bluuebunny/crossref_metadata_2025 huggingface dataset:
The burden of mental disorders in primary care
Authors: Grandes G. , Montoya I. , Arietaleanizbeaskoa M.S. , Arce V. , Sanchez A. ,   on behalf of the MAS group
Published: February 2011

Objectives

To describe and compare the prevalence of mental disorders across primary care populations, and estimate their impact on quality of life.

Methods

Cross-sectional multilevel analysis of a systematic sample of 2539 attendees to eight primary care centres in different regions of Spain, assessed with the WHO Composite International Diagnostic Interview (CIDI 1.1), the Short Form Health Survey (SF-36) quality of life questionnaire and the SF-6D utility index.

Results

The 12-month prevalence of any mental disorder was 23% (95% confidence interval: 21–24%), 10% had mood, 9% anxiety, 5% organic, 4% somatoform, and 1% alcohol use disorders, with a significant between-centre variability (P < 0.001). People with mental disorders had one standard deviation lower mental quality of life than the general population. We estimated that 1831 quality-adjusted life-years (QALYs) are lost annually per 100,000 patients due to mental disorders, without considering mortality. Mood disorders have the worst impact with an annual loss of 1124 QALYs per 100,000 patients, excluding mortality (95% confidence interval: 912–1351).

Conclusions

Prevalence rates were similar to those obtained in international studies using the same diagnostic instrument and, given the significant between-centre variability found, it is recommended that mental health statistics be considered at small area level. Mental disorders, and especially mood disorders, are associated with very poor quality of life and higher scores on disability indexes than other common chronic conditions.
Influence of epidural dexamethasone on maternal temperature and serum cytokine concentration after labor epidural analgesia
Authors: Wang Li‐Zhong , Hu Xiao‐Xia , Liu Xia , Qian Ping , Ge Jia‐Mei , Tang Bei‐Lei
Published: February 2011

Objective

To evaluate the effects of epidural dexamethasone on maternal temperature and serum cytokine levels after labor epidural analgesia.

Methods

Sixty healthy term nulliparas in spontaneous labor were randomized to receive epidural analgesia alone using bupivacaine 0.125% and fentanyl 1 μg/mL (group I) or epidural analgesia combined with dexamethasone 0.2 mg/mL (group II) (n = 30 per group). Maternal tympanic temperature was measured before epidural analgesia and hourly thereafter until delivery. Maternal and cord venous blood were sampled for analysis of interleukin‐6 (IL‐6), tumor necrosis factor‐α, and interleukin‐10 levels.

Results

There was no difference in the incidence of intrapartum fever (38 °C or more) between the 2 groups (3/30 versus 1/30, P = 0.612). The mean maternal temperature increased with time in group I, with the elevation reaching statistical significance at 4 hours post analgesia and at delivery compared with baseline (P = 0.012 and P = 0.043, respectively). A similar trend was observed with maternal serum IL‐6 levels in group I. In group II, maternal temperature and IL‐6 levels did not differ from baseline at any time point during labor.

Conclusion

Epidural dexamethasone alleviates maternal temperature elevation after epidural analgesia. This effect can be attributed to the decrease in IL‐6 levels.
Obstetric and neonatal outcomes for women with reversed and non‐reversed type III female genital mutilation
Authors: Raouf Sanaria A. , Ball Teresa , Hughes Alison , Holder Roger , Papaioannou Spyros
Published: February 2011

Objective

To record and compare obstetric and neonatal complication rates in women with reversed and non‐reversed type III female genital mutilation (FGM).

Methods

A retrospective observational study comparing cesarean delivery rates and neonatal outcomes of primiparous and multiparous women who had or had not undergone reversal of FGM III.

Results

Of the 250 women, 230 (92%) had an FGM reversal. Of these, 50 (21.7%) were primiparous (cesarean delivery rate 17/50; 34%) and 180 (78.3%) were multiparous (cesarean delivery rate 28/180; 15.6%). Of the 20 women who had not had an FGM reversal, 7 (35%) were primiparous (cesarean delivery rate 5/7; 71.4%) and 13 (65%) were multiparous (cesarean delivery rate 7/13; 53.8%). The cesarean delivery rates for primiparae and multiparae were 32.9% and 25%, respectively. Multiparous women with FGM III reversal had a lower possibility of cesarean delivery compared with the hospital multiparous population (P = 0.003) and multiparae who had not undergone FGM III reversal (P = 0.007). There was no significant association between Apgar scores or blood loss at vaginal delivery and FGM reversal.

Conclusion

Reversal of FGM III significantly reduced the increased risk of cesarean delivery seen with multiparae who have FGM III.
Epithelioid angiomyolipoma with involvement of inferior vena cava as a tumor thrombus: A case report
Authors: Luo Deyi , Gou Jiang , Yang Le , Xu Yong , Dong Qiang
Published: February 2011

A 27‐year‐old female with chronic right‐side flank pain was diagnosed with renal epithelioid angiomyolipoma (EAML) extending as a thrombus into the renal vein and vena cava. Intravascular extension of EAML is quite rare; however, it may result in fatal complications if not appropriately treated. She successfully underwent a radical nephrectomy and inferior vena caval thrombectomy. Intravascular extension of EAML, although rare, has been reported. We present a new case and a description of the surgical management. Furthermore, we reviewed and analyzed nine case reports of invasive renal EAMLs.
Hydrogen peroxide decreases the survival rate of HeLa cells with stable knockdown of survival motor neuron protein
Authors: Liu Ting‐Yuan , Yuo Chung‐Yee , Kao Cheng‐Hsing , Tseng Chao‐Neng , Jong Yuh‐Jyh , Chang Jan‐Gowth , Wu Shou‐Mei , Chang Yung‐Fu
Published: February 2011

