bluuebunny/crossref_metadata_2025 huggingface dataset:
MIXED INJECTIVE MODULES
Authors: TÜTÜNCÜ DERYA KESKIN , MOHAMED SAAD H. , ERTAŞ NIL ORHAN
Published: June 2010

Since Azumaya introduced the notion of A-injectivity in 1974, several generalizations have been investigated by a number of authors. We introduce some more generalizations and discuss their connection to the previous ones.
ACTIONS OF LIE SUPERALGEBRAS ON SEMIPRIME ALGEBRAS WITH CENTRAL INVARIANTS
Authors: GRZESZCZUK PIOTR , HRYNIEWICKA MAŁGORZATA
Published: June 2010

Let R be a semiprime algebra over a field of characteristic zero acted finitely on by a finite-dimensional Lie superalgebra L = L0 ⊕ L1. It is shown that if L is nilpotent, [L0, L1] = 0 and the subalgebra of invariants RL is central, then the action of L0 on R is trivial and R satisfies the standard polynomial identity of degree 2 ⋅ [$\sqrt{2^{\dim_{\mathbb{K}}L_1}}$]. Examples of actions of nilpotent Lie superalgebras, with central invariants and with [L0, L1] ≠ 0, are constructed.
ALMOST-PERFECT MODULES
Authors: AYDOĞDU PINAR , ÖZCAN A. ÇIĞDEM
Published: June 2010

We call a module Malmost perfect if every M-generated flat module is M-projective. Any perfect module is almost perfect. We characterize almost-perfect modules and investigate some of their properties. It is proved that a ring R is a left almost-perfect ring if and only if every finitely generated left R-module is almost perfect. R is left perfect if and only if every (projective) left R-module is almost perfect.
RINGS AND MODULES IN HONOUR OF PATRICK F. SMITH'S 65TH BIRTHDAY
Authors: Santa-Clara Catarina
Published: June 2010

The conference ‘Rings and Modules’, in honour of Patrick F. Smith's 65th birthday and on the occasion of his retirement, gathered in Lisbon 67 of Patrick Smith's students, co-authors and friends from all over the world. The conference was held at Centro de Álgebra da Universidade de Lisboa (CAUL), 16th–19th September 2008.
On the roles of chord-wise flexibility in a flapping wing with hovering kinematics
Authors: ELDREDGE JEFF D. , TOOMEY JONATHAN , MEDINA ALBERT
Published: June 2010

The aerodynamic performance of a flapping two-dimensional wing section with simplified chord-wise flexibility is studied computationally. Bending stiffness is modelled by a torsion spring connecting two or three rigid components. The leading portion of the wing is prescribed with kinematics that are characteristic of biological hovering, and the aft portion responds passively. Coupled simulations of the Navier–Stokes equations and the wing dynamics are conducted for a wide variety of spring stiffnesses and kinematic parameters. Performance is assessed by comparison of the mean lift, power consumption and lift per unit power, with those from an equivalent rigid wing, and two cases are explored in greater detail through force histories and vorticity snapshots. From the parametric survey, four notable mechanisms are identified through which flexible wings behave differently from rigid counterparts. Rigid wings consistently require more power than their flexible counterparts to generate the same kinematics, as passive deflection leads to smaller drag and torque penalties. Aerodynamic performance is degraded in very flexible wings undergoing large heaving excursions, caused by a premature detachment of the leading-edge vortex. However, a mildly flexible wing has consistently good performance over a wide range of phase differences between pitching and heaving – in contrast to the relative sensitivity of a rigid wing to this parameter – due to better accommodation of the shed leading-edge vortex into the wake during the return stroke, and less tendency to interact with previously shed trailing-edge vortices. Furthermore, a flexible wing permits lift generation even when the leading portion remains nearly vertical, as the wing passively deflects to create an effectively smaller angle of attack, similar to the passive pitching mechanism recently identified for rigid wings. It is found that an effective pitch angle can be defined that accounts for wing deflection to align the results with those of the equivalent rigid wing.
Lazzari felici: Neapolitan song and/as nostalgia
Authors: PLASTINO GOFFREDO
Published: June 2010

Although the canzone napoletana (Neapolitan song) is the best-known Italian popular music in the world, it is also the most misunderstood. It is mostly associated with operatic or quasi-operatic vocal styles, but all the other Neapolitan popular voices, the performance features and even the history of this musical genre are less well known. This essay in particular considers how the porous Neapolitan voice is a ‘space’ for complex negotiations between different musical styles, and how through this voice (that admits within itself the existence of other vocal styles) Neapolitan composers, musicians and singers articulate different relationships between music, history and nostalgia.
PrevalentLq-dimensions of measures
Authors: OLSEN L.
Published: June 2010

LetKbe a compact subset of ℝdand writesfor the Hausdorff dimension ofK. For a probability measure μ onK, the lower and upperLq-dimensions of orderq∈ ℝ are defined byIn this paper we studyLq-dimensions of measures that are generic in the sense of prevalence. In particular, we prove that ifKsatisfies a mild regularity condition, then a prevalent probability measure μ onKsatisfies:for all 0 ≤q≤ 1, andfor all 1 ≤q. This result is in sharp contrast to the behaviour of theLq-dimensions of measures that are generic in the sense of Baire category. Namely, ifKsatisfies a mild regularity condition, then a probability measure μ onKthat is generic in the sense of Baire category satisfies:for all 1 <q.
Environmental heterogeneity of World Wildlife Fund for Nature ecoregions and implications for conservation in Neotropical biodiversity hotspots
Authors: LONDOÑO-MURCIA MARÍA CECILIA , TELLEZ-VALDÉS OSWALDO , SÁNCHEZ-CORDERO VÍCTOR
Published: June 2010

