bluuebunny/crossref_metadata_2025_split huggingface dataset:
The production of warm rain in shallow maritime cumulus clouds
Authors: Blyth Alan M. , Lowenstein Jason H. , Huang Yahui , Cui Zhiqiang , Davies Stewart , Carslaw Kenneth S. 
Published: June 2012

AbstractThe problem of the production of warm rain by collision and coalescence has been studied for over half a century and several processes have been suggested to explain the observed production, which is more rapid than generally possible with models. A straightforward scenario in relatively shallow maritime cumulus clouds is one where cloud drops simply grow by condensation and coalescence, with no appeal to enhancement due to entrainment or turbulence or indeed the presence of giant and ultragiant aerosols that may exist in the boundary layer. However, it is difficult in a field experiment to measure the concentrations of aerosols and the time evolution of the droplet size distribution or reflectivity in individual clouds. The Rain in Cumulus Over the Ocean (RICO) field experiment overcame some of these difficulties due to the abundance of clouds and the statistical sampling strategy at all significant altitudes. In this article, we present the results of the rate of increase in the radar reflectivity in a couple of cases. Comparisons with a cloud model strongly suggest that the development of warm rain can be explained using the observed aerosol distribution alone. Sensitivity studies suggested that giant and ultragiant aerosols were unimportant for the production of rain in these clouds. Copyright © 2012 Royal Meteorological Society
On the role of a Rossby wave train during the extratropical transition of hurricane Helene (2006)
Authors: Pantillon F. , Chaboureau J.‐P. , Lac C. , Mascart P. 
Published: June 2012

AbstractThree successive interactions of hurricane Helene (2006) with a Rossby wave train during the extratropical transition of Helene over the North Atlantic were investigated. Numerical experiments were performed with different horizontal resolutions and configurations, over a domain that stretches from the eastern Pacific to the Western Mediterranean to encompass Helene and the whole Rossby wave train. In particular, a cloud‐resolving run offered an explicit representation of strong diabatic effects involved in the three successive interactions.While the circulation and moisture anomaly of Helene were essential to its own reintensification, it is shown that the Rossby wave train played an important role in the track and intensity of Helene and in explosive cyclogenesis downstream. First, the Rossby wave train steered Helene in such a way that a small difference in phasing resulted in large errors in the track of Helene. Only a run at kilometre scale was able to correctly forecast the 5‐day track of Helene. Second, through the formation of three filaments, the Rossby wave train created a quasi‐diurnal cycle in the intensity of Helene. Helene responded with strong diabatic activity that prevented the superposition of an upstream trough and enhanced a downstream ridge. Finally, model errors in the outflow of Helene propagated downstream with the group speed of the Rossby wave train, leading to the loss of predictability of a tropical‐like cyclone over the Mediterranean. This study suggests that, in addition to the horizontal resolution, uncertainty from the model microphysics and from initial conditions need to be characterized to improve mid‐range forecast downstream from an extratropical transition. Copyright © 2012 Royal Meteorological Society
First‐principles study of oxidized BC2N nanotubes
Authors: Rupp Caroline Jaskulski , Rossato Jussane , José Baierle Rogério 
Published: June 2012

AbstractSpin‐polarized density functional theory and norm conserving fully separable pseudopotentials are used to study the structural and electronic properties of atomic oxygen defects (substitution and adsorbed) as well as the O2 adsorption in (3,3) and (5,0) BC2N nanotubes. For the adsorbed molecules, detailed calculations are performed by introducing the van der Waals interactions through the B97‐D functional proposed by Grimme. The most stable configuration for the adsorbed oxygen atom is in the interstitial site binding with boron and carbon atoms (BOCI configuration), and for the substitutional doping, the most stable configuration occurs when the oxygen substitutes the nitrogen atom (ON). For these two defects, the calculated formation energies are −1.67 and 0.62 eV, respectively. The calculated electronic band structures show that the ON defect leads the system to exhibit a p‐type semiconductor character, whereas the interstitial oxygen atom does not introduce any significant changes in the electronic states near the band gap region. The interaction between the nanotubes and the O2 molecule is investigated by the adsorption of the molecule in the inner and outer surfaces of the nanotubes. The calculated binding energies show that the molecule in the triplet state is physically adsorbed in the inner surface with the molecular axis perpendicular to the nanotube axis. For the molecule in the singlet state, the most stable configuration occurs when the molecule interact with the outer surface and bind (weakly) with a boron atom. We also observe spin transference between the molecule and the tube leading the boron carbonitrides (BCN) nanostructures as candidate to storage and detect the O2 molecules. © 2012 Wiley Periodicals, Inc.
Expansion of a wave function in a Gaussian basis. I. Local versus global approximation
Authors: Kutzelnigg Werner 
Published: June 2012

