bluuebunny/crossref_metadata_2025 huggingface dataset:
SABP2, a methyl salicylate esterase is required for the systemic acquired resistance induced by acibenzolar‐S‐methyl in plants
Authors: Tripathi Diwaker , Jiang Yu-Lin , Kumar Dhirendra
Published: July 2010

Tobacco SABP2, a 29 kDa protein catalyzes the conversion of methyl salicylic acid (MeSA) into salicylic acid (SA) to induce SAR. Pretreatment of plants with acibenzolar‐S‐methyl (ASM), a functional analog of salicylic acid induces systemic acquired resistance (SAR). Data presented in this paper suggest that SABP2 catalyzes the conversion of ASM into acibenzolar to induce SAR. Transgenic SABP2‐silenced tobacco plants when treated with ASM, fail to express PR‐1 proteins and do not induce robust SAR expression. When treated with acibenzolar, full SAR is induced in SABP2‐silenced plants. These results show that functional SABP2 is required for ASM‐mediated induction of resistance.
Deletion of Swm2p selectively impairs trimethylation of snRNAs by trimethylguanosine synthase (Tgs1p)
Authors: Boon Kum-Loong , Koš Martin
Published: July 2010

MINT‐7949540: swm2 (uniprotkb:P40342) physically interacts (MI:0915) with TGS1 (uniprotkb:Q12052) by tandem affinity purification (MI:0676)
TFPI or uPA–PAI‐1 complex affect cell function through expression variation of type II very low density lipoprotein receptor
Authors: Di Yong , Liu Zhiguo , Tian Jun , Zong Yiqiang , Yang Pu , Qu Shen
Published: July 2010

Very low density lipoprotein receptors (VLDLR) including type I and type II are known to affect cell functions by binding to its extracellular ligands. However, the effect of these ligands on VLDLR expression remains elusive. Tissue factor pathway inhibitor (TFPI) and urokinase plasminogen activator and plasminogen activator inhibitor 1 (uPA–PAI‐1) complex, two ligands of VLDLR, were used to examine their effects on VLDLR expression. TFPI treatment decreased type II VLDLR expression, inhibited cell proliferation and migration, and degradated β‐catenin in SGC7901 cells. However, uPA–PAI‐1 complex, increased type II VLDLR expression with promoted cell proliferation and migration and stabilization of β‐catenin. These results indicated that extracellular ligands can change the expression of type II VLDLR to affect cell proliferation and migration.
p38 MAPK pathway is involved in high glucose‐induced thioredoxin interacting protein induction in mouse mesangial cells
Authors: Ren Yunzhuo , Shi Yonghong , Wang Yuehua , Li Yingmin , Wu Shuhui , Li Hang , Zhang Yanling , Duan Huijun
Published: July 2010

Excessive reactive oxygen species (ROS) play a key role in the pathogenesis of diabetic nephropathy. The thioredoxin (TRX) system, a major thiol antioxidant system, regulates the reduction of intracellular ROS. Here we show that high glucose (HG) inhibits TRX ROS‐scavenging function through p38 mitogen‐activated protein kinase (MAPK)‐mediated induction of thioredoxin interacting protein (TXNIP) in mouse mesangial cells (MMCs). Knockdown of TXNIP in MMCs reversed HG‐induced reduction of TRX activity and inhibited HG‐induced activation of p38 MAPK and increased synthesis of TGF‐β1 and fibronectin. These data suggest that HG‐induced overexpression of TXNIP in MMCs, which may be via the p38 MAPK pathway.
The fast‐mobility isoform of mouse Mcl‐1 is a mitochondrial matrix‐localized protein with attenuated anti‐apoptotic activity
Authors: Huang Chi-Ruei , Yang-Yen Hsin-Fang
Published: July 2010

MINT‐7965685: Mcl‐1 (uniprotkb:P97287) physically interacts (MI:0915) with PUMA (uniprotkb:Q9BXH1) by anti bait coimmunoprecipitation (MI:0006)
Social vulnerability predicts cognitive decline in a prospective cohort of older Canadians
Authors: Andrew Melissa K. , Rockwood Kenneth
Published: July 2010

Background

Although numerous social factors have been associated with cognition in older adults, these findings have been limited by the consideration of individual factors in isolation. We investigated whether social vulnerability, defined as an index comprising many social factors, is associated with cognitive decline.

Methods

In this secondary analysis of the Canadian Study of Health and Aging, 2468 community‐dwellers aged 70 and older were followed up for 5 years. The social vulnerability index incorporated 40 social variables. Each response was scored as 0 if the “deficit” was absent and 1 if it was present; the 40 deficit scores were then summed. For some analyses, index scores were split into tertiles of high, intermediate, and low social vulnerability. Cognitive decline was defined as a ≥5‐point decline in the Modified Mini‐Mental State Examination (3MS). Associations of social vulnerability with 5‐year cognitive decline (adjusting for age, sex, frailty, and baseline cognition) were analyzed by using logistic regression.

Results

Mean social vulnerability was 0.25 (standard deviation, 0.09) or 9.9 deficits of the list of 40. The median cognitive change of –1.0 (interquartile range, –6 to 2) points on the 3MS was noted at 5 years. About 743 individuals (30% of the sample) experienced a decline of ≥5 points on the 3MS. Each additional social deficit was associated with increased odds of cognitive decline (odds ratio, 1.03; 95% confidence interval, 1.00 to 1.06;P= .02). Compared with those with low social vulnerability, individuals with high social vulnerability had a 36% increased odds of experiencing cognitive decline (odds ratio, 1.36; 95% confidence interval, 1.06 to 1.74;P= .015).

