bluuebunny/crossref_metadata_2025 huggingface dataset:
Endogenous opioids modify dyspnoea during treadmill exercise in patients with COPD
Authors: Mahler D. A. , Murray J. A. , Waterman L. A. , Ward J. , Kraemer W. J. , Zhang X. , Baird J. C.
Published: February 2009

Exogenous opioid drugs, such as morphine, relieve breathlessness. The present study hypothesis was that endogenous opioids, released during the stress of exercise, modify dyspnoea in patients with chronic obstructive pulmonary disease.

After familiarisation, patients performed an incremental treadmill exercise test followed by constant work on the treadmill for 10 min. At subsequent visits (2 to 3 days apart), patients received two puffs of albuterol, had a catheter placed in an arm vein for removal of blood to measure β-endorphin immunoreactivity, received normal saline or 10 mg of naloxone intravenously in randomised order, and then performed high-intensity constant work rate exercise on the treadmill.

The mean±sdage of the 17 patients (eight females and nine males) was 63±7 yrs, and post-bronchodilator forced expiratory volume in one second was 50±17% predicted. In both conditions, β-endorphin levels increased three-fold from rest to end-exercise. The regression slope of breathlessness as a function of oxygen consumption (primary outcome), mean ratings of breathlessness throughout exercise and peak ratings of breathlessness were significantly higher with naloxone than normal saline. There were no differences in physiological responses throughout exercise between conditions.

In conclusion, endogenous opioids modify dyspnoea during treadmill exercise in patients with chronic obstructive pulmonary disease by apparent alteration of central perception.
Apnoeic and obstructive nonapnoeic sleep respiratory events
Authors: Masa J. F. , Corral J. , Teran J. , Martin M. J. , Disdier C. , Rubio M. , Mota M. , Zamorano J. , Montserrat J. M.
Published: February 2009

Obstructive nonapnoeic event (ONE) scoring is shrouded in confusion. This is important in patients with mild disease, in whom precision is crucial.

The aims of the present study were: 1) to identify ONEs using oesophageal pressure (OP) (OP-ONEs) and a noninvasive (NI) method (NI-ONEs); 2) to compare both methods of scoring; and 3) to determine the contribution of ONE definitions to clinical findings.

Patients with suspected sleep apnoeas (respiratory disturbance index ≤10) during a first polysomnography were subjected to a second with an OP measurement. OP-ONEs and NI-ONEs were defined as an increase in OP or discernible reduction in the amplitude of thoracoabdominal bands with both desaturation and/or arousal. Bland–Altman analysis established agreement. Comparisons were made between OP-ONEs, NI-ONEs and clinical findings.

In our sample (n = 90), the addition of an arousal to the NI-ONEs or OP-ONEs with only desaturation increased the number of NI-ONEs by 329 and 362%, respectively. NI-ONEs with arousal and/or desaturation detected 91% of OP-ONEs. The association with sleepiness depended on the incorporation of arousal into the definition of ONEs.

In patients with mild disease, the addition of an arousal to ONEs, with only desaturation, markedly increased respiratory disturbance index, with probable therapeutic implications. Scoring respiratory events as apnoea and ONEs is easier and sufficiently accurate.
A natural experiment on the impact of fruit supplementation on asthma symptoms in children
Authors: Fogarty A. W. , Antoniak M. , Venn A. J. , Davies L. , Goodwin A. , Salfield N. , Britton J. R. , Lewis S. A.
Published: February 2009

A high fruit intake may reduce the risk of asthma.

The English National School Fruit Scheme was introduced in the East Midlands region of the UK in June 2003 and in the Eastern region in September 2004. Questionnaires were distributed to children aged 4–6 yrs in schools in May 2003. This was repeated in May 2004 when those in the East Midlands had received free fruit for 1 yr and those in the Eastern region had not.

Responses were obtained in 2004 for 4,971 (53%) and 5,770 (54%) children in the intervention and control regions, respectively. Despite an increase in fruit consumption in the intervention compared with the control region between 2003 and 2004, there was no difference between the two regions in the prevalence or severity of asthma symptoms after 1 yr of fruit supplementation (odds ratio for wheeze in the past 12 months in intervention compared with control region 1.00, 95% confidence interval 0.88–1.14).

Providing free fruit at school for 1 yr does not have any immediate effect on prevalence or severity of asthma in young children, although these data do not refute the hypothesis that a higher increase in fruit intake improves measures of asthma control.
Exhaled nitric oxide in cystic fibrosis: relationships with airway and lung vascular impairments
Authors: Hubert D. , Aubourg F. , Fauroux B. , Trinquart L. , Sermet I. , Lenoir G. , Clément A. , Dinh-Xuan A. T. , Louis B. , Mahut B. , Delclaux C.
Published: February 2009

A reduction of exhaled nitric oxide (NO) fraction and endothelial-mediated dysfunction have been reported in cystic fibrosis (CF). The aims of the present study were to search for relationships between flow-independent NO exchange parameters (bronchial NO flux (J′aw,NO) and alveolar NO concentration (CA,NO)) and lung function tests characterising airflow limitation and pulmonary vascular bed (capillary blood volume and physiological dead space/tidal volume (VD/VT) ratio on exercise).

