bluuebunny/crossref_metadata_2025 huggingface dataset:
The serotonin transporter gene polymorphism (5-HTTLPR) and affective symptoms among women diagnosed with borderline personality disorder
Authors: Maurex L. , Zaboli G. , Öhman A. , Åsberg M. , Leopardi R.
Published: August 2009

Gene variants of the serotonin transporter have been associated with vulnerability to affective disorders. In particular, the presence of one or two copies of the short (s) allele of the 5-HTTLPR polymorphism has been associated with reduced serotonin transporter expression and function, and vulnerability to affective disorders. To test for an association between variants of the serotonin transporter gene polymorphism (5-HTTLPR) and relevant clinical features of borderline personality disorder (BPD), a psychiatric disorder with symptoms characteristic for serotonin dysfunction, 77 women with BPD were genotyped in the 5-HTTLPR polymorphism. They rated their subjective experience of borderline-specific, depressive, anxious and obsessive-compulsive symptoms, and were interviewed about lifetime incidence of suicide attempts and self-harming acts. Carriers of two s alleles of the 5-HTTLPR reported more symptoms of borderline, depression, anxiety and obsessive-compulsive behaviours, but not of suicidal and self-injury behaviour, compared to carriers of a long (l) allele. This indicates that the 5-HTTLPR ss homozygous genotype might influence serotonin function affecting susceptibility to both borderline-specific, depressive, anxious and obsessive-compulsive symptoms in BPD, and leading to a more severe symptomatology related to these clinical features. Further, this suggests that 5-HTT gene variants may not be as influential on suicidal and self-injury behaviour in BPD.
Extent and predictors of stigma experienced by patients with schizophrenia
Authors: Świtaj P. , Wciórka J. , Smolarska-Świtaj J. , Grygiel P.
Published: August 2009

Background

Schizophrenia is regarded as one of the most stigmatized mental illnesses. Relatively few studies have investigated actual stigma experiences among people with schizophrenia and the factors which may contribute to it.

Aims

This cross-sectional study assesses the extent of stigma experienced by patients with schizophrenia and attempts to establish its clinical and sociodemographic predictors.

Methods

A total of 153 subjects with schizophrenia (62 outpatients and 91 inpatients) were evaluated with the use of the Stigma section of the Consumer Experiences of Stigma Questionnaire (CESQ) and several instruments measuring their subjective quality of life, social functioning and severity of psychiatric symptoms.

Results

Stigmatization experiences were common among respondents who most frequently reported having concealed their illness (86%), witnessed others saying offensive things about the mentally ill (69%), worried about being viewed unfavorably (63%) and been treated as less competent (59%). Higher levels of stigma were related to lower subjective quality of life and younger age of illness onset. No significant associations were found between stigma and symptoms or level of social functioning.

Conclusion

Our findings point at the reduced life satisfaction as a key aspect of the subjective experience of the stigma of schizophrenia.
IMPACT OF SEASON AND HARVEST FREQUENCY ON BIOMASS AND ESSENTIAL OIL YIELDS OF ARTEMISIA HERBA-ALBA CULTIVATED IN SOUTHERN TUNISIA
Authors: MIGHRI HEDI , AKROUT AHMED , CASANOVA JOSEPH , TOMI FELIX , NEFFATI MOHAMED
Published: August 2009

Artemisia herba-alba Asso has been successfully cultivated in the Tunisian arid zone. However, information regarding the effects of the harvest frequency on its biomass and essential oil yields is very limited. In this study, the effects of three different frequencies of harvesting the upper half of the A. herba-alba plant tuft were compared. The harvest treatments were: harvesting the same individual plants at the flowering stage annually; harvesting the same individual plants at the full vegetative growth stage annually and harvesting the same individual plants every six months. Statistical analyses indicated that all properties studied were affected by the harvest frequency. Essential oil yield, depended both on the dry biomass and its essential oil content, and was significantly higher from plants harvested annually at the flowering stage than the other two treatments. The composition of the β- and α-thujone-rich oils did not vary throughout the experimental period.
Are non-abstract brain representations of number developmentally plausible?
Authors: Ansari Daniel
Published: August 2009

The theory put forward by Cohen Kadosh & Walsh (CK&W) proposing that semantic representations of numerical magnitude in the parietal cortex are format-specific, does not specify how these representations might be constructed over the course of learning and development. The developmental predictions of the non-abstract theory are discussed and the need for a developmental perspective on the abstract versus non-abstract question highlighted.
The case for a notation-independent representation of number
Authors: Dehaene Stanislas
Published: August 2009

Cohen Kadosh & Walsh (CK&W) neglect the solid empirical evidence for a convergence of notation-specific representations onto a shared representation of numerical magnitude. Subliminal priming reveals cross-notation and cross-modality effects, contrary to CK&W's prediction that automatic activation is modality and notation-specific. Notation effects may, however, emerge in the precision, speed, automaticity, and means by which the central magnitude representation is accessed.
Concrete magnitudes: From numbers to time
Authors: Falter Christine M. , Noreika Valdas , Kiverstein Julian , Mölder Bruno
Published: August 2009

Cohen Kadosh & Walsh (CK&W) present convincing evidence indicating the existence of notation-specific numerical representations in parietal cortex. We suggest that the same conclusions can be drawn for a particular type of numerical representation: the representation of time. Notation-dependent representations need not be limited to number but may also be extended to other magnitude-related contents processed in parietal cortex (Walsh 2003).
Numbers and numerosities: Absence of abstract neural realization doesn't mean non-abstraction
Authors: Núñez Rafael E.
Published: August 2009