Conclusions

Increasing social vulnerability, defined by using a social vulnerability index incorporating many social factors, was associated with increased odds of cognitive decline during a period of 5 years in this study of older Canadians. Further study of social vulnerability in relation to cognition is warranted, with particular attention to potential interventions to alleviate its burden.
Priorities for research consortia on Alzheimer's disease
Authors: Gauthier Serge , Garcia Angela , Sano Mary , Robert Philippe , Senanarong Vorapun , Woodward Michael , Brodaty Henry
Published: July 2010

Coordination and harmonization of efforts between five major research consortia on Alzheimer's disease may increase our understanding of this condition and improve our therapeutic approaches. Specific opportunities include a registry for families with early onset dementia, a study registry, minimal data sets, validation of assessment tools and outcomes, update on ethical issues, resolution of methodological issues, new investigators training, longitudinal observation studies, prevention studies, and liaison with stakeholders such as Alzheimer Disease International.
Sweet-taste receptors, low-energy sweeteners, glucose absorption and insulin release
Authors: Renwick Andrew G. , Molinary Samuel V.
Published: July 2010

The present review explores the interactions between sweeteners and enteroendocrine cells, and consequences for glucose absorption and insulin release. A combination of in vitro,in situ, molecular biology and clinical studies has formed the basis of our knowledge about the taste receptor proteins in the glucose-sensing enteroendocrine cells and the secretion of incretins by these cells. Low-energy (intense) sweeteners have been used as tools to define the role of intestinal sweet-taste receptors in glucose absorption. Recent studies using animal and human cell lines and knockout mice have shown that low-energy sweeteners can stimulate intestinal enteroendocrine cells to release glucagon-like peptide-1 and glucose-dependent insulinotropic peptide. These studies have given rise to major speculations that the ingestion of food and beverages containing low-energy sweeteners may act via these intestinal mechanisms to increase obesity and the metabolic syndrome due to a loss of equilibrium between taste receptor activation, nutrient assimilation and appetite. However, data from numerous publications on the effects of low-energy sweeteners on appetite, insulin and glucose levels, food intake and body weight have shown that there is no consistent evidence that low-energy sweeteners increase appetite or subsequent food intake, cause insulin release or affect blood pressure in normal subjects. Thus, the data from extensive in vivo studies in human subjects show that low-energy sweeteners do not have any of the adverse effects predicted by in vitro,in situ or knockout studies in animals.
Freely decaying two-dimensional turbulence
Authors: FOX S. , DAVIDSON P. A.
Published: July 2010

High-resolution direct numerical simulations are used to investigate freely decaying two-dimensional turbulence. We focus on the interplay between coherent vortices and vortex filaments, the second of which give rise to an inertial range. We find that Batchelor's prediction for the inertial-range enstrophy spectrum Eω(k, t) ~ β2/3k−1, where β is the enstrophy dissipation rate, is reasonably well satisfied once the turbulence is fully developed, but that the assumptions which underpin the usual interpretation of his theory are not valid. For example, the lack of a quasi-equilibrium cascade means the enstrophy flux Πω(k) is highly non-uniform throughout the inertial range, thus the common assumption that β can act as a surrogate for Πω(k) becomes questionable. We present a variant of Batchelor's theory which accounts for the wavenumber-dependence of Πω; in particular we propose Eω(k, t) ~ Πω(k1)2/3k−1, where k1 is the wavenumber marking the start of the observed k−1 region of the enstrophy spectrum. This provides a better collapse of the data and, unlike Batchelor's original theory, can be justified on theoretical grounds. The basis for our proposal is the observation that the straining of the vortex filaments, which fuels the enstrophy flux through the inertial range, comes almost exclusively from the strain field of the coherent vortices, and this can be characterized by Πω(k1)1/3. Thus Eω(k) is a function of only k and Πω(k1) in the inertial range, and dimensional analysis then yields Eω ~ Πω(k1)2/3k−1. We also confirm the prediction by Davidson (Phys. Fluids, vol. 20, 2008, 025106) that in the inertial range Πω varies as Πω(k)/Πω(k1) = 1 − a−1 ln(k/k1), where a is a constant of order 1. This corresponds to ∂Eω/∂t ~ k−1. Surprisingly, the measured enstrophy fluxes imply that the dynamics of the inertial range as defined by the behaviour of Πω extend to wavenumbers much smaller than k1, but this is masked in Eω(k, t) by the presence of coherent vortices which also contribute to Eω in this region. In fact, we find that kEω(k, t) ≈ H(k) + A(t), or ∂Eω/∂t ~ k−1 in this extended low-k region, where H(k) is almost independent of time and represents the signature of the coherent vortices. In short, the inertial range defined by ∂Eω/∂t ~ k−1 or Πω(k) ~ ln(k) is much broader than the observed Eω ~ k−1 region.
On higher order Bragg resonance of water waves by bottom corrugations
Authors: YU JIE , HOWARD LOUIS N.
Published: July 2010