The mutations of survival motor neuron (SMN) gene result in spinal muscular atrophy (SMA), a common neurodegenerative disease. Some of the motor neurons undergoing cell death is the predominant characteristic in SMA pathology. However, the viability and sensitivity to stresses of other cell types also need to be determined. In this article, we established HeLa stable cell line with inducible SMN knockdown to study its viability and sensitivity to oxidative stress. SMN knockdown in the HeLa stable cell line was induced by doxycycline. The proliferative and survival rates of SMN knockdown cells with or without hydrogen peroxide (H2O2) treatment were determined. Our results showed that the proliferative rate of SMN knockdown cells decreased only slightly compared with that of the cells without doxycycline treatment. In contrast, after H2O2 reached certain concentrations, the survival rate of SMN knockdown cells decreased significantly. Our data indicate that SMN knockdown alone is not critical to cell viability. However, when SMN knockdown cells are under stress, such as oxidative stress, their survival rate may significantly decrease. Our results will be helpful to prevent the detrimental effect caused by the cell death of non‐motor neurons under stress in SMA patients. In addition, the cell model we established can be used to study the mechanism and screen drugs to prevent the detrimental effects in cases of SMA disease.
CONVOLUTION OF ORBITAL MEASURES IN SYMMETRIC SPACES
Authors: ANCHOUCHE BOUDJEMÂA , GUPTA SANJIV KUMAR
Published: February 2011

Let G/K be a noncompact symmetric space, Gc/K its compact dual, 𝔤=𝔨⊕𝔭 the Cartan decomposition of the Lie algebra 𝔤 of G, 𝔞 a maximal abelian subspace of 𝔭, H be an element of 𝔞, a=exp (H) , and ac =exp (iH) . In this paper, we prove that if for some positive integer r, νrac is absolutely continuous with respect to the Haar measure on Gc, then νra is absolutely continuous with respect to the left Haar measure on G, where νac (respectively νa) is the K-bi-invariant orbital measure supported on the double coset KacK (respectively KaK). We also generalize a result of Gupta and Hare [‘Singular dichotomy for orbital measures on complex groups’, Boll. Unione Mat. Ital. (9) III (2010), 409–419] to general noncompact symmetric spaces and transfer many of their results from compact symmetric spaces to their dual noncompact symmetric spaces.
Changes in soil carbon and nitrogen under long-term cotton plantations in China
Authors: KAIYONG W. , HUA F. , RANAB T. , HANJRAC M. A. , BO D. , HUAN L. , FENGHUA Z.
Published: February 2011

Cotton is the dominant crop in the northern Xinjiang oasis of China; it accounts for 0·78 of the total planting area and represents a major contribution to economic development. The objective of the present study is to determine how cotton plantation age affected chemical and microbiological properties of the soil. The time substitution method was used on plantation farmlands, reclaimed from uncultivated land 0, 5, 10, 15 and 20 years ago. A total of 250 soil samples, at depths of 0–200, 200–400, 400–600, 600–800 and 800–1000 mm, were collected from cotton fields in 10 farms of each age category. There were significant differences in soil organic carbon (SOC), total soil nitrogen (TSN), soil available nitrogen (SAN), soil microbial biomass carbon (SMBC) and soil microbial biomass nitrogen (SMBN). There were also differences in the activities of cellulase, invertase and urease between soil layers and plantation ages, and these were most evident in the 200–400 mm layer. The cumulative rates of SOC and SMBC in the 0–1000 mm soil layer at the 5-, 10-, 15- and 20-year sites were 0·89, 0·99, 1·01 and 0·92 mg/kg/yr and 16, 16, 16 and 15 mg/kg/yr, respectively, compared to that at the control site (0 year). The cumulative amounts of SOC and SMBC increased gradually and then decreased, reaching a maximum at plantation ages of 13·1 years and 11·1 years, respectively. This suggests that incorporation of post-harvest cotton residues could be used as an effective measure to improve SOC in farmland of Xinjiang Oasis, and may be recommended for adoption in cotton growing in semi-arid oasis agriculture.
Variation in the sex ratio of Rhabdochona fortunatowi (Spirurida: Rhabdochonidae) in Capoeta capoeta gracilis (Cypriniformes: Cyprinidae), relative to levels of infection, host size and temperature
Authors: Golestaninasab M. , Malek M. , Jalali B. , Mobedi I.
Published: February 2011

In the present study, 81 specimens of Capoeta capoeta gracilis (Keyserling, 1861) were collected from the Shiroud River, the Caspian drainage basin, Iran in June and October 2007. The fish were examined for infection with the nematode Rhabdochona fortunatowi (Dinnik, 1933). Nematodes were counted and sexed, then the sex ratio and intestinal site preference of the R. fortunatowi individuals and the intersexual interactions of the parasites were investigated. Significant differences were observed in the prevalence and intensity of infection in relation to host size and sampling season, but not host sex. Parasite burden (mean intensity) was higher in October than in June and the results revealed a decrease in female-to-male sex ratio (FMR) in the fish in October compared to the ones in June. In other words, as the mean intensity of infection of R. fortunatowi increases, the proportion of male worms increases, too. The female-biased sex ratio in June was replaced by a male-biased one in October. Nematode distribution rose to a significant peak in the mid-region of the fish intestine relative to the anterior and posterior parts. Some changes in the distribution of male and female worms in different parts of the host intestine were also observed during June and October. Density-dependent selection and intersexual competition seem to be the main factors driving such a shift in the sex ratio and its variation in different parts of the host intestine.
Interaction between a history of depression and rumination on neural response to emotional faces
Authors: Thomas E. J. , Elliott R. , McKie S. , Arnone D. , Downey D. , Juhasz G. , Deakin J. F. W. , Anderson I. M.
Published: February 2011

