bluuebunny/crossref_metadata_2025 huggingface dataset:
Modified fluorescence in situ hybridization methods using pathology archives
Authors: Kitayama Yasuhiko
Published: August 2005

Brain tumors, like many other common tumors, are frequently associated with chromosomal numerical abnormalities. However, as the identification of abnormal characteristics by conventional cytogenetic or molecular methods has been hampered by technical difficulties, minimal information has been available about specific chromosomal or locus‐specific gene alterations. Recently, fluorescence in situ hybridization (FISH) has emerged as a powerful clinical and research tool for the assessment of genomic instability within interphase nuclei. Here, we developed a modified FISH protocol including short‐term microwave treatment to analyze specimens from the pathology archives that had been routinely processed and stored. The FISH signals obtained using this modified method showed a significant improvement compared with those obtained using the standard FISH method. This new technique thus enables the analysis of various paraffin‐embedded tissue sections of intracranial tumors obtained under inappropriate fixation conditions. We highlight the advantages of this modified FISH procedure on a tissue microarray of archival materials for current diagnostic and investigative neuropathology applications.
Aluminum chloride does not facilitate deposition of human synthetic amyloid β1–42 peptide in the rat ventricular system of a short‐term infusion model
Authors: Nakagawa Yasushi , Kawashima Toshiro , Yamada Tomomi , Harano Mutsuo , Monji Akira , Yuzuriha Takefumi , Iwaki Toru
Published: August 2005

Recent data have demonstrated that a 39–43 amino acid peptide called β‐amyloid peptide (Aβ), which predominantly contains 42 residues (Aβ1–42), has a strong tendency to form insoluble aggregates and that the toxic effects of Aβ are based on its aggregation. In a previous study, we reported that infusion of 100 µg of human synthetic Aβ1–42 (sAβ1–42), which is a main component of diffuse plaques, into the lateral ventricle of the rat brain of a short‐term infusion model resulted in almost complete disappearance of sAβ1–42 aggregates from the ventricles by 28 days. In addition, aluminum is considered a potential etiological factor in Alzheimer's disease (AD). Neurotoxicity from excess brain exposure to aluminum has been documented from both clinical observations and animal experiments, although a direct relationship between aluminum and AD has yet to be clearly established. We therefore investigated the effects of sAβ1–42 aggregates with aluminum chloride (AlCl3) in the ventricular system of the rat brain of a short‐term infusion model. At either 2 or 7 days following infusion, sAβ1–42 formed aggregates with AlCl3 that spread throughout the entire ventricular system. However, sAβ1–42 aggregates with AlCl3 had almost disappeared from the ventricles by 28 days, resulting in similarities with respect to the time‐course and the neuropathological changes observed in sAβ1–42 aggregation without AlCl3. We herein report for the first time that considerable amounts of sAβ1–42 aggregates with AlCl3 almost disappear from the rat ventricular system by 28 days post‐infusion.
Prognostic significance of microvessel density determined by an anti‐CD105/endoglin monoclonal antibody in astrocytic tumors: Comparison with an anti‐CD31 monoclonal antibody
Authors: Yao Yongxue , Kubota Toshihiko , Takeuchi Hiroaki , Sato Kazufumi
Published: August 2005

There are conflicting reports as to whether the degree of angiogenesis as measured by microvessel density (MVD) has a prognostic value in astrocytic tumors. This may be due to the use of different antibodies against endothelial cells to highlight microvessels. It has been reported that unlike pan‐endothelial antibodies, such as CD31, anti‐CD105 antibodies preferentially react with endothelial cells in angiogenic tissues. To clarify the validity of anti‐CD105 antibody in the evaluation of angiogenesis, we assessed MVD using an anti‐CD105 monoclonal antibody (mAb) (CD105‐MVD) and an anti‐CD31 mAb (CD31‐MVD) in a series of 50 astrocytic tumors, and correlated MVD with expression of the key angiogenic factor vascular endothelial growth factor (VEGF) and prognosis. The mean CD31‐MVD and CD105‐MVD was 36.7 and 24.8 for low‐grade astrocytoma (LGA), 48.0 and 42.7 for anaplastic astrocytoma, 55.3 and 51.9 for glioblastoma multiforme (GBM), respectively. CD105‐MVD was more closely correlated with VEGF expression than CD31‐MVD. Patients with LGA and GBM showing higher CD105‐MVD had a significantly shorter mean survival time (MST) than those with lower CD105‐MVD tumors (P = 0.0381 and 0.0131, respectively). Whereas the MST of patients with higher CD31‐MVD tumors seemed to be shorter than that of lower CD31‐MVD patients within each tumor grade, the differences were not statistically significant. These findings suggest that anti‐CD105 mAb may be a better marker than anti‐CD31 mAb in evaluation of angiogenesis and prediction of prognosis in astrocytic tumors.
Accuracy and diagnostic yield of stereotactic biopsy in the diagnosis of brain masses: Comparison of results of biopsy and resected surgical specimens
Authors: Aker Fügen V. , Hakan Tayfun , Karadereler Selhan , Erkan Murat
Published: August 2005