The exact theory of linearized water waves in a channel of indefinite length with bottom corrugations of finite amplitude (Howard & Yu, J. Fluid Mech., vol. 593, 2007, pp. 209–234) is extended to study the higher order Bragg resonances of water waves occurring when the corrugation wavelength is close to an integer multiple of half a water wavelength. The resonance tongues (ranges of water-wave frequencies) are given for these higher order cases. Within a resonance tongue, the wave amplitude exhibits slow exponential modulation over the corrugations, and slow sinusoidal modulation occurs outside it. The spatial rate of wave amplitude modulation is analysed, showing its quantitative dependence on the corrugation height, water-wave frequency and water depth. The effects of these higher order Bragg resonances are illustrated using the normal modes of a rectangular tank.
Short- to long-wave resonance and soliton formation in boundary-layer interaction with a liquid film
Authors: VLACHOMITROU M. , PELEKASIS N.
Published: July 2010

Dynamic interaction between a boundary layer of air and a liquid film is investigated in this paper. The low air-to-film-viscosity ratio is considered in which case the boundary layer is quasi-steady on the time scale within which interfacial waves develop. The base flow consists of a boundary layer that drags a film of constant shear. Linear analysis, in the context of triple-deck theory, predicts the formation of a wavepacket of capillary waves that advances and spreads with time. The Froude number of de-/anti-icing fluids or water interacting with air falls well within the supercritical regime, i.e. Fr > FrCr. Numerical simulations of such flow systems were performed in the context of triple-deck theory, and they do not exhibit wave saturation or formation of uniform wavetrains. The long-term interaction is mainly dependent on film inertia as this is characterized by parameter = (μ/μf)2(ρf/ρ), which involves film and air viscosity and density ratios, and the dimensionless film thickness, H0, and shear, λ, provided by the base flow. Weakly nonlinear analysis taking into consideration mean drift, i.e. generation of long waves, due to self-interaction of the linear wave to O(ϵ2) in amplitude of the initial disturbance, reveals resonance between the wavepacket predicted by linear theory and long waves when the group velocity of the former happens to coincide with the phase velocity, H0λ, of long interfacial waves. Numerical simulations with anti-icing fluids and water verify this pattern. In both cases, long waves eventually dominate the dynamics and, as they are modulated with time, they lead to soliton-type structures. Anti-icing fluids eventually exhibit oscillatory spikes whose mean value never exceeds 2H0, roughly. Water films exhibit a single spike that keeps growing, thus generating a large separation bubble.
Determination of CD4+ and CD8+ T cells in the peripheral blood of dogs with demodicosis
Authors: SINGH S. K. , DIMRI U. , SHARMA M. C. , SHARMA B. , SAXENA M.
Published: July 2010

The aim of this study was to evaluate the CD4+/CD8+ ratio in peripheral blood of dogs with localized and generalized demodicosis. Sixteen dogs were examined, 8 with localized and 8 with generalized demodicosis, while 8 healthy dogs were used as controls. Peripheral blood was obtained and CD4+ and CD8+ T cells were determined by flow cytometry. Significantly higher numbers of CD8+ T cells and lower numbers of CD4+ T cells were found in dogs with generalized demodicosis compared to dogs with localized demodicosis and healthy controls. Significantly higher numbers of CD8+ T cells and lower numbers of CD4+ T cells were also found in dogs with localized demodicosis compared to healthy controls. The CD4+/CD8+ ratio was also found to be significantly lower in dogs with generalized demodicosis in comparison with dogs with localized demodicosis and healthy controls. It is concluded that significant alteration in the CD4+/CD8+ ratio may be implicated in the pathogenesis of generalized canine demodicosis.
Gametocyte sex ratio in single-clone infections of the malaria parasite Plasmodium mexicanum
Authors: NEAL A.T. , SCHALL J.J.
Published: July 2010

Sex ratio theory predicts that malaria parasites should bias gametocyte production toward female cells in single-clone infections because they will experience complete inbreeding of parasite gametes within the vector. A higher proportion of male gametocytes is favoured under conditions that reduce success of male gametes at reaching females such as low gametocyte density or attack of the immune system later in the infection. Recent experimental studies reveal genetic variation for gametocyte sex ratio in single-clone infections. We examined these issues with a study of experimental single-clone infections for the lizard malaria parasite Plasmodium mexicanum in its natural host. Gametocyte sex ratios of replicate single-clone infections were determined over a period of 3–4 months. Sex ratios were generally female biased, but not as strongly as expected under simple sex ratio theory. Gametocyte density was not related to sex ratio, and male gametocytes did not become more common later in infections. The apparent surplus of male gametocytes could be explained if male fecundity is low in this parasite, or if rapid clotting of the lizard blood reduces male gamete mobility. There was also a significant clone effect on sex ratio, suggesting genetic variation for some life-history trait, possibly male fecundity.
Transubstantiation, essentialism, and substance
Authors: TONER PATRICK
Published: July 2010

According to the Eucharistic doctrine of Transubstantiation, when the priest consecrates the bread and wine, the whole substance of the bread and wine are converted into the body and blood of Christ. The ‘accidents’ of the bread and wine, however, remain present on the altar. This doctrine leads to a clutch of metaphysical problems, some of which are particularly troubling for essentialists. In this paper, I discuss some of these problems, which have recently been pressed by Brian Ellis and Justin Broackes. I argue that defenders of Transubstantiation have satisfactory replies.
Remembering Alston's ‘evaluative particularism’
Authors: KOWALSKI DEAN A.
Published: July 2010