AbstractThe expansion of the ground state wave function ψ(r) of hydrogen‐like ions in a Gaussian basis is derived from a discretization of a Gaussian integral transformation. This derivation involves an upper and a lower cut‐off of the integration variable and the evaluation of the truncated integral by means of the trapezoid approximation, after a variable transformation to an exponentially decaying bell‐shaped integrand. This automatically leads to an optimized even‐tempered basis. Two criteria are studied, (a) the best approximation of ψ(r) for r = 0, (b) the best approximation for the expectation value of the Hamiltonian. In either case, the rate of convergence obeys a square‐root exponential law with an error estimate
$\sim \exp (-a\sqrt{n})$, if n is the basis size. The value of the constant a depends on the considered property and on the criterion for the optimization of the basis. Simple analytic expressions for the basis parameters α and β of an even‐tempered Gaussian basis are derived. The comparison of the local and global criteria gives some new and even unexpected insight. © 2012 Wiley Periodicals, Inc.
High‐Speed Scanning of Critical Structures in Aviation Using Coordinate Measurement Machine and the Laser Ultrasonic
Authors: Swornowski Pawel J. 
Published: June 2012

SummaryAviation is one of the know‐how spheres containing a great deal of responsible sub‐assemblies, in this case landing gear. The necessity for reducing production cycle times while achieving better quality compels metrologists to look for new and improved ways to perform inspection of critical structures. This article describes the ability to determine the shape deviation and location of defects in landing gear using coordinate measuring machines and laser ultrasonic with high‐speed scanning. A nondestructive test is the basis for monitoring microcrack and corrosion propagation in the context of a damage‐tolerant design approach. This article presents an overview of the basics and of the various metrological aspects of coordinate measurement and a nondestructive testing method in terms of high‐speed scanning. The new test method (laser ultrasonic) promises to produce the necessary increase in inspection quality, but this is limited by the wide range of materials, geometries, and structure aeronautic parts used. A technique combining laser ultrasonic and F‐SAFT (Fourier‐Synthetic Aperture Focusing Technique) processing has been proposed for the detection of small defects buried in landing gear. The experimental results of landing gear inspection are also presented. SCANNING 34: 387‐394, 2012. © 2012 Wiley Periodicals, Inc.
Transitions and Brain Injury: A Qualitative Study Exploring the Journey of People with Traumatic Brain Injury
Authors: Conneeley Anne Louise 
Published: June 2012

This qualitative study aimed to explore transitions from hospital to the home over a period of one year.Methods and procedures: A longitudinal, phenomenological approach was employed and 18 individuals with severe traumatic brain injury, their family members and rehabilitation professionals were interviewed using semistructured interviews, when the person with brain injury was discharged from the ward, after 6 months and again after one year.Results: Themes identified within the data included returning home, getting back to normal, moving forward and the role of rehabilitation in the transitional period. Further subthemes were also identified including issues of life-course disruption, self-identity, status and reconstruction.Conclusions: Data suggested that access to rehabilitation programs employing individualised, contextual interventions following discharge to the home were integral in enabling the transition through to autonomy and independence. Consideration of issues of identity and status can enable a different and potentially important perspective on the experience of transitions for those with brain injury. Reclaiming personal autonomy and control appeared to be central to the reconstruction of a coherent sense of self, enabling a meaningful life after brain injury.
Community-Based Rehabilitation Following Brain Injury: Comparison of a Transitional Living Program and a Home-Based Program
Authors: Hopman Kate , Tate Robyn L. , McCluskey Annie 
Published: June 2012