The neural realization of number in abstract form is implausible, but from this it doesn't follow that numbers are not abstract. Clear definitions of abstraction are needed so they can be applied homogenously to numerical and non-numerical cognition. To achieve a better understanding of the neural substrate of abstraction, productive cognition – not just comprehension and perception – must be investigated.
Numerical abstraction: It ain't broke
Authors: Cantlon Jessica F. , Cordes Sara , Libertus Melissa E. , Brannon Elizabeth M.
Published: August 2009

The dual-code proposal of number representation put forward by Cohen Kadosh & Walsh (CK&W) accounts for only a fraction of the many modes of numerical abstraction. Contrary to their proposal, robust data from human infants and nonhuman animals indicate that abstract numerical representations are psychologically primitive. Additionally, much of the behavioral and neural data cited to support CK&W's proposal is, in fact, neutral on the issue of numerical abstraction.
Common mistakes about numerical representations
Authors: Pesenti Mauro , Andres Michael
Published: August 2009

Cohen Kadosh & Walsh (CK&W) argue that recent findings challenge the hypothesis of abstract numerical representations. Here we show that because, like many other authors in the field, they rely on inaccurate definitions of abstract and non-abstract representations, CK&W fail to provide compelling evidence against the abstract view.
Numerical representation, math skills, memory, and decision-making
Authors: Peters Ellen , Castel Alan
Published: August 2009

The consideration of deliberate versus automatic processing of numeric representations is important to math education, memory for numbers, and decision-making. In this commentary, we address the possible roles for numeric representations in such higher-level cognitive processes. Current evidence is consistent with important roles for both automatic and deliberative processing of the representations.
Abstract representations of number: What interactions with number form do not prove and priming effects do
Authors: Santens Seppe , Fias Wim , Verguts Tom
Published: August 2009

We challenge the arguments of Cohen Kadosh & Walsh (CK&W) on two grounds. First, interactions between number form (e.g., notation, format, modality) and an experimental factor do not show that the notations/formats/modalities are processed separately. Second, we discuss evidence that numbers are coded abstractly, also when not required by task demands and processed unintentionally, thus challenging the authors' dual-code account
In search of non-abstract representation of numbers: Maybe on the right track, but still not there
Authors: Tzelgov Joseph , Pinhas Michal
Published: August 2009

We agree that the default numerical representation is best accessed by probing automatic processing. The locus of this representation is apparently at the horizontal intraparietal sulcus (HIPS), the convergence zone of magnitude information. The parietal lobes are the right place to look for non-abstract representation of magnitude, yet the proof for that is still to be found.
Do infants count like scientists?
Authors: Wiefel Andreas , Pauen Sabina , Dueck Michael
Published: August 2009

We discuss methodological problems and present our own empirical data on calculation tasks in toddlers. We propose to develop enriching theoretical models concerning quantity representations, based on empirical findings from developmental psychology. A revitalization of the debate is worthy, because it is reminiscent of the philosophical dispute on universal entities in scholasticism and Plato's theory of ideal numbers.
What is an (abstract) neural representation of quantity?
Authors: Piazza Manuela , Izard Veronique
Published: August 2009

We argue that Cohen Kadosh & Walsh's (CK&W's) definitions of neural coding and of abstract representations are overly shallow, influenced by classical cognitive psychology views of modularity and seriality of information processing, and incompatible with the current knowledge on principles of neural coding. As they stand, the proposed dichotomies are not very useful heuristic tools to guide our research towards a better understanding of the neural computations underlying the processing of numerical quantity in the parietal cortex.
Abstract or not abstract? Well, it depends …
Authors: Pease Alison , Smaill Alan , Guhe Markus
Published: August 2009

The target article by Cohen Kadosh & Walsh (CK&W) raises questions as to the precise nature of the notion of abstractness that is intended. We note that there are various uses of the term, and also more generally in mathematics, and suggest that abstractness is not an all-or-nothing property as the authors suggest. An alternative possibility raised by the analysis of numerical representation into automatic and intentional codes is suggested.
A manoeuvre control strategy for flexible-joint manipulators with joint dry friction
Authors: Salmasi H. , Fotouhi R. , Nikiforuk P. N.
Published: August 2009

A new control strategy based on the singular perturbation method and integral manifold concept is introduced for flexible-joint manipulators with joint friction. In controllers so far developed based on the singular perturbation theory, the dynamics of actuators of flexible-joint manipulators are partially modelled, and the coupling between actuators and links is ignored. This assumption leads to inaccuracy in control performance and error in trajectory tracking which is crucial in high-precision manipulation tasks. In this paper, a comprehensive dynamic model which takes into account the coupling between actuators and links is developed and a composite controller is then designed based on the singular perturbation theorem and integral manifold concept. To overcome the joint friction, a novel method is introduced in which a linear feed-forward torque is designed using the principle of work and energy. Finally, the experimental set-up of a single rigid-link flexible-joint manipulator in the Robotics Laboratory at the University of Saskatchewan is used to verify the proposed controller. Experimental results employing the new controller show that the trajectory tracking error during and at the end of the motion of the robot manipulator is significantly reduced.
Autonomous rendezvous and robotic capturing of non-cooperative target in space
Authors: Xu Wenfu , Liang Bin , Li Cheng , Xu Yangsheng
Published: August 2009

