bluuebunny/crossref_metadata_2025 huggingface dataset:
Mediatized public crisis and civil society renewal: The racist murder of Stephen Lawrence
Authors: Cottle Simon
Published: March 2005

There have been many racist murders in Britain both before and since the killing of Stephen Lawrence, an 18-year-old black student, in April 1993. This particular murder, exceptionally, prompted widespread re-examination of questions of (in)justice, cultural identity and continuing racism in British society and it eventually initiated processes of institutional reflexivity including government policies targeting institutionalized racism within Britain’s most powerful organizations of state and civil society. The Stephen Lawrence case unfolded within the arenas and processes of the criminal justice system, but the public story of ‘Stephen Lawrence’, the central concern of this article, was principally played out within the nation’s media (and some international media too). It was here that the symbolic and moral charge of the case became generalized outwards to different publics in society, galvanizing emotions and appealing to a sense of moral solidarity subjunctively oriented to how society should or could be. This article, based upon analysis of the extensive media reporting over the ten year period 1993-2003 and developing theoretical ideas of ‘mediatized public crisis’ as a form of ‘society in action’, explores how the mainstream British media ‘performed’ the Stephen Lawrence case and thereby transformed it into a ‘mediatized public crisis’ embroiling as it did so powerful institutions of state (police, judiciary, government) and unleashing institutional reflexivity, social reforms and cultural change.
MAPPER: a search engine for the computational identification of putative transcription factor binding sites in multiple genomes
Authors: Marinescu Voichita D , Kohane Isaac S , Riva Alberto
Published: March 2005

Background

Cis-regulatory modules are combinations of regulatory elements occurring in close proximity to each other that control the spatial and temporal expression of genes. The ability to identify them in a genome-wide manner depends on the availability of accurate models and of search methods able to detect putative regulatory elements with enhanced sensitivity and specificity.

Results

We describe the implementation of a search method for putative transcription factor binding sites (TFBSs) based on hidden Markov models built from alignments of known sites. We built 1,079 models of TFBSs using experimentally determined sequence alignments of sites provided by the TRANSFAC and JASPAR databases and used them to scan sequences of the human, mouse, fly, worm and yeast genomes. In several cases tested the method identified correctly experimentally characterized sites, with better specificity and sensitivity than other similar computational methods. Moreover, a large-scale comparison using synthetic data showed that in the majority of cases our method performed significantly better than a nucleotide weight matrix-based method.

Conclusion

The search engine, available at http://mapper.chip.org, allows the identification, visualization and selection of putative TFBSs occurring in the promoter or other regions of a gene from the human, mouse, fly, worm and yeast genomes. In addition it allows the user to upload a sequence to query and to build a model by supplying a multiple sequence alignment of binding sites for a transcription factor of interest. Due to its extensive database of models, powerful search engine and flexible interface, MAPPER represents an effective resource for the large-scale computational analysis of transcriptional regulation.
Shooting darts: co-evolution and counter-adaptation in hermaphroditic snails
Authors: Koene Joris M , Schulenburg Hinrich
Published: March 2005

Background

Evolutionary conflicts of interest between the sexes often lead to co-evolutionary arms races consisting of repeated arisal of traits advantageous for one sex but harmful to the other sex, and counter-adaptations by the latter. In hermaphrodites, these antagonistic interactions are at least an equally important driving force. Here, we investigate the evolution of one of the most striking examples of sexual conflict in hermaphrodites, the so-called shooting of love-darts in land snails. Stabbing this calcareous dart through the partner's skin ultimately increases paternity. This trait is obviously beneficial for the shooter, but it manipulates sperm storage in the receiver. Hence, an arms race between the love-dart and the spermatophore receiving organs may be expected.

Results

We performed a detailed phylogenetic analysis of 28S ribosomal RNA gene sequences from dart-possessing land snail species. Both the Shimodaira-Hasegawa test and Bayesian posterior probabilities rejected a monophyletic origin of most reproductive structures, including the love-dart, indicating that most traits arose repeatedly. Based on the inferred phylogenetic trees, we calculated phylogenetically independent contrasts for the different reproductive traits. Subsequent principal component and correlation analyses demonstrated that these contrasts covary, meaning that correlated evolution of these traits occurred.

Conclusion

Our study represents the first comprehensive comparative analysis of reproductive organ characteristics in simultaneous hermaphrodites. Moreover, it strongly suggests that co-evolutionary arms races can result from sexual conflict in these organisms and play a key role in the evolution of hermaphroditic mating systems.
Effect of testosterone replacement or duration of castration on baroreflex bradycardia in conscious rats
Authors: Ward Gregg R , Abdel-Rahman Abdel A
Published: March 2005

Background

In this study, we tested the hypothesis that 17β-estradiol contributes to testosterone-mediated restoration of baroreflex-mediated bradycardia in short-term (3 weeks) castrated rats. Further, a reported increase in serum testosterone after long-term (6 weeks) castration constituted a basis for testing the hypothesis that a spontaneous increase in serum testosterone or androstenedione in this model causes a commensurate increase in baroreflex-mediated bradycardia.