The aim of this retrospective study was to investigate the diagnostic yield and accuracy of stereotactic biopsy in patients harboring brain mass. Stereotactic biopsy was performed in 130 patients between 1995 and 2000 in an educational and research hospital in Turkey. The results of histological analysis were compared to the resected specimens in 23 patients. The lesions were lobar in 62% of cases and deep‐seated in 38% of cases. During the biopsy procedures, the pathologist was in the operating theatre and a very small fragment was used for cytological examination. No frozen section was used in any of the cases. Samples were diagnostic in 122 cases. The overall diagnostic yield of the procedure was 94%. A definitive histological diagnosis was not made in eight patients. The histological diagnoses of the two procedures were identical (complete agreement) in 16 cases. In three cases, the histological diagnoses between the two procedures were slightly different without impact on patient care (minor disagreement). The diagnosis of the stereotactic biopsy was completely changed after craniotomy in four cases (major disagreement). The accuracy of the histological diagnosis was 83%. There was only one major complication, which involved intracerebral hemorrhage. Despite the limited number of patients who underwent resection, our data suggest that stereotactic biopsy of brain masses is a safe and accurate technique that can obtain adequate tissue for histological diagnosis, thus providing the best avaible treatment for patients. Cytological evaluation of the streotactic biopsy also is a highly effective tool for obtaining sufficient material during the procedure in many cases.
Oligodendroglioma: Impact of molecular biology on its definition, diagnosis and management
Authors: Ueki Keisuke
Published: August 2005

Molecular genetics and biology have been having significant influence on the practice of neuro‐oncology in recent years, with oligodendrogliomas being the most prominent example. The majority of oligodendrogliomas show remarkable sensitivity to chemotherapy, and the finding that the loss of chromosome 1p was tightly associated with the response opened a new era in which the treatment can be tailored for each tumor patient based on molecular genetic diagnosis. It has been noticed that histological features, when closely examined, are also correlated with the molecular genetic data, such as losses of 1p/19q/10q and TP53 mutation. Furthermore, expression profiling using microarray technology showed that oligodendrogliomas with 1p loss express high levels of neuronal genes, suggesting that the progenitor of those tumors may be shared with neurons. Considering the rapid progress of the knowledge in neural developmental biology, it is possible that the classification, definition and diagnosis of gliomas will be rewritten based on such knowledge at the molecular level in the near future, if they reflect the biological features of each tumor better than the histological diagnosis based mostly on morphology.
Comparison of habitat selection by two sympatric macropods, Thylogale billardierii and Macropus rufogriseus rufogriseus, in a patchy eucalypt‐forestry environment
Authors: LE MAR KIRSTEN , MCARTHUR CLARE
Published: August 2005

Abstract  Population density estimates and patterns of habitat selection by sympatric red‐bellied pademelons (Thylogale billardierii (Marsupialia: Macropodidae)) and red‐necked wallabies (Macropus rufogriseus rufogriseus (Marsupialia: Macropodidae)) were examined within a patchy forestry environment in north‐west Tasmania. Population density of both species was relatively high. Selection indices from both population surveys and animal movement data showed that T. billardierii and M. rufogriseus had similar patterns of habitat selection at two spatio‐temporal scales; home range within the study area and habitats selected while foraging at night. Both species selected for young Eucalyptus nitens plantation with high weed‐cover within their home range. At night, T. billardierii and M. rufogriseus selected for open habitats (young plantation and grassland) and avoided closed habitats (native forest and 5–7 years old E. nitens plantation). There was no evidence for resource partitioning between species at these scales. In contrast, the two species differed in their selection for daytime sheltering habitat; T. billardierii selected native forest while M. rufogriseus selected older plantation. This may reflect differences in their predator avoidance strategies; that is, crypsis versus flight, rather than resource partitioning as a result of interspecific competition. The environment appears to be of high quality for both species, with patches of feeding and shelter habitats within close proximity of one another.
Effect of shrubs and seasonal variability of rainfall on the establishment of Aspidosperma quebracho‐blanco in two edaphically contrasting environments
Authors: BARCHUK A. H. , VALIENTE‐BANUET A. , DÍAZ M. P.
Published: August 2005

Abstract  Three experiments were conducted to verify if an increase in environmental stress level would affect the interactions between two species of nurse shrubs and seedlings of Aspidosperma quebracho‐blanco. This is a mesic species with a generalist distribution over an extensive environments gradient. The relationship between Larrea divaricata and seedlings of A. quebracho‐blanco was studied in two contrasting soils, a silty loam soil with higher surface clay content and a sandy loam soil. The effect of seasonal variability of rainfall on the initial establishment of seedlings under the shade of L. divaricata was evaluated in three consecutive years. The effect of nurse plant shade was tested comparing two shrub species with different types of leaf life span (sclerophyllous‐evergreen and leguminous‐deciduous). The natural establishment of A. quebracho‐blanco depended on shaded microsites, but not on the type of shade provided by different nurse shrubs. Emergence and initial establishment depended on interactions of soil type and seasonal rainfall variation with nurse plants. The importance of facilitation increased with clay soil (CS). Sandy soil was ‘less humid’ than CS under shrub shade. However, establishment success depends on opportune even rainfall distribution in interaction with nurse plant presence.
Self‐sacrifice, self‐transcendence and nurses’ professional self
Authors: Pask Elizabeth J.
Published: August 2005