In total, 34 patients (16 children, 18 adults) with CF, without resting pulmonary hypertension, underwent spirometry, exhaled NO measurement (multiple constant flow analytical method), gas transfer assessment (carbon monoxide and NO, allowing the calculation of capillary volume and membrane conductance) and a graded exercise test with oxygen uptake (V′O2), carbon dioxide production (V′CO2) and arterial blood gas evaluations.

BothJ′aw,NOandCA,NOcorrelated positively with airflow limitation.CA,NOcorrelated positively with capillary/alveolar volume. During exercise, criteria of mild pulmonary vascular disease were evidenced in some patients that participated in exercise limitation (negative correlation between physiologicalVD/VTand peakV′O2).CA,NOat rest correlated positively with these parameters of wasted ventilation during exercise (physiologicalVD/VT, minute ventilation (V′E)/V′CO2at ventilatory threshold andV′E/V′CO2slope).

Flow-independent exhaled NO parameters are linked to airway and early vascular diseases in patients with CF.
Superoxide dismutases, lung function and bronchial responsiveness in a general population
Authors: Siedlinski M. , van Diemen C. C. , Postma D. S. , Vonk J. M. , Boezen H. M.
Published: February 2009

Oxidative stress is an important causative factor in the onset and progression of smoking-related lung diseases, such as chronic obstructive pulmonary disease (COPD). Superoxide dismutases (SODs) can prevent an increase in oxidative burden.

A total of 1,390 subjects from the prospective Vlagtwedde–Vlaardingen cohort were genotyped for two single nucleotide polymorphisms (SNPs) inSOD2and four SNPs inSOD3, which were further analysed for associations with the presence of bronchial hyperresponsiveness (BHR; provocative concentration causing a 10% fall in the forced expiratory volume in one second (FEV1; PC10≤8 mg·mL−1of histamine), COPD (defined as Global Initiative for Chronic Obstructive Lung Disease stage II or higher), lung function level and the longitudinal course of FEV1.

The intronic C5774T SNP ofSOD2was significantly associated with the presence of COPD and BHR in the total population. The T/T genotype for this polymorphism and the Val/Val genotype for theSOD2Ala16Val substitution were risk factors for BHR in individuals without COPD. TheSOD3Arg213Gly substitution was associated with slower FEV1decline in never-smokers exclusively, and theSOD3G(−4466)T SNP was associated with a lower vital capacity level.

BothSOD2polymorphisms are associated with bronchial hyperresponsiveness, a risk factor for chronic obstructive pulmonary disease, whileSOD2C5774T additionally confers a risk for chronic obstructive pulmonary disease in the total population. The current authors furthermore confirm previously reported associations ofSOD3single nucleotide polymorphisms with lung function in the general population.
Somatic, germline and sex hierarchy regulated gene expression during Drosophila metamorphosis
Authors: Lebo Matthew S , Sanders Laura E , Sun Fengzhu , Arbeitman Michelle N
Published: February 2009

Background

Drosophila melanogaster undergoes a complete metamorphosis, during which time the larval male and female forms transition into sexually dimorphic, reproductive adult forms. To understand this complex morphogenetic process at a molecular-genetic level, whole genome microarray analyses were performed.

Results

The temporal gene expression patterns during metamorphosis were determined for all predicted genes, in both somatic and germline tissues of males and females separately. Temporal changes in transcript abundance for genes of known functions were found to correlate with known developmental processes that occur during metamorphosis. We find that large numbers of genes are sex-differentially expressed in both male and female germline tissues, and relatively few are sex-differentially expressed in somatic tissues. The majority of genes with somatic, sex-differential expression were found to be expressed in a stage-specific manner, suggesting that they mediate discrete developmental events. The Sex-lethal paralog, CG3056, displays somatic, male-biased expression at several time points in metamorphosis. Gene expression downstream of the somatic, sex determination genes transformer and doublesex (dsx) was examined in two-day old pupae, which allowed for the identification of genes regulated as a consequence of the sex determination hierarchy. These include the homeotic gene abdominal A, which is more highly expressed in females as compared to males, as a consequence of dsx. For most genes regulated downstream of dsx during pupal development, the mode of regulation is distinct from that observed for the well-studied direct targets of DSX, Yolk protein 1 and 2.

Conclusion

The data and analyses presented here provide a comprehensive assessment of gene expression during metamorphosis in each sex, in both somatic and germline tissues. Many of the genes that underlie critical developmental processes during metamorphosis, including sex-specific processes, have been identified. These results provide a framework for further functional studies on the regulation of sex-specific development.
Effect of supplement with lactic-acid producing bacteria on fatigue and physical activity in patients with chronic fatigue syndrome
Authors: Sullivan Åsa , Nord Carl E , Evengård Birgitta
Published: February 2009