Background

Both past depressive episodes and the personality trait of depressive rumination are strong risk factors for future depression. Depression is associated with abnormal emotional processing, which may be a neurobiological marker for vulnerability to depression. A consistent picture has yet to emerge as to how a history of depression and the tendency to ruminate influence emotional processing. The aim of this study was to investigate the relationship between rumination, past depression and neural responses when processing face emotions.

Method

The Ruminative Responses Scale (RRS) was completed by 30 remitted depressives and 37 controls who underwent functional magnetic resonance imaging (fMRI) scanning while viewing happy, sad, fearful and neutral faces.

Results

The remitted depressives showed overall reductions in neural responses to negative emotions relative to the controls. However, in the remitted depressives, but not the controls, RRS scores were correlated with increased neural responses to negative emotions and decreased responses to happiness in limbic regions.

Conclusions

Automatic emotion processing biases and rumination seem to be correlated to aspects of vulnerability to depression. However, remission from depression may be maintained by a general suppression of limbic responsiveness to negative emotion.
Facial emotional expression in reaction to social exclusion in borderline personality disorder
Authors: Staebler K. , Renneberg B. , Stopsack M. , Fiedler P. , Weiler M. , Roepke S.
Published: February 2011

Background

Disturbances in social interaction are a defining feature of patients with borderline personality disorder (BPD). In this study, facial emotional expressions, which are crucial for adaptive interactions in social contexts, were assessed in patients with BPD in response to social exclusion.

Method

We examined facial emotional reactions of 35 patients with BPD and 33 healthy controls when playing Cyberball, a virtual ball-tossing game that reliably induces social exclusion. Besides self-reported emotional responses, facial emotional expressions were analyzed by applying the Emotional Facial Action Coding System (EMFACS).

Results

Patients with BPD showed a biased perception of participation. They more readily reported feeling excluded compared to controls even when they were included. In BPD, social exclusion led to an increase in self-reported other-focused negative emotions. Overall, EMFACS analyses revealed that BPD patients reacted with fewer positive expressions and with significantly more mixed emotional expressions (two emotional facial expressions at the same time) compared to the healthy control group when excluded.

Conclusions

Besides a negative bias for perceived social participation, ambiguous facial emotional expressions may play an important role in the disturbed relatedness in patients with BPD.
Major depression during and after the menopausal transition: Study of Women's Health Across the Nation (SWAN)
Authors: Bromberger J. T. , Kravitz H. M. , Chang Y.-F. , Cyranowski J. M. , Brown C. , Matthews K. A.
Published: February 2011

Background

It is unclear whether risk for major depression during the menopausal transition or immediately thereafter is increased relative to pre-menopause. We aimed to examine whether the odds of experiencing major depression were greater when women were peri- or post-menopausal compared to when they were pre-menopausal, independent of a history of major depression at study entry and annual measures of vasomotor symptoms (VMS), serum levels of, or changes in, estradiol (E2), follicular stimulating hormone (FSH) or testosterone (T) and relevant confounders.

Method

Participants included the 221 African American and Caucasian women, aged 42–52 years, who were pre-menopausal at entry into the Pittsburgh site of a community-based study of menopause, the Study of Women's Health Across the Nation (SWAN). We conducted the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID) to assess diagnoses of lifetime, annual and current major depression at baseline and at annual follow-ups. Psychosocial and health factors, and blood samples for assay of reproductive hormones, were obtained annually.

Results

Women were two to four times more likely to experience a major depressive episode (MDE) when they were peri-menopausal or early post-menopausal. Repeated-measures logistic regression analyses showed that the effect of menopausal status was independent of history of major depression and annually measured upsetting life events, psychotropic medication use, VMS and serum levels of or changes in reproductive hormones. History of major depression was a strong predictor of major depression throughout the study.

Conclusions

The risk of major depression is greater for women during and immediately after the menopausal transition than when they are pre-menopausal.
Is the no-minimum claim true? Reply to Cullison
Authors: JORDAN JEFF
Published: February 2011

Is the no-minimum claim true? I have argued that it is not. Andrew Cullison contends that my argument fails, since human sentience is variable; while Michael Schrynemakers has contended that the failure is my neglect of vagueness. Both, I argue, are wrong.
Sceptical theism and divine truths
Authors: SEGAL AARON
Published: February 2011

Sceptical theism has been employed by its adherents in an argument aimed at undermining the so called ‘noseeum inference’. Erik Wielenberg (2010) has recently argued that there is an equally plausible argument for the conclusion that sceptical theism implies that we do not know any proposition that has word-of-God justification only. Thus, sceptical theists need to give up their argument against the noseeum inference or accept the conclusion that we do not know any proposition that has word-of-God justification only. I claim that sceptical theists need not face such a difficult choice because the argument that Wielenberg offers is not as plausible as their argument against the noseeum inference.
Social Trinitarianism and polytheism
Authors: CAREY BRANDON
Published: February 2011