Abstract  In this paper I elaborate a notion of nurses’ professional self as one who is attracted towards intrinsic value. My previous work in 2003 has shown how nurses, who see intrinsic value in their work, experience self‐affirmation when they believe that they have made a difference to that which they see to have value. The aim of this work is to reveal a further aspect of nurses’ professional self. I argue that nurses’ desire towards that which they see to have intrinsic value, is a necessary and self‐transcending aspect of a nurses’ professional self. I argue further that nurses’ desire towards intrinsic value inevitably involves their vulnerability. Nurses who see intrinsic value are shown to be vulnerable to self‐sacrifice in their inclination to work for the good of their patients, at the expense of themselves. Yet an ability to transcend their self in this way remains a necessary aspect of a nurse's professional self, which requires nurture and support through nurse education.
An overview of structuration theory and its usefulness for nursing research
Authors: Hardcastle Mary‐Ann R. , Usher Kim J. , Holmes Colin A.
Published: August 2005

Abstract  Anthony Giddens’ theory of structuration is a theory of social action, which claims that society should be understood in terms of action and structure; a duality rather than two separate entities. This paper introduces some of the central characteristics of structuration theory, presenting a conceptual framework that helps to explore how people produce the systems and structures that shape their practice. By understanding how people produce and reproduce structures, then there is the potential for changing them. Criticisms that have been raised about the theory are introduced, followed by examples of how the theory might be useful to nursing research. Structuration theory can be employed to explore how nurses produce, reproduce, and transform nursing practice through social interaction across time and space.
I think, therefore I am: a twin study of attributional style in adolescents
Authors: Lau Jennifer Y.F. , Rijsdijk Frühling , Eley Thalia C.
Published: August 2005

Background:  Parenting factors may be important to the development of attributional style in adolescence, which in turn relates to depression symptoms. These relationships have mainly been considered in terms of social risk mechanisms, and little is known about the role of genetic influences.

Method:  Self‐reported measures of attributional style, depression symptoms and parental disciplinary styles were administered to over 1300 adolescent twin and sibling pairs. Model‐fitting techniques were used to examine the role of genetic and environmental influences.

Results:  Moderate genetic influences on attributional style were demonstrated, and furthermore, its association with depression reflected considerable genetic effects. Familial factors were implicated in the association between attributional style and punitive parenting, although genetic from shared environmental causes could not be distinguished.

Conclusions:  Our results demonstrate that attributional style is influenced by genetic, as well as social factors. Implications for aetiological pathways integrating cognitive, genetic and social factors on adolescent depression are discussed.
Female Violence Against Intimate Partners: An Introduction
Authors: Frieze Irene Hanson
Published: August 2005

This special issue addresses some of the contradictions found in the research literature on intimate partner violence. Much of this work is concerned with the problems of severely battered women. However, other research indicates that women can be just as violent as their partners. Articles in this issue begin to explore some of the ways that women express intimate partner violence and argue that there is more than one type of partner violence. Motives and other correlates of violence are examined and future research directions are outlined.
Relationship Quality and Domestic Violence in Women's Same-Sex Relationships: The Role of Minority Stress
Authors: Balsam Kimberly F. , Szymanski Dawn M.
Published: August 2005

Despite a large body of literature addressing relationship quality and domestic violence in women's same-sex relationships, few studies have empirically examined how stress specific to living as a lesbian or bisexual woman might correlate with these relationship variables. Degree of outness, internalized homophobia, lifetime and recent experiences of discrimination, butch/femme identity, relationship quality, and lifetime and recent experiences of domestic violence were assessed in a sample of 272 predominantly European American lesbian and bisexual women. Lesbian and bisexual women were found to be comparable on most relationship variables. In bivariate analyses, minority stress variables (internalized homophobia and discrimination) were associated with lower relationship quality and both domestic violence perpetration and victimization. Outness and butch/femme identity were largely unrelated to relationship variables. Path analysis revealed that relationship quality fully mediated the relationship between internalized homophobia and recent domestic violence.
Investigating Three Explanations of Women's Relationship Aggression
Authors: Graham-Kevan Nicola , Archer John
Published: August 2005

This study investigated explanations of women's partner aggression in a sample of 358 women. Women completed measures of physical aggression, control, and fear. Three explanations of women's partner aggression were explored: (a) that its use is associated with fear, (b) that it is reciprocal, and (c) that it is coercive. Each explanation received partial support, with multivariate analysis showing that collectively they explained significant proportions of the variance in women's self-reported use of physical aggression toward their male partners. These results indicate that women's physical aggression toward male partners cannot be understood using a unitary explanation.
A Postmodern Approach to Women's Use of Violence: Developing Multiple and Complex Conceptualizations
Authors: McHugh Maureen C. , Livingston Nichole A. , Ford Amy
Published: August 2005

We review the research on intimate partner abuse and, in particular, the articles in this issue, from within a feminist and postmodern framework. Research on women's use of violence is reviewed in terms of how researchers have constructed and measured violence and have conceptualized intimate partner violence (IPV) and gender. What and how we measure determines what we find ( McHugh & Cosgrove, 2005 ). We call for new conceptualizations of intimate violence and for more complex constructions of gender. We offer a postmodern perspective on gender and IPV arguing that interpersonal violence always involves gender, that approach and method influence results, and that men and women use violence in both similar and different ways.
Garden Warbler Sylvia borin migration in sub‐Saharan West Africa: phenology and body mass changes
Authors: OTTOSSON ULF , WALDENSTRÖM JONAS , HJORT CHRISTIAN , MCGREGOR ROSS
Published: August 2005