The technologies of autonomous rendezvous and robotic capturing of non-cooperative targets are very crucial for the future on-orbital service. In this paper, we proposed a method to achieve this aim. Three problems were addressed: the target recognition and pose (position and attitude) measurement based on the stereo vision, the guidance, navigation and control (GNC) of the chaser, and the coordinated plan and control of space robot (CP&C). The pose measurement algorithm includes image filtering, edge detection, line extraction, stereo match and pose computing, et al. Based on the measured values, a certain GNC algorithm was designed for the chaser to approach and rendezvous with the target. Then the CP&C algorithm, which is proved to be advantageous over the traditional separated method, was used to plan and track the trajectories of the base pose and the joint angle. At last, a 3D simulation system was developed to evaluate the proposed method. Simulation results verified the corresponding algorithms.
Causes of death and cardiovascular complications in adolescents and adults with congenitally malformed hearts: an autopsy study of 102 cases
Authors: Aiello Vera Demarchi , Binotto Maria Angélica , Demarchi Lea Maria , Lopes Antonio Augusto , Barbero Marcial Miguel
Published: August 2009

Objectives

To identify the causes of death and main cardiovascular complications in adolescents and adults with congenitally malformed hearts.

Design

Retrospective review of 102 necropsy reports from a tertiary centre obtained over a period of 19 years.

Methods

The diagnosis, the operated or non-operated state of the main defect, the cause of death, and main complications were related to the age and gender. Other clinically relevant conditions, and identifiable sequels of previous diseases, were also noted.

Results

The ages ranged from 15 to 69 years, with a mean of 31.1 and a median of 28 years, with no difference detected according to the gender. Of the patients, two-thirds had been submitted to at least one cardiac surgery. The mean age of death was significantly higher in non-operated patients (p = 0.003). The most prevalent cause of death in the whole group was related to recent surgery, found in one-third. From them, two-fifths corresponded to reoperations. Among the others, cardiac failure was the main terminal cause in another third, and the second cause was pulmonary thromboembolism in just over one-fifth, presenting a significant association with histopathological signs of pulmonary hypertension (p = 0.011). Infection was the cause of death in 7.8% of the patients, all previously operated. Acute infective endocarditis was present or was the indication for the recent surgery in one-tenth of the patients, this cohort having a mean age of 27.8 years. There was a statistically significant association between the occurrence of endocarditis and defects causing low pulmonary blood flow (p = 0.043).

Conclusions

Data derived from necropsies of adults with congenital heart defects can help the multidisciplinary team refine both their diagnosis and treatment.
Heterogeneity in mild cognitive impairment: Differences in neuropsychological profile and associated white matter lesion pathology
Authors: DELANO-WOOD LISA , BONDI MARK W. , SACCO JOSHUA , ABELES NORM , JAK AMY J. , LIBON DAVID J. , BOZOKI ANDREA
Published: August 2009

This study examined whether distinct neuropsychological profiles could be delineated in a sample with Mild Cognitive Impairment (MCI) and whether white matter lesion (WML) burden contributed to MCI group differences. A heterogeneous, clinical sample of 70 older adults diagnosed with MCI was assessed using cognitive scores, and WML was quantified using a semi-automated, volumetric approach on T2-weighted fluid-attenuated inversion recovery (FLAIR) images. Using cluster and discriminant analyses, three distinct groups (Memory/Language, Executive/Processing Speed, and Pure Memory) were empirically derived based on cognitive scores. Results also showed a dose dependent relationship of WML burden to MCI subgroup, with the Executive/Processing Speed subgroup demonstrating significantly higher levels of WML pathology when compared to the other subgroups. In addition, there was a dissociation of lesion type by the two most impaired subgroups (Memory/Language and Executive/Processing Speed) such that the Memory/Language subgroup showed higher periventricular lesion (PVL) and lower deep white matter lesion (DWML) volumes, whereas the Executive/Processing Speed demonstrated higher DWML and lower PVL volumes. Results demonstrate that distinct MCI subgroups can be empirically derived and reliably differentiated from a heterogeneous MCI sample, and that these profiles differ according to WML burden. Overall, findings suggest different underlying pathologies within MCI and contribute to our understanding of MCI subtypes. (JINS, 2009,15, 906–914.)
Individual differences in semantic switching flexibility: Effects of handedness
Authors: SONTAM VARALAKSHMI , CHRISTMAN STEPHEN D. , JASPER JOHN D.
Published: August 2009

The semantic fluency task is a widely used assessment tool for evaluating memory-related cognitive deficits in neurological and neuropsychiatric disorders. The present study investigates individual differences in performance on this task in a normal population. The aim is to explore handedness differences in switching and clustering tendencies when performing this task. Consistent with our prediction, when asked to produce as many animal names as possible in 1 min, mixed handers demonstrated greater switching between different subcategories of animals than strong handers. These findings are interpreted in terms of the more diffuse spread of activation among conceptual representations in the right hemisphere, and greater access to right hemisphere processes in mixed handers. The findings have implications for the research communities using the semantic fluency task, irrespective of whether or not they are looking at handedness differences per se. (JINS, 2009, 15, 1023–1027.)
The Preimaginal Phases and Development ofPachycrepoideus vindemmiae(Hymenoptera, Pteromalidae) on Mediterranean Fruit Fly,Ceratitis capitata(Diptera, Tephritidae)
Authors: Tormos José , Beitia Francisco , Böckmann Elias A. , Asís Josep D. , Fernández Severiano
Published: August 2009