Disturbances in intestinal microbial ecology and in the immune system of the host have been implicated as a part of the pathogenesis in chronic fatigue syndrome. Probiotic lactic acid producing bacteria have been shown to prevent and alleviate gastrointestinal disturbances and to normalize the cytokine profile which might be of an advantage for patients suffering from chronic fatigue syndrome. The aim of the study was to evaluate the effect of Lactobacillus paracasei ssp. paracasei F19, Lactobacillus acidophilus NCFB 1748 and Bifidobacterium lactis Bb12 on fatigue and physical activity in CFS patients. Fifteen patients fulfilling the criteria set by international researchers in the field at the US Centre for Disease Control and Prevention in 1994 for chronic fatigue syndrome, were included in the study. The patients had high fatigue severity scores and high disability scores. During the first two weeks baseline observations without treatment were assessed, succeeded by four weeks of intake of a probiotic product and a four-week follow-up period. The fatigue, health and physical activity was assessed by the use of the Visual Analogue Scales and the SF-12 Health Survey. Faecal samples were collected and the normal microflora was analysed. Neurocognitive functions improved during the study period while there were no significant changes in fatigue and physical activity scores. No major changes occurred in the gastrointestinal microflora. At the end of the study 6 of 15 patients reported that they had improved according to the assessment described. The findings in this study that improvement of health is possible to achieve should encourage further studies with interventions with probiotics in patients with CFS.
Pancreatic insulinoma co-existing with gastric GIST in the absence of neurofibromatosis-1
Authors: Alabraba Edward , Bramhall Simon , O'Sullivan Brendan , Mahon Brinder , Taniere Philippe
Published: February 2009

Background

Gastrointestinal stromal tumours (GIST) frequently occur in patients with neurofibromatosis type 1 (NF-1). It has been reported that GIST may co-exist with pancreatic endocrine tumors but this has only been in association with NF-1.

Case presentation

A 76 year old woman presented with a 12 month history of hypoglycaemia symptoms. Abdominal CT scan demonstrated a 13 mm insulinoma localized in the tail of her pancreas. She was commenced on diazoxide and later underwent surgery for enucleation of insulinoma when a small (< 1 cm) incidental tumour was discovered on her stomach wall which was identified as GIST.

Conclusion

This is the first case report of a pancreatic insulinoma co-existing with a GIST in a patient without NF-1. In addition, we make the first report of rapidly growing cystic GIST recurrence following resection of a primary GIST tumour.
Specialist training in Fiji: Why do graduates migrate, and why do they remain? A qualitative study
Authors: Oman Kimberly M , Moulds Robert , Usher Kim
Published: February 2009

Background

Specialist training was established in the late 1990s at the Fiji School of Medicine. Losses of graduates to overseas migration and to the local private sector prompted us to explore the reasons for these losses from the Fiji public workforce.

Methods

Data were collected on the whereabouts and highest educational attainments of the 66 Fiji doctors who had undertaken specialist training to at least the diploma level between 1997 and 2004. Semistructured interviews focusing on career decisions were carried out with 36 of these doctors, who were purposively sampled to include overseas migrants, temporary overseas trainees, local private practitioners and public sector doctors.

Results

120 doctors undertook specialist training to at least the diploma level between 1997 and 2004; 66 of the graduates were Fiji citizens or permanent residents; 54 originated from other countries in the region. Among Fiji graduates, 42 completed a diploma and 24 had either completed (21) or were enrolled (3) in a master's programme. Thirty-two (48.5%) were working in the public sectors, four (6.0%) were temporarily training overseas, 30.3% had migrated overseas and the remainder were mostly in local private practice. Indo-Fijian ethnicity and non-completion of full specialist training were associated with lower retention in the public sectors, while gender had little impact. Decisions to leave the public sectors were complex, with concerns about political instability and family welfare predominating for overseas migrants, while working conditions not conducive to family life or frustrations with career progression predominated for local private practitioners. Doctors remaining in the public sectors reported many satisfying aspects to their work despite frustrations, though 40% had seriously considered resigning from the public service and 60% were unhappy with their career progression.

Conclusion

Overall, this study provides some support for the view that local or regional postgraduate training may increase retention of doctors. Attention to career pathways and other sources of frustration, in addition to encouragement to complete training, should increase the likelihood of such programmes' reaching their full potentials.
Postnatal Glucocorticoid Excess Due to Pituitary Glucocorticoid Receptor Deficiency: Differential Short- and Long-Term Consequences
Authors: Schmidt Mathias V. , Sterlemann Vera , Wagner Klaus , Niederleitner Bertram , Ganea Karin , Liebl Claudia , Deussing Jan M. , Berger Stefan , Schütz Günther , Holsboer Florian , Müller Marianne B.
Published: February 2009