William Alston uniquely offers the divine-command theorist his ‘evaluative particularism’ – the idea that God Himself, the concrete individual, uniquely serves as the supreme standard of (moral) goodness. This allegedly retains God's sovereignty over the moral realm without subverting His goodness or entailing that there are moral principles, the truth of which does not depend on God. However, it is argued that Alston's view faces three initial challenges: justificatory analogies with the two most viable particularist programmes fail; disanalogies between scientific and scriptural data jeopardize the prospect of determining God's relevant essential properties a posteriori; and it harbours problematic entailments regarding (human) moral goodness even if the first two challenges are met.
The design studio “crit”: Teacher–student communication
Authors: Goldschmidt Gabriela , Hochman Hagay , Dafni Itay
Published: July 2010

The design studio has been, and will probably continue to be, the cornerstone of design education. Its major feature is the one-on-one desk critique (crit), in which student and teacher discuss the student's work in progress on a regular and frequent basis. The studio is a learning by doing environment, and the crit is the setting in which students acquire design skills and knowledge, under the guidance of the teacher. Design teachers are usually practitioners who receive no pedagogical training, and the effectiveness of their teaching depends on experience, awareness, and talent. Here we offer a detailed qualitative and quantitative representation of the crit through analyses of three case studies, which were collected in second-year architectural studios. We use two types of protocol analysis methods: coding of verbalizations and linkography, which looks at links among verbalizations. We show the diversity in teachers' performance and point to common trends. We propose that analyses of this kind may serve as a major feedback instrument in the framework of a badly needed pedagogical basis for design education.
Cognitive heuristics in design: Instructional strategies to increase creativity in idea generation
Authors: Yilmaz S. , Seifert C.M. , Gonzalez R.
Published: July 2010

This paper explores the use of heuristics as cognitive strategies invoked during the process of design. Heuristics are reasoning processes that do not guarantee the best solution, but often lead to potential solutions by providing a simple cognitive “shortcut.” We propose that designers use specific design heuristics to explore the problem space of potential designs, leading to the generation of creative solutions. We test whether design heuristics can be taught to novices, and suggest their use will facilitate the design process at multiple levels of instruction. In the present empirical study, we evaluate a set of six instructional heuristics and validate their effectiveness with product concepts generated by novice designers. Six hundred seventy-three drawings were created by 120 first-year college students under four instructional conditions. Drawings were coded according to their content, use of heuristics, creativity, and practicality. The most creative concepts emerged from the experimental conditions where heuristics were introduced. Heuristics appeared to help the participants “jump” to a new problem space, resulting in more varied designs, and a greater frequency of designs judged as more creative. Our findings suggest that simple demonstration of design heuristics may, at times, be sufficient to stimulate divergent thinking, perhaps because these heuristics are readily grasped and contextual application is not required. Based on these findings, a conceptual model for design education emphasizing the importance of using a variety of heuristics is proposed. This model suggests that learning can be enhanced through exposure to a variety of design heuristics, and can supplement formal education and foster personal development in design learning.
Naturally acquired hepatitis A antibodies after haematopoetic stem cell transplantation
Authors: YALÇIN S. S. , KONDOLOT M. , GÖKER H. , KUŞKONMAZ B. , KARACAN Y. , ÇETİN M. , AKSU S. , TEZCAN İ. , UÇKAN D.
Published: July 2010

Haematopoietic stem cell transplant (HSCT) recipients lose immune memory of exposure to infectious agents and vaccines accumulated throughout their lifetime and therefore need to be revaccinated. We aimed to evaluate the influence of different factors on hepatitis A virus (HAV) immunity in both child and adult HSCT recipients living in an intermediate endemic region, Turkey. Eighty patients (age range 2·5–57 years) who had HAV serology prior to HSCT were evaluated. The prevalence of HAV seropositivity was 85% (n=68) before HSCT. There was no history of HAV vaccination before HSCT in children and HAV vaccine was not available in Turkey 10 years ago, so it was assumed that all seropositive patients reflected natural immunity. After the exclusion of six patients with autologous HSCT, the remaining 62 seropositive and allogeneic patients were included in this retrospective study. The duration of HAV seropositivity was estimated using the Kaplan–Meier method, log-rank analysis and Cox regression models. Estimated mean time to loss of HAV seropositivity was 48·6 months after transplantation. Patients who were older (⩾18 years) at transplantation and who had older (⩾18 years) donors became seronegative later (P<0·05). Cox backward-stepwise regression confirmed that older age of recipient at transplantation was the only significant parameter for HAV seropositivity (P<0·05). HAV-inactivated vaccine might be recommended later to older HSCT recipients in intermediate endemic regions.
Incidence of surgical-site infections in orthopaedic surgery: a northern Italian experience
Authors: CASTELLA A. , ARGENTERO P. A. , FARINA E. C. , CHARRIER L. , DEL PREVER E. M. BRACH , ZOTTI C. M. ,   the Piemonte Nosocomial Infection Study Group
Published: July 2010

A prospective cohort study with a 1-year telephone follow-up was performed to estimate the incidence of surgical-site infections (SSIs) in hip and knee prostheses. Twenty-five public hospitals equipped with orthopaedic units in two Italian regions were involved. An 8-month surveillance period was set to obtain significant data at a regional level and data were collected by the infection control nurses of each centre. One-year follow-up was completed in 75% of cases. SSIs were recorded in 45 cases (incidence rate 1·9/100 person-years, 95% CI 1·4–2·5). Thirty-six percent of SSIs were diagnosed during hospitalization and 95·3% within 90 days post-operation. This incidence is similar to that reported by European and USA surveillance systems. The proposed investigative method proved to be reliable and feasible. A prolonged surveillance for at least 3 months post-operation yields a good estimate of SSI in joint replacements.
Heterogeneity in vaccination coverage explains the size and occurrence of measles epidemics in German surveillance data
Authors: HERZOG S. A. , PAUL M. , HELD L.
Published: July 2010

