bluuebunny/crossref_metadata_2025 huggingface dataset:
Over-formalising the formulation?
Authors: Lucas Richard
Published: June 2006

In their recent articles in APT Mace & Binyon described a four-level approach to the teaching of the psychodynamic formulation. The fourth level requires development of confidence in the use of an operationalised psychodynamic diagnostics (OPD) manual. Here I critically reconsider the aspects necessary to develop the ability to arrive at a psychodynamic formulation. I argue that as one develops more sophistication and clinical confidence, one needs to move from a manualised to a more open-minded reflective mode.
Experiences and expectations of refugee doctors
Authors: Cohn S. , Alenya J. , Murray K. , Bhugra D. , De Guzman J. , Schmidt U.
Published: June 2006

Background

Refugee doctors constitute a potentially valuable resource for reducing the recruitment crisis in psychiatry. However, various hurdles make their route into the National Health Service (NHS) difficult.

Aims

To explore the perceptions and experiences of refugee doctors trying to practise psychiatry in the UK.

Method

Thirty-one refugee doctors participated in qualitative interviews designed to elicit their experiences in trying to practise as doctors in the UK. Twenty were re-interviewed about 6 months later.

Results

Doctors identified a range of practical problems that made it difficult for them to take the required steps towards practising in the UK. These included lack of appropriate information, lack of a clear route through the system and feelings of isolation. The English language examination was seen as a particular bottleneck, as were finding clinical attachments. The psychological impact of the experience was profound.

Conclusions

These findings have important implications for how refugee doctors are introduced to the practice of psychiatry in the NHS.
Magnetic resonance imaging abnormalities in young euthymic patients with bipolar affective disorder
Authors: El-Badri Selim M. , Cousins David A. , Parker Sean , Ashton Heather C. , McAllister Victor L. , Ferrier I. Nicol , Moore P. Brian
Published: June 2006

Temporal lobe and limbic structures may be abnormal in bipolar disorder. T2-weighted magnetic resonance imaging (MRI) scans frequently show deep white matter lesions. MRI was performed on 50 young (19–39 years) euthymic patients with bipolar disorder and 26 controls. Mean temporal lobe volumes were reduced in patients (right, 9.42 cm3; left, 6.33 cm3) but this could not be ascribed to a specific structure. Deep white matter lesions were present in 5 patients but no controls raising questions of their aetiological significance.
Comparison of brief dynamic and cognitive–behavioural therapies in avoidant personality disorder
Authors: Emmelkamp Paul M. G. , Benner Ank , Kuipers Antoinette , Feiertag Guus A. , Koster Harrie C. , van Apeldoorn Franske J.
Published: June 2006

Background

There is a paucity of controlled trials examining the effectiveness of individual psychotherapy in personality disorders, especially in patients with cluster C disorders.

Aims

To compare the effectiveness of brief dynamic therapy and cognitive–behavioural therapy as out-patient treatment for people with avoidant personality disorder.

Method

Patients who met the criteria for avoidant personality disorder (n=62) were randomly assigned to 20 weekly sessions of either brief dynamic therapy (n=23) or cognitive–behavioural therapy (n=21), or they were assigned to the waiting-list control group (n=18). After the waiting period, patients in the control group were randomly assigned to one of the two therapies.

Results

Patients who received cognitive–behavioural therapy showed significantly more improvements on a number of measures in comparison with those who had brief dynamic psychotherapy or were in the waiting-list control group. Results were maintained at follow-up.

Conclusions

Cognitive–behavioural therapy is more effective than waiting-list control and brief dynamic therapy. Brief dynamic therapy was no better than the waiting-list control condition.
Duration of untreated symptoms in common mental disorders: association with outcomes
Authors: Kisely Stephen , Scott Anita , Denney Jennifer , Simon Gregory
Published: June 2006

Studies have assessed the association between a longer duration of untreated symptoms and outcome for psychoses in specialist care. We investigated the effect of longer duration on the outcome of common psychiatric disorders in primary care, where most patients are treated. Patients presenting to primary care for new episodes in 10 countries were recruited into a prospective cohort study. Information on duration of untreated symptoms and psychosocial status was collected for 351 individuals using standardised instruments and this was repeated 1 year later. At 1-year follow-up, longer duration was associated with worse psychiatric outcome even after controlling for potential confounders.
Beyond the Kraepelinian dichotomy: acute and transient psychotic disorders and the necessity for clinical differentiation
Authors: Marneros Andreas
Published: June 2006

The concept of acute and transient psychoses is, together with that of schizoaffective disorders, a challenge by the Kraepelinian dichotomy. Although these conditions have some similarities to schizophrenia, they differ significantly from schizophrenia regarding onset, duration, prognosis, gender and premorbid adaptation. They show some similarities with bipolar disorders. They do not fit into the dichotomous concept.
Switching from immediate- to sustained-release psychostimulants in routine treatment of children with attention-deficit hyperactivity disorder
Authors: Thompson Anne E. , Nazir Saeed A. , Abbas Mohammed J. , Clarke Julie
Published: June 2006

Aims and Method

To investigate the effectiveness of switching children with attention-deficit hyperactivity disorder (ADHD) from immediate- to sustained-release psychostimulants (Concerta XL, a novel methylphenidate hydro-chloride) and to examine factors associated with treatment success or failure. This was a retrospective study of all such children known to four clinicians in Lincolnshire, over a 2-year period. The initial response to treatment and the response to slow-release psychostimulant as judged by the clinicians were recorded. Data were analysed using the Statistical Package for the Social Sciences version 12.