A tight regulation of hypothalamic-pituitary-adrenal (HPA) axis activity is essential for successful adaptation to stressful stimuli. Disruption of normal HPA axis development is a main risk factor for diseases such as posttraumatic stress disorder or depression, but the molecular mechanisms that lead to these long-term consequences are poorly understood. Here, we test the hypothesis that the pituitary glucocorticoid receptor (GR) is involved in regulating HPA axis function in neonatal and adult animals. Furthermore, we investigate whether postnatal hypercortisolism induced by pituitary GR deficiency is a main factor contributing to the persistent effects of early-life stress. Conditional knockout mice with a deletion of the GR at the pituitary (GRPOMCCre) show excessive basal corticosterone levels during postnatal development, but not in adulthood. The hypercortisolemic state of neonatal GRPOMCCre mice is accompanied by central gene expression changes of CRH and vasopressin in the paraventricular nucleus, but these alterations normalize at later ages. In adult mice, pituitary GR deficiency results in impaired glucocorticoid negative feedback. Furthermore, adult GRPOMCCre mice display a more active coping strategy in the forced swim test, with no alterations in anxiety like behavior or cognitive functions. Postnatal GR antagonist treatment is able to prevent the long-term behavioral effects in GRPOMCCre mice. In conclusion, we show that pituitary GRs are centrally involved in regulating HPA axis activity in neonates and mediate negative feedback regulation in adult animals. Postnatal glucocorticoid excess results in an altered stress-coping behavior in adult animals, with no effects on anxiety like behavior or cognition.
Growth Differentiation Factor 9 Promotes Rat Preantral Follicle Growth by Up-Regulating Follicular Androgen Biosynthesis
Authors: Orisaka Makoto , Jiang Jin-Yi , Orisaka Sanae , Kotsuji Fumikazu , Tsang Benjamin K.
Published: February 2009

The transition from preantral to early antral stage is the penultimate stage of ovarian follicular development in terms of gonadotropin dependence and follicle destiny. Although oocyte-somatic cell communication is important in early follicular development, our knowledge of the precise role of the oocyte-derived growth differentiation factor (GDF)-9 during preantral follicle growth is incomplete. We examined whether and by what means oocyte-derived GDF-9 controls follicular development and steroidogenesis during the preantral to early antral transition, by a combination of in vitro gene manipulation (i.e. intraoocyte injection of GDF-9 antisense oligos) and preantral follicle culture. Intraoocyte injection of GDF-9 antisense suppressed rat preantral follicle growth in vitro, whereas GDF-9 enhanced follicular development. GDF-9 augmented testosterone production in preantral follicles. GDF-9 antisense suppressed androgen production and CYP17A1 mRNA expression in cultured follicles, a response attenuated by exogenous GDF-9. The nonaromatizable androgen 5α-dihydrotestosterone rescued the follicular growth arrest caused by GDF-9 down-regulation. The specific androgen receptor antagonist flutamide suppressed GDF-9-induced preantral follicle growth in vitro. The data suggest that GDF-9 plays an important role in promoting preantral follicle growth by up-regulating follicular androgen biosynthesis. GDF-9 is essential for CYP17A1 expression during follicular development from the preantral to the early antral stage.
Large Neurohypophysial Varicosities Amplify Action Potentials: Results from Numerical Simulations
Authors: Bennett C. Brad , Muschol Martin
Published: February 2009

Axons in the neurohypophysis are known for their “beads on a string” morphology, with numerous in-line secretory swellings lined up along the axon cable. A significant fraction of these secretory swellings, called Herring bodies, is large enough to serve as an identifying feature of the neural lobe in histological sections. Little is known about the physiological role such large axonal swellings might play in neuroendocrine physiology. Using numerical simulations, we have investigated whether large in-line varicosities affect the waveform and propagation of action potentials (APs) along neurohypophysial axons. Due to the strong nonlinear dependence of calcium influx on AP waveforms, such modulation would inevitably affect neuroendocrine release. The parameters for our numerical simulations were matched to established properties of voltage-gated ion channels in neurohypophysial swellings. We find that even a single in-line varicosity can severely depress AP waveforms far upstream in the axonal cable. In contrast, AP depolarization within varicosities becomes amplified. Amplification within varicosities varies in a nontrivial manner with varicosity dimensions, and is most pronounced for diameters close to those of Herring bodies. Overall, we find that large axonal varicosities significantly modulate AP waveforms and their propagation, and do so over large distances. Varicosity size is the main determinant for the observed AP amplification, with the kinetics of voltage-gated ion channels playing a noticeable but secondary role. Our results imply that large varicosities are sites of enhanced hormone release, suggesting that small and large varicosities target different neurohypophysial structures.
“Freedom with a Vengeance”: Choosing Kin in Antislavery Literature and Law
Authors: Wong Edlie
Published: February 2009

Wong's essay charts the legal controversies over slaves brought into New England after Massachusetts Chief Justice Lemuel Shaw's forceful application of the celebrated British civil suit, Somerset v. Stewart (1772), in the landmark case of the slave girl Med, or Commonwealth v. Aves (1836). It explores material that has been largely left out of the antislavery story: the cases brought by abolitionists to free slaves who had traveled with their masters into free territory. Wong's essay reconstructs the records of these cases from popular literature, newsprint, and legal pamphlets to explore what recent literary and historical scholarship has largely overlooked. Harriet and John S. Jacobs, Maria Weston Chapman, Sojourner Truth, and Ellis Gray Loring appear alongside a number of largely unknown slave attendants in an essay that explores the complex ways legal discourses circulating in newsprint constituted the agency and subjectivity of slaves who petitioned Northern courts for freedom (in counterdistinction from the criminal will of the fugitive). Their cases reveal the contradictory logic by which abolitionists disregarded the slaves' express desires to remain with their masters, and in many cases argued for the very sorts of separations from kin that usually figured so largely in abolitionist attacks on slavery. These legal stories compose a loose genre of antislavery literature, charting the struggles of jurists, slaveholders, free blacks, and abolitionists as they negotiated the predicament of a territorially bounded freedom.
Clear-Cutting and Colonialism: The Ethnopolitical Dynamics of Indigenous Environmental Activism in Northwestern Ontario
Authors: Willow Anna J.
Published: February 2009