The objective of this study was to characterize empirically the association between vaccination coverage and the size and occurrence of measles epidemics in Germany. In order to achieve this we analysed data routinely collected by the Robert Koch Institute, which comprise the weekly number of reported measles cases at all ages as well as estimates of vaccination coverage at the average age of entry into the school system. Coverage levels within each federal state of Germany are incorporated into a multivariate time-series model for infectious disease counts, which captures occasional outbreaks by means of an autoregressive component. The observed incidence pattern of measles for all ages is best described by using the log proportion of unvaccinated school starters in the autoregressive component of the model.
Epidemiology of anthroponotic and zoonotic human cryptosporidiosis in England and Wales, 2004–2006
Authors: CHALMERS R. M. , SMITH R. , ELWIN K. , CLIFTON-HADLEY F. A. , GILES M.
Published: July 2010

In order to monitor epidemiological trends,Cryptosporidium-positive samples (n=4509) from diarrhoeic patients were typed. Compared to the previous 4 years, the proportion ofCryptosporidium hominiscases in 2004–2006 increased to 57·3%, while 38·5% wereC. parvum. The remaining 4·2% cases included mixedC. parvumandC. hominisinfections,C. meleagridis,C. felis,C. ubiquitumand a novel genotype. When the typing results were combined with enhanced surveillance data to monitor risk exposures,C. hominiswas linked to urban dwelling, previous diarrhoea in the household, any travel especially abroad, and using a swimming or paddling pool.C. parvumwas linked to having a private water supply, contact with surface water, visiting or living on a farm, and contact with farm animal faeces. The proportion of laboratory-confirmed indigenous cases acquired from direct contact with farm animals was estimated to be 25% forC. parvumand 10% of all reportedCryptosporidiumcases.
Changes in blood culture methodology have an impact on time trends of bacteraemia: a 26-year regional study
Authors: SØGAARD M. , ENGEBJERG M. C. , LUNDBYE-CHRISTENSEN S. , SCHØNHEYDER H. C.
Published: July 2010

The incidence of bacteraemia has increased considerably during the last decades. This may be related to population ageing, increased use of invasive procedures, and increased ascertainment of bacteraemia. Generalized additive and generalized linear models were used to analyse the impact of four successive improvements in blood culture methodology on the recovery of prevalent blood culture isolates while simultaneously controlling for underlying time trend and seasonal variation. Between 1981 and 2006, 20 091 bacteraemias comprising 22 800 blood culture isolates were diagnosed. The changes in methodology increased the recovery of some bacterial groups; the greatest impact was observed for Enterobacteriaceae, pneumococci andStaphylococcus aureuswhereas recovery of β-haemolytic streptococci,Pseudomonas aeruginosa, other Gram-negative aerobes, and fungi was not affected. Changes in blood culture methodology should be taken into account when assessing time trends of bacteraemia.
Thermochemolysis of the Murchison meteorite: identification of oxygen bound and occluded units in the organic macromolecule
Authors: Watson Jonathan S. , Sephton Mark A. , Gilmour Iain
Published: July 2010

An organic macromolecular residue, prepared from the Murchison meteorite by treatment with hydrofluoric and hydrochloric acids, was subjected to online thermochemolysis with tetramethylammonium hydroxide (TMAH). The most abundant compound released by thermochemolysis was benzoic acid. Other abundant compounds include methyl and dimethyl benzoic acids as well as methoxy benzoic acids. Short chain dicarboxylic acids (C4–8) were also released from the organic macromolecule. Within the C1and C2benzoic acids all possible structural isomers are present reflecting the abiotic origin of these units. The most abundant isomers include 3,4-dimethylbenzoic acid (DMBA), 3,5-DMBA, 2,6-DMBA and phenylacetic acid. Thermochemolysis also liberates hydrocarbons that are not observed during thermal desorption; these compounds include naphthalene, methylnaphthalenes, biphenyl, methylbiphenyls, acenaphthylene, acenaphthene, phenanthrene, anthracene, fluoranthene and pyrene. The lack of oxygen containing functional groups in these hydrocarbons indicates that they represent non-covalently bound, occluded molecules within the organic framework. This data provides a valuable insight into oxygen bound and physically occluded moieties in the Murchison organic macromolecule and implies a relative order of synthesis or agglomeration for the detected organic constituents.
Survey of Poynting flux of whistler mode chorus in the outer zone
Authors: Santolík O. , Pickett J. S. , Gurnett D. A. , Menietti J. D. , Tsurutani B. T. , Verkhoglyadova O.
Published: July 2010