Mesoamerica, Chocó and the tropical Andes are recognized as biodiversity hotspots where conservation action is urgently needed. Because World Wildlife Fund for Nature (WWF) ecoregions are commonly used as the basis for conservation decisions, an understanding of WWF ecoregions’ environmental heterogeneity and their representation in current protected areas (PAs) is important for identifying priority areas for conservation. Thirteen environmental domain classifications based on 22 climatic and topographical variables and the Shannon diversity index were used to quantify environmental diversity for each WWF ecoregion. The area of each environmental domain and ecoregion was compared with the World Database on Protected Areas 2007. The most environmentally-diverse ecoregions were poorly represented in the PAs and several ecoregions showed low environmental heterogeneity representation inside PAs, for example the Balsas depression, Sierra Madre del Sur and the Chiapas Sierras in Mexico, some sierras in Central America, the Middle Magdalena, inter-Andean valleys, the Eastern Cordillera of Colombia and the Western Moist Forest of Ecuador. Using WWF ecoregions as equivalent units for conservation and management can be misleading, given their environmental heterogeneity; therefore, they have limited usefulness in assessing environmental representation in PAs. An underestimation of environmental heterogeneity representation in PAs can have misleading implications for conservation actions in regions where detailed biological information is lacking. Conservation efforts should focus on the environmental domains and ecoregions showing high environmental heterogeneity that is poorly represented in PAs.
Relations among maternal socialization, effortful control, and maladjustment in early childhood
Authors: Eisenberg Nancy , Spinrad Tracy L. , Eggum Natalie D. , Silva Kassondra M. , Reiser Mark , Hofer Claire , Smith Cynthia L. , Gaertner Bridget M. , Kupfer Anne , Popp Tierney , Michalik Nicole
Published: June 2010

In a sample of 18-, 30-, and 42-month-olds, the relations among parenting, effortful control (EC), and maladjustment were examined. Parenting was assessed with mothers' reports and observations; EC was measured with mothers' and caregivers' reports, as well as a behavioral task; and externalizing and internalizing symptoms were assessed with parents' and caregivers' reports. Although 18-month unsupportive (vs. supportive) parenting negatively predicted EC at 30 months, when the stability of these variables was taken into account, there was no evidence of additional potentially causal relations between these two constructs. Although EC was negatively related to both internalizing and externalizing problems within all three ages as well as across 1 year, EC did not predict maladjustment once the stability of the constructs and within time covariation between the constructs were taken into account. In addition, externalizing problems at 30 months negatively predicted EC at 42 months, and internalizing problems at 30 months positively predicted EC at 42 months, but only when the effects of externalizing on EC were controlled. The findings are discussed in terms of the reasons for the lack of causal relations over time.
Developmental cascades of peer rejection, social information processing biases, and aggression during middle childhood
Authors: Lansford Jennifer E. , Malone Patrick S. , Dodge Kenneth A. , Pettit Gregory S. , Bates John E.
Published: June 2010

This study tested a developmental cascade model of peer rejection, social information processing (SIP), and aggression using data from 585 children assessed at 12 time points from kindergarten through Grade 3. Peer rejection had direct effects on subsequent SIP problems and aggression. SIP had direct effects on subsequent peer rejection and aggression. Aggression had direct effects on subsequent peer rejection. Each construct also had indirect effects on each of the other constructs. These findings advance the literature beyond a simple mediation approach by demonstrating how each construct effects changes in the others in a snowballing cycle over time. The progressions of SIP problems and aggression cascaded through lower liking, and both better SIP skills and lower aggression facilitated the progress of social preference. Findings are discussed in terms of the dynamic, developmental relations among social environments, cognitions, and behavioral adjustment.
Developmental cascades: Externalizing, internalizing, and academic competence from middle childhood to early adolescence
Authors: Moilanen Kristin L. , Shaw Daniel S. , Maxwell Kari L.
Published: June 2010

The current study was initiated to increase understanding of developmental cascades in childhood in a sample of at-risk boys (N= 291; 52% White). Mothers, teachers, and boys reported on boys' externalizing problems, internalizing difficulties, and academic competence. Consistent with hypotheses regarding school-related transitions, high levels of externalizing problems were associated with both low levels of academic competence and high levels of internalizing problems during the early school-age period, and with elevations in internalizing problems during the transition to adolescence. Low levels of academic competence were associated with high levels of internalizing problems in middle childhood, and with high levels of externalizing problems during the transition from elementary school to middle school. Shared risk factors played a minimal role in these developmental cascades. Results suggest that there are cascading effects of externalizing problems and academic competence in childhood and early adolescence, and that some cascading effects are more likely to occur during periods of school-related transitions. Implications of developmental cascade effects for research and intervention are discussed.
A cascade model connecting life stress to risk behavior among rural African American emerging adults
Authors: Brody Gene H. , Chen Yi-Fu , Kogan Steven M.
Published: June 2010

A three-wave cascade model linking life stress to increases in risk behavior was tested with 347 African American emerging adults living in the rural South. Data analyses using structural equation modeling and latent growth curve modeling demonstrated that life stress was linked to increases in risk behavior as African Americans transitioned out of secondary school. The cascade model indicated that life stress fostered increases in negative emotions. Negative emotions, in turn, were linked to increases in affiliations with deviant peers and romantic partners; this forecast increases in risk behavior. The findings supported a stress proliferation framework, in which primary stressors affect increases in secondary stressors that carry forward to influence changes in risk behaviors that can potentially compromise mental health.
Intensive Cognitive Therapy for PTSD: A Feasibility Study
Authors: Ehlers Anke , Clark David M. , Hackmann Ann , Grey Nick , Liness Sheena , Wild Jennifer , Manley John , Waddington Louise , McManus Freda
Published: June 2010