Since December 2002 members of Grassy Narrows First Nation have maintained a blockade to slow the pace of clear-cut logging in their traditional territory. This article situates contemporary anti-clear-cutting activism at Grassy Narrows in its ethnohistorical and ethnopolitical context. It considers the blockade not as a manifestation of inherent indigenous environmentality but as a complex phenomenon predicated on Anishinaabe people's desires for self-determination, recognition of rights, and the power to decide what takes place on land they perceive as theirs. More broadly, it suggests that acknowledging indigenous environmental activism as a fundamentally political project challenges stereotypical images of ecological nobility and, concurrently, calls into question mainstream conceptions of a just modern society that has long since done away with colonialism.
Walking, running and the evolution of short toes in humans
Authors: Rolian Campbell , Lieberman Daniel E. , Hamill Joseph , Scott John W. , Werbel William
Published: February 2009

The phalangeal portion of the forefoot is extremely short relative to body mass in humans. This derived pedal proportion is thought to have evolved in the context of committed bipedalism, but the benefits of shorter toes for walking and/or running have not been tested previously. Here, we propose a biomechanical model of toe function in bipedal locomotion that suggests that shorter pedal phalanges improve locomotor performance by decreasing digital flexor force production and mechanical work, which might ultimately reduce the metabolic cost of flexor force production during bipedal locomotion. We tested this model using kinematic, force and plantar pressure data collected from a human sample representing normal variation in toe length (N=25). The effect of toe length on peak digital flexor forces, impulses and work outputs was evaluated during barefoot walking and running using partial correlations and multiple regression analysis, controlling for the effects of body mass,whole-foot and phalangeal contact times and toe-out angle. Our results suggest that there is no significant increase in digital flexor output associated with longer toes in walking. In running, however, multiple regression analyses based on the sample suggest that increasing average relative toe length by as little as 20% doubles peak digital flexor impulses and mechanical work,probably also increasing the metabolic cost of generating these forces. The increased mechanical cost associated with long toes in running suggests that modern human forefoot proportions might have been selected for in the context of the evolution of endurance running.
Phototropic growth in a reef flat acroporid branching coral species
Authors: Kaniewska Paulina , Campbell Paul R. , Fine Maoz , Hoegh-Guldberg Ove
Published: February 2009

Many terrestrial plants form complex morphological structures and will alter these growth patterns in response to light direction. Similarly reef building corals have high morphological variation across coral families, with many species also displaying phenotypic plasticity across environmental gradients. In particular, the colony geometry in branching corals is altered by the frequency, location and direction of branch initiation and growth. This study demonstrates that for the branching species Acropora pulchra,light plays a key role in axial polyp differentiation and therefore axial corallite development – the basis for new branch formation. A. pulchra branches exhibited a directional growth response, with axial corallites only developing when light was available, and towards the incident light. Field experimentation revealed that there was a light intensity threshold of 45 μmol m–2 s–1, below which axial corallites would not develop and this response was blue light(408–508 nm) dependent. There was a twofold increase in axial corallite growth above this light intensity threshold and a fourfold increase in axial corallite growth under the blue light treatment. These features of coral branch growth are highly reminiscent of the initiation of phototropic branch growth in terrestrial plants, which is directed by the blue light component of sunlight.
The relationships between muscle, external, internal and joint mechanical work during normal walking
Authors: Sasaki Kotaro , Neptune Richard R. , Kautz Steven A.
Published: February 2009

Muscle mechanical work is an important biomechanical quantity in human movement analyses and has been estimated using different quantities including external, internal and joint work. The goal of this study was to investigate the relationships between these traditionally used estimates of mechanical work in human walking and to assess whether they can be used as accurate estimates of musculotendon and/or muscle fiber work. A muscle-actuated forward dynamics walking simulation was generated to quantify each of the mechanical work measures. Total joint work (i.e. the time integral of absolute joint power over a full gait cycle) was found to underestimate total musculotendon work due to agonist–antagonist co-contractions, despite the effect of biarticular muscle work and passive joint work, which acted to decrease the underestimation. We did find that when the net passive joint work over the gait cycle is negligible, net joint work (i.e. the time integral of net joint power) was comparable to the net musculotendon work (and net muscle fiber work because net tendon work is zero over a complete gait cycle). Thus, during walking conditions when passive joint work is negligible, net joint work may be used as an estimate of net muscle work. Neither total external nor total internal work (nor their sum) provided a reasonable estimate of total musculotendon work. We conclude that joint work is limited in its ability to estimate musculotendon work, and that external and internal work should not be used as an estimation of musculotendon work.
Continuous light affects mineralization and delays osteoid incorporation in vertebral bone of Atlantic salmon (Salmo salar L.)
Authors: Wargelius Anna , Fjelldal Per Gunnar , Nordgarden Ulla , Hansen Tom
Published: February 2009