Results

Testosterone (1 week) replacement enhanced baroreflex-mediated bradycardia in short-term castrated rats without changing 17β-estradiol level. A spontaneous recovery of baroreflex-mediated bradycardia occurred following long-term castration, although circulating testosterone and androstenedione remained suppressed.

Conclusion

The data suggest: 1) 17β-Estradiol does not contribute to testosterone restoration of the baroreflex-mediated bradycardia in short-term castrated rats. 2) The long-term modulation of baroreflex-mediated bradycardia occurs independent of androgens, or the baroreflex mechanism may become adapted to low levels of circulating androgens.
Floral gene resources from basal angiosperms for comparative genomics research
Authors: Albert Victor A , Soltis Douglas E , Carlson John E , Farmerie William G , Wall P Kerr , Ilut Daniel C , Solow Teri M , Mueller Lukas A , Landherr Lena L , Hu Yi , Buzgo Matyas , Kim Sangtae , Yoo Mi-Jeong , Frohlich Michael W , Perl-Treves Rafael , Schlarbaum Scott E , Bliss Barbara J , Zhang Xiaohong , Tanksley Steven D , Oppenheimer David G , Soltis Pamela S , Ma Hong , dePamphilis Claude W , Leebens-Mack James H
Published: March 2005

Background

The Floral Genome Project was initiated to bridge the genomic gap between the most broadly studied plant model systems. Arabidopsis and rice, although now completely sequenced and under intensive comparative genomic investigation, are separated by at least 125 million years of evolutionary time, and cannot in isolation provide a comprehensive perspective on structural and functional aspects of flowering plant genome dynamics. Here we discuss new genomic resources available to the scientific community, comprising cDNA libraries and Expressed Sequence Tag (EST) sequences for a suite of phylogenetically basal angiosperms specifically selected to bridge the evolutionary gaps between model plants and provide insights into gene content and genome structure in the earliest flowering plants.

Results

Random sequencing of cDNAs from representatives of phylogenetically important eudicot, non-grass monocot, and gymnosperm lineages has so far (as of 12/1/04) generated 70,514 ESTs and 48,170 assembled unigenes. Efficient sorting of EST sequences into putative gene families based on whole Arabidopsis/rice proteome comparison has permitted ready identification of cDNA clones for finished sequencing. Preliminarily, (i) proportions of functional categories among sequenced floral genes seem representative of the entire Arabidopsis transcriptome, (ii) many known floral gene homologues have been captured, and (iii) phylogenetic analyses of ESTs are providing new insights into the process of gene family evolution in relation to the origin and diversification of the angiosperms.

Conclusion

Initial comparisons illustrate the utility of the EST data sets toward discovery of the basic floral transcriptome. These first findings also afford the opportunity to address a number of conspicuous evolutionary genomic questions, including reproductive organ transcriptome overlap between angiosperms and gymnosperms, genome-wide duplication history, lineage-specific gene duplication and functional divergence, and analyses of adaptive molecular evolution. Since not all genes in the floral transcriptome will be associated with flowering, these EST resources will also be of interest to plant scientists working on other functions, such as photosynthesis, signal transduction, and metabolic pathways.
The measurement of response shift in patients with advanced prostate cancer and their partners
Authors: Rees Jonathan , Clarke Michael G , Waldron Dympna , O'Boyle Ciaran , Ewings Paul , MacDonagh Ruaraidh P
Published: March 2005

Background

There is increasing evidence to support the phenomenon of response shift (RS) in quality of life (QoL) studies, with many current QoL measures failing to allow for this. If significant response shift occurs amongst prostate cancer patients, it will be necessary to allow for this in the design of future clinical research and to reassess the conclusions of previous studies that have not allowed for this source of bias. This study therefore aimed to assess the presence of RS and psychosocial morbidity in patients with advanced prostate cancer and their partners.

Methods

55 consecutive advanced prostate cancer patients and their partners completed the Prostate Cancer Patient & Partner questionnaire (PPP), shortly after diagnosis and again at 3 months and 6 months. At the follow-up visits, both patients and partners also completed a then-test in order to assess RS.

Results

Partners consistently showed greater psychological morbidity than patients in relation to the prostate cancer. This was most marked on the General Cancer Distress (GCD) subscale (p < 0.001, paired t-test), and regarding worries about treatment (p = 0.01). Significant RS was identified in partners and patients by the use of the then-test technique, particularly on the GCD subscale, the concerns about treatment and the concerns about urinary symptoms items.

Conclusion

These results suggest the presence of RS in patients with advanced prostate cancer and their partners, with higher levels of psychosocial morbidity noted amongst partners. This is the first study to identify RS in partners and calls into question the interpretation of all studies assessing changes in QoL that fail to allow for this phenomenon.
Mathematical model of blunt injury to the vascular wall via formation of rouleaux and changes in local hemodynamic and rheological factors. Implications for the mechanism of traumatic myocardial infarction
Authors: Ismailov Rovshan M
Published: March 2005

Background

Blood viscosity is fundamentally important in clinical practice yet the apparent viscosity at very low shear rates is not well understood. Various conditions such as blunt trauma may lead to the appearance of zones inside the vessel where shear stress equals zero. The aim of this research was to determine the blood viscosity and quantitative aspects of rouleau formation from erythrocytes at yield velocity (and therefore shear stress) equal to zero. Various fundamental differential equations and aspects of multiphase medium theory have been used. The equations were solved by a method of approximation. Experiments were conducted in an aerodynamic tube.