Results

Of the children who were switched (n=97) and on whom clinical judgement was available (n=92), a statistically significant number (32%) responded poorly (P<0.001). In 26 out of the 97 patients, the switching was considered as a treatment failure and they were switched back to the original immediate-release stimulants. There was no significant-difference with possible confounding variables between children who responded well and those who responded poorly after switching to sustained-release drug.

Clinical Implications

In a real-life clinical situation there is a significant failure rate when a child with ADHD is switched from an immediate- to sustained-release psychostimulant. Further studies are needed.
Training for interviews with the media
Authors: Illman John
Published: June 2006

Media training is designed to prepare people for print, radio and TV interviews. It is especially challenging to prepare psychiatrists for interviews with the media because reporting of issues related to mental health is often distorted and stigmatising. Although media coverage of women's rights, Black civil rights and disability has changed markedly, mental health coverage has yet to come in from the cold (Crisp et al, 2005; Nairn & Coverdale, 2005). Psychiatrists are better placed than anyone else to change the climate, but some fear being ineffectual or misrepresented. One even likened the challenge to climbing Everest (Harrison, 1998), a view highlighted by a national newspaper survey of 306 health-related articles in which psychiatry coverage was four times more likely to be negative than coverage of general clinical medicine (Lawrie, 2000).
Phase I Trial of Intravesical Docetaxel in the Management of Superficial Bladder Cancer Refractory to Standard Intravesical Therapy
Authors: McKiernan James M. , Masson Puneet , Murphy Alana M. , Goetzl Manlio , Olsson Carl A. , Petrylak Daniel P. , Desai Manisha , Benson Mitchell C.
Published: June 2006

Purpose

Up to 50% of patients treated with intravesical agents for superficial bladder cancer will experience recurrence. Response rates to second-line intravesical therapies range from 20% to 40%. For these high-risk patients, novel agents are necessary to prevent recurrence. Docetaxel is a microtubule depolymerization inhibitor with unique physiochemical properties, making it an excellent candidate for investigation as an intravesical agent.

Patients and Methods

This phase I trial included patients with recurrent Ta, T1, and Tis transitional cell carcinoma who experienced treatment failure with at least one prior intravesical treatment. Docetaxel was administered as six weekly instillations at a starting dose of 5 mg, with a dose-escalation model used until a maximum tolerated dose (MTD) was achieved. Primary end points were dose-limiting toxicity (DLT) and MTD. Efficacy was evaluated by cystoscopy with biopsy, cytology, and computed tomography imaging.

Results

Eighteen patients (100%) completed the trial, and the distribution of stages included six patients with Tis, seven with Ta, and five with T1 disease. No grade 3 or 4 DLTs occurred in 108 infusions, and no patient had systemic absorption of docetaxel. Eight (44%) of 18 patients experienced grade 1 or 2 toxicities, with dysuria being the most common. Ten (56%) of 18 patients had no evidence of disease at their post-treatment cystoscopy and biopsy. None of the patients who experienced relapse had disease progression.

Conclusion

Intravesical docetaxel exhibited minimal toxicity and no systemic absorption in the first human intravesical clinical trial. This suggests that docetaxel is a safe agent for further evaluation of efficacy in a phase II trial.
Isolated CNS Relapse of Acute Lymphoblastic Leukemia Treated With Intensive Systemic Chemotherapy and Delayed CNS Radiation: A Pediatric Oncology Group Study
Authors: Barredo Julio C. , Devidas Meenakshi , Lauer Stephen J. , Billett Amy , Marymont MaryAnne , Pullen Jeanette , Camitta Bruce , Winick Naomi , Carroll William , Ritchey A. Kim
Published: June 2006

Purpose

Prognosis and outcome of children with isolated CNS relapse of acute lymphoblastic leukemia (ALL) has depended on duration of first complete remission (CR1). This study intensified systemic therapy by delaying CNS radiation for 12 months and tailored CNS radiation by CR1 duration.

Patients and Methods

Seventy-six children with first isolated CNS relapse of ALL were treated with systemic chemotherapy that effectively penetrates into the CSF and intrathecal chemotherapy for 12 months. Patients with CR1 of less than 18 months received craniospinal radiation (24 Gy cranial/15 Gy spinal), whereas those with CR1 of 18 months or more received cranial radiation only (18 Gy), followed by maintenance chemotherapy. Additionally, asymptomatic patients were enrolled in a thiotepa up-front therapeutic window.

Results

Seventy-four (97.4%) of 76 eligible patients achieved a second remission. Overall 4-year event-free survival (EFS) for the 71 precursor B-cell patients was 70.1% ± 5.8%. CR1 duration and National Cancer Institute (NCI; National Institutes of Health, Bethesda, MD) risk group at initial diagnosis predicted outcome. Patients with CR1 of less than 18 months and 18 months or more had a 4-year EFS of 51.6% ± 11.3% and 77.7% ± 6.4% (P = .027), respectively. NCI high- versus standard-risk 4-year EFS was 51.4% ± 10.8% and 80.2% ± 6.3% (P = .0018), respectively. A significant difference in EFS between standard risk/CR1 of at least 18 months and both high risk/CR1 of less than 18 months and high risk/CR1 of at least 18 months groups was detected (P = .0068 and .0314, respectively). Response rate to thiotepa was 78%. Most relapses involved the bone marrow, and three second malignancies were reported.