The Garden Warbler is a classic subject for the study of Palaearctic–African bird migration strategies. Most studies have considered the situation close to the breeding areas, while the African and especially the sub‐Saharan part of the species’ migration have received comparatively little attention. Here we use autumn and spring ringing data from Nigeria and The Gambia to study the movements and energetics of the species in West Africa during the non‐breeding season. The first Garden Warblers arrive south of the desert around the beginning of September, roughly at the same time as the median date for their passage through the Baltic Sea region and c. 3 weeks before their median passage date through southern Italy. In the Nigerian Sahel savannahs, where, owing to the rainy season and its associated increase in food availability, many more Garden Warblers stop over in autumn than in the dry spring, the median date of passage is 1 October. The body mass on arrival south of the desert is normally only a few grams more than the lean body mass (LBM; 15 g) – with a mean of 16.6 g (sd = ±1.8 g) in The Gambia and 17.4 g (sd = ±1.8 g) in the Nigerian Sahel. After resting and refuelling in the Sahel, Sudan and Guinea‐type savannahs the Garden Warblers depart during November–December for wintering areas further south. Before leaving, they again increase their body mass, with an average fuel load of c. 20%, and often more than 50% relative to LBM. Some of the birds passing through Nigeria probably spend midwinter around the Congo Basin. During spring they return northwards to the Guinea savannah zone in April and fuel‐up there for the trans‐Sahara passage. At this time they normally increase their body reserves to around 50% of the LBM, but c. 10% of the birds gain 100%, thus doubling their mass. The passage there peaks around 20 April and continues well into May. That the main take‐off northwards is directly from the Guinea savannahs is indicated by the very low numbers trapped in the Sahel during spring.
Reducing Waiting Times: Using an Opt‐In System and Changing Prioritisation Criteria
Authors: Woodhouse Anne E.
Published: August 2005

Background:  The Highland Clinical Psychology Service for Children and Young People, faced with excessive waiting lists, a large geographical remit, and only three psychologists, sought to change waiting list management to improve services.

Method:  An opt‐in appointment system and outcome research were used to inform waiting list management. Referrals with the characteristics of cases where psychological interventions are helpful were prioritised over cases that had characteristics of poor outcomes.

Results:  Attendance at first appointments was significantly increased and waiting times were significantly reduced.

Conclusions:  The success of the opt‐in system replicated research in other CAMHS. It is also hypothesised that the new waiting list prioritisation criteria had an effect, although this needs further research. Issues associated with the change in waiting list prioritisation are discussed and it is suggested that prioritising treatable cases over complex cases is an appropriate, effective and ethical use of scarce resources.
Working a fraction and making a fraction work: a rough guide for geographers in the academy
Authors: Birnie Jacky , Madge Clare , Pain Rachel , Raghuram Parvati , Rose Gillian
Published: August 2005

Little is known about the issues facing geographers working on fractional appointments in higher education institutions in the UK. This paper draws on a survey of UK geography departments and personal experiences to explore some of that territory for the first time. The purpose is both to set the agenda for institutional policy issues and to provide some immediate points of reflection for staff intending to take up fractional work. We consider the place of fractional working in the dominant discourses around paid work, problems of workload division and the impact on professional standing (including the RAE). We suggest that while personal ‘life’ reasons for fractional working are often positive, fractional workers in the academy risk professional marginalization.
Landscape and the mask of self in George Orwell's ‘Shooting an elephant’
Authors: Tyner James A
Published: August 2005

Recent work in geography has focused attention on the imbrication of landscape and literature. A dominant thread of these ‘fictive geographies’ has been a concern with how imagined landscapes contribute to the constitution of self. Informed especially by post‐structuralism and post‐colonialism, geographers have recently provided critical readings of novels, short stories and essays. In this paper I provide a reading of George Orwell's essay ‘Shooting an elephant’. The writings of Orwell reveal a long‐standing engagement with issues of humanity and subjectivity, and I contend that this essay, rather than a straightforward polemic against British imperialism, reveals a concern primarily with the constitution of self within a colonial landscape. Orwell's essay thus provides insight into the processes whereby human subjectivities interact with space and structures.
Not in my back yard! Sports stadia location and the property market
Authors: Davies Larissa E
Published: August 2005

In recent years sports stadia have been built in the UK, not only for their intended sporting purpose but with the twin aim of stimulating economic and physical regeneration. However, proposals to locate stadia in urban areas often prompt a negative reaction from local communities, fearing a decline in property prices. This paper will use a case study of the Millennium Stadium in Cardiff and the City of Manchester Stadium to illustrate that in contrast to this widely held belief, sports stadia can actually enhance the value of residential property. Furthermore, it will argue that stadia also contribute indirectly to property value through the creation of pride, confidence and enhanced image of an area.
Financial inclusion, universal banking and post offices in Britain
Authors: Midgley J
Published: August 2005

The causes and consequences of financial exclusion have become a policy concern in Britain in recent years. This paper analyses policy discourses around financial exclusion and considers the (social and economic) geographical issues surrounding one particular policy response – universal banking services. It examines the policy background which led to the introduction of these services, and the institutional role of the Post Office, before discussing their potential social and spatial consequences.
‘Cultures of GM’: discourses of risk and labelling of GMOs in the UK and EU
Authors: Herrick Clare B
Published: August 2005