Results

The following were determined: (1) The dependence of the viscosity of a mixture on volume fraction during sedimentation of a group of particles (forming no aggregates), confirmed by published experimental data on the volume fractions of the second phase (f2) up to 0.6; (2) The dependence of the viscosity of the mixture on the volume fraction of erythrocytes during sedimentation of rouleaux when yield velocity is zero; (3) The increase in the viscosity of a mixture with an increasing erythrocyte concentration when yield velocity is zero; (4) The dependence of the quantity of rouleaux on shear stress (the higher the shear stress, the fewer the rouleaux) and on erythrocyte concentration (the more erythrocytes, the more rouleaux are formed).

Conclusions

This work represents one of few attempts to estimate extreme values of viscosity at low shear rate. It may further our understanding of the mechanism of blunt trauma to the vessel wall and therefore of conditions such as traumatic acute myocardial infarction. Such estimates are also clinically significant, since abnormal values of blood viscosity have been observed in many pathological conditions such as traumatic crush syndrome, cancer, acute myocardial infarction and peripheral vascular disease.
Synergistic effect of SCF and TNF-α on the up-regulation of cell-surface expression of ICAM-1 on human leukemic mast cell line (HMC)-1 cells
Authors: Tsang Chi-Man , Wong Chun-Kwok , Ip Wai-Ki , Lam Christopher Wai-Kei
Published: March 2005

Intercellular adhesion molecule-1 (ICAM-1) has been shown to play crucial roles in mast cell interaction with other inflammatory cells and recruitment into the inflamed tissue. In the present study, human mast cell line-1 (HMC-1) was stimulated with different cytokines including stem cell factor (SCF), tumor necrosis factor α (TNF-α), interleukin (IL)-13, IL-18, and IL-25. Cell-surface expression of ICAM-1 was assessed by flow cytometry. To elucidate the intracellular signal transduction regulating the ICAM-1 expression, phosphorylated extracellular signal-regulated kinase (ERK), phosphorylated p38 mitogen-activated protein kinase (MAPK), and nuclear factor (NF)-κB translocation were assessed by enzyme-linked immunosorbent assay. Results showed that SCF, TNF-α, and IL-13 but not IL-18 and IL-25 could up-regulate the surface expression of ICAM-1 on HMC-1 cells. A synergistic effect of SCF and TNF-α on ICAM-1 expression was demonstrated. This synergistic effect was shown to be dose-dependently enhanced by SCF but not TNF-α. Results indicated that SCF activated ERK, and TNF-α activated the p38 MAPK and NF-κB pathway. Selective inhibitor of ERK, PD098059, and c-kit inhibitors, STI571 and PP1, suppressed the combined SCF and TNF-α-induced ICAM-1 expression. BAY117082 but not SB203580, which are the inhibitors of NF-κB and p38 MAPK, respectively, suppressed the TNF-α-induced ICAM-1 expression. Therefore, SCF and TNF-α acted through ERK and the NF-κB pathway to regulate the ICAM-1 expression and elicited the synergistic effect. In conclusion, our results provide insight for cross-talk between different signaling pathways that can help in understanding the fine control of adhesion molecule expression under the concerted effects of cytokines.
Negative self-schemas and the onset of depression in women: longitudinal study
Authors: Evans Jonathan , Heron Jon , Lewis Glyn , Araya Ricardo , Wolke Dieter
Published: March 2005

Background

Beck's cognitive theory of depression has received little empirical support.

Aims

To test whether those with negative self-schemas were at risk of onset of depression.

Method

Data were collected by postal questionnaire from 12003 women recruited during early pregnancy; questionnaires included measures of depressive symptoms and negative self-schemas. Regular questionnaires were sent during pregnancy and following childbirth.

Results

Of 8540 women not depressed when recruited, 8.6% (95% CI 8.0–9.2) became depressed 14 weeks later. Those in the highest tertile for negative self-schema score were more likely to become depressed than those in the lowest tertile (odds ratio 3.04, 95% CI 2.48–3.73). The association remained after adjustment for baseline depressive symptoms and previous depression (OR 1.6, 95% CI1.27–2.02) and was of similar magnitude for onset 3 years later.

Conclusions

Holding a negative self-schema is an independent risk factor for the onset of depression in women. This finding supports a key element of Beck's cognitive theory. Understanding more about how negative self-schemas arise should help inform preventive policies.
Neurological findings in late-onset depressive disorder: comparison of individuals with and without depression
Authors: Baldwin Robert , Jeffries Suzanne , Jackson Alan , Sutcliffe Caroline , Thacker Neil , Scott Marietta , Burns Alistair
Published: March 2005

Background

Organic factors are thought to be important in late-life depressive disorder but there have been few studies specifically of neurological signs.

Aims

To compare neurological signs in a group of patients with late-onset depression and in healthy controls.