The development and morphology of the immature phases ofPachycrepoideus vindemmiae(Rondani, 1875) (Hymenoptera, Pteromalidae) are described from a laboratory rearing culture maintained onCeratitis capitata(Wiedemann, 1824) (Diptera, Tephritidae) using microscopic techniques, including light and scanning electron microscopy. The surface of the chorion of the egg is granulated, and the micropyle occurs at the anterior end. The labrum of the first instar larva does not have sensilla, and the second to fourth instar larvae have setae on the head. The mature larva is characterized by the position and number of the integumental differentations (sensilla and setae). On completion of larval development, an adecticous and exarate pupa is produced. As for the adult, the mandibles of the pupae are toothed. Five larval instars are recorded, based on statistical analyses of the sizes of the larval mandibles in combination with characters such as the number of exuviae and excretion of the meconium. Developmental time from egg to adult emergence was ∼18–20 days for males and ∼21–23 days for females at 21–26°C, 55–85 relative humidity, and a 16L:8D photoperiod. The results show that the eggs and different larval instars of this parasitoid can be unambiguously identified only by scanning electron microscope.
Research on the hygroscopic properties of aerosols by measurement and modeling during CAREBeijing‐2006
Authors: Liu Xingang , Zhang Yuanhang , Jung Jinsang , Gu Jianwei , Li Yunpeng , Guo Song , Chang Shih‐Yu , Yue Dingli , Lin Peng , Kim Young J. , Hu Min , Zeng Limin , Zhu Tong
Published: August 2009

To further understand and improve air quality for the 2008 Beijing Olympic Games, the Campaigns of Air Quality Research in Beijing and Surrounding Region 2006 (CAREBeijing‐2006) were carried out in an urban and a suburban area from 10 August to 12 September 2006. As a part of an intensive series of measurements, the optical and physical properties of the aerosol were monitored together with identification of the chemical species involved. A method to calculate the hygroscopic factor for aerosol scattering f(RH), defined as the ratio of the aerosol scattering coefficient at given relative humidity (RH) to that at 35% RH, is proposed on the basis of the optical parameters. Over the course of the study f(80%) = 1.63 ± 0.19. The observation that the molar ratio of NH4+ to (2*SO42− plus NO3−) was very close to 1 implies that the chemical form of the sulfate aerosol may be ammonium sulfate (NH4)2SO4 and that nitrate possibly existed as NH4NO3. On the basis of the measurements of size‐resolved chemistry, RH, and published functional relationships between the chemical composition and water uptake, the aerosol scattering coefficients could be calculated by the Mie theory for the major particle species (ammonium sulfate, ammonium nitrate, sodium chloride, particulate organic matter, elemental carbon, and residual material). This retrieval method synthesizes the high temporal resolution of mass concentration measurements and low temporal resolution size distribution for water soluble ionic components and carbonaceous aerosols. A local closure experiment is obtained by comparing the measured f(RH) with model calculations using aerosol chemical composition and chemical thermodynamics. Results from the closure study show that the measured and the predicted values of f(RH) agree within measurement uncertainties.
Source analysis of volatile organic compounds by positive matrix factorization in urban and rural environments in Beijing
Authors: Yuan Zibing , Lau Alexis Kai Hon , Shao Min , Louie Peter K. K. , Liu Shaw Chen , Zhu Tong
Published: August 2009

This paper applies advance receptor model positive matrix factorization (PMF) source analysis to 1‐h resolution VOC data collected at Yufa (rural site) and Peking University, or PKU (urban site), in Beijing. A range of major VOC sources was identified, including vehicle emissions, liquefied petroleum gas, coal combustion, and biogenic emissions. Vehicle activities contributed approximately 62% of VOC loading and 55% of ozone forming potential at the PKU site, compared to 38% of VOC loading and 42% of ozone forming potential at Yufa. These results indicate that the control of vehicle emissions is essential to alleviating VOC pollution, particularly in urban Beijing. We found that VOC emission strengths are relatively consistent throughout the day in the rural area; variation of mixing height therefore is a controlling factor for ground‐level VOC concentration. In the urban area, both vehicle activity and variation of mixing height strongly impact VOC levels. Local sources within Beijing appeared to contribute most of the VOCs recorded at both urban and rural areas. However, as some of the VOC species are quite reactive, VOC emitted from distant sources would have been depleted during transportation, concurrent with the formation of secondary pollutants such as ozone and sulfate. Such depletion would mean that this source apportionment analysis would tend to overestimate the ozone forming capacity of local VOC sources compared to emissions from distant sources. Nevertheless, this study illustrates that high‐resolution VOC measurements, especially those with a sampling frequency on the scale of less than 1 day, combined with PMF, can make a strong contribution to our understanding of pollutant emissions and transport characteristics and is a useful tool with which to formulate effective pollution control strategies.
Mars Reconnaissance Orbiter Mars Color Imager (MARCI): Instrument description, calibration, and performance
Authors: Bell J. F. , Wolff M. J. , Malin M. C. , Calvin W. M. , Cantor B. A. , Caplinger M. A. , Clancy R. T. , Edgett K. S. , Edwards L. J. , Fahle J. , Ghaemi F. , Haberle R. M. , Hale A. , James P. B. , Lee S. W. , McConnochie T. , Noe Dobrea E. , Ravine M. A. , Schaeffer D. , Supulver K. D. , Thomas P. C.
Published: August 2009