The debate over genetically modified foods has become one of the defining environmental and social issues of the past decade. As the public naturalize biotechnology within existing cultural systems, this produces what I term ‘cultures of GM’. This paper examines how these ‘cultures’ are legitimized and sustained through an appraisal of divergent North American and European conceptions of risk and their translation into food labelling policies. It is argued that the dialectical relationship between risk perception and its cultural context offers an instructive vantage point for critical reflection by geographers.
Environmental determinism in Holocene research: causality or coincidence?
Authors: Coombes Paul , Barber Keith
Published: August 2005

The past decade has seen a revival of environmental determinism in palaeoenvironmental research, with palaeoclimatic shifts implicated in the collapse of many past civilizations. Implicit in these studies is a belief that the observed cultural transitions can be causally related to the magnitude of climatic change. However, examination of the processes of these declines suggests that many exhibit patterns characteristic of complexity cascading within self‐organized systems. If so, the nonlinear nature of these systems’ responses to external forcing means that the assumption of causality in many of these cases should be considered questionable.
Land tenure type as an underrated legal constraint on the conservation management of coastal dunes: examples from Ireland
Authors: McKenna John , MacLeod Michael , Cooper Andrew , O'Hagan Anne Marie , Power James
Published: August 2005

Legal factors play an underrated but significant role as constraints on conservation management. In this paper, based on observations in both Northern Ireland and the Republic of Ireland, mode of land tenure is assessed to determine its influence on the conservation management of coastal dunes. The tenure types considered are: private ownership, corporate private ownership, tenancy, secured tenancy, leasing, common (joint) ownership, uncertain ownership, public ownership and its subset military ownership. It is suggested that multiple private ownership is least likely to favour effective conservation management. Public ownership by a statutory conservation authority and corporate private ownership by a conservation‐orientated NGO are regarded as the optimum tenure types for conservation management of coastal dunes.
Local provenance in rehabilitation of degraded landscapes: a case study from the Hawkesbury–Nepean catchment, Australia
Authors: Burgin Shelley , Carson J , Maheshwari B
Published: August 2005

Throughout Australia thousands of volunteers are engaged in Landcare projects that should help rehabilitate degraded landscapes. Many of these projects involve tree planting, but their seed is not necessarily of local provenance. Based on a survey of 85 Landcare groups working in the Hawkesbury–Nepean catchment, data were collected about Landcare groups’ knowledge of their seed source, understanding of local provenance and the ecosystem in which they were planting trees and the source of funding for their projects. The findings from the study indicate that about one in five (21%) of the groups surveyed that introduced plant material were not aware of local provenance issues. Indirect indications were that a large number of Landcare groups state‐wide may be doing more harm than good to the landscape while trying to rehabilitate it. The data also showed that one in seven (13%) of the groups funded by the Australian Government through the Natural Heritage Trust (NHT) had limited awareness of local provenance issues. With millions of dollars being spent on ‘works on the ground’, it would be prudent to allocate some funds to document and monitor current Landcare activities, so that the environmental outcomes can be quantified and more effective Landcare policies can be developed in the future.
Gender and agrobiodiversity: a case study from Bangladesh
Authors: OAKLEY EMILY , MOMSEN JANET HENSHALL
Published: August 2005

Local geography and gender are two major factors determining which crop varieties are cultivated in a case study of two rural villages in Bangladesh. This paper explores the interrelationships between gender, agrobiodiversity, and the use of, and preferences for, improved and local crop varieties. These are examined in relation to rice, minor field crops, and home garden fruits and vegetables. Reasons for both the displacement and the persistence of local varieties (LVs) are analysed in comparison to improved variety (IV) diffusion. The research evaluates agrobiodiversity through the number, types, and varieties of crops grown in fields and home gardens. The desired agroecological, economic, and cultural characteristics of crops grown document how respondents rank their variety preferences. Variety preferences and the perceived importance of LV preservation are compared with what is actually grown. The study indicates that there was little variation between villages in their approach towards the use of IV and LV rice; IVs were cultivated for their high yields and LV rice for taste and culinary uses. However, there were significant differences in relative agricultural dependence between the two villages which led to unique variety preferences. In both villages, women's preferences for IVs or LVs play a major role in crop choices, particularly as they manifest themselves in gendered domains of authority.
Genomic annotation and transcriptome analysis of the zebrafish (Danio rerio)hoxcomplex with description of a novel member,hoxb13a
Authors: Corredor‐Adámez M. , Welten M. C. M. , Spaink H. P. , Jeffery J. E. , Schoon R. T. , De Bakker M. A. G. , Bagowski C. P. , Meijer A. H. , Verbeek F. J. , Richardson M. K.
Published: August 2005