We present a survey of whistler mode chorus emissions based on high‐telemetry rate data of the Plasma Wave Instrument on board the Polar spacecraft. Using simultaneous measurements of full vectors of the electric field and the magnetic field we calculate the Poynting vectors of chorus, and we parameterize the observations by their L* coordinate. Our new analysis of the angle between the direction of the Poynting vector and the magnetic field line confirms previous results on propagation of the main chorus band away from the equator. Our systematic results also prove the existence of the magnetospherically reflected component of chorus found previously by case studies. We observe weak outer zone waves that propagate toward the equator. These waves can be attributed to a poleward reflected component of equatorial chorus or chorus generated in the dayside pockets of a low magnetic field strength. We analyze the probability distribution of the Poynting flux of chorus, and we find that it shows a “heavy tail” feature that can be modeled by a power law or lognormal model. This result has consequences for theories of chorus generation and for methods of statistical characterization of chorus intensities in the frame of radiation belt modeling. We find that the Poynting flux of dayside chorus increases with L* toward the outer zone at L* > 6. We estimate that approximately 1% of the Poynting flux of chorus in the outer zone could be sufficient to accelerate electrons in the outer Van Allen radiation belt on the timescale of days.
Parallel whistler instability in a plasma with an anisotropic bi‐kappa distribution
Authors: Mace R. L. , Sydora R. D.
Published: July 2010

The parallel‐propagating whistler instability in a magnetized plasma of electrons and positive ions having bi‐kappa velocity distributions is investigated for a wide range of parameters. The threshold condition for instability does not depend on the index, κe, of the electron bi‐kappa distribution, but the maximum growth rate depends strongly on this parameter. The functional dependence of the growth rate on κe is strongly influenced by the value of the electron temperature anisotropy. For small anisotropies the maximum growth rate is enhanced by the presence of a low‐κe power‐law tail, as is well known. At larger temperature anisotropies, however, the reverse applies. A hard tail on the electron velocity distribution is deleterious to the whistler instability in this parameter region. For electron temperature anisotropies intermediate between those described, the (maximum with respect to wave number) growth rate maximizes for a particular κe value. The dependence of the maximum growth rate on κe in this electron temperature anisotropy regime is non‐monotonic. For a fixed value of the electron temperature anisotropy, the growth rate is strongly controlled by the parallel electron beta. Larger values of this parameter increase the growth rate, and conversely. The parallel electron beta also governs the value of the electron temperature anisotropy that separates the different types of monotonic behavior of the growth rate described above. The instability is not very sensitive to the electron temperature, provided cases with similar parallel electron beta values are compared. It is pointed out that all whistler dispersion relations, regardless of the value of κe used, pass through a common (ω, k) point. This point is closely related to the instability threshold condition. A novel application is suggested.
Evidence that coupling to magma chambers controls the volume history and velocity of laterally propagating intrusions
Authors: Rivalta Eleonora
Published: July 2010

In this paper, I present a simple analytical solution for the unsolved problem of a propagating dike coupled to a magma chamber. As recognized by Segall et al. (2001), the flow of the magma from a chamber to a dike is described by an ordinary differential equation for the unknown pressures of chamber and dike. The most intuitive assumption on magma exchange is that the volume gained by the intrusion equals the volume lost by the chamber. This constraint, however, implies a chamber so large that its pressure does not drop during the feeding process and an incompressible magma that does not expand or vesiculate as it intrudes. Models assuming constant driving pressure fail to explain observations. Here, mass conservation constrains pressure as magma flows from the chamber to the dike and the compressibilities of magma and sources control volume changes. These assumptions allow me to decouple the equations and solve the system analytically. The model predicts that chamber and dike volume change exponentially with time as V(t) = V∞[1 − exp(−t/τ)]. The asymptotic volume V∞ and the timescale τ are found to be functions of rock, magma, chamber and dike parameters and of the initial pressure conditions. Assuming that the intrusion is shaped as an elongating cuboid, its velocity is found to change as v = v0exp(−t/τ), where v0 is the initial dike velocity. The model is successfully tested against the best observations available for lateral dike propagation events: the volume history of chamber and dike during the 2000 Miyakejima intrusion (Japan) and dike velocity during the 1978 Krafla event (Iceland) and during some intrusions following the 2005 event in Afar (Ethiopia). This paper confirms and extends the results of a previous study by Rivalta and Segall (2008), who found the final ratio between dike volume and the volume withdrawn from the chamber to be rV = 1 + 4μβm/3 > 1, where μ is the host rock rigidity and βm is the magma compressibility. Here, I demonstrate that the formula for rV holds at any time during the intrusion, not just at the end. This model confirms that some magma chambers behave as stiff magma‐tanks, able to inflate large dikes as balloons, and demonstrates that high volume ratios are unlikely if the chamber has a pure sill shape. Fitting observations with the model allows us to estimate several dike, chamber, magma and rock parameters.
Combination of geodetic observations and models for glacial isostatic adjustment fields in Fennoscandia
Authors: Hill Emma M. , Davis James L. , Tamisiea Mark E. , Lidberg Martin
Published: July 2010

We demonstrate a new technique for using geodetic data to update a priori predictions for Glacial Isostatic Adjustment (GIA) in the Fennoscandia region. Global Positioning System (GPS), tide gauge, and Gravity Recovery and Climate Experiment (GRACE) gravity rates are assimilated into our model. The technique allows us to investigate the individual contributions from these data sets to the output GIA model in a self‐consistent manner. Another benefit of the technique is that we are able to estimate uncertainties for the output model. These are reduced with each data set assimilated. Any uncertainties in the GPS reference frame are absorbed by reference frame adjustments that are estimated as part of the assimilation. Our updated model shows a spatial pattern and magnitude of peak uplift that is consistent with previous models, but our location of peak uplift is slightly to the east of many of these. We also simultaneously estimate a spatially averaged rate of local sea level rise. This regional rate (∼1.5 mm/yr) is consistent for all solutions, regardless of which data sets are assimilated or the magnitude of a priori GPS reference frame constraints. However, this is only the case if a uniform regional gravity rate, probably representing errors in, or unmodeled contributions to, the low‐degree harmonic terms from GRACE, is also estimated for the assimilated GRACE data. Our estimated sea level rate is consistent with estimates obtained using a more traditional approach of direct “correction” using collocated GPS and tide gauge sites.
Identification of typical scenarios for the surface Lagrangian residual circulation in the Iroise Sea
Authors: Muller Héloïse , Blanke Bruno , Dumas Franck , Mariette Vincent
Published: July 2010