Conclusion

Twelve months of intensive systemic chemotherapy with reduced dose cranial radiation (18 Gy) is highly effective for children with isolated CNS relapse and CR1 of 18 months or more. Novel strategies are needed for patients with CR1 of less than 18 months.
Placebo-Controlled Phase III Trial of Immunologic Therapy with Sipuleucel-T (APC8015) in Patients with Metastatic, Asymptomatic Hormone Refractory Prostate Cancer
Authors: Small Eric J. , Schellhammer Paul F. , Higano Celestia S. , Redfern Charles H. , Nemunaitis John J. , Valone Frank H. , Verjee Suleman S. , Jones Lori A. , Hershberg Robert M.
Published: June 2006

Purpose

Sipuleucel-T (APC8015) is an investigational immunotherapy product designed to stimulate T-cell immunity against prostatic acid phosphatase. A phase III study was undertaken to evaluate the safety and efficacy of sipuleucel-T in a placebo-controlled study.

Patients and Methods

A total of 127 patients with asymptomatic metastatic hormone refractory prostate cancer (HRPC) were randomly assigned in a 2:1 ratio to receive three infusions of sipuleucel-T (n = 82) or placebo (n = 45) every 2 weeks. On disease progression, placebo patients could receive APC8015F, a product made with frozen leukapheresis cells.

Results

Of the 127 patients, 115 patients had progressive disease at the time of data analysis, and all patients were followed for survival for 36 months. The median for time to disease progression (TTP) for sipuleucel-T was 11.7 weeks compared with 10.0 weeks for placebo (P = .052, log-rank; hazard ratio [HR], 1.45; 95%CI, 0.99 to 2.11). Median survival was 25.9 months for sipuleucel-T and 21.4 months for placebo (P = .01, log-rank; HR, 1.70; 95%CI, 1.13 to 2.56). Treatment remained a strong independent predictor of overall survival after adjusting for prognostic factors using a Cox multivariable regression model (P = .002, Wald test; HR, 2.12; 95%CI, 1.31 to 3.44). The median ratio of T-cell stimulation at 8 weeks to pretreatment was eight-fold higher in sipuleucel-T-treated patients (16.9 v 1.99; P < .001). Sipuleucel-T therapy was well tolerated.

Conclusion

While the improvement in the primary end point TTP did not achieve statistical significance, this study suggests that sipuleucel-T may provide a survival advantage to asymptomatic HRPC patients. Supportive studies are underway.
The Prolactin-Deficient Mouse Has an Unaltered Metabolic Phenotype
Authors: LaPensee Christopher R. , Horseman Nelson D. , Tso Patrick , Brandebourg Terry D. , Hugo Eric R. , Ben-Jonathan Nira
Published: June 2006

Prolactin (PRL), best recognized for its lactogenic activity, is also involved in the regulation of metabolic homeostasis in both mammalian and nonmammalian species. Although several mouse models have been used to study the metabolic functions of PRL, a clear-cut consensus has not emerged given the limited and often conflicting data. To clarify the role of PRL in metabolic homeostasis in males and nonlactating females, we used the PRL-deficient mouse. Our objectives were to compare: 1) weight gain, 2) body composition, 3) serum lipid profile, 4) circulating leptin and adiponectin levels, and 5) glucose tolerance in PRL knockout, heterozygous, and wild-type mice maintained on standard chow, high-fat, or low-fat diets. In addition, we compared the lipolytic actions of PRL using adipose tissue explants from mice, rats, and humans. We are reporting that PRL deficiency does not affect the rate of weight gain, body composition, serum lipids, or adiponectin levels in either sex on any diet. Glucose tolerance was slightly impaired in very young PRL knockout male pups but not in adults or in females at any age. Leptin was elevated in male, but not female, PRL knockout mice maintained on a low-fat diet. PRL did not affect lipolysis in adipose tissue explants from mice but significantly inhibited glycerol release from both rat and human adipose explants in a dose-dependent manner. We conclude that PRL deficiency has negligible gross metabolic effects in mice.
Urocortin 3 Modulates the Neuroendocrine Stress Response and Is Regulated in Rat Amygdala and Hypothalamus by Stress and Glucocorticoids
Authors: Jamieson Pauline M. , Li Chien , Kukura Christina , Vaughan Joan , Vale Wylie
Published: June 2006