Method

A case–control study comparing 50 patients with depression and 35 controls on three measures of central nervous system (CNS) signs: a structured CNS examination, the Neurological Evaluation Scale (NES) and the Webster rating scale for parkinsonism.

Results

After adjusting for major depression at the time of evaluation and prescription of tranquillisers, ratings on two of the NES sub-scales (complex motor sequencing and ‘other’ signs) and on the Webster scale were significantly higher (more impaired) in patients compared with controls (P <0.05). With logistic regression, the NES was the main measure predictive of group outcome. There were no differences in scores of vascular risk or white matter but patients had more atrophy.

Conclusions

The findings add to the evidence that late-life depression is associated with organic brain dysfunction, perhaps mediated by neurodegeneration or subtle vascular impairment. The use of the NES in subjects with depression should be replicated.
The PAS–ADD Checklist: independent replication of its psychometric properties in a community sample
Authors: Sturmey Peter , Newton Jonathon Timothy , Cowley Amy , Bouras Nick , Holt Geraldine
Published: March 2005

Background

The development of reliable, valid measures of psychopathology in people with intellectual disabilities is an important task. However, independent replication studies are rarely reported.

Aims

To report data on the psychometric properties of the Psychiatric Assessment Schedule for Adults with Developmental Disabilities (PAS–ADD) Checklist.

Method

The PAS–ADD Checklist was completed for 226 adults as part of the assessment process for a specialist mental health service for people with intellectual disabilities.

Results

Internal consistency was acceptable. Factor analysis revealed one main factor that was characterised by items related to mood. The Checklist was sensitive to differences between diagnostic groups and had an overall sensitivity of 66%; its specificity was 70%.

Conclusions

The PAS–ADD Checklist is a quick and easy to use screening tool. Although at present it is the best measure available, it should not be the only method used to identify psychiatric disorders in people with intellectual disabilities.
Cognitive–behavioural therapy for refractory psychotic symptoms of schizophrenia resistant to atypical antipsychotic medication
Authors: Valmaggia Lucia R. , van der Gaag Mark , Tarrier Nicholas , Pijnenborg Marieke , Slooff Cees J.
Published: March 2005

Background

There is increasing evidence that cognitive–behavioural therapy can be an effective intervention for patients experiencing drug-refractory positive symptoms of schizophrenia.

Aims

To investigate the effects of cognitive–behavioural therapy on in-patients with treatment-refractory psychotic symptoms.

Method

Manualised therapy was compared with supportive counselling in a randomised controlled study. Both interventions were delivered by experienced psychologists over 16 sessions of treatment. Therapy fidelity was assessed by two independent raters. Participants underwent masked assessment at baseline, after treatment and at 6 months' follow-up. Main outcome measures were the Positive and Negative Syndrome Scale and the Psychotic Symptoms Rating Scale. The analysis was by intention to treat.

Results

Participants receiving cognitive–behavioural therapy had improved with regard to auditory hallucinations and illness insight at the post-treatment assessment, but these findings were not maintained at follow-up.

Conclusions

Cognitive–behavioural therapy showed modest short-term benefits over supportive counselling for treatment-refractory positive symptoms of schizophrenia.
Causal beliefs and attitudes to people with schizophrenia
Authors: Angermeyer Matthias C. , Matschinger Herbert
Published: March 2005

Background

It is a widely shared belief that an increase in mental health literacy will result in an improvement of attitudes towards people with mental illness.

Aims

To examine how the German public's causal attributions of schizophrenia and their desire for social distance from people with schizophrenia developed over the 1990s.

Method

A trend analysis was carried out using data from two representative population surveys conducted in the Länder constituting the former Federal Republic of Germany in 1990 and 2001.

Results

Parallel to an increase in the public's tendency to endorse biological causes, an increase in the desire for social distance from people with schizophrenia was found.

Conclusions

The assumption underlying current anti-stigma programmes that there is a positive relationship between endorsing biological causes and the acceptance of people with mental illness appears to be problematic.
Assessing violence risk in general adult psychiatry
Authors: Higgins Nicola , Watts David , Bindman Jonathan , Slade Mike , Thornicroft Graham
Published: March 2005

Aims and Method

We aimed to establish current practice in the risk assessment of harm to others within general adult psychiatry and review risk assessment documentation in use. Consultants working across 66 randomly selected trusts across England were surveyed. A qualitative analysis of risk assessment documentation was carried out.

Results

Data were obtained from 45 trusts (68%). Consultants reported that 30 (67%) of the trusts had standardised forms for risk assessment. Forty-one forms were subjected to content analysis. Wide variation was found in the methods used to identify risk factors and in approaches to quantifying risk.

Clinical Implications

Current risk assessment practice is highly variable, indicating a lack of consensus about suitable methods.
Don't forget EDNOS (eating disorder not otherwise specified): patterns of service use in an eating disorders service
Authors: Button Eric J. , Benson Elizabeth , Nollett Claire , Palmer Robert L.
Published: March 2005

Aims and Method

The aim of the study was to track service consumption in adult referrals to a specialised NHS eating disorders service over a 3-year period. We examined clinical records of a year's cohort (1999) of 147 referrals (96% female) assessed from the local catchment area.