This paper describes the surface Lagrangian residual circulation (LRC) over 2.5 day intervals in the Iroise Sea, west of France, and evaluates, for operational purposes, the influence of the different physical mechanisms that govern it. The method consists of the calculation of water displacements with a diagnostic Lagrangian tool that computes the trajectories of numerical particles in a given velocity field. The LRC is inferred from trajectories integrated over five M2 tidal cycles. The analysis is applied to both gridded genuine current measurements and ocean model outputs: the sea surface currents are derived from high‐frequency (HF) radar measurements and from MARS, a 3‐D regional ocean model used here in idealized configurations. To substantiate the analysis, the Lagrangian residual currents are also compared to genuine movements of drifters released in the Iroise Sea in 2005 and 2007. The LRC is mapped for typical scenarios identified from the Lagrangian analysis of HF radar surface currents measured in winter and summer, under weak (<7 m/s) and strong (>10 m/s) wind conditions, and in neap tide and spring tide seasons. Idealized numerical simulations that switch on and off each individual physical process are used to isolate in the LRC the patterns induced by the atmospheric forcing, tides, and density‐driven currents.
Development of daily precipitation projections for the United States based on probabilistic downscaling
Authors: Schoof J. T. , Pryor S. C. , Surprenant J.
Published: July 2010

Projections of mid and late 21st century precipitation for 963 stations across the contiguous United States are derived using probabilistic downscaling of 10 coupled atmosphere‐ocean general circulation models (AOGCMs). The projections are constructed by downscaling the statistical parameters describing precipitation occurrence and intensity, using a first‐order Markov chain and two‐parameter gamma distribution, respectively. Future downscaled values of the parameters are used to derive projections of wet day probability, wet day precipitation intensity and its distribution, and total seasonal precipitation for the cold season (November through March) and the warm season (May through September). Downscaled results for the 10 AOGCMs indicate several robust features of possible changes in the U.S. regional precipitation climatology. Cold season projections are characterized by increases in precipitation in the northwest and northeast regions, decreases in precipitation in the southwest region, and smaller or inconsistent changes in other regions. With the exception of the northeast region, warm season projections reflect drier conditions overall resulting primarily from fewer wet days. In both the cold and warm seasons, changes in both the occurrence and intensity processes contribute to changes in total precipitation. Changes in total precipitation, and the relative roles of the occurrence and intensity processes, are found to be sensitive to the change in the distribution of wet day precipitation intensities. Regions with increasing seasonal precipitation totals are characterized by disproportionate increases in large precipitation events, while those with decreasing seasonal precipitation totals are characterized by the largest fractional decreases in small precipitation events.
Observation of blue sprite spectra at 10,000 fps
Authors: Kanmae Takeshi , Stenbaek‐Nielsen Hans C. , McHarg Matthew G. , Haaland Ryan K.
Published: July 2010

Spectra from individual sprite streamer heads and column‐shaped glows were observed with a high‐speed slit‐less spectrograph at 10,000 fps during an aircraft campaign in August 2009. Blue emissions were recorded from streamer heads in five events and from glows in one event. The streamer heads consistently have a larger fraction of blue emission spectra compared to the glows for the events in 19 August 2009. It confirms, at unprecedented spatial, temporal, and spectral resolution, the more energetic nature of sprite streamer heads than column‐shaped glows. For the events on 19 August 2009, estimated local electric fields in the streamer heads are 0.4–0.9Ek, and those in the glows are 0.3–0.6Ek, where Ek is the conventional breakdown threshold field.
Elastoplastic analysis of process induced residual stresses in thermally sprayed coatings
Authors: Chen Yongxiong , Liang Xiubing , Liu Yan , Xu Binshi
Published: July 2010

The residual stresses induced from thermal spraying process have been extensively investigated in previous studies. However, most of such works were focused on the elastic deformation range. In this paper, an elastoplastic model for predicting the residual stresses in thermally sprayed coatings was developed, in which two main contributions were considered, namely the deposition induced stress and that due to differential thermal contraction between the substrate and coating during cooling. The deposition induced stress was analyzed based on the assumption that the coating is formed layer-by-layer, and then a misfit strain is accommodated within the multilayer structure after the addition of each layer (plastic deformation is induced consequently). From a knowledge of specimen dimensions, processing temperatures, and material properties, residual stress distributions within the structure can be determined by implementing the model with a simple computer program. A case study for the plasma sprayed NiCoCrAlY on Inconel 718 system was performed finally. Besides some similar phenomena observed from the present study as compared with previous elastic model reported in literature, the elastoplastic model also provides some interesting features for prediction of the residual stresses.
Linearization stability of the Einstein constraint equations on an asymptotically hyperbolic manifold
Authors: Gicquaud Romain
Published: July 2010

