bluuebunny/crossref_metadata_2025 huggingface dataset:
Aero-optics of subsonic turbulent boundary layers
Authors: Wang Kan , Wang Meng
Published: February 2012

Compressible large-eddy simulations are carried out to study the aero-optical distortions caused by Mach 0.5 flat-plate turbulent boundary layers at Reynolds numbers of ${\mathit{Re}}_{\theta } = 875$, 1770 and 3550, based on momentum thickness. The fluctuations of refractive index are calculated from the density field, and wavefront distortions of an optical beam traversing the boundary layer are computed based on geometric optics. The effects of aperture size, small-scale turbulence, different flow regions and beam elevation angle are examined and the underlying flow physics is analysed. It is found that the level of optical distortion decreases with increasing Reynolds number within the Reynolds-number range considered. The contributions from the viscous sublayer and buffer layer are small, while the wake region plays a dominant role, followed by the logarithmic layer. By low-pass filtering the fluctuating density field, it is shown that small-scale turbulence is optically inactive. Consistent with previous experimental findings, the distortion magnitude is dependent on the propagation direction due to anisotropy of the boundary-layer vortical structures. Density correlations and length scales are analysed to understand the elevation-angle dependence and its relation to turbulence structures. The applicability of Sutton’s linking equation to boundary-layer flows is examined, and excellent agreement between linking equation predictions and directly integrated distortions is obtained when the density length scale is appropriately defined.
Water waves over a variable bottom: a non-local formulation and conformal mappings
Authors: Fokas A. S. , Nachbin A.
Published: February 2012

In Ablowitz, Fokas & Musslimani (J. Fluid Mech., vol. 562, 2006, pp. 313–343) a novel formulation was proposed for water waves in three space dimensions. In the flat-bottom case, this formulation consists of the Bernoulli equation, as well as of a non-local equation. The variable-bottom case, which now involves two non-local equations, was outlined but not explored in the above paper. Here, the variable-bottom formulation is addressed in more detail. First, it is shown that in the weakly nonlinear, weakly dispersive regime, the above system of three equations can be reduced to a system of two equations. Second, by combining the novel non-local formulation of the above authors with conformal mappings, it is shown that in the two-dimensional case, it is possible to obtain a system of two equations without any asymptotic approximations. Furthermore, for the weakly nonlinear, weakly dispersive regime, the nonlinear equations are simpler than the equations obtained without conformal mappings, since they contain lower order derivatives for the terms involving the bottom variable.
Wholegrain oat-based cereals have prebiotic potential and low glycaemic index
Authors: Connolly M. L. , Tuohy K. M. , Lovegrove J. A.
Published: February 2012

Population studies show a positive association between increased dietary intake of wholegrains and reduced risk of cardiometabolic disorders. Consumption of wholegrain food has been associated with lower blood glucose and therefore may contribute to a low-glycaemic load diet. The ability to mediate a prebiotic modulation of gut microbiota has recently been suggested to have an inverse correlation with risk of cardiometabolic disease. To date very little work has been carried out on the functionality of wholegrain breakfast cereals in terms of glycaemic response or impact on gut microbiota. An investigation into identifying wholegrain-based breakfast cereals demonstrating both low glycaemic index (GI) and prebiotic attributes was performed. Afterin vitrodigestion, cereal samples were supplemented to pH-controlled anaerobic batch cultures of the human faecal microbiota. Total bacteria populations increased significantly (P < 0·05) in all treated cultures, and the fermentation of a wholegrain oat cluster cereal was associated with proliferation of theBifidobacteriumgenus (P = 0·02). Smaller, but significant increases in theBifidobacteriumgenus were observed for a further four oat-based cereals. Significant increases in theLactobacillus–Enterococcusgroup were observed for granola (P = 0·01), 100 % wholegrain aggregate (P = 0·04) and 70 % wholegrain loops (P = 0·01). Cereals demonstrating prebiotic potential were selected for GI determination in twelve healthy subjects. The wholegrain oat aggregate cereal achieved the lowest GI value (40), three other cereals ranged between 44 and 74, with instant porridge resulting in a GI value similar to the standard glucose control. The present study suggests that wholegrain oat-based breakfast cereals may be prebiotics and have the potential to have low GI.
Random mating and reproductive compatibility among Argentinean and southern Brazilian populations of Anastrepha fraterculus (Diptera: Tephritidae)
Authors: Rull J. , Abraham S. , Kovaleski A. , Segura D.F. , Islam A. , Wornoayporn V. , Dammalage T. , Tomas U. Santo , Vera M.T.
Published: February 2012

As a prerequisite for area-wide application of the sterile insect technique in an area encompassing northern Argentina and southern Brazil, prezygotic and postzygotic reproductive compatibility among three geographically distant populations in the area was tested. In field cages, sexually mature adults of each population were found to be sexually compatible, mating duration was not affected by fly origin and there was no clear evidence of spatial partition of mating location. In the laboratory, homotypic and heterotypic crosses for all possible combinations displayed similar levels of fertility and yielded F1 adults without distortion of the sex ratio. Finally, F1 hybrid and parental adults produced equally viable F2 eggs. Put together, our results and those from earlier studies suggest that a large area, ranging from Buenos Aires to the surroundings of São Paulo, could be managed using a single A. fraterculus mass-reared strain. At the northern margin of this area, two A. fraterculus morphotypes appear to coexist in sympatry. We delineate future research to further delimit the distribution of the aff1 morphotype (Argentina-southern Brazil) and to gain insight into evolutionary patterns producing divergence and radiation of tropical fruit fly species.
Mode of inheritance of increased host acceptance in a seed beetle
Authors: Messina F.J. , Peña N.M.
Published: February 2012