Results

The most common diagnostic group (42.8%) presented with some form of eating disorder not otherwise specified (EDNOS). There was no significant relationship between diagnosis and service consumption, so that full syndrome eating disorders were no more labour-intensive overall than EDNOS patients. Indeed, EDNOS patients accounted for 50% of all outpatient appointments and over a half of all in-patient days.

Clinical Implications

The results suggest that those planning services for eating disorders need to take into account the substantial demand from EDNOS patients.
Experiences of a mixed court liaison and diversion scheme
Authors: Kingham Michael , Corfe Martin
Published: March 2005

Aims and Method

To examine the activity of the East Sussex Court Assessment and Diversion Scheme and to investigate its diagnostic formulations, recommendations and the short-term outcome of individuals referred, using a retrospective analysis of data collected over 3 years during the everyday clinical duties of scheme members.

Results

Diversion was recommended for 858 individuals from a total of 1830 referrals. Most were referred to community services, but 131 were admitted to hospital, the majority under compulsion. The number of individuals admitted to secure hospitals has increased, and delays in admitting them have lengthened. The ethnic minority population was over-represented in referrals.

Clinical Implications

Court liaison and diversion in East Sussex successfully directs defendants with mental disorders to appropriate resources, both general and specialist, in-patient and community. The expansion of in-patient secure services needs to continue to accommodate increased demand. Reasons why ethnic minorities are over-represented in referrals require further study.
A 7-year partnership between psychiatric services in Russia and the UK
Authors: Bakanov Mikhail , Bloor Roger , Emptsov Vasily , Pearson David
Published: March 2005

Historically, relationships with mental health professionals working in Russia have been difficult to sustain due to problems with access and perceived human rights infringements that existed earlier (Poloahij, 2001). This has resulted in many Russian psychiatric institutions having little opportunity to collaborate in international research or to take part in exchanges of information on service development. However, with the dissolution of the Soviet Union in 1991, Russia has been brought back into spheres of international cooperation in healthcare.
Developing local library and information services
Authors: Tait David
Published: March 2005

It fell to me to review the services we provide in our hospital library in Perth, which in turn lay behind my decision to stand for election to the post of Librarian of the Royal College of Psychiatrists. This has involved oversight of developing services for our members and others, and this paper is a response to a request often made to us – what advice can we give to those reviewing their own services? This paper is far from being a solo effort, the professional staff of the College Library and Information Service, and what we dubbed the Virtual Library Committee (colleagues representing faculties and other interests, who have advised us in cyberspace), deserve much of the credit.
Making your case to the mental health review tribunal in England and Wales
Authors: Lodge George J.
Published: March 2005

The function of the mental health review tribunal is defined in Part V of the Mental Health Act 1983. Together with statute and Common Law, it provides safeguards to those detained under the Act. The provisions of the Human Rights Act 1998 have strengthened these safeguards. The key articles in Schedule 1 of the Human Rights Act are 5(1)(e), relating to the lawful detention of persons of unsound mind; 5(4), providing that the lawfulness of such detention shall be decided speedily by a court; 6, providing for a fair and public hearing within a reasonable time by an independent and impartial tribunal established by law; and 8, establishing the right to respect for a private and family life. The latter is relevant to disclosure, nearest relatives' rights, and treatment.
Fgf10expression identifies parabronchial smooth muscle cell progenitors and is required for their entry into the smooth muscle cell lineage
Authors: Mailleux Arnaud A. , Kelly Robert , Veltmaat Jacqueline M. , De Langhe Stijn P. , Zaffran Stephane , Thiery Jean Paul , Bellusci Saverio
Published: March 2005

Lineage formation in the lung mesenchyme is poorly understood. Using a transgenic mouse line expressing LacZ under the control of Fgf10 regulatory sequences, we show that the pool of Fgf10-positive cells in the distal lung mesenchyme contains progenitors of the parabronchial smooth muscle cells. Fgf10 gene expression is slightly repressed in this transgenic line. This allowed us to create a hypomorphic Fgf10 phenotype by expressing the LacZtransgene in a heterozygous Fgf10 background. Hypomorphic Fgf10 mutant lungs display a decrease inβ-galactosidase-positive cells around the bronchial epithelium associated with an accumulation of β-galactosidase-expressing cells in the distal mesenchyme. This correlates with a marked reduction of α smooth muscle actin expression, thereby demonstrating that FGF10 is mostly required for the entry of mesenchymal cells into the parabronchial smooth muscle cell lineage. The failure of exogenous FGF10 to phosphorylate its known downstream targets ERK and AKT in lung mesenchymal cultures strongly suggests that FGF10 acts indirectly on the progenitor population via an epithelial intermediate. We provide support for a role of epithelial BMP4 in mediating the formation of parabronchial smooth muscle cells.
The homeobox transcription factor Barx2 regulates chondrogenesis during limb development
Authors: Meech Robyn , Edelman David B. , Jones Frederick S. , Makarenkova Helen P.
Published: March 2005

