, in response to allogeneic stimulation with or without CD3 ligation, lymphocytes of neonatal mice (day 5) have the capacity to produce equivalent or greater TcR‐dependent Th1 cytokine (IL‐2 and IFNγ) levels than adult mice. Findings also support the idea that the reported Th2 bias of neonatal T cells may be the result of in vitro manipulation and choice of mouse strain, not of an inherent bias.
Identification of Disjoint Bi‐decompositions in Boolean Functions through Walsh Spectrum
Authors: Falkowski Bogdan J. , Kannurao Sudha
Published: September 2002

A new algorithm for the identification of disjoint bi‐decomposition in Boolean functions from its Walsh spectrum is proposed. The type of bi‐decomposition and its existence is derived from the knowledge of a subset of Walsh spectrum for a Boolean function. All three types of bi‐decomposition are considered including OR, AND and EXOR type. A filtering procedure that uses just few Walsh spectral coefficients (SC) is applied to quickly eliminate the functions that are not bi‐decomposable and hence the algorithm is very efficient. The type of bi‐decomposition and affirmation/negation of variables in its logic sub‐functions are directly identified by manipulation on the reduced cubical representation of Boolean functions and their corresponding Walsh spectra. The presented algorithm has been implemented in C and tested on the standard benchmark functions. The number of Boolean functions having various disjoint bi‐decompositions has also been enumerated.
Citizenship, Social Welfare System And Social Policies In France
Authors: Bouget Denis , Brovelli Gérard
Published: September 2002

The French notion of citizenship comes largely from the French Revolution and the Republican conception of citizenship. In this context, the social fields were mainly the provision of public goods and services (especially schools) and public assistance in favour of vulnerable people. The creation and the expansion in social security schemes were largely based on Bismarckian foundations (negotiation between social partners) more than on citizenship. However, since the mid-1970s, the extension in unemployment and poverty created a new governmental concern. Several drawbacks of the social security system led to divergent reforms: some of them came under the principle of universalism and/or fundamental social rights; others required the local participation of users and the real use of social benefits. Finally, these new social policies have enlarged the concept of citizenship but, simultaneously, they have been correlated with a decrease in the ideological power of the notion of Republican citizenship.
Myosin 1c and myosin IIB serve opposing roles in lamellipodial dynamics of the neuronal growth cone
Authors: Diefenbach Thomas J. , Latham Vaughan M. , Yimlamai Dean , Liu Canwen A. , Herman Ira M. , Jay Daniel G.
Published: September 2002

The myosin family of motor proteins is implicated in mediating actin-based growth cone motility, but the roles of many myosins remain unclear. We previously implicated myosin 1c (M1c; formerly myosin Iβ) in the retention of lamellipodia (Wang et al., 1996). Here we address the role of myosin II (MII) in chick dorsal root ganglion neuronal growth cone motility and the contribution of M1c and MII to retrograde F-actin flow using chromophore-assisted laser inactivation (CALI). CALI of MII reduced neurite outgrowth and growth cone area by 25%, suggesting a role for MII in lamellipodial expansion. Micro-CALI of MII caused a rapid reduction in local lamellipodial protrusion in growth cones with no effects on filopodial dynamics. This is opposite to micro-CALI of M1c, which caused an increase in lamellipodial protrusion. We used fiduciary beads (Forscher et al., 1992) to observe retrograde F-actin flow during the acute loss of M1c or MII. Micro-CALI of M1c reduced retrograde bead flow by 76%, whereas micro-CALI of MII or the MIIB isoform did not. Thus, M1c and MIIB serve opposite and nonredundant roles in regulating lamellipodial dynamics, and M1c activity is specifically required for retrograde F-actin flow.
Phosphorylation and an ATP-dependent process increase the dynamic exchange of H1 in chromatin
Authors: Dou Yali , Bowen Josephine , Liu Yifan , Gorovsky Martin A.
Published: September 2002

In Tetrahymena cells, phosphorylation of linker histone H1 regulates transcription of specific genes. Phosphorylation acts by creating a localized negative charge patch and phenocopies the loss of H1 from chromatin, suggesting that it affects transcription by regulating the dissociation of H1 from chromatin. To test this hypothesis, we used FRAP of GFP-tagged H1 to analyze the effects of mutations that either eliminate or mimic phosphorylation on the binding of H1 to chromatin both in vivo and in vitro. We demonstrate that phosphorylation can increase the rate of dissociation of H1 from chromatin, providing a mechanism by which it can affect H1 function in vivo. We also demonstrate a previously undescribed ATP-dependent process that has a global effect on the dynamic binding of linker histone to chromatin.
T cell receptor ligation induces the formation of dynamically regulated signaling assemblies
Authors: Bunnell Stephen C. , Hong David I. , Kardon Julia R. , Yamazaki Tetsuo , McGlade C. Jane , Barr Valarie A. , Samelson Lawrence E.
Published: September 2002

Tcell antigen receptor (TCR) ligation initiates tyrosine kinase activation, signaling complex assembly, and immune synapse formation. Here, we studied the kinetics and mechanics of signaling complex formation in live Jurkat leukemic T cells using signaling proteins fluorescently tagged with variants of enhanced GFP (EGFP). Within seconds of contacting coverslips coated with stimulatory antibodies, T cells developed small, dynamically regulated clusters which were enriched in the TCR, phosphotyrosine, ZAP-70, LAT, Grb2, Gads, and SLP-76, excluded the lipid raft marker enhanced yellow fluorescent protein–GPI, and were competent to induce calcium elevations. LAT, Grb2, and Gads were transiently associated with the TCR. Although ZAP-70–containing clusters persisted for more than 20 min, photobleaching studies revealed that ZAP-70 continuously dissociated from and returned to these complexes. Strikingly, SLP-76 translocated to a perinuclear structure after clustering with the TCR. Our results emphasize the dynamically changing composition of signaling complexes and indicate that these complexes can form within seconds of TCR engagement, in the absence of either lipid raft aggregation or the formation of a central TCR-rich cluster.