Social Trinitarians attempt to solve the logical problem of the Trinity by claiming that there are three numerically distinct divine persons. A common objection to this view is that it is seemingly committed to the existence of multiple Gods and is therefore polytheistic. I consider Edward Wierenga's response to this objection, as well as two other possible responses, and show that each faces serious philosophical problems. I conclude that, in the absence of a better method of distinguishing the property of being divine from that of being a God, Social Trinitarians are committed to the existence of more than one God.
Deception and the Trinity: a rejoinder to Tuggy
Authors: HASKER WILLIAM
Published: February 2011

Dale Tuggy argues that his divine-deception argument against Social Trinitarianism remains unscathed, in spite of my recent objections. I maintain that his argument is question-begging and exegetically weak, and does not succeed in refuting Social Trinitarianism.
A case-marking cue for filler–gap dependencies in children's relative clauses in Japanese
Authors: SUZUKI TAKAAKI
Published: February 2011

Object relative clauses have traditionally been thought to be more difficult than subject relative clauses in child English. However, recent studies as well as Japanese data show contradictory results. This study disclosed preschool children's superior performance on object relative clauses in Japanese; however, this dominance disappeared for the children who could use both the nominative and accusative case markers as cues for the comprehension of single-argument sentences. Assuming a filler–gap dependency for the relative clause formation, we suggest that there is no difference in the difficulty between subject and object relative clauses in the grammar of Japanese-speaking children.
A hierarchical model for real-time monitoring of variation in risk of non-specific gastrointestinal infections
Authors: KAIMI I. , DIGGLE P. J.
Published: February 2011

The AEGISS (Ascertainment and Enhancement of Disease Surveillance and Statistics) project uses spatio-temporal statistical methods to identify anomalies in the incidence of gastrointestinal infections in the UK. The focus of this paper is the modelling of temporal variation in incidence using data from the Southampton area in southern England. We identified and fitted a hierarchical stochastic model for the time series of daily incident cases to enable probabilistic prediction of temporal variation in risk, and demonstrated the resulting gains in predictive accuracy by comparison with a conventional analysis based on an over-dispersed Poisson log-linear regression model. We used Bayesian methods of inference in order to incorporate parameter uncertainty in our predictive inference of risk. Incorporation of our model in the overall spatio-temporal model, will contribute to the accurate and timely prediction of unusually high food-poisoning incidence, and thus to the identification and prevention of future outbreaks.
Changes in antibiotic usage and susceptibility in nosocomial Enterobacteriaceae and Pseudomonas isolates following the introduction of ertapenem to hospital formulary
Authors: GRABER C. J. , HUTCHINGS C. , DONG F. , LEE W. , CHUNG J. K. , TRAN T.
Published: February 2011

There is concern that widespread usage of ertapenem may promote cross-resistance to other carbapenems. To analyse the impact that adding ertapenem to our hospital formulary had on usage of other broad-spectrum agents and on susceptibilities of nosocomial Enterobacteriaceae and Pseudomonas isolates, we performed interrupted time-series analyses to determine the change in linear trend in antibiotic usage and change in mean proportion and linear trend of susceptibility pre- (March 2004–June 2005) and post- (July 2005–December 2008) ertapenem introduction. Usage of piperacillin-tazobactam (P=0·0013) and ampicillin-sulbactam (P=0·035) declined post-ertapenem introduction. For Enterobacteriaceae, the mean proportion susceptible to ciprofloxacin (P=0·016) and piperacillin-tazobactam (P=0·038) increased, while the linear trend in susceptibility significantly increased for cefepime (P=0·012) but declined for ceftriaxone (P=0·0032). For Pseudomonas, the mean proportion susceptible to cefepime (P=0·011) and piperacillin-tazobactam (P=0·028) increased, as did the linear trend in susceptibility to ciprofloxacin (P=0·028). Notably, no significant changes in carbapenem susceptibility were observed.
Covering Complete r-Graphs with Spanning Complete r-Partite r-Graphs
Authors: CIOABĂ SEBASTIAN M. , KÜNDGEN ANDRÉ , TIMMONS CRAIG M. , VYSOTSKY VLADISLAV V.
Published: February 2011

An r-cut of the complete r-uniform hypergraph Krn is obtained by partitioning its vertex set into r parts and taking all edges that meet every part in exactly one vertex. In other words it is the edge set of a spanning complete r-partite subhypergraph of Krn. An r-cut cover is a collection of r-cuts such that each edge of Krn is in at least one of the cuts. While in the graph case r = 2 any 2-cut cover on average covers each edge at least 2-o(1) times, when r is odd we exhibit an r-cut cover in which each edge is covered exactly once. When r is even no such decomposition can exist, but we can bound the average number of times an edge is cut in an r-cut cover between $1+\frac1{r+1}$ and $1+\frac{1+o(1)}{\log r}$. The upper bound construction can be reformulated in terms of a natural polyhedral problem or as a probability problem, and we solve the latter asymptotically.
ON THE REPRESENTATION OF MULTI-IDEALS BY TENSOR NORMS
Authors: BOTELHO GERALDO , ÇALIŞKAN ERHAN , PELLEGRINO DANIEL
Published: February 2011

A tensor norm β=(βn)∞n=1 is smooth if the natural correspondence where 𝕂=ℝ or ℂ, is always an isometric isomorphism. In this paper we study the representation of multi-ideals and of ideals of multilinear forms by smooth tensor norms.
Musiktherapie für in Armut lebende Kinder
Authors: Lee Kyung-Ran , Chong Hyun Ju
Published: February 2011