Among the many factors involved in regulation of chondrogenesis, bone morphogenetic proteins (BMPs) and members of the Sox and homeobox transcription factor families have been shown to have crucial roles. Of these regulators, the homeobox transcription factors that function during chondrogenesis have been the least well defined. We show here that the homeobox transcription factor Barx2 is expressed in primary mesenchymal condensations, digital rays, developing joints and articular cartilage of the developing limb, suggesting that it plays a role in chondrogenesis. Using retroviruses and antisense oligonucleotides to manipulate Barx2 expression in limb bud micromass cultures, we determined that Barx2 is necessary for mesenchymal aggregation and chondrogenic differentiation. In accordance with these findings, Barx2 regulates the expression of several genes encoding cell-adhesion molecules and extracellular matrix proteins, including NCAM and collagen II (Col2a1) in the limb bud. Barx2 bound to elements within the cartilage-specific Col2a1 enhancer, and this binding was reduced by addition of Barx2 or Sox9 antibodies, or by mutation of a HMG box adjacent to the Barx2-binding element, suggesting cooperation between Barx2 and Sox proteins. Moreover, both Barx2 and Sox9 occupy Col2a1 enhancer during chondrogenesis in vivo. We also found that two members of the BMP family that are crucial for chondrogenesis, GDF5 and BMP4, regulate the pattern of Barx2 expression in developing limbs. Based on these data, we suggest that Barx2 acts downstream of BMP signaling and in concert with Sox proteins to regulate chondrogenesis.
Propulsive force calculations in swimming frogs I. A momentum–impulse approach
Authors: Nauwelaerts Sandra , Stamhuis Eize J. , Aerts Peter
Published: March 2005

Frogs are animals that are capable of locomotion in two physically different media, aquatic and terrestrial. A comparison of the kinematics of swimming frogs in a previous study revealed a difference in propulsive impulse between jumping and swimming. To explore this difference further, we determined the instantaneous forces during propulsion in swimming using an impulse–momentum approach based on DPIV flow data. The force profile obtained was compared with force profiles obtained from drag–thrust equilibrium of the centre of mass and with the force profiles generated during jumping. The new approach to quantifying the instantaneous forces during swimming was tested and proved to be a valid method for determining the external forces on the feet of swimming frogs.

On the kinematic profiles of swimming, leg extension precedes propulsion. This means that it is not only the acceleration of water backwards that provides thrust, but also that the deceleration of water flowing towards the frog as a result of recovery accelerates the centre of mass prior to leg extension.

The force profile obtained from the impulse–momentum approach exposed an overestimation of drag by 30% in the drag–thrust calculations. This means that the difference in impulse between jumping and swimming in frogs is even larger than previously stated. The difference between the force profiles,apart from a slightly higher peak force during jumping, lies mainly in a difference in shape. During swimming, maximal force is reached early in the extension phase, 20% into it, while during jumping, peak force is attained at 80% of the extension phase. This difference is caused by a difference in inter-limb coordination.
JuvenileLymnaeaventilate,learn and remember differently than do adultLymnaea
Authors: McComb Chloe , Varshney Nishi , Lukowiak Ken
Published: March 2005

Adult snails are capable of learning associatively not to perform aerial respiration and then to consolidate the acquired behaviour into long-term memory (LTM). Juvenile Lymnaea, however, perform aerial respiration significantly less often and the three-neuron circuit that drives this behaviour operates significantly differently than in it does in adults. We asked whether these ontogenic behavioural and neurophysiological differences are manifested as an altered ability of juveniles to learn and/or form LTM. We found that juvenile snails learn significantly less well than adults and are,as a group, incapable of forming LTM. To control for the possibility that the poor learning and inability to form memory were the result of juvenile's receiving on average fewer reinforcing stimuli because they perform aerial respiration less often than adults we subjected juveniles to an enforced period of hypoxia to `motivate' juveniles. Motivated juveniles perform aerial respiration as often as adults; yet these `motivated' juveniles continue to be poor learners and still cannot form LTM. Additionally, a small percentage of juveniles perform aerial respiration as often as adults (i.e. high responders). When these `high-responders were trained they still exhibited poorer learning ability compared with adults and could not form LTM. We conclude that juvenile snails have a more difficult time learning and remembering to suppress aerial respiratory activity than do adults.
Boosting intermediate-term into long-term memory
Authors: Parvez Kashif , Stewart Ory , Sangha Susan , Lukowiak Ken
Published: March 2005

Aerial respiration in the pond snail Lymnaea stagnalis can be operantly conditioned. Depending on the specific training procedure used (i.e. a 0.5 h vs a 1.0 h interval between training sessions) either intermediate (ITM) or long-term memory (LTM) is formed. ITM, which persists for 2–3 h, is dependent only on de novo protein synthesis,whilst LTM persists for up to 4 weeks and is dependent on both transcription and de novo protein synthesis. We found that although the behavioural phenotype of ITM was not apparent 24 h after the last training session, a residual memory trace was present that serves as a foundation upon which a subsequent ITM-training-procedure builds on to form LTM (i.e. a `changed memory'). This residual memory trace could be perturbed by cooling, the behavioural process of context-specific extinction and by increasing the interval between the training procedures. Furthermore in preparations where the somata of RPeD1 (one of three interneurons in the central pattern generator required for aerial respiratory behavior) had been ablated before training, LTM could not be observed following a second bout of ITM-training. These data support the concept that a molecular memory trace is established as a consequence of ITM-training, which serves as a `permissive substrate', when the ITM memory is made active, sufficient to permit the necessary transcription and translation processes that are causal for LTM formation.
A new model predicting locomotor cost from limb lengthviaforce production
Authors: Pontzer Herman
Published: March 2005