The endogenous corticotropin-releasing factor (CRF) type 2 receptor (CRFR2)-selective ligand urocortin 3 is expressed in discrete subcortical brain regions with fibers distributed mainly to hypothalamic and limbic structures. Close anatomical association between major urocortin 3 terminal fields and CRFR2 in hypothalamus, lateral septum, and medial amygdala (MEA) suggest it is well placed to modulate behavioral and hormonal responses to stress. Urocortin 3 was administered intracerebroventricularly to male rats under basal conditions or before a restraint stress, and circulating ACTH, corticosterone, glucose, and insulin were measured. Urocortin 3 activated the hypothalamic-pituitary-adrenal axis under basal conditions and augmented ACTH responses to restraint stress. Elevated blood glucose with lowered insulin to glucose ratios in both groups suggested increased sympathetic activity. Circulating catecholamines were also increased by urocortin 3, providing additional evidence for sympathoadrenomedullary stimulation. Intracerebroventricular urocortin 3 increased vasopressin mRNA expression in the parvocellular division of the hypothalamic paraventricular nucleus, whereas CRF expression was unchanged, providing a possible mechanism by which urocortin 3 mediates its actions. Urocortin 3 mRNA expression was examined after exposure to stress-related paradigms. Restraint increased levels in MEA with a trend to increased expression in the rostral perifornical hypothalamic area, whereas hemorrhage and food deprivation decreased expression in MEA. Adrenalectomy markedly increased expression in the rostral perifornical hypothalamic area, and high-level corticosterone replacement restored this to control levels. The evidence that urocortin 3 has the potential to influence hormonal components of the stress response and the changes in its expression levels after stressors is consistent with a potential function for the endogenous peptide in modulating stress responses.
Metabolic and neuroendocrine effects on diurnal urea excretion in the mangrove killifishRivulus marmoratus
Authors: Rodela Tammy M. , Wright Patricia A.
Published: June 2006

In mangrove killifish Rivulus marmoratus, urea excretion(Jurea) follows a distinct diurnal pattern with the highest rates between 12:00 h and 18:00 h. We investigated the regulating mechanisms that underlie temporal rhythms in Jurea in R. marmoratus. We hypothesized that the daily pattern of Jurea in R. marmoratus is (1) due to diurnal changes in urea synthesis rates and ultimately metabolic rate and/or (2)controlled by neuroendocrine messengers. Oxygen consumption and whole body urea content in R. marmoratus demonstrated a clear diurnal pattern with maximum rates for both parameters occurring at 12:00 h. A strong synchrony between diurnal patterns of oxygen consumption, whole body urea content and Jurea implicated metabolic regulation of the diurnal Jurea pattern. Ketanserin, a 5-HT2receptor antagonist, and RU-486, a cortisol receptor antagonist, were used to test the second hypothesis. Increasing antagonist concentrations of either ketanserin or RU-486 resulted in dose-dependent decreases in Jurea. Application of a single dose of either antagonist significantly decreases Jurea for up to 12 and 6 h for ketanserin and RU-48, respectively. Repeated exposure to doses of either ketanserin or RU-486 did not abolish the diurnal pattern in Jurea; however, there was a significant decrease in the amplitude of the rates. Taken together, these findings indicate that the diurnal pattern of Jurea in R. marmoratus are regulated by both metabolic and neuroendocrine factors. We propose that cortisol and 5-HT influence the absolute rate of urea excretion by altering the permeability of the gill membrane to urea and/or the rate of urea synthesis.
The cellular response to heat stress in the gobyGillichthys mirabilis: a cDNA microarray and protein-level analysis
Authors: Buckley Bradley A. , Gracey Andrew Y. , Somero George N.
Published: June 2006

The cellular response to stress relies on the rapid induction of genes encoding proteins involved in preventing and repairing macromolecular damage incurred as a consequence of environmental insult. To increase our understanding of the scope of this response, a cDNA microarray, consisting of 9207 cDNA clones, was used to monitor gene expression changes in the gill and white muscle tissues of a eurythermic fish, Gillichthys mirabilis(Gobiidae) exposed to ecologically relevant heat stress. In each tissue, the induction or repression of over 200 genes was observed. These genes are associated with numerous biological processes, including the maintenance of protein homeostasis, cell cycle control, cytoskeletal reorganization,metabolic regulation and signal transduction, among many others. In both tissues, the molecular chaperones, certain transcription factors and a set of additional genes with various functions were induced in a similar manner;however, the majority of genes displayed tissue-specific responses. In gill,thermal stress induced the expression of the major structural components of the cytoskeleton, whereas these same genes did not respond to heat in muscle. In muscle, many genes involved in promoting cell growth and proliferation were repressed, perhaps to conserve energy for repair and replacement of damaged macromolecules, but a similar repression was not observed in the gill. Many of the observed changes in gene expression were similar to those described in model species whereas many others were unexpected. Measurements of the concentrations of the protein products of selected genes revealed that in each case an induction in mRNA synthesis correlated with an increase in protein production, though the timing and magnitude of the increase in protein was not consistently predicted by mRNA concentration, an important consideration in assessing the condition of the stressed cell using transcriptomic analysis.
Division of labor in the honey bee (Apis mellifera): the role of tyramine β-hydroxylase
Authors: Lehman Herman K. , Schulz David J. , Barron Andrew B. , Wraight Lydia , Hardison Chris , Whitney Sandra , Takeuchi Hideaki , Paul Rajib K. , Robinson Gene E.
Published: June 2006