Zusammenfassung. Ein Musikprogramm wurde als musiktherapeutisch-pädagogische Arbeit für Kinder, die aus armen und sozial schwachen Familien stammen, durchgeführt. Diese Untersuchung basierte auf der Beobachtung des Verhaltens der Teilnehmer dahingehend, wie sich der/die Teilnehmer/in in den verschiedenen von ihm erlebten Situationen verhält. Erhalten Kinder eine dauerhafte Unterstützung wie diese therapeutisch-pädagogische Arbeit, kann sich dies positiv auf ihre Fähigkeit zur Zusammenarbeit auswirken, was auch ihr Ego beim Lernen und im Allgemeinen stärken kann. Um solch positive Ergebnisse zu erzielen, muss jedoch eine langfristig angelegte Unterstützung angeboten werden, einerseits durch direkte finanzielle Hilfe für die Familie und andererseits durch dauerhafte angebotene und variierende Bildungsprogramme für die Zeit außerhalb des Schulunterrichts, also nach der Schule.
Bilder für Märchen
Authors: Reinersmann Ieva , Gudaitė Gražina , Deutsch Werner
Published: February 2011

Zusammenfassung. Diese Untersuchung betrifft 80 litauische Vorschulkinder, die je zu Hälfte in Kinderheimen und vollständigen Familien aufwachsen. Die Kinder haben zu einem litauischen Märchen Zeichnungen angefertigt. Beim und nach dem Zeichnen haben sie sprachliche Kommentare abgegeben. Zwischen den Gruppen treten statistisch signifikante Unterschiede auf, die sowohl die Motivwahl als auch die Länge und den Inhalt der sprachlichen Kommentare betreffen. Heimkinder haben öfter als Familienkinder emotional negativ besetzte Motive gezeichnet. Darüber hinaus haben sie beim und nach dem Zeichnen längere sprachliche Kommentare als die Familienkinder abgegeben, deren Inhalt häufig keinen Bezug zum Märchen hatte. Insgesamt belegt die Untersuchung, dass emotionale Erfahrungen im Spiegel des symbolischen Ausdrucks systematisch erfasst und interpretiert werden können, wobei Zeichnungen und sprachlicher Kommentare eng zusammenhängend betrachtet werden sollten.
Perspektiven der Bindung, Verantwortung und der Kunst aus transaktionsanalytischer Sicht
Authors: Sell Matthias
Published: February 2011

Zusammenfassung. Der Satz „Ich bin ok. – Du bist ok.” steht im Mittelpunkt der Überlegungen, die einen tieferen Zusammenhang von Bindung und Verantwortung aufzeigen. Um diese Bedeutung zu verstehen, werden die Erkenntnisperspektiven unter dem Einfluss aktueller gesellschaftlicher Verhältnisse wie auch unter dem Einfluss einer historischen Betrachtung reflektiert. Maßgebliche Veränderungen werden fokussiert auf drei wesentliche Perspektiven: Zeitperspektive, Raumperspektive und Prozessperspektive. Ausgehend von einer Definition von Kunst, die auf ihrer höchsten Stufe sich ausschließlich mit der Wiedergabe der inneren Natur befasst, werden diese veränderten Erkenntnisperspektiven in einen Zusammenhang zur Übernahme von Verantwortung gerückt und aufgezeigt, dass Bindung und Verantwortung sich wechselseitig bedingen und ergänzen und somit unmittelbar für jeden, der in einem beruflichen Kontext arbeitet, in dem Menschen mit und für Menschen arbeiten, zu einer Grundhaltung gehören.
Modeling the dynamics of soil erosion and size‐selective sediment transport over nonuniform topography in flume‐scale experiments
Authors: Heng B. C. P. , Sander G. C. , Armstrong A. , Quinton J. N. , Chandler J. H. , Scott C. F.
Published: February 2011

Soil erosion and the associated nutrient fluxes can lead to severe degradation of surface waters. Given that both sediment transport and nutrient sorption are size selective, it is important to predict the particle size distribution (PSD) as well as the total amount of sediment being eroded. In this paper, a finite volume implementation of the Hairsine‐Rose soil erosion model is used to simulate flume‐scale experiments with detailed observations of soil erosion and sediment transport dynamics. The numerical implementation allows us to account for the effects of soil surface microtopography (measured using close range photogrammetry) on soil erosion. An in‐depth discussion of the model parameters and the constraints is presented. The model reproduces the dynamics of sediment concentration and PSD well, although some discrepancies can be observed. The calibrated parameters are also consistent with independent data in the literature and physical reason. Spatial variations in the suspended and deposited sediment and an analysis of model sensitivity highlight the value of collecting distributed data for a more robust validation of the model and to enhance parametric determinacy. The related issues of spatial resolution and scale in erosion prediction are briefly discussed.
Cerebral Formation of Free Radicals during Hypoxia Does Not Cause Structural Damage and is Associated with a Reduction in Mitochondrial PO2; Evidence of O2-Sensing in Humans?
Authors: Bailey Damian M , Taudorf Sarah , Berg Ronan M G , Lundby Carsten , Pedersen Bente K , Rasmussen Peter , Møller Kirsten
Published: February 2011