Notably absent from the existing literature is an explicit biomechanical model linking limb design to the energy cost of locomotion, COL. Here, I present a simple model that predicts the rate of force production necessary to support the body and swing the limb during walking and running as a function of speed, limb length, limb proportion, excursion angle and stride frequency. The estimated rate of force production is then used to predict COL via this model following previous studies that have linked COL to force production. To test this model, oxygen consumption and kinematics were measured in nine human subjects while walking and running on a treadmill at range of speeds. Following the model, limb length, speed, excursion angle and stride frequency were used to predict the rate of force production both to support the body's center of mass and to swing the limb. Model-predicted COL was significantly correlated with observed COL, performing as well or better than contact time and Froude number as a predictor of COL for running and walking, respectively. Furthermore, the model presented here predicts relationships between COL, kinematic variables and body size that are supported by published reduced-gravity experiments and scaling studies. Results suggest the model is useful for predicting COL from anatomical and kinematic variables, and may be useful in intra- and inter-specific studies of locomotor anatomy and performance.
A single control system for smooth and saccade-like pursuit in blowflies
Authors: Boeddeker Norbert , Egelhaaf Martin
Published: March 2005

During courtship, male blowflies perform aerobatic pursuits that rank among the fastest visual behaviours that can be observed in nature. The viewing strategies during pursuit behaviour of blowflies appear to be very similar to eye movements during pursuit in primates: a combination of smooth pursuit and catch-up saccades. Whereas in primates these two components of pursuit eye movements are thought to be controlled by distinct oculomotor subsystems, we present evidence that in blowflies both types of pursuit responses can be produced by a single control system. In numerical simulations of chasing behaviour the proposed control system generates qualitatively the same behaviour as with real blowflies. As a consequence of time constants in the control system, mimicking neuronal processing times, muscular dynamics and inertia, saccade-like changes in gaze direction are generated if the target is displaced rapidly on the pursuing fly's retina. In the behavioural context of visual pursuit, saccade-like changes of the fly's gaze direction can thus be parsimoniously explained as an emergent property of a smooth pursuit system without assuming a priori different mechanisms underlying smooth and saccadic tracking behaviour.
Development of oxygen sensing in the gills of zebrafish
Authors: Jonz Michael G. , Nurse Colin A.
Published: March 2005

Previous studies have described the morphology, innervation and O2-chemoreceptive properties of neuroepithelial cells (NECs) of the zebrafish gill filaments. The present work describes the ontogenesis of these cells, and the formation of functional O2-sensing pathways in developing zebrafish. Confocal immunofluorescence was performed on whole-mount gill preparations using antibodies against serotonin (5-HT) and a zebrafish-derived neuronal marker (zn-12) to identify the appearance and innervation of gill NECs during larval stages. NECs were first expressed in gill filament primordia of larvae at 5 days postfertilization (d.p.f.) and were fully innervated by 7 d.p.f. In vivo ventilation frequency analysis revealed that a behavioural response to hypoxia (11.2±2.8 min–1) developed in embryos as early as 2 d.p.f., and a significant increase (P<0.05) in the ventilatory response to hypoxia (200.8±23.0 min–1) coincided with innervation of NECs of the filaments. In addition, exogenous application of quinidine, a blocker of O2-sensitive background K+ channels in NECs,induced hyperventilation in adults in a dose-dependent manner and revealed the development of a quinidine-sensitive ventilatory response in 7 d.p.f. larvae. This study shows that NEC innervation in the gill filaments may account for the development of a functional O2-sensing pathway and the hyperventilatory response to hypoxia in zebrafish larvae. At earlier stages,however, O2-sensing must occur through another pathway. The possibility that a new type of 5-HT-positive NEC of the gill arches may account for this earlier hypoxic response is discussed.
Influence of environmental conditions on early development of the hydrothermal vent polychaete Alvinella pompejana
Authors: Pradillon Florence , Le Bris Nadine , Shillito Bruce , Young Craig M. , Gaill Françoise
Published: March 2005