We study the linearization stability of the Einstein constraint equations on an asymptotically hyperbolic manifold. In particular, we prove that these equations are linearization stable in the neighborhood of vacuum solutions for a nonpositive cosmological constant and of Friedman–Lemaître–Robertson–Walker spaces in a certain range of decays. We also prove that this result is no longer true for faster decays. The construction of the counterexamples is based on a new construction of transverse traceless tensors on the Euclidean space and on positive energy theorems.
Proton formation dynamics in the REMPI[2+n] process via the F Δ12 and f Δ32 Rydberg states of HCl investigated by three-dimensional velocity mapping
Authors: Kauczok S. , Maul C. , Chichinin A. I. , Gericke K.-H.
Published: July 2010

HCl in the bulk gas phase at a pressure of 10−5 mbar has been excited via selected Q-lines of the two-photon transition band systems F Δ12←X Σ1+(1,0) [Q(8)], V Σ1+←X Σ1+(14,0) [Q(8), Q(7)] and f Δ32←X Σ1+(0,0) [Q(2–6)]. Concerning the V←X excitation, subsequent photon absorption is known to yield HCl+, H(n=2)+Cl, H++Cl− and H+Cl(4s,4p,3d). Vibrationally excited HCl+ (v+≥5) can be photodissociated to H++Cl, and excited atoms can be easily photoionized by absorption of a fourth photon, respectively. Using three-dimensional velocity map imaging, the spatial proton velocity distributions resulting from these processes for these particular transitions were studied for the first time. Kvaran et al. [J. Chem. Phys. 131, 044324 (2009); J. Chem. Phys. 129, 164313 (2008)] recently reported a substantial increase in the formation of chlorine and hydrogen ions in single rovibrational transitions of the F Δ12 and f Δ32 band systems using mass resolved resonance enhanced multiphoton ionization spectroscopy and explained this by the vicinity of single rovibrational levels of the V Σ1+ state for which photorupture is the main feature. Thus, the known dissociation dynamics of the V Σ1+ state should also leave their fingerprint in the spatial proton velocity distribution emerging from the photodissociation of those states. Accordingly, we found a strong increase in the H+ ion signal for the Q(5) line of the f Δ32←X Σ1+(0,0) transition, the extra signal resulting from dissociation into H(n=2)+Cl(P21/2) and the ion pair. No increase for the HCl+(v+≥5) photodissociation channel or dissociation into H(n=2)+Cl(P23/2) has been observed. Furthermore, H+ distributions from the Q transitions of the f Δ32←X Σ1+(0,0) band system were found to show the two features previously ascribed to the “gateway” state [Π4⋯4s]Π3(0), i.e., autoionization into HCl+(5≤v+≤8) and nonadiabatic dissociation into H(n=2)+Cl(P23/2). The F Δ12←X Σ1+(1,0) band system only showed significant proton formation for the Q(8) line. The speed distribution is the same as for the Q(8,7) lines of the V Σ1+←X Σ1+(14,0) transition while the excitation history is conserved in the angular distribution confirming the resonance interpretation.
Intrinsic detection efficiency of superconducting nanowire single-photon detectors with different thicknesses
Authors: Hofherr M. , Rall D. , Ilin K. , Siegel M. , Semenov A. , Hübers H.-W. , Gippius N. A.
Published: July 2010

We evaluate experimentally the intrinsic detection efficiency (IDE) of superconducting NbN nanowire single-photon detectors in the range of wire thicknesses from 4 to 12 nm. The study is performed in the broad spectral interval between near-ultraviolet (wavelength 400 nm) and near-infrared (wavelength 2000 nm) light with plane waves at normal incidence. For visible light the IDE of the thinnest detectors reaches 70%. We use numerically computed absorptance of the nanowire-structures for the analysis of the experimental data. Variations in the detection efficiency with both the wire thickness and the wavelength evidence the red boundary of the hot-spot photon-detection mechanism. We explain the detection at larger wavelengths invoking thermal excitation of magnetic Pearl vortices over the potential barrier at the edges of the wire.
Electronic band structure calculations for biaxially strained Si, Ge, and III–V semiconductors
Authors: Kim Jiseok , Fischetti Massimo V.
Published: July 2010

Electronic band structure and effective masses for relaxed and biaxially strained Si, Ge, III–V compound semiconductors (GaAs, GaSb, InAs, InSb, InP) and their alloys (InxGa1−xAs, InxGa1−xSb) on different interface orientations, (001), (110), and (111), are calculated using nonlocal empirical pseudopotential with spin-orbit interaction. Local and nonlocal pseudopotential parameters are obtained by fitting transport-relevant quantities, such as band gap and deformation potentials, to available experimental data. A cubic-spline interpolation is used to extend local form factors to arbitrary q and to obtain correct workfunctions. The nonlocal and spin-orbit terms are linearly interpolated between anions and cations for III–V semiconductors. The virtual crystal approximation is employed for the InxGa1−xAs and InxGa1−xSb alloys and deformation potentials are determined using linear deformation-potential theory. Band gap bowing parameters are extracted using least-square fitting for relaxed alloys and for strained InxGa1−xAs on (001), (110), and (111) InP. The dependence on biaxial strain of the electron and hole effective masses at the symmetry points Γ, X, and L exhibits a continuous variation at Γ and L but sudden changes appear at Δ minima caused by the flatness of the dispersion along the Δ line near the minimum.