The biogenic amine octopamine (OA) is involved in the regulation of honey bee behavioral development; brain levels are higher in foragers than bees working in the hive, especially in the antennal lobes, and treatment causes precocious foraging. We measured brain mRNA and protein activity of tyramineβ-hydroxylase (T βh), an enzyme vital for OA synthesis, in order to begin testing the hypothesis that this enzyme is responsible for the rising levels of OA during honey bee behavioral development. Brain OA levels were greater in forager bees than in bees engaged in brood care, as in previous studies, but T βh activity was not correlated with bee behavior. Tβh mRNA levels, however, did closely track OA levels during behavioral development, and T βh mRNA was localized to previously identified octopaminergic neurons in the bee brain. Our results show that the transcription of this neurotransmitter synthetic enzyme is associated with regulation of social behavior in honey bees, but other factors may be involved.
Behavioral responses of Drosophila to biogenic levels of carbon dioxide depend on life-stage, sex and olfactory context
Authors: Faucher Cécile , Forstreuter Manfred , Hilker Monika , de Bruyne Marien
Published: June 2006

Drosophila melanogaster (Meigen) detects and uses many volatiles for its survival. Carbon dioxide (CO2) is detected in adults by a special class of olfactory receptor neurons, expressing the gustatory receptor Gr21a. The behavioral responses to CO2 were investigated in a four-field olfactometer bioassay that is new for Drosophila. We determined (1) whether the sensitivity of this response changes with odor context, and (2) if it depends on sex and life stage. When CO2 was added to ambient air in one field and tested against ambient air in the three other fields, individually observed adults avoided CO2 (0.1-1%above ambient), but did not respond to a low rise of 0.02%. We relate this behavior to measurements of CO2 production in bananas and flies. When 0.02% CO2 was combined with the odor of apple cider vinegar in one field of the olfactometer and tested against ambient air in the three other fields, the addition of CO2 did not affect the attractiveness of apple cider vinegar alone. However, this combination of CO2 and vinegar became repellent when it was tested against vinegar at ambient CO2 concentrations in the three other fields. This `odor background effect' was female-specific, revealing a sexually dimorphic behavior. The new assay allowed us to test larvae under similar conditions and compare their behavior to that of adults. Like adults, they avoided CO2, but with lower sensitivity. Larvae lacking neurons expressing Gr21a lost their avoidance behavior to CO2, but kept their positive response to vinegar odor. Hence, Gr21a-expressing neurons mediate similar behaviors in larvae and adults.
Nitric oxide and cnidarian bleaching: an eviction notice mediates breakdown of a symbiosis
Authors: Perez Santiago , Weis Virginia
Published: June 2006

Nitric oxide (NO) is a free radical implicated in numerous cell signaling,physiological and pathophysiological processes of eukaryotic cells. Here, we describe the production of NO as part of the cellular stress response of the symbiotic sea anemone Aiptasia pallida, which hosts dinoflagellates from the genus Symbiodinium. We show that exposure to elevated temperatures induces symbiotic anemones to produce high levels of NO, leading to the collapse of the symbiosis. These results shed light on the poorly understood cellular mechanism through which elevated seawater temperature causes the release of symbiotic algae from symbiotic cnidarians, a detrimental process known as coral (cnidarian) bleaching. The results presented here show that the host cell is a major source of NO during exposure to elevated temperatures and that this constitutes a cytotoxic response leading to bleaching. These results have important evolutionary implications as the observed NO production in these basal metazoans displays many parallels to the cytotoxic inflammatory response to pathogens, a well-understood process in mammalian model systems.
Mitochondrial proton leak rates in the slow, oxidative myotomal muscle and liver of the endothermic shortfin mako shark (Isurus oxyrinchus)and the ectothermic blue shark (Prionace glauca) and leopard shark(Triakis semifasciata)
Authors: Duong Cindy A. , Sepulveda Chugey A. , Graham Jeffrey B. , Dickson Kathryn A.
Published: June 2006

Mitochondrial proton leak was assessed as a potential heat source in the slow, oxidative (red) locomotor muscle and liver of the shortfin mako shark(Isurus oxyrinchus), a regional endotherm that maintains the temperature of both tissues elevated above ambient seawater temperature. We hypothesized that basal proton leak rates in red muscle and liver mitochondria of the endothermic shortfin mako shark would be greater than those of the ectothermic blue shark (Prionace glauca) and leopard shark(Triakis semifasciata). Respiration rate and membrane potential in isolated mitochondria were measured simultaneously at 20°C using a Clark-type oxygen electrode and a lipophilic probe(triphenylmethylphosphonium, TPMP+). Succinate-stimulated respiration was titrated with inhibitors of the electron transport chain, and the non-linear relationship between respiration rate and membrane potential was quantified. Mitochondrial densities of both tissues were measured by applying the point-contact method to electron micrographs so that proton leak activity of the entire tissue could be assessed. In all three shark species,proton leak occurred at a higher rate in red muscle mitochondria than in liver mitochondria. For each tissue, the proton leak curves of the three species overlapped and, at a membrane potential of 160 mV, mitochondrial proton leak rate (nmol H+ min-1 mg-1 protein) did not differ significantly between the endothermic and ectothermic sharks. This finding indicates that red muscle and liver mitochondria of the shortfin mako shark are not specialized for thermogenesis by having a higher proton conductance. However, mako mitochondria did have higher succinate-stimulated respiration rates and membrane potentials than those of the two ectothermic sharks. This means that under in vivo conditions mitochondrial proton leak rates may be higher in the mako than in the ectothermic species, due to greater electron transport activity and a larger proton gradient driving proton leak. We also estimated each tissue's total proton leak by combining mitochondrial proton leak rates at 160 mV and tissue mitochondrial density data with published values of relative liver or red muscle mass for each of the three species. In red muscle, total proton leak was not elevated in the mako shark relative to the two ectothermic species. In the liver, total proton leak would be higher in the mako shark than in both ectothermic species, due to a lower proton conductance in the blue shark and a lower liver mitochondrial content in the leopard shark, and thus may contribute to endothermy.
Why are so many adhesive pads hairy?
Authors: Federle Walter
Published: June 2006