SummaryThe zebrafish (Danio rerio) is an important model in evolutionary developmental biology, and its study is being revolutionized by the zebrafish genome project. Sequencing is at an advanced stage, but annotation is largely the result of in silico analyses. We have performed genomic annotation, comparative genomics, and transcriptional analysis using microarrays of thehoxhomeobox‐containing transcription factors. These genes have important roles in specifying the body plan. Candidate sequences were located in version Zv4 of the Ensembl genome database by TBLASTN searching withDanioand other vertebrate published Hox protein sequences. Homologies were confirmed by alignment with reference sequences, and by the relative position of genes along each cluster. RT‐PCR using adult Tübingen cDNA was used to confirm annotations, to check the genomic sequence and to confirm expression in vivo. Our RT‐PCR and microarray data show that all 49hoxgenes are expressed in adult zebrafish. Significant expression for all knownhoxgenes could be detected in our microarray analysis. We also find significant expression ofhox8paralogs andhoxb7ain the anti‐sense direction. A novel gene,D. rerio hoxb13a, was identified, and a preliminary characterization by in situ hybridization showed expression at 24 hpf at the tip of the developing tail. We are currently characterizing this gene at the functional level. We argue that the oligo design for microarrays can be greatly enhanced by the availability of genomic sequences.
Morphoregulation of teeth: modulating the number, size, shape and differentiation by tuning Bmp activity
Authors: Plikus Maksim V. , Zeichner‐David Maggie , Mayer Julie‐Ann , Reyna Julia , Bringas Pablo , Thewissen J. G. M. , Snead Malcolm L. , Chai Yang , Chuong Cheng‐Ming
Published: August 2005

Summary
During development and evolution, the morphology of ectodermal organs can be modulated so that an organism can adapt to different environments. We have proposed that morphoregulation can be achieved by simply tilting the balance of molecular activity. We test the principles by analyzing the effects of partial downregulation of Bmp signaling in oral and dental epithelia of the keratin 14‐Noggin transgenic mouse. We observed a wide spectrum of tooth phenotypes. The dental formula changed from 1.0.0.3/1.0.0.3 to 1.0.0.2(1)/1.0.0.0. All mandibular and M3 maxillary molars were selectively lost because of the developmental block at the early bud stage. First and second maxillary molars were reduced in size, exhibited altered crown patterns, and failed to form multiple roots. In these mice, incisors were not transformed into molars. Histogenesis and differentiation of ameloblasts and odontoblasts in molars and incisors were abnormal. Lack of enamel caused misocclusion of incisors, leading to deformation and enlargement in size. Therefore, subtle differences in the level, distribution, and timing of signaling molecules can have major morphoregulatory consequences. Modulation of Bmp signaling exemplifies morphoregulation hypothesis: simple alteration of key signaling pathways can be used to transform a prototypical conical‐shaped tooth into one with complex morphology. The involvement of related pathways and the implication of morphoregulation in tooth evolution are discussed.
Variation in thyroid hormone action and tissue content underlies species differences in the timing of metamorphosis in desert frogs
Authors: Buchholz Daniel R. , Hayes Tyrone B.
Published: August 2005

Summary
Hormonal control of post‐embryonic morphogenesis is well established, but it is not clear how differences in developmental endocrinology between species may underlie animal diversity. We studied this issue by comparing metamorphic thyroid hormone (TH) physiology and gonad development across spadefoot toad species divergent in metamorphic rate. Tissue TH content, in vitro tail tip sensitivity to TH, and rates of TH‐induced tail tip shrinkage correlated with species differences in larval period duration. Gonad differentiation occurred before metamorphosis in species with long larval periods and after metamorphosis in the species with short larval periods. These differences in TH physiology and gonad development, informed by phylogeny and ecology of spadefoot metamorphosis, provide evidence that selection for the short larval periods in spadefoot toads acted via TH physiology and led to dramatic heterochronic shifts in metamorphic climax relative to gonad development.
The anatomy, affinity, and phylogenetic significance of Markuelia
Authors: Dong Xi‐ping , Donoghue Philip C. J. , Cunningham John A. , Liu Jian‐bo , Cheng Hong
Published: August 2005

Summary
The fossil record provides a paucity of data on the development of extinct organisms, particularly for their embryology. The recovery of fossilized embryos heralds new insight into the evolution of development but advances are limited by an almost complete absence of phylogenetic constraint. Markuelia is an exception to this, known from cleavage and pre‐hatchling stages as a vermiform and profusely annulated direct‐developing bilaterian with terminal circumoral and posterior radial arrays of spines. Phylogenetic analyses have hitherto suggested assignment to stem‐Scalidophora (phyla Kinorhyncha, Loricifera, Priapulida). We test this assumption with additional data and through the inclusion of additional taxa. The available evidence supports stem‐Scalidophora affinity, leading to the conclusion that scalidophorans, cyclonerualians, and ecdysozoans are primitive direct developers, and the likelihood that scalidophorans are primitively metameric.
Larval and adult brains1
Authors: Nielsen Claus
Published: August 2005

Summary
Apical organs are a well‐known structure in almost all ciliated eumetazoan larvae, although their function is poorly known. A review of the literature indicates that this small ganglion is the “brain” of the early larva, and it seems probable that it represents the brain of the ancestral, holopelagic ancestor of all eumetazoans, the gastraea. This early brain is lost before or at metamorphosis in all groups. Protostomes (excluding phoronids and brachiopods) appear to have brains of dual origin. Their larvae develop a pair of cephalic ganglia at the episphere lateral to the apical organ, and these two ganglia become an important part of the adult brain. The episphere and the cerebral ganglia show Otx expression, whereas Hox gene expression has not been seen in this part of the brain. A ventral nervous system develops around the blastopore, which becomes divided into mouth and anus by fusion of the lateral blastopore lips. The circumblastoporal nerve ring becomes differentiated into a nerve ring around the mouth, becoming part of the adult brain, a pair of ventral nerve cords, in some cases differentiated into a chain of ganglia, and a ring around the anus. This part of the nervous system appears to be homologous with the oral nerve ring of cnidarians. This interpretation is supported by the expression of Hox genes around the cnidarian mouth and in the ventral nervous system of the protostomes. The development of phoronids, brachiopods, echinoderms, and enteropneusts does not lead to the formation of an episphere or to differentiation of cerebral ganglia. In general, a well‐defined brain is lacking, and Hox genes are generally not expressed in the larval organs, although this has not been well studied.
Preparation and Corrosion Resistance of Amorphous SiNx Films from Hexamethyldisiloxane Solution by PECVD
Authors: Li Y. S. , Shimada S.
Published: August 2005