Background:Cognitive Behaviour Therapy (CBT) of anxiety disorders is usually delivered in weekly or biweekly sessions. There is evidence that intensive CBT can be effective in phobias and obsessive compulsive disorder. Studies of intensive CBT for posttraumatic stress disorder (PTSD) are lacking.Method:A feasibility study tested the acceptability and efficacy of an intensive version of Cognitive Therapy for PTSD (CT-PTSD) in 14 patients drawn from consecutive referrals. Patients received up to 18 hours of therapy over a period of 5 to 7 working days, followed by 1 session a week later and up to 3 follow-up sessions.Results:Intensive CT-PTSD was well tolerated and 85.7 % of patients no longer had PTSD at the end of treatment. Patients treated with intensive CT-PTSD achieved similar overall outcomes as a comparable group of patients treated with weekly CT-PTSD in an earlier study, but the intensive treatment improved PTSD symptoms over a shorter period of time and led to greater reductions in depression.Conclusions:The results suggest that intensive CT-PTSD is a feasible and promising alternative to weekly treatment that warrants further evaluation in randomized trials.
Household and local forest impacts of Morocco's argan oil bonanza
Authors: LYBBERT TRAVIS J. , MAGNAN NICHOLAS , ABOUDRARE ABDELLAH
Published: June 2010

Morocco's argan oil is now the most expensive edible oil in the world. Growing high-value argan markets have sparked a bonanza of argan activity. NGOs, international and domestic development agencies, and argan oil cooperatives have promoted the win–win aim of simultaneously benefiting locals and the argan forest. We test this win–win claim by surveying households before and after rapid appreciation in argan prices. The argan boom has benefited some rural households. Those well positioned to benefit increased their goat herds more than other households, which bodes poorly for forest impacts, and were more likely to send their girls to secondary school. While locals are keeping their goats out of argan trees during the harvest, they may also be resorting to more aggressive harvesting techniques. The boom has made households vigilant guardians of fruit on their own trees, but has not incited investments in longer term tree and forest health.
Polyneuropathien – kurz und bündig
Authors: Eschle  , Jenni
Published: June 2010

Nicht wenige Patienten werden sich in der Hausarztpraxis mit Missempfindungen in den Füssen vorstellen, die sich z.B. mit einem brennenden Gefühl beim Einschlafen äussern. Klinisch finden sich meist fehlende Achillessehnenreflexe und ein herabgesetzter Vibrationssinn. Es handelt sich dabei um die besonders häufige distal-symmetrische sensible Form einer Polyneuropathie (PNP), deren Abklärung und Behandlung hier vorgestellt wird. Meist liegt ein bereits bekannter oder neu diagnostizierter Diabetes mellitus zugrunde. Eine PNP tritt beim Diabetes mellitus Typ 1 erst nach Jahren schlechter glykämischer Kontrolle auf. Beim Typ-2-Diabetes geht die PNP oft der Diagnose voraus!
Neuromuskuläre Erkrankungen im Kindesalter: Klinisches Vorgehen
Authors: Ramelli  , Herrmann  , Lütschg
Published: June 2010

Neuromuskuläre Erkrankungen (NME) umfassen eine Gruppe von Erkrankungen der Vorderhornzelle, des peripheren Nervs, der motorischen Endplatte und der Muskulatur. NME manifestieren sich von der Prä- und Perinatalzeit bis ins Erwachsenenalter. Die Prävalenz erblicher und erworbener NME beträgt mindestens 1:1500. In den letzten Jahren gab es entscheidende Entdeckungen im neuromuskulären System, und Neuentwicklungen insbesondere auf molekulargenetischer Ebene und in der bildgebenden Diagnostik. Diese Entdeckungen haben zu einer deutlichen Zunahme von definierten Muskelerkrankungen geführt. Im klinischen Alltag bleiben aber eine genaue Anamnese und eine detaillierte klinische Untersuchung entscheidend für die Wahl der richtigen Abklärungen. Die Symptomatik der Patienten und die sorgfältige Interpretation der einzelnen Untersuchungen sowie der Gesamtsituation ermöglichen in den allermeisten Fällen eine Diagnosesicherung. Das Ziel dieser Arbeit ist es, das anamnestische und klinische Procedere im Gebiet der neuromuskulären Erkrankungen im Kindesalter aufzuzeigen.
Halbseitenstörung nach Unfall
Authors: Egloff  , Gander  , Gerber  , von Känel  , Wiest
Published: June 2010

Ein 48-jähriger Industrieangestellter wird vorgestellt, welcher im Anschluss an einen Arbeitsunfall eine schmerz­assoziierte nicht-dermatombezogene somatosensorische Ausfallsstörung mit Halbseitenverteilung erleidet. Schmerzausweitung, Schmerzchronifizierung, halbseitige Hyperalgesie (einhergehend mit ipsilateraler Berührungs- und Wärmehypästhesie) weisen auf maladaptive neuroplastische Vorgänge der schmerzverarbeitenden neuronalen Strukturen hin. Die Stressbelastung des ZNS im Vorfeld oder zum Zeitpunkt des Auslöseereignisses scheint ein massgebender Risikofaktor zu sein.
Exanthem, Fieber, Eosinophilie und erhöhte Leberwerte
Authors: Derungs  , Rätz Bravo  , Kummer
Published: June 2010