Colonization of a novel plant by herbivorous insects is frequently accompanied by genetic changes that progressively improve larval or adult performance on the new host. This study examined the genetic basis of adaptation to a marginal host (lentil) by the seed beetleCallosobruchus maculatus(F.). Quasi-natural selection in the laboratory rapidly increased the tendency to oviposit on lentil. The mode of inheritance of this increase in host acceptance was determined from crosses between three lentil-adapted lines and a line maintained on the ancestral host, mung bean. In each set of crosses, females from the lentil lines laid two to three times more eggs on lentil than did females from the mung-bean line. Hybrid females consistently displayed an intermediate level of host acceptance, which did not differ between reciprocal crosses. Alleles promoting greater oviposition on lentil thus were inherited additively, with no evidence of sex-linkage or cytoplasmic effects. In a time-course study, hybrid females initially resembled the parent from the mung-bean line, as few eggs were laid on lentil during the first 24 h. However, oviposition rates on lentil after 72 h were closer to the rate observed in the lentil-line parent. Inferences about additivity vs. dominance in genes affecting oviposition may, therefore, depend on experimental protocol. Comparison with earlier work suggests that inheritance patterns observed in crosses between recently derived selection lines (as in this study) may differ from those obtained in crosses between long-divergent geographic populations.
The interaction of modality and negation in Finnish
Authors: THOMAS ROSE
Published: February 2012

In Finnish, negation is expressed via an auxiliary, and no other verb may occur above this auxiliary in the structure. This gives rise to a problem with respect to the modals of obligation and necessity, which take scope over negation yet appear below it. It is tempting to account for this in terms of LF-movement, but evidence suggests that there are in fact two modal phrases in Finnish, one above negation and the other below it, the higher of which encodes necessity/obligation. Evidence for the higher phrase comes from the negative imperative. Although the PF part of a verb in a negative sentence cannot move to the head of this higher phrase, the head itself is in the right position to take scope over negation. Thus, rather than attributing the scope properties of the modals to LF-movement, it will instead be argued that the LF-interpretable part of a head is merged precisely where it takes scope, and that the relation between the LF- and PF-interpretable parts of the modal is one ofchecking at a distance. Head-movement will be regarded solely as a PF phenomenon. It will be seen that the scope relations of the modals and the imperative mood can be accounted for under this hypothesis. Thus, Finnish provides evidence for a view of syntax which identifies syntactic structure largely with the LF-interpretable part of a sentence, and sees head movement as fundamentally a PF phenomenon. There are two morphological moods in Finnish, which seem to provide counter-examples to this hypothesis, which will be left as a problem for future research.
Examining variation in depressive symptoms over the life course: a latent class analysis
Authors: Mezuk B. , Kendler K. S.
Published: February 2012

Background

Older adults have the lowest prevalence and incidence of major depressive disorder, although it has been hypothesized that this finding is due in part to differences in expression of psychopathology in later life. The aim of this study was to examine variation in depressive symptomatology in the general population across the lifespan.

Method

Data came from three sites of the Epidemiologic Catchment Area (ECA) Project (n=10 529). Depressive symptoms during the past 6 months were assessed using the Diagnostic Interview Schedule (DIS). Latent class analysis (LCA) was used to identify homogeneous groups of depressive symptomatology based on 16 individual symptoms, and to examine variation in the prevalence and composition of depression classes across age groups.

Results

The DIS symptoms fit a four-class model composed of non-depressed (83.2%), mild depression (11.6%), severe depression (1.9%), and despondent (3.2%) groups. Relative to the non-depressed class, older age was inversely associated with being in the mild or severe depression class. The profile of the latent classes was similar across age groups with the exception of the despondent class, which was not well differentiated among the youngest adults and was not inversely associated with age.

Conclusions

The symptom profiles of depression are similar across age with the exception of the despondent class, which is more differentiated from severe depression among older adults. The findings demonstrate the benefit of examining individual symptoms rather than broad symptom groups for understanding the natural history of depression over the lifespan.
Pluralism and Reasonable Disagreement
Authors: Larmore Charles
Published: February 2012

Liberalism is a distinctively modern political conception. Only in modern times do we find, as the object of both systematic reflection and widespread allegiance and institutionalization, the idea that the principles of political association, being coercive, should be justifiable to all whom they are to bind. And so only here do we find the idea that these principles should rest, so far as possible, on a core, minimal morality which reasonable people can share, given their expectably divergent religious convictions and conceptions of the meaning of life. No longer does it seem evident—as it did, let us say, before the seventeenth century—that the aim of political association must be to bring man into harmony with God's purposes or to serve some comprehensive vision of the good life. The causes of this transformation are various, and not all of them lie at the level of moral principle. But a change in moral consciousness has certainly been one of the factors involved. As Hegel observed, modern culture is inherently areflectiveone: notions of principle are essential to our self-understanding and thus to the stability of the social forms in which we participate. Modern culture has no room for a dichotomy between “in principle” and “in practice.” It is worth determining, then, what new moral conceptions have been responsible for the emergence of modern liberalism. Not only will we thereby better understand how we have become who we are, we will also have a surer grasp of the principles that sustain our political life.
Foodborne outbreaks of shigellosis in the USA, 1998–2008
Authors: NYGREN B. L. , SCHILLING K. A. , BLANTON E. M. , SILK B. J. , COLE D. J. , MINTZ E. D.
Published: February 2012