Many arthropods and vertebrates possess tarsal adhesive pads densely covered with setae. The striking morphological convergence of `hairy' pads in lizards, spiders and several insect orders demonstrates the advantage of this design for substrate adhesion. Early functional explanations of hairy adhesive organs focused on the performance on rough substrates, where flexible setae can make more intimate contact. Recent theoretical and experimental work shows that the hairy design can also help to achieve self-cleaning properties,controllable detachment and increased adhesion. Several arguments have been proposed to explain why adhesive forces are maximised. First, the `Force scaling' hypothesis states that when adhesive forces scale linearly with the dimensions of the contact, adhesion is increased by dividing the contact zone into many microscopic subunits. Second, the `Fracture mechanics' argument implies that adhesion is maximised when the size of adhesive contacts is smaller than the critical crack length. Third, the `Work of adhesion' model suggests that adhesion increases due to the bending and stretching of setae and associated energy losses during detachment.

Several morphological traits of hairy adhesive pads can be explained by the need to maximise the work of adhesion, while avoiding the sticking of setae to each other (self-matting). Firstly, if setae are oblique and convex toward the foot tip as typical of most hairy pads, arrays should achieve greater adhesion. Secondly, a branched seta morphology not only confers the advantage that setae can adapt to roughness at different length scales but also prevents self-matting and increases the work of adhesion.

It is predicted from the `Work of adhesion' model that adhesion of pads with unbranched setae cannot be increased by subdividing the contact zone into ever finer subcontacts, because this would increasingly cause self-matting. However, contact splitting can increase adhesion if setae are branched. The greater density of setae in large animals has been interpreted by `Force scaling'. However, the existing data can be explained by the effect of seta branching and by a fundamental difference between `wet' and `dry' adhesive systems. As insects employ adhesive fluids, they can cope with small-scale surface roughness even with relatively blunt seta tips, whereas the dry systems of lizards and spiders require extremely fine endings.
Nervous control of ciliary beating by Cl-, Ca2+ and calmodulin inTritonia diomedea
Authors: Woodward Owen M. , Willows A. O. Dennis
Published: June 2006

In vertebrates, motile cilia line airways, oviducts and ventricles. Invertebrate cilia often control feeding, swimming and crawling, or gliding. Yet control and coordination of ciliary beating remains poorly understood. Evidence from the nudibranch mollusc, Tritonia diomedea, suggests that locomotory ciliated epithelial cells may be under direct electrical control. Here we report that depolarization of ciliated pedal epithelial (CPE)cells increases ciliary beating frequency (CBF), and elicits CBF increases similar to those caused by dopamine and the neuropeptide, TPep-NLS. Further,four CBF stimulants (zero external Cl-, depolarization, dopamine and TPep-NLS) depend on a common mode of action, viz. Ca2+influx, possibly through voltage-gated Ca2+ channels, and can be blocked by nifedipine. Ca2+ influx alone, however, does not provide all the internal Ca2+ necessary for CBF change. Ryanodine receptor(RyR) channel-gated internal stores are also necessary for CBF excitation. Caffeine can stimulate CBF and is sensitive to the presence of the RyR blocker dantrolene. Dantrolene also reduces CBF excitation induced by dopamine and TPep-NLS. Finally, W-7 and calmidazolium both block CBF excitation by caffeine and dopamine, and W-7 is effective at blocking TPep-NLS excitation. The effects of calmidazolium and W-7 suggest a role for Ca2+-calmodulin in regulating CBF, either directly or via Ca2+-calmodulin dependent kinases or phosphodiesterases. From these results we hypothesize dopamine and TPep-NLS induce depolarization-driven Ca2+ influx and Ca2+ release from internal stores that activates Ca2+-calmodulin, thereby increasing CBF.
Optimization of Pinion Roughing of Spiral Bevel and Hypoid Gear
Authors: Li J-G , Mao S-M , He J-L , Wu X-T
Published: June 2006

Roughing plays a very important role in spiral bevel and hypoid gear manufacturing. The roughing machine settings and cutter blade profile are optimized in this article on the basis of three considerations: the transition between the roughing root and the finishing fillet is smoothened, which causes the gear to obtain minimum possible bending stress and maximum bending strength; the finishing stock is distributed evenly to improve the residual stress, which causes the distortion of pinion during the process of heat treatment; and the working load of finishing cutter tip is minimized, and the maximum cutter life is obtained. The complex shape method is successfully used to optimize the roughing machine settings and cutter blade profile. The advantages and benefits of the newly developed roughing process are verified in the manufacture of hypoid gears for a heavy truck axle in a Chinese vehicle company.
Fabrication Error Sensitivity Analysis of Three-Degree-Of-Freedom Parallel Submicron Positioning Stage
Authors: Chen S-L , Huang Y-C , Tomizuka M
Published: June 2006

A new type of six-degree-of-freedom (DOF) precision positioning stage is designed and investigated in this study. This stage may be applied to couple and align an array waveguide grating (AWG) with a fibre array. It has an X-Y horizontal motion stage which consists of an X-Y horizontal motion mechanism and wedge-shaped mechanism for reducing positioning error. In addition, a rotational servo stage which provides the vertical γ-axis rotational DOF is arranged on the horizontal X-Y motion stage. The precision positioning stage is complete with three degrees of freedom parallel kinematic mechanism (α, β, and Z axes) on the rotational servo stage.