Wir berichten über einen Patienten mit einer Pneumocystis jirovecii-Pneumonie, der 10 Tage nach Beginn einer Therapie mit Sulfamethoxazol und Trimethoprim Fieber, ein Hautexanthem, eine Eosinophilie und eine Hepatitis entwickelte. Die Diagnose eines DRESS-Syndroms wurde gestellt und die Therapie erfolgreich auf Pyrimethamin und Dapson umgestellt. Wir beschreiben das klinische Bild, auslösende Medikamente, Pathogenese, Differentialdiagnosen und Therapie dieser lebensbedrohlichen Erkrankung, um sie dem allgemeinen Internisten und Allgemeinpraktiker vertraut zu machen.
Sexual Behavior, Depressive Feelings, and Suicidality Among Estonian School Children Aged 13 to 15 Years
Authors: Heidmets L. , Samm A. , Sisask M. , Kõlves K. , Aasvee K. , Värnik A.
Published: June 2010

Background: The present paper is based on a WHO Collaborative Cross-National Study “Health Behavior in School-Aged Children (HBSC).” Aims: It aimed at describing and analyzing how the sexual behaviors of 13- to 15-year-old Estonian school children were associated with self-reported depressive feelings and suicidality. Distinctive behavioral traits in relation to age of first sexual intercourse were also investigated. Methods: Self-reported questionnaires from school children (n = 3,055) were analyzed. Results: In total, 15.2% of school children reported being nonvirgin. Among 13-year-olds, 2.9% of girls and 6.8% of boys were nonvirgins. Approximately 25% of the 15-year-old girls and boys were nonvirgins. The likelihood of depressive feelings and suicidal ideation increased significantly in both genders with loss of virginity. Boys who had lost their virginity at 13 years or younger were 4.2 times more likely to have suicidal thoughts; comparable girls were 7.8 times more likely to have suicidal thoughts. Compared to virgins, youths who had lost their virginity reported poor self-assessed health and more risk behaviors in themselves and their peers. Conclusion: Experiences of sexual intercourse increased the odds ratios for depressive feelings and suicidality. The earlier sexual intercourse was initiated, the greater were the odds of lower mental well-being. Risk behaviors emerged as a complex phenomenon requiring complex prevention.
Body Investment, Depression, and Alcohol Use as Risk Factors for Suicide Proneness in College Students
Authors: Lamis Dorian A. , Malone Patrick S. , Langhinrichsen-Rohling Jennifer , Ellis Thomas E.
Published: June 2010

Background: Individuals who are less invested in their bodies, experiencing symptoms of depression, and consuming alcohol are at increased risk for engaging in suicidal behaviors. Aims: This study examined the relationships among three risk factors – body investment, depression, and alcohol use – and suicide proneness as measured by the Life Attitudes Schedule – Short Form (LAS-SF) in college students (N = 318). Methods: Path analysis was used to construct a causal model of suicide proneness. The Body Investment Scale (BIS) subscales were assumed to be causally prior to depression, which was in turn modeled as occurring prior to alcohol use, which was in turn modeled as prior to suicide proneness. Results: As expected, suicide proneness was positively predicted by alcohol use, alcohol use was positively predicted by depression, and depression was negatively predicted by the body image component of the BIS. Additionally, the body image-suicide proneness link was significantly mediated by depression and its direct effect on suicide proneness as well as by the two-mediator path of body image on depression on drinking on suicide proneness. Conclusions: Implications are offered for the improved identification and treatment of young adults at risk for suicidal and health-diminishing behaviors.
Does a Brief Suicide Prevention Gatekeeper Training Program Enhance Observed Skills?
Authors: Cross Wendi , Matthieu Monica M. , Lezine DeQuincy , Knox Kerry L.
Published: June 2010

Background: Suicide is a significant public health problem worldwide that requires evidence-based prevention efforts. One approach to prevention is gatekeeper training. Gatekeeper training programs for community members have demonstrated positive changes in knowledge and attitudes about suicide. Changes in gatekeeper skills have not been well established. Aims: To assess and to predict the impact of a brief, gatekeeper training on community members’ observed skills. Methods: Participants in a community gatekeeper training were employees at US universities. 50 participants were randomly selected for skills assessment and videotaped interacting with a standardized actor prior to and following training. Tapes were reliably rated for general and suicide-specific skills. Results: Gatekeeper skills increased from pre- to posttest: 10% of participants met criteria for acceptable gatekeeper skills before training, while 54% met criteria after training. Pretraining variables did not predict increased skills. Limitations: Results do not provide conclusions about the relationship between observed gatekeeper skills and actual use of those skills in the future. Conclusions: Gatekeeper training enhances suicide-specific skills for the majority of participants. Other strategies, such as behavioral rehearsal, may be necessary to enhance skills in the remaining participants.
Participant Roles in Bullying Behavior and Their Association with Thoughts of Ending One’s Life
Authors: Rivers Ian , Noret Nathalie
Published: June 2010