In order to study the effects of photoperiod on fish bone, Atlantic salmon(Salmo salar L.) were exposed to two light regimes (natural and continuous light) from January until June. During the experimental period,several parameters related to the inorganic (minerals) and organic (osteoid)phases were measured. Changes in the organic phase were related to mechanical strength (yield-load) and the expression of the genes sonic hedgehog(shh) and collagen type I alpha 2 (col I). Co-variation between yield-load and the expression of both shh and col I were detected in both groups. It was also shown that fish on the continuous light regime had delayed activation of osteoid incorporation. Mineralization properties were measured with stiffness, mineral incorporation per day and expression of alkaline phosphatase (alp) and matrix Gla protein (mgp). Stiffness, mineral incorporation and gene expression followed the same trend in both light groups in late spring, whereas an increase in the expression of mgp and alpwas detected in April, followed by significantly higher stiffness at last sampling in both light groups. These results indicate that constant light affects mineralization and delays osteoid incorporation in Atlantic salmon during the spring. However, in this experiment light treatment did not promote the development of vertebral deformities. Our results also suggest that shh can be used as a marker of osteoblast proliferation and col I a marker of osteoid incorporation, and that both alp and mgp expression could be associated with a rapid increase in mineralization in Atlantic salmon vertebrae.
Using omeprazole to link the components of the post-prandial alkaline tide in the spiny dogfish,Squalus acanthias
Authors: Wood Chris M. , Schultz Aaron G. , Munger R. Stephen , Walsh Patrick J.
Published: February 2009

After a meal, dogfish exhibit a metabolic alkalosis in the bloodstream and a marked excretion of basic equivalents across the gills to the external seawater. We used the H+, K+-ATPase pump inhibitor omeprazole to determine whether these post-prandial alkaline tide events were linked to secretion of H+ (accompanied by Cl–) in the stomach. Sharks were fitted with indwelling stomach tubes for pretreatment with omeprazole (five doses of 5 mg omeprazole per kilogram over 48 h) or comparable volumes of vehicle (saline containing 2% DMSO) and for sampling of gastric chyme. Fish were then fed an involuntary meal by means of the stomach tube consisting of minced flatfish muscle (2% of body mass) suspended in saline (4% of body mass total volume). Omeprazole pre-treatment delayed the post-prandial acidification of the gastric chyme, slowed the rise in Cl– concentration of the chyme and altered the patterns of other ions, indicating inhibition of H+ and accompanying Cl– secretion. Omeprazole also greatly attenuated the rise in arterial pH and bicarbonate concentrations and reduced the net excretion of basic equivalents to the water by 56% over 48 h. Arterial blood CO2pressure (PaCO2) and plasma ions were not substantially altered. These results indicate that elevated gastric H+ secretion (as HCl) in the digestive process is the major cause of the systemic metabolic alkalosis and the accompanying rise in base excretion across the gills that constitute the alkaline tide in the dogfish.
High-temperature mechanical and electrical properties of W-particle-reinforced Cu-matrix composites from improved electroless plated powders
Authors: Liao T-T , Kung C
Published: February 2009

Copper (Cu)-matrix composites combine the high electrical and thermal conductivities of Cu with the enhanced wear resistance and strength of the reinforcement material, and are therefore widely used for electrical contact applications in a diverse range of fields. In the current study, tungsten-reinforced copper (W—Cu) composite powders are fabricated using a novel electroless Cu plating process in which the homogeneity of the powder mixture is improved via the use of an ultrasonic agitation technique. The volume content of the tungsten particle reinforcement in the composite specimens is 3, 6, and 12 per cent, respectively, and standard powder metallurgical techniques are then applied to produce the final composite powders. The mechanical and electrical properties of the composite powders are evaluated at room temperature and at temperatures ranging from 100 to 300 °C. Fracture surfaces of the composite samples are ana-lysed using scanning electron microscopy. The results show that the mechanical properties of the W—Cu composite samples are significantly better than those of pure Cu specimens, particularly at higher temperatures. Furthermore, the addition of 3 vol% W particles to the W—Cu composite is found to yield a reduction of not more than 2 per cent in the electrical conductivity of the composite sample compared to that of a pure Cu specimen. Overall, the results indicate that the optimal mechanical and electrical properties are obtained by mixing pure Cu powder with 3 vol% of Cu-plated W particles with a mean dimension of 1 μm.
Synchronous machine model identification using continuous wavelet NARX network
Authors: Ravan M , Amineh R K , Karrari M , Rosehart W B , Malik O P
Published: February 2009

A new wavelet network structure combining polynomial models with continuous wavelet decomposition is introduced for the identification of a synchronous generator model. The proposed structure uses features of polynomial models and wavelet networks to model non-linearities in the system. In this study, a serial-parallel identification model is applied to system modelling. In this structure, real system outputs are exercised for prediction of the future system outputs, so that stability and approximation of the network are guaranteed. This method is applied to identify the model of a synchronous machine from experimental data collected on a physical machine. The results show that the identified model has very good accuracy and may be valid for a broad range of operating conditions.
Loss Functions in Option Valuation: A Framework for Selection
Authors: Bams Dennis , Lehnert Thorsten , Wolff Christian C. P.
Published: February 2009