To control this positioning stage precisely, an error model is obviously necessary and it is established in this paper. Because the assembly technology of three-DOF serial positioning stage is well developed, only the fabricating error parameters of the three-DOF parallel kinematic positioning stage are considered and investigated. The inverse and forward kinematics of the stage including error correction will be developed. The error sensitivity is analysed and the results will be used to improve the performance of the developed system. According to the analysis results, the positioning accuracy of Y0-axis is affected insignificantly by fabricating errors. Therefore, the optical axis of AWG or fibre array on the loading flat-top should be parallel to the X0-axis if this positioning stage is applied to couple an AWG with a fibre array.
A Tube with a Rectangular Cut-Out. Part 2: Subject to Axial Compression
Authors: Vartdal B. J. , Al-Hassani S. T. S. , Burley S. J.
Published: June 2006

Simply supported steel tubes with rectangular cut-outs of different sizes positioned at their mid-length were subject to axial compression to assess the effect of the cut-outs on the deformation behaviour. Experiments on 1000 mm long, 100 mm diameter, and 2.55 mm wall thickness DIN 2391 ST NBK supported steel tubes are described. The experimental tubes were relatively thick walled, with a thickness-to-diameter ratio typical of structural columns, rather than shell structures. The radial position of the cut-outs was such that the reduced cross-section was symmetric with respect to the direction of rotation of the pinned ends. Several permutations of the axial and circumferential dimensions of the cut-out were tested so that the effect of changing these dimensions could be assessed. Finite-element and semi-empirical analyses were carried out to predict the global load-deformation behaviour of the tubes. Both analyses gave good predictions of the experimental results for the majority of the cut-out parameters investigated. The motivation for the study was to investigate the feasibility of using cut-outs to initiate and control the toppling of offshore jacket structures.
Design and Evaluation of a Discretely Actuated Multi-Module Parallel Manipulator
Authors: Ottaviano E , Ceccarelli M , Giorgio J Di , Varone M
Published: June 2006

In this paper, a new discretely actuated spatial parallel manipulator is presented as designed with binary pneumatic actuation. It has been used as a basic module for the construction of a multi-module parallel manipulator. Major benefits of discretely actuated manipulators are high repeatability, relatively low cost, and no need for feedback control. In addition, hyper-redundancy allows executing tasks even when some actuators fail. Binary actuators can have only two stable states denoted by (0) and (1). In this paper, kinematic and static analyses have been reported to obtain design constraints that have been used to build a first prototype. A performance evaluation is carried out and the prototype has been built for experimental tests.
Density of CO2 Hydrate by Monte Carlo Simulation
Authors: Ferdows M , Ota M
Published: June 2006

In order to perform the density of CO2 hydrate, Monte Carlo simulations have been carried out under constant temperature and pressure conditions. The physical property of density have been focused for the clathrate hydrate of CO2: CO2.5.75H2O; CO2.7.67H2O at temperatures ranging from 150 to 280 K and pressure up to 10 Mpa in the number of particles, temperature, and pressure (NPT) ensemble using simple point charge (SPC) intermolecular potential model of water. Comparisons between Monte Carlo-calculated result SPC and the result calculated by transferable intermolecular potential (TIP4P) model are also presented.
Three New MDL-Based Pruning Techniques for Robust Rule Induction
Authors: Pham D T , Afify A A
Published: June 2006

Overfitting the training data is a major problem in machine learning, particularly when noise is present. Overfitting increases learning time and reduces both the accuracy and the comprehensibility of the generated rules, making learning from large data sets more difficult. Pruning is a technique widely used for addressing such problems and consequently forms an essential component of practical learning algorithms. An important class of pruning techniques is that based on the minimum description length (MDL) principle. This paper presents three new techniques using the MDL principle for pruning rule sets. An important advantage of these techniques is that all of the training data can be used for both inducing and evaluating rule sets. The performance of the techniques are evaluated using three criteria: classification accuracy, rule set complexity, and execution time. This shows that the new techniques, when incorporated into a rule induction algorithm, are more efficient and lead to accurate rule sets that are significantly smaller in size compared with the case before pruning.
Fuzzy Analysis of Geometric Tolerances Using Interval Method
Authors: Wu W , Rao S S
Published: June 2006