Background: Studies have shown that students who are bullied at school are at an increased risk of poor mental health and suicide. Little is known, however, about those who have other participant roles in bullying interactions (e.g., bystanders). Aims: To better understand the implications exposure to bullying has upon thoughts of ending life among students who have multiple participant roles. Methods: This study was a cross-sectional survey of a representative sample of 2,002 students (55% boys, 45% girls) aged 12 to 16 years (M = 13.60, SD = 1.06) attending 14 schools in the North of England. Results: The majority of students in this study were involved in bullying behavior at school as victims, bullies, bystanders, or a combination of all three. Those with multiple roles (victim, bully, and bystander) were significantly more likely to report having had thoughts of ending their life. Conclusions: The findings from this study have significant implications for clinicians, educational, and school psychologists working with students involved in bullying behavior. Whole school antibullying initiatives are necessary to reduce the psychological distress and thoughts of ending life found among members of the school population. Further studies exploring covictimization among bystanders and revictimization among former victims of bullying are recommended.
Evidence of time‐mean cyclonic cell southwest of Iberian Peninsula: The Mediterranean Outflow‐driven β‐plume?
Authors: Lamas Luísa , Peliz Álvaro , Ambar Isabel , Barbosa Aguiar Ana , Maximenko Nikolai , Teles‐Machado Ana
Published: June 2010

First observational evidence of time‐mean cyclonic recirculation southwest of Iberia is presented. Data sets of hydrography, satellite altimetry and surface drifters velocities are analyzed jointly in order to obtain an accurate time‐averaged circulation in the mid‐latitude northeast Atlantic off the Gulf of Cadiz. A cyclonic recirculation cell with characteristics similar to those predicted by theoretical and modeling studies is detected in all computed velocity fields. The cell in the upper 1000‐m layer exhibits transports of 3 to 4 Sv that are only slightly smaller than the model transports. The cell is centered at approximately 36°N, 10°W, is elongated zonally and extends to 15°W westwards. Wind driven Sverdrup transport and β‐plume dynamics are both suggested to play a role in the generation of the cyclonic cell, but the relative contribution of these effects is yet to be clarified. The core of the recirculation appears compact and the magnitude of the cell fades westwards much faster than predicted by the theoretical and modeling studies considered.
Survival of Escherichia coli in the environment: fundamental and public health aspects
Authors: van Elsas Jan Dirk , Semenov Alexander V , Costa Rodrigo , Trevors Jack T
Published: June 2010

In this review, our current understanding of the species Escherichia coli and its persistence in the open environment is examined. E. coli consists of six different subgroups, which are separable by genomic analyses. Strains within each subgroup occupy various ecological niches, and can be broadly characterized by either commensalistic or different pathogenic behaviour. In relevant cases, genomic islands can be pinpointed that underpin the behaviour. Thus, genomic islands of, on the one hand, broad environmental significance, and, on the other hand, virulence, are highlighted in the context of E. coli survival in its niches. A focus is further placed on experimental studies on the survival of the different types of E. coli in soil, manure and water. Overall, the data suggest that E. coli can persist, for varying periods of time, in such terrestrial and aquatic habitats. In particular, the considerable persistence of the pathogenic E. coli O157:H7 is of importance, as its acid tolerance may be expected to confer a fitness asset in the more acidic environments. In this context, the extent to which E. coli interacts with its human/animal host and the organism's survivability in natural environments are compared. In addition, the effect of the diversity and community structure of the indigenous microbiota on the fate of invading E. coli populations in the open environment is discussed. Such a relationship is of importance to our knowledge of both public and environmental health.
Succession of methanotrophs in oxygen–methane counter-gradients of flooded rice paddies
Authors: Krause Sascha , Lüke Claudia , Frenzel Peter
Published: June 2010

Little is known about population dynamics and contribution of specific taxa to methane oxidation in flooded rice paddies. In this article we investigate the succession of methanotrophs in oxygen–methane counter-gradients. We used a gradient microcosm system that simulates oxic–anoxic interfaces of a water-saturated paddy soils, and measured pmoA-based (gene encoding particulate methane monooxygenase) terminal restriction fragment length polymorphism (T-RFLP) profiles at both the transcription (mRNA) and the population (DNA) levels. The DNA T-RFLP profiles indicated that the methanotrophic community present clearly differed from the active methanotrophic community. We observed a succession of the methanotrophic community over time without any direct effect of pore water chemistry on the community structure. Both the total population and the active subpopulation changed with time, whereas methane oxidation rates remained nearly constant. Hence, we suggest that a diverse microbial seed bank of methanotrophs is important in maintaining the function in a dynamic ecosystem.
Efficacy of α‐Lactalbumin and Milk Protein on Weight Loss and Body Composition During Energy Restriction
Authors: Soenen Stijn , Hochstenbach‐Waelen Ananda , Westerterp‐Plantenga Margriet S.
Published: June 2010

Our objective was to examine whether elevated α‐lactalbumin (αlac) protein intake compared to elevated supra sustained milk protein (SSP) and sustained milk protein (SP) intake results into a difference in body weight and body composition over a 6‐month energy‐restriction intervention. Body weight, body composition, resting energy expenditure (REE), satiety and blood‐ and urine‐parameters of 87 subjects (BMI 31 ± 5 kg/m2 and fat percentage 40 ± 8%) were assessed before and after daily energy intakes of 100, 33, and 67% for 1, 1, and 2 months respectively (periods 1, 2, and 3), with protein intake from meal replacements and 2 months of 67% with ad libitum protein intake additional to the meal replacements (period 4). The diets resulted in 0.8 ± 0.3 g/kg body mass (BM) for SP and significant higher protein intake (24‐h nitrogen) of 1.2 ± 0.3 and 1.0 ± 0.3 g/kgBM for SSP and αlac (P < 0.05). Body weight and fat percentage was decreased in all groups after 6 months (SP −7 ± 5 kg and −5 ± 3%; SSP −6 ± 3 kg and −5 ± 3%; αlac −6 ± 4 kg and −4 ± 4%, P < 0.001; there was no significant group by time difference). Furthermore, sparing of fat‐free mass (FFM) and preservation of REE in function of FFM during weight loss was not significantly different between the αlac‐group and the SSP‐ and SP‐groups. In conclusion, the efficacy of αlac in reduction of body weight and fat mass (FM), and preservation of FFM does not differ from the efficacy of similar daily intakes of milk protein during 6 months of energy restriction.
Interaction of iron regulatory protein-1 (IRP-1) with ATP/ADP maintains a non-IRE-binding state
Authors: Popovic Zvezdana , Templeton Douglas M.
Published: June 2010