We examined reported outbreaks of foodborne shigellosis in the USA from 1998 to 2008 and summarized demographic and epidemiological characteristics of 120 confirmed outbreaks resulting in 6208 illnesses. Most reported foodborne shigellosis outbreaks (n = 70, 58%) and outbreak-associated illnesses (n = 3383, 54%) were restaurant-associated. The largest outbreaks were associated with commercially prepared foods distributed in multiple states and foods prepared in institutional settings. Foods commonly consumed raw were implicated in 29 (24%) outbreaks and infected food handlers in 28 (23%) outbreaks. Most outbreaks (n = 86, 72%) were caused by Shigella sonnei. Targeted efforts to reduce contamination during food handling at multiple points in the food processing and distribution system, including food preparation in restaurants and institutional settings, could prevent many foodborne disease outbreaks and outbreak-related illnesses including those due to Shigella.
Points of Law and Practice Concerning Ecclesiastical Visitations
Authors: Smith Peter M.
Published: February 2012

‘The wordVisitatio… denotes that act or office of the bishop, or of some other ordinary, going his circuit throughout his diocese or other district, with a full power of inquiring into such matters as relate to the government and discipline of the Church, and sometimes of correcting abuses and punishing excesses committed by his subjects …Visitation, as we would use the word here, implies some act of jurisdiction andcoerciveauthority …’
Alcohol-Related Social Gatherings with Coworkers: Intentions to Behave and Intentions to Not Behave
Authors: Park Hee Sun , Lee Dong Wook
Published: February 2012

Two studies are reported using the theory of planned behaviour (TPB) to examine Koreans' intentions and self-reported behaviour of joining and not joining alcohol-related social gatherings with work colleagues after work hours. Study 1 showed that group-related attitudes and perceived behavioural control of the TPB components regarding joining were significantly associated with intentions to join. Study 2 examined TPB components regarding not joining and intentions to not join. Study 2 found that although none of the TPB components was directly related to intentions, subjective norms from work colleagues moderated the effect of group-related attitudes on intentions to not join. The TPB components and intentions were not significantly related to self-reported behaviour of joining. The findings indicate that the relationships between the TPB components and intentions can be different for engaging and not engaging in a behaviour.
The Influence of Individualised Supports on the Self-Efficacy of Employed Diabetics in Hawai'i: Findings from a Mixed Method Study
Authors: Uehara Denise L. , Nishita Christy M. , Tom Tammy , Fukunaga Landry
Published: February 2012

Self-management is a key component of diabetes care and enhancing patient self-efficacy is an important factor. Typical diabetes education programs include strategies to increase self-efficacy, but little information exists about the effectiveness of such programs within Asian and Pacific populations. The Hawai'i Demonstration to Maintain Independence and Employment was a federally funded, community-based randomised trial in which treatment group participants received individualised life coaching and pharmacist counselling over a 12-month period. The study measured changes in diabetes self-efficacy among treatment and control group participants using repeated measures analysis of covariance. Focus group findings provided a comprehensive picture of participants' perception of their experiences in the trial and more specifically the individualised intervention. There was a significant effect of the intervention on diabetes self-efficacy at the p < .01 level [ F(1, 187) = 10.40, p = .002]. These findings demonstrate the efficacy of individually tailored approaches to diabetes self-management within a diverse, employed sample.
Commentary: Nuancing the Meaning of Cultural Diversity
Authors: Montiel Cristina Jayme , Macapagal Ma. Elizabeth J.
Published: February 2012

The featured articles in the section on cultural diversity across the Pacific address important cultural issues in psychology as applied to psychopathology (Marsella & Yamada, 2011), intercultural relations and acculturation (Berry, 2011) and the phenomenon of culture shock (Furnham, 2011). We appreciate how the three articles offer a wide multidisciplinary lens and view mental problems from this broader vantage point. Beyond narratives of biology and individual personality dispositions, the authors include an anthropologists' eye to viewing mental illness (Marsella & Yamada, 2011), use sociological explanations of intergroup relations in a multicultural model of acculturation (Berry, 2011) and refer to demographic migration patterns to elucidate culture shock among foreign students (Furnham, 2011). The contribution of this set of writings lies in its insightful emphasis on how culture interfaces with one's subjective life. Our essay unpacks the cultural lens used in the psychological accounts, points out conceptual spaces that are largely unexplored in cross-cultural psychology (something that is observed and lamented by these authors in their articles here and elsewhere) and suggests avenues for future research about cultural diversity.
Commentary: Embracing Culture as Essential to Pacific People
Authors: Vakalahi Halaevalu F.O.
Published: February 2012