Cellular hypoxia triggers a homeostatic increase in mitochondrial free radical signaling. In this study, blood was obtained from the radial artery and jugular venous bulb in 10 men during normoxia and 9 hours hypoxia (12.9% O2). Mitochondrial oxygen tension ([Formula: see text]) was derived from cerebral blood flow and blood gases. The ascorbate radical (A•−) was detected by electron paramagnetic resonance spectroscopy and neuron-specific enolase (NSE), a biomarker of neuronal injury, by enzyme-linked immunosorbent assay. Hypoxia increased the cerebral output of A•− in proportion to the reduction in [Formula: see text], but did not affect NSE exchange. These findings suggest that neuro-oxidative stress may constitute an adaptive response.
Metabolic Control of Resting Hemispheric Cerebral Blood Flow is Oxidative, not Glycolytic
Authors: Powers William J , Videen Tom O , Markham Joanne , Walter Vonn , Perlmutter Joel S
Published: February 2011

Although the close regional coupling of resting cerebral blood flow (CBF) with both cerebral metabolic rate of oxygen (CMRO2) and cerebral metabolic rate of glucose (CMRglc) within individuals is well documented, there are few data regarding the coupling between whole brain flow and metabolism among different subjects. To investigate the metabolic control of resting whole brain CBF, we performed multivariate analysis of hemispheric CMRO2, CMRglc, and other covariates as predictors of resting CBF among 23 normal humans. The univariate analysis showed that only CMRO2 was a significant predictor of CBF. The final multivariate model contained two additional terms in addition to CMRO2: arterial oxygen content and oxygen extraction fraction. Notably, arterial plasma glucose concentration and CMRglc were not included in the final model. Our data demonstrate that the metabolic factor controlling hemispheric CBF in the normal resting brain is CMRO2 and that CMRglc does not make a contribution. Our findings provide evidence for compartmentalization of brain metabolism into a basal component in which CBF is coupled to oxygen metabolism and an activation component in which CBF is controlled by another mechanism.
Inhibition of VEGF signaling pathway attenuates hemorrhage after tPA treatment
Authors: Kanazawa Masato , Igarashi Hironaka , Kawamura Kunio , Takahashi Tetsuya , Kakita Akiyoshi , Takahashi Hitoshi , Nakada Tsutomu , Nishizawa Masatoyo , Shimohata Takayoshi
Published: February 2011

An angiogenic factor, vascular endothelial growth factor (VEGF), might be associated with the blood-brain barrier (BBB) disruption after focal cerebral ischemia; however, it remains unknown whether hemorrhagic transformation (HT) after tissue plasminogen activator (tPA) treatment is related to the activation of VEGF signaling pathway in BBB. Here, we hypothesized that inhibition of VEGF signaling pathway can attenuate HT after tPA treatment. Rats subjected to thromboembolic focal cerebral ischemia were assigned to a permanent ischemia group and groups treated with tPA at 1 or 4 hours after ischemia. Anti-VEGF neutralizing antibody or control antibody was administered simultaneously with tPA. At 24 hours after ischemia, we evaluated the effects of the antibody on the VEGF expression, matrix metalloproteinase-9 (MMP-9) activation, degradation of BBB components, and HT. Delayed tPA treatment at 4 hours after ischemia promoted expression of VEGF in BBB, MMP-9 activation, degradation of BBB components, and HT. Compared with tPA and control antibody, combination treatment with tPA and the anti-VEGF neutralizing antibody significantly attenuated VEGF expression in BBB, MMP-9 activation, degradation of BBB components, and HT. It also improved motor outcome and mortality. Inhibition of VEGF signaling pathway may be a promising therapeutic strategy for attenuating HT after tPA treatment.
Mechanically induced generation of highly reactive excited-state oxygen molecules in cluster scattering
Authors: Nguyen Tao-Nhân V. , Timerghazin Qadir K. , Vach Holger , Peslherbe Gilles H.
Published: February 2011

Molecular electronic excitation in (O2)n clusters induced by mechanical collisions via the “chemistry with a hammer” is investigated by a combination of molecular dynamics simulations and quantum chemistry calculations. Complete active space self-consistent field augmented with triple-zeta polarizable basis set quantum chemistry calculations of a compressed (O2)2 cluster model in various configurations reveal the emergence of possible pathways for the generation of electronically excited singlet O2 molecules upon cluster compression and vibrational excitation, due to electronic curve-crossing and spin–orbit coupling. Extrapolation of the model (O2)2 results to larger clusters suggests a dramatic increase in the population of electronically excited O2 products, and may account for the recently observed cluster-catalyzed oxidation of silicon surfaces, via singlet oxygen generation induced by cluster impact, followed by surface reaction of highly reactive singlet O2 molecules. Extensive molecular dynamics simulations of (O2)n clusters colliding onto a hot surface indeed reveal that cluster compression is sufficient under typical experimental conditions for nonadiabatic transitions to occur. This work highlights the importance of nonadiabatic effects in the “chemistry with a hammer.”
Note: Design of a novel ultraprecision in-plane XYθ positioning stage
Authors: Hwang Donghyun , Lee Moon G. , Jeong Jaehwa
Published: February 2011

This paper presents the design, fabrication, and experimental results of a novel ultraprecision in-plane XYθ positioning stage with kinematic decoupling between translational motion and rotational motion components. Two translational motions are guided by four cymbal mechanisms that have both motion guide and motion amplifier. Four leaf springs guide a rotational motion amplified by a Scott–Russell linkage mechanism. The proposed stage has advantages such as an in-plane symmetrical configuration as well as ease of design and control by serial kinematics. The experimental results demonstrate that the stage has a translational full motion range of 58 μm and a rotational full motion range of 1.05 mrad. The crosstalk experimental results show good agreement with the theoretical prediction of the decoupling between translational motion and rotational motion.
Experimental facility for two- and three-dimensional ultrafast electron beam x-ray computed tomography
Authors: Stürzel T. , Bieberle M. , Laurien E. , Hampel U. , Barthel F. , Menz H.-J. , Mayer H.-G.
Published: February 2011