In this paper, we investigate the importance of different loss functions when estimating and evaluating option pricing models. Our analysis shows that it is important to take into account parameter uncertainty, because this leads to uncertainty in the predicted option price. We illustrate the effect on the out-of-sample pricing errors in an application of the ad hoc Black-Scholes model to DAX index options. We confirm the empirical results of Christoffersen and Jacobs (Christoffersen, P., K. Jacobs. 2004. The importance of the loss function in option valuation. J. Financial Econom. 72 291–318) and find strong evidence for their conjecture that the squared pricing error criterion may serve as a general-purpose loss function in option valuation applications. At the same time, we provide a first yardstick to evaluate the adequacy of the loss function. This is accomplished through a data-driven method to deliver not just a point estimate of the root mean squared pricing error, but a distribution.
Additive Utility in Prospect Theory
Authors: Bleichrodt Han , Schmidt Ulrich , Zank Horst
Published: February 2009

Prospect theory is currently the main descriptive theory of decision under uncertainty. It generalizes expected utility by introducing nonlinear decision weighting and loss aversion. A difficulty in the study of multiattribute utility under prospect theory is to determine when an attribute yields a gain or a loss. One possibility, adopted in the theoretical literature on multiattribute utility under prospect theory, is to assume that a decision maker determines whether the complete outcome is a gain or a loss. In this holistic evaluation, decision weighting and loss aversion are general and attribute-independent. Another possibility, more common in the empirical literature, is to assume that a decision maker has a reference point for each attribute. We give preference foundations for this attribute-specific evaluation where decision weighting and loss aversion are depending on the attributes.
Wave energy and the upper depth limit distribution of Posidonia oceanica
Authors: Infantes Eduardo , Terrados Jorge , Orfila Alejandro , Cañellas Bartomeu , Álvarez-Ellacuria Amaya
Published: February 2009

It is widely accepted that light availability sets the lower limit of seagrass bathymetric distribution, while the upper limit depends on the level of disturbance by currents and waves. The establishment of light requirements for seagrass growth has been a major focus of research in marine ecology, and different quantitative models provide predictions for seagrass lower depth limits. In contrast, the influence of energy levels on the establishment, growth, and maintenance of seagrasses has received less attention, and to date there are no quantitative models predicting the evolution of seagrasses as a function of hydrodynamics at a large scale level. Hence, it is not possible to predict either the upper depth limit of the distribution of seagrasses or the effects that different energy regimes will have on these limits. The aim of this work is to provide a comprehensible methodology for obtaining quantitative knowledge and predictive capacity for estimating the upper depth limit of seagrasses as a response to wave energy dissipated on the seafloor. The methodology has been applied using wave data from 1958 to 2001 in order to obtain the mean wave climate in deep water seaward from an open sandy beach in the Balearic Islands, western Mediterranean Sea where the seagrass Posidonia oceanica forms an extensive meadow. Mean wave conditions were propagated to the shore using a two-dimensional parabolic model over the detailed bathymetry. The resulting hydrodynamics were correlated with bottom type and the distribution of P. oceanica. Results showed a predicted near-bottom orbital velocity of between 38 and 42 cm s-1 as a determinant of the upper depth limit of P. oceanica. This work shows the importance of interdisciplinary effort in ecological modeling and, in particular, the need for hydrodynamical studies to elucidate the distribution of seagrasses in shallow depths. Moreover, the use of predictive models would permit evaluation of the effects of coastal activities (construction of ports, artificial reefs, beach nutrient-input, dredging) on benthic ecosystems.
Investigating the humor of gelotophobes: Does feeling ridiculous equal being humorless?
Authors: Ruch Willibald , Beermann Ursula , Proyer René T.
Published: February 2009

Titze (Humor and Health Journal 5:1–11, 1996) concluded from individual case studies that gelotophobes do not experience humor and laughter as a shared enjoyment but rather as a threat. Two studies examined whether gelotophobes are less humorous in general or whether this is true only for certain components of humor. In study I, three samples (N = 120 and 70 students; N = 169 adults) filled in the GELOPH〈46〉 along with several humor instruments (i.e., 3 WD, CHS, HBQD, HSQ, HUWO, STCI-T〈60〉). Results showed that gelotophobes are less cheerful and characterize their humor style as inept, socially cold, and mean-spirited. They report less frequent use of humor as a means for coping and indulge less often in self-enhancing and social humor. Appreciation of incongruity-resolution humor and nonsense humor (but not sexual humor) was lower than for non-gelotophobes. Study II (N = 131 adults) focused on the relation between gelotophobia, gelotophilia, and katagelasticism and the ability to create humor (i.e., the CPPT). The ability to create humor is unrelated to gelotophobia, and tends to be positively correlated with gelotophilia and katagelasticism. Future studies should investigate why gelotophobes see their humor style as inept despite not lacking wit, and how their beliefs can be made more consistent with their abilities.
The fear of being laughed at among psychiatric patients
Authors: Forabosco Giovannantonio , Ruch Willibald , Nucera Pietro
Published: February 2009