The quality and performance of any mechanical system are greatly influenced by the GD&T (geometric dimensioning and tolerancing) used in its design. A proper consideration of the various types of tolerances associated with different components could not only satisfy the assembly requirements, but also minimize the manufacturing cost. To satisfy the design and functional specifications, one has to know how various tolerance patterns affect the manufacturability and assemblability of the designed parts. Therefore, a thorough understanding of how different forms of mechanical tolerances interact with each other becomes a must for designers and manufacturers. The effects of form, orientation, and position tolerances on the kinematic features and dimensions of mechanical systems are analysed using a new approach, based on fuzzy logic, in this article. In this approach, the α-cut method is used with the mechanical tolerances concerned as intervals. The proposed approach represents a more natural and realistic way of dealing with uncertain properties like geometric dimensions. A typical mechanical assembly system involving form, orientation, and position tolerances is used as an illustrative example. As the fuzzy approach leads to systems of non-linear interval equations, a modified Newton-Raphson method is developed for the solution of these equations. The current approach is found to be effective, simple, and accurate and can be extended to the analysis and synthesis of any uncertain mechanical system where the probability distribution functions of the uncertain parameters are unknown.
Dynamic analysis of loads and stresses in connecting rods
Authors: Shenoy P. S. , Fatemi A
Published: June 2006

Automobile internal combustion engine connecting rod is a high volume production component subjected to complex loading. Proper optimization of this component, which is critical to the engine fuel efficiency and more vigorously pursued by the automotive industry in recent years, necessitates a detailed understanding of the applied loads and resulting stresses under in-service conditions. In this study, detailed load analysis under service loading conditions was performed for a typical connecting rod, followed by quasi-dynamic finite element analysis (FEA) to capture stress variations over a cycle of operation. On the basis of the resulting stress-time histories, variation of stress ratio, presence of mean and bending stresses, and multi-axiality of stress states in various locations of the connecting rod under service operating conditions were investigated. It was found that even though connecting rods are typically tested and analyzed under axial loading and stress state, bending stresses are significant and a multiaxial stress state exists at the critical regions of connecting rod. A comparison is also made between stresses obtained using static FEA which is commonly performed and stresses using quasi-dynamic FEA. It is shown that considerable differences in obtained stresses exist between the two sets of analyses.
Finite-Element Analysis for a Timoshenko Beam Subjected to a Moving Mass
Authors: Lou P , Dai G-L , Zeng Q-Y
Published: June 2006

This article presents a finite-element formulation of a Timoshenko beam subjected to a moving mass. The beam is discretized into a number of simple elements with four degrees of freedom each. The inertial effects of the moving mass are incorporated into a finite-element model. The equation of motion in matrix form with time-dependent coefficients for a Timoshenko beam subjected to a moving mass is derived from the variational approach. The equation is solved by the direct step-by-step integration method to obtain the dynamic response of a Timoshenko beam and the contact force between the moving mass and the beam. The correctness of this present method is validated by means of comparison with the solution obtained by the assumed-mode method. The present method can be effectively used in computation for a Timoshenko beam with various boundary conditions. Numerical simulations are performed to demonstrate the efficiency of the present method.
Residual Thermal Stresses Simulation of Television Panel in the Forming Process. Part 1: Modelling
Authors: Zhou H. M. , Xi G. D. , Li D. Q.
Published: June 2006

Internal residual stresses in glass-pressed components such as television panel are mainly frozen in thermal stresses because of inhomogeneous cooling when surface layers stiffen sooner than the core region as in free quenching. Additional factors in pressing are the effects of melt pressure history and mechanical restraints of the mould. The solidification of a molten layer of glass between cooled parallel plates is used to model the mechanics of the buildup of residual stresses in the pressing process. Flow effects are neglected, and a thermorheologically simple thermoviscoelastic material model is assumed. The equilibrium thermomechanical properties of the material and the shift function can be temperature- and pressure-dependent. The finite-element method employed in the numerical simulation is based on the theory of shells, as an assembly of flat elements. The approach allows the prediction of residual deformations and residual stresses layer by layer like a truly three-dimensional calculation while reducing the computational cost significantly.
Asymptotic Solutions for Contact Problems: The Effect of an Internal Discontinuity in Surface Profile
Authors: Churchman C M , Sackfield A , Hills D A
Published: June 2006

The contact pressure adjacent to the apex of a tilted punch is studied and used to form a refined, two-term asymptote for the contact pressure at a point of discontinuous gradient interior to a half-plane contact problem. The asymptote is compared with the full solution for an example problem, the wheel with a flat.
Profile Cutting on Alumina Ceramics by Abrasive Waterjet. Part 2: Cutting Performance Models
Authors: Wang J , Liu H
Published: June 2006

Predictive models for the major cutting performance measures, such as the kerf taper and depth of cut, are developed for both straight-slit cutting and profile cutting by an abrasive waterjet. The plausibility and predictive capability of the models are assessed and verified by comparing the model predictions with the corresponding experimental data. Very good correlations between the predicted and experimental results have been found, which confirm the adequacy of the models for use in process planning.
Multivariable System Regulation
Authors: Whalley R , Ebrahimi M
Published: June 2006

The regulation of multivariable systems which are subjected to input set point changes and disturbances is considered. A regulation strategy, for analysis purposes, employing both an inner- and an outer-loop feedback structure is proposed. Prescribed, closed-loop, dynamic behaviour using minimum control effort while confining steady-state output coupling is achieved. Output recovery, following disturbance perturbations, via proportional, outer-loop control is advocated. Elementary procedures enabling the computation of conventional pre and feedback compensators are provided, facilitating thereby cost-effective implementation. Stability assessment via established frequency domain techniques is acknowledged. Application studies, enabling comparisons with existing controller design methods, are outlined.