SiNx films were deposited on Si wafer and SUS steel (Fe–18Cr–8Ni) substrate from a hexamethyldisiloxane solution by N2 plasma‐enhanced chemical vapor deposition equipped with a liquid injection device. The SiNx films with dense columnar structures were identified to be amorphous by means of X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. An enhancement of deposition rate, in combination with a large amount of oxygen contaminant, was obtained after modifying the nozzle position from a top injection to a side injection method by providing a greater liquid supply. The corrosion performance of SiNx film‐coated SUS steel was evaluated by exposure test in KCl vapor atmosphere at 650°C, indicating that the high purity SiNx film demonstrated a significantly improved resistance, while an increased remanent oxygen content inside the films produced a deleterious effect on the anti‐corrosion behavior.
Oxidation of Polymer‐Derived SiAlCN Ceramics
Authors: Wang Yiguang , An Linan , Fan Yi , Zhang Ligong , Burton Sarah , Gan Zhehong
Published: August 2005

The oxidation behavior of polymer‐derived amorphous SiAlCNs was studied in the temperature range of 900°–1200°C. The results revealed that while at 900°C the oxidation of the SiAlCNs follows typical parabolic kinetics, at higher temperatures the oxidation rates of the materials decrease with annealing time. Long‐term oxidation rate of the SiAlCNs is much lower than the lowest values reported for chemical vapor deposition of SiC and Si3N4. Structures of the oxide scales were studied using solid‐state nuclear magnetic resonance. We proposed that oxide scales formed for the SiAlCNs possess a unique network structure of the oxide scale in which aluminum atoms block the path of oxygen diffusion, thus lowering the oxidation rates. Such a unique structure was likely formed gradually with annealing time, leading to a continuous decrease in oxidation rate.
Abnormal Grain Growth During Rapid Annealing of Sol–Gel Alumina Thin Film Deposited on Ni‐Based Superalloy
Authors: Su Yi‐Feng , Chen Haibiao , Lee Woo Y.
Published: August 2005

A ∼50 nm thick alumina layer was deposited on an Ni‐based superalloy substrate by a sol–gel method. α‐AlOOH particles presented in the layer after drying at 140°C transformed mostly to α‐Al2O3 grains within ∼1 min at 1100°C under a low oxygen partial pressure annealing environment. During the same time period, the α‐Al2O3 grains grew significantly in the lateral direction, resulting in the aspect ratio of grain diameter to thickness of ∼20. The presence of a preferred orientation in the α‐Al2O3 layer suggested that the mechanism for the lateral growth was abnormal. The lateral growth mechanism appeared to become very slow when a critical thickness (∼100 nm) was reached.
Tribophysical Properties of Polycrystalline Bulk Ti3AlC2
Authors: Hongxiang Zhai , Zhenying Huang , Mingxing Ai , Yang Zhou , Zhili Zhang , Shibo Li
Published: August 2005

A nearly pure, dense, polycrystalline bulk Ti3AlC2 sample was prepared by reactively hot pressing the element titanium, aluminum, and graphite powders. The tribophysical properties were investigated by sliding a Ti3AlC2 block dryly against a low‐carbon steel disk. It was found that the friction coefficient is as low as ∼0.1, and the wear rate of Ti3AlC2 is only ∼2.5 × 10−6 mm3/N·m for the highest sliding speed of 60 m/s and the largest normal pressure of 0.8 MPa. These unusual properties are attributable to the presence of a compact self‐generating film, which covers uniformly over the friction surface of Ti3AlC2 with a thickness of ∼0.5 μm.
Effect of (La0.8Sr0.2)CrO3 Coating on Carbon Deposition onto a Stainless‐Steel (SUS430) Substrate
Authors: Hwang Hae Jin , Lee Seunghun , Lee Eun A , Moon Ji‐Woong , Lim Yongho
Published: August 2005

In this study, a dense strontium‐doped lanthanum chromite (La0.8Sr0.2CrO3, LSC) thin layer was designed to protect a stainless‐steel (SUS430) substrate from carbon deposition. The LSC layer was coated onto an SUS430 substrate by a dipping technique from a precursor solution of La, Sr and Cr nitrates, acetylacetone (acac), and 2‐methoxyethanol. The effect of AcAc on the phase behavior and microstructure evolution of the LSC thin films was investigated. After being heat‐treated at 800°C in air, the thin film was found to consist of perovskite LaCrO3, Mn1.5Cr1.5O4, and Cr2O3 phases. The addition of a chelating agent, acac, to the precursor solution led to a reduction in the formation of the strontium chromite (SrCrO4) phase. As a consequence, a thin film having a dense microstructure could be obtained. It was confirmed by Fourier‐tranform Raman spectroscopic analysis and FESEM observations that the carbon deposited on the uncoated SUS430 substrate was amorphous with a spherical morphology. The LSC thin film thus obtained was found to be very effective at preventing carbon deposition when it was heat‐treated under a dry hydrocarbon atmosphere.
Synthesis of HA‐Seeded TTCP (Ca4(PO4)2O) Powders at 1230°C from Ca(CH3COO)2·H2O and NH4H2PO4
Authors: Jalota Sahil , Tas A. Cuneyt , Bhaduri Sarit B.
Published: August 2005