The Mars Color Imager (MARCI) instrument aboard the NASA Mars Reconnaissance Orbiter spacecraft is a wide‐angle, multispectral Charge‐Coupled Device (CCD) “push frame” imaging camera designed to provide frequent, synoptic‐scale color imaging of the Martian atmosphere and surface. MARCI uses a 1024 × 1024 pixel interline transfer CCD detector that has seven narrowband interference filters bonded directly to the CCD. Five of the filters are in the visible to short‐wave near‐infrared wavelength range (437, 546, 604, 653, and 718 nm) and two are in the ultraviolet range (258 and 320 nm). Here we describe the scientific objectives of the MARCI investigation and the basic characteristics, calibration, and in‐flight performance of the MARCI instrument. We include several examples of early scientific results and investigations enabled by an extensive preflight and in‐flight calibration program and by validation of the performance of the instrument in flight.
Holocene productivity changes off Adélie Land (East Antarctica)
Authors: Denis Delphine , Crosta Xavier , Schmidt Sabine , Carson Damien S. , Ganeshram Raja S. , Renssen Hans , Crespin Julien , Ther Olivier , Billy Isabelle , Giraudeau Jacques
Published: August 2009

This study presents the first high‐resolution multiproxy investigation of primary productivity (PP) during the Holocene from the Antarctic continental margins. Micropaleontological and geochemical data from the sediment core MD03‐2601, associated to sea ice model outputs, give unprecedented insights into the biological pump of the Antarctic coastal area off Adélie Land in response to climatic changes. Plurimillennial and millennial changes of PP are observed in the study area in response to changes in nutrient availability, stratification, and growing season duration, which are linked to sea ice, upwelling, wind, and glacier dynamics. The precessional cycle seems to be responsible in the PP long‐term variations, while forcing factors involved at the millennial timescale remain more enigmatic. Our results emphasize enhanced biological pump during warmer and windier Holocene phases because of a longer growing season and greater nutrient input. Antarctic coastal and continental shelf zones may therefore represent a more intense carbon sink in the future.
Cooling history of Atlantis Bank oceanic core complex: Evidence for hydrothermal activity 2.6 Ma off axis
Authors: Schwartz Joshua J. , John Barbara E. , Cheadle Michael J. , Reiners Peter W. , Baines A. Graham
Published: August 2009

We report 26 (U‐Th)/He zircon ages from Atlantis Bank, Southwest Indian Ridge, which constrain time scales and rates of lower crustal cooling in ultraslow spreading oceanic crust in this setting. Samples from the detachment fault surface indicate that denuded oceanic crust cooled rapidly (<1 Ma), yielding cooling rates >1200°C/Ma, consistent with existing models for the cooling of oceanic crust. (U‐Th)/He zircon ages from samples collected along N–S and E–W trending faults scarps record young ages inconsistent with standard cooling models for lower oceanic crust. These samples have a mean (U‐Th)/He zircon age 2.6 Ma younger than their corresponding igneous crystallization ages and record cooling through 200°C well outside the rift valley. Similar anomalously young ages are recorded by zircon, sphene, and apatite fission track data from ODP Hole 735B. We interpret these young ages as recording an off‐axis thermal/heating event associated with localized high‐temperature (>300°C) hydrothermal fluid flow resulting from underplated mafic magmas.
Manifestation of the Pacific Decadal Oscillation in the Kuroshio
Authors: Andres Magdalena , Park Jae‐Hun , Wimbush Mark , Zhu Xiao‐Hua , Nakamura Hirohiko , Kim Kuh , Chang Kyung‐Il
Published: August 2009

Pacific Decadal Oscillation (PDO) index is strongly correlated with vertically integrated transport carried by the Kuroshio through the East China Sea (ECS). Transport was determined from satellite altimetry calibrated with in situ data and its correlation with PDO index (0.76) is highest at zero lag. Total PDO‐correlated transport variation carried by the ECS‐Kuroshio and Ryukyu Current is about 4 Sv. In addition, PDO index is strongly negatively correlated, at zero lag, with NCEP wind‐stress‐curl over the central North Pacific at ECS latitudes. Sverdrup transport, calculated from wind‐stress‐curl anomalies, is consistent with the observed transport variations. Finally, PDO index and ECS‐Kuroshio transport are each negatively correlated with Kuroshio Position Index in the Tokara Strait; this can be explained by a model in which Kuroshio path is steered by topography when transport is low and is inertially controlled when transport is high.
Solar‐wind proton access deep into the near‐Moon wake
Authors: Nishino M. N. , Fujimoto M. , Maezawa K. , Saito Y. , Yokota S. , Asamura K. , Tanaka T. , Tsunakawa H. , Matsushima M. , Takahashi F. , Terasawa T. , Shibuya H. , Shimizu H.
Published: August 2009