In its aconitase-inactive form, IRP-1 (iron regulatory protein-1)/cytosolic aconitase binds to the IRE (iron-responsive element) of several mRNAs to effect post-transcriptional regulation. We have shown previously that IRP-1 has ATPase activity and that binding of ATP suppresses the IRP-1/IRE interaction. In the present study, we characterize the binding activity further. Binding is observed with both [α-32P]ATP and [α-32P]ADP, but not with [γ-32P]ATP. Recombinant IRP-1 binds approximately two molecules of ATP, and positive co-operativity is observed with a Hill coefficient of 1.67±0.36 (EC50=44 μM) commencing at 1 μM ATP. Similar characteristics are observed with both apoprotein and the aconitase form. On binding, ATP is hydrolysed to ADP, and similar binding parameters and co-operativity are seen with ADP, suggesting that ATP hydrolysis is not rate limiting in product formation. The non-hydrolysable analogue AMP-PNP (adenosine 5′-[β,γ-imido]triphosphate) does not induce co-operativity. Upon incubation of IRP-1 with increasing concentrations of ATP or ADP, the protein migrates more slowly on agarose gel electrophoresis, and there is a shift in the CD spectrum. In this new state, adenosine nucleotide binding is competed for by other nucleotides (CTP, GTP and AMP-PNP), although ATP and ADP, but not the other nucleotides, partially stabilize the protein against spontaneous loss of aconitase activity when incubated at 37 °C. A mutant IRP-1(C437S) lacking aconitase activity shows only one ATP-binding site and lacks co-operativity. It has increased IRE-binding capacity and lower ATPase activity (Km=75±17 nmol/min per mg of protein) compared with the wild-type protein (Km=147±48 nmol/min per mg of protein). Under normal cellular conditions, it is predicted that ATP/ADP will maintain IRP-1 in a non-IRE-binding state.
Genomic tagging reveals a random association of endogenous PtdIns5P 4-kinases IIα and IIβ and a partial nuclear localization of the IIα isoform
Authors: Wang Minchuan , Bond Nicholas J. , Letcher Andrew J. , Richardson Jonathan P. , Lilley Kathryn S. , Irvine Robin F. , Clarke Jonathan H.
Published: June 2010

PtdIns5P 4-kinases IIα and IIβ are cytosolic and nuclear respectively when transfected into cells, including DT40 cells [Richardson, Wang, Clarke, Patel and Irvine (2007) Cell. Signalling 19, 1309–1314]. In the present study we have genomically tagged both type II PtdIns5P 4-kinase isoforms in DT40 cells. Immunoprecipitation of either isoform from tagged cells, followed by MS, revealed that they are associated directly with each other, probably by heterodimerization. We quantified the cellular levels of the type II PtdIns5P 4-kinase mRNAs by real-time quantitative PCR and the absolute amount of each isoform in immunoprecipitates by MS using selective reaction monitoring with 14N,13C-labelled internal standard peptides. The results suggest that the dimerization is complete and random, governed solely by the relative concentrations of the two isoforms. Whereas PtdIns5P 4-kinase IIβ is >95% nuclear, as expected, the distribution of PtdIns4P 4-kinase IIα is 60% cytoplasmic (all bound to membranes) and 40% nuclear. In vitro, PtdIns5P 4-kinase IIα was 2000-fold more active as a PtdIns5P 4-kinase than the IIβ isoform. Overall the results suggest a function of PtdIns5P 4-kinase IIβ may be to target the more active IIα isoform into the nucleus.
Biphasic regulation of H2O2 on angiogenesis implicated NADPH oxidase
Authors: Mu Ping , Liu Qing , Zheng Rongliang
Published: June 2010

ROS (reactive oxygen species) take an important signalling role in angiogenesis. Although there are several ways to produce ROS in cells, multicomponent non‐phagocytic NADPH oxidase is an important source of ROS that contribute to angiogenesis. In the present work, we examined the effects of H2O2 on angiogenesis including proliferation and migration in HUVECs (human umbilical vein endothelial cells), new vessel formation in chicken embryo CAM (chorioallantoic membrane) and endothelial cell apoptosis, which is closely related to anti‐angiogenesis. Our results showed that H2O2 dose‐dependently increased the generation of O2 − (superoxide anion) in HUVECs, which was suppressed by DPI (diphenylene iodonium) and APO (apocynin), two inhibitors of NADPH oxidase. H2O2 at low concentrations (10 µM) stimulated cell proliferation and migration, but at higher concentrations, inhibited both. Similarly, H2O2 at 4 nmol/cm2 strongly induced new vessel formation in CAM, while it suppressed at high concentrations (higher than 4 nmol/cm2). Also, H2O2 (200∼500 µM) could stimulate apoptosis in HUVECs. All the effects of H2O2 on angiogenesis could be suppressed by NADPH oxidase inhibitors, which suggests that NADPH oxidase acts downstream of H2O2 to produce O2 − and then to regulate angiogenesis. In summary, our results suggest that H2O2 as well as O2 − mediated by NADPH oxidase have biphasic effects on angiogenesis in vitro and in vivo.
Normal fibroblasts promote myodifferentiation of myoblasts from sex‐linked dwarf chicken via up‐regulation of β1 integrin
Authors: Zhang Yu , Li Hai , Lian Zhengxing , Li Ning
Published: June 2010