Background and aims: Community-based rehabilitation programs for people with a brain injury are diverse. Comparative program evaluation is required to identify optimal type, intensity and duration of programs. The aim of this study was to compare the effectiveness of two community-based rehabilitation programs using a set of standardised outcome measures.Methods: The study used a quantitative, multicentre, longitudinal design. Persons with severe traumatic brain injury (TBI,n= 39) and acquired brain impairment (n= 2) were recruited from two residential, transitional living programs (TLU;n= 21) and two home-based community rehabilitation programs (CR;n= 20). Participants were assessed via interview at program entry, 2 months and 6 months later using a broad range of standardised measures. The quantity and types of intervention provided to study participants were recorded. Results: No significant differences were identified between the TLU and CR groups at baseline or 6-month follow-up. Two significant group-by-time interactions were identified on the Community Integration Questionnaire (CIQ). First, the CR group had significantly greater changes in productivity (p= .003;d= 1.0) compared to the TLU group over time; by contrast, the TLU group showed significantly greater improvements in social integration (p= .007;d= .86). The TLU participants received up to five times more intervention than the CR participants. This finding is significant considering the similar levels of improvement in function made by both TLU and CR participants.Conclusions: Both TLU and CR groups improved on a range of measures. The TLU group however, received significantly more face-to-face interventions. Further examination of the relationship between participant contextual factors, such as coping style and self-esteem, and impairments such as challenging behaviour and decreased self-awareness, of people attending TLU and CR programs is required.
Geometric K-homology with coefficients I: ℤ/kℤ-cycles and Bockstein sequence
Authors: Deeley Robin J. 
Published: June 2012

AbstractWe construct a Baum-Douglas type model for K-homology with coefficients in ℤ/kℤ. The basic geometric object in a cycle is a spinc ℤ/kℤ-manifold. The relationship between these cycles and the topological side of the Freed-Melrose index theorem is discussed in detail. Finally, using inductive limits, we construct geometric models for K-homology with coefficients in any countable abelian group.
The Motivic Cohomology of Stiefel Varieties
Authors: Williams Ben 
Published: June 2012

AbstractThe main result of this paper is a computation of the motivic cohomology of varieties of n × m-matrices of of rank m, including both the ring structure and the action of the reduced power operations. The argument proceeds by a comparison of the general linear group-scheme with a Tate suspension of a space which is -equivalent to projective n — 1-space with a disjoint basepoint.
Equivariant K-theory, groupoids and proper actions
Authors: Cantarero Jose 
Published: June 2012

AbstractIn this paper we define complex equivariant K-theory for actions of Lie groupoids using finite-dimensional vector bundles. For a Bredon-compatible Lie groupoid , this defines a periodic cohomology theory on the category of finite -CW-complexes. We also establish an analogue of the completion theorem of Atiyah and Segal. Some examples are discussed.
Motivic zeta functions in additive monoidal categories
Authors: Kimura Kenichiro , Kimura Shun-ichi , Takahashi Nobuyoshi 
Published: June 2012

AbstractLet C be a pseudo-abelian symmetric monoidal category, and X a Schur-finite object of C. We study the problem of rationality of the motivic zeta function ζx(t) of X. Since the coefficient ring is not a field, there are several variants of rationality — uniform, global, determinantal and pointwise rationality. We show that ζx(t) is determinantally rational, and we give an example of C and X for which the motivic zeta function is not uniformly rational.
K-theory for ring C*-algebras attached to function fields with only one infinite place
Authors: Li Xin 
Published: June 2012

AbstractWe study the K-theory of ring C*-algebras associated to rings of integers in global function fields with only a single infinite place. First, we compute the torsion-free part of the K-groups of these ring C*-algebras. Secondly, we show that, under a certain primeness condition, the torsion part of K-theory determines the inertia degrees at infinity of our function fields.
Flow topology in compressible turbulent boundary layer
Authors: Wang Li , Lu Xi-Yun 
Published: June 2012