We study solar wind (SW) entry deep into the near‐Moon wake using SELENE (KAGUYA) data. It has been known that SW protons flowing around the Moon access the central region of the distant lunar wake, while their intrusion deep into the near‐Moon wake has never been expected. We show that SW protons sneak into the deepest lunar wake (anti‐subsolar region at ∼100 km altitude), and that the entry yields strong asymmetry of the near‐Moon wake environment. Particle trajectory calculations demonstrate that these SW protons are once scattered at the lunar dayside surface, picked‐up by the SW motional electric field, and finally sneak into the deepest wake. Our results mean that the SW protons scattered at the lunar dayside surface and coming into the night side region are crucial for plasma environment in the wake, suggesting absorption of ambient SW electrons into the wake to maintain quasi‐neutrality.
Insufficient forcing uncertainty underestimates the risk of high climate sensitivity
Authors: Tanaka Katsumasa , Raddatz Thomas , O'Neill Brian C. , Reick Christian H.
Published: August 2009

Uncertainty in climate sensitivity is a fundamental problem for projections of the future climate. Equilibrium climate sensitivity is defined as the asymptotic response of global‐mean surface air temperature to a doubling of the atmospheric CO2 concentration from the preindustrial level (≈280 ppm). In spite of various efforts to estimate its value, climate sensitivity is still not well constrained. Here we show that the probability of high climate sensitivity is higher than previously thought because uncertainty in historical radiative forcing has not been sufficiently considered. The greater the uncertainty that is considered for radiative forcing, the more difficult it is to rule out high climate sensitivity, although low climate sensitivity (<2°C) remains unlikely. We call for further research on how best to represent forcing uncertainty.
Convergent temporal dynamics of the human infant gut microbiota
Authors: Trosvik Pål , Stenseth Nils Christian , Rudi Knut
Published: August 2009

Temporal dynamics of the human gut microbiota is of fundamental importance for the development of proper gut function and maturation of the immune system. Here we present a description of infant gut ecological dynamics using a combination of nonlinear data modeling and simulations of the early infant gut colonization processes. Principal component analysis of infant microbiota 16S rRNA gene microarray data showed that the main directions of variation were defined by three phylum-specific probes targeting Bacteroides, Proteobacteria and Firmicutes. Nonlinear regression analysis identified several dynamic interactions between these three phyla. Simulations of the early phylum-level colonization process showed the relatively rapid establishment of an equilibrium community after an unstable initial phase. In general, varying the initial composition of phyla in the simulations had little bearing on the final equilibrium. The dynamic interaction model was found to maintain its predictive ability for Proteobacteria and Firmicutes well into the simulation, whereas Bacteroides densities tended to be underestimated, possibly due to host top-down selection for Bacteroides. In accordance with our model, initial perturbation of the microbiota by different mode of delivery (vaginal and C-section) did not affect the later phylum composition in the infants investigated. Considering the predictive ability and convergence of our phylum-level model, we now propose that deterministic bacterial–bacterial interactions are more important for shaping the human infant gut microbiota than previously anticipated.
A High‐fat vs. a Moderate‐fat Meal in Obese Boys: Nutrient Balance, Appetite, and Gastrointestinal Hormone Changes
Authors: Maffeis Claudio , Surano Maria G. , Cordioli Sira , Gasperotti Sandra , Corradi Massimiliano , Pinelli Leonardo
Published: August 2009

Meal composition is a contributing factor to fat gain. In this study, we investigated the relationship between postprandial nutrient balance, satiety, and hormone changes induced by a high‐fat meal vs. a moderate‐fat meal. Ten prepubertal obese boys (BMI z‐score range: 1.3–3.0) were recruited. Two meals (energy: 590 kcal) were compared: (i) high‐fat (HF) meal: 12% protein, 52% fat, 36% carbohydrates; (ii) moderate‐fat (MF) meal: 12% protein, 27% fat, 61% carbohydrates. Pre‐ and postprandial (5 h) substrate oxidation (indirect calorimetry), appetite (visual analogue scale), biochemical parameters and gastrointestinal hormone concentrations were measured. Carbohydrate balance was significantly (P < 0.001) lower (31.3 (5.7) g/5 h vs. 66.9 (5.9) g/5 h) and fat balance was significantly (P < 0.001) higher (11.5 (3.3) g/5 h vs. −0.7 (2.9) g/5 h) after HF than MF meal. Appetite (area under the curve (AUC)) was significantly reduced after an MF than an HF meal (494 (55) cm·300 min vs. 595 (57) cm·300 min, P < 0.05). Postprandial triglyceride concentration (AUC) was significantly (P < 0.05) higher after an HF than an MF meal: 141.1 (30.3) mmol·300 min/l vs. 79.3 (23.8) mmol·300 min/l, respectively. Peptide YY (PYY), cholecystokinin (CCK), and ghrelin concentrations (AUC) were not significantly different after an HF and MF meal. Glucagon‐like peptide‐1 (GLP‐1) was significantly (P < 0.05) higher after an HF than after an MF meal (72.3 (9.8) ng/ml vs. 22.7 (7.6) ng/ml, respectively), but it did not affect subjective appetite. In conclusion, an MF meal induced a better postprandial metabolic nutrient balance, triglyceride levels, and appetite suppression than an HF meal. Gastrointestinal hormones were not related to clinically assessed hunger suppression after both meals.
Resistance Training Improves Cardiovascular Risk Factors in Obese Women Despite a Significative Decrease in Serum Adiponectin Levels
Authors: Ibáñez Javier , Izquierdo Mikel , Martínez‐Labari Cristina , Ortega Francisco , Grijalba Ana , Forga Luis , Idoate Fernando , García‐Unciti Marisol , Fernández‐Real José M. , Gorostiaga Esteban M.
Published: August 2009