An experimental facility is described, which has been designed to perform ultrafast two-dimensional (2D) and three-dimensional (3D) electron beam computed tomographies. As a novelty, a specially designed transparent target enables tomography with no axial offset for 2D imaging and high axial resolution 3D imaging employing the cone-beam tomography principles. The imaging speed is 10 000 frames per second for planar scanning and more than 1000 frames per second for 3D imaging. The facility serves a broad spectrum of potential applications; primarily, the study of multiphase flows, but also in principle nondestructive testing or small animal imaging. In order to demonstrate the aptitude for these applications, static phantom experiments at a frame rate of 2000 frames per second were performed. Resulting spatial resolution was found to be 1.2 mm and better for a reduced temporal resolution.
Biomolecules under mechanical stress: A simple mechanism of complex behavior
Authors: Suzuki Yohichi , Dudko Olga K.
Published: February 2011

The unfolding of a biomolecule by stretching force is commonly treated theoretically as one-dimensional dynamics along the reaction coordinate coincident with the direction of pulling. Here we explore a situation, particularly relevant to complex biomolecules, when the pulling direction alone is not an adequate reaction coordinate for the unfolding or rupture process. We show that in this case the system can respond to pulling force in unusual ways. Our theory points out a remarkably simple, but largely overlooked, mechanism of the complex responses of biomolecules to force. The mechanism originates from the basic property of the transition state to change its structure under applied force. A relationship is established between a key experimental observable—force-dependent lifetime—and the microscopic properties of the biomolecule in the form of an analytical solution to the problem of a force-induced molecular transition in two dimensions. The theory is applicable to biological contexts ranging from protein folding to ligand–receptor interactions.
Electromechanical phenomena in semiconductor nanostructures
Authors: Lew Yan Voon L. C. , Willatzen M.
Published: February 2011

Electromechanical phenomena in semiconductors are still poorly studied from a fundamental and an applied science perspective, even though significant strides have been made in the last decade or so. Indeed, most current electromechanical devices are based on ferroelectric oxides. Yet, the importance of the effect in certain semiconductors is being increasingly recognized. For instance, the magnitude of the electric field in an AlN/GaN nanostructure can reach 1–10 MV/cm. In fact, the basic functioning of an (0001) AlGaN/GaN high electron mobility transistor is due to the two-dimensional electron gas formed at the material interface by the polarization fields. The goal of this review is to inform the reader of some of the recent developments in the field for nanostructures and to point out still open questions. Examples of recent work that involves the piezoelectric and pyroelectric effects in semiconductors include: the study of the optoelectronic properties of III-nitrides quantum wells and dots, the current controversy regarding the importance of the nonlinear piezoelectric effect, energy harvesting using ZnO nanowires as a piezoelectric nanogenerator, the use of piezoelectric materials in surface acoustic wave devices, and the appropriateness of various models for analyzing electromechanical effects. Piezoelectric materials such as GaN and ZnO are gaining more and more importance for energy-related applications; examples include high-brightness light-emitting diodes for white lighting, high-electron mobility transistors, and nanogenerators. Indeed, it remains to be demonstrated whether these materials could be the ideal multifunctional materials. The solutions to these and other related problems will not only lead to a better understanding of the basic physics of these materials, but will validate new characterization tools, and advance the development of new and better devices. We will restrict ourselves to nanostructures in the current article even though the measurements and calculations of the bulk electromechanical coefficients remain challenging. Much of the literature has focused on InGaN/GaN, AlGaN/GaN, ZnMgO/ZnO, and ZnCdO/ZnO quantum wells, and InAs/GaAs and AlGaN/AlN quantum dots for their optoelectronic properties; and work on the bending of nanowires have been mostly for GaN and ZnO nanowires. We hope the present review article will stimulate further research into the field of electromechanical phenomena and help in the development of applications.
Note: Deperturbation of the ν3 band of BeD2
Authors: Shayesteh Alireza , Bernath Peter F.
Published: February 2011

High rotational levels of the 001 (Σu) state of BeD2 are perturbed by the nearby 0330 (Φu) state. Deperturbation analysis results in an experimental value for the vibrational energy of the 030 level.
Acoustic emissions from convected wave packets
Authors: Obrist Dominik
Published: February 2011

Localized acoustic sources can often be modeled by wave packets. It has been recognized for a long time that the particular structure of these wave packet sources has a strong influence on the character of the acoustic emission to the far field. In the present work, we study the acoustic emission patterns with respect to the phase velocity, group velocity, size, and aspect ratio of the wave packet sources. To this end, the acoustic problem is formulated on the basis of Lighthill’s acoustic analogy and then recast to the geometrical problem of conic sections. This leads to the notion of elliptic (subsonic), parabolic (sonic), and hyperbolic (supersonic) acoustic emission patterns. The resulting geometric theory for acoustic emissions from wave packets includes phenomena such as Mach waves, bi- and superdirectivity, Doppler shift, and silent directions.
Native defects in Al2O3 and their impact on III-V/Al2O3 metal-oxide-semiconductor-based devices
Authors: Weber J. R. , Janotti A. , Van de Walle C. G.
Published: February 2011