Fusion of monomyoblasts to form multinucleated myotubes is a prerequisite for skeletal myogenesis, and muscle fibroblast–myoblast interaction plays an important role in the process; however, relative studies are limited. In the current study, SLD (sex‐linked dwarf) chicken, a myogenic deficient model caused by GH (growth hormone)–IGF‐I axis deficiency due to dw gene mutation, was introduced to study effects of fibroblasts on myodifferentiation. Using a membrane insert co‐culture system, we identified that, compared with SLD fibroblasts, normal fibroblasts promoted myogenesis of primary SLD myoblasts by improving their differentiation potential in a paracrine fashion, and this effect was involved in both primary and secondary fusions. This process was also coupled with up‐regulation of β1 integrin, and reduced myogenesis, resulting from siRNA interference demonstrated that β1 integrin was required for the response. Further, in terms of genetic discrepancy between normal and SLD fibroblasts, GH–IGF‐I signalling might play a role in this paracrine control.
In situ reflection anisotropy spectroscopy analysis of heteroepitaxial GaP films grown on Si(100)
Authors: Döscher Henning , Hannappel Thomas
Published: June 2010

In situ reflection anisotropy spectroscopy (RAS)/reflection difference spectroscopy was applied as a quantitative probe of antiphase domains in heteroepitaxial films deposited on Si(100). The in situ probe was deduced from the spectroscopic signature of the P-rich, homoepitaxial GaP(100) surface and its well-established atomic reconstruction via a comparative investigation using RAS (homoepitaxial versus heteroepitaxial). For that, we determined changes in temperature, surface reconstruction, atomic order, and excess phosphorus on the surface of the homoepitaxial GaP(100) samples to specifically change the RA spectra in terms of shape and intensity. According to the presence of antiphase disorder a linear reduction in the RAS signal occurred. In addition, RA spectra of the heteroepitaxially prepared GaP/Si(100) films contained characteristic deviations from RA spectra of homoepitaxial GaP(100). They originated from reflections at the additional GaP/Si(100) heterointerface. Simple interference affecting the normalization of the RAS signal was found as a major source of the deviations and, thus, corresponding corrections were applied in the RA spectra. At photon energies around 3.2 eV, the correction even amplified the difference between the spectra of GaP/Si(100) and GaP(100) samples. This indicated an additional optical anisotropy induced by the interface reflection which peaked in the range of the determined spectral position.
Strain tensors in layer systems by precision ion channeling measurements
Authors: Trinkaus H. , Buca D. , Holländer B. , Minamisawa R. A. , Mantl S. , Hartmann J. M.
Published: June 2010

A powerful method for analyzing general strain states in layer systems is the measurement of changes in the ion channeling directions. We present a systematic derivation and compilation of the required relations between the strain induced angle changes and the components of the strain tensor for general crystalline layer systems of reduced symmetry compared to the basic (cubic) crystal. It is shown that, for the evaluation of channeling measurements, virtually all layers of interest may be described as being “pseudo-orthorhombic.” The commonly assumed boundary conditions and the effects of surface misorientations on them are discussed. Asymmetric strain relaxation in layers of reduced symmetry is attributed to a restriction in the slip system of the dislocations inducing it. The results are applied to {110}SiGe/Si layer systems.
How many atoms are required to characterize accurately trajectory fluctuations of a protein?
Authors: Cukier Robert I.
Published: June 2010

Large molecules, whose thermal fluctuations sample a complex energy landscape, exhibit motions on an extended range of space and time scales. Principal component analysis (PCA) is often used to extract dominant motions that in proteins are typically domain motions. These motions are captured in the large eigenvalue (leading) principal components. There is also information in the small eigenvalues, arising from approximate linear dependencies among the coordinates. These linear dependencies suggest that instead of using all the atom coordinates to represent a trajectory, it should be possible to use a reduced set of coordinates with little loss in the information captured by the large eigenvalue principal components. In this work, methods that can monitor the correlation (overlap) between a reduced set of atoms and any number of retained principal components are introduced. For application to trajectory data generated by simulations, where the overall translational and rotational motion needs to be eliminated before PCA is carried out, some difficulties with the overlap measures arise and methods are developed to overcome them. The overlap measures are evaluated for a trajectory generated by molecular dynamics for the protein adenylate kinase, which consists of a stable, core domain, and two more mobile domains, referred to as the LID domain and the AMP-binding domain. The use of reduced sets corresponding, for the smallest set, to one-eighth of the alpha carbon (CA) atoms relative to using all the CA atoms is shown to predict the dominant motions of adenylate kinase. The overlap between using all the CA atoms and all the backbone atoms is essentially unity for a sum over PCA modes that effectively capture the exact trajectory. A reduction to a few atoms (three in the LID and three in the AMP-binding domain) shows that at least the first principal component, characterizing a large part of the LID-binding and AMP-binding motion, is well described. Based on these results, the overlap criterion should be applicable as a guide to postulating and validating coarse-grained descriptions of generic biomolecular assemblies.
Correlation of structural properties with energy transfer of Eu-doped ZnO thin films prepared by sol-gel process and magnetron reactive sputtering
Authors: Petersen Julien , Brimont Christelle , Gallart Mathieu , Schmerber Guy , Gilliot Pierre , Ulhaq-Bouillet Corinne , Rehspringer Jean-Luc , Colis Silviu , Becker Claude , Slaoui Abdelillah , Dinia Aziz
Published: June 2010