AbstractThe flow topologies of compressible turbulent boundary layers at Mach 2 are investigated by means of direct numerical simulation (DNS) of the compressible Navier–Stokes equations, and statistical analysis of the invariants of the velocity gradient tensor. We identify a preference for an unstable focus/compressing topology in the inner layer and an unstable node/saddle/saddle (UN/S/S) topology in the outer layer. The dissipation and dissipation production originate mainly from this UN/S/S topology. The enstrophy depends mainly on an unstable focus/stretching (UFS) topology, and the enstrophy production relies on a UN/S/S topology in the inner layer and on a UFS topology in the outer layer. The compressibility effect on the statistical properties of the topologies is investigated in terms of the ‘incompressible’, compressed and expanding regions. It is found that the locally compressed region tends to be more stable and the locally expanding region tends to be more dissipative. The compressibility is mainly related to unstable focus/compressing and stable focus/stretching topologies. Moreover, the features of the average dissipation, enstrophy, dissipation production and enstrophy production of the various topologies are clarified in the locally compressed and expanding regions.
Shareholders in the Boardroom: Wealth Effects of the SEC’s Proposal to Facilitate Director Nominations
Authors: Akyol Ali C. , Lim Wei Fen , Verwijmeren Patrick 
Published: June 2012

AbstractCurrent attempts to reform financial markets presume that shareholder empowerment benefits shareholders. We investigate the wealth effects associated with the Securities and Exchange Commission’s rule to facilitate director nominations by shareholders. Our results are not in line with shareholder empowerment creating value: The average daily abnormal returns surrounding events that increase (decrease) the probability of the proposal’s passage are significantly negative (positive). Furthermore, given an increase in the probability of the proposal’s passage, firms whose shareholders are more likely to use the rule to nominate directors experience more negative abnormal returns.
Charge effect in secondary electron emission from silicon surface induced by slow neon ions
Authors: Xu Zhongfeng , Zeng Lixia , Zhao Yongtao , Wang Jianguo , Wang Yuyu , Zhang Xiaoan , Xiao Guoqing , Li Fuli 
Published: June 2012

AbstractTotal electron emission yield for impact of slow Neq+(q = 2, 4, 6, 8) ions with various kinetic energy under normal incidence on n-type Si has been measured. It is shown that for the same charge state, the total electron yield γ increases linearly as the kinetic energy of projectile at impact increases, up to velocities corresponding to the “classical” threshold. Separation of kinetic electron yield γKE and potential electron yield γPE shows that γPE is proportional to the ion charge state and γKE increases linearly with projectile velocity. Finally, based on “single hole without hopping” hypothesis, the expression of the “CRF” F(q) is given, and the relation between γKE and q is obtained successfully for the first time, which is also a basis for judging whether the “trampoline effect” exists.
Pericardial effusion in an infant with severe respiratory syncytial virus bronchiolitis
Authors: Dabbah Husein , Glikman Daniel , Zonis Zeev 
Published: June 2012

AbstractRespiratory syncytial virus is the most common pathogen causing lower respiratory tract infection in infants. Respiratory syncytial virus infection is also associated with a number of extrapulmonary manifestations, including the cardiac system. Pericardial effusion, however, is a very rare occurrence with respiratory syncytial virus infection. We report a very young infant with respiratory syncytial virus bronchiolitis whose clinical course was associated with pericardial effusion, treated conservatively.
Trends and determinants of undernutrition among young Kenyan children: Kenya Demographic and Health Survey; 1993, 1998, 2003 and 2008–2009
Authors: Masibo Peninah K , Makoka Donald 
Published: June 2012