Dispersal and colonisation processes at deep-sea vents are still not fully understood, essentially because early life stages of vent species remain unknown. The polychaete worm Alvinella pompejana forms colonies on chimney walls at East Pacific Rise vent sites where the temperature can frequently exceed 20°C. In vitro studies in pressure vessels showed that the early embryos tolerate temperatures in a lower range(10–14°C), suggesting that they would have to escape the colony to develop. Pressure vessels offer the advantage that each parameter can be independently controlled, but they do not simulate the more complex and dynamic conditions naturally encountered at vent sites. Accordingly, in addition to incubations in pressure vessels, we incubated embryos directly at a vent site, in different habitats along a gradient of hydrothermal influence. Embryos incubated on an adult A. pompejana colony where temperature and H2S concentrations were relatively high showed a very low survival rate and did not develop, whereas embryos incubated in a Riftia pachyptila clump environment with a lower hydrothermal signature, or at the base of the chimney where the influence of the hydrothermal activity was very weak, survived well and developed. Although the average temperature recorded in the A. pompejana colony was within the range tolerated by embryos (13°C), frequent peaks above 20°C were recorded. Estimated sulphide concentration at this site reached 200 μmol l–1. Punctuated exposure to both high temperature and elevated sulphide levels probably explain the low survival of embryos within the A. pompejanacolony. The in situ experiments further support the idea that embryos require conditions with moderate hydrothermal influence not generally found within an adult colony. However, as much more benign physicochemical conditions can be found within a few tens of cm of adult colonies, embryos do not necessarily have to leave their vent of origin to develop. Further analyses are needed to pinpoint the specific factors that affect the survival and development of embryos at vents.
The role of ultraviolet wavelengths in the mate-choice decisions of female three-spined sticklebacks
Authors: Boulcott P. D. , Walton K. , Braithwaite V. A.
Published: March 2005

Female three-spined sticklebacks have been found to use visual cues when responding sexually towards courting males, often preferring more intensely red-coloured males, and males with blue rather than silver irises. However,traditionally the literature has failed to test preference across the full spectral range to which females might be sensitive, limiting analysis to the human-visible wavelengths of the electromagnetic spectrum. We studied the effects that the addition of ultraviolet wavelengths has on the mate-choice preferences of female sticklebacks using a two-choice paradigm. We found that females preferred males that were viewed across the full spectrum to males whose display lacked an ultraviolet component. Using suitable controls we were able to establish that female preference was sexually motivated and was not caused by a general preference for the manipulated light conditions. Our results indicate that female preference may be due to an enhancement in visual contrast when males are viewed in full spectrum conditions.
Bennett's double helix
Authors: Baker J E
Published: March 2005

Among the tools deployed in proving mobility of a kinematic chain, the adhibition of a pair of coaxial helices could not be rarer. Ten years after Bennett gave public birth to his four-bar, he used this odd construct to determine the mobile state of a network comprising six of his basic loops. The provenance of the device being unavailable, algebraic means are called upon here to establish its validity, and subsequently to seek its relationship with quadric surfaces defined by the loop.
Design of parallel kinematic systems using the planar enveloping algorithm and ADAMS computer program
Authors: Orlandea N
Published: March 2005

The planar enveloping algorithm is combined with a parallel kinematic structure and a tool-optimization criterion to help in the design of a parallel kinematic machine (PKM). These three components, put together for the purpose of synthesis and design of a PKM, are defined as a parallel kinematic design system (PKDS). As a result, there are machining processes so that the PKM can be designed to use its actuators to position the tool, as well as to drive the cutting (grinding) motion of the tool, thus saving resources. This is in contrast to having a dedicated serial kinematic chain for the tool axis. The design process has successfully employed the virtual prototyping computer program ADAMS (Automatic Dynamic Analysis of Mechanical Systems) for defining the generalized coordinates and the loads in the parallel kinematic structure used to envelope convex surfaces.
Pilot study investigating the feasibility of an ulcer-specific quality of life questionnaire
Authors: Venkatraman P D , Anand S C , Dean C , Nettleton R , EL Sawi A , Afify S
Published: March 2005

Objective: This study explores the feasibility and reliability of a modified ulcer-specific quality of life (QOL) questionnaire on patients suffering from venous leg ulcers.

Methods: A cross-sectional survey was conducted on a cohort of patients suffering from venous leg ulcers who had been registered at Rochdale Infirmary to participate in a clinical trial. A self-administered six-page questionnaire – Freiburger Lebensqualitäts Questionnaire Assessment (FLQA) – on the QOL along with a checklist was used to collect data from March 2002 to June 2003. The feasibility and reliability of the venous leg ulcer specific questionnaire, the patient-reported QOL and their perspective on compression therapy were chosen as the main outcomes of the study.

Results: A response rate of 94% was obtained, of which 56% were women and 44% were men with an average age of 63 years. Approximately 72% of respondents reported that the questionnaire was suitable to reflect their perspectives on QOL and compression therapy. The questionnaire took an average of 20 minutes to complete. The average QOL score was 45.27 in all the eight domains, where 0 reflected good QOL and 100 reflected poor QOL, indicating that the respondents' QOL had been adversely affected due to venous leg ulcers. Men had an average score of 52.0 in all the eight domains and women scored 39.0 in a 0–100 scale. Hence, comparatively, men had poorer QOL than women. Reliability was assessed using measures of internal consistency and test–retest analysis. Cronbach's alpha, α = 0.934 indicated that the survey items were highly inter-correlated. Test–retest analysis indicated that there was moderate-to-strong correlation in seven out of eight domains, which meant that the reproducibility of the FLQA questionnaire was consistent.

Conclusions: The pilot survey conducted on a representative sample of patients indicated that the questionnaire is suitable and has the potential to reflect the perspective on compression therapy and overall QOL of patients suffering from venous leg ulcers. The survey tool demonstrated the clinical and research utility as a QOL outcome measure for clinical trials evaluating wound care products on patients suffering from venous leg ulcers.