Tetracalcium phosphate (TTCP) Ca4(PO4)2O is one of the major powder components of self‐setting orthopedic and dental cements. Traditionally, TTCP powders are produced by a solid‐state process by soaking Ca‐ and P‐containing precursors between 1350° and 1500°C. Such procedures require expensive high‐temperature furnaces and subsequent grinding of sintered particulates. Grinding not only introduces contamination but alters the structure of TTCP, thereby reducing its bioactivity. The present paper offers a lower temperature synthesis process for TTCP with several interesting features. First, the synthesis procedure used Ca(CH3COO)2·H2O and NH4H2PO4 as separate sources for Ca and P, respectively. Second, the reactants underwent multiple melting and decomposition stages, thus increasing the reactivity of the synthesis process. NH4H2PO4 melted at 190°C and engulfed the calcium acetate particles. The Ca‐acetate component decomposed into CaCO3 at around 400°C while still surrounded by the molten phosphate liquid and an amorphous Ca‐metaphosphate phase. Hydroxyapatite, Ca10(PO4)6(OH)2 (HA), and β‐Ca3(PO4)2 crystallized upon heating the powder mixture to 700°C. Slightly above 1200°C, the TTCP phase was formed. This sequence of reactions led to a process temperature of 1230°C, the lowest temperature ever reported for the synthesis of TTCP. Third, the resulting powders required much less grinding, which itself is advantageous. Fourth, the resulting powders were in situ seeded with HA. HA‐seeded TTCP powders were tested for their apatite‐inducing ability by soaking them in synthetic body fluid at 37°C. TTCP powders of this study were readily covered with carbonated apatitic calcium phosphates within the first 72 h.
Effect of Heat Treatments on the Crack‐Healing and Static Fatigue Behavior of Silicon Carbide Sintered with Sc2O3 and AlN
Authors: Lee Sang‐Kee , Ando Kotoji , Kim Young‐Wook
Published: August 2005

Crack‐healing behavior of silicon carbide ceramics sintered with AlN and Sc2O3 has been studied as a function of heat‐treatment temperature and applied stress. Results showed that heat treatment in air could significantly increase the indentation strength whether a stress is applied or not. After heat treatment with no applied stress at 1300°C for 1 h in air, the indentation strength of the specimen with an indentation crack of ∼100 μm (≈2c) recovered its strength fully at room temperature. In addition, a simple heat treatment at 1200°C for 5 h under an applied stress of 200 MPa in air resulted in a complete recovery of the unindented strength at the healing temperature. However, higher applied stress led to fracture of the specimens during heat treatment. The static fatigue limit of the specimens crack healed at 1200°C for 5 h under 200 MPa was ∼450 MPa at the healing temperature. The ratio of the static fatigue limit of the crack‐healed specimen to the unindented strength was ∼80%.
Tailoring the Microwave Dielectric Properties of Ca5Ta2TiO12 Ceramics Through Glass Addition
Authors: Bijumon Pazhoor Varghese , Sebastian Mailadil Thomas
Published: August 2005

Microwave dielectric properties of polycrystalline Ca5Ta2TiO12 ceramics have been tailored using different glass additives. Several glasses such as B2O3, SiO2, B2O3–SiO2, ZnO–B2O3, Al2O3–SiO2, Al2O3–B2O3–SiO2, BaO–B2O3–SiO2, MgO–B2O3–SiO2, ZnO–B2O3–SiO2, PbO–B2O3–SiO2, and 2MgO–Al2O3–5SiO2 were added to calcined Ca5Ta2TiO12 powder in different weight percentages. Among these glasses, addition of 0.1 wt% of SiO2, Al2O3–SiO2, Al2O3–B2O3–SiO2, MgO–B2O3–SiO2, and 2MgO–Al2O3–5SiO2 improved the microwave dielectric properties. Fluxing of Ca5Ta2TiO12 with 0.1 wt% of 2MgO–Al2O3–5SiO2 glass has ɛr=39, Qu×f>40 000 at 5 GHz and τf=+8 ppm/°C. Near‐zero τf was obtained with the addition of glasses like Al2O3–SiO2, Al2O3–B2O3–SiO2, MgO–B2O3–SiO2, and 2MgO–Al2O3–5SiO2. Addition of all the glasses except BaO–B2O3–SiO2 reduced the τf of Ca5Ta2TiO12 ceramics. Two weight percent glass addition to Ca5Ta2TiO12 ceramics reduced their sintering temperature down to 1450°C from 1625°C and τf close to zero but deteriorated the ɛr and unloaded quality factor. The effects of glass content on the structure and microstructure of Ca5Ta2TiO12 ceramics were studied by X‐ray diffraction and scanning electron microscopic techniques.