Al 2 O 3 is a promising material for use as a dielectric in metal-oxide-semiconductor devices based on III-V compound semiconductors. However, the presence of deep levels and fixed charge in the Al2O3 layer is still a concern, with native defects being a possible cause of traps, leakage, and fixed charge. We report hybrid density functional calculations for vacancies, self-interstitials, and antisites in Al2O3. The energetic positions of defect levels are discussed in terms of the calculated band alignment at the interface between the oxide and relevant III-V materials. We find that oxygen vacancies are the defects most likely to introduce gap levels that may induce border traps or leakage current in a gate stack. In addition, both self-interstitials and aluminum vacancies introduce fixed charge that leads to increased carrier scattering in the channel and shifts the threshold voltage of the device.
Magnetocaloric effect in Tb60Ni30Al10 glass: A material that can either heat or cool upon magnetization
Authors: Gorsse S. , Mayer C. , Chevalier B.
Published: February 2011

The Tb60Ni30Al10 amorphous alloy was prepared by melt-spinning in the form of ribbons. Its magnetic behavior shows upon magnetization the occurrence of a spin glass to ferromagnetic and a paramagnetic to ferromagnetic transitions at 5 and 48 K. The magnetocaloric effects associated with these transitions were investigated. Large positive and negative magnetic entropy changes upon magnetization have been observed in a temperature range interesting for gas liquefaction.
Observation of pressure gradient and related flow rate effect on the plasma parameters in plasma processing reactor
Authors: Lee Hyo-Chang , Kim Aram , Moon Se Youn , Chung Chin-Wook
Published: February 2011

In industrial plasma processes, flow rate has been known to a key to control plasma processing results and has been discussed with reactive radical density, gas residence time, and surface reaction. In this study, it was observed that the increase in the flow rate can also change plasma parameters (electron temperature and plasma density) and electron energy distribution function in plasma processing reactor. Based on the measurement of gas pressure between the discharge region and the pumping port region, the considerable differences in the gas pressure between the two regions were found with increasing flow rate. It was also observed that even in the discharge region, the pressure gradient occurs at the high gas flow rate. This result shows that increasing the flow rate results in the pressure gradient and causes the changes in the plasma parameters.
Experimental study of the asymmetric charge transfer reaction between Ar+ ions and Fe atoms
Authors: Korolov I. , Bánó G. , Donkó Z. , Derzsi A. , Hartmann P.
Published: February 2011

We investigate the Ar+–Fe asymmetric charge transfer (ACT) reaction using a combination of plasma diagnostics methods and a kinetic model of the afterglow plasma, which allow monitoring of the temporal evolution of the densities of different species. The iron vapor is created inside a discharge cell by cathode sputtering; its density is measured by atomic absorption spectroscopy. The rate coefficient of the reaction is evaluated from the emission intensity decay of Fe+* lines pumped by the ACT process in the He–Ar–Fe and Ar–Fe afterglow plasmas. The measurements yield a rate coefficient k = 7.6( ± 3.0) × 10−9 cm3 s−1 at T = 300 K.
A general set of order parameters for molecular crystals
Authors: Santiso Erik E. , Trout Bernhardt L.
Published: February 2011

Crystallization is fundamental to many aspects of physics and chemistry in addition to being of technological relevance, for example, in the chemical, food, and pharmaceutical industries. However, the design of crystalline materials and crystallization processes is often challenging due to the many variables that can influence the process. As a part of an effort to gain a molecular-level understanding of the way molecules aggregate and organize themselves into crystal structures, in this work we present a new method to construct order parameters suitable for the study of crystallization and polymorph transformations in molecular systems. Our order parameters can be systematically defined for complex systems using information that can be obtained from simple molecular dynamics simulations of the crystals. We show how to construct the order parameters for the study of three different systems: the formation of α-glycine crystals in solution, the crystallization of benzene from the melt, and the polymorph transformation of terephthalic acid. Finally, we suggest how these order parameters could be used to study order–disorder transitions in molecular systems.
Multisoliton, multipositon, multinegaton, and multiperiodic solutions of a coupled Volterra lattice system and their continuous limits
Authors: Zhao Hai-qiong , Zhu Zuo-nong
Published: February 2011

This paper aims to find new explicit solutions including multisoliton, multipositon, multinegaton, and multiperiodic for a coupled Volterra lattice system. This coupled lattice system is an integrable discrete version of the coupled Korteweg-deVries (KdV) equation which has many physical applications. The dynamical properties of these new solutions are discussed in detail. We also prove that the theory of the coupled Volterra lattice system including the Lax pair, the Darboux transformation, and explicit solutions yield the corresponding theory of the coupled KdV equation in the continuous limit.
Geometric phase for collinear conical intersections. I. Geometric phase angle and vector potentials
Authors: Li Xuan , Brue Daniel A. , Kendrick Brian K. , Blandon Juan D. , Parker Gregory A.
Published: February 2011

We present a method for properly treating collinear conical intersections in triatomic systems. The general vector potential (gauge theory) approach for including the geometric phase effects associated with collinear conical intersections in hyperspherical coordinates is presented. The current study develops an introductory method in the treatment of collinear conical intersections by using the phase angle method. The geometric phase angle, η, in terms of purely internal coordinates is derived using the example of a spin-aligned quartet lithium triatomic system. A numerical fit and thus an analytical form for the associated vector potentials are explicitly derived for this triatomic A3 system. The application of this methodology to AB2 and ABC systems is also discussed.