The fear of being laughed at brings to the fore the problematic side of an otherwise very positive aspect of human experience. In the streamline of investigations analyzing the presence and characteristics of gelotophobia, a study focusing on psychiatric patients was carried out. The diagnoses were established according to the criteria of the DSM IV TR (American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders (DSM), APA, 2000). Based both on clinical and empirical observations, the main hypothesis advanced was that using the Geloph〈15〉 scale, Ss with a psychiatric diagnosis would have higher mean scores than Normal Controls. An additional hypothesis was that intragroup differences were also expected among the various diagnostic categories. The main hypothesis was amply supported, and explanatory suggestions of the finding were proposed. Intragroup differences proved also to be significant. Patients with personality disorders and patients with schizophrenic disorders scored higher than Normal Controls and the other diagnostic groups. And also the number of years spent in psychiatric care resulted significantly associated with higher gelotophobia mean scores. From the present study, a circular, interactive relationship was confirmed between laughter and mental health, which can alternatively be highly positive or deeply negative.
Toward a Legal-Ethical Framework for Regulating Human Genetic Information in Vulnerable Populations: An Issue of Justice
Authors: de Ortúzar Maria Graciela
Published: February 2009

The main purpose of this work is to discuss the legal, psycho-social and ethical issues posed when handling genetic information in genomic research within developing countries. Following the method of “reflective equilibrium”(Rawls-Daniels) and from an interdisciplinary approach, I shall go through: (1) current normative laws concerning its regulation, advantages and limitations; (2) the psychosocial impact of genetics on health issues; and (3) the ethical grounds that should be taken into account in establishing the normative framework for the regulation of genetic information. In general terms, my opinion is that the ethical grounds of the normative framework regarding research with human beings cannot be formal or based exclusively on the law (e. g. “bureaucratisation of informed consent”). My suggestions is that a critical notion of real autonomy and material wellbeing of the moral person (following Doyal- Sen-Van Parijs) should be applied to justify the distributive principles implied in any research on human beings, in particular in genomic research (benefit sharing.)
A Review of the No Erosion Filter Test
Authors: Soroush Abbas , Shourijeh Piltan Tabatabaie
Published: February 2009

The no erosion filter (NEF) test is widely accepted as the most appropriate filtration test for the substantiation of suitable critical filters in embankment dams. No consistent standard method for NEF testing has been introduced; thus, various schemes have been implemented for performing NEF tests. This paper reviews critically the antecedent research on the NEF testing procedure. The cornerstone hypothesis of NEF testing and the evolution of the testing method are reviewed. The significance of different parameters encountered in the testing procedure and their relevance and importance in the judgment are elaborated. Practical guides for proper conduction of the NEF test are recommended throughout this paper.
Perceived Everyday Racism, Residential Segregation, and HIV Testing Among Patients at a Sexually Transmitted Disease Clinic
Authors: Ford Chandra L. , Daniel Mark , Earp Jo Anne L. , Kaufman Jay S. , Golin Carol E. , Miller William C.
Published: February 2009

Objectives. More than one quarter of HIV-infected people are undiagnosed and therefore unaware of their HIV-positive status. Blacks are disproportionately infected. Although perceived racism influences their attitudes toward HIV prevention, how racism influences their behaviors is unknown. We sought to determine whether perceiving everyday racism and racial segregation influence Black HIV testing behavior.

Methods. This was a clinic-based, multilevel study in a North Carolina city. Eligibility was limited to Blacks (N = 373) seeking sexually transmitted disease diagnosis or screening. We collected survey data, block group characteristics, and lab-confirmed HIV testing behavior. We estimated associations using logistic regression with generalized estimating equations.

Results. More than 90% of the sample perceived racism, which was associated with higher odds of HIV testing (odds ratio = 1.64; 95% confidence interval = 1.07, 2.52), after control for residential segregation, and other covariates. Neither patient satisfaction nor mechanisms for coping with stress explained the association.

Conclusions. Perceiving everyday racism is not inherently detrimental. Perceived racism may improve odds of early detection of HIV infection in this high-risk population. How segregation influences HIV testing behavior warrants further research.
Association Between HIV-1 RNA Level and CD4 Cell Count Among Untreated HIV-Infected Individuals
Authors: Lima Viviane D. , Fink Valeria , Yip Benita , Hogg Robert S. , Harrigan P. Richard , Montaner Julio S. G.
Published: February 2009

Objectives. We examined the significance of plasma HIV-1 RNA levels (or viral load alone) in predicting CD4 cell decline in untreated HIV-infected individuals.

Methods. Data were obtained from the British Columbia Centre for Excellence in HIV/AIDS. Participants included all residents who ever had a viral load determination in the province and who had never taken antiretroviral drugs (N = 890). We analyzed a total of 2074 viral load measurements and 2332 CD4 cell counts. Linear mixed-effects models were used to predict CD4 cell decline over time.

Results. Longitudinal viral load was strongly associated with CD4 cell decline over time; an average of 1 log10 increase in viral load was associated with a 55-cell/mm3 decrease in CD4 cell count.

Conclusions. Our results support the combined use of CD4 cell count and viral load as prognostic markers in HIV-infected individuals before the introduction of antiretroviral therapy.
Evaluation of methods for isolation of DNA for PCR based identification of pathogenic bacteria from pure cultures and water samples
Authors: Horáková K. , Mlejnková H. , Mlejnek P.
Published: February 2009

Water Science and Technology 58(5), 995–999

Publisher's note. We regret that the version of this article used in production did not incorporate a number of corrections and clarifications. The corrected versions of the text are as given below.