The existing written literature on Pacific people is generally limited and available information is often incomplete, inaccurate or outdated. In many geographical locations, including the United States, literature focusing specifically on Pacific people is extremely sparse because it is often subsumed within broader coverage of people throughout the Asia-Pacific region. As such, the experiences are often trivialised. The Journal of Pacific Rim Psychology is filling gaps in contemporary psychology. It is exposing the world to the phenomenally rich and diverse cultures and people of the Pacific Rim. This is not only groundbreaking; it is also a form of social justice work. It advocates the use of a cultural lens in viewing the world and human behaviour; in this case a Pacific-culture lens that emphasises inclusivity, collectivity and reciprocity. Helping to promote a social justice movement that celebrates and honours the rich and extraordinarily diverse region of the Pacific will continue to contribute to the betterment of research, services and programming in today's diverse society. Furthermore, it will contribute to the journal's quest to become a preferred forum for the ??First People of the Pacific inside and outside of their Pacific home.
Dynamics of slab detachment
Authors: Duretz T. , Schmalholz S. M. , Gerya T. V.
Published: February 2012

We investigate the dynamics of slab detachment around the detachment zone and evaluate the amount of time necessary for slabs to detach. The study combines results of two‐dimensional (2D) state‐of‐the‐art thermomechanical numerical simulations and a 1D analytical solution for viscous necking under gravity. We show that the dominant deformation mechanism during slab detachment is viscous necking, independent of the depth of slab detachment. When the slab dip is moderate (35–70°), slab detachment is partly affected by localized simple shearing in the colder parts of the slab. Brittle fracturing (breaking) plays a minor role during slab detachment. Our 2D thermomechanical models indicate that the duration of slab detachment, quantified from the onset of slab thinning until the actual detachment (i.e. vanishing of slab‐pull force), is relatively short (<5 Ma) and can occur in less than 0.5 Ma. No clear correlation between the depth and the duration of slab detachment was observed. The simulations suggest that even deep slab detachment (>250 km) can occur within a short time interval (<1 Ma) which has implications for geodynamic interpretations using slab detachment as explanation for processes such as melting, exhumation or surface uplift. The thinning of the slab during detachment, observed in 2D simulations, agrees well with predictions from a 1D analytical solution indicating that the 1D solution captures the first‐order features of the detachment process. We also evaluate the impact of shear heating on the duration of slab detachment. The predictions of a simple semi‐analytical solution, based on dimensionless parameters, agree well with our and previously published results.
On the origin of the ultradeep East Barents Sea basin
Authors: Gac Sébastien , Huismans Ritske S. , Podladchikov Yuri Y. , Faleide Jan Inge
Published: February 2012

Very large subsidence, with up to 20 km thick sediment layers, is observed in the East Barents Sea basin. Subsidence started in early Paleozoic, accelerated in Permo‐Triassic times, finished during the middle Cretaceous, and was followed by moderate uplift in Cenozoic times. The observed gravity signal suggests that the East Barents Sea is at present in isostatic balance and indicates that a mass excess is required in the lithosphere to produce the observed large subsidence. Several origins have been proposed for the mass excess. We use 1‐D thermokinematic modeling and 2‐D isostatic density models of continental lithosphere to evaluate these competing hypotheses. The crustal density in 2‐D thermokinematic models resulting from pressure‐, temperature‐, and composition‐dependent phase change models is computed along transects crossing the East Barents Sea. The results indicate the following. (1) Extension can only explain the observed subsidence provided that a 10 km thick serpentinized mantle lens beneath the basin center is present. We conclude that this is unlikely given that this highly serpentinized layer should be formed below a sedimentary basin with more than 10 km of sediments and crust at least 10 km thick. (2) Phase changes in a compositionally homogeneous crust do not provide enough mass excess to explain the present‐day basin geometry. (3) Phase change induced densification of a preexisting lower crustal gabbroic body, interpreted as a mafic magmatic underplate, can explain the basin geometry and observed gravity anomalies. The following model is proposed for the formation of the East Barents Sea basin: (1) Devonian rifting and extension related magmatism resulted in moderate thinning of the crust and a mafic underplate below the central basin area explaining initial late Paleozoic subsidence. (2) East‐west shortening during the Permian and Triassic resulted in densification of the previously emplaced mafic underplated body and enhanced subsidence dramatically, explaining the present‐day deep basin geometry.
Hygroscopicity and composition of California CCN during summer 2010
Authors: Moore R. H. , Cerully K. , Bahreini R. , Brock C. A. , Middlebrook A. M. , Nenes A.
Published: February 2012