Increased circulating adiponectin and insulin sensitivity are usually observed after body fat loss induced by a weight‐loss diet. Progressive resistance training (PRT) without a concomitant weight‐loss diet significantly decreases visceral fat, thus improving insulin sensitivity. Therefore, the purpose of this study was to ascertain the effects of combined 16‐week PRT and weight‐loss diet on circulating adiponectin and insulin sensitivity index. Thirty‐four obese (BMI: 30–40 kg/m2) women, aged 40–60 year, were randomized to three groups: a control group (C; n = 9); a diet group (WL; n = 12) with a caloric restriction of 500 kcal/d; and a diet plus resistance training group (WL+RT; n = 13) with the same caloric restriction as group WL and a 16‐week supervised whole body PRT of two sessions/week. Both WL and WL+RT groups showed similar decreases in body mass (−6.3% and −7.7%) and visceral fat (−19.9% and −20.5%). WL resulted in an expected increase in circulating levels of adiponectin (P = 0.07) and insulin sensitivity. However, circulating total adiponectin decreased (P < 0.05) in WL+RT group, whereas an improvement in different cardiovascular risk factors (insulin sensitivity, low‐density lipoprotein cholesterol (LDL‐C), etc.) was observed. In conclusion, in obese women a 16‐week combined PRT and weight‐loss diet is accompanied by significant improvements in different cardiovascular risk factors in spite of a significant decrease of circulating adiponectin.
The effect of tilted edges on the shape anisotropy and stray field coupling of uniformly magnetized rectangular elements
Authors: Pütter S. , Mikuszeit N. , Vedmedenko E. Y. , Oepen H. P.
Published: August 2009

The influence of tilted edges on the magnetostatic properties of uniformly magnetized thin rectangular elements is studied. To calculate the magnetostatic energy, the Poisson equation is solved. The shape of the magnetic element is approximated by horizontally assembled thin cuboids and the solutions of Rhodes and Rowlands [Proc. Leeds Phil. Soc. 6, 191 (1954)] are utilized. A second approach is the straightforward integration of the Poisson equation taking into account the trapezoidal shape of the side faces due to the tilted edges. For an adequate number of cuboids, both methods agree very well. It is found that the shape anisotropy of a single magnetic element with tilted edges is reduced compared to that of an ideal cuboid. For a two element system the shape anisotropy competes with the magnetostatic interaction favoring a magnetization orientation parallel to the connecting line of the elements. If the elements are oriented in-line with their short axes, the easy magnetization axis switches at a critical distance between the elements. This distance increases when the elements have tilted edges.
Spatially resolved x-ray diffraction study of GaSb layers grown laterally on SiO2-masked GaAs substrates
Authors: Wierzbicka A. , Domagala J. Z. , Zytkiewicz Z. R.
Published: August 2009

In this work spatially resolved x-ray diffraction (SRXRD) is used to analyze strain in GaSb layers grown by epitaxial lateral overgrowth (ELO) on SiO2-masked (001) GaAs substrates. We show that this heteroepitaxial structure contains local mosaicity in the wing area that cannot be detected by selective etching. While the standard x-ray diffraction measurements only suggest the presence of grain structure of the ELO layer, SRXRD allows examining the microscopic strain distribution in the sample. In particular, size of microblocks and their relative misorientation are determined.
First-principles investigation of Mn δ-layer doped GaN/AlN/GaN (0001) tunneling junctions
Authors: Cui X. Y. , Delley B. , Freeman A. J. , Stampfl C.
Published: August 2009

Highly spin polarized diluted ferromagnetic semiconductors are expected to be widely used as electrodes in spintronic devices. Based on density functional theory calculations, we investigate the feasibility of using Mn-doped wurtzite GaN/AlN/GaN(0001) trilayer junctions for tunnel magnetoresistance (TMR) devices. We address some key issues affecting the degree of spin polarization and spin tunneling transport with the aim of realizing the appealing half-metallicity and large TMR ratio. We propose digital δ-Mn layer doping in GaN, close to the GaN/AlN interfaces for enhanced performance. Layer-resolved band structure and density of states calculations reveal that Mn dopants produce local metallic or half-metallic states surrounded by the host semiconductor materials. Spin polarized electrons can transport across the interfaces, free of the conductivity mismatch problem owing to the strong hybridization between Mn 3d states and the states of surrounding host atoms. The calculated TMR ratio is found to depend sensitively on the dopant concentration. Half-metallicity and large TMR ratios are predicted for “low” dopant concentrations (1/2 and 1/4 monolayers), while a high concentration (1 monolayer) produces metallic states and thus a decreased TMR ratio. Very thin AlN barrier layers are predicted to yield low TMR ratios. We also study the role of two types of structural defects close to the Mn atoms at the interfaces, namely, atomic mixing (Al replaces Ga and vice versa), and N and Ga vacancies. While the studied atomic interdiffusion defects have little effect on the TMR ratio, both N and Ga vacancies are found to destroy the half-metallicity and lead to a substantial reduction of the TMR ratio, and thus should be eliminated for enhanced device performance.
Elongation and breaking mechanisms of gold nanowires under a wide range of tensile conditions
Authors: Tavazza F. , Levine L. E. , Chaka A. M.
Published: August 2009