We investigated the structural and optical properties of Eu-doped ZnO thin films made by sol-gel technique and magnetron reactive sputtering on Si (100) substrate. The films elaborated by sol-gel process are polycrystalline while the films made by sputtering show a strongly textured growth along the c-axis. X-ray diffraction patterns and transmission electron microscopy analysis show that all samples are free of spurious phases. The presence of Eu2+ and Eu3+ into the ZnO matrix has been confirmed by x-ray photoemission spectroscopy. This means that a small fraction of Europium substitutes Zn2+ as Eu2+ into the ZnO matrix; the rest of Eu being in the trivalent state. This is probably due to the formation of Eu2O3 oxide at the surface of ZnO particles. This is at the origin of the strong photoluminescence band observed at 2 eV, which is characteristic of the D50→F72 Eu3+ transition. In addition the photoluminescence excitonic spectra showed efficient energy transfer from the ZnO matrix to the Eu3+ ion, which is qualitatively similar for both films although the sputtered films have a better structural quality compared to the sol-gel process grown films.
Substrate influence on the optical and structural properties of pulsed laser deposited BiFeO3 epitaxial films
Authors: Himcinschi C. , Vrejoiu I. , Friedrich M. , Nikulina E. , Ding L. , Cobet C. , Esser N. , Alexe M. , Rafaja D. , Zahn D. R. T.
Published: June 2010

Epitaxial BiFeO3 films pulsed laser deposited on SrTiO3, Nb:doped SrTiO3, and DyScO3 were studied using variable angle spectroscopic ellipsometry, vacuum ultraviolet ellipsometry, micro-Raman spectroscopy, and x-ray diffraction. The energy band gap of the film deposited on DyScO3 is 2.75 eV, while the one for the film deposited on Nb:doped SrTiO3 is larger by 50 meV. The blueshift in the dielectric function of the BiFeO3 films deposited on Nb:doped SrTiO3 compared to the films deposited on DyScO3, indicates a larger compressive strain in the films deposited on Nb:doped SrTiO3. This is confirmed by Raman spectroscopy and by high resolution x-ray diffraction investigations.
Dynamic structural change in Pd-perovskite automotive catalyst studied by time-resolved dispersive x-ray absorption fine structure
Authors: Matsumura Daiju , Nishihata Yasuo , Mizuki Jun’ichiro , Taniguchi Masashi , Uenishi Mari , Tanaka Hirohisa
Published: June 2010

Dynamic structural change in Pd-perovskite automotive catalyst, LaFe0.9Pd0.1O3, which has a high catalytic activity during aging, was studied by in situ time-resolved dispersive x-ray absorption fine structure spectroscopy at 200–500 °C. An Al2O3-based conventional catalyst was also studied. In a reductive atmosphere, both catalysts showed similar temperature dependences of structural transformation from an oxide to a metal. However, different temperature dependence was observed in an oxidative atmosphere. A faster response in the structural change was observed in the Pd-perovskite catalyst than in the Pd/Al2O3 catalyst. It was revealed that Pd-perovskite shows a considerably fast structural change to the oxidized state via the movement of Pd atoms into the perovskite crystal, in comparison with Pd/Al2O3 showing two-step structural change for making PdO.
Structural, electrical, and magnetic properties of multiferroic Bi1−xLaxFe1−yCoyO3 thin films
Authors: Yang K. G. , Zhang Y. L. , Yang S. H. , Wang B.
Published: June 2010

Bi 1 − x La x Fe 1 − y Co y O 3 (x=0, 0.1; y=0, 0.05, 0.1) polycrystalline thin films were fabricated on Pt/Ti/SiO2/Si(111) substrates via chemical solution deposition method. X-ray diffraction analysis revealed a phase transition in La–Co codoped BiFeO3 (BFO) thin films. Saturated ferroelectric hysteresis characteristics in La–Co codoped BFO thin films were observed, and the conduction behavior of Bi1−xLaxFe1−yCoyO3 thin films investigated to understand the leakage mechanisms. In the low applied field, the conduction mechanism of Bi1−xLaxFe1−yCoyO3 thin films was found to be dominantly Ohmic. In the high applied field, the conduction mechanisms of pure and La doped BFO thin films were found to be trap-filled-limited and Poole–Frenkel emission, and that of Co doped and La–Co codoped BFO thin films Schottky emission. The dielectric constant of Bi0.9La0.1Fe0.9Co0.1O3 thin film, in the frequency range of 1 to 2000 kHz, was nearly two times higher than that of pure BFO thin film while the dielectric loss tan δ was small at values below 0.07. It was found that saturation magnetization in BFO thin films could be enhanced by La or Co doping, and obviously by La–Co codoping too.
Localization and preparation of recombination-active extended defects for transmission electron microscopy analysis
Authors: Falkenberg M. A. , Schuhmann H. , Seibt M. , Radisch V.
Published: June 2010

Recombination-active extended defects in semiconductors frequently occur at a low density which makes their structural and chemical analysis by transmission electron microscopy (TEM) techniques virtually impossible. Here an approach is described that uses in situ electron beam induced current (EBIC) in a focused ion beam machine to localize such defects for TEM lamella preparation. As an example, a defect complex occurring in block-cast multicrystalline silicon with a density of less than 104 cm−3 has been prepared and analyzed by TEM. The chemical sensitivity of the technique is estimated to be about 1013 atoms cm−2 which is comparable to synchrotron-based x-ray techniques. The localization accuracy of the TEM lamella is shown to be better than 50 nm when low-energy EBIC is used.