We present an overview and analysis of cloud condensation nuclei (CCN) sampled in California by a NOAA WP‐3D aircraft during the 2010 CalNex project. Four distinct geographical regions are characterized, including the Los Angeles basin, the San Joaquin and Sacramento Valleys, and the eastern Pacific Ocean west of southern California. Median size distributions in the Central Valley were unimodal (Dg ∼ 25 nm) with a larger fraction of organic species and smaller fraction of nitrate species in the Sacramento Valley aerosol than in the San Joaquin Valley aerosol. Size distributions in the Los Angeles basin and marine outflow were bimodal (geometric mean diameter, Dg ∼ 30, 90–100 nm) with similar organic fractions and some replacement of nitrate with sulfate in the marine outflow. Both fine particle and CCN concentrations were found to decrease rapidly above the planetary boundary layer (∼2 km altitude), with CCN concentrations in the boundary layer ranging from ∼102–104 cm−3 STP, while fine particle concentrations (0.004–1 μm diameters) ranged from ∼103–105 cm−3STP. The CCN‐active number fraction varied between 0–100% in the Los Angeles Basin and Marine Outflow, but was substantially lower (0–40%) in the San Joaquin and Sacramento Valleys. Values of the hygroscopicity parameter,κ, inferred from the CCN measurements varied from 0.1–0.25, with the highest values in the marine outflow and the lowest values in the Sacramento Valley. The κvalues agreed well with the predictions based on size‐resolved aerosol composition, but were overpredicted by almost twofold when size‐averaged composition was used. CCN closure was assessed for simplified compositional and mixing state assumptions, and it was found that assuming the aerosol to be internally mixed overpredicted CCN concentrations by 30–75% for all air mass types except within the Sacramento Valley, where good closure (overprediction < 10%) was achieved by assuming insoluble organics. Assuming an externally‐mixed aerosol fraction or incorporating size‐resolved composition data improved closure in the other three regions, consistent with the bimodal nature of the aerosol size distribution.
GLD100: The near‐global lunar 100 m raster DTM from LROC WAC stereo image data
Authors: Scholten F. , Oberst J. , Matz K.‐D. , Roatsch T. , Wählisch M. , Speyerer E. J. , Robinson M. S.
Published: February 2012

We derived near‐global lunar topography from stereo image data acquired by the Wide‐angle Camera (WAC) of the Lunar Reconnaissance Orbiter Camera (LROC) system. From polar orbit tracks, the LROC WAC provides image data with a mean ground resolution at nadir of 75 m/pixel with substantial cross‐track stereo overlap. WAC stereo images from the one‐year nominal mission and the first months of the science mission phase are combined to produce a near‐global digital terrain model (DTM) with a pixel spacing of 100 m, the Global Lunar DTM 100 m, or “GLD100.” It covers 79°S to 79°N latitudes, 98.2% of the entire lunar surface. We compare the GLD100 with results from previous stereo and altimetry‐based products, particularly with the Lunar Orbiter Laser Altimeter (LOLA) altimetry, which is the current topographic reference for the Moon. We describe typical characteristics of the GLD100 and, based upon the comparison to the LOLA data set, assess its vertical and lateral resolution and accuracy. We conclude that the introduced first version of the stereo‐based GLD100 is a valuable topographic representation of the lunar surface, complementary to the LOLA altimetry data set. Further improvements can be expected from continuative investigations.
Heat-shock proteins attenuate SERCA inactivation by the anti-apoptotic protein Bcl-2: possible implications for the ER Ca2+-mediated apoptosis
Authors: Dremina Elena S. , Sharov Victor S. , Schöneich Christian
Published: February 2012

We have demonstrated previously that Bcl-2 and Bcl-2Δ21, a C-terminally truncated Bcl-2 sequence, inactivate SERCA (sarcoplasmic/endoplasmic reticulum Ca2+-ATPase) 1 in isolated SR (sarcoplasmic reticulum), accompanied by a translocation from CRDs (caveolae-related domains) of the SR. In the present study, we obtained evidence for the interaction of Bcl-2 with SERCA2b in C2C12 myoblasts and HEK (human embryonic kidney)-293 cells. Bcl-2 and SERCA2b co-immunoprecipitated from lysate and microsomal fractions of Bcl-2-overexpressing cells. However, Bcl-2 overexpression resulted only in a slight translocation from the CRDs and no significant SERCA inactivation. In isolated HEK-293 cell microsomes, incubation with Bcl-2Δ21 afforded SERCA2b inactivation and some translocation. HSP (heat-shock protein) 70, HSP90, HSP27 and α-crystallin attenuated Bcl-2Δ21-dependent SERCA2b inactivation. An in vitro mechanistic study with the SERCA1 isoform shows that HSP70 (i) protects SERCA1 from the inactivation by Bcl-2Δ21, (ii) inhibits SERCA1 translocation from CRD fractions, and (iii) prevents the Bcl-2Δ21-dependent loss of FITC labelling. Our data demonstrate that the mechanism of SERCA inactivation by Bcl-2 established in vitro for the SERCA1 isoform can be extended to the main housekeeping SERCA2b isoform, and that functional interactions of SERCA2b and Bcl-2 in the cell may be modulated by HSP70 and other chaperones and stress-regulated proteins.
MEF2 is regulated by CaMKIIδ2 and a HDAC4–HDAC5 heterodimer in vascular smooth muscle cells
Authors: Ginnan Roman , Sun Li Yan , Schwarz John J. , Singer Harold A.
Published: February 2012