Semistatic density functional theory is used to explore the evolution of [1 1 0] and [1 1 1] gold nanowires during tensile deformation under a wide range of conditions, including different tensile axes (along high- and low-symmetry directions), nanowire shapes, and effective strain rates. Large structural changes are observed during the elongation. The analysis of such low-energy intermediate configurations provides quantitative information about the underlying energy landscape that cannot be obtained through experiments or more approximate modeling methods, and four stable intermediate atomic structures are identified. A rich diversity of deformation pathways is uncovered that converge to only two final local configurations with reproducible breaking strengths, in agreement with experimental results. Such a high reproducibility in the breaking force makes gold nanowires excellent candidates as intrinsic force standards at the nanolevel.
A contoured gap coaxial plasma gun with injected plasma armature
Authors: Witherspoon F. Douglas , Case Andrew , Messer Sarah J. , Bomgardner Richard , Phillips Michael W. , Brockington Samuel , Elton Raymond
Published: August 2009

A new coaxial plasma gun is described. The long term objective is to accelerate 100–200 μg of plasma with density above 1017 cm−3 to greater than 200 km/s with a Mach number above 10. Such high velocity dense plasma jets have a number of potential fusion applications, including plasma refueling, magnetized target fusion, injection of angular momentum into centrifugally confined mirrors, high energy density plasmas, and others. The approach uses symmetric injection of high density plasma into a coaxial electromagnetic accelerator having an annular gap geometry tailored to prevent formation of the blow-by instability. The injected plasma is generated by numerous (currently 32) radially oriented capillary discharges arranged uniformly around the circumference of the angled annular injection region of the accelerator. Magnetohydrodynamic modeling identified electrode profiles that can achieve the desired plasma jet parameters. The experimental hardware is described along with initial experimental results in which approximately 200 μg has been accelerated to 100 km/s in a half-scale prototype gun. Initial observations of 64 merging injector jets in a planar cylindrical testing array are presented. Density and velocity are presently limited by available peak current and injection sources. Steps to increase both the drive current and the injected plasma mass are described for next generation experiments.
Determination of the six rate constants of a three-state enzymatic network and a noninvasive test of detailed balance
Authors: Berthoumieux H. , Antoine C. , Lemarchand A.
Published: August 2009

The Michaelis–Menten mechanism is unanimously recognized by experimentalists and theoreticians as the reference model for the description of enzymatic catalysis. The recent explosion in the diversity of fluorescent probes solves the problem of in situ observation of proteins and the experimental investigation of enzymatic dynamics, which determines the Michaelis constant or a small number of relaxation times, is becoming more and more common. We propose a protocol for the full characterization of enzyme kinetics in the framework of the Michaelis–Menten mechanism. The method relies on the measurement of the oscillation amplitude of the enzymatic concentrations, when the biological medium is submitted to a temperature modulation of a few degrees. Analytical expressions of all the rate constants as functions of the concentration amplitudes are derived. The noninvasive character of the perturbation and the assessable uncertainty on the rate constant values make an in situ test of detailed balance possible.
Toward an ideal Schottky barrier on 3C-SiC
Authors: Eriksson Jens , Weng Ming Hung , Roccaforte Fabrizio , Giannazzo Filippo , Leone Stefano , Raineri Vito
Published: August 2009

The electrical characteristics of Au/3C-SiC Schottky diodes were studied as a function of contact area. While the larger diodes were characterized by conventional current-voltage measurements, conductive atomic force microscopy was used to perform current-voltage measurements on diodes of contact radius down to 5 μm. The results show that the Schottky barrier height increases upon reducing the contact area, and for the smallest diodes the value approaches the ideal barrier height of the system. The results were correlated with defects in the 3C-SiC and an analytical expression was derived to describe the dependence of the barrier height on the defect density.
m
-plane pure blue laser diodes with p-GaN/n-AlGaN-based asymmetric cladding and InGaN-based wave-guiding layers
Authors: Lin You-Da , Huang Chia-Yen , Hardy Matthew T. , Hsu Po Shan , Fujito Kenji , Chakraborty Arpan , Ohta Hiroaki , Speck James S. , DenBaars Steven P. , Nakamura Shuji
Published: August 2009

Asymmetric p-GaN/n-AlGaN-cladded InGaN-based pure blue (440–460 nm) laser diodes were fabricated based on the nonpolar m-plane GaN technology. Simulation results showed high indium content (5%–10%) InGaN wave-guiding layers mainly contributed to the optical confinement, so that n-AlGan layer can be used to control of the peak position of the optical mode to achieve high optical confinement factor and low internal loss. By using this laser structure, lasing wavelengths of 443 and 465 nm with threshold current densities 14 and 19 kA/cm2, respectively, were demonstrated without facet coating.
Excitation-induced energy shifts in the optical gain spectra of InN quantum dots
Authors: Lorke M. , Seebeck J. , Gartner P. , Jahnke F. , Schulz S.
Published: August 2009

A microscopic theory for the optical absorption and gain spectra of InN quantum-dot systems is used to study the combined influence of material properties and interaction-induced effects. Atomistic tight-binding calculations for the single-particle properties of the self-assembled quantum-dot and wetting-layer system are used in conjunction with a many-body description of Coulomb interaction and carrier phonon interaction. We analyze the carrier-density and temperature dependence of strong excitation-induced energy shifts of the dipole-allowed quantum-dot transitions.