AbstractObjectiveTo report on the trends and determinants of undernutrition among children <5 years old in Kenya.DesignData from four nationwide Kenya Demographic and Health Surveys, conducted in 1993, 1998, 2003 and 2008–2009, were analysed. The Demographic and Health Survey utilizes a multistage stratified sampling technique.SettingNationwide covering rural and urban areas in Kenya.SubjectsThe analysis included 4757, 4433, 4892 and 4958 Kenyan children aged <5 years in 1993, 1998, 2003 and 2009–2009, respectively.ResultsThe prevalence of stunting decreased by 4·6 percentage points from 39·9 % in 1993 to 35·3 % in 2008–2009, while underweight decreased by 2·7 percentage points from 18·7 % in 1993 to 16·0 % in 2008–2009. The effects of household wealth, maternal education and current maternal nutritional status on child nutrition outcomes have changed dynamically in more recent years in Kenya. Inadequate hygiene facilities increased the likelihood of chronic undernutrition in at least three of the surveys. Small size of the child at birth, childhood diarrhoea and male gender increased the likelihood of undernutrition in at least three of the surveys. Childhood undernutrition occurred concurrently with maternal overnutrition in some households.ConclusionsThe analysis reveals a slow decline of undernutrition among young children in Kenya over the last three decades. However, stunting and underweight still remain of public health significance. There is evidence of an emerging trend of a malnutrition double burden demonstrated by stunted and underweight children whose mothers are overweight.
Behavioural and neurochemical changes induced by stress-related conditions are counteracted by the neurokinin-2 receptor antagonist saredutant
Authors: Tamburella Alessandra , Leggio Gian Marco , Micale Vincenzo , Navarria Andrea , Bucolo Claudio , Cicirata Valentina , Drago Filippo , Salomone Salvatore 
Published: June 2012

Abstract
These experiments were undertaken to assess the mechanisms underlying the antidepressant-like effects of the neurokinin-2 (NK2) receptor antagonist saredutant (SR48968) in rats tested in the forced swim test (FST), by analysing hippocampal brain-derived neurotrophic factor (BDNF) and plasma corticosterone [as index of hypothalamic-pituitary-adrenal (HPA) axis activity]. Male Wistar rats received three intraperitoneal injections over 24 h of vehicle, saredutant (5 mg/kg), citalopram (15 mg/kg), clomipramine (50 mg/kg). Rats were subjected to restraint stress (4 h) 24 h prior to the FST procedure. This stress procedure increased immobility and decreased swimming behaviour in the FST; furthermore, it lowered hippocampal BDNF protein expression and increased plasma corticosterone levels. Saredutant and clomipramine or citalopram, used here as positive controls, reduced the immobility time in the FST both under basal conditions and after stress exposure. This effect was not attributable to changes in locomotion, because locomotor activity was unchanged when assessed in the open field test. Pretreatment with para-cholorophenylalanine (150 mg/kg, 72 h and 48 h prior to FST) abolished the effect of citalopram and saredutant on immobility time. At neurochemical level, saredutant attenuated activation of HPA axis in stressed animals more than clomipramine or citalopram. The behavioural effects of saredutant support the hypothesis that NK2 receptor activity is involved in stress-related disorders. These effects of saredutant may be related to normalization of the HPA axis. Moreover, saredutant increases BDNF expression in the hippocampus, confirming the role of NK2 receptor blockade in BDNF activation following stressor application.
Long-term farming systems research in the central High Plains
Authors: Ghimire Rajan , Norton Jay B. , Norton Urszula , Ritten John P. , Stahl Peter D. , Krall James M. 
Published: June 2012

AbstractIn recent decades, there has been growing interest among farming and scientific communities toward integrated crop–range–livestock farming because of evidence of increased crop production, soil health, environmental services and resilience to increased climatic variability. This paper reviews studies on existing cropping systems and integrated crop–range–livestock systems across the USA which are relevant in the context of summarizing opportunities and challenges associated with implementing long-term crop–range–livestock systems research in the highly variable environment of the central High Plains. With precipitation ranging from 305 to 484mm and uncertain irrigation water supply, this region is especially vulnerable to changing moisture and temperature patterns. The results of our review indicate that diverse crop rotations, reduced soil disturbance and integrated crop–livestock systems could increase economic returns and agroecosystem resilience. Integrating agricultural system components to acquire unique benefits from small- to medium-sized operations, however, is a challenging task. This is because assessment and identification of suitable farming systems, selection of the most efficient integration scheme, and pinpointing the best management practices are crucial for successful integration of components. Effective integration requires development of evaluation criteria that incorporate the efficiency of approaches under consideration and their interactions. Therefore, establishing the basis for more sustainable farming systems in the central High Plains relies on both long-term agricultural systems research and evaluation of short-term dynamics of individual components.