VSMCs (vascular smooth muscle cells) dedifferentiate from the contractile to the synthetic phenotype in response to acute vascular diseases such as restenosis and chronic vascular diseases such as atherosclerosis, and contribute to growth of the neointima. We demonstrated previously that balloon catheter injury of rat carotid arteries resulted in increased expression of CaMKII (Ca2+/calmodulin-dependent protein kinase) IIδ2 in the medial wall and the expanding neointima [House and Singer (2008) Arterioscler. Thromb. Vasc. Biol. 28, 441–447]. These findings led us to hypothesize that increased expression of CaMKIIδ2 is a positive mediator of synthetic VSMCs. HDAC (histone deacetylase) 4 and HDAC5 function as transcriptional co-repressors and are regulated in a CaMKII-dependent manner. In the present paper, we report that endogenous HDAC4 and HDAC5 in VSMCs are activated in a Ca2+- and CaMKIIδ2-dependent manner. We show further that AngII (angiotensin II)- and PDGF (platelet-derived growth factor)-dependent phosphorylation of HDAC4 and HDAC5 is reduced when CaMKIIδ2 expression is suppressed or CaMKIIδ2 activity is attenuated. The transcriptional activator MEF2 (myocyte-enhancer factor 2) is an important determinant of VSMC phenotype and is regulated in an HDAC-dependent manner. In the present paper, we report that stimulation of VSMCs with ionomycin or AngII potentiates MEF2's ability to bind DNA and increases the expression of established MEF2 target genes Nur77 (nuclear receptor 77) (NR4A1) and MCP1 (monocyte chemotactic protein 1) (CCL2). Suppression of CaMKIIδ2 attenuates increased MEF2 DNA-binding activity and up-regulation of Nur77 and MCP1. Finally, we show that HDAC5 is regulated by HDAC4 in VSMCs. Suppression of HDAC4 expression and activity prevents AngII- and PDGF-dependent phosphorylation of HDAC5. Taken together, these results illustrate a mechanism by which CaMKIIδ2 mediates MEF2-dependent gene transcription in VSMCs through regulation of HDAC4 and HDAC5.
Effect of nitric oxide on the daunorubicin efflux mechanism in K562 cells
Authors: Curta Juliana Costa , de Moraes Ana Carolina Rabello , Licínio Marley Aparecida , Costa Aline , Santos‐Silva Maria Cláudia
Published: February 2012

NO (nitric oxide) donating drugs have been investigated for their important role in the sensitization of neoplastic cells to chemotherapy drugs. The goal of this work was to investigate the involvement of NO in the resistance of K562 cells to DNR (daunorubicin). Only simultaneous addition of DNR and SNAP (S‐nitroso‐N‐acetyl‐dl‐penicillamine) caused significant cell death by apoptosis. Combination of the compounds decreased Bcl‐2 and survivin, and increased Bax and active‐caspase 3 expression. Fluorescence microscope and cytometric analysis showed that DNR and SNAP together caused DNR intracellular accumulation in K562 cells. RT—PCR (reverse transcription—PCR) analysis showed that DNR and SNAP, alone or in association, produced significant decreases in lrp expression. abcc1 gene expression was unaffected by the presence of SNAP, but when treated with DNR there was a small reduction that was intensified by DNR and SNAP in combination. The transport mechanism involved in the resistance to DNR in K562 cells involves ABCC1 and LRP (lung resistance protein) resistance proteins. DNR and SNAP inhibition of the expression of these proteins occurs by distinct mechanisms, and this disrupts the K562 resistance to DNR.
A Comparison of Developmental Social–Pragmatic and Naturalistic Behavioral Interventions on Language Use and Social Engagement in Children With Autism
Authors: Ingersoll Brooke , Meyer Katherine , Bonter Nicole , Jelinek Sara
Published: February 2012

Purpose

Developmental social–pragmatic and naturalistic behavioral interventions share a number of features, but they differ in their use of facilitative strategies and direct elicitation of child language. In this study, the authors investigated whether these approaches produce different language and social outcomes in young children with autism.

Method

The authors used an ABACAD design to compare the effects of a developmental social–pragmatic, naturalistic behavioral, and combined intervention on language type and function and social engagement in 5 children with autism.

Results

Milieu teaching and the combined intervention produced higher rates of language targets than did responsive interaction. An analysis of the type and function of language targets suggested that differences between conditions were driven primarily by prompted—and, to a lesser extent, spontaneous—requests. Social engagement ratings were higher during each intervention than at baseline, but differences between treatment conditions were not consistent across children.

Conclusions

For children with autism, naturalistic interventions that use direct elicitation of child language lead to greater short-term gains in the use of expressive language targets—in particular, prompted requests—than interventions that use facilitative strategies only. All 3 naturalistic language interventions can promote social engagement. For some children, the combined use of direct elicitation and responsiveness-based strategies may enhance treatment response.
Monosyllabic Mandarin Tone Productions by 3-Year-Olds Growing Up in Taiwan and in the United States: Interjudge Reliability and Perceptual Results
Authors: Wong Puisan
Published: February 2012

Purpose

The author compared monosyllabic Mandarin lexical tones produced by 3-year-old Mandarin-speaking children growing up in Taiwan and in the United States.

Method

Following the procedures in Wong, Schwartz, and Jenkins (2005), the author collected monosyllabic tone productions from 3-year-old Mandarin-speaking children in Taiwan and low-pass filtered them to eliminate lexical information but retain tone information. Five Mandarin-speaking adults residing in Taiwan categorized these filtered tones and those produced by the Mandarin-speaking children growing up in the United States, the latter of which was reported in Wong et al. (2005). Agreements on tone categorization by judges residing in Taiwan and in the United States were evaluated. Tone accuracy of children growing up in Taiwan and the United States were examined and compared.

Results

The Mandarin-speaking judges residing in the United States and in Taiwan showed high agreements on tone categorization. None of the 4 tones produced by the Mandarin-speaking children growing up in the United States and in Taiwan was adultlike.Children in Taiwan made more errors in Tone 2 and Tone 4 than didMandarin-speaking children growing up in the United States. Accuracy rates of Tone 1 and Tone 3 were comparable in the 2 groups of children.

Conclusion

Mandarin tone acquisition is a protracted process. Three-year-old Mandarin-speaking children growing up in Taiwan and the United States show similar developmental patterns and have not yet produced monosyllabic tones with adultlike accuracy.
Structure and properties of novel cobaltates Ln0.3CoO2 (Ln = La, Pr, and Nd)
Authors: Knížek K. , Jirák Z. , Hejtmánek J. , Maryško M. , Buršík J.
Published: February 2012

Layered cobaltates LnxCoO2 (Ln = La, Pr, Nd; x ∼ 0.30), isostructural with well known thermoelectrics NaxCoO2, have been characterized by diffraction methods and probed by the electric transport, magnetic and heat capacity measurements. The thermopower increases with temperature and saturates above room temperature at a large value ∼ 175 μV/K. The conductivity is affected by occupational disorder and follows Mott’s T−1/n law. The main attention is given to Pr0.3CoO2 and Nd0.3CoO2, in which the spins of hole carriers in the CoO2 layers coexist with localized magnetic moments of Pr3+ or Nd3+. The systems are found paramagnetic down to the lowest temperatures and behave accordingly to the non-Kramers or Kramers character of the rare earth ions.
Structure and exchange bias of Ni50Mn37Sn13 ribbons
Authors: Yang Y. B. , Ma X. B. , Chen X. G. , Wei J. Z. , Wu R. , Han J. Z. , Du H. L. , Wang C. S. , Liu S. Q. , Yang Y. C. , Zhang Y. , Yang J. B.
Published: February 2012

Ni50Mn37Sn13 ribbons were produced by the melt-spinning method. Structure and magnetic measurements on the Ni50Mn37Sn13 ribbons indicated that it is ferromagnetic below 340 K and undergoes an austenitic-to-martensitic phase transition just below room temperature. The austenitic phase has the cubic L21 structure, with the excess manganese atoms occupying the 4(b) sites. The martensitic phase has an orthorhombic structure. With increasing applied magnetic field, the martensite start temperature Ms and martensite finish temperature Mf shift to lower temperatures because of the field-induced phase transition. The exchange-bias effect is observed and strongly varied with different cooling fields at low temperature. At 5 K, the exchange-bias field reaches a maximum of 290 Oe when the cooling field increases to 200 Oe, and then reduces sluggishly with further increase of the cooling field because of weakening of exchange coupling between antiferromagnetic and ferromagnetic interfaces.
The effect of a ferromagnetic Gd marker on the effective work function of Fe in contact with Al2O3/Si
Authors: Zenkevich A. V. , Matveyev Yu. A. , Lebedinskii Yu. Yu. , Mantovan R. , Fanciulli M. , Thiess S. , Drube W.
Published: February 2012

The effect of a ferromagnetic Gd marker layer on the effective work function (WFeffFe) of Fe in a Fe/ Gd/Al2O3/Si stack has been systematically investigated by hard X-ray photoelectron spectroscopy (HAXPES) and capacitance-voltage measurements. A pronounced change in the band alignment at the buried Fe/Al2O3 interface WFeffFe=4.5/3.7eV is revealed by HAXPES as a function of the Gd marker thickness in the range 0/2.7 nm, in agreement with capacitance-voltage (C-V) data. Interface-sensitive 57Fe conversion-electron Mößbauer spectroscopy performed on Fe/Gd/Al2O3/Si stacks reveals major structural and magnetic changes at the Fe/Gd interface for different Gd thickness, which are correlated with the changes of the Fe/Al2O3 band alignment.
Large refrigerant capacity of RGa (R = Tb and Dy) compounds
Authors: Zheng X. Q. , Chen J. , Shen J. , Zhang Hu , Xu Z. Y. , Gao W. W. , Wu J. F. , Hu F. X. , Sun J. R. , Shen B. G.
Published: February 2012

The magnetic properties and magnetocaloric effects (MCEs) of RGa (R = Tb and Dy) compounds are investigated. The TbGa compound exhibits two successive magnetic transitions: spin-reorientation (SR) transition at TSR = 31 K and second-order ferromagnetic (FM)–paramagnetic (PM) transition at Curie temperature TC = 154 K, while the DyGa compound undergoes a SR transition with TSR=25 K and a FM–PM transition with TC = 113 K. It is noteworthy that a broad distribution of the magnetic entropy change peak is observed. The values of the refrigerant capacity (RC) for TbGa and DyGa are found to be 620.6 and 381.9 J/kg for a field change of 0–5 T, respectively. And for a field change of 0–7 T, the values are 900 and 584.2 J/kg, respectively. The large value of RC for TbGa and DyGa originates from the combined contribution from SR and FM–PM transitions, which enlarges the temperature span of large MCE.
Influence of dynamical dipolar coupling on spin-torque-induced excitations in a magnetic tunnel junction nanopillar
Authors: Kudo Kiwamu , Nagasawa Tazumi , Suto Hirofumi , Yang Tao , Mizushima Koichi , Sato Rie
Published: February 2012

Spin-torque-induced excitations are numerically analyzed for an MgO-based magnetic tunnel junction nanopillar composed of a CoFe/Ru/CoFeB synthetic ferrimagnetic layer and a CoFeB layer. By performing macrospin simulations, we demonstrate that dynamical coupling between ferromagnetic layers through dipole-dipole interactions has a significant influence on the oscillation modes. In particular, we show that acoustic-like and optical-like oscillation modes established by the dynamical dipolar coupling emerge, depending on the in-plane bias field. The optical-like oscillation mode is stable under a wider current range than the acoustic-like one.
Effect of Fe composition on the superconducting properties (Tc, Hc2 and Hirr) of FexSe1/2Te1/2 (x = 0.95, 1.00, 1.05 and 1.10)
Authors: Sudesh  , Rani S. , Das S. , Rawat R. , Bernhard C. , Varma G. D.
Published: February 2012

In the present work, we have studied the effect of Fe composition on the superconducting properties, such as transition temperature (Tc), upper critical field (Hc2), and irreversibility field (Hirr) of FeSe1/2Te1/2. The polycrystalline samples have been prepared via solid state reaction route with nominal compositions FexSe1/2Te1/2 (x = 0.95, 1.00, 1.05 and 1.10). The x-ray diffraction results show the presence of tetragonal α-FeSe phase with the p4/nmm space group symmetry in all the samples. The zero resistance temperatures, Tczero, measured in zero magnetic field, have been found to be 10.0, 12.4, 12.3, and 11.7 K for x = 0.95, 1.00, 1.05, and 1.10, respectively. The temperature dependence of Hc2(T) and Hirr(T) have been calculated from the magnetoresistance data using the criteria of 90% and 10% of normal state resistivity (ρn) values, respectively. The values of Hc2(0) are 121.3 T, 142.8 T, 82.7 T, and 79.3 T for x = 0.95, 1.00, 1.05, and 1.10, respectively. The possible reasons for the variation of superconducting properties with Fe composition (x) have been described and discussed in this paper.
Low-energy beam transport studies supporting the spallation neutron source 1-MW beam operation
Authors: Han B. X. , Kalvas T. , Tarvainen O. , Welton R. F. , Murray S. N. , Pennisi T. R. , Santana M. , Stockli M. P.
Published: February 2012

The H− injector consisting of a cesium enhanced RF-driven ion source and a 2-lens electrostatic low-energy beam transport (LEBT) system supports the spallation neutron source 1 MW beam operation with ∼38 mA beam current in the linac at 60 Hz with a pulse length of up to ∼1.0 ms. In this work, two important issues associated with the low-energy beam transport are discussed: (1) inconsistent dependence of the post-radio frequency quadrupole accelerator beam current on the ion source tilt angle and (2) high power beam losses on the LEBT electrodes under some off-nominal conditions compromising their reliability.
Producing persistent, high-current, high-duty-factor H− beams for routine 1 MW operation of Spallation Neutron Source (invited)
Authors: Stockli Martin P. , Han B. X. , Hardek T. W. , Kang Y. W. , Murray S. N. , Pennisi T. R. , Piller C. , Santana M. , Welton R.
Published: February 2012

Since 2009, the Spallation Neutron Source (SNS) has been producing neutrons with ion beam powers near 1 MW, which requires the extraction of ∼50 mA H− ions from the ion source with a ∼5% duty factor. The 50 mA are achieved after an initial dose of ∼3 mg of Cs and heating the Cs collar to ∼170 °C. The 50 mA normally persist for the entire 4-week source service cycles. Fundamental processes are reviewed to elucidate the persistence of the SNS H− beams without a steady feed of Cs and why the Cs collar temperature may have to be kept near 170 °C.
Dynamic properties of integrated nanostructure on metallic surface
Authors: Zerirgui D. , Tigrine R. , Bourahla B.
Published: February 2012

We investigated the vibration properties of integrated nanostructure on crystalline surface. The embedded chain of molecules is parallel to y-axis and takes three different positions: top, hollow, and bridge. The vibrational dynamics of the structure is considered within the harmonic approximation framework. The evanescent and propagating vibrational field of the perfect lattice is determined and interpreted. The presence of the diatomic molecule chain breakdown the translation symmetry in one direction, and gives rise to localized states on its neighborhood. Our study is based on the matching method and the Green functions, the spectral and state densities associated to localized modes are determined and calculated numerically. Our results show that the presence of the inhomogeneity contribute to the creation of new branches of localized vibrational modes, and their number and feature depend strongly on structural parameters of the system and the position of the diatomic chain.
Neural networks and chaos: Construction, evaluation of chaotic networks, and prediction of chaos with multilayer feedforward networks
Authors: Bahi Jacques M. , Couchot Jean-François , Guyeux Christophe , Salomon Michel
Published: February 2012

Many research works deal with chaotic neural networks for various fields of application. Unfortunately, up to now, these networks are usually claimed to be chaotic without any mathematical proof. The purpose of this paper is to establish, based on a rigorous theoretical framework, an equivalence between chaotic iterations according to Devaney and a particular class of neural networks. On the one hand, we show how to build such a network, on the other hand, we provide a method to check if a neural network is a chaotic one. Finally, the ability of classical feedforward multilayer perceptrons to learn sets of data obtained from a dynamical system is regarded. Various boolean functions are iterated on finite states. Iterations of some of them are proven to be chaotic as it is defined by Devaney. In that context, important differences occur in the training process, establishing with various neural networks that chaotic behaviors are far more difficult to learn.